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1
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Teichmann L, Luitwieler S, Bengtsson-Palme J, Ter Kuile B. Fluoroquinolone-specific resistance trajectories in E. coli and their dependence on the SOS-response. BMC Microbiol 2025; 25:37. [PMID: 39838279 PMCID: PMC11748515 DOI: 10.1186/s12866-025-03771-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2024] [Accepted: 01/13/2025] [Indexed: 01/23/2025] Open
Abstract
BACKGROUND Fluoroquinolones are indispensable antibiotics used in treating bacterial infections in both human and veterinary medicine. However, resistance to these drugs presents a growing challenge. The SOS response, a DNA repair pathway activated by DNA damage, is known to influence resistance development, yet its role in fluoroquinolone resistance is not fully understood. This study aims to unfold the mechanisms of fluoroquinolone resistance by investigating the impact of the SOS response on bacterial adaptation. RESULTS We exposed Escherichia coli to four fluoroquinolones-ciprofloxacin, enrofloxacin, levofloxacin, and moxifloxacin. Using a recA knockout mutant, deficient in the SOS response, as a control, we assessed how the presence or absence of this pathway affects resistance development. Our findings demonstrated that the rate of resistance evolution varied between the different fluoroquinolones. Ciprofloxacin, enrofloxacin, and moxifloxacin exposures led to the most evident reliance on the SOS response for resistance, whereas levofloxacin exposed cultures showed less dependency. Whole genome analysis indicated distinct genetic changes associated with each fluoroquinolone, highlighting potential different pathways and mechanisms involved in resistance. CONCLUSIONS This study shows that the SOS response plays a crucial role in resistance development to certain fluoroquinolones, with varying dependencies per drug. The characteristic impact of fluoroquinolones on resistance mechanisms emphasizes the need to consider the unique properties of each antibiotic in resistance studies and treatment strategies. These findings are essential for improving antibiotic stewardship and developing more effective, tailored interventions to combat resistance.
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Affiliation(s)
- Lisa Teichmann
- University of Amsterdam, Swammerdam Institute of Life Sciences, Molecular Biology and Microbial Food Safety, Amsterdam, The Netherlands
| | - Sam Luitwieler
- University of Amsterdam, Swammerdam Institute of Life Sciences, Molecular Biology and Microbial Food Safety, Amsterdam, The Netherlands
| | - Johan Bengtsson-Palme
- Department of Life Sciences, SciLifeLab, Division of Systems and Synthetic Biology, Chalmers University of Technology, Gothenburg, Sweden
- Institute of Biomedicine, Department of Infectious Diseases, University of Gothenburg, Gothenburg, Sweden
- Centre for Antibiotic Resistance Research (CARe), Gothenburg, Sweden
| | - Benno Ter Kuile
- University of Amsterdam, Swammerdam Institute of Life Sciences, Molecular Biology and Microbial Food Safety, Amsterdam, The Netherlands.
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2
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Herrera-Martí DA. Error thresholds in the presence of epistatic interactions. Phys Rev E 2024; 110:054412. [PMID: 39690608 DOI: 10.1103/physreve.110.054412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2024] [Accepted: 10/15/2024] [Indexed: 12/19/2024]
Abstract
Models for viral populations with high replication error rates (such as RNA viruses) rely on the quasispecies concept, in which mutational pressure beyond the so-called "error threshold" leads to a loss of essential genetic information and population collapse, an effect known as the "error catastrophe." We explain how crossing this threshold, as a result of increasing mutation rates, can be understood as a second-order phase transition, even in the presence of lethal mutations. In particular, we show that, in fitness landscapes with a single peak, this collapse is equivalent to a ferroparamagnetic transition, where the back-mutation rate plays the role of the external magnetic field. We then generalize this framework to rugged fitness landscapes, like the ones that arise from epistatic interactions, and provide numerical evidence that there is a transition from a high average fitness regime to a low average fitness one, similarly to single-peaked landscapes. The onset of the transition is heralded by a sudden change in the susceptibility to variations in the mutation rate. We use insight from replica symmetry breaking mechanisms in spin glasses, in particular by considering the fluctuations of the genotype similarity distribution as the order parameter.
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3
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Kocher CD, Dill KA. The prebiotic emergence of biological evolution. ROYAL SOCIETY OPEN SCIENCE 2024; 11:240431. [PMID: 39050718 PMCID: PMC11265915 DOI: 10.1098/rsos.240431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Accepted: 05/10/2024] [Indexed: 07/27/2024]
Abstract
The origin of life must have been preceded by Darwin-like evolutionary dynamics that could propagate it. How did that adaptive dynamics arise? And from what prebiotic molecules? Using evolutionary invasion analysis, we develop a universal framework for describing any origin story for evolutionary dynamics. We find that cooperative autocatalysts, i.e. autocatalysts whose per-unit reproductive rate grows as their population increases, have the special property of being able to cross a barrier that separates their initial degradation-dominated state from a growth-dominated state with evolutionary dynamics. For some model parameters, this leap to persistent propagation is likely, not rare. We apply this analysis to the Foldcat Mechanism, wherein peptides fold and help catalyse the elongation of each other. Foldcats are found to have cooperative autocatalysis and be capable of emergent evolutionary dynamics.
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Affiliation(s)
- Charles D. Kocher
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY 11794, USA
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794, USA
| | - Ken A. Dill
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY 11794, USA
- Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794, USA
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794, USA
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4
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Mohebbi F, Zelikovsky A, Mangul S, Chowell G, Skums P. Early detection of emerging viral variants through analysis of community structure of coordinated substitution networks. Nat Commun 2024; 15:2838. [PMID: 38565543 PMCID: PMC10987511 DOI: 10.1038/s41467-024-47304-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 03/20/2024] [Indexed: 04/04/2024] Open
Abstract
The emergence of viral variants with altered phenotypes is a public health challenge underscoring the need for advanced evolutionary forecasting methods. Given extensive epistatic interactions within viral genomes and known viral evolutionary history, efficient genomic surveillance necessitates early detection of emerging viral haplotypes rather than commonly targeted single mutations. Haplotype inference, however, is a significantly more challenging problem precluding the use of traditional approaches. Here, using SARS-CoV-2 evolutionary dynamics as a case study, we show that emerging haplotypes with altered transmissibility can be linked to dense communities in coordinated substitution networks, which become discernible significantly earlier than the haplotypes become prevalent. From these insights, we develop a computational framework for inference of viral variants and validate it by successful early detection of known SARS-CoV-2 strains. Our methodology offers greater scalability than phylogenetic lineage tracing and can be applied to any rapidly evolving pathogen with adequate genomic surveillance data.
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Affiliation(s)
- Fatemeh Mohebbi
- Department of Computer Science, Georgia State University, Atlanta, GA, USA
- Titus Family Department of Clinical Pharmacy, USC Alfred E. Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA, USA
| | - Alex Zelikovsky
- Department of Computer Science, Georgia State University, Atlanta, GA, USA
| | - Serghei Mangul
- Titus Family Department of Clinical Pharmacy, USC Alfred E. Mann School of Pharmacy and Pharmaceutical Sciences, University of Southern California, Los Angeles, CA, USA
- Department of Quantitative and Computational Biology, USC Dornsife College of Letters, Arts and Sciences, University of Southern California, Los Angeles, CA, USA
| | - Gerardo Chowell
- School of Public Health, Georgia State University, Atlanta, GA, USA
| | - Pavel Skums
- Department of Computer Science, Georgia State University, Atlanta, GA, USA.
- School of Computing, College of Engineering, University of Connecticut, Storrs, CT, USA.
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5
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Markovitch O, Wu J, Otto S. Binding of Precursors to Replicator Assemblies Can Improve Replication Fidelity and Mediate Error Correction. Angew Chem Int Ed Engl 2024; 63:e202317997. [PMID: 38380789 DOI: 10.1002/anie.202317997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 02/06/2024] [Accepted: 02/14/2024] [Indexed: 02/22/2024]
Abstract
Copying information is vital for life's propagation. Current life forms maintain a low error rate in replication, using complex machinery to prevent and correct errors. However, primitive life had to deal with higher error rates, limiting its ability to evolve. Discovering mechanisms to reduce errors would alleviate this constraint. Here, we introduce a new mechanism that decreases error rates and corrects errors in synthetic self-replicating systems driven by self-assembly. Previous work showed that macrocycle replication occurs through the accumulation of precursor material on the sides of the fibrous replicator assemblies. Stochastic simulations now reveal that selective precursor binding to the fiber surface enhances replication fidelity and error correction. Centrifugation experiments show that replicator fibers can exhibit the necessary selectivity in precursor binding. Our results suggest that synthetic replicator systems are more evolvable than previously thought, encouraging further evolution-focused experiments.
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Affiliation(s)
- Omer Markovitch
- Stratingh Institute, Centre for Systems Chemistry, University of Groningen, Groningen, The Netherlands
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
- Blue Marble Space Institute of Science, Seattle, Washington, USA
| | - Juntian Wu
- Stratingh Institute, Centre for Systems Chemistry, University of Groningen, Groningen, The Netherlands
| | - Sijbren Otto
- Stratingh Institute, Centre for Systems Chemistry, University of Groningen, Groningen, The Netherlands
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6
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Papastavrou N, Horning DP, Joyce GF. RNA-catalyzed evolution of catalytic RNA. Proc Natl Acad Sci U S A 2024; 121:e2321592121. [PMID: 38437533 PMCID: PMC10945747 DOI: 10.1073/pnas.2321592121] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 01/25/2024] [Indexed: 03/06/2024] Open
Abstract
An RNA polymerase ribozyme that was obtained by directed evolution can propagate a functional RNA through repeated rounds of replication and selection, thereby enabling Darwinian evolution. Earlier versions of the polymerase did not have sufficient copying fidelity to propagate functional information, but a new variant with improved fidelity can replicate the hammerhead ribozyme through reciprocal synthesis of both the hammerhead and its complement, with the products then being selected for RNA-cleavage activity. Two evolutionary lineages were carried out in parallel, using either the prior low-fidelity or the newer high-fidelity polymerase. The former lineage quickly lost hammerhead functionality as the population diverged toward random sequences, whereas the latter evolved new hammerhead variants with improved fitness compared to the starting RNA. The increase in fitness was attributable to specific mutations that improved the replicability of the hammerhead, counterbalanced by a small decrease in hammerhead activity. Deep sequencing analysis was used to follow the course of evolution, revealing the emergence of a succession of variants that progressively diverged from the starting hammerhead as fitness increased. This study demonstrates the critical importance of replication fidelity for maintaining heritable information in an RNA-based evolving system, such as is thought to have existed during the early history of life on Earth. Attempts to recreate RNA-based life in the laboratory must achieve further improvements in replication fidelity to enable the fully autonomous Darwinian evolution of RNA enzymes as complex as the polymerase itself.
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7
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Stevenson DS. Modelling the structure and evolution of cultural information as quasispecies. Biosystems 2024; 235:105104. [PMID: 38128874 DOI: 10.1016/j.biosystems.2023.105104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Revised: 12/08/2023] [Accepted: 12/14/2023] [Indexed: 12/23/2023]
Abstract
We present a novel mode of cultural evolution whereby some forms of transmission may be modelled as quasispecies. The model incorporates the effect of high rates of error in certain forms of communication; while also building on the structural similarities between biological molecules and written language. Firstly, both written language and key biological molecules, such as RNA and proteins, are modular. Within these molecules, structural domains may be recombined, while retaining their function. Likewise, sentences are structured as combinations of clauses, in which each clause contains a domain of information. The clausal structure permits the recombination of information to adopt different meanings, while allowing each unit to retain its identity. Secondly, by virtue of intrinsically-high error rates, we show that some, but not all, aspects of communicated culture information exists as rapidly evolving clouds within the population. These clouds of cultural information behave as quasispecies, which we model with varying mutation rates and suitable selection coefficients. We then integrate these ideas with the application of Shannon Diversity Index to produce a more holistic view of culture that is centred on the evolution of its information. Re-imagining culture, as evolving clouds of information, unifies the mode in which information is stored culturally and biologically, and opens up new avenues of comparative analysis.
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8
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Wills PR. Origins of Genetic Coding: Self-Guided Molecular Self-Organisation. ENTROPY (BASEL, SWITZERLAND) 2023; 25:1281. [PMID: 37761580 PMCID: PMC10527755 DOI: 10.3390/e25091281] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 08/22/2023] [Accepted: 08/28/2023] [Indexed: 09/29/2023]
Abstract
The origin of genetic coding is characterised as an event of cosmic significance in which quantum mechanical causation was transcended by constructive computation. Computational causation entered the physico-chemical processes of the pre-biotic world by the incidental satisfaction of a condition of reflexivity between polymer sequence information and system elements able to facilitate their own production through translation of that information. This event, which has previously been modelled in the dynamics of Gene-Replication-Translation systems, is properly described as a process of self-guided self-organisation. The spontaneous emergence of a primordial genetic code between two-letter alphabets of nucleotide triplets and amino acids is easily possible, starting with random peptide synthesis that is RNA-sequence-dependent. The evident self-organising mechanism is the simultaneous quasi-species bifurcation of the populations of information-carrying genes and enzymes with aminoacyl-tRNA synthetase-like activities. This mechanism allowed the code to evolve very rapidly to the ~20 amino acid limit apparent for the reflexive differentiation of amino acid properties using protein catalysts. The self-organisation of semantics in this domain of physical chemistry conferred on emergent molecular biology exquisite computational control over the nanoscopic events needed for its self-construction.
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Affiliation(s)
- Peter R Wills
- Department of Physics, University of Auckland, Auckland PB 92019, New Zealand
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9
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Kozyrev S. Learning by Population Genetics and Matrix Riccati Equation. ENTROPY (BASEL, SWITZERLAND) 2023; 25:348. [PMID: 36832714 PMCID: PMC9955902 DOI: 10.3390/e25020348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/26/2023] [Accepted: 02/12/2023] [Indexed: 06/18/2023]
Abstract
A model of learning as a generalization of the Eigen's quasispecies model in population genetics is introduced. Eigen's model is considered as a matrix Riccati equation. The error catastrophe in the Eigen's model (when the purifying selection becomes ineffective) is discussed as the divergence of the Perron-Frobenius eigenvalue of the Riccati model in the limit of large matrices. A known estimate for the Perron-Frobenius eigenvalue provides an explanation for observed patterns of genomic evolution. We propose to consider the error catastrophe in Eigen's model as an analog of overfitting in learning theory; this gives a criterion for the presence of overfitting in learning.
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Affiliation(s)
- Sergei Kozyrev
- Steklov Mathematical Institute of Russian Academy of Sciences, Gubkina St. 8, 119991 Moscow, Russia
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10
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Scott AD, King DM, Ordway SW, Bahar S. Phase transitions in evolutionary dynamics. CHAOS (WOODBURY, N.Y.) 2022; 32:122101. [PMID: 36587338 DOI: 10.1063/5.0124274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2022] [Accepted: 12/05/2022] [Indexed: 06/17/2023]
Abstract
Sharp changes in state, such as transitions from survival to extinction, are hallmarks of evolutionary dynamics in biological systems. These transitions can be explored using the techniques of statistical physics and the physics of nonlinear and complex systems. For example, a survival-to-extinction transition can be characterized as a non-equilibrium phase transition to an absorbing state. Here, we review the literature on phase transitions in evolutionary dynamics. We discuss directed percolation transitions in cellular automata and evolutionary models, and models that diverge from the directed percolation universality class. We explore in detail an example of an absorbing phase transition in an agent-based model of evolutionary dynamics, including previously unpublished data demonstrating similarity to, but also divergence from, directed percolation, as well as evidence for phase transition behavior at multiple levels of the model system's evolutionary structure. We discuss phase transition models of the error catastrophe in RNA virus dynamics and phase transition models for transition from chemistry to biochemistry, i.e., the origin of life. We conclude with a review of phase transition dynamics in models of natural selection, discuss the possible role of phase transitions in unraveling fundamental unresolved questions regarding multilevel selection and the major evolutionary transitions, and assess the future outlook for phase transitions in the investigation of evolutionary dynamics.
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Affiliation(s)
- Adam D Scott
- Department of Physics and Astronomy and Center for Neurodynamics, University of Missouri at St. Louis, One University Blvd., St. Louis, Missouri 63121, USA
| | - Dawn M King
- Department of Physics and Astronomy and Center for Neurodynamics, University of Missouri at St. Louis, One University Blvd., St. Louis, Missouri 63121, USA
| | - Stephen W Ordway
- Department of Physics and Astronomy and Center for Neurodynamics, University of Missouri at St. Louis, One University Blvd., St. Louis, Missouri 63121, USA
| | - Sonya Bahar
- Department of Physics and Astronomy and Center for Neurodynamics, University of Missouri at St. Louis, One University Blvd., St. Louis, Missouri 63121, USA
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11
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Path probability selection in nature and path integral. Sci Rep 2022; 12:19044. [PMID: 36351916 PMCID: PMC9646751 DOI: 10.1038/s41598-022-20235-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 09/12/2022] [Indexed: 11/10/2022] Open
Abstract
Understanding of any biological evolutions, such as speciation, adaptation behavior and biodiversity pattern, is based on a fundamental concept of fitness, in which natural selection implies the improvement and progress of fitness in either direct/indirect benefit or genetic transmission to the next generation. However, this basic idea of biological evolution, which is mathematically described by Price equation or its relations, has not fully considered feedback effects from the environment or other generations. They lost the global dynamics of the evolutions consequently. Drawing on the idea of modern physics, we introduce the path integral by iterating the Price equation step by step to characterize the evolutionary path in which the stationary fitness is replaced by the path probability. The evolutionary selection therefore will depend on path probability instead of fitness advantage. In such a framework of the evolutionary path, the intermediate process of evolution is not always pointing to the fitness-maximizing equilibrium and multiple evolutionary paths could thus coexist without fitness advantage discrimination. This mechanism could potentially explain fitness evolutionary strategies with the diversified fitness (e.g., coexistence of altruism and selfishness) and thus species diversity.
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12
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Abstract
In order to accommodate the empirical fact that population structures are rarely simple, modern studies of evolutionary dynamics allow for complicated and highly heterogeneous spatial structures. As a result, one of the most difficult obstacles lies in making analytical deductions, either qualitative or quantitative, about the long-term outcomes of evolution. The "structure-coefficient" theorem is a well-known approach to this problem for mutation-selection processes under weak selection, but a general method of evaluating the terms it comprises is lacking. Here, we provide such a method for populations of fixed (but arbitrary) size and structure, using easily interpretable demographic measures. This method encompasses a large family of evolutionary update mechanisms and extends the theorem to allow for asymmetric contests to provide a better understanding of the mutation-selection balance under more realistic circumstances. We apply the method to study social goods produced and distributed among individuals in spatially heterogeneous populations, where asymmetric interactions emerge naturally and the outcome of selection varies dramatically, depending on the nature of the social good, the spatial topology, and the frequency with which mutations arise.
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13
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Caldwell HS, Pata JD, Ciota AT. The Role of the Flavivirus Replicase in Viral Diversity and Adaptation. Viruses 2022; 14:1076. [PMID: 35632818 PMCID: PMC9143365 DOI: 10.3390/v14051076] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 05/03/2022] [Accepted: 05/06/2022] [Indexed: 02/04/2023] Open
Abstract
Flaviviruses include several emerging and re-emerging arboviruses which cause millions of infections each year. Although relatively well-studied, much remains unknown regarding the mechanisms and means by which these viruses readily alternate and adapt to different hosts and environments. Here, we review a subset of the different aspects of flaviviral biology which impact host switching and viral fitness. These include the mechanism of replication and structural biology of the NS3 and NS5 proteins, which reproduce the viral genome; rates of mutation resulting from this replication and the role of mutational frequency in viral fitness; and the theory of quasispecies evolution and how it contributes to our understanding of genetic and phenotypic plasticity.
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Affiliation(s)
- Haley S. Caldwell
- The Arbovirus Laboratory, Wadsworth Center, New York State Department of Health, Slingerlands, NY 12159, USA;
- Department of Biomedical Sciences, State University of New York at Albany, School of Public Health, Rensselaer, NY 12144, USA;
| | - Janice D. Pata
- Department of Biomedical Sciences, State University of New York at Albany, School of Public Health, Rensselaer, NY 12144, USA;
- Wadsworth Center, New York State Department of Health, Albany, NY 12208, USA
| | - Alexander T. Ciota
- The Arbovirus Laboratory, Wadsworth Center, New York State Department of Health, Slingerlands, NY 12159, USA;
- Department of Biomedical Sciences, State University of New York at Albany, School of Public Health, Rensselaer, NY 12144, USA;
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14
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Modified quasispecies model: the analysis of a periodic therapy. J Math Biol 2022; 84:29. [DOI: 10.1007/s00285-022-01726-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 01/26/2022] [Accepted: 01/31/2022] [Indexed: 10/18/2022]
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15
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Diaz Arenas C, Ardaševa A, Miller J, Mikheyev AS, Yokobayashi Y. Ribozyme Mutagenic Evolution: Mechanisms of Survival. ORIGINS LIFE EVOL B 2022; 51:321-339. [PMID: 34994918 DOI: 10.1007/s11084-021-09617-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 11/16/2021] [Indexed: 11/24/2022]
Abstract
Primeval populations replicating at high error rates required a mechanism to overcome the accumulation of mutations and information deterioration. Known strategies to overcome mutation pressures include RNA processivity, epistasis, selection, and quasispecies. We investigated the mechanism by which small molecular ribozyme populations can survive under high error rates by propagating several lineages under different mutagen concentrations. We found that every population that evolved without mutagen went extinct, while those subjected to mutagenic evolution survived. To understand how they survived, we characterized the evolved genotypic diversity, the formation of genotype-genotype interaction networks, the fitness of the most common mutants for each enzymatic step, and changes in population size along the course of evolution. We found that the elevated mutation rate was necessary for the populations to survive in the novel environment, in which all the steps of the metabolism worked to promote the survival of even less catalytically efficient ligases. Besides, an increase in population size and the mutational coupling of genotypes in close-knit networks, which helped maintain or recover lost genotypes making their disappearance transient, prevented Muller's ratchet and extinction.
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Affiliation(s)
- Carolina Diaz Arenas
- Okinawa Institute of Science and Technology Graduate University (OIST), Okinawa Prefecture, Japan. .,Yale University, New Haven, CT, USA.
| | - Aleksandra Ardaševa
- Wolfson Centre for Mathematical Biology, Mathematical Institute, University of Oxford, Oxford, UK
| | - Jonathan Miller
- Okinawa Institute of Science and Technology Graduate University (OIST), Okinawa Prefecture, Japan
| | - Alexander S Mikheyev
- Okinawa Institute of Science and Technology Graduate University (OIST), Okinawa Prefecture, Japan.,Evolutionary Genomics Lab, Research School of Biology, Australian National University, Canberra, Australia
| | - Yohei Yokobayashi
- Okinawa Institute of Science and Technology Graduate University (OIST), Okinawa Prefecture, Japan
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16
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Quack M, Seyfang G, Wichmann G. Perspectives on parity violation in chiral molecules: theory, spectroscopic experiment and biomolecular homochirality. Chem Sci 2022; 13:10598-10643. [PMID: 36320700 PMCID: PMC9491092 DOI: 10.1039/d2sc01323a] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 06/26/2022] [Indexed: 11/21/2022] Open
Abstract
The reflection (or ‘mirror’) symmetry of space is among the fundamental symmetries of physics. It is connected to the conservation law for the quantum number parity and a fundamental ‘non-observable’ property of space (as defined by an absolute ‘left-handed’ or ‘right-handed’ coordinate system). The discovery of the violation of this symmetry – the non-conservation of parity or ‘parity violation’ – in 1956/1957 had an important influence on the further development of physics. In chemistry the mirror symmetry of space is connected to the existence of enantiomers as isomers of chiral (‘handed’) molecules. These isomers would relate to each other as idealized left or right hand or as image and mirror image and would be energetically exactly equivalent with perfect space inversion symmetry. Parity violation results in an extremely small ‘parity violating’ energy difference between the ground states of the enantiomers which can be theoretically calculated to be about 100 aeV to 1 feV (equivalent to 10−11 to 10−10 J mol−1), depending on the molecule, but which has not yet been detected experimentally. Its detection remains one of the great challenges of current physical–chemical stereochemistry, with implications also for fundamental problems in physics. In biochemistry and molecular biology one finds a related fundamental question unanswered for more than 100 years: the evolution of ‘homochirality’, which is the practically exclusive preference of one chiral, enantiomeric form as building blocks in the biopolymers of all known forms of life (the l-amino acids in proteins and d-sugars in DNA, not the reverse d-amino acids or l-sugars). In astrobiology the spectroscopic detection of homochirality could be used as strong evidence for the existence of extraterrestrial life, if any. After a brief conceptual and historical introduction we review the development, current status, and progress along these three lines of research: theory, spectroscopic experiment and the outlook towards an understanding of the evolution of biomolecular homochirality. The reflection (or ‘mirror’) symmetry of space is among the fundamental symmetries of physics. It is connected to the conservation law for the quantum number purity and its violation and has a fundamental relation to stereochemistry and molecular chirality.![]()
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Affiliation(s)
- Martin Quack
- Physical Chemistry, ETH Zürich, CH-8093 Zurich, Switzerland
| | - Georg Seyfang
- Physical Chemistry, ETH Zürich, CH-8093 Zurich, Switzerland
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17
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Solé R, Sardanyés J, Elena SF. Phase transitions in virology. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2021; 84:115901. [PMID: 34584031 DOI: 10.1088/1361-6633/ac2ab0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 09/28/2021] [Indexed: 06/13/2023]
Abstract
Viruses have established relationships with almost every other living organism on Earth and at all levels of biological organization: from other viruses up to entire ecosystems. In most cases, they peacefully coexist with their hosts, but in most relevant cases, they parasitize them and induce diseases and pandemics, such as the AIDS and the most recent avian influenza and COVID-19 pandemic events, causing a huge impact on health, society, and economy. Viruses play an essential role in shaping the eco-evolutionary dynamics of their hosts, and have been also involved in some of the major evolutionary innovations either by working as vectors of genetic information or by being themselves coopted by the host into their genomes. Viruses can be studied at different levels of biological organization, from the molecular mechanisms of genome replication, gene expression and encapsidation, to global pandemics. All these levels are different and yet connected through the presence of threshold conditions allowing for the formation of a capsid, the loss of genetic information or epidemic spreading. These thresholds, as occurs with temperature separating phases in a liquid, define sharp qualitative types of behaviour. Thesephase transitionsare very well known in physics. They have been studied by means of simple, but powerful models able to capture their essential properties, allowing us to better understand them. Can the physics of phase transitions be an inspiration for our understanding of viral dynamics at different scales? Here we review well-known mathematical models of transition phenomena in virology. We suggest that the advantages of abstract, simplified pictures used in physics are also the key to properly understanding the origins and evolution of complexity in viruses. By means of several examples, we explore this multilevel landscape and how minimal models provide deep insights into a diverse array of problems. The relevance of these transitions in connecting dynamical patterns across scales and their evolutionary and clinical implications are outlined.
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Affiliation(s)
- Ricard Solé
- ICREA-Complex Systems Lab, Universitat Pompeu Fabra-PRBB, Dr Aiguader 80, 08003 Barcelona, Spain
- Institut de Biologia Evolutiva, CSIC-Universitat Pompeu Fabra, Passeig Maritim de la Barceloneta 37, 08003 Barcelona, Spain
- Santa Fe Institute, 1399 Hyde Park Road, Santa Fe NM 87501, United States of America
| | - Josep Sardanyés
- Centre de Recerca Matemàtica (CRM), Edifici C, Campus de Bellaterra, Cerdanyola del Vallès, 08193 Barcelona, Spain
- Dynamical Systems and Computational Virology, CSIC Associated Unit, Institute for Integrative Systems Biology (I2SysBio)-CRM, Spain
| | - Santiago F Elena
- Santa Fe Institute, 1399 Hyde Park Road, Santa Fe NM 87501, United States of America
- Evolutionary Systems Virology Lab (I2SysBio), CSIC-Universitat de València, Catedrático Agustín Escardino 9, Paterna, 46980 València, Spain
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18
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Kahana A, Lancet D. Self-reproducing catalytic micelles as nanoscopic protocell precursors. Nat Rev Chem 2021; 5:870-878. [PMID: 37117387 DOI: 10.1038/s41570-021-00329-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/03/2021] [Indexed: 12/31/2022]
Abstract
Protocells at life's origin are often conceived as bilayer-enclosed precursors of life, whose self-reproduction rests on the early advent of replicating catalytic biopolymers. This Perspective describes an alternative scenario, wherein reproducing nanoscopic lipid micelles with catalytic capabilities were forerunners of biopolymer-containing protocells. This postulate gains considerable support from experiments describing micellar catalysis and autocatalytic proliferation, and, more recently, from reports on cross-catalysis in mixed micelles that lead to life-like steady-state dynamics. Such results, along with evidence for micellar prebiotic compatibility, synergize with predictions of our chemically stringent computer-simulated model, illustrating how mutually catalytic lipid networks may enable micellar compositional reproduction that could underlie primal selection and evolution. Finally, we highlight studies on how endogenously catalysed lipid modifications could guide further protocellular complexification, including micelle to vesicle transition and monomer to biopolymer progression. These portrayals substantiate the possibility that protocellular evolution could have been seeded by pre-RNA lipid assemblies.
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19
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Dickey AM, Smith TPL, Clawson ML, Heaton MP, Workman AM. Classification of small ruminant lentivirus subtype A2, subgroups 1 and 2 based on whole genome comparisons and complex recombination patterns. F1000Res 2021; 9:1449. [PMID: 35035904 PMCID: PMC8749911 DOI: 10.12688/f1000research.27898.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/19/2021] [Indexed: 11/20/2022] Open
Abstract
Background: Small ruminant lentiviruses (SRLVs) cause a multisystemic chronic wasting disease in sheep across much of the world. SRLV subtype A2 is prevalent in North America and further classified into multiple subgroups based on variation in the group antigens gene (gag) and envelope (env) genes. In sheep, the ovine transmembrane protein 154 (TMEM154) gene is associated with SRLV susceptibility. Ewes with at least one copy of TMEM154 encoding a full-length protein with glutamate at position 35 (E35; haplotypes 2 and 3), are highly susceptible to SRLV infection while ewes with any combination of TMEM154 haplotypes which encodes lysine (K35; haplotype 1), or truncated proteins (haplotypes 4 and 6) are several times less so. A2 subgroups 1 and 2 are associated with host TMEM154 genotypes; subgroup 1 with the K35/K35 genotype and subgroup 2 with the E35/E35 genotype. Methods: Sequence variation within and among full-length assemblies of SRLV subtype A2 subgroups 1 and 2 was analyzed to identify genome-scale recombination patterns and subgroup-specific variants. Results: Consensus viral genomes were assembled from 23 infected sheep, including animals of assorted TMEM154 genotypes comprised of haplotypes 1, 2, or 3. Viral genome analysis identified viral subgroups 1 and 2 among the samples, and revealed additional sub-structure within subgroup 2 based on models predicting complex patterns of recombination between the two subgroups in several genomes. Animals with evidence of dual subgroup infection also possessed the most diverse quasi-species and the most highly recombined consensus genomes. After accounting for recombination, 413 subgroup diagnostic single nucleotide polymorphisms (SNPs) were identified. Conclusions: The viral subgroup framework developed to classify SRLV consensus genomes along a continuum of recombination suggests that animals with the TMEM154 E35/K35 genotype may represent a reservoir for producing viral genomes representing recombination between A2 subgroups 1 and 2.
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Affiliation(s)
- Aaron M. Dickey
- US Department of Agriculture, Agricultural Research Service, US Meat Animal Research Center, Clay Center, NE, 68933, USA
| | - Timothy P. L. Smith
- US Department of Agriculture, Agricultural Research Service, US Meat Animal Research Center, Clay Center, NE, 68933, USA
| | - Michael L. Clawson
- US Department of Agriculture, Agricultural Research Service, US Meat Animal Research Center, Clay Center, NE, 68933, USA
| | - Michael P. Heaton
- US Department of Agriculture, Agricultural Research Service, US Meat Animal Research Center, Clay Center, NE, 68933, USA
| | - Aspen M. Workman
- US Department of Agriculture, Agricultural Research Service, US Meat Animal Research Center, Clay Center, NE, 68933, USA
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20
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Dias Louro MA, Bettencourt-Dias M, Bank C. Patterns of selection against centrosome amplification in human cell lines. PLoS Comput Biol 2021; 17:e1008765. [PMID: 33979341 PMCID: PMC8143425 DOI: 10.1371/journal.pcbi.1008765] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 05/24/2021] [Accepted: 02/03/2021] [Indexed: 11/18/2022] Open
Abstract
The presence of extra centrioles, termed centrosome amplification, is a hallmark of cancer. The distribution of centriole numbers within a cancer cell population appears to be at an equilibrium maintained by centriole overproduction and selection, reminiscent of mutation-selection balance. It is unknown to date if the interaction between centriole overproduction and selection can quantitatively explain the intra- and inter-population heterogeneity in centriole numbers. Here, we define mutation-selection-like models and employ a model selection approach to infer patterns of centriole overproduction and selection in a diverse panel of human cell lines. Surprisingly, we infer strong and uniform selection against any number of extra centrioles in most cell lines. Finally we assess the accuracy and precision of our inference method and find that it increases non-linearly as a function of the number of sampled cells. We discuss the biological implications of our results and how our methodology can inform future experiments.
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Affiliation(s)
| | | | - Claudia Bank
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
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21
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Abstract
Codon-dependent translation underlies genetics and phylogenetic inferences, but its origins pose two challenges. Prevailing narratives cannot account for the fact that aminoacyl-tRNA synthetases (aaRSs), which translate the genetic code, must collectively enforce the rules used to assemble themselves. Nor can they explain how specific assignments arose from rudimentary differentiation between ancestral aaRSs and corresponding transfer RNAs (tRNAs). Experimental deconstruction of the two aaRS superfamilies created new experimental tools with which to analyze the emergence of the code. Amino acid and tRNA substrate recognition are linked to phase transfer free energies of amino acids and arise largely from aaRS class-specific differences in secondary structure. Sensitivity to protein folding rules endowed ancestral aaRS-tRNA pairs with the feedback necessary to rapidly compare alternative genetic codes and coding sequences. These and other experimental data suggest that the aaRS bidirectional genetic ancestry stabilized the differentiation and interdependence required to initiate and elaborate the genetic coding table.
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Affiliation(s)
- Charles W Carter
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7260, USA;
| | - Peter R Wills
- Department of Physics, University of Auckland, Auckland 1142, New Zealand
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22
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Riaz N, Leung P, Barton K, Smith MA, Carswell S, Bull R, Lloyd AR, Rodrigo C. Adaptation of Oxford Nanopore technology for hepatitis C whole genome sequencing and identification of within-host viral variants. BMC Genomics 2021; 22:148. [PMID: 33653280 PMCID: PMC7923462 DOI: 10.1186/s12864-021-07460-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 02/19/2021] [Indexed: 01/23/2023] Open
Abstract
Background Hepatitis C (HCV) and many other RNA viruses exist as rapidly mutating quasi-species populations in a single infected host. High throughput characterization of full genome, within-host variants is still not possible despite advances in next generation sequencing. This limitation constrains viral genomic studies that depend on accurate identification of hemi-genome or whole genome, within-host variants, especially those occurring at low frequencies. With the advent of third generation long read sequencing technologies, including Oxford Nanopore Technology (ONT) and PacBio platforms, this problem is potentially surmountable. ONT is particularly attractive in this regard due to the portable nature of the MinION sequencer, which makes real-time sequencing in remote and resource-limited locations possible. However, this technology (termed here ‘nanopore sequencing’) has a comparatively high technical error rate. The present study aimed to assess the utility, accuracy and cost-effectiveness of nanopore sequencing for HCV genomes. We also introduce a new bioinformatics tool (Nano-Q) to differentiate within-host variants from nanopore sequencing. Results The Nanopore platform, when the coverage exceeded 300 reads, generated comparable consensus sequences to Illumina sequencing. Using HCV Envelope plasmids (~ 1800 nt) mixed in known proportions, the capacity of nanopore sequencing to reliably identify variants with an abundance as low as 0.1% was demonstrated, provided the autologous reference sequence was available to identify the matching reads. Successful pooling and nanopore sequencing of 52 samples from patients with HCV infection demonstrated its cost effectiveness (AUD$ 43 per sample with nanopore sequencing versus $100 with paired-end short read technology). The Nano-Q tool successfully separated between-host sequences, including those from the same subtype, by bulk sorting and phylogenetic clustering without an autologous reference sequence (using only a subtype-specific generic reference). The pipeline also identified within-host viral variants and their abundance when the parameters were appropriately adjusted. Conclusion Cost effective HCV whole genome sequencing and within-host variant identification without haplotype reconstruction are potential advantages of nanopore sequencing. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07460-1.
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Affiliation(s)
- Nasir Riaz
- Kirby Institute, UNSW Sydney, Sydney, NSW, 2052, Australia.,Department of Microbiology, Hazara University, KPK, Maneshra, 21120, Pakistan
| | - Preston Leung
- Kirby Institute, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Kirston Barton
- Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Sydney, Australia
| | - Martin A Smith
- Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Sydney, Australia
| | - Shaun Carswell
- Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Sydney, Australia
| | - Rowena Bull
- Kirby Institute, UNSW Sydney, Sydney, NSW, 2052, Australia.,Department of Pathology, School of Medical Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Andrew R Lloyd
- Kirby Institute, UNSW Sydney, Sydney, NSW, 2052, Australia
| | - Chaturaka Rodrigo
- Kirby Institute, UNSW Sydney, Sydney, NSW, 2052, Australia. .,Department of Pathology, School of Medical Sciences, UNSW Sydney, Sydney, NSW, 2052, Australia.
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23
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Abstract
What were the physico-chemical forces that drove the origins of life? We discuss four major prebiotic 'discoveries': persistent sampling of chemical reaction space; sequence-encodable foldable catalysts; assembly of functional pathways; and encapsulation and heritability. We describe how a 'proteins-first' world gives plausible mechanisms. We note the importance of hydrophobic and polar compositions of matter in these advances.
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Affiliation(s)
- K. A. Dill
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY, USA
- Department of Chemistry, Stony Brook University, Stony Brook, NY, USA
- Department Physics and Astronomy, Stony Brook University, Stony Brook, NY, USA
| | - L. Agozzino
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, NY, USA
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24
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Knyazev S, Hughes L, Skums P, Zelikovsky A. Epidemiological data analysis of viral quasispecies in the next-generation sequencing era. Brief Bioinform 2021; 22:96-108. [PMID: 32568371 PMCID: PMC8485218 DOI: 10.1093/bib/bbaa101] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 04/24/2020] [Accepted: 05/04/2020] [Indexed: 01/04/2023] Open
Abstract
The unprecedented coverage offered by next-generation sequencing (NGS) technology has facilitated the assessment of the population complexity of intra-host RNA viral populations at an unprecedented level of detail. Consequently, analysis of NGS datasets could be used to extract and infer crucial epidemiological and biomedical information on the levels of both infected individuals and susceptible populations, thus enabling the development of more effective prevention strategies and antiviral therapeutics. Such information includes drug resistance, infection stage, transmission clusters and structures of transmission networks. However, NGS data require sophisticated analysis dealing with millions of error-prone short reads per patient. Prior to the NGS era, epidemiological and phylogenetic analyses were geared toward Sanger sequencing technology; now, they must be redesigned to handle the large-scale NGS datasets and properly model the evolution of heterogeneous rapidly mutating viral populations. Additionally, dedicated epidemiological surveillance systems require big data analytics to handle millions of reads obtained from thousands of patients for rapid outbreak investigation and management. We survey bioinformatics tools analyzing NGS data for (i) characterization of intra-host viral population complexity including single nucleotide variant and haplotype calling; (ii) downstream epidemiological analysis and inference of drug-resistant mutations, age of infection and linkage between patients; and (iii) data collection and analytics in surveillance systems for fast response and control of outbreaks.
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25
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Dickey AM, Smith TPL, Clawson ML, Heaton MP, Workman AM. Classification of small ruminant lentivirus subtype A2, subgroups 1 and 2 based on whole genome comparisons and complex recombination patterns. F1000Res 2020; 9:1449. [PMID: 35035904 PMCID: PMC8749911 DOI: 10.12688/f1000research.27898.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/19/2021] [Indexed: 01/08/2024] Open
Abstract
Background: Small ruminant lentiviruses (SRLVs) cause a multisystemic chronic wasting disease in sheep across much of the world. SRLV subtype A2 is prevalent in North America and further classified into multiple subgroups based on variation in the group antigens gene (gag) and envelope (env) genes. In sheep, the ovine transmembrane protein 154 (TMEM154) gene is associated with SRLV susceptibility. Ewes with at least one copy of TMEM154 encoding a full-length protein with glutamate at position 35 (E35; haplotypes 2 and 3), are highly susceptible to SRLV infection while ewes with any combination of TMEM154 haplotypes which encodes lysine (K35; haplotype 1), or truncated proteins (haplotypes 4 and 6) are several times less so. A2 subgroups 1 and 2 are associated with host TMEM154 genotypes; subgroup 1 with the K35/K35 genotype and subgroup 2 with the E35/E35 genotype. Methods: Sequence variation within and among full-length assemblies of SRLV subtype A2 subgroups 1 and 2 was analyzed to identify genome-scale recombination patterns and subgroup-specific variants. Results: Consensus viral genomes were assembled from 23 infected sheep, including animals of assorted TMEM154 genotypes comprised of haplotypes 1, 2, or 3. Viral genome analysis identified viral subgroups 1 and 2 among the samples, and revealed additional sub-structure within subgroup 2 based on models predicting complex patterns of recombination between the two subgroups in several genomes. Animals with evidence of dual subgroup infection also possessed the most diverse quasi-species and the most highly recombined consensus genomes. After accounting for recombination, 413 subgroup diagnostic single nucleotide polymorphisms (SNPs) were identified. Conclusions: The viral subgroup framework developed to classify SRLV consensus genomes along a continuum of recombination suggests that animals with the TMEM154 E35/K35 genotype may represent a reservoir for producing viral genomes representing recombination between A2 subgroups 1 and 2.
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Affiliation(s)
- Aaron M. Dickey
- US Department of Agriculture, Agricultural Research Service, US Meat Animal Research Center, Clay Center, NE, 68933, USA
| | - Timothy P. L. Smith
- US Department of Agriculture, Agricultural Research Service, US Meat Animal Research Center, Clay Center, NE, 68933, USA
| | - Michael L. Clawson
- US Department of Agriculture, Agricultural Research Service, US Meat Animal Research Center, Clay Center, NE, 68933, USA
| | - Michael P. Heaton
- US Department of Agriculture, Agricultural Research Service, US Meat Animal Research Center, Clay Center, NE, 68933, USA
| | - Aspen M. Workman
- US Department of Agriculture, Agricultural Research Service, US Meat Animal Research Center, Clay Center, NE, 68933, USA
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26
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Abstract
Thresholds are widespread in origin of life scenarios, from the emergence of chirality, to the appearance of vesicles, of autocatalysis, all the way up to Darwinian evolution. Here, we analyze the “error threshold,” which poses a condition for sustaining polymer replication, and generalize the threshold approach to other properties of prebiotic systems. Thresholds provide theoretical predictions, prescribe experimental tests, and integrate interdisciplinary knowledge. The coupling between systems and their environment determines how thresholds can be crossed, leading to different categories of prebiotic transitions. Articulating multiple thresholds reveals evolutionary properties in prebiotic scenarios. Overall, thresholds indicate how to assess, revise, and compare origin of life scenarios.
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Affiliation(s)
- Cyrille Jeancolas
- Laboratoire de Biochimie, UMR CNRS-ESPCI 8231 Chimie Biologie Innovation, PSL University, ESPCI Paris, 10 rue Vauquelin, 75005 Paris, France.,Laboratoire d'Anthropologie Sociale, Collège de France, 52 rue du Cardinal Lemoine, 75005 Paris, France
| | - Christophe Malaterre
- Département de Philosophie and Centre de Recherche Interuniversitaire sur la Science et la Technologie (CIRST), Université du Québec à Montréal (UQAM), 455 boulevard René-Lévesque Est, Montréal, QC H3C 3P8, Canada
| | - Philippe Nghe
- Laboratoire de Biochimie, UMR CNRS-ESPCI 8231 Chimie Biologie Innovation, PSL University, ESPCI Paris, 10 rue Vauquelin, 75005 Paris, France
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27
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Rix G, Watkins-Dulaney EJ, Almhjell PJ, Boville CE, Arnold FH, Liu CC. Scalable continuous evolution for the generation of diverse enzyme variants encompassing promiscuous activities. Nat Commun 2020; 11:5644. [PMID: 33159067 PMCID: PMC7648111 DOI: 10.1038/s41467-020-19539-6] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 10/19/2020] [Indexed: 01/11/2023] Open
Abstract
Enzyme orthologs sharing identical primary functions can have different promiscuous activities. While it is possible to mine this natural diversity to obtain useful biocatalysts, generating comparably rich ortholog diversity is difficult, as it is the product of deep evolutionary processes occurring in a multitude of separate species and populations. Here, we take a first step in recapitulating the depth and scale of natural ortholog evolution on laboratory timescales. Using a continuous directed evolution platform called OrthoRep, we rapidly evolve the Thermotoga maritima tryptophan synthase β-subunit (TmTrpB) through multi-mutation pathways in many independent replicates, selecting only on TmTrpB's primary activity of synthesizing L-tryptophan from indole and L-serine. We find that the resulting sequence-diverse TmTrpB variants span a range of substrate profiles useful in industrial biocatalysis and suggest that the depth and scale of evolution that OrthoRep affords will be generally valuable in enzyme engineering and the evolution of biomolecular functions.
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Affiliation(s)
- Gordon Rix
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, USA
| | - Ella J Watkins-Dulaney
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Patrick J Almhjell
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Christina E Boville
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Aralez Bio, Emeryville, CA, USA
| | - Frances H Arnold
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Chang C Liu
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, USA.
- Department of Biomedical Engineering, University of California, Irvine, CA, USA.
- Department of Chemistry, University of California, Irvine, CA, USA.
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28
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Roy C, Mandal SM, Mondal SK, Mukherjee S, Mapder T, Ghosh W, Chakraborty R. Trends of mutation accumulation across global SARS-CoV-2 genomes: Implications for the evolution of the novel coronavirus. Genomics 2020; 112:5331-5342. [PMID: 33161087 PMCID: PMC7644180 DOI: 10.1016/j.ygeno.2020.11.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 10/27/2020] [Accepted: 11/02/2020] [Indexed: 12/22/2022]
Abstract
To understand SARS-CoV-2 microevolution, this study explored the genome-wide frequency, gene-wise distribution, and molecular nature of all point-mutations detected across its 71,703 RNA-genomes deposited in GISAID till 21 August 2020. Globally, nsp1/nsp2 and orf7a/orf3a were the most mutation-ridden non-structural and structural genes respectively. Phylogeny of 4618 spatiotemporally-representative genomes revealed that entities belonging to the early lineages are mostly spread over Asian countries, including India, whereas the recently-derived lineages are more globally distributed. Of the total 20,163 instances of polymorphism detected across global genomes, 12,594 and 7569 involved transitions and transversions, predominated by cytidine-to-uridine and guanosine-to-uridine conversions, respectively. Positive selection of nonsynonymous mutations (dN/dS >1) in most of the structural, but not the non-structural, genes indicated that SARS-CoV-2 has already harmonized its replication/transcription machineries with the host metabolism, while it is still redefining virulence/transmissibility strategies at the molecular level. Mechanistic bases and evolutionary/pathogenicity-related implications are discussed for the predominant mutation-types.
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Affiliation(s)
- Chayan Roy
- College of Veterinary Medicine, Western University of Health Sciences, 309 East Second Street, Pomona, CA 91766, USA
| | - Santi M Mandal
- Central Research Facility, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India
| | - Suresh K Mondal
- Central Research Facility, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal, India
| | - Shriparna Mukherjee
- Department of Botany, Prasannadeb Women's College, Jalpaiguri, West Bengal, India
| | - Tarunendu Mapder
- Division of Clinical Pharmacology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Wriddhiman Ghosh
- Department of Microbiology, Bose Institute, P-1/12 CIT Scheme VII M, Kolkata 700054, West Bengal, India.
| | - Ranadhir Chakraborty
- Department of Biotechnology, University of North Bengal, Raja Rammohanpur, Darjeeling 734013, West Bengal, India.
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Divergent Mutational Landscapes of Consensus and Minority Genotypes of West Nile Virus Demonstrate Host and Gene-Specific Evolutionary Pressures. Genes (Basel) 2020; 11:genes11111299. [PMID: 33143358 PMCID: PMC7692055 DOI: 10.3390/genes11111299] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 10/19/2020] [Accepted: 10/29/2020] [Indexed: 01/12/2023] Open
Abstract
Our current understanding of the natural evolution of RNA viruses comes largely from consensus level genetic analyses which ignore the diverse mutant swarms that comprise within-host viral populations. The breadth and composition of viral mutant swarms impact viral fitness and adaptation, and the capacity for swarm plasticity is likely to be particularly important for arthropod-borne viruses (arboviruses) that cycle between taxonomically divergent hosts. Despite this, characterization of the relationship between the selective pressures and genetic signatures of the mutant swarm and consensus sequences is lacking. To clarify this, we analyzed previously generated whole genome, deep-sequencing data from 548 West Nile virus samples isolated from avian tissues or mosquitoes in New York State from 1999-2018. Both consensus level (interhost) and minority level (intrahost) nucleotide and amino acid sequences were analyzed, and diversity at each position was calculated across the genome in order to assess the relationship between minority and consensus sequences for individual genes and hosts. Our results indicate that consensus sequences are an inept representation of the overall genetic diversity. Unique host and gene-specific signatures and selective pressures were identified. These data demonstrate that an accurate and comprehensive understanding of arbovirus evolution and adaptation within and between hosts requires consideration of minority genotypes.
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30
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Wills PR, Carter CW. Impedance Matching and the Choice Between Alternative Pathways for the Origin of Genetic Coding. Int J Mol Sci 2020; 21:E7392. [PMID: 33036401 PMCID: PMC7582391 DOI: 10.3390/ijms21197392] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 09/28/2020] [Accepted: 09/30/2020] [Indexed: 01/07/2023] Open
Abstract
We recently observed that errors in gene replication and translation could be seen qualitatively to behave analogously to the impedances in acoustical and electronic energy transducing systems. We develop here quantitative relationships necessary to confirm that analogy and to place it into the context of the minimization of dissipative losses of both chemical free energy and information. The formal developments include expressions for the information transferred from a template to a new polymer, Iσ; an impedance parameter, Z; and an effective alphabet size, neff; all of which have non-linear dependences on the fidelity parameter, q, and the alphabet size, n. Surfaces of these functions over the {n,q} plane reveal key new insights into the origin of coding. Our conclusion is that the emergence and evolutionary refinement of information transfer in biology follow principles previously identified to govern physical energy flows, strengthening analogies (i) between chemical self-organization and biological natural selection, and (ii) between the course of evolutionary trajectories and the most probable pathways for time-dependent transitions in physics. Matching the informational impedance of translation to the four-letter alphabet of genes uncovers a pivotal role for the redundancy of triplet codons in preserving as much intrinsic genetic information as possible, especially in early stages when the coding alphabet size was small.
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Affiliation(s)
- Peter R. Wills
- Department of Physics and Te Ao Marama Centre for Fundamental Inquiry, University of Auckland, PB 92019, Auckland 1142, New Zealand
| | - Charles W. Carter
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7260, USA
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31
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Abstract
Vaccinations and therapies targeting evolving pathogens aim to curb the pathogen and to steer it toward a controlled evolutionary state. Control is leveraged against the pathogen’s intrinsic evolutionary forces, which in turn, can drive an escape from control. Here, we analyze a simple model of control, in which a host produces antibodies that bind the pathogen. We show that the leverages of host (or external intervention) and pathogen are often highly imbalanced: an error threshold separates parameter regions of efficient control from regions of compromised control, where the pathogen retains the upper hand. Because control efficiency can be predicted from few measurable fitness parameters, our results establish a proof of principle how control theory can guide interventions against evolving pathogens. Control can alter the eco-evolutionary dynamics of a target pathogen in two ways, by changing its population size and by directed evolution of new functions. Here, we develop a payoff model of eco-evolutionary control based on strategies of evolution, regulation, and computational forecasting. We apply this model to pathogen control by molecular antibody–antigen binding with a tunable dosage of antibodies. By analytical solution, we obtain optimal dosage protocols and establish a phase diagram with an error threshold delineating parameter regimes of successful and compromised control. The solution identifies few independently measurable fitness parameters that predict the outcome of control. Our analysis shows how optimal control strategies depend on mutation rate and population size of the pathogen, and how monitoring and computational forecasting affect protocols and efficiency of control. We argue that these results carry over to more general systems and are elements of an emerging eco-evolutionary control theory.
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32
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Bauer DC, Tay AP, Wilson LOW, Reti D, Hosking C, McAuley AJ, Pharo E, Todd S, Stevens V, Neave MJ, Tachedjian M, Drew TW, Vasan SS. Supporting pandemic response using genomics and bioinformatics: A case study on the emergent SARS-CoV-2 outbreak. Transbound Emerg Dis 2020; 67:1453-1462. [PMID: 32306500 PMCID: PMC7264654 DOI: 10.1111/tbed.13588] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 03/30/2020] [Accepted: 04/07/2020] [Indexed: 12/15/2022]
Abstract
Pre‐clinical responses to fast‐moving infectious disease outbreaks heavily depend on choosing the best isolates for animal models that inform diagnostics, vaccines and treatments. Current approaches are driven by practical considerations (e.g. first available virus isolate) rather than a detailed analysis of the characteristics of the virus strain chosen, which can lead to animal models that are not representative of the circulating or emerging clusters. Here, we suggest a combination of epidemiological, experimental and bioinformatic considerations when choosing virus strains for animal model generation. We discuss the currently chosen SARS‐CoV‐2 strains for international coronavirus disease (COVID‐19) models in the context of their phylogeny as well as in a novel alignment‐free bioinformatic approach. Unlike phylogenetic trees, which focus on individual shared mutations, this new approach assesses genome‐wide co‐developing functionalities and hence offers a more fluid view of the ‘cloud of variances’ that RNA viruses are prone to accumulate. This joint approach concludes that while the current animal models cover the existing viral strains adequately, there is substantial evolutionary activity that is likely not considered by the current models. Based on insights from the non‐discrete alignment‐free approach and experimental observations, we suggest isolates for future animal models.
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Affiliation(s)
- Denis C Bauer
- Commonwealth Scientific and Industrial Research Organisation, Transformational Bioinformatics Group, Sydney, NSW, Australia.,Department of Biomedical Sciences, Macquarie University, NSW, Australia
| | - Aidan P Tay
- Commonwealth Scientific and Industrial Research Organisation, Transformational Bioinformatics Group, Sydney, NSW, Australia
| | - Laurence O W Wilson
- Commonwealth Scientific and Industrial Research Organisation, Transformational Bioinformatics Group, Sydney, NSW, Australia
| | - Daniel Reti
- Commonwealth Scientific and Industrial Research Organisation, Transformational Bioinformatics Group, Sydney, NSW, Australia
| | - Cameron Hosking
- Commonwealth Scientific and Industrial Research Organisation, Transformational Bioinformatics Group, Sydney, NSW, Australia
| | - Alexander J McAuley
- Commonwealth Scientific and Industrial Research Organisation, Health and Biosecurity, Geelong, Vic, Australia
| | - Elizabeth Pharo
- Commonwealth Scientific and Industrial Research Organisation, Health and Biosecurity, Geelong, Vic, Australia
| | - Shawn Todd
- Commonwealth Scientific and Industrial Research Organisation, Health and Biosecurity, Geelong, Vic, Australia
| | - Vicky Stevens
- Commonwealth Scientific and Industrial Research Organisation, Australian Centre for Disease Preparedness, Geelong, Vic, Australia
| | - Matthew J Neave
- Commonwealth Scientific and Industrial Research Organisation, Australian Centre for Disease Preparedness, Geelong, Vic, Australia
| | - Mary Tachedjian
- Commonwealth Scientific and Industrial Research Organisation, Health and Biosecurity, Geelong, Vic, Australia
| | - Trevor W Drew
- Commonwealth Scientific and Industrial Research Organisation, Australian Centre for Disease Preparedness, Geelong, Vic, Australia
| | - Seshadri S Vasan
- Commonwealth Scientific and Industrial Research Organisation, Health and Biosecurity, Geelong, Vic, Australia.,Department of Health Sciences, University of York, York, United Kingdom
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33
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Qu G, Li A, Acevedo‐Rocha CG, Sun Z, Reetz MT. Die zentrale Rolle der Methodenentwicklung in der gerichteten Evolution selektiver Enzyme. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201901491] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Ge Qu
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences 32 West 7th Avenue, Tianjin Airport Economic Area Tianjin 300308 China
| | - Aitao Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering Hubei Collaborative Innovation Center for Green Transformation of Bio-resources Hubei Key Laboratory of Industrial Biotechnology College of Life Sciences Hubei University 368 Youyi Road Wuchang Wuhan 430062 China
| | | | - Zhoutong Sun
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences 32 West 7th Avenue, Tianjin Airport Economic Area Tianjin 300308 China
| | - Manfred T. Reetz
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences 32 West 7th Avenue, Tianjin Airport Economic Area Tianjin 300308 China
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim Deutschland
- Department of Chemistry, Hans-Meerwein-Straße 4 Philipps-Universität 35032 Marburg Deutschland
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34
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Qu G, Li A, Acevedo‐Rocha CG, Sun Z, Reetz MT. The Crucial Role of Methodology Development in Directed Evolution of Selective Enzymes. Angew Chem Int Ed Engl 2020; 59:13204-13231. [PMID: 31267627 DOI: 10.1002/anie.201901491] [Citation(s) in RCA: 269] [Impact Index Per Article: 53.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Indexed: 12/14/2022]
Affiliation(s)
- Ge Qu
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences 32 West 7th Avenue, Tianjin Airport Economic Area Tianjin 300308 China
| | - Aitao Li
- State Key Laboratory of Biocatalysis and Enzyme Engineering Hubei Collaborative Innovation Center for Green Transformation of Bio-resources Hubei Key Laboratory of Industrial Biotechnology College of Life Sciences Hubei University 368 Youyi Road Wuchang Wuhan 430062 China
| | | | - Zhoutong Sun
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences 32 West 7th Avenue, Tianjin Airport Economic Area Tianjin 300308 China
| | - Manfred T. Reetz
- Tianjin Institute of Industrial Biotechnology Chinese Academy of Sciences 32 West 7th Avenue, Tianjin Airport Economic Area Tianjin 300308 China
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim Germany
- Department of Chemistry, Hans-Meerwein-Strasse 4 Philipps-University 35032 Marburg Germany
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35
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Ribó JM, Hochberg D. Spontaneous mirror symmetry breaking: an entropy production survey of the racemate instability and the emergence of stable scalemic stationary states. Phys Chem Chem Phys 2020; 22:14013-14025. [DOI: 10.1039/d0cp02280b] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Stability of non-equilibrium stationary states and spontaneous mirror symmetry breaking, provoked by the destabilization of the racemic thermodynamic branch, is studied for enantioselective autocatalysis in an open flow system, and for a continuous range n of autocatalytic orders.
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Affiliation(s)
- Josep M. Ribó
- Department of Organic Chemistry
- University of Barcelona
- E-08028 Barcelona
- Spain
- Institute of Cosmos Science (IEEC-UB)
| | - David Hochberg
- Department of Molecular Evolution
- Centro de Astrobiology (CSIC-INTA)
- E-28850 Torrejón de Ardoz
- Spain
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36
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Berger M, Cerf R. A basic model of mutations. ESAIM-PROBAB STAT 2020. [DOI: 10.1051/ps/2020024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
We study a basic model for mutations. We derive exact formulae for the mean time needed to discover the master sequence, the mean returning time to the initial state, or to any Hamming class. These last two formulae are the same than the formulae obtained by Mark Kac for the Ehrenfest model.
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37
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Nichol D, Robertson-Tessi M, Anderson ARA, Jeavons P. Model genotype-phenotype mappings and the algorithmic structure of evolution. J R Soc Interface 2019; 16:20190332. [PMID: 31690233 PMCID: PMC6893500 DOI: 10.1098/rsif.2019.0332] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 10/04/2019] [Indexed: 12/13/2022] Open
Abstract
Cancers are complex dynamic systems that undergo evolution and selection. Personalized medicine approaches in the clinic increasingly rely on predictions of tumour response to one or more therapies; these predictions are complicated by the inevitable evolution of the tumour. Despite enormous amounts of data on the mutational status of cancers and numerous therapies developed in recent decades to target these mutations, many of these treatments fail after a time due to the development of resistance in the tumour. The emergence of these resistant phenotypes is not easily predicted from genomic data, since the relationship between genotypes and phenotypes, termed the genotype-phenotype (GP) mapping, is neither injective nor functional. We present a review of models of this mapping within a generalized evolutionary framework that takes into account the relation between genotype, phenotype, environment and fitness. Different modelling approaches are described and compared, and many evolutionary results are shown to be conserved across studies despite using different underlying model systems. In addition, several areas for future work that remain understudied are identified, including plasticity and bet-hedging. The GP-mapping provides a pathway for understanding the potential routes of evolution taken by cancers, which will be necessary knowledge for improving personalized therapies.
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Affiliation(s)
- Daniel Nichol
- Department of Computer Science, University of Oxford, Oxford, UK
- Department of Integrated Mathematical Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Mark Robertson-Tessi
- Department of Integrated Mathematical Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Alexander R. A. Anderson
- Department of Integrated Mathematical Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA
| | - Peter Jeavons
- Department of Computer Science, University of Oxford, Oxford, UK
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38
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R AAA, Madhok V. Typicality in quasispecies evolution in high dimensions. Phys Rev E 2019; 100:042407. [PMID: 31771005 DOI: 10.1103/physreve.100.042407] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Indexed: 11/07/2022]
Abstract
We study quasispecies and closely related evolutionary dynamics like the replicator-mutator equation in high dimensions. In particular, we show that under certain conditions, the average fitness of almost all quasispecies of a given dimension becomes independent of mutational probabilities in high dimensional sequence spaces. This result is a consequence of concentration of measure on a high dimensional hypersphere and its extension to Lipschitz functions known as the Levy's Lemma. Our results naturally extend to other functional capabilities that can be described as Lipschitz functions and whose input parameters are the frequencies of individual constituents of the quasispecies. In order to show this, we give a generalization of Levy's Lemma and discuss possible biological consequences of our work.
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Affiliation(s)
| | - Vaibhav Madhok
- Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
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39
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Tupper AS, Pudritz RE, Higgs PG. Can the RNA World Still Function without Cytidine? Mol Biol Evol 2019; 37:71-83. [DOI: 10.1093/molbev/msz200] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Abstract
Most scenarios for the origin of life assume that RNA played a key role in both catalysis and information storage. The A, U, G, and C nucleobases in modern RNA all participate in secondary structure formation and replication. However, the rapid deamination of C to U and the absence of C in meteorite samples suggest that prebiotic RNA may have been deficient in cytosine. Here, we assess the ability of RNA sequences formed from a three-letter AUG alphabet to perform both structural and genetic roles in comparison to sequences formed from the AUGC alphabet. Despite forming less thermodynamically stable helices, the AUG alphabet can find a broad range of structures and thus appears sufficient for catalysis in the RNA World. However, in the AUG case, longer sequences are required to form structures with an equivalent complexity. Replication in the AUG alphabet requires GU pairing. Sequence fidelity in the AUG alphabet is low whenever G’s are present in the sequence. We find that AUG sequences evolve to AU sequences if GU pairing is rare, and to RU sequences if GU pairing is common (R denotes A or G). It is not possible to conserve a G at a specific site in either case. These problems do not rule out the possibility of an RNA World based on AUG, but they show that it wouldbe significantly more difficult than with a four-base alphabet.
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Affiliation(s)
- Andrew S Tupper
- Origins Institute and Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Ralph E Pudritz
- Origins Institute and Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada
| | - Paul G Higgs
- Origins Institute and Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada
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40
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Carter CW, Wills PR. Experimental solutions to problems defining the origin of codon-directed protein synthesis. Biosystems 2019; 183:103979. [PMID: 31176803 PMCID: PMC6693952 DOI: 10.1016/j.biosystems.2019.103979] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 05/27/2019] [Accepted: 05/29/2019] [Indexed: 12/13/2022]
Abstract
How genetic coding differentiated biology from chemistry is a long-standing challenge in Biology, for which there have been few experimental approaches, despite a wide-ranging speculative literature. We summarize five coordinated areas-experimental characterization of functional approximations to the minimal peptides (protozymes and urzymes) necessary to activate amino acids and acylate tRNA; showing that specificities of these experimental models match those expected from the synthetase Class division; population of disjoint regions of amino acid sequence space via bidirectional coding ancestry of the two synthetase Classes; showing that the phase transfer equilibria of amino acid side chains that form a two-dimensional basis set for protein folding are embedded in patterns of bases in the tRNA acceptor stem and anticodon; and identification of molecular signatures of ancestral synthetases and tRNAs necessary to define the earliest cognate synthetase:tRNA pairs-that now compose an extensive experimentally testable paradigm for progress toward understanding the coordinated emergence of the codon table and viable mRNA coding sequences. We briefly discuss recent progress toward identifying the remaining outstanding questions-the nature of the earliest amino acid alphabets and the origin of binding discrimination via distinct amino acid sequence-independent protein secondary structures-and how these, too, might be addressed experimentally.
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Affiliation(s)
- Charles W Carter
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7260, United States
| | - Peter R Wills
- Department of Physics and Te Ao Marama Centre for Fundamental Inquiry, University of Auckland, PB 92019, Auckland 1142, New Zealand
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41
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Shah V, de Bouter J, Pauli Q, Tupper AS, Higgs PG. Survival of RNA Replicators is much Easier in Protocells than in Surface-Based, Spatial Systems. Life (Basel) 2019; 9:life9030065. [PMID: 31394866 PMCID: PMC6789734 DOI: 10.3390/life9030065] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 07/24/2019] [Accepted: 07/30/2019] [Indexed: 01/27/2023] Open
Abstract
In RNA-World scenarios for the origin of life, replication is catalyzed by polymerase ribozymes. Replicating RNA systems are subject to invasion by non-functional parasitic strands. It is well-known that there are two ways to avoid the destruction of the system by parasites: spatial clustering in models with limited diffusion, or group selection in protocells. Here, we compare computational models of replication in spatial models and protocells as closely as possible in order to determine the relative importance of these mechanisms in the RNA World. For the survival of the polymerases, the replication rate must be greater than a minimum threshold value, kmin, and the mutation rate in replication must be less than a maximum value, Mmax, which is known as the error threshold. For the protocell models, we find that kmin is substantially lower and Mmax is substantially higher than for the equivalent spatial models; thus, the survival of polymerases is much easier in protocells than on surfaces. The results depend on the maximum number of strands permitted in one protocell or one lattice site in the spatial model, and on whether replication is limited by the supply of monomers or the population size of protocells. The substantial advantages that are seen in the protocell models relative to the spatial models are robust to changing these details. Thus, cooperative polymerases with limited accuracy would have found it much easier to operate inside lipid compartments, and this suggests that protocells may have been a very early step in the development of life. We consider cases where parasites have an equal replication rate to polymerases, and cases where parasites multiply twice as fast as polymerases. The advantage of protocell models over spatial models is increased when the parasites multiply faster.
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Affiliation(s)
- Vismay Shah
- Origins Institute and Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, CA L8S 4L8, USA
| | - Jonathan de Bouter
- Origins Institute and Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, CA L8S 4L8, USA
| | - Quinn Pauli
- Origins Institute and Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, CA L8S 4L8, USA
| | - Andrew S Tupper
- Origins Institute and Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, CA L8S 4L8, USA
| | - Paul G Higgs
- Origins Institute and Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, CA L8S 4L8, USA.
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42
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Boucher JI, Whitfield TW, Dauphin A, Nachum G, Hollins C, Zeldovich KB, Swanstrom R, Schiffer CA, Luban J, Bolon DNA. Constrained Mutational Sampling of Amino Acids in HIV-1 Protease Evolution. Mol Biol Evol 2019; 36:798-810. [PMID: 30721995 DOI: 10.1093/molbev/msz022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The evolution of HIV-1 protein sequences should be governed by a combination of factors including nucleotide mutational probabilities, the genetic code, and fitness. The impact of these factors on protein sequence evolution is interdependent, making it challenging to infer the individual contribution of each factor from phylogenetic analyses alone. We investigated the protein sequence evolution of HIV-1 by determining an experimental fitness landscape of all individual amino acid changes in protease. We compared our experimental results to the frequency of protease variants in a publicly available data set of 32,163 sequenced isolates from drug-naïve individuals. The most common amino acids in sequenced isolates supported robust experimental fitness, indicating that the experimental fitness landscape captured key features of selection acting on protease during viral infections of hosts. Amino acid changes requiring multiple mutations from the likely ancestor were slightly less likely to support robust experimental fitness than single mutations, consistent with the genetic code favoring chemically conservative amino acid changes. Amino acids that were common in sequenced isolates were predominantly accessible by single mutations from the likely protease ancestor. Multiple mutations commonly observed in isolates were accessible by mutational walks with highly fit single mutation intermediates. Our results indicate that the prevalence of multiple-base mutations in HIV-1 protease is strongly influenced by mutational sampling.
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Affiliation(s)
- Jeffrey I Boucher
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA
| | - Troy W Whitfield
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA.,Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, MA
| | - Ann Dauphin
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Gily Nachum
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA
| | - Carl Hollins
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA
| | - Konstantin B Zeldovich
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Ronald Swanstrom
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC
| | - Celia A Schiffer
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA
| | - Jeremy Luban
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA.,Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA
| | - Daniel N A Bolon
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA
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43
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Horowitz JM, Kardar M. Bacterial range expansions on a growing front: Roughness, fixation, and directed percolation. Phys Rev E 2019; 99:042134. [PMID: 31108639 DOI: 10.1103/physreve.99.042134] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Indexed: 06/09/2023]
Abstract
Directed percolation (DP) is a classic model for nonequilibrium phase transitions into a single absorbing state (fixation). It has been extensively studied by analytical and numerical techniques in diverse contexts. Recently, DP has appeared as a generic model for the evolutionary and ecological dynamics of competing bacterial populations. Range expansion-the stochastic reproduction of bacteria competing for space to be occupied by their progeny-leads to a fluctuating and rough growth front, which is known from experiment and simulation to affect the underlying critical behavior of the DP transition. In this work, we employ symmetry arguments to construct a pair of nonlinear stochastic partial differential equations describing the coevolution of surface roughness with the composition field of DP. Macroscopic manifestations (phenomenology) of these equations on growth patterns and genealogical tracks of range expansion are discussed; followed by a renormalization group analysis of possible scaling behaviors at the DP transition.
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Affiliation(s)
- Jordan M Horowitz
- Physics of Living Systems Group, Department of Physics, Massachusetts Institute of Technology, 400 Technology Square, Cambridge, Massachusetts 02139, USA
- Department of Biophysics, University of Michigan, Ann Arbor, Michigan 48109, USA
- Center for the Study of Complex Systems, University of Michigan, Ann Arbor, Michigan 48104, USA
| | - Mehran Kardar
- Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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44
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Abstract
Central to the “RNA world” hypothesis of the origin of life is the emergence of an RNA catalyst capable of RNA replication. However, possible replicase ribozymes are quite complex and were likely predated by simpler non-enzymatic replication reactions. The templated polymerisation of phosphorimidazolide (Imp) activated ribonucleotides currently appears as the most tractable route to both generate and replicate short RNA oligomer pools from which a replicase could emerge. Herein we demonstrate the rapid assembly of complex ribozymes from such Imp-activated RNA fragment pools. Specifically, we show assembly of a newly selected minimal RNA polymerase ribozyme variant (150 nt) by RNA templated ligation of 5’-2-methylimidazole-activated RNA oligomers <30 nucleotides long. Our results provide support for the possibility that complex RNA structures could have emerged from pools of activated RNA oligomers and outlines a path for the transition from non-enzymatic/chemical to enzymatic RNA replication.
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Affiliation(s)
- Falk Wachowius
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH (UK)
| | - Philipp Holliger
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH (UK)
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45
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Scheuermann B, Diem T, Ivics Z, Andrade-Navarro MA. Evolution-guided evaluation of the inverted terminal repeats of the synthetic transposon Sleeping Beauty. Sci Rep 2019; 9:1171. [PMID: 30718656 PMCID: PMC6362248 DOI: 10.1038/s41598-018-38061-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 12/18/2018] [Indexed: 11/09/2022] Open
Abstract
Sleeping Beauty (SB) is a synthetic Tc1/mariner transposon that is widely used for genetic engineering in vertebrates, including humans. Its sequence was derived from a consensus of sequences found in fish species including the Atlantic salmon (Salmo salar). One of the functional components of SB, the transposase enzyme, has been subject to extensive mutagenesis yielding hyperactive protein variants for advanced applications. The second functional component, the transposon inverted terminal repeats (ITRs), has so far not been extensively modified, mainly due to a lack of natural sequence information. Importantly, as genome sequences become available, they can provide a rich source of information for a refined molecular definition of the functional components of these transposons. Here we have mined the Salmo salar genome for a comprehensive set of transposon sequences that were used to build a refined consensus sequence. We synthetically produced the new consensus ITR sequences and used them to build a new transposon, the performance of which has been tested in cell-based transposition assays. The consensus sequence did not support enhanced transposition, suggesting alternative mechanisms responsible for the preferential amplification of these sequence variants in the salmon genome.
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Affiliation(s)
- Barbara Scheuermann
- Faculty of Biology, Johannes Gutenberg University of Mainz, 55128, Mainz, Germany
| | - Tanja Diem
- Division of Medical Biotechnology, Paul Ehrlich Institute, Langen, Germany
| | - Zoltán Ivics
- Division of Medical Biotechnology, Paul Ehrlich Institute, Langen, Germany.
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46
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Sun Z, Liu Q, Qu G, Feng Y, Reetz MT. Utility of B-Factors in Protein Science: Interpreting Rigidity, Flexibility, and Internal Motion and Engineering Thermostability. Chem Rev 2019; 119:1626-1665. [PMID: 30698416 DOI: 10.1021/acs.chemrev.8b00290] [Citation(s) in RCA: 323] [Impact Index Per Article: 53.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Zhoutong Sun
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West Seventh Avenue, Tianjin Airport Economic Area, Tianjin 300308, China
| | - Qian Liu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ge Qu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West Seventh Avenue, Tianjin Airport Economic Area, Tianjin 300308, China
| | - Yan Feng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Manfred T. Reetz
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West Seventh Avenue, Tianjin Airport Economic Area, Tianjin 300308, China
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
- Chemistry Department, Philipps-University, Hans-Meerwein-Strasse 4, 35032 Marburg, Germany
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47
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Rodrigo C, Luciani F. Dynamic interactions between RNA viruses and human hosts unravelled by a decade of next generation sequencing. Biochim Biophys Acta Gen Subj 2018; 1863:511-519. [PMID: 30528489 DOI: 10.1016/j.bbagen.2018.12.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Revised: 11/27/2018] [Accepted: 12/04/2018] [Indexed: 01/15/2023]
Abstract
BACKGROUND Next generation sequencing (NGS) methods have significantly contributed to a paradigm shift in genomic research for nearly a decade now. These methods have been useful in studying the dynamic interactions between RNA viruses and human hosts. SCOPE OF THE REVIEW In this review, we summarise and discuss key applications of NGS in studying the host - pathogen interactions in RNA viral infections of humans with examples. MAJOR CONCLUSIONS Use of NGS to study globally relevant RNA viral infections have revolutionized our understanding of the within host and between host evolution of these viruses. These methods have also been useful in clinical decision-making and in guiding biomedical research on vaccine design. GENERAL SIGNIFICANCE NGS has been instrumental in viral genomic studies in resolving within-host viral genomic variants and the distribution of nucleotide polymorphisms along the full-length of viral genomes in a high throughput, cost effective manner. In the future, novel advances such as long read, single molecule sequencing of viral genomes and simultaneous sequencing of host and pathogens may become the standard of practice in research and clinical settings. This will also bring on new challenges in big data analysis.
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Affiliation(s)
- Chaturaka Rodrigo
- School of Medical Sciences and Kirby Institute for Infection and Immunity, UNSW Australia, 2052, NSW, Australia
| | - Fabio Luciani
- School of Medical Sciences and Kirby Institute for Infection and Immunity, UNSW Australia, 2052, NSW, Australia.
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Using high-throughput sequencing for investigating intra-host hepatitis C evolution over long retrospective periods. INFECTION GENETICS AND EVOLUTION 2018; 67:136-144. [PMID: 30395998 DOI: 10.1016/j.meegid.2018.11.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 09/11/2018] [Accepted: 11/02/2018] [Indexed: 12/13/2022]
Abstract
Collections of biological samples held by hospitals represent invaluable resources for conducting retrospective evolutionary studies of chronic infections. Using high-throughput sequencing, those collections permit analysis of within-host genetic diversity over long follow-up periods, and allow a better understanding of resistance to treatment regimes during disease evolution. Here, we studied the evolution of hepatitis C virus (HCV) populations in two patients with an absence of response to dual therapies. We implemented amplicon sequencing to survey genomic variation at the Core and NS5B regions of HCV over a period of 13 years from blood samples obtained at multiple time points. We observed mixed infection by multiple HCV genotypes in both patients. Genetic heterogeneity and sample composition analysis provided information about the changes in viral population over the course of clinical treatment, with NS5B experiencing an increase in diversity after treatment initiation. Secondary infections were estimated to predate treatment year, and our results pointed towards diversifying selection occurring post-treatment, acting on standing genomic variation and maintaining high genetic heterogeneity during infection. For these two patients infected with multiple HCV genotypes, the maintenance of viral diversity was explained with the hypothesis of soft selective sweep started at the same time as antiviral treatment was initiated.
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Replicability of Introgression Under Linked, Polygenic Selection. Genetics 2018; 210:1411-1427. [PMID: 30274989 DOI: 10.1534/genetics.118.301429] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Accepted: 09/28/2018] [Indexed: 11/18/2022] Open
Abstract
We study how a block of genome with a large number of weakly selected loci introgresses under directional selection into a genetically homogeneous population. We derive exact expressions for the expected rate of growth of any fragment of the introduced block during the initial phase of introgression, and show that the growth rate of a single-locus variant is largely insensitive to its own additive effect, but depends instead on the combined effect of all loci within a characteristic linkage scale. The expected growth rate of a fragment is highly correlated with its long-term introgression probability in populations of moderate size, and can hence identify variants that are likely to introgress across replicate populations. We clarify how the introgression probability of an individual variant is determined by the interplay between hitchhiking with relatively large fragments during the early phase of introgression and selection on fine-scale variation within these, which at longer times results in differential introgression probabilities for beneficial and deleterious loci within successful fragments. By simulating individuals, we also investigate how introgression probabilities at individual loci depend on the variance of fitness effects, the net fitness of the introduced block, and the size of the recipient population, and how this shapes the net advance under selection. Our work suggests that even highly replicable substitutions may be associated with a range of selective effects, which makes it challenging to fine map the causal loci that underlie polygenic adaptation.
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Said Mohammed K, Kibinge N, Prins P, Agoti CN, Cotten M, Nokes D, Brand S, Githinji G. Evaluating the performance of tools used to call minority variants from whole genome short-read data. Wellcome Open Res 2018; 3:21. [PMID: 30483597 PMCID: PMC6234735 DOI: 10.12688/wellcomeopenres.13538.2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/03/2018] [Indexed: 01/06/2023] Open
Abstract
Background: High-throughput whole genome sequencing facilitates investigation of minority virus sub-populations from virus positive samples. Minority variants are useful in understanding within and between host diversity, population dynamics and can potentially assist in elucidating person-person transmission pathways. Several minority variant callers have been developed to describe low frequency sub-populations from whole genome sequence data. These callers differ based on bioinformatics and statistical methods used to discriminate sequencing errors from low-frequency variants. Methods: We evaluated the diagnostic performance and concordance between published minority variant callers used in identifying minority variants from whole-genome sequence data from virus samples. We used the ART-Illumina read simulation tool to generate three artificial short-read datasets of varying coverage and error profiles from an RSV reference genome. The datasets were spiked with nucleotide variants at predetermined positions and frequencies. Variants were called using FreeBayes, LoFreq, Vardict, and VarScan2. The variant callers' agreement in identifying known variants was quantified using two measures; concordance accuracy and the inter-caller concordance. Results: The variant callers reported differences in identifying minority variants from the datasets. Concordance accuracy and inter-caller concordance were positively correlated with sample coverage. FreeBayes identified the majority of variants although it was characterised by variable sensitivity and precision in addition to a high false positive rate relative to the other minority variant callers and which varied with sample coverage. LoFreq was the most conservative caller. Conclusions: We conducted a performance and concordance evaluation of four minority variant calling tools used to identify and quantify low frequency variants. Inconsistency in the quality of sequenced samples impacts on sensitivity and accuracy of minority variant callers. Our study suggests that combining at least three tools when identifying minority variants is useful in filtering errors when calling low frequency variants.
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Affiliation(s)
- Khadija Said Mohammed
- Pwani University, Kilifi, Kenya
- KEMRI-Wellcome Trust Research Programme, KEMRI Centre for Geographic Medicine Research – Coast, Kilifi, Kenya
| | - Nelson Kibinge
- KEMRI-Wellcome Trust Research Programme, KEMRI Centre for Geographic Medicine Research – Coast, Kilifi, Kenya
| | - Pjotr Prins
- KEMRI-Wellcome Trust Research Programme, KEMRI Centre for Geographic Medicine Research – Coast, Kilifi, Kenya
- University Medical Center Utrecht, Utrecht, The Netherlands
| | - Charles N. Agoti
- Pwani University, Kilifi, Kenya
- KEMRI-Wellcome Trust Research Programme, KEMRI Centre for Geographic Medicine Research – Coast, Kilifi, Kenya
| | - Matthew Cotten
- Virosciences Department, Erasmus Medical Centre, Rotterdam, The Netherlands
| | - D.J. Nokes
- KEMRI-Wellcome Trust Research Programme, KEMRI Centre for Geographic Medicine Research – Coast, Kilifi, Kenya
- School of Life Sciences and Zeeman Institute (SBIDER), University of Warwick, Coventry, UK
| | - Samuel Brand
- School of Life Sciences and Zeeman Institute (SBIDER), University of Warwick, Coventry, UK
| | - George Githinji
- KEMRI-Wellcome Trust Research Programme, KEMRI Centre for Geographic Medicine Research – Coast, Kilifi, Kenya
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