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The evolutionary origin of the universal distribution of mutation fitness effect
An intriguing fact long defying explanation is the observation of a universal exponential distribution of beneficial mutations in fitness effect for different microorganisms. To explain this effect, we use a population model including mutation, directional selection, linkage, and genetic drift. The...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Public Library of Science
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7971868/ https://www.ncbi.nlm.nih.gov/pubmed/33684109 http://dx.doi.org/10.1371/journal.pcbi.1008822 |
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author | Barlukova, Ayuna Rouzine, Igor M. |
author_facet | Barlukova, Ayuna Rouzine, Igor M. |
author_sort | Barlukova, Ayuna |
collection | PubMed |
description | An intriguing fact long defying explanation is the observation of a universal exponential distribution of beneficial mutations in fitness effect for different microorganisms. To explain this effect, we use a population model including mutation, directional selection, linkage, and genetic drift. The multiple-mutation regime of adaptation at large population sizes (traveling wave regime) is considered. We demonstrate analytically and by simulation that, regardless of the inherent distribution of mutation fitness effect across genomic sites, an exponential distribution of fitness effects emerges in the long term. This result follows from the exponential statistics of the frequency of the less-fit alleles, f, that we predict to evolve, in the long term, for both polymorphic and monomorphic sites. We map the logarithmic slope of the distribution onto the previously derived fixation probability and demonstrate that it increases linearly in time. Our results demonstrate a striking difference between the distribution of fitness effects observed experimentally for naturally occurring mutations, and the "inherent" distribution obtained in a directed-mutagenesis experiment, which can have any shape depending on the organism. Based on these results, we develop a new method to measure the fitness effect of mutations for each variable residue using DNA sequences sampled from adapting populations. This new method is not sensitive to linkage effects and does not require the one-site model assumptions. |
format | Online Article Text |
id | pubmed-7971868 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | Public Library of Science |
record_format | MEDLINE/PubMed |
spelling | pubmed-79718682021-03-31 The evolutionary origin of the universal distribution of mutation fitness effect Barlukova, Ayuna Rouzine, Igor M. PLoS Comput Biol Research Article An intriguing fact long defying explanation is the observation of a universal exponential distribution of beneficial mutations in fitness effect for different microorganisms. To explain this effect, we use a population model including mutation, directional selection, linkage, and genetic drift. The multiple-mutation regime of adaptation at large population sizes (traveling wave regime) is considered. We demonstrate analytically and by simulation that, regardless of the inherent distribution of mutation fitness effect across genomic sites, an exponential distribution of fitness effects emerges in the long term. This result follows from the exponential statistics of the frequency of the less-fit alleles, f, that we predict to evolve, in the long term, for both polymorphic and monomorphic sites. We map the logarithmic slope of the distribution onto the previously derived fixation probability and demonstrate that it increases linearly in time. Our results demonstrate a striking difference between the distribution of fitness effects observed experimentally for naturally occurring mutations, and the "inherent" distribution obtained in a directed-mutagenesis experiment, which can have any shape depending on the organism. Based on these results, we develop a new method to measure the fitness effect of mutations for each variable residue using DNA sequences sampled from adapting populations. This new method is not sensitive to linkage effects and does not require the one-site model assumptions. Public Library of Science 2021-03-08 /pmc/articles/PMC7971868/ /pubmed/33684109 http://dx.doi.org/10.1371/journal.pcbi.1008822 Text en © 2021 Barlukova, Rouzine http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
spellingShingle | Research Article Barlukova, Ayuna Rouzine, Igor M. The evolutionary origin of the universal distribution of mutation fitness effect |
title | The evolutionary origin of the universal distribution of mutation fitness effect |
title_full | The evolutionary origin of the universal distribution of mutation fitness effect |
title_fullStr | The evolutionary origin of the universal distribution of mutation fitness effect |
title_full_unstemmed | The evolutionary origin of the universal distribution of mutation fitness effect |
title_short | The evolutionary origin of the universal distribution of mutation fitness effect |
title_sort | evolutionary origin of the universal distribution of mutation fitness effect |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7971868/ https://www.ncbi.nlm.nih.gov/pubmed/33684109 http://dx.doi.org/10.1371/journal.pcbi.1008822 |
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