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Similar Efficacies of Selection Shape Mitochondrial and Nuclear Genes in Both Drosophila melanogaster and Homo sapiens
Deleterious mutations contribute to polymorphism even when selection effectively prevents their fixation. The efficacy of selection in removing deleterious mitochondrial mutations from populations depends on the effective population size (N(e)) of the mitochondrial DNA and the degree to which a lack...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Genetics Society of America
2015
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4592998/ https://www.ncbi.nlm.nih.gov/pubmed/26297726 http://dx.doi.org/10.1534/g3.114.016493 |
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author | Cooper, Brandon S. Burrus, Chad R. Ji, Chao Hahn, Matthew W. Montooth, Kristi L. |
author_facet | Cooper, Brandon S. Burrus, Chad R. Ji, Chao Hahn, Matthew W. Montooth, Kristi L. |
author_sort | Cooper, Brandon S. |
collection | PubMed |
description | Deleterious mutations contribute to polymorphism even when selection effectively prevents their fixation. The efficacy of selection in removing deleterious mitochondrial mutations from populations depends on the effective population size (N(e)) of the mitochondrial DNA and the degree to which a lack of recombination magnifies the effects of linked selection. Using complete mitochondrial genomes from Drosophila melanogaster and nuclear data available from the same samples, we reexamine the hypothesis that nonrecombining animal mitochondrial DNA harbor an excess of deleterious polymorphisms relative to the nuclear genome. We find no evidence of recombination in the mitochondrial genome, and the much-reduced level of mitochondrial synonymous polymorphism relative to nuclear genes is consistent with a reduction in N(e). Nevertheless, we find that the neutrality index, a measure of the excess of nonsynonymous polymorphism relative to the neutral expectation, is only weakly significantly different between mitochondrial and nuclear loci. This difference is likely the result of the larger proportion of beneficial mutations in X-linked relative to autosomal loci, and we find little to no difference between mitochondrial and autosomal neutrality indices. Reanalysis of published data from Homo sapiens reveals a similar lack of a difference between the two genomes, although previous studies have suggested a strong difference in both species. Thus, despite a smaller N(e), mitochondrial loci of both flies and humans appear to experience similar efficacies of purifying selection as do loci in the recombining nuclear genome. |
format | Online Article Text |
id | pubmed-4592998 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2015 |
publisher | Genetics Society of America |
record_format | MEDLINE/PubMed |
spelling | pubmed-45929982015-10-15 Similar Efficacies of Selection Shape Mitochondrial and Nuclear Genes in Both Drosophila melanogaster and Homo sapiens Cooper, Brandon S. Burrus, Chad R. Ji, Chao Hahn, Matthew W. Montooth, Kristi L. G3 (Bethesda) Investigations Deleterious mutations contribute to polymorphism even when selection effectively prevents their fixation. The efficacy of selection in removing deleterious mitochondrial mutations from populations depends on the effective population size (N(e)) of the mitochondrial DNA and the degree to which a lack of recombination magnifies the effects of linked selection. Using complete mitochondrial genomes from Drosophila melanogaster and nuclear data available from the same samples, we reexamine the hypothesis that nonrecombining animal mitochondrial DNA harbor an excess of deleterious polymorphisms relative to the nuclear genome. We find no evidence of recombination in the mitochondrial genome, and the much-reduced level of mitochondrial synonymous polymorphism relative to nuclear genes is consistent with a reduction in N(e). Nevertheless, we find that the neutrality index, a measure of the excess of nonsynonymous polymorphism relative to the neutral expectation, is only weakly significantly different between mitochondrial and nuclear loci. This difference is likely the result of the larger proportion of beneficial mutations in X-linked relative to autosomal loci, and we find little to no difference between mitochondrial and autosomal neutrality indices. Reanalysis of published data from Homo sapiens reveals a similar lack of a difference between the two genomes, although previous studies have suggested a strong difference in both species. Thus, despite a smaller N(e), mitochondrial loci of both flies and humans appear to experience similar efficacies of purifying selection as do loci in the recombining nuclear genome. Genetics Society of America 2015-08-21 /pmc/articles/PMC4592998/ /pubmed/26297726 http://dx.doi.org/10.1534/g3.114.016493 Text en Copyright © 2015 Cooper et al. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Investigations Cooper, Brandon S. Burrus, Chad R. Ji, Chao Hahn, Matthew W. Montooth, Kristi L. Similar Efficacies of Selection Shape Mitochondrial and Nuclear Genes in Both Drosophila melanogaster and Homo sapiens |
title | Similar Efficacies of Selection Shape Mitochondrial and Nuclear Genes in Both Drosophila melanogaster and Homo sapiens |
title_full | Similar Efficacies of Selection Shape Mitochondrial and Nuclear Genes in Both Drosophila melanogaster and Homo sapiens |
title_fullStr | Similar Efficacies of Selection Shape Mitochondrial and Nuclear Genes in Both Drosophila melanogaster and Homo sapiens |
title_full_unstemmed | Similar Efficacies of Selection Shape Mitochondrial and Nuclear Genes in Both Drosophila melanogaster and Homo sapiens |
title_short | Similar Efficacies of Selection Shape Mitochondrial and Nuclear Genes in Both Drosophila melanogaster and Homo sapiens |
title_sort | similar efficacies of selection shape mitochondrial and nuclear genes in both drosophila melanogaster and homo sapiens |
topic | Investigations |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4592998/ https://www.ncbi.nlm.nih.gov/pubmed/26297726 http://dx.doi.org/10.1534/g3.114.016493 |
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