Near neutrality, rate heterogeneity, and linkage govern mitochondrial genome evolution in Atlantic cod (Gadus morhua) and other gadine fish
The mitochondrial DNA (mtDNA) genome figures prominently in evolutionary investigations of vertebrate animals due to a suite of characteristics that include absence of Darwinian selection, high mutation rate, and inheritance as a single linkage group. Given complete linkage and selective neutrality,...
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Online Access: | https://pure.uhi.ac.uk/en/publications/7ac27168-6852-41a2-9042-168b3df790b0 https://doi.org/10.1093/molbev/msn279 |
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ftuhipublicatio:oai:pure.atira.dk:publications/7ac27168-6852-41a2-9042-168b3df790b0 2024-02-04T09:58:47+01:00 Near neutrality, rate heterogeneity, and linkage govern mitochondrial genome evolution in Atlantic cod (Gadus morhua) and other gadine fish Marshall, H Dawn Coulson, Mark W Carr, Steven M 2009 https://pure.uhi.ac.uk/en/publications/7ac27168-6852-41a2-9042-168b3df790b0 https://doi.org/10.1093/molbev/msn279 eng eng info:eu-repo/semantics/restrictedAccess Marshall , H D , Coulson , M W & Carr , S M 2009 , ' Near neutrality, rate heterogeneity, and linkage govern mitochondrial genome evolution in Atlantic cod (Gadus morhua) and other gadine fish ' , Molecular Biology and Evolution , vol. 26 , no. 3 , pp. 579-89 . https://doi.org/10.1093/molbev/msn279 Animals Evolution Molecular Gadiformes Gadus morhua Genome Mitochondrial Kinetics Linkage Disequilibrium Recombination Genetic Journal Article Research Support Non-U.S. Gov't article 2009 ftuhipublicatio https://doi.org/10.1093/molbev/msn279 2024-01-11T23:21:19Z The mitochondrial DNA (mtDNA) genome figures prominently in evolutionary investigations of vertebrate animals due to a suite of characteristics that include absence of Darwinian selection, high mutation rate, and inheritance as a single linkage group. Given complete linkage and selective neutrality, mtDNA gene trees are expected to correspond to intraspecific phylogenies, and mtDNA diversity will reflect population size. The validity of these assumptions is, however, rarely tested on a genome-wide scale. Here, we analyze rates and patterns of molecular evolution among 32 whole mitochondrial genomes of Atlantic Cod (Gadus morhua) as compared with its sister taxon, the walleye pollock (Gadus [Theragra] chalcogrammus), and genomes of seven other gadine codfish. We evaluate selection within G. morhua, between sister species, and among species and intraspecific measures of linkage disequilibrium and recombination within G. morhua. Strong rate heterogeneity occurs among sites and genes at all levels of hierarchical comparison, consistent with variation in mutation rates across the genome. Neutrality indices (dN/dS) are significantly greater than unity among G. morhua genomes and between sister species, which suggests that polymorphisms within species are slightly deleterious, as expected under the nearly neutral theory of molecular evolution. Among species of gadines, dN/dS ratios are heterogeneous among genes, consistent with purifying selection and variation in functional constraint among genes rather than positive selection. The dN/dS ratio for ND4L is anomalously high across all hierarchical levels. There is no evidence for recombination within G. morhua. These patterns contrast strongly with those reported for humans: genome-wide patterns in other vertebrates should be investigated to elucidate the complex patterns of mtDNA molecular evolution. Article in Journal/Newspaper atlantic cod Gadus morhua University of the Highlands and Islands: Research Database of UHI Molecular Biology and Evolution 26 3 579 589 |
institution |
Open Polar |
collection |
University of the Highlands and Islands: Research Database of UHI |
op_collection_id |
ftuhipublicatio |
language |
English |
topic |
Animals Evolution Molecular Gadiformes Gadus morhua Genome Mitochondrial Kinetics Linkage Disequilibrium Recombination Genetic Journal Article Research Support Non-U.S. Gov't |
spellingShingle |
Animals Evolution Molecular Gadiformes Gadus morhua Genome Mitochondrial Kinetics Linkage Disequilibrium Recombination Genetic Journal Article Research Support Non-U.S. Gov't Marshall, H Dawn Coulson, Mark W Carr, Steven M Near neutrality, rate heterogeneity, and linkage govern mitochondrial genome evolution in Atlantic cod (Gadus morhua) and other gadine fish |
topic_facet |
Animals Evolution Molecular Gadiformes Gadus morhua Genome Mitochondrial Kinetics Linkage Disequilibrium Recombination Genetic Journal Article Research Support Non-U.S. Gov't |
description |
The mitochondrial DNA (mtDNA) genome figures prominently in evolutionary investigations of vertebrate animals due to a suite of characteristics that include absence of Darwinian selection, high mutation rate, and inheritance as a single linkage group. Given complete linkage and selective neutrality, mtDNA gene trees are expected to correspond to intraspecific phylogenies, and mtDNA diversity will reflect population size. The validity of these assumptions is, however, rarely tested on a genome-wide scale. Here, we analyze rates and patterns of molecular evolution among 32 whole mitochondrial genomes of Atlantic Cod (Gadus morhua) as compared with its sister taxon, the walleye pollock (Gadus [Theragra] chalcogrammus), and genomes of seven other gadine codfish. We evaluate selection within G. morhua, between sister species, and among species and intraspecific measures of linkage disequilibrium and recombination within G. morhua. Strong rate heterogeneity occurs among sites and genes at all levels of hierarchical comparison, consistent with variation in mutation rates across the genome. Neutrality indices (dN/dS) are significantly greater than unity among G. morhua genomes and between sister species, which suggests that polymorphisms within species are slightly deleterious, as expected under the nearly neutral theory of molecular evolution. Among species of gadines, dN/dS ratios are heterogeneous among genes, consistent with purifying selection and variation in functional constraint among genes rather than positive selection. The dN/dS ratio for ND4L is anomalously high across all hierarchical levels. There is no evidence for recombination within G. morhua. These patterns contrast strongly with those reported for humans: genome-wide patterns in other vertebrates should be investigated to elucidate the complex patterns of mtDNA molecular evolution. |
format |
Article in Journal/Newspaper |
author |
Marshall, H Dawn Coulson, Mark W Carr, Steven M |
author_facet |
Marshall, H Dawn Coulson, Mark W Carr, Steven M |
author_sort |
Marshall, H Dawn |
title |
Near neutrality, rate heterogeneity, and linkage govern mitochondrial genome evolution in Atlantic cod (Gadus morhua) and other gadine fish |
title_short |
Near neutrality, rate heterogeneity, and linkage govern mitochondrial genome evolution in Atlantic cod (Gadus morhua) and other gadine fish |
title_full |
Near neutrality, rate heterogeneity, and linkage govern mitochondrial genome evolution in Atlantic cod (Gadus morhua) and other gadine fish |
title_fullStr |
Near neutrality, rate heterogeneity, and linkage govern mitochondrial genome evolution in Atlantic cod (Gadus morhua) and other gadine fish |
title_full_unstemmed |
Near neutrality, rate heterogeneity, and linkage govern mitochondrial genome evolution in Atlantic cod (Gadus morhua) and other gadine fish |
title_sort |
near neutrality, rate heterogeneity, and linkage govern mitochondrial genome evolution in atlantic cod (gadus morhua) and other gadine fish |
publishDate |
2009 |
url |
https://pure.uhi.ac.uk/en/publications/7ac27168-6852-41a2-9042-168b3df790b0 https://doi.org/10.1093/molbev/msn279 |
genre |
atlantic cod Gadus morhua |
genre_facet |
atlantic cod Gadus morhua |
op_source |
Marshall , H D , Coulson , M W & Carr , S M 2009 , ' Near neutrality, rate heterogeneity, and linkage govern mitochondrial genome evolution in Atlantic cod (Gadus morhua) and other gadine fish ' , Molecular Biology and Evolution , vol. 26 , no. 3 , pp. 579-89 . https://doi.org/10.1093/molbev/msn279 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1093/molbev/msn279 |
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Molecular Biology and Evolution |
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26 |
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3 |
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579 |
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589 |
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1789963356143091712 |