Publication Date:
2006-02-18
Description:
Theory predicts that linkage between genetic loci reduces the efficiency of purifying selection. Because of the permanent linkage of all heritable genetic material, asexual lineages may be exceptionally prone to deleterious-mutation accumulation in both nuclear and organelle genes. Here, we show that the ratio of the rate of amino acid to silent substitution (Ka/Ks) in mitochondrial protein-coding genes is higher in obligately asexual lineages than in sexual lineages of the microcrustacean Daphnia pulex. Using a phylogeny-based approach to quantify the frequency of mutational-effect classes, we estimate that mitochondrial protein-coding genes in asexual lineages accumulate deleterious amino acid substitutions at four times the rate in sexual lineages. These results support the hypothesis that sexual reproduction plays a prominent role in reducing the mutational burden in populations.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Paland, Susanne -- Lynch, Michael -- GM36827/GM/NIGMS NIH HHS/ -- R01 GM036827/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2006 Feb 17;311(5763):990-2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biology, Indiana University, 1001 East 3rd Street, Bloomington, IN 47405, USA. spaland@indiana.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16484491" target="_blank"〉PubMed〈/a〉
Keywords:
*Amino Acid Substitution
;
Animals
;
Bayes Theorem
;
Daphnia/*genetics/*physiology
;
Evolution, Molecular
;
Female
;
Genes, Mitochondrial
;
Likelihood Functions
;
Male
;
Mitochondrial Proteins/*genetics
;
*Mutation
;
*Parthenogenesis
;
Phylogeny
;
Recombination, Genetic
;
*Selection, Genetic
;
Sex
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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