title: An evolutionary footprint of age-related natural selection in mitochondrial DNA.
abstract: By comparing mtDNA sequences between different orders of mammals, we show that both longevity and generation time are significantly correlated with the nucleotide content of the mtDNA. Specifically, there is a positive correlation between generation time and mt GC content. This correlation is repeated, at a finer evolutionary scale, within the primates. Moreover, a comparison of human and chimpanzee mtDNAs shows that the effect has been very pronounced during the short evolutionary period since the divergence of these two species, with human mtDNA showing a GC-biased pattern of substitution at the variable sites. In addition to these DNA sequence patterns, comparisons between the human and the chimp mt protein sequences also revealed a surprisingly high substitution rate for threonine residues, resulting in a reduction of threonine in the human mt proteome. These patterns of both DNA and protein evolution can be explained by a balance between AT-biased mutational pressure and age-related purifying selection.
authors.affiliation: Department of Biological Sciences, Youngstown State University, Youngstown, OH 44555, USA. xmin@ysu.edu
authors.forename: Xiang Jia
authors.initials: XJ
authors.lastname: Min
authors.forename: Donal A
authors.initials: DA
authors.lastname: Hickey
mesh_terms: D000375:Aging / Q000235:genetics*; D000596:Amino Acids / Q000235:genetics; D000818:Animals; D001482:Base Composition / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics*; D019143:Evolution, Molecular; D006801:Humans; D009711:Nucleotides / Q000235:genetics; D002679:Pan troglodytes / Q000235:genetics; D012641:Selection, Genetic; D013997:Time Factors
chemical_list: D000596:Amino Acids; D004272:DNA, Mitochondrial; D009711:Nucleotides