Evidence of convergent evolution in humans and macaques supports an adaptive role for copy number variation of the β-defensin-2 gene.
Bottom Line: Remarkably, we found that the structure of the CNV is different between primates, with distinct mutational origins and CNV boundaries defined by retroviral long terminal repeat elements.In addition, the rhesus macaque gene has been subject to divergent positive selection at the amino acid level following its initial duplication event between 3 and 9.5 Ma, suggesting adaptation of this gene as the macaque successfully colonized novel environments outside Africa.Therefore, the molecular phenotype of β-defensin-2 CNV has undergone convergent evolution, and this gene shows evidence of adaptation at the amino acid level in rhesus macaques.
Affiliation: Department of Genetics, University of Leicester, United Kingdom.Show MeSH
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Mentions: The identification of true paralogs from BAC sequences allows a McDonald–Kreitman test to be constructed comparing the diversity between allelic copies with distance between paralogous copies (fig. 5). Analysis of the four BAC DEFB2L coding sequences, with a Jukes–Cantor correction, suggests that positive selection has acted on the two paralogs following duplication (P = 0.015), further supporting an adaptive role for amino acid substitutions differing between DEFB2L variants.Fig. 5.—
Affiliation: Department of Genetics, University of Leicester, United Kingdom.