Molecular evolution of cytochrome b in high- and low-altitude deer mice (genus Peromyscus)

Authors

E.J. Gering, University of Texas, 1 University Station C0930, Austin, TXFollow
J. C. Opazo, Instituto de Ecologia y Evolucion, Facultad de Ciencias, Universidad Austral de Chile, Casilla 567, Valdivia, Chile
Jay F. Storz, University of Nebraska - LincolnFollow

Date of this Version

2008

Comments

Published in Heredity (2008), doi: 10.1038/hdy.2008.124 Copyright © 2008 The Genetics Society; published by Macmillan/Nature Publishing Group. Used by permision. http://www.nature.com/hdy/index.html

Abstract

Patterns of amino-acid polymorphism in human mitochondrial genes have been interpreted as evidence for divergent selection among populations that inhabit climatically distinct environments. If similar patterns are mirrored in other broadly distributed mammalian species, then adaptive modifications of mitochondrial protein function may be detected in comparisons among locally adapted populations of a single wide-ranging species, or among closely related species that have adapted to different environments. Here, we test for evidence of positive selection on cytochrome b variation within and among species of the ecologically diverse rodent genus Peromyscus. We used likelihood-based comparisons of synonymous and nonsynonymous substitution rates to test for evidence of divergent selection between high- and low-altitude haplogroups of the deer mouse, Peromyscus maniculatus. We also tested for evidence of divergent selection among different species of Peromyscus that inhabit different thermal environments. In contrast to the purported evidence for positive selection on mitochondrial proteins in humans and other nonhuman mammals, results of our tests suggest that the evolution of cytochrome b in Peromyscus is chiefly governed by purifying selection.