@article {538541, title = {Effects of X-linkage and sex-biased gene expression on the rate of adaptive protein evolution in Drosophila}, journal = {Mol Biol Evol}, volume = {25}, number = {8}, year = {2008}, note = {

Baines, John FSawyer, Stanley AHartl, Daniel LParsch, JohnengGM61351/GM/NIGMS NIH HHS/GM68465/GM/NIGMS NIH HHS/Comparative StudyResearch Support, N.I.H., ExtramuralResearch Support, Non-U.S. Gov{\textquoteright}tResearch Support, U.S. Gov{\textquoteright}t, Non-P.H.S.2008/05/15 09:00Mol Biol Evol. 2008 Aug;25(8):1639-50. doi: 10.1093/molbev/msn111. Epub 2008 May 13.

}, month = {Aug}, pages = {1639-50}, abstract = {

Patterns of polymorphism and divergence in Drosophila protein-coding genes suggest that a considerable fraction of amino acid differences between species can be attributed to positive selection and that genes with sex-biased expression, that is, those expressed predominantly in one sex, have especially high rates of adaptive evolution. Previous studies, however, have been restricted to autosomal sex-biased genes and, thus, do not provide a complete picture of the evolutionary forces acting on sex-biased genes across the genome. To determine the effects of X-linkage on sex-biased gene evolution, we surveyed DNA sequence polymorphism and divergence in 45 X-linked genes, including 17 with male-biased expression, 13 with female-biased expression, and 15 with equal expression in the 2 sexes. Using both single- and multilocus tests for selection, we found evidence for adaptive evolution in both groups of sex-biased genes. The signal of adaptive evolution was particularly strong for X-linked male-biased genes. A comparison with data from 91 autosomal genes revealed a "fast-X" effect, in which the rate of adaptive evolution was greater for X-linked than for autosomal genes. This effect was strongest for male-biased genes but could be seen in the other groups as well. A genome-wide analysis of coding sequence divergence that accounted for sex-biased expression also uncovered a fast-X effect for male-biased and unbiased genes, suggesting that recessive beneficial mutations play an important role in adaptation.

}, keywords = {*Evolution, Molecular, *Gene Expression, *Polymorphism, Genetic, Adaptation, Biological/*genetics, Animals, Base Sequence, Drosophila Proteins/*genetics/metabolism, Drosophila/*genetics, Female, Genes, X-Linked/*genetics, Male, Molecular Sequence Data, Sequence Analysis, DNA, Sex Factors}, isbn = {1537-1719 (Electronic)0737-4038 (Linking)}, author = {Baines, J. F. and Sawyer, S. A. and Hartl, D. L. and Parsch, J.} }