X chromosomes and autosomes evolve at similar rates in Drosophila: no evidence for faster-X protein evolution.

ABSTRACT: Recent data from Drosophila suggest that a substantial fraction of amino acid substitutions observed between species are beneficial. If these beneficial mutations are on average partially recessive, then the rate of protein evolution is predicted to be faster for X-linked genes compared to autosomal genes (the "faster-X" hypothesis). We test this prediction by comparing rates of protein substitutions between orthologous genes, taking advantage of variations in chromosome fusions within the genus Drosophila. In members of the Drosophila melanogaster species group, the chromosomal arm 3L segregates as an ordinary autosome (i.e., two homologous copies in both males and females). However, in the Drosophila pseudoobscura species group, this chromosomal arm has become fused to the ancestral X ch

SUBMITTER: Thornton K 

PROVIDER: S-EPMC1457026 | biostudies-literature | 2006 Apr

REPOSITORIES: biostudies-literature