Evolution of amino-acid sequences and codon usage on the Drosophila miranda neo-sex chromosomes.

ABSTRACT: We have studied patterns of DNA sequence variation and evolution for 22 genes located on the neo-X and neo-Y chromosomes of Drosophila miranda. As found previously, nucleotide site diversity is greatly reduced on the neo-Y chromosome, with a severely distorted frequency spectrum. There is also an accelerated rate of amino-acid sequence evolution on the neo-Y chromosome. Comparisons of nonsynonymous and silent variation and divergence suggest that amino-acid sequences on the neo-X chromosome are subject to purifying selection, whereas this is much weaker on the neo-Y. The same applies to synonymous variants affecting codon usage. There is also an indication of a recent relaxation of selection on synonymous mutations for genes on other chromosomes. Genes that are weakly expressed on the neo-

SUBMITTER: Bartolome C 

PROVIDER: S-EPMC1698622 | biostudies-literature | 2006 Dec

REPOSITORIES: biostudies-literature