Age-dependent chromosomal distribution of male-biased genes in Drosophila
- 1 Department of Ecology and Evolution, University of Chicago;
- 2 Committee on Evolutionary Biology, University of Chicago
- * Corresponding author; email: mlong{at}uchicago.edu
Abstract
We investigated the correlation between the chromosomal location and age distribution of new male-biased genes formed by duplications via DNA intermediates (DNA-level) or by de novo origination in Drosophila. Our genome-wide analysis revealed an excess of young X-linked male-biased genes. The proportion of X-linked male-biased genes then diminishes through time leading to an autosomal excess of male-biased genes. The switch between X-linked and autosomal enrichment of male-biased genes was also present in the distribution of both protein-coding genes on the D. pseudoobscura neo-X chromosome and microRNA genes of D. melanogaster. These observations revealed that the evolution of male-biased genes is more complicated than the previously detected one-step X->A gene traffic and the enrichment of the male-biased genes on autosomes. The pattern we detected suggests that the interaction of various evolutionary forces such as the meiotic sex chromosome inactivation (MSCI), faster-X effect, and sexual antagonism in the male germline might have shaped the chromosomal distribution of male-biased genes on different evolutionary time scales.
Footnotes
- Received March 4, 2010.
- Accepted August 24, 2010.
- Copyright © 2010, Cold Spring Harbor Laboratory Press
