The effect of sex-ratio meiotic drive on sequence evolution and gene expression in Drosophila affinis. Robert Unckless, Andrew Clark. Department of Entomology, Cornell University, Ithaca, NY.

   Organisms must adapt not only to their external environment, but also to challenges from within their own genome. Sex-ratio meiotic drive occurs when one sex-chromosome contains elements that are able to disable or kill the opposite sex-chromosome resulting in highly skewed sex-ratios in offspring. Several consequences of sex-ratio meiotic drive have been examined both theoretically and empirically, including extinction, the evolution of reproductive isolation and polyandry. One of the first sex-ratio systems discovered was in X-drive Drosophila affinis. Through a combination of genome and transcriptome sequencing we examine the effect of the X-drive system in Drosophila affinis on both gene expression and sequence evolution in tightly linked regions of the X-chromosome. Several candidates for the causative locus for drive have emerged and drive appears to have had a significant impact on gene expression both in linked regions and genomewide.