S6-1.1 Jan. 5 A sperm's eye view of evolution KARR, T*; DORUS, S; GERIKE, U; University of Bath; University of Bath; University of Bath T.L.Karr@bath.ac.uk
A very limited amount of knowledge exists concerning the genetic and molecular basis underlying the diversity of sperm form and function. We have identified 381 proteins of the Drosophila melanogaster sperm proteome using whole-sperm mass spectrometry. This direct empirical approach has increased the number of characterized D. melanogaster sperm proteins by at least 60-fold. The major functional categories, including mitochondrial, metabolic and cytoskeletal proteins in addition to several unexpected categories suggestive of novel functional capacities are discussed. Evolutionary analyses identified global functional conservation and nonrandom gene clustering and underrepresentation on the X chromosome indicating that sexual selection has played a limited role in sperm evolution and function in this taxa. This suggests that a large number of proteins in the DmSP may serve critical, yet in many cases unknown, functions in reproduction including male-infertility factors. A substantial number of sperm genes have recent evolutionary origins including a recently expanded and functionally diversified family of leucyl aminopeptidases that are testis specific in expression and encode predominant sperm proteins by mass. Finally, significant homology between the DmSP and mouse sperm flagellum proteins highlights the power of comparative evolutionary proteomics in determining fundamental and conserved properties of sperm. Also discussed will be the effect of the paternal-effect gene ms(3)K81 on proteins of the DmSP.