PgmNr P2097: The genetics of giant sperm in Drosophila.

Authors:
M. Manier 1 ; S. Pitnick 2 ; J. Belote 2 ; S. Dorus 2


Institutes
1) George Washington University, Washington, DC; 2) Syracuse University, Syracuse, NY.


Abstract:

Spermatozoa are the most morphologically variable cell type among Metazoa, and the Drosophila lineage displays the greatest variation in sperm length, ranging from 0.3 mm to 5.8 cm. Available evidence suggests that sperm length in this group is evolving rapidly, driving by postcopulatory sexual selection via sperm competition and cryptic female choice. Longer sperm outcompete shorter sperm and especially in longer female sperm storage organs. To investigate the genetic basis of sperm length in Drosophila, we used a QTL sequencing approach that identified ~500 SNPs enriched within or near ~300 protein coding genes. We prioritized candidate genes based on known patterns of expression during spermatogenesis, GO functions, patterns of rapid evolution, and number of SNPs identified within the gene. The effect of candidate gene disruption on sperm length was assessed using GAL4/UAS RNAi or insertion mutation lines. We also characterized allelic variation and differential gene expression for a subset of candidate genes in populations previously selected for long or short sperm.