NSF Postdoctoral Fellowship in Biology FY 2016

Turnell Biz R, Ithaca NY

Investigators

Abstract

This award funds an NSF Postdoctoral Research Fellowship in Biology for FY 2016, Broadening Participation of Groups Under-represented in Biology. The fellowship supports a research and training plan for the Fellow that will increase the participation of groups underrepresented in biology. The title of the research plan for this fellowship to Biz Turnell is "Female mediation of sperm metabolism in storage: an investigation across time, species, and storage organs." The host institution for this fellowship is the Dresden University of Technology, and the sponsoring scientist is Klaus Reinhardt. The goal of this research is to understand the functional consequences of sperm senescence, or aging during storage. Sperm age has long been appreciated by human fertility researchers and livestock breeders as an important factor in sperm functionality, but has largely been ignored by evolutionary biologists studying natural selection. Nonetheless, the age distribution of stored sperm is likely to account for a substantial portion of variation in reproductive success of males and to play a significant role in sperm competition and cryptic female choice since sperm can be damaged during the aging period. Previous research has shown that some female insects delay the senescence of stored sperm by reducing the sperm cells' metabolic rates, thereby limiting the cells' production of damaging reactive oxygen species. Using the cutting-edge method of time-resolved microfluorimetry, the Fellow is determining whether this mechanism underlies the spatial and temporal patterns of sperm storage and use exhibited by fruit flies (Drosophila), an excellent invertebrate model species. Drosophila females have two types of storage organ, the seminal receptacle and the spermathecae. In Drosophila melanogaster, the former is used in short-term storage while the latter are used in long-term storage. In contrast, in the closely related Drosophila simulans, the seminal receptacle favors the sperm of the first male to mate with a female while the spermathecae favor the sperm of the second male. Although decades of research have produced a detailed account of these patterns, little is known about the biochemical processes underlying them. By studying these processes at the cellular level, the Fellow will be the first to link storage and use patterns with the genomics and transcriptomics of sperm storage. The Fellow is being trained in the acquisition of new empirical skills, broadening intellectual and theoretical perspectives, formulating collaborations with European scientists, and developing mentoring and outreach skills. This Fellow will serve as a role model for groups underrepresented in biology, and will promote broader participation in biology by encouraging young and LGBT students as research assistants, presenting to local youth groups, and by organizing an interactive workshop.