Discipline: Biological Sciences
Room: Exhibit Hall A
Heather Davis - Fayetteville State University
Co-Author(s): Kaitlyn Whitehead, Dept. of Biology, East Carolina University, Greenville, NC 27858; Elizabeth Ables, Dept. of Biology, East Carolina University, Greenville, NC 27858
Sexually reproducing organisms use specialized cells, called gametes, to create offspring. Proper production of female gametes (oocytes) is particularly important, as they harbor genetic information and essential mRNA and proteins necessary for early embryo development. Gamete production is stimulated and sustained by cholesterol derived steroid hormones in both vertebrates and invertebrates. The molecular mechanisms by which steroid hormones control early oocyte differentiation, however, are incompletely described. The fruitfly, Drosophila melanogaster, provides an elegant model to study these mechanisms. In Drosophila, the steroid hormone ecdysone (comparable to human estrogen and progesterone) is required for multiple aspects of oocyte development. Importantly, ecdysone signaling through the Ecdysone Receptor (EcR) in somatic escort cells supports oocyte development; but it is unclear whether this role depends on ecdysone. We hypothesize that EcR activates specific gene targets in escort cells that non-autonomously control germ cell division.To test the function of the EcR in escort cells, we expressed a transgenic version of the EcR that binds ecdysone but does not activate transcription and examined oocyte development. Our preliminary data suggest that EcR activates targets in escorts cells in response to ecdysone that promote germ cell mitotic division. Moreover, we find that a nuclear receptor co-repressor, encoded by Smrter, is highly expressed in escort cells, suggesting a mechanism for suppressing EcR activation in the absence of ecdysone. However, further studies are needed to determine whether Smrter functions in the ecdysone signaling pathway. Together, our data provide a novel model to study the roles of steroid hormones in somatic-germ cell crosstalk during oocyte formation.
Funder Acknowledgement(s): Fly stocks and reagents: Bloomington Stock Center, Drummond- Barbosa, A. Spradling, and Developmental Stock Hybridoma Bank; National Institutes of Health (NIH), Fayetteville State University, Fayetteville State University RISE, and Eastern Carolina University
Faculty Advisor: James Raynor, firstname.lastname@example.org
Role: I have conducted all experiments and developed all hypotheses for this preliminary experiment. Furthermore, I have presented this preliminary data at various conferences.