The coupling of organism physiology and reproduction is essential for species survival. Nuclear receptors (NRs) are widely expressed transcription factors that mediate the effects of many circulating factors to modulate physiology and reproduction. My research focuses on an understudied aspect of nuclear receptor signaling in the control of oogenesis. Specifically, I am investigating how the functions of two nuclear receptors (Svp and Hr4, the homologs of COUP-TFs and GCNF) in various somatic tissues are integrated to regulate the germline stem cell (GSC) lineage in the Drosophila ovary. In contrast to many studies focused on the intrinsic roles of nuclear receptor signaling within specific cell types, my lab will investigate the circulating factors downstream of Svp and Hr4 that remotely regulate various steps of the GSC lineage. For example, my postdoctoral work revealed that global reduction of Hr4 activity in somatic cells leads to a reduction in egg laying, GSC maintenance and proliferation, egg chamber growth, and survival of early germline cysts and vitellogenic egg chambers. Interestingly, I found that Hr4 is required in distinct tissues and cell types to control different processes of oogenesis. These results suggest that NRs can have multiple parallel roles in controlling reproduction and that secreted molecules from peripheral tissues can communicate with the ovary to influence oogenesis. As an independent investigator, my lab has continued to address how communication between the ovary and various endocrine organs regulates oogenesis to ensure reproductive fitness.

Host: Laura Buttitta