Meeting Abstract
The breakdown of postovulatory and unovulated follicles relies on apoptosis or programmed cell death and is essential for ovarian remodeling and optimizing the production of viable eggs. Characterization of the apoptotic responses in the fish ovaries is critical for understanding the reproductive physiology of female fish, which can produce thousands of eggs. Previous studies found that testosterone activation of the membrane androgen receptor, ZIP9, induces intracellular zinc transport and apoptosis within Atlantic croaker ovarian follicle cells. In this study, we characterized the androgen-induced apoptotic response of ovarian follicle cells in the model organism zebrafish (Danio rerio). We found that testosterone treatment resulted in significantly higher amounts of apoptosis in zebrafish ovarian follicle cells compared to vehicle (ethanol). Furthermore, testosterone treated ovarian follicle cells showed a significant increase in expression of pro-apoptotic genes, bax and p53. Testosterone treated zebrafish ovarian follicle cells also showed significantly higher levels of intracellular zinc, which is associated with ZIP9 activation. Consequently, our results show that testosterone induces a similar apoptotic response in zebrafish ovarian follicle cells to that seen in the Atlantic croaker. These results suggest that teleosts may share the mechanism for ZIP9 mediation of ovarian cell apoptosis. Future studies should build upon our research by utilizing ZIP9-knockout zebrafish to investigate whether other vertebrates share the mechanism regulating ovarian apoptosis in teleosts.
