부산대학교 도서관

The ovoand ovarian tumorgenes are required during early and late stages of Drosophila oogenesis. The ovoproduct, a zinc-finger transcription factor, can bind to sites and influence the level of expression of the ovarian tumorpromoter. Our examination of ovonull mutant organelles demonstrate that it is required for the differentiation of XXgerm cells during larval gonial stages, in addition to its known role in maintaining germ cell numbers. In contrast, ovarian tumoris required during pupal and adult stages for the cystocyte divisions that give rise to the egg chamber. Studies on sexually transformed flies indicate that both the ovoand ovarian tumornull mutant phenotypes are distinctive from and more severe than the germline defects produced when male germ cells develop in female soma. This suggests that ovoand ovarian tumorhave oogenic functions other than their putative role in germline sex determination. We also demonstrate that the regulation of ovarian tumorby ovois stage-specific, as ovarian tumorpromoter activity does not require ovoduring larval stages but becomes ovo-dependent in the adult ovary. This coincides with when the ovarian tumorpromoter becomes responsive to sex-specific signals from the soma suggesting a convergence of somatic and germline regulatory pathways on ovarian tumorduring oogenesis.