Date of Award
Doctor of Philosophy (PhD)
Spermatogenesis is an evolutionarily conserved developmental program, which entails a sequence of fundamental biological processes: stem cell division, restricted mitotic proliferation, meiosis and morphogenetic reorganization. We have initiated a molecular genetic dissection of the early steps of spermatogenesis in Drosophila. We generated a collection of enhancer trap lines that identify all cell types and stages of the developmental program. We used marker lines to show that somatic cell fates are altered in the absence of germ cells, suggestive of signaling events between germ line and soma - during wild-type spermatogenesis. We also used markers to examine whether bag-of marbles and benign gonial cell neoplasm, two previously identified sterile mutations, affect the fate of the gonial daughter of the germ line stem cell. We next isolated Pelement induced male-sterile mutants, which underwent mapping, complementation and phenotypic analyses. Three of these mutants were characterized in more detail. First, we showed that chickadee is required, presumably in stem cells, for germ cell proliferation. Second, we identified that ms(2)916 is needed to restrict the extent of germ cell proliferation during spermatogenesis. Third, we demonstrated that roughex is a novel dose-dependent regulator of the second meiotic division. Finally, we designed a FLPIFRT-based screen that should allow us to directly identify loci regulating germ cell proliferation, without relying on a male-sterile phenotype. This opens up the possibility of saturating the genome for mutations affecting this key early step of spermatogenesis.
Gonczy, Pierre, "Towards a Molecular Genetic Analysis of Spermatogenesis in Drosophila" (1995). Student Theses and Dissertations. 339.