title: The master switch gene sex-lethal promotes female development by negatively regulating the N-signaling pathway.
abstract: Notch (N) signaling is used for cell-fate determination in many different developmental contexts. Here, we show that the master control gene for sex determination in Drosophila melanogaster, Sex-lethal (Sxl), negatively regulates the N-signaling pathway in females. In genetic assays, reducing Sxl activity suppresses the phenotypic effects of N mutations, while increasing Sxl activity enhances the effects. Sxl appears to negatively regulate the pathway by reducing N protein accumulation, and higher levels of N are found in Sxl(-) clones than in adjacent wild-type cells. The inhibition of N expression does not depend on the known downstream targets of Sxl; however, we find that Sxl protein can bind to N mRNAs. Finally, our results indicate that downregulation of the N pathway by Sxl contributes to sex-specific differences in morphology and suggest that it may also play an important role in follicle cell specification during oogenesis.
authors.affiliation: Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA.
authors.forename: Jill K M
authors.initials: JK
authors.lastname: Penn
authors.forename: Paul
authors.initials: P
authors.lastname: Schedl
mesh_terms: D000483:Alleles; D000818:Animals; D002999:Clone Cells; D015536:Down-Regulation; D029721:Drosophila Proteins / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism; D004331:Drosophila melanogaster / Q000235:genetics / Q000254:growth & development*; D005260:Female; D005812:Genes, Switch; D008297:Male; D009154:Mutation / Q000235:genetics; D006080:Ovarian Follicle / Q000166:cytology; D010063:Ovum / Q000166:cytology; D010641:Phenotype; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics*; D051880:Receptors, Notch / Q000235:genetics / Q000378:metabolism*; D012727:Sex Characteristics; D019849:Sex Determination Processes; D015398:Signal Transduction; D015854:Up-Regulation; D014921:Wings, Animal / Q000196:embryology
chemical_list: D029721:Drosophila Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D051880:Receptors, Notch; C067777:Sxl protein, Drosophila