Effects of Sxl on gene expression in the male head of Drosophila

Sex-lethal (Sxl), a feminizing switch gene in Drosophila, also generates male-specific proteins and non-sex-specific mRNAs, despite the fact that deleting the gene from males causes no obvious phenotypic abnormalities. We specifically investigate how Sxl may affect gene expression in the male head, where SXL isoforms have been detected. The information may help us understand how Sxl acquired its functional roles in sex determination during evolution in Drosophila Keywords: Comparative expression, genetic modification Sxlfp7BO is a small deletion that removes the entire Sxl locus. The mutant Sxlfp7BO males were backcrossed to the wild-type Oregon-R flies for more than six generations to homogenize the genetic background. Two flanking phenotypic markers, cm and ct, on the proximal and distal sides of Sxlfp7BO, were used to trace the mutant allele during the backcross. [cm Sxlfp7BO ct] and WT males were brothers from a single-pair cross: [cm Sxlfp7BO ct]/+ X [cm Sxlfp7BO ct]/Y. Male flies of 2-5 day old were decapitated on an ice pack; the heads were transferred directly into TRIzol before RNA extraction. Three biological replicates were performed for each male type.