Feminization of the Blood Brain Barrier changes the brain transcriptome of Drosophila melanogaster males

Beyond its crucial role as a tight barrier to protect the nervous system, the Blood Brain Barrier (BBB) is increasingly being recognized for its physiological processes that affect brain function and behavior. In Drosophila melanogaster, the BBB expresses sex-specific transcripts, and a change in the sexual identity of adult BBB cells results in a significant reduction of male courtship behavior. The molecular nature of this BBB/brain interaction is unknown. Here we feminize BBB cells by targeted expression of the Drosophila female specific master regulator TraF in otherwise normal males. We examined the effect on RNA expression in dissected brains by RNA sequencing. We find that 284 transcripts change in comparison to normal males. Transcripts representing cell signaling processes and synaptic communication are enriched, as are hormonal mediators. These transcripts are candidates for the sex-specific interaction between the BBB and the brain circuits that regulate behavior. Overall design: The blood brain barrier (BBB) of otherwise normal Drosophila males was feminzed by expression of the TraF protein using the Gal4/UAS system. Adult brains were isolated from experimental and control males and RNA extracted. Following Poly-A selection, RNA-seq was performed using paired-end sequencing.