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 in male courtship behavior. The molecular nature of this BBB/brain interaction and the molecules that mediate it are 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 sequenc-ing. We find that 283 transcripts change in comparison to normal control males. Tran-scripts representing cell signaling processes and synaptic communication are enriched, as are hormonal mediators. These transcripts provide a valuable resource for addressing questions about BBB and brain interaction.