No abstract

Methods to visualize gene expression in the Drosophila central nervous system are important in fly neurogenetic studies. In this chapter, we describe a detailed protocol that sequentially combines in situ hybridization chain reaction (HCR) and immunostaining to detect mRNA and protein expression in whole-mount Drosophila larval and adult central nervous systems. We demonstrate the application of in situ HCR in comparisons of nervous system gene expression between Drosophila species, and in the validation of single-cell RNA-Seq results in the fly nervous system. Our protocol provides a simple, robust, multiplexable, and relatively affordable means to quantitatively visualize gene expression in the nervous system of flies, facilitating its general use in fly neurogenetic studies.

No abstract

Sexually dimorphic courtship behaviors in Drosophila melanogaster develop from the activity of the sexual differentiation genes, doublesex (dsx) and fruitless (fru), functioning with other regulatory factors that have received little attention. The dissatisfaction gene (dsf) encodes an orphan nuclear receptor homologous to vertebrate Tlx and Drosophila tailless that is critical for the development of several aspects of female- and male-specific sexual behaviors. Here, we report the pattern of dsf expression in the central nervous system and show that the activity of sexually dimorphic abdominal interneurons that co-express dsf and dsx is necessary and sufficient for vaginal plate opening in virgin females and abdominal curling in males during courtship. We find that dsf activity results in different neuroanatomical outcomes in females and males, promoting and suppressing, respectively, female development and function of the DDAG neurons depending upon the sexual state of dsx expression. We posit that dsf and dsx interact to specify sex differences in the neural circuitry for dimorphic abdominal behaviors.