The hector G-Protein Coupled Receptor Is Required in a Subset of fruitless Neurons for Male Courtship Behavior

Yuanli Li,Christina N Vo,Bich Hien Dinh,Chamala Lama,Brigitte Dauwalder,Valbona Hoxha,Brian D Mccabe

doi:10.1371/journal.pone.0028269

Abstract

Male courtship behavior in Drosophila melanogaster is controlled by two main regulators, fruitless (fru) and doublesex (dsx). Their sex-specific expression in brain neurons has been characterized in detail, but little is known about the downstream targets of the sex-specific FRU and DSX proteins and how they specify the function of these neurons. While sexual dimorphism in the number and connections of fru and dsx expressing neurons has been observed, a majority of the neurons that express the two regulators are present in both sexes. This poses the question which molecules define the sex-specific function of these neurons. Signaling molecules are likely to play a significant role. We have identified a predicted G-protein coupled receptor (GPCR), CG4395, that is required for male courtship behavior. The courtship defect in the mutants can be rescued by expression of the wildtype protein in fru neurons of adult males. The GPCR is expressed in a subset of fru-positive antennal glomeruli that have previously been shown to be essential for male courtship. Expression of 4395-RNAi in GH146 projection neurons lowers courtship. This suggests that signaling through the CG4395 GPCR in this subset of fru neurons is critical for male courtship behavior.

Highlights

One critical aspect of understanding how complex behaviors are regulated is to understand the circuits and molecules that are required to generate and display the behavior
We describe here the identification of a novel putative G-protein coupled receptor (GPCR), encoded by the gene CG4395, that is required for male courtship
Like in the case of the rescue with the 4395-Gal4 driver, conditional rescue in adult males using fru-Gal4 completely rescued the mutant phenotype (Figure 4E). Taken together these findings demonstrate that the hector GPCR is required in fru neurons of adult males for normal male courtship behavior

Summary

Introduction

One critical aspect of understanding how complex behaviors are regulated is to understand the circuits and molecules that are required to generate and display the behavior. The malespecific fruM and dsxM proteins are both critically required for normal male courtship behavior [6,7,8,9]. Exploring which genes are expressed in these neurons and how this determines their function and their connections is a critical step in trying to understand how mating behavior is regulated. Both Fru and Dsx are transcription factors that in microarray studies have been shown to control a large number of genes [21,22]. Co-localization studies of fru and hec suggest that the 4395 GPCR is required in a subset of glomeruli in the antennal lobes

Methods

Results

Conclusion