Publication Date

Summer 2016

Degree Type


Degree Name

Master of Science (MS)


Biological Sciences


Rachael French


courtship, drosophila, tre1

Subject Areas

Molecular biology


Understanding how genes can direct behaviors has been a prevailing goal of neuroscience. Courtship in D. melanogaster is a complex yet stereotyped array of behaviors established by sex-specific genetic pathways mediated by sensory inputs by the nervous system. However, much remains to be discovered about the neurobiological and molecular mechanisms that regulate this complex set of behaviors. We have identified a group of cells expressing Trapped in endoderm 1 (Tre1) in which male Fruitless proteins are required to reduce the speed of courtship initiation. Tre1 encodes a G-protein-coupled receptor required for establishment of cell polarity and cell migration and has previously not been shown to be involved in courtship behavior. By monitoring the latency to courtship initiation of male flies, we found the expression of female-specific transcription factors in Tre1-expressing neurons, or “feminization,” resulted in rapid courtship initiation. The Tre1-feminized males produced an increased number of offspring when challenged in a competitive fertility assay, suggesting that rapid courtship initiation led to a reproductive advantage. Interestingly, this did not hinder male flies’ ability to select an appropriate mate when they were confronted with a variety of mating targets. Using immunofluorescence, we showed that Tre1 is expressed in a sexually dimorphic pattern in the central and peripheral nervous systems. Ultimately, we believe these cells may participate in an unforeseen “quality control” step that ensures the correct performance of the courtship ritual.