Molecular and cellular analysis of Drosophila melanogaster lovesong

Drosophila melanogaster lovesong is a genetically programmed behaviour that is important because of its role in mate recognition. Previous work on D. melanogaster lovesong identified 10 genes and several general areas within the neural tissue that influenced song production. The aims of this project were to identify more genes and more specific neurons involved in lovesong production. This study describes the use of the GAL4 enhancer trap technology to identify genes and neurons involved in the production of D. melanogaster lovesong. The initial screen made use of the binary nature of the system to test the songs of the enhancer trap lines themselves and of flies expressing transformer or tetanus toxin in subsets of cells defined by the enhancers. Defects were found in both the number of cycles per pulse and the inter pulse interval. Lines picked up in the screen were used to drive the expression of GFP to allow identification of the cells in which the enhancers were active. For the most interesting lines, the surrounding DNA was rescued and candidate genes identified that may have had an influence on song. Mutants of these genes were obtained and tested for their abilities to sing. Ultimately, several brain structures were identified that appear to influence song production and ten genes were identified that had mutants with song defects. Some of these produced aberrant song when the enhancer trap line was placed over a deletion, some when the mutations were placed over a deletion, some when the mutations were placed over the enhancer trap lines and some when tested directly as homozygotes or hemizygotes. Two of these genes, argos and elav, have a known interaction and several of the candidate genes were known to interact with Ras85D.