Abstract: How does DIP-alpha contribute to the development of the olfactory circuit in Drosophila?

The assembly of neural circuits is a highly complex process that has not yet been fully understood. The olfactory system of Drosophila offers an excellent model system to better understand this organization, as 50 classes of olfactory receptor neurons (ORNs) synapse with their target projection neurons within 50 class-specific and uniquely positioned glomeruli in the brain’s antennal lobes. By analyzing the antennal transcriptome data from four stages of the antennal lobe development, we have identified a gene family of interest containing DIPs and DPRs, which are known to have homophilic and heterophilic interactions that regulate the assembly of several neural circuits. Through an RNAi mediated screening of this Ig Superfamily, we hypothesized DIP-alpha is important to the organization of ORNs into specific glomerular formations via axon terminal guiding.  We used several genetic methods to test this hypothesis, including the downregulation and knockdown of DIP-alpha in all ORNs and explored glomerular formation in various DIP-alpha mutant flies. In addition, we used genetic labelling techniques and antibody staining to identify the expression pattern of DIP-alpha. Although we were unable to identify a clear expression pattern, our results from the glomeruli structures in flies where the function of DIP-alpha was genetically perturbed suggests that DIP-alpha is important to glomerular formation. Further study of its roles in class sorting will give us more insight into the molecular basis of this complex circuit assembly.