Twenty-second Annual Meeting of the Association for Chemoreception Sciences

2000 Chemical Senses  
Insects like Drosophila segregate olfactory neurons into discrete hairlike sensilla. Each sensillum contains one to four olfactory neurons that project dendrites into the hollow, fluid-filled core of the hair. In different sensilla, different repertoires of odorantbinding proteins (OBPs) are secreted into the lymph bathing the dendrites. OBPs are, therefore, potentially important regulators of chemical specificity for olfactory neurons in insects. We have identified LUSH, a member of the
more » ... ila OBP family, and have generated and characterized mutants defective for expression of this OBP. LUSH represents the only known OBP mutant in any species. We demonstrated that LUSH mutants have defective olfactory behavioral responses to a small subset of odorants. The behavioral defects are completely reversed by introducing a LUSH transgene into the mutants. These results demonstrate a clear role for an OBP in chemical discrimination. We are generating transgenic flies that mis-express various OBP members in the Drosophila olfactory sensilla to identify any olfactory behavior effects. These experiments will be discussed. We use Drosophila melanogaster as a model system to investigate how the coordinated expression of ensembles of genes regulates odor-guided behavior. P-element insertional mutagenesis in an isogenic strain of flies combined with a statistical assay that enables reliable quantification of olfactory avoidance behavior resulted in the identification of a set of 14 smell-impaired (smi) loci, 12 of which were suitable for further characterization. Quantitative genetic analysis of double heterozygotes constructed from parents homozygous for different smi genes revealed extensive epistatic interactions among this group of smi loci. P-element insertional mutagenesis tags the smi loci for cloning enabling expression levels of gene products to be quantitatively correlated with the behavioral phenotype. Initial characterization of three smi loci, smi35A, smi60E and smi97B, revealed new proteins that are essential for the coordination of olfactory signal processing, including a novel kinase (Dyrk2), a voltage-gated sodium channel of previously unknown function and a novel, yet uncharacterized, leucine-rich repeat protein likely to play a role in postsynaptic signaling. Genetic dissection of food search behaviors in Drosophila During postnatal rat development, a relationship is established between the size of individual taste buds and the number of innervating neurons. This relationship is not apparent until postnatal day (P) 40, when taste bud size reaches maturity. The focus of this presentation will be to demonstrate that the number of neurons innervating taste buds at P10, when taste bud size is small and relatively homogeneous, predicts the size that the respective taste 596 AChemS Abstracts Central neural integration of sensory input from different modalities is critical for many types of perception and behavior. The perception that one has taken a bite from an apple, for instance,
doi:10.1093/chemse/25.5.593 fatcat:2mctixni4rdqrnlahislpjekxi