2010 Annual Report
1a.Objectives (from AD-416)
To characterize and develop the SNMPs of Ae. aegypti as molecular targets for the disruption of chemosensory based behaviors in the mosquito Ae. aegypti.
1b.Approach (from AD-416)
The goal of this project is to develop chemically based strategies that disrupt chemosensory mediated mosquito behavior; these strategies should dramatically reduce mosquito-human interaction and be safe for use around humans and non-mosquito animals. To accomplish this goal, biochemical processes must be identified that are (1) accessible to chemical treatment, (2) are appropriately unique to the target species, and (3) are sufficiently centrally localized such that their disruption will maximally distress the target species. This project focuses on the characterization of a mosquito chemosensory protein called SNMP (Sensory Neuron Membrane Protein), and the development of methodologies that will disrupt SNMP function.
This is a joint effort with the Department of Biological Sciences, University of South Carolina (USC). Transgenic mosquitoes, Ae. aegypti, were successfully generated which express the reporter gene cd8:GFP under the control of the SNMP1 promoter.
In Drosophila, tissue specific analysis was completed documenting the expression patterns of SNMP1 and SNMP2, based on the expression of cd8:GFP under the control of the SNMP1 and SNMP2 promoters. In the olfactory system, SNMP1 expresses in most trichoid sensory neurons (pheromone specific) while SNMP2 expresses in most coeloconic sensilla (amine specific) and CO2 sensitive neurons. In the gustatory system of mouthparts, legs, wings and genitalia, SNMP1 expresses in non-neuronal support cells of most if not all sensilla, while SNMP2 expresses in sensory neurons of most if not all sensilla. SNMP1 may also express in support cells of mechanosensilla of legs and abdomen, but not wings. These findings indicate SNMP1 and SNMP2 have broad activity throughout the chemosensory system of Drosophila, suggesting that targeting SNMPs for disruption may have a sweeping inhibitory effect on insect behavior.
Behavioral studies showed that SNMP1 knockout males (SNMP1 gene deleted) could not compete with wild type males in mating with wild type females, although they could successfully mate with either knockout females or wild type females, demonstrating a central role for SNMP1 in mediating social interactions. These important findings establish a baseline for evaluating the role of SNMP and ORs in our studies using transgenic mosquitoes and drug (attractants & repellents) screening in frog oöcytes. ADODR discussed research with collaborators at USC through numerous e-mails and telephone communications. Results and plans for future research provided by the collaborator were presented by the ADODR at a review of DWFP projects in College Station, Texas December 2-4, 2008 as the collaborator was unable to attend due to a scheduling conflict.