Examining the genetic and environmental influences on nicotinic acetylcholine receptor trafficking. (#54)
Nicotinic Acetylcholine Receptors (nAChRs) are pentameric ionotropic channels that mediate fast synaptic transmission and are evolutionarily conserved across taxonomies, ranging from C. elegans to humans. The Dα6 nAChR subunit is known to be the target of the insecticide spinosad in D. melanogaster. Loss of Dα6 function confers high level resistance to this insecticide. We have tagged the Drosophila Dα6nAChR subunit with fluorescent markers to study nAChR trafficking and localization in vivo in Drosophila. The tagged receptor is functional in vivo as tagged Dα6 subunits are able to complement a Dα6 null mutation by restoring susceptibility to spinosad. Creating this system where nAChRs can be tracked allows us to examine how nAChR trafficking is affected by genetic and environmental changes. We exposed Drosophila larvae expressing the fluorescent Dα6 nAChR subunit to a sub lethal concentration of spinosad to determine its impact on trafficking. Larvae raised on food spiked with spinosad showed decreased levels of Dα6 expression in the central nervous system compared to larvae raised on control food. These data suggest that trafficking may be induced to remove nAChRs from the membrane, allowing the fly to adapt to exposure to toxins.