Description

This transgenic strain contains, integrated in its genome, the AalOR2 coding region downstream of the UAS sequences.  In order to analyze its activity in vivo it is necessary to express it in the Delta-halo Drosophila mutant -that lacks its endogenous Odorant Receptor genes, OR22a and OR22b- under the guidance of OR-22a-GAL4, which is transcribed only in the ab3A neuron. To this aim,  the final strain to be used will be:  y[1] w[*]; Dhalo/Dhalo; P{w[+mC]=Or22a-GAL4.7.717}14.2/UAS-AalOR2. Under these conditions, AalOR2 responds with high sensitivity to indole. Indole, which constitutes nearly 30% of the volatile headspace of human sweat, is a ubiquitous volatile compound that has been linked to host seeking, and oviposition in aedine as well as in anopheline mosquitoes. Moreover, in this assay (–)-menthone produces an inhibitory effect on the AalOR2 expressed in the ‘‘empty neuron’’ of D. melanogaster, in the absence of applied odorants.