The sextuple co-expression of Gr32aUAS.cSa, Gr33aUAS.cMa, Gr39aUAS.a.cSa, Gr59cUAS.cUa, Gr66aUAS.Tag:MYC and Gr89aUAS.cSa under the control of Scer\GAL4Gr64f.9.7 makes L-type sensilla responsive to the bitter chemicals LOB, BER, and DEN, but not to the bitter chemicals CAF, STR, SOA or UMB. Control L-type sensilla, however, are only responsive to sucrose; this sextuple co-expression has no effect on the normal response to sucrose.
Only quintuple co-expression combinations that include Gr32aUAS.cSa, Gr59cUAS.cUa and Gr66aUAS.Tag:MYC induce responsiveness of L-type sensilla to LOB, BER, and DEN. In agreement, the triple co-expression of Gr32aUAS.cSa, Gr59cUAS.cUa and Gr66aUAS.Tag:MYC is sufficient to induce responsiveness to LOB, BER, and DEN, but not to CAF, STR, SOA, or UMP, whereas all double combinations of these three do not. All mentioned quintuple, triple and double co-expression have no effect on the normal response to sucrose.
As in control flies, co-expression of Gr32aScer\UAS.cMa, Gr33aScer\UAS.cMa, Gr47aScer\UAS.cLa and Gr66aScer\UAS.T:Hsap\MYC under the control of Scer\GAL4Gr5a.PUn does not elicit action potentials in sugar-responsive gustatory receptor neurons upon application of strychnine.
Scer\GAL4Gr33a-GAL4/Gr33aUAS.cMa partially rescues Gr33a1/Gr33a[+]
Expression of Gr33aScer\UAS.cMa under the control of Scer\GAL4Gr33a-GAL4 rescues the male courtship defect of Gr33a1/Gr33aGAL4 mutants.
Expression of Gr33aScer\UAS.cMa under the control of Scer\GAL4Gr33a-GAL4 in the Gr33a1 heterozygote adults significantly recovers the perturbed avoidance of umbelliferone in a two-way choice feeding assay as well as the site selection for oviposition assay and restores the reduction in frequency of action potentials invoked in the S6 sensilla upon umbelliferone exposure.