The expression of Gr28b^{Scer\UAS.A.cDa} under the control of Scer\GAL4^Gr89a.2 leads to the following electrophysiological response changes of labellar sensilla to bitter tastants, as compared to controls: I-a sensilla display a novel and a significantly increased response to Myricetin and (-)-lobeline HCl, respectively; I-b sensilla display significantly increased responses to Aristolochic acid and Berberine chloride; S-a sensilla display no significant changes to the aforementioned tastants; these labellar sensilla types display no significant electrophysiological response changes to Rotenone, N,N-Diethyl-m-toluamide, Escin, Gossypol, Theobromine, Caffeine, Umbelliferone, Theophylline, Cucurbitacin I hydrate, D-(+)-sucrose octaacetate, Azadirachtin, Strychnine nitrate salt, Coumarin, Saponin, Sparteine sulfate salt, Quinine, and Denatonium benzoate.

Gr28b^UAS.A.cDa, Gr59c^Δ, Scer\GAL4^Gr89a.2 has abnormal neurophysiology phenotype

Gr28b^UAS.A.cDa, Gr59c^Δ, Scer\GAL4^Gr89a.2 has intermediate labellar taste bristle phenotype