Df(3L)ex83 mutant flies do not show significant changes in the expected avoidance response to food laced with 5% acetic acid, as compared to controls.

Df(3L)ex83 mutants lack the expected I-a, S-a and S-b sensilla responsiveness to the bitter chemicals LOB, BER, DEN normally observed in controls; there are no changes in I-b sensilla responsiveness to LOB, BER, DEN.

Df(3L)ex83 mutant adults show normal preference for less solid sucrose-agarose food than a harder one (higher agarose conc., same sucrose content) one in a two-way food choice assay.

Df(3L)ex83 mutant flies do not exhibit any defects in response to strychnine.

Df(3L)ex83 mutant adults display impaired avoidance of umbelliferone in a two-way choice feeding assay compared to wild-type as well as reduced frequency of action potentials invoked upon exposure to umbelliferone (measured on S3, S5, S6 and S9 sensillae).

Df(3L)ex83 mutant females display impaired umbelliferone as well as lobeline and quinine avoidance in an assay testing site selection for oviposition and unlike wild-type controls show aversion to high sucrose-content media in favor of substrate containing only lobeline or only umbelliferone (without sucrose).

Df(3L)ex83 mutant larvae, like the wild-type, show preference for sucrose containing media over agarose-only in a binary choice larval behavior assay but unlike the wild-type keep preferring the sucrose media even if contaminated with umbelliferone.

Df(3L)ex83 mutant flies do not exhibit the preference for sucrose over sucrose laced with L-canavanine seen in wild type flies.

The gustatory aversion of mutant flies to 6mM camphor in a two way-choice test is not significantly different from that seen in wild-type flies.

Mutant flies show normal responses to both low salt (50mM NaCl) and high salt (500mM NaCl) in a two-way choice test.

Mutant flies display severely impaired L-canavanine avoidance in a two-way choice test.

L-canavanine-induced action potentials are eliminated in the S3, S5 and S10 taste sensilla of mutant flies.

Mutant flies show reduced avoidance to caffeine and to theophylline in a binary food-choice assay, although avoidance responses to theobromine and paraxanthine are normal. Caffeine- or theophylline-induced action potentials are virtually eliminated in the gustatory receptor neurons in the mutant animals, although theobromine- or paraxanthine-induced action potentials are normal.

Df(3L)ex83 flies are viable and fertile.

Df(3L)ex83 flies display a strong defect in the avoidance of caffeine but show the same preferences for sucrose and avoidance of quinine as wild-type flies. Df(3L)ex83 gustatory receptor neurons produce action potentials in response to sucrose and quinine, but fail to produce caffiene-induced action potentials. Further, Df(3L)ex83 flies produce a reduced number of action potentials in response to the methylxanthines theophylline or 1,7-dimethylxanthine, but exhibit normal nerve firings when exposed to theobromine.