Adults respond normally to sucrose in a feeding preference test. Adults show an enhanced attraction to 100mM sodium chloride compared to wild-type. This phenotype is fully recessive. Homozygous adults show an elevated spike frequency from the labellar chemoreceptors in response to 100mM NaCl. The electrophysiological response to sucrose is normal.
Homozygous adults show a markedly greater preference for sodium chloride (NaCl) in feeding preference and proboscis extension tests compared to wild-type flies. The proboscis extension response evoked by 10mM sucrose shows an increased tolerance to NaCl. The chemosensory neurons of homozygous labellar taste hairs show an enhanced electrophysiological response when stimulated by NaCl compared to wild-type flies. The S neuron is stimulated by NaCl in homozygotes, in contrast to wild-type. The S neuron is also stimulated by sucrose in homozygotes, as in wild-type flies. Taste sensilla of all types are affected, but the effect is most clearly seen in the P-type hairs. The branching pattern and the dendritic morphology of the neurons of the labellar taste hairs appear normal.