The L-type sensilla of homozygous flies show a significantly reduced spike rate in response to sucrose (over a range of concentrations extending from 20 to 500mM) compared to wild-type control sensilla. The mutant L-type sensilla show a normal electrophysiological response to maltose and trehalose, but show a reduced spike rate in response to glucose or fructose.
Homozygous flies have a reduced ability to distinguish between 5mM and 2mM sucrose in a 2-choice preference assay compared to wild-type controls.
Homozygotes show a normal avoidance response to caffeine and to quinine in a 2-choice preference assay. The S6 sensilla of these flies show a normal electrophysiological response to caffeine and to quinine.