Fig. 1

Identification of Grs for LOB, BER, and DEN detection. a Spatial localization of each class of taste bristle in the labellum. Figure modified from Weiss et al.³ (2011). b Schematic for the misexpression of bitter Grs from I-a sensilla in the sweet GRNs of L-type sensilla using Gr64f-GAL4. The Grs normally expressed in bitter GRNs of I-a sensilla and their bitter ligands (red), as well as the sweet Grs normally expressed in sweet GRNs of L-type sensilla and their sugar ligands (blue) are indicated. c Representative traces from L-type sensilla of flies of the indicated genotypes upon application of 1 mM stimuli of LOB, BER, or DEN. d Mean responses of L-type sensilla induced by the indicated chemicals: 100 mM sucrose (SUC), 1 mM LOB, 1 mM BER, 1 mM DEN, 5 mM CAF, 1 mM STR, 1 mM SOA, and 1 mM UMB. n = 6–10. Unpaired t-test or the Mann−Whitney U-tests as appropriate. e Identification of the Grs required for LOB, BER, and DEN detection. The mean responses of L-type sensilla of the indicated genotypes upon application of 1 mM stimuli of LOB, BER, and DEN as well as 100 mM SUC are shown. n = 6–10. ANOVAs followed by Dunnet T3 post hoc tests for LOB and the Kruskal−Wallis tests followed by Mann−Whitney U post hoc tests for BER and DEN. The asterisks indicate statistically significant differences from Gr64f >6 Grs flies in d. f The mean responses of L-type sensilla expressing Gr32a, Gr59c, and Gr66a induced by the indicated chemicals. n = 6–10. Unpaired Student’s t-tests or the Mann−Whitney U-tests as appropriate. All data are presented as means ± S.E.M. *p < 0.05, **p < 0.01. Complete genotypes are listed in Supplementary Table 6