Figure 5

sim deficient larvae have a decreased yeast odorant attractant response. Individual sim⁴³⁰ or sim⁷¹⁸ knockdown (KD) vs. control-fed L4 animals were assessed for their response to a yeast odorant attractant. In each assay (replicate one = red, replicate two = orange) individual control-fed animals that were attracted to the yeast were awarded a score of 1, while animals that were not attracted to the yeast received a score of 0. Average scores for control vs. knockdown animals are plotted for each replicate experiment, for which n numbers are indicated; error bars represent standard error (panel A1). The mean score for knockdown animals fed with either sim⁴³⁰ or sim⁷¹⁸ was significantly lower than that of control-fed animals in both replicate experiments (p < 0.001, A1). Levels of sim RNA were severely reduced in the antennae (B2, B3) and brains (C2, C3) of sim knockdown animals (sim⁴³⁰ in B2, C2; sim⁷¹⁸ in B3, C3) that failed to respond to the yeast, while normal levels of sim transcript were observed in control-fed antennae (B1) and brains (C1; red asterisks mark clusters of sim expression) of animals that were attracted to the yeast. The proximal ends of antennae are oriented upward in panels B1-B3. Dorsal is oriented upward in C1-C3, in which the antennal lobe is marked by yellow dots. Scale bars = 25 microns.