Figure 1. Expression of IR60b in the LSO.
(A) Drosophila head. The box indicates the region of the proboscis containing the labral sense organ (LSO, shaded) of the pharynx. (B) The pharyngeal region containing the LSO. The position of sensillum 7 is indicated. (C) IR60b-GAL4; UAS-GFP shows expression in a single pair of neurons that project dendrites (d) to the pore of sensillum 7, whose position is indicated. (cb), cell body. To maximize the fidelity of the driver, GAL4 was placed between sequences lying 5’ and 3’ to IR60b. Scale bar = 5 μm. Green color represents UAS-GFP fluorescence, visualized with a 488 nm laser. Magenta color represents cuticular autofluorescence, visualized with a 514 nm laser. (D) IR60b is the only member of the IR20a clade that shows a significantly negative Direction of Selection (DoS) signature. Values were generated by using polymorphism data from the Drosophila Genetic Reference Panel (Huang et al., 2014; Mackay et al., 2012) to perform McDonald-Kreitman Tests (Stoletzki and Eyre-Walker, 2011) for the IR20a clade genes. Values were generated using the popDrowser website (Ràmia et al., 2012). Briefly, the values are calculated by comparing sequence variation within Drosophila melanogaster to the sequence divergence between Drosophila melanogaster and its sibling species Drosophila simulans. *p<0.05; **p<0.01. Figure adapted from data displayed in Figure 6K in Koh et al. (2014).