Figure 5.

Bx-C Hox genes are expressed throughout the PNS and are down-regulated specifically in class IV da neurons. (A–C) Anti-Ubx (FP3-38 antibody) staining (A) in two neighboring segments (abdominal segments 3 and 4) of embryos carrying the md neuron enhancer trap E7-2-36 (B). Here and in subsequent images the position of ddaC is marked with a white arrow, and both ddaC and ddaF are outlined in white. Anti-Ubx staining in class IV neurons was independently verified with the pickpocket-EGFP marker. A merge of the images is shown in C. In all images dorsal is up, and posterior is left. Bar, 50 μm. (D–F) Anti-Ubx staining in abdominal segment 3 of late third instar larvae (D) costained with anti-HRP (E) to label all sensory neurons. A merge of the images is shown in F. (G) Quantitation of Ubx expression levels at 24 h AEL and 120 h AEL (third instar). To facilitate comparison of different developmental stages, the expression level is presented as a ratio of the mean pixel intensity of ddaC and another dorsal cluster da neuron, ddaF. Error bars represent one standard deviation, and asterisks (*) denote p < 0.05. (H–J) Anti-AbdA (6A8.12 antibody) staining (H) in two neighboring segments (abdominal segments 3 and 4) of stage 16 embryos carrying the md neuron enhancer trap E7-2-36 (I). A merge of the images is shown in J. (K–M) Anti-AbdA staining in abdominal segment 3 of late third instar larvae (K) costained with anti-HRP (L). A merge of the images is shown in M. (N) Quantitation of AbdA expression levels at 24 h AEL and 120 h AEL (third instar). As in G, the expression level is presented as a ratio of the mean pixel intensity of ddaC and ddaF. Error bars represent one standard deviation, and asterisks (*) denote p < 0.05.