Figure 8. egl-5/Abd-B/Hox9-Hox13 affects synaptic wiring of the DA9 neurons.
(A) Schematic showing the location of DA9 neuromuscular synapses in WT, egl-5(n945), egl-5(n945); Ex [glr-4prom::egl-5] animals. On the right, the pre-synaptic boutons of the DA9 synapses were visualized using mig-13 prom::mCherry::rab-3. Since mig-13 expression is partially affected in DA9 by egl-5 (Figure 4E), we quantified the location of presynaptic boutons only in egl-5 mutant animals in which mig-13 expression was unaffected by the absence of egl-5. To quantify the location of the DA9 neuromuscular synapses (data provided on the right of each image), the seam cells (V5, V6a, V6p, T) were used as a reference since their location is not affected in egl-5(n945) mutants. It is noted that the gene promoter used for rescue (glr-4) is also under the partial control of egl-5 in DA9 (Figure 4E). For the heat maps shown on the right N = 50. Each row represents a single animal. P value = 0.0238 for egl-5(n945) and egl-5(n945); Ex [glr-4prom::egl-5] comparison. (B) Schematic of AVG>DA9 synapse, which is male-specific in the adult stage (see also Figure 1B). Synaptic inputs from AVG to DA9 were visualized with GRASP in C. elegans males and hermaphrodites at the first larval (L1) and adult stages and found to be defective in egl-5(n945) mutant male adult animals. The otEx6342 (inx-18prom::nlg-1::GFP1-10, acr-2 prom::NLG-1::GFP11, inx-18 prom::wCherry) transgene was used to visualize the AVG>DA9 synapse with gfp and the AVG axon with wCherry. Quantification of fluorescent micrographs was performed by quantifying the number of synaptic puncta observed using GRASP (AVG>DA9) in L1 and adult hermaphrodites and males. ***p<0.001; n.s., not significant. Magenta horizontal bars represent the median, black boxes indicate quartiles, black lines indicate range. Each gray dot represents one quantified animal. Region of observed synaptic puncta marked with white boxes. Scale bar, 10 µm.