Fig. 6.

CaP and MiP form normal arbors after muscle pioneer ablation. Side views of three whole-mount embryos at 24 h after laser-irradiation and immunostaining with 4D9 and znp-1.A, CaP axon (arrow) in experimental segment (asterisk) is similar to CaP axon in control segment (left). B, MiP axon (arrow) in experimental segment (asterisk) is similar to MiP axon in control segment (right); 30 of 31 experimental segments had normal MiP axons. Infrequent perturbations such as ectopic branching (C, arrowheads) were observed in experimental segments (asterisks) but not in control segments (right). In 12 of 47 cases, ectopic branching was observed at the following positions: along the common pathway (7 of 12), in the ventral myotome (4 of 12), or along the common pathway and in the ventral myotome (1 of 12). Scale bar, 25 μm.