|
Fig. 3 Hh signaling is required indirectly for the recovery of fast-twitch fibers in laminin mutant embryos. B-I: Side views, anterior left, dorsal top, 48-hpf embryos treated with EtOH or CyA at the 10-somite stage and stained with F59 (green) to visualize slow muscle fibers and phalloidin (red) to visualize actin. A: Cartoon describing expected results if Hh signaling is directly or indirectly required. B-E: Anterior somites are shown. Panels numbered 1 are 3-D projections. Panels numbered 3 are higher-magnification views of individual focal planes. Note the presence of slow-twitch fibers and elongated fast fibers in all conditions. F-I: Posterior somites are shown. The boxes in panels numbered 1 and 2 correspond with the higher-magnification medial focal plane shown in panels numbered 3. Slow-twitch fibers are present in EtOH-treated embryos (F, G) but are reduced and/or absent in posterior somites in CyA-treated embryos (H, I). Note that defects in fast fiber elongation correlate with the lack of slow fibers in the posterior of CyA-treated lam gamma1 mutant embryos (I).