Muscular analysis in perlecan morphant embryos. (A and C) Filamentous actin confocal immunohistochemistry. Arows in C highlight clear spaces between the muscle fibers. (B and D) Corresponding DIC analysis of the trunk musculature from a control and morphant embryo at 5 dpf. (E–J) Birefringence analyses under polarizing light comparing control and morphant trunk muscle at 2–3 dpf. F, H, and J are magnified views of the boxed regions in E, G, and I, respectively. Arrows in H indicate regions of hypobirefringence. (K–N) Binding of fluorescently labeled α-bungarotoxin and fasciculin to 4-dpf control and morphant embryos as a means to examine the distribution of AChR (red; highlighted by arrowheads in K and N) and AChE (green; highlighted by arrows in L and M). Bars, 300 μm.