(E) Smyhc1 immunohistochemistry stain of 24 hpf (hour post fertilization) zebrafish larvae. Filamentous actin is stained with phalloidin (red). Nuclei are stained with DAPI (blue). Smyhc1 is stained with the F59 antibody (green) (Elworthy et al, 2008). smyhc1+/+, smyhc1R673H/+, and smyhc1R673H/R673H larvae display Smyhc1 in the muscle fibers at 24hpf. smyhc1-/- larvae at 24 do not stain positively for Smyhc1. Scale bar represents 50 µm. 