Tmod1 is dispensable for myofibril assembly. (A) Western blots of E15.5 mouse embryonic leg and flank muscle tissue lysates show absence of Tmod1 in Tmod1^−/−Tg+ muscles. Tubulin and actin were loading controls. Molecular mass is indicated in kilodaltons. (B–I) Skeletal muscle from Tmod1^+/+ and Tmod1^−/−Tg+ E15.5 mouse embryos stained for Tmod1, F-actin, and α-actinin. Arrowheads denote H-zones. Bars, 3 µm.