479135.fig.009a
(a)
479135.fig.009b
(b)
479135.fig.009c
(c)
479135.fig.009d
(d)
Figure 9: New myofibril assembly occurs along the sarcolemma with a consistent relationship between myofibrils in adjacent myocytes. Skeletal muscles from 20 hpf zebrafish embryos were evaluated by transmission electron microscopy. (a) In control (Ctrl) embryos, new myofibril assembly occurs along the sarcolemma (white line) with a slight offset in the alignment of the Z disks (arrowheads). (b)–(d) In obscurin morphant (ObsMO) embryos, myofibril assembly continues to occur adjacent to the sarcolemma (white lines) but there is a greater distance and a greater variability in the distance between superficial myofibrils in adjacent cells. There was also a greater variability in the alignment of Z disks across adjacent myocytes, ranging from very offset ((c): arrowheads) to nearly precisely aligned ((d): arrowheads). Scale bars are 500 nm.