Figure 3. Abnormal histology of MTMR12-deficient zebrafish.

(A)Toluidine blue stained longitudinal sections of skeletal muscle in control and morphant fish at 3 dpf. In comparison to the control fish, mtmr12 morphants showed disorganized myofibers (arrowhead) with central nucleation (arrow), similar to histological changes observed in the skeletal muscle of mtm1 morphant fish (arrow). Knockdown of both mtm1 as well as mtmr12 results in severe muscle disorganization greater than seen in mtm1 or mtmr12 alone morphants. (B) Centrally nucleated myofibers were quantified. Serial sections from 3–4 different embryos were analyzed and the relative number of centrally nucleated fibers in the middle somites (10–13) were counted. (C) Hematoxylin and Eosin staining of mtmr12 morphant zebrafish at different time points. An increase in sarcomeric disorganization was observed at 3 dpf in comparison to 2 dpf in mtmr12 morphants (arrow) (D) Centrally nucleated myofibers were quantified. Serial sections from 6 different embryos were analyzed and the relative number of centrally nucleated fibers in the middle somites (10–13) were counted. Scale bar = 10 µm.