Fig. 3. Muscle growth is impaired in myod^fh261 mutants.

In situ mRNA hybridization for miR-206, myog and myhz1 and immunodetection of MyHC. Lateral (A,C,D) views, anterior to left or transverse cryosections (B). A. miR-206 in sequence-genotyped 48 hpf embryos from a myod^+/fh261 incross is primarily in fast fibres and is strongly reduced. B. Embryos from A were sectioned and stained with MyHC. miR-206 expression is strongly reduced in myod^fh261 mutants compared with their siblings, while MyHC immunodetection is only mildly reduced. C. At 72hpf, miR-206 has increased in myod morphants, but is still less than in siblings. D. Compared to sibs, myod^fh261 mutants (identified by head muscle defects) had less myog mRNA (arrowheads) and reduction in dorsoventral extent of somitic miR-206 and myhz1 mRNA (brackets). E. Somite volume increases with age, but is reduced in myod^fh261 mutant. These differences were consistent in live and fixed embryos. Number of embryos per condition are shown on columns and t-test statistics are indicated above columns. F. Adult fish mass and length. Bars = 100 μm.