Fig. 1

Musculoskeletal labelling of stm^hy024 zebrafish mutants reveals specific muscle defects. (A-D) Immunolabelling of muscle (red) and cartilage (green) reveals that stm^hy024 mutants (B,D) have reduced dilator operculi (do), adductor operculi (ao), levator operculi (lo) and hyohyoideus superiores (hh sup) muscles (arrowheads) relative to wild type (WT; A,C). e, eye. (E,F) stm^hy024 mutants (F) have tightly closed mouths (arrow) relative to WT (E). (G,H) Higher magnification views of dorsal pharyngeal arch muscles reveal that the do, ao and lo attaching to the opercular bone (op, green) are reduced in stm^hy024; the non-opercular muscles levator arcus palatini (lap) and adductor hyoideous (ah) are unaffected. (I) Quantification of fibre number in dorsal arch muscles (mean ± s.e.m.) reveals a specific and significant reduction (*P<0.0001) of the opercular muscles in stm^hy024 relative to WT (n=10), during muscle development at 72, 96 and 120 hours post-fertilisation (hpf). Scale bars: 100 μm in A-D; 50 μm in G,H.