Figure 3.

Depletion of Actn2 leads to broader Z band without affecting other myofibril substructures, including I bands and A bands. A) Images of dissected ventricles from WT and acnt2 MO fish at 48 hpf with phalloidin staining (a, e), immunostaining using an anti-Actn2 antibody (b, f), merged images of phalloidin (red) and Actn2 antibody staining (green) (c, g), and immunostaining using an anti-myosin antibody (d, h). In actn2 morphant fish, Actn2 immunoreactivity is essentially undetectable (b, f), but the striated pattern of thin and thick filaments remain normal. B) Subcellular localization of Cypher in Tg(cmlc2:cypher-egfp) fish is shown in low and high magnification (boxed area in low magnification). Cypher-EGFP exhibits as striated bands in both WT and actn2 MO fish, but the bands are wider in actn2 MO fish heart than in WT. Brackets indicate bandwidth; line with double-ended arrow indicates band length. C) Pseudo-line scan analysis of the fluorescence intensity change along the white line in B. Arrows indicate that actn2 MO fish has wider cypher-GFP band than WT fish. D, E) Measurement of the width (D) and length (E) of Cypher-EGFP bands shows that the width is significantly increased in actn2 MO fish heart, while the length of the bands is not affected. MO, fish injected with actn2 MO; NS, not significant. Scale bars = 10 μm (A); 2 μm (B). *P < 0.05.