Fig. 6

Disrupted assembly of the Z-disc, thick filaments and the M-line in morphants. (A) Shown are images of 48 hpf embryos after immunostaining to reveal Z-disc assembly using α-actinin antibody. Irregular dots were detected in both MO-ATG morphants and sih mutants, whereas periodic dots were detected in MO-E13 morphants. Arrowheads, periodic α-actinin dots. Open arrowheads, irregular α-actinin dots. (B) Shown are images of MO-ATG morphant embryos at the 48 hpf stage after two-color immunostaining to reveal α-actinin (green) and actin filament (red). α-actinin dots and the F-actin network are still co-localized. (C) Shown are images of 48 hpf embryos after immunostaining to reveal M-line assembly using the anti-myomesin antibody. Arrowheads, striated M-lines. Open arrowheads, irregular myomesin dots. Indented arrowheads, periodic myomesin dots separated by a short distance. (D) Shown are images of 48 hpf embryos after immunostaining to reveal thick filaments using the F59 antibody. Arrowheads, striated thick filaments. Brackets, continuous thick filaments. (E) Quantification of the distance between two neighboring α-actinin dots in ventricles from WT and MO-E13 morphants at 48 hpf. Shown are mean ± s.d. N, number of heart and sarcomere units quantified. (F) Quantification of the distance between two periodically neighboring myomesin dots in ventricles from WT and morphants at 48 hpf. Shown are mean ± s.d. N, number of heart and sarcomere units quantified. *p < 0.01. Scale bar = 5 μm.