Fig. 6

Rotenone exposure induced skeletal muscle atrophy in developing zebrafish embryos. Wild-type and Tg(mito:EGFP) embryos aged 7–8 h post fertilization (hpf) were exposed with 30 nM rotenone to 72 hpf. (A) Representative images of the trunk cross-section diameter 1 (D1) and trunk cross-section diameter 2 (D2). Quantified values of (B) D1 and (C) D2 lengths, Scale bar: 20 µm, N = 36. (D) Representative confocal microscope image of phalloidin-stained muscles with arrows presenting muscle degeneration. Red arrow: muscle fiber crossings at myosepta. Yellow arrow: muscle fiber detachments at myosepta. White star symbol: muscle fiber deformation. Scale bar: 100 µm. (E) Occurrence percentage of muscle degeneration in triplication, N = 6–7 (F) Quantified muscle fiber crossings at myosepta per embryo. (G) Quantified muscle fiber detachment at myosepta, N = 20. The relative mRNA expressions of (H) myostatin mstna, (I) muscle ring finger-1, trim63a, and (J) atrogin-1 with muscle protein degradation function, fbxo32, and (K) protein kinase B (PKB)/Akt, akt1, (L) mechanistic target of rapamycin (mTOR), mtor, and (M) insulin-like growth factor 1, igf-1, N = 24–30. Data presented as the mean ± SD. SD: standard deviation. * p < 0.05, * * p < 0.01, * ** p < 0.001, ns: not significant.