P300/CBP histone acetyltransferase activity inhibition induces muscle cells detachment in zebrafish. (a–c) Confocal projections of transgenic Tg(smyhc1:EGFP)ⁱ¹⁰⁴ embryos treated with either DMSO (vehicle), 2 μM or 3.5 μM C646 at 10 hpf for 24 h, fixed and imaged at 6 dpf. (a’–c’): higher magnification views of the boxed area in a–c. Arrowheads indicate muscle cell attachment abnormalities. (d–g) Confocal projections of transgenic Tg(smyhc1:EGFP)ⁱ¹⁰⁴ embryos treated with either DMSO or 2 μM C646 from 10 hpf for 24 h, and further raised in water (−Methylcellulose; d,e) or in viscous medium (+Methylcellulose; f,g) until 5 dpf. (h–m) Immunostaining against either H3K27ac (h–j) or p53ac (k–m). Confocal sections of embryos treated with either DMSO (vehicle), or 2 μM or 3.5 μM C646 at 10 hpf for 10 h and fixed at 20 hpf, as indicated on the panels. Fluorescent intensity is color-coded. (n) Relative mRNA expressions were determined by RT-qPCR in 3 dpf embryos treated with either DMSO, or 2 μM or 3.5 μM C646 from 10 hpf for 24 h. Error bars represent S.D. Statistical significance is relative to control and was calculated with an unpaired t-test. ns: not significant; *p < 0.05, **p < 0.01, ***p < 0.001. A minimum of 12 embryos were analysed per condition.

P300/CBP histone Acetyltransferase activity inhibition does not induce apotosis in muscle cells when fivers detach in zebrafish

(a) Confocal projections of embryos treated with either DMSO (vehicle), 2μm or 3.5 μM C646 at 10 hpf for 24 h, fixed and immunostained against caspase 3 and imaged at 6 dpf (6D). Topro3 was used to stain the nuclei. (b) Relative mRNA expressions of bcl2,bax and puma were determined by RT-qPCR in 3 dpf embryos treated with either DMSO, or 2 μm or 3.5 μm C646 from 10 hpf for 24 h. Error bars represent S.D of 3 independent experiments. Statistical significance is relative to control and was calculated with an unpaired t-test. ns: not significant. A minimum of 12 embryos were analysed per condition.