hccs downregulation induces apoptosome‐independent caspase‐9 activation in mitochondria.A–C.TUNEL assays on st30 embryos co‐injected with hccs‐MO and Apaf1‐MO (A), wt embryos exposed to staurosporine (B) and embryos injected with Apaf1‐MO exposed to staurosporine (C) (n = 100/each treatment). hccsdownregulation induces apoptosome‐independent caspase‐9 activation in mitochondria.A–C.TUNEL assays on st30 embryos co‐injected with hccs‐MO and Apaf1‐MO (A), wt embryos exposed to staurosporine (B) and embryos injected with Apaf1‐MO exposed to staurosporine (C) (n = 100/each treatment). Apaf1 down‐regulation was able to protect the embryos from cell death induced by staurosporine, but not from the increased cell death due to hccs knockdown.D–F.TUNEL assays on st30 embryos co‐injected with hccs‐MO and Bcl‐xL mRNA (D) and embryos injected with hccs‐MO treated with CsA (E) or vehicle alone (F). Note that Bcl‐xL overexpression and CsA treatment block cell death. Scale bars: 20 µm.G.Number of TUNEL positive cells/eye (n ≥ 5 embryos/stage; Error bars are SEM; p‐values were calculated by ANOVA).H.Caspase‐9 activation in morphant embryos treated with CsA or vehicle alone. Histograms show the relative levels of emitted signals displayed in arbitrary units of luminescence. Values represent means of three samples. Each sample represents a group of 20 embryos (error bars are SEM; p‐values were calculated by ANOVA). Alessia Indrieri et al. EMBO Mol Med. 2013;5:280-293 © as stated in the article, figure or figure legend