Fig. 2

Short term phenotype of Sirt1 ^-/- mutants.

Four-days post fertilization embryos were used to obtain representative images of short term phenotypes of wildtype and Sirt1^-/- mutants. (A) Phenotypes of wildtype and Sirt1^-/- zebrafish embryos. Note there are no differences in appearance between wildtype and Sirt1^-/- mutant embryos. (B) The embryo survival curves of wildtype and Sirt1^-/- mutants after treatment with 0.5 or 1 mM tBOOH. Note that wildtype embryos died earlier than Sirt1^-/- mutants. (C) ROS levels in 0.5 mM tBOOH-treated wildtype and Sirt1^-/- embryos were examined by H₂DCFDA fluorescence. (D) Detection of apoptosis in 0.5 mM tBOOH-treated wildtype and Sirt1^-/- mutant embryos by TdT-mediated dUTP nick end labeling (TUNEL). Note that Sirt1^-/- mutants showed higher levels of ROS and TUNEL than wildtype embryos. The effect of NAC treatment on ROS content and apoptosis incidence was studied by H₂DCFDA fluorescence (E) and the TUNEL assay (F). Embryos were exposed to treatment with NAC treatment for 24 h. Results showed that TUNEL-positive cells increased in both, tBOOH-treated wildtype and Sirt1^-/-groups; furthermore, NAC treatment was effective for both groups.