Figure 2
Determination of caspase 9 and caspase 3 involvement in mitochondrial apoptosis in C. gigas. (a) Caspase 9 and (b) Caspase 3 activity in oyster hemocytes was measured at 20 hpi. Non-irradiated cells were used as a negative control. Data are displayed as the mean±S.D. (N=6). **P<0.01. (c) Cytosolic extracts from oyster hemocytes were treated with cytochrome c (cyt c), Z-LEHD-FMK, and dATP. Caspase 9 activity was measured at 2 h post cyt c treatment (10 μM of horse cyt c or oyster cyt c). In Cg-cyt c+Z-LEHD-FMK group, the cytosolic extracts were preincubated with Z-LEHD-FMK (35 μM) for 1 h and then treated with Cg-cyt c. For Cg-cyt c+dATP treatment, the extracts were incubated with both Cg-cyt c and dATP (1 mM) for 2 h before activity assessment. Different letters indicate significant differences at P<0.05, whereas conditions annotated with the same letter were not significantly different. (d) Caspase 3 activity in oyster cytosolic extracts was monitored at different time points after treatment with 10 μM oyster cyt c with or without 1 mM dATP. Untreated extract served as a negative control. (e) Caspase 3 activity was examined in irradiated and non-irradiated hemocytes pretreated with Z-LEHD-FMK, DMSO vehicle, or left untreated at 20 hpi. Different small letters denote significant differences at P<0.05 while same letters denote not. All of the results in Figure 2 are shown as the mean±S.D. (N=6)
