Figure 6

The effects of four caspase inhibitors on amphioxus embryogenesis. (A-D) Embryos treated with 50 μM DMSO were presented as the negative control. (E-H) Embryos were treated with 50 μM caspase-1 inhibitor z-YVAD-fmk and collected at 2.5, 5.5, 8 and 30 h post-fertilization. (I-L) Embryos were treated with 50 μM caspase-2 inhibitor z-VDVAD-fmk and collected at 2.5, 5.5, 8 and 30 h post-fertilization. (M-O) Embryos were treated with 50 μM effector caspase inhibitor z-DEVD-fmk in which more than 90% of embryos stopped developing at early blastula. (P-Q) Embryos were treated with 50 μM caspase-8 inhibitor z-IETD-fmk and more than 90% of embryos stopped developing at late morula. Scale bar, 100 μm. (R) The survival rate of each group was calculated with the number of observable eumorphism embryos divided by the number of zygotes at 0, 2.5, 4, 5.5, 8, 20 and 30 h post-fertilization using a somatotype microscope. Results were confirmed by at least three separate experiments. Values were considered to be significant when P < 0.05.