Figure 5. Inhibition of CHK2 induced apoptosis during early embryonic development in mice. (A) Embryos at the 2-cell stage were stained with Annexin-V (green). The Annexin-V signal was stronger in embryos in the CHK2 inhibition group. Bar = 30 μm. (B) The percentages of cells in early apoptosis in mouse embryos treated with BML-277 and mouse embryos in the control group (62.2 ± 2.52%, n = 64, 25 μM vs. 38.6 ± 1.77%, n =92, control, p < 0.001). (C) The expression of apoptosis-related genes in the 25 μM treatment group and control group. (D) Relative Caspase 3 activity in embryos in the control and CHK2 inhibition groups. (E) The protein expression of Bax and BCL2 in embryos in the control and CHK2 inhibition groups was determined by immunoblotting. (F) Band intensity analysis of Bax and BCL2 in the two groups. **significant difference (p < 0.01). *significant difference (p < 0.05).