Research Paper Volume 12, Issue 11 pp 10415—10426

CHK2 is essential for spindle assembly and DNA repair during the first cleavage of mouse embryos

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Figure 3. CHK2 inhibition affected spindle morphology and chromosome alignment at the first cleavage of early mouse embryos. (A) Embryos at metaphase were stained with anti-α-tubulin (green) and counterstained with Hoechst 33342 to visualize chromosomes (blue). Unlike those in the control group, embryos in the 25 μM treatment group showed a variety of defects, including multipolar and nonpolar spindles. The chromosomes in embryos in the 25 μM treatment group were severely misaligned. Bar = 20 μm. (B) A significantly higher proportion of embryos in the 25 μM treatment group exhibited spindle defects than those in the control group (35.5 ± 5.51%, n = 173 vs. 20.3 ± 3.55%, n = 165, p < 0.001). (C) The incidence of chromosome misalignment was also higher in embryos in the 25 μM treatment group than in those in the control group (35.8 ± 2.80%, n = 81 vs. 18.7 ± 1.82%, n = 55, p < 0.05). ***significant difference (p < 0.001). *significant difference (p < 0.05). (D) Chromosomal aberrations were observed in embryos in the CHK2 inhibition group. Blue, DNA. Bar = 5 μm.