Checkpoint kinases are required for oocyte meiotic progression by the maintenance of normal spindle structure and chromosome condensation
- Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction, Education Ministry of China, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan, 430070 (China)
- Reproductive Medicine Centre, Department of Obstetrics and Gynecology, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000 (China)
Highlights: • Inhibition of Chk1/2 has no significant effects on germinal vesicle breakdown. • Chk1/2 inhibition results in the first polar body extrusion defects. • Chk1/2 is critically involved in meiotic spindle organization. • Inhibition of Chk1/2 leads to abnormal chromosome condensation. • Chk1/2 is important for the development of MII stage oocytes. Checkpoint kinases (Chk) 1/2 are known for DNA damage checkpoint and cell cycle control in somatic cells. According to recent findings, the involvement of Chk1 in oocyte meiotic resumption and Chk2 is regarded as an essential regulator for progression at the post metaphase I stage (MI). In this study, AZD7762 (Chk1/2 inhibitor) and SB218078 (Chk1 inhibitor) were used to uncover the joint roles of Chk1/2 and differentiate the importance of Chk1 and Chk2 during oocyte meiotic maturation. Inhibition of Chk1/2 or Chk1 alone had no significant effect on germinal vesicle breakdown (GVBD) but significantly inhibited the first polar body (PB1). Interestingly, inhibition of Chk1 alone could not increase or completely block the extrusion of PB1 like Chk1/2 inhibition. Also, Chk1/2 inhibition resulted in defective meiotic spindle organization and chromosome condensation both in MI and metaphase II (MII) stages of oocytes. The location of γ-tubulin and Securin were abnormal or missing, while P38 MAPK was activated by Chk1/2 inhibition. Meanwhile, Chk1/2 inhibition reduced the percentage of the second polar body extrusion and pronuclear formation. In conclusion, our results further understand the functions and regulatory mechanism of Chk1/2 during oocyte meiotic maturation.
- OSTI ID:
- 23195588
- Journal Information:
- Experimental Cell Research, Vol. 405, Issue 2; Other Information: Copyright (c) 2021 Elsevier Inc. All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0014-4827
- Country of Publication:
- United States
- Language:
- English
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