Artificially Increasing Cortical Tension Improves Mouse Oocytes Development by Attenuating Meiotic Defects During Vitrification

Xingzhu Du; Jun Li; Qingrui Zhuan; Luyao Zhang; Lin Meng; Panyu Ren; Xiaohan Huang; Jiachen Bai; Pengcheng Wan; Wenquan Sun; Yunpeng Hou; Shien Zhu; Xiangwei Fu

doi:10.3389/fcell.2022.876259

Artificially Increasing Cortical Tension Improves Mouse Oocytes Development by Attenuating Meiotic Defects During Vitrification

Front Cell Dev Biol. 2022 Mar 24:10:876259. doi: 10.3389/fcell.2022.876259. eCollection 2022.

Authors

Xingzhu Du¹, Jun Li², Qingrui Zhuan¹, Luyao Zhang³, Lin Meng³, Panyu Ren³, Xiaohan Huang³, Jiachen Bai⁴, Pengcheng Wan⁵, Wenquan Sun⁴, Yunpeng Hou³, Shien Zhu¹, Xiangwei Fu^{1

5}

Affiliations

¹ Key Laboratory of Animal Genetics, Breeding and Reproduction of the Ministry of Agriculture and Rural Affairs, National Engineering Laboratory for Animal Breeding, Beijing Key Laboratory for Animal Genetic Improvement, College of Animal Science and Technology, China Agricultural University, Beijing, China.
² Department of Reproductive Medicine, Reproductive Medical Center, The First Hospital of Hebei Medical University, Shijiazhuang, China.
³ State Key Laboratories of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China.
⁴ Institute of Biothermal Science and Technology, School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai, China.
⁵ State Key Laboratory of Sheep Genetic Improvement and Healthy Breeding, Institute of Animal Husbandry and Veterinary Sciences, Xinjiang Academy of Agricultural and Reclamation Sciences, Shihezi, China.

Abstract

Oocyte cryopreservation demonstrates great benefits in the conservation of animal germplasm resources and assisted reproductive technology. However, vitrification causes damages in oocytes, which would lead to the decrease of oocyte quality, and embryonic development post fertilization. Cytoskeleton plays an important role in regulating cell shape, organelle migration, cell division and mechanical signal transduction. Cortical tension is a reflection of the physiological state and contractile ability of cortical cytoskeleton. Appropriate cortical tension is prerequesite for normal oocyte meiosis. In the present study, oocyte cortical tension was examined by evaluating the levels of cortical tension-related protein pERM (Phospho-Ezrin/Radixin/Moesin) and pMRLC (Phospho-Myosin Light Chain 2). We found that the cortical tension of vitrified oocytes was decreased. Increasing cortical tension of vitrified oocytes by adding 10 μg/ml ConA during in vitro culture could significantly improve the polar body extrusion rate and embryo development. Furthermore, increasing the cortical tension could improve spindle positioning, maintain kinetochore-microtubule (KT-MT) attachment, strengthen spindle assembly checkpoint (SAC) activity, and reduce the aneuploidy rate in vitrified oocytes. In conclusion, vitrification induced a remarkable decrease in cortical tension, and increasing the cortical tension could rescue the meiosis defect and improve oocyte quality.

Keywords: aneuploidy; cortical tension; meiosis; oocyte vitrificaion; spindle assembly checkpoint.