AAS ›› 2013, Vol. 44 ›› Issue (5 ): 675-679.doi: 10.3969/j.issn.0529-1356.2013.05.018

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Effects of mitochondrial metabolic activity and mitochondrial DNA replication on maturation, fertilization and developmental competence in vitro of rat oocytes

GE Hong-shan* LI Xiao-he ZHANG Fan CHEN Hua XI Hai-tao HUANG Jian-ying ZHU Chun-fang Lü Jie-qiang   

  1. Reproductive Health Center, the Second Affiliated Hospital of Wenzhou Medical College, Zhejiang Wenzhou 325000, Chinese
  • Received:2012-12-04 Revised:2013-01-17 Online:2013-10-06 Published:2013-10-06

Abstract:

Objective To investigate the roles of mitochondrion on whether either mitochondrial DNA copy number or its metabolic capacity is an essential factor for both oocyte maturation and embryo development. Methods Both the metabolic inhibitor (FCCP) and the inhibitor of mitochondrial DNA replication(ddC) were introduced into the culture medium in order to analyze the affection of mitochondria rates of germinal vesicle breakdown. Nuclear maturation, fertilization and blastulation were assessedin vitro. Results The inhibiting mitochondrial DNA replication did not coincide with the mitochondrial metabolic capacity in oocytes. FCCP treatment significantly reduced the rate of nuclear maturation of oocytes and the development potential of embryos compared to untreated controls. Treatment of ddC did not affect maturationin vitro of oocytes, but impaired blastulation. Neither FCCP nor ddC treatment had an effect on the rate of fertilization. Conclusion Inhibiting mitochondrial metabolic activity during oocyte maturation has a negative impact on oocyte maturation and ensuing embryo developmental competence. Reduction in mitochondrial DNA copy number mainly affects embryonic development potential, but has little effect on oocyte maturation and fertilizationin vitro.

Key words: Mitochondrial energy metabolism, Mitochondrial DNA, Oocyte maturation, Developmental competence, Fertilization in vitro, Mouse