Biotechnology Bulletin ›› 2016, Vol. 32 ›› Issue (5): 226-233.doi: 10.13560/j.cnki.biotech.bull.1985.2016.05.030

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Dynamic Changes of Sheep Oocyte Meiosis from Metaphase I to Metaphase III Matured in vitro

LI Xin-xin,BAI Chun-ling,WEI Zhu-ying,LI Guang-peng   

  1. The Key Laboratory of National Education Ministry for Mammalian Reproductive Biology and Biotechnology,Inner Mongolia University,Hohhot 010021
  • Received:2015-07-22 Online:2016-05-25 Published:2016-05-27

Abstract: Meiosis is a division mode in diploid organism to produce haploid gametes,which is the special mechanism of ensuring the chromosome’s number of a species after fertilization to be constant. The key step in the meiotic division is to separate the homologous chromosome and sister chromatids correctly,the dynamic changes of the cytoskeleton,in particular microtubules(MTs)and microfilaments(MFs),play critical roles in this process. In this study,the dynamic changes of chromosomes and spindle MTs and MFs during the maturing and parthenogenetic activation of sheep oocyte cells were studied by immunohistochemistry method. The results showed that:1)The morphology of spindle changed from barrel-shaped at metaphase stage to cylinder-shaped at early anaphase,and then to long,thin cone-shaped at late anaphase and telophase. Chromatin connected with the floor of the cone became the polar bodies and expelled. 2)Chromosome morphology changed from visible individual at metaphase to condensed chromatin during anaphase and telophase stages,and then backed to visible individual chromosomes at the next metaphase. 3)The size of MI spindle was larger than that of the MII spindle and MIII. MII spindle,however,was more barrel-shaped than the MI spindle. 4)Almost all of the MTs and MFs composing the spindles were partitioned into the polar bodies.

Key words: meiosis, microtubule, microfilament, spindle, oocyte, sheep