title: [The tempo of meiosis of goat oocytes].
abstract: The meiotic progression of goat oocytes from follicles of different diameters was investigated in this study. The results were summarized as follows: (1) The in vitro meiotic maturation capacity was different among oocytes from follicles of different diameters. And thus oocytes from < or = 0.5 mm follicles were unable to resume meiosis; oocytes from 0.8-1.2 mm follicles were capable to resume meiosis, but could develop only to MI stage (60% at 24 h); oocytes from 1.5-5 mm follicles had acquired full-meiotic maturation capacity and 91% of them developed to M II stage at 24 h of culture. (2) The percentage of oocytes with intact-germinal vesicles from 1.5-5 mm follicles decreased significantly during 2-8 h of in vitro maturation and the decrease was even more rapid during 4-6 h of culture (from 60% to 19%, p < 0.0005). The percentage of oocytes at M I-stage increased from 24% to 61% during 6-12 h of in vitro maturation, and it then decreased. By 24 h of culture, only 2% oocytes remained at M I-stage. Twenty one percent of the oocytes in this group developed to M II-stage at 16 h of culture, and by 24 h of culture, 91% were at M II-stage. (3) Statistic analysis of the meiotic progression (the duration of each cell cycle stage) of oocytes from 1.5-5 mm follicles showed that GV stage lasted from 0 to 3 h of culture, prometaphase-I stage was from 3.0 to 7.0 h, metaphase-I stage was from 7.0 to 14.6 h, anaphase-I/telophase-I was from 14.6 to 18.4 h and metaphase-II stage lasted from 18.4 to 24 h. (4) Whether the oocytes capable of GVBD and entrance of M I developed to M II, the timing of meiotic progression prior to M I was similar. In summary, our results provided necessary data for studies on the mechanisms and control of meiosis in mammalian oocytes.
authors.affiliation: College of Animal Science and Technology, Shandong Agriculture University, Taian 271018.
authors.forename: Suo Feng
authors.initials: SF
authors.lastname: Ma
authors.forename: Ming Jiu
authors.initials: MJ
authors.lastname: Luo
authors.forename: Yi Liang
authors.initials: YL
authors.lastname: Miao
authors.forename: Guo Cheng
authors.initials: GC
authors.lastname: Lan
authors.forename: Zi Yu
authors.initials: ZY
authors.lastname: Wang
authors.forename: Xin Yong
authors.initials: XY
authors.lastname: Liu
authors.forename: Zhong Le
authors.initials: ZL
authors.lastname: Chang
authors.forename: Jing He
authors.initials: JH
authors.lastname: Tan
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D005260:Female; D006041:Goats; D008540:Meiosis / Q000502:physiology*; D008677:Metaphase; D009865:Oocytes / Q000166:cytology / Q000502:physiology*; D006080:Ovarian Follicle / Q000033:anatomy & histology*