注射hCG后不同时间猪所排卵泡内COC的形态和卵母细胞减数分裂进程

Morphology of Cumulus-complexs and Meiotic Dynamics of Porcine Oocytes in Preovulatory Follicules at Different Time after hCG Injection

研究了超排处理注射 h CG后不同时间猪卵丘卵母细胞复合体 (COC)的回收率和形态、卵母细胞减数分裂进程以及 COC形态与生发泡 (GV)染色质构型之间的关系。结果表明 :(1)注射 h CG后 4 h COC的回收率为 5 3.1% ,明显低于注射 h CG后 18、2 2、2 4 h(71.2 %、76 .5 %、70 .0 % ,P<0 .0 5 ) ;(2 )注射 h CG后 18、2 2、2 4 h收集的 COC分别有98.9%、98.0 %、91.4 %的卵丘已经发生扩展 ,而注射 h CG后 4 h收集的 COC则无一发生卵丘扩展 ;(3)注射 h CG后 4h,有少量卵母细胞开始恢复减数分裂 ,至 18h左右开始发生生发泡破裂 (GVBD) ,到 2 2～ 2 4 h有 5 8.4 %～ 6 0 .0 %的卵母细胞发生 GVBD;(4)外层卵丘扩展、放射冠轻微扩展的卵母细胞处于 GV- 1期的比例 (6 9.6 % )明显高于卵丘完全扩展的卵母细胞 (47.8% )和放射冠部分扩展、卵丘已经脱落的卵母细胞 (2 9.3% ) ,而后 2者发生 GVBD的比例(40 %、4 4 % )则略高于前者 (2 7% )。

The recovery of cumulus oocyte complexes(COCs),dynamics of meiosis and the relationship between COC morphology and GV chromatin configuration of porcine oocytes in pre ovulatory follicles were investigated at different time after hCG injection.The results were as follows:(1)The rate of oocyte recovery at 4 hours(53 1%) was significantly( P <0 05) lower than those at 18,22 and 24 hours(71 2%,76 5% and 70 0%,respectively) after hCG injection.(2)Most COCs recovered at 18,22 and 24 hours post hCG injection(98 9%,98 0% and 91 4%,respectively) showed expanded cumulus,but none of those recovered 4 hours after hCG injection showed cumulus expansion. (3)Germinal vesicle began to break down at about 18 hours after hCG injection,and by 22 24 hours after hCG injection,the rate of germinal vesicle breakdown reached 58 4% 60 0%.(4)The GV chromatin configuration in oocytes with expanded cumulus was different.The rate of GV 1 oocytes in COCs with expanded cumulus and a piece of slightly expanded granulosa cells(69 6%) was significantly higher than that of COCs with fully expanded cumulus(47 8%) and that of COCs with a partially expanded corona radiata and the outer part of expanded cumulus dissociated(29 3%),but the percentages of oocytes undergoing GVBD in the latter two cases(40% and 44%,respectively) were markedly higher than that in the former(27%).