Fukui Y
Department of Meat Animal Reproduction, Obihiro University of Agriculture and Veterinary Medicine, Japan.
Mol Reprod Dev. 1990 May;26(1):40-6. doi: 10.1002/mrd.1080260107.
The role of follicle cells in the acrosome reaction of frozen-thawed bovine spermatozoa, in vitro fertilization, cleavage, and development in vitro was investigated. Cumulus-oocyte complexes were cocultured and matured in vitro with additional granulosa cells for 24 hr. Immediately before in vitro insemination, the oocytes were divided into three types with different follicle cells: denuded and corona- and cumulus-enclosed oocytes. The proportion of live, acrosome-reacted spermatozoa significantly increased at 3 and 6 hr after insemination in all types of oocytes. However, the mean proportion of live, acrosome-reacted spermatozoa that inseminated cumulus-enclosed oocytes at 6 hr after insemination was significantly higher than that of spermatozoa inseminating denuded oocytes (18.3% and 13.3%, respectively). The frequency of in vitro fertilization was significantly higher for cumulus-enclosed oocytes (65.4%) than for denuded and corona-enclosed oocytes (30.8% and 39.4%, respectively). Cumulus-enclosed oocytes when cocultured with oviduct epithelial cells also had significantly higher rates of cleavage (two- to eight-cell, 59.8%; eight-cell, 22.4%) and blastocyst formation (7.7%) than denuded and corona-enclosed oocytes. No eight-cell embryos or more advanced stages of embryonic development were observed in either denuded or corona-enclosed oocytes without the coculture. The present results indicate that cumulus cells at fertilization play an important role in inducing the acrosome reaction and promoting a high fertilization rate, cleavage, and development into blastocysts in vitro.
研究了卵泡细胞在冻融牛精子顶体反应、体外受精、卵裂及体外发育中的作用。卵丘 - 卵母细胞复合体与额外的颗粒细胞共培养并在体外成熟24小时。在体外受精前，将卵母细胞分为三种具有不同卵泡细胞类型的：裸卵、有透明带和卵丘包裹的卵母细胞。授精后3小时和6小时，所有类型卵母细胞中活的、发生顶体反应的精子比例均显著增加。然而，授精后6小时，授精于有卵丘包裹卵母细胞的活的、发生顶体反应精子的平均比例显著高于授精于裸卵的精子（分别为18.3%和13.3%）。有卵丘包裹的卵母细胞的体外受精频率（65.4%）显著高于裸卵和有透明带包裹的卵母细胞（分别为30.8%和39.4%）。与输卵管上皮细胞共培养时，有卵丘包裹的卵母细胞的卵裂率（二细胞至八细胞，59.8%；八细胞，22.4%）和囊胚形成率（7.7%）也显著高于裸卵和有透明带包裹的卵母细胞。在没有共培养的情况下，裸卵或有透明带包裹的卵母细胞中均未观察到八细胞胚胎或更高级阶段的胚胎发育。目前的结果表明，受精时的卵丘细胞在诱导顶体反应、促进高受精率、卵裂及体外发育成囊胚方面发挥着重要作用。
