山羊早期胚胎发育的初步研究

本实验以黑龙江地方山羊为材料,经FSH超数排卵后,在不同时间屠宰母山羊,并冲洗输卵管及子宫,获取新鲜卵及各发育时间的胚胎。实验中发现山羊的排卵时间为发情开始后约30小时。受精卵的第一次卵裂的发生在排卵24小时以后。2细胞、4细胞、8细胞、16细胞、桑椹及胚泡期胚胎所处的时间分别为排卵后约32～42、48～52、62、72、96小时以及7～8天。16细胞期以前的胚胎移行于输卵管中,桑椹胚及胚泡则移行于子宫中。在每一时间从每只羊中所收集的胚胎基本上处于几个相邻的发育时期。在桑椹胚的动物极有明显的突起,这可能是内细胞群已开始形成的标志。到胚泡期时,胚胎体积增大,透明带变薄。正在孵化或已经孵化的胚泡中,内细胞群外端无滋养层细胞包围。

A PRELIMINARY STUDY ON THE PREIMPLANTATION DEVELOPMENT OF GOATS

Heilongjiang native goats were used in this experiment. The super-ovulated goats were slaughtered at the different times after ovulation, and the oviducts and uteri were flushed to gain the fresh eggs and the embryos at the different stages. The time of ovulation in goat was about 30 hours after heat. The first cleavage took place 24 hours after ovu-lation. The times at the stage of 2-cell, 4-cell, 8-cell,16-cell,morula and blastocyst were about 32-42hours, 48~52 hours, 62 hours, 72-80 hours, 96 hours, and 7-8 days after ovulation, respectively. The embryos prior to 16-cell stage were in oviduct, and the morulae and blastocysts were in uterus.The embryos at several near stages of development were often obtained from one goat. There was an apparent protruding at the animal pole of morula, which might be the mark that the inner cell mass began to form. At the blastocyst stage, the embryos increased in volume and the zona pellucida became thin. The inner cell mass was covered by trophoblast in the unhatched blastocyst. But the inner cell mass was exposed in the hatched blastocyst. The peculiar form of blastocyst was considered to be related to the time of implantation.