利用IVM/IVF技术生产试管犊牛的研究

本研究利用卵母细胞体外成熟(IVM)、体外受精(IVF)技术,体外生产牛胚胎,以获得试管牛.结果表明:卵母细胞体外培养22～24h后,其成熟率为85％;体外受精率为83％.体外受精卵分别在颗粒细胞单层(GCM)和输卵管细胞单层(OCM)上培养,其胚胎最后产量(以授精时卵母细胞的数目为基数)分别为19％和29％,差异极显著(P<0.01).若体外受精卵先在GCM中培养72h后,再将已发生卵裂的(>4细胞)胚胎移到OCM中培养,其胚胎最后产量为35％.由此表明,早期胚胎在其发育过程中至少存在着3个发育相期,即1～8细胞、8～16细胞和16细胞～囊胚3个阶段,各阶段需要不同的培养环境.IVM/IVF胚胎移植到受体黄牛体内后,其足月时的妊娠率为15％.第一头试管犊牛已于1993年4月18日凌晨产出.

Production of Tubal Calves by Means of IVM/IVF Technique

The effects of somatic cells on early embryo development from the culti-vation of IVM/IVF bovine zygotes to morula/blastocyst stage were evaluated. The fol-licular oocytes were matured and fertilized in vitro. Eight hours after insemination, thezygotes were cultured by the following 3 approaches: (1) cocultured with granulosacell/cumulus cell monolayer (GCM); (2) cocultured with oviduct cell monolayer(OCM); (3) zygotes were first cultured in GCM for 72h, then the cleaved ova (>4-cell) were transferred to OCM. The results showed that: (a) all the 3 approaches didnot influence the cleavage of zygotes, but the percentage of 4-8-cell embryos in GCMwas significantly higher than that in OCM (82% vs 65%, P<0.005); (b) after 7-8days of in vitro cultivation (day 0=commencement of cultivation), the percentages ofabove 8-cell embryos developing to morula or blastocysts were 58%, 61% and 56% re-spectively (P<0.05, each); (c) the yields of morula/blastocysts expressed on insemi-nated ova were 19%, 29% and 35% respectively (P<0.01 and P<0.05). Presentwork suggested that early embryo development may undergo three phases, each phaserequires different enviroment. The first tubal calf was born on April 18, 1993.