Shelton J N
John Curtin School of Medical Research, Australian National University, Canberra, A.C.T. Australia.
Theriogenology. 1992 Mar;37(3):713-21. doi: 10.1016/0093-691x(92)90150-p.
The addition of 0.1 M sucrose to the medium in which sheep embryos were bisected had no effect (39.5 vs 36.4%) on the survival rate of demi-embryos transferred (one per ewe) to recipients. There was a trend to greater survival of demi-blastocysts (44.7%) compared to demi-morulae (30%), and all the surviving twins were derived from the demi-blastocysts. It is suggested that the survival of demi-morulae is enhanced by the transfer of two demi-morulae to one uterine horn. In three experiments demi-embryos were frozen after the addition of 1.5 M glycerol in three or six steps or after the addition of 1.5 M ethylene glycol in six steps. No treatment resulted in acceptable survival rates of the demi-embryos transferred to recipients after thawing and step-wise removal of the cryoprotectant. Overall, 8 of 142 (5.6%) cryopreserved demi-embryos survived as 50-day fetuses or term lambs compared with 14 of 31 (45.2%) whole embryos.
在分割绵羊胚胎时向培养基中添加0.1M蔗糖，对移植到受体（每只母羊移植一个）的半胚胎的存活率没有影响（分别为39.5%和36.4%）。与半桑葚胚（30%）相比，半囊胚的存活率有更高的趋势（44.7%），并且所有存活的双胞胎都来自半囊胚。有人提出，将两个半桑葚胚移植到一个子宫角可提高半桑葚胚的存活率。在三个实验中，在添加1.5M甘油后分三步或六步，或在添加1.5M乙二醇后分六步对半胚胎进行冷冻。解冻并逐步去除冷冻保护剂后，没有一种处理能使移植到受体的半胚胎获得可接受的存活率。总体而言，142个冷冻保存的半胚胎中有8个（5.6%）存活为50天的胎儿或足月羔羊，而31个完整胚胎中有14个（45.2%）存活。
