체외 배양 과정 중에 나타나는 생쥐 초기 2-세포 배의 "in vitro 2-cell block" 현상은 세포내 농도 변화와 밀접한 관련이 있다. 다양한 종류의 세포에서 acetylcholine은 세포막에 존재하는 muscarnic acetylcholine receptor를 통해 세포내 농도 증가를 유도한다. 본 실험에서는 생쥐 "in vitro 2-cell block" 현상에 있어서 ACh의 영향을 알아보기 위해 세포 내 농도 조절 물질을 처리한 후,

This study investigated full-term development potential of ultrarap idly frozen and thawed mouse 2-cell embryos. Mouse 2-cell embryos, dehydrated by exposure to freezing medium, were directly immersed into liquid nitrogen and thawed in 37 water. The embryos that were frozen and thawed were cultured in uitro and transferred to foster mothers to examine there developmental potential. As a result, the frozen-thawed 2-cell embryos developed to blastocysts in vitro as a similar rate as control 2-cell embryos did(in vitro 2-cell, 86.4%; in vivo 2-cell, 90.9%; solution control, 89.9%; control, 89.7%). Normal live young were obtained from transfer of frozen-thawed embryos to the oviduct and uterus of pseudopregnant recipients (3l.4~56.7%).

In vitro developmental ability of early preimplantation monse embryos was shown to be depend on the embryonic stages, media and snpplements and their interaction(Experiment 1). The development of I-cell embryos were more promoted in the complex medinm(Ham's Fl0) than in the simple one(m-KRB), but that of 2-cell embryos showed the reverse effect. The bovine serum albumin(BSA) as a medium snpplement more promoted the development of I- and 2-cell embryos, compared with human fetal cord serum(HCS). On the other hand, the harmful effect of HCS was especially shown on the early cleavage in the embryonic development of the two stages. The effect of serum, in the respect of interaction between media and snpplements. was also more significantly appeared in m-KRB than Ham's Fl0. In the experiment 2, when the harmful effect of HCS was compared with that of fetal bovine serum(FBS), the former more promoted the development of l - and 2-cell embryos than the latter. The effect of HCS was more significantly shown in the development of I-cell than that of 2-cell embryos. Conclusively, as I- and 2-cell embryos were different in the requirements for the in vitro development. the optimal medium and supplement have to be selected for each embryonic stage. It is also respected to the better result if it take into consideration into the kinds of sera when serum is used for culture of early preimplantation embryos.