| Abstract: | The difference in growth behavior between bovine embryos and murine embryos was studied on PMEF(primary murine embryos fibroblast)feeder layer. The results showed as follows: With embryos having attached, bovine embryonic trophoblast formed a transparent membranous structure covering on inner cell mass (ICM), however, murine embryonic trophoblast formed disc structure. Bovine embryos formed four kinds of ICM colonies with different morphology including the mass-like, the net-like, the stream-like and the mixture-like colonies. Compared with Murine ICM, the bovine ICM grew more fast. So, the bovine ICM was passaged at first after a culture of approximately 5 - 6 days in vitro, but murine ICM was passaged at first after an attachment of 3 - 4 days on PMEF feeder layer. The mixture colonies of bovine ICM differentiated very early, while the others differentiated very late. Most ICM-like mass of Bovine grew in a defined spot, but bovine ICMs like stream and ICMs like net proliferated fast and dispersed quickly. We found that the single blastomeres derived from late bovine morula and late murine morula formed sub-blastophere; moreover, the bovine ICM cell would differentiate rapidly if the trophoblast was removed. |
