哺乳类胚胎的一半遗传基因来自其父系,具有异体移植物特性,母体能识别某些胚胎合成的抗原分子,而胚胎几乎不受免疫排斥。显然,胎盘构成了有效的屏障,保护了胚胎,甚至包括异位妊娠。但胎盘如何发挥作用仍不清楚。本文作者探讨了胚胎发育中胎母细胞间互相作用对异种间妊娠成败的决定性影响。为了研究母胎间的互相作用,胚胎移植实验发现,异种的胚胎常被母体排斥。在某些动物中排斥较快,而在另一些动物则排斥较慢。但最终仍被排斥。(如山羊和绵羊之间的胚胎移植存活时间较长,而田鼠各种系间的胚胎移植很快被排斥)。山羊和绵羊的 Half of the mammalian embryos have their genes inherited from their paternal lineage, have the characteristics of allografts, maternal recognize antigen molecules synthesized by some embryos, and embryos are almost immune-immune. Obviously, the placenta constitutes an effective barrier that protects the embryo, even including ectopic pregnancy. However, it is unclear how the placenta functions. The authors investigated the decisive impact of the interaction of the fetal cells in embryo development on the success or failure of an interspecific pregnancy. In order to study the interaction between maternal and fetal, embryo transfer experiments found that heterogeneous embryos are often excluded from the mother. In some animals, the rejection is faster, while in others the rejection is slower. But in the end is still excluded. (Eg, embryo transfer between goats and sheep survives longer, and embryo transfer between various lines of vole is quickly excluded). Goat and sheep