Sherman M I, Chew N J
Proc Natl Acad Sci U S A. 1972 Sep;69(9):2551-5. doi: 10.1073/pnas.69.9.2551.
A genetic variant of esterase in mice is used to demonstrate for the first time that an enzyme of maternal origin is taken up intracellularly by two mid-gestation tissues dervied from the embryo: trophoblast and yolk sac (visceral endoderm). Although other alternatives are still possible, it is likely that the esterase is transported from the mother to the trophoblast via the serum. If so, the phenomenon is selective, since at least one other prominent serum esterase is not found in trophoblast or yolk sac cells. The enzyme has not been detected in the embryo proper, even at very late stages of pregnancy. Trophoblast cells-developing from blastocysts implanted under the kidney capsule of a male mouse also appear to have the ability to take up host esterase. Efforts to demonstrate uptake of the enzyme by trophoblast cells in blastocyst cultures have been unsuccessful.
小鼠酯酶的一种基因变体首次被用于证明，一种源自母体的酶被胚胎发育中期的两种组织细胞内摄取，这两种组织分别是滋养层和卵黄囊（脏内胚层）。尽管仍有其他可能性，但这种酯酶很可能是通过血清从母体转运至滋养层的。如果是这样，这种现象具有选择性，因为在滋养层或卵黄囊细胞中未发现至少一种其他显著的血清酯酶。即使在怀孕后期，也未在胚胎本身中检测到这种酶。从植入雄性小鼠肾被膜下的囊胚发育而来的滋养层细胞似乎也有摄取宿主酯酶的能力。在囊胚培养中证明滋养层细胞摄取该酶的努力尚未成功。
