Luckett W P
Am J Anat. 1978 May;152(1):59-97. doi: 10.1002/aja.1001520106.
Reexamination of presomite human and rhesus monkey embryos in the Carnegie Collection provides no evidence to corroborate the hypothesis that the trophoblast is the source of all extraembryonic tissues in these embryos. Instead, the present study indicates that the developmental pattern of the yolk sac and extraembryonic mesoderm is homologous to that in other eutharian mammals. The primary yolk sac of 10- to 11-day human blastocysts is partially filled with a meshwork of extraembryonic endoderm, whereas such a meshwork is absent in the rhesus monkey. It is suggested that this endodermal meshwork develops as the result of interstitial implantation in the human embryo. A small secondary yolk sac develops in 12- to 13-day human and macaque embryos as the result of pinching off of a portion of the larger primary yolk sac. Development of a secondary yolk sac in higher primates appears to be related causally to differential rates of expansion of the blastocyst and primary yolk sac within the simplex uterus. The caudal margin of the primitive streak develops precociously in 12- to 14-day human and macaque embryos, and this appears to be the source of all the extraembryonic mesoderm of the chorion, chorionic villi, and body stalk. It is suggested that the peripheral spread of extraembryonic mesoderm plays in inductive role in the development of chorionic villi, similar to other types of epithelial-mesenchymal inductive interactions. In contrast to previous hypotheses, the human and macaque trophoblasts appear to give rise only to additional trophoblast.
重新检查卡内基胚胎学研究所收藏的原肠胚形成前的人类和恒河猴胚胎，没有证据支持滋养层是这些胚胎中所有胚外组织来源的假说。相反，本研究表明，卵黄囊和胚外中胚层的发育模式与其他真兽类哺乳动物的相同。10至11天人类囊胚的初级卵黄囊部分充满了胚外内胚层的网状结构，而恒河猴的这种网状结构不存在。有人认为，这种内胚层网状结构是人类胚胎间质着床的结果。12至13天的人类和猕猴胚胎中，由于较大的初级卵黄囊的一部分被掐断，形成了一个小的次级卵黄囊。高等灵长类动物次级卵黄囊的发育似乎与单角子宫内囊胚和初级卵黄囊的不同扩张速率有因果关系。原条的尾缘在12至14天的人类和猕猴胚胎中早熟发育，这似乎是绒毛膜、绒毛和体蒂所有胚外中胚层的来源。有人认为，胚外中胚层的外周扩散在绒毛的发育中起诱导作用，类似于其他类型的上皮-间充质诱导相互作用。与先前的假说相反，人类和猕猴的滋养层似乎只产生额外的滋养层。
