Stern C D, Ireland G W
Anat Embryol (Berl). 1981;163(3):245-63. doi: 10.1007/BF00315703.
The formation of the endoderm during primitive streak stages in avian embryos was studied by combining several of the following techniques for each embryo. These included microsurgery, time-lapse filming, use of chick-quail chimaeras, tritiated thymidine autoradiography and a novel technique for identifying the morphology of the cells after small pieces of tissue from known areas had been maintained in culture for 24 h. Using these techniques we have confirmed that the ventral layer of the early chick embryo receives contributions from both the marginal and the central regions of the area pellucida. The former seems to consist of yolky cells derived from the germ wall, whilst the latter consists of smaller, less yolky cells derived from the more dorsal layers of the embryo. The movement of the lower layer anteriorly during these stages appears to be dependent upon mechanical constraints imposed upon it by the expanding tissue in more caudal regions. The extent of each of the two contributions to the lower layer was determined as a function of stage and presence or absence of a lower layer, and the findings are discussed in the light of the existing literature.
通过对每个胚胎综合运用以下几种技术，研究了鸟类胚胎原条期内胚层的形成。这些技术包括显微手术、延时摄影、鸡 - 鹌鹑嵌合体的应用、氚标记胸腺嘧啶核苷放射自显影术，以及一种新技术，即从已知区域获取小块组织并在培养24小时后鉴定细胞形态。运用这些技术，我们证实了早期鸡胚的腹侧层接受来自明区边缘和中央区域的细胞贡献。前者似乎由源自胚壁的含卵黄细胞组成，而后者由源自胚胎背侧更深层的较小、含卵黄较少的细胞组成。在这些阶段，下层向前的移动似乎取决于更尾侧区域扩张组织对其施加的机械限制。根据阶段以及下层的有无，确定了这两种对下层贡献的程度，并结合现有文献对研究结果进行了讨论。
