Fukuda-Taira S
J Embryol Exp Morphol. 1981 Aug;64:73-85.
The location of the pre-hepatic cells which can respond to the inductive influence of the cardiac mesoderm and differentiate to the hepatic epithelium was investigated in quail embryos between the unincubated and 8-somite stages. These cells were found to exist in the whole area of the blastoderm of unincubated and prestreak stages. At the short-streak stage, just before the beginning of gastrulation, pre-hepatic cells are confined to the anterior part of the primitive streak. During gastrulation, prehepatic cells invaginate through this area of the primitive streak and enter the endoblastic layer. They are found in the anterior half of the endoblastic layer as well as in the lower half of the anterior part of the primitive streak at the medium- to definitive-streak stages. After gastrulation, they are consistently found only in the anterior half of the endoblastic layer. From the 1-somite stage, at least up to the 8-somite stage, the pre-hepatic cells are localized in the endoderm, anterior to the level of the 3rd somite. Since the pre-hepatic cells or their progenitors were always found within the definitive endoblast which invaginates from the epiblast during gastrulation, it can be presumed that the pre-hepatic cells originate from the epiblast, invaginate through the anterior part of the primitive streak between the short- and the definitive-streak stage, and enter the definitive endoblast.
在未孵化至8体节期的鹌鹑胚胎中，研究了能够响应心脏中胚层诱导影响并分化为肝上皮的肝前细胞的位置。发现这些细胞存在于未孵化和原条前期胚盘的整个区域。在原条前期，就在原肠胚形成开始之前，肝前细胞局限于原条的前部。在原肠胚形成期间，肝前细胞通过原条的这个区域内陷并进入内胚层。在中胚层至定形原条期，它们存在于内胚层的前半部分以及原条前部的下半部分。原肠胚形成后，它们始终仅存在于内胚层的前半部分。从1体节期开始，至少到8体节期，肝前细胞位于第3体节水平前方的内胚层中。由于肝前细胞或其祖细胞总是在原肠胚形成期间从外胚层内陷的确定内胚层内被发现，因此可以推测肝前细胞起源于外胚层，在原条前期至定形原条期之间通过原条前部内陷，并进入确定内胚层。
