Skromne Isaac, Stern Claudio D
Department of Genetics and Development, College of Physicians and Surgeons of Columbia University, 701 West 168th Street, New York, NY 10032, USA.
Mech Dev. 2002 Jun;114(1-2):115-8. doi: 10.1016/s0925-4773(02)00034-5.
In the chick embryo, two secreted factors have recently be shown to cooperate in inducing the first axial structure, the primitive streak: cWnt8C (normally expressed around the circumference of the embryo, in the marginal zone) and the TGF beta superfamily member cVg1 (expressed in the posterior part of the marginal zone) (Development 128 (2001) 2915). Misexpression of Vg1 in the anterior marginal zone induces an ectopic primitive streak and recapitulates the morphological changes associated with normal primitive streak formation. Here, we analyse the time-course of appearance and disappearance of expression of 12 genes (cVg1, Lef1, Nodal, FGF8, cWnt8C, cBra, cNot1, goosecoid, HNF3 beta, Chordin, Otx2 and Sox3, whose normal expression is also polarized at early stages of development) in response to cVg1 misexpression in the anterior marginal zone. We show that a hierarchy of gene expression accompanies induction of the ectopic axis, reminiscent of the order in which the same genes begin to be expressed in the normal embryo.
在鸡胚中，最近有研究表明两种分泌因子协同诱导了首个轴向结构——原条的形成：cWnt8C（通常在胚胎周边的边缘区表达）和TGFβ超家族成员cVg1（在边缘区后部表达）（《发育》128卷（2001年）第2915页）。Vg1在前边缘区的异位表达会诱导异位原条的形成，并重现与正常原条形成相关的形态学变化。在此，我们分析了12个基因（cVg1、Lef1、Nodal、FGF8、cWnt8C、cBra、cNot1、鹅膏蕈氨酸、HNF3β、脊索蛋白、Otx2和Sox3，它们在发育早期的正常表达也呈极化状态）在响应前边缘区cVg1异位表达时表达出现和消失的时间进程。我们发现基因表达的层次结构伴随着异位轴的诱导，这让人想起这些相同基因在正常胚胎中开始表达的顺序。
