Morphological left-right asymmetry of Hensen's node precedes the asymmetric expression of Shh and Fgf8 in the chick embryo
Morphological left-right asymmetry of Hensen's node precedes the asymmetric expression of Shh and Fgf8 in the chick embryo
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DOI：
10.1007/s00429-002-0269-2
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发表时间：
2002-10-01
期刊：
影响因子：
--
通讯作者：
Christ, B
中科院分区：
文献类型：
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作者：
Dathe, V;Gamel, A;Christ, B
应用扫描电镜、半薄切片和整体原位杂交技术，对HH 4-7期鸡胚的Hensen结和原条吻端部分进行了研究。Shh和Fgf 8的不对称表达首次发现于HH-5期。这两个偏侧基因的不对称表达之前的鸟类组织者的不对称形态。条纹和节的右唇比左唇突出得多，包含与头突相连的圆柱形细胞凝聚。由于密集的细胞在亨森结和原始条纹的头部连接上胚层与内胚层，纤毛产生的“节点流”之间的上胚层和内胚层的鸟类胚胎似乎是不可能的。
Hensen's node and the rostral part of the primitive streak of chick embryos at HH-stage 4-7 were investigated using scanning electron microscopy, a series of semithin sections, and whole-mount in situ hybridization. An asymmetric expression of Shh and Fgf8 was first found at HH-stage 5. The asymmetric expression of both laterality genes is preceded by an asymmetric morphology of the avian organizer. The right lip of the streak and the node is much more prominent than the left one and contains a cylindrical cell condensation that is connected with the head process. Since the densely packed cells in Hensen's node and in the cranial part of the primitive streak connect the epiblast with the endoderm, a cilia-generated "nodal flow" between epiblast and endoderm in the avian embryo seems to be unlikely.