Smithers Lucy E, Jones C Michael
Section of Gene Function and Regulation, Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK.
Mech Dev. 2002 Dec;119(2):191-200. doi: 10.1016/s0925-4773(02)00361-1.
Two regions expressing Hex in the early gastrula contribute to organizing the anterior of the vertebrate embryo. In Xenopus, these include the anterior yolky endoderm and the suprablastoporal endoderm (SBE), which is fated to form the epithelial lining of the gut. These tissues may correspond to the anterior visceral endoderm and anterior definitive endoderm of amniotes. Genetic studies in mice have demonstrated the important roles of these tissues in producing anterior identity in the adjacent neural ectoderm. In Xenopus, both the anterior endoderm and the SBE have anterior inducing properties; furthermore, the SBE can organize a full anterior-posterior axis. Inhibition of Xhex function shows that both these Xhex-expressing endodermal tissues are required for anterior development in Xenopus.
原肠胚早期表达Hex的两个区域有助于构建脊椎动物胚胎的前部。在非洲爪蟾中，这些区域包括前侧卵黄内胚层和原口背侧内胚层（SBE），后者注定会形成肠道的上皮内衬。这些组织可能与羊膜动物的前侧脏壁内胚层和前侧定形内胚层相对应。小鼠的遗传学研究表明，这些组织在相邻神经外胚层产生前部特征方面发挥着重要作用。在非洲爪蟾中，前侧内胚层和SBE都具有前部诱导特性；此外，SBE能够构建完整的前后轴。对Xhex功能的抑制表明，非洲爪蟾的前部发育需要这两个表达Xhex的内胚层组织。
