Sokol S, Melton D A
Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, Massachusetts 02138.
Nature. 1991 May 30;351(6325):409-11. doi: 10.1038/351409a0.
Activin, a peptide growth factor related to tumour growth factor-beta, has been implicated in early inductive interactions in vertebrates and can induce Xenopus blastula ectodermal explants to develop a rudimentary axial pattern with anteroposterior and dorsoventral polarity. Here we demonstrate that prospective dorsal and ventral regions of the ectoderm respond differently to the same concentration of activin. Thus, activin does not seem to endow ectodermal cells with polarity but rather reveals a pre-existent pattern. Our results suggest that patterning of mesoderm is determined not only by a localized inducer, but also by the differential competence of cells in the responding tissue.
激活素是一种与肿瘤生长因子-β相关的肽生长因子，它参与了脊椎动物早期的诱导性相互作用，并且能够诱导非洲爪蟾囊胚期外胚层外植体发育出具有前后和背腹极性的基本轴向模式。在此，我们证明外胚层预期的背侧和腹侧区域对相同浓度的激活素反应不同。因此，激活素似乎并未赋予外胚层细胞极性，而是揭示了一种预先存在的模式。我们的结果表明，中胚层的模式形成不仅由局部诱导物决定，还由反应组织中细胞的不同感受态决定。
