Expression of a dominant-negative Wnt blocks induction of MyoD in Xenopus embryos
Expression of a dominant-negative Wnt blocks induction of MyoD in Xenopus embryos
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DOI：
10.1101/gad.10.21.2805
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发表时间：
1996-11-01
影响因子：
10.5
通讯作者：
Moon, RT
中科院分区：
文献类型：
--
作者：
Hoppler, S;Brown, JD;Moon, RT
在非洲爪蟾胚胎的原肠胚形成过程中，预期的中胚层最初由背侧和腹侧命运的区域诱导，然后通过来自原肠胚组织者的信号进一步形成闪族中胚层。尽管 Xwnt-8 在未来的腹外侧中胚层中表达，并诱导未来表皮在体外分化为腹侧中胚层，但没有功能丧失研究表明原肠胚中中胚层基因的正常表达需要 Wnt 信号传导。我们报告了显性失活 Wnt (dnXwnt-8) 的发展，它以细胞非自主方式抑制胚胎对 Wnt 信号传导的反应。通过在非洲爪蟾胚胎中表达 dnXwnf-8，我们发现了 Wnt 信号传导在 XMyoDa 和非洲爪蟾后部 (Xpo) 预期中胚层中局部表达的需要。由于功能性 Xwnt-8 在原肠胚背侧边缘区的异位表达会诱导异位 XMyoDa 和 Xpo，因此功能获得和功能丧失实验都支持这样的模型：内源性 Xwnt-8 具有诱导参与腹侧和闪族中胚层规范的基因表达的模型。
During gastrulation of Xenopus embryos the prospective mesoderm is induced initially with domains of dorsal and ventral fate, then further patterned to generate semitic mesoderm by signals from the gastrula organizer. Although Xwnt-8 is expressed in future ventrolateral mesoderm and induces prospective epidermis to differentiate in vitro as ventral mesoderm, no loss-of-function studies have demonstrated a requirement for Wnt signaling for the normal expression of mesodermal genes in the gastrula. We report development of a dominant-negative Wnt (dnXwnt-8) that inhibits embryonic responses to Wnt signaling in a cell-nonautonomous fashion. By expressing dnXwnf-8 in Xenopus embryos, we uncover a requirement of Wnt signaling for localized expression in prospective mesoderm of XMyoDa and Xenopus-posterior (Xpo). Because ectopic expression of functional Xwnt-8 in the dorsal marginal zone of the gastrula induces ectopic XMyoDa and Xpo, both gain-of-function and loss-of-function experiments support a model in which endogenous Xwnt-8 functions to induce expression of genes involved in specification of ventral and semitic mesoderm.