INJECTED XWNT-8 RNA ACTS EARLY IN XENOPUS EMBRYOS TO PROMOTE FORMATION OF A VEGETAL DORSALIZING CENTER
INJECTED XWNT-8 RNA ACTS EARLY IN XENOPUS EMBRYOS TO PROMOTE FORMATION OF A VEGETAL DORSALIZING CENTER
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DOI：
10.1016/0092-8674(91)90070-f
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发表时间：
1991-11-15
期刊：
影响因子：
64.5
通讯作者：
HARLAND, RM
中科院分区：
文献类型：
--
作者：
SMITH, WC;HARLAND, RM
从原胚cdna库中克隆表达鉴定出Wnt家族成员Xwnt-8在爪蟾胚胎中具有诱导背轴的活性。微注射Xwnt-8 mRNA能够在暴露于紫外线下的胚胎中挽救背侧完整的前后轴的发育。在32细胞期注射边缘或植物卵裂球的胚胎均观察到轴诱导。接受Xwnt-8 mRNA的植物卵裂球的后代不是形成诱导的背轴，而是形成内胚层，这与Xwnt-8导致细胞充当Nieuwkoop中心（正常背轴形成的植物诱导成分）而不是Spemann组织者（直接形成背中胚层的诱导背边缘区成分）的结果一致。Xwnt-8通常在中原胚和神经胚中腹侧表达，当注射时，似乎模仿母体编码的在发育早期起作用的背中胚层诱导因子。
Expression cloning from a pool of gastrula cDNAs identified the Wnt family member Xwnt-8 as having dorsal axis-inducing activity in Xenopus embryos. Microinjected Xwnt-8 mRNA was able to rescue the development of a dorsally complete anterior-posterior axis in embryos ventralized by exposure to UV light. Axis induction was observed in embryos injected in either marginal or vegetal blastomeres at the 32-cell stage. Vegetal blastomeres receiving Xwnt-8 mRNA contributed progeny not to the induced dorsal axis, but to the endoderm, a result consistent with Xwnt-8 causing cells to act as a Nieuwkoop center (the vegetal-inducing component of normal dorsal axis formation), rather than as a Spemann organizer (the induced dorsal marginal zone component that directly forms the dorsal mesoderm). Xwnt-8, which is normally expressed ventrally in midgastrula and neurula embryos, appears to mimic, when injected, maternally encoded dorsal mesoderm-inducing factors that act early in development.