Mesoderm induction in Xenopus is a zygotic event regulated by maternal VegT via TGFbeta growth factors.
Mesoderm induction in Xenopus is a zygotic event regulated by maternal VegT via TGFbeta growth factors.
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发表时间：
1999-12
期刊：
影响因子：
4.6
通讯作者：
M. Kofron;Teresa Demel;Jennifer B. Xanthos;J. Lohr;B. Sun;H. Sive;S. Osada;C. V. Wright;C. Wylie;J. Heasman
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作者：
M. Kofron;Teresa Demel;Jennifer B. Xanthos;J. Lohr;B. Sun;H. Sive;S. Osada;C. V. Wright;C. Wylie;J. Heasman
母源转录因子VegT在非洲爪蟾初级胚层的形成中起重要作用。在以前的工作中，我们发现，缺乏母体VegT的胚胎的植物群不产生中胚层诱导信号，并且这些胚胎中的中胚层形成发生异位，从植物区而不是囊胚的赤道区。在这里，我们提高了效率的母亲VegT mRNA的耗竭，并研究了中胚层形成的影响。我们发现，母亲的VegT是需要形成90%的中胚层组织，测量中胚层标记物MyoD，心脏肌动蛋白，Xbra，Xwnt 8和α T4珠蛋白的表达。此外，FGF和TGF β，Xnr 1，Xnr 2，Xnr 4和derrière的转录在VegT耗尽的胚胎中不发生。我们测试这些生长因子是否可能是内源性因素中胚层诱导，通过研究他们的能力，拯救的表型的VegT-耗尽的胚胎，当他们的表达被限制在植物质量。我们发现，Xnr 1，Xnr 2，Xnr 4和derrière mRNA都拯救中胚层的形成，以及囊胚孔和野生型体轴的形成。Derrière拯救躯干和尾巴，而nr 1，nr 2和nr 4拯救头部，躯干和尾巴。我们的结论是中胚层诱导非洲爪蟾依赖于一个母亲的转录因子调节这些合子生长因子。
The maternal transcription factor VegT is important for establishing the primary germ layers in Xenopus. In previous work, we showed that the vegetal masses of embryos lacking maternal VegT do not produce mesoderm-inducing signals and that mesoderm formation in these embryos occurred ectopically, from the vegetal area rather than the equatorial zone of the blastula. Here we have increased the efficiency of the depletion of maternal VegT mRNA and have studied the effects on mesoderm formation. We find that maternal VegT is required for the formation of 90% of mesodermal tissue, as measured by the expression of mesodermal markers MyoD, cardiac actin, Xbra, Xwnt8 and alphaT4 globin. Furthermore, the transcription of FGFs and TGFbetas, Xnr1, Xnr2, Xnr4 and derrière does not occur in VegT-depleted embryos. We test whether these growth factors may be endogenous factors in mesoderm induction, by studying their ability to rescue the phenotype of VegT-depleted embryos, when their expression is restricted to the vegetal mass. We find that Xnr1, Xnr2, Xnr4 and derrière mRNA all rescue mesoderm formation, as well as the formation of blastopores and the wild-type body axis. Derrière rescues trunk and tail while nr1, nr2 and nr4 rescue head, trunk and tail. We conclude that mesoderm induction in Xenopus depends on a maternal transcription factor regulating these zygotic growth factors.