Xenopus VegT RNA is localized to the vegetal cortex during oogenesis and encodes a novel T-box transcription factor involved in mesodermal patterning.
Xenopus VegT RNA is localized to the vegetal cortex during oogenesis and encodes a novel T-box transcription factor involved in mesodermal patterning.
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DOI：
10.1242/dev.122.12.4119
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发表时间：
1996-12
期刊：
影响因子：
4.6
通讯作者：
Jian Zhang;M. L. King
中科院分区：
文献类型：
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作者：
Jian Zhang;M. L. King
定位于非洲爪哇卵母细胞营养皮质的RNA编码一种新的T-box蛋白(Vegt)，它能在发育的不同时期诱导背侧或后腹侧中胚层。Vegt是一种核蛋白，其C-末端结构域可以在酵母报告实验中激活转录，观察到的结果与Vegt作为转录因子的作用一致。合子的表达沿着背腹轴是动态的，转录本首先在背缘区域表达。在原肠发育结束时，Vegt仅在后腹侧中胚层表达，而不在脊索中表达。后来的表达仅限于罗洪-比尔德细胞的一个子集，这是一种初级感觉神经元。在动物帽子分析中，Vegt能够将预期的外胚层转化为腹侧中胚层。Vegt的这种异位表达诱导了其自身的表达，同时也诱导了Xwnt-8在CAPS中的表达，提示可能参与了Wnt途径。VEGET在动物背部卵裂球中的错误表达注定会有助于大脑抑制头部的形成。我们的结果表明，Vegt是一种局部转录因子，在胚胎发育过程中依次在几个发育途径中发挥作用，包括中胚层的背腹和后方模式。
An RNA localized to the vegetal cortex of Xenopus oocytes encodes a novel T-box protein (VegT) capable of inducing either dorsal or posterior ventral mesoderm at different times in development. VegT is a nuclear protein and its C-terminal domain can activate transcription in a yeast reporter assay, observations consistent with VegT functioning as a transcription factor. Zygotic expression is dynamic along the dorsoventral axis, with transcripts first expressed in the dorsal marginal zone. By the end of gastrulation, VegT is expressed exclusively in posterior ventral and lateral mesoderm and is excluded from the notochord. Later expression is confined to a subset of Rohon-Beard cells, a type of primary sensory neuron. In animal cap assays, VegT is capable of converting prospective ectoderm into ventral lateral mesoderm. Such ectopic expression of VegT induces its own expression as well as that of Xwnt-8 in caps, suggesting that a Wnt pathway may be involved. Mis-expression of VegT in dorsal animal blastomeres fated to contribute to brain suppresses head formation. Our results suggest that VegT is a localized transcription factor, which operates sequentially in several developmental pathways during embryogenesis, including dorsoventral and posterior patterning of mesoderm.