Sox3 expression is maintained by FGF signaling and restricted to the neural plate by Vent proteins in the Xenopus embryo
Sox3 expression is maintained by FGF signaling and restricted to the neural plate by Vent proteins in the Xenopus embryo
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DOI：
10.1016/j.ydbio.2007.10.023
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发表时间：
2008-01-01
影响因子：
2.7
通讯作者：
Casey, Elena M. Silva
中科院分区：
文献类型：
--
作者：
Rogers, Crystal D.;Archer, Tenley C.;Casey, Elena M. Silva
神经系统的形成始于外胚层细胞接受神经命运。对非洲爪蟾的研究表明，抑制BMP会导致神经组织的形成。然而，驱动早期神经基因表达以响应这种抑制的分子机制尚不清楚。此外，关于BMP抑制神经诱导的充分性仍存在争议。为了解决这些问题，我们对soxB1基因sox3的调控进行了详细的分析，sox3是神经外胚层中最早表达的基因之一。通过外胚层外植体实验，我们分析了BMP、Wnt和FGF信号在sox3及其密切相关的soxB1基因sox2的调控中的作用。我们的研究结果表明，sox3和sox2都能被诱导响应BMP拮抗，但通过不同的机制，这两个基因的激活都独立于FGF信号传导。然而，两者都需要FGF来维持其表达。最后，鉴定和表征了sox3基因组元件，并通过转基因和计算分析鉴定了通过Vent蛋白介导的bmp抑制所需的元件。有趣的是，sox2基因座中没有鉴定出sox3表达所需的元件。我们的数据表明，两个密切相关的基因在神经发育开始时具有独特的基因调控机制。(c) 2007爱思唯尔公司版权所有。
The formation of the nervous system is initiated when ectodermal cells adopt the neural fate. Studies in Xenopus demonstrate that inhibition of BMP results in the formation of neural tissue. However, the molecular mechanism driving the expression of early neural genes in response to this inhibition is unknown. Moreover, controversy remains regarding the sufficiency of BMP inhibition for neural induction. To address these questions, we performed a detailed analysis of the regulation of the soxB1 gene, sox3, one of the earliest genes expressed in the neuroectoderm. Using ectodermal explant assays, we analyzed the role of BMP, Wnt and FGF signaling in the regulation of sox3 and the closely related soxB1 gene, sox2. Our results demonstrate that both sox3 and sox2 are induced in response to BMP antagonism, but by distinct mechanisms and that the activation of both genes is independent of FGF signaling. However, both require FGF for the maintenance of their expression. Finally, sox3 genomic elements were identified and characterized and an element required for BMP-mediated repression via Vent proteins was identified through the use of transgenesis and computational analysis. Interestingly, none of the elements required for sox3 expression were identified in the sox2 locus. Together our data indicate that two closely related genes have unique mechanisms of gene regulation at the onset of neural development. (c) 2007 Elsevier Inc. All rights reserved.