BMP, Wnt and FGF signals are integrated through evolutionarily conserved enhancers to achieve robust expression of Pax3 and Zic genes at the zebrafish neural plate border
BMP, Wnt and FGF signals are integrated through evolutionarily conserved enhancers to achieve robust expression of Pax3 and Zic genes at the zebrafish neural plate border
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DOI：
10.1242/dev.081497
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发表时间：
2012-11-15
期刊：
影响因子：
4.6
通讯作者：
Medeiros, Daniel M.
中科院分区：
文献类型：
--
作者：
Garnett, Aaron T.;Square, Tyler A.;Medeiros, Daniel M.
神经嵴细胞在脊椎动物的头部和躯干中产生一系列细胞和组织，包括周围神经元、色素细胞和软骨。神经嵴细胞起源于新生中枢神经系统的边缘，这一区域被称为神经板边界（NPB）。已知NPB诱导涉及BMP、Wnt和FGF信号通路。然而，对于这些信号如何整合以实现NPB细胞中基因的时间和空间特异性表达知之甚少。此外，这些信号在NPB形成中的时间和相对重要性似乎在脊椎动物物种之间有所不同。在这里，我们使用热休克过表达和化学抑制剂来确定BMP、Wnt和FGF信号是否以及何时需要在斑马鱼中表达NPB指示物pax3a和zic3。然后，我们从pax3a和zic3基因座中鉴定了四个进化上保守的增强子，并测试了它们对BMP、Wnt和FGF扰动的反应。我们发现，在斑马鱼NPB中，所有三个信号通路都是原肠胚形成过程中pax3a和zic3正确表达所必需的。我们还发现，尽管pax3a和zic3增强子驱动的表达模式在很大程度上重叠，但它们对BMP、Wnt和FGF信号的不同组合做出反应。最后，我们发现两个pax3a增强子的组合比单独的增强子更不容易受到信号扰动的影响。综上所述，我们的研究结果揭示了bmp、fgf和wnt如何通过部分冗余的增强子协同和冗余地发挥作用，从而在斑马鱼NPB中实现稳健的、特异性的基因表达。
Neural crest cells generate a range of cells and tissues in the vertebrate head and trunk, including peripheral neurons, pigment cells, and cartilage. Neural crest cells arise from the edges of the nascent central nervous system, a domain called the neural plate border (NPB). NPB induction is known to involve the BMP, Wnt and FGF signaling pathways. However, little is known about how these signals are integrated to achieve temporally and spatially specific expression of genes in NPB cells. Furthermore, the timing and relative importance of these signals in NPB formation appears to differ between vertebrate species. Here, we use heat-shock overexpression and chemical inhibitors to determine whether, and when, BMP, Wnt and FGF signaling are needed for expression of the NPB specifiers pax3a and zic3 in zebrafish. We then identify four evolutionarily conserved enhancers from the pax3a and zic3 loci and test their response to BMP, Wnt and FGF perturbations. We find that all three signaling pathways are required during gastrulation for the proper expression of pax3a and zic3 in the zebrafish NPB. We also find that, although the expression patterns driven by the pax3a and zic3 enhancers largely overlap, they respond to different combinations of BMP, Wnt and FGF signals. Finally, we show that the combination of the two pax3a enhancers is less susceptible to signaling perturbations than either enhancer alone. Taken together, our results reveal how BMPs, FGFs and Wnts act cooperatively and redundantly through partially redundant enhancers to achieve robust, specific gene expression in the zebrafish NPB.