A gene network that coordinates preplacodal competence and neural crest specification in zebrafish
A gene network that coordinates preplacodal competence and neural crest specification in zebrafish
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DOI：
10.1016/j.ydbio.2012.10.012
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发表时间：
2013-01-01
影响因子：
2.7
通讯作者：
Riley, Bruce B.
中科院分区：
文献类型：
--
作者：
Bhat, Neha;Kwon, Hye-Joo;Riley, Bruce B.
前基板外胚层（PPE）和神经嵴（NC）位于神经外胚层和非神经外胚层的交界处，共同参与所有脊椎动物的外周神经系统。Bmp在囊胚晚期激活两种命运的早期步骤。低Bmp激活转录因子Tfap2a和Tfap2c在外侧神经板中的表达，从而指定神经嵴命运。升高的BMP通过共诱导Tfap2a、Tfap2c、Foxi1和Gata3在整个腹侧外胚层建立前基板能力。PPE规范发生在原肠胚形成结束后，需要完全衰减的BMP，但PPE能力因子的表达继续过去原肠胚形成。在这里，我们表明，能力因素积极调节彼此的表达在原肠胚形成，形成一个自我维持的网络，独立运作的BMP。在囊胚晚期阻断BMP的胚胎中Tfap2a的错误表达可以恢复PPE和NC的发育。然而，单独的Tfap2a不足以激活任何其他感受态因子，也不拯救个体基板。另一方面，在Bmp阻断的胚胎中，任何两个感受态因子的错误表达都可以激活整个转录因子网络，并支持NC、PPE和一些个体基板的发育。我们还表明，虽然这些因素是部分冗余的PPE规范，他们后来提供非冗余的功能需要开发特定的基板。因此，我们已经确定了一个基因调控网络，协调发展的NC，PPE和个人基板在斑马鱼。(C)2012 Elsevier Inc. All rights reserved.
Preplacodal ectoderm (PPE) and neural crest (NC) are specified at the interface of neural and nonneural ectoderm and together contribute to the peripheral nervous system in all vertebrates. Bmp activates early steps for both fates during late blastula stage. Low Bmp activates expression of transcription factors Tfap2a and Tfap2c in the lateral neural plate, thereby specifying neural crest fate. Elevated Bmp establishes preplacodal competence throughout the ventral ectoderm by coinducing Tfap2a, Tfap2c, Foxi1 and Gata3. PPE specification occurs later at the end of gastrulation and requires complete attenuation of Bmp, yet expression of PPE competence factors continues well past gastrulation. Here we show that competence factors positively regulate each other's expression during gastrulation, forming a self-sustaining network that operates independently of Bmp. Misexpression of Tfap2a in embryos blocked for Bmp from late blastula stage can restore development of both PPE and NC. However, Tfap2a alone is not sufficient to activate any other competence factors nor does it rescue individual placodes. On the other hand, misexpression of any two competence factors in Bmp-blocked embryos can activate the entire transcription factor network and support the development of NC, PPE and some individual placodes. We also show that while these factors are partially redundant with respect to PPE specification, they later provide non-redundant functions needed for development of specific placodes. Thus, we have identified a gene regulatory network that coordinates development of NC, PPE and individual placodes in zebrafish. (C) 2012 Elsevier Inc. All rights reserved.