Tfap2 transcription factors in zebrafish neural crest development and ectodermal evolution
Tfap2 transcription factors in zebrafish neural crest development and ectodermal evolution
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DOI：
10.1002/jez.b.21189
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发表时间：
2007-09-15
影响因子：
2.2
通讯作者：
Schilling, Thomas F.
中科院分区：
文献类型：
--
作者：
Hoffman, Trevor L.;Javier, Anna L.;Schilling, Thomas F.
转录因子AP 2（Tfap 2）基因在脊椎动物胚胎表皮和神经嵴迁移细胞的发育中起重要作用。这些转录激活因子是外胚层中最早表达的基因之一，并通过直接和间接机制指定表皮/嵴内的命运。Tfap 2家族起源于脊索动物祖先中的一个祖先基因，该基因经历了基因复制，在活的脊椎动物中放弃了多达五个家族成员。这与Tfap 2基因在NC发育中的重要作用相吻合，表明该基因家族在外胚层进化中很重要，并可能在NC的起源中。在这里，我们表明，斑马鱼tfap 2c在非神经外胚层在早期发展和功能冗余与tfap 2a在NC规范。在耗尽tfap 2a和tfap 2c的斑马鱼胚胎中，NC细胞几乎被消除。细胞移植实验表明，tfap 2c功能细胞自主的NC规范。在tfap 2c缺陷的胚胎中，形成围绕外胚层的临时皮肤层的包被层的细胞也不能分化或表达适当的角蛋白。Tfap 2基因在表皮和NC发展中的作用被认为是在更广泛的背景下外胚层进化。Tfap 2基因在不同脊椎动物中的不同组织特异性功能可能反映了祖先基因的亚功能化，从而导致不同亚家族成员在表皮和NC模式中获得新的角色。
Transcription factor AP2 (Tfap2) genes play essential roles in development of the epidermis and migratory cells of the neural crest (NC) in vertebrate embryos. These transcriptional activators are among the earliest genes expressed in the ectoderm and specify fates within the epidermis/crest through both direct and indirect mechanisms. The Tfap2 family arose from a single ancestral gene in a chordate ancestor that underwent gene duplication to give up to five family members in living vertebrates. This coincided with the acquisition of important roles in NC development by Tfap2 genes suggesting that this gene family was important in ectodermal evolution and possibly in the origin of NC. Here, we show that a zebrafish tfap2c is expressed in the nonneural ectoderm during early development and functions redundantly with tfap2a in NC specification. In zebrafish embryos depleted of both tfap2a and tfap2c, NC cells are virtually eliminated. Cell transplantation experiments indicate that tfap2c functions cell-autonomously in NC specification. Cells of the enveloping layer, which forms a temporary skin layer surrounding the ectoderm, also fail to differentiate or to express appropriate keratins in tfap2c deficient embryos. The role of Tfap2 genes in epidermal and NC development is considered here in the broader context of ectodermal evolution. Distinct, tissue-specific functions for Tfap2 genes in different vertebrates may reflect subfunctionalisation of an ancestral gene that consequently led to the gain of novel roles for different subfamily members in patterning the epidermis and NC.