An early role for Sonic hedgehog from foregut endoderm in jaw development: Ensuring neural crest cell survival
An early role for Sonic hedgehog from foregut endoderm in jaw development: Ensuring neural crest cell survival
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DOI：
10.1073/pnas.0604751103
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发表时间：
2006-08-01
影响因子：
11.1
通讯作者：
Le Douarin, Nicole M.
中科院分区：
文献类型：
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作者：
Brito, Jose M.;Teillett, Marie-Aimee;Le Douarin, Nicole M.
我们通过在神经嵴细胞（NCC）迁移到第一鳃弓（BA1）之前剥夺鸡胚胎最前部的这种形态发生素来源，包括前脊索板和前肠的前腹侧内胚层，研究了声刺猬（Shh）在面部结构发育中的作用。整个前额，包括前肠内胚层，在5至10体节阶段（ss）被切除，这导致在7-ss之前进行手术时下颌缺失。如果胚胎在 8 至 10 秒时被剥夺了前额，那么它们随后就会被赋予较低的喙。在早期进行手术的胚胎中，NCC 正常迁移至 BA1，但数小时后发生大量细胞凋亡。后期进行前额切除时，没有发生细胞死亡。在这种情况下，腹侧前肠内胚层中Shh的向前表达向尾部延伸超过了切除极限，我们假设早期手术的胚胎中内胚层不产生Shh可能是导致NCC细胞凋亡和BA1发育失败的原因。因此，我们向 7-ss 之前进行手术的胚胎提供外源性 Shh。在这种情况下，下颌的发育得到了挽救。因此，源自腹侧前肠内胚层的Shh确保了NCC在BA1发育的关键阶段的存活。
We have investigated the role of Sonic hedgehog (Shh) in the development of facial structures by depriving chicken embryos of the most anterior sources of this morphogen, including the prechordal plate and the anterior ventral endoderm of the foregut, before the onset of neural crest cell (NCC) migration to the first branchial arch (BA1). The entire forehead, including the foregut endoderm, was removed at 5- to 10-somite stage (ss), which led to the absence of the lower jaw when the operation was performed before 7-ss. If the embryos were deprived of their forehead at 8- to 10-ss, they were later on endowed with a lower beak. In embryos that were operated on early, the NCCs migrated normally to BA1 but were subjected to massive apoptosis a few hours later. Cell death did not occur when forehead excision was performed at a later stage. In this case, onward expression of Shh in the ventral foregut endoderm extended caudally over the excision limit, and we hypothesized that absence of Shh production by the endoderm in embryos that were operated on early could be responsible, for the NCC apoptosis and the failure of BA1 development. We thus provided exogenous Shh to the embryos that were operated on before 7-ss. In this case, the development of the lower jaw was rescued. Therefore, Shh derived from the ventral foregut endoderm ensures the survival of NCCs at a critical stage of BA1 development.