Regionalisation of early head ectoderm is regulated by endoderm and prepatterns the orofacial epithelium
Regionalisation of early head ectoderm is regulated by endoderm and prepatterns the orofacial epithelium
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DOI：
10.1242/dev.01337
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发表时间：
2004-10-01
期刊：
影响因子：
4.6
通讯作者：
Sharpe, PT
中科院分区：
文献类型：
--
作者：
Haworth, KE;Healy, C;Sharpe, PT
口腔上皮在发育的早期就变得区域化，这反映在信号分子如Fgf 8和Bmp 4的空间表达上。这种区域化负责调节底层间充质中基因的空间表达。这些基因是骨骼、软骨口面发育和哺乳动物牙齿的空间模式所必需的。头部上皮发育过程中这种重要区域化的机制和时间尚不清楚。使用亲脂性染料的命运映射鸡胚口腔上皮，我们表明，细胞，将占据的远端和近端的下颌骨原基的上皮细胞已经占据不同的空间位置，在发育中的头部外胚层形成的第一咽弓和神经嵴迁移之前。此外，注定成为近端口腔上皮的外胚层细胞表达Fgf 8，并且这种表达需要内胚层的存在。因此，在颌骨形态发生的第一个基本的图案化过程是由外胚层的特定区域的早期分离，由外胚层-内胚层相互作用调节，并不涉及神经嵴细胞控制。
The oral epithelium becomes regionalised proximodistally early in development, and this is reflected by the spatial expression of signalling molecules such as Fgf8 and Bmp4. This regionalisation is responsible for regulating the spatial expression of genes in the underlying mesenchyme. These genes are required for the spatial patterning of bone, cartilage orofacial development and, in mammals, teeth. The mechanism and timing of this important regionalisation during head epithelium development are not known. Using lipophilic dyes to fate map the oral epithelium in chick embryos, we show that the cells that will occupy the epithelium of the distal and the proximal mandible primordium already occupy different spatial locations in the developing head ectoderm prior to the formation of the first pharyngeal arch and neural crest migration. Moreover, the ectoderm cells fated to become proximal oral epithelium express Fgf8 and this expression requires the presence of endoderm. Thus, the first fundamental patterning process in jaw morphogenesis is controlled by the early separation of specific areas of ectoderm that are regulated by ectoderm-endoderm interactions, and does not involve neural crest cells.