Regional specification of the endoderm in the early chick embryo
Regional specification of the endoderm in the early chick embryo
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DOI：
10.1111/j.1440-169x.2007.00933.x
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发表时间：
2007-06-01
影响因子：
2.5
通讯作者：
Fukuda, Kimiko
中科院分区：
文献类型：
--
作者：
Kimura, Wataru;Yasugi, Sadao;Fukuda, Kimiko
在鸟类胚胎中，内胚层在原肠胚形成后形成一个简单的扁平结构，沿着前后轴和背腹轴逐渐在区域上指定，并最终分化为具有明确形态和基因表达谱的特定器官。在我们的研究中，我们用早期的鸡胚胎进行移植实验，以阐明命运在内胚层建立的时间。我们发现，在第5期，后移植的推定前肠内胚层表达CdxA（后内胚层标记物），但不表达cSox2（前内胚层标记物）。相反，前移植的推定中后肠内胚层表达cSox2而不表达CdxA。在第8期，后移植的推定前肠内胚层也表达CdxA而不表达cSox2，但前移植的推定中后肠内胚层的后特异性基因表达模式没有变化。在第10期，前后移植的前肠内胚层和前移植的中后肠内胚层均保持原有的基因表达模式。这些结果表明，内胚层的区域规格发生在前肠的第8期和第10期之间，以及中后肠的第5期和第8期之间。
In the avian embryo, the endoderm, which forms a simple flat-sheet structure after gastrulation, is regionally specified in a gradual manner along the antero-posterior and dorso-ventral axes, and eventually differentiates into specific organs with defined morphologies and gene expression profiles. In our study, we carried out transplantation experiments using early chick embryos to elucidate the timing of fate establishment in the endoderm. We showed that at stage 5, posteriorly grafted presumptive foregut endoderm expressed CdxA, a posterior endoderm marker, but not cSox2, an anterior endoderm marker. Conversely, anteriorly grafted presumptive mid-hindgut endoderm expressed cSox2 but not CdxA. At stage 8, posteriorly grafted presumptive foregut endoderm also expressed CdxA and not cSox2, but anteriorly grafted presumptive mid-hindgut endoderm showed no changes in its posterior-specific gene expression pattern. At stage 10, both posteriorly grafted foregut endoderm and anteriorly grafted mid-hindgut endoderm maintain their original gene expression patterns. These results suggest that the regional specification of the endoderm occurs between stages 8 and 10 in the foregut, and between stages 5 and 8 in the mid-hindgut.