The C. elegans pharynx: a model for organogenesis.
The C. elegans pharynx: a model for organogenesis.
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DOI：
10.1895/wormbook.1.129.1
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发表时间：
2007-01
期刊：
影响因子：
--
通讯作者：
S. Mango
中科院分区：
文献类型：
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作者：
S. Mango
秀丽隐杆线虫的前肠（咽）已成为研究胚胎发生过程中器官形成的一个强大系统。在这里，我回顾了咽发育过程中细胞命运规范和上皮形态发生的最新进展。母体提供的基因产物在原肠胚形成之前起作用，建立多能性卵裂球。随着原肠形成的进行，咽部前体参与咽部命运，这一过程需要pa -4/FoxA和Tbox转录因子TBX-2、TBX-35、TBX-37和TBX-38。随后的基因表达依赖于PHA-4对其目标启动子的亲和力，再加上前馈和正反馈回路等组合策略。在胚胎发生后期，咽前体经历重组和间质到上皮的转变，形成线性肠管。令人惊讶的是，上皮的形成并不依赖于钙粘蛋白、连环蛋白或整合蛋白。相反，驱动蛋白ZEN-4/MKLP1和CYK-4/RhoGAP在上皮极化过程中对建立顶端结构域至关重要。最后，我讨论了线虫咽和脊椎动物心脏之间的异同。
The C. elegans foregut (pharynx) has emerged as a powerful system to study organ formation during embryogenesis. Here I review recent advances regarding cell-fate specification and epithelial morphogenesis during pharynx development. Maternally-supplied gene products function prior to gastrulation to establish pluripotent blastomeres. As gastrulation gets under way, pharyngeal precursors become committed to pharyngeal fate in a process that requires PHA-4/FoxA and the Tbox transcription factors TBX-2, TBX-35, TBX-37 and TBX-38. Subsequent waves of gene expression depend on the affinity of PHA-4 for its target promoters, coupled with combinatorial strategies such as feed-forward and positive-feedback loops. During later embryogenesis, pharyngeal precursors undergo reorganization and a mesenchymal-to-epithelial transition to form the linear gut tube. Surprisingly, epithelium formation does not depend on cadherins, catenins or integrins. Rather, the kinesin ZEN-4/MKLP1 and CYK-4/RhoGAP are critical to establish the apical domain during epithelial polarization. Finally, I discuss similarities and differences between the nematode pharynx and the vertebrate heart.