| 论文摘要： |
Pharyngeal endoderm cells undergo convergence and extension (C&E), which is essential for endoderm pouch formation and craniofacial development. Our previous work implicates G alpha(13)/RhoAmediated signaling in regulating this process, but the underlying mechanisms remain unclear. Here, we have used endoderm-specific transgenic and G alpha(13) mutant zebrafish to demonstrate that G alpha(13) plays a crucial role in pharyngeal endoderm C&E by regulating RhoA activation and E-cadherin expression. We showed that during C&E, endodermal cells gradually establish stable cell-cell contacts, acquire apical-basal polarity and undergo actomyosin-driven apical constriction, which are processes that require G alpha(13). Additionally, we found that G alpha(13)-deficient embryos exhibit reduced E-cadherin expression, partially contributing to endoderm C&E defects. Notably, interfering with RhoA function disrupts spatial actomyosin activation without affecting E-cadherin expression. Collectively, our findings identify crucial cellular processes for pharyngeal endoderm C&E and reveal that G alpha(13) controls this through two independent pathways - modulating RhoA activation and regulating E-cadherin expression - thus unveiling intricate mechanisms governing pharyngeal endoderm morphogenesis. |
