中文摘要：

上皮细胞间形成的Adherensjunctions复合物通过E—cadherin胞质区段，经由catenin家族蛋白介导，与细胞中微丝骨架系统（micrOfilament）相互作用，参与控制细胞极性、迁移，发育中的形态建成运动以及组织稳态维持等重要生命现象。多方面实验证据表明，cadherin复合物与微丝骨架系统的相互作用是高度动态的；作者前期的工作发现，在非洲爪蛙早期胚胎中，经典cadherin（C-cadherin）在细胞膜上的表达量决定细胞中微丝骨架合成总量。该研究进一步提供实验证据，表明随着囊胚期细胞增殖的进行，囊胚中期以后，细胞表面c—cadherin逐步富集，相应地细胞中微丝骨架的合成量也增加。我们还通过细胞解聚，C-cadherin敲降和过量表达，以及c-cadherin与F-actin共定位分析等实验验证在囊胚期外胚层细胞中，细胞膜C—cadherin表达量与细胞微丝骨架的合成量高度正相关。

英文摘要：

Both classical cadherins and cortical F-actin are involved in the control of multiple aspects of cellular function. The dynamic interaction between cadherin complex and cortical F-actin is critical for the homeo- stasis of epithelial tissues and the morphogenetic movements during embryogenesis. Our previous work showed that cadherin complex on the cell surface can actively promote cortical F-actin assembly and the expression level of C-cadherin on the cell surface of the primary ectoderm of Xenopus blastula determines the amount of cortical F-actin assembly. In this study we demonstrate that the cortical F-actin assembly is dramatically increased in the late blas- tula compared to the early blastula, and this increase is highly correlated with the accumulation of C-cadherin on the cell surface during Xenopus blastula formation. By depleting the maternally stored C-cadherin and dissociating the animal caps at late blastula stage, we show the reduction of the expression level of C-cadherin on the cell sur- face resulted in the decrease of cortical F-actin assembly. These results further support our hypothesis that cortical F-actin assembly in the early Xenopus embryo is largely controlled by the expression level of C-cadherin on the cell surface.