College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China.
Microsc Microanal. 2013 Jun;19(3):559-64. doi: 10.1017/S1431927613000032. Epub 2013 Apr 4.
During mitosis nucleation-promoting factors (NPFs) bind to the Arp2/3 complex and activate actin assembly. JMY and WAVE2 are two critical members of the NPFs. Previous studies have demonstrated that NPFs promote multiple processes such as cell migration and cytokinesis. However, the role of NPFs in development of mammalian embryos is still unknown. Results of the present study show that the NPFs JMY and WAVE2 are critical for cytokinesis during development of mouse embryos. Both JMY and WAVE2 are expressed in mouse embryos. After injection of JMY or WAVE2 siRNA, all embryos failed to develop to the morula or blastocyst stages. Moreover, using fluorescence intensity analysis, we found that the expression of actin decreased, and multiple nuclei were observed within a single cell indicating that NPFs-induced actin reduction caused the failure of cell division. In addition, injection of JMY and WAVE2 siRNA also caused ARP2 degradation, indicating that involvement of NPFs in development of mouse embryos is mainly through regulation of ARP2/3-induced actin assembly. Taken together, these data suggested that WAVE2 and JMY are involved in development of mouse embryos, and their regulation may be through a NPFs-Arp2/3-actin pathway.
在有丝分裂中，核启动因子（NPF）与 Arp2/3 复合物结合并激活肌动蛋白组装。JMY 和 WAVE2 是 NPF 的两个关键成员。先前的研究表明，NPF 促进了细胞迁移和胞质分裂等多种过程。然而，NPF 在哺乳动物胚胎发育中的作用尚不清楚。本研究结果表明，NPF JMY 和 WAVE2 对于小鼠胚胎发育过程中的胞质分裂是至关重要的。JMY 和 WAVE2 均在小鼠胚胎中表达。注射 JMY 或 WAVE2 siRNA 后，所有胚胎均未能发育至桑椹胚或囊胚阶段。此外，通过荧光强度分析，我们发现肌动蛋白的表达减少，并且在单个细胞内观察到多个核，表明 NPF 诱导的肌动蛋白减少导致细胞分裂失败。此外，注射 JMY 和 WAVE2 siRNA 也导致 ARP2 降解，表明 NPF 参与小鼠胚胎发育主要是通过调节 ARP2/3 诱导的肌动蛋白组装。综上所述，这些数据表明 WAVE2 和 JMY 参与了小鼠胚胎的发育，其调节可能是通过 NPFs-Arp2/3-actin 途径。
