In vivo analysis of cell polarity during cell-cell fusion

在质膜上的各种磷脂酰肌醇（PI）中，最丰富的产物PI(4,5)P2和局部产生的PI(3,4,5)P3和PI(3,4)P2似乎在细胞极性形成中特别重要。PLC delta1的PH结构域与PI(4,5)P2结合，而Akt的PH结构域与PI(3,4)P2和PI(3,4,5)P3结合，这取决于pi3激酶活性在局部产生。通过使用这些结构域，我成功地观察到了融合细胞的极性。为了在体内应用该系统，产生了能够表达响应强力霉素融合GFP或RFP的结构域的KH2 ES细胞。由于确认了胚胎干细胞的遗传性质，正在培育能够表达极性探针的小鼠。

Among various phosphatidylinositols (PI) on the plasma membrane, the most abundant product, PI(4,5)P2 and locally-produced PI(3,4,5)P3 and PI(3,4)P2 seem to be particularly important in polarity formation of the cells. The PH domain of PLC delta1 binds to PI(4,5)P2 while the PH domain of Akt binds to PI(3,4)P2 and PI(3,4,5)P3, which is locally produced depending on PI3-kinase activity. By using these domains, I succeeded in observing the polarity of fusing cells. To apply this system in vivo, KH2 ES cells which can express those domains fused to GFP or RFP in response to doxycyclin were generated. Now that genetic quality of the ES cells were confirmed, the mice who express the polarity probe is being generated.