Development of a mouse model for live-imaging of hepatic epithelial patterning in mouse embryonic liver using a HAC carrying BACs

内胚层器官具有树形结构的内胚层上皮，这是实现其功能所必需的。这些结构是通过不同细胞群之间的细胞间相互作用自主组织的。由于内胚层上皮管最终的树形结构是分形的，这些结构似乎是根据一定的数学规则形成的。然而，这些规律是未知的，因为我们无法对相关细胞的行为进行实时观察。为了利用Foxa2-nEGFP-CreERT2、WT1-EGFPCre和Tek-Cre对胚胎器官组织发生过程中不同的两种细胞群进行同步实时成像，我们生成了新的ROSA26报告系Ai-3tTom。该小鼠系可以从ROSA26位点以cre依赖的方式表达肉豆蔻串联番茄，该位点发出很强的红色荧光。因此，我们能够使用该小鼠系对细胞进行实时实时成像。

Endodermal organs have tree-like structures of endodermal epithelia which are essential for performing their functions. The structures are autonomously organized by cell-to-cell interactions among different cell populations. As their final tree-like pattern of the endodermal epithelial tubes are fractal, the patterns appear to be formed based on the some mathematical rules. However, the rules have been unknown because we were not able to perform real-time observation of the behaviors of the cells involved. In order to perform simultaneous real-time imaging for different two cell populations in histogenesis of the embryonic organs using Foxa2-nEGFP-CreERT2, WT1-EGFPCre, and Tek-Cre, we generated Ai-3tTom, a new ROSA26 reporter line. This mouse line can expresses myristyl tandem Tomato in a Cre-dependent manner from ROSA26 locus, which emits very strong red fluorescence. Therefore, we are able to perform a real-time live imaging of the cells using this mouse line.