Fig. 2.

Transgenesis in rat ESCs. a Oct4-Venus transgene is introduced in rat ESCs by a nucleofection method. Some clones receive random integration of the transgene, with subsequent green fluorescence. After subcloning and passaging, Venus fluorescence was decreased in a majority of the clones (upper), while a minority of the clones expressed the fluorescence homogeneously. b The Oct4-Venus transgenic rat (arrow) was produced through germline transmission of the recombinant ESCs from a chimeric rat. c Oct4-Venus positive-germ cells in E16.0 gonad of the transgenic rats. d An ESC line derived from the Oct4-Venus transgenic rat. Venus fluorescence was kept in undifferentiated cells after 18 passages. All scale bars, 100 μm