Figure 2

Targeted insertion in ES cells. (A) Introduction of donor vector (pBDR) harboring promoter-less tdTomato gene into targeted ES cells (#BDU7) with each expression vector for iCre recombinase, FLPo recombinase or PhiC31 integrase. Red fluorescent ES cells, as analyzed by FACS, are regarded as successfully targeted tdTomato cassette inserted cells. (B) Co-introduction of combinations of recombinases or integrase expression vectors increases transgene insertion efficiency.