The transgene construct consisting of truncated CAG promoter followed by CreMer fusion protein and truncated Pgk poly-A was inserted into the intorn 3 of Rprd1b gene. Rprd1b is created by FLP-mediated excision of GFP/neo fusion gene from the conditional transgene Rprd1b. After FLP-mediated excision, tissue-specific expression of inducible cre is detected. (J:240153)