Using the TARGATT integrase-mediated cassette exchange, the targeting construct containing a bidirectional tetO (TRE) promoter directing the expression of human SHH cDNA and a ZsGreen1 fluorescent marker gene cassette was inserted into Gt(ROSA)26Sor docking attP site using phiC31 integrase. At least three founder lines were generated with line2 and 3 showing similar reporter expressions. Line 2 was used for most of the study. (J:310473)