Gt(ROSA)26Sor^{tm1.1(rtTA2S*M2)Whsu}

A synthetic, modified version of the rtTA gene preceded by a loxP flanked STOP sequence was inserted into the Gt(ROSA)26Sor locus. Carriers were bred with mice transgenic for cre recombinase under the control of beta actin, excising the STOP sequence and leaving rtTA under the endogenous Gt(ROSA)26Sor promoter. This version of rtTA contains 5 amino acid changes in the TetR moiety (S12G, E19G, A56P, D148E, and H179R) and a synthetic optimized transactivating domain. This rtTA has reduced basal activity and enhanced doxycycline sensitivity compared to wild-type rtTA. (J:99718)