Rax^{tm1.1(rTA,tetO-cre)Lan}

A cassette encoding an IRES-tTA (tetracycline transactivator) and tetO-cre was inserted into the 3' UTR of the Rax (Rx) gene, 104 bp from the stop codon. A neo resistance marker was included in the cassette. The construct was electroporated into ES cells for homologous recombination. Correctly targeted germline mutants were crossed to flpe-expressing transgenic mice to remove the neo marker. Further breeding to wild-type mice removed the flpe transgene. Removal of doxycycline from the animals' diets permits Rax-dependent cre expression. (J:195568)