Sod2^{tm1(rtTA*M2,tetO)Jsg}

The MnSOD targeting vector was designed to insert a 5.3 kbp Tet-On regulatory cassette approximately 30 nucleotides upstream of the initiation codon in the first exon. The Tet-On regulatory cassette contains the optimized form of reverse tetracycline controlled transactivator (rtTA-M2), polyA sequence, loxP site, neomycin resistance gene (neo), polyA sequence, loxP site and five copies of tetracycline operator 5' of a minimal cytomegalovirus promoter. The Tet-On regulatory fragment is a modification of the neo version of Tet-Off regulatory cassette. The Tet-Off cassette was converted to Tet-On by changing five codons via site-directed mutagenesis: S12G(GGC), E19G(GGG), A56P(CCC), D148E(GAG) and H179R(CGC). These amino acid changes converted tTA to the M2 form of rtTA (rtTA-M2). (J:209713)