Igh^tm11.1Cgn

A targeting vetor was used to replace the JH1 and JH2 elements with the D23stop joint. A floxed neo included in the vector was subsequently removed by transient transfection of cre recombinase. A second targeting vector was then used to introduce a double loxP site and frt-flanked neo into the VH81x position. Crossing these mice with cre deleter mice results in the loss of the DH elements and the insertion of a D23stop VDJ cassette. (J:113434)