Gt(ROSA)26Sor^{tm2(RNAi:Braf)Rkuhn}

Recombinase mediated cassette exchange (RMCE) was used to generate an allele where upon expression of Cre recombinase a knockdown RNAi to Braf mRNA is generated. A short hairpin RNA was designed with a loxP-flanked stop cassette in the loop portion of the RNAi between the sense and anti-sense sequences. The RNAi was put under the control of human U6 promoter and the entire cassette was placed downstream of a splice acceptor and a frt-flanked neomycin resistance gene. RMCE was then performed on ES cells containing the Gt(ROSA)26tm1Rkuhn allele. Upon expression of Cre recombinase in the forebrain of mice containing this allele, Braf protein expression was reduced by 70%. (J:133638)