A loxP site followed by FRT-flanked Neo cassette was inserted into intron 1 and an F3-flanked Puro cassette followed by a second loxP site was inserted into intron 12 to produce Ddx5tm1Arte. The selection cassettes were removed by Flp-mediated recombination, leaving exons 2-11 flanked by lox P sites. (J:191933)