Dicer1^tm1Dli

LoxP sites were inserted to flank exons 18-20, which encode part of the first RNase III domain. Deletion of this sequence putatively leads to out-of-frame splicing of all downstream exons, including the second RNase III and the dsRNA-binding domains, and results in complete ablation of enzymactic activity. An frt-flanked neo was inserted into intron 17 and was removed by crossing mice with a strain that expresses Flp recombinase in the germ line. (J:100546)