Snord116^tm1Uta

Two individual targeting vectors were used to place a loxP site (and an Frt1-flanked PGK-neo cassette) upstream, and a loxP site (and an Frt5-flanked puromycin resistance/TK cassette) downstream of the Snord116 cluster. The upstream targeting vector was transfected into C57BL/6-derived embryonic stem ES cells, and correctly targeted ES cells were next transfected with the downstream targeting vector. Doubly targeted ES cells were then transiently transfected with an FLP expressing plasmid to remove the two selection cassettes. The resulting 2-loxP ES cells (with a single loxP site just upstream, and a single loxP site just downstream of the Snord116 cluster. (J:131427)