Chrd^tm2.1Vlcg

A conditional by inversion (COIN) intron consisting of a lox66_SA-Egpf-polyA_lox71 was inserted in the antisense orientation into intron 2 via homologous recombination, splitting intron 2 into 2 new exons (206 and 105 bp in length). The two lox sites are in reverse complementation orientation, thus cre-mediated recombination will irreversibly invert the inserted sequence. In addition, an FRT flanked drug selection cassette (hygromycin- or neomycin-delta-thymidine kinase cassette was inserted after the COIN intron. Flp-mediated recombination removed the drug selection cassette. (J:200671)