Gcsam^tm1.1Rsky

A 4.5 kb region containing exons 4 and 5 of the gene were flanked by loxP sites. A loxP flanked neo cassette was place upstream of exon 4, and a frt-flanked reporter cassette consisting of a splice acceptor site, an IRES domain, and a GFP gene was placed down stream of exon 5. Chimeric mice were crossed with a Cre-expressing transgenic, removing the neo cassette and the two coding exons. Inactivation of the gene was confirmed by RT-PCR on RNA from germinal center B-cells. No GFP expression was detected, possibly due to unstable RNA. (J:125784)