Grn^tm1.2Blrl

Parental line mouse Grntm1Blrl consisting of a loxP site inserted upstream of exon 3 and a cassette containing (5' to 3') a loxP site, FRT site, splice acceptor, IRES, beta-geo cassette, stop codon, polyadenylation sequence, and FRT site inserted downstream of exon 4 was crossed with Flp-deleter to remove the cassette leaving loxP flanked exons 3 and 4. The mice was further crossed with cre-deleter to remove exon 3 and 4, resulting in constitutively null mice. (J:211725)