B6.129P2-Runx1tm1Tani/J transgenic mice (HHMI) (Jax No. 008772)
Exon 4 of these Runx1 (runt related transcription factor 1) targeted mutant mice is flanked by loxP sites. When crossed with a Cre recombinase-expressing strain, this strain is useful in eliminating tissue-specific expression of the gene. When crossed to a CD4-cre mouse strain, progeny have fewer CD4+ T cells than wildtype mice and completely lack NK T cells.
Exon 4 of these targeted mutant mice is flanked by loxP sites. Mice that are homozygous for this floxed allele are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. When crossed with a Cre recombinase-expressing strain, this strain is useful in eliminating tissue-specific expression of the gene. When crossed to a CD4-cre mouse strain, progeny have fewer CD4+ T cells than wildtype mice and completely lack NK T cells. A loxP site was placed 5' of exon 4 and a loxP-flanked neomycin cassette was placed in intron 4 of the targeted gene. Transient infection with Cre excised the neomycin cassette, leaving a loxP-flanked exon 4. This mutation was created in 129P2/OlaHsd-derived E14 embryonic stem (ES) cells.