B6;129S1-Smarcb1^tm3Sho/J

Stock number: 004596
Product name: Snf5^inv
Research areas: Research Tools

Description

These floxed mutant mice possess loxP sites flanking the the Smarcb1 gene in opposing orientation and the mice are useful in generating mutants of the floxed allele that exhibit partial penetrance.

Detailed description

This strain contains loxP sites, in opposing orientation, flanking the targeted gene resulting in an reversible Cre-mediated conditional null allele. Mice that are homozygous for this allele are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. When used in conjunction with an inducible Cre recombinase-expressing strain, this strain is useful in generating mutants of the floxed allele that exhibit partial penetrance. In the presence of high levels of Cre protein, the orientation of the floxed allele is continually in a reversible reaction. All progeny resulting from a cross of these mice with Mx-Cre mice developed T-cell lymphoma or rhabdoid tumors at a median onset of age 11 weeks. The rhaboid tumors exhibited in these progeny mice closely resemble human malignant rhaboid tumors.

Development

A targeting vector containing a neomycin resistance cassette flanked by loxP sites in the 5' orientation, a herpes simplex virus thymidine kinase gene and 8.8 Kb of sequence encoding exon 1 and flanking regions was used to construct the conditional allele. The construct was electroporated into 129S1 derived CJ7 embryonic stem (ES) cells which were transiently transfected with a Cre-recombinase vector (pMC-Cre expression plasmid) to remove the selection cassette. Correctly targeted ES cells were injected into C57BL/6 blastocysts. The resulting chimeric animals were bred to C57BL/6 mice.
SNP analysis performed at The Jackson Laboratory indicates that genomic contribution from a strain other than C57BL/6 or 129/S1 is present on chromosomes 9, 13, 17 and 19.

Allele

Symbol: Smarcb1^tm3Sho
Name: targeted mutation 3, Stuart Orkin
MGI accession ID: MGI:2447708
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Marker symbol: Smarcb1
Marker name: SWI/SNF related, matrix associated, actin dependent regulator of chromatin, subfamily b, member 1
Chromosome: 10
Strain of origin: 129S1/Sv-Oca2⁺ Tyr⁺ Kitl⁺
Molecular note: A loxP-flanked neomycin selection cassette was inserted into intron 1 and a single loxP site in the opposite orientation was inserted 0.8 kb upstream of exon 1. The neomycin selection cassette was removed by transient Cre expression in ES cells, leaving oppositely oriented loxP sites flanking exon 1 in the final allele. Upon Cre-mediated recombination, exon 1 and flanking sequences are inverted in orientation with respect to the rest of the gene.