B6(129S4)-Lox^tm1.1Rivp/J

Stock number: 041892
Product name: Lox^f
Research areas: Cancer Research, Cardiovascular Research, Research Tools

Description

The Lox^f allele contains loxP sites flanking exons 1–2 and rox sites flanking exon 3 of the mouse Lox gene, which encodes lysyl oxidase. This design enables Cre recombinase–dependent deletion of exons 1–2 when crossed with a Cre-expressing mouse or Dre recombinase–dependent deletion of exon 3, encoding for the pro-peptide, when crossed with a Dre-expressing mouse. These mice may be useful in studies of the function of Lox in connective tissue crosslinking and cardiovascular diseases, including hypertension, heart failure, aortic aneurysm, and atherosclerosis.

Detailed description

The Lox gene encodes a lysyl oxidase that catalyzes the cross-linking of collagen and elastin, giving strength and flexibility to connective tissues, and has been implicated in various cardiovascular diseases, including hypertension, heart failure, aortic aneurysm, and atherosclerosis. The Lox^f mice have a conditional, Cre recombinase-dependent knock-out allele of the Lox gene. Prior to the introduction of Cre recombinase, mice heterozygous or homozygous for the Lox^f allele are viable and fertile with normal breeding and have no gross physical or behavioral abnormalities. When Lox^f/f mice are bred to mice that express Cre recombinase, the resulting offspring will have exon 1-2 deleted, creating a null allele in the cells/tissues as determined by the Cre promoter. In addition, the Lox^f mice have rox-flanked exon 3 for Dre recombinase-dependent deletion of the LOX propeptide.

Development

A loxP site was inserted upstream of exon 1; a second loxP site, an FRT-flanked neomycin selection cassette, and an ROX site were inserted downstream of exon 2; and a second ROX site was inserted downstream of exon 3 (Reference transcript: ENSMUST00000025409.10). The resulting allele has exons 1-2 flanked by loxP, containing the ATG start codon for Cre-mediated complete knockout. Additionally, exon 3 is flanked by ROX sites for potential deletion of the LOX pro-peptide by Dre recombinase. The linearized vector was subsequently delivered to C57BL/6 derived embryonic stem (ES) cells via electroporation. Correctly targeted ES cells were injected into blastocysts. Chimeric males were crossed to C57BL/6J (Stock No. 000664) females for germline transmission. Mice carrying the targeted loxP and ROX insertions were identified by Southern blot. One confirmed founder was crossed to ROSA26::FLPe knock-in mice (Stock No. 009086) to remove the neo cassettes, then further backcrossed to C57BL/6J inbred mice for at least 10 generations and maintained on a C57BL/6J genetic background by the donating laboratory. Upon arrival at The Jackson Laboratory, sperm were cryopreserved. An aliquot of frozen sperm was used to fertilize C57BL/6J (Stock No. 000664) oocytes. Then, a recovered heterozygous female was mated to a C57BL/6J male to establish a live colony.

Allele

Symbol: Lox^tm1.1Rivp
Name: targeted mutation 1.1, Roberto I Vazquez-Padron
MGI accession ID: MGI:7783638
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Synonyms: Lox^f
Marker symbol: Lox
Marker name: lysyl oxidase
Marker synonyms: AAT10; H-rev142; ras recision gene (rrg); Rrg1; TSC-160
Chromosome: 18
Strain of origin: C57BL/6
Molecular note: A loxP site was inserted upstream of exon 1, a second loxP site and FRT-flanked neomycin selection cassette and ROX site were inserted downstream of exon 2, and a second ROX site was inserted downstream of exon 3. The neomycin selection cassette was removed via flp-mediated recombination leaving exons 1-2 floxed and exon 3 flanked by ROX sites.