B6.129P2-P2rx7^tm1Gab/J

Stock number: 005576
Product name: P2X(7)R KO
Research areas: Developmental Biology Research, Immunology, Inflammation and Autoimmunity Research

Description

Mutant mice exhibit reduced induction and severity of monoclonal anti-collagen-induced arthritis, significant reduction in femoral periosteal circumference, reduced periosteal bone formation, and a reduction in total and cortical bone content. This mutant mouse strain may therefore be useful in studies examining the consequences of disrupted interleukin 1 beta processing and the regulation of bone formation and resorption.

Detailed description

Mice that are homozygous for the targeted allele are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. No full length gene product (mRNA or protein) is detected in cultured bone marrow mast cells or peritoneal macrophages. Samples of whole blood, as well as peritoneal macrophages, derived from mutant mice fail to produce extracellular interleukin 1 beta in response to lipopolysaccharide (LPS) and ATP treatment. Similarly, peritoneal lavage fluids from mutant animals that have been primed with LPS and subsequently challenged with ATP, are deficient in mature interleukin 1 beta, and at later time points, exhibit attenuated interleukin 6 levels when compared to fluids from similarly treated wildtype mice. Peripheral blood monocytes and leukocytes fail to change shape/volume and shed L-selectin in response to ATP. Mutant mice exhibit reduced induction and severity of monoclonal anti-collagen-induced arthritis. Mutant mice also display significant reduction in femoral periosteal circumference, reduced periosteal bone formation, and a reduction in total and cortical bone content. Increased resorption in tibial trabecular bone tissue is observed.

Development

A targeting vector containing a neomycin resistance gene driven by the mouse phosphoglycerate kinase promoter was used to disrupt the carboxyl-terminal coding region of the targeted gene. The construct was electroporated into 129P2/OlaHsd-derived E14TG2a embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6 blastocysts. The donating investigator stated that the resulting chimeric animals were backcrossed to C57BL/6 mice (see SNP note below) for 7 generations.

A 32 SNP (single nucleotide polymorphism) panel analysis, with 27 markers covering all 19 chromosomes and the X chromosome, as well as 5 markers that distinguish between the C57BL/6J and C57BL/6N substrains, was performed on the rederived living colony at The Jackson Laboratory Repository. While the 27 markers throughout the genome suggested a C57BL/6 genetic background, 3 of 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6J ; C57BL/6N genetic background.

Allele

Symbol: P2rx7^tm1Gab
Name: targeted mutation 1, Christopher A Gabel
MGI accession ID: MGI:2386080
Generation method: Targeted
Attributes: Modified isoform(s)
Marker symbol: P2rx7
Marker name: purinergic receptor P2X, ligand-gated ion channel, 7
Chromosome: 5
Strain of origin: 129P2/OlaHsd
Molecular note: Sequence encoding amino acids 506 through 532 was replaced by the insertion of a neomycin selection cassette. Transcript was undetected by Northern blot analysis of bone marrow mast cells isolated from homozygous mutant mice. Western blot analysis of homozygous mutant peritoneal macrophages showed an absence of normal and truncated protein. Subsequent analysis found low levels of expression of the 13b isoform in the brain, salivary gland and spleen as well as a C-terminal truncated variant transcript.