C57BL/6-Trim21^tm1Hm/J

Stock number: 010724
Product name: Trim21^EGFP KO
Research areas: Immunology, Inflammation and Autoimmunity Research, Research Tools

Description

Trim21^EGFP is a knock-out allele that expresses EGFP at high levels in lymph node, spleen, and thymus and at lower levels in kidney, heart and liver. Very low EGFP expression occurs in brain. Homozygous mice display enhanced proinflammatory cytokine expression patterns.

Detailed description

Mice that are homozygous for the targeted mutation are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. EGFP expression is observed at high levels in lymph node, spleen, and thymus and at lower levels in kidney, heart and liver. Very low EGFP expression occurs in brain. Stimulated (LPS or polyI:C) embryonic fibroblasts derived from these mice exhibit enhanced expression of proinflammatory cytokines (TNFA, IL6 and CXCL10). A similar response is not observed in bone marrow dendritic cells or macrophages. Dendritic cells (CD11c+) generated from homozygous bone marrow are reduced by 25% as compared to controls, although, numbers of bone marrow macrophages are not altered. This mutant mouse strain may be useful in study of NFKB regulation and inflammatory responses.

Development

A targeting vector was designed to insert the coding sequence of Enhanced Green Fluorescent Protein (EGFP) into exon 3 and a polyA signal and loxP-flanked PGK-neomycin resistance cassette downstream of exon 3. The construct was electroporated into C57BL/6 derived Bruce 4 embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts. The resulting chimeric animals were interbred and crossed to a C57BL/6J OzCre deleter mouse produced by Ozgene to excise the neo cassette leaving a single loxP site downstream of the EGFP in exon 3. Selected breeding eliminated Cre recombinase. Upon arrival in 2009, mice were bred to C57BL/6J for at least 1 generation to establish the colony.

Allele

Symbol: Trim21^tm1Hm
Name: targeted mutation 1, Herbert Morse III
MGI accession ID: MGI:3849316
Generation method: Targeted
Attributes: Reporter; Null/Knockout
Marker symbol: Trim21
Marker name: tripartite motif-containing 21
Marker synonyms: RNF81; Ro/SSA; RO52; SSA; Ssa1
Chromosome: 7
Strain of origin: B6.Cg-Thy1^a
Expressed genes: GFP,Green Fluorescent Protein,
Site of expression: EGFP expression is observed in lymph node, spleen, and thymus and at lower levels in kidney, heart, liver, and brain.
Molecular note: Exons 3 through 5 were replaced with EGFP and a floxed neo cassette. Cre mediated recombination removed the neo cassette.