RAG2 knock-out mice produce no mature T cells or B cells. Their phenotype can be described as a "non-leaky" immune deficiency. These mice may be useful in the study of hematopoietic and immune system defects, cancer, toxicology, and xenograft/transplant studies.
Of note, a C57BL/6J isogenic Rag2 knock-out strain is also available as Stock No. 033526.
IMR Colony, The Jackson Laboratory
The Rag2 gene is critical for (V(D)J) recombination in the process of B and T cell maturation. The RAG2 knock-out allele (also called RAG-2del) has exon 3 (which contains the entire RAG-2 protein coding region) deleted by Cre-mediated excision. Homozygous mice are viable and fertile and may be expected to have the same knockout phenotype as other RAG-2 null mutants or similarly created RAG-2 exon 3 pan-deleted mutants; with hematopoietic and immune system defects including arrested B cell and T cell development at the pro-B and the pro-T cell stages, respectively. Whereas Prkdcscid homozygotes produce some B cells and IgM (i.e., are "leaky"), RAG-2del homozygotes lack all mature lymphocytes (i.e., are "non-leaky") and do not have an increased sensitivity to irradiation or genotoxic drugs. These RAG-2del mice may be useful in studying cancer and toxicology (as a xenograft/transplant host), hematopoiesis, hematology, immunology, and inflammation research.
A targeting vector was designed to insert a loxP-flanked neomycin resistance gene on one side, and a third loxP site on the other side of exon 3 of the recombination activating gene 2 (Rag2) locus. This construct was electroporated into B6.Cg-Thy1a-derived Bruce-4 embryonic stem (ES) cells. Correctly targeted ES cells were transiently transfected with a cre-expressing vector to remove the selection cassette. ES cells in which the neomycin resistance cassette was deleted (leaving a single loxP site upstream, and a single loxP downstream of exon 3) were injected into recipient blastocysts. Chimeric males were bred with C57BL/6 females to generate RAG-2fl mice. The RAG-2fl mice were bred with transgenic mice on mixed genetic background, and then bred with mutant mice on a C57BL/6 genetic background for 8 generations (see SNP note below). The donating investigator reports that both the transgene and other mutant gene were bred out of the RAG-2fl mice prior to arrival at The Jackson Laboratory (as Stock No. 008309). Upon arrival, some RAG-2fl males were bred to cre-deleter females (Zp3-Cre transgenic mice on a C57BL/6 genetic background; Stock No. 003651), and then F1 males were bred back to B6.Zp3-Cre females. The resulting RAG-2del (exon 3 deleted) offspring were bred to C57BL/6J inbred mice (selecting for the RAG-2del mutation and against the cre transgene) for at least 1 generation to generate this RAG-2 "knockout" strain (Stock No. 008449).
|Allele Name||targeted mutation 1.1, University of Cologne|
|Allele Type||Targeted (Null/Knockout)|
|Gene Symbol and Name||Rag2, recombination activating gene 2|
|Strain of Origin||B6.Cg-Thy1a|
|Molecular Note||This allele is a derivative of Rag2tm1Cgn in which the sequences flanked by loxP sites were deleted in vivo by crossing mice carrying this allele to a deleter strain.|
|Mutations Made By|| |
Klaus Rajewsky, Max Delbruck Centre for Molecular Medicine
When maintaining a live colony, homozygous RAG2 KO mice may be bred together.
When using the RAG2 KO mouse strain in a publication, please cite the originating article(s) and include JAX stock #008449 in your Materials and Methods section.