B6.129P2-Cd19^{tm1(cre/ERT2)Rsky}/J

Stock number: 027116
Product name: CD19creERT2
Strain synonyms: CD19^-
Research areas: Research Tools, Virology Research

Description

CD19creERT2 mice express tamoxifen-inducible Cre recombinase under the direction of the Cd19 promoter in B lymphocytes.

Detailed description

CD19creERT2 mice express a Cre-ERT2 fusion protein from endogenous CD19 antigen (Cd19) promoter/enhancer regions in B cells. This mutation is designed to abolish CD19 gene expression. CD19 is a phosphoglycoprotein, found on the surface of B lymphocytes, which binds to antigen receptors in order to decrease the threshold for antigen receptor-dependent stimulation.

Restricted to the cytoplasm, Cre-ER^T2 can only gain access to the nuclear compartment after exposure to tamoxifen. When CD19creERT2 mice are bred with mice containing loxP-flanked sequence, tamoxifen-inducible, Cre-mediated recombination will result in deletion of the floxed sequences. The insertion of the Cre-ERT2 fusion protein results in a KO allele. Homozygous mice are viable and fertile. Induction of cre-mediated recombination through the CD19creERT2 knock-in allele is a rare event, occurring only in a few percent of B cells. In a model of Epstein–Barr viral infection (EBV) this model mimics the infection seen in humans where just a few B cells are infected in its initial phase.

Development

A targeting vector was designed to insert a CreERT2 (Cre recombinase fused to an estrogen receptor ligand binding domain) coding sequence into exon 2 of the CD19 antigen (Cd19) gene. This construct, which also contains a frt-flanked neomycin selelction cassette, was electroporated into 129P2/OlaHsd-Hprt^b-m3-derived HM-1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts. The donating investigator reported that resulting chimeric mice were bred to C57BL/6J mice and were subsequently backcrossed to C57BL/6J mice for at least 10 generations (see SNP note below). Upon arrival at The Jackson Laboratory, mice were bred to C57BL/6J inbred mice (Stock No. 000664) for at least one generation to establish the colony.

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 one of the 27 markers throughout the genome suggested a C57BL/6 genetic background, all 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 C57BL/6N genetic background.

 

Allele

Symbol: Cd19^{tm1(cre/ERT2)Rsky}
Name: targeted mutation 1, Klaus Rajewsky
MGI accession ID: MGI:5614310
Generation method: Targeted
Attributes: Recombinase-expressing; Inducible; Null/Knockout
Marker symbol: Cd19
Marker name: CD19 antigen
Chromosome: 7
Strain of origin: 129P2/OlaHsd-Hprt1^b-m3
Expressed genes: cre/ERT2,Cre recombinase and estrogen receptor 1 (human) fusion gene,
Site of expression: B lymphocytes
Molecular note: The cre/ERT2 fusion gene was knocked into exon 2.