B6NCrl.129P2(B6)-Apoe^tm1Unc Ccr2^tm1.1Blck/BlckJ

Stock number: 030893
Product name: 2AE-Bd
Research areas: Cardiovascular Research, Mouse/Human Gene Homologs, Research Tools

Description

2AE-Bd mice are C57BL/6NCrl-congenic animals harboring the ApoE knock-out allele (Apoe^tm1Unc) and the CCR2 knock-out allele (Ccr2^tm1.1Blck). These mice are useful for studying the pathogenesis and treatment of atherosclerosis, as well as lipoprotein/cholesterol metabolism, neurovascular function, inflammation and neurodegenerative cardiovascular disease.

Detailed description

C57BL/6N-congenic 2AE-Bd mice homozygous for knock-out alleles of ApoE and Ccr2 (ApoE-/-Ccr2-/-) are viable and fertile with no significant reproductive abnormalities.

Of note, the Ccr2 knock-out allele (Ccr2^tm1.1Blck) has an EGFP replacing most of the Ccr2 coding region. The donating investigator reports that mice homozygous for this Ccr2 knock-out allele exhibit EGFP fluorescence in blood monocytes (which are CCR2+) via flow cytometry and and fluorescence microscopy.

Dr. Bruno Luckow has made the following C57BL/6N-congenic strains available: ApoE knock-out (AE-B; Stock No. 030891), ApoE Ccr1 double knock-out (1AE-B; Stock No. 030892), ApoE Ccr2 double knock-out (2AE-Bd; Stock No. 030893), ApoE Ccr5 double knock-out (5AE-B; Stock No. 030894), ApoE Ccr1 Ccr5 triple knock-out (15AE-B; Stock No. 030895) and ApoE Ccr2 Ccr5 triple knock-out (25AE-Bd; Stock No. 030896).

Development

These 2AE-Bd mice (Stock No. 030893) are C57BL/6NCrl-congenic animals harboring the ApoE knock-out allele (Apoe^tm1Unc) and the CCR2 knock-out allele (Ccr2^tm1.1Blck). Each mutant allele is described below.

The ApoE knock-out allele (Apoe^tm1Unc) was created in the laboratory of Dr. Nobuyo Maeda (University of North Carolina at Chapel Hill) to have a neo cassette replacing part of the coding region of the apolipoprotein E Locus on chromosome 7. In 2005, Dr. Bruno Luckow (Klinikum der Universitaet Muenchen) obtained C57BL/6J-congenic ApoE knock-out mice from The Jackson Laboratory (Stock No. 002052), bred them several generations to C57BL/6NCrl mice (Charles River Laboratories), and then used them as described below.

The CCR2 knock-out allele (Ccr2^tm1.1Blck) was created in the laboratory of Dr. Bruno Luckow (Klinikum der Universitaet Muenchen) to have an enhanced green fluorescent protein gene (EGFP) replacing most of the coding region of the chemokine (C-C motif) receptor 2 locus on chromosome 9. After electroporation into 129P2/OlaHsd-derived E14.1 embryonic stem (ES) cells, chimeras were bred to C57BL/6 mice to establish the mutant colony. After backcrossing ten generations to C57BL/6NCrl, a floxed neo cassette was permanently removed by exposure to Cre recombinase. Next, the CCR2 knock-out [2-Bd] colony was backcrossed to C57BL/6NCrl for another four generations, and then used as described below.

To generate the ApoE/CCR2 double mutant colony [2AE-Bd], Dr. Luckow bred the two mutant mouse lines together. The donating investigator reports that the 2AE-Bd colony was then backcrossed to C57BL/6NCrl for an additional three generations. In 2017, Dr. Luckow sent 2AE-Bd mice to The Jackson Laboratory as Stock No. 030893. Upon arrival, sperm was cryopreserved.
Of note, the donating investigator reports that the Y chromosome may not have been fixed to the C57BL/6N background during backcrossing.

In 2017, a SNP (single nucleotide polymorphism) panel analysis, with 43 markers covering all 19 chromosomes and the X chromosome, as well as 5 markers that distinguish between the C57BL/6N and C57BL/6J substrains, was performed on the male mice sent to The Jackson Laboratory Repository. All markers were C57BL/6 allele-type. In addition, all markers that determine C57BL/6 substrains were C57BL/6N allele-type with one exception - the marker on chromosome 6 [~107.8 Mbp] was found to be homozygous for C57BL/6J allele-type. This suggests that C57BL/6NCrl allele-type at this marker is the same as C57BL/6J allele-type (rather than C57BL/6NJ allele-type).

Allele

Symbol: Ccr2^tm1.1Blck
Name: targeted mutation 1.1, Bruno Luckow
MGI accession ID: MGI:6272721
Generation method: Targeted
Attributes: Reporter; Null/Knockout
Marker symbol: Ccr2
Marker name: chemokine (C-C motif) receptor 2
Marker synonyms: CC-CKR-2; CCR-2; CCR2A; CCR2B; CD192; CKR2; CKR2A; CKR2B; CMKBR2; MCP-1-R; PCLUD
Chromosome: 9
Strain of origin: 129P2/OlaHsd
Molecular note: Most of the open reading frame is replaced by an EGFP reporter gene and a floxed neomycin resistance cassette. Cre-mediated recombination removed the floxed neo cassette.
General note: The version of this allele that contains the neomycin selection cassette, Ccr2^tm1Blck, has been analyzed.

Allele

Symbol: Apoe^tm1Unc
Name: targeted mutation 1, University of North Carolina
MGI accession ID: MGI:1857129
Generation method: Targeted
Attributes: Null/Knockout
Synonyms: AopE(-); apoE-; APOE KO; Apoe^tm1Un; apoE0; ApoE-KO; EKO; epsilon-; mE^-; mEKO
Marker symbol: Apoe
Marker name: apolipoprotein E
Marker synonyms: AD2; APO-E; ApoE4; APOEA; LDLCQ5; LPG
Chromosome: 7
Strain of origin: 129P2/OlaHsd
Molecular note: Insertion of a neomycin resistance cassette deleted part of exon 3 and part of intron 3 of the Apoe gene. Plasma from homozygous mutant mice gave no detectable immunoprecipitate by the Ouchterlony double immunodiffusion test using a rabbit antibody to rat APOE.