B6.129(Cg)-Ccr2^tm2.1Ifc/J

Stock number: 017586
Product name: Ccr2^RFP
Research areas: Immunology, Inflammation and Autoimmunity Research, Internal/Organ Research, Research Tools

Description

In this strain, a monomeric red fluorescent protein (RFP) sequence replaces the coding sequence of the chemokine (C-C motif) receptor 2 (Ccr2) gene, abolishing gene function. These mice may be useful for studying the role of CCR2 during monocyte recruitment to sites of inflammation.

Detailed description

In this strain, a monomeric red fluorescent protein (RFP) sequence replaces the coding sequence of the chemokine (C-C motif) receptor 2 (Ccr2) gene, abolishing gene function. CCR2 is a chemokine receptor expressed on monocytes which directs their recruitment to sites of inflammation found in diseases such as multiple sclerosis, atherosclerosis, rheumatoid arthritis, and experimental autoimmune encephalitis (EAE), following activation by monocyte chemoattractant proteins (MCPs). CCR2 is essential to innate and adaptive immune responses during injury repair. Homozygous mice are viable, fertile, normal in size, and do not display any gross physical or behavioral abnormalities. In these mice RFP expression is seen in circulating monocytes, T cells, and natural killer cells. They exhibit a reduction in monocyte recruitment during thioglycolate-induced peritonitis and EAE. These mice may be useful for studying the role of CCR2 during monocyte recruitment to sites of inflammation.

Development

A targeting vector was designed to replace the coding sequence of the chemokine (C-C motif) receptor 2 (Ccr2) gene with a monomeric red fluorescent protein (RFP) sequence followed by a polyadenylation signal and a loxP-flanked neomycin resistance cassette. The construct was electroporated into 129-derived embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts and the resulting chimeric mice were bred to C57BL/6 mice. The resulting offspring were bred to Tg(EIIa-cre)C5379Lmgd transgenic mice to delete the neo cassette. The donating investigator reported that these mice were then backcrossed to C57BL/6J mice for at least 9 generations (see SNP note below). Upon arrival, mice were bred to C57BL/6J mice (Stock No. 000664) for at least one generation.

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: Ccr2^tm2.1Ifc
Name: targeted mutation 2.1, Israel F Charo
MGI accession ID: MGI:4868431
Generation method: Targeted
Attributes: Reporter; Null/Knockout
Marker symbol: Ccr2
Marker name: chemokine (C-C motif) receptor 2
Chromosome: 9
Strain of origin: 129
Expressed genes: RFP,Red Fluorescent Protein,coral
Site of expression: The red fluorescent protein (RFP) reporter allows visualization of Ly6C^hi monocytes.
Molecular note: The coding region was replaced with an RFP and floxed neo cassette. Cre-mediated recombination removed the neo cassette. The absence of transcript expression was confirmed by RT-PCR.