B6;129-Ncr1^tm1Oman/J

Stock number: 022739
Product name: Ncr1^gfp
Research areas: Immunology, Inflammation and Autoimmunity Research, Research Tools

Description

Ncr1^gfp mice are useful when tracking natural killer cells during infection.

Detailed description

An internal ribosome entry site (IRES)-GFP (green fluorescent protein) fusion protein, replaces exons 5-7 of the natural cytotoxicity triggering receptor 1 (Ncr1 or NKp46), abolishing gene function. NCR1 is expressed specifically on natural killer (NK) cells and possibly on related innate lymphocytes. Homozygous mice are viable and fertile. These mice are more susceptible to influenza viral infection at the LD50 dose. The GFP reported reveals increased numbers of NK cells at sites of infection and decreased circulating NK cells during infection. This reporter also enables the identification of Interferon Producing Killer Dendritic Cells-like (IKDCs) as activated NK cells.

Development

A targeting vector was designed to replace exons 5-7 of the natural cytotoxicity triggering receptor 1 (Ncr1) with an internal ribosome entry site (IRES)-GFP (green fluorescent protein) fusion protein followed by a loxP-flanked neomycin (neo) resistance cassette. This construct was electroporated into (129X1/SvJ x 129S1/Sv)F1-Kitl⁺-derived R1 embryonic stem (ES) cells. Chimeras were made by ES cell aggregation and chimeric mice were bred with C57BL/6-Tg(Zp3-cre)93Knw/J mice (Stock No. 003651) to delete the neo cassette. These Ncr1^gfp mice were bred to C57BL/6 mice for at least 10 generations (see SNP note below). Upon arrival at The Jackson Laboratory Repository, mice were bred with 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. Three of the markers throughout the genome were still segregating for 129 suggesting an incomplete backcross.

Allele

Symbol: Ncr1^tm1Oman
Name: targeted mutation 1, Ofer Mandelboim
MGI accession ID: MGI:3664443
Generation method: Targeted
Attributes: Reporter; Null/Knockout
Marker symbol: Ncr1
Marker name: natural cytotoxicity triggering receptor 1
Chromosome: 7
Strain of origin: (129X1/SvJ x 129S1/Sv)F1-Kitl⁺
Expressed genes: GFP,Green Fluorescent Protein,
Site of expression: Ncr1 is expressed specifically on natural killer (NK) cells and possibly on related innate lymphocytes.
Molecular note: A targeting vector was designed to replace exons 5-7 with an IRES-GFP-PGK-neo. The neo was removed via cre-mediated recombination. Absence of endogenous transcript was confirmed by RT-PCR. Fluorescence is more intense after excision by Tg(Prm-cre)58Og (129/Sv background) or by Tg(Sp3-cre)93Knw (C57BL/6 background). When allele is made congenic on 129 or C57BL/6 background, immune system phenotype is not altered by removal of PGK-neo or by background.