B6.129P2-Lyz2^tm1(cre)Ifo/J

Stock number: 004781
Product name: LysMcre
Research areas: Developmental Biology Research, Hematological Research, Immunology, Inflammation and Autoimmunity Research, Internal/Organ Research, Research Tools

Description

The LysMcre knock-in/knock-out allele has a nuclear-localized Cre recombinase inserted into the first coding ATG of the lysozyme 2 gene (Lyz2); both abolishing endogenous Lyz2 gene function and placing NLS-Cre expression under the control of the endogenous Lyz2 promoter/enhancer elements. These LysMcre mice may be useful for Cre-lox studies of the myeloid cell lineage (monocytes, mature macrophages and granulocytes) and the innate immune response.

Detailed description

The LysMcre knock-in/knock-out allele has a nuclear-localized Cre recombinase inserted into the first coding ATG of the lysozyme 2 gene (Lyz2); both abolishing endogenous Lyz2 gene function and placing NLS-Cre expression under the control of the endogenous Lyz2 promoter/enhancer elements. When crossed with a strain containing loxP site flanked sequence of interest, Cre-mediated recombination results in deletion of the targeted gene in the myeloid cell lineage, including monocytes, mature macrophages, and granulocytes. Mice that are homozygous for the targeted mutation are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. This strain represents an effective tool for generating myeloid cell-specific targeted mutants.

View cre expression characterization by the Genetic Resource Science group at The Jackson Laboratory.

If the recombinase activity pattern of this allele is further annotated, such findings may be reported on the Mouse Genome Informatics (MGI) Allele Detail entry (Lyz2^tm1(cre)Ifo). This same information would also be found searching the MGI Recombinase Activity database.

Development

A targeting vector was designed to insert a frt-flanked neomycin resistance gene and Cre recombinase cDNA sequence (with nuclear localization signal) into the ATG-start site within exon 1 of the lysozyme 2 gene (Lyz2). The construct was electroporated into 129P2/OlaHsd-derived E14.1 embryonic stem (ES) cells. Correctly targeted ES cells were transiently transfected with a Flp expression vector to remove the frt-flanked neo cassette. ES cells that had successfully undergone Flp recombination were injected in blastocysts. The resulting chimeric animals were crossed to C57BL/6 mice. The donating investigator reported that mutant mice were then backcrossed to C57BL/6 mice for at least six generations prior to sending to The Jackson Laboratory Repository (see SNP notes below).

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: Lyz2^tm1(cre)Ifo
Name: targeted mutation 1, Irmgard Forster
MGI accession ID: MGI:1934631
Generation method: Targeted
Attributes: Recombinase-expressing
Marker symbol: Lyz2
Marker name: lysozyme 2
Chromosome: 10
Strain of origin: 129P2/OlaHsd
Expressed genes: cre,cre recombinase,bacteriophage P1
Site of expression: myeloid cells - including monocytes, mature macrophages, and granulocytes
Molecular note: An NLS-cre gene was inserted into the endogenous ATG start site of the gene. An frt-flanked neomycin cassette was removed in ES cells via Flp-mediated recombination prior to production of chimeric mice.