These Mif knock-out mice exhibit resistance to lethal effects of endotoxemia in response to intraperitoneally injected LPS.
Mihaela Gadjeva , Brigham and Women's Hospital
These mice have a neo cassette disrupting exons 2-3 of the macrophage migration inhibitory factor (glycosylation-inhibiting factor) (MIf) gene, abolishing gene expression. MIF is a lymphokine involved in cell-mediated immunity, immunoregulation, and inflammation. It plays a role in the regulation of macrophage function. Mice that are homozygous null for the Mif gene are viable and fertile. No Mif gene product (mRNA or protein) is detected. On a mixed genetic background mice carrying this allele exhibit signs of endotoxemia in response to intraperitoneally injected LPS (25 mg/kg), however they are resistant to its lethal effects. Plasma levels of tumor necrosis factor alpha assayed after LPS administration is half that observed in wildtype mice.
Of note, this allele is also available on a congenic BALB/c background as Stock No. 003830.
A targeting vector containing a neomycin resistance gene and a herpes simplex virus thymidine kinase gene was used to disrupt exons 2-3 of the macrophage migration inhibitory factor (glycosylation-inhibiting factor) (MIf) gene. The construct was electroporated into 129S4/SvJae-derived J1 embryonic stem (ES) cells and correctly targeted ES cells were injected into C57BL/6 blastocysts. The resulting chimeric animals were backcrossed to BALB/cAnNTac mice for at least 6 generations and are available as Stock No. 003830). Some of these mice were purchased by Dr. Mihaela Gadjeva (Brigham and Women's Hospital). This group of mice were backcrossed for 12 generations to C57BL/6J mice (Stock No. 000664) before being sent back to The Jackson Laboratory (see SNP note below). Upon arrival at The Jackson Laboratory, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664). This B6 congenic line is available as this Stock No. 030087.
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, 4 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 Name||targeted mutation 1, John R David|
|Allele Type||Targeted (Null/Knockout)|
|Allele Synonym(s)||MIF-; MIF-KO|
|Gene Symbol and Name||Mif, macrophage migration inhibitory factor (glycosylation-inhibiting factor)|
|Strain of Origin||129S4/SvJae|
|Molecular Note||A neomycin resistance cassette replaced a genomic fragment containing part of exon 2 and exon 3. Northern blot analysis on RNA derived from liver of LPS-treated homozygous mice demonstrated that no detectable transcript was produced form this allele. ELISA assays on serum of LPS-treated animals confirmed that no functional protein was expressed from this allele.|
|Mutations Made By|| |
John David, Harvard School of Public Health
When maintaining a live colony, homozygous mice may be bred together.
When using the Mif KO mouse strain in a publication, please cite the originating article(s) and include JAX stock #030087 in your Materials and Methods section.