C57BL/6-Ch25h^tm1.1Syfu/J

Stock number: 037647
Product name: Ch25h floxed
Research areas: Cancer Research, Immunology, Inflammation and Autoimmunity Research, Metabolism Research, Research Tools

Description

Ch25h floxed mice possess loxP sites flanking the only exon of the cholesterol 25-hydroxylase (Ch25h) gene. These mice may be useful for studying the role of Ch25h in lipid metabolism, inflammation, and innate immune responses.

Detailed description

Ch25h floxed mice have loxP sites flanking the only exon of the cholesterol 25-hydroxylase (Ch25h) gene. Ch25h belongs to the family of interferon-stimulating genes (ISGs), which are involved with modulation of inflammatory processes, innate immunity, and subsequent adaptive immune responses through interferon signaling. CH25H is a monooxygenase, which catalyzes the conversion of cholesterol to 25-hydroxycholesterol (25HC), an oxysterol with an important role in controlling the properties of lipid membranes and related processes of autophagy, lysosomal proteolysis, uptake of extracellular vesicles and trogocytosis. CH25H plays an important role in the regulation of intratumoral angiogenesis as well as innate immune responses.

Homozygous Ch25h floxed mice are viable and fertile with no overt phenotype. When bred to mice that express tissue-specific Cre recombinase, resulting offspring will have exon 1 deleted in the cre-expressing tissues. These mice may be useful for studying the role of Ch25h in lipid metabolism, cancer, inflammation, and innate immune responses.

Development

The Ch25h floxed allele was designed to insert loxP sites around the only exon of the Ch25h gene. The targeting vector was composed of a neomycin (neo) cassette flanked by self-deletion anchor sites (SDA) and diphtheria toxin A (DTA), which used for negative selection. The loxP sites were inserted ~1.8 kb upstream of exon 1 and ~0.5 kb downstream of exon 1. The targeting construct was electroporated into C57BL/6 derived embryonic stem (ES) cells and correctly targeted ES cells were injected into C57BL/6 blastocysts. The resulting Ch25h floxed mice, with neo cassette removed and floxed exon 1 intact, were back-crossed to a C57BL/6J genetic background for more than 10 generations by the donating 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).

In 2022, a 48 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/6J and C57BL/6N substrains, was performed on the males sent to The Jackson Laboratory Repository. Three of the 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating, including the rd8 recessive mutation associated with retinal degeneration on Chromosome 1 within the Crb1 locus. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6N;C57BL/6J genetic background.

Allele

Symbol: Ch25h^tm1.1Syfu
Name: targeted mutation 1.1, Serge Fuchs
MGI accession ID: MGI:7336292
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed)
Marker symbol: Ch25h
Marker name: cholesterol 25-hydroxylase
Marker synonyms: C25H; m25OH
Chromosome: 19
Strain of origin: C57BL/6
Molecular note: The targeting vector is composed of a neomycin (neo) cassette flanked by self-deletion anchor sites (SDA) and diphtheria toxin A (DTA), which is used for negative selection. The loxP sites were inserted ~1.8 kb upstream of exon 1 and ~0.5 kb downstream of exon 1.