STOCK Hopx^tm3.1Joe/J

Stock number: 029271
Product name: Hopx^3FlagGFP
Research areas: Research Tools

Description

Hopx^3FlagGFP knock-in mice express a 3xFLAG tagged Hopx and EGFP under the direction of the Hopx promoter. They may be useful for cellular fate mapping of hair follicle stem cells.

Detailed description

Hopx^3FlagGFP mice express 3xFLAG tagged Hopx and EGFP from the endogenous HOP homeobox (Hopx) promoter, while still expressing endogenous Hopx. HOPX is a specific marker of intestinal stem cells and labels long-lived hair follicle stem cells residing in the telogen basal bulge. HOPX⁺ cells contribute to all mature hair follicle lineages and to the interfollicular epidermis upon epidermal wounding. Homozygous mice are viable and fertile. Hopx^3FlagGFP mice exhibit fluorescence in the basal layer of the telogen hair follicle, specifically in lower hair bulb progenitor cells. Expression is also seen in the small intestines and the embryonic heart.

Development

A targeting construct was designed to insert (from 5’ to 3’) a 3xFLAG tag, a viral 2A (V2A) sequence, an enhanced green fluorescent protein (EGFP) sequence, and a frt-flanked neomycin resistance (neo) cassette into exon 3 of the HOP homeobox (Hopx) gene. This construct was electroporated into 129S6/SvEvTac-derived W4 embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts and the resulting chimeric animals were crossed to Tg(ACTFLPe)9205Dym mice on a mixed background to remove the neo selection cassette. These Hopx^3FlagGFP mice were bred together to remove the Flp-expressing transgene and were subsequently maintained on a mixed background. Upon arrival, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J (Stock No. 000664) oocytes.

Allele

Symbol: Hopx^tm3.1Joe
Name: targeted mutation 3.1, Jonathan A Epstein
MGI accession ID: MGI:5502918
Generation method: Targeted
Attributes: Reporter; Null/Knockout
Marker symbol: Hopx
Marker name: HOP homeobox
Chromosome: 5
Strain of origin: 129S6/SvEvTac
Expressed genes: GFP,Green Fluorescent Protein,; FLAG, FLAG octapeptide,; Hopx,HOP homeobox,mouse, laboratory
Site of expression: Mice exhibit EGFP fluorescence in the basal layer of the telogen hair follicle, specifically in lower hair bulb progenitor cells. Expression is also seen in the small intestines and the embryonic heart.
Molecular note: A 3XFlag sequence followed by a GFP and an Frt flanked neomycin cassette were appended to exon 3. Subsequent expression of flp recombinase excised the selection cassette.