STOCK Adgra3^{tm1.1(HBEGF,-cre/ERT2)Pac}/Mmjax

Stock number: 036735
Product name: Adgra3^cre; Adgra3-CreER^T2
Research areas: Cancer Research, Developmental Biology Research, Research Tools, Sensorineural Research

Description

Adgra3^cre knock-in/knock-out mice carry a human diphtheria toxin receptor gene (HBEGF) and an inducible Cre recombinase/ERT2 fusion under the control of the Adgra3 (adhesion G protein-coupled receptor A3 or Gpr125) promoter. Embryonic Adgra3 (Gpr125) is expressed in multiple stem cell/progenitor compartments and high expression of Gpr125 is correlated with tumor onset and outcome in several types of cancers. Homozygous mice develop blepharitis, which progresses to blepharedema as well as several characteristics of dry eye syndrome. This strain may be useful in studies of dry eye syndrome as well as in identifying stem/progenitor cells involved in cancers.

Detailed description

Adgra3^cre knock-in/knock-out mice carry a human diphtheria toxin receptor gene (HBEGF) and an inducible Cre recombinase/ERT2 inserted into the endogenous translation start site of the adhesion G protein-coupled receptor A3 (Adgra3 or Gpr125) gene. The inserted sequences abolish expression of ADGRA3. Adgra3 encodes a member of the G protein-coupled receptor superfamily and is involved in tumor angiogenesis, Wnt signaling, cell polarity and adhesion, and cell migration.  It is expressed in multiple discrete cell populations that function as myoepithelial progenitors in the lacrimal gland, spermatogonial progenitors, bipotent embryonic mammary stem cells, and multiple unipotent basal progenitors in perinatal and postnatal glands. High expression of Gpr125 in several cancers is correlated with both good (colon cancer) and poor (basal-type breast cancer and myeloid leukemia) outcome.

Mice that are heterozygous for this knock-in/knock-out allele are viable and fertile. Homozygotes are small and develop an ocular phenotype similar to human dry eye syndrome with squinting, abnormal lacrimation, mucus accumulation, swollen eyelids (blepharitis), and inflammatory infiltration of lacrimal and meibomian glands. The eye phenotype is most prominent on the FVB/N background. The phenotype becomes more severe in older males and waxes and wanes in females (likely with the hormonal cycle) but becomes prominent during pregnancy. Their eyes do not respond to antibiotics. Approximately, 30% of homozygous males develop sudden sterility with age (7-8 months) likely due to testicular stem cell exhaustion. In addition, 30% of females exhibit vaginal fusion, which become obvious as a protrusion around 6-8 weeks of age.

When crossed with a strain containing a conditional reporter (such as B6.Cg-Gt(ROSA)26Sor^{tm14(CAG-tdTomato)Hze}/J, Stock No. 007914), progeny treated with tamoxifen can be used to trace Gpr125 expression.

Development

The Adgra3^cre knock-in/knock-out targeting vector contains a human diphtheria toxin receptor gene (HBEGF) fused to an enhanced green fluorescent protein (EGFP), a self-cleaving peptide T2A, an FRT-flanked neomycin cassette and cre/ERT2 inserted immediately after the first methionine codon of the Adgra3 gene on chromosome 5. The construct places the diphtheria toxin receptor, EGFP, and cre/ERT2 under the control of the Adgra3 promoter, and excises 502 bp encompassing 221 bp of exon 1 and part of the following intron to generate a knock-out of Adgra3. The donating investigator confirms that mice treated with diptheria toxin die due to expression of HBEGF in vital organs. EGFP was not detected in living cells by immunofluorescence or FACS. The linearized construct was introduced into (129S6/SvEvTac x C57BL/6NTac)F1-derived embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts. Chimeric males were crossed to C57BL/6N females. Progeny were crossed to B6.Cg-Tg(ACTFLPe)9205Dym/J to remove the neomycin cassette. At some point mice were crossed to B6.Cg-Gt(ROSA)26Sor^{tm14(CAG-tdTomato)Hze}/J, the TdT allele was later bred out of the colony. Offspring were maintained on a mixed background which included FVB/N and outbred Swiss Webster mice. Upon arrival, mice were bred to C57BL/6J for at least 1 generation to establish the colony.

Allele

Symbol: Adgra3^{tm1.1(HBEGF,-cre/ERT2)Pac}
Name: targeted mutation 1.1, Pamela Cowin
MGI accession ID: MGI:6759474
Generation method: Targeted
Attributes: Recombinase-expressing; Inducible; Null/Knockout; Inserted expressed sequence
Synonyms: Adgra3^cre
Marker symbol: Adgra3
Marker name: adhesion G protein-coupled receptor A3
Marker synonyms: 3830613O22Rik; Gpr125; PGR21; TEM5L; Tem5-like
Chromosome: 5
Strain of origin: (129S6/SvEvTac x C57BL/6NTac)F1
Molecular note: The targeting vector contains a human diphtheria toxin receptor gene (HBEGF) fused to an enhanced green fluorescent protein (EGFP), a self-cleaving peptide T2A, an FRT-flanked neomycin cassette and cre/ERT2 inserted immediately after the first methionine codon. The construct places the diphtheria toxin receptor, EGFP, and cre/ERT2 under the control of the Adgra3 promoter, and excises 502 bp encompassing 221 bp of exon 1 and part of the following intron to generate a knockout. Mice treated with diptheria toxin die due to expression of HBEGF in vital organs. EGFP is not detected in living cells by immunofluorescence or FACS. Flp-mediated recombination removed the FRT-flanked neo cassette.