B6;129S4-Foxd1^{tm2(GFP/cre/ERT2)Amc}/J

Stock number: 012464
Research areas: Developmental Biology Research, Endocrine Deficiency Research, Internal/Organ Research, Research Tools

Description

The Foxd1GCE allele expresses an eGFPCreERT2 fusion protein (EGFP and creERT2 fusion protein) from the Foxd1 promoter/enhancer elements. These mice may be useful for studying therapeutic strategies directly targeting pericyte differentiation in vivo and may productively impact fibrotic kidney disease.

Detailed description

Heterozygous mice are viable and fertile, normal in size and do not display any gross physical or behavioral abnormalities. The DI states that the strain is homozygous lethal. The Foxd1^GCE allele expresses an eGFPCreER^T2 fusion protein (EGFP and creERT2 fusion protein) from the Foxd1 promoter/enhancer elements. Foxd1 is induced, and EGFP immunofluorescence is observed, during kidney development in metanephric mesenchyme in cells fated to become stromal cells of the kidney. Cre-ER^T2 fusion gene activity is inducible; observed in the same cells only following tamoxifen administration. When Foxd1^GCE mice are bred with mice containing loxP-flanked sequence, tamoxifen-inducible, Cre-mediated recombination will result in deletion of the floxed sequences in the FoxD1-expressing cells of the offspring. These mice may be useful for studying therapeutic strategies directly targeting pericyte differentiation in vivo and may productively impact fibrotic kidney disease.

The Cre-ERT2 fusion protein consists of Cre recombinase fused to a triple mutant form of the human estrogen receptor which does not bind its natural ligand (17β-estradiol) at physiological concentrations but will bind the synthetic estrogen receptor ligands 4-hydroxytamoxifen (OHT or tamoxifen) and, with lesser sensitivity, ICI 182780. Restricted to the cytoplasm, Cre-ERT2 can only gain access to the nuclear compartment after exposure to tamoxifen. To counteract the mixed estrogen agonist effects of tamoxifen injections, which can result in late fetal abortions in pregnant mice, progesterone may be coadministered.

Development

A targeting vector was designed to insert an eGFPCreER^T2 (GCE) fusion protein coding sequence and frt-flanked PGKneobpA selection cassette into the initiation codon of the Forkhead box D1 (Foxd1) targeted gene. Specifically, this targeting vector contained an enhanced green fluorescent protein (EGFP) and a CreER^T2 fusion gene (Cre-ER^T2; Cre recombinase fused to a G400V/M543A/L544A triple mutation of the human estrogen receptor ligand binding domain). This construct was electroporated into F1 hybrid (C57BL/6 x 129S4Sv/Jae)-derived v6.5 embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts and chimeric males were bred with C57BL/6J females. These FoxD1-GCE (Foxd1^GCE) mutant mice were maintained on this mixed C57BL/6J;129/Sv genetic background. Upon arrival at The Jackson Laboratory, mice were bred with C57BL/6J inbred mice (Stock No. 000664) for at least one generation to establish the colony.

Allele

Symbol: Foxd1^{tm2(GFP/cre/ERT2)Amc}
Name: targeted mutation 2, Andrew P McMahon
MGI accession ID: MGI:4437895
Generation method: Targeted
Attributes: Recombinase-expressing; Reporter; Inducible
Marker symbol: Foxd1
Marker name: forkhead box D1
Chromosome: 13
Strain of origin: (C57BL/6 x 129S4/SvJae)F1
Expressed genes: GFP,Green Fluorescent Protein,; cre/ERT2,Cre recombinase and estrogen receptor 1 (human) fusion gene,
Site of expression: Foxd1 is induced, and EGFP immunofluorescence is observed, during kidney development in metanephric mesenchyme in cells fated to become stromal cells of the kidney.
Molecular note: A targeting vector was designed to insert an eGFP/Cre/ERT2 (GCE) fusion protein coding sequence and frt-flanked PGKneobpA selection cassette into the initiation codon of the Forkhead box D1 (Foxd1) targeted gene.