STOCK Hcn4^{tm2.1(cre/ERT2)Sev}/J

Stock number: 024283
Product name: HCN4CreERT2
Research areas: Cardiovascular Research, Developmental Biology Research, Internal/Organ Research, Research Tools

Description

HCN4CreERT2 mice express CreERT2 in the first heart field of differentiating myocytes in the developing cardiac crescent.

Detailed description

Heterozygous mice are viable and fertile, homozygotes are embryonic lethal. The HCN4CreERT2 allele expresses CreER^T2 from the hyperpolarization-activated, cyclic nucleotide-gated K+ 4 (HCN4) promoter/enhancer elements. HCN4 is expressed in the first heart field of differentiating myocytes in the developing cardiac crescent. Cre-ER^T2 fusion gene activity is observed in the same cells only following tamoxifen administration. When these mice are bred with mice containing loxP-flanked sequence, Cre-mediated recombination will result in deletion of the floxed sequences in the cardiac conduction system (CCS) of the offspring.

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 a CreER^T2 coding sequence and frt-flanked neomycin resistance selection cassette immediately before endogenous start codon of hyperpolarization-activated, cyclic nucleotide-gated K+ 4 (HCN4) gene. This construct was electroporated into embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts and chimeric males were bred. Mice were bred to Flp-transgenic mice on a Black Swiss background to remove the neo cassette, and progeny were crossed to remove the Flp transgene. These mice were maintained on a Black Swiss outbred 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: Hcn4^{tm2.1(cre/ERT2)Sev}
Name: targeted mutation 2.1, Sylvia Evans
MGI accession ID: MGI:5529675
Generation method: Targeted
Attributes: Recombinase-expressing; Inducible
Synonyms: HCN4CreERT2
Marker symbol: Hcn4
Marker name: hyperpolarization-activated, cyclic nucleotide-gated K+ 4
Marker synonyms: BRGDA8; EIG18; SSS2
Chromosome: 9
Strain of origin: Not Specified
Expressed genes: cre/ERT2,Cre recombinase and estrogen receptor 1 (human) fusion gene,
Site of expression: Mice carrying this allele express CreERT2 in the first heart field of differentiating myocytes in the developing cardiac crescent.
Molecular note: A targeting vector was designed to insert a CreERT2 coding sequence and frt-flanked neomycin resistance selection cassette immediately before endogenous start codon. The neo cassette was removed by FLP mediated recombination.