B6.129S6-Shh^{tm2(cre/ERT2)Cjt}/J

Stock number: 005623
Product name: ShhcreER^T2
Research areas: Developmental Biology Research, Research Tools

Description

This strain is currently unavailable due to replenishing of cryopreserved stocks.  Interested customers can register interest.

Tamoxifen administration in these mice induces Cre recombinase expression in all cells of the mouse limb that express the endogenous gene. Cells that contribute to more anterior digits cease to express Shh at an earlier stage of limb development.This mutant mouse strain may be useful in studies of limb patterning and development.

Detailed description

This strain expresses a fusion product involving Cre recombinase and a mutant form of the human estrogen receptor ligand binding domain from the endogenous Shh locus. The mutant human estrogen receptor does not bind natural ligand at physiological concentrations but will bind the synthetic ligand, 4-hydroxytamoxifen. Restricted to the cytoplasm, the Cre/ESR1 protein can only gain access to the nuclear compartment after exposure to tamoxifen. Tamoxifen administration induces Cre recombinase expression in all cells of the mouse limb that express the endogenous gene resulting in the deletion of the first 35 base pairs following the ATG. Introduction of tamoxifen at E10.5 resulted in the labeling of LacZ-positive cells that contributed to digit 5 and the posterior half of digit 4 in E14.5 limbs. Injection of tamoxifen at E11.5 resulted in the labeling of cells only in digit 5. Homozygous mice are not viable or fertile. Heterozygous mutant mice are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. This mutant mouse strain may be useful in studies of limb patterning and development.

Development

A targeting vector containing a fusion product involving Cre recombinase and a mutant form of the human estrogen receptor ligand binding domain was inserted at the ATG of Shh. The construct was electroporated into 129S6/SvEv-derived TC-1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts. The donating investigator reported that the resulting chimeric animals were crossed to C57BL/6 mice, and then backcrossed to the same for five generations (see SNP note below).

A 32 SNP (single nucleotide polymorphism) panel analysis, with 27 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 rederived living colony at The Jackson Laboratory Repository. While the 27 markers throughout the genome suggested a C57BL/6 genetic background, 2 of 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6J ; C57BL/6N genetic background.

In 2018, genotyping results suggest that the Shh^{tm2(cre/ERT2)Cjt} allele contains a neomycin resistance gene.

 

Allele

Symbol: Shh^{tm2(cre/ERT2)Cjt}
Name: targeted mutation 2, Clifford J Tabin
MGI accession ID: MGI:3053960
Generation method: Targeted
Attributes: Recombinase-expressing; Inducible
Marker symbol: Shh
Marker name: sonic hedgehog
Chromosome: 5
Strain of origin: 129S6/SvEvTac
Expressed genes: cre/ERT2,Cre recombinase and estrogen receptor 1 (human) fusion gene,
Site of expression: tamoxifen inducible Cre recombinase protein fused to a mutant form of the human estrogen receptor ligand binding domain; expression in all cells that express the Shh gene
Molecular note: A cassette containing CreER^T2 was inserted at the ATG. Upon recombination, the first 35 base pairs after the ATG were deleted. Cre was produced in all cells in which the endogenous mRNA was normally expressed.