B6.Cg-Wif1^{em1(icre/ERT2)Nono}/J

Stock number: 041802
Product name: Wif1-P2A-iCreER
Research areas: Cancer Research, Cell Biology Research, Developmental Biology Research, Research Tools

Description

Wif1-P2A-iCreER knock-in (KI) mice have an icre/ERT2 fusion gene inserted immediately upstream of the of the 3' UTR of the Wif1 gene. When bred with mice containing a loxP-flanked sequence of interest, tamoxifen-inducible, Cre-mediated recombination will result in deletion of the floxed sequences in the Wif1-expressing cells of the offspring. These mice are useful for tracking Wif1-expressing cells in embryonic development.

Detailed description

Wnt inhibitory factor 1 (Wif1) codes for a protein that binds to WNT proteins and inhibits their activities and is essential for embryonic development. WIF1 also has a tumor-suppressing role and is often epigenetically silenced in various types of human cancers. These Wif1-P2A-iCreER knock-in (KI) mice have a codon-improved icre/ERT2 fusion gene inserted immediately upstream of the of the 3' UTR of the Wif1 gene, allowing for lineage-tracing of Wif1-expressing cells, while retaining endogenous Wif1 expression.

Heterozygous and homozygous mice are viable and fertile with no overt phenotype. When these mice are bred with mice containing a loxP-flanked sequence of interest, tamoxifen-inducible, Cre-mediated recombination will result in deletion of the floxed sequences in the Wif1-expressing cells of the offspring. To evaluate Wif1 expression in tooth root formation, the donating laboratory bred these mice to a R26R^tdTomato reporter mouse line (Stock No. 007914) and confirmed tdTomato fluorescence was localized to the apical mesenchyme in tamoxifen-induced Wif1^iCreER;R26R^tdTomato progeny, which correlated to endogenous Wif1 mRNA expression patterns. These mice are useful for tracking Wif1-expressing cells in embryonic development.

Development

The Wif1-P2A-iCreER knock-in (KI) allele was generated using CRISPR/Cas9 endonuclease-mediated genome editing. A guide RNA [5'- CCTACCCCACCATCTGAAAC-3' (PAM CGG)] was used to introduce a P2A-iCreERT2-bGH poly(A) cassette, harboring a codon-improved Cre recombinase fused to a human estrogen receptor ligand binding domain, immediately upstream of the stop codon in exon 10 of the Wnt inhibitory factor 1 (Wif1) gene on chromosome 10. Wif1 transcript Wif1-201 (ENSMUST00000020439.11) was used as reference for exon number and sequence. The sgRNA, Cas9 nuclease, and donor plasmid were introduced into the cytoplasm of B6D2F1/J-derived fertilized eggs with well recognized pronuclei. Correctly targeted pups were identified by PCR and sequencing. The resulting Wif1-P2A-iCreER KI mice were bred to C57BL/6J mice for at least 12 generations by the donating laboratory. Upon arrival at The Jackson Laboratory, 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: Wif1^{em1(icre/ERT2)Nono}
Name: endonuclease-mediated mutation 1, Noriaki Ono
MGI accession ID: MGI:8393895
Generation method: Endonuclease-mediated
Attributes: Recombinase-expressing; Inducible
Synonyms: Wif1-P2A-iCreER
Marker symbol: Wif1
Marker name: Wnt inhibitory factor 1
Marker synonyms: WIF-1
Chromosome: 10
Strain of origin: (C57BL/6J x DBA/2J)F1/J
Molecular note: Using CRISPR/Cas9 endonuclease-mediated genome editing, a guide RNA [5'- CCTACCCCACCATCTGAAAC-3' (PAM CGG)] was used to introduce a P2A-iCreERT2-bGH poly(A) cassette, harboring a codon-improved Cre recombinase fused to a human estrogen receptor ligand binding domain, immediately upstream of the stop codon in exon 10 of the Wnt inhibitory factor 1 (Wif1) gene on chromosome 10.