B6(Cg)-Tcf7^tm1Hhx/J

Stock number: 030909
Product name: Tcf7^GFP flox
Research areas: Cancer Research, Immunology, Inflammation and Autoimmunity Research, Research Tools

Description

These Tcf7^GFP mice express an EGFP fluorescent reporter from the endogenous Tcf7 locus and possess loxP sites flanking exon 2. This strain may be useful for generating conditional mutations in applications related to T cell development and differentiation and tumorigenesis.

Detailed description

The transcription factor encoded by the Tcf7 gene can complex with beta-catenin, and is involved in the Wnt signaling pathway, T cell development and differentiation and tumorigenesis. These Tcf7^GFP knock-in mice possess an EGFP reporter and loxP sites on either side of exon 2 of the targeted Tcf7 gene. EGFP expression is detected in cells expressing Tcf7: early innate lymphoid cells and T cells. When these mutant mice are bred to mice that express Cre recombinase, resulting offspring will have exon 2 deleted in the cre-expressing tissues. Removal of the floxed sequence creates a null allele while EGFP expression is retained.

The donating investigator reports that homozygous mice are viable and fertile. In 2019, colonists at The Jackson Laboratory reported a decrease in productivity in our colony, with 20% non-productive homozygous breeding pairs.

Development

A targeting vector containing (5’ to 3’): FRT site, En2 gene-splicing acceptor, IRES, EGFP, poly adenylation signal sequence, neo cassette, FRT site, loxP site, was utilized in the construction of this mutant. This selection cassette was inserted downstream of exon 2 (in intron 1) of the targeted gene, and another loxP site was inserted upstream of exon 2. This construct was electroporated into unspecified C57BL/6 derived embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts. The resulting chimeric animals were bred to C57BL/6 mice to achieve germline transmission. The mice were backcrossed to C57BL/6 for 2 or 3 generations by the donating lab. Heterozygotes were crossed to generate homozygotes. As the mice were crossed to other mutant lines there may be other genetic background contributions (see SNP note below). Upon arrival, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).

In 2019 a 48 SNP (single nucleotide polymorphism) panel analysis, with 43 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 43 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.

Allele

Symbol: Tcf7^tm1Hhx
Name: targeted mutation 1, Hai-Hui Xue
MGI accession ID: MGI:5805838
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); Reporter; Modified isoform(s)
Synonyms: p45^-; Tcf7^GFP
Marker symbol: Tcf7
Marker name: transcription factor 7, T cell specific
Marker synonyms: T cell factor-1; T-cell factor 1; Tcf1; TCF-1
Chromosome: 11
Strain of origin: C57BL/6
Expressed genes: GFP,Green Fluorescent Protein,
Site of expression: EGFP expression is detected in cells expressing Tcf7: early innate lymphoid cells and T cells. EGFP expression is retained after creation of a null allele by Cre recombinase removal of the floxed sequence.
Molecular note: An FRT-flanked En2-SA-IRES-EGFP-polyA with a neomycin resistance cassette followed by a 3'loxP site was inserted upstream of exon 2. An additional loxP site was inserted downstream of exon 2. Placement of the cassette interferes with the expression of the long (p45 and p42) isoforms but not the short (p33 and p30) isoforms.