B6.Cg-Tcra^tm1Cgn/J

Stock number: 040741
Product name: TCR-Cα^fl
Strain synonyms: TCRa-Flox
Research areas: Cancer Research, Immunology, Inflammation and Autoimmunity Research, Research Tools

Description

These TCR-Cα^fl mice possess loxP sites flanking the constant region of the TCRα chain in mature T cells. These mice may be useful for studying T cell homeostasis.

Detailed description

The Tcra (T cell receptor alpha chain) gene codes for the alpha chain of the T cell receptor (TCR), which is necessary for antigen binding. These TCR-Cα^fl mice possess loxP sites flanking the constant region of the TCRα chain in mature T cells.

Heterozygous and homozygous mice are viable and fertile with no overt phenotype. When bred to mice that express tissue-specific Cre recombinase, resulting offspring will have the TCR-α C1, C2 and C3 regions deleted, whereas the C4 region is frame-shift deleted, in the cre-expressing tissues.

The donating laboratory crossed these TCR-Cα^fl mice to a TCRα^-/- knock-out model generating TCR-Cα^fl/+; TCRα^-/+ progeny, which were then crossed to an inducible Mx-Cre mouse line (Stock No. 003556). Ten days after exposure to a single dose of pI/pC, the resulting progeny demonstrated cells that were negative for TCRβ and CD3ε, suggesting that these cells had largely lost the TCRαβ/CD3 complex from the cell surface, while fully retaining CD4 or CD8 expression. These TCR-Cα^fl mice may be useful when studying T cell homeostasis.

Development

The TCR-Cα^fl targeting vector was designed to insert loxP sites flanking the T cell receptor alpha chain (Tcra) via homologous recombination. The targeting construct included an initial loxP site inserted upstream of the Tcra-C element C1, and a loxP flanked neomycin cassette was inserted between elements C3 and C4. The construct was electroporated into B6.Cg-Thy1^a-derived Bruce4 embryonic stem (ES) cells and correctly targeted ES cells were injected into recipient blastocysts. Transient transfection of targeted ES cells removed the floxed neomycin cassette leaving the conditional Cα allele with C1, C2 and C3 elements flanked by loxP sites. TCR-Cα^fl mice were maintained on a C57BL/6 background 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: Tcra^tm1Cgn
Name: targeted mutation 1,University of Cologne
MGI accession ID: MGI:2388328
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Synonyms: Calpha^fl; Trac^fl
Marker symbol: Tcra
Marker name: T cell receptor alpha chain
Marker synonyms: Tcr alpha; Tcralpha
Chromosome: 14
Strain of origin: B6.Cg-Thy1^a
Molecular note: A loxP site was inserted upstream of Tcra-C element C1, and a loxP flanked neo was inserted between elements C3 and C4 via homologous recombination. Transient transfection of targeted ES cells removed the neo cassette leaving the conditional Calpha allele with C1, C2 and C3 flanked by loxP sites.