These Tbx21F/F mutant mice possess loxP sites flanking exons 2-6 of the T-box 21 (Tbx21) gene. This strain may be useful for studying the role of T-bet in selected immune system lineages.
Steven L Reiner, Columbia University
These Tbx21F/F mutant mice possess loxP sites flanking exons 2-6 of the T-box 21 (Tbx21) gene. Tbx21 encodes T-bet, a transcription factor that controls gene expression in many cell types of the immune system. Mice that are homozygous for this allele are viable and fertile. When these mutant mice are bred to mice that express Cre recombinase, resulting offspring will have exon 2-6 deleted in cre-expressing tissues.
For example, when crossed to STOCK Tg(Cd4-cre)1Cwi/BfluJ mice (Stock No. 017336) expressing Cre recombinase, which deletes Tbx21 during thymic development, the T cell-specific Tbx21 deficient mice exhibit alterations in their response to some infections. CD8+ T cells from LCMV-infected T cell-specific Tbx21 deficient mice have impaired proliferative expansion and increased expression of Il-17, Il-2, and TNF.
A targeting vector was developed by Drs. Nezih Cereb and Soo Young Yang at Histogenetics (Ossining, NY) to insert a single loxP site upstream of exon 2, and a loxP-flanked neomycin resistance (neo) cassette downstream of exon 6 of the T-box 21 (Tbx21) gene. The construct was electroporated into 129-derived embryonic stem (ES) cells. Correctly targeted ES cells were transiently transfected with a Cre expression plasmid to delete the neo cassette. Resulting ES cells contained multiple gene rearrangments; intact floxed-exons 2-6, intact floxed-neo cassette, or excision of both exons 2-6 and the neo cassette. Correctly targeted ES cells, containing only the floxed-exons but no neo cassette, were sent to Dr Steve Reiner at The University of Pennsylvania. The ES cells were injected into C57BL/6J blastocysts and resulting chimeric mice were bred with C57BL/6J mice. Resulting offspring were bred to C57BL/6J mice for at least 14 generations. Upon arrival, mice were bred to C57BL/6J inbred mice (Stock No. 000664) for at least one generation to establish the colony.
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. One of the 43 markers, on Chromosome 3, was segregating with 129.
|Allele Name||targeted mutation 2, Steven L Reiner|
|Allele Type||Targeted (Conditional ready (e.g. floxed), No functional change)|
|Gene Symbol and Name||Tbx21, T-box 21|
|Strain of Origin||129|
|Molecular Note||Exons 2 through 6 were flanked with loxP sites.|
When maintaining a live colony mice homozygous for the floxed allele may be bred together.
When using the Tbx21F mouse strain in a publication, please cite the originating article(s) and include JAX stock #022741 in your Materials and Methods section.