This Tradd knockout strain may be useful in studies of apoptosis, TNF signaling and inflammatory response.
Dr. Tak Mak, University Health Network/Un of Toronto
The targeted Tradd gene encodes a death receptor or adaptor protein that interacts with TRAF2 to suppress apoptosis, and is involved in TNFR1 signaling and NF-kappaB activation.
These knock-out mice carry an allele in which exons 3-5 of the Tradd gene have been excised. Exons 3-5 include sequence encoding the death domain.
No gene product (protein) is detected by Western blot analysis of MEFs from homozygotes.
Mice that are homozygous for this allele are viable and fertile. Mouse embryonic fibroblast cells (MEFs) isolated from homozygotes (E14.5) are resistant to resistant to TNFα-induced apoptosis.
Homozygotes exhibit diminished production of inflammatory cytokines after challenge, including disorganized splenic follicular dendritic cell and absent splenic germinal center formation. Macrophages isolated from homozygotes respond to LPS-induction with decreased TNFα- production. Macrophages from heterozygotes also exhibit a reduced acute inflammatory response after challenge.
During backcrossing, the Y chromosome may not have been fixed to the C57BL/6 genetic background.
A targeting vector containing a loxP site flanked TK/Neo selection cassette (in reverse orientation) was utilized in the construction of this mutant. This selection cassette was inserted downstream of exon 5 of the targeted gene, and another loxP site was inserted upstream of exon 3. The construct was electroporated into 129P2/OlaHsd derived IB10 embryonic stem (ES) cells.
Correctly targeted ES cells were injected into C57BL/6 blastocysts. The resulting chimeric animals were tested for germline transmission. Heterozygotes were crossed with Deleter CRE mice carrying the Tg(CMV-cre)1Cgn/J transgene, on an unspecified background, to delete the floxed exons 3 through 5.
The mice were then backcrossed to C57BL/6 for 10 generations. During backcrossing, the Y chromosome may not have been fixed to the C57BL/6 genetic background.
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).
|Allele Name||targeted mutation 1.1, Tak W Mak|
|Allele Type||Targeted (Null/Knockout)|
|Gene Symbol and Name||Tradd, TNFRSF1A-associated via death domain|
|Strain of Origin||129P2/OlaHsd|
|Molecular Note||Mice containing the Traddtm1Mak allele were crossed with Cre-deleter mice to excise exons 3-5 that encode the functional "death domain" of the gene product. Gene inactivation was confirmed by a lack of protein product as determined by western blotting of embryonic fibroblasts from homozygote mice.|
When maintaining a live colony, these mice can be bred as homozygotes.
When using the tradd knock-out mouse strain in a publication, please cite the originating article(s) and include JAX stock #029256 in your Materials and Methods section.