Tlr4 KO mice lack exon 3 of the toll-like receptor 4 (Tlr4) gene. The Tlr4, toll-like receptor 4, gene encodes a protein that has a critical role in pathogen recognition and activation of the innate immune system. Mice that are homozygous for this allele are viable and fertile. Mice may exhibit a defective response to LPS stimulation and defects in Toll signaling pathways involved with inflammation.
A targeting vector containing a FRT site flanked NEO selection cassette was utilized in the construction of this mutant. This selection cassette and a loxP site were inserted downstream of exon 3 coding region of the toll-like receptor 4 (Tlr4) gene, in non-coding sequence, and another loxP site was inserted upstream of exon 3. This construct was electroporated into C57BL/6J derived CMTI-2 embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts. The resulting chimeric animals were crossed to albino C57BL/6 mice (Stock No. 000058). The mice were then bred to transgenic mice (on the B6.Cg genetic background) expressing FLPe recombinase under the control of the human ACTB promoter (Stock No. 005703) to remove the FRT flanked selection cassette. Resulting mice were crossed to remove the Flp-expressing transgene and subsequently mice were bred to C57BL/6J mice (Stock No. 000664). Heterozygotes were then bred to generate homozygotes. These Tlr4flox mice arrived at The Jackson Laboratory as Stock No. 024872. Upon arrival, some mice were bred to B6.Cg-Tg(Sox2-cre)1Amc/J transgenic mice (Stock No. 008454) to remove the floxed sequence. Resulting mice were crossed to C57BL/6J mice for a few generations to remove the Cre-expressing transgene, resulting in a colony of Tlr4 KO mice (Stock No. 029015).
|Allele Name||targeted mutation 1.2, Christopher Karp|
|Allele Type||Targeted (Null/Knockout)|
|Gene Symbol and Name||Tlr4, toll-like receptor 4|
|Strain of Origin||C57BL/6J|
|Molecular Note||A targeting vector containing a FRT site flanked neomycin selection cassette and a loxP site was inserted downstream of exon 3 of the targeted gene, and another loxP site was inserted upstream of exon 3. Flp-mediated recombination removed the FRT-flanked neo cassette. Cre-mediated recombination removed exon 3.|
When maintaining a live colony, these mice can be bred as homozygotes.
When using the Tlr4 KO mouse strain in a publication, please cite the originating article(s) and include JAX stock #029015 in your Materials and Methods section.