B6.129S1-Tlr7^tm1Flv/J

Stock number: 008380
Product name: TLR7^-
Research areas: Immunology, Inflammation and Autoimmunity Research, Virology Research

Description

These toll-like receptor 7 (Tlr7) targeted mutation mice may be useful in studies of viral immunity. Homozygotes demonstrate reduced responses to in vivo infection with vesicular stomatitis virus. The lacZ reporter introduced under the gene's promoter shows that within mesenteric lymph nodes, expression is normally confined to the perifollicular regions.

The Jackson Laboratory has two Tlr7 knock-in alleles available: the Tlr7 knock-in/knock-out allele with lacZ replacing exon 3 (Tlr7^tm1Flv; Stock No. 008380) and the TLR7KI-tdTom knock-in allele with an IRES-tdTomato at the 3' end (Tlr7^tm1.1Gbrt; Stock No. 031827).

Detailed description

These toll-like receptor 7 targeted mutation mice may be useful in studies of viral immunity. Homozygotes demonstrate reduced responses to in vivo infection with vesicular stomatitis virus. This emphasizes the roll of the gene in viral recognition by plasmacytoid dendritic cells and B cells which activate costimulatory molecules and produce cytokines. No RNA expression is detected in bone marrow-derived macrophages by Northern blot analysis. The lacZ reporter introduced under the gene's promoter shows that within mesenteric lymph nodes, expression is normally confined to the perifollicular regions. Homozygotes are viable, fertile, have no obvious developmental problems, but are poor breeders for unknown reasons.

Development

A segment of exon 3 was replaced by a lacZ gene and loxP-flanked neomycin resistance cassette. The targeting vector was introduced to 129S1/Sv-p⁺ Tyr⁺ Kitl⁺-derived CJ7 embryonic stem (ES) cells. This line was backcrossed ten times to C57BL/6Ncr by the donating laboratory (see SNP note below). Upon arrival at The Jackson Laboratory, this strain was crossed one time to C57BL/6J.

In 2021, 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. Two of the 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating, including the rd8 recessive mutation associated with retinal degeneration on Chromosome 1 within the Crb1 locus. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6N;C57BL/6J genetic background.

Allele

Symbol: Tlr7^tm1Flv
Name: targeted mutation 1, Richard A Flavell
MGI accession ID: MGI:3040902
Generation method: Targeted
Attributes: Reporter; Null/Knockout
Marker symbol: Tlr7
Marker name: toll-like receptor 7
Chromosome: X
Strain of origin: 129S1/Sv-Oca2⁺ Tyr⁺ Kitl⁺
Expressed genes: lacZ,beta-galactosidase,E. coli
Molecular note: A cassette containing lacZ and floxed neo replaced a portion of exon 3. Northern blot analysis of mutant bone marrow-derived macrophages indicated no mRNA was present. Beta galactose staining showed expression of lacZ in mutant lymph nodes.