C57BL/6-Mir155^tm1.1Ggard/J

Stock number: 026700
Product name: Mir155^fl/fl
Research areas: Cell Biology Research, Research Tools

Description

These mutant floxed mice possess loxP sites flanking exon 2 of the Mir155 gene. This strain may be useful for generating conditional mutations in applications related to the regulation of T follicular helper cells and germinal center B cells development, inflammation and immunity.

Detailed description

Mir155 encodes an evolutionarily conserved multifunctional miRNA that is involved in regulation of hematopoiesis, inflammation and immunity. These mice possess loxP sites on either side of the exon 2 of Mir155. Exon 2 includes sequence that encodes the hairpin sequence. 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 the coding exon deleted in the cre-expressing tissues.

When bred to a strain with Cre recombinase expression in T cells, this mutant mouse strain may be useful in studies of chronic, low-grade inflammation and development of T follicular helper (Tfh) cells, and germinal center (GC) B cells.

Development

A targeting vector containing a FRT site flanked PGK-Neo selection cassette was utilized in the construction of this mutant. This selection cassette was inserted downstream of exon 2 of the targeted gene, and another loxP site was inserted upstream of the coding exon. This construct was electroporated into unspecified C57BL/6 derived embryonic stem (ES) cells which were transiently transfected with a FLPe recombinase vector to remove the selection cassette. Correctly targeted ES cells were injected into blastocysts. The resulting chimeric animals were tested for germline transmission. The mice were backcrossed to C57BL/6 for 7 generations. Upon arrival at The Jackson Laboratory, the mice were crossed to C57BL/6J (Stock No. 000664) at least once to establish the colony.

Upon arrival at The Jackson Laboratory, the mice were crossed to C57BL/6J (Stock No. 000664) at least once to establish the colony.

Allele

Symbol: Mir155^tm1.1Ggard
Name: targeted mutation 1.1, Gwenn Garden
MGI accession ID: MGI:5616592
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Marker symbol: Mir155
Marker name: microRNA 155
Chromosome: 16
Strain of origin: C57BL/6
Molecular note: The targeting vector contains an FRT-flanked PGK-neomycin selection cassette, followed by a loxP site inserted downstream of exon 2 of the targeted gene, and another loxP site inserted upstream of this coding exon. The neomycin cassette was deleted by transient transfection of a flp recombinase expression vector in the ES cells.