B6(Cg)-Mir23a^tm1.1Qjl/J

Stock number: 032430
Product name: Mir23a flox
Research areas: Cancer Research, Immunology, Inflammation and Autoimmunity Research, Research Tools

Description

Mir23a flox mutant mice possess loxP sites flanking the sequence encoding the stem-loop structure of the Mir23a gene. This strain may be useful for generating conditional mutations in applications related to the regulation of T cell activation and tumor invasion and metastasis.

Detailed description

The targeted Mir23a gene encodes a micro non-coding RNA. Dysregulated expression of this gene has been associated with effector CD4+ T cell expansion, Warburg effect in cancer cells and autophagy in melanoma. These mice possess loxP sites on either side of the sequence encoding the stem-loop structure of the targeted Mir23a gene. While sequence shared between Mir23a and Mir27a was floxed to ensure the entirety of the Mir23a stem-loop structure would be excised, duplicate sequence encoding the left arm of Mir27a was inserted downstream of the 3’ loxP site to maintain endogenous Mir27a expression. 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 stem-loop structure of Mir23a deleted in the cre-expressing tissues. Removal of the floxed sequence creates a null allele.

When bred to a strain with Cre recombinase expression in in CD4-expressing T cells (see Stock No. 022071 for example), this mutant mouse strain may be useful in studies of early T cell activation.

Development

A targeting vector containing a loxP site, the region of sequence encoding Mir23a and Mir27a, an FRT site flanked PGK-Neo-pA cassette, duplicate sequence encoding the left arm of Mir27a and a second loxP site was utilized in the construction of this mutant. Sequence shared between Mir23a and Mir27a was floxed to ensure the entirety of the Mir23a stem-loop structure would be excised. The duplicate sequence encoding the left arm of Mir27a was included to maintain the endogenous Mir27a expression. This construct was electroporated into unspecified C57BL/6 derived embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts. The resulting chimeric animals were tested for germline transmission. The mice were crossed to a FLPe-expressing strain (FLPe under the control of the CAG, CMV enhancer/chicken beta-actin promoter) on the C57BL/6 background to excise the FRT-flanked selection cassette. The mice were later crossed with another transgenic line on a congenic C57BL/6 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), and the mice bred to remove the transgene (see SNP note below).



IN 2019 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 with an unknown source. Also, 3 of the 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6N;C57BL/6J genetic background.

Allele

Symbol: Mir23a^tm1.1Qjl
Name: targeted mutation 1.1, Qi-Jing Li
MGI accession ID: MGI:6281405
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed)
Synonyms: Mir23a^f
Marker symbol: Mir23a
Marker name: microRNA 23a
Marker synonyms: hsa-mir-23a; mir-23a; MIRN23A; miRNA23A; mmu-mir-23a
Chromosome: 8
Strain of origin: C57BL/6
Molecular note: FLP-mediated recombination removed the neomycin cassette from Mir23a^tm1Qjl.