These mice carry a floxed allele of the mouse Mir203 locus. Cre-mediated excision of the loxP-flanked region produces a knockout allele useful in studies of skin cancer.
Rui Yi, University of Colorado Boulder
Messenger RNA (mRNA) and microRNA sequencing (miR-Seq) screens of the transcriptome has revealed that Mir203 (microRNA 203) expression is downregulated in keratinocytes in response to the G12V mutation of Hras (a potent driver of tumorigenesis in skin that stimulates clonal expansion in papillomas).
These mice carry a floxed allele of the mouse Mir203 locus which enables the generation of cre-mediated conditional knockouts.
When crossed with EIIa-Cre mice, mice exhibit mild epidermal hyperplasia during skin development and have increased skin tumor burden in the DMBA/TPA skin chemical carcinogenesis model. Loss of Mir203 expression promotes selection and expansion of tumor-initiating cells. Mir203 acts to limit the proliferation of skin cells when they are rapidly dividing.
LoxP sites were introduced on either side of pre-Mir203 sequences and an FRT-flanked neomycin cassette via homologous recombination in B6(Cg)-Tyrc-2J/J- derived Cy2.4 ES cells. Resultant mice were bred with a C57BL/6J-background ACTB-Flpe strain to excise the neomycin cassette. The albino Tyrc-2J allele was bred out of the line. This strain was maintained on a C57BL/6J background by the donating lab.
|Allele Name||targeted mutation 1.1, Rui Yi|
|Allele Type||Targeted (Conditional ready (e.g. floxed))|
|Gene Symbol and Name||Mir203, microRNA 203|
|Strain of Origin||B6(Cg)-Tyrc-2J|
|Molecular Note||The targeting constructs contains a loxP site upstream of the Mir203 hairpin loop and a FRT-flanked neomycin cassette followed by a loxP site downstream of the hairpin loop. Flp-mediated recombination removed the FRT-flanked neo cassette.|
Heterozygous and homozygous floxed mice are viable and fertile.
When using the miR-203fl/fl mouse strain in a publication, please cite the originating article(s) and include JAX stock #028362 in your Materials and Methods section.