Mirc21 (microRNA cluster 21, including Mir34c through Mir34b) KO mutant mice may have applications in studies related to the regulatory control of p53 pathways.
Andrea Ventura, Memorial Sloan Kettering Cancer Center
The miR-34 family of miRNAs (miR-34a, miR-34b, and miR-34c) are expressed mainly in the testis, brain, and lung. miR-34 proteins are induced upon p53 activation and are associated with tumor suppression, aging, neurodegeneration, and spermatogenesis. Mirc21 is a micro RNA cluster including Mir34c through Mir34b. In this strain, an frt-flanked neomycin cassette was used to disrupt Mirc21; the neomycin cassette was subsequently removed. Homozygous Mirc21-/- mice are viable and fertile. When bred to miR-34a-/- mice (derived from Stock No. 018545 after ubiquitous cre recombination), the resultant mice lack all three miR-34 family members, show normal development and an intact p53 pathway.
A targeting vector was designed to replace the microRNA 34b (miR-34b) and miR-34c sequence with a frt-flanked neomycin resistance (neo) cassette. The construct was electroporated into (C57BL/6 x 129S4/SvJae)F1-derived V6.5 embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6 blastocysts and resulting chimeric mice were bred to Tg(ACTFLPe)9205Dym transgenic mice on a B6 background to delete the neo cassette. Progeny were crossed to remove the Flp-expressing transgene, resulting in a colony of miR-34b~c-/- mice. These mice were backcrossed to C57BL/6 mice for at least 6 generations. Upon arrival, mice were bred to C57BL/6J inbred mice (Stock No. 000664) for at least one generation to establish the colony.
|Allele Name||targeted mutation 1.1, Andrea Ventura|
|Allele Type||Targeted (Null/Knockout)|
|Allele Synonym(s)||Mir34b/Mir34ctm1.1Aven; miR-34b~c-|
|Gene Symbol and Name||Mirc21, microRNA cluster 21, including Mir34c through Mir34b|
|Strain of Origin||(C57BL/6 x 129S4/SvJae)F1|
|Molecular Note||A targeting vector was designed to replace the microRNA 34b (miR-34b) and miR-34c sequence with a frt-flanked neomycin resistance (neo) cassette. Flp-mediated recombination removed the neo cassette.|
When maintaining a live colony, homozygous mice may be bred together.
When using the B6.Cg-Mirc21tm1.1Aven/J mouse strain in a publication, please cite the originating article(s) and include JAX stock #018546 in your Materials and Methods section.