This miR-17~92Δ18 knock-out strain is useful in studies of the miR-18 seed family, and the Mirc1 microRNA cluster.
Andrea Ventura, Memorial Sloan Kettering Cancer Center
The polycistronic Mirc1, microRNA cluster, or miR-17~92, consists of 6 members: Mir17, microRNA 17; Mir18, microRNA 18; Mir19a, microRNA 19a; Mir20a, microRNA 20a; Mir19b-1, microRNA 19b-1; and Mir92-1, microRNA 92-1. The region of nucleotides 2–7 from the mature miRNA 5´-end is called the miRNA seed sequence, which is essential for target recognition and binding to mRNA. The same seed sequence is often shared amongst miRNAs within the same family.
These miR-17~92Δ18 mice have the miR-18 single seed family (Mir18) knocked out of the Mirc1, microRNA cluster.
No Mir18 miRNAs are detected by RT-qPCR and small RNA sequencing analysis of tail tissue from homozygotes. Mice that are homozygous for the targeted mutation are viable and fertile.
This strain is part of a miR-17~92 (Mirc1, microRNA cluster 1, including Mir17 through Mir92-1) allelic series:
(Stock No. 027317), (Stock No. 027318),
(Stock No. 027319), (Stock No. 027320), (Stock No. 027321), (Stock No. 027322).
A targeting vector containing a FRT site flanked neo selection cassette was utilized in the construction of this mutant. PCR-mediated mutagenesis was employed to delete
pre-miRNA sequences for Mir18 from the targeting vector.
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. The resulting chimeric animals were tested for germline transmission. Heterozygotes were then bred to beta-Actin-Flpe mice, carrying the Tg(ACTFLPe)9205Dym transgene, on the C57BL/6 background, to excise the FRT flanked NEO cassette. The mice were then backcrossed to C57BL/6J for 10 generations. Upon arrival at The Jackson Laboratory, the mice were crossed to C57BL/6J (Stock No. 000664) at least once to establish the colony.
|Allele Name||targeted mutation 1.1, Andrea Ventura|
|Allele Type||Targeted (Null/Knockout)|
|Gene Symbol and Name||Mir18, microRNA 18|
|Strain of Origin||(C57BL/6 x 129S4/SvJae)F1|
|Molecular Note||The Mir18 within the Mirc1 cluster was replaced by an FRT-flanked neomycin cassette. Flp-mediated recombination removed the FRT-flanked neo cassette.|
When maintaining a live colony, these mice can be bred as homozygotes.
When using the B6.Cg-Mir18tm1.1Aven/J mouse strain in a publication, please cite the originating article(s) and include JAX stock #027318 in your Materials and Methods section.