STOCK Cdkn2a^tm1Bzsh/J

Stock number: 039747
Product name: p16-tdT
Strain synonyms: Cdkn2a-P2A-tdtomato , p16INK4a-P2A-tdtomato
Research areas: Neurobiology Research, Research Tools

Description

p16-tdT knock-in mice are a fluorescence-based reporter line having a P2A-tdtomato cassette inserted after the endogenous cyclin dependent kinase inhibitor 2A gene (Cdkn2a; also known as p16INK4a). These mice are useful for visualizing senescent cell populations and as a tool for studying the roles of cellular senescence in physiological and pathological processes, including embryonic development, cancer, aging, and multiple other diseases.

Detailed description

Cdkn2a encodes a cyclin-dependent kinase (CDK) inhibitor protein expressed in senescent cell populations. The expression of p16INK4a is essentially undetectable in young and healthy tissues, but p16INK4a+ cells accumulate in many aged or diseased tissues.

These p16-tdT knock-in mice have a P2A-tdtomato cassette inserted between the last exon and 3'UTR of the cyclin dependent kinase inhibitor 2A gene (Cdkn2a; also known as p16INK4a). Insertion of this reporter cassette does not affect endogenous Cdkn2a gene expression. In these mice, tdTomato is evident in cultured mouse embryonic fibroblasts (MEFs) isolated from p16-tdTomato embryos at E13.5 and induced cellular senescence by repeated passaging. Whole-mount fluorescence imaging of various organs and immunofluorescence staining of tissue sections showed that tdTomato-positive cells increased significantly with age in various lineage cells. Homozygous mice are viable and fertile.

Of note, in addition to these mice, the donating investigator provided The Jackson Laboratory Repository with p16-CreER mice (Stock No. 039748), p16-LSL-Dre mice (Stock No. 039749), and p16-CrexER mice (Stock No. 039750).

Development

A targeting vector containing the self-cleaving peptide 2A sequence and a complementary DNA (cDNA) encoding tdTomato fluorescent reporter, followed by a woodchuck hepatitis virus post-transcriptional regulatory element (WPRE), polyA signal, and FRT-flanked neomycin resistance cassette, was inserted into the last exon of the Cdkn2a gene, replacing the stop codon. The construct was electroporated into unspecified embryonic stem (ES) cells derived from the C57BL/6x129S3 genetic background. Correctly targeted ES cells were injected into blastocysts. The resulting chimeric animals crossed to C57BL/6J and offspring were crossed to ICR to maintain under the C57BL/6;ICR mixed background by donating laboratory. Upon arrival at The Jackson Laboratory, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J (Stock No. 000664) oocytes.

Allele

Symbol: Cdkn2a^tm1Bzsh
Name: targeted mutation 1, Bin Zhou
MGI accession ID: MGI:8172886
Generation method: Targeted
Attributes: Reporter
Marker symbol: Cdkn2a
Marker name: cyclin dependent kinase inhibitor 2A
Marker synonyms: Arf; ARF-INK4a; CAI2; CDK4I; CDKN2; CMM2; INK4; INK4A; Ink4a/Arf; INK4a-ARF; MLM; MTS1; MTS-1; P14; P14ARF; P16; p16Cdkn2a; P16INK4; P16INK4A; P19; p19^ARF; P19ARF; Pctr1; TP16
Chromosome: 4
Strain of origin: (C57BL/6 x 129S)F1
Molecular note: A targeting vector containing the self-cleaving peptide 2A sequence and a complementary DNA (cDNA) encoding tdTomato fluorescent reporter followed by a woodchuck hepatitis virus post-transcriptional regulatory element (WPRE), polyA signal, and FRT-flanked neomycin resistance cassette was inserted into the last exon of the Cdkn2a gene replacing the stop codon.