C57BL/6N-Tg(Cdkn1a*/tdTomato)260Rein/J

Stock number: 032928
Product name: Cdkn1a^LSL.SUPER
Research areas: Cancer Research, Research Tools

Description

Cdkn1a^LSL.SUPER mice conditionally express the mouse Cdkn1a gene fused to tdTomato. This strain may be useful for studying Trp53-mediated tumor suppression.

Detailed description

Cdkn1a (cyclin-dependent kinase inhibitor 1A (P21)) encodes a protein that inhibits the activity of cyclin-dependent kinase complexes and is involved in regulating cell cycle progression. Expression of Cdkn1a is controlled by the tumor suppressor Trp53. The Cdkn1a^LSL.SUPER mice conditionally express the mouse Cdkn1a allele fused to the tdTomato reporter. Mice hemizygous for the transgene are viable and fertile with no obvious abnormal phenotype. Upon removal of the loxP-STOP-loxP (LSL) cassette by cre-mediated recombination, mice overexpress Cdkn1a with the tdTomato reporter. TdTomato expression is visible by direct fluorescence. When treated with DMBA or TPA (induced skin carcinogenesis model) or 3MC (induced fibrosarcoma model) these Cdkn1a^SUPER mice develop fewer tumors than controls.

Mouse embryonic fibroblasts (MEFs) from Cdkn1a^SUPER mice exposed to genotoxic agents (etoposide, hydroxyurea and cisplatin) contain smaller fractions of EdU-positive cells (a measure of cell cycle arrest) as well as reduced fractions of gammaH2AX+ cells (a measure of DNA damage). In addition, treated-MEFs display a reduced percentage of apoptotic cells and increased cell survival as compared to controls. This strain may be useful for studying Trp53-mediated tumor suppression.

Development

BAC BMQ-448E21 carrying the genomic Cdkn1a mouse sequence was modified to replace the stop codon in exon 3 with a tdTomato reporter followed by polyA sequence. A loxP-STOP-loxP (LSL) cassette containing neomycin was inserted into intron 2. The modified BAC was introduced into the fertilized oocytes from C57BL/6N by pronuclear injection. Founder 260 was selected to establish this line and maintained on C57BL/6N. The donating investigator reports that the modified BAC includes only the Cdkn1a gene. Upon arrival at The Jackson Laboratory, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6NJ (Stock No. 005304) oocytes.

Allele

Symbol: Tg(Cdkn1a*/tdTomato)260Rein
Name: transgene insertion 260, H Christian Reinhardt
MGI accession ID: MGI:6270403
Generation method: Transgenic
Attributes: Conditional ready (e.g. floxed); Reporter; Inserted expressed sequence
Synonyms: Cdkn1a^LSL.SUPER
Marker symbol: Tg(Cdkn1a*/tdTomato)260Rein
Marker name: transgene insertion 260, H Christian Reinhardt
Chromosome: UN
Strain of origin: C57BL/6N
Site of expression:

The endogenous mouse Cdkn1a promoter directs conditional expression of the tdTomato reporter.

Molecular note: BAC BMQ-448E21 carrying the genomic Cdkn1a mouse sequence was modified to replace the stop codon in exon 3 with a tdTomato reporter followed by polyA sequence. A loxP-STOP-loxP (LSL) cassette was inserted into intron 2. The transgene inserted on the centromeric region of chromosome 6.