B6.129(Cg)-Csnk1a1^tm1.1Ybn/J

Stock number: 025398
Product name: CsnK1a1^fl
Research areas: Cancer Research, Cell Biology Research, Immunology, Inflammation and Autoimmunity Research, Neurobiology Research, Research Tools

Description

These CsnK1a1^fl floxed mice allow Cre recombinase-inducible knockout of casein kinase Ia (CKIα) for studying multiple cellular processes (Wnt pathway, cell cycle regulation, DNA damage response, KRAS-MEK-ERK mitogenic signaling, β-catenin-destruction complex) in cancer and senescence-associated inflammatory response (SIR)/para-inflammation suppression.

Detailed description

The CsnK1a1^fl (also called Slc6a8^fl) conditional allele has loxP sites flanking exons 1-2 of the casein kinase Ia gene (CKIα). When bred to mice that express Cre recombinase, the resulting offspring will have the floxed sequences deleted in the cre-expressing tissues. Homozygous mice (CsnK1a1^flox/flox) are viable and fertile with no reported abnormalities. When CsnK1a1^fl mice are bred to the germline Cre-deleter strain Pgk1-Cre (e.g., Stock No. 020811), the resulting CsnK1a1 pan-deletion homozygotes die before embryonic day (E)6.5.
These CsnK1a1^fl mice are a Cre-lox tool for generating tissue-specific CsnK1a1 deletions, and may be useful for studying cancer, tumorigenesis and multiple cellular processes including Wnt pathway, cell cycle regulation, DNA damage response and β-catenin-destruction complex.
For example, breeding CsnK1a1^fl to mice expressing Cre recombinase in intestinal tissue (e.g., Vil1-Cre; Stock No. 021504) results in intestinal CsnK1a1 ablation mice. Such mice recapitulate many features of human colorectal tumors (including Wnt hyperinduction, induction of the DNA damage response and cellular senescence), as well as widespread cyclin D1 expression and substantial p53 expression, all in the absence of tumorigenesis (absence of Wnt-associated excessive proliferation or tumorigenesis; gut homeostasis is maintained). Subsequent breeding to p53^flox (Stock No. 008462) or p21-/- (Stock No. 003263) allow further investigation into the factors initiating highly invasive carcinoma.

Development

A targeting vector was designed by Dr. Yinon Ben-Neriah (The Hebrew University of Jerusalem) to place loxP sites flanking exons 1-2 of the casein kinase 1, alpha 1 gene (Csnk1a1 or CKIα) on chromosome 18. This also inserted a loxP-flanked neomycin cassette. The construct was electroporated into (129X1/SvJ x 129S1/Sv)F1-Kitl⁺-derived R1 embryonic stem (ES) cells. Next, ES cells were transiently transfected with the pCA-NLS-Cre vector. The resulting ES cells with the CsnK1a1^fl genotype (retaining the floxed exons 1-2 with deletion of the neo cassette) were identified and used for aggregation with CD1-derived morulae. Chimeric mice were bred to CD1 for germline transmission. The donating investigator reported that the CsnK1a1^fl colony was bred with C57BL/6 inbred mice (a mixture of C57BL/6JOlaHsd and C57BL/6J) for at least ten generations (see SNP results below). During backcrossing, the Y chromosome may not have been fixed to the C57BL/6 genetic background. In 2015, CsnK1a1^fl males were sent to The Jackson Laboratory Repository. Upon arrival, sperm was cryopreserved. To generate the living CsnK1a1^fl colony, an aliquot of the frozen sperm was used to fertilize oocytes from C57BL/6J female mice (Stock No. 000664). The CsnK1a1^fl colony was then maintained by breeding heterozygous or homozygous mice together.

In 2015, a 32 SNP (single nucleotide polymorphism) panel analysis, with 27 markers covering all 19 chromosomes and the X chromosome, as well as 5 markers that distinguish between the C57BL/6J and C57BL/6N substrains, was performed on all 14 heterozygous mice from the first generation rederived living colony at The Jackson Laboratory Repository. All 26 markers on somatic chromosomes throughout the genome suggest a C57BL/6 genetic background. All heterozygous females, but none of the heterozygous males, had one marker on the X chromosome [~66.9 Mbp] segregating for C57BL/6 and 129 allele-type.
In addition, 3 of 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating in all tested mice (chromosomes 8 [~15.2 Mbp], 15 [~57.6 Mbp] and 19 [~49.9 Mbp]), and some mice had one marker segregating on chromosome 13 [~41.0 Mbp]. These data suggest that the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6N;C57BL/6J genetic background, or alternatively, the C57BL/6JOlaHsd contributions may have similar SNPs as C57BL/6N.

Allele

Symbol: Csnk1a1^tm1.1Ybn
Name: targeted mutation 1.1, Yinon Ben-Neriah
MGI accession ID: MGI:5543667
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Marker symbol: Csnk1a1
Marker name: casein kinase 1, alpha 1
Chromosome: 18
Strain of origin: (129X1/SvJ x 129S1/Sv)F1-Kitl⁺
Molecular note: A floxed neomycin resistance cassette was inserted upstream of exon 1. An additional loxP site was inserted downstream of exon 2. Cre-mediated recombination removed the neomycin resistance cassette and left exons 1 and 2 floxed.