This Ppm1d knock-out strain is useful in studies of tumorigenesis, cell proliferation, inflammation, autophagy, obesity, and atherosclerosis.
Lawrence A. Donehower, Baylor College of Medicine
The targeted Ppm1d gene encodes a serine/threonine phosphatase involved in DNA damage repair pathways and tumor proliferation. These mice carry a knock-out allele of the Ppm1d gene in which exons 4 and 5 have been replaced by a PGK-puro cassette. Heterozygous males and homozygous females are viable and fertile. On the mixed B6;129S7 background, homozygotes are born at a lower than expected frequency (16%), with fewer homozygous male pups than homozygous female pups. Homozygous males exhibit reduced fertility. No gene product (mRNA) is detected by northern blot analysis of testis tissue from homozygotes, although a truncated unstable transcript is detected by RT-PCR analysis. No gene product (protein) is detected by western blot analysis of testis tissue from homozygotes. Homozygous males have reduced body mass and smaller reproductive organs not due to reduced body mass, compared to wildtype controls. Fewer homozygous males survive to 2 years of age, compared to homozygous female mice.
In addition to splenic myeloid and plasmactyic hyperplasia, sometimes with loss of splenic architecture, homozygotes exhibit decreased B and T cell proliferation when stimulated, reduced B cell numbers, insulin resistance and increase susceptibility to viral and bacterial infections.
Homozygotes display reduced exploratory behavior and enhanced anxiety-like and depression-like behavior.
A targeting vector containing a PGK-Puro cassette was used to disrupt exons 4 and 5. The construct was electroporated into 129S7/SvEvBrd-Hprt+ derived AB1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts.
The resulting chimeric animals were crossed to albino C57BL/6 mice. The mice were then backcrossed to C57BL/6 for 4 generations. The mice may have been crossed to a mutant line containing FVB.
Upon arrival, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).
|Allele Name||targeted mutation 1, Lawrence A Donehower|
|Allele Type||Targeted (Null/Knockout)|
|Allele Synonym(s)||Wip1-; WIP1-|
|Gene Symbol and Name||Ppm1d, protein phosphatase 1D magnesium-dependent, delta isoform|
|Strain of Origin||129S7/SvEvBrd-Hprt+|
|Molecular Note||Exons 4 and 5 were replaced with a PGK-puro cassette via homologous recombination resulting in protein truncation. Northern blot analysis of tissues from homozygous mutant animals did not detect gene transcript although a transcript with deleted exons 4 and 5, presumed to be unstable, was detected by RT-PCR. Western blot of irradiated testes from homozygous mutants did not detect protein product.|
When maintaining a live colony, these mice can be bred as homozygous females and heterozygous males. On the mixed B6;129S7 background, homozygotes are produced at a lower than expected frequency (16%) from heterozygous crosses. Homozygous males exhibit reduced fertility.
When using the Wip1 KO mouse strain in a publication, please cite the originating article(s) and include JAX stock #028980 in your Materials and Methods section.