B6;129-Ppif^tm1Maf/J

Stock number: 022308
Product name: CyPD-KO
Research areas: Apoptosis Research, Cell Biology Research, Metabolism Research, Neurobiology Research, Research Tools

Description

Exons 1 through 3 and 20 bp upstream of the initiation codon of the Ppif, peptidylprolyl isomerase F (cyclophilin F), gene are disrupted in this mutant mouse strain. Homozygotes exhibit Ca²⁺ desensitized mitochondrial permeability transition pore and may useful in studies of mitochondrial homeostasis and dysfunction, and neuroprotection during oxidative stress.

Detailed description

The Ppif, peptidylprolyl isomerase F (cyclophilin F), gene encodes for a protein that is a component of the mitochondrial permeability transition pore in the inner mitochondrial membrane and that is involved in apoptosis and necrosis. These mice carry a targeted mutation in which a NEO cassette replaced exons 1 through 3 and 20 bp upstream of the ATG translation initiation codon. Mice that are homozygous for the targeted mutation are viable and fertile. No gene product (protein) is detected by Western blot analysis of mitochondrial extracts from homozygous mouse livers, kidney, or heart. Mitochondrial permeability transition pore in homozygotes is desensitized to calcium ions, with twice as much Ca²⁺ to required open the permeability transition pore when compared to wildtype controls. Cyclosporin A treatment does not increase Ca²⁺ retention capacity of mitochondria of null mice. Neurons isolated from adult homozygotes exhibit greater capacity to accumulate Ca²⁺ and are resistant to oxidative stress. Homozygous mice develop adult onset obesity (due to increased accumulation of white adipose tissue) and exhibit increased anxiety in open field and elevated plus maze assessments. The Donating Investigator reports that mice shipped to JAX have an agouti coat color; upon arrival at JAX the mice were bred to C57BL/6J and selected for a black coat color.

During backcrossing, the Y chromosome may not have been fixed to the C57BL/6 genetic background.

Development

A targeting vector designed by Dr. Michael A. Forte (Vollum Institute, Oregon Health and Sciences University) containing a NEO selection cassette was used to disrupt the first 3 exons and 20 bp upstream of the ATG translation initiation codon. The construct was electroporated into unspecified 129Sv derived embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6 blastocysts. The donating investigator reports that the resulting male chimeric animals were crossed to C57BL/6 female mice, and then backcrossed to C57BL/6 for 8 generations (see SNP note below). Heterozygotes were crossed to generate homozygotes. The mice were then backcrossed for another 3 generations to C57BL/6. During backcrossing, the Y chromosome may not have been fixed to the C57BL/6 genetic background. The Donating Investigator reports that mice shipped to JAX have an agouti coat color. Upon arrival at The Jackson Laboratory, the mice were crossed to C57BL/6J (Stock No. 000664) at least once to establish the colony and select for black coat color.

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 the rederived living colony at The Jackson Laboratory Repository. Two the 27 markers throughout the genome suggested a 129 was still present in the background. Two of 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating, suggesting the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6J ; C57BL/6N genetic background.

Allele

Symbol: Ppif^tm1Maf
Name: targeted mutation 1, Michael A Forte
MGI accession ID: MGI:3586298
Generation method: Targeted
Attributes: Null/Knockout
Marker symbol: Ppif
Marker name: peptidylprolyl isomerase F (cyclophilin F)
Chromosome: 14
Strain of origin: 129
Molecular note: The insertion of a neomycin resistance cassette resulted in the deletion of the first three exons of the locus, including 20 bp upstream of the ATG. No protein was detected in mutant liver, kidney or heart samples.