STOCK Ptpmt1^tm1.1Jedi/J

Stock number: 020775
Product name: Ptpmt1^floxed
Research areas: Cancer Research, Cell Biology Research, Neurobiology Research, Research Tools

Description

The Ptpmt1^flox floxed allele has loxP sites flanking exons 1-2 of the protein tyrosine phosphatase mitochondrial 1 gene. Removal of the floxed sequence creates a null allele. These mice may be useful in studying mitochondrial signal transduction and mitochondria deficiency-related diseases.

Detailed description

The Ptpmt1^flox allele has loxP sites flanking Ptpmt1 exons 1-2. Mice homozygous for this floxed allele are viable and fertile with no reported gross physical or behavioral abnormalities. When bred to mice that express Cre recombinase, the resulting offspring will have the floxed region deleted in cre-expressing tissues - resulting in a knock-out allele (Ptpmt1^-). Global PTPMT1-deficiency in mice is embryonic lethal.

For example, the knock-out allele is created after breeding to mice expressing Cre recombinase in male germ cells during spermatogenesis (Protamine1-Cre; see Stock No. 003328). The resulting animals allow in vitro studies identifying that PTPMT1-deficient cells have profound defects in mitochondrial respiratory capacity and inner mitochondrial membrane morphology due to cardiolipin deficiency.

Development

The Ptpmt1^flox (floxed exons 1-2) allele was created in the laboratory of Dr. Jack E. Dixon (University of California, San Diego). First, a targeting vector was designed to insert a loxP site upstream of exon 1, and an frt-flanked neo cassette followed by a second loxP site downstream of exon 2 of the protein tyrosine phosphatase mitochondrial 1 locus (Ptpmt1) on chromosome 2. The targeting vector was electroporated into (129X1/SvJ x 129S1/Sv)F1-Kitl⁺-derived R1 embryonic stem (ES) cells. Chimeric animals were bred to C57BL/6J mice for germline transmission. The Ptpmt1^targeted mutant mice were then bred with FLPe-deleter mice (Tg(ACTFLPe)9205Dym on an undisclosed genetic background) for germline removal of the neo cassette. The resulting Ptpmt1^flox offspring were selected. The donating investigator reported that the Ptpmt1^flox colony was backcrossed to C57BL/6J wildtype mice for several generations (and the FLP-expressing transgene was removed) (see SNP note below). In 2017, Ptpmt1^targeted males with black coat color were sent to The Jackson Laboratory Repository. 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).
Of note, it is not known if the Y chromosome has been fixed to the C57BL/6 background during backcrossing.

In 2017, a 48 single nucleotide polymorphism (SNP) panel analysis, with markers covering all 19 chromosomes and the X chromosome, as well as several markers that distinguish between the C57BL/6J and C57BL/6N substrains, was performed on the males sent to The Jackson Laboratory Repository. This revealed several markers were not fixed for C57BL/6 allele-type (i.e., still segregating for 129S and other allele-type markers). Collectively, these data suggest that the mice sent to The Jackson Laboratory Repository were incompletely backcrossed onto C57BL/6, and the genetic background of the mice was more than 50% C57BL/6 with contributions from other mouse genetic backgrounds.

Allele

Symbol: Ptpmt1^tm1.1Jedi
Name: targeted mutation 1.1, Jack E Dixon
MGI accession ID: MGI:5291923
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Marker symbol: Ptpmt1
Marker name: protein tyrosine phosphatase, mitochondrial 1
Chromosome: 2
Strain of origin: (129X1/SvJ x 129S1/Sv)F1-Kitl⁺
Molecular note: A loxP site was inserted upstream of exon 1. An FRT-flanked neo cassette with a 3' loxP site was inserted downstream of exon 2. The neo cassette as deleted by flp recombinase.