Ptenflox mice have loxP sites flanking exon 5 of the tumor suppressor phosphatase and tensin homolog gene. This FVB/NJ-congenic Ptenflox strain is useful for generating Cre recombinase-inducible, tissue-specific PTEN knock-out mice for studies of oncology, neurogenesis, glial differentiation and cerebellar development, for example.
Hong Wu, UCLA
Jung-Whan Kim, The University of Texas at Dallas
In an attempt to offer alleles on well-characterized or multiple genetic backgrounds, alleles are frequently moved to a genetic background different from that on which an allele was first characterized. The phenotype summarized below is for the parental line: Ptenflox mice on a C57BL/6 genetic background (Stock No. 006440). It should be noted that the phenotype of this FVB/NJ-congenic Ptenflox line (Stock No. 034621) could vary from that of the parental line from which it was derived.
These mice possess loxP sites flanking exon 5 of the targeted gene. Mice homozygous for the "floxed" allele are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. When used in conjunction with a Cre recombinase-expressing strain, this strain is useful in generating tissue-specific mutants of the floxed allele.
For example, when crossed to a strain expressing Cre recombinase in astrocytes (see Stock No. 012887), this mutant mouse strain may be useful in studies of neurogenesis.
When crossed to a strain expressing Cre recombinase in the central nervous system (see Stock No. 004600), this mutant mouse strain may be useful in studies of glia differentiation and cerebellar development.
When crossed to B6.129X1-Twist2tm1.1(cre)Dor/J mice (Stock No. 008712) expressing Cre recombinase in mesoderm-derived tissues (including chondrocytes and osteoblasts) offspring die at birth and exhibit defects in angioblast differentiation.
A loxP site flanked targeting vector containing hygromycin resistance and thymidine kinase genes was used in the construction of this mutant. This selection cassette was inserted downstream of exon 5 of the targeted gene, and another loxP site was inserted upstream of exon 5. This construct was electroporated into 129S4/SvJae derived LW-1 embryonic stem (ES) cells, which were transiently transfected with a Cre-recombinase vector to remove the selection cassette. Correctly targeted ES cells were injected into BALB/c blastocysts. The resulting chimeric animals were crossed to BALB/cAnNTac mice before being made homozygous. The mice were then backcrossed onto the C57BL/6J background for at least 12 generations before being donated to The Jackson Laboratory in 2006 as Stock No. 006440.
In 2016, Dr. Jung-Whan Kim purchased some Stock No. 006440 animals (~N12 onto C57BL/6) and then backcrossed them at least ten generations to FVB/NJ inbred mice (from Stock No. 001800). The resulting FVB/NJ-congenic strain is called FVB.Ptenflox. Of note, the donating investigator reports that, at least once during backcrossing, a Ptenflox female was bred to an FVB/NJ inbred male (thus the Y chromosome of the congenic strain is of FVB/NJ origin). In 2020, FVB.Ptenflox males (white coat color) were sent to The Jackson Laboratory Repository as Stock No. 034621. Upon arrival, males were used to cryopreserve sperm. To establish our live colony, an aliquot of frozen sperm was used to fertilize FVB/NJ oocytes (Stock No. 001800).
|Allele Name||targeted mutation 1, Hong Wu|
|Allele Type||Targeted (Conditional ready (e.g. floxed), No functional change)|
|Allele Synonym(s)||Ptenex5lox; PTENF; Ptenfl; Ptenflox; Ptenflx; Ptenfx; Ptenlox; Ptenloxp|
|Gene Symbol and Name||Pten, phosphatase and tensin homolog|
|Site of Expression||Pten is a widely expressed tumor suppresser gene.|
|Strain of Origin||129S4/SvJae|
|General Note||Phenotypic Similarity to Human Syndrome: PTEN Hamartoma Tumor Syndrome (see OMIM:601728 Phosphatase And Tensin Homolog; PTEN) J:199362|
|Molecular Note||A loxP flanked hygromycin resistance cassette was inserted 5' to exon 5, and a single loxP site was inserted 3' to exon 5, which encodes the phosphatase domain. The hygromycin cassette was removed in ES cells by transient Cre recombinase expression prior to the production of chimeric mice, leaving a single loxP site in place of the cassette. These insertions do not appear to have any effect on the normal function of the gene.|
|Mutations Made By|| |
Hong Wu, UCLA
When maintaining a live colony, these mice may be bred as homozygotes.
When using the FVB.Ptenflox mouse strain in a publication, please cite the originating article(s) and include JAX stock #034621 in your Materials and Methods section.