Pabpn1 floxed mice possess a loxP sited flanking exons 1-2, including the start codon, of the poly(A) binding protein, nuclear 1 (Pabpn1) gene. These mice may be useful when studying Oculopharyngeal muscular dystrophy (OPMD).
Grace Pavlath, Emory University School of Medicine
Pabpn1 floxed mice possess loxP sites flanking exons 1-2 of the poly(A) binding protein, nuclear 1 (PABPN1) gene. PABPN1 is a ubiquitously expressed RNA binding protein that is most well characterized as a regulator of polyadenosine (poly[A]) tail length and alternative polyadenylation (APA), as well as a regulator of expression of antisense RNAs associated with gene promoters. A stretch of ten alanines just after the initial methionine and a dominant GCG expansion to 11-18 alanines in PABPN1 is associated with the onset of Oculopharyngeal muscular dystrophy (OPMD). This is a late onset disease that causes ptosis, dysphagia, and loss of mobility due to progressive weakness of eyelid, pharyngeal, and proximal limb muscles. Patients are affected by loss of nutrition and aspiration pneumonia. When these mutant mice are bred to mice that express Cre recombinase, resulting offspring will have exons 1-2, including the start codon and the 10-alanine residues, removed in cre-expressing tissues. Mice that are homozygous for this allele are viable and fertile.
When bred to B6.FVB-Tg(EIIa-cre)C5379Lmgd/J (Stock No. 003724) mice, with early embryonic Cre Recombinase expression, resulting Pabpn1 deficient mice exhibit mild myopathic phenotype in adult and aged animals. They have shorter poly(A) tails and evidence of mitochondrial damage as noted by loss of mtDNA copy number. They also have smaller hind limb muscles.
The Pabpn1 floxed targeting vector was designed to insert a loxP-site upstream of the start codon of the poly(A) binding protein, nuclear 1 (Pabpn1) gene, and a frt-flanked puromycin resistance (puro) cassette and a second loxP-site downstream of exon 2. The construct was electroporated into C57BL/6-derived HZ1.1 embryonic stem (ES) cells. Correctly targeted ES cells were transiently transfected with a FLP expression plasmid to delete the puro cassette. Resulting ES cells were injected into blastocysts and chimeric males were bred with C57BL/6J females, and were subsequently bred to C57BL/6J mice for at least 5 generations. 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 2.1, Grace Pavlath|
|Allele Type||Targeted (Conditional ready (e.g. floxed))|
|Gene Symbol and Name||Pabpn1, poly(A) binding protein, nuclear 1|
|Strain of Origin||C57BL/6|
|General Note||ES cell line = HZ1.1|
|Molecular Note||A loxP site was inserted upstream of exon 1 and an FRT site flanked puromycin resistance gene cassette and a second loxP site into intron 2. The puro cassette was removed through subsequent Flp-mediated recombination. Exons 1 and 2 were deleted through Cre-mediated recombination, creating a null allele.|
When maintaining a live colony, mice homozygous for the floxed allele may be bred together.
When using the Pabpn1 floxed mouse strain in a publication, please cite the originating article(s) and include JAX stock #029237 in your Materials and Methods section.