STOCK Ptf1a^tm1(cre)Hnak/RschJ

Stock number: 023329
Product name: p48-cre
Research areas: Developmental Biology Research, Research Tools

Description

The p48-cre knock-in/knock-out allele has a Cre recombinase gene inserted into the first coding exon of the Ptf1a gene; both abolishing endogenous Ptf1a gene function and placing cre expression under the control of the endogenous Ptf1a promoter/enhancer elements. Cre recombinase activity occurs in the developing pancreas, neural tube, cerebellum, retina and male germline. These mice may be useful for Cre-lox studies of pancreatic development.

Detailed description

The Ptf1a gene encodes a transcription factor involved in pancreatic organogenesis. This p48-cre strain expresses Cre recombinase from the endogenous Ptf1a locus and results in a null allele. Cre recombinase sequence was inserted at the start codon of the gene. When crossed with a strain containing loxP site flanked sequence of interest, Cre-mediated recombination results in tissue-specific deletion of the target. Recombination occurs in embryonic mice, at E10.5, in the pancreas (specifically the prepancreatic endoderm and progenitor and exocrine cells), neural tube, cerebellum and retina. Germline expression is also described below. Mice that are heterozygous for the targeted mutation are viable and fertile. Homozygotes are not viable, dying within 3 hours of birth.

Kabacaoglu et al. 2021 Gastroenterology 161:1695 reports that p48-cre mice express Cre in male germline. The recombination event was observed in multiple floxed alleles, while the frequency varied depending on the target gene. Additionally, Cre allele transmission into progeny was not necessary for the germline recombination. As such, for Cre-lox experiments and to avoid/minimize germline deletion of the floxed allele, researchers may consider breeding p48-cre females with floxed males.
If the recombinase activity pattern of this allele is further characterized by the Genetic Resource Science group at The Jackson Laboratory, such findings will be reported on the Mouse Genome Informatics (MGI) Allele Detail entry (Ptf1a^tm1(cre)Hnak). This same information may also be found searching the MGI Recombinase Activity and MGI Gene Expression + Recombinase Activity Comparison Matrix.

Development

A targeting vector containing cre coding sequence and a FRT site flanked NEO cassette was used to disrupt part of exon 1 of the targeted Ptf1a gene. The endogenous Ptf1a promoter drives expression of the Cre recombinase coding sequence. The construct was electroporated into unspecified embryonic stem (ES) cells which were transiently transfected with a FLP recombinase plasmid to remove the selection cassette. ES cells that had successfully undergone FLP-mediated recombination and no longer retained the NEO cassette were injected into blastocysts. The resulting chimeric animals were tested for germline transmission. The strain was maintained on a mixed B6;129 background but could contain contributions from other genetic backgrounds. 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

Symbol: Ptf1a^tm1(cre)Hnak
Name: targeted mutation 1, Hassan Nakhai
MGI accession ID: MGI:3701996
Generation method: Targeted
Attributes: Recombinase-expressing
Marker symbol: Ptf1a
Marker name: pancreas specific transcription factor, 1a
Chromosome: 2
Strain of origin: Not Specified
Expressed genes: cre,cre recombinase,bacteriophage P1
Site of expression: Cre recombination occurs in embryonic mice, at E10.5, in the pancreas (specifically the prepancreatic endoderm and progenitor and exocrine cells), neural tube, cerebellum and retina.
Molecular note: Cre recombinase replaced part of exon 1. A neomycin resistance gene included in the vector was subsequently removed via transient FLP expression.