STOCK Igs2^{tm2(ACTB-tdTomato,-EGFP)Luo} Trp53^tm1Tyj Nf1^tm1Par/J

Stock number: 017530
Product name: MADM-TG,p53KO,NF1flox
Research areas: Apoptosis Research, Cancer Research, Immunology, Inflammation and Autoimmunity Research, Mouse/Human Gene Homologs, Neurobiology Research, Research Tools

Description

The MADM-TG,p53KO,NF1-flox strain may be used as a genetic mosaicism model for different types of cancers when bred to the companion MADM strain (Stock No. 013749), and to a Cre recombinase expressing strain.

Detailed description

Mice that are heterozygous for the Nf1^tm1Par Trp53^tm1Tyj alleles and homozygous for the Tg(ACTB-tdTomato,-EGFP)11Luo transgene are viable and fertile. The mosaic analysis with double markers (MADM) system (MADAM strains, Stock No. 013751 and Stock No. 013749), plus the Nf1^tm1Par Trp53^tm1Tyj alleles, coupled with a Cre recombinase expressing strain allows fluorescent labeling and tracking of cancer cells of origin, which are normal cells that acquire the first cancer conducive mutation(s) and initiate tumorigenesis. Cre-mediated inter-chromosomal recombination in the MADM system generates a small number of cells homozygous for the double reporter and the mutations, mimicking the intermittent loss of heterozygosity of tumor suppressor genes observed in human cancer. The system also labels the mutant daughter cells with Green Fluorescent Protein, while the sibling wildtype cells are labeled with Red Fluorescent Protein. Initially, mutant and wildtype sibling cells are produced in equal numbers. The mutant cell (cell of origin) population expansion can be quantified by the change in ratio of green to red fluorescently labeled cells.

When bred to the companion MADM strain (Stock No. 013749), and to the strain expressing Cre recombinase under the control of the human glial fibrillary acidic protein, GFAP, promoter (Stock No. 004600) the resulting mutant mice are a genetic mosaicism model for glioma.

Development

This triple mutant strain was generated by crossing Stock No. 013751, Stock No. 002101 and mice carrying the Nf1^tm1Par targeted mutation.

For the Nf1^tm1Par targeted mutation, a targeting vector containing a loxP site and a PGKNeo cassette was inserted upstream of exon 31. A second loxP site was inserted downstream of exon 32. The construct was electroporated into 129 derived R1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6 blastocysts. The resulting chimeric animals were crossed to C57BL/6 mice.

The Donating Investigator maintained the triple mutant line on the CD1 background. Upon arrival at The Jackson Laboratory, the triple mutant mice were crossed to (Stock No. 013751) females to establish the colony.

Allele

Symbol: Igs2^{tm2(ACTB-tdTomato,-EGFP)Luo}
Name: targeted mutation 2, Liqun Luo
MGI accession ID: MGI:4837863
Generation method: Targeted
Attributes: Reporter; Null/Knockout
Marker symbol: Igs2
Marker name: intergenic site 2
Chromosome: 11
Strain of origin: (129X1/SvJ x 129S1/Sv)F1-Kitl⁺
Expressed genes: GFP,Green Fluorescent Protein,; RFP,Red Fluorescent Protein,coral
Site of expression: Mutant daughter cells express GFP, while the sibling wildtype cells are labeled with RFP.
Molecular note: The TG MADM targeting construct was designed with a CMV enhancer/chicken beta-actin core promoter (pCA), the N-terminal portion of a red fluorescent protein (tdTomato; aa 1-3), a beta-globin intronic sequence containing an frt site and loxP-flanked neomycin resistance gene, the C-terminal portion of a mutant enhanced green fluorescent protein (mut4-EGFP; aa 274-724), and an SV40 T-antigen poly(A) signal. This entire TG MADM construct was inserted into the "Hipp11" locus on chromosome 11 (cytoband A1 at ~3cM between the Eif4enif1 and Drg1 loci).

Allele

Symbol: Trp53^tm1Tyj
Name: targeted mutation 1, Tyler Jacks
MGI accession ID: MGI:1857263
Generation method: Targeted
Attributes: Null/Knockout
Marker symbol: Trp53
Marker name: transformation related protein 53
Chromosome: 11
Strain of origin: 129S2/SvPas
Site of expression: Normal Trp53 expression is widespread.
Molecular note: A neomycin cassette replaced 40% of the coding sequences beginning with exon 2 (upstream of the translation start site) and extending into exon 6.
General note: This mutant allele was produced by a targeted neo insertion into the Trp53 locus. Homozygotes show no visible phenotype but develop tumors at 3-6 months of age. Heterozygotes develop tumors at 10 months of age. These mice model some of the features of human Li-Fraumeni syndrome (OMIM 151623), a form of familial breast cancer with mutations in TRP53 (J:16022)(J:16023) A specific human mutation found in hepatocellular carcinomas caused by hepatitis B infection or by aflatoxin exposure has been created in a mouse model, resulting in a similar gene product (J:27363).

Allele

Symbol: Nf1^tm1Par
Name: targeted mutation 1, Luis F Parada
MGI accession ID: MGI:2176057
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Marker symbol: Nf1
Marker name: neurofibromin 1
Chromosome: 11
Strain of origin: (129X1/SvJ x 129S1/Sv)F1-Kitl⁺
Site of expression: When mice carrying this allele are mated to a Synapsin I promoter driven Cre transgenic mouse strain, NF1 function is abated in most differentiated neuronal populations, resulting in abnormal development of the cerebral cortex.
Molecular note: A loxP-neomycin selection cassette was inserted into intron 30 and a single loxP site was inserted into intron 32.