STOCK Igs2^{tm1(CAG-Myc*T58A/luc)Wrey}/J

Stock number: 035557
Product name: LSL-Myc^T58A
Research areas: Cancer Research, Research Tools

Description

LSL-Myc^T58A mice contain a Cre recombinase regulatable Myc^T58A allele under control of a CAG promoter. They are useful as a model of small cell lung cancer (SCLC).

Detailed description

LSL-Myc^T58A mice contain a Cre recombinase regulatable Myc^T58A allele under control of a CAG promoter from the endogenous intergenic site 2, Igs2 locus (Hipp11 or H11; an intergenic region on chromosome 11 [cytoband A1 at ~3cM between the Eif4enif1 and Drg1 loci] reported to support high-level global gene expression in conjunction with the CAG (CAGGS) promoter).

Myc (myelocytomatosis oncogene) gene encodes a transcription factor involved in cellular metabolism, cell proliferation and gene transcription regulation which is often up-regulated in tumors, leukemias and lymphomas, including Burkitt lymphoma. Mutations in myc have been associated with poor outcome, tumor progression and treatment resistance due to increased genomic instability and suppressed apoptosis.

LSL-Myc^T58A homozygous mice are viable and fertile. When these LSL-Myc^T58A mice are bred to mice that express Cre recombinase or Cre recombinase is administered via viral vector, resulting offspring will have the floxed STOP cassette removed in cre-expressing tissues. After cre excision, Myc^T58A is expressed.

The donating lab states that the luciferase gene is functional. It has some background activity in the absence of Cre. In the presence of Cre, the luciferase activity is induced to a much higher level.

Development

A transgene was designed to contain (from 5’to 3’) an attB site, a CMV-IE enhancer/chicken beta-actin/rabbit beta-globin hybrid promoter (CAG), a loxP-flanked stop cassette (LSL), a myelocytomatosis oncogene (Myc) cDNA with a T58A mutation. An internal ribosome entry site (IRES) followed by a Luciferase gene, a woodchuck hepatitis virus post-transcriptional regulatory element (WPRE; to enhance the mRNA transcript stability), and a polyadenylation sequence were fused to the 3’ end. This construct was microinjected, along with the ΦC31 integrase mRNA, into the pronuclei of zygotes collected from the H11 TARGATT mice on a FVB genetic background. These zygotes contain three attP sites inserted in the Hipp1 locus, Igs2 (intergenic site 2) gene, (H11^attPx3). One founder mouse carried the correctly targeted transgenic insertion of the construct into the first and second attP sites of the H11^attPx3 locus. This LSL-Myc^T58A founder was bred to Trp53 floxed females from MMHCC (Strain #01XC2) on a FVB/129 background (see Stock No. 008462).

The resulting LSL-Myc^T58A Trp53^fl/fl mice were bred to mice containing a floxed retinoblastoma 1 (Rb1) allele (Rb1^fl/fl) (similar to Stock No. 008186). Offspring were intercrossed to obtain Rb1^fl/fl Trp53^fl/fl Myc^LSL/LSL (RPM) mice were maintained on a mixed genetic background. Male and female carriers were sent to The Jackson Laboratory Repository to establish a colony of RPM mice as Stock No. 029971.

Some of these RPM mice were further crossed to C57BL/6J mice (Stock No. 000664) to isolate the LSL-Myc^T58A allele being offered as this new Stock No. 035557.

Allele

Symbol: Igs2^{tm1(CAG-Myc*T58A/luc)Wrey}
Name: targeted mutation 1, Robert Wechsler-Reya
MGI accession ID: MGI:5812580
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); Reporter; Inserted expressed sequence
Synonyms: H11^{lox-STOP-lox -MycT58A}; Igs2^{tm1(CAG-Myc*T58A/luc)Olvr}; LSL-Myc^T58A
Marker symbol: Igs2
Marker name: intergenic site 2
Marker synonyms: H11; Hipp11; Iis2
Chromosome: 11
Strain of origin: STOCK Igs2^tm3.1Luo/Luo
Expressed genes: Myc,myelocytomatosis oncogene,mouse, laboratory; luc,luciferase,firefly
Site of expression: Upon Cre recombinase, resulting offspring will have the floxed STOP cassette removed in cre-expressing tissues with subsequent expression of Myc^T58A and Luciferase bioluminescence.
Molecular note: The construct is designed to contain (from 5'to 3') an attB site, a CMV-IE enhancer/chicken beta-actin/rabbit beta-globin hybrid promoter (CAG), a loxP-flanked stop cassette (LSL), a myelocytomatosis oncogene (Myc) cDNA with a T58A mutation fused to an internal ribosome entry site (IRES) followed by a luciferase gene, a woodchuck hepatitis virus post-transcriptional regulatory element (WPRE; to enhance the mRNA transcript stability), and a polyadenylation sequence. This construct was microinjected, along with the PhiC31 integrase mRNA, into the pronuclei of zygotes collected from the TARGATT mice on a FVB/N congenic background. TARGATT mice carry the H11 allele ( Igs2^tm3.1Luo) or H11P3; a unique sequence from the promoter of the yeast his3 gene followed by three shortened tandem attP sites and one FRT5 site. One founder mouse carried the correctly targeted transgenic insertion of the construct into the first and second attP sites of the locus.
General note: This allele was produced in zygotes collected from mice carrying the Igs2^tm3.1Luo allele, which was generated in (129X1/SvJ x 129S1/Sv)F1-Kitl⁺-derived R1 ES cells on a mixed background with 129S1/SvJ, 129X1/SvJ, C57BL/6J, DBA/2J, and FVB/N.