B6.129S4-Mtor^tm1.2Koz/J

Stock number: 011009
Product name: Frap1^fl
Strain synonyms: mTOR^fl
Research areas: Cancer Research, Cell Biology Research, Immunology, Inflammation and Autoimmunity Research, Neurobiology Research, Research Tools

Description

These mTOR^fl mutant mice harbor loxP sites flanking exons 1-5 of the mechanistic target of rapamycin (serine/threonine kinase) locus, and may be useful in generating conditional mutations for studying mTOR and mTOR complex signaling; including regulation of cell growth, cell proliferation/differentiation, cell survival, cancer, tumor cell motility and metastasis, the RTK-PI3K-mTOR signaling axis, stem cell development, cytokine signaling, and T cell lineage commitment.

Detailed description

Mice homozygous for this mTOR^fl allele are viable and fertile, with loxP sites flanking exons 1-5 of the targeted gene. When bred to mice that express Cre recombinase, the resulting offspring will have the sequences encoding the putative transcription start site and the coding sequence through coding exon 5 deleted in the cre-expressing tissue(s). These mTOR^fl mutant mice may be useful in generating conditional mutations for studying mTOR and mTOR complex signaling; including regulation of cell growth, cell proliferation/differentiation, cell survival, cancer, tumor cell motility and metastasis, the RTK-PI3K-mTOR signaling axis, stem cell development, cytokine signaling, and T cell lineage commitment.

For example, when bred to a strain expressing Cre recombinase in adult striated muscle fibers and embryonic striated muscle cells of the somites and heart (see Stock No. 006149 for example), this mutant mouse strain may be useful in studies of myopathies.

Development

The mTOR^neo targeting vector was designed to insert a loxP site upstream of the promoter region (upstream of exon 1) and a loxP-flanked PGK-neo cassette just downstream of exon 5 of the targeted gene. This construct was electroporated into 129SvJae-derived embryonic stem (ES) cells (probably 129S4/SvJae-derived ES cells). The resulting original mTOR^neo ES cell clone was then transiently transfected with a Cre recombinase-expressing plasmid. The resulting ES cells with the mTOR^fl genotype (neo selection cassette removed; leaving a single loxP site upstream of the promoter region and a single loxP site downstream of exon 5) were injected into recipient blastocysts. Chimeric mice were bred with C57BL/6J mice to generate the mTOR^fl colony. The donating investigator reported that mTOR^fl mutant mice were subsequently backcrossed to C57BL/6J mice (see SNP note below) for ten generations prior to sending to The Jackson Laboratory Repository. Upon arrival, mutant mice were bred to C57BL/6J (Stock No. 000664) for at least one generation to establish the colony.

A 32 SNP (single nucleotide polymorphism) panel analysis, with 27 markers covering all 19 chromosomes and the X chromosome, as well as 5 markers that distinguish between the C57BL/6J and C57BL/6N substrains, was performed on the rederived living colony at The Jackson Laboratory Repository. While the 27 markers throughout the genome suggested a C57BL/6 genetic background, 1 of 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6J ; C57BL/6N genetic background.

Allele

Symbol: Mtor^tm1.2Koz
Name: targeted mutation 1.2, Sara C Kozma
MGI accession ID: MGI:3850506
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Marker symbol: Mtor
Marker name: mechanistic target of rapamycin kinase
Chromosome: 4
Strain of origin: 129S4/SvJae
Molecular note: A loxP site was inserted upstream of exon 1 and a floxed neo cassette was inserted downstream of exon 5. Transient cre expression in ES cells removed the neo cassette creating this allele.