C57BL/6-Xpo1^tm1.1Oaw/J

Stock number: 033957
Product name: XPO1^E571K
Research areas: Cancer Research, Research Tools

Description

Xpo1^E571K/WT mice have an inverted cassette containing exons 15-17, carrying a glutamic acid to lysine mutation (E571K) in the inverted exon 16, downstream of the endogenous exon 17 of the exportin 1 (Xpo1) gene. The inverted exons are able to be placed in transcriptional orientation by Cre-mediated removal of the endogenous exons 15-17 and inversion of the mutated cassette. These mice may be useful when studying some types of cancer, including chronic lymphocytic leukemia (CLL), Hodgkin's lymphoma (HL), and esophageal carcinoma.

Detailed description

XPO1 encodes the main nuclear export receptor in eukaryotic cells and is misregulated or mutated in some myeloproliferative diseases and cancers. E571K, the most common XPO1 mutation, is only found in the heterozygous state and never occurs as homozygous or hemizygous. E571K mutation is commonly found in patients with some types of cancers. It is enriched in B-cell lymphomas, including primary mediastinal B-cell lymphoma (PMBL), classical Hodgkin's lymphoma (HL), and diffuse large B-cell lymphoma (DLBCL), and in chronic lymphocytic leukemia (CLL), and esophageal carcinoma.

Xpo1^E571K/WT mice have an inverted cassette containing exons 15-17, carrying a glutamic acid to lysine mutation (E571K) in the inverted exon 16, downstream of the endogenous exon 17 of the exportin 1 (Xpo1) gene. The inverted exons are able to be placed in transcriptional orientation by Cre-mediated removal of the endogenous exons 15-17 and inversion of the mutated cassette.

Mice that are heterozygous for this allele are viable and fertile, while floxed homozygous mice are not viable. When bred to mice that express tissue-specific Cre recombinase, resulting offspring will have the floxed endogenous exons 15-17 removed and the E571K mutant exon 16 placed into transcriptional orientation.

When bred to CD19-cre mice (see Stock No. 006785) with Cre expression in the B-cell compartment, resulting offspring are smaller than wildtype mice and have significantly larger spleens at 12 weeks of age. These CD19-cre Xpo1^E571K/WT mice die more rapidly than littermate controls and have increased B-cell proliferation, B-cell lymphocytosis, anemia, and thrombocytopenia.

Development

The Xpo1^E571K targeting vector was designed to insert a cassette containing an inverted exons 15-17 with a mutated exon 16 downstream of endogenous exon 17 of the exportin 1 (Xpo1) gene. Specifically, the vector included, from 5' to 3', a loxP site, endogenous exons 15-17, a frt-flanked neomycin resistance (neo) cassette, a lox71 site, a cassette containing inverted exons 15-17 and a lox66 site. The inverted cassette was modified to harbor a guanine to adenine substitution at amino acid 571 in exon 16, resulting in a glutamic acid to lysine mutation (E571K), commonly found in patients with a variety of cancer types, including chronic lymphocytic leukemia (CLL), Hodgkin's lymphoma (HL), and esophageal carcinoma. The construct was electroporated into C57BL/6-derived embryonic stem (ES) cells containing Flp Recombinase. Correctly targeted ES cells were injected into BALB/c blastocysts and resulting Xpo1^E571K/WT offspring, lacking the neo cassette, were bred to C57BL/6J mice for at least 10 generations. Upon arrival at The Jackson Laboratory Repository, 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: Xpo1^tm1.1Oaw
Name: targeted mutation 1.1, Omar Abdel-Wahab
MGI accession ID: MGI:6356540
Generation method: Targeted
Attributes: Humanized sequence
Synonyms: Xpo1^E571K
Marker symbol: Xpo1
Marker name: exportin 1
Marker synonyms: Crm1; CRM-1; emb; exp1
Chromosome: 11
Strain of origin: C57BL/6
Molecular note: The targeting vector is designed to insert a cassette containing an inverted exons 15-17 with a mutated exon 16 downstream of endogenous exon 17 of the gene. Specifically, the vector includes, from 5' to 3', a loxP site, endogenous exons 15-17, an FRT-flanked neomycin resistance (neo) cassette, a lox71 site, a cassette containing inverted exons 15-17, a lox66 site. The inverted cassette is modified to harbor a guanine to adenine substitution at amino acid 571 in exon 16, resulting in a glutamic acid to lysine mutation (E571K), commonly found in patients with a variety of cancer types, including chronic lymphocytic leukemia (CLL), Hodgkin's lymphoma (HL), and esophageal carcinoma. Flp-mediated recombination removed the FRT-flanked neo cassette.