B6.129X1(FVB)-Mybl2^tm1.1Epr/J

Stock number: 040554
Product name: B-myb floxed
Research areas: Cancer Research, Cell Biology Research, Research Tools

Description

B-myb floxed mice carry loxP sites flanking exon 6 of the Mybl2 gene. These mice may be useful for studying the regulatory role of MYBL2 in hematopoietic stem cell and myeloid development, as well as tumorigenesis.

Detailed description

The Mybl2 (myeloblastosis oncogene-like 2) codes for a transcription factor that is essential for cell cycle regulation, cell migration, and cell survival. Low expression of Mybl2 has been associated with hematological malignancies while overexpression of Mybl2 has been noted in numerous other cancers, such as prostate, bladder and breast cancer. These B-Myb floxed mice possess loxP sites flanking exon 6 of the Mybl2 gene.

Homozygous mice are viable and fertile with no overt phenotype. When bred to mice that express tissue-specific Cre recombinase, resulting offspring will have exon 6 deleted in the cre-expressing tissues, resulting in no detectable MYBL2 protein production. When these floxed mice were crossed to an Mx-cre (Stock No. 003556) strain and treated with polyinosinic:polycytidylic acid (pIpC), resulting progeny demonstrated significant loss of hematopoietic stem cells, multipotent progenitors and pancytopenia. These B-Myb floxed mice maybe useful when studying the regulatory role of MYBL2 in hematopoietic stem cell and myeloid development, as well as tumorigenesis.

Development

The B-myb floxed targeting vector was designed to insert loxP sites flanking exon 6 of the myeloblastosis oncogene-like 2 (Mybl2) gene. The targeting construct included an initial loxP site, followed by a neomycin selection cassette and a second loxP site inserted upstream of exon 6 with a third loxP site immediately downstream of exon 6. The construct was electroporated into 129X1/SvJc-derived RW4 embryonic stem (ES) cells and correctly targeted ES cells were injected into recipient blastocysts. Chimeric mice were bred to an EIIa-Cre (Stock No. 003724) to excise the floxed neomycin cassette. Resulting B-myb floxed mice, with neo cassette removed and floxed exon 6 intact, were then backcrossed to C57BL/6J (Stock No. 000664) mice for at least 10 generations. The C57BL/6J -congenic B-myb floxed mice were maintained by breeding to an Mx-cre (Stock No. 003556) mouse line by the donating laboratory. The males provided to The Jackson Laboratory were homozygous for the B-myb floxed allele, but wildtype for the Mx-cre allele. Upon arrival, sperm was cryopreserved. To establish a live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes.

Allele

Symbol: Mybl2^tm1.1Epr
Name: targeted mutation 1.1, E Premkumar Reddy
MGI accession ID: MGI:5577181
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Synonyms: B-myb^F
Marker symbol: Mybl2
Marker name: myeloblastosis oncogene-like 2
Marker synonyms: BMYB; B-Myb
Chromosome: 2
Strain of origin: 129X1/SvJ
Molecular note: A loxP-flanked neo cassette was inserted at 5' of exon 6 and a third loxP sequence downstream of exon 6. Cre mediated recombination removed the neo cassette, creating an allele with exon 6 flanked by loxP sites.