B6N(129S4)-Mafb^{tm1.1(cre)Kmm}/J

Stock number: 029664
Product name: MafB-mCherry-Cre
Research areas: Immunology, Inflammation and Autoimmunity Research, Research Tools

Description

MafB-mCherry-Cre knock-in mice express a FLAG-tagged-mCherry fluorescent protein and a Cre Recombinase sequence under the direction of the MafB promoter. These mice are useful for lineage tracing.

Detailed description

MafB-mCherry-Cre knock-in mice have a FLAG-tagged-mCherry fluorescent protein and a Cre Recombinase sequence inserted into the coding sequence of the Mafb (v-maf musculoaponeurotic fibrosarcoma oncogene family, protein B) gene. The presence of viral 2A oligopeptides that mediate ribosomal skipping allow the expression of mCherry and cre, while maintaining Mafb expression. MAFB is a basic leucine zipper transcription factor regulating lineage-specific hematopoiesis required for the differentiation of monocytic, macrophage, osteoclast, podocyte and islet beta cells lines. Homozygous mice are viable and fertile. mCherry expression in splenic red pulp macrophages can be visualized by two-photon microscopy. mCherry may only be detected in other, low-expressing, cell types by direct immunofluorescence. When these mice are bred with mice containing loxP-flanked sequence, Cre-mediated recombination will result in deletion of the floxed sequences in the Cre-expressing cells of the offspring.

Development

A targeting construct was designed to insert a FLAG-tagged-mCherry fluorescent protein and a Cre Recombinase sequence, separated by two different viral 2A oligopeptides that mediate ribosomal skipping (P2A [from porcine teschovirus-1] and T2A [from insect Thosea asigna virus], into the coding sequence of the Mafb (v-maf musculoaponeurotic fibrosarcoma oncogene family, protein B (avian)) gene. A frt-flanked neomycin resistance (neo) cassette was inserted 3’ of the cre sequence. This construct was electroporated into C57BL/6N-derived JM8.N4 embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts and the resulting chimeric males were bred to C57BL/6NJ females. Resulting MafB-mCherry-Cre mice were bred to B6N.129S4-Gt(ROSA)26Sor^tm1(FLP1)Dym/J (Stock No. 016226) mice to remove the neo cassette and offspring were crossed to remove the Flp gene. Mice were maintained by the donating lab on a C57BL/6NJ genetic background. Upon arrival at The Jackson Laboratory, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6NJ oocytes (Stock No. 005304).

Allele

Symbol: Mafb^{tm1.1(cre)Kmm}
Name: targeted mutation 1.1, Kenneth Murphy
MGI accession ID: MGI:5795905
Generation method: Targeted
Attributes: Recombinase-expressing; Reporter
Synonyms: Mafb^{tm1.1(mCherry,cre)Kmm}; MafB-mCherry-Cre
Marker symbol: Mafb
Marker name: v-maf musculoaponeurotic fibrosarcoma oncogene family, protein B (avian)
Marker synonyms: b-maf; DURS3; Kreisler; KRML; Krml1; MCTO
Chromosome: 2
Strain of origin: C57BL/6N
Expressed genes: FLAG, FLAG octapeptide,; RFP,Red Fluorescent Protein,coral; cre,cre recombinase,bacteriophage P1
Site of expression: mCherry and cre are expressed in Mafb expressing cells. MAFB regulates lineage-specific hematopoiesis required for the differentiation of monocytic, macrophage, osteoclast, podocyte and islet beta cells lines.
Molecular note: A targeting construct was designed to insert a FLAG-tagged-mCherry fluorescent protein and a Cre Recombinase sequence, separated by two different viral 2A oligopeptides that mediate ribosomal skipping (P2A [from porcine teschovirus-1] and T2A [from insect Thosea asigna virus], into the coding sequence of the Mafb (v-maf musculoaponeurotic fibrosarcoma oncogene family, protein B (avian)) gene. A frt-flanked neomycin resistance (neo) cassette was inserted 3' of the cre sequence. Resulting mice were bred to FLP1 exspressing mice to remove the neo cassette.