B6.Cg-Ebf1^tm2.1Mbu/J

Stock number: 028104
Product name: Ebf1^fl
Research areas: Immunology, Inflammation and Autoimmunity Research, Research Tools

Description

These floxed mutant mice possess loxP sites flanking last 429 codons of the Ebf1 gene. Removal of the floxed sequence results in the expression of an EBF1-GFP fusion protein. This strain may be useful for generating conditional mutations and lineage tracking in applications related to B cell development, and adipocyte differentiation.

Detailed description

The Ebf1 gene encodes a transcription factor important during early and late B cell development, adipocyte lipolysis, olfactory sensory neuron development, and regulation of the osteoblast lineage. These mice carry the Ebf1^fl allele. Mice that are homozygous for this allele are viable and fertile. When these mutant mice are bred to mice that express Cre recombinase, resulting offspring will have the last 429 codons of the Ebf1 gene deleted and expression of an EBF1-GFP fusion protein in the cre-expressing tissues. Removal of the floxed sequence results in the expression of an EBF1-GFP fusion protein, with GFP expression detected only in lymphoid progenitors and pro–B cells.

When bred to a strain with Cre recombinase expression in early embryos (see Stock No. 003755 for example), this mutant mouse strain may be useful in studies of B cell lineage progression.

Development

A targeting vector containing the following (5’ to 3’): loxP site, cDNA encoding exons 6 through 16, 3' UTR sequence, 6 copies of the SV40 polyA sequence, another loxP site, cDNA of the first 14 codons of exon 6 fused in-frame with GFP, polyadenylation sequence, a FRT site, polyadenylation sequence, a PGK-NEO resistance gene (in opposite orientation), a 2nd FRT site; was electroporated into (C57BL/6 x 129P2/OlaHsd)F1 derived A9 embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6 blastocysts. The resulting chimeric animals were tested for germline transmission. The Ebf1^fl-neo/+ mice were then crossed to transgenic mice expressing FLPe recombinase (Stock No. 005703, for example), producing progeny carrying the Ebf1^fl allele. The mice were then backcrossed to C57BL/6J for more than 6 generations. Upon arrival, 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: Ebf1^tm2.1Mbu
Name: targeted mutation 2.1, Meinrad Busslinger
MGI accession ID: MGI:5617009
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); Reporter
Marker symbol: Ebf1
Marker name: early B cell factor 1
Chromosome: 11
Strain of origin: (C57BL/6 x 129P2/OlaHsd)F1
Expressed genes: GFP,Green Fluorescent Protein,
Site of expression: When bred to a strain carrying cre recombinase, GFP expression is detected only in lymphoid progenitors and pro-B cells.
Molecular note: Exon 6 was replaced with a floxed cDNA encoding exons 6-16, the 3' UTR and a 6x polyA signal, followed by exon 6 fused to a GFP reporter gene and an FRT flanked neo selection cassette in the inverse orientation. Flp mediated recombination removed the neo cassette.