These floxed mutant mice possess loxP sites flanking exon 1 of the Efnb2 gene. This strain may be useful for generating conditional mutations in applications related to vasculogenesis and angiogenesis, including tumor angiogenesis.
David J Anderson, California Institute of Technology
Mice that are homozygous for this floxed allele are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. When bred to mice with a cre recombinase gene under the control of a promoter of interest, exon 1 of the targeted gene is deleted in the tissue of interest. These mutant mice may be useful in studying the cellular and molecular mechanisms underlying vasculogenesis and angiogenesis, the topography of neovascularization, and adult neovascularization, including tumor angiogenesis.
To test the effectiveness of this model, these mutant mice were bred to an endothelial-specific Cre-expressing transgenic mice, Tg(Tek-cre)12Flv (Stock No. 004128) . Offspring homozygous for the Cre-mediated exon 1 deletion show angiogenic remodeling defects and embryonic death identical to homozygous Efnb2tm1And mice (see Stock No. 006039).
A targeting vector was designed to insert a loxP site upstream of the transcriptional start site and a loxP-flanked PGKneo cassette downstream of exon 1 of the endogenous gene. This construct was microinjected into 129S7/SvEvBrd-derived AB1 embryonic stem (ES) cells. Correctly targeted ES cells were then transiently transfected with a Cre-expressing vector to remove the PGKneo cassette. Cells harboring the recombined loxP-flanked exon 1 were injected into blastocysts. Chimeric males were bred to C57BL/6 females. Heterozygous mice were bred to C57BL/6 for 3 generations before being made homozygous. After arriving at The Jackson Laboratory, mutant mice were bred with C57BL/6J for more than two generations.
|Allele Name||targeted mutation 2, David J Anderson|
|Allele Type||Targeted (Conditional ready (e.g. floxed), No functional change)|
|Allele Synonym(s)||Efnb2flox; EphrinB2LoxP|
|Gene Symbol and Name||Efnb2, ephrin B2|
|Strain of Origin||129S7/SvEvBrd-Hprt+|
|Molecular Note||A loxP site was inserted 45 bp upstream in the 5' UTR and a floxed PGKneo cassette was inserted downstream of the first exon. The floxed PGKneo cassette was removed by transient Cre expression in the ES cells which resulted in a floxed intact exon I.|
|Mutations Made By|| |
David Anderson, California Institute of Technology
When maintaining a live colony, these mice can be bred as heterozygotes or homozygotes.
When using the ephrinB2loxP mouse strain in a publication, please cite the originating article(s) and include JAX stock #006042 in your Materials and Methods section.