STOCK Vegfa^tm1.1Nagy/J

Stock number: 027314
Product name: VEGF-A Hyper
Research areas: Cardiovascular Research, Developmental Biology Research, Research Tools

Description

This VEGF-LacZ KI-Δneo strain overexpresses VEGF-A two- to threefold and functions as a reporter strain for VEGF positive cells and tissues during embryonic vasculature development.

Detailed description

Vascular endothelial growth factor A is a mitogenic glycoprotein specific for endothelial cells and is involved in vascular permeability, angiogenesis, vasculogenesis, cell migration, as well as endothelial cell growth. These VEGF-A hypermorphic mice, VEGF-A^hyper, carry a nuclear localized beta-galactosidase knock in mutation of the Vegfa gene. Mice that are homozygous for the targeted knock-in allele have an embryonic lethal phenotype, dying between E12.5 and E14.5 with cardiac defects. Heterozygous mice are viable and fertile. Northern blot analysis of homozygous embryos and Western blot analysis of heterozygous and homozygous embryos detects increased levels (two- to threefold) of mRNA and protein. While all 3 isoforms of the protein are detected (by RT-PCR of kidney tissue from E12.5 homozygotes), the increased levels of protein observed may be due to the 3’ UTR insertion site of the IRES-lacZ. Beta-galactosidase staining is detected as early as E4.0 in the primitive endoderm of heterozygotes. Single beta-galactosidase/VEGF positive cells are detected at E8.0 in the endoderm of heterozygotes. The lacZ reporter expression mimics the endogenous Vegfa gene expression pattern during development and adulthood. Homozygous embryos exhibit edema, enlarged hearts with thin ventricle walls, and increased endocardial tissue. After hindlimb ischemia or cerebral artery ligation, heterozygotes have increased perfusion with improved recovery, collateral remodeling, and angiogenesis compared to wildtype controls.

Development

A targeting vector containing a lacZ fused to a nuclear localization signal and IRES, SV40 polyadenylation signal, and floxed PGK-NEO cassette, was inserted into the 3' UTR (noncoding region of exon 8) of the Vegfa gene, 200bp downstream of the stop codon. The construct was electroporated into 129 derived R1 embryonic stem (ES) cells. Chimeric mice were generated by aggregating correctly targeted ES cells with CD-1 morula-stage embryos. The chimeric VEGF-LacZ-KI heterozygotes were crossed to CMV-Cre transgenic mice (most likely on the CD-1 genetic background) to remove the loxP site flanked NEO cassette. The resulting mice VEGF-LacZ KI-Δneo were then crossed to CD-1 mice. Upon arrival at The Jackson Laboratory, the mice were crossed to 129S1/SvImJ (Stock No. 002448) at least once to establish the colony.

Allele

Symbol: Vegfa^tm1.1Nagy
Name: targeted mutation 1.1, Andras Nagy
MGI accession ID: MGI:1889787
Generation method: Targeted
Attributes: Reporter; Null/Knockout
Marker symbol: Vegfa
Marker name: vascular endothelial growth factor A
Chromosome: 17
Strain of origin: (129X1/SvJ x 129S1/Sv)F1-Kitl⁺
Expressed genes: lacZ,beta-galactosidase,E. coli; Vegfa,vascular endothelial growth factor A,mouse, laboratory
Site of expression: Endothelial cells
Molecular note: This allele is a derivative of Vegf^tm1Nagy where the PGK-neomycin resistance cassette has been deleted via a Cre/loxP recombination event. The allele expresses a bicistronic message encoding VEGF and LacZ proteins.
General note: The LacZ staining from this allele is indistinguishable from Vegf^tm1Nagy.