Constitutive over-expression of endothelin-2 (Edn2) in the mouse retina perturbs vascular development by inhibiting endothelial cell migration across the retinal surface and subsequent endothelial cell invasion into the retina.
The Z/Edn2 knock-in, located 2 kb 5' of the ubiquitin b gene (the integration site of the Z/AP reporter), gives constitutive expression of a nuclear-localized beta-galactosidase/neomycin resistance protein reporter (NLS-beta-geo) in the absence of Cre-mediated recombination. Following Cre-mediated recombination, the NLS-beta-geo coding region is excised and the downstream Edn2 coding region is expressed.
When crossed with Sox2-Cre mice (see Stock No. 008454), Z/Edn;Sox2-Cre embryos recovered at E9.5-E10.5 are severely growth-retarded and display an open neural tube, an enlarged heart, and pooled blood in the head and thorax. Flatmount immunostaining for PECAM1 shows a nearly complete absence of vascular development. GFP is present in the targeting construct, but does not produce detectable fluorescence upon cre-mediated excision of the stop.
