PATTERNS & PHENOTYPES VE-cadherin-CreER Transgenic Mouse: A Model for Inducible Recombination in the Endothelium

To introduce temporal control in genetic experiments targeting the endothelium, we established a mouse line expressing tamoxifen-inducible Cre-recombinase (Cre-ER) under the regulation of the vascular endothelial cadherin promoter (VECad). Specificity and efficiency of Cre activity was documented by crossing VECad-Cre-ER with the ROSA26R reporter mouse, in which a floxed-stop cassette has been placed upstream of the -galactosidase gene. We found that tamoxifen specifically induced widespread recombination in the endothelium of embryonic, neonatal, and adult tissues. Recombination was also documented in tumor-associated vascular beds and in postnatal angiogenesis assays. Furthermore, injection of tamoxifen in adult animals resulted in negligible excision (lower than 0.4%) in the hematopoietic lineage. The VECad-Cre-ER mouse is likely to be a valuable tool to study the function of genes involved in vascular development, homeostasis, and in complex processes involving neoangiogenesis, such as tumor growth. Developmental Dynamics 235:3413–3422, 2006. © 2006 Wiley-Liss, Inc.