Col2-Cre recombinase is co-expressed with endogenous type II collagen in embryonic renal epithelium and drives development of polycystic kidney disease following inactivation of ciliary genes.

Here we report on the severe defects in renal epithelium induced by the transgenic Col2-Cre line used previously for skeletal tissue-specific gene targeting. We demonstrate that conditional ablation of the Kif3a or Pkd1 genes encoding primary cilium/intraflagellar transport-associated proteins using type II collagen-specific Cre transgenic strain results in a severe form of polycystic kidney disease in mice. We detect Col2-Cre recombinase expression in kidney epithelium, which reflects expression of the endogenous Col1alpha(II) gene in the embryonic renal tubules. We determine the exon 2-containing splice variant of the Col1alpha(II) gene as a major transcript expressed in kidney. Furthermore, the confocal immunocytochemical analysis demonstrates deposition of the type II collagen within the mesenchymal-epithelial renal tissue interfaces and its co-localization with the basement membrane marker collagen IV during embryonic kidney morphogenesis.