Distinct and common developmental expression patterns of the murine Pkd2 and Pkd1 genes.

Autosomal dominant polycystic kidney disease (ADPKD) is one of the most commonly inherited renal diseases. At least two genes, PKD2 and PKD1 are implicated in the development of this disease. Our pathogenetic studies showed that the human and murine polycystic kidney disease (PKD) involves failure to switch out of a renal developmental program. We have thus undertaken a detailed comparative expression analysis of Pkd2 and Pkd1 from the morula stage to adulthood. Pkd2 expression was detected as early as the morula and blastocyst stages as observed for Pkd1. Strong Pkd2 expression, similar to Pkd1, was displayed in all mesenchymal and cartilaginous tissues during mouse development. However major differences in Pkd2 expression in comparison to Pkd1 were identified. First, in contrast to Pkd1, the neural crest cell-derived tissues displayed a low to undetectable Pkd2 expression at all ages. Second, no increase in Pkd2 expression was detected during mesenchymal condensation. Third, high Pkd2 expression in the kidneys was localized mainly to the tubular epithelium of the cortical region from murine development to adulthood.