Planar cell polarity and the kidney.

Planar cell polarity (PCP) is a form of spatial organization in tissue that was first described in Drosophila melanogaster. PCP plays a critical conserved role in several aspects of mammalian development. Exciting data implicate PCP in normal kidney development and suggest the loss of oriented cell division and convergent extension downstream of defective PCP signaling lead to cystic kidney disease in mouse models. In this review, I first cover the current knowledge of PCP signaling in invertebrate and vertebrate models and then explore how loss of PCP might underlie some forms of cystic kidney disease.