[The multiple links between cilia and planar cell polarity]

Since our seminal study in 2003, much has been written about core planar cell polarity (core PCP) signaling and the inner ear. In just a few years, and using the inner ear as a model system, our understanding of the molecular basis of this signaling pathway and how it can influence the development of tissues in mammals has increased considerably. Recently, a number of studies using various animal models of development have uncovered original relationships between the cilia and PCP, and the study of the hair cells of the inner ear has helped elucidating one of these links. In this review, we highlight the differences of PCP signaling between mammals and invertebrates. In the light of recent results, we sum up our current knowledge about PCP signaling in the mammalian cochlear epithelium and we discuss the impact of recent data in the field. We focus our attention on the interrelationship between asymmetric polarity complexes and the position of the cilium, which is essential for the establishment of the overall tissue polarity.