Actin and microtubules drive differential aspects of planar cell polarity in multiciliated cells.

Planar cell polarization represents the ability of cells to orient within the plane of a tissue orthogonal to the apical basal axis. The proper polarized function of multiciliated cells requires the coordination of cilia spacing and cilia polarity as well as the timing of cilia beating during metachronal synchrony. The planar cell polarity pathway and hydrodynamic forces have been shown to instruct cilia polarity.

The PCP pathway instructs the planar orientation of ciliated cells in the Xenopus larval skin.

Planar cell polarity (PCP) is a property of epithelial tissues where cellular structures coordinately orient along a two-dimensional plane lying orthogonal to the axis of apical-basal polarity. PCP is particularly striking in tissues where multiciliate cells generate a directed fluid flow, as seen, for example, in the ciliated epithelia lining the respiratory airways or the ventricles of the brain. To produce directed flow, ciliated cells orient along a common planar axis in a direction set by tissue patterning, but how this is achieved in any ciliated epithelium is unknown.