Multiciliated cells: Development, functions and disease relevance.

Multiciliated cells (MCCs) differentiate numerous motile cilia on their apical surface. Beating of these ciliary arrays drive organismal locomotion in fluid medium and function to promote fluid flow over epithelia in various tissues. Besides these mechanical functions, MCC cilia are also sensory organelles, capable of transducing a variety of environmental and intercellular signals. Defective form and functioning of these cells can lead to a variety of clinical manifestations in humans, ranging from severe airway disease to infertility. This review gives an overview of multiple aspects of the biology of MCCs such as their distribution in plants and animals, the gene regulatory networks that organize their specification and differentiation, particularly the latest insights into the fascinating ability of post-mitotic MCC precursor cells to generate hundreds of centrioles for multiciliation. We also discuss how disruption to MCC formation or abnormalities in their ciliary motility cause ciliopathies, affecting multiple organs of the human body, and current status of treatment for these diseases.