Ciliary arrays in organisms across the tree of life are exposed to environments with diverse physical properties. While ciliated protists swim in water, the airway epithelium propels a thin layer of mucus. We are puzzled by the mechanisms that allow for proper function of ciliary arrays in these diverse physical contexts. To gain insight into this conundrum we study the planarian S. mediterranea.
Planarians glide by secreting mucus on their ventral surface and use motile cilia to move the mucus. Their ventral epithelium is exposed, making this system amenable to perturbations in the surrounding fluid in vivo. By understanding how changes in the fluid impact flow properties and organism motility we aim to uncover the role of the physical environment in the function or a ciliary array.