Abstract
Hundreds of different cell types emerge in the developing embryo, each of which must compartmentalize cell type specific biochemical processes in a crowded intracellular environment. To study cell type specific compartmentalization, we examined motile ciliated cells, which must assemble vast numbers of dynein motors to drive ciliary beating, as mutation of dyneins or their assembly factors causes motile ciliopathy. We show that dyneins, their assembly factors, and chaperones all concentrate together in Dynein Assembly Particles (DynAPs). These phase-separated organelles are specific to ciliated cells but share machinery with stress granules. Our data suggest that a common framework underlies ubiquitous and cell-type specific phase separated organelles and that one such organelle is defective in a human genetic disease.