Seriously cilia: A tiny organelle illuminates evolution, disease, and intercellular communication

The borders between cell and developmental biology, which have always been permeable, have largely dissolved. One manifestation is the blossoming of cilia biology, with cell and developmental approaches (increasingly complemented by human genetics, structural insights, and computational analysis) fruitfully advancing understanding of this fascinating, multifunctional organelle. The last eukaryotic common ancestor probably possessed a motile cilium, providing evolution with ample opportunity to adapt cilia to many jobs. Over the last decades, we have learned how non-motile, primary cilia play important roles in intercellular communication. Reflecting their diverse motility and signaling functions, compromised cilia cause a diverse range of diseases collectively called ciliopathies.In this review, we highlight how cilia signal, focusing on how second messengers generated in cilia convey distinct information; how cilia are a potential source of signals to other cells; how evolution may have shaped ciliary function; and how cilia research may address thorny outstanding questions.

Automated summary

The boundaries between cell and developmental biology have dissolved, leading to the emergence of cilia biology which combines different approaches to understand this multifunctional organelle. Cilia play important roles in intercellular communication and their dysfunction can lead to various diseases. This review highlights the signaling mechanism of cilia, their potential as signaling sources, the influence of evolution on ciliary function, and the unresolved questions in cilia research.