Advances in high-resolution imaging of centrioles and cilia.

Centrioles, cilia and flagella are evolutionarily conserved organelles essential for a wide range of cellular functions, including division, polarity, signaling, motility and fluid flow. Despite their fundamental roles in development and disease, their small size and intricate architecture have historically limited high-resolution imaging and molecular-scale analysis. These cylindrical structures, measuring ∼200-250 nm in diameter, approach the diffraction limit of conventional fluorescence microscopy. In this Review, we highlight recent advances in imaging modalities that have significantly deepened our understanding of centriolar and ciliary structure and function. We focus on innovations in cryo-electron tomography, cryo-electron microscopy, super-resolution microscopy, atomic force microscopy and expansion microscopy, and discuss how these approaches have provided unprecedented insights into the molecular organization of these organelles, bridging the gap between cellular and molecular scales in health and disease contexts.