Critical constituents and assembly principles of centriole biogenesis in human cells

The centriole is an evolutionarily conserved microtubule-bearing organelle with a striking 9-fold symmetrical architecture that is crucial for fundamental cellular processes in eukaryotes, including polarity, signalling and motility. The last two decades have witnessed important progress in uncovering the molecular architecture and assembly principles governing centriole biogenesis, which are discussed in this Review, with a focus on human cells. Recently developed advanced microscopy approaches have increased our understanding of the mechanisms governing centriole biogenesis, from initiating the assembly process to forming a full-fledged organelle. Some two billion years after its emergence during evolution, and more than 100 years after its identification by pioneering scientists, these advances make the centriole ripe for another era of discoveries.