Chlamydomonas as a model system for the study of cilia and eukaryotic flagella

Chlamydomonas is a haploid, unicellular green alga that serves as an excellent model system for studying ciliary biology. It possesses two motile cilia of equal length, making it ideal for investigating both ciliogenesis and ciliary motility, as well as cilia-based signaling. The organism's ease of cultivation, the simplicity of cilia isolation, and the availability of well-established experimental systems for rapid and synchronous cilia regeneration and disassembly contribute to its utility in laboratory research. Furthermore, Chlamydomonas is highly amenable to a variety of genetic approaches, enhancing its value as a model organism. Due to the high degree of conservation in the core mechanisms governing ciliary structure and function, discoveries made in Chlamydomonas have significantly advanced our understanding of cilia across species and have provided important insights into cilia-related human disorders. In this overview, we summarize the key cellular features, life cycle stages, ciliary architecture and dynamics, ciliary behavior, biochemical and genetic advantages of Chlamydomonas as a model organism. Our goal is to provide a foundational perspective for those new to ciliary research in Chlamydomonas - including early-career scientists, experienced researchers transitioning from other fields, and cilia experts working with alternative model systems.