Mother and Daughter Centrioles Are Not Equivalent

Abstract

For decades, centrioles were viewed as symmetrical, semi-conservatively duplicated organelles. This review synthesizes contemporary evidence to establish a fundamental paradigm shift: mother (mature) and daughter (newly formed) centrioles are intrinsically non-equivalent, serving as distinct cellular compartments with specialized roles. We systematically analyze data from super-resolution microscopy, comparative proteomics, live-cell tracking, and functional genetics to delineate a multi-layered hierarchy of asymmetry. This encompasses profound differences in ultrastructure (possession of appendages), molecular composition, functional capacity (as microtubule-organizing centers and basal bodies), dynamic properties, and fate during asymmetric cell divisions. We explore the sequential biochemical maturation program and post-translational modifications that establish this asymmetry and examine its critical manifestations across diverse cellular systems, from fibroblasts and stem cells to epithelia and sperm. Furthermore, the pathological consequences of disrupting this hierarchy are detailed, linking failures in centriole maturation to ciliopathies, neurodevelopmental disorders like microcephaly, and oncogenic processes driven by centrosomal amplification and chromosomal instability. We propose an integrative "Master-Apprentice" model, wherein the mother centriole acts as a stable organizing and signaling hub instructing its dynamic daughter counterpart. This inherent non-equivalence is not a minor detail but a core organizing principle essential for cellular polarity, accurate division, and tissue homeostasis.