Centriole amplification by mother and daughter centrioles differs in multiciliated cells

Abstract

The semi-conservative centrosome duplication in cycling cells gives rise to a centrosome composed of a mother and a newly formed daughter centriole. Both centrioles are regarded as equivalent in their ability to form new centrioles and their symmetric duplication is crucial for cell division homeostasis. Multiciliated cells do not use the archetypal duplication program and instead form more than a hundred centrioles that are required for the growth of motile cilia and the efficient propelling of physiological fluids. The majority of these new centrioles are thought to appear de novo, that is, independently from the centrosome, around electron-dense structures called deuterosomes. Their origin remains unknown. Using live imaging combined with correlative super-resolution light and electron microscopy, we show that all new centrioles derive from the pre-existing progenitor cell centrosome through multiple rounds of procentriole seeding. Moreover, we establish that only the daughter centrosomal centriole contributes to deuterosome formation, and thus to over ninety per cent of the final centriole population. This unexpected centriolar asymmetry grants new perspectives when studying cilia-related diseases and pathological centriole amplification observed in cycling cells and associated with microcephaly and cancer.

Multiciliated Cells in Animals

“…Multiple rounds of deuterosome formation provide the cell with more than a hundred proBBs. Electron and superresolution microscopies indicate that the short pro-BBs remain latent during this phase of amplification (Kalnins and Porter 1969;Al Jord et al 2014). Once the last deuterosome has been produced, pro-BBs then elongate simultaneously from all the deuterosomes and from the centrosomal centrioles (Zhao et al 2013;Al Jord et al 2014).…”

“…Electron and superresolution microscopies indicate that the short pro-BBs remain latent during this phase of amplification (Kalnins and Porter 1969;Al Jord et al 2014). Once the last deuterosome has been produced, pro-BBs then elongate simultaneously from all the deuterosomes and from the centrosomal centrioles (Zhao et al 2013;Al Jord et al 2014). This explains the coexistence of both "deuterosome" and "centriolar" pathways during MCC differentiation, which are seemingly the outcome of the same process originating at the centrosome.…”

Seeing is believing: multi-scale spatio-temporal imaging towards in vivo cell biology

“…The engineered peroxidase APEX, by contrast, can be used for EM and proximity labeling upon its fusion to a protein of interest, (Mick et al, 2015). Alternatively, events or regions of interest can be tracked over the two imaging modalities, with recording of coordinates imprinted on the culture dish, by using either commercialized (Al Jord et al, 2014) or lasermicropatterned culture substrates (Spiegelhalter et al, 2010). This method allows the fast freezing (e.g.…”

“…A similar approach has recently been used to characterize centriole duplication in multi-ciliated ependymal cells, which grow multiple motile cilia that efficiently propel the cerebrospinal fluid in brain ventricles. By combining live superresolution imaging of ependymal progenitors by using EM, Al Jord and colleagues could show that multiple centrioles derive from the pre-existing progenitor cell centrosome following multiple rounds of procentriole seeding, thereby unraveling an unexpected centriolar asymmetry that differs from the archetypal duplication program found in other ciliated cells (Al Jord et al, 2014). Similarly, in vitro CLEM has been combined with the 3D electron microscopy (3DEM) technique focused ion beam scanning electron microscopy (FIB-SEM) to show that invadopodia of cancer cells potentially mature in response to a mechanical interplay with the nucleus (Revach et al, 2015).…”

Amplification des centrioles

“…Cette étude [5] montre que dans un contexte physiologique, le centrosome peut se dupliquer lorsqu'il est dans une cellule en division, mais également orchestrer une amplification massive de centrioles lorsqu'il est dans une cellule en cours de différenciation multiciliée. Le centriole fils du centrosome s'avère jouer un rôle clef dans la biogenèse des centrioles, en tout cas lorsque ceux-ci sont massivement amplifiés ( Figure 2C).…”