Development of a multiciliated cell

Abstract

Multiciliated cells (MCC) are evolutionary conserved, highly specialized cell types that contain dozens to hundreds of motile cilia that they use to propel fluid directionally. To template these cilia, each MCC produces between 30 and 500 basal bodies via a process termed centriole amplification. Much progress has been made in recent years in understanding the pathways involved in MCC fate determination, differentiation, and ciliogenesis. Recent studies using mammalian cell culture systems, mice, Xenopus, and other model organisms have started to uncover the mechanisms involved in centriole and cilia biogenesis. Yet, how MCC progenitor cells regulate the precise number of centrioles and cilia during their differentiation remains largely unknown. In this review, we will examine recent findings that address this fundamental question.

Figure 1. Variability in centriole and cilia abundance of multiciliated cells.

(a) Scanning Electron Microscopy images of mouse respiratory (trachea) and ependymal (brain ventricle) MCC. (b) Fluorescent microscopy images of cultured mouse airway basal progenitor cells and mature airway MCC (left and center), and en face image of ventricular ependymal MCC from mouse brain. (c) Schematic of the proliferation and differentiation steps of multiciliated epithelia. The key stages of centriole amplification from parental centrioles and deuterosomes (dark spheres) are depicted. (d) Quantification of centriole number and cell surface area of mouse airway MCC in vitro and in vivo., highlighting a linear relationship between the two. Data reproduced and modified from Ref. [27].