The phenomenon of ciliary coordination has garnered increasing attention in
recent decades and multiple theories have been proposed to explain its
occurrence in different biological systems. While hydrodynamic interactions
are thought to dictate the large-scale coordinated activity of epithelial cilia
for fluid transport, it is ...
The phenomenon of ciliary coordination has garnered increasing attention in
recent decades and multiple theories have been proposed to explain its
occurrence in different biological systems. While hydrodynamic interactions
are thought to dictate the large-scale coordinated activity of epithelial cilia
for fluid transport, it is rather basal coupling that accounts for synchronous
swimming gaits in model microeukaryotes such as Chlamydomonas. Unicellular ciliates present a fascinating yet understudied context in which
coordination is found to persist in ciliary arrays positioned across millimetre
scales on the same cell. Here, we focus on the ciliate Stentor coeruleus, chosen
for its large size, complex ciliary organization, and capacity for cellular
regeneration. These large protists exhibit ciliary differentiation between cortical rows of short body cilia used for swimming, and an anterior ring of
longer, fused cilia called the membranellar band (MB). The oral cilia in the
MB beat metachronously to produce strong feeding currents. Remarkably,
upon injury, the MB can be shed and regenerated de novo. Here, we
follow and track this developmental sequence in its entirety to elucidate
the emergence of coordinated ciliary beating: from band formation,
elongation, curling and final migration towards the cell anterior. We
reveal a complex interplay between hydrodynamics and ciliary restructuring
in Stentor, and highlight for the first time the importance of a ring-like
topology for achieving long-range metachronism in ciliated structures.
This article is part of the Theo Murphy meeting issue ‘Unity and diversity
of cilia in locomotion and transport’.
