Motility in Filamentous Cyanobacteria

Filamentous cyanobacteria are multicellular organisms that perform oxygenic photosynthesis and frequently exhibit surface motility. This review discusses the underlying mechanism facilitating motility in these organisms, with a focus on recent molecular and genetic studies. While previous explanations for this motility have proposed exotic mechanisms, the current data indicate that all filamentous cyanobacteria produce a similar motility-associated extracellular polysaccharide (EPS) or slime essential for movement and employ a type IV pilus (T4P) motor to power motility. The (a) regulation of the motor to facilitate coordinated polarity and phototaxis and (b) possible bidirectional feedback between the T4P and motility-associated polysaccharide are discussed as well. Finally, the role of motility in promoting diverse biological phenomena, including dispersal, phototaxis, biofilm formation, granulation, and symbiosis, is explored.