Bacterial nanotubes: a conduit for intercellular molecular trade

Bacteria use elaborate molecular machines for intercellular contact-dependent interactions. We discuss a relatively less explored type of intercellular connections mediated by tubular membranous bridges, termed nanotubes. Increasing evidence suggests that nanotube structures mediate cytoplasmic molecular trade among neighboring cells of the same and different species. Further, nanotubes were found to facilitate both antagonistic and cooperative interspecies interactions, thereby allowing the emergence of new non-heritable phenotypes in multicellular bacterial communities. We propose that nanotube-mediated cytoplasmic sharing represents a widespread form of bacterial interactions in nature, providing an enormous potential for the emergence of new features. Here we review the current knowledge on bacterial nanotubes, and highlight the gaps in our current understanding of their operation.