摘要：SummaryMicrobial communities display behavioral changes in response to variable environmental conditions. In some bacteria, motility increases as a function of cell density, allowing for population dispersal before the onset of nutrient scarcity. Utilizing automated particle tracking, we now report on a population-dependent increase in the swimming speeds of the photosynthetic unicellular eukaryotesChlamydomonas reinhardtiiandC. moewussi. Our findings confirm that this acceleration in swimming speed arises as a function of culture density, rather than with age and/or nutrient availability. Furthermore, this phenomenon depends on the synthesis and detection of a low-molecular-weight compound which can be transferred between cultures and stimulates comparable effects across both species, supporting the existence of a conserved phenomenon, not unlike bacterial quorum sensing, among members of this genus. The potential expansion of density-dependent phenomena to a new group of unicellular eukaryotes provides important insight into how microbial populations evolve and regulate “social” behaviors.Graphical AbstractDisplay OmittedHighlights•Swimming speed inChlamydomonas reinhardtiiincreases as with population density•Increased swimming speed depends on a low-molecular-weight organic compound•This response is conserved and interchangeable betweenC. reinhardtiiandC. moewusii•This indicates expansion of quorum sensing to a new genus of unicellular eukaryotesCell; Microbiology; Molecular Microbiology
