Dynamic cytoplasmic fluidity at the mesoscale during morphogenesis in a human fungal pathogen

The molecular crowding of the cytoplasm impacts a range of cellular processes. Using a fluorescent microrheological probe (GEMs), we observed a striking increase in mesoscale diffusion during the yeast to filamentous growth transition in the human fungal pathogen Candida albicans. This increase in mesoscale diffusion is due to a decrease in ribosome concentration that results in part from an inhibition of ribosome biogenesis, combined with an increase in cytoplasmic volume, leading to a dilution of a major cytoplasmic crowder at the mesoscale. Moreover, our results suggest that inhibition of ribosome biogenesis is a trigger for C. albicans morphogenesis.