Title: Cell position fates and collective fountain flow in bacterial biofilms revealed by light-sheet microscopy
Author: Boyang Qin, Chenyi Fei, Andrew A. Bridges, Ameya A. Mashruwala, Howard A. Stone, Ned S. Wingreen, Bonnie L. Bassler
Abstract: Abstract Bacterial biofilms represent a basic form of multicellular organization that confers survival advantages to constituent cells. The sequential stages of cell ordering during biofilm development have been studied in the pathogen and model biofilm-former Vibrio cholerae. How do the spatial trajectories of individual cells and the collective motions of many cells drive biofilm expansion We developed dual-view light-sheet microscopy to investigate biofilm developmental dynamics from a founder cell to a mature three-dimensional community. Tracking of individual cells revealed two distinct fates: one set of biofilm cells expanded ballistically outward, while the other became trapped at the substrate. A collective fountain-like flow transported cells to the biofilm front, bypassing members trapped at the substrate and facilitating lateral biofilm expansion. This collective flow pattern was quantitatively captured by a continuum model of biofilm growth against substrate friction. Coordinated cell movement required the matrix protein RbmA, without which cells expanded erratically. Thus, tracking cell lineages and trajectories in space and time revealed how multicellular structures form from a single founder cell.