A novel live cell imaging system reveals a reversible hydrostatic pressure impact on cell cycle progression

Life is dependent upon the ability of a cell to rapidly respond to changes in

environment. Small perturbations in local environments change the ability of

molecules to interact and hence communicate. Hydrostatic pressure provides

a rapid non-invasive, fully-reversible method for modulating affinities between

molecules both in vivo and in vitro. We have developed a simple fluorescence

imaging chamber that allows intracellular protein dynamics and molecular

events to be followed at pressures up to 200 bar in living cells. Using yeast we

investigate the impact of hydrostatic pressure upon cell growth and cell cycle

progression. While 100 bar has no affect upon viability, it induces a delay in

chromosome segregation, resulting in the accumulation of long-undividedbent

cells, consistent with disruption of the cytoskeletons. This delay is

independent of stress signalling and induces synchronisation of cell-cycle

progression. Equivalent affects were observed in Candida albicans, with

pressure inducing a reversible cell-cycle delay and hyphal growth. We present

a simple novel non-invasive fluorescence microscopy based approach to

transiently impact molecular dynamics to visualise, dissect and study signalling pathways and cellular processes in living cells.