Microgravity Changes Membrane Properties and Triggers Bioluminescence in Pyrocystis noctiluca as an Approach for New Biosensor Concepts

Abstract

Cell membranes with their well-defined chemo-physical properties play a crucial role in cellular functions and are indispensable for maintaining the physiological status of a cell. Recently, gravity-related changes in membrane fluidity and uptake of pharmaceutical substances have been observed in artificially produced membranes of liposomes. In order to test gravity impacts on in vivo cell membranes, we exposed an unicellular organism, the dinoflagellate Pyrocystis noctiluca, to microgravity conditions. P. noctiluca represents a quickly responding bioassay for membrane disturbances. It generates a luminescence signal in response to mechanical stimulation, which correlates to local changes in membrane fluidity. A free-fall of 4.7 s in a drop tower induced a significant luminescent signal demonstrating that even very short microgravity conditions induce alterations at the membrane level in in vivo cells of P. noctiluca.