Berlin 2012 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 18: Posters: Statistical Physics in Biological Systems
BP 18.28: Poster
Mittwoch, 28. März 2012, 17:30–19:30, Poster A
Cell-Cell-Desynchronization in Yeast Cell Populations — •André Weber1,2, Werner Zuschratter2 und Marcus Hauser1 — 1Institut für Experimentelle Physik, Otto-von-Guericke-Universität Magdeburg, Germany — 2Leibniz-Institut für Neurobiologie Magdeburg, Germany
Colonies of the yeasts Saccharomyces carlsbergensis and Saccharomyces cerevisiae have been used as stable model organisms to investigate glycolytic oscillations over years. The dynamics of the cell population depend on the cell density: At high cell densities all cells of the population show synchronous and coherent oscillations, which can be detected as global oscillations. The collective behaviour ceases at a critical, low cell density, but the nature of the dynamics at single cell level remained an open question. Recent reports predicted a ’quorum sensing’ mechanism, where all cells stop oscillating synchronously below the quorum. Using single photon counting fluorescence microscopy, we study the dynamics of individual yeast cells at low cell densities for both yeast strains. Our focus lies in elucidating the mechanism of the transition between individual and collective dynamics. At very low cell densities, the individual cells still perform metabolic oscillations, the frequencies of which show a very broad distribution. Thus the cells oscillate in a desynchronous fashion. As the cell density increases, we observe that the frequency distribution narrows and synchronized collective behaviour sets in. We can preclude a dynamical quorum sensing phenomenon for glycolytic oscillations in yeast strains S. carlsbergensis and S. cerevisiae.