Regensburg 2013 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 23: Statistical Physics in Biological Systems II (joint with BP)
DY 23.4: Vortrag
Mittwoch, 13. März 2013, 16:00–16:15, H43
NAD(P)H Dynamics in Yeast Populations — •André Weber1,2, Yury Prokazov2, Werner Zuschratter2, and Marcus J B Hauser1 — 1Institut für Experimentelle Physik, Otto-von-Guericke-Universität Magdeburg, Germany — 2Leibniz-Institut für Neurobiologie Magdeburg, Germany
NAD(P)H is the most important electron carrier in living cells and therefore it plays a key-role in numerous cellular processes. It is directly involved in glycolysis and Krebs cycle and its autofluorescence acts as an indicator for metabolic dynamics and enzyme activity in cells. The amount of NAD(P)H is reflected by its emitted light intensity. Furthermore, it is possible to discriminate between free and protein-bound NAD(P)H through fluorescence lifetimes. Using single photon counting fluorescence microscopy, we study glycolytic oscillations and metabolic changes in yeast cell populations via NAD(P)H imaging.
Yeast cells show synchronised glycolytic oscillations for high population densities which can be detected as global oscillations. These global oscillations become quiescent, when the population density drops below a critical value. Our results show that individual cells remain oscillatory even at very low cell densities (e.g. 1 × 105 cells/ml). The transition from global oscillations to a quiescent population signal is caused by the desynchronisation of the oscillations of individual cells. This is characteristic for a Kuramoto transition to incoherence. Spatially resolved measurements at low cell densities uncover that even cells that adhere to their neighbours oscillate with their own, independent frequencies and phases.