title: Single and cell population respiratory oscillations in yeast: a 2-photon scanning laser microscopy study.
abstract: Two-photon scanning laser and confocal microscopies were used to image metabolic dynamics of single or cell populations of Saccharomyces cerevisiae strain 28033. Autofluorescence of reduced nicotinamide nucleotides, and mitochondrial membrane potential (DeltaPsim), were simultaneously monitored. Spontaneous, large-scale synchronized oscillations of NAD(P)H and DeltaPsim throughout the entire population of yeasts occurred under perfusion with aerated buffer in a continuous single-layered film of organisms. These oscillations stopped in the absence of perfusion and the intracellular NAD(P)H pool became reduced. Individual mitochondria within a single yeast also showed in-phase synchronous responses with the cell population, in both tetramethylrhodamine ethyl ester (or tetramethylrhodamine methyl ester) and autofluorescence. A single, localized, laser flash also triggered mitochondrial oscillations in single cells suggesting that the mitochondrion may behave as an autonomous oscillator. We conclude that spontaneous oscillations of S. cerevisiae mitochondrial redox states and DeltaPsim occur within individual yeasts, and synchrony of populations of organisms indicates the operation of an efficient system of cell-cell interaction to produce concerted metabolic multicellular behaviour on the minute time scale in both cases.
authors.affiliation: The Institute of Molecular Cardiobiology, Johns Hopkins Medicine, 1059 Ross Building, Baltimore, MD 21205-2195, USA.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Aon
authors.forename: Sonia
authors.initials: S
authors.lastname: Cortassa
authors.forename: Katey M
authors.initials: KM
authors.lastname: Lemar
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Hayes
authors.forename: David
authors.initials: D
authors.lastname: Lloyd
mesh_terms: D001683:Biological Clocks / Q000502:physiology*; D002450:Cell Communication / Q000502:physiology*; D005456:Fluorescent Dyes / Q000494:pharmacology; D053078:Membrane Potential, Mitochondrial / Q000502:physiology*; D018613:Microscopy, Confocal; D008928:Mitochondria / Q000502:physiology*; D009249:NADP / Q000378:metabolism*; D009942:Organometallic Compounds / Q000494:pharmacology; D010084:Oxidation-Reduction; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000502:physiology*
chemical_list: D005456:Fluorescent Dyes; D009942:Organometallic Compounds; C110932:tetramethyl rhodamine ethyl ester; D009249:NADP