MBI Videos

Videos by Workshop 2: Circadian Clocks in Plants and Fungi

  • Wavelet Analysis of Circadian Oscillations
    Tanya Leise
    No description available....
  • Amplitude/Temperature-Compensation: Data and Models
    Stuart Brody
    Amplitude is a measurable parameter of an oscillator, yet it is often not considered as a variable, Amplitude can be measured in several ways: 1) as an output of an oscillator; 2) directly as the amplitude of a "key" clock protein; or 3) indirectly via a Phase-response curve. Data will be presented for a particular mutant (frq7) of Neurospora which shows how the ...
  • Can mathematical analysis help uncover the design principles behind circadian rhythms?
    David Rand
    I will survey what some recent mathematical results suggest about the design principles behind circadian clocks. In particular, I will discuss flexibility, robustness, buffering mechanisms against environmental heterogeneity, temperature compensation in physiological entrained conditions and tracking of multiple phases. If time permits I will also discuss new methods for f...
  • Homeostatic and Oscillatory Mechanisms in Plant and Fungal Nitrate Assimilation
    Peter Ruoff
    Homeostatic control mechanisms are essential to keep cells and organisms fit in a changing and challenging environment. An important task is to identify the factors which contribute to the functionality and robustness of homeostatic mechanisms in the presence of environmental perturbations. Kinetic conditions which lead to robust homeostasis and perfect adaptation together...
  • Mathematical modeling of cell cycle and circadian rhythms as a coupled oscillator
    Chris Hong
    In most eukaryotic organisms, networks of cell cycle and circadian rhythms coexist and work coordinately to create optimal conditions for cells to grow and adapt to the surrounding environment. Cell cycle regulatory mechanisms include multiple checkpoints for controlled growth and cell divisions. The period of this oscillation, however, varies with external conditions such...
  • How Fungi Keep Time: Circadian Oscillators And Rhythmic Outputs
    Deborah Bell-Pedersen
    About 20% of Neurospora genes are under control of the circadian clock system at the level of transcript accumulation, and the bulk of the clock-controlled mRNAs have peak accumulation in the late night to early morning. These data suggested the existence of global mechanisms for rhythmic control of gene expression. Consistent with this idea, we found that the Neurospora O...
  • Circadian Control at the Post-Transcriptional Level: the Gonyaulax story
    Woody Hastings
    Several different circadian rhythms, as well as an annual rhythm, have been studied in the marine dinoflagellate Gonyaulax polyedra (now Lingulodinium polyedrum), many features of which may be grist for modeling mills, whatever they may be. The rhythm of bioluminescence provides an easy "hand" for the automation of its measurement in vivo, and the luciferase and ...
  • Circadian gating of cell divisions revealed in single cyanobacterial cells
    Qiong Yang
    Cyclic processes in biology span a wide dynamic range, from the sub-second periods of neural spike trains to annual rhythms in animal and plant reproduction. Even an individual cell exposed to a constant environment may exhibit many parallel periodic activities with different frequencies. It is therefore important to elucidate how multiple clocks coordinate their oscillati...
  • Understanding Conflicting Zeitgeber Experiments
    Gisele Oda
    Several experimental studies have altered the natural phase relationship between photic and non-photic zeitgebers, in order to assess their hierarchy in the entrainment of circadian rhythms. In order to interpret the complex results that emerge from these conflicting zeitgeber protocols, we present computer simulations of two coupled oscillator systems forced by two indepe...
  • Modeling the mammalian circadian clock: from single cells to cell populations
    Didier Gonze, Didier Gonze

    Circadian rhythms represent one of the more conspicuous examples of biological rhythms. Manifested at the physiological, behavioral, and cellular levels, these 24-hour rhythms originate at the molecular level, through a complex gene regulatory network. In mammals, the circ...

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