Physarum polycephalum mitosis

Physarum polycephalum mitosis calcium, 596 Physical development photography, 113,115 Phywphthora dnnamotni sporulation calcium transport, 572 Phytosiderophores, 680 Picolinic acid... 

Experiments carried out on mitosis in Physarum polycephalum (Kaufmann Wille, 1975 Tyson Sachsenmaier, 1978) did not allow a definitive conclusion in favour of one of the two views. The difficulty came from the fact that, short of the identification of the true biochemical variables driving the cell cycle, it was difficult to demonstrate the existence of a limit cycle in Physarum. Experiments based on the fusion of two plasmodia taken at different phases of the mitotic cycle or on the effect of heat shocks aimed at demonstrating the existence of a singular point from which the limit cycle would be reached with an indefinite phase (Winfree, 1974,1980,1987). These experiments did not allow the distinction to be made between a limit cycle characterized by relaxation oscillations and a discontinuous mechanism of the type discussed above. 

Cyclic uptake and release of Ca " from the extracellular medium occur during mitosis in Physarum polycephalum, and correlate with specific structural and kinetic events in the mitotic nuclei." The membrane system in the mitotic apparatus in Haemanthus endosperm cells functions in the localized release of Ca ", so regulating the events of mitosis. It is known that calcium exerts effects on the stability of spindle microtubules. An alternative view is that free magnesium... 

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