Confirmation of gravisensitivity in the slime mold Physarum polycephalum under near weightlessness.

We have investigated Physarum polycephalum, a unicellular organism with no special gravity receptors, on its ability to react to gravity. The first experiments were 0 g-simulation experiments on the fast-rotating clinostat conducted with plasmodial strands of this acellular slime mold. In these earth-bound experiments the observed parameters were periodicity of the contractions and dilatations of the strand's ectoplasm as well as the periodicity and velocity of the striking cytoplasmic (endoplasmic) shuttle streaming.

Influence of zero gravity simulation on time course of mitosis in microplasmodia of Physarum polycephalum.

Detrimental effects of weigntlessness are no longer expected to hinder successful mitosis. Experiments in space and on the fast clinostat give no hints of this. Nevertheless we are thinking of a g sensitivity during the process of chromosome condensation and distribution.

Responses of roots to simulated weightlessness on the fast-rotating clinostat.

Sedimentable cell particles are distributed randomly along the horizontal axis of the fast-rotating clinostat. They neither sediment in the direction of gravity, nor in the direction of the centrifugal force, nor in the direction of the resultant force of both. The effect of this "weightlessness" and that of very small centrifugal forces on the perception of mass acceleration was examined using young primary roots of Lepidium sativum L.