Block I, Briegleb W, Sobick V, Wohlfarth-Bottermann K E
DFVLR-Institute for Aerospace Medicine, Koln, FRG.
Adv Space Res. 1986;6(12):143-50. doi: 10.1016/0273-1177(86)90078-5.
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. During 0 g-simulation these parameters showed significant changes indicating the existence of a gravisensitivity of the slime mold. The Space-Shuttle experiment (ESA-Biorack in D 1-Mission) should demonstrate the validity of the 0 g-simulation on the fast-rotating clinostat. The experiment was designed in a way enabling the registration of the same parameters as on the clinostat (using the light microscope in combination with a photo diode and a cinecamera). Only one of the two planned measurement sessions was fully successful and provided us with data confirming the results gained on the fast-rotating clinostat: The slime mold showed under real near weightlessness in the D 1-Space Shuttle Mission a transient frequency increase in tis contraction rhythmicity and a (steady) increase in the streaming velocity of its endoplasm.
我们研究了多头绒泡菌，一种没有特殊重力感受器的单细胞生物，对重力的反应能力。最初的实验是在快速旋转的回转器上进行的0g模拟实验，使用的是这种无细胞黏菌的原质团丝。在这些地面实验中，观察到的参数包括丝的外质收缩和扩张的周期性，以及显著的细胞质（内质）穿梭流动的周期性和速度。在0g模拟期间，这些参数显示出显著变化，表明黏菌存在重力敏感性。航天飞机实验（欧洲航天局生物舱D1任务）旨在验证在快速旋转回转器上进行的0g模拟的有效性。该实验的设计方式能够记录与回转器上相同的参数（使用光学显微镜结合光电二极管和电影摄像机）。两个计划的测量时段中只有一个完全成功，并为我们提供了数据，证实了在快速旋转回转器上获得的结果：在D1航天飞机任务的实际近失重条件下，黏菌的收缩节律出现短暂的频率增加，其内质的流动速度（持续）增加。
