PRINCIPAL INVESTIGATOR(S ): John H. Able, David W. Haack, and Richard W. Price 



EXPERIMENT TITLE/NUMBER : Effects of Weightlessness on the Nutrition and 



Growth of Pelomvxa carolinensis . P-1035 



PROGRAM/MISSION : Biosatellite II 



CLASSIFICATION : Animal - Amoeba ( Pelomvxa carolinensis ) 



DISCIPLINE(S) : Cell biology 



OBJECTIVES : To survey the fine structure and distribution of mitochondria, 

 nuclei, nucleoli, Golgi apparatus, and endoplasmic reticulum for changes that 

 may have been induced by weightlessness, and to determine if there were normal 

 growth patterns or normal progression of food vacuole digestion in amoebae 

 subjected to a weightless environment. 



PROTOCOL : The amoebae were cultured and subcultured, placed in a buffer and 

 fed Paramecium. Five complete units of 24 chambers were assembled 2 days 

 before launch. The organisms were loaded at F-18.3 hr. The amoebae were 

 screened and counted as they were selected for the chambers. After the 

 amoebae and Paramecium were loaded, the chambers were filled with THAM glycyl 

 glycine buffer, with a small airspace left. The fixations were actuated 5 

 times inflight. At recovery, the organisms were counted, examined for mitotic 

 forms, food vacuoles counted and the gross morphology described. 



EQUIPMENT : Experiment package with 24 chambers, each divided into three 5-ml 

 compartments containing either amoebae, Paramecium or fixitive. The chambers 

 were mounted on magnesium plates. Four of the chambers contained thermistors. 



RESULTS : The amoebae fed normally while in orbit, and specimens fixed in 

 orbit retained the ordinary heteropodal shape. Growth rates of orbited 

 amoebae, both fed and starved, were slower than controls following reentry and 

 recovery procedures. In continuous-fed organisms there was little or no 

 effect of flight detectable in growth rate or actual number of divisions. 

 Electron micrographs showed no abnormalities and few differences between 

 flight and control organisms. 



CONCLUSIONS : The weightless environment did not produce any gross 

 irreversible alterations in the normal physiologic processes of the amoebae. 



PUBLICATIONS : 1, 431 



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