PRINCIPAL INVESTIGATOR(S ) : Michael A. Bender, Frederick J. deSerres, P. 



Carolyn Gooch , I. R. Miller, D. B. Smith and Sohei 

 Kondo 



EXPERIMENT TITLE/NUMBER : Radiation and Zero-Gravity Effects on Human 



Leukocytes and Neurospora crassa . S004 



PROGRAM/MISSION : Gemini 3, 11 



CLASSIFICATION : Human, Microorganism 



DISCIPLINE(S) : Radiobiology, Hematology, Cell biology, Genetics 



OBJECTIVES : To determine if there is any synergism between radiation and 

 space flight in white blood cells, and in Neurospora crassa . and if there are 

 any large radiobiological effects following space flight. 



PROTOCOL : Whole human blood and Neurospora crassa spores were irridiated with 

 J£ P B-rays during orbit. Irradiation was accomplished by identical 

 experimental devices, one on the righthand hatch of the spacecraft, and one on 

 the ground. Upon completion, a cytogenetic analysis was made of each blood 

 sample, and the frequencies of chromosome aberration determined. Yields of 

 both single and multiple break aberrations were calculated for the flight and 

 ground-control samples. Survival of the spores and mutability of two 

 different genes were studied for frequencies of chromosome breakage and of 

 gene mutation. Spore samples were irradiated on the surface of filters and in 

 suspension form. Gemini 3 carried only human blood while Gemini 11 carried 

 both specimens . 



32 



EQUIPMENT : P source, aluminum blood-sample holder, dosimeter rods. 



RESULTS : A synergism between radiation and some space flight parameters 

 appeared to exist for human chromosome aberration production on the Gemini 3 

 flight. It seems likely that this effect is on the normal restitution of 

 chromosome breaks. Both the Gemini 11 blood experiment and the Neurospora 

 crassa experiment failed to result in data confirmatory of the apparent 

 synergism observed on the Gemini 3 mission. 



CONCLUSIONS : The two parts of this experiment have shown that neither orbital 

 space flight nor any of the stresses connected with it produced significant, 

 unpredicted genetic damage, at least insofar as chromosomal aberration 

 production is a valid measure of this general type of effect. 



PUBLICATIONS : 30, 31, 32, 33, 34, 145, 149, 152 



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