PRINCIPAL INVESTIGATOR (S ); A. Gib DeBusk 



EXPERIMENT TITLE/NUMBER : Preliminary Report of Genetic Studies on Discoverer 



XVIII 



PROGRAM/MISSION : Discoverer XVIII 



CLASSIFICATION : Microorganism - ( Neurospora crassa ) 



DISCIPLINE(S) : Cell biology, Radiobiology, Genetics 



OBJECTIVES : To correlate traversal of primary cosmic rays with an increase in 

 mutation in a population of cells lying along the track path. 



PROTOCOL : A double mutant of Neurospora was used (adenineless and ~ 

 inositolless colonial). 75 millpore filters had 10 ml aliquots of 8.75 x 10 

 cells/ml placed on them, were dried over CaCl , mounted on orientation racks, 

 and placed on four track plates. Each plate was wrapped in polyethelyene and 

 were stored at 27 C. Two plates were ground control, and two were flight 

 experiment plates. The plates were air mailed to SAM and subsequently flown. 



EQUIPMENT : Biological track plate, millipore filters, photographic emulsion 

 on a 2" x 2" sheet of glass, with Neurospora covered filters on top, neutron 

 sensitve film, Ansco 552 film, antimony foil, alanine, and albumin. 



RESULTS : The emulsion was faulty with no correlation of cosmic ray path and 

 mutation being made. No forward or back mutation were observed. 



CONCLUSIONS : No reverse mutation was observed at the inositol locus in either 

 the experimental or control population examined (5.25 x 10 control and 2.b x 

 10 experimental). The phenomena of physiological cell injury observed in 

 NERV 1 was not observed in the cells in Discoverer XVI11. No significant 

 increase in forward mutation was observed in the experimental cell population 

 examined. 



PUBLICATIONS : 143, 144 



159 



