Radiation effects in nematodes:  results from IML-1 experiments.
The nematode Caenorhabditis elegans was exposed to natural space radiation using the ESA Biorack facility aboard Spacelab on International Microgravity Laboratory 1, STS-42.  For the major experimental objective dormant animals were suspended in buffer or on agar or immobilized next to CR-39 plastic nuclear track detectors to correlate fluence of HZE particles with genetic events.  This configuration was used to isolate mutations in a set of 350 essential genes as well as in the unc-22 structural gene.  From flight samples 13 mutants in the unc-22 gene were isolated along with 53 lethal mutations from autosomal regions balanced by a translocation eT1(III;V).  Preliminary analysis suggests that mutants from worms correlated with specific cosmic ray tracks may have a higher proportion of rearrangements than those isolated from tube cultures on a randomly sampled basis.  Right sample mutation rate was approximately 8-fold higher than ground controls which exhibited laboratory spontaneous frequencies.
Nelson
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Jet Propulsion Laboratory, California Institute of Technology, Pasadena 91109, USA.
Schubert
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WW
Kazarians
G A
GA
Richards
G F
GF
Benton
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Benton
E R
ER
Henke
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R
D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000528:radiation effects*; D003359:Cosmic Radiation; D017238:Genes, Helminth / Q000528:radiation effects; D018499:Linear Energy Transfer; D009154:Mutation; D011829:Radiation Dosage; D011834:Radiation Monitoring; D013026:Space Flight; D013819:Thermoluminescent Dosimetry; D014893:Weightlessness