title: Radiation effects in nematodes:  results from IML-1 experiments.
abstract: 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.
authors.affiliation: Jet Propulsion Laboratory, California Institute of Technology, Pasadena 91109, USA.
authors.forename: G A
authors.initials: GA
authors.lastname: Nelson
authors.forename: W W
authors.initials: WW
authors.lastname: Schubert
authors.forename: G A
authors.initials: GA
authors.lastname: Kazarians
authors.forename: G F
authors.initials: GF
authors.lastname: Richards
authors.forename: E V
authors.initials: EV
authors.lastname: Benton
authors.forename: E R
authors.initials: ER
authors.lastname: Benton
authors.forename: R
authors.initials: R
authors.lastname: Henke
mesh_terms: 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