Objectives:This experiment studied the direct effect of weightlessness and combined effects of gamma radiation and weightlessness on somatic wing development, germ cells, and the pupal period of flour beetles. From preflight testing, it was found that the predominant abnormality produced was a morphologic, easily recognizable deformation in the size and structure of the membranous wings. Low numbers of these abnormalities were found to occur spontaneously, while at high doses to pupae, almost 100% of the adult animals will develop the abnormality.
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Approach:
Seven hundred twenty beetle pupae between 19 and 27 hours of age were orbited, half in the presence of 85Sr and half shielded from it. Two-thirds of each pupae group had received a preflight radiation dose (1,350 r) of 180 keV x-rays. Identical ground controls were maintained. It was found that, by choosing an appropriate temperature, the rate of development of the organism could be slowed down or speeded up in such a manner that the organisms could be maintained in pupal stage, so most of the wing development would take place after reaching weightlessness. Upon return, the pupal period, wing abnormalities, and genetic damage were determined by mating experimental beetles with controls. In addition to the Biosatellite controls, a study was conducted to determine if variations could be found from in a different control capsule, as well as a postflight vibration control.
Results:
Pupal period, wing abnormalities, and dominant lethality were significantly increased. "Split" mutation increased from ground values of 30% to 45% for flight. Numerically, the vibrated irradiated groups had fewer wing abnormalities than did the appropriate controls, whereas the flight-irradiated sample had more abnormalities than the ground-controls, suggesting that vibration was not the cause of the increased wing abnormalities in flight samples. No differences were detected as a result of the capsule comparison control. Some factor in space flight, probably weightlessness, either facilitated the development of radiation- induced chromosome breaks and/or DNA damage in the meiotic cells (oocytes), or hindered the normal correction of such errors. Another possible explanation is a temperature drop of the flight samples that occurred between separation and retrieval of the flight capsule.
Buckhold, B. and J.V. Slater: Effect of Temperature and X-Irradiation on Pupae of the Flour Beetle Tribolium confusum. Radiation Research, vol. 37, 1969, pp. 567-576.
Buckhold, B. et al.: Some Effects of Spaceflight on the Flour Beetle, Tribolium confusum. BIOSPEX: Biological Space Experiments, NASA TM-58217, 1979, p. 102.
Buckhold, B. et al.: Some Effects of Spaceflight on the Flour Beetle, Tribolium confusum. The Experiments of Biosatellite II, NASA SP-204, 1971, pp. 79-95.
Buckhold, B.: Biosatellite II: Physiological and Somatic Effects on Insects. Life Sciences and Space Research: Proceedings of the 11th Plenary Meeting of COSPAR, Tokyo, Japan, May 14-16, 1968, North Holland Publishing, 1969, pp. 77-83.
Slater, J.V. et al.: Effect on a Flour Bettle of Irradiation During Space Flight. Bioscience, Vol 18 (No. 6):595-597, 1968
Slater, J.V. et al.: Environmental Studies with the Flour Beetle Tribolium confusum. Life Sciences and Space Research: Proceedings of the 12th Plenary Meeting of COSPAR, Prague, Czechoslovakia, May 11-14, 1969, North Holland Publishing, 1970, p. 5.
Slater, J.V. et al.: Spaceflight Enhancement of Irradiation Effects in the Flour Beetle Tribolium confusum. Radiation Research, vol. 39, 1969, pp. 68-81.
Slater, J.V. et al.: Synergism of X-Irradiation and Spaceflight in the Flour Beetle. Radiation Research, vol. 35, 1968, p. 501.
von Borstel, R.C. et al.: Experiments with Habrobracon and Tribolium on Biosatellite II. Japanese Journal of Genetics, vol. 63, 1968, p. 464.
Behavior: insect
Chromosome breakage
Mutation rate, lethal-dominant
Mutation rate, wing
Radiation, dose, Provided, for study of synergism with weightlessness
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Reproduction: insect
Survival rate, Pupae, flour beetle (Tribolium confusum ), Observation (number)
Temperature
Temperature, Capsule, Biosatellite II, Recorder