Biosatellite II--physiological and somatic effects on insects.
Interesting physiological and somatic effects of space flight have been observed in a variety of insects on board Biosatellite II. Wasps, beetles and fruit flies have demonstrated positive effects of the space flight alone or in combination with irradiation. In the flour beetle, Tribolium confusum, the incidence of a developmental wing abnormality was measured. This abnormality, which mimics the mutation known as "split", was significantly increased in beetles which were flown as young pupae, pre-irradiated with X rays to bring them into their sensitive dose range and gamma irradiated during flight. Wing abnormalities increased from a ground value of 29.9 per cent to a value of 44.8 per cent. The length of the pupal period was also measured. Although there was a significant increase of the flight pupal period over that of the ground control, the most likely explanation seems to be the temperature drop of the flight samples between separation and retrieval of the flight capsule. In the parasitic wasp, Habrobracon juglandis, flown in the adult stage, several interesting results have been obtained in terms of reproductive performance, life span and enzyme activity. Reproductive performance, measured by the average number of eggs laid/female/day, was unaffected by flight for control unirradiated wasps. However, for females X rayed with 2000 R prior to flight, the characteristic depression of egg-laying at 10 days post-irradiation was negligible in the flight animals. A more pronounced effect was observed in those females which received the chronic 2667 R gamma ray dose in flight; egg production actually progressively increased to twice the level of the ground sample. It was observed that males were disoriented in their mating behavior for 2 days after the flight. When the dose level data was pooled, the life span of females was found to be significantly longer in the flight group. Upon analysis of the activity of the enzyme, xanthine dehydrogenase (XDH), adult flight males were found to have a significantly decreased XDH activity compared with ground controls. No significant difference was found between female F1 progeny of flight and ground males. XDH activity was also analyzed in F1 progeny of Drosophila melanogaster, orbited as adults and larvae. For the F1 male progeny of adult males, there was a significantly depressed average XDH activity compared with ground controls for the highest irradiation dose. For F1 male progeny of flight larvae, there was a statistically decrease of XDH activity only between the off-spring of irradiated flight and ground larvae. Further somatic changes were observed in Drosophila larvae, in which chromosome aberrations were studied.
Buckhold
B
B
University of California, Berkeley, California, USA.
D000818:Animals; D004331:Drosophila melanogaster / Q000528:radiation effects; D005720:Gamma Rays; D006801:Humans; D008297:Male; D010063:Ovum / Q000528:radiation effects*; D011679:Pupa / Q000254:growth & development / Q000528:radiation effects*; D012726:Sexual Behavior, Animal; D013026:Space Flight; D014231:Tribolium / Q000528:radiation effects; D014863:Wasps / Q000196:embryology / Q000201:enzymology / Q000528:radiation effects; D014893:Weightlessness; D014921:Wings, Animal / Q000254:growth & development* / Q000528:radiation effects; D014968:Xanthine Dehydrogenase / Q000378:metabolism*
D014968:Xanthine Dehydrogenase