Effects of temperature on responses to anoxia and oxygen reperfusion in Drosophila melanogaster

SCHILMAN, P.E.; WATERS, J.S.; HARRISON, J.F.; LIGHTON, J.R.B.

JOURNAL OF EXPERIMENTAL BIOLOGY

COMPANY OF BIOLOGISTS LTD

Año: 2011 vol. 214 p. 1271 - 1275

0022-0949

Insects in general, and Drosophila in particular, are much more capable of surviving anoxia than vertebrates, and the mechanisms of this capacity are of considerable biomedical and ecological interest. Temperature is likely to strongly affect both the rates of damage occurring in anoxia and the recovery processes in normoxia, but as yet there is no information on the effect of this critical variable on recovery rates from anoxia in any animal. We studied the effects of temperature, and thus indirectly of metabolic flux rates, on survival and recovery times of individual male Drosophila melanogaster following anoxia and oxygen reperfusion. Individual flies were reared at 25 ºC and exposed to an anoxic period of 7.5, 25, 42.5 or 60 minutes at 20, 25 or 30 ºC. Before, during and after anoxic exposure the flies’ metabolic rates (MRs), rates of water loss, and activity indices were recorded. Temperature strongly affected the MR of the flies with a Q10 of 2.21. Temperature did not affect the slope of the relation between time to recovery and duration of anoxic exposure, suggesting that thermal effects on damage and repair rates were similar. However the intercept of that relation was significantly lower (i.e. recovery was most rapid) at 25 °C, which was the rearing temperature. When temperatures during exposure to anoxia and during recovery were switched, observed recovery times matched those predicted on the basis of a model in which the accumulation and clearance of metabolic end-products share a similar dependence on temperature.