Resistance to stress as a function of age in Drosophila melanogaster living in hypergravity.

Male and female fruitflies (Drosophila melanogaster) living at different gravity levels [1g: terrestrial gravity; 3 and 5g: hypergravity (HG)] were used to investigate the age-specific (young: 7 days; middle-aged: 28 days; and old: 49 days) resistance to various stresses (starvation, desiccation, and cold). The experiment showed that the resistance of the flies to the studied stresses decreased with age, except in the case of females submitted to starvation which was increased. These variations were explained by the amount of lipid. Variation in desiccation resistance was not explained by the amount of water. As a function of gravity, no or slight differences were observed for the studied stresses. The resistance to heat of young flies increased with the gravity level. This resistance was not explained by a decreased locomotor activity of HG-living flies during heat stress, nor by the water and lipid contents.