Evolution of ammonia and urea tolerance in Drosophila melanogaster: resistance and cross-tolerance

Abstract

We examined whether populations of Drosophila melanogaster could evolve a genetically based tolerance to high levels of toxic compounds (urea or ammonia) added to their larval food medium. We also examined whether tolerance to one compound may impart cross-tolerance to other compounds. Five populations selected for ammonia tolerance (AX), five populations selected for urea tolerance (UX), and five unselected controls (AUC) were assayed for developmental time, viability, and female fertility. These characteristics were measured on each of the 15 populations reared on one of three larval food conditions (plain banana-molasses, 0.35 M NH(4)Cl, or 0.266 M urea). On urea-supplemented media, the urea-selected populations developed fastest and expressed the highest viability; the ammonia-selected populations developed significantly faster and had a higher viability than the controls. Similarly, on ammonia-supplemented media, the ammonia-selected populations developed fastest and expressed the highest viability; the urea-selected populations developed significantly faster and had a higher viability than the controls. This suggests that a cross-tolerance exists for resisting different toxic compounds. Urea-selected females reared on urea-containing food media displayed superior fecundity, without any observable cross-tolerance effect. When all populations were reared on food containing 0.266 M urea, the urea-selected populations had the lowest levels of urea in their tissues. All populations reared on food containing 0.37 M ammonia or 0.266 M urea, contained more ammonia in their tissues than did populations reared on plain food.

Bioreactor culture of recombinant Drosophila melanogaster S2 cells: characterization of metabolic features related to cell growth and production of the rabies virus glycoprotein

“…The bars represent the standard error now, such a high ammonia concentration has never been reported in animal cell culture, indicating that these cells are very resistant to high levels of ammonia. Interestingly, Borash et al (2000) have shown that the insect Drosophila melanogaster also has a high tolerance to ammonia. Lactate was present in very low concentrations in all the experiments.…”

Egg Viability, Mating Frequency and Male Mating Ability Evolve in Populations of Drosophila melanogaster Selected for Resistance to Cold Shock

“…The ability to resist environmental stress is an important component of fitness. Using Drosophila , a large number of studies have investigated the evolution of resistance to various environmental stresses such as larval crowding [1], increased urea and ammonia content in larval food [2], adult desiccation, starvation [3, 4] and extreme temperatures [5–9]. …”

Ammonium secretion by Malpighian tubules ofDrosophila melanogaster: application of a novel ammonium-selective microelectrode

“…) showed the greatest fitness when assayed on ammonia-supplemented food (Borash et al, 2000). These data suggest that such larvae increase the capacity to detoxify or excrete ammonia.…”

“…For instance, ammonia concentrations in the diet of Drosophila cultures increase from ~10mmoll −1 after 4days tõ 30mmoll −1 after 20days (Borash et al, 1998). Whole-body ammonia content of larvae reared on dietary medium containing 370mmoll −1 ammonia was three times above that of larvae fed a control diet (Borash et al, 2000). Survival during exposure to high concentrations of ammonia in the diet suggests that both larvae and adults are tolerant of the toxic effects of ammonia.…”