The effect of urea exposure on isoaspartyl content and protein l-isoaspartate methyltransferase activity in Drosophila melanogaster

Pierce, Valerie A.; Aswad, Dana W.; Gibbs, Allen G.

doi:10.1016/s0305-0491(99)00135-2

Cited by 10 publications

(6 citation statements)

References 22 publications

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“…These causal changes indicate that dietary accumulation of metabolic waste may directly affect ( positively or negatively) stress tolerance. Both heat stress and urea exposure induce protein unfolding (David et al, 1999). The combination of these two protein-denaturing treatments was probably overly cytotoxic, therefore explaining the poor survival of urea-supplemented larvae exposed to high temperature.…”

Section: Discussionmentioning

confidence: 99%

Hormesis-like effect of mild larval crowding on thermotolerance inDrosophilaflies

Henry

Renault

Colinet

2017

Journal of Experimental Biology

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Crowding is a complex stress that can affect organisms' physiology, especially through decreased food quality and accessibility. Here, we evaluated the effect of larval density on several biological traits of An increasing gradient, from 1 to 1000 eggs per milliliter of food, was used to characterize life-history traits variations. Crowded conditions resulted in striking decreases of fresh mass (up to 6-fold) and viability, as well as delayed development. Next, we assessed heat and cold tolerance in L3 larvae reared at three selected larval densities: low (LD, 5 eggs ml), medium (MD, 60 eggs ml) and high (HD, 300 eggs ml). LT values of MD and, to a lesser extent, HD larvae were repeatedly higher than those from LD larvae, under both heat and cold stress. We investigated potential physiological correlates associated with this density-dependent thermotolerance shift. No marked pattern could be drawn from the expression of stress-related genes. However, a metabolomic analysis differentiated the metabotypes of the three density levels, with potential candidates associated with this clustering (e.g. glucose 6-phosphate, GABA, sugars and polyols). Under HD, signs of oxidative stress were noted but not confirmed at the transcriptional level. Finally, urea, a common metabolic waste, was found to accumulate substantially in food from MD and HD larvae. When supplemented in food, urea stimulated cold tolerance but reduced heat tolerance in LD larvae. This study highlights that larval crowding is an important environmental parameter that induces drastic consequences on flies' physiology and can affect thermotolerance in a density-specific way.

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Section: Discussionmentioning

confidence: 99%

Hormesis-like effect of mild larval crowding on thermotolerance inDrosophilaflies

Henry

Renault

Colinet

2017

Journal of Experimental Biology

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“…Differently from many toxic chemicals that attack a single or few targets [57,58], ammonia and urea are able to impact the whole organism [20,59,60]. Strategies to resist and respond to the globally detrimental effects of these toxins include uptake reduction, detoxifying pathways, as well as efficient excretory mechanisms [61].…”

Section: Discussionmentioning

confidence: 99%

“…High larval density combined with microorganism metabolic activity and protein-rich microbial community [16,17] results in accumulation of nitrogen waste products such as ammonia and, at a lower extent, urea [18,19]. Both are relatively toxic when concentrated in organism tissues [20,21]. The concentration of ammonia in fruit flies vials can reach 30 mM [22], while ammonia environmental rich-sources may approach 100 mM [23,24].…”

Section: Introductionmentioning

confidence: 99%

Evolutionary compromises to metabolic toxins: Ammonia and urea tolerance in Drosophila suzukii and Drosophila melanogaster

Belloni

Galeazzi

Bernini

et al. 2018

Physiology & Behavior

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The invasive pest Drosophila suzukii has evolved morphological and behavioural adaptations to lay eggs under the skin of fresh fruits. This results in severe damage to a wide range of small fruits. Drosophila suzukii females typically lay few eggs per fruit, preferring healthy fruits. Hence, larvae are exposed to a reduced amount of nitrogenous waste. Differently, the innocuous Drosophila melanogaster lays eggs on fermented fruits already infested by conspecifics, with larvae developing in a crowded environment with the accumulation of nitrogenous waste such as ammonia and urea. These compounds derive from nitrogen metabolism, protein degradation, and amino acids catabolism and are relatively toxic at high concentrations in an organism. The observed differences in oviposition site and larval ecological niche suggest that these species might differ in behavioural and physiological mechanisms used to cope with nitrogenous waste. We investigated how different concentrations of ammonia and urea affect oviposition and larval development in both species. Females and larvae of D. suzukii showed greater susceptibility to high concentrations of both compounds, with a dramatic decrease in the number of eggs laid and egg viability. Moreover, we tested the chemotactic response of third instar larvae to high concentrations of the compounds. Interestingly, ammonia resulted in a repulsive behaviour in respect of the control and urea groups. To better understand the pathways underlying these differences, we evaluated the effect on ornithine aminotransferase and glutathione-S-transferase, two enzymes involved in nitrogen metabolism and stress response that are expressed during larval development. Both ammonia and urea significantly reduced the expression of these enzymes in D. suzukii compared to D. melanogaster. This shows how the ecological shift of D. suzukii to fresh fruit is accompanied by less efficient detoxifying and excretory mechanisms, with important implications for evolutionary biology and applied research. Our data suggest that the ecological shift of D. suzukii to fresh fruit as oviposition substrate is accompanied by a reduced tolerance to metabolic toxins during larval development.

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“…decreases in cuticular or membrane permeability). We have already initiated a more detailed examination of the physiological basis of tolerance in these populations David et al, 1999). These populations may also serve as a model system to study the mechanisms of adaptation to pollution and toxic compounds.…”

Section: Cross-tolerance To Toxic Substancesmentioning

confidence: 99%

“…They do not appear to target any specific biochemical processes, but instead have general cytotoxic effects. Urea is a protein denaturant (Somero and Yancey, 1997), and larvae reared on urea-containing media have increased levels of proteins containing isoaspartyl residues, a form of protein damage (David et al, 1999). Ammonia's effects are less well understood.…”

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confidence: 99%

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

Borash

Pierce

Gibbs

et al. 2000

Journal of Insect Physiology

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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.

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The effect of urea exposure on isoaspartyl content and protein l-isoaspartate methyltransferase activity in Drosophila melanogaster

Cited by 10 publications

References 22 publications

Hormesis-like effect of mild larval crowding on thermotolerance inDrosophilaflies

Hormesis-like effect of mild larval crowding on thermotolerance inDrosophilaflies

Evolutionary compromises to metabolic toxins: Ammonia and urea tolerance in Drosophila suzukii and Drosophila melanogaster

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

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