Biology subjects

Piper, M. D. W.

Publications and source records attributed to Piper, M. D. W..

7 recordsLinked to original sources

bioRxiv2024

Dietary zinc limitation dictates lifespan and reproduction trade-offs of Drosophila mothers

Dietary metal ions significantly influence the lifespan and reproduction of Drosophila females. In this study, we show that while the depletion of all metal ions from the diet adversely affects reproduction and lifespan, the absence of Zn alone negatively impacts reproduction without adversely altering maternal lifespan, indicating it can dictate resource reallocation between key fitness traits. Although our data show that flies sense varying dietary Zn levels, they apparently do not alter their feeding preferences to optimise egg production when faced with a choice between Zn- depleted or Zn- sufficient food, but they can choose to preferentially oviposit on Zn containing food, perhaps indicating a strategy to assure offspring survival. We also uncovered a role for the white gene in sustaining high levels of egg viability when Zn is diluted in the diet. These insights into the role of dietary metal ions, particularly Zn, point to a central role for these dietary micronutrients to indicate environmental quality and so govern trade-offs between lifespan and reproduction in flies.

evolutionary biology↗

bioRxiv2024

Transiently restricting individual amino acids protects D. melanogaster against multiple stressors

Nutrition and resilience are linked, though it is not yet clear how diet confers stress resistance or the breadth of stressors that it can protect against. We have previously shown that transiently restricting an essential amino acid can extend lifespan and also protect against nicotine exposure in Drosophila melanogaster, raising the possibility that amino acid restriction is geroprotective because of elevated detoxification capacity. Here, we sought to characterise the nature of this dietary mediated protection, and determine whether it was sex, amino acid, and/or nicotine specific. When we compared between sexes, we found that isoleucine deprivation increases female, but not male, nicotine resistance. Surprisingly, we found that this protection afforded to females was not replicated by dietary protein restriction and was instead specific to individual amino acid restriction. Other studies have documented methionine or leucine restriction conferring stress resistance, though we previously found that individually depriving them did not increase nicotine resistance. We therefore wondered whether reducing the severity of restriction of these amino acids could confer nicotine resistance. This was true for methionine restriction, and we found that flies fed a diet containing 25% methionine for 7 days protected against subsequent nicotine poisoning ([~]30% longer lived than controls with all amino acids). However, when dietary leucine was altered, nicotine resistance changed, but no single diet was protective. To understand whether these beneficial effects of diet were specific to nicotine or were generalisable across stressors, we pre-treated with amino acid restriction diets and exposed them to other types of stress. We did not find any diets that protected against heat stress or infection with the bacterium Enterococcus faecalis. However, we found that some of the diets that protected against nicotine also protected against oxidative and starvation stress, and improved survival following cold shock. Interestingly, we found that a diet lacking isoleucine was the only diet to protect against all these stressors. These data point to isoleucine as a critical determinant of robustness in the face of environmental challenges.

genetics↗

bioRxiv2023

Short-term fasting of a single amino acid extends lifespan.

Diet and health are strongly linked, though the strict changes in diet required to improve health outcomes are usually difficult to sustain. We sought to understand whether short term bouts of amino acid-specific modifications to the diet of Drosophila melanogaster could mimic the lifespan and stress resistance benefits of dietary restriction, without the requirement for drastic reductions in food intake. We found that flies fed diets lacking the essential amino acid isoleucine, but otherwise nutritionally complete, exhibited enhanced nicotine tolerance, indicating elevated detoxification capacity. The protection from isoleucine deprivation increased with the duration of exposure, up to a maximum at 7-day isoleucine deprivation for flies 2, 3, or 4 weeks of age, and a 5-day deprivation when flies were 5 weeks of age. Because of these beneficial effects on toxin resistance, we intermittently deprived flies of isoleucine during the first 6 weeks of adulthood and monitored the effect on lifespan. Lifespan was significantly extended when flies experienced short term isoleucine deprivation at 3 and 5 weeks of age, regardless of whether they were also deprived at 1 week. These results indicate that short-term bouts of isoleucine deprivation can extend lifespan and highlight its cumulative and time-dependent benefits. Interestingly, we found that isoleucine-deprived flies lost their protection against nicotine within three days of returning to fully fed conditions. Therefore, the mechanisms underlying lifespan extension may involve transient damage clearance during the bouts of isoleucine deprivation rather than sustained enhanced detoxification capacity. These data highlight a new time-restricted, nutritionally precise method to extend life in Drosophila melanogaster and point to a more manageable dietary method to combat ageing.

physiology↗

bioRxiv2023

Early-adult methionine restriction reduces methionine sulfoxide and extends lifespan in Drosophila

Methionine restriction (MetR) extends lifespan in various organisms, but its mechanistic understanding remains incomplete. Whether MetR during a specific period of adulthood increases lifespan is not shown. In Drosophila, MetR is reported to extend lifespan only when amino acid levels are low. Here, by using an exome-matched holidic medium, we show that decreasing Met levels to 10% extends Drosophila lifespan with or without decreasing total amino acid levels. MetR during the first four weeks of adult life robustly extends lifespan. MetR induces the expression of Methionine sulfoxide reductase A (MsrA) in young flies, which reduces the oxidatively-damaged Met. MsrA induction is foxo-dependent and persists for two weeks after cessation of the MetR diet. Loss of MsrA attenuates lifespan extension by early-adult MetR. Our study highlights the age-dependency of the organismal response to specific nutrient and suggests that nutrient restriction at a particular period of life is sufficient for healthspan extension.

physiology↗

bioRxiv2023

Identifying the proximate mechanisms that generate variation in nutritional plasticity for fecundity in Drosophila melanogaster

Nutrition is an important determinant of an animals survival and fitness. Phenotypic plasticity allows a genotype to adjust life history traits to changes in its nutritional environment, and it varies among individuals. To understand how variation in plasticity is achieved, we made use of a Drosophila melanogaster isogenic panel to characterize nutritional plasticity for fecundity by feeding flies diets differing in their yeast content and counting the number of eggs produced. We then identified lines with the highest and lowest plastic responses to diet and dissected the potential proximate mechanisms responsible for these differences in plasticity, including morphology, behaviour, and physiology. Our results suggest that genetic variation in plasticity is not due to differences in ovariole number, but due to both increased food intake, and higher efficiency at converting food into eggs. Our results show that, in this population of D. melanogaster, variation in behaviour and physiology, but not morphology, underlies differences in plasticity for fecundity. Further, they set the stage for future studies aiming to understand how the proximate mechanisms that generate genetic variation in plasticity contribute to a populations persistence when faced with environmental changes.

evolutionary biology↗

bioRxiv2022

Ageing impairs protein leveraging in a sex-specific manner in Drosophila melanogaster

Modifying the relative proportions of macronutrients in an animals diet has noteworthy effects on its reproduction, lifelong health, and lifespan. Because of this, a wide range of animals carefully regulate their nutrient intake toward species and stage-specific targets. However, when animals are unable to reach their nutrient target from their existing food resources, they will compromise between overconsuming one nutrient and under-consuming the deficit nutrient. In this study, we used capillary feeding (CAFE) assays to understand the rules of compromise of adult fruit flies (Drosophila melanogaster) of different sex, mating status, and age when constrained to single diets. We found that young male and female D. melanogaster compromised by consuming more food on diets with low protein to carbohydrate (P:C) ratios compared to diets with high P:C ratios. Further, young male and female flies varied their carbohydrate intake significantly more than their protein intake, and female flies varied their carbohydrate intake significantly more than males. To test for effects of mating status on nutrient intake, we compared food intake of young mated and virgin females. We found that both virgin and mated females compromised by consuming more food on the low P:C diet compared to high P:C diets; however, mated females consumed more food than virgin females. As flies aged, they decreased their overall food intake and showed more modest alterations in their food intake across varying P:C diets. Further, mated females ceased to compromise for the protein deficit at a younger age than males. These findings provide new understanding about differences in protein leveraging behaviour across sexes, and how these behaviours change with age. HighlightsO_LIYoung fruit flies exhibit protein leveraging behaviour, varying their carbohydrate consumption more than protein C_LIO_LIYoung mated female flies vary their carbohydrate consumption significantly more than young males C_LIO_LIBoth virgin and mated female flies balance their nutrient intake similarly C_LIO_LIAs flies age, their ability to protein leverage declines, and this occurs faster in female flies C_LI

animal behavior and cognition↗

bioRxiv2020

A dietary sterol trade off determines lifespan responses to dietary restriction in Drosophila melanogaster

Diet plays a significant role in maintaining lifelong health. In particular, lowering the dietary protein : carbohydrate ratio can improve lifespan. This has been interpreted as a direct effect of these macronutrients on physiology. Using Drosophila melanogaster, we show that the role of protein and carbohydrate on lifespan is indirect, acting by altering the partitioning of limiting amounts of dietary sterols between reproduction and lifespan. Shorter lifespans in flies fed on high protein : carbohydrate diets can be rescued by supplementing their food with cholesterol. Not only does this fundamentally alter the way we interpret the mechanisms of lifespan extension by dietary restriction, these data highlight the important principle that life histories can be affected by nutrient-dependent trade-offs that are indirect and independent of the nutrients (often macronutrients) that are the focus of study. This brings us closer to understanding the mechanistic basis of dietary restriction.

evolutionary biology↗