Fitness benefits of dietary restriction

Dietary restriction (DR) improves survival across a wide range of taxa yet remains poorly understood. The key unresolved question is whether this evolutionarily conserved response to temporary lack of food is adaptive. Recent work suggests that early-life DR reduces survival and reproduction when nutrients subsequently become plentiful, thereby challenging adaptive explanations. A new hypothesis maintains that increased survival under DR results from reduced costs of overfeeding. We tested the adaptive value of DR response in an outbred population of Drosophila melanogaster fruit flies. We found that DR females did not suffer from reduced survival upon subsequent re-feeding and had increased reproduction and mating success compared to their continuously fully fed (FF) counterparts. The increase in post-DR reproductive performance was of sufficient magnitude that females experiencing early-life DR had the same total fecundity as continuously FF individuals. Our results suggest that the DR response is adaptive and increases fitness when temporary food shortages cease.

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Protector and Casualty

The Oxford Handbook of Positive Emotion and Psychopathology ◽

10.1093/oxfordhb/9780190653200.013.31 ◽

2019 ◽

pp. 495-522

Author(s):

Meg Dennison ◽

Katie McLaughlin

Keyword(s):

Early Life ◽

Positive Emotion ◽

Positive Emotions ◽

Protective Factor ◽

Mental Health Problems ◽

Positive Emotionality ◽

Early Life Adversity ◽

Adverse Experiences ◽

Wide Range ◽

Positive Valence

Early-life adversity is associated with elevated risk for a wide range of mental disorders across the lifespan, including those that involve disruptions in positive emotionality. Although extensive research has evaluated heightened negative emotionality and threat processing as developmental mechanisms linking early-life adversity with mental health problems, emerging evidence suggests that positive emotions play an integral, but complex, role in the association of early-life adversity with psychopathology. This chapter identifies two pathways through which positive emotion influences risk for psychopathology following early-life adversity. First, experiences of early-life adversity may alter the development of the “positive valence system”, which in turn increases risk for psychopathology. Second, the association between adversity and psychopathology may vary as a function of individual differences in positive emotionality. We consider how the development of positive emotionality—measured at psychological, behavioral and neurobiological levels—may be altered by early-life adversity, creating a diathesis for psychopathology. We additionally review evidence for the role of positive emotion, measured at multiple levels, as a protective factor that buffers against the adverse impacts of adversity. In integrating these two roles, it is proposed that characteristics of environmental adversity, including developmental timing, duration, and type of adversity, may differentially impact the development of positive emotionality, leading to a better understanding of risks associated with specific adverse experiences. Methodological issues regarding the measurement of adverse environments as well as implications for early intervention and treatment are discussed.

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Effects of Temperature on Anoplophora chinensis (Coleoptera: Cerambycidae) Adult Survival, Reproduction, and Egg Hatch

Forests ◽

10.3390/f12040432 ◽

2021 ◽

Vol 12 (4) ◽

pp. 432 ◽

Cited By ~ 1

Author(s):

Melody A. Keena ◽

Paul M. Moore ◽

Gregg Bradford

Keyword(s):

Invasive Species ◽

Tree Species ◽

Adult Survival ◽

Optimum Temperature ◽

Egg Hatch ◽

Laboratory Conditions ◽

Wide Range ◽

Survival And Reproduction ◽

Summer Temperatures ◽

Effects Of Temperature

Anoplophora chinensis (Forster) is an invasive species that can damage many tree species in orchard, urban, and forested habitats. Adult survival, reproduction, and egg hatch of A. chinensis from Italy and China are evaluated at eight constant temperatures (5, 10, 15, 20, 25, 30, 35, and 40 °C) under laboratory conditions. The estimated Tmax for longevity was 42 and 33 °C for females and 42 and 39 °C for males from China and Italy, respectively. The estimated Tmax, Tmin, and optimum temperature for fecundity were 35, 9, and 29 °C, respectively. Females laid eggs at 15–30 °C and eggs hatched at 15–35 °C. Days to first oviposition increased exponentially from 13 days at 30 °C to >300 days near 10 °C. The estimated Tmin for egg hatch was 13 °C, the Tmax at 38 °C, and the optimum 29 °C. Percentage hatch was estimated to be highest at 26 °C and have a Tmax of 31 °C and Tmin of 10 °C. These results indicate that summer temperatures over a wide range of latitudes should support beetle survival and reproduction, but at temperatures ≥35 °C, oviposition ceases, and adult survivorship declines. In addition, females may survive into the fall, but lay fewer eggs that may not hatch. These responses of A. chinensis to temperature can be used for developing phenological models to predict the timing of stages for management or eradication efforts.

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Distribution, feeding behaviour, and condition of Cape horse mackerel early life stages, Trachurus capensis, under different environmental conditions in the northern Benguela upwelling ecosystem

ICES Journal of Marine Science ◽

10.1093/icesjms/fsu087 ◽

2014 ◽

Vol 72 (2) ◽

pp. 543-557 ◽

Cited By ~ 3

Author(s):

S. J. Geist ◽

A. Kunzmann ◽

H. M. Verheye ◽

A. Eggert ◽

A. Schukat ◽

...

Keyword(s):

Dissolved Oxygen ◽

Feeding Ecology ◽

Environmental Conditions ◽

Early Life ◽

Early Life History ◽

Horse Mackerel ◽

Larval Phase ◽

Recruitment Success ◽

Wide Range ◽

Variable Recruitment

Abstract Early life history (ELH) traits are key to understand variable recruitment success and hence the stock size of marine fish. One of the currently most puzzling ecosystems in this regard is the northern part of the Benguela Current upwelling system off Namibia. Here, populations of the formerly dominant pelagic species, sardine and anchovy, failed to recover during the last three decades after a dramatic decline. In contrast, Cape horse mackerel, Trachurus capensis, maintained a constant population size. Warming of the system and shoaling of hypoxic zones together with feedback loops within an altered foodweb are discussed to be responsible for this regime shift. In this study, we address the role of larval traits for the successful performance of the T. capensis population under the present environmental conditions with the focus on feeding ecology. We investigated seasonal variations of the geographical distribution, growth rate, feeding ecology, and nutritional condition of their ELH stages and examined relationships with water temperature, dissolved oxygen concentration, and micro-zooplankton composition. T. capensis' ELH stages showed a wide spatial and seasonal distribution, a preference for higher water temperatures (18–21°C) and presence over a wide range of dissolved oxygen concentrations (0.13–6.35 ml O2 l−1). Feeding success was high and mainly different groups of Copepoda were targeted, which were strongly size selected. The high dietary importance of micro-copepods during large parts of the larval phase indicates successful exploitation of this food source, which has increased in abundance during the last decade. It also explains observed best nutritional conditions at temperatures between 18 and 21°C, since these small copepods are commonly associated with warmer temperatures. Altogether, these traits enhance the species' probability to encounter suitable environments for the survival of their ELH stages, which is likely to lead to their high recruitment success in the northern Benguela ecosystem.

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Transgenerational fitness effects of lifespan extension by dietary restriction in Caenorhabditis elegans

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2021.0701 ◽

2021 ◽

Vol 288 (1950) ◽

Author(s):

Edward R. Ivimey-Cook ◽

Kris Sales ◽

Hanne Carlsson ◽

Simone Immler ◽

Tracey Chapman ◽

...

Keyword(s):

Caenorhabditis Elegans ◽

Dietary Restriction ◽

Mortality Risk ◽

Lifespan Extension ◽

Dietary Interventions ◽

Negative Effects ◽

Trade Offs ◽

Wide Range ◽

Broad Variety

Dietary restriction (DR) increases lifespan in a broad variety of organisms and improves health in humans. However, long-term transgenerational consequences of dietary interventions are poorly understood. Here, we investigated the effect of DR by temporary fasting (TF) on mortality risk, age-specific reproduction and fitness across three generations of descendants in Caenorhabditis elegans . We show that while TF robustly reduces mortality risk and improves late-life reproduction of the individuals subject to TF (P 0 ), it has a wide range of both positive and negative effects on their descendants (F 1 –F 3 ). Remarkably, great-grandparental exposure to TF in early life reduces fitness and increases mortality risk of F 3 descendants to such an extent that TF no longer promotes a lifespan extension. These findings reveal that transgenerational trade-offs accompany the instant benefits of DR, underscoring the need to consider fitness of future generations in pursuit of healthy ageing.

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Transgenerational fitness effects of lifespan extension by dietary restriction in Caenorhabditis elegans

10.1101/2020.06.24.168922 ◽

2020 ◽

Author(s):

Edward R. Ivimey-Cook ◽

Kris Sales ◽

Hanne Carlsson ◽

Simone Immler ◽

Tracey Chapman ◽

...

Keyword(s):

Dietary Restriction ◽

Mortality Risk ◽

Future Generations ◽

Lifespan Extension ◽

Dietary Interventions ◽

C Elegans ◽

Trade Offs ◽

Wide Range ◽

Broad Variety

AbstractDietary restriction increases lifespan in a broad variety of organisms and improves health in humans. However, long-term transgenerational consequences of dietary interventions are poorly understood. Here we investigated the effect of dietary restriction by temporary fasting (TF) on mortality risk, age-specific reproduction and fitness across three generations of descendants in C. elegans. We show that while TF robustly reduces mortality risk and improves late-life reproduction in the parental generation (P0), it has a wide range of both positive and deleterious effects on future generations (F1-F3). Remarkably, great-grandparental exposure to TF in early-life reduces fitness and increases mortality risk of F3 descendants to such an extent that TF no longer promotes a lifespan extension. These findings reveal that transgenerational trade-offs accompany the instant benefits of dietary restriction underscoring the need to consider fitness of future generations in pursuit of healthy ageing.

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Abstract 17: Early Life Stress Sensitizes The Angiotensin II-elicited Hypertensive Response

Hypertension ◽

10.1161/hyp.76.suppl_1.17 ◽

2020 ◽

Vol 76 (Suppl_1) ◽

Author(s):

Baojian Xue ◽

Terry Beltz ◽

Fang Guo ◽

David M Pollock ◽

Jennifer S Pollock ◽

...

Keyword(s):

Mrna Expression ◽

Proinflammatory Cytokines ◽

Life Stress ◽

Early Life ◽

Early Life Stress ◽

Male Rats ◽

Sprague Dawley ◽

Cns Inflammation ◽

Wide Range ◽

The Brain

Separation of neonatal rodent pups from their mothers has been used as a model to study the effects of early life stress (ELS) on behavioral and physiological responses in adults. Using an Induction-Delay-Expression experimental paradigm, our previous studies demonstrate that a wide range of stressors administered during an induction period produces hypertensive response sensitization (HTRS) in response to a subsequent pro-hypertensive stimulus. HTRS is accompanied by activation of the brain renin-angiotensin system (RAS) and CNS inflammation. The present study investigated whether ELS induces HTRS and changes in brain-related underlying mechanisms. Rat neonates from Sprague-Dawley breeders were subjected to ELS by separating them each morning from their mothers for 3 h on postnatal days 2 to 14. Pups from non-handled litters formed control groups. At 10 weeks of age, male rats were used to evaluate blood pressure and autonomic function using telemetric probes and pharmacological methods. In addition, in separate control and ELS groups, the lamina terminalis (LT) structures and the hypothalamic paraventricular nucleus (PVN) were analyzed for mRNA expression of RAS components and proinflammatory cytokines. Adult ELS rats as compared to non-separated controls exhibited 1) HTRS during expression testing using 2 week ANG II infusions (120 ng/kg/min s.c.; ELS animals, Δ45.5±4.5 mmHg vs. controls, Δ22.4±3.1 mmHg); 2) a greater reduction in mean arterial pressure following ganglionic blockade (hexamethonium, 30 mg/kg, ip), 3) increased sympathetic drive to the heart (atenolol, 8 mg/kg, ip), 4) decreased vagal tone (atropine, 8 mg/kg, ip), and 5) increased mRNA expression of several components of the brain RAS and proinflammatory cytokines in the LT and PVN. These results suggest that maternal ELS may predispose individuals to hypertension that is mediated by upregulation of the brain RAS and proinflammatory cytokines and increased sympathetic drive to the cardiovascular system.

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Hormetic Effects of Early Juvenile Radiation Exposure on Adult Reproduction and Offspring Performance in the Cricket (Acheta domesticus)

Dose-Response ◽

10.1177/1559325818797499 ◽

2018 ◽

Vol 16 (3) ◽

pp. 155932581879749 ◽

Cited By ~ 6

Author(s):

Alexander M. Shephard ◽

Vadim Aksenov ◽

Jonathan Tran ◽

Connor J. Nelson ◽

Douglas R. Boreham ◽

...

Keyword(s):

Low Dose ◽

Acheta Domesticus ◽

Anthropogenic Sources ◽

Offspring Size ◽

Radiation Stress ◽

Natural Ecosystems ◽

Offspring Performance ◽

Early Juvenile ◽

Wide Range ◽

Survival And Reproduction

Exposure to low-dose ionizing radiation can have positive impacts on biological performance—a concept known as hormesis. Although radiation hormesis is well-documented, the predominant focus has been medical. In comparison, little research has examined potential effects of early life radiation stress on organismal investment in life history traits that closely influence evolutionary fitness (eg, patterns of growth, survival, and reproduction). Evaluating the fitness consequences of radiation stress is important, given that low-level radiation pollution from anthropogenic sources is considered a major threat to natural ecosystems. Using the cricket ( Acheta domesticus), we tested a wide range of doses to assess whether a single juvenile exposure to radiation could induce hormetic benefits on lifetime fitness measures. Consistent with hormesis, we found that low-dose juvenile radiation positively impacted female fecundity, offspring size, and offspring performance. Remarkably, even a single low dose of radiation in early juvenile development can elicit a range of positive fitness effects emerging over the life span and even into the next generation.

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Alexander Fleck, Baron Fleck of Saltcoats, 1889-1968

Biographical Memoirs of Fellows of the Royal Society ◽

10.1098/rsbm.1971.0010 ◽

1971 ◽

Vol 17 ◽

pp. 242-254

Keyword(s):

Early Life ◽

Policy Making ◽

Academic Career ◽

Scientific Discovery ◽

Considerable Proportion ◽

Science Students ◽

The Public ◽

Wide Range ◽

The Many ◽

Waste Accumulation

Lord Fleck who died in London on 6 August 1968 was most widely known as a distinguished leader in chemical industry and as Chairman of Imperial Chemical Industries Ltd from 1953 to 1960. It was very apparent, however, to all with a closer acquaintance with him, that he could have been just as successful in other fields. In early life, following his outstanding scientific researches at his university, a promising academic career had been open to him and, later, the keen mind, sound judgement and gifts of leadership, shown in the many and diverse official enquiry committees which he chaired, were clear evidence of the wide range of his capabilities. But, to those who were privileged to work with him or to know him really well, admiration of his abilities and achievements gave second place to affection for the man himself and to profound respect for the concern about people, individually and collectively, which motivated his whole life. Alec Fleck had very definite views on the place and responsibilities of science and scientists in society. Although he fully appreciated the fascination and value of scientific discovery for its own sake, he felt that it should be the primary duty of a considerable proportion of scientists, including the most able, to apply their skill and knowledge to practical objectives aimed at the welfare and happiness of mankind. Among these objectives he ascribed particular importance to elimination of social ills which, ironically, can so easily arise as byproducts of industrial progress; for example, air and water pollution, waste accumulation and unpleasant or dangerous jobs for plant operators. Fleck believed that more senior positions with policy-making responsibilities in industry and the public services could, with advantage, be filled by people with a first-class scientific background and advocated that company organization and staff policy should be such as to give maximum opportunity to able young scientists to widen their experience and interests. He was also of the opinion that educational establishments could do far more to widen the outlook of science students by stimulating their interest in history, politics, economics and general world affairs.

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Thermal performance curves reveal shifts in optima, limits and breadth in early life

Journal of Experimental Biology ◽

10.1242/jeb.233254 ◽

2020 ◽

Vol 223 (22) ◽

pp. jeb233254

Author(s):

Adriana P. Rebolledo ◽

Carla M. Sgrò ◽

Keyne Monro

Keyword(s):

Embryo Development ◽

Thermal Performance ◽

Early Life ◽

Thermal Sensitivity ◽

Life Stage ◽

Life Stages ◽

Parametric Bootstrapping ◽

Performance Curves ◽

Survival And Reproduction ◽

Mixed Modelling

ABSTRACTUnderstanding thermal performance at life stages that limit persistence is necessary to predict responses to climate change, especially for ectotherms whose fitness (survival and reproduction) depends on environmental temperature. Ectotherms often undergo stage-specific changes in size, complexity and duration that are predicted to modify thermal performance. Yet performance is mostly explored for adults, while performance at earlier stages that typically limit persistence remains poorly understood. Here, we experimentally isolate thermal performance curves at fertilization, embryo development and larval development stages in an aquatic ectotherm whose early planktonic stages (gametes, embryos and larvae) govern adult abundances and dynamics. Unlike previous studies based on short-term exposures, responses with unclear links to fitness or proxies in lieu of explicit curve descriptors (thermal optima, limits and breadth), we measured performance as successful completion of each stage after exposure throughout, and at temperatures that explicitly capture curve descriptors at all stages. Formal comparisons of descriptors using a combination of generalized linear mixed modelling and parametric bootstrapping reveal important differences among life stages. Thermal performance differs significantly from fertilization to embryo development (with thermal optimum declining by ∼2°C, thermal limits shifting inwards by ∼8–10°C and thermal breadth narrowing by ∼10°C), while performance declines independently of temperature thereafter. Our comparisons show that thermal performance at one life stage can misrepresent performance at others, and point to gains in complexity during embryogenesis, rather than subsequent gains in size or duration of exposure, as a key driver of thermal sensitivity in early life.

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The adaptive and maladaptive continuum of stress responses – a hippocampal perspective

Reviews in the Neurosciences ◽

10.1515/revneuro-2014-0083 ◽

2015 ◽

Vol 26 (4) ◽

Cited By ~ 17

Author(s):

Deepika Suri ◽

Vidita A. Vaidya

Keyword(s):

Stress Responses ◽

Life Stress ◽

Early Life ◽

Early Life Stress ◽

Negative Consequences ◽

Functional Responses ◽

Physiological Level ◽

Early Stress ◽

Wide Range ◽

Potential Factors

AbstractExposure to stressors elicits a spectrum of responses that span from potentially adaptive to maladaptive consequences at the structural, cellular and physiological level. These responses are particularly pronounced in the hippocampus where they also appear to influence hippocampal-dependent cognitive function and emotionality. The factors that influence the nature of stress-evoked consequences include the chronicity, severity, predictability and controllability of the stressors. In addition to adult-onset stress, early life stress also elicits a wide range of structural and functional responses, which often exhibit life-long persistence. However, the outcome of early stress exposure is often contingent on the environment experienced in adulthood, and could either aid in stress coping or could serve to enhance susceptibility to the negative consequences of adult stress. This review comprehensively examines the consequences of adult and early life stressors on the hippocampus, with a focus on their effects on neurogenesis, neuronal survival, structural and synaptic plasticity and hippocampal-dependent behaviors. Further, we discuss potential factors that may tip stress-evoked consequences from being potentially adaptive to largely maladaptive.

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