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Lemaître JF, Moorad J, Gaillard JM, Maklakov AA, Nussey DH. A unified framework for evolutionary genetic and physiological theories of aging. PLoS Biol 2024; 22:e3002513. [PMID: 38412150 PMCID: PMC10898761 DOI: 10.1371/journal.pbio.3002513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/29/2024] Open
Abstract
Why and how we age are 2 intertwined questions that have fascinated scientists for many decades. However, attempts to answer these questions remain compartmentalized, preventing a comprehensive understanding of the aging process. We argue that the current lack of knowledge about the evolution of aging mechanisms is due to a lack of clarity regarding evolutionary theories of aging that explicitly involve physiological processes: the disposable soma theory (DST) and the developmental theory of aging (DTA). In this Essay, we propose a new hierarchical model linking genes to vital rates, enabling us to critically reevaluate the DST and DTA in terms of their relationship to evolutionary genetic theories of aging (mutation accumulation (MA) and antagonistic pleiotropy (AP)). We also demonstrate how these 2 theories can be incorporated in a unified hierarchical framework. The new framework will help to generate testable hypotheses of how the hallmarks of aging are shaped by natural selection.
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Affiliation(s)
- Jean-François Lemaître
- Université Lyon 1, CNRS, Laboratoire de Biométrie et Biologie Évolutive UMR 5558, Villeurbanne, France
| | - Jacob Moorad
- Institute of Ecology & Evolution, School of Biological Science, University of Edinburgh, Edinburgh, United Kingdom
| | - Jean-Michel Gaillard
- Université Lyon 1, CNRS, Laboratoire de Biométrie et Biologie Évolutive UMR 5558, Villeurbanne, France
| | - Alexei A. Maklakov
- School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
| | - Daniel H. Nussey
- Institute of Ecology & Evolution, School of Biological Science, University of Edinburgh, Edinburgh, United Kingdom
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2
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Yang Z, Zhao A, Teng M, Li M, Wang H, Wang X, Liu Z, Zeng Q, Hu L, Hu J, Bao Z, Huang X. Signatures of selection in Mulinia lateralis underpinning its rapid adaptation to laboratory conditions. Evol Appl 2024; 17:e13657. [PMID: 38357357 PMCID: PMC10866071 DOI: 10.1111/eva.13657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Revised: 01/17/2024] [Accepted: 01/26/2024] [Indexed: 02/16/2024] Open
Abstract
The dwarf surf clam, Mulinia lateralis, is considered as a model species for bivalves because of its rapid growth and short generation time. Recently, successful breeding of this species for multiple generations in our laboratory revealed its acquisition of adaptive advantages during artificial breeding. In this study, 310 individuals from five different generations were genotyped with 22,196 single nucleotide polymorphisms (SNPs) with the aim of uncovering the genetic basis of their adaptation to laboratory conditions. Results revealed that M. lateralis consistently maintained high genetic diversity across generations, characterized by high observed heterozygosity (H o: 0.2733-0.2934) and low levels of inbreeding (F is: -0.0244-0.0261). Population analysis indicated low levels of genetic differentiation among generations of M. lateralis during artificial breeding (F st <0.05). In total, 316 genomic regions exhibited divergent selection, with 168 regions under positive selection. Furthermore, 227 candidate genes were identified in the positive selection regions, which have functions including growth, stress resistance, and reproduction. Notably, certain selection signatures with significantly higher F st value were detected in genes associated with male reproduction, such as GAL3ST1, IFT88, and TSSK2, which were significantly upregulated during artificial breeding. This suggests a potential role of sperm-associated genes in the rapid evolutionary response of M. lateralis to selection in laboratory conditions. Overall, our findings highlight the phenotypic and genetic changes, as well as selection signatures, in M. lateralis during artificial breeding. This contributes to understanding their adaptation to laboratory conditions and underscores the potential for using this species to explore the adaptive evolution of bivalves.
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Affiliation(s)
- Zujing Yang
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life SciencesOcean University of ChinaQingdaoChina
| | - Ang Zhao
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life SciencesOcean University of ChinaQingdaoChina
| | - Mingxuan Teng
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life SciencesOcean University of ChinaQingdaoChina
| | - Moli Li
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life SciencesOcean University of ChinaQingdaoChina
| | - Hao Wang
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life SciencesOcean University of ChinaQingdaoChina
| | - Xuefeng Wang
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life SciencesOcean University of ChinaQingdaoChina
| | - Zhi Liu
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life SciencesOcean University of ChinaQingdaoChina
| | - Qifan Zeng
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life SciencesOcean University of ChinaQingdaoChina
- Laboratory of Tropical Marine Germplasm Resources and Breeding EngineeringSanya Oceanographic Institution, Ocean University of ChinaSanyaChina
| | - Liping Hu
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life SciencesOcean University of ChinaQingdaoChina
- Yantai Marine Economic Research InstituteYantaiChina
| | - Jingjie Hu
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life SciencesOcean University of ChinaQingdaoChina
- Laboratory of Tropical Marine Germplasm Resources and Breeding EngineeringSanya Oceanographic Institution, Ocean University of ChinaSanyaChina
| | - Zhenmin Bao
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life SciencesOcean University of ChinaQingdaoChina
- Laboratory of Tropical Marine Germplasm Resources and Breeding EngineeringSanya Oceanographic Institution, Ocean University of ChinaSanyaChina
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and TechnologyQingdaoChina
| | - Xiaoting Huang
- MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life SciencesOcean University of ChinaQingdaoChina
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and TechnologyQingdaoChina
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3
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Shephard AM, Hund AK, Snell-Rood EC. Metabolic stress as a driver of life-history plasticity: flight promotes longevity and antioxidant production in monarch butterflies. Proc Biol Sci 2023; 290:20231616. [PMID: 37817587 PMCID: PMC10565393 DOI: 10.1098/rspb.2023.1616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 09/15/2023] [Indexed: 10/12/2023] Open
Abstract
Life-history theory predicts that increased investment in traits related to reproduction will be associated with a reduced ability to invest in survival or longevity. One mechanistic explanation for this trade-off is that metabolic stress generated from current fitness activities (e.g. reproduction or locomotion) will increase somatic damage, leading to reduced longevity. Yet, there has been limited support for this damage-based hypothesis. A possible explanation is that individuals can respond to increases in metabolic stress by plastically inducing cellular maintenance responses, which may increase, rather than decrease, longevity. We tested this possibility by experimentally manipulating investment in flight activity (a metabolic stressor) in the migratory monarch butterfly (Danaus plexippus), a species whose reproductive fitness is dependent on survival through a period of metabolically intensive migratory flight. Consistent with the idea that metabolic stress stimulated investment in self-maintenance, increased flight activity enhanced monarch butterfly longevity and somatic tissue antioxidant capacity, likely at a cost to reproductive investment. Our study implicates a role for metabolic stress as a driver of life-history plasticity and supports a model where current engagement in metabolically stressful activities promotes somatic survival by stimulating investment in self-maintenance processes.
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Affiliation(s)
- Alexander M. Shephard
- Department of Ecology, Evolution, and Behavior, University of Minnesota – Twin Cities, Saint Paul, MN 55108, USA
| | - Amanda K. Hund
- Department of Ecology, Evolution, and Behavior, University of Minnesota – Twin Cities, Saint Paul, MN 55108, USA
| | - Emilie C. Snell-Rood
- Department of Ecology, Evolution, and Behavior, University of Minnesota – Twin Cities, Saint Paul, MN 55108, USA
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4
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Fricke C, Sanghvi K, Emery M, Lindenbaum I, Wigby S, Ramm SA, Sepil I. Timeless or tainted? The effects of male ageing on seminal fluid. Front Ecol Evol 2023. [DOI: 10.3389/fevo.2023.1066022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023] Open
Abstract
Reproductive ageing can occur due to the deterioration of both the soma and germline. In males, it has mostly been studied with respect to age-related changes in sperm. However, the somatic component of the ejaculate, seminal fluid, is also essential for maintaining reproductive function. Whilst we know that seminal fluid proteins (SFPs) are required for male reproductive success across diverse taxa, age-related changes in SFP quantity and composition are little understood. Additionally, only few studies have explored the reproductive ageing of the tissues that produce SFPs, and the resulting reproductive outcomes. Here we provide a systematic review of studies addressing how advancing male age affects the production and properties of seminal fluid, in particular SFPs and oxidative stress, highlighting many open questions and generating new hypotheses for further research. We additionally discuss how declines in function of different components of seminal fluid, such as SFPs and antioxidants, could contribute to age-related loss of reproductive ability. Overall, we find evidence that ageing results in increased oxidative stress in seminal fluid and a decrease in the abundance of various SFPs. These results suggest that seminal fluid contributes towards important age-related changes influencing male reproduction. Thus, it is essential to study this mostly ignored component of the ejaculate to understand male reproductive ageing, and its consequences for sexual selection and paternal age effects on offspring.
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5
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Sekajova Z, Rosa E, Spagopoulou F, Zervakis P, Lind MI. Temperature‐induced compensatory growth in the nematode
C. elegans
is regulated by a thermosensitive
TRP
channel and influences reproductive rate. Funct Ecol 2022. [DOI: 10.1111/1365-2435.14116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Zuzana Sekajova
- Animal Ecology, Department of Ecology and Genetics Uppsala University 752 36 Uppsala Sweden
| | - Elena Rosa
- Animal Ecology, Department of Ecology and Genetics Uppsala University 752 36 Uppsala Sweden
| | - Foteini Spagopoulou
- Animal Ecology, Department of Ecology and Genetics Uppsala University 752 36 Uppsala Sweden
| | | | - Martin I. Lind
- Animal Ecology, Department of Ecology and Genetics Uppsala University 752 36 Uppsala Sweden
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6
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Abstract
A thought-provoking article by Gems and de Magalhães suggests that canonic hallmarks of aging are superficial imitations of hallmarks of cancer. I took their work a step further and proposed hallmarks of aging based on a hierarchical principle and the hyperfunction theory. To do this, I first reexamine the hallmarks of cancer proposed by Hanahan and Weinberg in 2000. Although six hallmarks of cancer are genuine, they are not hierarchically arranged, i.e., molecular, intra-cellular, cellular, tissue, organismal and extra-organismal. (For example, invasion and angiogenesis are manifestations of molecular alterations on the tissue level; metastasis on the organismal level, whereas cell immortality is observed outside the host). The same hierarchical approach is applicable to aging. Unlike cancer, however, aging is not a molecular disease. The lowest level of its origin is normal intracellular signaling pathways such as mTOR that drive developmental growth and, later in life, become hyperfunctional, causing age-related diseases, whose sum is aging. The key hallmark of organismal aging, from worms to humans, are age-related diseases. In addition, hallmarks of aging can be arranged as a timeline, wherein initial hyperfunction is followed by dysfunction, organ damage and functional decline.
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7
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Dabrowska A, Kumar J, Rallis C. Nutrient-Response Pathways in Healthspan and Lifespan Regulation. Cells 2022; 11:1568. [PMID: 35563873 PMCID: PMC9102925 DOI: 10.3390/cells11091568] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 05/02/2022] [Accepted: 05/05/2022] [Indexed: 02/01/2023] Open
Abstract
Cellular, small invertebrate and vertebrate models are a driving force in biogerontology studies. Using various models, such as yeasts, appropriate tissue culture cells, Drosophila, the nematode Caenorhabditis elegans and the mouse, has tremendously increased our knowledge around the relationship between diet, nutrient-response signaling pathways and lifespan regulation. In recent years, combinatorial drug treatments combined with mutagenesis, high-throughput screens, as well as multi-omics approaches, have provided unprecedented insights in cellular metabolism, development, differentiation, and aging. Scientists are, therefore, moving towards characterizing the fine architecture and cross-talks of growth and stress pathways towards identifying possible interventions that could lead to healthy aging and the amelioration of age-related diseases in humans. In this short review, we briefly examine recently uncovered knowledge around nutrient-response pathways, such as the Insulin Growth Factor (IGF) and the mechanistic Target of Rapamycin signaling pathways, as well as specific GWAS and some EWAS studies on lifespan and age-related disease that have enhanced our current understanding within the aging and biogerontology fields. We discuss what is learned from the rich and diverse generated data, as well as challenges and next frontiers in these scientific disciplines.
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8
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Athar F, Templeman NM. C. elegans as a model organism to study female reproductive health. Comp Biochem Physiol A Mol Integr Physiol 2022; 266:111152. [PMID: 35032657 DOI: 10.1016/j.cbpa.2022.111152] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 01/04/2022] [Accepted: 01/07/2022] [Indexed: 12/17/2022]
Abstract
Female reproductive health has been historically understudied and underfunded. Here, we present the advantages of using a free-living nematode, Caenorhabditis elegans, as an animal system to study fundamental aspects of female reproductive health. C. elegans is a powerful high-throughput model organism that shares key genetic and physiological similarities with humans. In this review, we highlight areas of pressing medical and biological importance in the 21st century within the context of female reproductive health. These include the decline in female reproductive capacity with increasing chronological age, reproductive dysfunction arising from toxic environmental insults, and cancers of the reproductive system. C. elegans has been instrumental in uncovering mechanistic insights underlying these processes, and has been valuable for developing and testing therapeutics to combat them. Adopting a convenient model organism such as C. elegans for studying reproductive health will encourage further research into this field, and broaden opportunities for making advancements into evolutionarily conserved mechanisms that control reproductive function.
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Affiliation(s)
- Faria Athar
- Department of Biology, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Nicole M Templeman
- Department of Biology, University of Victoria, Victoria, British Columbia V8P 5C2, Canada.
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9
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Izgi H, Han D, Isildak U, Huang S, Kocabiyik E, Khaitovich P, Somel M, Dönertaş HM. Inter-tissue convergence of gene expression during ageing suggests age-related loss of tissue and cellular identity. eLife 2022; 11:68048. [PMID: 35098922 PMCID: PMC8880995 DOI: 10.7554/elife.68048] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 01/28/2022] [Indexed: 11/13/2022] Open
Abstract
Developmental trajectories of gene expression may reverse in their direction during ageing, a phenomenon previously linked to cellular identity loss. Our analysis of cerebral cortex, lung, liver and muscle transcriptomes of 16 mice, covering development and ageing intervals, revealed widespread but tissue-specific ageing-associated expression reversals. Cumulatively, these reversals create a unique phenomenon: mammalian tissue transcriptomes diverge from each other during postnatal development, but during ageing, they tend to converge towards similar expression levels, a process we term Divergence followed by Convergence, or DiCo. We found that DiCo was most prevalent among tissue-specific genes and associated with loss of tissue identity, which is confirmed using data from independent mouse and human datasets. Further, using publicly available single-cell transcriptome data, we showed that DiCo could be driven both by alterations in tissue cell type composition and also by cell-autonomous expression changes within particular cell types.
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Affiliation(s)
- Hamit Izgi
- Department of Biological Sciences, Middle East Technical University, Ankara, Turkey
| | - DingDing Han
- CAS Key Laboratory of Computational Biology, Shanghai Institutes for Biological Sciences, Shanghai, China
| | - Ulas Isildak
- Department of Biological Sciences, Middle East Technical University, Ankara, Turkey
| | - Shuyun Huang
- CAS Key Laboratory of Computational Biology, Shanghai Institutes for Biological Sciences, Shanghai, China
| | - Ece Kocabiyik
- Department of Biological Sciences, Middle East Technical University, Ankara, Turkey
| | - Philipp Khaitovich
- Center for Neurobiology and Brain Restoration, Skolkovo Institute of Science and Technology, Moscow, Russian Federation
| | - Mehmet Somel
- Department of Biological Sciences, Middle East Technical University, Ankara, Turkey
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10
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Warne RW, Dallas J. Microbiome mediation of animal life histories
via
metabolites and insulin‐like signalling. Biol Rev Camb Philos Soc 2022; 97:1118-1130. [DOI: 10.1111/brv.12833] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 01/05/2022] [Accepted: 01/06/2022] [Indexed: 12/15/2022]
Affiliation(s)
- Robin W. Warne
- School of Biological Sciences Southern Illinois University 1125 Lincoln Dr. Carbondale IL 62901‐6501 U.S.A
| | - Jason Dallas
- School of Biological Sciences Southern Illinois University 1125 Lincoln Dr. Carbondale IL 62901‐6501 U.S.A
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11
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Purchase CF, Rooke AC, Gaudry MJ, Treberg JR, Mittell EA, Morrissey MB, Rennie MD. A synthesis of senescence predictions for indeterminate growth, and support from multiple tests in wild lake trout. Proc Biol Sci 2022; 289:20212146. [PMID: 34982951 PMCID: PMC8727146 DOI: 10.1098/rspb.2021.2146] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 12/06/2021] [Indexed: 01/14/2023] Open
Abstract
Senescence-the deterioration of functionality with age-varies widely across taxa in pattern and rate. Insights into why and how this variation occurs are hindered by the predominance of laboratory-focused research on short-lived model species with determinate growth. We synthesize evolutionary theories of senescence, highlight key information gaps and clarify predictions for species with low mortality and variable degrees of indeterminate growth. Lake trout are an ideal species to evaluate predictions in the wild. We monitored individual males from two populations (1976-2017) longitudinally for changes in adult mortality (actuarial senescence) and body condition (proxy for energy balance). A cross-sectional approach (2017) compared young (ages 4-10 years) and old (18-37 years) adults for (i) phenotypic performance in body condition, and semen quality-which is related to fertility under sperm competition (reproductive senescence)-and (ii) relative telomere length (potential proxy for cellular senescence). Adult growth in these particular populations is constrained by a simplified foodweb, and our data support predictions of negligible senescence when maximum size is only slightly larger than maturation size. Negative senescence (aka reverse senescence) may occur in other lake trout populations where diet shifts allow maximum sizes to greatly exceed maturation size.
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Affiliation(s)
- Craig F. Purchase
- Department of Biology, Memorial University of Newfoundland, St John's, Canada
| | - Anna C. Rooke
- Department of Biology, Memorial University of Newfoundland, St John's, Canada
| | - Michael J. Gaudry
- Department of Biological Sciences, University of Manitoba, Winnipeg, Canada
| | - Jason R. Treberg
- Department of Biological Sciences, University of Manitoba, Winnipeg, Canada
- Centre on Aging, University of Manitoba, Winnipeg, Canada
| | | | | | - Michael D. Rennie
- Department of Biology, Lakehead University, Thunder Bay, Canada
- IISD Experimental Lakes Area, Canada
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12
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Douhard F, Douhard M, Gilbert H, Monget P, Gaillard J, Lemaître J. How much energetic trade-offs limit selection? Insights from livestock and related laboratory model species. Evol Appl 2021; 14:2726-2749. [PMID: 34950226 PMCID: PMC8674892 DOI: 10.1111/eva.13320] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 10/22/2021] [Accepted: 10/22/2021] [Indexed: 12/22/2022] Open
Abstract
Trade-offs between life history traits are expected to occur due to the limited amount of resources that organisms can obtain and share among biological functions, but are of least concern for selection responses in nutrient-rich or benign environments. In domestic animals, selection limits have not yet been reached despite strong selection for higher meat, milk or egg yields. Yet, negative genetic correlations between productivity traits and health or fertility traits have often been reported, supporting the view that trade-offs do occur in the context of nonlimiting resources. The importance of allocation mechanisms in limiting genetic changes can thus be questioned when animals are mostly constrained by their time to acquire and process energy rather than by feed availability. Selection for high productivity traits early in life should promote a fast metabolism with less energy allocated to self-maintenance (contributing to soma preservation and repair). Consequently, the capacity to breed shortly after an intensive period of production or to remain healthy should be compromised. We assessed those predictions in mammalian and avian livestock and related laboratory model species. First, we surveyed studies that compared energy allocation to maintenance between breeds or lines of contrasting productivity but found little support for the occurrence of an energy allocation trade-off. Second, selection experiments for lower feed intake per unit of product (i.e. higher feed efficiency) generally resulted in reduced allocation to maintenance, but this did not entail fitness costs in terms of survival or future reproduction. These findings indicate that the consequences of a particular selection in domestic animals are much more difficult to predict than one could anticipate from the energy allocation framework alone. Future developments to predict the contribution of time constraints and trade-offs to selection limits will be insightful to breed livestock in increasingly challenging environments.
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Affiliation(s)
| | - Mathieu Douhard
- Laboratoire de Biométrie & Biologie EvolutiveCNRSUMR 5558Université Lyon 1VilleurbanneFrance
| | - Hélène Gilbert
- GenPhySEINRAEENVTUniversité de ToulouseCastanet‐TolosanFrance
| | | | - Jean‐Michel Gaillard
- Laboratoire de Biométrie & Biologie EvolutiveCNRSUMR 5558Université Lyon 1VilleurbanneFrance
| | - Jean‐François Lemaître
- Laboratoire de Biométrie & Biologie EvolutiveCNRSUMR 5558Université Lyon 1VilleurbanneFrance
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13
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Hozer C, Pifferi F. Relationships between endogenous circadian period, physiological and cognitive parameters and sex in aged gray mouse lemurs ( Microcebus murinus). Chronobiol Int 2021; 39:363-373. [PMID: 34802342 DOI: 10.1080/07420528.2021.2001478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The biological clock generates circadian rhythms, with an endogenous period tau close to 24 h. The circadian resonance theory proposes that lifespan is reduced when endogenous period goes far from 24 h. It has been suggested that daily resetting of the circadian clock to the 24 h external photoperiod might induce marginal costs that would accumulate over time and forward accelerate aging and affect fitness. In this study, we aimed to evaluate the link between the endogenous period and biomarkers of aging in order to investigate the mechanisms of the circadian resonance theory. We studied 39 middle-aged and aged Microcebus murinus, a nocturnal non-human primate whose endogenous period is about 23.1 h, measuring the endogenous period of locomotor activity, as well as several physiological and behavioral parameters (rhythm fragmentation and amplitude, energetic expenditure, oxidative stress, insulin-like growth factor-1 (IGF-1) concentrations and cognitive performances) in both males and females. We found that aged males with tau far from 24 h displayed increased oxidative stress. We also demonstrated a positive correlation between tau and IGF-1 concentrations, as well as learning performances, in males and females. Together these results suggest that a great deviation of tau from 24 h leads to increased biomarkers of age-related impairments.
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Affiliation(s)
- Clara Hozer
- Department of Adaptive Mechanisms and Evolution, National Center for Scientific Research/National Museum of Natural History, Brunoy, France
| | - Fabien Pifferi
- Department of Adaptive Mechanisms and Evolution, National Center for Scientific Research/National Museum of Natural History, Brunoy, France
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14
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Carlsson H, Ivimey-Cook E, Duxbury EML, Edden N, Sales K, Maklakov AA. Ageing as "early-life inertia": Disentangling life-history trade-offs along a lifetime of an individual. Evol Lett 2021; 5:551-564. [PMID: 34621540 PMCID: PMC8484722 DOI: 10.1002/evl3.254] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 07/19/2021] [Accepted: 08/13/2021] [Indexed: 11/10/2022] Open
Abstract
The theory that ageing evolves because of competitive resource allocation between the soma and the germline has been challenged by studies showing that somatic maintenance can be improved without impairing reproduction. However, it has been suggested that cost‐free improvement in somatic maintenance is possible only under a narrow range of benign conditions. Here, we show that experimental downregulation of insulin/IGF‐1 signaling (IIS) in C. elegans nematodes, a robustly reproducible life span‐ and health span‐extending treatment, reduces fitness in a complex variable environment when initiated during development but does not reduce fitness when initiated in adulthood. Thus, our results show that the costs and benefits of reduced IIS can be uncoupled when organisms inhabit variable environments, and, therefore, do not provide support for the resource allocation theory. Our findings support the theory that the force of natural selection on gene expression in evolutionarily conserved signaling pathways that shape life‐history traits declines after the onset of reproduction resulting in organismal senescence.
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Affiliation(s)
- Hanne Carlsson
- School of Biological Sciences University of East Anglia Norwich NR4 7TJ United Kingdom
| | - Edward Ivimey-Cook
- School of Biological Sciences University of East Anglia Norwich NR4 7TJ United Kingdom
| | - Elizabeth M L Duxbury
- School of Biological Sciences University of East Anglia Norwich NR4 7TJ United Kingdom
| | - Nathan Edden
- School of Biological Sciences University of East Anglia Norwich NR4 7TJ United Kingdom
| | - Kris Sales
- School of Biological Sciences University of East Anglia Norwich NR4 7TJ United Kingdom
| | - Alexei A Maklakov
- School of Biological Sciences University of East Anglia Norwich NR4 7TJ United Kingdom
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15
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Ngo KS, R-Almási B, Barta Z, Tökölyi J. Experimental manipulation of body size alters life history in hydra. Ecol Lett 2021; 24:728-738. [PMID: 33606896 DOI: 10.1111/ele.13698] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 12/18/2020] [Accepted: 01/07/2021] [Indexed: 11/26/2022]
Abstract
Body size has fundamental impacts on animal ecology and physiology but has been strongly influenced by recent climate change and human activities, such as size-selective harvesting. Understanding the ecological and life history consequences of body size has proved difficult due to the inseparability of direct effects of body size from processes connected to it (such as growth rate and individual condition). Here, we used the cnidarian Hydra oligactis to directly manipulate body size and understand its causal effects on reproduction and senescence. We found that experimentally reducing size delayed sexual development and lowered fecundity, while post-reproductive survival increased, implying that smaller individuals can physiologically detect their reduced size and adjust life history decisions to achieve higher survival. Our experiment suggests that ecological or human-induced changes in body size will have immediate effects on life history and population dynamics through a growth-independent link between body size, reproduction and senescence.
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Affiliation(s)
- Kha Sach Ngo
- MTA-DE Behavioral Ecology Research Group, Department of Evolutionary Zoology, Univ. of Debrecen, Debrecen, Hungary
| | - Berta R-Almási
- MTA-DE Behavioral Ecology Research Group, Department of Evolutionary Zoology, Univ. of Debrecen, Debrecen, Hungary
| | - Zoltán Barta
- MTA-DE Behavioral Ecology Research Group, Department of Evolutionary Zoology, Univ. of Debrecen, Debrecen, Hungary
| | - Jácint Tökölyi
- MTA-DE Behavioral Ecology Research Group, Department of Evolutionary Zoology, Univ. of Debrecen, Debrecen, Hungary
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16
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Abstract
Failure of rapamycin to extend lifespan in DNA repair mutant and telomerase-knockout mice, while extending lifespan in normal mice, indicates that neither DNA damage nor telomere shortening limits normal lifespan or causes normal aging.
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17
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Lind MI, Carlsson H, Duxbury EML, Ivimey-Cook E, Maklakov AA. Cost-free lifespan extension via optimization of gene expression in adulthood aligns with the developmental theory of ageing. Proc Biol Sci 2021; 288:20201728. [PMID: 33529563 PMCID: PMC7893226 DOI: 10.1098/rspb.2020.1728] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 01/11/2021] [Indexed: 01/11/2023] Open
Abstract
Ageing evolves because the force of selection on traits declines with age but the proximate causes of ageing are incompletely understood. The 'disposable soma' theory of ageing (DST) upholds that competitive resource allocation between reproduction and somatic maintenance underpins the evolution of ageing and lifespan. In contrast, the developmental theory of ageing (DTA) suggests that organismal senescence is caused by suboptimal gene expression in adulthood. While the DST predicts the trade-off between reproduction and lifespan, the DTA predicts that age-specific optimization of gene expression can increase lifespan without reproduction costs. Here we investigated the consequences for lifespan, reproduction, egg size and individual fitness of early-life, adulthood and post-reproductive onset of RNAi knockdown of five 'longevity' genes involved in key biological processes in Caenorhabditis elegans. Downregulation of these genes in adulthood and/or during post-reproductive period increases lifespan, while we found limited evidence for a link between impaired reproduction and extended lifespan. Our findings demonstrate that suboptimal gene expression in adulthood often contributes to reduced lifespan directly rather than through competitive resource allocation between reproduction and somatic maintenance. Therefore, age-specific optimization of gene expression in evolutionarily conserved signalling pathways that regulate organismal life histories can increase lifespan without fitness costs.
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Affiliation(s)
- Martin I. Lind
- Animal Ecology, Department of Ecology and Genetics, Uppsala University, Uppsala, SE-75236, Sweden
| | - Hanne Carlsson
- School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK
| | | | - Edward Ivimey-Cook
- School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK
| | - Alexei A. Maklakov
- School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK
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19
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Abstract
A rapidly growing body of literature in several organisms suggests that environmentally-induced adaptive changes in phenotype can be transmitted across multiple generations. Although within-generation plasticity has been well documented, multigenerational plasticity represents a significant departure from conventional evolutionary thought. Studies of C. elegans have been particularly influential because this species exhibits extensive phenotypic plasticity, it is often essentially isogenic, and it has well-documented molecular and cellular mechanisms through which nongenetic inheritance occurs. However, while experimentalists are eager to claim that nongenetic modes of inheritance characterized in this and other model systems enhance fitness, many biologists remain skeptical given the extraordinary nature of this claim. We establish three criteria to evaluate how compelling the evidence for adaptive multigenerational plasticity is, and we use these criteria to critically examine putative cases of it in C. elegans. We conclude by suggesting potentially fruitful avenues for future research.
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Affiliation(s)
- L Ryan Baugh
- Department of Biology, Center for Genomics and Computational Biology, Duke UniversityDurhamUnited States
| | - Troy Day
- Departments of Mathematics and Statistics, Department of Biology, Queens UniversityKingstonCanada
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21
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Affiliation(s)
- Matthias Galipaud
- Department of evolutionary biology and environmental studies University of Zurich Zurich Switzerland
| | - Hanna Kokko
- Department of evolutionary biology and environmental studies University of Zurich Zurich Switzerland
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22
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Affiliation(s)
- Alan A. Cohen
- Groupe de recherche PRIMUS Department of Family Medicine University of Sherbrooke Sherbrooke QC Canada
| | - Christophe F. D. Coste
- Center for Biodiversity Dynamics Norwegian University of Science and Technology Trondheim Norway
- Unité Eco‐anthropologie (EA) Muséum National d'Histoire Naturelle CNRS 7206 Université Paris Diderot Paris France
| | - Xiang‐Yi Li
- Institute of Biology University of Neuchâtel Neuchâtel Switzerland
- Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich Switzerland
| | - Salomé Bourg
- CNRS Laboratoire de Biométrie et Biologie Évolutive UMR5558 Université Lyon 1 Villeurbanne France
| | - Samuel Pavard
- Unité Eco‐anthropologie (EA) Muséum National d'Histoire Naturelle CNRS 7206 Université Paris Diderot Paris France
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23
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Abstract
Despite tremendous progress in recent years, our understanding of the evolution of ageing is still incomplete. A dominant paradigm maintains that ageing evolves due to the competing energy demands of reproduction and somatic maintenance leading to slow accumulation of unrepaired cellular damage with age. However, the centrality of energy trade-offs in ageing has been increasingly challenged as studies in different organisms have uncoupled the trade-off between reproduction and longevity. An emerging theory is that ageing instead is caused by biological processes that are optimized for early-life function but become harmful when they continue to run-on unabated in late life. This idea builds on the realization that early-life regulation of gene expression can break down in late life because natural selection is too weak to optimize it. Empirical evidence increasingly supports the hypothesis that suboptimal gene expression in adulthood can result in physiological malfunction leading to organismal senescence. We argue that the current state of the art in the study of ageing contradicts the widely held view that energy trade-offs between growth, reproduction, and longevity are the universal underpinning of senescence. Future research should focus on understanding the relative contribution of energy and function trade-offs to the evolution and expression of ageing.
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Affiliation(s)
- Alexei A Maklakov
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Tracey Chapman
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
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