51
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Eastwood JR, Hall ML, Teunissen N, Kingma SA, Hidalgo Aranzamendi N, Fan M, Roast M, Verhulst S, Peters A. Early-life telomere length predicts lifespan and lifetime reproductive success in a wild bird. Mol Ecol 2019; 28:1127-1137. [PMID: 30592345 DOI: 10.1111/mec.15002] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 11/26/2018] [Accepted: 12/07/2018] [Indexed: 12/30/2022]
Abstract
Poor conditions during early development can initiate trade-offs that favour current survival at the expense of somatic maintenance and subsequently, future reproduction. However, the mechanisms that link early and late life-history are largely unknown. Recently it has been suggested that telomeres, the nucleoprotein structures at the terminal end of chromosomes, could link early-life conditions to lifespan and fitness. In wild purple-crowned fairy-wrens, we combined measurements of nestling telomere length (TL) with detailed life-history data to investigate whether early-life TL predicts fitness prospects. Our study differs from previous studies in the completeness of our fitness estimates in a highly philopatric population. The association between TL and survival was age-dependent with early-life TL having a positive effect on lifespan only among individuals that survived their first year. Early-life TL was not associated with the probability or age of gaining a breeding position. Interestingly, early-life TL was positively related to breeding duration, contribution to population growth and lifetime reproductive success because of their association with lifespan. Thus, early-life TL, which reflects growth, accumulated early-life stress and inherited TL, predicted fitness in birds that reached adulthood but not noticeably among fledglings. These findings suggest that a lack of investment in somatic maintenance during development particularly affects late life performance. This study demonstrates that factors in early-life are related to fitness prospects through lifespan, and suggests that the study of telomeres may provide insight into the underlying physiological mechanisms linking early- and late-life performance and trade-offs across a lifetime.
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Affiliation(s)
- Justin R Eastwood
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Michelle L Hall
- School of BioSciences, University of Melbourne, Melbourne, Victoria, Australia.,Max Planck Institute for Ornithology, Vogelwarte Radolfzell, Radolfzell, Germany
| | - Niki Teunissen
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Sjouke A Kingma
- Max Planck Institute for Ornithology, Vogelwarte Radolfzell, Radolfzell, Germany.,Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | | | - Marie Fan
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Michael Roast
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Simon Verhulst
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Anne Peters
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia.,Max Planck Institute for Ornithology, Vogelwarte Radolfzell, Radolfzell, Germany
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52
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Chatelain M, Drobniak SM, Szulkin M. The association between stressors and telomeres in non‐human vertebrates: a meta‐analysis. Ecol Lett 2019; 23:381-398. [DOI: 10.1111/ele.13426] [Citation(s) in RCA: 99] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 10/10/2019] [Accepted: 10/16/2019] [Indexed: 12/21/2022]
Affiliation(s)
- Marion Chatelain
- Centre of New Technologies University of Warsaw Banacha 2C 02‐097 Warszawa Poland
| | - Szymon M. Drobniak
- Institute of Environmental Sciences Jagiellonian University Gronostajowa 7 30‐387 Kraków Poland
- Ecology & Evolution Research Centre School of Biological, Environmental and Earth Sciences University of New South Wales Sydney Australia
| | - Marta Szulkin
- Centre of New Technologies University of Warsaw Banacha 2C 02‐097 Warszawa Poland
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53
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Impact of continuous predator threat on telomere dynamics in parent and nestling pied flycatchers. Oecologia 2019; 191:757-766. [PMID: 31612326 PMCID: PMC6853860 DOI: 10.1007/s00442-019-04529-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 10/03/2019] [Indexed: 11/03/2022]
Abstract
In addition to direct mortality, predators can have indirect effects on prey populations by affecting prey behaviour or physiology. For example, predator presence can increase stress hormone levels, which can have physiological costs. Stress exposure accelerates the shortening of telomeres (i.e. the protective caps of chromosomes) and shorter telomeres have been linked to increased mortality risk. However, the effect of perceived predation risk on telomeres is not known. We investigated the effects of continuous predator threat (nesting Eurasian pygmy owl Glaucidium passerinum) on telomere dynamics of both adult and partially cross-fostered nestling pied flycatchers (Ficedula hypoleuca) in the wild. Females nesting at owl-inhabited sites showed impaired telomere maintenance between incubation and chick rearing compared to controls, and both males and females ended up with shorter telomeres at owl-inhabited sites in the end of chick rearing. On the contrary, both original and cross-fostered chicks reared in owl sites had consistently longer telomeres during growth than chicks reared at control sites. Thus, predation risk may cause a long-term cost in terms of telomeres for parents but not for their offspring. Predators may therefore affect telomere dynamics of their preys, which could have implications for their ageing rate and consequently for population dynamics.
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54
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Lieshout SHJ, Bretman A, Newman C, Buesching CD, Macdonald DW, Dugdale HL. Individual variation in early‐life telomere length and survival in a wild mammal. Mol Ecol 2019; 28:4152-4165. [DOI: 10.1111/mec.15212] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 07/12/2019] [Accepted: 07/23/2019] [Indexed: 12/18/2022]
Affiliation(s)
- Sil H. J. Lieshout
- School of Biology Faculty of Biological Sciences University of Leeds Leeds UK
- NERC Biomolecular Analysis Facility Department of Animal and Plant Sciences University of Sheffield Sheffield UK
| | - Amanda Bretman
- School of Biology Faculty of Biological Sciences University of Leeds Leeds UK
| | - Chris Newman
- Wildlife Conservation Research Unit Department of Zoology University of Oxford Abingdon UK
| | - Christina D. Buesching
- Wildlife Conservation Research Unit Department of Zoology University of Oxford Abingdon UK
| | - David W. Macdonald
- Wildlife Conservation Research Unit Department of Zoology University of Oxford Abingdon UK
| | - Hannah L. Dugdale
- School of Biology Faculty of Biological Sciences University of Leeds Leeds UK
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55
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Nettle D, Seeker L, Nussey D, Froy H, Bateson M. Consequences of measurement error in qPCR telomere data: A simulation study. PLoS One 2019; 14:e0216118. [PMID: 31042766 PMCID: PMC6493763 DOI: 10.1371/journal.pone.0216118] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 04/14/2019] [Indexed: 02/04/2023] Open
Abstract
The qPCR method provides an inexpensive, rapid method for estimating relative telomere length across a set of biological samples. Like all laboratory methods, it involves some degree of measurement error. The estimation of relative telomere length is done subjecting the actual measurements made (the Cq values for telomere and a control gene) to non-linear transformations and combining them into a ratio (the TS ratio). Here, we use computer simulations, supported by mathematical analysis, to explore how errors in measurement affect qPCR estimates of relative telomere length, both in cross-sectional and longitudinal data. We show that errors introduced at the level of Cq values are magnified when the TS ratio is calculated. If the errors at the Cq level are normally distributed and independent of true telomere length, those in the TS ratio are positively skewed and proportional to true telomere length. The repeatability of the TS ratio declines sharply with increasing error in measurement of the Cq values for telomere and/or control gene. In simulated longitudinal data, measurement error alone can produce a pattern of low correlation between successive measures of relative telomere length, coupled with a strong negative dependency of the rate of change on initial relative telomere length. Our results illustrate the importance of reducing measurement error: a small increase in error in Cq values can have large consequences for the power and interpretability of qPCR estimates of relative telomere length. The findings also illustrate the importance of characterising the measurement error in each dataset-coefficients of variation are generally unhelpful, and researchers should report standard deviations of Cq values and/or repeatabilities of TS ratios-and allowing for the known effects of measurement error when interpreting patterns of TS ratio change over time.
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Affiliation(s)
- Daniel Nettle
- Centre for Behaviour and Evolution & Institute of Neuroscience, Newcastle University, Newcastle, United Kingdom
| | - Luise Seeker
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Dan Nussey
- Institute of Evolutionary Biology, University of Edinburgh, Edinburgh, United Kingdom
| | - Hannah Froy
- Centre for Biodiversity Dynamics, Norwegian Institute of Science and Technology, Trondheim, Norway
| | - Melissa Bateson
- Centre for Behaviour and Evolution & Institute of Neuroscience, Newcastle University, Newcastle, United Kingdom
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56
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Hammers M, Kingma SA, Spurgin LG, Bebbington K, Dugdale HL, Burke T, Komdeur J, Richardson DS. Breeders that receive help age more slowly in a cooperatively breeding bird. Nat Commun 2019; 10:1301. [PMID: 30899016 PMCID: PMC6428877 DOI: 10.1038/s41467-019-09229-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 02/28/2019] [Indexed: 11/09/2022] Open
Abstract
Helping by group members is predicted to lead to delayed senescence by affecting the trade-off between current reproduction and future survival for dominant breeders. Here we investigate this prediction in the Seychelles warbler, Acrocephalus sechellensis, in which mainly female subordinate helpers (both co-breeders and non-breeding helpers) often help dominants raise offspring. We find that the late-life decline in survival usually observed in this species is greatly reduced in female dominants when a helper is present. Female dominants with a female helper show reduced telomere attrition, a measure that reflects biological ageing in this and other species. Finally, the probability of having female, but not male, helpers increases with dominant female age. Our results suggest that delayed senescence is a key benefit of cooperative breeding for elderly dominants and support the idea that sociality and delayed senescence are positively self-reinforcing. Such an effect may help explain why social species often have longer lifespans. Sociality explains substantial variation in ageing across species, but less is known about this relationship within species. Here, the authors show that female dominant Seychelles warblers with helpers at the nest have higher late-life survival and lower telomere attrition and the probability of having helpers increases with age.
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Affiliation(s)
- Martijn Hammers
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9712 CP, Groningen, The Netherlands.
| | - Sjouke A Kingma
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9712 CP, Groningen, The Netherlands.,Department of Animal Science, Wageningen University & Research, 6708 PB, Wageningen, The Netherlands
| | - Lewis G Spurgin
- School of Biological Sciences, University of East Anglia, Norwich, NR47TJ, UK
| | - Kat Bebbington
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9712 CP, Groningen, The Netherlands.,School of Biological Sciences, University of East Anglia, Norwich, NR47TJ, UK
| | | | - Terry Burke
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, S102TN, UK
| | - Jan Komdeur
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9712 CP, Groningen, The Netherlands
| | - David S Richardson
- School of Biological Sciences, University of East Anglia, Norwich, NR47TJ, UK.,Nature Seychelles, Victoria, Mahé, Seychelles
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57
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Dugdale HL, Richardson DS. Heritability of telomere variation: it is all about the environment! Philos Trans R Soc Lond B Biol Sci 2019; 373:rstb.2016.0450. [PMID: 29335377 PMCID: PMC5784070 DOI: 10.1098/rstb.2016.0450] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/21/2017] [Indexed: 01/07/2023] Open
Abstract
Individual differences in telomere length have been linked to survival and senescence. Understanding the heritability of telomere length can provide important insight into individual differences and facilitate our understanding of the evolution of telomeres. However, to gain accurate and meaningful estimates of telomere heritability it is vital that the impact of the environment, and how this may vary, is understood and accounted for. The aim of this review is to raise awareness of this important, but much under-appreciated point. We outline the factors known to impact telomere length and discuss the fact that telomere length is a trait that changes with age. We highlight statistical methods that can separate genetic from environmental effects and control for confounding variables. We then review how well previous studies in vertebrate populations including humans have taken these factors into account. We argue that studies to date either use methodological techniques that confound environmental and genetic effects, or use appropriate methods but lack sufficient power to fully separate these components. We discuss potential solutions. We conclude that we need larger studies, which also span longer time periods, to account for changing environmental effects, if we are to determine meaningful estimates of the genetic component of telomere length. This article is part of the theme issue ‘Understanding diversity in telomere dynamics'.
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Affiliation(s)
- Hannah L Dugdale
- Faculty of Biological Sciences, School of Biology, University of Leeds, Leeds LS2 9JT, UK
| | - David S Richardson
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, Norfolk NR4 7TJ, UK
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58
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Apfelbeck B, Haussmann MF, Boner W, Flinks H, Griffiths K, Illera JC, Mortega KG, Sisson Z, Smiddy P, Helm B. Divergent patterns of telomere shortening in tropical compared to temperate stonechats. Ecol Evol 2019; 9:511-521. [PMID: 30680132 PMCID: PMC6342124 DOI: 10.1002/ece3.4769] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 11/04/2018] [Accepted: 11/12/2018] [Indexed: 12/11/2022] Open
Abstract
Telomeres have emerged as important biomarkers of health and senescence as they predict chances of survival in various species. Tropical birds live in more benign environments with lower extrinsic mortality and higher juvenile and adult survival than temperate birds. Therefore, telomere biology may play a more important role in tropical compared to temperate birds. We measured mean telomere length of male stonechats (Saxicola spp.) at four age classes from tropical African and temperate European breeding regions. Tropical and temperate stonechats had similarly long telomeres as nestlings. However, while in tropical stonechats pre-breeding first-years had longer telomeres than nestlings, in temperate stonechats pre-breeding first-years had shorter telomeres than nestlings. During their first breeding season, telomere length was again similar between tropical and temperate stonechats. These patterns may indicate differential survival of high-quality juveniles in tropical environments. Alternatively, more favorable environmental conditions, that is, extended parental care, may enable tropical juveniles to minimize telomere shortening. As suggested by previous studies, our results imply that variation in life history and life span may be reflected in different patterns of telomere shortening rather than telomere length. Our data provide first evidence that distinct selective pressures in tropical and temperate environments may be reflected in diverging patterns of telomere loss in birds.
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Affiliation(s)
- Beate Apfelbeck
- Institute of Biodiversity, Animal Health and Comparative MedicineUniversity of GlasgowGlasgowUK
- Terrestrial Ecology Research Group, Department of Ecology and Ecosystem Management, School of Life Sciences WeihenstephanTechnische Universität MünchenFreisingGermany
| | | | - Winnie Boner
- Institute of Biodiversity, Animal Health and Comparative MedicineUniversity of GlasgowGlasgowUK
| | | | - Kate Griffiths
- Institute of Biodiversity, Animal Health and Comparative MedicineUniversity of GlasgowGlasgowUK
| | - Juan Carlos Illera
- Research Unit of Biodiversity (UO‐CSIC‐PA), Oviedo UniversityMieresSpain
| | - Kim G. Mortega
- Institute of Biodiversity, Animal Health and Comparative MedicineUniversity of GlasgowGlasgowUK
- Department of Migration and Immunoecology, Max‐Planck‐Institut für OrnithologieRadolfzellGermany
- Museum für Naturkunde—Leibniz‐Institut für Evolutions‐und BiodiversitätsforschungBerlinGermany
| | - Zachary Sisson
- Department of BiologyBucknell UniversityLewisburgPennsylvania
| | - Patrick Smiddy
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
| | - Barbara Helm
- Institute of Biodiversity, Animal Health and Comparative MedicineUniversity of GlasgowGlasgowUK
- Groningen Institute for Evolutionary Life Sciences (GELIFES)University of GroningenGroningenThe Netherlands
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59
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Bebbington K, Fairfield EA, Spurgin LG, Kingma SA, Dugdale H, Komdeur J, Richardson DS. Joint care can outweigh costs of nonkin competition in communal breeders. Behav Ecol 2017; 29:169-178. [PMID: 29622934 PMCID: PMC5873242 DOI: 10.1093/beheco/arx137] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 09/04/2017] [Accepted: 10/06/2017] [Indexed: 01/21/2023] Open
Abstract
Competition between offspring can greatly influence offspring fitness and parental investment decisions, especially in communal breeders where unrelated competitors have less incentive to concede resources. Given the potential for escalated conflict, it remains unclear what mechanisms facilitate the evolution of communal breeding among unrelated females. Resolving this question requires simultaneous consideration of offspring in noncommunal and communal nurseries, but such comparisons are missing. In the Seychelles warbler Acrocephalus sechellensis, we compare nestling pairs from communal nests (2 mothers) and noncommunal nests (1 mother) with singleton nestlings. Our results indicate that increased provisioning rate can act as a mechanism to mitigate the costs of offspring rivalry among nonkin. Increased provisioning in communal broods, as a consequence of having 2 female parents, mitigates any elevated costs of offspring rivalry among nonkin: per-capita provisioning and survival was equal in communal broods and singletons, but lower in noncommunal broods. Individual offspring costs were also more divergent in noncommunal broods, likely because resource limitation exacerbates differences in competitive ability between nestlings. It is typically assumed that offspring rivalry among nonkin will be more costly because offspring are not driven by kin selection to concede resources to their competitors. Our findings are correlational and require further corroboration, but may help explain the evolutionary maintenance of communal breeding by providing a mechanism by which communal breeders can avoid these costs.
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Affiliation(s)
- Kat Bebbington
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, UK.,Behavioural Ecology and Physiological Group, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Eleanor A Fairfield
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Lewis G Spurgin
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, UK
| | - Sjouke A Kingma
- Behavioural Ecology and Physiological Group, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Hannah Dugdale
- Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Jan Komdeur
- Behavioural Ecology and Physiological Group, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - David S Richardson
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, UK.,Nature Seychelles, Mahé, Republic of Seychelles
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60
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Kinship and familiarity mitigate costs of social conflict between Seychelles warbler neighbors. Proc Natl Acad Sci U S A 2017; 114:E9036-E9045. [PMID: 29073100 PMCID: PMC5664493 DOI: 10.1073/pnas.1704350114] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
In nature, animals must compete with their neighbors for access to limited resources. Since conflict over resources can be extremely costly in terms of time, energy, and reproductive success, investigating how individuals resolve conflict is crucial to understanding the evolution of social behaviors. In the Seychelles warbler, we demonstrate two mechanisms by which individuals minimize costs of conflict and show the benefits individuals gain from doing so. Birds that live near relatives or familiar individuals invest less energy in defending and maintaining territory borders and also show less aging-related signs of physiological damage. Our results suggest that conflict between neighbors can be mitigated by kin-selected benefits of sharing resources with relatives but also through direct mutual benefits of cooperation. Because virtually all organisms compete with others in their social environment, mechanisms that reduce conflict between interacting individuals are crucial for the evolution of stable families, groups, and societies. Here, we tested whether costs of social conflict over territorial space between Seychelles warblers (Acrocephalus sechellensis) are mitigated by kin-selected (genetic relatedness) or mutualistic (social familiarity) mechanisms. By measuring longitudinal changes in individuals’ body mass and telomere length, we demonstrated that the fitness costs of territoriality are driven by a complex interplay between relatedness, familiarity, local density, and sex. Physical fights were less common at territory boundaries shared between related or familiar males. In line with this, male territory owners gained mass when living next to related or familiar males and also showed less telomere attrition when living next to male kin. Importantly, these relationships were strongest in high-density areas of the population. Males also had more rapid telomere attrition when living next to unfamiliar male neighbors, but mainly when relatedness to those neighbors was also low. In contrast, neither kinship nor familiarity was linked to body mass or telomere loss in female territory owners. Our results indicate that resolving conflict over territorial space through kin-selected or mutualistic pathways can reduce both immediate energetic costs and permanent somatic damage, thus providing an important mechanism to explain fine-scale population structure and cooperation between different social units across a broad range of taxa.
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61
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Hares MC, Vitikainen EIK, Marshall HH, Thompson FJ, Blount JD, Cant MA. Telomere dynamics in wild banded mongooses: Evaluating longitudinal and quasi-longitudinal markers of senescence. Exp Gerontol 2017; 107:67-73. [PMID: 28964829 PMCID: PMC5956279 DOI: 10.1016/j.exger.2017.09.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 09/25/2017] [Accepted: 09/26/2017] [Indexed: 11/06/2022]
Abstract
Telomere length and the rate of telomere shortening have been suggested as particularly useful physiological biomarkers of the processes involved in senescent decline of somatic and reproductive function. However, longitudinal data on changes in telomere length across the lifespan are difficult to obtain, particularly for long-lived animals. Quasi-longitudinal studies have been proposed as a method to gain insight into telomere dynamics in long-lived species. In this method, minimally replicative cells are used as the baseline telomere length against which telomere length in highly replicative cells (which represent the current state) can be compared. Here we test the assumptions and predictions of the quasi-longitudinal approach using longitudinal telomere data in a wild cooperative mammal, the banded mongoose, Mungos mungo. Contrary to our prediction, telomere length (TL) was longer in leukocytes than in ear cartilage. Longitudinally, the TL of ear cartilage shortened with age, but there was no change in the TL of leukocytes, and we also observed many individuals in which TL increased rather than decreased with age. Leukocyte TL but not cartilage TL was a predictor of total lifespan, while neither predicted post-sampling survival. Our data do not support the hypothesis that cross-tissue comparison in TL can act as a quasi-longitudinal marker of senescence. Rather, our results suggest that telomere dynamics in banded mongooses are more complex than is typically assumed, and that longitudinal studies across whole life spans are required to elucidate the link between telomere dynamics and senescence in natural populations. We find no evidence that somatic tissues can be used as a quasi-longitudinal marker for telomere length in leukocytes. Telomere dynamics in different tissue types appear to be complex and likely to be influenced by telomerase activity. Telomere length may be a useful marker for somatic quality in wild animal populations.
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Affiliation(s)
- Michelle C Hares
- University of Exeter, Penryn Campus, Penryn, Cornwall TR10 9FE, United Kingdom.
| | - Emma I K Vitikainen
- University of Exeter, Penryn Campus, Penryn, Cornwall TR10 9FE, United Kingdom.
| | - Harry H Marshall
- Centre for Research in Ecology, University of Roehampton, London, SW15 4JD, United Kingdom
| | - Faye J Thompson
- University of Exeter, Penryn Campus, Penryn, Cornwall TR10 9FE, United Kingdom
| | - Jonathan D Blount
- University of Exeter, Penryn Campus, Penryn, Cornwall TR10 9FE, United Kingdom
| | - Michael A Cant
- University of Exeter, Penryn Campus, Penryn, Cornwall TR10 9FE, United Kingdom
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62
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Spurgin LG, Bebbington K, Fairfield EA, Hammers M, Komdeur J, Burke T, Dugdale HL, Richardson DS. Spatio-temporal variation in lifelong telomere dynamics in a long-term ecological study. J Anim Ecol 2017; 87:187-198. [PMID: 28796902 PMCID: PMC5765431 DOI: 10.1111/1365-2656.12741] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 07/15/2017] [Indexed: 11/30/2022]
Abstract
Understanding individual‐level variation in response to the environment is fundamental to understanding life‐history evolution and population dynamics. Telomeres, the protective caps at the ends of chromosomes, shorten in response to oxidative stress, and telomere shortening is correlated with reduced survival and life span. Investigating telomere dynamics may help us quantify individual variation in the costs experienced from social and ecological factors, and enhance our understanding of the dynamics of natural populations. Here, we study spatio‐temporal variation in lifelong telomere dynamics in the Seychelles warbler, Acrocephalus sechellensis. We combine long‐term life history and ecological data with a large longitudinal dataset of mean telomere lengths, consisting of 1,808 samples from 22 cohorts born between 1993 and 2014. We provide a detailed analysis of how telomere dynamics vary over individual life spans and cohorts, and with spatio‐temporal variation in the social and ecological environment. We found that telomere length decreases with cross‐sectional and longitudinal measures of age, and most rapidly very early in life. However, both cross‐sectional and longitudinal data suggested that against this overall pattern of shortening, bouts of telomere length increase occur in some individuals. Using a large number of repeated measurements we show statistically that these increases are unlikely to be explained solely by qPCR measurement error. Telomere length varied markedly among cohorts. Telomere length was positively associated with temporal variation in island‐wide insect abundance—a key resource for the insectivorous Seychelles warbler—suggesting that the costs associated with living in harsher environments can be studied by investigating telomere dynamics. We also found evidence for sex‐specific relationships between telomeres and tarsus length, potentially reflecting differential costs of growth. Our long‐term data show that in a natural population, telomere dynamics vary in a complex manner over individual life spans, and across space and time. Variance in telomere dynamics among individuals is the product of a wide array of genetic, parental and environmental factors. Explaining this variation more fully will require the integration of comprehensive long‐term ecological and genetic data from multiple populations and species.
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Affiliation(s)
- Lewis G Spurgin
- School of Biological Sciences, University of East Anglia, Norwich Research Park, UK
| | - Kat Bebbington
- School of Biological Sciences, University of East Anglia, Norwich Research Park, UK
| | - Eleanor A Fairfield
- School of Biological Sciences, University of East Anglia, Norwich Research Park, UK
| | - Martijn Hammers
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Jan Komdeur
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Terry Burke
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK
| | - Hannah L Dugdale
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands.,School of Biology, The Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - David S Richardson
- School of Biological Sciences, University of East Anglia, Norwich Research Park, UK.,Nature Seychelles, Roche Caiman, Mahé, Republic of Seychelles
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