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McNew SM, Taff CC, Vitousek MN. Manipulation of a social signal affects DNA methylation of a stress-related gene in a free-living bird. J Exp Biol 2024; 227:jeb246819. [PMID: 39022893 DOI: 10.1242/jeb.246819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 07/02/2024] [Indexed: 07/20/2024]
Abstract
Social status directly affects the health of humans and other animals. Low status individuals receive more antagonistic encounters, have fewer supportive relationships and have worse health outcomes. However, the physiological and cellular processes that mediate the relationship between the social environment and health are incompletely known. Epigenetic regulation of the hypothalamic-pituitary-adrenal (HPA) axis, the neuroendocrine pathway that activates in response to stressors, may be one process that is sensitive to the social environment. Here, we experimentally manipulated plumage, a key social signal in female tree swallows (Tachycineta bicolor) and quantified methylation of four genes in the HPA axis before and after treatment. We found that dulling the white breast plumage affected methylation in one gene, CRHR1; however, the effect depended on the original brightness of the bird. Methylation in this gene was correlated with baseline corticosterone levels, suggesting that DNA methylation of CRHR1 helps regulate glucocorticoid production in this species. Methylation in two other genes, FKBP5 and GR, changed over the course of the experiment, independent of treatment. These results show that methylation of these genes is labile into adulthood and suggest that epigenetic regulation of the HPA axis could help birds respond to current environmental conditions.
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Affiliation(s)
- Sabrina M McNew
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
- Cornell Lab of Ornithology, Cornell University, Ithaca, NY 14850, USA
- Department of Ecology & Evolutionary Biology, University of Arizona, Tucson, AZ 85719, USA
| | - Conor C Taff
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
- Cornell Lab of Ornithology, Cornell University, Ithaca, NY 14850, USA
- Department of Biology, Colby College, Waterville, ME 04901, USA
| | - Maren N Vitousek
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
- Cornell Lab of Ornithology, Cornell University, Ithaca, NY 14850, USA
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2
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Ruuskanen S. Early-life environmental effects on birds: epigenetics and microbiome as mechanisms underlying long-lasting phenotypic changes. J Exp Biol 2024; 227:jeb246024. [PMID: 38449325 DOI: 10.1242/jeb.246024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2024]
Abstract
Although the long-lasting effects of variation in early-life environment have been well documented across organisms, the underlying causal mechanisms are only recently starting to be unraveled. Yet understanding the underlying mechanisms of long-lasting effects can help us predict how organisms will respond to changing environments. Birds offer a great system in which to study developmental plasticity and its underlying mechanisms owing to the production of large external eggs and variation in developmental trajectories, combined with a long tradition of applied, physiological, ecological and evolutionary research. Epigenetic changes (such as DNA methylation) have been suggested to be a key mechanism mediating long-lasting effects of the early-life environment across taxa. More recently, changes in the early-life gut microbiome have been identified as another potential mediator of developmental plasticity. As a first step in understanding whether these mechanisms contribute to developmental plasticity in birds, this Review summarizes how changes in early-life environment (both prenatal and postnatal) influence epigenetic markers and the gut microbiome. The literature shows how both early-life biotic (such as resources and social environment) and abiotic (thermal environment and various anthropogenic stressors) factors modify epigenetic markers and the gut microbiome in birds, yet data concerning many other environmental factors are limited. The causal links of these modifications to lasting phenotypic changes are still scarce, but changes in the hypothalamic-pituitary-adrenal axis have been identified as one putative pathway. This Review identifies several knowledge gaps, including data on the long-term effects, stability of the molecular changes, and lack of diversity in the systems studied, and provides directions for future research.
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Affiliation(s)
- Suvi Ruuskanen
- Department of Biological and Environmental Science, University of Jyväskylä, Survontie 9C, 40500 Jyväskylä, Finland
- Department of Biology, University of Turku, Vesilinnankatu 5, 20500 Turku, Finland
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3
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Laine VN, Sepers B, Lindner M, Gawehns F, Ruuskanen S, van Oers K. An ecologist's guide for studying DNA methylation variation in wild vertebrates. Mol Ecol Resour 2023; 23:1488-1508. [PMID: 35466564 DOI: 10.1111/1755-0998.13624] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 03/29/2022] [Accepted: 04/13/2022] [Indexed: 11/30/2022]
Abstract
The field of molecular biology is advancing fast with new powerful technologies, sequencing methods and analysis software being developed constantly. Commonly used tools originally developed for research on humans and model species are now regularly used in ecological and evolutionary research. There is also a growing interest in the causes and consequences of epigenetic variation in natural populations. Studying ecological epigenetics is currently challenging, especially for vertebrate systems, because of the required technical expertise, complications with analyses and interpretation, and limitations in acquiring sufficiently high sample sizes. Importantly, neglecting the limitations of the experimental setup, technology and analyses may affect the reliability and reproducibility, and the extent to which unbiased conclusions can be drawn from these studies. Here, we provide a practical guide for researchers aiming to study DNA methylation variation in wild vertebrates. We review the technical aspects of epigenetic research, concentrating on DNA methylation using bisulfite sequencing, discuss the limitations and possible pitfalls, and how to overcome them through rigid and reproducible data analysis. This review provides a solid foundation for the proper design of epigenetic studies, a clear roadmap on the best practices for correct data analysis and a realistic view on the limitations for studying ecological epigenetics in vertebrates. This review will help researchers studying the ecological and evolutionary implications of epigenetic variation in wild populations.
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Affiliation(s)
- Veronika N Laine
- Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland
| | - Bernice Sepers
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
- Behavioural Ecology Group, Wageningen University & Research (WUR), Wageningen, The Netherlands
| | - Melanie Lindner
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
- Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Groningen, The Netherlands
| | - Fleur Gawehns
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Suvi Ruuskanen
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland
- Department of Biology, University of Turku, Finland
| | - Kees van Oers
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
- Behavioural Ecology Group, Wageningen University & Research (WUR), Wageningen, The Netherlands
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Troyee AN, Peña-Ponton C, Medrano M, Verhoeven KJF, Alonso C. Herbivory induced methylation changes in the Lombardy poplar: A comparison of results obtained by epiGBS and WGBS. PLoS One 2023; 18:e0291202. [PMID: 37682835 PMCID: PMC10490839 DOI: 10.1371/journal.pone.0291202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 08/23/2023] [Indexed: 09/10/2023] Open
Abstract
DNA cytosine methylation is an epigenetic mechanism involved in regulation of plant responses to biotic and abiotic stress and its ability to change can vary with the sequence context in which a cytosine appears (CpG, CHG, CHH, where H = Adenine, Thymine, Cytosine). Quantification of DNA methylation in model plant species is frequently addressed by Whole Genome Bisulfite Sequencing (WGBS), which requires a good-quality reference genome. Reduced Representation Bisulfite Sequencing (RRBS) is a cost-effective potential alternative for ecological research with limited genomic resources and large experimental designs. In this study, we provide for the first time a comprehensive comparison between the outputs of RRBS and WGBS to characterize DNA methylation changes in response to a given environmental factor. In particular, we used epiGBS (recently optimized RRBS) and WGBS to assess global and sequence-specific differential methylation after insect and artificial herbivory in clones of Populus nigra cv. 'italica'. We found that, after any of the two herbivory treatments, global methylation percentage increased in CHH, and the shift was detected as statistically significant only by epiGBS. As regards to loci-specific differential methylation induced by herbivory (cytosines in epiGBS and regions in WGBS), both techniques indicated the specificity of the response elicited by insect and artificial herbivory, together with higher frequency of hypo-methylation in CpG and hyper-methylation in CHH. Methylation changes were mainly found in gene bodies and intergenic regions when present at CpG and CHG and in transposable elements and intergenic regions at CHH context. Thus, epiGBS succeeded to characterize global, genome-wide methylation changes in response to herbivory in the Lombardy poplar. Our results support that epiGBS could be particularly useful in large experimental designs aimed to explore epigenetic changes of non-model plant species in response to multiple environmental factors.
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Affiliation(s)
- A. Niloya Troyee
- Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (CSIC), Sevilla, Spain
| | - Cristian Peña-Ponton
- Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Mónica Medrano
- Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (CSIC), Sevilla, Spain
| | - Koen J. F. Verhoeven
- Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Conchita Alonso
- Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (CSIC), Sevilla, Spain
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Sepers B, Mateman AC, Gawehns F, Verhoeven KJF, van Oers K. Developmental stress does not induce genome-wide DNA methylation changes in wild great tit (Parus major) nestlings. Mol Ecol 2023. [PMID: 37154074 DOI: 10.1111/mec.16973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 03/30/2023] [Accepted: 04/12/2023] [Indexed: 05/10/2023]
Abstract
The environment experienced during early life is a crucial factor in the life of many organisms. This early life environment has been shown to have profound effects on morphology, physiology and fitness. However, the molecular mechanisms that mediate these effects are largely unknown, even though they are essential for our understanding of the processes that induce phenotypic variation in natural populations. DNA methylation is an epigenetic mechanism that has been suggested to explain such environmentally induced phenotypic changes early in life. To investigate whether DNA methylation changes are associated with experimentally induced early developmental effects, we cross-fostered great tit (Parus major) nestlings and manipulated their brood sizes in a natural study population. We assessed experimental brood size effects on pre-fledging biometry and behaviour. We linked this to genome-wide DNA methylation levels of CpG sites in erythrocyte DNA, using 122 individuals and an improved epiGBS2 laboratory protocol. Brood enlargement caused developmental stress and negatively affected nestling condition, predominantly during the second half of the breeding season, when conditions are harsher. Brood enlargement, however, affected nestling DNA methylation in only one CpG site and only if the hatch date was taken into account. In conclusion, this study shows that nutritional stress in enlarged broods does not associate with direct effects on genome-wide DNA methylation. Future studies should assess whether genome-wide DNA methylation variation may arise later in life as a consequence of phenotypic changes during early development.
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Affiliation(s)
- Bernice Sepers
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
- Behavioural Ecology Group, Wageningen University & Research (WUR), Wageningen, The Netherlands
| | - A Christa Mateman
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Fleur Gawehns
- Bioinformatics Unit, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Koen J F Verhoeven
- Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Kees van Oers
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
- Behavioural Ecology Group, Wageningen University & Research (WUR), Wageningen, The Netherlands
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van Oers K, van den Heuvel K, Sepers B. The Epigenetics of Animal Personality. Neurosci Biobehav Rev 2023; 150:105194. [PMID: 37094740 DOI: 10.1016/j.neubiorev.2023.105194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 04/12/2023] [Accepted: 04/21/2023] [Indexed: 04/26/2023]
Abstract
Animal personality, consistent individual differences in behaviour, is an important concept for understanding how individuals vary in how they cope with environmental challenges. In order to understand the evolutionary significance of animal personality, it is crucial to understand the underlying regulatory mechanisms. Epigenetic marks such as DNA methylation are hypothesised to play a major role in explaining variation in phenotypic changes in response to environmental alterations. Several characteristics of DNA methylation also align well with the concept of animal personality. In this review paper, we summarise the current literature on the role that molecular epigenetic mechanisms may have in explaining personality variation. We elaborate on the potential for epigenetic mechanisms to explain behavioural variation, behavioural development and temporal consistency in behaviour. We then suggest future routes for this emerging field and point to potential pitfalls that may be encountered. We conclude that a more inclusive approach is needed for studying the epigenetics of animal personality and that epigenetic mechanisms cannot be studied without considering the genetic background.
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Affiliation(s)
- Kees van Oers
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands; Behavioural Ecology Group, Wageningen University & Research (WUR), Wageningen, the Netherlands.
| | - Krista van den Heuvel
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands; Behavioural Ecology Group, Wageningen University & Research (WUR), Wageningen, the Netherlands
| | - Bernice Sepers
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands; Behavioural Ecology Group, Wageningen University & Research (WUR), Wageningen, the Netherlands
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7
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Lundregan SL, Mäkinen H, Buer A, Holand H, Jensen H, Husby A. Infection by a helminth parasite is associated with changes in
DNA
methylation in the house sparrow. Ecol Evol 2022; 12:e9539. [PMCID: PMC9702581 DOI: 10.1002/ece3.9539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 10/24/2022] [Accepted: 11/03/2022] [Indexed: 11/29/2022] Open
Affiliation(s)
- Sarah L. Lundregan
- Department of Biology, Centre for Biodiversity Dynamics Norwegian University of Science and Technology Trondheim Norway
| | - Hannu Mäkinen
- Department of Biology, Centre for Biodiversity Dynamics Norwegian University of Science and Technology Trondheim Norway
- Evolutionary Biology, Department of Ecology and Genetics Uppsala University Uppsala Sweden
| | - Amberly Buer
- Department of Biology, Centre for Biodiversity Dynamics Norwegian University of Science and Technology Trondheim Norway
| | - Håkon Holand
- Department of Biology, Centre for Biodiversity Dynamics Norwegian University of Science and Technology Trondheim Norway
| | - Henrik Jensen
- Department of Biology, Centre for Biodiversity Dynamics Norwegian University of Science and Technology Trondheim Norway
| | - Arild Husby
- Department of Biology, Centre for Biodiversity Dynamics Norwegian University of Science and Technology Trondheim Norway
- Evolutionary Biology, Department of Ecology and Genetics Uppsala University Uppsala Sweden
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Mounger J, Boquete MT, Schmid MW, Granado R, Robertson MH, Voors SA, Langanke KL, Alvarez M, Wagemaker CAM, Schrey AW, Fox GA, Lewis DB, Lira CF, Richards CL. Inheritance of DNA methylation differences in the mangrove Rhizophora mangle. Evol Dev 2021; 23:351-374. [PMID: 34382741 DOI: 10.1111/ede.12388] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 05/15/2021] [Accepted: 07/02/2021] [Indexed: 12/11/2022]
Abstract
The capacity to respond to environmental challenges ultimately relies on phenotypic variation which manifests from complex interactions of genetic and nongenetic mechanisms through development. While we know something about genetic variation and structure of many species of conservation importance, we know very little about the nongenetic contributions to variation. Rhizophora mangle is a foundation species that occurs in coastal estuarine habitats throughout the neotropics where it provides critical ecosystem functions and is potentially threatened by anthropogenic environmental changes. Several studies have documented landscape-level patterns of genetic variation in this species, but we know virtually nothing about the inheritance of nongenetic variation. To assess one type of nongenetic variation, we examined the patterns of DNA sequence and DNA methylation in maternal plants and offspring from natural populations of R. mangle from the Gulf Coast of Florida. We used a reduced representation bisulfite sequencing approach (epi-genotyping by sequencing; epiGBS) to address the following questions: (a) What are the levels of genetic and epigenetic diversity in natural populations of R. mangle? (b) How are genetic and epigenetic variation structured within and among populations? (c) How faithfully is epigenetic variation inherited? We found low genetic diversity but high epigenetic diversity from natural populations of maternal plants in the field. In addition, a large portion (up to ~25%) of epigenetic differences among offspring grown in common garden was explained by maternal family. Therefore, epigenetic variation could be an important source of response to challenging environments in the genetically depauperate populations of this foundation species.
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Affiliation(s)
- Jeannie Mounger
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - M Teresa Boquete
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA.,Department of Evolutionary Ecology, CSIC, Estación Biológica de Doñana, Sevilla, Spain
| | | | - Renan Granado
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA.,Diretoria de Pesquisas, Instituto de Pesquisas Jardim Botânico do Rio de Janeiro, Rio de Janeiro/RJ, Brazil
| | - Marta H Robertson
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Sandy A Voors
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Kristen L Langanke
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Mariano Alvarez
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA.,Avalo, Durham, NC, USA
| | | | - Aaron W Schrey
- Department of Biology, Georgia Southern University, Armstrong Campus, Savannah, Georgia, USA
| | - Gordon A Fox
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - David B Lewis
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Catarina Fonseca Lira
- Diretoria de Pesquisas, Instituto de Pesquisas Jardim Botânico do Rio de Janeiro, Rio de Janeiro/RJ, Brazil
| | - Christina L Richards
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA.,Plant Evolutionary Ecology, University of Tübingen, Institute of Evolution & Ecology, Tübingen, Germany
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