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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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Fu Y, Lai D, Xu Y, Liu J, Wang Y, Jiang D, Pan J, Ouyang H, Tian Y, Huang Y, Shen X. The DNA methylation status of the vitamin A signaling associated with testicular degeneration induced by long-day photoperiods in Magang geese. Poult Sci 2024; 103:103769. [PMID: 38917605 PMCID: PMC11250879 DOI: 10.1016/j.psj.2024.103769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 04/10/2024] [Accepted: 04/10/2024] [Indexed: 06/27/2024] Open
Abstract
Magang geese are typical short-day breeders whose reproductive behaviors are significantly influenced by photoperiod. Exposure to a long-day photoperiod results in testicular regression and spermatogenesis arrest in Magang geese. To investigate the epigenetic influence of DNA methylation on the seasonal testicular regression in Magang geese, we conducted whole-genome bisulfite sequencing and transcriptome sequencing of testes across 3 reproductive phases during a long-day photoperiod. A total of 250,326 differentially methylated regions (DMR) were identified among the 3 comparison groups, with a significant number showing hypermethylation, especially in intronic regions of the genome. Integrating bisulfite sequencing with transcriptome sequencing data revealed that DMR-associated genes tend to be differentially expressed in the testes, highlighting a potential regulatory role for DNA methylation in gene expression. Furthermore, there was a significant negative correlation between changes in the methylation of CG DMRs and changes in the expression of their associated genes in the testes. A total of 3,359 DMR-associated differentially expressed genes (DEG) were identified; functional enrichment analyses revealed that motor proteins, MAPK signaling pathway, ECM-receptor interaction, phagosome, TGF-beta signaling pathway, and calcium signaling might contribute to the testicular regression process. GSEA revealed that the significantly enriched activated hallmark gene set was associated with apoptosis and estrogen response during testicular regression, while the repressed hallmark gene set was involved in spermatogenesis. Our study also revealed that methylation changes significantly impacted the expression level of vitamin A metabolism-related genes during testicular degeneration, with hypermethylation of STRA6 and increased calmodulin levels indicating vitamin A efflux during the testicular regression. These findings were corroborated by pyrosequencing and real-time qPCR, which revealed that the vitamin A metabolic pathway plays a pivotal role in testicular degeneration under long-day conditions. Additionally, metabolomics analysis revealed an insufficiency of vitamin A and an abnormally high level of oxysterols accumulated in the testes during testicular regression. In conclusion, our study demonstrated that testicular degeneration in Magang geese induced by a long-day photoperiod is linked to vitamin A homeostasis disruption, which manifests as the hypermethylation status of STRA6, vitamin A efflux, and a high level of oxysterol accumulation. These findings offer new insights into the effects of DNA methylation on the seasonal testicular regression that occurs during long-day photoperiods in Magang geese.
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Affiliation(s)
- Yuting Fu
- College of Animal Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
| | - Diyu Lai
- College of Animal Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
| | - Yanglong Xu
- College of Animal Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
| | - Jiaxin Liu
- College of Animal Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
| | - Yushuai Wang
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, Guangdong, China
| | - Danli Jiang
- College of Animal Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
| | - Jianqiu Pan
- College of Animal Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
| | - Hongjia Ouyang
- College of Animal Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
| | - Yunbo Tian
- College of Animal Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
| | - Yunmao Huang
- College of Animal Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China
| | - Xu Shen
- College of Animal Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China.
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3
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Lindner M, Verhagen I, Mateman AC, van Oers K, Laine VN, Visser ME. Genetic and epigenetic differentiation in response to genomic selection for avian lay date. Evol Appl 2024; 17:e13703. [PMID: 38948539 PMCID: PMC11211926 DOI: 10.1111/eva.13703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 04/20/2024] [Accepted: 04/29/2024] [Indexed: 07/02/2024] Open
Abstract
Anthropogenic climate change has led to globally increasing temperatures at an unprecedented pace and, to persist, wild species have to adapt to their changing world. We, however, often fail to derive reliable predictions of species' adaptive potential. Genomic selection represents a powerful tool to investigate the adaptive potential of a species, but constitutes a 'blind process' with regard to the underlying genomic architecture of the relevant phenotypes. Here, we used great tit (Parus major) females from a genomic selection experiment for avian lay date to zoom into this blind process. We aimed to identify the genetic variants that responded to genomic selection and epigenetic variants that accompanied this response and, this way, might reflect heritable genetic variation at the epigenetic level. We applied whole genome bisulfite sequencing to blood samples of individual great tit females from the third generation of bidirectional genomic selection lines for early and late lay date. Genomic selection resulted in differences at both the genetic and epigenetic level. Genetic variants that showed signatures of selection were located within genes mostly linked to brain development and functioning, including LOC107203824 (SOX3-like). SOX3 is a transcription factor that is required for normal hypothalamo-pituitary axis development and functioning, an essential part of the reproductive axis. As for epigenetic differentiation, the early selection line showed hypomethylation relative to the late selection line. Sites with differential DNA methylation were located in genes important for various biological processes, including gonadal functioning (e.g., MSTN and PIK3CB). Overall, genomic selection for avian lay date provided insights into where within the genome the heritable genetic variation for lay date, on which selection can operate, resides and indicates that some of this variation might be reflected by epigenetic variants.
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Affiliation(s)
- Melanie Lindner
- Department of Animal EcologyNetherlands Institute of Ecology (NIOO‐KNAW)WageningenThe Netherlands
- Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences (GELIFES)University of GroningenGroningenThe Netherlands
| | - Irene Verhagen
- Wageningen University & Research (WUR)WageningenThe Netherlands
| | - A. Christa Mateman
- Department of Animal EcologyNetherlands Institute of Ecology (NIOO‐KNAW)WageningenThe Netherlands
| | - Kees van Oers
- Department of Animal EcologyNetherlands Institute of Ecology (NIOO‐KNAW)WageningenThe Netherlands
- Behavioural Ecology GroupWageningen University & Research (WUR)WageningenThe Netherlands
| | - Veronika N. Laine
- Finnish Museum of Natural HistoryUniversity of HelsinkiHelsinkiFinland
| | - Marcel E. Visser
- Department of Animal EcologyNetherlands Institute of Ecology (NIOO‐KNAW)WageningenThe Netherlands
- Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences (GELIFES)University of GroningenGroningenThe Netherlands
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4
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Baduel P, Sammarco I, Barrett R, Coronado‐Zamora M, Crespel A, Díez‐Rodríguez B, Fox J, Galanti D, González J, Jueterbock A, Wootton E, Harney E. The evolutionary consequences of interactions between the epigenome, the genome and the environment. Evol Appl 2024; 17:e13730. [PMID: 39050763 PMCID: PMC11266121 DOI: 10.1111/eva.13730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 03/30/2024] [Accepted: 05/22/2024] [Indexed: 07/27/2024] Open
Abstract
The epigenome is the suite of interacting chemical marks and molecules that helps to shape patterns of development, phenotypic plasticity and gene regulation, in part due to its responsiveness to environmental stimuli. There is increasing interest in understanding the functional and evolutionary importance of this sensitivity under ecologically realistic conditions. Observations that epigenetic variation abounds in natural populations have prompted speculation that it may facilitate evolutionary responses to rapid environmental perturbations, such as those occurring under climate change. A frequent point of contention is whether epigenetic variants reflect genetic variation or are independent of it. The genome and epigenome often appear tightly linked and interdependent. While many epigenetic changes are genetically determined, the converse is also true, with DNA sequence changes influenced by the presence of epigenetic marks. Understanding how the epigenome, genome and environment interact with one another is therefore an essential step in explaining the broader evolutionary consequences of epigenomic variation. Drawing on results from experimental and comparative studies carried out in diverse plant and animal species, we synthesize our current understanding of how these factors interact to shape phenotypic variation in natural populations, with a focus on identifying similarities and differences between taxonomic groups. We describe the main components of the epigenome and how they vary within and between taxa. We review how variation in the epigenome interacts with genetic features and environmental determinants, with a focus on the role of transposable elements (TEs) in integrating the epigenome, genome and environment. And we look at recent studies investigating the functional and evolutionary consequences of these interactions. Although epigenetic differentiation in nature is likely often a result of drift or selection on stochastic epimutations, there is growing evidence that a significant fraction of it can be stably inherited and could therefore contribute to evolution independently of genetic change.
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Affiliation(s)
- Pierre Baduel
- Institut de Biologie de l'Ecole Normale SupérieurePSL University, CNRSParisFrance
| | - Iris Sammarco
- Institute of Botany of the Czech Academy of SciencesPrůhoniceCzechia
| | - Rowan Barrett
- Redpath Museum and Department of BiologyMcGill UniversityMontrealCanada
| | | | | | | | - Janay Fox
- Redpath Museum and Department of BiologyMcGill UniversityMontrealCanada
| | - Dario Galanti
- Institute of Evolution and Ecology (EvE)University of TuebingenTübingenGermany
| | | | - Alexander Jueterbock
- Algal and Microbial Biotechnology Division, Faculty of Biosciences and AquacultureNord UniversityBodøNorway
| | - Eric Wootton
- Redpath Museum and Department of BiologyMcGill UniversityMontrealCanada
| | - Ewan Harney
- Institute of Evolutionary BiologyCSIC, UPFBarcelonaSpain
- School of BiosciencesUniversity of SheffieldSheffieldUK
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5
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Boman J, Qvarnström A, Mugal CF. Regulatory and evolutionary impact of DNA methylation in two songbird species and their naturally occurring F 1 hybrids. BMC Biol 2024; 22:124. [PMID: 38807214 PMCID: PMC11134931 DOI: 10.1186/s12915-024-01920-2] [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: 01/19/2024] [Accepted: 05/15/2024] [Indexed: 05/30/2024] Open
Abstract
BACKGROUND Regulation of transcription by DNA methylation in 5'-CpG-3' context is a widespread mechanism allowing differential expression of genetically identical cells to persist throughout development. Consequently, differences in DNA methylation can reinforce variation in gene expression among cells, tissues, populations, and species. Despite a surge in studies on DNA methylation, we know little about the importance of DNA methylation in population differentiation and speciation. Here we investigate the regulatory and evolutionary impact of DNA methylation in five tissues of two Ficedula flycatcher species and their naturally occurring F1 hybrids. RESULTS We show that the density of CpG in the promoters of genes determines the strength of the association between DNA methylation and gene expression. The impact of DNA methylation on gene expression varies among tissues with the brain showing unique patterns. Differentially expressed genes between parental species are predicted by genetic and methylation differentiation in CpG-rich promoters. However, both these factors fail to predict hybrid misexpression suggesting that promoter mismethylation is not a main determinant of hybrid misexpression in Ficedula flycatchers. Using allele-specific methylation estimates in hybrids, we also determine the genome-wide contribution of cis- and trans effects in DNA methylation differentiation. These distinct mechanisms are roughly balanced in all tissues except the brain, where trans differences predominate. CONCLUSIONS Overall, this study provides insight on the regulatory and evolutionary impact of DNA methylation in songbirds.
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Affiliation(s)
- Jesper Boman
- Department of Ecology and Genetics (IEG), Division of Evolutionary Biology, Uppsala University, Norbyvägen 18D, Uppsala, SE-752 36, Sweden.
| | - Anna Qvarnström
- Department of Ecology and Genetics (IEG), Division of Animal Ecology, Uppsala University, Norbyvägen 18D, Uppsala, SE-752 36, Sweden
| | - Carina F Mugal
- Department of Ecology and Genetics (IEG), Division of Evolutionary Biology, Uppsala University, Norbyvägen 18D, Uppsala, SE-752 36, Sweden.
- CNRS, Laboratory of Biometry and Evolutionary Biology (LBBE), UMR 5558, University of Lyon 1, Villeurbanne, France.
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6
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Hanski E, Joseph S, Raulo A, Wanelik KM, O'Toole Á, Knowles SCL, Little TJ. Epigenetic age estimation of wild mice using faecal samples. Mol Ecol 2024; 33:e17330. [PMID: 38561950 DOI: 10.1111/mec.17330] [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: 10/16/2023] [Revised: 02/19/2024] [Accepted: 03/01/2024] [Indexed: 04/04/2024]
Abstract
Age is a key parameter in population ecology, with a myriad of biological processes changing with age as organisms develop in early life then later senesce. As age is often hard to accurately measure with non-lethal methods, epigenetic methods of age estimation (epigenetic clocks) have become a popular tool in animal ecology and are often developed or calibrated using captive animals of known age. However, studies typically rely on invasive blood or tissue samples, which limit their application in more sensitive or elusive species. Moreover, few studies have directly assessed how methylation patterns and epigenetic age estimates compare across environmental contexts (e.g. captive or laboratory-based vs. wild animals). Here, we built a targeted epigenetic clock from laboratory house mice (strain C57BL/6, Mus musculus) using DNA from non-invasive faecal samples, and then used it to estimate age in a population of wild mice (Mus musculus domesticus) of unknown age. This laboratory mouse-derived epigenetic clock accurately predicted adult wild mice to be older than juveniles and showed that wild mice typically increased in epigenetic age over time, but with wide variation in epigenetic ageing rate among individuals. Our results also suggested that, for a given body mass, wild mice had higher methylation across targeted CpG sites than laboratory mice (and consistently higher epigenetic age estimates as a result), even among the smallest, juvenile mice. This suggests wild and laboratory mice may display different CpG methylation levels from very early in life and indicates caution is needed when developing epigenetic clocks on laboratory animals and applying them in the wild.
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Affiliation(s)
- Eveliina Hanski
- University of Oxford, Oxford, UK
- University of Helsinki, Helsinki, Finland
| | | | - Aura Raulo
- University of Oxford, Oxford, UK
- University of Turku, Turku, Finland
| | - Klara M Wanelik
- University of Oxford, Oxford, UK
- University of Surrey, Guildford, UK
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7
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Seebacher F, Little AG. Thyroid hormone links environmental signals to DNA methylation. Philos Trans R Soc Lond B Biol Sci 2024; 379:20220506. [PMID: 38310936 PMCID: PMC10838643 DOI: 10.1098/rstb.2022.0506] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 08/14/2023] [Indexed: 02/06/2024] Open
Abstract
Environmental conditions experienced within and across generations can impact individual phenotypes via so-called 'epigenetic' processes. Here we suggest that endocrine signalling acts as a 'sensor' linking environmental inputs to epigenetic modifications. We focus on thyroid hormone signalling and DNA methylation, but other mechanisms are likely to act in a similar manner. DNA methylation is one of the most important epigenetic mechanisms, which alters gene expression patterns by methylating cytosine bases via DNA methyltransferase enzymes. Thyroid hormone is mechanistically linked to DNA methylation, at least partly by regulating the activity of DNA methyltransferase 3a, which is the principal enzyme that mediates epigenetic responses to environmental change. Thyroid signalling is sensitive to natural and anthropogenic environmental impacts (e.g. light, temperature, endocrine-disrupting pollution), and here we propose that thyroid hormone acts as an environmental sensor to mediate epigenetic modifications. The nexus between thyroid hormone signalling and DNA methylation can integrate multiple environmental signals to modify phenotypes, and coordinate phenotypic plasticity at different time scales, such as within and across generations. These dynamics can have wide-ranging effects on health and fitness of animals, because they influence the time course of phenotypic adjustments and potentially the range of environmental stimuli that can elicit epigenetic responses. This article is part of the theme issue 'Endocrine responses to environmental variation: conceptual approaches and recent developments'.
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Affiliation(s)
- Frank Seebacher
- School of Life and Environmental Sciences A08, University of Sydney, New South Wales 2006, Australia
| | - Alexander G. Little
- Department of Biology, Life Sciences Building, McMaster University, Ontario, Canada L8S 4K1
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8
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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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9
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Stuart KC, Johnson RN, Major RE, Atsawawaranunt K, Ewart KM, Rollins LA, Santure AW, Whibley A. The genome of a globally invasive passerine, the common myna, Acridotheres tristis. DNA Res 2024; 31:dsae005. [PMID: 38366840 PMCID: PMC10917472 DOI: 10.1093/dnares/dsae005] [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: 08/24/2023] [Revised: 02/13/2024] [Accepted: 02/15/2024] [Indexed: 02/18/2024] Open
Abstract
In an era of global climate change, biodiversity conservation is receiving increased attention. Conservation efforts are greatly aided by genetic tools and approaches, which seek to understand patterns of genetic diversity and how they impact species health and their ability to persist under future climate regimes. Invasive species offer vital model systems in which to investigate questions regarding adaptive potential, with a particular focus on how changes in genetic diversity and effective population size interact with novel selection regimes. The common myna (Acridotheres tristis) is a globally invasive passerine and is an excellent model species for research both into the persistence of low-diversity populations and the mechanisms of biological invasion. To underpin research on the invasion genetics of this species, we present the genome assembly of the common myna. We describe the genomic landscape of this species, including genome wide allelic diversity, methylation, repeats, and recombination rate, as well as an examination of gene family evolution. Finally, we use demographic analysis to identify that some native regions underwent a dramatic population increase between the two most recent periods of glaciation, and reveal artefactual impacts of genetic bottlenecks on demographic analysis.
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Affiliation(s)
- Katarina C Stuart
- School of Biological Sciences, University of Auckland, Auckland, Aotearoa, New Zealand
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia
| | - Rebecca N Johnson
- National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
| | - Richard E Major
- Australian Museum Research Institute, Australian Museum, Sydney, Australia
| | | | - Kyle M Ewart
- Australian Museum Research Institute, Australian Museum, Sydney, Australia
- School of Life and Environmental Sciences,University of Sydney, Sydney, Australia
| | - Lee A Rollins
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia
| | - Anna W Santure
- School of Biological Sciences, University of Auckland, Auckland, Aotearoa, New Zealand
| | - Annabel Whibley
- School of Biological Sciences, University of Auckland, Auckland, Aotearoa, New Zealand
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10
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Tennenbaum SR, Bortner R, Lynch C, Santymire R, Crosier A, Santiestevan J, Marinari P, Pukazhenthi BS, Comizzoli P, Hawkins MTR, Maldonado JE, Koepfli K, vonHoldt BM, DeCandia AL. Epigenetic changes to gene pathways linked to male fertility in ex situ black-footed ferrets. Evol Appl 2024; 17:e13634. [PMID: 38283602 PMCID: PMC10818088 DOI: 10.1111/eva.13634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 12/06/2023] [Accepted: 12/07/2023] [Indexed: 01/30/2024] Open
Abstract
Environmental variation can influence the reproductive success of species managed under human care and in the wild, yet the mechanisms underlying this phenomenon remain largely mysterious. Molecular mechanisms such as epigenetic modifiers are important in mediating the timing and progression of reproduction in humans and model organisms, but few studies have linked epigenetic variation to reproductive fitness in wildlife. Here, we investigated epigenetic variation in black-footed ferrets (Mustela nigripes), an endangered North American mammal reliant on ex situ management for survival and persistence in the wild. Despite similar levels of genetic diversity in human-managed and wild-born populations, individuals in ex situ facilities exhibit reproductive problems, such as poor sperm quality. Differences across these settings suggest that an environmentally driven decline in reproductive capacity may be occurring in this species. We examined the role of DNA methylation, one well-studied epigenetic modifier, in this emergent condition. We leveraged blood, testes, and semen samples from male black-footed ferrets bred in ex situ facilities and found tissue-type specificity in DNA methylation across the genome, although 1360 Gene Ontology terms associated with male average litter size shared functions across tissues. We then constructed gene networks of differentially methylated genomic sites associated with three different reproductive phenotypes to explore the putative biological impact of variation in DNA methylation. Sperm gene networks associated with average litter size and sperm count were functionally enriched for candidate genes involved in reproduction, development, and its regulation through transcriptional repression. We propose that DNA methylation plays an important role in regulating these reproductive phenotypes, thereby impacting the fertility of male ex situ individuals. Our results provide information into how DNA methylation may function in the alteration of reproductive pathways and phenotypes in artificial environments. These findings provide early insights to conservation hurdles faced in the protection of this rare species.
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Affiliation(s)
| | - Robyn Bortner
- U.S. Fish & Wildlife Service National Black‐Footed Ferret Conservation CenterCarrColoradoUSA
| | | | - Rachel Santymire
- Biology DepartmentGeorgia State UniversityAtlantaGeorgiaUSA
- Center for Species SurvivalSmithsonian's National Zoo and Conservation Biology InstituteFront RoyalVirginiaUSA
| | - Adrienne Crosier
- Center for Animal Care SciencesSmithsonian's National Zoo & Conservation Biology InstituteFront RoyalVirginiaUSA
| | - Jenny Santiestevan
- Center for Species SurvivalSmithsonian's National Zoo and Conservation Biology InstituteFront RoyalVirginiaUSA
| | - Paul Marinari
- Center for Animal Care SciencesSmithsonian's National Zoo & Conservation Biology InstituteFront RoyalVirginiaUSA
| | - Budhan S. Pukazhenthi
- Center for Species SurvivalSmithsonian's National Zoo and Conservation Biology InstituteFront RoyalVirginiaUSA
| | - Pierre Comizzoli
- Center for Species SurvivalSmithsonian's National Zoo and Conservation Biology InstituteFront RoyalVirginiaUSA
| | - Melissa T. R. Hawkins
- Division of Mammals, Department of Vertebrate ZoologyNational Museum of Natural HistoryWashingtonDCUSA
| | - Jesús E. Maldonado
- Center for Conservation GenomicsSmithsonian's National Zoo and Conservation Biology InstituteWashingtonDCUSA
| | - Klaus‐Peter Koepfli
- Center for Species SurvivalSmithsonian's National Zoo and Conservation Biology InstituteFront RoyalVirginiaUSA
- Smithsonian‐Mason School of ConservationGeorge Mason UniversityFront RoyalVirginiaUSA
| | | | - Alexandra L. DeCandia
- Center for Conservation GenomicsSmithsonian's National Zoo and Conservation Biology InstituteWashingtonDCUSA
- BiologyGeorgetown UniversityWashingtonDCUSA
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11
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Le Clercq LS, Kotzé A, Grobler JP, Dalton DL. Biological clocks as age estimation markers in animals: a systematic review and meta-analysis. Biol Rev Camb Philos Soc 2023; 98:1972-2011. [PMID: 37356823 DOI: 10.1111/brv.12992] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 06/04/2023] [Accepted: 06/08/2023] [Indexed: 06/27/2023]
Abstract
Various biological attributes associated with individual fitness in animals change predictably over the lifespan of an organism. Therefore, the study of animal ecology and the work of conservationists frequently relies upon the ability to assign animals to functionally relevant age classes to model population fitness. Several approaches have been applied to determining individual age and, while these methods have proved useful, they are not without limitations and often lack standardisation or are only applicable to specific species. For these reasons, scientists have explored the potential use of biological clocks towards creating a universal age-determination method. Two biological clocks, tooth layer annulation and otolith layering have found universal appeal. Both methods are highly invasive and most appropriate for post-mortem age-at-death estimation. More recently, attributes of cellular ageing previously explored in humans have been adapted to studying ageing in animals for the use of less-invasive molecular methods for determining age. Here, we review two such methods, assessment of methylation and telomere length, describing (i) what they are, (ii) how they change with age, and providing (iii) a summary and meta-analysis of studies that have explored their utility in animal age determination. We found that both attributes have been studied across multiple vertebrate classes, however, telomere studies were used before methylation studies and telomere length has been modelled in nearly twice as many studies. Telomere length studies included in the review often related changes to stress responses and illustrated that telomere length is sensitive to environmental and social stressors and, in the absence of repair mechanisms such as telomerase or alternative lengthening modes, lacks the ability to recover. Methylation studies, however, while also detecting sensitivity to stressors and toxins, illustrated the ability to recover from such stresses after a period of accelerated ageing, likely due to constitutive expression or reactivation of repair enzymes such as DNA methyl transferases. We also found that both studied attributes have parentally heritable features, but the mode of inheritance differs among taxa and may relate to heterogamy. Our meta-analysis included more than 40 species in common for methylation and telomere length, although both analyses included at least 60 age-estimation models. We found that methylation outperforms telomere length in terms of predictive power evidenced from effect sizes (more than double that observed for telomeres) and smaller prediction intervals. Both methods produced age correlation models using similar sample sizes and were able to classify individuals into young, middle, or old age classes with high accuracy. Our review and meta-analysis illustrate that both methods are well suited to studying age in animals and do not suffer significantly from variation due to differences in the lifespan of the species, genome size, karyotype, or tissue type but rather that quantitative method, patterns of inheritance, and environmental factors should be the main considerations. Thus, provided that complex factors affecting the measured trait can be accounted for, both methylation and telomere length are promising targets to develop as biomarkers for age determination in animals.
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Affiliation(s)
- Louis-Stéphane Le Clercq
- South African National Biodiversity Institute, P.O. Box 754, Pretoria, 0001, South Africa
- Department of Genetics, University of the Free State, P.O. Box 339, Bloemfontein, 9300, South Africa
| | - Antoinette Kotzé
- South African National Biodiversity Institute, P.O. Box 754, Pretoria, 0001, South Africa
- Department of Genetics, University of the Free State, P.O. Box 339, Bloemfontein, 9300, South Africa
| | - J Paul Grobler
- Department of Genetics, University of the Free State, P.O. Box 339, Bloemfontein, 9300, South Africa
| | - Desiré Lee Dalton
- School of Health and Life Sciences, Teesside University, Middlesbrough, TS1 3BA, UK
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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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13
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Kadalayil L, Alam MZ, White CH, Ghantous A, Walton E, Gruzieva O, Merid SK, Kumar A, Roy RP, Solomon O, Huen K, Eskenazi B, Rzehak P, Grote V, Langhendries JP, Verduci E, Ferre N, Gruszfeld D, Gao L, Guan W, Zeng X, Schisterman EF, Dou JF, Bakulski KM, Feinberg JI, Soomro MH, Pesce G, Baiz N, Isaevska E, Plusquin M, Vafeiadi M, Roumeliotaki T, Langie SAS, Standaert A, Allard C, Perron P, Bouchard L, van Meel ER, Felix JF, Jaddoe VWV, Yousefi PD, Ramlau-Hansen CH, Relton CL, Tobi EW, Starling AP, Yang IV, Llambrich M, Santorelli G, Lepeule J, Salas LA, Bustamante M, Ewart SL, Zhang H, Karmaus W, Röder S, Zenclussen AC, Jin J, Nystad W, Page CM, Magnus M, Jima DD, Hoyo C, Maguire RL, Kvist T, Czamara D, Räikkönen K, Gong T, Ullemar V, Rifas-Shiman SL, Oken E, Almqvist C, Karlsson R, Lahti J, Murphy SK, Håberg SE, London S, Herberth G, Arshad H, Sunyer J, Grazuleviciene R, Dabelea D, Steegers-Theunissen RPM, Nohr EA, Sørensen TIA, Duijts L, Hivert MF, Nelen V, Popovic M, Kogevinas M, Nawrot TS, Herceg Z, Annesi-Maesano I, Fallin MD, Yeung E, Breton CV, Koletzko B, Holland N, Wiemels JL, Melén E, Sharp GC, Silver MJ, Rezwan FI, Holloway JW. Analysis of DNA methylation at birth and in childhood reveals changes associated with season of birth and latitude. Clin Epigenetics 2023; 15:148. [PMID: 37697338 PMCID: PMC10496224 DOI: 10.1186/s13148-023-01542-5] [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: 02/13/2023] [Accepted: 07/27/2023] [Indexed: 09/13/2023] Open
Abstract
BACKGROUND Seasonal variations in environmental exposures at birth or during gestation are associated with numerous adult traits and health outcomes later in life. Whether DNA methylation (DNAm) plays a role in the molecular mechanisms underlying the associations between birth season and lifelong phenotypes remains unclear. METHODS We carried out epigenome-wide meta-analyses within the Pregnancy And Childhood Epigenetic Consortium to identify associations of DNAm with birth season, both at differentially methylated probes (DMPs) and regions (DMRs). Associations were examined at two time points: at birth (21 cohorts, N = 9358) and in children aged 1-11 years (12 cohorts, N = 3610). We conducted meta-analyses to assess the impact of latitude on birth season-specific associations at both time points. RESULTS We identified associations between birth season and DNAm (False Discovery Rate-adjusted p values < 0.05) at two CpGs at birth (winter-born) and four in the childhood (summer-born) analyses when compared to children born in autumn. Furthermore, we identified twenty-six differentially methylated regions (DMR) at birth (winter-born: 8, spring-born: 15, summer-born: 3) and thirty-two in childhood (winter-born: 12, spring and summer: 10 each) meta-analyses with few overlapping DMRs between the birth seasons or the two time points. The DMRs were associated with genes of known functions in tumorigenesis, psychiatric/neurological disorders, inflammation, or immunity, amongst others. Latitude-stratified meta-analyses [higher (≥ 50°N), lower (< 50°N, northern hemisphere only)] revealed differences in associations between birth season and DNAm by birth latitude. DMR analysis implicated genes with previously reported links to schizophrenia (LAX1), skin disorders (PSORS1C, LTB4R), and airway inflammation including asthma (LTB4R), present only at birth in the higher latitudes (≥ 50°N). CONCLUSIONS In this large epigenome-wide meta-analysis study, we provide evidence for (i) associations between DNAm and season of birth that are unique for the seasons of the year (temporal effect) and (ii) latitude-dependent variations in the seasonal associations (spatial effect). DNAm could play a role in the molecular mechanisms underlying the effect of birth season on adult health outcomes.
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Affiliation(s)
- Latha Kadalayil
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, UK
| | - Md Zahangir Alam
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, UK
- Department of Computer Science and Engineering, Bangladesh University of Engineering and Technology, Dhaka, Bangladesh
| | - Cory Haley White
- Merck Exploratory Science Center in Cambridge MA, Merck Research Laboratories, Cambridge, MA, 02141, USA
| | - Akram Ghantous
- Epigenomics and Mechanisms Branch, International Agency for Research on Cancer, Lyon, France
| | - Esther Walton
- Department of Psychology, University of Bath, Bath, UK
| | - Olena Gruzieva
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
- Centre for Occupational and Environmental Medicine, Region Stockholm, Sweden
| | - Simon Kebede Merid
- Centre for Occupational and Environmental Medicine, Region Stockholm, Sweden
| | - Ashish Kumar
- Department of Clinical Science and Education, Södersjukhuset, Karolinska Institutet, Stockholm, Sweden
| | - Ritu P Roy
- Helen Diller Family Comprehensive Cancer Center University of California, San Francisco, CA, 94143, USA
- Computational Biology and Informatics Core, University of California, San Francisco, CA, 94143, USA
| | - Olivia Solomon
- Children's Environmental Health Laboratory, University of California, Berkeley, CA, USA
| | - Karen Huen
- Children's Environmental Health Laboratory, University of California, Berkeley, CA, USA
| | - Brenda Eskenazi
- Children's Environmental Health Laboratory, University of California, Berkeley, CA, USA
| | - Peter Rzehak
- Division of Metabolic and Nutritional Medicine, Dr. von Hauner Children's Hospital, Ludwig-Maximilians Universität München (LMU), Munich, Germany
| | - Veit Grote
- Division of Metabolic and Nutritional Medicine, Dr. von Hauner Children's Hospital, Ludwig-Maximilians Universität München (LMU), Munich, Germany
| | | | - Elvira Verduci
- Department of Pediatrics, Vittore Buzzi Children Hospital, University of Milan, Milan, Italy
| | - Natalia Ferre
- Pediatric Nutrition and Human Development Research Unit, Universitat Rovira i Virgili, IISPV, Reus, Spain
| | - Darek Gruszfeld
- Neonatal Department, Children's Memorial Health Institute, Warsaw, Poland
| | - Lu Gao
- Department of Preventive Medicine, University of Southern California, Los Angeles, CA, USA
| | - Weihua Guan
- Division of Biostatistics, School of Public Health, University of Minnesota, A460 Mayo Building, MMC 303, 420 Delaware St. SE, Minneapolis, MN, 55455, USA
| | | | - Enrique F Schisterman
- Department of Biostatistics, Epidemiology and Informatics, Perelman School of Medicine, University of Pennsylvania, 423 Guardian Drive, Philadelphia, PA, 19104, USA
| | - John F Dou
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, USA
| | - Kelly M Bakulski
- Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, USA
| | - Jason I Feinberg
- Wendy Klag Center for Autism and Developmental Disabilities Johns Hopkins University, Baltimore, MD, USA
- Department of Mental Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Munawar Hussain Soomro
- Sorbonne Université and INSERM, Epidemiology of Allergic and Respiratory Diseases Department, Pierre Louis Institute of Epidemiology and Public Health (IPLESP UMRS 1136), Saint-Antoine Medical School, Paris Cedex 12, France
- Department of Community Medicine and Public Health, SMBB Medical University, Larkana, Pakistan
| | - Giancarlo Pesce
- Sorbonne Université and INSERM, Epidemiology of Allergic and Respiratory Diseases Department, Pierre Louis Institute of Epidemiology and Public Health (IPLESP UMRS 1136), Saint-Antoine Medical School, Paris Cedex 12, France
| | - Nour Baiz
- Institut Desbrest de Santé Publique (IDESP), INSERM and Montpellier University, Montpellier, France
| | - Elena Isaevska
- Cancer Epidemiology Unit, Department of Medical Sciences, University of Turin, CPO Piemonte, Italy
| | - Michelle Plusquin
- Center for Environmental Sciences, University of Hasselt, 3590, Diepenbeek, Belgium
| | - Marina Vafeiadi
- Department of Social Medicine, School of Medicine, University of Crete, Heraklion, Greece
| | - Theano Roumeliotaki
- Department of Social Medicine, School of Medicine, University of Crete, Heraklion, Greece
| | - Sabine A S Langie
- Unit Health, Flemish Institute for Technological Research (VITO), Mol, Belgium
- Faculty of Sciences, Hasselt University, Diepenbeek, Belgium
- Department of Pharmacology and Toxicology, School for Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Limburg, The Netherlands
| | - Arnout Standaert
- Unit Health, Flemish Institute for Technological Research (VITO), Mol, Belgium
| | - Catherine Allard
- Centre de Recherche du Centre Hospitalier de l'Universite de Sherbrooke, Sherbrooke, Canada
| | - Patrice Perron
- Department of Medicine, Universite de Sherbrooke, Sherbrooke, Canada
| | - Luigi Bouchard
- Department of Biochemistry and Functional Genomics, Universite de Sherbrooke, Sherbrooke, Canada
- Clinical Department of Laboratory Medicine, Centre intégré universitaire de santé et de services sociaux (CIUSSS) du Saguenay-Lac-Saint-Jean - Hôpital de Chicoutimi, Chicoutimi, Canada
| | - Evelien R van Meel
- The Generation R Study Group, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
- Division of Respiratory Medicine and Allergology, Department of Pediatrics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Janine F Felix
- The Generation R Study Group, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
- Department of Pediatrics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Vincent W V Jaddoe
- The Generation R Study Group, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
- Department of Pediatrics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Paul D Yousefi
- Medical Research Council Integrative Epidemiology Unit, University of Bristol, Bristol, UK
- Population Health Science, Bristol Medical School, University of Bristol, Bristol, UK
| | | | - Caroline L Relton
- Medical Research Council Integrative Epidemiology Unit, University of Bristol, Bristol, UK
- Population Health Science, Bristol Medical School, University of Bristol, Bristol, UK
| | - Elmar W Tobi
- Periconceptional Epidemiology, Department of Obstetrics and Gynecology, Erasmus MC, University Medical Center, PO Box 2040, 3000 CA, Rotterdam, The Netherlands
| | - Anne P Starling
- Life Course Epidemiology of Adiposity and Diabetes (LEAD) Center, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Department of Epidemiology, Colorado School of Public Health, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Ivana V Yang
- Department of Epidemiology, Colorado School of Public Health, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Division of Biomedical Informatics and Personalized Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Center for Genes, Environment and Health, National Jewish Health, Denver, CO, USA
| | - Maria Llambrich
- Institute for Global Health (ISGlobal), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
- CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | | | - Johanna Lepeule
- Institute for Advanced Biosciences, University Grenoble-Alpes, INSERM, CNRS, Grenoble, France
| | - Lucas A Salas
- Institute for Global Health (ISGlobal), Barcelona, Spain
- Department of Epidemiology, Geisel School of Medicine, Dartmouth College, Lebanon, NH, USA
- Center for Molecular Epidemiology, Geisel School of Medicine, Dartmouth College, Lebanon, NH, USA
- Children's Environmental Health and Disease Prevention Research Center at Dartmouth, Lebanon, NH, USA
| | - Mariona Bustamante
- Institute for Global Health (ISGlobal), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
- CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - Susan L Ewart
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA
| | - Hongmei Zhang
- Division of Epidemiology, Biostatistics, and Environmental Health, School of Public Health, University of Memphis, Memphis, USA
| | - Wilfried Karmaus
- Division of Epidemiology, Biostatistics, and Environmental Health, School of Public Health, University of Memphis, Memphis, USA
| | - Stefan Röder
- Department of Environmental Immunology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Ana Claudia Zenclussen
- Department of Environmental Immunology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Jianping Jin
- 2530 Meridian Pkwy, Suite 200, Durham, NC 27713, USA
| | - Wenche Nystad
- Department of Chronic Diseases and Ageing, Norwegian Institute of Public Health, Oslo, Norway
| | - Christian M Page
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
- Section for Statistics and Data Science, Department of Mathematics, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Maria Magnus
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Dereje D Jima
- Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, USA
- Bioinformatics Research Center, North Carolina State University, Raleigh, NC, USA
| | - Cathrine Hoyo
- Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, USA
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, USA
| | - Rachel L Maguire
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, USA
- Department of Obstetrics and Gynaecology, Duke University Medical Center, Durham, NC, USA
| | - Tuomas Kvist
- Department of Psychology and Logopedics, University of Helsinki, Helsinki, Finland
| | - Darina Czamara
- Department of Translational Research in Psychiatry, Max-Planck-Institute of Psychiatry, 80804, Munich, Germany
| | - Katri Räikkönen
- Department of Psychology and Logopedics, University of Helsinki, Helsinki, Finland
| | - Tong Gong
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Vilhelmina Ullemar
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Sheryl L Rifas-Shiman
- Department of Population Medicine, Harvard Medical School, Harvard Pilgrim Health Care Institute, Boston, USA
| | - Emily Oken
- Department of Population Medicine, Harvard Medical School, Harvard Pilgrim Health Care Institute, Boston, USA
| | - Catarina Almqvist
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
- Pediatric Allergy and Pulmonology Unit at Astrid Lindgren Children's Hospital, Karolinska University Hospital, Stockholm, Sweden
| | - Robert Karlsson
- Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden
| | - Jari Lahti
- Department of Psychology and Logopedics, University of Helsinki, Helsinki, Finland
| | - Susan K Murphy
- Department of Obstetrics and Gynaecology, Duke University Medical Center, Durham, NC, USA
| | - Siri E Håberg
- Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Stephanie London
- Department of Health and Human Services, National Institute of Environmental Health Sciences, National Institutes of Health, RTP, NC, 27709, USA
| | - Gunda Herberth
- Department of Environmental Immunology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Hasan Arshad
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
- David Hide Asthma and Allergy Research Centre, Isle of Wight, UK
- NIHR Southampton Biomedical Research Centre, Southampton General Hospital, Southampton, UK
| | - Jordi Sunyer
- Institute for Global Health (ISGlobal), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
- CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - Regina Grazuleviciene
- Department of Environmental Science, Vytautas Magnus University, 44248, Kaunas, Lithuania
| | - Dana Dabelea
- Life Course Epidemiology of Adiposity and Diabetes (LEAD) Center, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Department of Epidemiology, Colorado School of Public Health, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Department of Pediatrics, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Régine P M Steegers-Theunissen
- Periconceptional Epidemiology, Department of Obstetrics and Gynecology, Erasmus MC, University Medical Center, PO Box 2040, 3000 CA, Rotterdam, The Netherlands
| | - Ellen A Nohr
- Department of Clinical Research, Odense Universitetshospital, Odense, Denmark
| | - Thorkild I A Sørensen
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department Public Health, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Liesbeth Duijts
- The Generation R Study Group, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
- Division of Respiratory Medicine and Allergology, Department of Pediatrics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
- Division of Neonatology, Department of Pediatrics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Marie-France Hivert
- Department of Population Medicine, Harvard Medical School, Harvard Pilgrim Health Care Institute, Boston, USA
- Diabetes Unit, Massachusetts General Hospital, Boston, MA, USA
| | - Vera Nelen
- Provincial Institute for Hygiene, Antwerp, Belgium
| | - Maja Popovic
- Cancer Epidemiology Unit, Department of Medical Sciences, University of Turin, CPO Piemonte, Italy
| | | | - Tim S Nawrot
- Center for Environmental Sciences, University of Hasselt, 3590, Diepenbeek, Belgium
- Department of Public Health and Primary Care, Leuven University, Louvain, Belgium
| | - Zdenko Herceg
- Epigenomics and Mechanisms Branch, International Agency for Research on Cancer, Lyon, France
| | - Isabella Annesi-Maesano
- Institut Desbrest de Santé Publique (IDESP), INSERM and Montpellier University, Montpellier, France
| | - M Daniele Fallin
- Wendy Klag Center for Autism and Developmental Disabilities Johns Hopkins University, Baltimore, MD, USA
- Department of Mental Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Edwina Yeung
- Epidemiology Branch, Division of Population Health Research, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, 6710B Rockledge Dr, MSC 7004, Bethesda, MD, USA
| | - Carrie V Breton
- Department of Preventive Medicine, University of Southern California, Los Angeles, CA, USA
| | - Berthold Koletzko
- Division of Metabolic and Nutritional Medicine, Dr. von Hauner Children's Hospital, Ludwig-Maximilians Universität München (LMU), Munich, Germany
| | - Nina Holland
- Children's Environmental Health Laboratory, CERCH, Berkeley Public Health, University of California, 2121 Berkeley Way #5216, Berkeley, CA, 94720, USA
| | - Joseph L Wiemels
- Center for Genetic Epidemiology, University of Southern California, Los Angeles, CA, 90033, USA
- Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA, 90033, USA
| | - Erik Melén
- Department of Clinical Science and Education, Södersjukhuset, Karolinska Institutet, Stockholm, Sweden
- Sachs' Children and Youth Hospital, Södersjukhuset, Stockholm, Sweden
| | - Gemma C Sharp
- Medical Research Council Integrative Epidemiology Unit, University of Bristol, Bristol, UK
- School of Psychology, University of Exeter, Exeter, UK
| | - Matt J Silver
- Medical Research Council Unit, The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, The Gambia
- Medical Research Council Unit, The Gambia at the London School of Hygiene and Tropical Medicine, London, UK
| | - Faisal I Rezwan
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, UK
- Department of Computer Science, Aberystwyth University, Aberystwyth, Ceredigion, UK
| | - John W Holloway
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, UK.
- NIHR Southampton Biomedical Research Centre, Southampton General Hospital, Southampton, UK.
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14
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Le Clercq LS, Bazzi G, Cecere JG, Gianfranceschi L, Grobler JP, Kotzé A, Rubolini D, Liedvogel M, Dalton DL. Time trees and clock genes: a systematic review and comparative analysis of contemporary avian migration genetics. Biol Rev Camb Philos Soc 2023; 98:1051-1080. [PMID: 36879518 DOI: 10.1111/brv.12943] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 02/16/2023] [Accepted: 02/20/2023] [Indexed: 03/08/2023]
Abstract
Timing is a crucial aspect for survival and reproduction in seasonal environments leading to carefully scheduled annual programs of migration in many species. But what are the exact mechanisms through which birds (class: Aves) can keep track of time, anticipate seasonal changes, and adapt their behaviour? One proposed mechanism regulating annual behaviour is the circadian clock, controlled by a highly conserved set of genes, collectively called 'clock genes' which are well established in controlling the daily rhythmicity of physiology and behaviour. Due to diverse migration patterns observed within and among species, in a seemingly endogenously programmed manner, the field of migration genetics has sought and tested several candidate genes within the clock circuitry that may underlie the observed differences in breeding and migration behaviour. Among others, length polymorphisms within genes such as Clock and Adcyap1 have been hypothesised to play a putative role, although association and fitness studies in various species have yielded mixed results. To contextualise the existing body of data, here we conducted a systematic review of all published studies relating polymorphisms in clock genes to seasonality in a phylogenetically and taxonomically informed manner. This was complemented by a standardised comparative re-analysis of candidate gene polymorphisms of 76 bird species, of which 58 are migrants and 18 are residents, along with population genetics analyses for 40 species with available allele data. We tested genetic diversity estimates, used Mantel tests for spatial genetic analyses, and evaluated relationships between candidate gene allele length and population averages for geographic range (breeding- and non-breeding latitude), migration distance, timing of migration, taxonomic relationships, and divergence times. Our combined analysis provided evidence (i) of a putative association between Clock gene variation and autumn migration as well as a putative association between Adcyap1 gene variation and spring migration in migratory species; (ii) that these candidate genes are not diagnostic markers to distinguish migratory from sedentary birds; and (iii) of correlated variability in both genes with divergence time, potentially reflecting ancestrally inherited genotypes rather than contemporary changes driven by selection. These findings highlight a tentative association between these candidate genes and migration attributes as well as genetic constraints on evolutionary adaptation.
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Affiliation(s)
- Louis-Stéphane Le Clercq
- South African National Biodiversity Institute, P.O. Box 754, Pretoria, 0001, South Africa
- Department of Genetics, University of the Free State, PO Box 339, Bloemfontein, 9300, South Africa
| | - Gaia Bazzi
- Area Avifauna Migratrice, Istituto Superiore per la Protezione e la Ricerca Ambientale, via Ca' Fornacetta 9, Ozzano Emilia (BO), I-40064, Italy
| | - Jacopo G Cecere
- Area Avifauna Migratrice, Istituto Superiore per la Protezione e la Ricerca Ambientale, via Ca' Fornacetta 9, Ozzano Emilia (BO), I-40064, Italy
| | - Luca Gianfranceschi
- Dipartimento di Bioscienze, Università degli Studi di Milano, via Celoria 26, Milan, I-20133, Italy
| | - Johannes Paul Grobler
- Department of Genetics, University of the Free State, PO Box 339, Bloemfontein, 9300, South Africa
| | - Antoinette Kotzé
- South African National Biodiversity Institute, P.O. Box 754, Pretoria, 0001, South Africa
- Department of Genetics, University of the Free State, PO Box 339, Bloemfontein, 9300, South Africa
| | - Diego Rubolini
- Dipartimento di Scienze e Politiche Ambientali, Università degli Studi di Milano, via Celoria 26, Milan, I-20133, Italy
- Istituto di Ricerca sulle Acque, IRSA-CNR, Via del Mulino 19, Brugherio (MB), I-20861, Italy
| | - Miriam Liedvogel
- Max Planck Research Group Behavioral Genomics, Max Planck Institute for Evolutionary Biology, Plön, 24306, Germany
- Institute of Avian Research, An der Vogelwarte 21, Wilhelmshaven, 26386, Germany
| | - Desiré Lee Dalton
- School of Health and Life Sciences, Teesside University, Middlesbrough, TS1 3BA, UK
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15
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Liu J, Xu Y, Wang Y, Zhang J, Fu Y, Liufu S, Jiang D, Pan J, Ouyang H, Huang Y, Tian Y, Shen X. The DNA methylation status of the serotonin metabolic pathway associated with reproductive inactivation induced by long-light exposure in Magang geese. BMC Genomics 2023; 24:355. [PMID: 37365488 DOI: 10.1186/s12864-023-09342-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 04/27/2023] [Indexed: 06/28/2023] Open
Abstract
BACKGROUND Domestic geese are seasonal breeders and have the lowest reproductive capacity among all poultry species. Magang geese is a topical short-day breeder, short photoperiod exposure stimulates its reproductive activity while long photoperiod inhibits. To explore epigenetic change that could influence reproductive activity, we performed whole genome bisulfite sequencing and transcriptome sequencing in the hypothalamus at three reproductive stages during long-light exposure in male Magang geese. RESULTS A total number of 10,602 differentially methylated regions (DMRs) were identified among three comparison groups. We observed that the vast majority of DMRs were enriched in intron regions. By integrating the BS-sequencing and RNA-seq data, the correlation between methylation changes of CG DMRs and expression changes of their associated genes was significant only for genes containing CG DMRs in their intron. A total of 278 DMR-associated DEGs were obtained among the three stages. KEGG analysis revealed that the DMR-associated DEGs were mainly involved in 11 pathways. Among them, the neuroactive ligand-receptor interaction pathway was significantly enriched in both two comparisons (RA vs.RD and RD vs.RI); the Wnt signaling pathway, apelin signaling pathway, melanogenesis, calcium signaling pathway, focal adhesion, and adherens junction were significantly enriched in the RA vs. RI comparison. In addition, the expression level of two serotonin-metabolic genes was significantly altered during reproductive axis inactivation by the methylation status of their promoter region (TPH2) and intron region (SLC18A2), respectively. These results were confirmed by Bisulfite sequencing PCR (BSP), pyrosequencing, and real-time qPCR, indicating that serotonin metabolic signaling may play a key role in decreasing the reproductive activity of Magang geese induced by long-light exposure. Furthermore, we performed a metabolomics approach to investigate the concentration of neurotransmitters among the three stages, and found that 5-HIAA, the last product of the serotonin metabolic pathway, was significantly decreased in the hypothalamus during RI. CONCLUSIONS Our study reveals that the methylation status of the serotonin metabolic pathway in the hypothalamus is associated with reproductive inactivation, and provided new insight into the effect of DNA methylation on the reproductive regulation of the hypothalamus in Magang geese.
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Affiliation(s)
- Jiaxin Liu
- College of Animal Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Yanglong Xu
- College of Animal Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Yushuai Wang
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, Guangdong, 510275, China
| | - Jinning Zhang
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, Guangdong, 510275, China
| | - Yuting Fu
- College of Animal Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Sui Liufu
- College of Animal Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Danli Jiang
- College of Animal Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Jianqiu Pan
- College of Animal Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Hongjia Ouyang
- College of Animal Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Yunmao Huang
- College of Animal Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China.
| | - Yunbo Tian
- College of Animal Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China.
| | - Xu Shen
- College of Animal Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China.
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16
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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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17
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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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18
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von Holdt BM, Kartzinel RY, van Oers K, Verhoeven KJF, Ouyang JQ. Changes in the rearing environment cause reorganization of molecular networks associated with DNA methylation. J Anim Ecol 2023; 92:648-664. [PMID: 36567635 DOI: 10.1111/1365-2656.13878] [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: 06/17/2022] [Accepted: 12/22/2022] [Indexed: 12/27/2022]
Abstract
Disentangling the interaction between the genetic basis and environmental context underlying phenotypic variation is critical for understanding organismal evolution. Environmental change, such as increased rates of urbanization, can induce shifts in phenotypic plasticity with some individuals adapting to city life while others are displaced. A key trait that can facilitate adaptation is the degree at which animals respond to stressors. This stress response, which includes elevation of baseline circulating concentrations of glucocorticoids, has a heritable component and exhibits intra- and inter-individual variation. However, the mechanisms behind this variability and whether they might be responsible for adaptation to different environments are not known. Variation in DNA methylation can be a potential mechanism that mediates environmental effects on the stress response, as early-life stressors increase glucocorticoid concentrations and change adult phenotype. We used an inter- and intra-environmental cross-foster experiment to analyse the contribution of DNA methylation to early-life phenotypic variation. We found that at hatching, urban house wren (Troglodytes aedon) offspring had higher methylation frequencies compared with their rural counterparts. We also observed age-related patterns in offspring methylation, indicating the developmental effects of the rearing environment on methylation. At fledgling, differential methylation analyses showed that cellular respiration genes were differentially methylated in broods of different origins and behavioural and metabolism genes were differentially methylated in broods of different rearing environments. Lastly, hyper-methylation of a single gene (CNTNAP2) is associated with decreased glucocorticoid levels and the rearing environment. These differential methylation patterns linked to a specific physiological phenotype suggest that DNA methylation may be a mechanism by which individuals adjust to novel environments during their lifespan. Characterizing genetic and environmental influences on methylation is critical for understanding the role of epigenetic mechanisms in evolutionary adaptation.
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Affiliation(s)
- Bridgett M von Holdt
- Ecology & Evolutionary Biology, Princeton University, Princeton, New Jersey, USA
| | - Rebecca Y Kartzinel
- Ecology & Evolutionary Biology, Brown University, Providence, Rhode Island, USA
| | - Kees van Oers
- Department of Animal Ecology, 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
| | - Jenny Q Ouyang
- Department of Biology, University of Nevada, Reno, Nevada, USA
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19
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Abstract
We organized this special issue to highlight new work and review recent advances at the cutting edge of 'wild quantitative genomics'. In this editorial, we will present some history of wild quantitative genetic and genomic studies, before discussing the main themes in the papers published in this special issue and highlighting the future outlook of this dynamic field.
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Affiliation(s)
- Susan E Johnston
- Institute of Ecology and Evolution, School of Biological Sciences, University of Edinburgh, Edinburgh, Edinburgh EH9 3FL, UK
| | - Nancy Chen
- Department of Biology, University of Rochester, Rochester, 14627, NY, USA
| | - Emily B Josephs
- Department of Plant Biology and Ecology, Evolution, and Behavior Program, Michigan State University, East Lansing, 48824, MI, USA
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20
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Functional genomic tools for emerging model species. Trends Ecol Evol 2022; 37:1104-1115. [PMID: 35914975 DOI: 10.1016/j.tree.2022.07.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 07/08/2022] [Accepted: 07/11/2022] [Indexed: 01/12/2023]
Abstract
Most studies in the field of ecology and evolution aiming to connect genotype to phenotype rarely validate identified loci using functional tools. Recent developments in RNA interference (RNAi) and clustered regularly interspaced palindromic repeats (CRISPR)-Cas genome editing have dramatically increased the feasibility of functional validation. However, these methods come with specific challenges when applied to emerging model organisms, including limited spatial control of gene silencing, low knock-in efficiencies, and low throughput of functional validation. Moreover, many functional studies to date do not recapitulate ecologically relevant variation, and this limits their scope for deeper insights into evolutionary processes. We therefore argue that increased use of gene editing by allelic replacement through homology-directed repair (HDR) would greatly benefit the field of ecology and evolution.
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21
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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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22
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The Mutagenic Consequences of DNA Methylation within and across Generations. EPIGENOMES 2022; 6:epigenomes6040033. [PMID: 36278679 PMCID: PMC9624357 DOI: 10.3390/epigenomes6040033] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 09/20/2022] [Accepted: 09/28/2022] [Indexed: 12/28/2022] Open
Abstract
DNA methylation is an epigenetic modification with wide-ranging consequences across the life of an organism. This modification can be stable, persisting through development despite changing environmental conditions. However, in other contexts, DNA methylation can also be flexible, underlying organismal phenotypic plasticity. One underappreciated aspect of DNA methylation is that it is a potent mutagen; methylated cytosines mutate at a much faster rate than other genetic motifs. This mutagenic property of DNA methylation has been largely ignored in eco-evolutionary literature, despite its prevalence. Here, we explore how DNA methylation induced by environmental and other factors could promote mutation and lead to evolutionary change at a more rapid rate and in a more directed manner than through stochastic genetic mutations alone. We argue for future research on the evolutionary implications of DNA methylation driven mutations both within the lifetime of organisms, as well as across timescales.
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23
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Liu J, Dai S, Shao X, Wei C, Dai Z, Yang P, Lei M, Chen R, Zhu H. Spexin mRNA profile and its response to different photoperiods in Chinese Yangzhou geese (Anas cygnoides). Front Vet Sci 2022; 9:961431. [PMID: 36118333 PMCID: PMC9479540 DOI: 10.3389/fvets.2022.961431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Accepted: 07/29/2022] [Indexed: 11/14/2022] Open
Abstract
Spexin (SPX, NPQ), a novel neuropeptide composed of 14 amino acid residues, is evolutionarily conserved among different species. Spexin has been suggested to have pleiotropic functions in mammals. However, reports on spexin in birds are limited. To clarify the role of spexin in goose reproduction, the spexin gene was cloned and analyzed. Analysis of tissue distribution by RT-PCR showed that the expression of spexin and its two receptors was widespread. During the long photoperiod, the expression levels of spexin in the pituitary and hypothalamus and of GALR2/3 in the pituitary decreased, and the GnRH, LHβ, and FSHβ expression levels increased significantly. This suggests that a long photoperiod regulates reproductive activities by activating the gonadotrope-axis, which is modulated by decreased spexin levels.
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Affiliation(s)
- Jie Liu
- Key Laboratory of Crop and Livestock Integration, Ministry of Agriculture, Nanjing, China
- Institute of Animal Science, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Shudi Dai
- School of Life Science, Jiangsu University, Zhenjiang, China
| | - Xibing Shao
- Anhui Tianzhi-jiao Goose Industry Co., Ltd., Chuzhou, China
| | - Chuankun Wei
- Anhui Tianzhi-jiao Goose Industry Co., Ltd., Chuzhou, China
| | - Zichun Dai
- Key Laboratory of Crop and Livestock Integration, Ministry of Agriculture, Nanjing, China
- Institute of Animal Science, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Pengxia Yang
- Key Laboratory of Crop and Livestock Integration, Ministry of Agriculture, Nanjing, China
- Institute of Animal Science, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Mingming Lei
- Key Laboratory of Crop and Livestock Integration, Ministry of Agriculture, Nanjing, China
- Institute of Animal Science, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Rong Chen
- Key Laboratory of Crop and Livestock Integration, Ministry of Agriculture, Nanjing, China
- Institute of Animal Science, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Huanxi Zhu
- Key Laboratory of Crop and Livestock Integration, Ministry of Agriculture, Nanjing, China
- Institute of Animal Science, Jiangsu Academy of Agricultural Sciences, Nanjing, China
- *Correspondence: Huanxi Zhu
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24
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Aubry LM, Williams CT. Vertebrate Phenological Plasticity: from Molecular Mechanisms to Ecological and Evolutionary Implications. Integr Comp Biol 2022; 62:958-971. [PMID: 35867980 DOI: 10.1093/icb/icac121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 03/28/2022] [Accepted: 04/04/2022] [Indexed: 11/12/2022] Open
Abstract
Seasonal variation in the availability of essential resources is one of the most important drivers of natural selection on the phasing and duration of annually recurring life-cycle events. Shifts in seasonal timing are among the most commonly reported responses to climate change and the capacity of organisms to adjust their timing, either through phenotypic plasticity or evolution, is a critical component of resilience. Despite growing interest in documenting and forecasting the impacts of climate change on phenology, our ability to predict how individuals, populations, and species might alter their seasonal timing in response to their changing environments is constrained by limited knowledge regarding the cues animals use to adjust timing, the endogenous genetic and molecular mechanisms that transduce cues into neural and endocrine signals, and the inherent capacity of animals to alter their timing and phasing within annual cycles. Further, the fitness consequences of phenological responses are often due to biotic interactions within and across trophic levels, rather than being simple outcomes of responses to changes in the abiotic environment. Here, we review the current state of knowledge regarding the mechanisms that control seasonal timing in vertebrates, as well as the ecological and evolutionary consequences of individual, population, and species-level variation in phenological responsiveness. Understanding the causes and consequences of climate-driven phenological shifts requires combining ecological, evolutionary, and mechanistic approaches at individual, populational, and community scales. Thus, to make progress in forecasting phenological responses and demographic consequences, we need to further develop interdisciplinary networks focused on climate change science.
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Affiliation(s)
- Lise M Aubry
- Department of Fish, Wildlife, and Conservation Biology, Colorado State University, 1474 Campus Delivery, Fort Collins, CO, 80523, USA
| | - Cory T Williams
- Department of Biology, Colorado State University, 1878 Campus Delivery Fort Collins, CO 80523, USA
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25
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Harrison MC, Dohmen E, George S, Sillam-Dussès D, Séité S, Vasseur-Cognet M. Complex regulatory role of DNA methylation in caste- and age-specific expression of a termite. Open Biol 2022; 12:220047. [PMID: 35857972 PMCID: PMC9256085 DOI: 10.1098/rsob.220047] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The reproductive castes of eusocial insects are often characterized by extreme lifespans and reproductive output, indicating an absence of the fecundity/longevity trade-off. The role of DNA methylation in the regulation of caste- and age-specific gene expression in eusocial insects is controversial. While some studies find a clear link to caste formation in honeybees and ants, others find no correlation when replication is increased across independent colonies. Although recent studies have identified transcription patterns involved in the maintenance of high reproduction throughout the long lives of queens, the role of DNA methylation in the regulation of these genes is unknown. We carried out a comparative analysis of DNA methylation in the regulation of caste-specific transcription and its importance for the regulation of fertility and longevity in queens of the higher termite Macrotermes natalensis. We found evidence for significant, well-regulated changes in DNA methylation in mature compared to young queens, especially in several genes related to ageing and fecundity in mature queens. We also found a strong link between methylation and caste-specific alternative splicing. This study reveals a complex regulatory role of fat body DNA methylation both in the division of labour in termites, and during the reproductive maturation of queens.
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Affiliation(s)
- Mark C. Harrison
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | - Elias Dohmen
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | | | - David Sillam-Dussès
- University Sorbonne Paris Nord, Laboratory of Experimental and Comparative Ethology (LEEC), UR4443, Villetaneuse, France
| | - Sarah Séité
- UMR IRD 242, UPEC, CNRS 7618, UPMC 113, INRAE 1392, Institute of Ecology and Environmental Sciences of Paris, Paris 7 113, Bondy, France,University of Paris-Est, Créteil, France
| | - Mireille Vasseur-Cognet
- UMR IRD 242, UPEC, CNRS 7618, UPMC 113, INRAE 1392, Institute of Ecology and Environmental Sciences of Paris, Paris 7 113, Bondy, France,University of Paris-Est, Créteil, France,INSERM, Paris, France
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26
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Lamka GF, Harder AM, Sundaram M, Schwartz TS, Christie MR, DeWoody JA, Willoughby JR. Epigenetics in Ecology, Evolution, and Conservation. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.871791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Epigenetic variation is often characterized by modifications to DNA that do not alter the underlying nucleotide sequence, but can influence behavior, morphology, and physiological phenotypes by affecting gene expression and protein synthesis. In this review, we consider how the emerging field of ecological epigenetics (eco-epi) aims to use epigenetic variation to explain ecologically relevant phenotypic variation and predict evolutionary trajectories that are important in conservation. Here, we focus on how epigenetic data have contributed to our understanding of wild populations, including plants, animals, and fungi. First, we identified published eco-epi literature and found that there was limited taxonomic and ecosystem coverage and that, by necessity of available technology, these studies have most often focused on the summarized epigenome rather than locus- or nucleotide-level epigenome characteristics. We also found that while many studies focused on adaptation and heritability of the epigenome, the field has thematically expanded into topics such as disease ecology and epigenome-based ageing of individuals. In the second part of our synthesis, we discuss key insights that have emerged from the epigenetic field broadly and use these to preview the path toward integration of epigenetics into ecology. Specifically, we suggest moving focus to nucleotide-level differences in the epigenome rather than whole-epigenome data and that we incorporate several facets of epigenome characterization (e.g., methylation, chromatin structure). Finally, we also suggest that incorporation of behavior and stress data will be critical to the process of fully integrating eco-epi data into ecology, conservation, and evolutionary biology.
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Hibernation slows epigenetic ageing in yellow-bellied marmots. Nat Ecol Evol 2022; 6:418-426. [PMID: 35256811 PMCID: PMC8986532 DOI: 10.1038/s41559-022-01679-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 01/20/2022] [Indexed: 01/02/2023]
Abstract
Species that hibernate generally live longer than would be expected based solely on their body size. Hibernation is characterized by long periods of metabolic suppression (torpor) interspersed by short periods of increased metabolism (arousal). The torpor–arousal cycles occur multiple times during hibernation, and it has been suggested that processes controlling the transition between torpor and arousal states cause ageing suppression. Metabolic rate is also a known correlate of longevity; we thus proposed the ‘hibernation–ageing hypothesis’ whereby ageing is suspended during hibernation. We tested this hypothesis in a well-studied population of yellow-bellied marmots (Marmota flaviventer), which spend 7–8 months per year hibernating. We used two approaches to estimate epigenetic age: the epigenetic clock and the epigenetic pacemaker. Variation in epigenetic age of 149 samples collected throughout the life of 73 females was modelled using generalized additive mixed models (GAMM), where season (cyclic cubic spline) and chronological age (cubic spline) were fixed effects. As expected, the GAMM using epigenetic ages calculated from the epigenetic pacemaker was better able to detect nonlinear patterns in epigenetic ageing over time. We observed a logarithmic curve of epigenetic age with time, where the epigenetic age increased at a higher rate until females reached sexual maturity (two years old). With respect to circannual patterns, the epigenetic age increased during the active season and essentially stalled during the hibernation period. Taken together, our results are consistent with the hibernation–ageing hypothesis and may explain the enhanced longevity in hibernators. Species that hibernate generally have longer lifespans than expected based on their body size. The authors show epigenetic ageing patterns from a natural population of hibernating yellow-bellied marmots consistent with the hypothesis that ageing is suspended during hibernation.
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Abstract
Epigenetic mechanisms such as DNA methylation, histone modifications and non-coding RNAs are increasingly targeted in studies of natural populations. Here, I review some of the insights gained from this research, examine some of the methods currently in use and discuss some of the challenges that researchers working on natural populations are likely to face when probing epigenetic mechanisms. While studies supporting the involvement of epigenetic mechanisms in generating phenotypic variation in natural populations are amassing, many of these studies are currently correlative in nature. Thus, while empirical data point to widespread contributions of epigenetic mechanisms in generating phenotypic variation, there are still concerns as to whether epigenetic variation is instead ultimately controlled by genetic variation. Disentangling these two sources of variation will be a key to resolving the debate about the importance of epigenetic mechanisms, and studies on natural populations that partition the relative contribution of genetic and epigenetic factors to phenotypic variation can play an important role in this debate.
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Affiliation(s)
- Arild Husby
- Evolutionary Biology, Department of Ecology and Genetics, Uppsala University, Norbyvägen 18D, SE-75236 Uppsala, Sweden.,Centre for Biodiversity Dynamics, Norwegian University for Science and Technology, Trondheim, Norway
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Caizergues AE, Le Luyer J, Grégoire A, Szulkin M, Senar J, Charmantier A, Perrier C. Epigenetics and the city: Non-parallel DNA methylation modifications across pairs of urban-forest Great tit populations. Evol Appl 2022; 15:149-165. [PMID: 35126653 PMCID: PMC8792475 DOI: 10.1111/eva.13334] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 11/23/2021] [Accepted: 12/01/2021] [Indexed: 12/18/2022] Open
Abstract
Identifying the molecular mechanisms involved in rapid adaptation to novel environments and determining their predictability are central questions in evolutionary biology and pressing issues due to rapid global changes. Complementary to genetic responses to selection, faster epigenetic variations such as modifications of DNA methylation may play a substantial role in rapid adaptation. In the context of rampant urbanization, joint examinations of genomic and epigenomic mechanisms are still lacking. Here, we investigated genomic (SNP) and epigenomic (CpG methylation) responses to urban life in a passerine bird, the Great tit (Parus major). To test whether urban evolution is predictable (i.e. parallel) or involves mostly nonparallel molecular processes among cities, we analysed both SNP and CpG methylation variations across three distinct pairs of city and forest Great tit populations in Europe. Our analyses reveal a polygenic response to urban life, with both many genes putatively under weak divergent selection and multiple differentially methylated regions (DMRs) between forest and city great tits. DMRs mainly overlapped transcription start sites and promotor regions, suggesting their importance in modulating gene expression. Both genomic and epigenomic outliers were found in genomic regions enriched for genes with biological functions related to the nervous system, immunity, or behavioural, hormonal and stress responses. Interestingly, comparisons across the three pairs of city-forest populations suggested little parallelism in both genetic and epigenetic responses. Our results confirm, at both the genetic and epigenetic levels, hypotheses of polygenic and largely nonparallel mechanisms of rapid adaptation in novel environments such as urbanized areas.
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Affiliation(s)
| | - Jeremy Le Luyer
- Ifremer, IRD, Institut Louis‐MalardéUniv Polynésie Française, EIOTaravaoFrench Polynesia
| | | | - Marta Szulkin
- Centre of New TechnologiesUniversity of WarsawWarsawPoland
| | | | | | - Charles Perrier
- CBGP, INRAe, CIRAD, IRD, Montpellier SupAgroUniv. MontpellierMontpellierFrance
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Lindner M, Gawehns F, Te Molder S, Visser ME, van Oers K, Laine VN. Performance of methods to detect genetic variants from bisulphite sequencing data in a non-model species. Mol Ecol Resour 2021; 22:834-846. [PMID: 34435438 PMCID: PMC9290141 DOI: 10.1111/1755-0998.13493] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 08/10/2021] [Accepted: 08/20/2021] [Indexed: 12/17/2022]
Abstract
The profiling of epigenetic marks like DNA methylation has become a central aspect of studies in evolution and ecology. Bisulphite sequencing is commonly used for assessing genome‐wide DNA methylation at single nucleotide resolution but these data can also provide information on genetic variants like single nucleotide polymorphisms (SNPs). However, bisulphite conversion causes unmethylated cytosines to appear as thymines, complicating the alignment and subsequent SNP calling. Several tools have been developed to overcome this challenge, but there is no independent evaluation of such tools for non‐model species, which often lack genomic references. Here, we used whole‐genome bisulphite sequencing (WGBS) data from four female great tits (Parus major) to evaluate the performance of seven tools for SNP calling from bisulphite sequencing data. We used SNPs from whole‐genome resequencing data of the same samples as baseline SNPs to assess common performance metrics like sensitivity, precision, and the number of true positive, false positive, and false negative SNPs for the full range of variant and genotype quality values. We found clear differences between the tools in either optimizing precision (bis‐snp), sensitivity (biscuit), or a compromise between both (all other tools). Overall, the choice of SNP caller strongly depends on which performance parameter should be maximized and whether ascertainment bias should be minimized to optimize downstream analysis, highlighting the need for studies that assess such differences.
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Affiliation(s)
- Melanie Lindner
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Fleur Gawehns
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Sebastiaan Te Molder
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Marcel E Visser
- 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
| | - Kees van Oers
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Veronika N Laine
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.,Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland
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Mäkinen H, van Oers K, Eeva T, Ruuskanen S. The effect of experimental lead pollution on DNA methylation in a wild bird population. Epigenetics 2021; 17:625-641. [PMID: 34369261 DOI: 10.1080/15592294.2021.1943863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Anthropogenic pollution is known to negatively influence an organism's physiology, behaviour, and fitness. Epigenetic regulation, such as DNA methylation, has been hypothesized as a potential mechanism to mediate such effects, yet studies in wild species are lacking. We first investigated the effects of early-life exposure to the heavy metal lead (Pb) on DNA methylation levels in a wild population of great tits (Parus major), by experimentally exposing nestlings to Pb at environmentally relevant levels. Secondly, we compared nestling DNA methylation from a population exposed to long-term heavy metal pollution (close to a copper smelter), where birds suffer from pollution-related decrease in food quality, and a control population. For both comparisons, the analysis of about one million CpGs covering most of the annotated genes revealed that pollution-related changes in DNA methylation were not genome wide, but enriched for genes underlying developmental processes. However, the results were not consistent when using binomial or beta binomial regression highlighting the difficulty of modelling variance in CpGs. Our study indicates that post-natal anthropogenic heavy metal exposure can affect methylation levels of development related genes in a wild bird population.
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Affiliation(s)
- Hannu Mäkinen
- Department of Biological and Environmental Sciences, University of Jyväskylä, Turku, Finland
| | - Kees van Oers
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Tapio Eeva
- Department of Biological and Environmental Sciences, University of Jyväskylä, Turku, Finland
| | - Suvi Ruuskanen
- Department of Biological and Environmental Sciences, University of Jyväskylä, Turku, Finland
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32
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Sepers B, Erven JAM, Gawehns F, Laine VN, van Oers K. Epigenetics and Early Life Stress: Experimental Brood Size Affects DNA Methylation in Great Tits (Parus major). Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.609061] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Early developmental conditions are known to have life-long effects on an individual’s behavior, physiology and fitness. In altricial birds, a majority of these conditions, such as the number of siblings and the amount of food provisioned, are controlled by the parents. This opens up the potential for parents to adjust the behavior and physiology of their offspring according to local post-natal circumstances. However, the mechanisms underlying such intergenerational regulation remain largely unknown. A mechanism often proposed to possibly explain how parental effects mediate consistent phenotypic change is DNA methylation. To investigate whether early life effects on offspring phenotypes are mediated by DNA methylation, we cross-fostered great tit (Parus major) nestlings and manipulated their brood size in a natural study population. We assessed genome-wide DNA methylation levels of CpG sites in erythrocyte DNA, using Reduced Representation Bisulfite Sequencing (RRBS). By comparing DNA methylation levels between biological siblings raised in enlarged and reduced broods and between biological siblings of control broods, we assessed which CpG sites were differentially methylated due to brood size. We found 32 differentially methylated sites (DMS) between siblings from enlarged and reduced broods, a larger number than in the comparison between siblings from control broods. A considerable number of these DMS were located in or near genes involved in development, growth, metabolism, behavior and cognition. Since the biological functions of these genes line up with previously found effects of brood size and food availability, it is likely that the nestlings in the enlarged broods suffered from nutritional stress. We therefore conclude that early life stress might directly affect epigenetic regulation of genes related to early life conditions. Future studies should link such experimentally induced DNA methylation changes to expression of phenotypic traits and assess whether these effects affect parental fitness to determine if such changes are also adaptive.
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Lindner M, Laine VN, Verhagen I, Viitaniemi HM, Visser ME, van Oers K, Husby A. Rapid changes in DNA methylation associated with the initiation of reproduction in a small songbird. Mol Ecol 2021; 30:3645-3659. [PMID: 33453134 PMCID: PMC8359384 DOI: 10.1111/mec.15803] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 12/06/2020] [Accepted: 01/07/2021] [Indexed: 12/12/2022]
Abstract
Species with a circannual life cycle need to match the timing of their life history events to the environment to maximize fitness. However, our understanding of how circannual traits such as timing of reproduction are regulated on a molecular level remains limited. Recent studies have implicated that epigenetic mechanisms can be an important part in the processes that regulate circannual traits. Here, we explore the role of DNA methylation in mediating reproductive timing in a seasonally breeding bird species, the great tit (Parus major), using genome‐wide DNA methylation data from individual females that were blood sampled repeatedly throughout the breeding season. We demonstrate rapid and directional changes in DNA methylation within the promoter region of several genes, including a key transcription factor (NR5A1) known from earlier studies to be involved in the initiation of timing of reproduction. Interestingly, the observed changes in DNA methylation at NR5A1 identified here are in line with earlier gene expression studies of reproduction in chicken, indicating that the observed shifts in DNA methylation at this gene can have a regulatory role. Our findings provide an important step towards elucidating the genomic mechanism that mediates seasonal timing of a key life history traits and provide support for the idea that epigenetic mechanisms may play an important role in circannual traits. see also the Perspective by Melanie J. Heckwolf and Britta S. Meyer
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Affiliation(s)
- 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
| | - Veronika N Laine
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands.,Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland
| | - Irene Verhagen
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Heidi M Viitaniemi
- Organismal and Evolutionary Biology Research Programme (OEB), University of Helsinki, Helsinki, Finland
| | - Marcel E Visser
- 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
| | - Kees van Oers
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Arild Husby
- Organismal and Evolutionary Biology Research Programme (OEB), University of Helsinki, Helsinki, Finland.,Centre for Biodiversity Dynamics, NTNU, Trondheim, Norway.,Evolutionary Biology, Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
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Lindner M, Verhagen I, Viitaniemi HM, Laine VN, Visser ME, Husby A, van Oers K. Temporal changes in DNA methylation and RNA expression in a small song bird: within- and between-tissue comparisons. BMC Genomics 2021; 22:36. [PMID: 33413102 PMCID: PMC7792223 DOI: 10.1186/s12864-020-07329-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 12/15/2020] [Indexed: 12/25/2022] Open
Abstract
Background DNA methylation is likely a key mechanism regulating changes in gene transcription in traits that show temporal fluctuations in response to environmental conditions. To understand the transcriptional role of DNA methylation we need simultaneous within-individual assessment of methylation changes and gene expression changes over time. Within-individual repeated sampling of tissues, which are essential for trait expression is, however, unfeasible (e.g. specific brain regions, liver and ovary for reproductive timing). Here, we explore to what extend between-individual changes in DNA methylation in a tissue accessible for repeated sampling (red blood cells (RBCs)) reflect such patterns in a tissue unavailable for repeated sampling (liver) and how these DNA methylation patterns are associated with gene expression in such inaccessible tissues (hypothalamus, ovary and liver). For this, 18 great tit (Parus major) females were sacrificed at three time points (n = 6 per time point) throughout the pre-laying and egg-laying period and their blood, hypothalamus, ovary and liver were sampled. Results We simultaneously assessed DNA methylation changes (via reduced representation bisulfite sequencing) and changes in gene expression (via RNA-seq and qPCR) over time. In general, we found a positive correlation between changes in CpG site methylation in RBCs and liver across timepoints. For CpG sites in close proximity to the transcription start site, an increase in RBC methylation over time was associated with a decrease in the expression of the associated gene in the ovary. In contrast, no such association with gene expression was found for CpG site methylation within the gene body or the 10 kb up- and downstream regions adjacent to the gene body. Conclusion Temporal changes in DNA methylation are largely tissue-general, indicating that changes in RBC methylation can reflect changes in DNA methylation in other, often less accessible, tissues such as the liver in our case. However, associations between temporal changes in DNA methylation with changes in gene expression are mostly tissue- and genomic location-dependent. The observation that temporal changes in DNA methylation within RBCs can relate to changes in gene expression in less accessible tissues is important for a better understanding of how environmental conditions shape traits that temporally change in expression in wild populations. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-020-07329-9.
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Affiliation(s)
- Melanie Lindner
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, Wageningen, 6700, AB, The Netherlands. .,Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Groningen, The Netherlands.
| | - Irene Verhagen
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, Wageningen, 6700, AB, The Netherlands.,Wageningen University & Research, Wageningen, The Netherlands
| | - Heidi M Viitaniemi
- Organismal and Evolutionary Biology Research Programme, University of Helsinki, Helsinki, Finland.,Institute of Vertebrate Biology, Czech Academy of Sciences, Prague, Czech Republic.,Department of Biology, University of Turku, Turku, Finland
| | - Veronika N Laine
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, Wageningen, 6700, AB, The Netherlands.,Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland
| | - Marcel E Visser
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, Wageningen, 6700, AB, The Netherlands.,Chronobiology Unit, Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Groningen, The Netherlands
| | - Arild Husby
- Organismal and Evolutionary Biology Research Programme, University of Helsinki, Helsinki, Finland.,Evolutionary Biology, Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden.,Department of Biology, NTNU, Centre for Biodiversity Dynamics, Trondheim, Norway
| | - Kees van Oers
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, Wageningen, 6700, AB, The Netherlands.
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Watson H, Powell D, Salmón P, Jacobs A, Isaksson C. Urbanization is associated with modifications in DNA methylation in a small passerine bird. Evol Appl 2021; 14:85-98. [PMID: 33519958 PMCID: PMC7819559 DOI: 10.1111/eva.13160] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 10/20/2020] [Accepted: 10/22/2020] [Indexed: 12/13/2022] Open
Abstract
Urbanization represents a fierce driver of phenotypic change, yet the molecular mechanisms underlying observed phenotypic patterns are poorly understood. Epigenetic changes are expected to facilitate more rapid adaption to changing or novel environments, such as our towns and cities, compared with slow changes in gene sequence. A comparison of liver and blood tissue from great tits Parus major originating from an urban and a forest site demonstrated that urbanization is associated with variation in genome-wide patterns of DNA methylation. Combining reduced representation bisulphite sequencing with transcriptome data, we revealed habitat differences in DNA methylation patterns that suggest a regulated and coordinated response to the urban environment. In the liver, genomic sites that were differentially methylated between urban- and forest-dwelling birds were over-represented in regulatory regions of the genome and more likely to occur in expressed genes. DNA methylation levels were also inversely correlated with gene expression at transcription start sites. Furthermore, differentially methylated CpG sites, in liver, were over-represented in pathways involved in (i) steroid biosynthesis, (ii) superoxide metabolism, (iii) secondary alcohol metabolism, (iv) chylomicron remodelling, (v) cholesterol transport, (vi) reactive oxygen species (ROS) metabolic process and (vii) epithelial cell proliferation. This corresponds with earlier studies identifying diet and exposure to ROS as two of the main drivers of divergence between organisms in urban and nonurban environments. Conversely, in blood, sites that were differentially methylated between urban- and forest-dwelling birds were under-represented in regulatory regions, more likely to occur in nonexpressed genes and not over-represented in specific biological pathways. It remains to be determined whether diverging patterns of DNA methylation represent adaptive evolutionary responses and whether the conclusions can be more widely attributed to urbanization.
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Affiliation(s)
- Hannah Watson
- Evolutionary Ecology, Biology DepartmentLund UniversityLundSweden
| | - Daniel Powell
- Evolutionary Ecology, Biology DepartmentLund UniversityLundSweden
- Global Change Ecology, School of Science, Technology and EngineeringUniversity of the Sunshine CoastSippy DownsQLDAustralia
| | - Pablo Salmón
- Institute of Biodiversity, Animal Health and Comparative MedicineUniversity of GlasgowGlasgowUK
| | - Arne Jacobs
- Institute of Biodiversity, Animal Health and Comparative MedicineUniversity of GlasgowGlasgowUK
- Department of Natural ResourcesCornell UniversityIthacaNYUSA
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McCaw BA, Stevenson TJ, Lancaster LT. Epigenetic Responses to Temperature and Climate. Integr Comp Biol 2020; 60:1469-1480. [PMID: 32470117 DOI: 10.1093/icb/icaa049] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Epigenetics represents a widely accepted set of mechanisms by which organisms respond to the environment by regulating phenotypic plasticity and life history transitions. Understanding the effects of environmental control on phenotypes and fitness, via epigenetic mechanisms, is essential for understanding the ability of organisms to rapidly adapt to environmental change. This review highlights the significance of environmental temperature on epigenetic control of phenotypic variation, with the aim of furthering our understanding of how epigenetics might help or hinder species' adaptation to climate change. It outlines how epigenetic modifications, including DNA methylation and histone/chromatin modification, (1) respond to temperature and regulate thermal stress responses in different kingdoms of life, (2) regulate temperature-dependent expression of key developmental processes, sex determination, and seasonal phenotypes, (3) facilitate transgenerational epigenetic inheritance of thermal adaptation, (4) adapt populations to local and global climate gradients, and finally (5) facilitate in biological invasions across climate regions. Although the evidence points towards a conserved role of epigenetics in responding to temperature change, there appears to be an element of temperature- and species-specificity in the specific effects of temperature change on epigenetic modifications and resulting phenotypic responses. The review identifies areas of future research in epigenetic responses to environmental temperature change.
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Affiliation(s)
- Beth A McCaw
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
| | - Tyler J Stevenson
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
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Husby A. On the Use of Blood Samples for Measuring DNA Methylation in Ecological Epigenetic Studies. Integr Comp Biol 2020; 60:1558-1566. [PMID: 32835371 PMCID: PMC7742428 DOI: 10.1093/icb/icaa123] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
There is increasing interest in understanding the potential for epigenetic factors to contribute to phenotypic diversity in evolutionary biology. One well studied epigenetic mechanism is DNA methylation, the addition of a methyl group to cytosines, which have the potential to alter gene expression depending on the genomic region in which it takes place. Obtaining information about DNA methylation at genome-wide scale has become straightforward with the use of bisulfite treatment in combination with reduced representation or whole-genome sequencing. While it is well recognized that methylation is tissue specific, a frequent limitation for many studies is that sampling-specific tissues may require sacrificing individuals, something which is generally undesirable and sometimes impossible. Instead, information about DNA methylation patterns in the blood is frequently used as a proxy tissue. This can obviously be problematic if methylation patterns in the blood do not reflect that in the relevant tissue. Understanding how, or if, DNA methylation in blood reflect DNA methylation patterns in other tissues is therefore of utmost importance if we are to make inferences about how observed differences in methylation or temporal changes in methylation can contribute to phenotypic variation. The aim of this review is to examine what we know about the potential for using blood samples in ecological epigenetic studies. I briefly outline some methods by which we can measure DNA methylation before I examine studies that have compared DNA methylation patterns across different tissues and, finally, examine how useful blood samples may be for ecological studies of DNA methylation. Ecological epigenetic studies are in their infancy, but it is paramount for the field to move forward to have detailed information about tissue and time dependence relationships in methylation to gain insights into if blood DNA methylation patterns can be a reliable bioindicator for changes in methylation that generate phenotypic variation in ecologically important traits.
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Affiliation(s)
- Arild Husby
- Evolutionary Biology, Department of Ecology and Genetics, Uppsala University, SE-75236 Uppsala, Sweden
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van Oers K, Sepers B, Sies W, Gawehns F, Verhoeven KJF, Laine VN. Epigenetics of Animal Personality: DNA Methylation Cannot Explain the Heritability of Exploratory Behavior in a Songbird. Integr Comp Biol 2020; 60:1517-1530. [PMID: 33031487 PMCID: PMC7742756 DOI: 10.1093/icb/icaa138] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The search for the hereditary mechanisms underlying quantitative traits traditionally focused on the identification of underlying genomic polymorphisms such as single-nucleotide polymorphisms. It has now become clear that epigenetic mechanisms, such as DNA methylation, can consistently alter gene expression over multiple generations. It is unclear, however, if and how DNA methylation can stably be transferred from one generation to the next and can thereby be a component of the heritable variation of a trait. In this study, we explore whether DNA methylation responds to phenotypic selection using whole-genome and genome-wide bisulfite approaches. We assessed differential erythrocyte DNA methylation patterns between extreme personality types in the Great Tit (Parus major). For this, we used individuals from a four-generation artificial bi-directional selection experiment and siblings from eight F2 inter-cross families. We find no differentially methylated sites when comparing the selected personality lines, providing no evidence for the so-called epialleles associated with exploratory behavior. Using a pair-wise sibling design in the F2 intercrosses, we show that the genome-wide DNA methylation profiles of individuals are mainly explained by family structure, indicating that the majority of variation in DNA methylation in CpG sites between individuals can be explained by genetic differences. Although we found some candidates explaining behavioral differences between F2 siblings, we could not confirm this with a whole-genome approach, thereby confirming the absence of epialleles in these F2 intercrosses. We conclude that while epigenetic variation may underlie phenotypic variation in behavioral traits, we were not able to find evidence that DNA methylation can explain heritable variation in personality traits in Great Tits.
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Affiliation(s)
- Kees van Oers
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, Wageningen, 6708 PB, The Netherlands
- Behavioural Ecology Group, Wageningen University & Research, Wageningen, P.O. Box 338, 6700 AH, the Netherlands
| | - Bernice Sepers
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, Wageningen, 6708 PB, The Netherlands
- Behavioural Ecology Group, Wageningen University & Research, Wageningen, P.O. Box 338, 6700 AH, the Netherlands
| | - William Sies
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, Wageningen, 6708 PB, The Netherlands
| | - Fleur Gawehns
- Bioinformatics Unit, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, Wageningen, 6708 PB, The Netherlands
| | - Koen J F Verhoeven
- Department of Terrestrial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, Wageningen, 6708 PB, The Netherlands
| | - Veronika N Laine
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Droevendaalsesteeg 10, Wageningen, 6708 PB, The Netherlands
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Höglund A, Henriksen R, Fogelholm J, Churcher AM, Guerrero-Bosagna CM, Martinez-Barrio A, Johnsson M, Jensen P, Wright D. The methylation landscape and its role in domestication and gene regulation in the chicken. Nat Ecol Evol 2020; 4:1713-1724. [PMID: 32958860 DOI: 10.1038/s41559-020-01310-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 08/26/2020] [Indexed: 01/06/2023]
Abstract
Domestication is one of the strongest examples of artificial selection and has produced some of the most extreme within-species phenotypic variation known. In the case of the chicken, it has been hypothesized that DNA methylation may play a mechanistic role in the domestication response. By inter-crossing wild-derived red junglefowl with domestic chickens, we mapped quantitative trait loci for hypothalamic methylation (methQTL), gene expression (eQTL) and behaviour. We find large, stable methylation differences, with 6,179 cis and 2,973 trans methQTL identified. Over 46% of the trans effects were genotypically controlled by five loci, mainly associated with increased methylation in the junglefowl genotype. In a third of eQTL, we find that there is a correlation between gene expression and methylation, while statistical causality analysis reveals multiple instances where methylation is driving gene expression, as well as the reverse. We also show that methylation is correlated with some aspects of behavioural variation in the inter-cross. In conclusion, our data suggest a role for methylation in the regulation of gene expression underlying the domesticated phenotype of the chicken.
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Affiliation(s)
- Andrey Höglund
- AVIAN Behavioural Genomics and Physiology Group, Linköping University, Linköping, Sweden
| | - Rie Henriksen
- AVIAN Behavioural Genomics and Physiology Group, Linköping University, Linköping, Sweden
| | - Jesper Fogelholm
- AVIAN Behavioural Genomics and Physiology Group, Linköping University, Linköping, Sweden
| | | | - Carlos M Guerrero-Bosagna
- AVIAN Behavioural Genomics and Physiology Group, Linköping University, Linköping, Sweden.,Evolutionary Biology Centrum, Dept of Organismal Biology, Uppsala University, Uppsala, Sweden
| | | | - Martin Johnsson
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, The University of Edinburgh, Edinburgh, UK.,Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Per Jensen
- AVIAN Behavioural Genomics and Physiology Group, Linköping University, Linköping, Sweden
| | - Dominic Wright
- AVIAN Behavioural Genomics and Physiology Group, Linköping University, Linköping, Sweden.
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40
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Tolla E, Stevenson TJ. Sex Differences and the Neuroendocrine Regulation of Seasonal Reproduction by Supplementary Environmental Cues. Integr Comp Biol 2020; 60:1506-1516. [PMID: 32869105 DOI: 10.1093/icb/icaa096] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Seasonal rhythms in reproduction are conserved across nature and optimize the timing of breeding to environmental conditions favorable for offspring and parent survival. The primary predictive cue for timing seasonal breeding is photoperiod. Supplementary cues, such as food availability, social signals, and temperature, fine-tune the timing of reproduction. Male and female animals show differences in the sensory detection, neural integration, and physiological responses to the same supplementary cue. The neuroendocrine regulation of sex-specific integration of predictive and supplementary cues is not well characterized. Recent findings indicate that epigenetic modifications underlie the organization of sex differences in the brain. It has also become apparent that deoxyribonucleic acid methylation and chromatin modifications play an important role in the regulation and timing of seasonal rhythms. This article will highlight evidence for sex-specific responses to supplementary cues using data collected from birds and mammals. We will then emphasize that supplementary cues are integrated in a sex-dependent manner due to the neuroendocrine differences established and maintained by the organizational and activational effects of reproductive sex hormones. We will then discuss how epigenetic processes involved in reproduction provide a novel link between early-life organizational effects in the brain and sex differences in the response to supplementary cues.
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Affiliation(s)
- Elisabetta Tolla
- Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, UK
| | - Tyler J Stevenson
- Institute of Biodiversity, Animal Health & Comparative Medicine, University of Glasgow, Glasgow, UK
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Laine VN, Verhagen I, Mateman AC, Pijl A, Williams TD, Gienapp P, van Oers K, Visser ME. Exploration of tissue-specific gene expression patterns underlying timing of breeding in contrasting temperature environments in a song bird. BMC Genomics 2019; 20:693. [PMID: 31477015 PMCID: PMC6720064 DOI: 10.1186/s12864-019-6043-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 08/19/2019] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Seasonal timing of breeding is a life history trait with major fitness consequences but the genetic basis of the physiological mechanism underlying it, and how gene expression is affected by date and temperature, is not well known. In order to study this, we measured patterns of gene expression over different time points in three different tissues of the hypothalamic-pituitary-gonadal-liver axis, and investigated specifically how temperature affects this axis during breeding. We studied female great tits (Parus major) from lines artificially selected for early and late timing of breeding that were housed in two contrasting temperature environments in climate-controlled aviaries. We collected hypothalamus, liver and ovary samples at three different time points (before and after onset of egg-laying). For each tissue, we sequenced whole transcriptomes of 12 pools (n = 3 females) to analyse gene expression. RESULTS Birds from the selection lines differed in expression especially for one gene with clear reproductive functions, zona pellucida glycoprotein 4 (ZP4), which has also been shown to be under selection in these lines. Genes were differentially expressed at different time points in all tissues and most of the differentially expressed genes between the two temperature treatments were found in the liver. We identified a set of hub genes from all the tissues which showed high association to hormonal functions, suggesting that they have a core function in timing of breeding. We also found ample differentially expressed genes with largely unknown functions in birds. CONCLUSIONS We found differentially expressed genes associated with selection line and temperature treatment. Interestingly, the latter mainly in the liver suggesting that temperature effects on egg-laying date may happen down-stream in the physiological pathway. These findings, as well as our datasets, will further the knowledge of the mechanisms of tissue-specific avian seasonality in the future.
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Affiliation(s)
- Veronika N. Laine
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, 6700 AB Wageningen, The Netherlands
| | - Irene Verhagen
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, 6700 AB Wageningen, The Netherlands
| | - A. Christa Mateman
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, 6700 AB Wageningen, The Netherlands
| | - Agata Pijl
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, 6700 AB Wageningen, The Netherlands
| | - Tony D. Williams
- Department of Biological Sciences, Simon Fraser University, Burnaby, Canada
| | - Phillip Gienapp
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, 6700 AB Wageningen, The Netherlands
| | - Kees van Oers
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, 6700 AB Wageningen, The Netherlands
| | - Marcel E. Visser
- Department of Animal Ecology, Netherlands Institute of Ecology (NIOO-KNAW), P.O. Box 50, 6700 AB Wageningen, The Netherlands
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Watson H, Salmón P, Isaksson C. Dynamic changes in DNA methylation during embryonic and postnatal development of an altricial wild bird. Ecol Evol 2019; 9:9580-9585. [PMID: 31534676 PMCID: PMC6745840 DOI: 10.1002/ece3.5480] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 06/18/2019] [Accepted: 06/25/2019] [Indexed: 12/12/2022] Open
Abstract
DNA methylation could shape phenotypic responses to environmental cues and underlie developmental plasticity. Environmentally induced changes in DNA methylation during development can give rise to stable phenotypic traits and thus affect fitness. In the laboratory, it has been shown that the vertebrate methylome undergoes dynamic reprogramming during development, creating a critical window for environmentally induced epigenetic modifications. Studies of DNA methylation in the wild are lacking, yet are essential for understanding how genes and the environment interact to affect phenotypic development and ultimately fitness. Furthermore, our knowledge of the establishment of methylation patterns during development in birds is limited. We quantified genome-wide DNA methylation at various stages of embryonic and postnatal development in an altricial passerine bird, the great tit Parus major. While, there was no change in global DNA methylation in embryonic tissue during the second half of embryonic development, a twofold increase in DNA methylation in blood occurred between 6 and 15 days posthatch. Though not directly comparable, DNA methylation levels were higher in the blood of nestlings compared with embryonic tissue at any stage of prenatal development. This provides the first evidence that DNA methylation undergoes global change during development in a wild bird, supporting the hypothesis that methylation mediates phenotypic development. Furthermore, the plasticity of DNA methylation demonstrated during late postnatal development, in the present study, suggests a wide window during which DNA methylation could be sensitive to environmental influences. This is particularly important for our understanding of the mechanisms by which early-life conditions influence later-life performance. While, we found no evidence for differences in genome-wide methylation in relation to habitat of origin, environmental variation is likely to be an important driver of variation in methylation at specific loci.
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Affiliation(s)
- Hannah Watson
- Evolutionary Ecology, Biology DepartmentLund UniversityLundSweden
| | - Pablo Salmón
- Institute of Biodiversity, Animal Health and Comparative MedicineUniversity of GlasgowGlasgowUK
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Trivedi AK, Sur S, Sharma A, Taufique ST, Gupta NJ, Kumar V. Temperature alters the hypothalamic transcription of photoperiod responsive genes in induction of seasonal response in migratory redheaded buntings. Mol Cell Endocrinol 2019; 493:110454. [PMID: 31121264 DOI: 10.1016/j.mce.2019.110454] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Revised: 05/13/2019] [Accepted: 05/19/2019] [Indexed: 12/12/2022]
Abstract
We investigated the temperature effects on hypothalamic transcription of genes involved in the induction of photoperiodic response in redheaded buntings. Birds were exposed at 22 and 38 °C to 13-h long photoperiods (LP), with controls at 22 °C on 8-h short photoperiods (SP). At 22 °C, compared to SP, we found higher tshb, eya3 and dio2 and low dio3 and gnih mRNA expressions after a week of LP; concomitant with testis recrudescence this confirmed buntings' responsiveness to LP-induced photostimulation. tshb, dio2 and gnrh mRNA levels were further increased by 2.5 weeks of LP at 38 °C. Temperature sensitive trpm8, but not trpv4, bdnf or adcyap1 also showed LP-induced expression at 22 °C. Concomitant changes in dnmt3b and tet2 mRNA expressions further suggested epigenetic modification of temperature influence on photoperiodic responses. These results demonstrate the role of temperature in hypothalamic molecular regulation of the photoperiodic gonadal response in seasonally breeding birds.
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Affiliation(s)
| | - Sayantan Sur
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Aakansha Sharma
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | | | - Neelu Jain Gupta
- Department of Zoology, University of Delhi, Delhi, 110007, India
| | - Vinod Kumar
- Department of Zoology, University of Delhi, Delhi, 110007, India.
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