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Bertucci-Richter EM, Shealy EP, Parrott BB. Epigenetic drift underlies epigenetic clock signals, but displays distinct responses to lifespan interventions, development, and cellular dedifferentiation. Aging (Albany NY) 2024; 16:1002-1020. [PMID: 38285616 PMCID: PMC10866415 DOI: 10.18632/aging.205503] [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: 08/03/2023] [Accepted: 12/01/2023] [Indexed: 01/31/2024]
Abstract
Changes in DNA methylation with age are observed across the tree of life. The stereotypical nature of these changes can be modeled to produce epigenetic clocks capable of predicting chronological age with unprecedented accuracy. Despite the predictive ability of epigenetic clocks and their utility as biomarkers in clinical applications, the underlying processes that produce clock signals are not fully resolved, which limits their interpretability. Here, we develop a computational approach to spatially resolve the within read variability or "disorder" in DNA methylation patterns and test if age-associated changes in DNA methylation disorder underlie signals comprising epigenetic clocks. We find that epigenetic clock loci are enriched in regions that both accumulate and lose disorder with age, suggesting a link between DNA methylation disorder and epigenetic clocks. We then develop epigenetic clocks that are based on regional disorder of DNA methylation patterns and compare their performance to other epigenetic clocks by investigating the influences of development, lifespan interventions, and cellular dedifferentiation. We identify common responses as well as critical differences between canonical epigenetic clocks and those based on regional disorder, demonstrating a fundamental decoupling of epigenetic aging processes. Collectively, we identify key linkages between epigenetic disorder and epigenetic clocks and demonstrate the multifaceted nature of epigenetic aging in which stochastic processes occurring at non-random loci produce predictable outcomes.
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Affiliation(s)
- Emily M. Bertucci-Richter
- Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802, USA
- Eugene P. Odum School of Ecology, University of Georgia, Athens, GA 30602, USA
| | - Ethan P. Shealy
- Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802, USA
- Eugene P. Odum School of Ecology, University of Georgia, Athens, GA 30602, USA
- Interdisciplinary Toxicology Program, University of Georgia, Athens, GA 30602, USA
| | - Benjamin B. Parrott
- Savannah River Ecology Laboratory, University of Georgia, Aiken, SC 29802, USA
- Eugene P. Odum School of Ecology, University of Georgia, Athens, GA 30602, USA
- Interdisciplinary Toxicology Program, University of Georgia, Athens, GA 30602, USA
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Mayne B, Espinoza T, Crook DA, Anderson C, Korbie D, Marshall JC, Kennard MJ, Harding DJ, Butler GL, Roberts B, Whiley J, Marshall S. Accurate, non-destructive, and high-throughput age estimation for Golden perch (Macquaria ambigua spp.) using DNA methylation. Sci Rep 2023; 13:9547. [PMID: 37308782 PMCID: PMC10260977 DOI: 10.1038/s41598-023-36773-2] [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: 10/26/2022] [Accepted: 06/09/2023] [Indexed: 06/14/2023] Open
Abstract
Age structure information of animal populations is fundamental to their conservation and management. In fisheries, age is routinely obtained by counting daily or annual increments in calcified structures (e.g., otoliths) which requires lethal sampling. Recently, DNA methylation has been shown to estimate age using DNA extracted from fin tissue without the need to kill the fish. In this study we used conserved known age-associated sites from the zebrafish (Danio rerio) genome to predict the age of golden perch (Macquaria ambigua), a large-bodied native fish from eastern Australia. Individuals aged using validated otolith techniques from across the species' distribution were used to calibrate three epigenetic clocks. One clock was calibrated using daily (daily clock) and another with annual (annual clock) otolith increment counts, respectively. A third used both daily and annual increments (universal clock). We found a high correlation between the otolith and epigenetic age (Pearson correlation > 0.94) across all clocks. The median absolute error was 2.4 days in the daily clock, 184.6 days in the annual clock, and 74.5 days in the universal clock. Our study demonstrates the emerging utility of epigenetic clocks as non-lethal and high-throughput tools for obtaining age estimates to support the management of fish populations and fisheries.
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Affiliation(s)
- Benjamin Mayne
- Environomics Future Science Platform, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Indian Ocean Marine Research Centre, Crawley, WA, Australia.
| | - Tom Espinoza
- Department of Regional Development, Manufacturing and Water, Brisbane, QLD, Australia
| | - David A Crook
- Department of Primary Industries, Narrandera Fisheries Centre, Narrandera, NSW, Australia
| | - Chloe Anderson
- Environomics Future Science Platform, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Indian Ocean Marine Research Centre, Crawley, WA, Australia
| | - Darren Korbie
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, Australia
| | - Jonathan C Marshall
- Queensland Department of Environment and Science, Brisbane, QLD, Australia
- Australian Rivers Institute and Griffith School of Environment and Science, Griffith University, Nathan, QLD, 4111, Australia
| | - Mark J Kennard
- Australian Rivers Institute and Griffith School of Environment and Science, Griffith University, Nathan, QLD, 4111, Australia
| | - Doug J Harding
- Department of Regional Development, Manufacturing and Water, Brisbane, QLD, Australia
| | - Gavin L Butler
- NSW Department of Primary Industries (Fisheries), Grafton, NSW, Australia
| | - Brien Roberts
- Fisheries Division, Department of Industry, Tourism and Trade, Darwin, NT, Australia
| | - Josh Whiley
- Australian Rivers Institute and Griffith School of Environment and Science, Griffith University, Nathan, QLD, 4111, Australia
| | - Sharon Marshall
- Department of Regional Development, Manufacturing and Water, Brisbane, QLD, Australia
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3
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Bock SL, Smaga CR, McCoy JA, Parrott BB. Genome-wide DNA methylation patterns harbour signatures of hatchling sex and past incubation temperature in a species with environmental sex determination. Mol Ecol 2022; 31:5487-5505. [PMID: 35997618 PMCID: PMC9826120 DOI: 10.1111/mec.16670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 08/15/2022] [Accepted: 08/18/2022] [Indexed: 01/11/2023]
Abstract
Conservation of thermally sensitive species depends on monitoring organismal and population-level responses to environmental change in real time. Epigenetic processes are increasingly recognized as key integrators of environmental conditions into developmentally plastic responses, and attendant epigenomic data sets hold potential for revealing cryptic phenotypes relevant to conservation efforts. Here, we demonstrate the utility of genome-wide DNA methylation (DNAm) patterns in the face of climate change for a group of especially vulnerable species, those with temperature-dependent sex determination (TSD). Due to their reliance on thermal cues during development to determine sexual fate, contemporary shifts in temperature are predicted to skew offspring sex ratios and ultimately destabilize sensitive populations. Using reduced-representation bisulphite sequencing, we profiled the DNA methylome in blood cells of hatchling American alligators (Alligator mississippiensis), a TSD species lacking reliable markers of sexual dimorphism in early life stages. We identified 120 sex-associated differentially methylated cytosines (DMCs; FDR < 0.1) in hatchlings incubated under a range of temperatures, as well as 707 unique temperature-associated DMCs. We further developed DNAm-based models capable of predicting hatchling sex with 100% accuracy (in 20 training samples and four test samples) and past incubation temperature with a mean absolute error of 1.2°C (in four test samples) based on the methylation status of 20 and 24 loci, respectively. Though largely independent of epigenomic patterning occurring in the embryonic gonad during TSD, DNAm patterns in blood cells may serve as nonlethal markers of hatchling sex and past incubation conditions in conservation applications. These findings also raise intriguing questions regarding tissue-specific epigenomic patterning in the context of developmental plasticity.
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Affiliation(s)
- Samantha L. Bock
- Eugene P. Odum School of EcologyUniversity of GeorgiaAthensGeorgiaUSA
- Savannah River Ecology LaboratoryAikenSouth CarolinaUSA
| | - Christopher R. Smaga
- Eugene P. Odum School of EcologyUniversity of GeorgiaAthensGeorgiaUSA
- Savannah River Ecology LaboratoryAikenSouth CarolinaUSA
| | - Jessica A. McCoy
- Department of BiologyCollege of CharlestonCharlestonSouth CarolinaUSA
| | - Benjamin B. Parrott
- Eugene P. Odum School of EcologyUniversity of GeorgiaAthensGeorgiaUSA
- Savannah River Ecology LaboratoryAikenSouth CarolinaUSA
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Gardner ST, Bertucci EM, Sutton R, Horcher A, Aubrey D, Parrott BB. Development of DNA methylation-based epigenetic age predictors in loblolly pine (Pinus taeda). Mol Ecol Resour 2022; 23:131-144. [PMID: 35957540 PMCID: PMC10087248 DOI: 10.1111/1755-0998.13698] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 08/01/2022] [Accepted: 08/03/2022] [Indexed: 11/27/2022]
Abstract
Biological aging is connected to life history variation across ecological scales and informs a basic understanding of age-related declines in organismal function. Altered DNA methylation dynamics are a conserved aspect of biological aging and have recently been modeled to predict chronological age among vertebrate species. In addition to their utility in estimating individual age, differences between chronological and predicted ages arise due to acceleration or deceleration of epigenetic aging, and these discrepancies are linked to disease risk and multiple life history traits. Although evidence suggests that patterns of DNA methylation can describe aging in plants, predictions with epigenetic clocks have yet to be performed. Here, we resolve the DNA methylome across CpG, CHG, and CHH-methylation contexts in the loblolly pine tree (Pinus taeda) and construct epigenetic clocks capable of predicting ages in this species within 6% of its maximum lifespan. Although patterns of CHH-methylation showed little association with age, both CpG and CHG-methylation contexts were strongly associated with aging, largely becoming hypomethylated with age. Among age-associated loci were those in close proximity to malate dehydrogenase, NADH dehydrogenase, and 18S and 26S ribosomal RNA genes. This study reports one of the first epigenetic clocks in plants and demonstrates the universality of age-associated DNA methylation dynamics which can inform conservation and management practices, as well as our ecological and evolutionary understanding of biological aging in plants.
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Affiliation(s)
- Steven T Gardner
- Savannah River Ecology Laboratory, University of Georgia, Aiken, SC, USA
| | - Emily M Bertucci
- Savannah River Ecology Laboratory, University of Georgia, Aiken, SC, USA.,Odum School of Ecology, University of Georgia, Athens, GA, USA
| | | | - Andy Horcher
- US Forest Service Savannah River, New Ellenton, SC, USA
| | - Doug Aubrey
- Savannah River Ecology Laboratory, University of Georgia, Aiken, SC, USA.,Warnell School of Forestry, University of Georgia, Athens, GA, USA
| | - Benjamin B Parrott
- Savannah River Ecology Laboratory, University of Georgia, Aiken, SC, USA.,Odum School of Ecology, University of Georgia, Athens, GA, USA
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