Using epigenetic clocks to investigate changes in the age structure of critically endangered Māui dolphins.

Autor: Hernandez KM; Marine Mammal Institute Oregon State University Oregon Newport USA., O'Neill KB; Marine Mammal Institute Oregon State University Oregon Newport USA., Bors EK; Marine Mammal Institute Oregon State University Oregon Newport USA., Steel D; Marine Mammal Institute Oregon State University Oregon Newport USA., Zoller JA; Fielding School of Public Health, Department of Biostatistics University of California California Los Angeles USA., Constantine R; School of Biological Sciences & Institute of Marine Science University of Auckland - Waipapa Taumata Rau Auckland New Zealand., Horvath S; Fielding School of Public Health, Department of Biostatistics University of California California Los Angeles USA.; David Geffen School of Medicine, Department of Human Genetics University of California California Los Angeles USA.; Altos Labs California San Diego USA., Baker CS; Marine Mammal Institute Oregon State University Oregon Newport USA.
Jazyk: angličtina
Zdroj: Ecology and evolution [Ecol Evol] 2023 Sep 28; Vol. 13 (10), pp. e10562. Date of Electronic Publication: 2023 Sep 28 (Print Publication: 2023).
DOI: 10.1002/ece3.10562
Abstrakt: The age of an individual is an essential demographic parameter but is difficult to estimate without long-term monitoring or invasive sampling. Epigenetic approaches are increasingly used to age organisms, including nonmodel organisms such as cetaceans. Māui dolphins ( Cephalorhynchus hectori maui ) are a critically endangered subspecies endemic to Aotearoa New Zealand, and the age structure of this population is important for informing conservation. Here we present an epigenetic clock for aging Māui and Hector's dolphins ( C. h. hectori ) developed from methylation data using DNA from tooth aged individuals ( n  = 48). Based on this training data set, the optimal model required only eight methylation sites, provided an age correlation of .95, and had a median absolute age error of 1.54 years. A leave-one-out cross-validation analysis with the same parameters resulted in an age correlation of .87 and median absolute age error of 2.09 years. To improve age estimation, we included previously published beluga whale ( Delphinapterus leucas ) data to develop a joint beluga/dolphin clock, resulting in a clock with comparable performance and improved estimation of older individuals. Application of the models to DNA from skin biopsy samples of living Māui dolphins revealed a shift from a median age of 8-9 years to a younger population aged 7-8 years 10 years later. These models could be applied to other dolphin species and demonstrate the ability to construct a clock even when the number of known age samples is limited, removing this impediment to estimating demographic parameters vital to the conservation of critically endangered species.
Competing Interests: SH is a founder of the nonprofit Epigenetic Clock Development Foundation which plans to license several of his patents from his employer UC Regents. The other authors declare no conflict of interest.
(© 2023 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.)
Databáze: MEDLINE
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