An epigenetic clock to estimate the age of living beluga whales

Evolutionary Applications

Steve Horvath¹  Zhe Fei¹  Kaimyn B. O'Neill²  C. Scott Baker²  Eleanor K. Bors²  Kim E. W. Shelden³  Paul R. Wade³  Michael J. Thompson⁴  Simon Jarman⁵ 

[1] Department of Biostatistics School of Public Health University of California‐Los Angeles Los Angeles CA USA;Marine Mammal Institute Oregon State University Newport OR USA;Marine Mammal Laboratory Alaska Fisheries Science Center National Marine Fisheries Service National Oceanographic and Atmospheric Administration Seattle WA USA;Molecular, Cell and Developmental Biology University of California Los Angeles Los Angeles CA USA;School of Biological Sciences University of Western Australia Perth WA Australia;

关键词: aging;    Alaska;    cetaceans;    conservation biology;    Cook Inlet;    DNA methylation;   

DOI  :  10.1111/eva.13195

来源: DOAJ

【 摘 要 】

Abstract DNA methylation data facilitate the development of accurate molecular estimators of chronological age or “epigenetic clocks.” We present a robust epigenetic clock for the beluga whale, Delphinapterus leucas, developed for an endangered population in Cook Inlet, Alaska, USA. We used a custom methylation array to measure methylation levels at 37,491 cytosine–guanine sites (CpGs) from skin samples of dead whales (n = 67) whose chronological ages were estimated based on tooth growth layer groups. Using these calibration data, a penalized regression model selected 23 CpGs, providing an R2 = 0.92 for the training data; and an R2 = 0.74 and median absolute age error = 2.9 years for the leave one out cross‐validation. We applied the epigenetic clock to an independent dataset of 38 skin samples collected with a biopsy dart from living whales between 2016 and 2018. Age estimates ranged from 11 to 27 years. We also report sex correlations in CpG data and describe an approach of identifying the sex of an animal using DNA methylation. The epigenetic estimators of age and sex presented here have broad applications for conservation and management of Cook Inlet beluga whales and potentially other cetaceans.

【 授权许可】

Unknown