Epigenetic estimation of age in humpback whales
Open Access
- 7 April 2014
- journal article
- research article
- Published by Wiley in Molecular Ecology Resources
- Vol. 14 (5), 976-987
- https://doi.org/10.1111/1755-0998.12247
Abstract
Age is a fundamental aspect of animal ecology, but is difficult to determine in many species. Humpback whales exemplify this as they have a lifespan comparable to humans, mature sexually as early as 4 years and have no reliable visual age indicators after their first year. Current methods for estimating humpback age cannot be applied to all individuals and populations. Assays for human age have recently been developed based on age-induced changes in DNA methylation of specific genes. We used information on age-associated DNA methylation in human and mouse genes to identify homologous gene regions in humpbacks. Humpback skin samples were obtained from individuals with a known year of birth and employed to calibrate relationships between cytosine methylation and age. Seven of 37 cytosines assayed for methylation level in humpback skin had significant age-related profiles. The three most age-informative cytosine markers were selected for a humpback epigenetic age assay. The assay has an R2 of 0.787 (P = 3.04e−16) and predicts age from skin samples with a standard deviation of 2.991 years. The epigenetic method correctly determined which of parent–offspring pairs is the parent in more than 93% of cases. To demonstrate the potential of this technique, we constructed the first modern age profile of humpback whales off eastern Australia and compared the results to population structure 5 decades earlier. This is the first epigenetic age estimation method for a wild animal species and the approach we took for developing it can be applied to many other nonmodel organisms.Keywords
Funding Information
- Australian Antarctic Science grants scheme (4014)
This publication has 54 references indexed in Scilit:
- Correlation between DNA methylation and chronological age of Moso bamboo (Phyllostachys heterocycla var. pubescens)Botanical Studies, 2014
- Analysis of Age-Related Global DNA Methylation in ChickenBiochemical Genetics, 2013
- Hot topics in epigenetic mechanisms of aging: 2011Aging Cell, 2012
- Empirical evaluation of humpback whale telomere length estimates; quality control and factors causing variability in the singleplex and multiplex qPCR methodsBMC Genomic Data, 2012
- Widespread and tissue specific age-related DNA methylation changes in miceGenome Research, 2010
- Removal of deaminated cytosines and detection of in vivo methylation in ancient DNANucleic Acids Research, 2009
- Telomere length inheritance and agingMechanisms of Ageing and Development, 2008
- The use of transcriptional profiles to predict adult mosquito age under field conditionsProceedings of the National Academy of Sciences of the United States of America, 2006
- Against the current: an inter-oceanic whale migration eventBiology Letters, 2005
- Cross-Validation of Regression ModelsJournal of the American Statistical Association, 1984