AGE ESTIMATION IN HUMPBACK WHALES BY ANALYSIS OF DNA METHYLATION

AGE ESTIMATION IN HUMPBACK WHALES BY ANALYSIS OF DNA METHYLATION

Simon Jarman (CIBIO-InBIO, Portugal) | July 5, 2017 | Humpback Whale World Congress, Reunion Island, France

Animal age is an important ecological feature. It is linked to many individual characteristics  such as reproductive capacity, foraging ability and likelihood of mortality. At the population level, the proportions of animals in different age classes affects future population growth rates and reflects past demographic events. However, estimating the age of anonymous individuals from many wild animal species is often impossible. Humpback whales are a classic example of this as they mature sexually after 5-8 years, reach maximum size one or two years after that and subsequently have no external features that allow their age to be estimated in cross-sectional studies. Attempts to establish non-lethal age estimation methods initially focused on telomere length assays, but these were not effective. More recently, a different molecular age biomarker was developed based on measurement of DNA methylation levels at a combination of three specific CpG sites. In this talk, I will discuss why age estimation is useful for humpback whale population biology; the history of age estimation in humpbacks; the key features and limitations of the current DNA-methylation based methodology; and the future prospects for age estimation in this species.

Image credits: Simon Jarman