Methods for analysing wildlife DNA methylation data

Area of Science:

• Wildlife conservation epigenetics
• Population health assessment
• Genomic data analysis

Background:

• DNA methylation analysis is increasingly used in wildlife conservation for insights into age, traits, and health.
• Existing statistical methods are primarily developed for human biomedical research, necessitating adaptation for wildlife studies.

Purpose of the Study:

• To review key DNA methylation methodologies for wildlife research, including those from human studies.
• To illustrate these methods with a case study on bottlenose dolphins.
• To evaluate the accuracy of epigenetic clocks for age and health assessment in wildlife.

Main Methods:

• Review of statistical methodologies for DNA methylation data analysis.
• Application of methods to a dataset of wild bottlenose dolphins (Tursiops spp.).
• Comparison of epigenetic clock models for estimating chronological age and health indicators.

Main Results:

• Epigenetic clocks can estimate chronological age but struggle to accurately assess health indicators simultaneously.
• A single epigenetic model cannot reliably predict both age and health due to confounding factors.
• The limitations of clock-type models may explain inconsistencies in age-related health findings.

Conclusions:

• Decoupling age and health analyses is crucial for accurate wildlife epigenomic studies.
• Further development of statistical methods is needed to address the dual goals of age prediction and health assessment in wildlife.
• Understanding these limitations is vital for advancing wildlife conservation through epigenetics.