Because of its near universal occurrence, understanding the causes and consequences of aging is central to broad biological, ecological, and evolutionary questions. Recent advances demonstrate a central role of the epigenome in mediating biological aging as it provides a molecular context for integrating both intrinsic and extrinsic forces. The purpose of this project is to discover fundamental mechanisms by which the environment directs epigenetic aging trajectories to ultimately impact organismal function. The project will utilize the tractable and ecologically relevant fish, Japanese medaka as a model system as much of their genome and physiology are broadly conserved across the animal kingdom. The study will support the training and mentoring of a postdoctoral researcher, two graduate students, and an undergraduate researcher, with recruiting efforts aimed at under-represented groups in the sciences. The project will develop a primer that introduces fundamental concepts in life history ecology and evolution, and will highlight variable life histories observed across the animal kingdom. The primer and project findings will be presented to students at area schools as part of an established outreach program. Together, this work will advance current understanding of how interactions between organisms and their environment affect biological aging and will provide training opportunities for the next generation of scientists.
The work will focus on recently developed epigenetic aging clocks to advance an ontogenetic- and endocrine-based understanding of how ecological and environmental challenges shape biological aging and attendant variation in the timing of live history events (e.g., age at maturity). Epigenetic aging clocks are based on age-dependent DNA methylation patterning and summarize the readout of age-associated hyper- and hypo-methylation from a selection of loci across the genome which are collectively capable of predicting chronological age with high accuracy. Despite their unprecedented accuracy, the age indicated by epigenetic clocks can differ from an individual’s actual age. This is referred to as epigenetic-to-chronological age discordance, and the magnitude and directionality of this discordance are associated with physiological function and life history traits. The origins of epigenetic-to-chronological age discordance are not resolved, and this project aims to investigate the role of ecological and environmental dynamics in driving this discordance. The project will also test the role of specific endocrine signaling pathways in mediating the influence of the environment on epigenetic aging. Interactions between organisms and their environments can result in different outcomes depending on when during life they occur. Age-dependent epigenetic patterning appears especially dynamic during early life and experiments will test if environment-organism interactions exert disproportionate influences during specific life stages. Collectively, project findings will provide a novel perspective regarding the proximal mechanisms by which environmental factors are translated into aging trajectories to affect organismal function and produce variable life histories.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
