Collaborative Research: EAGER: Non-Lethal Tools to Estimate the Ages and Lifespans of Chondrichthyan Fishes

University Of Florida, Gainesville FL

Investigators

Abstract

This project develop new methods for aging chondrichthyans (e.g., sharks, skates, and rays) using DNA sequencing technology. In doing so, it will advance both the conservation of these species, many of which are critically endangered, and our evolutionary understanding of the aging process across species in taxonomic groups with highly variable lifespans and life histories. Biological aging is a fundamental component of organismal life. Recent advances in our understanding of changes in DNA during aging are yielding novel tools to probe the linkages between genomic variability, ecological dynamics, and organismal lifespans. These changes over the lifespan of all vertebrates, when calibrated against animals of known age, can be used to create highly accurate “clocks.” Such clocks have the potential to provide non-lethal approaches for determining aging populations of species of conservation concern, and comparative studies of aging across related species with diverse lifespans are likely to provide insight into the mechanisms contributing to life history evolution. In addition, the project will provide training for both undergraduates and a postdoctoral scholar and engage the general and local public through association with the Georgia Aquarium. Living systems cycle through life-history stages characterized by initiation, growth and development, reproduction, senescence, and death. Most hypotheses of the evolutionary drivers of life-history patterns center around the idea that periodic resetting in conjunction with the slow, but constant, introduction of new mutations augmented by reshuffling (e.g., sexual reproduction), provides the phenotypic variability necessary to ensure survival in changing environments. If this is correct, cycling times should be shorter in rapidly changing environments than they are in more constant environments. This project will develop an epigenetic DNA methylation “clock” using novel molecular and computational approaches to measure life spans in chondrichthyan fishes that vary widely in their lifespans and life histories and that inhabit environments that range from the relative constancy of the deep sea to highly dynamic environments at the sea surface in temperate and tropical regions. 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.