NSF PRFB FY 2023: Heritable phenotypes and mechanisms through transgenerational plasticity in response to hypoxia in fish

Negrete, Benjamin, Corpus Christi TX

Investigators

Abstract

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2023, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment, and Phenotypes. The fellowship supports research and training of the fellow that will contribute to the area of Rules of Life in innovative ways. This research investigates the physiological implications of long-term hypoxia (low oxygen) in marine environments on fish. Hypoxia is an environmental stressor that is becoming more prevalent around the world and, compounded with warming oceans, is increasing in duration, severity, and size. Chronic exposure to hypoxia is particularly threatening as it limits the ability of fish to generate energy through aerobic metabolism. Additionally, hypoxia has many downstream impacts, including causing fish to make changes to their behavior, morphology, physiology, and gene expression. The sum of these flexible changes can be referred to as plasticity. Marine fish at all life stages, particularly early-life stages, are susceptible to environmental hypoxia as not all species can undergo long migrations to oxygenated waters. The fellow will investigate the plastic response of the marine stickleback to chronic hypoxia and how these plastic traits are transferred to the next generation. Populations of stickleback in the same habitats express distinct phenotypes that differ in their response to environmental stress, suggesting phenotypic traits are inherited in species from the same genotype to benefit offspring. This work will explore the changes to the oxygen cascade from the whole-animal oxygen uptake to metabolic pathways and to genetic control of these mechanisms. The proposed research will explore whole-animal oxygen consumption and critical oxygen thresholds using respirometry. This oxygen uptake, and thus aerobic respiration, will be further investigated in aerobically-demanding tissues, including cardiac and skeletal muscles, by the sum of metabolic pathways down to changes in the use of oxygen at the mitochondria. The fellow will use transcriptomics to look at widespread changes in gene expression that underpins changes in aerobic respiration and the role of epigenetics in controlling the expression of specific traits. Through this work, the fellow will prioritize recruiting and mentoring undergraduates to provide hands-on research experience and mentorship through navigating college and graduate school. 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.