All ETDs from UAB

Advisory Committee Chair

Peggy R Biga

Advisory Committee Members

Beth M Cleveland

Nicole C Riddle

Melissa L Harris

Matthew S Alexander

Document Type

Dissertation

Date of Award

2023

Degree Name by School

Doctor of Philosophy (PhD) College of Arts and Sciences

Abstract

With the expansion of the aquaculture industry, sustainable shifts in aquaculture must be made to access nutrients essential to human health in response to a decline in marine resources for aquafeeds. Along with shifts in aquafeed composition, selective breeding programs aid in enhancing production-related traits, like growth and feed efficiency, and disease resistance to improve overall profits. Dietary components are important in relation to the growth and metabolism of fishes. Recent research has focused on the benefits of micronutrient supplementation (e.g., choline, methionine, selenium, etc.) on growth performance in fishes. Rainbow trout are a commercially important aquaculture species in the United States and serve as a non-model organism to investigate toxicology, evolutionary biology, and nutritional programming. Understanding the impacts of nutritional programming in aquaculture species will aid in understanding the effects of broodstock nutrition on offspring growth performance via inherited epigenetic mechanisms while providing information regarding potential mechanisms of maternal effects. Therefore, this dissertation focuses in part on the interactions between maternal nutrition and genetic selection in rainbow trout, (Oncorhynchus mykiss) used within the industry – disease-resistant selected rainbow trout maintained by the National Center for Cool and Cold-Water Aquaculture. The project used treatment effects on the methylome and transcriptome to analyze potential mechanisms altered by maternal choline intake and establish links between epigenetic modifications in the genome and phenotype of the offspring. Results indicate that several metabolic and tissue-specific pathways are under, at least, partial maternal regulation. The effects nutrition has on subsequent generations from initial broodstock feeding is another pertinent question in nutrigenomics. The remaining dissertation focuses on this question by investigating if the epigenetic modifications observed in first generation offspring translates to offspring generations later who were unexposed to choline supplementation and restriction. Initial results indicate choline availability in the maternal broodstock diet effects reproduction, including fecundity and hatch rate. Methylation and gene expression in offspring results indicate epigenetic regulatory pathways are also under partial maternal regulation. The culmination of this research furthers our understanding in nutritional programming through epigenetic regulation in subsequent generations.

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