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Document Type

Campus-Only Access for Five (5) Years

Degree Name

Doctor of Philosophy (PhD)

Degree Program

Food Science

Year Degree Awarded

2018

Month Degree Awarded

September

First Advisor

Yeonhwa Park

Subject Categories

Animal Experimentation and Research | Molecular Biology | Other Food Science

Abstract

Drosophila melanogaster is a versatile model organism that provides several unique features, such as highly conserved disease pathways with humans as well as availability of environmental and genetic manipulations. Meanwhile, there is increasing interest in the potential role of bioactive food components, epigallocatechin gallate (EGCG) and conjugated linoleic acid (CLA), in metabolic research. However, there is limited knowledge on the sex-dependent effects of EGCG and CLA on energy metabolism. In this study, Drosophila melanogaster was used to investigate the sex-dependent effects of EGCG and CLA with respect to energy metabolism, including body fat, locomotion, and their key metabolic regulators. We observed that female flies fed with EGCG showed decreased fat accumulation along with reduced food intake. For the males, EGCG increased lean mass, locomotor activity, and the key energy homeostasis regulator spargel (srl). CLA-fed females and males had reduced triglycerides and increased locomotor activity when compared to linoleic acid (control). In addition, CLA increased muscle content when compared to the blank. Moreover, following CLA supplementation, increased AMP-activated kinase (AMPK) activity was observed in females, but not in males. As polyunsaturated fatty acids play an essential role in the mating behavior, fecundity, and oogenesis, this study further evaluated the effects of CLA on reproduction and development in D. melanogaster. CLA decreased brood size in part via reduction of sex pheromone and lipid deposition in oogenesis. In summary, EGCG and CLA promote lean phenotype and locomotion behavior in D. melanogaster via sex-specific metabolic regulations, and the sex-dependent metabolic effects of EGCG and CLA may be due to physiological differences in lipid metabolism, nutrient requirement, and/or odor receptors in D. melanogaster. As key metabolic processes are conserved between human and D. melanogaster, knowledge obtained from this research may provide valuable insight into sex-dependent responses to EGCG and CLA.

Available for download on Sunday, September 01, 2019

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