碩士 / 國立臺灣大學 / 環境衛生研究所 / 103 / Food restriction, one of the environmental stresses, could produce serious effects to organisms and may cause to population decline and extinction. In different life stages, wild fish often encounter to food restriction because they usually expose to extreme environment or special status, such as climatic change, low temperature, environmental pollution, habitat destruction or spawning migration.
Green sturgeon was listed as ‘‘threatened’’ in 2006 under the U.S. Endangered Species Act. Overfishing and habitat degradation lead to green sturgeon population decline. Since green sturgeon is susceptible to environmental stress, subtle changes from temperature, climatic factors, chemical exposure and nutritional situation will affect its physiological status.
Metabolomic approach is a high-throughput screening method to examine changes of metabolic profiles in biological systems to understand possible mechanisms for phenotype development. Nuclear magnetic resonance (NMR) spectroscopy, a common instrument applied in the field of metabolomics, supplies a fast, non-disruptive, high-throughput method that requires the least sample preparation. NMR coupled with multivariate statistical analysis such as principal components analysis (PCA) can be used to examine metabolic effects of environment stress in organisms.
The purpose of this study is to study effects of feed restriction in different tissues and life stages of green sturgeon by using NMR-based metabolomics. Green sturgeon fingerling and juvenile were fed four feed restriction (100%, 50%, 25% and 12.5%) for 2 and 4 weeks, respectively. Both hydrophilic and hydrophobic metabolites from the muscle, liver, and kidney were extracted and analyzed by NMR followed PCA.
The PCA results showed feed-restriction dependant trends from the analysis of all tissues types of different life stages, except the analysis of hydrophobic muscle metaolome from the fingerling. We found a lot of energy-related metabolites changed in different tissues of sturgeon after feed restriction. Our results showed that numerous amino acids or lactate were altered which are relate to imbalanced glycogenesis in muscle, liver and kidney of different stages of sturgeon. We also found decreased glucose probably due to glycolysis in all tissues of different stages of sturgeon except for the muscle and liver of fingerling. In addition, we also found fatty acids and glycerol degraded in the liver of fingerling and all tissues of juvenile for supplemental energy supply. Besides energy disturbance after feed restriction, we also discovered changes of osmolyte-related metabolites and antioxidants. These results suggested feed restriction may cause changes of osmotic balance and oxidative stress. We conducted that NMR-based metabolomics is useful in understanding the metabolic changes due to environmental stresses.
| Identifer | oai:union.ndltd.org:TW/103NTU05519002 |
| Date | January 2015 |
| Creators | Lu-Hsueh Huang, 黃律學 |
| Contributors | 林靖愉 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 138 |
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