The study was to investigate the changes in (1) triacylglycerol (TAG) contents and its relationship to (2) lipid synthesis- and metabolism-related enzyme activity and (3) their gene expression in cobia (Rachycentron canadum) during the fast growth period (from October 2006 to April 2007) in ventral muscle and liver in Hsiao-Lu-Chiao island in southwestern Taiwan. The crude lipid was 12% for fed diet, 30-40% for liver while 13% in February and 11% to 9% in other month for muscle. The TAG content of crude lipid was 36 % for fed diets, and from 22% (December) to 40% (February) for muscle, and from 63% (October to February) to 47% (March) for liver. Oil red-O (ORO) staining showed that TAG accumulated in muscle in February but in December in liver. Muscle TAG contents and enzyme activities and mRNA levels of GPDH and FAS increased in February. A decrease in GPDH enzyme activity and mRNA levels but an increase in PEPCK enzyme activity and mRNA levels indicate the increased supply of acetyl-CoA for fatty acid synthesis is in muscle. An increase in FATP2 mRNA levels suggest the influx of fatty acid also contributes to increased fatty acid accumulation in muscle.In liver, TAG and fatty acid contents decreased in March April but increased FAS and PEPCK enzyme activity and mRNA levels. It is possible that fatty acid synthesis is enhanced in March, but a fast transport to other organs results in a net decline in liver fatty acid contents and subsequently a decrease in TAG contents. FATP contents decreased in March-April mRNA, indicating that the influx of fatty acid in decreasing in liver in adult fish. GPDH and GAPDH were not related to lipid metabolism in liver. These data from enzyme activity and mRNA level, demonstrated that a potentially increase in acetyl-CoA via PEPCK contributes to fatty acid synthesis and GPDH-mediated synthesis of G-3-P provide the C skeleton for TAG synthesis.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0730109-185602 |
| Date | 30 July 2009 |
| Creators | Lee, Lin-han |
| Contributors | Te-Jin Chow, Tse-Min Lee, Tsui-Chun Tsou |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0730109-185602 |
| Rights | not_available, Copyright information available at source archive |
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