Estimation of Tissue Distribution of mRNA Transcripts for Desaturase and Elongase Enzymes in Channa striata (Bloch, 1793) Fingerlings Using PCR Technique

利用聚合酶連鎖反應技術估測線鱧仔稚魚組織內去飽和酶與延長酶mRNA轉錄產物之分布

M. Aliyu-Paiko ； A. Jaya-Ram ； A. S. C. Chong ； R. Hashim ； O. Amuzat Aliyu

《TAIWANIA》 58卷2期 (2013/06) Pp. 112-118

https://doi.org/10.6165/tai.2013.58.112

摘要

Fish species are varied in their capacity to biosynthesize n-3 highlyunsaturated fatty acids (HUFA) such as eicosapentaenoic and docosahexaenoic acids (EPA & DHA) that are crucial to the health and well-being of all higher vertebrates. Experts report that HUFA metabolism involves enzyme-mediated fatty acyl desaturation (FAD) and elongation (FAE) processes. In previous studies, different workers cloned, characterized, identified and reported several genes for FAD and FAE enzymes in different fish species such as Atlantic salmon, gilthead seabream, rainbow trout and zebrafish, and also demonstrated the up- and down-regulation in the activity of these enzymes in response to fluctuations in dietary HUFA. In this paper, we report on the expression of genes (mRNA transcripts) for FAD and FAE enzymes in different tissues of Channa striata (Bloch, 1793) fingerling, to evaluate the tissues of the fish in which activity of both enzymes are high. To achieve this objective, we used conventional polymerase chain reaction (PCR) technique to isolate and quantify the absolute copy number for each gene transcripts from 8 different tissues of the fish (reared with a commercial feed). Our estimate show that the distribution of the 2 enzyme transcripts were significantly (P ＜ 0.05) higher in the liver and brain of C. striata than detected in the 6 other tissues evaluated (muscle, ovary, testis, intestine, kidney and skin). Subsequently, we discuss here extensively, the implication of this observation with respect to the use of vegetable oils (VO) as substitute to fish oil (FO) in diets for freshwater fish species.

關鍵字

線鱧 ； 去飽和酶 ； 脂肪酸 ； 基因 ； mRNA表現 ； 聚合酶連鎖反應

並列摘要

Fish species are varied in their capacity to biosynthesize n-3 highlyunsaturated fatty acids (HUFA) such as eicosapentaenoic and docosahexaenoic acids (EPA & DHA) that are crucial to the health and well-being of all higher vertebrates. Experts report that HUFA metabolism involves enzyme-mediated fatty acyl desaturation (FAD) and elongation (FAE) processes. In previous studies, different workers cloned, characterized, identified and reported several genes for FAD and FAE enzymes in different fish species such as Atlantic salmon, gilthead seabream, rainbow trout and zebrafish, and also demonstrated the up- and down-regulation in the activity of these enzymes in response to fluctuations in dietary HUFA. In this paper, we report on the expression of genes (mRNA transcripts) for FAD and FAE enzymes in different tissues of Channa striata (Bloch, 1793) fingerling, to evaluate the tissues of the fish in which activity of both enzymes are high. To achieve this objective, we used conventional polymerase chain reaction (PCR) technique to isolate and quantify the absolute copy number for each gene transcripts from 8 different tissues of the fish (reared with a commercial feed). Our estimate show that the distribution of the 2 enzyme transcripts were significantly (P ＜ 0.05) higher in the liver and brain of C. striata than detected in the 6 other tissues evaluated (muscle, ovary, testis, intestine, kidney and skin). Subsequently, we discuss here extensively, the implication of this observation with respect to the use of vegetable oils (VO) as substitute to fish oil (FO) in diets for freshwater fish species.

並列關鍵字

Channa striata ； desaturase ； fatty acid ； gene ； mRNA expression ； PCR

參考文獻

Agaba M. K., D. R. Tocher, C. A. Dickson, X. Zheng, J. R. Dick and A. J. Teale. 2005. Cloning and functional characterisation of polyunsaturated fatty acid elongases from marine and freshwater teleost fish. Comp. Biochem. Physiol. 142: 342–352.

Bell J. G., R. J. Henderson, D. R. Tocher, F. McGhee, J. R. Dick, A. Porter, R. P. Smullen and J. R. Sargent. 2002. Substituting fish oil with crude palm oil in the diet of Atlantic salmon (Salmo salar) affects muscle fatty acid composition and hepatic fatty acid metabolism. J. Nutr. 132: 222–230.

Bell J. G., J. McEvoy, D. R. Tocher, F. McGhee, P. J. Campbell and J. R. Sargent. 2001. Replacement of fish oil with rape seed oil in diets of Atlantic salmon (Salmo salar) affects tissue lipid compositions and hepatocyte fatty acid metabolism. J. Nutr. 131: 1535–1543.

Bell M. V., R. S. Batty, J. R. Dick, K. Fretwell, J. C. Navarro and J. R. Sargent. 1995. Dietary deficiency of docosahexaenoic acid impairs vision at low light intensiries in juvenile herrinig (Clupea harengus L.)Lipids 30: 443–449.

Brenner R. R. 1981. Nutritional and hormonal factors influencing desaturation of essential fatty acids. Prog. Lipid Res. 20: 41–47.