Effects of dietary linolenic acid to linoleic acid ratio on growth performance, proximate composition and fatty acid contents of pacu ( Piaractus mesopotamicus )

Abstract Background Cottonseed is one of the major sources of vegetable oil. Analysis of the dynamic changes of fatty acid components and the genes regulating the composition of fatty acids of cottonseed oil is of great significance for understanding the biological processes underlying biosynthesis of fatty acids and for genetic improving the oil nutritional qualities. Results In this study, we investigated the dynamic relationship of 13 fatty acid components at 12 developmental time points of cottonseed (Gossypium hirsutum L.) and generated cottonseed transcriptome of the 12 time points. At 5–15 day post anthesis (DPA), the contents of polyunsaturated linolenic acid (C18:3n-3) and saturated stearic acid (C18:0) were higher, while linoleic acid (C18:2n-6) was mainly synthesized after 15 DPA. Using 5 DPA as a reference, 15,647 non-redundant differentially expressed genes were identified in 10–60 DPA cottonseed. Co-expression gene network analysis identified six modules containing 3275 genes significantly associated with middle-late seed developmental stages and enriched with genes related to the linoleic acid metabolic pathway and α-linolenic acid metabolism. Genes (Gh_D03G0588 and Gh_A02G1788) encoding stearoyl-ACP desaturase were identified as hub genes and significantly up-regulated at 25 DPA. They seemed to play a decisive role in determining the ratio of saturated fatty acids to unsaturated fatty acids. FAD2 genes (Gh_A13G1850 and Gh_D13G2238) were highly expressed at 25–50 DPA, eventually leading to the high content of C18:2n-6 in cottonseed. The content of C18:3n-3 was significantly decreased from 5 DPA (7.44%) to 25 DPA (0.11%) and correlated with the expression characteristics of Gh_A09G0848 and Gh_D09G0870. Conclusions These results contribute to our understanding on the relationship between the accumulation pattern of fatty acid components and the expression characteristics of key genes involved in fatty acid biosynthesis during the entire period of cottonseed development.

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Effect of dietary conjugated linoleic acid levels on growth performance, muscle fatty acid profile, hepatic intermediary metabolism and antioxidant responses in genetically improved farmed Tilapia strain of Nile tilapia Oreochromis niloticus

Aquaculture Research ◽

10.1111/j.1365-2109.2011.02942.x ◽

2011 ◽

Vol 43 (9) ◽

pp. 1392-1403 ◽

Cited By ~ 9

Author(s):

Zhi Luo ◽

Xiao-Ying Tan ◽

Cai-Xia Liu ◽

Xiao-Dong Li ◽

Xiang-Jiang Liu ◽

...

Keyword(s):

Fatty Acid ◽

Linoleic Acid ◽

Growth Performance ◽

Fatty Acid Profile ◽

Oreochromis Niloticus ◽

Nile Tilapia ◽

Antioxidant Responses ◽

Nile Tilapia Oreochromis Niloticus ◽

Genetically Improved ◽

Dietary Conjugated Linoleic Acid

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Saccharomyces kluyveri FAD3 encodes an ω3 fatty acid desaturase

Microbiology ◽

10.1099/mic.0.27049-0 ◽

2004 ◽

Vol 150 (6) ◽

pp. 1983-1990 ◽

Cited By ~ 34

Author(s):

Takahiro Oura ◽

Susumu Kajiwara

Keyword(s):

Fatty Acids ◽

Fatty Acid ◽

Linoleic Acid ◽

Linolenic Acid ◽

Functional Characterization ◽

Fatty Acid Desaturase ◽

Fatty Acid Desaturases ◽

Desaturase Gene ◽

Saccharomyces Kluyveri ◽

Fatty Acid Desaturase Gene

Fungi, like plants, are capable of producing the 18-carbon polyunsaturated fatty acids linoleic acid and α-linolenic acid. These fatty acids are synthesized by catalytic reactions of Δ12 and ω3 fatty acid desaturases. This paper describes the first cloning and functional characterization of a yeast ω3 fatty acid desaturase gene. The deduced protein encoded by the Saccharomyces kluyveri FAD3 gene (Sk-FAD3) consists of 419 amino acids, and shows 30–60 % identity with Δ12 fatty acid desaturases of several eukaryotic organisms and 29–31 % identity with ω3 fatty acid desaturases of animals and plants. During Sk-FAD3 expression in Saccharomyces cerevisiae, α-linolenic acid accumulated only when linoleic acid was added to the culture medium. The disruption of Sk-FAD3 led to the disappearance of α-linolenic acid in S. kluyveri. These findings suggest that Sk-FAD3 is the only ω3 fatty acid desaturase gene in this yeast. Furthermore, transcriptional expression of Sk-FAD3 appears to be regulated by low-temperature stress in a manner different from the other fatty acid desaturase genes in S. kluyveri.

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