Barramundi is a commercially farmed fish in Australia. To examine the potential for barramundi to metabolise dietary α-linolenic acid (ALA, 18:3 n-3), the existence of barramundi desaturase enzymes was examined. A putative fatty acid Δ6 desaturase was cloned from barramundi liver and expressed in yeast. Functional expression revealed Δ6 desaturase activity with both the 18 carbon (C18) and C24 n-3 fatty acids, ALA and 24:5 n-3 as well as the C18 n-6 fatty, linoleic acid (LA, 18:2 n-6). Metabolism of ALA was favoured over LA. The enzyme also had Δ8 desaturase activity which raises the potential for synthesis in barramundi of omega-3 (n-3) long chain polyunsaturated fatty acids from ALA via a pathway that bypasses the initial Δ6 desaturase step. Our findings not only provide molecular evidence for the fatty acid desaturation pathway in the barramundi but also highlight the importance of taking extracellular fatty acid levels into account when assessing enzyme activity expressed in Saccharomyces cerevisiae.
Wei-Chun Tu, Rebecca J. Cook-Johnson, Michael J. James, Beverly S. Mühlhäusler, David A. J. Stone, Robert A. Gibson
Endothelial nitric oxide synthase polymorphism G298T in association with oxidative DNA damage in coronary atherosclerosis
Content Type Journal Article
Category Research Note
RAJESH G. KUMAR, Department of Genetics, Osmania Univers ... more
A micropropagation protocol was developed for multiplication of seedless lemon (Citrus limon L. cv. Kaghzi Kalan) using nodal explants. The maximum shoot regeneration was observed on low level of BAP (0.1 mg l−1) or kinetin (0.5 mg l−1). BA was recorded to be better than kinetin in terms of ... more
The objective of this study was to evaluate the activity, kinetic behavior, and thermal inactivation kinetics of peroxidase (POD) in aqueous extracts from two kinds of milk ripe stage corn, sweet corn and waxy corn. Optimum activities using guaiacol as the hydrogen donor were obtained for s ... more