Metabolomic Investigations of American Oysters Using 1H-NMR Spectroscopy

Abstract

The Eastern oyster (Crassostrea virginica) is a useful, robust model marine organism for tissue metabolism studies. Its relatively few organs are easily delineated and there is sufficient understanding of their functions based on classical assays to support interpretation of advanced spectroscopic approaches. Here we apply high-resolution proton nuclear magnetic resonance (1H NMR)-based metabolomic analysis to C. virginica to investigate the differences in the metabolic profile of different organ groups, and magnetic resonance imaging (MRI) to non-invasively identify the well separated organs. Metabolites were identified in perchloric acid extracts of three portions of the oyster containing: (1) adductor muscle, (2) stomach and digestive gland, and (3) mantle and gills. Osmolytes dominated the metabolome in all three organ blocks with decreasing concentration as follows: betaine > taurine > proline > glycine > ß-alanine > hypotaurine. Mitochondrial metabolism appeared most pronounced in the adductor muscle with elevated levels of carnitine facilitating ß-oxidation, and ATP, and phosphoarginine synthesis, while glycogen was elevated in the mantle/gills and stomach/digestive gland. A biochemical schematic is presented that relates metabolites to biochemical pathways correlated with physiological organ functions. This study identifies metabolites and corresponding 1H NMR peak assignments for future NMR-based metabolomic studies in oysters.

Using the critical salinity (S crit) concept to predict invasion potential of the anemone Diadumene lineata in the Baltic Sea

“…This procedure yielded specific metabolic profiles visualizing possible changes in the osmolyte composition of D. lineata and their relative concentrations caused by salinity alterations. Specific metabolites were identified using the Chenomx Software database and chemical shift tables (Tikunov et al 2010). Osmolyte signals of interest were analysed in more detail.…”

The influence of salinity on toxicological effects of arsenic in digestive gland of clam Ruditapes philippinarum using metabolomics

“…High resolution proton nuclear magnetic resonance (HR-1 H NMR) spectroscopy is particularly suitable for the measurement of a large number of metabolites in biological samples because it is rapid, non-invasive and is rich in structural and quantitative information (Brindle et al, 2002;Lindon et al, 2000). NMRbased metabolomics has been effi ciently used in several recent studies in marine environmental toxicology (Viant et al, 2001;Viant et al, 2006aViant et al, , 2006bJones et al, 2008;Williams et al, 2009;Gordon and Leggat, 2010;Lannig et al, 2010;Santos et al, 2010;Tikunov et al, 2010).…”

Assessment of Metabolism of the Eastern Oyster and Eastern Elliptio Using NMR Spectroscopy

“…2,14 In a previous 1 H NMR metabolomic study, we have shown that betaine was the most abundant metabolite in all oyster tissues. 9 Betaine is an important metabolite functioning both as an osmolyte to protect against osmotic stress and a methyl group donor. 9,15 Hence, glucose was chosen to probe glycolysis and the Krebs cycle, while glycine was chosen to probe betaine, which is trimethylglycine, a catabolic product of glycine.…”

“…9 Betaine is an important metabolite functioning both as an osmolyte to protect against osmotic stress and a methyl group donor. 9,15 Hence, glucose was chosen to probe glycolysis and the Krebs cycle, while glycine was chosen to probe betaine, which is trimethylglycine, a catabolic product of glycine. 14 Therefore, the major goal of this study was to establish baseline distributions of metabolites derived from U-13 C-glucose and 2-13 C-glycine over oyster tissues by using 13 C NMR measurement and to demonstrate the feasibility of using NMR for that purpose.…”

“…8 As an extension of MRI applications, we have shown that usage of MR spectroscopic imaging technique, also called chemical shift imaging (CSI), permits metabolic profiles to be generated in a conventional MR image format representing the various metabolites. 9 As a part of our ongoing effort to apply MR techniques to study metabolic status of the marine and mammalian biological systems, we have examined the metabolic profiles of the bivalve mollusks, using NMR.…”