HP4 Environmental Metabolomics
204 Oregon Ballroom
1:20 PM - 5:20 PM, Thursday
() Characterization of the Metabolic Actions of Natural Stresses in the California Red Abalone, Haliotis rufescens Using 1H NMR Based Metabolomics.
Rosenblum, E1, Viant, M2, Braid, B3, Moore, J3, Friedman, C4, Tjeerdema, R1, 5, 1 Department of Environmental Toxicology, University of California, davis, ca, usa2 School of Biosciences, The University of Birmingham, Birmingham, UK3 Bodega Bay Marine Laboratory, Bodega Bay, ca, usa4 School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA, usa5
ABSTRACT- Withering syndrome in California red abalone (Haliotis rufescens) is caused by the Rickettsiales-like prokaryote (RLP) Candidatus Xenohaliotis californiensis. Affected animals undergo metaplastic changes within the digestive gland and it is hypothesized that as digestive gland architecture changes animals lose the ability to digest food. RLP-infection, however, does not necessarily produce signs of withering, and for reasons not yet well understood additional stressors such as elevated seawater temperature appear to influence the development of the disease. Using nuclear magnetic resonance (NMR) based metabolomics we have investigated the effects of bacterial infection, temperature, and food availability, both individually and in combination, on the metabolic status of the red abalone. High-resolution 1H NMR spectroscopy was particularly appropriate for investigating metabolic status since multiple endogenous metabolites could be quantified rapidly in foot muscle and digestive gland tissues. Food limitation caused dramatic reductions in all classes of foot muscle metabolites while at the same time metabolite levels within the digestive gland were preserved or increased. We also found that food limitation along with the additional stress of elevated seawater temperature led to greater metabolic perturbations in both tissue types than those observed under food limitation alone. RLP infection and food limitation resulted in many of the same metabolic changes within the tissues studied, although the effects of infection were less severe. We observed increased levels of homarine in the digestive gland of both food limited and RLP-infected animals yet only observed increased homarine levels in the foot muscle of infected abalone. These results further support the recently established glucose to homarine ratio for differentiating foot muscle tissue of RLP-infected animals from that of both healthy and starved abalone. Furthermore, we found that the NMR metabolic data correlates well with histological measurements supporting the use of the metabolomics approach for characterizing both normal and pathological events in marine species, particularly during periods of environmentally relevant stress.
Key words: NMR, metabolomics, Abalone, Withering Syndrome