Metabolomic analysis of sex specific metabolites in gonads of the mussel, Mytilus edulis

Marine mussels have been used as sentinel organisms to monitor exposure to a variety of chemical contaminants, including endocrine disrupting chemicals, in the aquatic environment. Although they are an important species for use in ecotoxicology investigations, information on their reproductive physiology and biochemistry is fragmentary. Mass spectrometry-based profiling techniques are increasingly being used to study how the metabolome of an organism changes as a result of tissue differentiation, disease or in response to environmental stressors. In this study, ultraperformance liquid chromatography-time-of-flight-mass spectrometry (UPLC-TOFMS) was used to investigate sex specific differences in the mussel metabolome in order to further investigate the reproductive physiology of this species. Using this method, a comparison of female and male mantle tissues containing mature gonad, revealed significant differences in glycerophosphatidylcholine (PC) and lysophosphatidylcholine (LPC) metabolites. A number of other unidentified metabolites, including those putatively identified as conjugated sterols, were also differentially expressed between male and female mantle/gonadal tissue.