Dreissena polymorpha metabolome

The freshwater zebra mussel, Dreissena polymorpha, is extensively used as a sentinel species for biosurvey of environmental contaminants in freshwater ecosystems and for ecotoxicological studies. However, little is still known about the input of its metabolome and particularly concerning a potential molecular sexual dimorphism observable in the different tissues of this organism. In an ecotoxicological point of view, inter-sex and inter-organ differences in the metabolome composition might induce bias and influence the robustness of data analysis or interpretation, especially in the case males and females would be used indifferently for specific biomarker measurements. Recent metabolomic approaches are more and more often used to identify new potent biomarkers. They can also be useful to develop experimental protocols and to specify the type of sample to focus on, in terms of sex and tissues. The purpose of this study is to use a non-target metabolomic approach to assess if the molecular fingerprints of various tissues of D. polymorpha may reveal tissue-specific molecular sexual dimorphism. Our results highlight the critical need of considering inter-sex differences in the metabolome of D. polymorpha, particularly if studies are focused on the observation of environmental effects on the molecular regulation in genital or digestive glands.