Mass spectrometry imaging of the sentinel freshwater crustacean Daphnia: a novel tool for environmental diagnostics

Daphnia is a model organism in biology, with immediate relevance for ecology, human and environmental health. Their short generation time, large clutch sizes and ease of laboratory and field manipulation have assured their importance for setting environmental health standards, for testing chemical safety, for monitoring water quality, and as a model for ecological and evolutionary research. The importance of this organism inspired the development of the international Daphnia Genomics Consortium and subsequent publishing of the Daphnia genome (Science 2011; 331: 555-561); also the extensive and on-going Deep Metabolome Annotation and metabolite identification at the University of Birmingham. However, to date, there has been no studies mapping the spatial localisation of endogenous metabolites in Daphnia species, nor the location of toxicants (and metabolic products) following exposure to chemical pollutants.
In this project desorption electrospray ionisation (DESI) mass spectrometry, will be used to address the lack of spatial information extracted in metabolomic studies of Daphnia. Mapping the endogenous metabolites and toxicants in exposure studies will aid mechanistically understanding the toxicity caused by environmental pollutants.
Additionally, rapid evaporative ionisation (REIMS) based mass spectrometry workflows will be developed for Daphnia metabolomics studies to greatly increase sample throughput, towards enabling studies of large sample sets in a statistically robust manner.