Project description:The freshwater mussel Dreissena bugensis was exposed for nine days to different microplastic particles, in detail, to three petroleum-based polymers (polyamide (PA), polyethylene terephthalate (PET), polystyrene (PS)), to one bio-based polymer (polylactic acid (PLA)) and to ground mussel shells (MS), serving as a natural particle control (size range: 20-75 µm;1000 p ml-1). Behavior endpoints were analyzed with hall sensor based real-time valvometry. Additionally, biochemical alterations of ROS detoxifying enzymes were analyzed, and a proteomic profiling on digestive gland tissue was performed.
Project description:Differential tolerance to stress is partly responsible for the heterogeneity of biomarker responses between populations of a sentinel species. Although currently used for freshwater biomonitoring, studies concerning inter-populational variability in tolerance to contaminants for the zebra mussel (Dreissena polymorpha) are scarce. Moreover, this well-known invader is currently replaced by another, the quagga mussel (Dreissena rostriformis bugensis). To evaluate the differential tolerance between dreissenids, several populations of both species were exposed to a high concentration of nickel. A LT50 (time when 50% of individuals were dead) was established for each population. Biomarker responses and internal nickel concentration were also measured, to link tolerance with physiological status. Results evidenced that D. polymorpha populations are more heterogeneous and more tolerant than D. r. bugensis ones. For D. polymorpha populations only, LT50 values were positively correlated with the nickel contamination in situ, with higher anti-oxidative defences and a higher Integrated Biomarker Response value in the field. Such findings may be explained by local adaptation and invasion dynamic within each species. The significance of this differential tolerance when using biomarker responses for biomonitoring purposes is thus discussed.
Project description:Factorial Microarray Analysis of Zebra Mussel (Dreissena polymorpha) Adhesion Process under the Impact of Multiple Environmental Factors The expression profiles of the zebra mussel byssus unique genes in our cDNA microarray can be influenced by multiple factors. Three environmental factors plus adhesion status were considered as four main factors in this study.
