title: Exploring the effects of seasonality and chemical pollution on the hepatopancreas transcriptome of the Manila clam.
abstract: The assessment of marine environmental health is a complex but fundamental task both for ecosystem conservation and food safety related to the human consumption of marine products. Manila clams inhabiting the Venice Lagoon constitute an excellent case study for evaluating the effects of complex mixtures of industrial and urban effluents on aquatic organisms. Clams were collected in different seasons at four locations within the Venice Lagoon. The sampling sites were characterized by a range of pollutant concentrations and included Porto Marghera, a highly polluted industrial area where clam harvesting for human consumption is strictly forbidden. Pooled soft tissues were subjected to mass spectroscopy analysis to measure the concentrations of PCDDs/PCDFs/PCBs-DL, PCBs, PBDEs, HCB and PAHs, and pooled digestive gland samples were used for gene expression profiling. While seasonal variation was found to be responsible for the largest proportion of transcriptional changes, significance analysis of microarrays quantitative correlation analysis identified 162 transcripts that were correlated with at least one class of chemicals measured in the samples from the four different sampling sites. Prediction Analysis of Microarrays (PAM) identified a minimal set of seven genes that correctly assigned samples collected in the restricted polluted area (Porto Marghera), independent of the season in which they were collected. An integrated approach combining transcriptomics and chemical analyses of the Manila clam provided a global picture of how Manila clams respond to complex mixtures of xenobiotics and their interplay with other biotic and abiotic factors. We were also able to identify gene expression signatures for different classes of chemicals and a set of robust biomarkers of exposure to these chemicals.
authors.affiliation: Department of Comparative Biomedicine and Food Science, University of Padova, Legnaro (PD), Italy. massimo.milan@unipd.it
authors.forename: Massimo
authors.initials: M
authors.lastname: Milan
authors.forename: Serena
authors.initials: S
authors.lastname: Ferraresso
authors.forename: Claudio
authors.initials: C
authors.lastname: Ciofi
authors.forename: Guido
authors.initials: G
authors.lastname: Chelazzi
authors.forename: Claudio
authors.initials: C
authors.lastname: Carrer
authors.forename: Giorgio
authors.initials: G
authors.lastname: Ferrari
authors.forename: Lino
authors.initials: L
authors.lastname: Pavan
authors.forename: Tomaso
authors.initials: T
authors.lastname: Patarnello
authors.forename: Luca
authors.initials: L
authors.lastname: Bargelloni
mesh_terms: D000818:Animals; D049872:Bivalvia / Q000235:genetics* / Q000502:physiology; D017753:Ecosystem; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects; D015386:Hazardous Substances / Q000302:isolation & purification; D043143:Hepatopancreas / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D011078:Polychlorinated Biphenyls / Q000302:isolation & purification; D012621:Seasons; D014877:Water Pollution, Chemical
chemical_list: D015386:Hazardous Substances; D011078:Polychlorinated Biphenyls