title: Can ecological history influence response to pollutants? Transcriptomic analysis of Manila clam collected in different Venice lagoon areas and exposed to heavy metal.
abstract: Chronic exposure to environmental pollutants can exert strong selective pressures on natural populations, favoring the transmission over generations of traits that enable individuals to survive and thrive in highly impacted environments. The lagoon of Venice is an ecosystem subject to heavy anthropogenic impact, mainly due to the industrial activities of Porto Marghera (PM), which led to a severe chemical contamination of soil, groundwater, and sediments. Gene expression analysis on wild Manila clams collected in different Venice lagoon areas enabled to identify differences in gene expression profiles between clams collected in PM and those sampled in clean areas, and the definition of molecular signatures of chemical stress. However, it remains largely unexplored to which extent modifications of gene expression patterns persists after removing the source of contamination. It is also relatively unknown whether chronic exposure to xenobiotics affects the response to other chemical pollutants. To start exploring such issues, in the present study a common-garden experiment was coupled with transcriptomic analysis, to compare gene expression profiles of PM clams with those of clams collected in the less impacted area of Chioggia (CH) during a period under the same control conditions. Part of the two experimental groups were also exposed to copper for seven days to assess whether different "ecological history" does influence response to such pollutant. The results obtained suggest that the chronic exposure to chemical pollution generated a response at the transcriptional level that persists after removal for the contaminated site. These transcriptional changes are centered on key biological processes, such as defense against either oxidative stress or tissue/protein damage, and detoxification, suggesting an adaptive strategy for surviving in the deeply impacted environment of Porto Marghera. On the other hand, CH clams appeared to respond more effectively to copper exposure than PM animals, proposing that chronic exposure to chemical toxicants either lowers the sensitivity to additional toxicants or blunts the capacity to respond to novel chemical challenges in PM clams.
authors.affiliation: Department of Comparative Biomedicine and Food Science, University of Padova, 35020, Legnaro, Italy. Electronic address: massimo.milan@unipd.it.
authors.forename: Massimo
authors.initials: M
authors.lastname: Milan
authors.affiliation: Department of Biology, University of Padova, via G. Colombo 3, 35131 Padova, Italy.
authors.forename: Valerio
authors.initials: V
authors.lastname: Matozzo
authors.affiliation: Department of Comparative Biomedicine and Food Science, University of Padova, 35020, Legnaro, Italy.
authors.forename: Marianna
authors.initials: M
authors.lastname: Pauletto
authors.affiliation: Department of Information Engineering, University of Padova, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Di Camillo
authors.affiliation: Department of Biology, University of Padova, via G. Colombo 3, 35131 Padova, Italy; Department of Environmental Sciences University of Quèbec at Trois-Rivières, Canada.
authors.forename: Matteo
authors.initials: M
authors.lastname: Giacomazzo
authors.affiliation: Azienda ULSS n. 14 Chioggia, Italy.
authors.forename: Luciano
authors.initials: L
authors.lastname: Boffo
authors.affiliation: Laboratory of Chemistry, Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Binato
authors.affiliation: Department of Biology, University of Padova, via G. Colombo 3, 35131 Padova, Italy.
authors.forename: Maria Gabriella
authors.initials: MG
authors.lastname: Marin
authors.affiliation: Department of Comparative Biomedicine and Food Science, University of Padova, 35020, Legnaro, Italy.
authors.forename: Tomaso
authors.initials: T
authors.lastname: Patarnello
authors.affiliation: Department of Comparative Biomedicine and Food Science, University of Padova, 35020, Legnaro, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Bargelloni
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects / Q000235:genetics; D000818:Animals; D049872:Bivalvia / Q000187:drug effects* / Q000235:genetics / Q000502:physiology*; D003300:Copper / Q000633:toxicity; D004781:Environmental Exposure; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects*; D019216:Metals, Heavy / Q000633:toxicity*; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D019216:Metals, Heavy; D014874:Water Pollutants, Chemical; D003300:Copper
keywords: Adaptation; Ecological status; Gene expression; Heavy metal; Manila clam; Pollutants