Is metal contamination responsible for increasing aneuploidy levels in the Manila clam Ruditapes philippinarum?
The present study assessed the metal genotoxicity potential at chromosome-level in the bivalve Ruditapes philippinarum collected along different areas of the Tagus estuary. Higher levels of aneuploidy on gill cells were detected at the most sediment contaminated area both in May (31.7%) and October (36.0%) when compared to a less contaminated area over the same periods (20.3% and 29.0% respectively). Interestingly, metal bioaccumulation in gills was higher in the specimens collected at the least contaminated area with the exception of Pb. Indeed, the multivariate analysis revealed a stronger relation between aneuploidy and sediment contamination than between aneuploidy and the bioaccumulation of the metals. The temporal and spatial inconsistency found for the bioaccumulation of metals in R. philippinarum and the positive correlation between sediment contamination and aneuploidy at the most contaminated area suggest that these chromosome-level effects might be due to chronic metal contamination occurring in the Tagus estuary, rather than a direct result of the temporal variation of bioavailable contaminants. The vertical transmission phenomenon of bivalve aneuploidy levels may then be perpetuating those levels on clams from the most contaminated area. The present results shed light about the effect of metal toxicity at the chromosome-level in species inhabiting chronic contaminated areas and highlight the use of aneuploidy as an effective tool to identify persistent contamination in worldwide transitional waters.
Portuguese Institute for the Ocean and Atmosphere (IPMA), Avenida 5 de Outubro, 8700-305 Olhão, Portugal; Department of Biology, Faculty of Marine and Environment Sciences, University of Cadiz, Campus de Excelencia International del Mar (CEIMAR), Avda. República Saharaui S/N Puerto Real, 11510 Puerto Real, Cadiz, Spain. Electronic address: david.pilo@ipma.pt.
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Piló
King Abdullah University of Science and Technology (KAUST), Red Sea Research Center, Thuwal 23955-6900, Saudi Arabia.
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Carvalho
Portuguese Institute for the Ocean and Atmosphere (IPMA), Av. Brasília, 1449-006 Lisbon, Portugal; Centre for Environmental and Marine Studies and Department of Biology (CESAM), University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
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Pereira
Portuguese Institute for the Ocean and Atmosphere (IPMA), Avenida 5 de Outubro, 8700-305 Olhão, Portugal; Centre of Marine Sciences (CCMAR), University of Algarve (UAlg), Campus de Gambelas, 8005-139 Faro, Portugal.
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Gaspar
Environmental Science Center (ESC), Qatar University, P.O. Box 2713, Doha, Qatar.
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Leitão
D000782:Aneuploidy; D000818:Animals; D049872:Bivalvia / Q000187:drug effects / Q000235:genetics*; D063366:Estuaries; D019015:Geologic Sediments; D005880:Gills / Q000187:drug effects; D008670:Metals / Q000633:toxicity*; D011174:Portugal; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D008670:Metals; D014874:Water Pollutants, Chemical
Aneuploidy; Chromosome; Estuary; Metal contamination; Ruditapes philippinarum; Vertical transmission