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(80-05) Allozyme analysis, DNA adducts and cytogenetic damage in two mollusk species of the Venice lagoon. Venier, Paola*,1, Dolcetti, Luigi1, Ghiotto, Rossella1, Bisol, Paolo M.1, 1 University of Padova, Padova, Italy, Italy ABSTRACT- In the frame of the project "Production, change and vulnerability of transitional aquatic environments along the Adriatic coast", Mytilus galloprovincialis and Tapes philippinarum were collected in June 2000 from three sites (1-offshore, rearing mussel zone, 2-Malamocco lagoon outlet, 3- inner lagoon, Marghera industrial district). In addition to single measures, a number of biological parameters were studied in parallel on small sub-samples of each species, as alternative pilot characterization of the local mollusk populations. Simple morphometric measures, allozyme analysis by isoelectrofocusing (OCT, octopine dehydrogenase, GPI, glucose-6-phosphate isomerase, IDH, isocitrate dehydrogenase, PGM, phosphoglucomutase) and genetic damage detection (DNA adducts, micronuclei and other nuclear abnormalities) were carried out. Results refer to individual mollusks with the exception of the DNA adducts, measured on pooled gill tissues from 5 individuals by means of the nuclease- and butanol-enhanced 32P-postlabelling assay. The allelic frequencies at polymorphic loci were analyzed in about 50 individuals/site and varied between the two species and among the three sites: the observed heterozigosity was higher in T. philippinarum than in M. galloprovincialis and, in both cases, no univocal trends were detected from the open sea towards the inner lagoon. In contrast, increasing levels of bulky DNA adducts and nuclear abnormalities, the latter measured in gill and haemolymph cells, were found along the same direction, thus confirming the presence of genotoxic pollutants in the Venice lagoon. The multiparametric data referring to 5 individuals/site were finally interpreted by cluster analysis. Overall, the results obtained support the complexity of relationships between environmental stress factors and biological responses and the importance of biomarkers of genetic damage in the evaluation of the Venice lagoon ecosystem. Granted by MURST 1999. Key words: Mytilus galloprovincialis, Tapes philippinarum, allozymes, genetic damage |
