Caging exposure of freshwater crayfish Astacus leptodactylus for in situ detection of pollutionrelated genotoxicity
Maja Šrut1, Olga Malev2, Ivana Maguire1, Anamaria Štambuk1, Simonetta Lorenzon3, Enrico A.
Ferrero2, Göran I.V. Klobučar1
1
Department of Zoology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000 Zagreb,
Croatia
2
Department of Biology, Faculty of Science, University of Trieste, via Giorgieri 7, I-34127 Trieste,
Italy
3
Biological Oceanography Department, National Institute of Oceanography and Experimental
Geophysics, via A. Piccard 54, I-34010 S. Croce, Trieste, Italy
Among the cellular components DNA is one of the main targets of environmental stress. Influence of
environmental pollution was assessed by measuring DNA damage in haemocytes of caged freshwater
crayfish Astacus leptodactylus by the means of the comet assay and micronucleus test. Animals were
collected at the reference site (river Mrežnica) and exposed for a period of one week at the three sites
of different pollution intensity along the river Sava (Zagreb, Sisak, Krapje). Separate crayfish group
caged at the reference site was used as a control. On each location sediment was collected for
chemical analysis. Statistically significant increase in DNA damage measured by the comet assay was
observed at all three polluted sites comparing to the reference site. Micronuclei induction showed
similar gradient of DNA damage, but did not reach the statistical significance. On the site Zagreb,
representing medium polluted freshwater, individuals from mildly polluted site (Krapje) were exposed
along with the ones from the reference site. After one week exposure individuals from mildly polluted
site showed lower level of DNA damage than the ones from the reference site, indicating activity of
adaptive mechanisms in animals from pollution stressed environment. In this study freshwater
crustaceans were used for the first time as sentinel organisms in environmental genotoxicity studies.
Our results have proved applicability of caging exposure of a freshwater crayfish A. leptodactylus in
environmental biomonitoring and confirmed usefulness of comet assay and micronucleus test as
suitable tools for detection of pollution-related genotoxicity.
Corresponding address: msrut@biol.pmf.hr