Mutagenic effects of tributyltin and inorganic lead (Pb II) on the fish H. malabaricus as evaluated using the comet assay and the piscine micronucleus and chromosome aberration tests

Abstract

Genotoxicity studies on toxic metals and their organic compounds are very important, especially so in the investigation of the effects of these compounds on the aquatic environments where they tend to accumulate. The use of endemic aquatic organisms as biological sentinels has proved useful to environmental monitoring. We assessed the mutagenic potential of tributyltin (TBT) and inorganic lead (PbII) using samples of the fish Hoplias malabaricus (commonly called traíra) using the comet assay and the piscine micronucleus and chromosome aberration tests. Eighteen H. malabaricus were acclimatized in three individual aquariums, each containing six fish, six fish being exposed to 0.3 µg/g of body weight (bw) of TBT, six to 21 µg/g bw of PbII and six being used as controls. Exposure to TBT and PbII was achieved by feeding the fish every five days with Astyanax (a small fish that is part of the normal diet of H. malabaricus) which had been injected with solutions of TBT, PbII or with water (the control group). After two months the H. malabaricus were sacrificed and their peripheral blood collected and subjected to the comet and micronucleus assays, the chromosome aberration assay being conducted using kidney-tissue. Although the comet assay showed now mutagenic effects at the lead concentrations used but encountered results with TBT, the micronucleus and chromosome aberrations assays both indicated that TBT and PbII are potentially mutagenic (p < 0.01), the micronucleus assay showing morphological alterations of the nucleus.

Environmental genotoxicity and cytotoxicity in the offshore zones of the Baltic and the North Seas

“…Water concentrations of TBT in such areas can reach 100 ng l -1 while, in other offshore areas, its concentration can be less than 1 ng l -1 (OSPAR, 2000). Several studies have demonstrated that TBT can induce shell malformations in oysters, imposex in gastropods, reduced resistance to infection in flatfish and that it is genotoxic and cytotoxic to molluscs and fish (Mičić et al, 2001;Ruedel et al, 2003;HELCOM, 2003;Ferraro et al, 2004;Hagger et al, 2005). Despite the ban of it use, studies performed on herring, flounder, pikeperch, sea birds, and blue mussels demonstrated that TBT is still present in the Baltic Sea water organisms at elevated concentrations (Kannan et al, 1999;Albalat et al, 2002;Strand and Jacobsen, 2005).…”

Scenario of Genotoxicity in Fishes and Its Impact on Fish Industry

“…Marcon et al (2010) found that a high content of certain metals in the water could be one of the factors that might cause genetic damages in fish. The comet assay has been successfully used to investigate effects of genotoxic pollutants on the integrity of DNA (Çok et al, 2011;Ferraro et al, 2004;Scalon et al, 2010). Micronucleus test was the only genotoxicity test applied thus far on barbel specimens from the natural population in the Danube River (Boettcher et al, 2010).…”

Assessment of Genome Damage in Bird and Mammal Species as a Tool for Improvements in ex-situ Conservation at Zoos

“…A number of studies have been carried out for a better understanding of the role chemical substances play in ecosystems as well as how and where they occur in the environment, their interactions, effects on the biota and duration in the environment (Ferraro et al 2004). However, little attention has been given to chemical substances and their effect on the quality of enclosure environments at zoos, which are home to many rare and often threatened animal species.…”

“…In both cases, the differences in genotoxic responses may reside in the inherent biology of these species submitted to similar selective pressure (Zúñiga et al 1996;Meier et al 1999;Ferraro et al 2004;Newman 2001). Analyzing the expression of micronucleated cells in intra-species terms, Mazama gouazoubira achieved the lowest mean values of micronucleated cells (Tables 1 and 3), which may be related to the low metabolic rate of the species in artificial environments.…”