Micronucleus Test and Comet Assay in Erythrocytes of the Amazonian Electric Fish Apteronotus bonapartii Exposed to Benzene

Abstract

In this study we address the genotoxicity and putative mutagenic effects of benzene (BZN) in the erythrocytes of the electric fish Apteronotus bonapartii (Gymnotiformes, Apteronotidae) using the micronucleus test (MN) and comet assay, under controlled laboratory conditions. Electric fish were collected in the Solimões River, Manaus-AM, Brazil, and the specimens were exposed to 10 and 25 ppm concentrations of BZN, in 150L tanks. Blood samples were collected at 0 (T 0), 24, 48, 72 and 96 hours of exposure. For the concentration of 10 ppm BZN, the number of comets was significantly higher than T 0 levels after exposure of 48 hours, whereas the nuclear abnormalities (including MN) did not show any increase in relation to the controls (T 0) up to 96 hours. For the 25 ppm BZN, MN rates presented a significant increase after 72 hours, whereas other types of nuclear abnormalities increased in frequency after various exposure times, ranging from 24 to 72 hours. The number of comets increased significantly from 24 hours onwards for 25 ppm BZN. Both assays also showed a gradual increase in the number of damaged cells after longer exposure periods, indicating a time-dependent effect, especially at the highest BZN concentrations tested. This investigation reinforces the potential use of the endemic South American electric fish as a suitable genotoxicity biological model for biomonitoring purposes in the Amazon.

Genotoxicity and histopathological assessment of raw and simulated leachates exposed to mice

“…Micronucleus assay has been extensively used to assess genetic damage during cell division. Although the mechanism of the damage is not known but it is believed that induction of micronucleus is a true reflection of damage to the DNA (Bücker, et al, 2012). Comparison between the level of induction of cellular damage and micronucleus as shown in Table 4 is another evidence to show that simulated leachates contains more genotoxic substances than raw leachate samples.…”

Genetic and Hematologic Endpoints in Astyanax altiparanae (Characidae) After Exposure and Recovery to Water-Soluble Fraction of Gasoline (WSFG)

“…This is due to the fact that they are the aromatic hydrocarbons found in larger amounts in gasoline (Adami et al 2006) and they are more soluble than PAHs (Desai et al 2010). After spills and leakages of oil and derivates, BTEX compounds are likely to be present in the greatest amounts, with the potential to cause various kinds of damage to organisms in aquatic organisms (Bücker et al 2012).…”

<i>IN-VIVO</i> EVALUATION OF HEXAVALENT CHROMIUM INDUCED DNA DAMAGE BY ALKALINE COMET ASSAY AND OXIDATIVE STRESS IN <i>CATLA CATLA</i>

“…At the end of 24 h of exposure, at least six fish for each of the four groups were anesthetized with benzocaine (0.1 g L −1 ) and blood was collected from the caudal vein, using heparin-coated syringes (Bucker et al, 2012;Heuser et al, 2002). On each sampling day, the whole blood was collected and immediately processed for Micronuclei assay as described below.…”

“…The DNA damage was evaluated by Micronucleus (MN) and comet assays which are the two sensitive, rapid and extensively used tools for detecting the mutagenic and genotoxic effects of chemicals in the environment, since Micronucleus (MN) assay is an easy and ideal monitoring system that uses aquatic organisms to assess the Genotoxicity of water in the field and in the laboratory (Ali et al, 2008a;Bucker et al, 2012). Muid et al (2012) has pointed out that the comet assay is considered a suitable and rapid test for DNA-damaging potential in environmental and biomonitoring studies.Research reports indicate that it can be applicable to freshwater and marine fishes and that gill cells are more sensitive than the hematopoietic cells to micronucleus inducing agents which has been reported by most of the researchers (Al-Sabti and Metcalfe, 1995;Cavas et al, 2005;Fontanetti et al, 2010;Palus et al, 2003).…”