[Assessment of Erythropoiesis Status in Roach (Rutilus rutilus) of the Radioactively Contaminated Techa River].

At present volumetric activity of ß-emitting radionuclides in water at various locations of the Techa River ranges from 5 to 40-Bq/L; a specific activity of ß-emitting radionuclides in the bottom sediments at various locations ranges 10 Ito 106 Bq/kg dry weight. A significant increase of the erythroblast content in blood as compared to that in the roach from the reference watercourse (the Miass River) was observed during spawning in the spring. Due to this fact the number of erythrocytes was equal to that in the control animals under chronic radiation exposure at the dose rates of 0.9 and 16 µGy/day, and was insufficient at the dose rate of 108 gGy/day. During summer feeding no changes in the indexes of erythropoiesis in roach were observed under chronic radiation exposure at the dose rate of 0.9 µGy/day; the number of erythrocytes in the peripheral blood declines when the dose rates are 16 and 108 µGy/day. When performing a regression analysis, we revealed a dose-rate-dependent decrease in the absolute number of erythrocytes, normocytes, polychromatocytes, dividing and non-dividing erythroid cells in the peripheral blood of roach from the Techa River and an increase of a relative number of normochromatophylic erythrocytes.

Genotoxicity assessment of the Danube River using tissues of freshwater bream (Abramis brama).

This study examines the use of freshwater bream (Abramis brama) as a sentinel organism for genotoxicity assessment of the Danube River using the comet assay. Sampling of bream was performed during February, April, August, and November in 2014 to assess seasonal variation of DNA damage level as a response to genotoxicity in annual cycle. Additionally, concentrations of fecal coliforms and enterococci were analyzed and they indicated a critical to strong level of fecal pollution on investigated locality during annual cycle. Comet assay was performed on blood, liver, and gill cells of bream. DNA damage level was expressed using tail intensity (TI %), Olive tail moment (OTM), and tail length (TL pix). According to TI and OTM, all three tissues had the highest level of DNA damage in August. The lowest level of DNA damage in liver was measured during February, in blood during November, and in gills during April. According to TL, gills had the highest level of DNA damage in February, and liver cells had the lowest level of damage during April. Multiple correspondence analysis (MCA) showed that DNA damage in blood cells is under the strong influence of variations in NO2, NO3-, NH4+ levels and also the variation in temperature and oxygen levels. DNA damage in liver cells is highly associated with the variations of Mn, Fe, Cu, Zn, and PO43- levels. DNA damage in gill cells is strongly affected by the variations of As, Cd, Pb, Cr, and COD (Mn) levels. Freshwater bream is shown to be a potentially good indicator organism in genotoxic potential field studies.

Assessment of genotoxic and mutagenic potential of hexavalent chromium in the freshwater fish Labeo rohita (Hamilton, 1822).

The present study was undertaken to investigate the genotoxicity and mutagenicity of sublethal concentrations of hexavalent chromium (potassium dichromate) in the Indian major carp, Labeo rohita. The 96 h LC50 value of potassium dichromate estimated was 118 mg L(-1) by probit analysis using SPSS (version 16.0) software. Based on 96 h LC50 value, three sublethal test concentrations of potassium dichromate (29.5, 59.0 and 88.5 mg L(-)(1)) were selected and specimens were exposed in vivo to these test concentrations for 96 h. The mutagenic and genotoxic effects of potassium dichromate were evaluated in gill and blood cells using micronucleus (MN) test and comet assay. In general, significant (p < 0.05) effects due to the concentrations and the exposure durations were observed in exposed specimens. The MN induction was highest at 96 h at all the test concentrations in the peripheral blood. A similar trend was observed for the DNA damage, measured in terms of percentage of tail DNA, in erythrocyte and gill cells. The study indicated hazardous effect of the hexavalent chromium to fish and other aquatic organisms and indirectly to human beings.

[Assessment of erythrocytes pathology level in peripheral blood in roach (Rutilus rutilus L.) from reservoirs with different levels of radioactive contamination].

In summer 2009, the level of pathology of erythrocytes was assessed in the peripheral blood of roach (Rutilus rutilus L.) from the reservoirs for water-storage of low level radioactive waste of PA "Mayak". Roach from the Shershny reservoir and the Buffer reservoir (Chelyabinsk region) was used as a control. Radionuclide maintenance in water, sediment, and roach was determined and dose rates for the roach were calculated using the software package ERICA Assessment Tool 1.0 May 2009. It is revealed that chronic radiation exposure with the dose rates in the range from 0.8 up to 19 mGy/d leads to a twofold increase in the frequency of erythrocytes with micronuclei in peripheral blood, dose-dependent increase in the frequency of red blood cells with the nuclear pyknosis and causes no significant increase in the level oferythrocyte amitosis. It is suggested that the frequency rate of apoptosis in peripheral blood erythrocytes of the fish could be used in the biological monitoring of contaminated aquatic ecosystems.

Ecotoxicogenomics to support ecological risk assessment: a case study with bisphenol A in fish.

Effects of bisphenol A (BPA) on ovarian transcript profiles as well as targeted end points with endocrine/reproductive relevance were examined in two fish species, fathead minnow (Pimephales promelas) and zebrafish (Danio rerio), exposed in parallel using matched experimental designs. Four days of waterborne exposure to 10 µg BPA/L caused significant vitellogenin induction in both species. However, zebrafish were less sensitive to effects on hepatic gene expression and steroid production than fathead minnow and the magnitude of vitellogenin induction was more modest (i.e., 3-fold compared to 13,000-fold in fathead minnow). The concentration-response at the ovarian transcriptome level was nonmonotonic and violated assumptions that underlie proposed methods for estimating hazard thresholds from transcriptomic results. However, the nonmonotonic profile was consistent among species and there were nominal similarities in the functions associated with the differentially expressed genes, suggesting potential activation of common pathway perturbation motifs in both species. Overall, the results provide an effective case study for considering the potential application of ecotoxicogenomics to ecological risk assessments and provide novel comparative data regarding effects of BPA in fish.