Effect of Pb, Cu and Zn on development and Wnt/ß-catenin signaling pathway genes expression of Ctenopharyngodon idella.

Pollution of the aquatic environment with heavy metals is a serious environmental problem, since they accumulate in aquatic organisms and can affect their development and worsen their condition. According to the scheme of Fig. 1 zinc (Zn), copper (Cu) or lead (Pb) were studied when exposed to concentrations of: Zn (0.01; 0.1; 1 mg/L), Cu (0.001; 0.01; 0.1 mg/L), Pb (0.006; 0.06; 0.6 mg/L) for 144 h after fertilization (hpf) on the grass carp (Ctenopharyngodon idella), one of the important commercial fish species of Kazakhstan, the activity of superoxide dismutase (SOD) and the expression of genes of the Wnt/ß-catenin signaling pathway involved in development. All metals significantly reduced survival, hatching rate, and changed biometric parameters and heart rate of cupid larvae. In addition, these metals (mainly Pb and Cu) inhibited superoxide dismutase (SOD) activity and mRNA transcription of genes encoding genes of the Wnt/ß-catenin signaling pathway. These results showed that Pb, Cu and Zn not only affect the survival and development of fish at an early stage of life, but also cause oxidative stress and prevent fish detoxification.

Effect of glyphosate-based herbicide on hematological and hemopoietic parameters in common carp (Cyprinus carpio L).

The effects of Roundup (glyphosate-based herbicide) on peripheral blood parameters and hematopoietic tissue cellular composition and activity in common carp juveniles were evaluated. The fish were exposed for 7 days at 0.0, 0.1, 0.5, or 5.0 mg/L of glyphosate. In fish exposed to Roundup, hematological alterations were observed; however, most of them were not directly related to the herbicide concentration. An increase in Ht and MCV, and decrease in Hb, MCH, and MCHC compared to the control were observed. Fish exposed to Roundup showed also a reduction in WBC and oxidative metabolic activity of phagocytes (NBT) compared to the control. The fish exposed to 0.1 and 5.0 mg/L showed increased glucose values, whereas in those subjected to 0.5 mg/L blood glucose concentration declined compared to the control. Cholesterol significantly increased at 0.1 mg/L and decreased at 5.0 mg/L. Analysis of head kidney hematopoietic tissue revealed that Roundup at concentrations 0.5 and 5.0 mg/L caused a significant increase in the rate of cell proliferation accompanied by an increase in frequency of early blast cells. No significant differences occurred in percentages of most cell lineages but the frequency of monocytoid, eosinophilic, and basophilic lineage cells significantly increased in the herbicide-exposed fish compared to the control. The obtained results revealed that sublethal concentrations of Roundup that may occur in polluted natural waters caused a slight anemic and significant immunosuppressive response in common carp juveniles. On the other hand, they indicate a considerable compensatory potential of carp hematopoietic system.