Acronym GENOTOPE
Category
Fisheries
Title Mechanisms of pesticide-induced dna damage in fish and interference from co-exposure to other pollutants Programme National Programme
Instrument (FP6)
Contact Type (FP7)
Strand (Interreg)
NA
Theme (FP7)
Activity Area (FP6)
Regional Area (Interreg)
Action (COST)
NA
Specific Programme (FP7)
NA
Funding source National Coordinator Mario Pacheco Coordinator email NA
Coordinator institution
CESAM - Centre for Environmental and Marine Studies (Portugal)
Institutions involved
UTAD - University of Tras-os-Montes and Alto Douro (Portugal) ,
Start year 2011 End year 2014 Funding (€) € 90,050 Website https://www.cesam-la.pt/projetos/genopes-mecanismos-de-dano-no-adn-induzido-por-pesticidas-em-peixes-e-interferencia-da-co-exposicao-a-outros-poluentes/ Summary "Genotoxicity is one of the main effects of contaminants. Considering pesticides among the most ubiquitous and dangerous contaminants, the “leitmotiv” of the project was the discovery of a gap in the literature regarding their genotoxicity in fish. The well-documented genotoxicity in bacteria and mammals [1-3], as well as the positive results obtained in the few studies on fish [4-7], justify a redirection of research in this direction. Although studies with mammals have demonstrated that DNA damage and oxidative stress may be related in the context of exposure to pesticides [8-9], in fish the mechanisms involved remain to be identified.
Therefore, the main issues of the project are the assessment of pesticide genotoxicity in fish and the development of solid knowledge about the respective mechanisms. The strategy involves the assessment of genotoxicity (i), accompanied by the study of processes crucial to the extent and type of damage, such as (ii) enzymatic activation/detoxification, (iii) defense mechanisms and (iv) DNA repair/renewal cell phone.
As a marker of genotoxicity (i) the comet assay will be adopted in its standard version and in combination with DNA repair enzymes (FPG, endonuclease III), in order to determine breaks and oxidized bases, respectively. In addition, micronucleus (MN) and erythrocytic nuclear anomalies (ANE) tests will be adopted as measures of clastogenesis/aneugenesis. As indicators of activation and detoxification (ii) activities of cytochrome P450-oxidases and conjugases will be measured. The levels of antioxidants and stress proteins will express defense mechanisms (iii). The assessment of the transient nature of DNA lesions (iv), a result of cell repair and renewal, will be carried out following the genotoxicity indicators in the post-exposure period.
All parameters will be determined in blood, gills, kidney, liver and brain, with the exception of the MN and ANE tests which will only be applied to blood, in order to compare the vulnerability of each tissue. The test organism will be the European eel (Anguilla anguilla), as it has the main characteristics required for a bioindicator species.
The simultaneous use of multiple pesticides is the rule rather than the exception in agricultural practices. The real situation is even more complex as pesticides appear in the aquatic environment as part of a cocktail of different classes of contaminants, so co-exposure to pesticides and metals or nutrients is a likely scenario, particularly in eutrophic rivers and lakes. Therefore, in order to evaluate the genotoxicity of pesticides under ecologically realistic conditions, the project will be developed in 3 consecutive and complementary phases: 1 – Laboratory exposures (hours-days) to pesticides representing the main classes, such as endosulfan (organochlorine), glyphosate (organophosphate) and carbofuran (carbamate), individually or in binary mixtures; 2 – Laboratory exposures (hours-days) to pesticide-metal (Cr or Cu) and pesticide-nutrient (nitrate or nitrite) mixtures; 3 – In situ exposures (hours-days) in a freshwater lagoon – Pateira de Fermentelos (central Portugal), adopted as a prototype of a multi-contaminated system (receiver of domestic discharges, pesticides and industrial effluents containing metals). The fish will be caged seasonally and biomarker analysis will be complemented with analyzes of pesticides and metals in the water, sediment and fish tissues.
The research team includes members with extensive experience in studying the toxicity of various contaminants in fish [10,11], but also young researchers, fulfilling the objective of providing scientific training. The group has demonstrated its awareness of the importance of interactions between compounds in multi-contamination conditions (in the field [12] and in the laboratory [13]), as well as its commitment to investigating the association between oxidative stress/biotransformation and damage to the DNA [14,15]. Additionally, the group has excellent knowledge of the experimental model (A. anguilla), accumulated over two decades of research [16]. These aspects constitute important support for the pursuit of the stated objectives.
The proposed strategy is innovative in the context of fish, on the one hand, due to its integrative nature, embodied in the wide variety of processes studied and with a modulating role in DNA damage, and on the other, due to the application of the comet assay combined with endonucleases, which can offer valuable information about breakage induction mechanisms. Finally, the expected results will provide highly useful recommendations for decision-makers, fundamental for the (re)formulation of regulations towards environmental protection."
Keywords
Toxic substances;
Fish;
Fish health;
Eel;
Genetic;
Impacts;
Marine Region
0
NA
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