Metodi ecotossicogenomici nel monitoraggio degli ambienti acquatici: modulazione dell’attività trascrizionale in Daphnia magna.

Within a research aimed at the development and application of “effect-based” methods in environmental monitoring, a study based on the toxicogenomic approach was undertaken. Specifi cally, a procedure for assessing the alteration of gene expression was developed and applied in Daphnia magna in vivo exposed to environmental samples taken from sections of the Val Parma hydrographic network subjected to different anthropogenic pressures. The transcriptional profi le of genes involved in reproductive activity (vitellogenin1, vtg1), development (cuticle 12, cut12, and the carboxypeptidase A1 precursor, cpa1) and in energy resource allocation (hemoglobin, dhb1) was analyzed. To select the most appropriate development stage and to evaluate the sensitivity of the method, the fi rst phase of the study was devoted to the analysis of the effects of known endocrine disruptors (20-hydroxyecdysone and cadmium) on gene transcriptional profi le. The standardized protocol was then applied to the monitoring of watercourses. A mountain section of Parma river was selected as a possible reference station. Considering the results as a whole, a general alteration of gene expression is evident in organisms exposed to samples from small waterways in the plain and, in the main watercourse, along a downstream gradient. Additionally, evidences obtained from the toxicogenomic approach are in accordance with the classifi cation of the sections based on biological elements.