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The exploitation of solar energy is considered one of the possible solutions to the increasing energy demand and for this reason the use of photovoltaic cells (PVC) has progressively increased in the last thirty years. First commercially available PVC have been installed in the early ’80; they are now at the end of their life and need to be dismissed, a costy procedure due to the potential toxicity of theircomponents. The purpose of this work was to assess the environmental risk associated with an incorrect disposal of PVC and, in particular, to verify if damaged panels release in water components harmful to the aquatic environment. For this purpose, fragments of PVC panels were kept in infusion in water for 30 days. The resulting solutions were analyzed to determine chemicals released and to asses toxicity on Daphnia magna, Artemia salina and sea urchin (Paracentrotus lividus). Results demonstrate that the panels, if damaged, release different metals (especially antimonium, aluminum and nickel) that exert a significant toxicity on the three species examined. In particular in the two crustaceans PVC solution increase mortality and induces cytological damages in the naupliar eyes. In P. lividus, PVC solutions alter normal progression of embryo development, causing asynchrony and producing amorphous plutei. In conclusion, data obtained indicate that it is essential to set up programs for safe disposal of photovoltaic panels.

In the present paper we investigated the role played by apoptosis during oogenesis in the cartilagineous fish Torpedo marmorata. TEM, TUNEL and immunohistochemical techniques were employed to specifically reveal morphological and biochemical hallmarks of apoptosis in specimens from birth to sexual maturity. Data obtained demonstrate that apoptosis occurs in prefollicular oocyte selection, in maintaining the homeostasis of granulosa in healthy growing oocyte and in resorbing atretic follicles. In this respect, the involvement of apoptosis in Torpedo marmorata oogenesis closely parallels that found in mammals, thus confirming that strategies of germ cell selection among vertebrates have been evolutively preserved. Mol. Reprod. Dev. 66: 54–59, 2003. © 2003 Wiley-Liss, Inc.

The Angitola lake is an artificial basin located in Calabria Region, in South Italy, part of the “Natural Regional Park of Serre”. Its surface area is 1.96 km2 and it is approximately 3 km away from Sant’Eufemia gulf. The basin was created in 1966 by damming the homonymous river. Four major rivers enter the lake: three in the far southeast, the fourth, smaller and active only during the winter period, in the southwest area. The international Ramsar Convention includes the basin and surroundings; in light of the Rio Convention, its directives have been transposed in the “Birds Directive” (BD) and “Habitats Directive” (HD). The Angitola lake, entrusted to the WWF Calabria, is one of the 2299 Italian SIC (code IT9340086): this area significantly contributes in maintaining and restoring the endangered freshwater habitat listed in HD, in protecting biodiversity of the region and it is part of the Natura 2000 network. The present study is part of the Angitola FISH2O project (European Fisheries Fund/FEP code 02/BA/12) and it aimed to examine the benthic macro-invertebrates community of the southeast part of Angitola lake. The first 15 cm in depths of sediments have a very variable composition, from fine sand to mud (rich in organic matter). This variability can be explained by the different characteristic of the chosen sampling transepts. Fauna sampling, carried out by core drills and plankton nets, shows presence of Diptera and Tricoptera larvae and some Nematoda, Polichaeta and Mollusca. Preliminary conclusion is that the Angitola lake is a diversified environment in which areas with different anthropic interference are present. The benthic macro-invertebrates community might be involved by possible disturbances induced by chemicals (e.g. water pollution) and/or physical variations (e.g. high sedimentation). Medium and long-term investigations are imperative to protect and promote the lake biodiversity, to verify the effects of seasonal fluctuations and how these are related to human activities such as tourism, demographic increase and industrial activities.

Cadmium is one of the most harmful heavy metal present in aquatic systems since its toxic effects are exerted on many animal species, including teleosts. Damages interest a plethora of organs and tissues including the visual system. For teleosts, the sense of sight is important both for hunting and for escape and, therefore, a damage at this level alters behavior and reduce the fitness. In this study, we describe the ultrastructural alterations produced by cadmium on the photoreceptors and ganglion cells in retina of adult zebrafish, a model organism. To check whether the effects are dose-related, we tested two different concentrations of CdCl2: 0,3mg/L mouth of the river Sarno, Italy and 3mg/L. Results indicate that cadmium exposure induces a moderate retinal disorganization, in particular, that it induces apoptosis among photoreceptors and ganglion cells. This event activates a regenerative response by the Müller glial cells, stem cells, present in the inner nuclear layer. They differentiate and then migrate as, neuronal cells progenitors, thus regenerating the damaged retina.

Sight is the sense mainly used by teleosts to hunt for food and escape predators. As a consequence, the eyes are large and a complex visual behavior has been developed. This consist in a series of ‘instinctive’ responses that the animal puts into action when exposed to a stimulation of visual nature. These mechanisms are potentially threatened by the fact that the eye is an easy target for many xenobiotics: in fact, it is directly exposed to the environment and, also, contains a large vitreal chamber that facilitates contaminants distribution to all its compartments. In the present work, we verified whether cadmium, at environmental concentrations, interferes with the visually mediated behaviors in adult Danio rerio,a model system for behavioral screens since 1970’s. Re-illumination tests were carried out with white and colored lights (red, yellow, green and blue), to test color sensitivity in fish contaminated for 30 days. Results reveal that cadmium exposure induces a marked escape response to all light wavelengths. Parallel light and electron microscope investigations demonstrate that cadmium alters retinal organization: the ion, in particular, induces occasional retinal folding, a marked swelling, especially in the ganglion cell and, most important, induces degeneration among ganglion and inner nuclear layer cells. In conclusion, results indicate that cadmium has detrimental effects on visual behavior and that this probably depends on an altered signals transmission from the photoreceptors to the central nervous system. Further studies are required to fully understand the mechanisms underlying cadmium response in the retina; however, the evidences collected so far clearly indicate that animals living in contaminated sites have a reduced fitness. The implications at the ecological level are obvious.

EFFETTI DEL METALLO SULLA STRUTTURA ED ORGANIZZAZIONE DEL FOLLICOLO DELLA LUCERTOLA.

Il lavoro descrive le caratteristiche delle cellule follicolari del rettile Podarcis ed illustra come queste possano costituire un buon modello sperimentale per lo studio dei meccanismi di proliferazione, differenziamento e morte clelulare.

In Podarcis, undifferentiated, pre-differentiated and differentiated follicle cells can be recognised by shape, size, position and function. Undifferentiated (stromal) and pre-differentiated (small) cells are stem cells destined to proliferate and differentiate while differentiated cells (pyriforms) are nurse cells programmed to sustain oocyte growth and then degenerate at the end of previtellogenesis. The present work clarifies whether competence to undergo apoptosis in pyriforms is acquired at the time they originate from the small cells or later during aging. For this purpose the expression of Fas, Fas-L, caspase 3 and DNase I have been investigated by immunocytochemistry in small and pyriform cells. Results indicate that all these cell death factors are present exclusively in pyriforms. Their synthesis starts as soon as cells differentiate and that while aging, Fas and Fas-L are down and up regulated respectively. We conclude that pyriforms are committed for apoptosis since differentiation and that death occurs via mechanisms alternative to receptor or mitochondrial mediated pathways.