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Spermatogenesis is a fascinating biological process aiming to generate haploid spermatozoa from diploid spermatogonia through a specific hormonal network between gonadotropins and steroids. Increasing evidence suggests that the primary female sex hormone estrogen plays an active role in this process. This research points out on the role of estrogen during lizard spermatogenesis by using three experimental approaches: (1) exposure to an analogue of nonsteroidal estrogen as Clomiphene citrate that acts both as estrogen agonist and antagonist; (2) exposure to the gonadotropin FSH; and (3) exposures to FSH followed by Clomiphene. Histological and immunohistochemical results demonstrate that in the lizardPodarcis siculaduring the mating period, Clomiphene as well as FSH determines the breakdown of spermatogenesis and the epididymal regression, presumably through estrogens input as indirectly demonstrated by the appearance of ERαand vitellogenin in the liver. The ability of Clomiphene to restore the gonadal natural condition after FSH treatment is also demonstrated. Finally, data indicate that lizard testis and epididymis control their morphophysiology regulating the intracellular presence of ERα.

The potential toxicity of glyphosate, a widely used broad-spectrum herbicide, is currently a great matter of debate. As vertebrate insectivores, lizards protect plants from herbivorous insects increasing plant biomass via the trophic cascade and represent an important link between invertebrates and higher predators. A negative effect of glyphosate on lizards’ survival could have major impacts at the ecological levels. In this study, we investigated the effects of the exposure to low doses of glyphosate on the liver of the wall lizard Podarcis siculus, a suitable bioindicator of soil pollution. Two different doses of pure glyphosate (0.05 and 0.5 μg/kg body weight) were orally administered every other day for 3 weeks to sexually mature males and females. The results demonstrated that both doses, despite being very low, are toxic for the liver that showed clear signs of suffering, regardless of sex. The histological analysis provided a scenario of severe hepatic condition, which degenerated until the appearance of fibrotic formations. The morphological observations were consistent with a loss of liver physiological functions. Immunocytochemical investigations allowed us to detect an involvement of antioxidant/cytoprotective proteins, such as superoxide dismutase 1 (Cu/Zn SOD, known as SOD1), glutathione peroxidase 1 (GPx1), metallothionein (MT), and tumor suppressor protein 53, (p53) suggesting that the liver was trying to react against stress signals and damage induced by glyphosate. Finally, in situ hybridization and Real-Time PCR analysis showed the upregulation of estrogen receptor α and vitellogenin gene expression, thus demonstrating the xenoestrogenic action of glyphosate. The imbalance of the hormonal homeostasis could threaten the lizards’ reproductive fitness and survival, altering the trophic cascade.

The concentration of cadmium and lead ions was determined in digestive gland and mantle of mussels (Mytilus galloprovincialis) from five aquaculture stations located in the Gulf of Naples (Southern Italy, Tyrrhenian Sea). Metallothionein (MT) levels in the same tissues were also evaluated. This gulf represents a greatly urbanized area, characterized by an important commercial port and past industrial activities, terminated in the last decade of the 20th century. The results were compared with those obtained from mussels cultivated in a more pristine neighbouring area. Data demonstrate that the amount of both metals found in mussels harvested at the highly anthropogenic sites in the Gulf of Naples was comparable with that found in mussels from the more naturalistic site. The content of both cadmium and lead was not related with that of MT. Indeed, the amount of both metals in the digestive gland was greater than in the mantle, whereas the MT preferentially accumulated in the mantle. Possibly, the MT content in mantle was associated to the physiological function of the tissue, rather than heavy metals exposure.