Spermatogenesis is a complex process of male germ cells proliferation and maturation from diploid spermatogonia, through meiosis, to mature haploid spermatozoa. The process involves dynamic interactions between the developing germ cells and their supporting Sertoli cells. The gonadal tissue, with abundance of highly unsaturated fatty acids, high rates of cell division, and variety of testis enzymes results very vulnerable to the overexpression of reactive oxygen species (ROS). In order to address this risk, testis has developed a sophisticated array of antioxidant systems comprising both enzymes and free radical scavengers. This chapter sets out the major pathways of testis generation, the metabolism of ROS, and highlights the transcriptional regulation by steroid receptors of antioxidant stress enzymes and their functional implications. It also deals with of the advantages of the system biology for an antioxidant under steroid control, the major selenoprotein expressed by germ cells in the testis, the phospholipid hydroperoxide glutathione peroxidase (PHGPx/GPx4) having multiple functions and representing the pivotal link between selenium, sperm quality, and species preservation.

No abstract

Model of the our research was the adult male amphibian anura, Pelophylax bergeri, poikilotherm species not considered threatened by the IUCN, sampled in representative sites at different degree. In the first phase, a biochemical characterization of the ADP-ribosylation on the skin of barcoded amphibian anura collected from Matese Lake (clean reference site in CE, Italy) was carried out. Two PARP isoforms were evidence: the first of 66 kDa is localized into nucleus and activated by DNA damage; the second of 150 kDa is in cytoplasm, as demonstrated by biochemical and immunohistochemical analysis. Subsequently, the PARP activity, the quantitative expression of androgen receptor gene, and the levels of arsenic and chromium in skin and testis of frog and soil, water, and sediment collected from sites at different degrees of pollution were measured. A significant variation of PARP activity and androgen receptor expression levels was detected in both tissues of barcoded frogs from Sarno and Scafati, along Sarno River (SA, Italy), suggesting that a PARP activation is correlated to pollution and to steroid-regulated physiology disruption.

There is rising concern for the interaction of environmental contaminants with brain transcriptome and the potential effect on reproductive processes. The present study sought to determine selenoprotein glutathione peroxidase 4 (gpx4) transcriptional activity in the brain and testis of the soil biosentinel, Podarcis sicula, through the main phases of the reproductive cycle and whether pharmaceuticals exert an endocrine disruption. Based on gpx4 cloned amminoacids sequence (GenBank AEX09236.1.), we used a bioinformatic approach to assess the structural role. Specifically, we detected seasonally the reactive oxygen species (ROS) level using electron spin resonance spectroscopy and gpx4 transcriptional activity using quantitative real-time polymerase chain reaction. In addition, the impact of pharmaceuticals was assessed after 21-days of treatment with ICI 182,780 and human chorionic gonadotropin administration in mating and winter stasis, respectively. Bioinformatic data shows the gpx4 proteic activity and a phylogenetic profile. ROS contents in lizard brain are significantly less than in testis and display higher levels after treatments. Brain gpx4 expression gives statistically significant seasonal differences, opposite trends in testis and altered expression in both tissues, with evidence of testis morphological and DNA disruption.Taken together, these results provide direct evidence that gpx4 in P. sicula plays a seasonal regulatory role and may be a reliable biomarker for reproductive health toxicity screening. K E Y W O R D S endocrine disruption, gpx4, pharmaceutical oxidative insult, Podarcis sicula, ROS