Interferences of an environmental pollutant with estrogen-like action in the male reproductive system of the terrestrial vertebrate Podarcis sicula

• NP polluted diet affects the morpho-physiology of the testis and epididymis.
• NP interferes with the expression of estrogen and androgen receptors in the testis.
• NP switches off the secretion of the epididymal channel through ERα expression.
• The lizard Podarcis sicula is a good bio-indicator of environmental pollution.

Nonylphenol (NP) is classified among the endocrine disruptor chemicals with estrogen-like properties. It is widely used in many industries and to dilute pesticides in agriculture, and is known to affect the reproductive system of many aquatic and semi-aquatic organisms. This study aimed to verify how NP, administered via food and water, may interfere with the reproductive cycle of a terrestrial vertebrate. Our model was the male Italian wall lizard Podarcis sicula, a seasonal breeding species that may be naturally exposed to environmental pollution. From our findings it emerges that an NP-polluted diet administered during the mating period causes in this lizard a slowdown of spermatogenesis and affects the testicular and epididymal structure, making it similar to that of the non-reproductive period. The distribution in the testis and epididymis of mRNA for steroid hormone receptors, i.e., estrogen α and β and androgen receptors, was also investigated. NP treatment inhibits the expression of AR, ERα, and ERβ-mRNA in spermatogonia and primary spermatocytes and causes a switch-off of the secretory activity of the epididymal corpus by inducing the expression of ERα.