Glyphosate (Gly) is a broad-spectrum herbicide widely used thanks to its high efficiency and low toxicity. However, evidence exists of its toxic effects on non-target organisms. Among these, the animals inhabiting agricultural fields are particularly threatened. Recent studies demonstrated that exposure to Gly markedly affected the morphophysiology of the liver and testis of the Italian field lizard Podarcis siculus. The present study aimed to investigate the effects of the herbicide on the female reproductive system of this lizard in order to have a full picture of Gly-induced reproductive impairment. The animals were exposed to 0.05 and 0.5 μg/kg of pure Gly by gavage for 3 weeks. The results demonstrated that Gly, at both doses tested, profoundly interfered with ovarian function. It induced germ cells' recruitment and altered follicular anatomy by anticipating apoptotic regression of the pyriform cells. It also induced thecal fibrosis and affected oocyte cytoplasm and zona pellucida organizations. At the functional levels, Gly stimulated the synthesis of estrogen receptors, suggesting a serious endocrine-disrupting effect. Overall, the follicular alterations, combined with those found at the level of the seminiferous tubules in males, suggest serious damage to the reproductive fitness of these non-target organisms, which over time could lead to a decline in survival.
Keywords: estrogen disruptors; oogenesis; reproductive toxicology; reptiles.