Long-term disruption of oviductal immune homeostasis in Caiman latirostris following in ovo exposure to endosulfan or atrazine.

The oviduct of reptiles can be infected by a wide range of pathogens, potentially compromising organ health and egg viability. Early exposure to endocrine-disrupting compounds (EDC) can lead to immune system alterations, by either suppressing or exacerbating the immune response. In this study, we investigate immune homeostasis in the oviduct of Caiman latirostris and assess whether in ovo exposure to endosulfan (END) or atrazine (ATZ) disrupts immune homeostasis at the pre-pubertal juvenile stage. We analyzed the mRNA expression of β-defensin 12 (BD12), the correlation between defensin expression and circulating sex hormones, the presence of circulating and infiltrating immune cells (lymphocytes, heterophils, basophils, eosinophils, monocytes, macrophages, and mast cells), and the pattern of acidic and neutral epithelial secretions in the oviduct of C. latirostris. Exposure to END increased the percentage of acidic epithelial secretions and established a positive correlation between circulating estradiol levels and BD12 expression. Meanwhile, ATZ exposure decreases the percentage of neutral epithelial secretions in the oviduct. These findings suggest that EDC may disrupt oviductal immune homeostasis in C. latirostris, potentially compromising future reproductive health and embryo survival.