Reproductive Parameters Affected by Atrazine Exposure in Males of the Eared Dove (Zenaida auriculata)

BACH, N.; FILIPPA, V.; CHEDIACK, J. G.; CID, F. D.

Montevideo

Congreso; SETAC Latin America 15th Biennial Meeting; 2023

SETAC LA

Reproduction is fundamental for species survival and enables physiological processes, associatedbehaviors and structures involved in the next generation production. Thus, it is important to includereproductive endpoints when conducting ecotoxicology studies, taking into account the current global wildlife crisis. Atrazine (ATZ) is an herbicide of the triazine family widely used in the world. In Argentina, it is the second most used herbicide, associated with corn and sorghum crops. Its effects as an endocrine disruptor in amphibians are widely documented, with known cases of feminization and intersex gonads in exposed individuals. In birds, some effects on gonads size and circulating steroid hormones are known in ATZ exposed individuals, however, there are no studies involving bird native species. In this context, the aim of this study was to evaluate ATZ effects on reproductive tissue in males of the native bird Zenaida auriculata. Eighteen organisms distributed in three groups (0, 25 and 250 mg ATZ/kg) were assayed with 6 replicates each. ATZ diluted in corn oil was administered by intermittent gavage during 15 days, being administered only corn oil (without ATZ) in the control group (0 mg ATZ/kg). Once the experiment was finished, body mass of each organism was recorded and birds were dissected (prior anesthesia). Gonad mass was recorded for Gonadosomatic Index (GSI) determination. Subsequently, the testes were fixed inbouin solution, embedded in paraffin, and serially cut 6 um thick for histological analysis of the germinal epithelium. Seminiferous epithelium was classified in VII categories according cellular maturation and association, being stage I-VII of growing maturity. To contrast body mass and GSI between groups, oneway ANOVA was performed (Tukey post-hoc test, p 0.05) between treatments. These results suggest that there is an increase in germinal epithelium development in birds exposed to high concentrations of ATZ. Further studies evaluating steroid hormone levels in doves exposed to atrazine are needed to confirm an endocrine disruption effect.