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

BACH N; FILIPPA VP; CHEDIACK, J. G.; CID F.

Montevideo

Congreso; SETAC Latin America 15th Biennial Meeting.; 2023

SETAC

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 globalwildlife crisis. Atrazine (ATZ) is an herbicide of the triazine family widely used in the world. In Argentina, it isthe second most used herbicide, associated with corn and sorghum crops. Its effects as an endocrinedisruptor in amphibians are widely documented, with known cases of feminization and intersex gonads inexposed individuals. In birds, some effects on gonads size and circulating steroid hormones are known inATZ exposed individuals, however, there are no studies involving bird native species. In this context, theaim of this study was to evaluate ATZ effects on reproductive tissue in males of the native bird Zenaidaauriculata. Eighteen organisms distributed in three groups (0, 25 and 250 mg ATZ/kg) were assayed with 6replicates each. ATZ diluted in corn oil was administered by intermittent gavage during 15 days, beingadministered only corn oil (without ATZ) in the control group (0 mg ATZ/kg). Once the experiment wasfinished, body mass of each organism was recorded and birds were dissected (prior anesthesia). Gonadmass 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 germinalepithelium. Seminiferous epithelium was classified in VII categories according cellular maturation andassociation, being stage I-VII of growing maturity. To contrast body mass and GSI between groups, onewayANOVA was performed (Tukey post-hoc test, p<0.05). Data that failed to meet ANOVA assumptionswere analyzed by Kruskall-Wallis test. Seminiferous epithelium stage VII were recorded only in 250 mgATZ/Kg exposed birds, with mature stages of spermatid and residual bodies at the lumen of seminiferoustubules. In addition, GSI resulted higher in birds exposed to 250 mg ATZ/Kg (p < 0.05) and no effects wereobserved in body mass (p > 0.05) between treatments. These results suggest that there is an increase ingerminal epithelium development in birds exposed to high concentrations of ATZ. Further studies evaluatingsteroid hormone levels in doves exposed to atrazine are needed to confirm an endocrine disruption effect.