Endocrine Disruption and Transgenerational effect of Atrazine herbicide in the nematode Caenorhabditis elegans life cycle

MOYA, ALDANA; MAZZARELLA, DANIEL; CLAVIJO, ARACELI; MUNARRIZ, ELIANA; KRONBERG, M. FLORENCIA; PAGANO, EDUARDO

Cordoba

Congreso; VI Congreso Argentino de la Sociedad de Toxicología y Química Ambiental SETAC; 2016

Sociedad de Toxicología y Química Ambiental SETAC.

Endocrine disrupting chemicals (EDCs) are exogenous agents that interfere with hormone signaling. A wide range of substances like pesticides, polychlorinated biphenyls and plasticizers cause endocrine disruption. Atrazine (ATZ) is a worldwide used herbicide to control broadleaf and grassy weeds on crops such as corn, sorghum and sugarcane. Reports shown that ATZ have endocrine disruptor activity; nevertheless, their adverse effects on human and animal health are not fully understood. ATZ use was banned in the European Union in 2004 while the Environmental Protection Agency approved its use, consequently the safety of ATZ remains controversial. The aim of this study is to assess ATZ endocrine disrupting effects using the nematode Caenorhabditis elegans as a biological model. Specifically, we were interested in study how the life cycle was affected in second-generation descendent of nematodes treated with low doses of ATZ. C. elegans in L4 larval stage were exposed to different concentrations of ATZ (0.001; 0.01; 0.1; 1; 10 mg/l) for 24 hours till they reached adulthood. After the ATZ treatments, worms were washed and kept in culture for two generations (F1 and F2). Nematode growth and reproduction were measured in all three nematodes populations (F0, F1 and F2). Post embryonic development in F1 and F2 was analyzed and percentage of developmental stages was calculated. C. elegans F2 population (second-generation from parental generation treated with low doses ATZ) showed a no-monotonic in ?W" shape dose-response curve for growth and reproduction. The maximum effect on growth and reproduction was determinate at 0.001 and 0.01 mg/l ATZ. At 0,001mg/L, grown and reproduction were decreased 10% and 30% respectively, compared to the control; while at 0,01mg/L the reduction was 15% and 30%. The postembryonic developmental analysis showed a delay in F1 and F2. In fact, 0,001mg/L ATZ samples had 18% less adult worms compared to the control. The same concentration showed a 31% decrease in F2 compared to F1. Our results suggested that the herbicide ATZ has a transgenerational effect in C. elegans life cycle. Specifically, low doses of ATZ can interfere with the normal postembryonic development till two generation after the worms which were treated with the herbicide. As a consequence of these alterations, low doses of ATZ decrease the growth and reproduction rates in the nematode C. elegans.