Developmental Toxicity of the herbicide Glyphosate (Roundup®) in Caiman latirostris embryos

POLETTA, G.; M.D. MUDRY; E. KLEINSORGE AND A. LARRIERA

Montelimar, Francia

Congreso; 18th Working Meeting of the IUCN-Species Survival Commission Crocodile Specialist Group; 2006

CSG/IUCN/SSC

Glyphosate (N-Phosphonomethyl glycine) is the active ingredient of Roundup®, a broad spectrum, non-selective herbicide widely used in agriculture to control weeds in soya plantations and others crops. The relative low toxicity of  the active ingredient glyphosate increases in the formulation Roundup® due to addition of surfactants. Various of these compounds are reported to be capable of interacting with the DNA of living cells and therefore cause genotoxic effects.  In Santa Fe province, Argentina, some areas of the broad-snouted caiman (Caiman latirostris) habitat are near to agricultural zones were agrochemicals such as Roundup® are being used increasingly. Therefore, it was necessary to evaluate the potential contamination risk to which the specie is environmentally exposed.   The assessment of toxicological effects in embryonic development is a bioindicator of ecological risk that permits the analysis of possible consequences in subsequent stages of the animal life. The aim of this study was to evaluate the potential developmental toxicity and teratogenesis of sublethal dosis of Roundup® in embryonic development of C. latirostris. We exposed 100 embryos to different concentrations of Roundup® at early embryonic stage and after hatching we examined morphological endpoints and evaluate genotoxic effects aplying two assays: the Comet assay and the Micronucleus (MN) test. The results of this study indicated that Roundup®, at the concentration tested, had no effect on body mass and size examined in C. latirostris shortly after hatching. However, the results of the Comet assay showed that Roundup® induced an increase in DNA damage at 500 and 1000 µg/egg compared to negative control group. Results corresponding to the MN test are not available yet because slides are still being scored. These data agree with other researches which have concluded that the low toxicity considered for Glyphosate increases in commercial formulations. Further research is needed in order to accurately assess the hazards of the agrochemical product that really is going to the field, to evaluate better the consequences of environmental exposure of these and other important species.