Genotoxicity of agrochemicals evaluated in Caiman latirostris using ISSR markers

VANZETTI, AGUSTÍN; SIROSKI, PABLO A.; POLETTA, GISELA L.; AMAVET, PATRICIA S.

Santa Fe

Congreso; 25th Working Meeting of the Crocodile Specialist Group (SSC-IUCN); 2018

CSG-UNL

Due its life habits, broad-snouted caiman (Caiman latirostris) is constantly exposed to the action of agrochemicals. This work aimed to evaluate possible genetic alterations caused by pesticides in C. latirostris, using ISSR markers. To achieve this goal, 27 broad-snouted caiman from an environment presumably without contamination, and 25 individuals from an agricultural-livestock area, both from the province of Santa Fe, Argentina, were analyzed. In addition, an experimental work was carried out with 33 individuals of approximately one year old, divided into two enclosures: one of them was sprayed with a mixture of widely used pesticide formulations (glyphosate, cypermethrin and chloropyrifos) at concentrations recommended for their application in soybean crops, and the other with tap potable water (control). In the case of experimental tests, blood samples were taken of all animals before and after exposure to obtain the data of each individual pre and post- treatment. DNA samples were amplified with a set of Operon® ISSR markers, from which markers 8 and 36 were chosen as variability indicators due to the large number of amplified bands (118 loci in total). The amplified PCR products were analyzed in 4% polyacrylamide gels and stained with silver nitrate solution. Gels photographs were taken for elaboration of matrices, and subsequent analyses were performed with TFPGA 1.3 software??? to estimate parameters of variability (Heterozygosis expected ?He- and Percentage of polymorphic loci -P-); and Genetic Identity (I). Results obtained from caiman living in natural environments without contamination (control) showed differences with exposed environment samples in P values (P control = 88.98; P exposed environment = 94.91), but He values were similar (He control = 0.391, He exposed environment = 0.383). The genetic identity between both sample pools was 0.937. On the other hand, the results from experimental samples showed no differences in control samples before and after treatment, but some differences were observed in animals exposed to the agrochemicals between the values before and after treatment (He pre-treatment 0.272 vs. He post-treatment = 0.349; P pre-treatment = 61.86 vs. P post-treatment = 80.51). These results suggest a tendency to the increase of genetic?? variability in the animals experimentally and environmentally exposed probable due to genotoxic effects of pesticides. We consider appropriate to expand the number of markers analyzed as well as the number of sampled individuals to confirm the present results.