CONICET | Buscador de Institutos y Recursos Humanos

Characterization of baseline DNA damage in sentinel organisms would provide early information about the genotoxic potential of agents occurring in their habitat. The effects of these agents depend on many aspects, some of them concerning the species under study. The aim of this study was to evaluate the variation of spontaneous genetic damage values associated with age using Micronucleus Test (MN) and comet assay (CA). Twenty-four newborns (NB), twenty-one juveniles (JUV) and twenty adults (AD) tegu lizard (Tupinambis merianae) were used for this study. The MN and CA were applied on peripheral blood erythrocyte of this reptilian species. Baseline frequency of micronuclei (BFMN= MN/1000 erythrocytes) and basal damage index (BDI: 100 comet images classified in arbitrary units) determined for the different age groups were: NB= 0.16 ± 0.07 and 146.21 ± 4.22, JUV= 0.29 ± 0.12 and 104.5 ± 0.65, AD= 0.95 ± 0.27 and 103.85 ± 0.97, respectively. A significant increase in the BFMN according to increasing age was observed, with significant difference only between NB and AD (p< 0.016). On the contrary, the BDI showed decreasing values with increasing age of tegu lizard. NB presented a significantly higher BDI that JUV and AD (p< 0.016). Regarding the nest of origin and sex of the AD animals, no significant differences were found for any of the biomarkers (p> 0.05). A very low linear relationship was found between BFMN and weight of NB (p= 0.014; R2= 0.245) but no relation was found between BDI and size of the animals for any age (p> 0.05). We found only a moderate influence of age on baseline values of these biomarkers of genotoxicity, confirming the suitability of tegu lizard as sentinel species for future monitoring studies of genotoxicity induced by xenobiotics in its natural habitat in Argentina.