Cell cycle kinetics and basal values of genetic damage in C. villosus (Xenarthra) as a sentinel organism for monitoring genotoxicity in Argentina

ROSSI L. F.; LUACES, J. P.; CHIRINO M. G.; MUDRY M. D.; MERANI M. S.

Ciudad Autónoma de Buenos Aires

Congreso; SETAC Latin America 11th Bienal Meeting; 2015

Society of Environmental Toxicology And Chemistry Argentina

The large hairy armadillo (Chaetophractus villosus) is an endemic mammal with a broader distribution in Argentina. Its distribution overlaps with regions of intensive agricultural activity. Consequently, some agrochemicals released to the environment may induce genetic alterations in this mammal. Up to the moment, no studies had been made concerning the possibility to apply biomarkers of genotoxic effect in C. villosus, as a consequence to the environmental action. The aim of this study was to determine the baseline values of genetic damage in this native species, in order to establish its suitability as a sentinel organism for monitoring environmental pesticide hazard. Cytotoxic (mitotic index (MI), index of blast formation (BI), replication index (RI)), and genotoxic biomarkers (percentage of chromosome aberrations (CA) and frequency of sister chromatid exchange (SCE)) were analyzed on peripheral blood lymphocytes culture. The MI, BI, and CA were performed in a total of 20 adults (10 females and 10 males) from different localities along the endemic species distribution [Bahía Blanca (n=2), General Madariaga (n=1), Loma Verde (n=3), Monteverde (n=4), Navarro (n=2), Pellegrini (n=1), Pipinas (n=1), Saladillo (n=3), and Santo Domingo (n=3)]. Also, from 6 adults (3 females and 3 males) chosen randomly RI (counted in 1,000 cells) and SCE (counted in 30 cells) were carried out. Values for positive control were established adding 0.3 μg/ml of mitomycin C to the culture after 24 h of incubation. Our results show in all studied individuals that BI (86.8 ± 5.59 blast cells/total cells), MI (2.9 ± 1.37 metaphases/total cells) and CA (1.5 ± 0.84%) present statistically no significant differences respect to our historical controls (t=0.65, P=0.52, t=0.67, P=0.51 and t=0.49, P=0.62 respectively). RI was 1.7 ± 0.1 and the frequency of SCE was 7.4 ± 1.3/cell. All the biomarkers evaluated are quite stable among armadillos.These findings confirm the value of these short term tests as accurate screening tools for the evaluation of cytotoxic and genotoxic effects in C. villosus. This is the first reference of the application of these biomarkers in C. villosus and first in wild Xenarthra from Argentina. C. villosus may be considered a good biological model as sentinel organism in their natural distribution in order to monitor genotoxic xenobiotics as pesticides.