Validation of Comet assay in Oregon-R and Wild type strains of Drosophila melanogaster exposed to a natural radioactive environment in Brazilian semiarid region

• Published in: Ecotoxicology and environmental safety Vol. 141; pp. 148 - 153
• Main Authors: Verçosa, Cícero Jorge, Moraes Filho, Aroldo Vieira de, Castro, Ícaro Fillipe de Araújo, Santos, Robson Gomes dos, Cunha, Kenya Silva, Silva, Daniela de Melo e, Garcia, Ana Cristina Lauer, Navoni, Julio Alejandro, Amaral, Viviane Souza do, Rohde, Claudia
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01.07.2017
• Subjects: Animals; Background Radiation - adverse effects; Brazil; Comet Assay - methods; Desert Climate; DNA Damage; Drosophila melanogaster - genetics; Drosophila melanogaster - radiation effects; Environmental Exposure; Environmental genotoxicity; Hemocytes - chemistry; Model organism; Radon (222Rn); Radon - toxicity; Rio Grande do Norte – Brazil; Sensitivity and Specificity; Uranium - toxicity; Radon (222Rn); Environmental genotoxicity; Rio Grande do Norte – Brazil; Model organism; DNA damage; Radon (Rn)
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2017.03.024

Natural radiation of geological origin is a common phenomenon in Brazil, a country where radioactive agents such as uranium may be often found. As an unstable atom, uranium undergoes radioactive decay with the generation of a series of decay by-products, including radon, which may be highly genotoxic and trigger several pathological processes, among which cancer. Because it is a gas, radon may move freely between cracks and gaps in the ground, seeping upwards into the buildings and in the environment. In this study, two Drosophila melanogaster Meigen (Diptera, Drosophilidae) strains called Oregon-R and Wild (collected in a non-radioactive environment) were exposed to atmospheric radiation in the Lajes Pintadas city, in the semiarid zone of northeastern Brazil. After six days of environmental exposure, the organisms presented genetic damage significantly higher than that of the negative control group. The genotoxic effects observed reinforce the findings of other studies carried out in the same region, which warn about the environmental risks related to natural radioactivity occurrence. The results also validate the use of the Comet assay in hemocytes of D. melanogaster as a sensitive test to detect genotoxicity caused by natural radiation, and the use of a recently collected D. melanogaster strain in the environmental of radon. [Display omitted] •Comet Assay was improved in hemolymph cells of Drosophila melanogaster.•Oregon-R strain and an outward wild population showed strong sensibility to Radon in air.•Drosophila is a useful model for study the genotoxic risks of Radon to humans and other organisms.•The results represent a new toxicological approach to investigate the effect of natural radiation.