Alterações genômicas e mutagênicas em duas espécies de anfíbios anuros

• Autor(a) principal: Gonçalves, Macks Wendhell
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/5066
• topic: Anuros; Bioindicadores; Girinos; Genotoxicidade; Mutagenicidade; Anura; Bioindicators; Tadpoles; Genotoxicity; Mutagenicity; BIOQUIMICA::BIOLOGIA MOLECULAR

Amphibian populations have declined in many areas of the world. These declines seem to have worsened over the past 25 years and amphibians are now more threatened than other taxa, such as mammals or birds. Numerous factors contribute to this decrease; however, environmental pollution has recently been cited as a major factor. These vertebrates are important in natural control of several pests in natural and agricultural areas, where they are constantly exposed to large amounts of pesticides. Genotoxicity studies with amphibians are important to detect indicator species of environmental change. Amphibians are particularly sensitive to these variations due to their behavioral and physiological characteristics, such as, permeable skin (cutaneous respiration), low mobility and life cycle with simultaneous dependence of the aquatic and terrestrial environment. In this context, these animals could be used as bioindicators of the environmental quality in genotoxicity and mutagenicity studies. The aim of this study was to analyze the genomic damage in tadpoles of Dendropsophus minutus and Physalaemus cuvieri sampled in perturbed and natural areas, by the comet assay and micronucleus test. We found that the tadpoles of D. minutus and P. cuvieri collected in perturbed areas had the highest extensions of DNA damage compared to the tadpoles of natural areas. Tadpoles sampled in soybean crop areas had higher DNA damage, followed by those sampled in the cornfields. In contrast, the frequency of DNA damage in tadpoles of natural areas were significantly lower in relation to DNA damage suffered by tadpoles of agricultural areas. Thus, we can conclude that tadpoles of D. minutus and P. cuvieri sampled in this study can be considered excellent sentinel organisms, as they were sensitive to environmental changes. In addition, we can highlight the advantages of using the comet assay in environmental genotoxicity studies, such as its speed, high sensitivity in detecting DNA damage in the genome of amphibians, for a relatively low cost. However, it is necessary to invest in the standardization of methodologies for field studies, thus the results could be compared between different laboratories, and make environmental genotoxicity studies, involving aquatic organisms, more informative and applicable as a practical laboratory routine.