Expressão diferencial de genes relacionados ao estresse oxidativo no peixe anual Austrolebias charrua (Cypridontiformes: Rivulidae) em resposta à exposição ao herbicida Roundup Transorb®

Abstract

Roundup Transorb (RDT) is the most popular glyphosate-based herbicide (GHB), used in agriculture worldwide. Due to its increasing application, GHB may reach non-target enviroments generating concern about potential toxicological and environmental damage when these compounds are present in aquatic environments, reaching non target organisms such as fishes. The annual fish Austrolebias charrua is an endangered species, endemic in the southern region of Brazil (Rio Grande do Sul) and Uruguay, occurring in regions close to soy and rice crops. The present study aims to evaluate the effects of A. charrua exposure to different concentrations of RDT 0.065 and 5 mg/L glyphosate acid equivalent, on gene expression of genes related to electron transport chain and antioxidant system on liver and gills by quantitative real time PCR.The individuals were exposed to RDT during 96 hours, followed by 96 hours of water without contaminants. Afterwards, the animalswere euthanized, and the tissues were collected. In liver, the results showed an up-regulation on gene expression of gclc and gstα when animals are exposed to 5 mg/L RDT and a down-regulation of ucp1 ene expression at both concentrations of RDT. In gills, the gene expression of cat was down-regulated at both concentrations of RDT and ucp1 gene expression was up regulated at 0.065 mg/L RDT. This is the first study that evaluates the gene modulation after RDT exposure in A. charrua. This study is important for understanding the molecular mechanisms involved in toxicology of GHB on non-target species and can generate subsidies for adaptation of legislation in order to protect endengered species.