HERBICIDE GENOTOXICITY REVEALED WITH THE SOMATIC WING SPOT ASSAY OF Drosophila melanogaster

Abstract

The genotoxicity of the herbicides clomazone, linuron and simazine was detected using the somatic wing spot assay of Drosophila melanogaster. For the evaluation of the mutagenic and recombinogenic activities induced by the herbicides two crosses were used: the standard cross (ST) which expresses basal levels of cytochrome P450 enzymes and the high bioactivation cross (HB) with overexpression of P450 genes conferring increased sensitivity to promutagens and procarcinogens. Third-instar larvae were exposed by chronic feeding (48 h) to three different concentrations of each herbicide. The frequencies of spots per individual in the treated series were compared to the negative concurrent control series (water or 5 % ethanol solution depending on the herbicide). Clomazone showed positive results for small and total spots in both the ST and the HB crosses. Linuron was positive at all concentrations tested for small and total spots in the ST cross while only positive for small and total spots at the highest concentration assayed in the HB cross. Simazine did not produce positive results in the ST cross while it was positive in the HB cross. The bifunctional cross-linking agent mitomycin C (MMC-0.15 mM) was used as positive control and produced as expected a significant increase of all types of spots in both crosses. In conclusion, the positive results were due to induced mutations and not by recombinogenic activity, furthermore the significant increase in the frequency of total spots was mainly due to the induction of small single spots. Palabras clave: clomazón, linurón, simacina, ensayo de mutación y recombinación somática RESUMEN La genotoxicidad de los herbicidas clomazón, linurón y simacina se detectó empleando el ensayo somático en alas de Drosophila melanogaster. Para la evaluación de la actividad mutagénica y recombinogénica inducida por los herbicidas se emplearon dos cruzas: la cruza estándar (ST) que expresa niveles basales de enzimas citocromo P450 y

Publication trends of somatic mutation and recombination tests research: a bibliometric analysis (1984‒2020)

“…Although both tests are accurate, sensitive, and specific, the wing-spot test allows the visual scoring of wings over time, whereas in the eye-spot test, the analysis should be performed quickly since no preserving actions are available on the eyes [ 17 ]. In fact, the SMART assays have been applied in the analysis of the genotoxicity and the antimutagenicity of several chemicals and agents such as pesticides [ 18 - 20 ], nanomaterials [ 21 , 22 ], food products [ 23 , 24 ], hormones [ 25 ], plant extracts [ 26 ], and drugs [ 27 - 29 ]. With this variety of studies, a bibliometric analysis is required to assess the impact of this methodology on the genotoxicity studies.…”