Application of the micronucleus test and comet assay in Trachemys callirostris erythrocytes as a model for in situ genotoxic monitoring

ABSTRACT: Trachemys callirostris is a turtle species endemic to northern South America. In northern Colombia it occurs in the middle and lower Magdalena River drainage and its principal tributaries (lower Cauca and San Jorge rivers) and in other minor drainages such as the lower Sinú River. In recent years, industrial, agricultural, and mining activities have altered natural habitats in Colombia where this species occurs, and many of the pollutants released there are known to induce genetic alterations in wildlife species. The micronucleus test and comet assay are two of the most widely used methods to characterize DNA damage induced by physical and chemical agents in wildlife species, but have not been employed previously for genotoxic evaluations in T. callirostris. The goal of this study was to optimize these genotoxic biomarkers for T. callirostris erythrocytes in order to establish levels of DNA damage in this species and thereby evaluate its potential as a sentinel species for monitoring genotoxic effects in freshwater environments in northern Colombia. Both genotoxic techniques were applied on peripheral blood erythrocytes from 20 captive-reared T. callirostris individuals as a negative control, as well as from samples obtained from 49 individuals collected in Magangué (Magdalena River drainage) and 24 individuals collected in Lorica (Sinú River drainage) in northern Colombia. Negative control individuals exhibited a baseline frequency of micronuclei of 0.78±0.58 and baseline values for comet tail length and tail moment of 3.34±0.24 µm and 10.70±5.5, respectively. In contrast, samples from both field sites exhibited significantly greater evidence of genotoxic effects for both tests. The mean MN frequencies in the samples from Magangué and Lorica were 8.04±7.08 and 12.19±12.94, respectively. The mean tail length for samples from Magangué and Lorica were 5.78±3.18 and 15.46±7.39, respectively. Finally, the mean tail moment for samples from Magangué and Lorica were 23.59±18.22 and 297.94±242.18, respectively. The frequency of micronuclei in the samples was positively related to comet tail length and tail moment. Thus, this study showed that both genotoxicity biomarkers may be applied to T. callirostris erythrocytes as a sentinel organism for assessing the effects of environmental pollutants in freshwater ecosystems in northern South America.

• Autores: Zapata Restrepo, Lina María; Bock Garnier, Brian Carl; Orozco Jiménez, Luz Yaneth; Palacio Baena, Jaime Alberto
• Tipo de recurso: Article of investigation
• Fecha de publicación: 2016
• Institución: Universidad de Antioquia
• Repositorio: Repositorio UdeA
• Idioma: eng
• OAI Identifier: oai:bibliotecadigital.udea.edu.co:10495/39814
• Acceso en línea: https://hdl.handle.net/10495/39814
• Palabra clave: Colombia; Genotoxicidad; Genotoxicity; Ensayo Cometa - métodos; Comet Assay - methods; Daño del ADN - efectos de los fármacos; DNA Damage - drug effects; Monitoreo del Ambiente - métodos; Environmental Monitoring - methods; Eritrocitos - efectos de los fármacos; Erythrocytes - drug effects; Agua Dulce; Fresh Water; Marcadores Genéticos; Genetic Markers; Pruebas de Micronúcleos; Micronucleus Tests; Modelos Biológicos; Models, Biological; Ríos - química; Rivers - chemistry; Tortugas - sangre; Turtles - blood; Contaminantes del Agua - toxicidad; Water Pollutants - toxicity; Contaminación del Agua - efectos adversos; Water Pollution - adverse effects; https://id.nlm.nih.gov/mesh/D003105; https://id.nlm.nih.gov/mesh/D020552; https://id.nlm.nih.gov/mesh/D004249; https://id.nlm.nih.gov/mesh/D004784; https://id.nlm.nih.gov/mesh/D004912; https://id.nlm.nih.gov/mesh/D005618; https://id.nlm.nih.gov/mesh/D005819; https://id.nlm.nih.gov/mesh/D015162; https://id.nlm.nih.gov/mesh/D008954; https://id.nlm.nih.gov/mesh/D045483; https://id.nlm.nih.gov/mesh/D014426; https://id.nlm.nih.gov/mesh/D014873; https://id.nlm.nih.gov/mesh/D014876
• Rights: openAccess
• License: http://creativecommons.org/licenses/by-nc-nd/2.5/co/