Evaluation of Micronucleus Assay and Genotoxic Effect in Oreochromis mossambicus Exposed to a Fumaronitrile

Abstract

Chemical contaminants of major concern in a polluted environment include persistent organic chemical, pesticides, oils, nutrients, heavy metals, etc. Some of these chemicals are known genotoxicants and can cause damage to the genetic material of the exposed organism. Apart from the enzymatic biomarkers, other parameters, such as DNA damage, should be evaluated for assessing the consequences of exposure of chemical. Damaged DNA may potentiate subsequent deleterious cellular events such as disease (e.g. cancer) and reduced reproductive competence. DNA damage in a variety of aquatic animals has been associated with reduced growth, abnormal development and reduced survival of embryos, larvae and adults. The DNA damage which is induced by fumaronitrile exposure could be evaluated by using the comet assay. The comet assay [alkaline single-cell gel electrophoresis] is a widely used technique to detect DNA damage due to environmental stress. The toxicological effect of fumaronitrile originates from its oxidizing action. Once entered in to the cell, in the presence of cellular reluctant, it induces DNA fragmentation, which is considered to be premutagenic change. The kind of the nuclear alterations observed in erythrocytes of Oreochromis mossambicus exposed to the fumaronitrile is binucleated cells, cells with bleb bed and lobed nuclei.