CHAPTER 14: The Piscine Erythrocyte Micronucleus Cytome Assay

Technological advancements introduce several genotoxic chemicals that adversely affect the health status of aquatic organisms and may eventually pose a risk to human health via the contaminated food chain. Biomarkers of genotoxicity such as micronuclei (MN) and other nuclear abnormalities can be measured by the erythrocyte micronucleus assay, a relatively simple technique that is highly useful in assessing the health conditions of biota and their surrounding ecosystems. This chapter briefly describes the micronucleus assay in fish and highlights DNA damage detection using this method under laboratory and in situ conditions. Plausible mechanisms of the formation of nuclear and cytoplasmic abnormalities upon exposure to mutagenic agents, literature evidence on the occurrence of MN and other cellular abnormalities and a simplified protocol for conducting the assay in fish peripheral erythrocytes are also described. Ample evidence for renaming the assay as the erythrocyte MN cytome assay (EMNCA) are presented based on the advantage of measuring MN together with other nuclear anomalies in identifying biomarker profiles specific to physical and chemical genotoxin exposures in fish.