Parallel monitoring of mixed-functional oxygenase (MFO) induction and DNA damage in marine organisms

• Published in: Marine environmental research Vol. 39; no. 1; pp. 355 - 356
• Main Authors: Herbert, A., Warnecke, D., Krumbeck, H., Hansen, P.-D.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 1995
• ISSN: 0141-1136; 1879-0291
• DOI: 10.1016/0141-1136(95)98404-Z

Induction of MFO activities in marine fish is now widely used as a biomarker indicating exposure to organic pollutants such as polycyclic aromatic hydrocarbons or chlorinated aromatic hydrocarbons. Although MFOs are part of a detoxifying system, they generate reactive intermediate metabolites; which may damage the primary biological information matrix DNA. Since studies of MFO induction in fish may suffer from interferences of parameters like, e.g. sex and season, it appears useful to supplement MFO monitoring with parallel monitoring of DNA damage. Rather than being simply an indicating parameter for genotoxic exposure, the genotoxic event itself is detected and quantified. To provide an instrument for large-scale monitoring of DNA damage, the authors have adapted a method from cell culture research - an alkaline DNA unwinding assay - to the study of marine organisms, which fits the following requirements: (a) wide spectrum of sensitivites providing a sum parameter for different types of DNA lesions; (b) high cost efficiency; (c) easy use; (d) high sample throughput; and (e) portability for the use in field studies, e.g. on research vessels. The non-radioactive method has been successfully used since 1985 in laboratory and field studies, both in marine invertebrates and fish. Results indicate, that fish might be more sensitive to some types of pollutants, possibly due to different capacities of the MFO system. In a case study, DNA damage in liver of fish from a wild-life population coincided with an induction of mixed-functional oxygenase (MFO) activity, when compared to fish held in laboratory tanks with filtered sea-water.