Journal of Environmental Biology

Identification of DNA damage in marine fish Therapon jarbua

by comet assay technique

Author Details

N. Nagarani

(Corresponding author)

Department of Marine and Coastal Studies, Madurai Kamaraj University, Madurai - 625 021, India

e-mail: nagaranikannan@yahoo.co.in

V. Janaki Devi

Department of Marine and Coastal Studies, Madurai Kamaraj University, Madurai - 625 021, India

A.K. Kumaraguru????

Department of? Marine and Coastal Studies, Madurai Kamaraj University, Madurai - 625 021, India

Publication Data

Paper received:

21 October 2010

Revised received:

03 March 2011

Re-revised received:

26 March 2011

Accepted:

26 May 2011

Abstract

The marine fish Therapon jarbua was exposed to acute concentration of mercuric chloride (HgCl₂). In static acute toxicity bioassays at 24, 48, 72 and 96 hr LC₅₀ values were estimated for each concentrations such as control, 2, 1, 0.5, 0.25 and 0.125 ppm, respectively. DNA damage (single-strand break) was also studied in gill, kidney and blood tissues at single-cell levels in the specimens exposed to different acute doses of HgCl₂, by applying single-cell electrophoresis (comet assay). Dose- dependent responses were observed in DNA damage in all tissues. A comparison of DNA damage in all tissue at two concentration namely, 0.125 and 0.25 ppm indicated that the gill cells (maximum damage as 249.3? and 289.7 AU) were more sensitive to the heavy metal exposure than kidney (maximum 225.17 AU) and blood cells (maximum 200.3 AU). This study explored the utility of the comet assay for in vivo laboratory studies using fish for screening the genotoxic potential for various agents.

Key words

Acute toxicity, Genotoxicity, Mercuric chloride, Therapon jarbua

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