title: Microelectrophoretic study of environmentally induced DNA damage in fish and its use for early toxicity screening of freshwater bodies.
abstract: This study investigates the potential of the comet and micronucleus assays of fish DNA as a means of screening the toxicity of aquatic environments. Catla catla and Cirrhinus mrigala collected from the River Chenab in Pakistan were used as a case study for the application of comet and micronucleus techniques. Comet and micronucleus assays were used to compare DNA damage in C. catla and C. mrigala collected from polluted areas of the River Chenab and farmed fish. Atomic absorption spectrophotometry showed an acute level of toxicity from Cd, Cu, Mn, Zn, Pb, Cr, Sn, and Hg in river water. Comet assay showed significant (p < 0.05) DNA damage in C. catla representing 17.33 ± 2.42, 11.53 ± 2.14, and 14.17% DNA in the comet tail, averaged from three sites of the polluted area of the river. Tail moment was observed as 10.06 ± 2.71, 3.11 ± 0.74, and 14.70 ± 1.89, while olive moment was 8.85 ± 1.84, 3.83 ± 0.76, and 7.11 ± 0.73, respectively. Highly significant (p < 0.01) damage was reported in C. mrigala as 37.29 ± 2.51, 34.96 ± 2.53, and 38.80 ± 2.42% DNA in comet tail, tail moment was 23.48 ± 3.90, 19.78 ± 4.26, and 14.30 ± 1.82, and olive moment was 16.22 ± 2.04, 13.83 ± 1.96, and10.99 ± 0.90. Significant (p < 0.05) differences were observed in genotoxicity between farmed and polluted area fish. Micronucleus assay showed a similar picture of significant difference in respect to single and double micronucleus induction: i.e., 23.20 ± 4.19 and 2.80 ± 1.07‰ in C. catla and 44.80 ± 3.73 and 06.20 ± 0.97‰, respectively, in C. mrigala. Nuclear abnormalities were found as 6.00 ± 0.84 and 09.60 ± 1.72/thousand cells, respectively, in both species. The results of this study suggest that these novel fish DNA damage assays can be used as an expedient toxicity screening for aquatic environments.
authors.affiliation: Department of Zoology, Government College University, Faisalabad, Pakistan. shahidmahboob60@hotmail.com.
authors.forename: Bilal
authors.initials: B
authors.lastname: Hussain
authors.affiliation: Department of Zoology, Government College University, Faisalabad, Pakistan.
authors.forename: Tayyaba
authors.initials: T
authors.lastname: Sultana
authors.affiliation: Department of Zoology, Government College University, Faisalabad, Pakistan.
authors.forename: Salma
authors.initials: S
authors.lastname: Sultana
authors.affiliation: Department of Zoology, College of Science, King Saud University, P. O. Box 2455, Riyadh, Saudi Arabia.
authors.forename: K A
authors.initials: KA
authors.lastname: Al-Ghanim
authors.affiliation: Department of Bioinformatics and Biotechnology, Government College University, Faisalabad, Pakistan.
authors.forename: Shahreef
authors.initials: S
authors.lastname: Masood
authors.affiliation: Center of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Ali
authors.affiliation: Department of Zoology, Government College University, Faisalabad, Pakistan.|Department of Zoology, College of Science, King Saud University, P. O. Box 2455, Riyadh, Saudi Arabia.
authors.forename: Shahid
authors.initials: S
authors.lastname: Mahboob
mesh_terms: D000818:Animals; D020552:Comet Assay / Q000379:methods*; D004249:DNA Damage; D004784:Environmental Monitoring / Q000379:methods*; D005399:Fishes; D005618:Fresh Water; D015162:Micronucleus Tests / Q000379:methods*; D010154:Pakistan; D045483:Rivers
keywords: Biomarker; DNA fragmentation; Genotoxicity; Indian major carps