Detection of metal induced cytopathological alterations and DNA damage in the gills and hepatopancreas of green mussel Perna viridis from Ennore Estuary, Chennai, India Lourduraj A. Vasanthi a, ⁎, Peranandam Revathi a , Ramaswamy Babu Rajendran a , Natesan Munuswamy b a Department of Environmental Biotechnology, School of Environmental Sciences, Bharathidasan University, Tiruchirappalli 620 024, Tamilnadu, India b Department of Zoology, University of Madras, Guindy Campus, Chennai 600 025, Tamilnadu, India abstract article info Article history: Received 14 July 2016 Received in revised form 27 September 2016 Accepted 22 January 2017 Available online xxxx This study report the impact of heavy metals on cytopathology and DNA damage in the gills and hepatopancreas of Perna viridis collected from Ennore estuary and the Kovalam coastal waters. Principal Component Analysis (PCA) showed significant differences among all variables at the scale of plots. The ultrastructural alterations such as lack of microvilli, distorted mitochondria, electron dense particles and the presence of large mucous drop- lets were common in the gill and hepatopancreatic cells of mussels from Ennore estuary. However, the gill and hepatopancreatic cells of P. viridis from Kovalam revealed normal compartmentalization of cells. The percentage of tail DNA in the mussels from Ennore estuary was recorded as 12.44 and 10.14% in the gills and hepatopancreas respectively. Overall, it has been demonstrated that the Comet and cytopathological assays are useful biomarkers to assess the level of pollution and it provide reliable information on ecotoxicology and genotoxicology of coastal waters. © 2017 Elsevier Ltd. All rights reserved. Keywords: Perna viridis Heavy metals DNA damage TEM Cytopathology Biomarker 1. Introduction Bivalve molluscs, in particular mussels, constitute one of the best bi- ological indicators of coastal pollution because they exhibit several un- surpassed advantageous characteristics: a sedentary nature; a wide geographical distribution; in general there are enough individuals at the sampling sites; they can be sampled easily; and finally, they accu- mulate pollutants (i.e., contaminant levels in their tissue respond to changes in environmental levels and pollutants accumulate with little metabolic transformation) (Chase et al., 2001; Arockia Vasanthi et al., 2012). As several chemicals with genotoxic potential are emitted to sur- face water through municipal and industrial waste water effluents, genotoxicity tests are gaining importance (Wirzinger et al., 2007). Aquatic organisms respond to chemical insults at different biological levels. Thus toxicological responses can be accessed from biochemical to cellular, tissue and population levels. The Green mussel Perna viridis are filter feeders in nature due to their sedentary habitat (they are found attached to a solid substratum with the help of byssal threads produced by their foot (Rajagopal et al., 2005)). The Indian green mussel P. viridis was selected as an experimental organism because it is an accepted marine pollution indicator organism. There are several ac- counts of this animal to account for effects of genotoxicants (Ching et al., 2001). Toxic effects occur when excretory, metabolic, storage, and detoxifi- cation mechanisms are no longer able to counter uptake. This capacity, however, also varies between different species and different metals (Heath, 1987; Langston, 1990). Like accumulation, several factors also influence the elimination of metals from the tissues, such as duration, temperature, interaction with other heavy metals and metabolic activi- ty of animals, as well as the tissue concerned (Heath, 1987; Muramoto, 1983; Douben, 1989). The elimination routes of metals from aquatic an- imals are generally mucus, bile, liver, urine, gills, and hepatopancreas (Lock and Overbeeke, 1981; Wu et al., 2008; Frias-Espericueta et al., 2008). In bivalve mollusks such as the mussel Mytilus sp. the gills are key or- gans involved in nutrient uptake, digestion and respiration (Gomez- Mendikute et al., 2005). The gills of suspension-feeding bivalves are or- gans with a large surface that create water currents by undulating movement of their surface epithelia (David et al., 2005). In particular, gills are a sensitive target for reactive chemicals and their histopatho- logical modifications are frequently used as an indicator of exposure (Giamberini et al., 1993; Yonkos et al., 2000; Alvarez-Muñoz et al., 2009). Due to the importance of this organ to the bivalve mollusks and the fact that gills have a large surface constantly exposed to water and its substances (harmful or not), the gill filaments morphology has been Marine Pollution Bulletin xxx (2017) xxx–xxx ⁎ Corresponding author at: Department of Environmental Biotechnology, School of Environmental Sciences, Bharathidasan University, Tiruchirappalli 620 024, Tamilnadu, India. E-mail address: arockiavasanthi@gmail.com (L.A. Vasanthi). MPB-08340; No of Pages 9 http://dx.doi.org/10.1016/j.marpolbul.2017.01.040 0025-326X/© 2017 Elsevier Ltd. All rights reserved. Contents lists available at ScienceDirect Marine Pollution Bulletin journal homepage: www.elsevier.com/locate/marpolbul Please cite this article as: Vasanthi, L.A., et al., Detection of metal induced cytopathological alterations and DNA damage in the gills and hepatopancreas of green mussel Perna virid..., Marine Pollution Bulletin (2017), http://dx.doi.org/10.1016/j.marpolbul.2017.01.040