Sarkar A, Gaitonde Dipak C S, Sarkar Amit, Vashistha D, D'Silva Classy, Dalal S G
Marine Pollution Assessment and Ecotoxicology Laboratory, National Institute of Oceanography, Dona Paula, Goa 403004, India.
Ecotoxicol Environ Saf. 2008 Oct;71(2):473-82. doi: 10.1016/j.ecoenv.2008.01.006. Epub 2008 Mar 20.
The measurement of the impairment of DNA in marine gastropod (Cronia contracta) provides an insight into the genotoxic effects of contaminants on marine organisms along the Goa coast. The impact of genotoxic contaminants on Goan coastal environment was evaluated in terms of the loss of DNA integrity (expressed as the value of 'I') in marine snails with respect to those from the reference site (Palolem) over a period from April 2004 to May 2005 using the technique of alkaline unwinding assay. The DNA integrity in marine snails was found to be significantly damaged at Dona Paula (58%), Vasco (73.5%), and Velsao (48.5%) during the monsoon period (July-August 2004). Similar trend in the loss of DNA integrity in marine gastropods was also detected during the post-monsoon (November-December 2004) and the pre-monsoon (April-May 2005) periods. The low integrities of DNA in marine gastropods at these sites can be attributed to exposure to genotoxic contaminants especially polycyclic aromatic hydrocarbons (PAHs) and toxic heavy metals (Pb, Cd, Cu, Fe, and Mn) prevalent in the marine environment as evident by their accumulation in the tissues of the marine snails inhabiting different sites along the Goa coast. The contaminant-induced DNA strand breaks in marine snails increased significantly at Dona Paula, Vasco, and Velsao clearly indicating the levels of contamination of the sites by genotoxic compounds in those regions. The genotoxic effects of contaminants were further substantiated by detection of the impairment (39%) of DNA integrity in marine snails in a field experiment in which the same species of marine snails (C. contracta) collected from the reference site, Palolem, were deployed at Dona Paula and caged for 25 days for exposure to ambient marine pollutants. The impairment of DNA integrity in marine gastropods along the Goa coast can thus act as a biomarker for marine pollution monitoring of genotoxic contaminants.
对海洋腹足纲动物（Cronia contracta）DNA损伤的测量，有助于深入了解污染物对果阿海岸沿线海洋生物的遗传毒性效应。在2004年4月至2005年5月期间，采用碱性解旋测定技术，通过比较海洋蜗牛（相对于参考地点（帕洛勒姆））的DNA完整性损失（以“I”值表示），评估了遗传毒性污染物对果阿沿海环境的影响。在季风期（2004年7 - 8月），多纳·保拉（58%）、瓦斯科（73.5%）和韦尔绍（48.5%）的海洋蜗牛DNA完整性被发现受到显著破坏。在季风后期（2004年11 - 12月）和季风前期（2005年4 - 5月），也检测到海洋腹足纲动物DNA完整性损失的类似趋势。这些地点海洋腹足纲动物DNA完整性较低，可归因于接触遗传毒性污染物，特别是海洋环境中普遍存在的多环芳烃（PAHs）和有毒重金属（铅、镉、铜、铁和锰），这在栖息于果阿海岸不同地点的海洋蜗牛组织中的积累情况中明显可见。多纳·保拉、瓦斯科和韦尔绍的海洋蜗牛中，污染物诱导的DNA链断裂显著增加，清楚地表明这些地区的这些地点受到遗传毒性化合物的污染程度。在一项实地实验中，从参考地点帕洛勒姆收集的同一种海洋蜗牛（C. contracta）被放置在多纳·保拉并笼养25天以接触周围海洋污染物，结果检测到海洋蜗牛DNA完整性受损（39%），进一步证实了污染物的遗传毒性效应。因此，果阿海岸沿线海洋腹足纲动物DNA完整性的损伤可作为遗传毒性污染物海洋污染监测的生物标志物。
