Huang Dejun, Zhang Yingmei, Wang Yejing, Xie Zhuoyi, Ji Weihong
School of Life Sciences, Lanzhou University, Lanzhou 730000, PR China.
Mutat Res. 2007 May 18;629(2):81-8. doi: 10.1016/j.mrgentox.2007.01.007. Epub 2007 Feb 2.
Single cell gel electrophoresis or comet assay, micronucleus (MN) test and global DNA methylation detection were used to assess the genotoxicity in toad Bufo raddei exposed to the petrochemical (mainly oil and phenol) polluted area in Lanzhou Region (LZR) comparing with a relatively unpolluted area in Liujiaxia Region (LJXR). The results from the present study indicated that DNA damage and MN frequency in toad from LZR were significantly higher than those from LJXR at the same sampling month, whereas the degree of global DNA methylation was lower, which implies that the petrochemical contaminants at environmental level in LZR were genotoxic to B. raddei. The degree of genotoxic damage was obviously related with the extent of pollution among the three sampling months in LZR. The significantly positive correlations between DNA damage and concentrations of oil and/or phenol existed in liver cells but erythrocytes, implying that liver is more suitable as a sentinel tissue for the assessment of genotoxic impact of low-level contamination. The results from both comet assay and global DNA methylation detection on liver cells showed that the genotoxicity varied significantly with oil and/or phenol concentrations, suggesting that these two methods are relatively sensitive and suitable for monitoring the genotoxicity of petrochemical pollutants on amphibians.
采用单细胞凝胶电泳或彗星试验、微核（MN）试验及全基因组DNA甲基化检测，对兰州地区（LZR）石化（主要是石油和苯酚）污染区的中华大蟾蜍进行遗传毒性评估，并与刘家峡地区（LJXR）相对未受污染的区域进行比较。本研究结果表明，在同一采样月份，LZR地区蟾蜍的DNA损伤和MN频率显著高于LJXR地区，而全基因组DNA甲基化程度较低，这意味着LZR地区环境水平的石化污染物对中华大蟾蜍具有遗传毒性。在LZR地区的三个采样月份中，遗传毒性损伤程度与污染程度明显相关。肝细胞中DNA损伤与石油和/或苯酚浓度之间存在显著正相关，但红细胞中不存在，这表明肝脏更适合作为评估低水平污染遗传毒性影响的哨兵组织。彗星试验和肝细胞全基因组DNA甲基化检测结果均表明，遗传毒性随石油和/或苯酚浓度的变化而显著不同，表明这两种方法相对敏感，适用于监测石化污染物对两栖动物的遗传毒性。
