Department of Biological Sciences, Faculty of Sciences, University of Naples Federico II, Via Mezzocannone 8, 80134, Naples, Italy.
Ecotoxicology. 2011 Jun;20(4):885-91. doi: 10.1007/s10646-011-0655-8. Epub 2011 Apr 2.
The increasing use of pesticides in modern agriculture has raised the need to evaluate their potential threat to animal and human health. In the present study, the genotoxic effects of environmentally relevant exposure to the fungicide thiophanate-methyl (TM) were assessed in the lizard Podarcis sicula (Reptilia, Lacertidae) using micronucleus test, chromosome aberration analysis and single-cell gel electrophoresis (comet) assay. The number of micronuclei increased significantly with exposure time in lizard specimens exposed to 1.5% TM for 30-40 days. In situ hybridization with the specific HindIII centromeric satellite was positive in 18.7% of the micronuclei observed, suggesting an aneugenic effect of TM during mitosis. DNA damage, evaluated by the comet assay, documented a significant gain in comet length in relation to exposure time that was paralleled by a reduction in head size. Finally, cytogenetic analysis showed a significant increase in chromosome aberrations in exposed animals compared with controls. Our data suggest that long-term TM exposure induces a genomic damage that is positively correlated to exposure time. If such genotoxic effects arise so clearly in an ectothermal vertebrate, such as P. sicula, prolonged exposure TM must be considered as a cytogenetic hazard.
现代农业中农药使用的增加，使得评估其对动物和人类健康的潜在威胁变得尤为重要。在本研究中，我们使用微核试验、染色体畸变分析和单细胞凝胶电泳（彗星）试验评估了环境相关浓度的杀菌剂噻菌灵（TM）对蜥蜴 Podarcis sicula（爬行动物，蜥蜴科）的遗传毒性作用。在暴露于 1.5% TM 的蜥蜴标本中，暴露时间为 30-40 天时，微核数量显著增加。原位杂交分析显示，在所观察到的微核中，有 18.7% 的微核呈 HindIII 着丝粒卫星阳性，这表明 TM 在有丝分裂过程中具有着丝粒外毒素效应。彗星试验评估的 DNA 损伤表明，彗星长度与暴露时间呈正相关，且头部大小减小。最后，细胞遗传学分析显示，暴露组动物的染色体畸变显著增加，与对照组相比。我们的数据表明，长期 TM 暴露会导致基因组损伤，且这种损伤与暴露时间呈正相关。如果这种遗传毒性作用在像 P. sicula 这样的冷血脊椎动物中如此明显，那么长期暴露于 TM 必须被视为细胞遗传学危害。
