Rizki Mostapha, Kossatz Elk, Creus Amadeu, Marcos Ricardo
Grup de Mutagènesi, Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Bellaterra, Spain.
Environ Mol Mutagen. 2004;43(3):196-203. doi: 10.1002/em.20010.
The genotoxic activity of cadmium chloride (CC) has been evaluated in the somatic mutation and recombination test (SMART) in Drosophila melanogaster. In addition, its possible modulating effect on the genotoxicity of two known mutagenic agents, potassium dichromate (PDC) and ethyl methanesulfonate (EMS), was investigated. Three different types of combined treatments of CC with the two genotoxins were performed: pretreatment, cotreatment, and posttreatment. The SMART assay is based on the principle that loss of heterozygosity for the recessive markers, multiple wing hairs (mwh) and flare-3 (flr(3)), leads to the formation of mutant clones in the imaginal disks of larvae, which are expressed as mutant spots on the wings of adult flies. Thus, after adult emergence, the wings of the adult flies were scored for the presence of single and/or twin spots. Our results show that CC alone was not effective in increasing the frequency of any of the three categories of spots (small, large, and twin). In the cotreatment experiments, CC increased the genotoxicity of PDC but it decreased the genotoxicity of EMS. No effects of CC were observed in the pretreatment or posttreatment experiments; however, only low concentrations of CC, PDC, and EMS were tested in the pretreatment assays due to the high toxicity of the treatment. Although our results with PDC are consistent with the hypothesis that cadmium can interfere with repair mechanisms, the EMS data suggest that other modulating mechanisms are also involved in the genotoxicity of this metal.
已在黑腹果蝇的体细胞突变和重组试验（SMART）中评估了氯化镉（CC）的遗传毒性活性。此外，还研究了其对两种已知诱变剂重铬酸钾（PDC）和甲磺酸乙酯（EMS）遗传毒性的可能调节作用。进行了CC与这两种基因毒素的三种不同类型的联合处理：预处理、共处理和后处理。SMART试验基于这样的原理，即隐性标记多翅毛（mwh）和flare-3（flr(3)）的杂合性丧失会导致幼虫成虫盘上形成突变克隆，这些克隆在成年果蝇的翅膀上表现为突变斑点。因此，在成虫羽化后，对成年果蝇的翅膀进行评分，以确定是否存在单个和/或双斑点。我们的结果表明，单独的CC在增加三类斑点（小、大、双）中的任何一类的频率方面均无效。在共处理实验中，CC增加了PDC的遗传毒性，但降低了EMS的遗传毒性。在预处理或后处理实验中未观察到CC的影响；然而，由于处理的高毒性，在预处理试验中仅测试了低浓度的CC、PDC和EMS。尽管我们关于PDC的结果与镉可干扰修复机制的假设一致，但EMS数据表明，其他调节机制也参与了这种金属的遗传毒性。
