Graf U, Würgler F E
Institute of Toxicology, Swiss Federal Institute of Technology (ETH), Schwerzenbach, Switzerland.
Environ Mol Mutagen. 1996;27(3):219-26. doi: 10.1002/(SICI)1098-2280(1996)27:3<219::AID-EM7>3.0.CO;2-9.
A groups of six chemical compounds was tested in parallel in two different somatic genotoxicity assays in Drosophila melanogaster, the wing somatic mutation and recombination test (SMART) and the white-ivory eye spot test. The wing spot test makes use of the wing cell markers multiple wing hairs (mwh) and flare (flr) and detects both mitotic recombination and various types of mutational events. The white-ivory eye spot test makes use of the white-ivory (wi) quadruplication and detects the somatic reversion of the recessive eye color mutation wi to the wild-type (w+). Three- or two-day-old larvae were fed chronically with the compounds ethylnitrosourea (ENU), N-nitrosopyrrolidine (NNP), caffeine (CAF), chromium (VI) oxide (CRO), potassium chromate (POC), and 2,4-dichlorophenoxyacetic acid (2,4-D). All six compounds are genotoxic to various degrees in the wing spot test. The percentage of the genotoxic activity that is due to mitotic recombination was between 84% and 91% for the hexavalent chromium compounds CRO and POC and about 68% for 2,4-D. In contrast, ENU and NNP showed only 46% and 25% recombinagenic activity, respectively. In the white-ivory eye spot test, the three compounds (CRO, POC, and 2,4-D) with high recombinagenic activity and CAF were clearly nongenotoxic, whereas only ENU and NNP gave a positive response. From these results, it is concluded that the spectrum of genotoxic events detected by the two assays is different. In particular, the white-ivory eye spot test appears not to detect mitotic recombination the way the wing spot test does.
一组六种化合物在黑腹果蝇的两种不同体细胞遗传毒性试验中进行了平行测试，即翅体细胞突变和重组试验（SMART）以及白象牙眼点试验。翅斑试验利用翅细胞标记多翅毛（mwh）和耀斑（flr），检测有丝分裂重组和各种类型的突变事件。白象牙眼点试验利用白象牙（wi）四倍体，检测隐性眼色突变wi向野生型（w+）的体细胞回复突变。用化合物乙基亚硝基脲（ENU）、N-亚硝基吡咯烷（NNP）、咖啡因（CAF）、三氧化铬（VI）（CRO）、铬酸钾（POC）和2,4-二氯苯氧乙酸（2,4-D）对3日龄或2日龄幼虫进行长期喂食。所有六种化合物在翅斑试验中均有不同程度的遗传毒性。对于六价铬化合物CRO和POC，由有丝分裂重组引起的遗传毒性活性百分比在84%至91%之间，对于2,4-D约为68%。相比之下，ENU和NNP的重组活性分别仅为46%和25%。在白象牙眼点试验中，具有高重组活性的三种化合物（CRO、POC和2,4-D）以及CAF明显无遗传毒性，而只有ENU和NNP给出了阳性反应。从这些结果可以得出结论，两种试验检测到的遗传毒性事件谱不同。特别是，白象牙眼点试验似乎无法像翅斑试验那样检测到有丝分裂重组。
