Kligerman A D, Bishop W E, Valentine L C
Natl Cancer Inst Monogr. 1984 May;65:111-8.
Elevated frequencies of sister chromatid exchange (SCE) have been observed in the chromosomes of mammals and birds as a result of exposure to mutagenic carcinogens. More recently, this phenomenon has been demonstrated in the chromosomes of fishes exposed to genotoxicants. A short-term screening system for mutagenic carcinogens with the use of the mudminnow, Umbra sp., has been developed with SCE as the indicator of genetic damage. This genus of fish possesses a small number (2n = 22) of large chromosomes enabling easy and rapid quantitation of cytogenetic damage. When mudminnows were exposed by ip injection or in situ by the aquatic environment to either direct- or indirect-acting mutagens, dose-dependent increases in SCE were observed. In addition to screening capabilities, the mudminnow system has had application as a biological monitor for genotoxicants in contaminated water systems. The increasing use of the mudminnow SCE system illustrates a renewed interest in the utilization of fishes in mutagenicity and carcinogenicity testing.
由于接触致突变致癌物，在哺乳动物和鸟类的染色体中已观察到姐妹染色单体交换（SCE）频率升高。最近，在接触遗传毒性物质的鱼类染色体中也证实了这一现象。已开发出一种以泥螈（Umbra sp.）为材料、以SCE作为遗传损伤指标的致突变致癌物短期筛选系统。这种鱼类拥有数量较少（2n = 22）的大型染色体，便于快速准确地定量细胞遗传学损伤。当通过腹腔注射或经水生环境让泥螈接触直接或间接作用的诱变剂时，观察到SCE呈剂量依赖性增加。除了具备筛选能力外，泥螈系统还被用作受污染水系统中遗传毒性物质的生物监测手段。泥螈SCE系统越来越广泛的应用表明，人们对利用鱼类进行致突变性和致癌性测试重新产生了兴趣。
