title: Use of the mudminnow, Umbra sp., in an in vivo sister chromatid exchange test.
abstract: 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.
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine / Q000378:metabolism; D002869:Chromosome Aberrations; D003434:Crossing Over, Genetic / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005399:Fishes / Q000235:genetics*; D009152:Mutagenicity Tests; D012854:Sister Chromatid Exchange / Q000187:drug effects*
chemical_list: D001973:Bromodeoxyuridine