A Preliminary Study of the Micronucleus Test by Acridine Orange Fluorescent Staining Compared with Chromosomal Aberration Test Using Fish Erythropoietic and Embryonic Cells

The micronucleus test using fish peripheral blood has been introduced to assess the contamination of water with some mutagenic chemicals. The applicability of the micronucleus test erythrocytes combining acridine orange (AO) fluorescent staining to fish was evaluated as compared with the chromosomal aberration test method. Peripheral blood cells were smeared on glass slides, fixed with methanol, and stained with AO. AO fluorescence microscopy could differentiate between young and mature erythrocytes, thus only young erythrocytes could be observed. The sensitivity to detect the clastogenic effects of chemicals could be increased especially after acute treatment. Mitomycin C (MMC), a potent clastogen, was injected intraperitoneally to gold fishes and rose bitterlings at doses of 2, 4, 10, and 20 mg/kg. The mean frequencies of micronucleated young erythrocytes of three gold fishes peaked 3 days after treatment at 4 mg/kg body weight. Rose bitterlings showed maximum response of micronucleated young erythrocytes and chromosomal aberrations 2 days after treatment with 4 mg/kg of MMC. The cells from embryos of rose bitterlings and metropolitan bitterlings were used for the micronucleus and the chromosomal aberration test. The cultured cells established from fins of rose bitterlings were also used as materials of the chromosomal aberration.