Chromosome mutation test

In the chromosome mutation test Chinese hamster lung fibroblast cell line (CHL) can be used. The cells are treated for 24 or 48 hours with a test compound at different dose levels. Both with and without the metabolic activation system, the cells are treated with colcemid (0.2 mg/ml) for 2 h to arrest cell divisions and chromosome preparations are made. The chromosome aberrations are recorded in at least 100 metaphases of each treatment. Five groups of structural chromosome aberrations can be found ... 

Non bacterial in vitro tests Mammalian cell mutation Test with the following Test-System L5178Y mouse lymphoma gene and chromosomal mutation test or Chromosomal aberration Test with e g. human lymphocytes ... 

In vitro chromosome aberration test In vitro gene mutation assay Acute oral toxicity Acute inhalation or dermal toxicity... 

In vivo mammalian mutation tests are not restricted to germ cell tests. The mouse spot test described below is, again, a test used first for studying radiation-induced mutation but has also been used for screening chemicals for in vivo mutagenic potential. This test has had several proponents but compared with in vivo chromosomal assays is not widely used. 

Positive results in the in vivo mammalian spermatogonial chromosome aberration test indicate that a substance induces structural chromosome aberrations in the germ cells of the species tested. This test measures chromosome events in spermatogonial germ cells and is, therefore, expected to be predictive of induction of inheritable mutations in germ cells. 

Itoh, S., Nakayama, S. and Shimada, H. (2002) In vitro photochemical clasto-genicity of quinolone antibacterial agents studied by a chromosomal aberration test with light irradiation. Mutation Research, 517, 113-121. 

In a test for sex-linked recessive lethal mutations in Drosophila, Wild et al. 8 found no evidence of mutagenicity of CS. More than 9,000 chromosomes were tested, and the frequencies of mutations in the treated groups did not differ from those in the concurrent negative controls or the historical negative controls. The available information on the toxicity of CS under the treatment conditions is minimal. The actual dosages received by the flies are also uncertain, particularly because CS breaks down rapidly in water. Nevertheless, the available data give no indication of mutagenicity of CS in Drosophila. 

Like many other Irritants, PS has not been tested thoroughly for mutagenicity. However, in one early study, Auerbach tested its capacity to Induce sex-linked recessive lethal mutations In the fruit fly, Drosophila melanogaster. In all broods of flies derived from PS-treated males, the mutation frequencies were consistent with those of untreated laboratory stocks. A total of 4,454 chromosomes were tested, and the mutation frequency was 0.2%. In contrast, flies treated with mustard gas had a frequency of 5.2%. 

Ishidate, M., Jr Sofimi, T. (1985) The in vitro chromosomal aberration test using Chinese hamster lung (CHL) fibroblast cells in cnlture. In Ashby, J., de Serres, EJ., Draper, M., Ishidate, M., Jr, Margolin, B.H., Matter, B.E. Shelby, M.D., eds, Progress in Mutation Research, Volume 5, Evaluation of Short-Term Tests for Carcinogens. Report of the International Programme on Chemical Safety s Collaborative Study on in vitro assays, Amsterdam, Elsevier Science, pp. 427M32... 

Matsuoka A, Hayashi M, Ishidate M Jr. 1979. Chromosomal aberration tests on 29 chemicals combined with S9 mix in vitro. Mutation Research 66 277-290. 

Ishidate, M.J. Sofuni, T. (1985) The in vitro chromosomal aberration test using Chinese hamster lung (CHL) fibroblast cells in culture. Prog. Mutat. Res., 5, 427-432... 

One system uses mouse lymphoma cells and detects mutations that cause deficiency of thymidine kinase (TK). Another uses Chinese hamster cells and detects mutations in the gene that produces hypoxanthine-guanine phosphoribosyl transferase (HGPRT). Both tests cure efficient, are widely applied, and can be completed in a few weeks. Although not as simple, rapid, and efficient as the Salmonella tests, they have the advantage of being done in a eukaryote. Mammalian-cell cultures cure also used to test for chromosomal mutation. 

The classical mutation tests in Drosophila use special strains that detect recessive lethal mutations on the X chromosome. They have the advantage that mutations at all lethal-producing loci on the chromosome, and not just those at a few selected loci, are detected. Various germ cell stages can be tested in both sexes. There are also tests for chromosomal breakage and rearrangement. These Drosophila tests require a few weeks. 

For the short-term tests, we recommend a two-tier system. Tier I consists of a microbial gene-mutation test (Salmonella/microsome test), a mammalian cell-culture gene-mutation test (HGPRT or IK), and a mammalian cell-culture chromosomal-breakage test. All these cure to be done both with and without metabolic activation. If the... 

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