Dominant lethal bioassay

Fortunately, a number of in situ, short-term bioassays to detect genotoxic and related effects have become available. These include a variety of measured endpoints such as aneuploids, chromosal aberrations, DNA damage, dominant lethal mutation, gene mutation, inhibition of intercellular communication, micronuclei, mitotic recombination and gene conversions, and sister chromatid exchange and cell transformation (IARC, 1989). A detailed discussion of these tests is beyond the scope of this book. However, such tests are important from our perspective as atmospheric chemists because, as we shall see, they can be used to detect biologically active compounds in very complex mixtures, and hence serve to focus chemical analysis efforts (IARC, 1989, p. 20). We emphasize in advance the... 

Lewis, S.C. (1979) Dominant lethal mutagenic bioassay of dimethylformamide (DMF) (Abstract No. Ea-7). Environ. Mutag., 1, 166... 

M. Manandhar, C. Sheu, and B.L. Whitfield. Dominant lethal assay, p. 64. In Current Status of Bioassays in Genetic Toxicology (GENE-TOX). Conference held December 3-5, 1980. Washington, D.C. U.S. Environmental Protection Agency, 1980. (abstract)... 

Green S, Auletta A, Fabricant J, et al. 1985. Current status of bioassays in genetic toxicology2 the dominant lethal assay. A report of the U.S. Environmental Protection Agency Gene-Tox Program. Mutat Res 154 49-67. 

Of the 19 pesticides grouped in Table II, all were negative in five Phase I bioassays and the Phase 2 bioassays performed. These compounds included insecticides (I), fungicides (F), and herbicides (H). Malath ion, parathion, pentachloronitrobenzene (PCNB), and phorate were also negative for heritable chromosomal effects in the mouse dominant lethal test. The six compounds grouped in Table III that were positive in three or more bioassays were acephate, captan, demeton, folpet, monocrotophos, and trichlorfon. Positive results were seen for demeton in all in vitro tests in Phase 1 and Phase 2. Folpet and captan were positive in all Phase 1 and all Phase 2 in vitro assays except the test for unscheduled DNA synthesis in WI-38 cells. Trichlorfon was positive in all Phase 1 and Phase 2 in vitro tests, with the exclusion of relative toxicity tests with E coli and subtiI is. 

Chemicals commonly are screened for carcinogenic potential using two basic types of tests, animal bioassay and in vitro assays. Animal bioassays for carcinogenic activity are most commonly conducted in mammalian species, such as rats, mice, and hamsters. The second type of assay using in vitro procedures screens either for transformation in mammalian cells or for the mutagenic potential of a chemical in a bacterial system after metabolic activation of the test substance (130). Other test systems, such as dominant-lethal mutation tests, translocation tests that screen for chromosomal ab-... 

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