Chromosome assay

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. 

Damage induced in whole animals can be detected in in vivo chromosome assays in either somatic or germinal cells by examination of metaphases or the formation of micronuclei. The micronucleus test can also detect whole chromosome loss or aneuploidy in the absence of clastogenic activity and is considered comparable in sensitivity to chromosome analysis (Tsuchimoto and Matter, 1979). 

Primarily negative results have been found in in vitro and in vivo gene mutation and chromosome assays. ... 

Dean BJ, Hodson-Walker G. 1979. An in vitro chromosome assay using cultured rat-liver cells. Mutat Res 64 329-337. 

Dean, B.J. (1981) Activity of 27 coded compounds in the RLi chromosome assay. In de Serres, F.J. Ashby, J., eds, Progress in Mutation Research, Vol., Evaluation of Short-Term Tests for Carcinogens. Report of the International Collaborative Program, Amsterdam, Elsevier/ North-Holland, pp. 570-579... 

Dean, B.J. (1981) Activity of 27 coded compounds inthe RLl chromosome assay. In de Serres, F.J. 

During studies on the insecticidal toxicity of Pb(C2H5)4 it appeared to be relatively nontox-Ic to the housefly [210]. In a Drosophila melanogaster population, exposed for 25 generations to 60 jig Pb(C2H5)4 per g of medium, selection resulted in an increase of fecundity, hatcha-bility and larva-to-adult viability. Chromosome assay showed that response in these traits is generally under additive control [382]. 

Assays for chromosome aberrations and micronuclei Assays for aneuploidy... 

An in-vitro test with mammalian cells (chromosomal damage or mouse lymphoma tk assay)... 

Results of methyl parathion assays involving effects on chromosomes have also been contradictory. For sister chromatid exchange, Waters et al. (1982) reported a positive response in Chinese hamster ovary cells only in the presence of metabolic activation system, while methyl parathion tested positive without a metabolic activation system in Chinese hamster V79 cells (Chen et al. 1981), cultured normal human lymphoid cells (Chen et al. 1981 Gomez-Arroyo et al. 1987 Sobti et al. 1982), and Burkitt s l5miphoma cells (Chen et al. 1981). Chen et al. (1981) found a significant dose-related increase in sister chromatid exchange in both hamster and human cultured cells, but dose-related cell cycle delays were less pronounced in human cell lines than in V79 cells. Negative results were obtained for chromosomal aberrations in human lymphocytes without a metabolic activation system (Kumar et al. 1993). 

Inherited deficiencies of the clotting system that result in bleeding are found in humans. The most common is deficiency of factor VIII, causing hemophilia A, an X chromosome-hnked disease that has played a major role in the history of the royal families of Europe. Hemophilia B is due to a deficiency of factor IX its clinical Feamres are almost identical to those of hemophilia A, but the conditions can be separated on the basis of specific assays that distinguish between the two factors. 

Nasmyth Cytologically we don t see it associated with chromosomes. From an indirect assay, if we isolate yeast chromosomes there is Espl there. We have a biological assay for that. 

Eleven male volunteers aged 20-30 years ingested lead acetate for 49 days. PbB levels were kept at approximately 40 pg/dL. The frequency of chromosome aberrations was assayed after lymphocyte culture for 72 hours and found to be no different from that of 10 controls. The lymphocytes from lead-exposed subjects did show a higher mitotic activity (Bulsma and DeFrance 1976). 

Kanaya N, Gill BS, Grover IS, Murin A, Osiecka R, Sandhu SS, Andersson HC (1994) Vicia faba chromosomal aberration assay. Mutat Res 310 231-247 Matsuda H, Ose Y, Nagase H, Sato T, Kito H, Sumida K (1991) Mutagenicity of the components of ozonated humic substance. Sci Total Environ 103 129-140... 

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