An evaluation of the use of in vitro tubulin polymerisation, fungal and wheat assays to detect the activity of potential chemical aneugens.

The test chemicals included in the EC Aneuploidy Project were evaluated for their ability to induce aneuploidy or aneuploidy related endpoints in assays using in vitro tubulin polymerisation, fungi and wheat. The results obtained demonstrated considerable qualitative and quantitative differences between the responses of the assays to the 10 test chemicals. Fungal assays failed to respond to the potent mammalian spindle poisons colchicine and vinblastine and only three chemicals were positive in all three fungal test systems i.e. chloral hydrate, thimerosol and thiabendazole. The in vitro tubulin polymerisation assays produced unambiguous positive results with three chemicals i.e. colchicine, thimerosol and vinblastine sulphate. The hexaploid wheat assay produced a positive response with 8 of the test chemicals i.e. colchicine, econazole, thimerosol, pyrimethamine, thiabendazole, cadmium chloride, vinblastine and diazepam. However, the wheat assay was relatively insensitive to the potent spindle poison colchicine.