When legally required mutagenicity testing of chemicals is undertaken, the important genetic end point of
aneuploidy is not included because validated test methods are lacking. Therefore, the Commission of the European Communities (CEC) has funded a research program to develop and validate tests for
aneuploidy induction. Ten chemicals, selected on the basis of their ability to interact with cell organelles relevant for
aneuploidy induction, were tested in 11 laboratories. The assays ranged from in vitro
tubulin assembly studies to in vivo germ-cell tests. The results allow several conclusions: a) Fungal
aneuploidy tests are not capable of detecting inhibitors of mammalian
tubulin polymerization such as
colchicine and
vinblastine. Therefore, they will not play a role in screening for
aneuploidy but are of value for studying the relationship between induced
aneuploidy and recombination. b) Chemicals that induce
aneuploidy in mammalian germ cells are readily detected in the in vitro mammalian cell systems. Some chemicals such as
thiabendazole and
thimerosal induce
aneuploidy in vitro but do not appear to be very effective in vivo. c) Cell division aberrations induced in mammalian cells in vitro seem to be predictive for
aneuploidy induction in the same cell type. Likewise, c-mitotic effects and cell cycle delay in vivo in mitotic and meiotic cells correlate with
aneuploidy induction in the respective tissue. A second CEC
Aneuploidy Program has started recently to refine the most promising test protocols, to provide understanding of variety of mechanisms by which chemicals induce
aneuploidy, and to establish a data base for
aneugens among
environmental pollutants.