The micronucleus test in cultured mammalian cells and in Mytilus gill tissue

By Gabriele, M. - Brunetti, R. - Majone, F.

The kinetochore-containing micronuclei induced in CHO cells by clastogenic and aneuploidogenic substances, such as mitomycin C (MMC) or colchicine, were distinguished by means of a technique based on the use of human CREST antikinetochore antibodies. Both substances induced their expected effects. However, 48 hours after the end of treatment, colchicine and MMC induced a significant increase of CREST- and CREST+ micronuclei, respectively, suggesting an induction of clastogenicity by colchicine and of aneuploidy by MMC. These results were confirmed by the characterisation of the micronuclei induced by the same substances in gill cells of the marine mussel, Mytilus, treated in vivo. A cytofluorimetric analysis on the isolated gill of this animal showed that the cell cycle remained unaltered until almost 24 hours after excision. This suggests the possibility of using the isolated gill of Mytilus as a new biological system for laboratory experiments.