Differentiation of micronuclei in mouse bone marrow cells: a comparison between CREST staining and fluorescent in situ hybridization with centromeric and telomeric DNA probes

Lnmunofluorescent staining (CREST) of kinetochore proteins and in situ hybridization (MSH) with centromeric DNA probes are able to distinguish between micronuclei (MN) containing lagging chromosomes or acentric fragments. Different frequencies of signal-positive MN induced by mitomycin C (MMC) were obtained by Miller et al. (Mutagenesis, 6, 297-302, 1991) between CREST labelling and FISH with the mouse major-γ-satellite DNA probe (major probe). Both modes of identify the presence of an entire chromosome in a MN are theoretically prone to mis-classification. Breaks induced in pericentric heterochromatin can produce fragment-containing MN with a major signal. Alternatively, alterations of kinetochore proteins can produce CREST-negative MN containing lagging chromosomes