A comparison of N-methyl-N-nitrosourea-induced chromatid aberrations and micronuclei in barley meristems using FISH...

Chromatid aberrations (CA) and micronuclei (MN) in combination with fluorescent in situ hybridization (FISH) using telomere- and centromere-specific probes were studied to compare the cytogenetic effects of N-methyl-N-nitrosourea (MNU) on root tip meristem cells of barley (Hordeum vulgare). A similar dose-dependent increase was observed for CA and MN. The frequency of MN with telomere and/or centromere-specific signals corresponded well with the expectation derived from the frequency of the different types of aberrations. Thus, the micronucleus test offers an easy and fast assay to measure chromosome damage and clastogenic adaptation in barley meristems. Combined with FISH it is also possible to elucidate the origin of MN and to discriminate between aneugenic and clastogenic effects.