Cytokinesis block micronucleus assay in field plants for monitoring radiation-induced genotoxicity of the environment

Publication date: 1 November 2014 Source:Mutation Research/Genetic Toxicology and Environmental Mutagenesis, Volume 774 Author(s): Yoshito Watanabe , Yoshihisa Kubota , Shoichi Fuma , Maruyama Kouichi , San’ei Ichikawa , Masahide Kubota , Satoshi Yoshida Effective biomonitoring for detection of radiation-induced genotoxicity of contaminants in natural environments involves testing of field plants for cytogenetic changes. To increase the efficiency and precision of cytogenetic analyses of field plants that have naturally high individual variability, an improved micronucleus assay is proposed that employs a cytokinesis block technique similar to the lymphocyte test system used in mammals. In seed embryonic meristems of the Japanese cedar, application of a methylxanthine derivative, 3-isobutyl-1-methylxanthine (IBMX), was found to be effective in inhibiting cytokinesis to make once-divided cells easily recognizable by their binucleate appearance. In the meristem of IBMX-treated seminal roots from X-ray-irradiated seeds, variation in micronucleus frequency in the binucleate cell population was reduced compared to that in the total cell population. The highest efficiency of measurement of micronucleus frequencies was obtained in the root meristems where 0.2- to 1.5-mm-long seminal roots were incubated with IBMX for 24h. This result indicated that this root elongation stage corresponded to the first divisions of the root meristematic cells, and was therefore suitable f...
Source: Mutation Research Genetic Toxicology and Environmental Mutagenesis - Category: Genetics & Stem Cells Source Type: research