Species specificity of karyotype instability under conditions of radionuclide contamination (the Chernobyl Nuclear Power Plant) in the voles, Micrototus oeconomus, Micrototus arvalis, and Clethrionomys glareolus

The comparative analysis of frequencies of different type cytogenetic anomalies in voles Microtus oeconomus, Microtus arvalis, Clethrionomys glareolus trapped in territories with different levels of radionuclide contamination inside the 30-km zone of estrangement around the Chernobyl NPP was carried out. Animals with constitutive chromosome abnormalities were not revealed. The frequency of lympocytes with micronuclei was the most universal and sensitive character to chronic low-dose radiation in investigated species. The species-specific relation was observed between level of radionuclide contamination in trapping zone and increase in frequencies of cytogenetic abnormalities: aneuploidy in Microtus arvalis and metaphase plates with asynchronous centromere fission in Microtus oeconomus. Common vole appears to be the most sensitive species of investigated ones to chronic low-dose ionizing irradiation.