Evaluation of DNA damage in tobacco male meiocytes involved in cytomixis using comet assay.

Cytomixis is a process of nuclear migration between plant cells. As a rule, it is detectable in male meiocytes and gives rise to the cells with micronuclei. Examination of the integrity and functional state of migrating chromatin is of great interest, since cytomixis is assumed to change the gamete karyotype. We, for the first time, used comet assay to assess the DNA integrity in the chromatin that migrates between plant meiocytes. As was shown, the cells involved in cytomixis are viable and display no signs of DNA damage. Any comet tails are undetectable in both the main nuclei of the cells involved in cytomixis and cytomictic micronuclei. On the other hand, the cytomictic micronuclei after heat shock (positive control) form typical comet tails.