June 7, 2022 We held an IER Special Seminar online.＜Dr. Geras’kin＞

In some of the classes of the Master’s Program of Major in Environmental Radioactivity, distinguished external researchers are invited as guest lecturers, and their classes are open to other faculty members on campus as “Special Seminars”.

On June 7, the lecture on the subject “Effects of Radiation Exposure” by Prof. Stanislav Geras’kin was attended by five IER graduate school students, and two IER members. Prof. Geras’kin talked about the effects of chronic radiation on plants observed in severe contaminated lands, such as the Chornobyl zone, the Semipalatinsk test site, and the evacuation area in Fukushima. The overall approach was to trace radiation-induced effects occurring at different levels of biological complexity, from molecules to ecosystems. Prof. Geras’kin presented a comprehensive set of data demonstrating the plant response to radiation exposure, including cytogenetic alterations, mutations, genetic variability in exposed plant populations, epigenetic changes and differential gene expression, and changes in morphometric indices, hormone balance, and enzyme and transposable elements* activities. In the Q&A session, the lecture participants discussed the physical mechanisms that may underlie the changes in the levels of the genome methylation and transposable elements activity in the exposed plants.

* Transposable elements (TEs, or mobile elements, or transposons, or “jumping genes”) are DNA sequences that can change their positions (“jump”) within a genome. For a long time, TEs were considered the “junk” DNA; however, later it was shown that TEs can cause mutations and modify the genome functioning.