Mutation research, 849, 503141
January, 2020

Premature chromosome condensation assay to study influence of high-level natural radiation on the initial DNA double strand break repair in human G, [email protected], lymphocytes.

Vivek Kumar, P. R., Karuppasamy, C. V., Ramachandran, E. N., Anil Kumar, V., Jaikrishan, G., Das, Birajalaxmi

<p>The inherent capacity of individuals to efficiently repair ionizing radiation induced DNA double strand breaks (DSBs) may be inherited, however, it is influenced by several epigenetic and environmental factors. A pilot study tested whether chronic low dose natural radiation exposure influences the rejoining of initial DNA DSBs induced by a 2 Gy γ-irradiation in 22 individuals from high (&gt;1.5 mGy/year) and normal (≤1.5 mGy/year) level natural radiation areas (H&amp;NLNRA) of Kerala. Rejoining of DSBs (during 1 h at 37 °C, immediately after irradiation) was evaluated at the chromosome level in the presence and absence of wortmannin (a potent inhibitor of DSB repair in normal human cells) using a cell fusion-induced premature chromosome condensation (PCC) assay. The PCC assay quantitates DSBs in the form of excess chromosome fragments in human G lymphocytes without the requirement for cell division. A quantitative difference was observed in the early rejoining of DNA DSBs between individuals from HLNRA and NLNRA, with HLNRA individuals showing a higher (P = 0.05) mean initial repair ratio. The results indicate an influence of chronic low dose natural radiation on initial DNA DSB repair in inhabitants of HLNRA of the Kerala coast.</p>

Digital object identifier (DOI): 10.1016/j.mrgentox.2020.503141

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