Tag Archives: DNA loops

DNA loop domain rearrangements in blast transformed human lymphocytes and lymphoid leukaemic Jurkat T cells

K. Afanasieva1, V. Olefirenko1, A. Martyniak1,
L. Lukash2, A. Sivolob1*

1Taras Shevchenko National University of Kyiv, Ukraine;
2Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kyiv;
*e-mail: sivolob@univ.kiev.ua

Received: 06 April 2020; Accepted: 25 June 2020

Chromatin loops are important elements of both chromatin higher-order structure and transcription regulation system. Our previous works have shown that several features of the loop domain organization could be investigated by single cell gel electrophoresis (the comet assay) using the kinetic approach. In this study we applied this technique to study DNA loop domain organization in lymphoid cells: human lymphocytes, lymphoblasts cultivated during 24 h and 44 h, and T cells of Jurkat cell line. Two features of the loop domain organization were found to depend on the cell functional state. First, DNA fraction in the loops of large sizes (more than ~200 kb) was essentially increased in proliferating (de-differentiated) cells in comparison with terminally differentiated lymphocytes. Second, the linear density of the loops not larger than ~200 kb was decreased in transcriptionally active cells and was increased upon their inactivation.