Chromosomal heterochromatin regions: cell division or cell thermoregulation?


  • Abyt Ibraimov International Higher School of Medicine, Intergelpo str, 1F, Bishkek, Kyrgyzstan.
  • Stalbek Akhunbaev International Higher School of Medicine, Intergelpo str, 1F, Bishkek, Kyrgyzstan.
  • Orozali Uzakov International Higher School of Medicine, Intergelpo str, 1F, Bishkek, Kyrgyzstan.


heterochromatin regions, cell thermoregulation, cell division, cell nucleus, nucleolus, chromocentres


Despite the over 90-year history of studying the heterochromatin part of the genome of higher eukaryotes, its biological role remains unclear. Our ignorance of the true role of heterochromatin has left the field open for a variety of hypotheses ranging from the idea that it is “selfish DNA” simply perpetuating itself to ascribing to it an important function in development and evolution. Currently, most researchers believe, that chromosomal heterochromatin regions (HRs) are responsible for accurate chromosome segregation in cell division. Our experience shows that chromosomal HRs is more likely to be associated with cell thermoregulation (CT) than the guiding correct chromosome segregation during mitosis. Based on investigations of chromosomal HRs variability in human populations, as well as on the analysis of existing literary data on the condensed chromatin (CC) in the genome, an attempt is made to justify the view of possible participation of HRs in СT. CC, being the densest domains in a cell, apparently conducts heat between the cytoplasm and nucleus when there is a difference in temperature between them. The essence of the proposed hypothesis is the assumption that the  CC, nucleolus, along with the chromocenters participate in  CT. Namely, they are involved in the removal of excess heat from the  "hot”  areas of the interphase nucleus through a  dense layer of peripheral CC in the cytoplasm. We believe that such a complex process as mitosis and meiosis cannot rely on the chromosomal HRs, which differ from euchromatin in their high variability in evolution and in individual development.


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