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  • 100 -3 (77) 2025 - С.М. Ахунбаев - WHY IS THE MOST IMPORTANT ROLE OF CHROMATIN CONSIDERED TO BE ONLY THE PACKAGING OF GENETIC MATERIAL AND THE REGULATION OF GENE EXPRESSION?

100 -3 (77) 2025 - С.М. Ахунбаев - WHY IS THE MOST IMPORTANT ROLE OF CHROMATIN CONSIDERED TO BE ONLY THE PACKAGING OF GENETIC MATERIAL AND THE REGULATION OF GENE EXPRESSION?

WHY IS THE MOST IMPORTANT ROLE OF CHROMATIN CONSIDERED TO BE ONLY THE PACKAGING OF GENETIC MATERIAL AND THE REGULATION OF GENE EXPRESSION?

S.M. Axunbaev - International Higher School of Medicine, Bishkek, Kyrgyzstan

Resume

Chromatin is a complex of DNA and histone proteins. There are two types of chromatin: euchromatin and heterochromatin. It is now generally accepted that the packaging of genetic material and the regulation of gene expression are the most important roles of chromatin. However, we believe that some fundamental features and properties of heterochromatin do not support this point of view. Namely, heterochromatin: a) represents the densest domains in the interphase cell; b) it is spatially isolated from euchromatin in the nucleus and is localized mainly towards the periphery of the nucleus; c) is closely related to the lamina and the inner nuclear membrane; d) surrounds the nucleolus; e) forms chromocenters; f) the heterochromatin regions of human autosomes 1, 9, and 19 and Y chromosomes, which do not contain ribosomal cistrons, are closely related (in the body) to the nucleolus; h) it is characterized by wide variability of quantitative content both within and between species; d) the regions of chromosomal heterochromatin of plants, poikilothermic and homoeothermic animals, as well as humans have significant differences. Studies of the variability of regions of chromosomal heterochromatin in human populations permanently residing in various climatic and geographical conditions of Eurasia and Africa, in norm and pathology, as well as an analysis of the available literature data on condensed chromatin (CX) support the view that perhaps the most important role of heterochromatin, as the main component of CX, lies in its participation in maintaining intracellular temperature homeostasis. CX, being the densest domains in the cell and located between the nucleus and cytoplasm, apparently conducts heat when there is a temperature difference between them. The proposed thermally conductive effect of CX is due to its fundamental features: its condensed state in the interphase, association with the lamina and the inner nuclear membrane, replication at the end of the S-period of the cell cycle, formation of a chromocenter, close association with the nucleolus, genetic inertia, and wide variability in quantitative content both within and between species.

Key words: chromatin, condensed chromatin, heterochromatin, thermoregulation, cellular thermoregulation, temperature homeostasis.

First page

573

Last page

583

For citation:S.M. Axunbaev - WHY IS THE MOST IMPORTANT ROLE OF CHROMATIN CONSIDERED TO BE ONLY THE PACKAGING OF GENETIC MATERIAL AND THE REGULATION OF GENE EXPRESSION?//New Day in Medicine 3(77)2025 573-583 https://https://newdayworldmedicine.com/en/new_day_medicine/3-77-2025

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