[Role of non-histone proteins in the transformations and genetic functioning of the chromosome]

The functional relationship between the transformations of chromosome structure and parallel changes of its major components, i. e. DNA, histones and non-histone proteins (NHP) has been analysed. These changes of chromosome have been checked in the early development, in the highly differentiated undividing cells, in the mitotic and meiotic cells, till the gamete formation. The analysis performed enable us to propose that chromosomal non-histone proteins play the main role in the transformation of chromosome structure, decreasing its genetic activity. NHPs aged without renewal in the undivided nuclei and chromosomes. These proteins take part in the formation of synaptonemal complex (SC) in the early meiotic prophase during chromosome pairing; SC is subsequently eliminated in the diplotene. Thus mature sperms and eggs are characterized by NHP deficiency. NHPs are synthesized de novo in the chromosomes after fertilization providing genetic function of the chromosomes in the development and differentiation of cell systems in new generation of organisms.