Biopolymers and cell. 1996; 12 (6): 5 - 24

The epigene concept after 20 yers

M. D. Golubovsky

The main terminology and conceptual frame for description of structural and dynamic hereditary memory are presented. The gene as an elementary hereditary unit is discussed in the epigene concept proposed by K. N. Tchuraev (1975) for the description of the epigene variability. The epigene concept includes number terms which were introduced independently by various authors: epigenotype, epiheterozygote, epiallele, epimutation, epivariation. The principles of organization and function of lambda phage epigene (plus-minus autoregulation, alternative promoters, the complexity of promoter region, cooperative protein-pro¬tein interactions) are shown to be true for different bacterial and eukaryoticepigenes. The next transposons are discussed as epigenes: Tn3 in Escherichia coli, Spm in maize, P-element in Drosophila as well as the master sex regulator Sxl gene in Drosophila, It is evident a great value of an epigene concept usage for the description and analysis of various forms of non-canonical, non-Mendel inheritance (transposons be¬havior, paramutations, imprinting, cosupression of genes in transgenic plants etc.) for planning experi¬ments and understanding the theory of evolution.