Biopolymers and cell. 1995; 11 (5): 51 - 55

THE PHYSIOLOGICAL SIGNIFICANCE OF NUCLEAR DNA STRUCTURAL DOMAIN DISINTEGRATION: EVIDENCE FOR NON-RANDOM DNA DOMAIN CLEAVAGE

V. T. Solov'yan, I. O. Andreev

We examined the pattern of ordered high molecular weight DNA cleavage In plant tissues showing diverse proliferative status or differentiation level, as well as that in human cultured lymphoblastoma cells during serum starvation. It was demonstrated that in quiescent or differentiated tissues there occur increased high molecular weight DNA cleavage, with the cleaved DNA domains being distinct from non-cleaved ones by the genome sequence composition. Lymphoblastoid cell culturing in serum-free medium was shown to be accompanied by progressive accumulation of high molecular weight DNA fragments which is rapidly decreased after serum addition. Transient increase in high molecular weight DNA fragmentation was found to accompany by temporal changes in C-myc sequence localization within cleaved DNA domains. The results obtained suggest that ordered disintegration of nuclear DNA into high molecular weight DNA fragments may present the specific genome reaction accompanying the physiolo¬gical changes in the cells and may be presumably implicated to reprogramming of gene expression.