CONSERVATION AND CONTINUITY OF PERIODIC BENT DNA IN GENOMIC REARRANGEMENTS BETWEEN THE C-MYC AND IMMUNOGLOBULIN HEAVY-CHAIN MU-LOCI

Periodic bent DNA was mapped in the human c-myc and immunoglobulin hea vy chain mu (Ig mu) loci. A total of 12 DNA bend sites in the c-myc ge ne and 11 sites ire the Ig mu locus were aligned at average intervals of 694.2 +/- 281.4 and 654.5 +/- 222.7 bp respectively Although some o f the bend sites retained the distance of 700 bp, their periodicity wa s disturbed at several locations, including the exons of the c-myc gen e and the enhancer element present in the Ig mu locus. Analysis of rea rrangements that resulted in tumorigenesis of lymphocytes showed that the continuity of DNA bend sites was conserved in three lymphoma cell lines, Manca, BL22 and Ramos, suggesting that the genomic rearrangemen ts gain stability by retaining their periodicity. This adds further ev idence that the periodic bent DNA plays a crucial role in genomic stru cture.