DNA LOOP ANCHORAGE REGION COLOCALIZES WITH THE REPLICATION ORIGIN LOCATED DOWNSTREAM TO THE HUMAN GENE ENCODING LAMIN B2

The recently developed procedure of topoisomerase It-mediated DNA loop excision has been used to analyze the topological organization of a h uman genome fragment containing the gene encoding lamin B2 and the ppv 1 gene. A 3.5 kb long DNA loop anchorage/topoisomerase II cleavage reg ion was found within the area under study. This region includes the en d of the lamin B2 coding unit and an intergenic region where an origin of DNA replication was previously found. These observations further c orroborate the hypothesis that DNA replication origins are located at or close to DNA loop anchorage regions. (C) 1998 Wiley-Liss, Inc.