An initiation zone of chromosomal DNA replication located upstream of the c-myc gene in proliferating HeLa cells.

摘要: Studies on origins of DNA replication in mammalian cells have long been hampered by a lack methods sensitive enough for the localization such chromosomal DNA. We employed new method mapping origins, based polymerase chain reaction amplification nascent strand segments, to examine initiated vivo near c-myc gene human cells. Nascent DNA, pulse-labeled unsynchronized HeLa cells, was size fractionated and purified immunoprecipitation with anti-bromodeoxyuridine antibodies. Lengths strands that allow were determined hybridization probes homologous amplified segments used calculate position origin. found through initiates zone centered approximately 1.5 kilobases upstream exon I. Replication proceeds bidirectionally from origin, as indicated comparison patterns three segments. The initiation includes locus previously reported drive autonomous plasmids