Asynchronous DNA replication within the human beta-globin gene locus.
The timing of DNA replication of the human beta-globin gene locus has been studied by blot hybridization of newly synthesized BrdUrd-substituted DNA from cells in different stages of the S phase. Using probes that span greater than 120 kilobases across the human beta-globin gene locus, we show that the majority of this domain replicates in early S phase in the human erythroleukemia cell line K562 and in middle-to-late S phase in the lymphoid cell line Manca. However, in K562 cells three small regions display a strikingly different replication pattern than adjacent sequences. These islands, located in the inter-gamma-globin gene region and approximately 20 kilobases 5' to the epsilon-globin gene and 20 kilobases 3' to the beta-globin gene, replicate later and throughout S phase. A similar area is also present in the alpha-globin gene region in K562 cells. We suggest that these regions may represent sites of termination of replication forks.
Epner
E
E
Fred Hutchinson Cancer Research Center, Seattle, WA 98104.
Forrester
W C
WC
Groudine
M
M
D002453:Cell Cycle; D002460:Cell Line; D015342:DNA Probes; D004261:DNA Replication; D003850:Deoxyribonuclease I / Q000378:metabolism; D005914:Globins / Q000235:genetics*; D006801:Humans; D009693:Nucleic Acid Hybridization; D013997:Time Factors
D015342:DNA Probes; D005914:Globins; D003850:Deoxyribonuclease I