Transitions in replication timing in a 340 kb region of human chromosomal R-Band 1p36.1.

摘要: DNA replication is initiated within a few chromosomal bands as normal human fibroblasts enter the S phase (Cohen et al. [1998]: Exp Cell Res. 245:321–329). In present study, we determined timing of sequences along 340 kb region in one these bands, 1p36.13, an R band on chromosome 1. Within this region, identified segment (approximately 140 kb) that replicated first hour and flanked by segments 1–2 h later. Using quantitative PCR-based assay to measure sequence abundance size-fractionated (900–1,700 nt) nascent (Giacca [1994]: Proc Natl Acad Sci USA. 91:7119), mapped two functional origins separated 54 firing 1 apart. One origin was found be during located CpG island associated with predicted gene unknown function (Genscan NT_004610.2). The second activated near promoter aldehyde dehydrogenase 4A1 (ALDH4A1) gene. At opposite end early replicating segment, more gradual change observed span approximately 100 kb. These data suggest adjacent 1p36.13 organized differently, perhaps terms replicon number length, or rate fork progression. transition areas mark boundaries between different temporal domains, forks are likely pause delay progression before contig completed. © 2004 Wiley-Liss, Inc.