Replication timing and nuclear structure

Nuclear Position Leaves Its Mark on Replication Timing

The multiple replication origins of eukaryotic chromosomes are programmed to replicate at specific times throughout S phase of the cell cycle. The functional significance of this program is not understood, but, in general, transcriptionally active chromatin replicates early in S phase, whereas hypoacetylated, transcriptionally inactive chromatin replicates later. During metazoan development, mu...

SnapShot: Replication Timing

Systematic Determination of Replication Activity Type Highlights Interconnections between Replication, Chromatin Structure and Nuclear Localization

DNA replication is a highly regulated process, with each genomic locus replicating at a distinct time of replication (ToR). Advances in ToR measurement technology enabled several genome-wide profiling studies that revealed tight associations between ToR and general genomic features and a remarkable ToR conservation in mammals. Genome wide studies further showed that at the hundreds kb-to-megaba...

4 Roles of Nuclear Structure in DNA Replication

The cell nucleus is the defining feature of eukaryotes. It is bounded by a nuclear envelope consisting of two concentric layers of membrane perforated by nuclear pores that serve as channels of communication between the nucleus and the cytoplasm. DNA is not randomly packed into the nucleus but packaged precisely in such a way that all regions are accessible for replication each cell cycle. Part...

Bacterial artificial chromosomes establish replication timing and sub-nuclear compartment de novo as extra-chromosomal vectors

The role of DNA sequence in determining replication timing (RT) and chromatin higher order organization remains elusive. To address this question, we have developed an extra-chromosomal replication system (E-BACs) consisting of ∼200 kb human bacterial artificial chromosomes (BACs) modified with Epstein-Barr virus (EBV) stable segregation elements. E-BACs were stably maintained as autonomous min...