Genetic Variation in Human DNA Replication Timing Cell Biology Diagrams

Genetic Variation in Human DNA Replication Timing Cell Biology Diagrams Models for the organization of eukaryotic DNA replication have to account for two diametrically opposed conceptions of replication. On one side of the spectrum is the replicon paradigm, exemplified by the mechanism of bacterial replication, in which origins are well-defined sites that fire once in each cell cycle, leading to uniform replication that is identical in every cell 1. Figure 4: A diagrammatic representation of replication timing in a 70-Mb segment of human chromosome 2.The red horizontal line represents time in S-phase, from early (top) to late (bottom). Grey data points each represent a different DNA sequence position along the length of chromosome 2 as indicated on the x axis, with more positive values on the y-axis indicating earlier replication. DNA replication timing influences gene expression level. J Cell Biol. 2017; 216:1907-1914. Whole genome replication timing analysis of 7 phylogenetically diverse yeast identified genomic features with conserved replication timing and demonstrated that early replication timing might facilitate maximal expression of genes expressed in S-phase

DNA replication timing leads to variation in DNA copy number along chromosomes among S phase cells (e.g., early-replicating regions are duplicated in most cells), causing read depth fluctuations The study of genome architecture and DNA replication timing in cleavage-stage embryos will be facilitated by the recent development of single-cell Hi-C, single-cell RNA sequencing and single-cell DNA replication timing is deterministic at the level of chromosomal domains but stochastic at the level of replicons in Xenopus egg extracts. Nucleic Acids Res 36: 5623-5634 [PMC free article] [Google Scholar] Lande-Diner L, Zhang J, Cedar H 2009. Shifts in replication timing actively affect histone acetylation during nucleosome reassembly.

DNA Replication Timing Biology Diagrams

Aberrant DNA replication timing is associated with changes in gene expression, changes in epigenetic modifications and an increased frequency of structural rearrangements. Furthermore, certain replication timing changes can directly lead to overt genomic instability and may explain unique mutational signatures that are present in cells that

DNA replication timing Cold Spring Harb Perspect Biol. 2013 Aug 1;5(8):a010132. doi: 10.1101/cshperspect.a010132. One striking new correlation to emerge from these analyses is between replication timing and the three-dimensional structure of chromosomes. This correlation, which is significantly stronger than with any single histone