Project description:Single Embryo Repli-Seq was utilized to investigate the replication timing in zygotes and 2-cell cleavage stage embryos. The aim was to understand the temporal progression of DNA replication during the early stages of embryonic development in mammals.
Project description:Deregulated DNA replication is a major contributor to human developmental disorders and cancer, yet our understanding of how replication is coordinated with changes in transcription and chromatin structure is limited. Our lab has employed the zebrafish model to investigate the mechanisms driving changes in the replication timing program during development. Previous studies have identified changes in replication timing patterns from the onset of zygotic transcription through gastrulation in zebrafish embryos. The protein Rif1 is crucial for replication timing in a wide range of eukaryotes, yet its role in establishing the replication timing program and chromatin structure during early vertebrate development is not well understood. Using Rif1 mutant zebrafish and performing RNA sequencing and whole-genome replication timing analysis, we found that Rif1 mutants were viable but had a defect in female sex determination. Interestingly, Rif1 loss primarily affected DNA replication timing after gastrulation, while its impact on transcription was more pronounced during zygotic genome activation. Our results indicate that Rif1 has distinct roles in regulating DNA replication and transcription at different stages of development.
Project description:We present here the characterization of the replication timing program in 6 human cell lines : U2OS, RKO, 293T, HeLa, MRC5 and K562
Project description:Fourteen yeast mutants with an extended S-phase were identified by a novel genome-wide screen. These mutants are associated with the DNA replication machinery, cell-cycle control and dNTP synthesis. We determined the genome-wide DNA replication timing profile of all these mutants as well as wild type, by FACS-sorting G1- and S-phase cells and co-hybridizing their DNA to Agilent genomic tiling arrays, in four repeats each. We find that MRC1 is required for scaling of the DNA replication timing program upon replication perturbation.