Project description:This approach was used to increase the continuity of the killifish genome, and assess the relative distance of specific genes from the sex locus.
Project description:In this work we took 9 samples from brain and 6 samples from muscle of the African turquoise killifish (Nothobranchius furzeri) at 3.5, 8.5 and 14 weeks. Total RNA was sequenced and circRNAs were detected.
Project description:Chromosome conformation capture (3C)-based assays are used to map chromatin interactions genome-wide. Quantitative analyses of chromatin interaction maps can lead to insights into the spatial organization of chromosomes and the mechanisms by which they fold. A number of protocols such as in situ Hi-C and Micro-C are now widely used and these differ in key experimental parameters including cross-linking chemistry and chromatin fragmentation strategy. To understand how the choice of experimental protocol determines the ability to detect and quantify aspects of chromosome folding we have performed a systematic evaluation of experimental parameters of 3C-based protocols. We find that different protocols capture different 3D genome features with different efficiencies. First, the use of crosslinkers such as DSG in addition to formaldehyde improves signal-to-noise allowing detection of thousands of additional loops and strengthening compartment signal. Second, fragmenting chromatin to the level of nucleosomes using MNase allows detection of more loops. On the other hand, protocols that generate larger multi-kb fragments produce stronger compartmentalization signals. We confirmed our results in multiple cell states such as pluripotent and differentiated cells as well as cell cycle stages; Mitosis and G1. Based on these insights we developed Hi-C 3.0, a single protocol that can be used to both efficiently detect chromatin loops and to quantify compartmentalization. Finally, this study produced ultra-deeply sequenced reference interaction maps using in situ Hi-C, Micro-C and Hi-C 3.0 for commonly cell lines in the 4D Nucleome Project.
Project description:The mammalian central nervous system (CNS) and its retina are susceptible to age-related patholgoies, resulting in progressive, irreversible diseases like glaucoma and age-related macular degeneration (AMD), which are increasingly prevalent with rising life expectancy. Currently, there are no targeted long-term therapies to prevent vision loss. The short lived African turquoise killifsh (Nothobranchius furzeri, GRZ-AD) is a valuable genetic model for ageing studies, displaying rapid ageing phenotypes within its four to six-month lifespan. Our investigation on the molecular consequences of ageing in the retina, employing scRNA-sequencing, shows a a comprehensive overview of the cellular heterogeneity of the killifish retina, uncovering age-related gene expression changes specific to certain retinal cell populations.
Project description:Chromosome conformation capture (3C)-based assays are used to map chromatin interactions genome-wide. Quantitative analyses of chromatin interaction maps can lead to insights into the spatial organization of chromosomes and the mechanisms by which they fold. A number of protocols such as in situ Hi-C and Micro-C are now widely used and these differ in key experimental parameters including cross-linking chemistry and chromatin fragmentation strategy. To understand how the choice of experimental protocol determines the ability to detect and quantify aspects of chromosome folding we have performed a systematic evaluation of experimental parameters of 3C-based protocols. We find that different protocols capture different 3D genome features with different efficiencies. First, the use of crosslinkers such as DSG in addition to formaldehyde improves signal-to-noise allowing detection of thousands of additional loops and strengthening compartment signal. Second, fragmenting chromatin to the level of nucleosomes using MNase allows detection of more loops. On the other hand, protocols that generate larger multi-kb fragments produce stronger compartmentalization signals. We confirmed our results in multiple cell states such as pluripotent and differentiated cells as well as cell cycle stages; Mitosis and G1. Based on these insights we developed Hi-C 3.0, a single protocol that can be used to both efficiently detect chromatin loops and to quantify compartmentalization. Finally, this study produced ultra-deeply sequenced reference interaction maps using in situ Hi-C, Micro-C and Hi-C 3.0 for commonly cell lines in the 4D Nucleome Project.
Project description:Chromosome conformation capture (3C)-based assays are used to map chromatin interactions genome-wide. Quantitative analyses of chromatin interaction maps can lead to insights into the spatial organization of chromosomes and the mechanisms by which they fold. A number of protocols such as in situ Hi-C and Micro-C are now widely used and these differ in key experimental parameters including cross-linking chemistry and chromatin fragmentation strategy. To understand how the choice of experimental protocol determines the ability to detect and quantify aspects of chromosome folding we have performed a systematic evaluation of experimental parameters of 3C-based protocols. We find that different protocols capture different 3D genome features with different efficiencies. First, the use of crosslinkers such as DSG in addition to formaldehyde improves signal-to-noise allowing detection of thousands of additional loops and strengthening compartment signal. Second, fragmenting chromatin to the level of nucleosomes using MNase allows detection of more loops. On the other hand, protocols that generate larger multi-kb fragments produce stronger compartmentalization signals. We confirmed our results in multiple cell states such as pluripotent and differentiated cells as well as cell cycle stages; Mitosis and G1. Based on these insights we developed Hi-C 3.0, a single protocol that can be used to both efficiently detect chromatin loops and to quantify compartmentalization. Finally, this study produced ultra-deeply sequenced reference interaction maps using in situ Hi-C, Micro-C and Hi-C 3.0 for commonly cell lines in the 4D Nucleome Project.
Project description:Chromosomes must be highly compacted and organized within cells, but how this is achieved in vivo remains poorly understood. We report the first use of Hi-C to map the structure of bacterial chromosomes at a high, unprecedented resolution. Analysis of Hi-C data and polymer modeling indicates that the Caulobacter crescentus chromosome consists of multiple, largely independent spatial domains likely comprised of supercoiled plectonemes arrayed into a bottlebrush-like fiber. These domains are stable throughout the cell cycle and re-established concomitantly with DNA replication. We provide strong evidence that domain boundaries are established by highly-expressed genes and the formation of plectoneme-free regions. Additionally, we use Hi-C to demonstrate that supercoiling, the histone-like protein HU, and SMC act at different length-scales and in complementary ways to organize and structure chromosomes within cells. Hi-C experiments were performed on untreated wild type swarmer cells and drug-treated swarmer cells (Novobiocin or Rifampicin) of Caulobacter crescentus CB15N. Hi-C were also performed on swarmer cells of smc knock-out and hup1hup2 knock-out mutants of Caulobacter crescentus. Time-course Hi-C were performed on a synchronous population of Caulobacter crescentus at 5, 10, 30, 45, 60 and 75 minutes after synchronization. The progression of DNA replication during the cell cycle was followed by total genomic DNA sequencing.
Project description:It is becoming increasingly important to understand the mechanism of regulatory elements on target genes in long-range genomic distance. 3C (chromosome conformation capture) and its derived methods are now widely applied to investigate three-dimensional (3D) genome organizations and gene regulation. Digestion-ligation-only Hi-C (DLO Hi-C) is a new technology with high efficiency and cost-effectiveness for whole-genome chromosome conformation capture. Here, we introduce the DLO Hi-C tool, a flexible and versatile pipeline for processing DLO Hi-C data from raw sequencing reads to normalized contact maps and for providing quality controls for different steps. It includes more efficient iterative mapping and linker filtering. We applied the DLO Hi-C tool to different DLO Hi-C datasets and demonstrated its ability in processing large data with multithreading. The DLO Hi-C tool is suitable for processing DLO Hi-C and in situ DLO Hi-C datasets. It is convenient and efficient for DLO Hi-C data processing.