Project description:<p>The Human Connectome Project (HCP) has acquired vast amounts of data about the pattern of long-distance connections (wiring) in the brains of large numbers of healthy participants aged 22-35 using cutting-edge MRI and MEG neuroimaging, and extensive behavioral testing. Types of MR data collected included diffusion MRI (dMRI), resting-state functional MRI (r-fMRI), and structural MRI at both 3T and 7T, and task-evoked functional MRI (t-fMRI) at 3T. </p> <p>Following an extensive period of development and optimization of data acquisition and analysis methods, at Washington University in St. Louis we studied 1,206 participants comprising twins and their non-twin siblings. A subset of 184 twins was scanned again at the University of Minnesota using a 7T scanner. A different subset of 95 twins was studied at St. Louis University using combined resting state and/or task-activated MEG.</p> <p>We were able to collect genetic data on 1142 of our 1206 participants, including 149 pairs of genetically-confirmed monozygotic twins (298 participants) and 94 pairs of genetically-confirmed dizygotic twins (188 participants). Overall, there are 457 different families in the study, as determined by genetic analysis.</p> <p>Our rich set of imaging, behavioral and genetic data - available through the <a href="https://www.humanconnectome.org/data/">Human Connectome</a> database - will enable many types of analysis of brain circuitry, its relationship to behavior, and the contributions of genetic and environmental factors to brain circuits. </p>
Project description:The long non-coding RNA (lncRNA) Xist is a master regulator of X-chromosome inactivation in mammalian cells. Models for how Xist and other lncRNAs function depend on thermodynamically stable secondary and higher-order structures that RNAs can form in the context of a cell. Probing accessible RNA bases can provide data to build models of RNA conformation that provide insight into RNA function, molecular evolution, and modularity. To study the structure of Xist in cells, we built upon recent advances in RNA secondary structure mapping and modeling to develop Targeted Structure-Seq, which combines chemical probing of RNA structure in cells with target-specific massively parallel sequencing. By enriching for signals from the RNA of interest, Targeted Structure-Seq achieves high coverage of the target RNA with relatively few sequencing reads, thus providing a targeted and scalable approach to analyze RNA conformation in cells. We use this approach to probe the full-length Xist lncRNA to develop new models for functional elements within Xist, including the repeat A element in the 5'-end of Xist. This analysis also identified new structural elements in Xist that are evolutionarily conserved, including a new element proximal to the C repeats that is important for Xist function. Examination of dimethylsufate reactivity of Xist lncRNA and 18S rRNA in cells using targeted reverse transcription to determine reactivity, and comparisons with untreated control samples.
Project description:Genome-wide association studies have reported more than 100 risk loci for rheumatoid arthritis, and there loci have been shown to be enriched in immune cell-specific enhancers, we add Synovial fibroblasts (FLS), the local stromal cells of joints to this analysis. We integrated ChIP-seq, Hi-C, Capture Hi-C, ATAC-seq and RNA-seq datasets from FLS , with genetic fine-mapping of RA loci. From this we identified putative casual variants, enhancers and genes for 30-60% of RA loci and demonstrated that FLS regulatory elements accounts for up to 24% of RA heritability. We also examined the effects of TNF stimulation on the chromatin landscape of FLS, and we found there are significant alterations in the organization of topologically associated domains, chromatin interactions and the expression of several putative causal genes.
Project description:The intrinsic complexity of quantitative traits was evident even before the molecular nature of the gene was understood. Yet we still lack a detailed molecular understanding of complex heritability. Here we alleviated statistical roadblocks to high-resolution genetic mapping by using an inbred population of diploid yeast with very low linkage disequilibrium and more individuals than segregating polymorphisms. We mapped over 18,000 quantitative trait loci, resolving more than 3,300 to single nucleotides. This allowed us to explore the molecular origins of complexity, hybrid vigor, pleiotropy, and gene ´ environment interactions and to rigorously estimate the distribution of fitness effects of natural genetic variation. Our results describe a comprehensive, high-resolution genotype-to-phenotype map and define general principles underlying the complexity of heredity.
Project description:The long non-coding RNA (lncRNA) Xist is a master regulator of X-chromosome inactivation in mammalian cells. Models for how Xist and other lncRNAs function depend on thermodynamically stable secondary and higher-order structures that RNAs can form in the context of a cell. Probing accessible RNA bases can provide data to build models of RNA conformation that provide insight into RNA function, molecular evolution, and modularity. To study the structure of Xist in cells, we built upon recent advances in RNA secondary structure mapping and modeling to develop Targeted Structure-Seq, which combines chemical probing of RNA structure in cells with target-specific massively parallel sequencing. By enriching for signals from the RNA of interest, Targeted Structure-Seq achieves high coverage of the target RNA with relatively few sequencing reads, thus providing a targeted and scalable approach to analyze RNA conformation in cells. We use this approach to probe the full-length Xist lncRNA to develop new models for functional elements within Xist, including the repeat A element in the 5'-end of Xist. This analysis also identified new structural elements in Xist that are evolutionarily conserved, including a new element proximal to the C repeats that is important for Xist function.
Project description:The functional interpretation of GWAS remains challenging due to the cell-type dependent influences of genetic variants. Here, we generated comprehensive maps of expression quantitative trait loci (eQTL) for 659 microdissected human kidney samples and identified cell-type eQTLs by mapping interactions between cell type abundance and genotype. By partitioning heritability using stratified LD-score regression to integrate GWAS with scRNA-seq and snATAC-seq data, we prioritized proximal tubules in kidney function and endothelial cells and distal tubule segments in blood pressure pathogenesis. Bayesian colocalization analysis nominated more than 200 genes for kidney function and hypertension. Our study clarifies the mechanism of commonly used antihypertensive and renal protective drugs and identifies drug repurposing opportunities for kidney disease.
Project description:RNA binding proteins can modulate RNA secondary structures, thus participating in post-transcriptional regulation. The DEAH-box helicase 36 (DHX36) has a remarkable ability to bind and unwind RNA G-quadruplex (rG4) and duplex. However, the transcriptome-wide RNA structure dynamic induced by DHX36 and how structure change subsequently influences RNA fate remain poorly understood. Here, we first identify the endogenous binding sites and specificity of DHX36 based on binding profiles. Next, we capture in vivo RNA structuromes to investigate the structure change of DHX36-bound mRNAs following DHX36 knockout. DHX36 induces structure remodeling on not only the localized binding sites but also the other sites across the entire mRNA especially in 3’UTR. DHX36-induced more accessible structures of 3’UTR are revealed to correlate with post-transcriptional mRNA decrease. Furthermore, we demonstrate that DHX36 binding sites are enriched for N6-methyladenosine (m6A) modification and YTHDF1 binding. Finally, we experimentally validate that YTHDF1 binding is repelled to DHX36 loss-induced structure inaccessibility and YTHDF1 loss-induced mRNA stabilization could be a source of DHX36 loss-induced mRNA increase. Altogether, our findings uncover the effect of DHX36 binding on in vivo mRNA structure and propose a plausible mechanism of how RNA secondary structure change involves in post-transcriptional regulation through orchestrating YTHDF1 binding.