Project description:Gene expression differs between cell types and regions within complex tissues such as the developing brain. To discover regulatory elements underlying this specificity, we generated genome-wide maps of chromatin accessibility in nine anatomically-defined regions of the developing human telencephalon. Additionally, we defined the histone modification landscape of the prefrontal cortex and generated chromatin accessibility maps of its upper and deep layers. We predicted a subset of open chromatin regions (18%) that are most likely to be active enhancers, many of which are dynamic with 26% differing between early and late mid-gestation and 28% present in only one brain region. These predicted regulatory elements (pREs) are enriched proximal to genes with expression differences across developmental stages, regions, and cortical laminae; they harbor distinct sequence motifs that suggest potential upstream regulators. We leveraged this atlas to predict and validate novel regulatory elements of genes that control cortex laminar identity and genes associated with autism spectrum disorder (ASD). These include enhancers proximal to FEZF2 and BCL11A that were validated in mouse, and an enhancer of ASD gene SLC6A1 containing two functional de novo mutations in individuals with ASD whose enhancer function we validated via CRISPRa. These applications demonstrate the utility of this atlas for decoding neurodevelopmental gene regulation in health and disease.
Project description:The mammalian telencephalon plays critical roles in cognition, motor function, and emotion. While many of the genes required for its development have been identified, the distant‐acting regulatory sequences orchestrating their in vivo expression are mostly unknown. Here we describe a digital atlas of in vivo enhancers active in subregions of the developing telencephalon. We identified over 4,600 candidate embryonic forebrain enhancers and studied the in vivo activity of 329 of these sequences in transgenic mouse embryos. We generated serial sets of histological brain sections for 145 reproducible forebrain enhancers, resulting in a publicly accessible web‐based enhancer atlas comprising over 33,000 sections. We show how this large collection of annotated telencephalon enhancers can be used to study the regulatory architecture of individual genes, to examine the sequence motif content of enhancers, and to drive targeted reporter or effector protein expression in experimental applications. Furthermore, we used epigenomic analysis of human and mouse cortex tissue to directly compare the genome‐wide enhancer architecture in these species. This atlas provides a primary resource for investigating gene regulatory mechanisms of telencephalon development and enables studies of the role of distant‐acting enhancers in neurodevelopmental disorders. Examination of p300 binding in mouse embryonic stage 11.5 forebrain, mouse postnatal (P0) cortex tissue and human fetal (gestational week 20) cortex
Project description:To discover regulatory elements driving the specificity of gene expression in different cell types and regions of the developing human brain, we generated an atlas of open chromatin from nine dissected regions of the mid-gestation human telencephalon, as well as microdissected upper and deep layers of the prefrontal cortex. We identified a subset of open chromatin regions (OCRs), termed predicted regulatory elements (pREs), that are likely to function as developmental brain enhancers. pREs showed temporal, regional, and laminar differences in chromatin accessibility and were correlated with gene expression differences across regions and gestational ages. We identified two functional de novo variants in a pRE for autism risk gene SLC6A1, and using CRISPRa, demonstrated that this pRE regulates SCL6A1. Additionally, mouse transgenic experiments validated enhancer activity for pREs proximal to FEZF2 and BCL11A. Thus, this atlas serves as a resource for decoding neurodevelopmental gene regulation in health and disease.
Project description:The mammalian telencephalon plays critical roles in cognition, motor function, and emotion. While many of the genes required for its development have been identified, the distant‐acting regulatory sequences orchestrating their in vivo expression are mostly unknown. Here we describe a digital atlas of in vivo enhancers active in subregions of the developing telencephalon. We identified over 4,600 candidate embryonic forebrain enhancers and studied the in vivo activity of 329 of these sequences in transgenic mouse embryos. We generated serial sets of histological brain sections for 145 reproducible forebrain enhancers, resulting in a publicly accessible web‐based enhancer atlas comprising over 33,000 sections. We show how this large collection of annotated telencephalon enhancers can be used to study the regulatory architecture of individual genes, to examine the sequence motif content of enhancers, and to drive targeted reporter or effector protein expression in experimental applications. Furthermore, we used epigenomic analysis of human and mouse cortex tissue to directly compare the genome‐wide enhancer architecture in these species. This atlas provides a primary resource for investigating gene regulatory mechanisms of telencephalon development and enables studies of the role of distant‐acting enhancers in neurodevelopmental disorders.
Project description:<p>Non-coding regions comprise most of the human genome and harbor a significant fraction of risk alleles for neuropsychiatric diseases, yet their functions remain poorly defined. We created a high-resolution map of non-coding elements involved in human cortical neurogenesis by contrasting chromatin accessibility and gene expression in the germinal zone and cortical plate of the developing cerebral cortex. To obtain a high resolution depiction of chromatin structure and gene expression in developing human fetal cortex, we dissected the post-conception week (PCW) 15-17 human neocortex into two major anatomical divisions to distinguish between proliferating neural progenitors and post mitotic neurons: (1) GZ: the neural progenitor-enriched region encompassing the ventricular zone (VZ), subventricular zone (SVZ), and intermediate zone (IZ) and (2) CP: the neuron-enriched region containing the subplate (SP), cortical plate (CP), and marginal zone (MZ). Tissues were obtained from three independent donors and three to four technical replicates from each tissue were processed for ATAC-seq to define the landscape of accessible chromatin and RNA-seq for genome-wide gene expression profiling.</p>
Project description:A number of studies have reported cell heterogeneity within the developing mouse pancreas, as well as the transcriptional profiles corresponding to various cell states. The upstream mechanisms that initiate and maintain gene expression programs across cell states, however, remain largely unknown. Here, we applied single-nucleus ATAC-Seq to developing mouse pancreas to generate an atlas of chromatin accessibility, at single-cell resolution. Our goals were first, to generate an atlas of chromatin accessibility of embryonic mouse pancreas, at single-cell resolution, that can serve as a resource for the field. We aimed to provide such a resource not only for epithelial cells within the pancreas, but for non-epithelial (e.g., mesenchymal) as well. Our second goal was to identify gene regulatory networks governing cell fate transitions through integration of single-cell chromatin accessibility and gene expression data.