Project description:We report the application of genome architecture mapping in specific cell types in mouse brain. We generated cell-type specific chromatin contact maps in mouse dopaminergic neurons from the midbrain ventral tegmental area (VTA DN), pyramidal glutamatergic neurons from the cornus ammonis 1 region of the hippocampus (CA1 PGN), and non-neuronal post-mitotic oligodendrocytes from the somatosensory cortex (SSC_Olig). We explored cell-type specific chromatin topologies genome-wide at multiple genomic scales. Our data demonstrates that chromatin organization is cell type specific and reflects cell specialization at all genomic scales.
Project description:We report the application of genome architecture mapping in specific cell types in mouse brain. We generated cell-type specific chromatin contact maps in mouse dopaminergic neurons from the midbrain ventral tegmental area (VTA DN), pyramidal glutamatergic neurons from the cornus ammonis 1 region of the hippocampus (CA1 PGN), and non-neuronal post-mitotic oligodendrocytes from the somatosensory cortex (SSC_Olig). We explored cell-type specific chromatin topologies genome-wide at multiple genomic scales. Our data demonstrates that chromatin organization is cell type specific and reflects cell specialization at all genomic scales.
Project description:The field of structural biology is increasingly focusing on studying proteins in situ, i.e. in a larger biological context. Crosslinking mass spectrometry is contributing to this effort, typically through the use of MS-cleavable crosslinkers. Here, we apply the popular non-cleavable crosslinker disuccinimidyl suberate to mitochondria and identify 5,518 distance restraints between protein residues. Each distance restraint within or between proteins provides structural information on proteins and their processes within mitochondria. Comparing these restraints to high-throughput comparative models and PDB deposited structures reveals novel protein conformations. Our data suggest substrates and flexibility of mitochondrial heat shock proteins. Crosslinking mass spectrometry is progressing towards large-scale in situ structural biology that reveals protein dynamics in addition to protein-protein interaction topologies.
Project description:Neuroscience has made remarkable progress in understanding the architecture of human intelligence, identifying a distributed network of brain structures that support goal-directed, intelligent behavior. However, the neural foundations of cognitive flexibility and adaptive aspects of intellectual function remain to be well characterized. Here, we report a human lesion study (n=149) that investigates the neural bases of key competencies of cognitive flexibility (i.e., mental flexibility and the fluent generation of new ideas) and systematically examine their contributions to a broad spectrum of cognitive and social processes, including psychometric intelligence (Wechsler Adult Intelligence Scale), emotional intelligence (Mayer, Salovey, Caruso Emotional Intelligence Test), and personality (Neuroticism-Extraversion-Openness Personality Inventory). Latent variable modeling was applied to obtain error-free indices of each factor, followed by voxel-based lesion-symptom mapping to elucidate their neural substrates. Regression analyses revealed that latent scores for psychometric intelligence reliably predict latent scores for cognitive flexibility (adjusted R(2)=0.94). Lesion mapping results further indicated that these convergent processes depend on a shared network of frontal, temporal, and parietal regions, including white matter association tracts, which bind these areas into an integrated system. A targeted analysis of the unique variance explained by cognitive flexibility further revealed selective damage within the right superior temporal gyrus, a region known to support insight and the recognition of novel semantic relations. The observed findings motivate an integrative framework for understanding the neural foundations of adaptive behavior, suggesting that core elements of cognitive flexibility emerge from a distributed network of brain regions that support specific competencies for human intelligence.
Project description:With the advent of massively parallel sequencing, considerable work has gone into adapting chromosome conformation capture (3C) techniques to study chromosomal architecture at a genome-wide scale. We recently demonstrated that the inactive murine X chromosome adopts a bipartite structure using a novel 3C protocol, termed in situ DNase Hi-C. Like traditional Hi-C protocols, in situ DNase Hi-C requires that chromatin be chemically cross-linked, digested, end-repaired, and proximity-ligated with a biotinylated bridge adaptor. The resulting ligation products are optionally sheared, affinity-purified via streptavidin bead immobilization, and subjected to traditional next-generation library preparation for Illumina paired-end sequencing. Importantly, in situ DNase Hi-C obviates the dependence on a restriction enzyme to digest chromatin, instead relying on the endonuclease DNase I. Libraries generated by in situ DNase Hi-C have a higher effective resolution than traditional Hi-C libraries, which makes them valuable in cases in which high sequencing depth is allowed for, or when hybrid capture technologies are expected to be used. The protocol described here, which involves ?4 d of bench work, is optimized for the study of mammalian cells, but it can be broadly applicable to any cell or tissue of interest, given experimental parameter optimization.