Project description:Allele-specific circular chromosome conformation capture sequencing (4C-seq) using the single nucleotide polymorphism rs2836411 as a bait was performed in two cell types: human umibilical vein endothelial cells (HUVECs) and human aortic smooth muscle cells (HASMCs).
Project description:In developing B cells the immunoglobulin heavy chain (IgH) locus is thought to move from repressive to permissive chromatin compartments to facilitate its scheduled rearrangement. In mature B cells, maintenance of allelic exclusion has been proposed to involve recruitment of the non-productive IgH allele to pericentromeric heterochromatin. Here we used an allele-specific chromosome conformation capture combined with sequencing (4C-seq) approach to unambigously follow the individual IgH alleles in mature B lymphocytes. Despite their physical and functional difference, productive and non-productive IgH alleles in B cells and unrearranged IgH alleles in T cells share many chromosomal contacts and largely reside in active chromatin. In brain, however, the locus resides in a different, repressive environment. We conclude that IgH adopts a lymphoid-specific nuclear location that is however unrelated to maintenance of allelic exclusion. We additionally find that in mature B cells - but not in T cells – the distal VH regions of both IgH alleles position themselves away from active chromatin. This, we speculate, may help to restrict enhancer activity to the productively rearranged VH promoter element. Allele specific analysis of the nuclear organization of the IgH locus in resting and activated B cells and T cells and fetal brain cells
Project description:A reporter transgene displayed parental imprinting in mouse embryos when positioned into the Itga6 gene. The strong lacZ pattern of expression scored in embryos inheriting the transgene from a male was not present when transmitted from a female. The transgene exhibited maternal allele-specific DNA hyper-methylation acquired in the germ-line and histone modifications corresponded to profiles described at known imprinted loci. Chromosome conformation analyzes revealed distinct, parent-of-origin interaction domains, with a more compact structure characterizing the maternally inherited repressed allele. The analysis of such transgene insertions with a selective potential to induce imprinting may help understanding the mechanisms identifying particular loci as targets for allele-specific repression. Data were quantile normalized within 4C/input replicate groups and scaled to medial feature intensity of 100 using TAS software (Affymetrix), generating signal.bar files. For each genomic position, a data set was generated consisting of all (PM-MM) pairs mapping within a sliding window of 250 bp. For Inv(rel5-Itga6) tissues, two independent 4C experiments were performed and merged in the .bar file.
Project description:In developing B cells the immunoglobulin heavy chain (IgH) locus is thought to move from repressive to permissive chromatin compartments to facilitate its scheduled rearrangement. In mature B cells, maintenance of allelic exclusion has been proposed to involve recruitment of the non-productive IgH allele to pericentromeric heterochromatin. Here we used an allele-specific chromosome conformation capture combined with sequencing (4C-seq) approach to unambigously follow the individual IgH alleles in mature B lymphocytes. Despite their physical and functional difference, productive and non-productive IgH alleles in B cells and unrearranged IgH alleles in T cells share many chromosomal contacts and largely reside in active chromatin. In brain, however, the locus resides in a different, repressive environment. We conclude that IgH adopts a lymphoid-specific nuclear location that is however unrelated to maintenance of allelic exclusion. We additionally find that in mature B cells - but not in T cells – the distal VH regions of both IgH alleles position themselves away from active chromatin. This, we speculate, may help to restrict enhancer activity to the productively rearranged VH promoter element.
Project description:We describe a method for identifying peptides that result from missense changes and identify peptides among 2 human brains that would have otherwise not been detected. Next, we use this data to estimate of allele-specific protein abundance in human brain for an average per individual, and to estimate apolipoprotein E allele specific abundance in human brain across individuals. Finally, we estimate the heritability of allele-specific protein abundance.
Project description:Purpose: Isolating chromatin interactions from a specific viewpoint, we utilized Next-generation sequencing (NGS) to profile specific chromatin interaction differences between two populations, a selected carrier (C) alele of SNP (rs10846744) associated with cardiovascular disease (CVD) and a selected non-carrier (G) allele. Methods: Chromatin was isolated from two subjects, one homozygous for the rs10846744 reference (G) allele and one homozygous for the rs10846744 risk (C) allele, processed for 4C-Seq (van de Werken et al., 2012). Results: 4C-ker (Raviram et al, 2016) analyzed the chromatin interaction data from the specific viewpoint. The results were visualized using the Washington University EpiGenome Browser (Zhou and Wang, 2013). Conclusions: Our study represents the first detailed analysis of significant changes in gene expression by an altered chromatin interaction network from SCARB1 to NR2F2 and LAG3, contributing to CAD proinflammatory gene networks.
