scholarly journals The Transcriptional Status but Not the Imprinting Control Region Determines Allele-Specific Histone Modifications at the Imprinted H19 Locus

2007 ◽  
Vol 28 (1) ◽  
pp. 71-82 ◽  
Author(s):  
Raluca I. Verona ◽  
Joanne L. Thorvaldsen ◽  
Kimberly J. Reese ◽  
Marisa S. Bartolomei
Keyword(s):  
Genomic Imprinting ◽  
Histone Modifications ◽  
Cell Types ◽  
Specific Gene ◽  
Histone Marks ◽  
Exon 1 ◽  
Allele Specific ◽  
Multiple Cell ◽  
Imprinting Control Region

ABSTRACT Genomic imprinting governs allele-specific gene expression in an epigenetically heritable manner. The characterization of histone modifications at imprinted gene loci is incomplete, and whether specific histone marks determine transcription or are dependent on it is not understood. Using chromatin immunoprecipitations, we examined in multiple cell types and in an allele-specific manner the active and repressive histone marks of several imprinted loci, including H19, KvDMR1, Snrpn promoter/exon 1, and IG-DMR imprinting control regions. Expressed alleles are enriched for specific actively modified histones, including H3 di- and trimethylated at Lys4 and acetylated histones H3 and H4, while their silent counterparts are associated with repressive marks such as H3 trimethylated at Lys9 alone or in combination with H3 trimethylated at Lys27 and H4/H2A symmetrically dimethylated at Arg3. At H19, allele-specific histone modifications occur throughout the entire locus, including nontranscribed regions such as the differentially methylated domain (DMD) as well as sequences in the H19 gene body that are not differentially methylated. Significantly, the presence of active marks at H19 depends on transcriptional activity and occurs even in the absence of the DMD. These findings suggest that histone modifications are dependent on the transcriptional status of imprinted alleles and illuminate epigenetic mechanisms of genomic imprinting.

scholarly journals Exo-enzymatic addition of diazirine-modified sialic acid to cell surfaces enables photocrosslinking of glycoproteins

2021 ◽  
Author(s):  
Nageswari Yarravarapu ◽  
Rohit Sai Reddy Konada ◽  
Narek Darabedian ◽  
Nichole J. Pedowtiz ◽  
Soumya N. Krishnamurthy ◽  
...  
Keyword(s):  
Sialic Acid ◽  
Cell Surface ◽  
Cell Types ◽  
Cell Surfaces ◽  
Binding Interactions ◽  
Multiple Cell ◽  
Labeling Method ◽  
Cell Surface Glycoconjugates

Glycan binding often mediates extracellular macromolecular recognition events. Accurate characterization of these binding interactions can be difficult because of dissociation and scrambling that occur during purification and analysis steps. Use of photocrosslinking methods has been pursued to covalently capture glycan-dependent interactions in situ however use of metabolic glycan engineering methods to incorporate photocrosslinking sugar analogs is limited to certain cell types. Here we report an exo-enzymatic labeling method to add a diazirine-modified sialic acid (SiaDAz) to cell surface glycoconjugates. The method involves chemoenzymatic synthesis of diazirine-modified CMP-sialic acid (CMP-SiaDAz), followed by sialyltransferase-catalyzed addition of SiaDAz to desialylated cell surfaces. Cell surface SiaDAz-ylation is compatible with multiple cell types and is facilitated by endogenous extracellular sialyltransferase activity present in Daudi B cells. This method for extracellular addition of α2-6-linked SiaDAz enables UV-induced crosslinking of CD22, demonstrating the utility for covalent capture of glycan-mediated binding interactions.

scholarly journals Bulk Tissue Cell Type Deconvolution with Multi-Subject Single-Cell Expression Reference

2018 ◽  
Author(s):  
Xuran Wang ◽  
Jihwan Park ◽  
Katalin Susztak ◽  
Nancy R. Zhang ◽  
Mingyao Li
Keyword(s):  
Single Cell ◽  
Cell Types ◽  
Cellular Heterogeneity ◽  
Tissue Cell ◽  
Specific Gene ◽  
Rna Seq ◽  
Cell Type ◽  
Cell Type Specific ◽  
Cell Expression

AbstractWe present MuSiC, a method that utilizes cell-type specific gene expression from single-cell RNA sequencing (RNA-seq) data to characterize cell type compositions from bulk RNA-seq data in complex tissues. When applied to pancreatic islet and whole kidney expression data in human, mouse, and rats, MuSiC outperformed existing methods, especially for tissues with closely related cell types. MuSiC enables characterization of cellular heterogeneity of complex tissues for identification of disease mechanisms.

scholarly journals Joint inference and alignment of genome structures enables characterization of compartment-independent reorganization across cell types

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Lila Rieber ◽  
Shaun Mahony
Keyword(s):  
K562 Cells ◽  
Cell Types ◽  
Data Sets ◽  
Cell Type ◽  
Histone Marks ◽  
Joint Inference ◽  
3D Localization ◽  
Topologically Associated Domains ◽  
Cell Type Specific

Abstract Background Comparisons of Hi–C data sets between cell types and conditions have revealed differences in topologically associated domains (TADs) and A/B compartmentalization, which are correlated with differences in gene regulation. However, previous comparisons have focused on known forms of 3D organization while potentially neglecting other functionally relevant differences. We aimed to create a method to quantify all locus-specific differences between two Hi–C data sets. Results We developed MultiMDS to jointly infer and align 3D chromosomal structures from two Hi–C data sets, thereby enabling a new way to comprehensively quantify relocalization of genomic loci between cell types. We demonstrate this approach by comparing Hi–C data across a variety of cell types. We consistently find relocalization of loci with minimal difference in A/B compartment score. For example, we identify compartment-independent relocalizations between GM12878 and K562 cells that involve loci displaying enhancer-associated histone marks in one cell type and polycomb-associated histone marks in the other. Conclusions MultiMDS is the first tool to identify all loci that relocalize between two Hi–C data sets. Our method can identify 3D localization differences that are correlated with cell-type-specific regulatory activities and which cannot be identified using other methods.

scholarly journals A Generalized Linear Model for Decomposing Cis-regulatory, Parent-of-Origin, and Maternal Effects on Allele-Specific Gene Expression

2017 ◽  
Vol 7 (7) ◽  
pp. 2227-2234 ◽  
Author(s):  
Yasuaki Takada ◽  
Ryutaro Miyagi ◽  
Aya Takahashi ◽  
Toshinori Endo ◽  
Naoki Osada
Keyword(s):  
Gene Expression ◽  
Maternal Effects ◽  
Genomic Imprinting ◽  
Whole Body ◽  
Specific Gene ◽  
Rna Seq ◽  
Simple Method ◽  
Specific Gene Expression ◽  
Allele Specific ◽  
Parent Of Origin

Abstract Joint quantification of genetic and epigenetic effects on gene expression is important for understanding the establishment of complex gene regulation systems in living organisms. In particular, genomic imprinting and maternal effects play important roles in the developmental process of mammals and flowering plants. However, the influence of these effects on gene expression are difficult to quantify because they act simultaneously with cis-regulatory mutations. Here we propose a simple method to decompose cis-regulatory (i.e., allelic genotype), genomic imprinting [i.e., parent-of-origin (PO)], and maternal [i.e., maternal genotype (MG)] effects on allele-specific gene expression using RNA-seq data obtained from reciprocal crosses. We evaluated the efficiency of method using a simulated dataset and applied the method to whole-body Drosophila and mouse trophoblast stem cell (TSC) and liver RNA-seq data. Consistent with previous studies, we found little evidence of PO and MG effects in adult Drosophila samples. In contrast, we identified dozens and hundreds of mouse genes with significant PO and MG effects, respectively. Interestingly, a similar number of genes with significant PO effect were detect in mouse TSCs and livers, whereas more genes with significant MG effect were observed in livers. Further application of this method will clarify how these three effects influence gene expression levels in different tissues and developmental stages, and provide novel insight into the evolution of gene expression regulation.

scholarly journals Males That Silence Their Father’s Genes: Genomic Imprinting of a Complete Haploid Genome

2021 ◽  
Author(s):  
Andrés G de la Filia ◽  
Andrew J Mongue ◽  
Jennifer Dorrens ◽  
Hannah Lemon ◽  
Dominik R Laetsch ◽  
...  
Keyword(s):  
Genomic Imprinting ◽  
Reproductive Tract ◽  
Expression Patterns ◽  
Mendelian Inheritance ◽  
Specific Gene ◽  
Paternal Genome ◽  
Genetic Conflict ◽  
Maternal Genome ◽  
Allele Specific ◽  
Parent Of Origin

AbstractGenetic conflict is considered a key driver in the evolution of reproductive systems with non-Mendelian inheritance, where parents do not contribute equally to the genetic makeup of their offspring. One of the most extraordinary examples of non-Mendelian inheritance is paternal genome elimination (PGE), a form of haplodiploidy which has evolved repeatedly across arthropods. Under PGE, males are diploid but only transmit maternally inherited chromosomes, while the paternally inherited homologues are excluded from sperm. This asymmetric inheritance is thought to have evolved through an evolutionary arms race between the paternal and maternal genomes over transmission to future generations. In several PGE clades, such as the mealybugs (Hemiptera: Pseudococcidae), paternal chromosomes are not only eliminated from sperm, but also heterochromatinized early in development and thought to remain inactive, which could result from genetic conflict between parental genomes. Here, we present a parent-of-origin allele-specific transcriptome analysis in male mealybugs showing that expression is globally biased toward the maternal genome. However, up to 70% of somatically expressed genes are to some degree paternally expressed, while paternal genome expression is much more restricted in the male reproductive tract, with only 20% of genes showing paternal contribution. We also show that parent-of-origin-specific gene expression patterns are remarkably similar across genotypes, and that genes with completely biparental expression show elevated rates of molecular evolution. Our results provide the clearest example yet of genome-wide genomic imprinting in insects and enhance our understanding of PGE, which will aid future empirical tests of evolutionary theory regarding the origin of this unusual reproductive strategy.

scholarly journals Males that silence their father’s genes: genomic imprinting of a complete haploid genome

2020 ◽  
Author(s):  
Andrés G. de la Filia ◽  
Andrew J. Mongue ◽  
Jennifer Dorrens ◽  
Hannah Lemon ◽  
Dominik R. Laetsch ◽  
...  
Keyword(s):  
Gene Expression ◽  
Genomic Imprinting ◽  
Mendelian Inheritance ◽  
Specific Gene ◽  
Paternal Genome ◽  
Genetic Conflict ◽  
Specific Gene Expression ◽  
Maternal Genome ◽  
Allele Specific ◽  
Parent Of Origin

AbstractGenetic conflict is considered a key driver in the evolution of new reproductive and sex determining systems. In particular, reproductive strategies with non-Mendelian inheritance, where parents do not contribute equally to the genetic makeup of their offspring. One of the most extraordinary examples of non-Mendelian inheritance is paternal genome elimination (PGE), a form of haplodiploidy which has evolved repeatedly across arthropods. Under PGE, males are diploid but only transmit maternally-inherited chromosomes to their offspring, while the paternal homologues are excluded from sperm. This asymmetric inheritance is thought to have evolved through an evolutionary arms race between paternal and maternal genomes over transmission to future generations. In several clades with PGE, such as the mealybugs (Hemiptera: Pseudococcidae), paternal chromosomes are not just eliminated from sperm, but also heterochromatinised early in development and thought to remain inactive. Such paternal genome silencing could alleviate genetic conflict between paternal alleles over transmission. However, it is unclear if paternal chromosomes are indeed genetically inert in both soma and germline. Here, we present a parent-of-origin allele-specific transcriptome analysis in male mealybugs. We show that expression is globally biased towards the maternal genome, but detect activity of paternal chromosomes in both somatic and reproductive tissues. Up to 70% of somatically-expressed genes are to some degree paternally-expressed. However, paternal genome expression is much more restricted in the testis, with only 20% of genes showing paternal contribution. Finally, we show that the patterns of parent-of-origin-specific gene expression are remarkably similar across genotypes and that those genes with biparental expression show elevated rates of molecular evolution. Our results provide the clearest example yet of genome-wide genomic imprinting (parent-of-origin specific gene expression) in insects. Furthermore, it enhances our understanding of PGE, which will aid future empirical tests of evolutionary theory regarding the origin of this unusual reproductive strategy.

scholarly journals The Hematopoietic Niche in Myeloproliferative Neoplasms

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Annette H. Schmitt-Graeff ◽  
Roland Nitschke ◽  
Robert Zeiser
Keyword(s):  
Myeloproliferative Neoplasms ◽  
Treatment Strategies ◽  
Cell Types ◽  
Additional Treatment ◽  
Molecular Networks ◽  
Hematopoietic Stem ◽  
Endosteal Niche ◽  
Hsc Niche ◽  
Multiple Cell

Specialized microanatomical areas of the bone marrow provide the signals that are mandatory for the maintenance and regulation of hematopoietic stem cells (HSCs) and progenitor cells. A complex microenvironment adjacent to the marrow vasculature (vascular niche) and close to the endosteum (endosteal niche) harbors multiple cell types including mesenchymal stromal cells and their derivatives such as CAR cells expressing high levels of chemokines C-X-C motif ligand 12 and early osteoblastic lineage cells, endothelial cells, and megakaryocytes. The characterization of the cellular and molecular networks operating in the HSC niche has opened new perspectives for the understanding of the bidirectional cross-talk between HSCs and stromal cell populations in normal and malignant conditions. A structural and functional remodeling of the niche may contribute to the development of myeloproliferative neoplasms (MPN). Malignant HSCs may alter the function and survival of MSCs that do not belong to the neoplastic clone. For example, a regression of nestin+MSCs by apoptosis has been attributed to neuroglial damage in MPN. Nonneoplastic MSCs in turn can promote aggressiveness and drug resistance of malignant cells. In the future, strategies to counteract the pathological interaction between the niche and neoplastic HSCs may offer additional treatment strategies for MPN patients.

scholarly journals Genomic Imprinting Controls Matrix Attachment Regionsin the Igf2Gene

2003 ◽  
Vol 23 (24) ◽  
pp. 8953-8959 ◽  
Author(s):  
Michaël Weber ◽  
Hélène Hagège ◽  
Adele Murrell ◽  
Claude Brunel ◽  
Wolf Reik ◽  
...  
Keyword(s):  
Genomic Imprinting ◽  
Dna Sequences ◽  
Nuclear Matrix ◽  
Regulatory Elements ◽  
Paternal Allele ◽  
Matrix Attachment Regions ◽  
Binding Assays ◽  
Allele Specific ◽  
Imprinting Control Region ◽  
Matrix Fraction

ABSTRACT Genomic imprinting at the Igf2/H19 locus originates from allele-specific DNA methylation, which modifies the affinity of some proteins for their target sequences. Here, we show that AT-rich DNA sequences located in the vicinity of previously characterized differentially methylated regions (DMRs) of the imprinted Igf2 gene are conserved between mouse and human. These sequences have all the characteristics of matrix attachment regions (MARs), which are known as versatile regulatory elements involved in chromatin structure and gene expression. Combining allele-specific nuclear matrix binding assays and real-time PCR quantification, we show that retention of two of these Igf2 MARs (MAR0 and MAR2) in the nuclear matrix fraction depends on the tissue and is specific to the paternal allele. Furthermore, on this allele, the Igf2 MAR2 is functionally linked to the neighboring DMR2 while, on the maternal allele, it is controlled by the imprinting-control region. Our work clearly demonstrates that genomic imprinting controls matrix attachment regions in the Igf2 gene.

scholarly journals PIRCh-seq: functional classification of non-coding RNAs associated with distinct histone modifications

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Jingwen Fang ◽  
Qing Ma ◽  
Ci Chu ◽  
Beibei Huang ◽  
Lingjie Li ◽  
...  
Keyword(s):  
Histone Modifications ◽  
Cell Types ◽  
Functional Classification ◽  
Chromatin Interactions ◽  
Specific Manner ◽  
Comprehensive Survey ◽  
Allele Specific ◽  
Non Coding Rnas ◽  
Nascent Transcripts

AbstractWe develop PIRCh-seq, a method which enables a comprehensive survey of chromatin-associated RNAs in a histone modification-specific manner. We identify hundreds of chromatin-associated RNAs in several cell types with substantially less contamination by nascent transcripts. Non-coding RNAs are found enriched on chromatin and are classified into functional groups based on the patterns of their association with specific histone modifications. We find single-stranded RNA bases are more chromatin-associated, and we discover hundreds of allele-specific RNA-chromatin interactions. These results provide a unique resource to globally study the functions of chromatin-associated lncRNAs and elucidate the basic mechanisms of chromatin-RNA interactions.

Sign in / Sign up

Export Citation Format

Share Document