Mechanism suppressing transcription of the globin genes in Danio rerio nonerythroid cells
Ontology highlight
ABSTRACT:
ORGANISM(S): Danio rerio
PROVIDER: GSE154562 | GEO | 2020/07/17
REPOSITORIES: GEO
Similar Datasets
Project description:To get insights into domain organization and functioning of the Danio rerio major α/β-globin locus (Mα/βGL), we have characterized profiles of histone H3 panacetylation across this locus in erythrocytes of adult fish and 18 dpf larvas. To identify enriched domains in our ChipSeq data we used our original protocol and peak caller MACS2. Histone acetylation profiles of Mα/βGL for adult and embryo cells reveal a breaking point in upstream region of the first embryo-larval gene βe1.There are two sub-segments of acetylation: sub-segment to the left of βe1 harbors adult-specific globin genes and is acetylated only in adult cells. Embryo sub-segment contains embryo-larval globin genes and is located to the right of βe1 gene. Acetylation in this subsegment was detected only in 18 dpf larva. Acetylation profile in adult subs-egment possess largest acetylation domain which covers two pairs of adult-stage globins: αa1, and βa1. High acetylation level in this domain well correlates with high expression level observed for these 4 genes in adult erythrocyte. Pattern of H3 panacetylation in 18 dpf larval erythrocytes differs strikingly from that for adult cells. Embryo-larval segment is fragmented in small domains co-located with gene bodies with gaps in intergenic regions. Adult subsegment in adult cells contains strong acetylation domain that cover 4 globin genes along with a part of intergenic regions and few smaller domains. Alternative stage-specific acetylation of subdomains and different pattern of embryonic-larval and adult domain acetylation strongly support the hypothesis of deep structural and functional segregation of stage-specific subdomains within Mα/βGL locus in zebrafish.
2017-01-01 | GSE86548 | GEO
Project description:We have demonstrated that, in developing Danio rerio, the embryo-larval and adult subloci of the major globin locus acquire stage-specific hyperacetylation of histone H3 and that H3 hyperacetylation profiles differ significantly between the embryo-larval sublocus (high level of acetylation within gene bodies but not in intergenic regions) and adult sublocus (extended domains of H3 acetylation covering both gene bodies and intergenic regions). The spatial organization of the two subloci is also found to be different. Whereas the adult sublocus is organized into a relatively compact contact domain, the embryo-larval sublocus has a rather low density of spatial contacts. Finally, we have demonstrated that the conserved upstream enhancer of the locus establishes spatial contacts with transcribed adult genes, but not with transcribed embryo-larval genes, and that the embryo-larval and adult subloci of the major globin gene locus are separated by an insulator colocalizing with a CTCF-binding site.
2017-07-12 | GSE87604 | GEO
Project description:Haemoglobin, the oxygen-carrying molecule of red blood cells, at all stages of development comprises a tetramer of two α-like and two β-like globin chains. In humans and mice the highly conserved α- and β-globin loci contain genes encoding globin chains specifically expressed only during the first trimester of gestation (termed embryonic globins) in addition to the genes encoding globin chains expressed throughout adult life. In humans the β-globin locus also encodes a β-like chain that is expressed throughout the second and third trimesters of development; this is termed γ-globin and complexes with α-globin to form fetal haemoglobin (HbF). The sequential activation and repression of the genes at each of these loci throughout development to maturity is termed haemoglobin switching and is a poorly understood process. α-thalassemia, which results from insufficient production of α-globin, is a major global health problem with several hundred thousand sufferers world-wide. The embryonically expressed ζ-globin, encoded by the gene HBZ (Hba-x in mice), can functionally substitute for α-globin in adult erythroid cells. Reactivation of this gene is consequently likely to ameliorate the symptoms of α-thalassemia in individuals with a severe phenotype. Little is currently known about the regulation of ζ-globin expression in terms of both the trans- and cis-acting regulatory elements responsible for high-levels of expression of this gene during embryonic erythropoiesis and its maintenance in a transcriptionally inactive state throughout adult life. Using ATACseq and NG Capture C and mutant mouse lines this work aims to identify and define the cis-acting regulatory network underlying zeta-globin expression, and define the contribution of each regulatory element.
2021-05-06 | GSE108432 | GEO
Project description:Haemoglobin, the oxygen-carrying molecule of red blood cells, at all stages of development comprises a tetramer of two α-like and two β-like globin chains. In humans and mice the highly conserved α- and β-globin loci contain genes encoding globin chains specifically expressed only during the first trimester of gestation (termed embryonic globins) in addition to the genes encoding globin chains expressed throughout adult life. In humans the β-globin locus also encodes a β-like chain that is expressed throughout the second and third trimesters of development; this is termed γ-globin and complexes with α-globin to form fetal haemoglobin (HbF). The sequential activation and repression of the genes at each of these loci throughout development to maturity is termed haemoglobin switching and is a poorly understood process. α-thalassemia, which results from insufficient production of α-globin, is a major global health problem with several hundred thousand sufferers world-wide. The embryonically expressed ζ-globin, encoded by the gene HBZ (Hba-x in mice), can functionally substitute for α-globin in adult erythroid cells. Reactivation of this gene is consequently likely to ameliorate the symptoms of α-thalassemia in individuals with a severe phenotype. Little is currently known about the regulation of ζ-globin expression in terms of both the trans- and cis-acting regulatory elements responsible for high-levels of expression of this gene during embryonic erythropoiesis and its maintenance in a transcriptionally inactive state throughout adult life. Using ATACseq and NG Capture C and mutant mouse lines this work aims to identify and define the cis-acting regulatory network underlying zeta-globin expression, and define the contribution of each regulatory element.
2021-05-06 | GSE108430 | GEO
Project description:Haemoglobin, the oxygen-carrying molecule of red blood cells, at all stages of development comprises a tetramer of two α-like and two β-like globin chains. In humans and mice the highly conserved α- and β-globin loci contain genes encoding globin chains specifically expressed only during the first trimester of gestation (termed embryonic globins) in addition to the genes encoding globin chains expressed throughout adult life. In humans the β-globin locus also encodes a β-like chain that is expressed throughout the second and third trimesters of development; this is termed γ-globin and complexes with α-globin to form fetal haemoglobin (HbF). The sequential activation and repression of the genes at each of these loci throughout development to maturity is termed haemoglobin switching and is a poorly understood process. α-thalassemia, which results from insufficient production of α-globin, is a major global health problem with several hundred thousand sufferers world-wide. The embryonically expressed ζ-globin, encoded by the gene HBZ (Hba-x in mice), can functionally substitute for α-globin in adult erythroid cells. Reactivation of this gene is consequently likely to ameliorate the symptoms of α-thalassemia in individuals with a severe phenotype. Little is currently known about the regulation of ζ-globin expression in terms of both the trans- and cis-acting regulatory elements responsible for high-levels of expression of this gene during embryonic erythropoiesis and its maintenance in a transcriptionally inactive state throughout adult life. Using ATACseq, ChIP-seq and NG Capture C and mutant mouse lines this work aims to identify and define the cis-acting regulatory network underlying zeta-globin expression, and define the contribution of each regulatory element.
2021-05-18 | GSE174593 | GEO
Project description:The benign condition Hereditary Persistence of Foetal Haemoglobin (HPFH) is known to ameliorate symptoms when co-inherited with beta-haemoglobinopathies, such as sickle cell disease and beta-thalassaemia. The condition is sometimes associated with point mutations in the foetal globin promoters that disrupt the binding of the repressors BCL11A or ZBTB7A/LRF, which have been extensively studied. HPFH is also associated with a range of deletions within the beta-globin locus that all reside downstream of the foetal HBG2 gene. These deletional forms of HPFH are poorly understood and are the focus of this study. Numerous different mechanisms have been proposed to explain how downstream deletions can boost the expression of the foetal globin genes, including the deletion of silencer elements, of genes encoding non-coding RNA, and bringing downstream enhancer elements into proximity with the foetal globin gene promoters. Here we systematically analyse the deletions associated with both HPFH and a related condition known as beta-thalassaemia and propose a unifying mechanism. In all cases where foetal globin is up-regulated, the proximal adult beta-globin (HBB) promoter is deleted. We use CRISPR gene editing to delete or disrupt elements within the promoter and find that virtually all mutations that reduce promoter activity, result in elevated foetal globin expression. These results fit with previous models where the foetal and adult globin genes compete for the distal Locus Control Region and suggest that targeting the promoter might be explored to elevate foetal globin and reduce sickle globin expression as a treatment for beta-haemoglobinopathies.
2022-01-20 | GSE194064 | GEO
Project description:Background: Developmental stage-specific globin expression is a complex phenomenon that involves both trans- and cis-acting elements. While functional analyses ensuing recent genome-wide association studies have highlighted the important roles of trans-factors in regulating hemoglobin expression, these factors can not exert their functions without permissive chromatin domains. By transferring thoroughly profiled beta globin locus of undifferentiated human embryonic stem cells (hESCs) or hESC-derived erythroid cells into an adult erythroid transcriptional environment, we studied the influences of histone modifications on the globin expression decision within a fixed transcriptional environment. Shortly after the locus transfer, embryonic epsilon globin was not expressed regardless of original chromatin states, whereas fetal gamma globin was either expressed or not activated depending on original chromatin configurations, and the originally silent adult beta globin either remained silent or became activated depending on the expression status of gamma globin. These data suggest the interplay between transcriptional environment and the chromatin modifications determine the outcome of globin expression. As the ultimate silencing of gamma globin from hESC-derived erythroid cells in the adult transcriptional environment occurred after months-long cell proliferation, our work also has implications on attempts to generate beta globin expressing erythroid cells from hESCs or induced pluripotent stem cells. hESC line H1 (NIH code WA01, WiCell, Madison, WI) and adeno-associated virus (AAV)-targeted lines, were maintained and differentiated as previously described.12 (Details can be found in the supplemental information.) The expression of stem cell markers including SSEA-3, SSEA-4, TRA-1-60, and TRA-1-61 was detected by flow cytometry. To determine whether AAV-targeted lines retained their hematopoietic differentiation potential, confluent hESCs were harvested off the feeder layers and transferred to ultra-low attachment plates to allow for the formation of embryoid bodies (EBs). Day-14 EBs were dissociated into single cells and the expression of surface markers including CD34, CD71, CD45, CD31, CD41 and glycophorin-A was determined by flow cytometry. To induce erythroid differentiation, day-7 EBs were made into single cell suspension and cultured in erythroid-inducing medium for 14 days. Primers for real time PCR analysis of beta locus globin mRNA expression are provided in the supplemental information.
2012-08-19 | E-GEOD-31523 | biostudies-arrayexpress
Project description:Background: Developmental stage-specific globin expression is a complex phenomenon that involves both trans- and cis-acting elements. While functional analyses ensuing recent genome-wide association studies have highlighted the important roles of trans-factors in regulating hemoglobin expression, these factors can not exert their functions without permissive chromatin domains. By transferring thoroughly profiled beta globin locus of undifferentiated human embryonic stem cells (hESCs) or hESC-derived erythroid cells into an adult erythroid transcriptional environment, we studied the influences of histone modifications on the globin expression decision within a fixed transcriptional environment. Shortly after the locus transfer, embryonic epsilon globin was not expressed regardless of original chromatin states, whereas fetal gamma globin was either expressed or not activated depending on original chromatin configurations, and the originally silent adult beta globin either remained silent or became activated depending on the expression status of gamma globin. These data suggest the interplay between transcriptional environment and the chromatin modifications determine the outcome of globin expression. As the ultimate silencing of gamma globin from hESC-derived erythroid cells in the adult transcriptional environment occurred after months-long cell proliferation, our work also has implications on attempts to generate beta globin expressing erythroid cells from hESCs or induced pluripotent stem cells.
2012-08-19 | GSE31523 | GEO
Project description:Transcriptional enhancers can be in physical proximity with their target genes via chromatin looping. The enhancer at the beta-globin locus (LCR) contacts the fetal (HBG) and adult (HBB) type beta-globin genes during corresponding developmental stages. We previously demonstrated that forcing proximity between the LCR and HBG genes in cultured adult-stage erythroid cells can activate HBG transcription. Activation of HBG expression in erythroid cells is of benefit to patients with sickle cell disease. Here, using the beta-globin locus as a model we provide proof-of-concept at the organismal level that forced enhancer re-wiring might present a strategy to alter gene expression for therapeutic purposes. Hematopoietic stem and progenitor cells (HSPC) from mice bearing human beta-globin genes were transduced with lentiviral vectors expressing a synthetic transcription factor (ZF-Ldb1) that fosters LCR-HBG contacts. When engrafted into host animals, HSPCs gave rise to adult-type erythroid cells with elevated HBG expression. Vectors containing ZF-Ldb1 were optimized for activity in cultured human and rhesus erythroid cells. Upon transplantation into rhesus macaques, erythroid cells from HSPCs expressing ZF-Ldb1 displayed elevated HBG production. These findings in two animal models suggest that forced redirection of gene regulatory elements may be used to alter gene expression to treat disease.
2023-02-08 | GSE221182 | GEO
Project description:Bekaert2012 - Reconstruction of D.rerio Metabolic Network
Danio rerio
metabolic model accounting for subcellular compartmentalisation (ZebraGEM)
This SBML representation of the D. rerio
(zebrafish) metabolic network is made available under the Creative Commons Attribution-Share Alike 3.0 Unported Licence (see www.creativecommons.org
).
This model is described in the article:
Reconstruction of Danio rerio Metabolic Model Accounting for Subcellular Compartmentalisation.
Bekaert M.
PLoS One. 2012;7(11):e49903.
Abstract:
Plant and microbial metabolic engineering is commonly used in the production of functional foods and quality trait improvement. Computational model-based approaches have been used in this important endeavour. However, to date, fish metabolic models have only been scarcely and partially developed, in marked contrast to their prominent success in metabolic engineering. In this study we present the reconstruction of fully compartmentalised models of the Danio rerio (zebrafish) on a global scale. This reconstruction involves extraction of known biochemical reactions in D. rerio for both primary and secondary metabolism and the implementation of methods for determining subcellular localisation and assignment of enzymes. The reconstructed model (ZebraGEM) is amenable for constraint-based modelling analysis, and accounts for 4,988 genes coding for 2,406 gene-associated reactions and only 418 non-gene-associated reactions. A set of computational validations (i.e., simulations of known metabolic functionalities and experimental data) strongly testifies to the predictive ability of the model. Overall, the reconstructed model is expected to lay down the foundations for computational-based rational design of fish metabolic engineering in aquaculture.
This model is hosted on BioModels Database
and identified by: MODEL1204120000
.
To cite BioModels Database, please use: BioModels Database: An enhanced, curated and annotated resource for published quantitative kinetic models. PMID: 20587024
.
To the extent possible under law, all copyright and related or neighbouring rights to this encoded model have been dedicated to the public domain worldwide. Please refer to [CC0 Public Domain Dedication>http://creativecommons.org/publicdomain/zero/1.0/] for more information.
2005-01-01 | MODEL1204120000 | BioModels