1
|
Manjón AG, Manzo SG, Prekovic S, Potgeter L, van Schaik T, Liu NQ, Flach K, Peric-Hupkes D, Joosten S, Teunissen H, Friskes A, Ilic M, Hintzen D, Franceschini-Santos VH, Zwart W, de Wit E, van Steensel B, Medema RH. Perturbations in 3D genome organization can promote acquired drug resistance. Cell Rep 2023; 42:113124. [PMID: 37733591 DOI: 10.1016/j.celrep.2023.113124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 08/05/2023] [Accepted: 08/25/2023] [Indexed: 09/23/2023] Open
Abstract
Acquired drug resistance is a major problem in the treatment of cancer. hTERT-immortalized, untransformed RPE-1 cells can acquire resistance to Taxol by derepressing the ABCB1 gene, encoding for the multidrug transporter P-gP. Here, we investigate how the ABCB1 gene is derepressed. ABCB1 activation is associated with reduced H3K9 trimethylation, increased H3K27 acetylation, and ABCB1 displacement from the nuclear lamina. While altering DNA methylation and H3K27 methylation had no major impact on ABCB1 expression, nor did it promote resistance, disrupting the nuclear lamina component Lamin B Receptor did promote the acquisition of a Taxol-resistant phenotype in a subset of cells. CRISPRa-mediated gene activation supported the notion that lamina dissociation influences ABCB1 derepression. We propose a model in which nuclear lamina dissociation of a repressed gene allows for its activation, implying that deregulation of the 3D genome topology could play an important role in tumor evolution and the acquisition of drug resistance.
Collapse
Affiliation(s)
- Anna G Manjón
- Oncode Institute, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands; Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands
| | - Stefano Giustino Manzo
- Oncode Institute, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands; Division of Gene Regulation, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands; Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
| | - Stefan Prekovic
- Oncode Institute, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands; Division of Oncogenomics, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands; Center for Molecular Medicine, University Medical Center Utrecht and Utrecht University, 3584 CX Utrecht, the Netherlands
| | - Leon Potgeter
- Oncode Institute, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands; Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands
| | - Tom van Schaik
- Oncode Institute, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands; Division of Gene Regulation, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands
| | - Ning Qing Liu
- Division of Gene Regulation, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands; Department of Hematology, Erasmus Medical Center (MC) Cancer Institute, Rotterdam, the Netherlands
| | - Koen Flach
- Division of Gene Regulation, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands
| | - Daniel Peric-Hupkes
- Oncode Institute, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands; Division of Gene Regulation, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands
| | - Stacey Joosten
- Oncode Institute, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands; Division of Oncogenomics, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands
| | - Hans Teunissen
- Division of Gene Regulation, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands
| | - Anoek Friskes
- Oncode Institute, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands; Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands
| | - Mila Ilic
- Oncode Institute, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands; Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands
| | - Dorine Hintzen
- Oncode Institute, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands; Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands
| | - Vinícius H Franceschini-Santos
- Oncode Institute, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands; Division of Gene Regulation, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands
| | - Wilbert Zwart
- Oncode Institute, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands; Division of Oncogenomics, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands
| | - Elzo de Wit
- Division of Gene Regulation, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands
| | - Bas van Steensel
- Oncode Institute, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands; Division of Gene Regulation, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands.
| | - René H Medema
- Oncode Institute, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands; Division of Cell Biology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066CX Amsterdam, the Netherlands.
| |
Collapse
|
2
|
Razin SV, Zhegalova IV, Kantidze OL. Domain Model of Eukaryotic Genome Organization: From DNA Loops Fixed on the Nuclear Matrix to TADs. BIOCHEMISTRY. BIOKHIMIIA 2022; 87:667-680. [PMID: 36154886 DOI: 10.1134/s0006297922070082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/18/2022] [Accepted: 06/22/2022] [Indexed: 06/16/2023]
Abstract
The article reviews the development of ideas on the domain organization of eukaryotic genome, with special attention on the studies of DNA loops anchored to the nuclear matrix and their role in the emergence of the modern model of eukaryotic genome spatial organization. Critical analysis of results demonstrating that topologically associated chromatin domains are structural-functional blocks of the genome supports the notion that these blocks are fundamentally different from domains whose existence was proposed by the domain hypothesis of eukaryotic genome organization formulated in the 1980s. Based on the discussed evidence, it is concluded that the model postulating that eukaryotic genome is built from uniformly organized structural-functional blocks has proven to be untenable.
Collapse
Affiliation(s)
- Sergey V Razin
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia.
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Irina V Zhegalova
- Skolkovo Institute of Science and Technology, Moscow, 121205, Russia
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, 119991, Russia
- Kharkevich Institute for Information Transmission Problems, Moscow, 127051, Russia
| | - Omar L Kantidze
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia
| |
Collapse
|
3
|
Chauhan W, Shoaib S, Fatma R, Zaka‐ur‐Rab Z, Afzal M. β‐thalassemia, and the advent of new Interventions beyond Transfusion and Iron chelation. Br J Clin Pharmacol 2022; 88:3610-3626. [DOI: 10.1111/bcp.15343] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 03/10/2022] [Accepted: 03/29/2022] [Indexed: 01/19/2023] Open
Affiliation(s)
- Waseem Chauhan
- Human Genetics and Toxicology Laboratory, Department of Zoology Aligarh Muslim University Aligarh India
| | - Shoaib Shoaib
- Department of Biochemistry, JNMC Aligarh Muslim University Aligarh India
| | - Rafat Fatma
- Human Genetics and Toxicology Laboratory, Department of Zoology Aligarh Muslim University Aligarh India
| | - Zeeba Zaka‐ur‐Rab
- Department of Pediatrics, JNMC Aligarh Muslim University Aligarh India
| | - Mohammad Afzal
- Human Genetics and Toxicology Laboratory, Department of Zoology Aligarh Muslim University Aligarh India
| |
Collapse
|
4
|
Mohanta TK, Mishra AK, Al-Harrasi A. The 3D Genome: From Structure to Function. Int J Mol Sci 2021; 22:11585. [PMID: 34769016 PMCID: PMC8584255 DOI: 10.3390/ijms222111585] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 10/18/2021] [Accepted: 10/20/2021] [Indexed: 01/09/2023] Open
Abstract
The genome is the most functional part of a cell, and genomic contents are organized in a compact three-dimensional (3D) structure. The genome contains millions of nucleotide bases organized in its proper frame. Rapid development in genome sequencing and advanced microscopy techniques have enabled us to understand the 3D spatial organization of the genome. Chromosome capture methods using a ligation approach and the visualization tool of a 3D genome browser have facilitated detailed exploration of the genome. Topologically associated domains (TADs), lamin-associated domains, CCCTC-binding factor domains, cohesin, and chromatin structures are the prominent identified components that encode the 3D structure of the genome. Although TADs are the major contributors to 3D genome organization, they are absent in Arabidopsis. However, a few research groups have reported the presence of TAD-like structures in the plant kingdom.
Collapse
Affiliation(s)
- Tapan Kumar Mohanta
- Natural and Medical Sciences Research Center, University of Nizwa, Nizwa 616, Oman
| | - Awdhesh Kumar Mishra
- Department of Biotechnology, Yeungnam University, Gyeongsan 38541, Gyeongsangbuk-do, Korea; or
| | - Ahmed Al-Harrasi
- Natural and Medical Sciences Research Center, University of Nizwa, Nizwa 616, Oman
| |
Collapse
|
5
|
Razin SV, Ioudinkova ES, Kantidze OL, Iarovaia OV. Co-Regulated Genes and Gene Clusters. Genes (Basel) 2021; 12:907. [PMID: 34208174 PMCID: PMC8230824 DOI: 10.3390/genes12060907] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 06/09/2021] [Accepted: 06/10/2021] [Indexed: 12/27/2022] Open
Abstract
There are many co-regulated genes in eukaryotic cells. The coordinated activation or repression of such genes occurs at specific stages of differentiation, or under the influence of external stimuli. As a rule, co-regulated genes are dispersed in the genome. However, there are also gene clusters, which contain paralogous genes that encode proteins with similar functions. In this aspect, they differ significantly from bacterial operons containing functionally linked genes that are not paralogs. In this review, we discuss the reasons for the existence of gene clusters in vertebrate cells and propose that clustering is necessary to ensure the possibility of selective activation of one of several similar genes.
Collapse
Affiliation(s)
- Sergey V. Razin
- Institute of Gene Biology Russian Academy of Sciences, 119334 Moscow, Russia; (E.S.I.); (O.L.K.); (O.V.I.)
- Faculty of Biology, M.V. Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Elena S. Ioudinkova
- Institute of Gene Biology Russian Academy of Sciences, 119334 Moscow, Russia; (E.S.I.); (O.L.K.); (O.V.I.)
| | - Omar L. Kantidze
- Institute of Gene Biology Russian Academy of Sciences, 119334 Moscow, Russia; (E.S.I.); (O.L.K.); (O.V.I.)
| | - Olga V. Iarovaia
- Institute of Gene Biology Russian Academy of Sciences, 119334 Moscow, Russia; (E.S.I.); (O.L.K.); (O.V.I.)
| |
Collapse
|
6
|
Razin SV, Ulianov SV, Gavrilov AA. 3D Genomics. Mol Biol 2019; 53:802-812. [DOI: 10.1134/s0026893319060153] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 06/01/2019] [Accepted: 06/03/2019] [Indexed: 08/30/2023]
|
7
|
Iarovaia OV, Kovina AP, Petrova NV, Razin SV, Ioudinkova ES, Vassetzky YS, Ulianov SV. Genetic and Epigenetic Mechanisms of β-Globin Gene Switching. BIOCHEMISTRY (MOSCOW) 2018; 83:381-392. [PMID: 29626925 DOI: 10.1134/s0006297918040090] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Vertebrates have multiple forms of hemoglobin that differ in the composition of their polypeptide chains. During ontogenesis, the composition of these subunits changes. Genes encoding different α- and β-polypeptide chains are located in two multigene clusters on different chromosomes. Each cluster contains several genes that are expressed at different stages of ontogenesis. The phenomenon of stage-specific transcription of globin genes is referred to as globin gene switching. Mechanisms of expression switching, stage-specific activation, and repression of transcription of α- and β-globin genes are of interest from both theoretical and practical points of view. Alteration of balanced expression of globin genes, which usually occurs due to damage to adult β-globin genes, leads to development of severe diseases - hemoglobinopathies. In most cases, reactivation of the fetal hemoglobin gene in patients with β-thalassemia and sickle cell disease can reduce negative consequences of irreversible alterations of expression of the β-globin genes. This review focuses on the current state of research on genetic and epigenetic mechanisms underlying stage-specific switching of β-globin genes.
Collapse
Affiliation(s)
- O V Iarovaia
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia.
| | | | | | | | | | | | | |
Collapse
|
8
|
Razin SV, Gavrilov AA. Structural–Functional Domains of the Eukaryotic Genome. BIOCHEMISTRY (MOSCOW) 2018; 83:302-312. [DOI: 10.1134/s0006297918040028] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 11/27/2017] [Indexed: 08/30/2023]
|
9
|
Razin SV, Ulianov SV. Gene functioning and storage within a folded genome. Cell Mol Biol Lett 2017; 22:18. [PMID: 28861108 PMCID: PMC5575855 DOI: 10.1186/s11658-017-0050-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Accepted: 08/24/2017] [Indexed: 01/28/2023] Open
Abstract
In mammals, genomic DNA that is roughly 2 m long is folded to fit the size of the cell nucleus that has a diameter of about 10 μm. The folding of genomic DNA is mediated via assembly of DNA-protein complex, chromatin. In addition to the reduction of genomic DNA linear dimensions, the assembly of chromatin allows to discriminate and to mark active (transcribed) and repressed (non-transcribed) genes. Consequently, epigenetic regulation of gene expression occurs at the level of DNA packaging in chromatin. Taking into account the increasing attention of scientific community toward epigenetic systems of gene regulation, it is very important to understand how DNA folding in chromatin is related to gene activity. For many years the hierarchical model of DNA folding was the most popular. It was assumed that nucleosome fiber (10-nm fiber) is folded into 30-nm fiber and further on into chromatin loops attached to a nuclear/chromosome scaffold. Recent studies have demonstrated that there is much less regularity in chromatin folding within the cell nucleus. The very existence of 30-nm chromatin fibers in living cells was questioned. On the other hand, it was found that chromosomes are partitioned into self-interacting spatial domains that restrict the area of enhancers action. Thus, TADs can be considered as structural-functional domains of the chromosomes. Here we discuss the modern view of DNA packaging within the cell nucleus in relation to the regulation of gene expression. Special attention is paid to the possible mechanisms of the chromatin fiber self-assembly into TADs. We discuss the model postulating that partitioning of the chromosome into TADs is determined by the distribution of active and inactive chromatin segments along the chromosome. This article was specially invited by the editors and represents work by leading researchers.
Collapse
Affiliation(s)
- Sergey V Razin
- Institute of Gene Biology, Russian Academy of Sciences, Vavilov Street 34/5, 119334 Moscow, Russia.,Lomonosov Moscow State University, Biological Faculty, Leninskie Gory 1, building 12, 119192 Moscow, Russia
| | - Sergey V Ulianov
- Institute of Gene Biology, Russian Academy of Sciences, Vavilov Street 34/5, 119334 Moscow, Russia.,Lomonosov Moscow State University, Biological Faculty, Leninskie Gory 1, building 12, 119192 Moscow, Russia
| |
Collapse
|
10
|
Kovina AP, Petrova NV, Gushchanskaya ES, Dolgushin KV, Gerasimov ES, Galitsyna AA, Penin AA, Flyamer IM, Ioudinkova ES, Gavrilov AA, Vassetzky YS, Ulianov SV, Iarovaia OV, Razin SV. Evolution of the Genome 3D Organization: Comparison of Fused and Segregated Globin Gene Clusters. Mol Biol Evol 2017; 34:1492-1504. [DOI: 10.1093/molbev/msx100] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
|
11
|
Kovina AP, Petrova NV, Razin SV, Yarovaia OV. Main regulatory element (MRE) of the Danio rerio α/β-globin gene domain exerts enhancer activity toward the promoters of the embryonic-larval and adult globin genes. Mol Biol 2016. [DOI: 10.1134/s002689331606011x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
12
|
3D genomics imposes evolution of the domain model of eukaryotic genome organization. Chromosoma 2016; 126:59-69. [DOI: 10.1007/s00412-016-0604-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 05/11/2016] [Accepted: 06/06/2016] [Indexed: 10/21/2022]
|
13
|
Nefedochkina AV, Petrova NV, Ioudinkova ES, Kovina AP, Iarovaia OV, Razin SV. Characterization of the enhancer element of the Danio rerio minor globin gene locus. Histochem Cell Biol 2016; 145:463-73. [PMID: 26847176 DOI: 10.1007/s00418-016-1413-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/19/2016] [Indexed: 12/23/2022]
Abstract
In Danio rerio, the alpha- and beta-globin genes are present in two clusters: a major cluster located on chromosome 3 and a minor cluster located on chromosome 12. In contrast to the segregated alpha- and beta-globin gene domains of warm-blooded animals, in Danio rerio, each cluster contains both alpha- and beta-globin genes. Expression of globin genes present in the major cluster is controlled by an erythroid-specific enhancer similar to the major regulatory element of mammalian and avian alpha-globin gene domains. The enhancer controlling expression of the globin genes present in the minor locus has not been identified yet. Based on the distribution of epigenetic marks, we have selected two genomic regions that might harbor an enhancer of the minor locus. Using transient transfection of constructs with a reporter gene, we have demonstrated that a ~500-bp DNA fragment located ~1.7 Kb upstream of the αe4 gene possesses an erythroid-specific enhancer active with respect to promoters present in both the major and the minor globin gene loci of Danio rerio. The identified enhancer element harbors clustered binding sites for GATA-1, NF-E2, and EKLF similar to the enhancer of the major globin locus on chromosome 3. Both enhancers appear to have emerged as a result of independent evolution of a duplicated regulatory element present in an ancestral single alpha-/beta-globin locus that existed before teleost-specific genome duplication.
Collapse
Affiliation(s)
- Anastasia V Nefedochkina
- Institute of Gene Biology, Russian Academy of Sciences, Vavilov Street 34/5, Moscow, Russia, 119334.,Molecular Biology Department, Biological Faculty, Lomonosov Moscow State University, Moscow, Russia, 119992
| | - Natalia V Petrova
- Institute of Gene Biology, Russian Academy of Sciences, Vavilov Street 34/5, Moscow, Russia, 119334
| | - Elena S Ioudinkova
- Institute of Gene Biology, Russian Academy of Sciences, Vavilov Street 34/5, Moscow, Russia, 119334
| | - Anastasia P Kovina
- Institute of Gene Biology, Russian Academy of Sciences, Vavilov Street 34/5, Moscow, Russia, 119334.,Molecular Biology Department, Biological Faculty, Lomonosov Moscow State University, Moscow, Russia, 119992
| | - Olga V Iarovaia
- Institute of Gene Biology, Russian Academy of Sciences, Vavilov Street 34/5, Moscow, Russia, 119334
| | - Sergey V Razin
- Institute of Gene Biology, Russian Academy of Sciences, Vavilov Street 34/5, Moscow, Russia, 119334. .,Molecular Biology Department, Biological Faculty, Lomonosov Moscow State University, Moscow, Russia, 119992.
| |
Collapse
|
14
|
Harraghy N, Calabrese D, Fisch I, Girod PA, LeFourn V, Regamey A, Mermod N. Epigenetic regulatory elements: Recent advances in understanding their mode of action and use for recombinant protein production in mammalian cells. Biotechnol J 2015; 10:967-78. [DOI: 10.1002/biot.201400649] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Revised: 04/20/2015] [Accepted: 05/20/2015] [Indexed: 12/18/2022]
|
15
|
Dolgushin KV, Iudinkova ES, Petrova NV, Razin SV, Iarovaia OV. Joint locus of a/b-globin genes in Danio rerio is segregated into structural subdomains active at different stages of development. Mol Biol 2015. [DOI: 10.1134/s0026893315030048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
16
|
Iarovaia OV, Ioudinkova ES, Petrova NV, Dolgushin KV, Kovina AV, Nefedochkina AV, Vassetzky YS, Razin SV. Evolution of α- and β-globin genes and their regulatory systems in light of the hypothesis of domain organization of the genome. BIOCHEMISTRY (MOSCOW) 2014; 79:1141-50. [PMID: 25539999 DOI: 10.1134/s0006297914110017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The α- and β-globin gene domains are a traditional model for study of the domain organization of the eucaryotic genome because these genes encode hemoglobin, a physiologically important protein. The α-globin and β-globin gene domains are organized in completely different ways, while the expression of globin genes is tightly coordinated, which makes it extremely interesting to study the origin of these genes and the evolution of their regulatory systems. In this review, the organization of the α- and β-globin gene domains and their genomic environment in different taxonomic groups are comparatively analyzed. A new hypothesis of possible evolutionary pathways for segregated α- and β-globin gene domains of warm-blooded animals is proposed.
Collapse
Affiliation(s)
- O V Iarovaia
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, 119334, Russia.
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Arriaga-Canon C, Fonseca-Guzmán Y, Valdes-Quezada C, Arzate-Mejía R, Guerrero G, Recillas-Targa F. A long non-coding RNA promotes full activation of adult gene expression in the chicken α-globin domain. Epigenetics 2013; 9:173-81. [PMID: 24196393 DOI: 10.4161/epi.27030] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Long non-coding RNAs (lncRNAs) were recently shown to regulate chromatin remodelling activities. Their function in regulating gene expression switching during specific developmental stages is poorly understood. Here we describe a nuclear, non-coding transcript responsive for the stage-specific activation of the chicken adult α(D) globin gene. This non-coding transcript, named α-globin transcript long non-coding RNA (lncRNA-αGT) is transcriptionally upregulated in late stages of chicken development, when active chromatin marks the adult α(D) gene promoter. Accordingly, the lncRNA-αGT promoter drives erythroid-specific transcription. Furthermore, loss of function experiments showed that lncRNA-αGT is required for full activation of the α(D) adult gene and maintenance of transcriptionally active chromatin. These findings uncovered lncRNA-αGT as an important part of the switching from embryonic to adult α-globin gene expression, and suggest a function of lncRNA-αGT in contributing to the maintenance of adult α-globin gene expression by promoting an active chromatin structure.
Collapse
Affiliation(s)
- Cristian Arriaga-Canon
- Instituto de Fisiología Celular; Departamento de Genética Molecular; Universidad Nacional Autónoma de México; Distrito Federal, México
| | - Yael Fonseca-Guzmán
- Instituto de Fisiología Celular; Departamento de Genética Molecular; Universidad Nacional Autónoma de México; Distrito Federal, México
| | - Christian Valdes-Quezada
- Instituto de Fisiología Celular; Departamento de Genética Molecular; Universidad Nacional Autónoma de México; Distrito Federal, México
| | - Rodrigo Arzate-Mejía
- Instituto de Fisiología Celular; Departamento de Genética Molecular; Universidad Nacional Autónoma de México; Distrito Federal, México
| | - Georgina Guerrero
- Instituto de Fisiología Celular; Departamento de Genética Molecular; Universidad Nacional Autónoma de México; Distrito Federal, México
| | - Félix Recillas-Targa
- Instituto de Fisiología Celular; Departamento de Genética Molecular; Universidad Nacional Autónoma de México; Distrito Federal, México
| |
Collapse
|
18
|
Valdes-Quezada C, Arriaga-Canon C, Fonseca-Guzmán Y, Guerrero G, Recillas-Targa F. CTCF demarcates chicken embryonic α-globin gene autonomous silencing and contributes to adult stage-specific gene expression. Epigenetics 2013; 8:827-38. [PMID: 23880533 DOI: 10.4161/epi.25472] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Genomic loci composed of more than one gene are frequently subjected to differential gene expression, with the chicken α-globin domain being a clear example. In the present study we aim to understand the globin switching mechanisms responsible for the epigenetic silencing of the embryonic π gene and the transcriptional activation of the adult α(D) and α(A) genes at the genomic domain level. In early stages, we describe a physical contact between the embryonic π gene and the distal 3' enhancer that is lost later during development. We show that such a level of regulation is achieved through the establishment of a DNA hypermethylation sub-domain that includes the embryonic gene and the adjacent genomic sequences. The multifunctional CCCTCC-binding factor (CTCF), which is located upstream of the α(D) gene promoter, delimits this sub-domain and creates a transition between the inactive sub-domain and the active sub-domain, which includes the adult α(D) gene. In avian-transformed erythroblast HD3 cells that are induced to differentiate, we found active DNA demethylation of the adult α(D) promoter, coincident with the incorporation of 5-hydroxymethylcytosine (5hmC) and concomitant with adult gene transcriptional activation. These results suggest that autonomous silencing of the embryonic π gene is needed to facilitate an optimal topological conformation of the domain. This model proposes that CTCF is contributing to a specific chromatin configuration that is necessary for differential α-globin gene expression during development.
Collapse
Affiliation(s)
- Christian Valdes-Quezada
- Instituto de Fisiología Celular; Departamento de Genética Molecular; Universidad Nacional Autónoma de México; México D.F., México
| | | | | | | | | |
Collapse
|
19
|
Jost J, Scherrer K. Information theory, gene expression, and combinatorial regulation: a quantitative analysis. Theory Biosci 2013; 133:1-21. [PMID: 23674094 DOI: 10.1007/s12064-013-0182-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Accepted: 04/19/2013] [Indexed: 02/04/2023]
Abstract
According to a functional definition of the term "gene", a protein-coding gene corresponds to a polypeptide and, hence, a coding sequence. It is therefore as such not yet present at the DNA level, but assembled from possibly heterogeneous pieces in the course of RNA processing. Assembly and regulation of genes require, thus, information about when and in which quantity specific polypeptides are to be produced. To assess this, we draw upon precise biochemical data. On the basis of our conceptual framework, we also develop formal models for the coordinated expression of specific sets of genes through the interaction of transcripts and mRNAs and with proteins via a precise putative regulatory code. Thus, the nucleotides in transcripts and mRNA are not only arranged into amino acid-coding triplets, but at the same time may participate in regulatory oligomotifs that provide binding sites for specific proteins. We can then quantify and compare product and regulatory information involved in gene expression and regulation.
Collapse
|
20
|
Ioudinkova ES, Petrova NV, Bunina DA, Vishniakova HS, Sklyar IV, Razin SV, Iarovaia OV. Chromatin structure of the joint α/β-globin gene locus of Danio rerio. DOKL BIOCHEM BIOPHYS 2013; 448:59-61. [PMID: 23478991 DOI: 10.1134/s1607672913010171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Indexed: 11/23/2022]
|
21
|
Razin SV, Ulianov SV, Ioudinkova ES, Gushchanskaya ES, Gavrilov AA, Iarovaia OV. Domains of α- and β-globin genes in the context of the structural-functional organization of the eukaryotic genome. BIOCHEMISTRY (MOSCOW) 2012; 77:1409-1423. [DOI: 10.1134/s0006297912130019] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
|
22
|
Ioudinkova ES, Barat A, Pichugin A, Markova E, Sklyar I, Pirozhkova I, Robin C, Lipinski M, Ogryzko V, Vassetzky YS, Razin SV. Distinct distribution of ectopically expressed histone variants H2A.Bbd and MacroH2A in open and closed chromatin domains. PLoS One 2012; 7:e47157. [PMID: 23118866 PMCID: PMC3484066 DOI: 10.1371/journal.pone.0047157] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Accepted: 09/13/2012] [Indexed: 12/12/2022] Open
Abstract
Background It becomes increasingly evident that nuclesomes are far from being identical to each other. This nucleosome diversity is due partially to the existence of histone variants encoded by separate genes. Among the known histone variants the less characterized are H2A.Bbd and different forms of macroH2A. This is especially true in the case of H2A.Bbd as there are still no commercially available antibodies specific to H2A.Bbd that can be used for chromatin immunoprecipitation (ChIP). Methods We have generated HeLa S3 cell lines stably expressing epitope-tagged versions of macroH2A1.1, H2A.Bbd or canonical H2A and analyzed genomic distribution of the tagged histones using ChIP-on-chip technique. Results The presence of histone H2A variants macroH2A1.1 and H2A.Bbd has been analyzed in the chromatin of several segments of human chromosomes 11, 16 and X that have been chosen for their different gene densities and chromatin status. Chromatin immunoprecipitation (ChIP) followed by hybridization with custom NimbleGene genomic microarrays demonstrated that in open chromatin domains containing tissue-specific along with housekeeping genes, the H2A.Bbd variant was preferentially associated with the body of a subset of transcribed genes. The macroH2A1.1 variant was virtually absent from some genes and underrepresented in others. In contrast, in closed chromatin domains which contain only tissue-specific genes inactive in HeLa S3 cells, both macroH2A1.1 and H2A.Bbd histone variants were present and often colocalized. Conclusions Genomic distribution of macro H2A and H2A.Bbd does not follow any simple rule and is drastically different in open and closed genomic domains.
Collapse
Affiliation(s)
- Elena S. Ioudinkova
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
- CNRS UMR 8126, Univ. Paris-Sud 11, Institut de cancérologie Gustave Roussy, Villejuif, France
- LIA1066, Laboratoire Franco-Russe de recherches en oncologie, Villejuif, France
| | - Ana Barat
- CNRS UMR 8126, Univ. Paris-Sud 11, Institut de cancérologie Gustave Roussy, Villejuif, France
- The Centre for Scientific Computing & Complex Systems Modelling (SCI-SYM), School of Computing, Dublin City University, Dublin, Ireland
| | - Andrey Pichugin
- CNRS UMR 8126, Univ. Paris-Sud 11, Institut de cancérologie Gustave Roussy, Villejuif, France
- LIA1066, Laboratoire Franco-Russe de recherches en oncologie, Villejuif, France
| | - Elena Markova
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
- CNRS UMR 8126, Univ. Paris-Sud 11, Institut de cancérologie Gustave Roussy, Villejuif, France
- LIA1066, Laboratoire Franco-Russe de recherches en oncologie, Villejuif, France
| | - Ilya Sklyar
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
- CNRS UMR 8126, Univ. Paris-Sud 11, Institut de cancérologie Gustave Roussy, Villejuif, France
- LIA1066, Laboratoire Franco-Russe de recherches en oncologie, Villejuif, France
| | - Iryna Pirozhkova
- CNRS UMR 8126, Univ. Paris-Sud 11, Institut de cancérologie Gustave Roussy, Villejuif, France
- LIA1066, Laboratoire Franco-Russe de recherches en oncologie, Villejuif, France
| | - Chloe Robin
- CNRS UMR 8126, Univ. Paris-Sud 11, Institut de cancérologie Gustave Roussy, Villejuif, France
- LIA1066, Laboratoire Franco-Russe de recherches en oncologie, Villejuif, France
| | - Marc Lipinski
- CNRS UMR 8126, Univ. Paris-Sud 11, Institut de cancérologie Gustave Roussy, Villejuif, France
- LIA1066, Laboratoire Franco-Russe de recherches en oncologie, Villejuif, France
| | - Vasily Ogryzko
- CNRS UMR 8126, Univ. Paris-Sud 11, Institut de cancérologie Gustave Roussy, Villejuif, France
- LIA1066, Laboratoire Franco-Russe de recherches en oncologie, Villejuif, France
| | - Yegor S. Vassetzky
- CNRS UMR 8126, Univ. Paris-Sud 11, Institut de cancérologie Gustave Roussy, Villejuif, France
- LIA1066, Laboratoire Franco-Russe de recherches en oncologie, Villejuif, France
- * E-mail:
| | - Sergey V. Razin
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
- LIA1066, Laboratoire Franco-Russe de recherches en oncologie, Villejuif, France
| |
Collapse
|
23
|
Ulianov SV, Gavrilov AA, Razin SV. Spatial organization of the chicken beta-globin gene domain in erythroid cells of embryonic and adult lineages. Epigenetics Chromatin 2012; 5:16. [PMID: 22958419 PMCID: PMC3502096 DOI: 10.1186/1756-8935-5-16] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 08/16/2012] [Indexed: 12/31/2022] Open
Abstract
Background The β-globin gene domains of vertebrate animals constitute popular models for studying the regulation of eukaryotic gene transcription. It has previously been shown that in the mouse the developmental switching of globin gene expression correlates with the reconfiguration of an active chromatin hub (ACH), a complex of promoters of transcribed genes with distant regulatory elements. Although it is likely that observations made in the mouse β-globin gene domain are also relevant for this locus in other species, the validity of this supposition still lacks direct experimental evidence. Here, we have studied the spatial organization of the chicken β-globin gene domain. This domain is of particular interest because it represents the perfect example of the so-called ‘strong’ tissue-specific gene domain flanked by insulators, which delimit the area of preferential sensitivity to DNase I in erythroid cells. Results Using chromosome conformation capture (3C), we have compared the spatial configuration of the β-globin gene domain in chicken red blood cells (RBCs) expressing embryonic (3-day-old RBCs) and adult (9-day-old RBCs) β-globin genes. In contrast to observations made in the mouse model, we found that in the chicken, the early embryonic β-globin gene, Ε, did not interact with the locus control region in RBCs of embryonic lineage (3-day RBCs), where this gene is actively transcribed. In contrast to the mouse model, a strong interaction of the promoter of another embryonic β-globin gene, ρ, with the promoter of the adult β-globin gene, βA, was observed in RBCs from both 3-day and 9-day chicken embryos. Finally, we have demonstrated that insulators flanking the chicken β-globin gene domain from the upstream and from the downstream interact with each other, which places the area characterized by lineage-specific sensitivity to DNase I in a separate chromatin loop. Conclusions Taken together, our results strongly support the ACH model but show that within a domain of tissue-specific genes, the active status of a promoter does not necessarily correlate with the recruitment of this promoter to the ACH.
Collapse
Affiliation(s)
- Sergey V Ulianov
- Institute of Gene Biology of the Russian Academy of Sciences, 34/5 Vavilov str,, 119334, Moscow, Russia.
| | | | | |
Collapse
|
24
|
Hasanali Z, Sharma K, Epner E. Flipping the cyclin D1 switch in mantle cell lymphoma. Best Pract Res Clin Haematol 2012; 25:143-52. [PMID: 22687450 DOI: 10.1016/j.beha.2012.03.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Mantle cell lymphoma (MCL) is a rare, aggressive subtype of B cell NHL for which there is no standard of care. It is characterized by the t(11;14) translocation, implicating cyclin D1 (CCND1) in its pathogenesis. Cyclin D1 is one of a family of 3 unlinked D type cyclin genes, CCND1, 2, 3. CCND1 is not expressed in normal B cells. Deregulated expression occurs as a result of juxtaposition of cis IgH enhancer elements, Eμ and 3' Cα, to the cyclin D1 gene. These enhancer elements and regions upstream of the CCND1 gene are hypomethylated on the translocated allele. Histones surrounding the translocation have shown hyperacetylation as well, a hallmark of transcriptionally active chromatin. The t(11;14) translocation is an epigenetic event, leading to cyclin D1 deregulated transcription. These findings provide the rationale for the use of epigenetic and targeted cyclin D1 therapies to overcome resistance and induce durable remissions in MCL.
Collapse
Affiliation(s)
- Zainul Hasanali
- Penn State Hershey Cancer Institute, Experimental Therapeutics A - CH74, Room T3319, 500 University Drive, Hershey, PA 17033-0850, USA
| | | | | |
Collapse
|
25
|
Yudinkova ES, Bunina DA, Ulyanov SV, Gavrilov AA, Razin SV. Patterns of histone modifications across the chicken alfa-globin genes’ domain. Mol Biol 2011. [DOI: 10.1134/s0026893311030216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
26
|
Philonenko ES, Gavrilov AA, Razin SV, Iarovaia OV. Expansion of the functional domain of chicken alpha-globin genes. RUSS J GENET+ 2010. [DOI: 10.1134/s1022795410090036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
27
|
Philonenko ES, Klochkov DB, Borunova VV, Gavrilov AA, Razin SV, Iarovaia OV. TMEM8 - a non-globin gene entrapped in the globin web. Nucleic Acids Res 2010; 37:7394-406. [PMID: 19820109 PMCID: PMC2794187 DOI: 10.1093/nar/gkp838] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
For more than 30 years it was believed that globin gene domains included only genes encoding globin chains. Here we show that in chickens, the domain of α-globin genes also harbor the non-globin gene TMEM8. It was relocated to the vicinity of the α-globin cluster due to inversion of an ∼170-kb genomic fragment. Although in humans TMEM8 is preferentially expressed in resting T-lymphocytes, in chickens it acquired an erythroid-specific expression profile and is upregulated upon terminal differentiation of erythroblasts. This correlates with the presence of erythroid-specific regulatory elements in the body of chicken TMEM8, which interact with regulatory elements of the α-globin genes. Surprisingly, TMEM8 is not simply recruited to the α-globin gene domain active chromatin hub. An alternative chromatin hub is assembled, which includes some of the regulatory elements essential for the activation of globin gene expression. These regulatory elements should thus shuttle between two different chromatin hubs.
Collapse
Affiliation(s)
- Elena S Philonenko
- Institute of Gene Biology of the Russian Academy of Sciences, Vavilov street 34/5, 119334 Moscow, Russia
| | | | | | | | | | | |
Collapse
|
28
|
The B-type lamin is required for somatic repression of testis-specific gene clusters. Proc Natl Acad Sci U S A 2009; 106:3282-7. [PMID: 19218438 DOI: 10.1073/pnas.0811933106] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Large clusters of coexpressed tissue-specific genes are abundant on chromosomes of diverse species. The genes coordinately misexpressed in diverse diseases are also found in similar clusters, suggesting that evolutionarily conserved mechanisms regulate expression of large multigenic regions both in normal development and in its pathological disruptions. Studies on individual loci suggest that silent clusters of coregulated genes are embedded in repressed chromatin domains, often localized to the nuclear periphery. To test this model at the genome-wide scale, we studied transcriptional regulation of large testis-specific gene clusters in somatic tissues of Drosophila. These gene clusters showed a drastic paucity of known expressed transgene insertions, indicating that they indeed are embedded in repressed chromatin. Bioinformatics analysis suggested the major role for the B-type lamin, LamDm(o), in repression of large testis-specific gene clusters, showing that in somatic cells as many as three-quarters of these clusters interact with LamDm(o). Ablation of LamDm(o) by using mutants and RNAi led to detachment of testis-specific clusters from nuclear envelope and to their selective transcriptional up-regulation in somatic cells, thus providing the first direct evidence for involvement of the B-type lamin in tissue-specific gene repression. Finally, we found that transcriptional activation of the lamina-bound testis-specific gene cluster in male germ line is coupled with its translocation away from the nuclear envelope. Our studies, which directly link nuclear architecture with coordinated regulation of tissue-specific genes, advance understanding of the mechanisms underlying both normal cell differentiation and developmental disorders caused by lesions in the B-type lamins and interacting proteins.
Collapse
|
29
|
Klochkov DB, Gavrilov AA, Vassetzky YS, Razin SV. Early replication timing of the chicken alpha-globin gene domain correlates with its open chromatin state in cells of different lineages. Genomics 2009; 93:481-6. [PMID: 19187796 DOI: 10.1016/j.ygeno.2009.01.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2008] [Revised: 12/10/2008] [Accepted: 01/06/2009] [Indexed: 10/21/2022]
Abstract
The vertebrate alpha-globin gene domain is an open chromatin domain overlapping a neighboring house-keeping gene. The tissue-specific cluster of alpha-globin genes and the overlapping housekeeping gene share the same replication origin. We have studied the replication timing of chicken alpha-globin genes in cells of different lineages using the FISH-based approach and found that alpha-globin genes replicate early both in erythroid and in non-erythroid cells, i.e. regardless of their transcriptional activity. Early replication timing of chicken alpha-globin genes in cells of different lineages was in good correlation with the open chromatin configuration of the alpha-globin gene domain in both erythroid and non-erythroid cells. We propose that active transcription of the housekeeping gene overlapping the alpha-globin gene domain enables an access of Origin Recognition Complex (ORC) proteins to the replication origin resulting in early replication of alpha-globin genes even in non-erythroid cells.
Collapse
Affiliation(s)
- Denis B Klochkov
- Institute of Gene Biology, Russian Academy of Sciences, Vavilov Street 34/5, 119334 Moscow, Russia
| | | | | | | |
Collapse
|
30
|
Rincón-Arano H, Furlan-Magaril M, Recillas-Targa F. Protection against telomeric position effects by the chicken cHS4 beta-globin insulator. Proc Natl Acad Sci U S A 2007; 104:14044-9. [PMID: 17715059 PMCID: PMC1955792 DOI: 10.1073/pnas.0704999104] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2007] [Indexed: 12/26/2022] Open
Abstract
Epigenetic silencing of genes relocated near telomeres, termed telomeric position effect, has been extensively studied in yeast and more recently in vertebrates. However, protection of a transgene against telomeric position effects by chromatin insulators has not yet been addressed. In this work we investigated the capacity of the chicken beta-globin insulator cHS4 to shield a transgene against silencing by telomeric heterochromatin. Using telomeric repeats, we targeted transgene integration into telomeres of the chicken cell line HD3. When the chicken cHS4 insulator is incorporated to the transgene, we observe a sustained gene expression of single-copy integrants that can be maintained for >100 days of continuous culture. However, uninsulated single-copy clones showed an accelerated gene expression extinction profile. Unexpectedly, telomeric silencing was not reversed with trichostatin A or nicotidamine. In contrast, significant reactivation was obtained with 5-aza-2'-deoxycytidine, consistent with the subtelomeric DNA methylation status. Strikingly, insulated transgenes integrated into telomeric regions were enriched in histone methylation, such as H3K4me2 and H3K79me2, but not in histone acetylation. Furthermore, the cHS4 insulator counteracts telomeric position effects in an upstream stimulatory factor-independent manner. Our results suggest that this insulator has the capacity to adapt to different chromatin propagation signals in distinct insertional epigenome environments.
Collapse
Affiliation(s)
- Héctor Rincón-Arano
- Instituto de Fisiología Celular, Departamento de Genética Molecular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, 04510 México, D.F., México
| | - Mayra Furlan-Magaril
- Instituto de Fisiología Celular, Departamento de Genética Molecular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, 04510 México, D.F., México
| | - Félix Recillas-Targa
- Instituto de Fisiología Celular, Departamento de Genética Molecular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, 04510 México, D.F., México
| |
Collapse
|
31
|
Razin SV, Ioudinkova ES. Mechanisms controlling activation of the alpha-globin gene domain in chicken erythroid cells. BIOCHEMISTRY (MOSCOW) 2007; 72:467-70. [PMID: 17573699 DOI: 10.1134/s000629790705001x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In this review we consider the organization of the chicken alpha-globin gene domain and mechanisms regulating the activity of this tissue-specific gene domain located in a potentially active (characterized by an increased sensitivity to nucleases) chromatin configuration in cells of all lineages. Both regulatory mechanisms ensuring repression of alpha-globin genes in non-erythroid cells and mechanisms responsible for activation of transcription of these genes during erythroid cell differentiation are discussed. The analysis of the structure-function organization of the chicken alpha-globin gene domain presented in this review is based mainly on the authors' own results obtained over the last 20 years. On discussing the hypotheses explaining the mechanisms controlling the functional activity of chicken alpha-globin gene domain, data obtained in studies of alpha-globin gene domains of other vertebrates are also analyzed.
Collapse
Affiliation(s)
- S V Razin
- Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia.
| | | |
Collapse
|
32
|
|
33
|
Razin SV, Iarovaia OV, Sjakste N, Sjakste T, Bagdoniene L, Rynditch AV, Eivazova ER, Lipinski M, Vassetzky YS. Chromatin domains and regulation of transcription. J Mol Biol 2007; 369:597-607. [PMID: 17466329 DOI: 10.1016/j.jmb.2007.04.003] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2007] [Revised: 03/27/2007] [Accepted: 04/02/2007] [Indexed: 12/20/2022]
Abstract
Compartmentalization and compaction of DNA in the nucleus is the characteristic feature of eukaryotic cells. A fully extended DNA molecule has to be compacted 100,000 times to fit within the nucleus. At the same time it is critical that various DNA regions remain accessible for interaction with regulatory factors and transcription/replication factories. This puzzle is solved at the level of DNA packaging in chromatin that occurs in several steps: rolling of DNA onto nucleosomes, compaction of nucleosome fiber with formation of the so-called 30 nm fiber, and folding of the latter into the giant (50-200 kbp) loops, fixed onto the protein skeleton, the nuclear matrix. The general assumption is that DNA folding in the cell nucleus cannot be uniform. It has been known for a long time that a transcriptionally active chromatin fraction is more sensitive to nucleases; this was interpreted as evidence for the less tight compaction of this fraction. In this review we summarize the latest results on structure of transcriptionally active chromatin and the mechanisms of transcriptional regulation in the context of chromatin dynamics. In particular the significance of histone modifications and the mechanisms controlling dynamics of chromatin domains are discussed as well as the significance of spatial organization of the genome for functioning of distant regulatory elements.
Collapse
Affiliation(s)
- Sergey V Razin
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Abstract
Active and silenced chromatin domains are often in close juxtaposition to one another, and enhancer and silencer elements operate over large distances to regulate the genes in these domains. The lack of promiscuity in the function of these elements suggests that active mechanisms exist to restrict their activity. Insulators are DNA elements that restrict the effects of long-range regulatory elements. Studies on different insulators from different organisms have identified common themes in their mode of action. Numerous insulators map to promoters of genes or have binding sites for transcription factors and like active chromatin hubs and silenced loci, insulators also cluster in the nucleus. These results bring into focus potential conserved mechanisms by which these elements might function in the nucleus.
Collapse
Affiliation(s)
- Lourdes Valenzuela
- Unit on Chromatin and Transcription, NICHD/NIH, Bethesda, Maryland 20892, USA
| | | |
Collapse
|
35
|
Guerrero G, Delgado-Olguín P, Escamilla-Del-Arenal M, Furlan-Magaril M, Rebollar E, De La Rosa-Velázquez IA, Soto-Reyes E, Rincón-Arano H, Valdes-Quezada C, Valadez-Graham V, Recillas-Targa F. Globin genes transcriptional switching, chromatin structure and linked lessons to epigenetics in cancer: a comparative overview. Comp Biochem Physiol A Mol Integr Physiol 2006; 147:750-760. [PMID: 17188536 DOI: 10.1016/j.cbpa.2006.10.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2006] [Revised: 09/14/2006] [Accepted: 10/22/2006] [Indexed: 12/28/2022]
Abstract
At the present time research situates differential regulation of gene expression in an increasingly complex scenario based on interplay between genetic and epigenetic information networks, which need to be highly coordinated. Here we describe in a comparative way relevant concepts and models derived from studies on the chicken alpha- and beta-globin group of genes. We discuss models for globin switching and mechanisms for coordinated transcriptional activation. A comparative overview of globin genes chromatin structure, based on their genomic domain organization and epigenetic components is presented. We argue that the results of those studies and their integrative interpretation may contribute to our understanding of epigenetic abnormalities, from beta-thalassemias to human cancer. Finally we discuss the interdependency of genetic-epigenetic components and the need of their mutual consideration in order to visualize the regulation of gene expression in a more natural context and consequently better understand cell differentiation, development and cancer.
Collapse
Affiliation(s)
- Georgina Guerrero
- Instituto de Fisiología Celular, Departamento de Genética Molecular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, México, D.F., 04510, Mexico
| | - Paul Delgado-Olguín
- Instituto de Fisiología Celular, Departamento de Genética Molecular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, México, D.F., 04510, Mexico
| | - Martín Escamilla-Del-Arenal
- Instituto de Fisiología Celular, Departamento de Genética Molecular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, México, D.F., 04510, Mexico
| | - Mayra Furlan-Magaril
- Instituto de Fisiología Celular, Departamento de Genética Molecular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, México, D.F., 04510, Mexico
| | - Eria Rebollar
- Instituto de Fisiología Celular, Departamento de Genética Molecular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, México, D.F., 04510, Mexico
| | - Inti A De La Rosa-Velázquez
- Instituto de Fisiología Celular, Departamento de Genética Molecular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, México, D.F., 04510, Mexico
| | - Ernesto Soto-Reyes
- Instituto de Fisiología Celular, Departamento de Genética Molecular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, México, D.F., 04510, Mexico
| | - Héctor Rincón-Arano
- Instituto de Fisiología Celular, Departamento de Genética Molecular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, México, D.F., 04510, Mexico
| | - Christian Valdes-Quezada
- Instituto de Fisiología Celular, Departamento de Genética Molecular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, México, D.F., 04510, Mexico
| | - Viviana Valadez-Graham
- Instituto de Fisiología Celular, Departamento de Genética Molecular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, México, D.F., 04510, Mexico
| | - Félix Recillas-Targa
- Instituto de Fisiología Celular, Departamento de Genética Molecular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, México, D.F., 04510, Mexico.
| |
Collapse
|
36
|
Klochkov D, Rincón-Arano H, Ioudinkova ES, Valadez-Graham V, Gavrilov A, Recillas-Targa F, Razin SV. A CTCF-dependent silencer located in the differentially methylated area may regulate expression of a housekeeping gene overlapping a tissue-specific gene domain. Mol Cell Biol 2006; 26:1589-97. [PMID: 16478981 PMCID: PMC1430243 DOI: 10.1128/mcb.26.5.1589-1597.2006] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The tissue-specific chicken alpha-globin gene domain represents one of the paradigms, in terms of its constitutively open chromatin conformation and the location of several regulatory elements within the neighboring housekeeping gene. Here, we show that an 0.2-kb DNA fragment located approximately 4 kb upstream to the chicken alpha-globin gene cluster contains a binding site for the multifunctional protein factor CTCF and possesses silencer activity which depends on CTCF binding, as demonstrated by site-directed mutagenesis of the CTCF recognition sequence. CTCF was found to be associated with this recognition site in erythroid cells but not in lymphoid cells where the site is methylated. A functional promoter directing the transcription of the apparently housekeeping ggPRX gene was found 120 bp from the CTCF-dependent silencer. The data are discussed in terms of the hypothesis that the CTCF-dependent silencer stabilizes the level of ggPRX gene transcription in erythroid cells where the promoter of this gene may be influenced by positive cis-regulatory signals activating alpha-globin gene transcription.
Collapse
Affiliation(s)
- Denis Klochkov
- Laboratory of Structural-Functional Organization of Chromosomes, Institute of Gene Biology of the Russian Academy of Sciences, 34/5 Vavilov Street, 117334 Moscow, Russia
| | | | | | | | | | | | | |
Collapse
|
37
|
Ioudinkova ES, Petrov AV, Vassetzky YS, Razin SV. Spatial Organization of the Chicken α-Globin Gene Domain in Cells of Different Origins. Mol Biol 2005. [DOI: 10.1007/s11008-005-0105-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
38
|
Ren X, Katoh M, Hoshiya H, Kurimasa A, Inoue T, Ayabe F, Shibata K, Toguchida J, Oshimura M. A novel human artificial chromosome vector provides effective cell lineage-specific transgene expression in human mesenchymal stem cells. Stem Cells 2005; 23:1608-16. [PMID: 16141362 DOI: 10.1634/stemcells.2005-0021] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Mesenchymal stem cells (MSCs) hold promise for use in adult stem cell-mediated gene therapy. One of the major aims of stem cell-mediated gene therapy is to develop vectors that will allow appropriate levels of expression of therapeutic genes along differentiation under physiological regulation of the specialized cells. Human artificial chromosomes (HACs) are stably maintained as independent chromosomes in host cells and should be free from potential insertional mutagenesis problems of conventional transgenes. Therefore, HACs have been proposed as alternative implements to cell-mediated gene therapy. Previously, we constructed a novel HAC, termed 21 Deltapq HAC, with a loxP site in which circular DNA can be reproducibly inserted by the Cre/loxP system. We here assessed the feasibility of lineage-specific transgene expression by the 21Deltapq HAC vector using an in vitro differentiation system with an MSC cell line, hiMSCs, which has potential for osteogenic, chondrogenic, and adipogenic differentiation. An enhanced green fluorescent protein (EGFP) gene driven by a promoter for osteogenic lineage-specific osteopontin (OPN) gene was inserted onto the 21 Deltapq HAC and then transferred into hiMSC. The expression cassette was flanked by the chicken HS4 insulators to block promoter interference from adjacent drug-resistant genes. The EGFP gene was specifically expressed in the hiMSC that differentiated into osteocytes in coordination with the transcription of endogenous OPN gene but was not expressed after adipogenic differentiation induction or in noninduction culture. These results suggest that use of the HAC vector is suitable for regulated expression of transgenes in stem cell-mediated gene therapy.
Collapse
Affiliation(s)
- Xianying Ren
- Department of Molecular and Cell Genetics, Institute of Regenerative Medicine and Biofunction, Graduate School of Medical Science, Tottori University, Yonago, Tottori 683-8503, Japan
| | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Ioudinkova E, Razin SV, Borunova V, De Conto F, Rynditch A, Scherrer K. RNA-dependent nuclear matrix contains a 33 kb globin full domain transcript as well as prosomes but no 26S proteasomes. J Cell Biochem 2005; 94:529-39. [PMID: 15543557 DOI: 10.1002/jcb.20306] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Previously, we have shown that in murine myoblasts prosomes are constituents of the nuclear matrix; a major part of the latter was found to be RNase sensitive. Here, we further define the RNA-dependent matrix in avian erythroblastosis virus (AEV) transformed erythroid cells in relation to its structure, presence of specific RNA, prosomes and/or proteasomes. These cells transcribe but do not express globin genes prior to induction. Electron micrographs show little difference in matrices treated with DNase alone or with both, DNase and RNase. In situ hybridization with alpha globin riboprobes shows that this matrix includes globin transcripts. Of particular interest is that, apparently, a nearly 35 kb long globin full domain transcript (FDT), including genes, intergenic regions and a large upstream domain is a part of the RNA-dependent nuclear matrix. The 23K-type of prosomes, previously shown to be co-localized with globin transcripts in the nuclear RNA processing centers, were found all over the nuclear matrix. Other types of prosomes show different distributions in the intact cell but similar distribution patterns on the matrix. Globin transcripts and at least 80% of prosomes disappear from matrices upon RNase treatment. Interestingly, the 19S proteasome modulator complex is insensitive to RNase treatment. Only 20S prosomes but not 26S proteasomes are thus part of the RNA-dependent nuclear matrix. We suggest that giant pre-mRNA and FDTs in processing, aligning prosomes and other RNA-binding proteins are involved in the organization of the dynamic nuclear matrix. It is proposed that the putative function of RNA within the nuclear matrix and, thus, the nuclear dynamic architecture, might explain the giant size and complex organization of primary transcripts and their introns.
Collapse
|
40
|
Rincón-Arano H, Valadez-Graham V, Guerrero G, Escamilla-Del-Arenal M, Recillas-Targa F. YY1 and GATA-1 interaction modulate the chicken 3'-side alpha-globin enhancer activity. J Mol Biol 2005; 349:961-75. [PMID: 15913647 DOI: 10.1016/j.jmb.2005.04.040] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2005] [Revised: 04/11/2005] [Accepted: 04/19/2005] [Indexed: 11/21/2022]
Abstract
Studying the chicken alpha-globin domain as a model system of gene regulation, we have previously identified contiguous silencer-enhancer elements located on the 3'-side of the domain. To better characterize the enhancer we performed a systematic functional analysis to define its expression influence range and the ubiquitous and stage-specific transcriptional regulators interacting with this control element. In contrast to previous reports, we found that, in addition to a core element that includes three GATA-1 binding sites, the enhancer incorporates a 120 base-pair DNA fragment where EKLF, NF-E2 and a fourth GATA-1 factor could interact. Functional experiments demonstrate that the enhancer activity over the adult alpha(D) promoter is differentially regulated. We found that the transcriptional factor Ying Yang 1 (YY1) binds to the 120 base-pair DNA fragment and its effect over the enhancer activity is GATA-1-dependent. In addition, we characterize a novel physical interaction between GATA-1 and YY1 that influences the enhancer function. Experiments using a histone deacetylation inhibitor indicate that, in pre-erythroblasts, the enhancer down-regulation could be influenced by a closed chromatin conformation. Our observations show that the originally defined enhancer possesses a more complex composition than previously assumed. We propose that its activity is modulated through differential nuclear factor interactions and chromatin modifications at distinct erythroid stages.
Collapse
Affiliation(s)
- Héctor Rincón-Arano
- Instituto de Fisiología Celular, Departamento de Genética Molecular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, México D.F. 04510, México
| | | | | | | | | |
Collapse
|
41
|
Kalmykova AI, Nurminsky DI, Ryzhov DV, Shevelyov YY. Regulated chromatin domain comprising cluster of co-expressed genes in Drosophila melanogaster. Nucleic Acids Res 2005; 33:1435-44. [PMID: 15755746 PMCID: PMC1062873 DOI: 10.1093/nar/gki281] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Recently, the phenomenon of clustering of co-expressed genes on chromosomes was discovered in eukaryotes. To explore the hypothesis that genes within clusters occupy shared chromatin domains, we performed a detailed analysis of transcription pattern and chromatin structure of a cluster of co-expressed genes. We found that five non-homologous genes (Crtp, Yu, CK2betates, Pros28.1B and CG13581) are expressed exclusively in Drosophila melanogaster male germ-line and form a non-interrupted cluster in the 15 kb region of chromosome 2. The cluster is surrounded by genes with broader transcription patterns. Analysis of DNase I sensitivity revealed 'open' chromatin conformation in the cluster and adjacent regions in the male germ-line cells, where all studied genes are transcribed. In contrast, in somatic tissues where the cluster genes are silent, the domain of repressed chromatin encompassed four out of five cluster genes and an adjacent non-cluster gene CG13589 that is also silent in analyzed somatic tissues. The fifth cluster gene (CG13581) appears to be excluded from the chromatin domain occupied by the other four genes. Our results suggest that extensive clustering of co-expressed genes in eukaryotic genomes does in general reflect the domain organization of chromatin, although domain borders may not exactly correspond to the margins of gene clusters.
Collapse
Affiliation(s)
| | - Dmitry I. Nurminsky
- Department of Anatomy and Cell Biology, Tufts University School of MedicineBoston, MA 02111, USA
| | | | - Yuri Y. Shevelyov
- To whom correspondence should be addressed. Tel: +7 095 1960809; Fax: +7 095 1960221;
| |
Collapse
|
42
|
Valadez-Graham V, Razin SV, Recillas-Targa F. CTCF-dependent enhancer blockers at the upstream region of the chicken alpha-globin gene domain. Nucleic Acids Res 2004; 32:1354-62. [PMID: 14981153 PMCID: PMC390289 DOI: 10.1093/nar/gkh301] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The eukaryotic genome is partitioned into chromatin domains containing coding and intergenic regions. Insulators have been suggested to play a role in establishing and maintaining chromatin domains. Here we describe the identification and characterization of two separable enhancer blocking elements located in the 5' flanking region of the chicken alpha-globin domain, 11-16 kb upstream of the embryonic alpha-type pi gene in a DNA fragment harboring a MAR (matrix attachment region) element and three DNase I hypersensitive sites (HSs). The most upstream enhancer blocking element co-localizes with the MAR element and an erythroid-specific HS. The second enhancer blocking element roughly co-localizes with a constitutive HS. The third erythroid-specific HS present within the DNA fragment studied harbors a silencing, but not an enhancer blocking, activity. The 11 zinc-finger CCCTC-binding factor (CTCF), which plays an essential role in enhancer blocking activity in many previously characterized vertebrate insulators, is found to bind the two alpha-globin enhancer blocking elements. Detailed analysis has demonstrated that mutation of the CTCF binding site within the most upstream enhancer blocking element abolishes the enhancer blocking activity. The results are discussed with respect to special features of the tissue-specific alpha-globin gene domain located in a permanently open chromatin area.
Collapse
Affiliation(s)
- Viviana Valadez-Graham
- Instituto de Fisiología Celular, Departamento de Genética Molecular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, México D.F. 04510, México
| | | | | |
Collapse
|
43
|
Recillas-Targa F, Valadez-Graham V, Farrell CM. Prospects and implications of using chromatin insulators in gene therapy and transgenesis. Bioessays 2004; 26:796-807. [PMID: 15221861 DOI: 10.1002/bies.20059] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Gene therapy has emerged from the idea of inserting a wild-type copy of a gene in order to restore the proper expression and function of a damaged gene. Initial efforts have focused on finding the proper vector and delivery method to introduce a corrected gene to the affected tissue or cell type. Even though these first attempts are clearly promising, several problems remain unsolved. A major problem is the influence of chromatin structure on transgene expression. To overcome chromatin-dependent repressive transgenic states, researchers have begun to use chromatin regulatory elements to drive transgene expression. Insulators or chromatin boundaries are able to protect a transgene against chromatin position effects at their genomic integration sites, and they are able to maintain transgene expression for long periods of time. Therefore, these elements may be very useful tools in gene therapy applications for ensuring high-level and stable expression of transgenes.
Collapse
Affiliation(s)
- Félix Recillas-Targa
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México.
| | | | | |
Collapse
|