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Glunčić M, Vlahović I, Rosandić M, Paar V. Novel Cascade Alpha Satellite HORs in Orangutan Chromosome 13 Assembly: Discovery of the 59mer HOR-The largest Unit in Primates-And the Missing Triplet 45/27/18 HOR in Human T2T-CHM13v2.0 Assembly. Int J Mol Sci 2024; 25:7596. [PMID: 39062839 PMCID: PMC11276891 DOI: 10.3390/ijms25147596] [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: 06/20/2024] [Revised: 07/05/2024] [Accepted: 07/09/2024] [Indexed: 07/28/2024] Open
Abstract
From the recent genome assembly NHGRI_mPonAbe1-v2.0_NCBI (GCF_028885655.2) of orangutan chromosome 13, we computed the precise alpha satellite higher-order repeat (HOR) structure using the novel high-precision GRM2023 algorithm with Global Repeat Map (GRM) and Monomer Distance (MD) diagrams. This study rigorously identified alpha satellite HORs in the centromere of orangutan chromosome 13, discovering a novel 59mer HOR-the longest HOR unit identified in any primate to date. Additionally, it revealed the first intertwined sequence of three HORs, 18mer/27mer/45mer HORs, with a common aligned "backbone" across all HOR copies. The major 7mer HOR exhibits a Willard's-type canonical copy, although some segments of the array display significant irregularities. In contrast, the 14mer HOR forms a regular Willard's-type HOR array. Surprisingly, the GRM2023 high-precision analysis of chromosome 13 of human genome assembly T2T-CHM13v2.0 reveals the presence of only a 7mer HOR, despite both the orangutan and human genome assemblies being derived from whole genome shotgun sequences.
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Affiliation(s)
- Matko Glunčić
- Faculty of Science, University of Zagreb, 10000 Zagreb, Croatia;
| | - Ines Vlahović
- Department of Interdisciplinary Sciences, Algebra University College, 10000 Zagreb, Croatia;
| | - Marija Rosandić
- University Hospital Centre Zagreb (Ret.), 10000 Zagreb, Croatia;
- Croatian Academy of Sciences and Arts, 10000 Zagreb, Croatia
| | - Vladimir Paar
- Faculty of Science, University of Zagreb, 10000 Zagreb, Croatia;
- Croatian Academy of Sciences and Arts, 10000 Zagreb, Croatia
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2
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Glunčić M, Vlahović I, Rosandić M, Paar V. Novel Concept of Alpha Satellite Cascading Higher-Order Repeats (HORs) and Precise Identification of 15mer and 20mer Cascading HORs in Complete T2T-CHM13 Assembly of Human Chromosome 15. Int J Mol Sci 2024; 25:4395. [PMID: 38673983 PMCID: PMC11050224 DOI: 10.3390/ijms25084395] [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: 03/06/2024] [Revised: 04/08/2024] [Accepted: 04/11/2024] [Indexed: 04/28/2024] Open
Abstract
Unraveling the intricate centromere structure of human chromosomes holds profound implications, illuminating fundamental genetic mechanisms and potentially advancing our comprehension of genetic disorders and therapeutic interventions. This study rigorously identified and structurally analyzed alpha satellite higher-order repeats (HORs) within the centromere of human chromosome 15 in the complete T2T-CHM13 assembly using the high-precision GRM2023 algorithm. The most extensive alpha satellite HOR array in chromosome 15 reveals a novel cascading HOR, housing 429 15mer HOR copies, containing 4-, 7- and 11-monomer subfragments. Within each row of cascading HORs, all alpha satellite monomers are of distinct types, as in regular Willard's HORs. However, different HOR copies within the same cascading 15mer HOR contain more than one monomer of the same type. Each canonical 15mer HOR copy comprises 15 monomers belonging to only 9 different monomer types. Notably, 65% of the 429 15mer cascading HOR copies exhibit canonical structures, while 35% display variant configurations. Identified as the second most extensive alpha satellite HOR, another novel cascading HOR within human chromosome 15 encompasses 164 20mer HOR copies, each featuring two subfragments. Moreover, a distinct pattern emerges as interspersed 25mer/26mer structures differing from regular Willard's HORs and giving rise to a 34-monomer subfragment. Only a minor 18mer HOR array of 12 HOR copies is of the regular Willard's type. These revelations highlight the complexity within the chromosome 15 centromeric region, accentuating deviations from anticipated highly regular patterns and hinting at profound information encoding and functional potential within the human centromere.
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Affiliation(s)
- Matko Glunčić
- Faculty of Science, University of Zagreb, 10000 Zagreb, Croatia;
| | - Ines Vlahović
- Algebra LAB, Algebra University College, 10000 Zagreb, Croatia;
| | - Marija Rosandić
- Department of Internal Medicine, University Hospital Centre Zagreb, 10000 Zagreb, Croatia;
- Croatian Academy of Sciences and Arts, 10000 Zagreb, Croatia
| | - Vladimir Paar
- Faculty of Science, University of Zagreb, 10000 Zagreb, Croatia;
- Croatian Academy of Sciences and Arts, 10000 Zagreb, Croatia
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Sikder S, Baek S, McNeil T, Dalal Y. Unraveling the mechanism of centromere inactivation in human aging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.30.573721. [PMID: 38313258 PMCID: PMC10836067 DOI: 10.1101/2023.12.30.573721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2024]
Abstract
Aging involves a range of genetic, epigenetic, and physiological alterations. A key characteristic of aged cells is the loss of global heterochromatin, accompanied by a reduction in canonical histone levels. In this study, we track the fate of centromeres during aging in human cells. Our findings reveal that the centromeric histone H3 variant CENP-A is downregulated in aged cells, in a p53-dependent manner. We observe repression of centromeric noncoding transcription through an epigenetic mechanism via recruitment of a lysine-specific demethylase 1 (LSD1/KDM1A) to centromeres. This suppression results in defective de novo CENP-A loading at aging centromeres. By dual inhibition of p53 and LSD1/KDM1A in aged cells, we mitigate the reduction in centromeric proteins and centromeric transcripts, leading to mitotic rejuvenation of these cells. These results offer insights into a novel mechanism for centromeric inactivation during aging and provide potential strategies to reactivate centromeres.
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Kyriacou E, Heun P. Centromere structure and function: lessons from Drosophila. Genetics 2023; 225:iyad170. [PMID: 37931172 PMCID: PMC10697814 DOI: 10.1093/genetics/iyad170] [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: 06/15/2023] [Accepted: 09/01/2023] [Indexed: 11/08/2023] Open
Abstract
The fruit fly Drosophila melanogaster serves as a powerful model organism for advancing our understanding of biological processes, not just by studying its similarities with other organisms including ourselves but also by investigating its differences to unravel the underlying strategies that evolved to achieve a common goal. This is particularly true for centromeres, specialized genomic regions present on all eukaryotic chromosomes that function as the platform for the assembly of kinetochores. These multiprotein structures play an essential role during cell division by connecting chromosomes to spindle microtubules in mitosis and meiosis to mediate accurate chromosome segregation. Here, we will take a historical perspective on the study of fly centromeres, aiming to highlight not only the important similarities but also the differences identified that contributed to advancing centromere biology. We will discuss the current knowledge on the sequence and chromatin organization of fly centromeres together with advances for identification of centromeric proteins. Then, we will describe both the factors and processes involved in centromere organization and how they work together to provide an epigenetic identity to the centromeric locus. Lastly, we will take an evolutionary point of view of centromeres and briefly discuss current views on centromere drive.
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Affiliation(s)
- Eftychia Kyriacou
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Patrick Heun
- Wellcome Centre of Cell Biology, School of Biological Sciences, University of Edinburgh, EH9 3BF Edinburgh, UK
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
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5
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Glunčić M, Vlahović I, Rosandić M, Paar V. Tandem NBPF 3mer HORs (Olduvai triplets) in Neanderthal and two novel HOR tandem arrays in human chromosome 1 T2T-CHM13 assembly. Sci Rep 2023; 13:14420. [PMID: 37660151 PMCID: PMC10475015 DOI: 10.1038/s41598-023-41517-3] [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: 05/24/2023] [Accepted: 08/28/2023] [Indexed: 09/04/2023] Open
Abstract
It is known that the ~ 1.6 kb Neuroblastoma BreakPoint Family (NBPF) repeats are human specific and contributing to cognitive capabilities, with increasing frequency in higher order repeat 3mer HORs (Olduvai triplets). From chimpanzee to modern human there is a discontinuous jump from 0 to ~ 50 tandemly organized 3mer HORs. Here we investigate the structure of NBPF 3mer HORs in the Neanderthal genome assembly of Pääbo et al., comparing it to the results obtained for human hg38.p14 chromosome 1. Our findings reveal corresponding NBPF 3mer HOR arrays in Neanderthals with slightly different monomer structures and numbers of HOR copies compared to humans. Additionally, we compute the NBPF 3mer HOR pattern for the complete telomere-to-telomere human genome assembly (T2T-CHM13) by Miga et al., identifying two novel tandem arrays of NBPF 3mer HOR repeats with 5 and 9 NBPF 3mer HOR copies. We hypothesize that these arrays correspond to novel NBPF genes (here referred to as NBPFA1 and NBPFA2). Further improving the quality of the Neanderthal genome using T2T-CHM13 as a reference would be of great interest in determining the presence of such distant novel NBPF genes in the Neanderthal genome and enhancing our understanding of human evolution.
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Affiliation(s)
- Matko Glunčić
- Faculty of Science, University of Zagreb, 10000, Zagreb, Croatia.
| | | | - Marija Rosandić
- University Hospital Centre Zagreb (Ret.), 10000, Zagreb, Croatia
- Croatian Academy of Sciences and Arts, 10000, Zagreb, Croatia
| | - Vladimir Paar
- Faculty of Science, University of Zagreb, 10000, Zagreb, Croatia
- Croatian Academy of Sciences and Arts, 10000, Zagreb, Croatia
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Logsdon GA, Eichler EE. The Dynamic Structure and Rapid Evolution of Human Centromeric Satellite DNA. Genes (Basel) 2022; 14:92. [PMID: 36672831 PMCID: PMC9859433 DOI: 10.3390/genes14010092] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 12/22/2022] [Accepted: 12/24/2022] [Indexed: 12/31/2022] Open
Abstract
The complete sequence of a human genome provided our first comprehensive view of the organization of satellite DNA associated with heterochromatin. We review how our understanding of the genetic architecture and epigenetic properties of human centromeric DNA have advanced as a result. Preliminary studies of human and nonhuman ape centromeres reveal complex, saltatory mutational changes organized around distinct evolutionary layers. Pockets of regional hypomethylation within higher-order α-satellite DNA, termed centromere dip regions, appear to define the site of kinetochore attachment in all human chromosomes, although such epigenetic features can vary even within the same chromosome. Sequence resolution of satellite DNA is providing new insights into centromeric function with potential implications for improving our understanding of human biology and health.
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Affiliation(s)
- Glennis A. Logsdon
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Evan E. Eichler
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA 98195, USA
- Howard Hughes Medical Institute, University of Washington, Seattle, WA 98195, USA
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7
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Glunčić M, Vlahović I, Rosandić M, Paar V. Tandemly repeated NBPF HOR copies (Olduvai triplets): Possible impact on human brain evolution. Life Sci Alliance 2022; 6:6/1/e202101306. [PMID: 36261226 PMCID: PMC9584774 DOI: 10.26508/lsa.202101306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 09/29/2022] [Accepted: 09/30/2022] [Indexed: 11/24/2022] Open
Abstract
Previously it was found that the neuroblastoma breakpoint family (NBPF) gene repeat units of ∼1.6 kb have an important role in human brain evolution and function. The higher order organization of these repeat units has been discovered by both methods, the higher order repeat (HOR)-searching method and the HLS searching method. Using the HOR searching method with global repeat map algorithm, here we identified the tandemly organized NBPF HORs in the human and nonhuman primate NCBI reference genomes. We identified 50 tandemly organized canonical 3mer NBPF HOR copies (Olduvai triplets), but none in nonhuman primates chimpanzee, gorilla, orangutan, and Rhesus macaque. This discontinuous jump in tandemly organized HOR copy number is in sharp contrast to the known gradual increase in the number of Olduvai domains (NBPF monomers) from nonhuman primates to human, especially from ∼138 in chimpanzee to ∼300 in human genome. Using the same global repeat map algorithm method we have also determined the 3mer tandems of canonical 3mer HOR copies in 20 randomly chosen human genomes (10 male and 10 female). In all cases, we found the same 3mer HOR copy numbers as in the case of the reference human genome, with no mutation. On the other hand, some point mutations with respect to reference genome are found for some NBPF monomers which are not tandemly organized in canonical HORs.
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Affiliation(s)
- Matko Glunčić
- Faculty of Science, University of Zagreb, Zagreb, Croatia
| | | | - Marija Rosandić
- University Hospital Centre Zagreb (ret), Zagreb, Croatia,Croatian Academy of Sciences and Arts, Zagreb, Croatia
| | - Vladimir Paar
- Faculty of Science, University of Zagreb, Zagreb, Croatia,Croatian Academy of Sciences and Arts, Zagreb, Croatia
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8
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Saayman X, Esashi F. Breaking the paradigm: early insights from mammalian DNA breakomes. FEBS J 2022; 289:2409-2428. [PMID: 33792193 PMCID: PMC9451923 DOI: 10.1111/febs.15849] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 03/04/2021] [Accepted: 03/29/2021] [Indexed: 12/13/2022]
Abstract
DNA double-strand breaks (DSBs) can result from both exogenous and endogenous sources and are potentially toxic lesions to the human genome. If improperly repaired, DSBs can threaten genome integrity and contribute to premature ageing, neurodegenerative disorders and carcinogenesis. Through decades of work on genome stability, it has become evident that certain regions of the genome are inherently more prone to breakage than others, known as genome instability hotspots. Recent advancements in sequencing-based technologies now enable the profiling of genome-wide distributions of DSBs, also known as breakomes, to systematically map these instability hotspots. Here, we review the application of these technologies and their implications for our current understanding of the genomic regions most likely to drive genome instability. These breakomes ultimately highlight both new and established breakage hotspots including actively transcribed regions, loop boundaries and early-replicating regions of the genome. Further, these breakomes challenge the paradigm that DNA breakage primarily occurs in hard-to-replicate regions. With these advancements, we begin to gain insights into the biological mechanisms both invoking and protecting against genome instability.
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Affiliation(s)
- Xanita Saayman
- Sir William Dunn School of Pathology, University of Oxford, UK
| | - Fumiko Esashi
- Sir William Dunn School of Pathology, University of Oxford, UK
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9
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Brändle F, Frühbauer B, Jagannathan M. Principles and functions of pericentromeric satellite DNA clustering into chromocenters. Semin Cell Dev Biol 2022; 128:26-39. [PMID: 35144860 DOI: 10.1016/j.semcdb.2022.02.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 02/03/2022] [Accepted: 02/03/2022] [Indexed: 12/29/2022]
Abstract
Simple non-coding tandem repeats known as satellite DNA are observed widely across eukaryotes. These repeats occupy vast regions at the centromere and pericentromere of chromosomes but their contribution to cellular function has remained incompletely understood. Here, we review the literature on pericentromeric satellite DNA and discuss its organization and functions across eukaryotic species. We specifically focus on chromocenters, DNA-dense nuclear foci that contain clustered pericentromeric satellite DNA repeats from multiple chromosomes. We first discuss chromocenter formation and the roles that epigenetic modifications, satellite DNA transcripts and sequence-specific satellite DNA-binding play in this process. We then review the newly emerging functions of chromocenters in genome encapsulation, the maintenance of cell fate and speciation. We specifically highlight how the rapid divergence of satellite DNA repeats impacts reproductive isolation between closely related species. Together, we underline the importance of this so-called 'junk DNA' in fundamental biological processes.
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Affiliation(s)
- Franziska Brändle
- Institute of Biochemistry, ETH Zürich, Otto-Stern-Weg 3, Zürich CH-8093, Switzerland
| | - Benjamin Frühbauer
- Institute of Biochemistry, ETH Zürich, Otto-Stern-Weg 3, Zürich CH-8093, Switzerland
| | - Madhav Jagannathan
- Institute of Biochemistry, ETH Zürich, Otto-Stern-Weg 3, Zürich CH-8093, Switzerland.
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10
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Jeffery D, Lochhead M, Almouzni G. CENP-A: A Histone H3 Variant with Key Roles in Centromere Architecture in Healthy and Diseased States. Results Probl Cell Differ 2022; 70:221-261. [PMID: 36348109 DOI: 10.1007/978-3-031-06573-6_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Centromeres are key architectural components of chromosomes. Here, we examine their construction, maintenance, and functionality. Focusing on the mammalian centromere- specific histone H3 variant, CENP-A, we highlight its coevolution with both centromeric DNA and its chaperone, HJURP. We then consider CENP-A de novo deposition and the importance of centromeric DNA recently uncovered with the added value from new ultra-long-read sequencing. We next review how to ensure the maintenance of CENP-A at the centromere throughout the cell cycle. Finally, we discuss the impact of disrupting CENP-A regulation on cancer and cell fate.
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Affiliation(s)
- Daniel Jeffery
- Equipe Labellisée Ligue contre le Cancer, Institut Curie, PSL Research University, CNRS, Sorbonne Université, Nuclear Dynamics Unit, UMR3664, Paris, France
| | - Marina Lochhead
- Equipe Labellisée Ligue contre le Cancer, Institut Curie, PSL Research University, CNRS, Sorbonne Université, Nuclear Dynamics Unit, UMR3664, Paris, France
| | - Geneviève Almouzni
- Equipe Labellisée Ligue contre le Cancer, Institut Curie, PSL Research University, CNRS, Sorbonne Université, Nuclear Dynamics Unit, UMR3664, Paris, France.
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11
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Lopes M, Louzada S, Gama-Carvalho M, Chaves R. Genomic Tackling of Human Satellite DNA: Breaking Barriers through Time. Int J Mol Sci 2021; 22:4707. [PMID: 33946766 PMCID: PMC8125562 DOI: 10.3390/ijms22094707] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/24/2021] [Accepted: 04/27/2021] [Indexed: 12/12/2022] Open
Abstract
(Peri)centromeric repetitive sequences and, more specifically, satellite DNA (satDNA) sequences, constitute a major human genomic component. SatDNA sequences can vary on a large number of features, including nucleotide composition, complexity, and abundance. Several satDNA families have been identified and characterized in the human genome through time, albeit at different speeds. Human satDNA families present a high degree of sub-variability, leading to the definition of various subfamilies with different organization and clustered localization. Evolution of satDNA analysis has enabled the progressive characterization of satDNA features. Despite recent advances in the sequencing of centromeric arrays, comprehensive genomic studies to assess their variability are still required to provide accurate and proportional representation of satDNA (peri)centromeric/acrocentric short arm sequences. Approaches combining multiple techniques have been successfully applied and seem to be the path to follow for generating integrated knowledge in the promising field of human satDNA biology.
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Affiliation(s)
- Mariana Lopes
- Laboratory of Cytogenomics and Animal Genomics (CAG), Department of Genetics and Biotechnology (DGB), University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal; (M.L.); (S.L.)
- Biosystems and Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal;
| | - Sandra Louzada
- Laboratory of Cytogenomics and Animal Genomics (CAG), Department of Genetics and Biotechnology (DGB), University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal; (M.L.); (S.L.)
- Biosystems and Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal;
| | - Margarida Gama-Carvalho
- Biosystems and Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal;
| | - Raquel Chaves
- Laboratory of Cytogenomics and Animal Genomics (CAG), Department of Genetics and Biotechnology (DGB), University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal; (M.L.); (S.L.)
- Biosystems and Integrative Sciences Institute (BioISI), Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal;
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12
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Navarro AP, Cheeseman IM. Kinetochore assembly throughout the cell cycle. Semin Cell Dev Biol 2021; 117:62-74. [PMID: 33753005 DOI: 10.1016/j.semcdb.2021.03.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/12/2021] [Accepted: 03/13/2021] [Indexed: 11/29/2022]
Abstract
The kinetochore plays an essential role in facilitating chromosome segregation during cell division. This massive protein complex assembles onto the centromere of chromosomes and enables their attachment to spindle microtubules during mitosis. The kinetochore also functions as a signaling hub to regulate cell cycle progression, and is crucial to ensuring the fidelity of chromosome segregation. Despite the fact that kinetochores are large and robust molecular assemblies, they are also highly dynamic structures that undergo structural and organizational changes throughout the cell cycle. This review will highlight our current understanding of kinetochore structure and function, focusing on the dynamic processes that underlie kinetochore assembly.
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Affiliation(s)
- Alexandra P Navarro
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA
| | - Iain M Cheeseman
- Whitehead Institute for Biomedical Research, 455 Main Street, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.
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13
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Nagpal H, Fierz B. The Elusive Structure of Centro-Chromatin: Molecular Order or Dynamic Heterogenetity? J Mol Biol 2021; 433:166676. [PMID: 33065112 DOI: 10.1016/j.jmb.2020.10.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 10/07/2020] [Accepted: 10/08/2020] [Indexed: 01/09/2023]
Abstract
The centromere is an essential chromatin domain required for kinetochore recruitment and chromosome segregation in eukaryotes. To perform this role, centro-chromatin adopts a unique structure that provides access to kinetochore proteins and maintains stability under tension during mitosis. This is achieved by the presence of nucleosomes containing the H3 variant CENP-A, which also acts as the epigenetic mark defining the centromere. In this review, we discuss the role of CENP-A on the structure and dynamics of centromeric chromatin. We further discuss the impact of the CENP-A binding proteins CENP-C, CENP-N, and CENP-B on modulating centro-chromatin structure. Based on these findings we provide an overview of the higher order structure of the centromere.
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Affiliation(s)
- Harsh Nagpal
- Laboratory of Biophysical Chemistry of Macromolecules, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.
| | - Beat Fierz
- Laboratory of Biophysical Chemistry of Macromolecules, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.
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14
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Peichel CL, McCann SR, Ross JA, Naftaly AFS, Urton JR, Cech JN, Grimwood J, Schmutz J, Myers RM, Kingsley DM, White MA. Assembly of the threespine stickleback Y chromosome reveals convergent signatures of sex chromosome evolution. Genome Biol 2020; 21:177. [PMID: 32684159 PMCID: PMC7368989 DOI: 10.1186/s13059-020-02097-x] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 07/08/2020] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Heteromorphic sex chromosomes have evolved repeatedly across diverse species. Suppression of recombination between X and Y chromosomes leads to degeneration of the Y chromosome. The progression of degeneration is not well understood, as complete sequence assemblies of heteromorphic Y chromosomes have only been generated across a handful of taxa with highly degenerate sex chromosomes. Here, we describe the assembly of the threespine stickleback (Gasterosteus aculeatus) Y chromosome, which is less than 26 million years old and at an intermediate stage of degeneration. Our previous work identified that the non-recombining region between the X and the Y spans approximately 17.5 Mb on the X chromosome. RESULTS We combine long-read sequencing with a Hi-C-based proximity guided assembly to generate a 15.87 Mb assembly of the Y chromosome. Our assembly is concordant with cytogenetic maps and Sanger sequences of over 90 Y chromosome BAC clones. We find three evolutionary strata on the Y chromosome, consistent with the three inversions identified by our previous cytogenetic analyses. The threespine stickleback Y shows convergence with more degenerate sex chromosomes in the retention of haploinsufficient genes and the accumulation of genes with testis-biased expression, many of which are recent duplicates. However, we find no evidence for large amplicons identified in other sex chromosome systems. We also report an excellent candidate for the master sex-determination gene: a translocated copy of Amh (Amhy). CONCLUSIONS Together, our work shows that the evolutionary forces shaping sex chromosomes can cause relatively rapid changes in the overall genetic architecture of Y chromosomes.
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Affiliation(s)
- Catherine L. Peichel
- Divisions of Human Biology and Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109 USA
- Institute of Ecology and Evolution, University of Bern, Baltzerstrasse 6, 3012 Bern, Switzerland
| | - Shaugnessy R. McCann
- Divisions of Human Biology and Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109 USA
| | - Joseph A. Ross
- Divisions of Human Biology and Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109 USA
- Graduate Program in Molecular and Cellular Biology, University of Washington, Seattle, WA 98195 USA
| | | | - James R. Urton
- Divisions of Human Biology and Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109 USA
- Graduate Program in Molecular and Cellular Biology, University of Washington, Seattle, WA 98195 USA
| | - Jennifer N. Cech
- Divisions of Human Biology and Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109 USA
- Graduate Program in Molecular and Cellular Biology, University of Washington, Seattle, WA 98195 USA
| | - Jane Grimwood
- HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806 USA
| | - Jeremy Schmutz
- HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806 USA
| | - Richard M. Myers
- HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806 USA
| | - David M. Kingsley
- Department of Developmental Biology and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305 USA
| | - Michael A. White
- Divisions of Human Biology and Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109 USA
- Department of Genetics, University of Georgia, Athens, GA 30602 USA
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15
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Kixmoeller K, Allu PK, Black BE. The centromere comes into focus: from CENP-A nucleosomes to kinetochore connections with the spindle. Open Biol 2020; 10:200051. [PMID: 32516549 PMCID: PMC7333888 DOI: 10.1098/rsob.200051] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Eukaryotic chromosome segregation relies upon specific connections from DNA to the microtubule-based spindle that forms at cell division. The chromosomal locus that directs this process is the centromere, where a structure called the kinetochore forms upon entry into mitosis. Recent crystallography and single-particle electron microscopy have provided unprecedented high-resolution views of the molecular complexes involved in this process. The centromere is epigenetically specified by nucleosomes harbouring a histone H3 variant, CENP-A, and we review recent progress on how it differentiates centromeric chromatin from the rest of the chromosome, the biochemical pathway that mediates its assembly and how two non-histone components of the centromere specifically recognize CENP-A nucleosomes. The core centromeric nucleosome complex (CCNC) is required to recruit a 16-subunit complex termed the constitutive centromere associated network (CCAN), and we highlight recent structures reported of the budding yeast CCAN. Finally, the structures of multiple modular sub-complexes of the kinetochore have been solved at near-atomic resolution, providing insight into how connections are made to the CCAN on one end and to the spindle microtubules on the other. One can now build molecular models from the DNA through to the physical connections to microtubules.
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Affiliation(s)
- Kathryn Kixmoeller
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Penn Center for Genome Integrity, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Graduate Program in Biochemistry and Molecular Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Praveen Kumar Allu
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Penn Center for Genome Integrity, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ben E Black
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Penn Center for Genome Integrity, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Graduate Program in Biochemistry and Molecular Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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16
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DNA methylation in satellite repeats disorders. Essays Biochem 2020; 63:757-771. [PMID: 31387943 DOI: 10.1042/ebc20190028] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 07/22/2019] [Accepted: 07/24/2019] [Indexed: 02/06/2023]
Abstract
Despite the tremendous progress made in recent years in assembling the human genome, tandemly repeated DNA elements remain poorly characterized. These sequences account for the vast majority of methylated sites in the human genome and their methylated state is necessary for this repetitive DNA to function properly and to maintain genome integrity. Furthermore, recent advances highlight the emerging role of these sequences in regulating the functions of the human genome and its variability during evolution, among individuals, or in disease susceptibility. In addition, a number of inherited rare diseases are directly linked to the alteration of some of these repetitive DNA sequences, either through changes in the organization or size of the tandem repeat arrays or through mutations in genes encoding chromatin modifiers involved in the epigenetic regulation of these elements. Although largely overlooked so far in the functional annotation of the human genome, satellite elements play key roles in its architectural and topological organization. This includes functions as boundary elements delimitating functional domains or assembly of repressive nuclear compartments, with local or distal impact on gene expression. Thus, the consideration of satellite repeats organization and their associated epigenetic landmarks, including DNA methylation (DNAme), will become unavoidable in the near future to fully decipher human phenotypes and associated diseases.
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17
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Gamba R, Fachinetti D. From evolution to function: Two sides of the same CENP-B coin? Exp Cell Res 2020; 390:111959. [DOI: 10.1016/j.yexcr.2020.111959] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 03/07/2020] [Accepted: 03/12/2020] [Indexed: 10/24/2022]
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18
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Cechova M, Harris RS, Tomaszkiewicz M, Arbeithuber B, Chiaromonte F, Makova KD. High Satellite Repeat Turnover in Great Apes Studied with Short- and Long-Read Technologies. Mol Biol Evol 2019; 36:2415-2431. [PMID: 31273383 PMCID: PMC6805231 DOI: 10.1093/molbev/msz156] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 06/12/2019] [Accepted: 06/13/2019] [Indexed: 12/23/2022] Open
Abstract
Satellite repeats are a structural component of centromeres and telomeres, and in some instances, their divergence is known to drive speciation. Due to their highly repetitive nature, satellite sequences have been understudied and underrepresented in genome assemblies. To investigate their turnover in great apes, we studied satellite repeats of unit sizes up to 50 bp in human, chimpanzee, bonobo, gorilla, and Sumatran and Bornean orangutans, using unassembled short and long sequencing reads. The density of satellite repeats, as identified from accurate short reads (Illumina), varied greatly among great ape genomes. These were dominated by a handful of abundant repeated motifs, frequently shared among species, which formed two groups: 1) the (AATGG)n repeat (critical for heat shock response) and its derivatives; and 2) subtelomeric 32-mers involved in telomeric metabolism. Using the densities of abundant repeats, individuals could be classified into species. However, clustering did not reproduce the accepted species phylogeny, suggesting rapid repeat evolution. Several abundant repeats were enriched in males versus females; using Y chromosome assemblies or Fluorescent In Situ Hybridization, we validated their location on the Y. Finally, applying a novel computational tool, we identified many satellite repeats completely embedded within long Oxford Nanopore and Pacific Biosciences reads. Such repeats were up to 59 kb in length and consisted of perfect repeats interspersed with other similar sequences. Our results based on sequencing reads generated with three different technologies provide the first detailed characterization of great ape satellite repeats, and open new avenues for exploring their functions.
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Affiliation(s)
- Monika Cechova
- Department of Biology, Pennsylvania State University, University Park, PA
| | - Robert S Harris
- Department of Biology, Pennsylvania State University, University Park, PA
| | | | | | - Francesca Chiaromonte
- Department of Statistics, Pennsylvania State University, University Park, PA
- EMbeDS, Sant’Anna School of Advanced Studies, Pisa, Italy
- Center for Medical Genomics, Penn State, University Park, PA
| | - Kateryna D Makova
- Department of Biology, Pennsylvania State University, University Park, PA
- Center for Medical Genomics, Penn State, University Park, PA
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19
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Discovery of 33mer in chromosome 21 - the largest alpha satellite higher order repeat unit among all human somatic chromosomes. Sci Rep 2019; 9:12629. [PMID: 31477765 PMCID: PMC6718397 DOI: 10.1038/s41598-019-49022-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 08/13/2019] [Indexed: 11/10/2022] Open
Abstract
The centromere is important for segregation of chromosomes during cell division in eukaryotes. Its destabilization results in chromosomal missegregation, aneuploidy, hallmarks of cancers and birth defects. In primate genomes centromeres contain tandem repeats of ~171 bp alpha satellite DNA, commonly organized into higher order repeats (HORs). In spite of crucial importance, satellites have been understudied because of gaps in sequencing - genomic “black holes”. Bioinformatical studies of genomic sequences open possibilities to revolutionize understanding of repetitive DNA datasets. Here, using robust (Global Repeat Map) algorithm we identified in hg38 sequence of human chromosome 21 complete ensemble of alpha satellite HORs with six long repeat units (≥20 mers), five of them novel. Novel 33mer HOR has the longest HOR unit identified so far among all somatic chromosomes and novel 23mer reverse HOR is distant far from the centromere. Also, we discovered that for hg38 assembly the 33mer sequences in chromosomes 21, 13, 14, and 22 are 100% identical but nearby gaps are present; that seems to require an additional more precise sequencing. Chromosome 21 is of significant interest for deciphering the molecular base of Down syndrome and of aneuploidies in general. Since the chromosome identifier probes are largely based on the detection of higher order alpha satellite repeats, distinctions between alpha satellite HORs in chromosomes 21 and 13 here identified might lead to a unique chromosome 21 probe in molecular cytogenetics, which would find utility in diagnostics. It is expected that its complete sequence analysis will have profound implications for understanding pathogenesis of diseases and development of new therapeutic approaches.
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20
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Haliki E, Alpagut Keskin N, Masalci O. Boolean gene regulatory network model of centromere function in Saccharomyces cerevisiae. J Biol Phys 2019; 45:235-251. [PMID: 31175490 DOI: 10.1007/s10867-019-09526-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 05/09/2019] [Indexed: 10/26/2022] Open
Abstract
Centromeres, a highly conserved locus of eukaryotic chromosomes, have critical function for genome stability and integrity. Because their centromeric DNA sequences are necessary and sufficient for kinetochore recruitment and DNA segregation, point centromeres of Saccharomyces cerevisiae chromosomes provide an attractive system for the study of the regulation of centromere function. Using the mathematical model of Boolean gene regulatory networks, the gene regulatory dynamics of centromere region of S. cerevisiae (budding yeast), which is actively involved in the cell-cycle, has been examined. A gene regulatory network containing the relevant centromere genes of the model organism from biological databases was established and all possible cellular phenotypes subjected to a synchronous gene regulation and attracted to several basins. Gene expression in the largest attractor was compared with the biological data by obtaining changes in the cell-cycle. We show that the model for centromere function recovers a single cyclic attractor. The trajectory flow diagram plotted over all initial conditions of the system also shows good correspondence with the cell-cycle phases. Although other upstream signals are possibly involved in the regulation of centromere genes, proposed interactions with selected cell-cycle genes were sufficient to recover whole cell-cycle process. To truly clarify these proposed regulatory interactions of candidate genes for centromere function, profiling and analyzing their expression levels over time with expanded nodes/edges are required. Moreover, a previously modeled gene knock-down mechanism applied to the network and robustness versus knock-down was interpreted based on the obtained consequences.
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21
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McNulty SM, Sullivan BA. Alpha satellite DNA biology: finding function in the recesses of the genome. Chromosome Res 2018; 26:115-138. [PMID: 29974361 DOI: 10.1007/s10577-018-9582-3] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 06/14/2018] [Indexed: 02/05/2023]
Abstract
Repetitive DNA, formerly referred to by the misnomer "junk DNA," comprises a majority of the human genome. One class of this DNA, alpha satellite, comprises up to 10% of the genome. Alpha satellite is enriched at all human centromere regions and is competent for de novo centromere assembly. Because of the highly repetitive nature of alpha satellite, it has been difficult to achieve genome assemblies at centromeres using traditional next-generation sequencing approaches, and thus, centromeres represent gaps in the current human genome assembly. Moreover, alpha satellite DNA is transcribed into repetitive noncoding RNA and contributes to a large portion of the transcriptome. Recent efforts to characterize these transcripts and their function have uncovered pivotal roles for satellite RNA in genome stability, including silencing "selfish" DNA elements and recruiting centromere and kinetochore proteins. This review will describe the genomic and epigenetic features of alpha satellite DNA, discuss recent findings of noncoding transcripts produced from distinct alpha satellite arrays, and address current progress in the functional understanding of this oft-neglected repetitive sequence. We will discuss unique challenges of studying human satellite DNAs and RNAs and point toward new technologies that will continue to advance our understanding of this largely untapped portion of the genome.
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Affiliation(s)
- Shannon M McNulty
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Beth A Sullivan
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, 27710, USA. .,Division of Human Genetics, Duke University Medical Center, Durham, NC, 27710, USA.
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22
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Jain M, Olsen HE, Turner DJ, Stoddart D, Bulazel KV, Paten B, Haussler D, Willard HF, Akeson M, Miga KH. Linear assembly of a human centromere on the Y chromosome. Nat Biotechnol 2018; 36:321-323. [PMID: 29553574 PMCID: PMC5886786 DOI: 10.1038/nbt.4109] [Citation(s) in RCA: 167] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 02/22/2018] [Indexed: 01/21/2023]
Abstract
The human genome reference sequence remains incomplete owing to the challenge of assembling long tracts of near-identical tandem repeats in centromeres. We implemented a nanopore sequencing strategy to generate high-quality reads that span hundreds of kilobases of highly repetitive DNA in a human Y chromosome centromere. Combining these data with short-read variant validation, we assembled and characterized the centromeric region of a human Y chromosome.
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Affiliation(s)
- Miten Jain
- UC Santa Cruz Genomics Institute, University of California, Santa Cruz, California USA
| | - Hugh E Olsen
- UC Santa Cruz Genomics Institute, University of California, Santa Cruz, California USA
| | | | | | - Kira V Bulazel
- Duke Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina USA
| | - Benedict Paten
- UC Santa Cruz Genomics Institute, University of California, Santa Cruz, California USA
| | - David Haussler
- UC Santa Cruz Genomics Institute, University of California, Santa Cruz, California USA
| | - Huntington F Willard
- Duke Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina USA
- Geisinger National, Bethesda, Maryland USA
| | - Mark Akeson
- UC Santa Cruz Genomics Institute, University of California, Santa Cruz, California USA
| | - Karen H Miga
- UC Santa Cruz Genomics Institute, University of California, Santa Cruz, California USA
- Duke Institute for Genome Sciences and Policy, Duke University, Durham, North Carolina USA
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23
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Sen S, Sharma T. ROLE OF CONSTITUTIVE HETEROCHROMATIN IN EVOLUTIONARY DIVERGENCE: RESULTS OF CHROMOSOME BANDING AND CONDENSATION INHIBITION STUDIES IN MUS MUSCULUS, MUS BOODUGA
AND MUS DUNNI. Evolution 2017; 37:628-636. [DOI: 10.1111/j.1558-5646.1983.tb05579.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/1981] [Revised: 07/18/1982] [Indexed: 11/29/2022]
Affiliation(s)
- S. Sen
- Cytogenetics Laboratory, Department of Zoology; Banaras Hindu University; Varanasi 221005 INDIA
| | - T. Sharma
- Cytogenetics Laboratory, Department of Zoology; Banaras Hindu University; Varanasi 221005 INDIA
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24
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Dumont M, Fachinetti D. DNA Sequences in Centromere Formation and Function. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2017; 56:305-336. [PMID: 28840243 DOI: 10.1007/978-3-319-58592-5_13] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Faithful chromosome segregation during cell division depends on the centromere, a complex DNA/protein structure that links chromosomes to spindle microtubules. This chromosomal domain has to be marked throughout cell division and its chromosomal localization preserved across cell generations. From fission yeast to human, centromeres are established on a series of repetitive DNA sequences and on specialized centromeric chromatin. This chromatin is enriched with the histone H3 variant, named CENP-A, that was demonstrated to be the epigenetic mark that maintains centromere identity and function indefinitely. Although centromere identity is thought to be exclusively epigenetic, the presence of specific DNA sequences in the majority of eukaryotes and of the centromeric protein CENP-B that binds to these sequences, suggests the existence of a genetic component as well. In this review, we will highlight the importance of centromeric sequences for centromere formation and function, and discuss the centromere DNA sequence/CENP-B paradox.
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Affiliation(s)
- M Dumont
- Institut Curie, PSL Research University, CNRS, UMR 144, 26 rue d'Ulm, 75005, Paris, France
| | - D Fachinetti
- Institut Curie, PSL Research University, CNRS, UMR 144, 26 rue d'Ulm, 75005, Paris, France.
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25
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Abstract
Genomic studies rely on accurate chromosome assemblies to explore sequence-based models of cell biology, evolution and biomedical disease. However, even the extensively studied human genome has not yet reached a complete, 'telomere-to-telomere', chromosome assembly. The largest assembly gaps remain in centromeric regions and acrocentric short arms, sites known to contain megabase-sized arrays of tandem repeats, or satellite DNAs. This review aims to briefly address the progress and challenges of generating correct assemblies of satellite DNA arrays. Although the focus is placed on the human genome, many concepts presented here are applicable to other genomes.
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Affiliation(s)
- Karen H Miga
- Center for Biomolecular Science and Engineering, University of California Santa Cruz, Santa Cruz, CA, 95064, USA.
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26
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Wang X, Ma Z, Kong X, Lv Z. Effects of RNAs on chromatin accessibility and gene expression suggest RNA-mediated activation. Int J Biochem Cell Biol 2016; 79:24-32. [PMID: 27497987 DOI: 10.1016/j.biocel.2016.08.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 08/02/2016] [Accepted: 08/03/2016] [Indexed: 01/20/2023]
Abstract
The study of the interaction between RNA and DNA sequences in activating genes has important significance for understanding the mechanisms of RNA-mediated activation. Here, we used in vitro chromatin reconstitution approach to observe whether RNAs increase DNase I digestion, plasmid transfection to observe whether RNAs promote gene expression, and bioinformatics analysis to predict the binding ability of RNAs to centromere DNA (constitutive heterochromatin). Synthetic RNAs (23nt) that were complementary to mouse albumin gene and total liver RNA increased DNase I digestion sensitivity of mouse albumin gene, suggesting that RNAs can increase chromatin accessibility. Transcribed sense-antisense tandem Alu elements activated an enhanced green fluorescent protein reporter gene after stable transfection. Bioinformatics analysis showed that the binding strength of RNA population to centromere DNAs is significantly lower than that of their flanking sequences, which suggests that the centromere is not easily affected by RNAs produced from other transcribed regions and may be the reason why centromeres consist of constitutive heterochromatin. The results in this paper illustrate that RNAs complementary to DNA sequences play roles in activating genes. Since RNA is mainly produced from the cell's own DNA, the work presented in this paper suggests that RNAs transcribed from DNA create feedback that activates DNA transcription.
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Affiliation(s)
- Xiufang Wang
- Department of Genetics, Hebei Medical University, Hebei Key Lab of Laboratory Animal, Shijiazhuang, Hebei Province, China.
| | - Zhihong Ma
- Department of Genetics, Hebei Medical University, Hebei Key Lab of Laboratory Animal, Shijiazhuang, Hebei Province, China; Clinical Laboratory, The Second Hospital of Tangshan, 21 North Jianshe Road, Tangshan, Hebei Province, China.
| | - Xianglong Kong
- Department of Genetics, Hebei Medical University, Hebei Key Lab of Laboratory Animal, Shijiazhuang, Hebei Province, China; Clinical Laboratory, Hebei Chest Hospital, 372 Shengli North Street, Shijiazhuang, Hebei Province, China.
| | - Zhanjun Lv
- Department of Genetics, Hebei Medical University, Hebei Key Lab of Laboratory Animal, Shijiazhuang, Hebei Province, China.
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27
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Lemke KH, Weier JF, Weier HUG, Lawin-O'Brien AR. High Performance DNA Probes for Perinatal Detection of Numerical Chromosome Aberrations. ACTA ACUST UNITED AC 2015; 3. [PMID: 26855976 PMCID: PMC4739796 DOI: 10.4172/2379-1764.1000155] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Human reproduction is a tightly controlled process of stepwise evolution with multiple, mostly yet unknown milestones and checkpoints. Healthy halpoid gametes have to be produced by the parents, which will fuse to form the diploid zygote that implants in the female uterus and grows to become first an embryo, then a fetus and finally matures into a newborn. There are several known risk factors that interfere with normal production of gametes, spermatocytes or oocytes, and often cause embryonic mortality and fetal demise at an early stage. Yet some embryos with chomosomal abnormalities can develop beyond the critical first trimester of pregnancy and, while those with supernumary chromosomes in their hyperdiploid cells will be spontaneously aborted, a small fraction of fetuses with an extra chromosome continues to grow to term and will be delivered as a liveborn baby. While minor clinical symptoms displayed by children with trisomies are manageable for many parents, the burden of caring for a child with numerical chromosome abnormalities can be overwhelming to partners or individual families. It also poses a significant financial burden to the society and poses ethical dilemma. In this communication, we will review the progress that has been made in the development of molecular techniques to test individual fetal cells for chromosomal imbalances. We will focus our discussion on the direct visualization of chromosome-specific DNA sequences in live or fixed specimens using fluorescence in situ hybridization (FISH) and, more specifically, talk about the groundbreaking progress that in recent years has been achieved towards an improved diagnosis with novel, chromosome-specific DNA probes.
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Affiliation(s)
- Kalistyn H Lemke
- Life Sciences Division, University of California, E.O. Lawrence Berkeley National Laboratory (LBNL), Berkeley, USA
| | - Jingly F Weier
- Life Sciences Division, University of California, E.O. Lawrence Berkeley National Laboratory (LBNL), Berkeley, USA; Dermatopathology Service, School of Medicine, University of California, San Francisco, USA
| | - Heinz-Ulrich G Weier
- Life Sciences Division, University of California, E.O. Lawrence Berkeley National Laboratory (LBNL), Berkeley, USA
| | - Anna R Lawin-O'Brien
- Centre for Fetal Care, Queen Charlotte's and Chelsea Hospital, Imperial College Healthcare, London, UK
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28
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McKinley KL, Cheeseman IM. The molecular basis for centromere identity and function. Nat Rev Mol Cell Biol 2015; 17:16-29. [PMID: 26601620 DOI: 10.1038/nrm.2015.5] [Citation(s) in RCA: 397] [Impact Index Per Article: 44.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The centromere is the region of the chromosome that directs its segregation in mitosis and meiosis. Although the functional importance of the centromere has been appreciated for more than 130 years, elucidating the molecular features and properties that enable centromeres to orchestrate chromosome segregation is an ongoing challenge. Most eukaryotic centromeres are defined epigenetically and require the presence of nucleosomes containing the histone H3 variant centromere protein A (CENP-A; also known as CENH3). Ongoing work is providing important molecular insights into the central requirements for centromere identity and propagation, and the mechanisms by which centromeres recruit kinetochores to connect to spindle microtubules.
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Affiliation(s)
- Kara L McKinley
- Whitehead Institute and Department of Biology, MIT, Nine Cambridge Center, Cambridge, Massachusetts 02142, USA
| | - Iain M Cheeseman
- Whitehead Institute and Department of Biology, MIT, Nine Cambridge Center, Cambridge, Massachusetts 02142, USA
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29
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Cech JN, Peichel CL. Identification of the centromeric repeat in the threespine stickleback fish (Gasterosteus aculeatus). Chromosome Res 2015; 23:767-79. [PMID: 26424612 DOI: 10.1007/s10577-015-9495-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 09/11/2015] [Accepted: 09/17/2015] [Indexed: 01/09/2023]
Abstract
Centromere sequences exist as gaps in many genome assemblies due to their repetitive nature. Here we take an unbiased approach utilizing centromere protein A (CENP-A) chomatin immunoprecipitation followed by high-throughput sequencing to identify the centromeric repeat sequence in the threespine stickleback fish (Gasterosteus aculeatus). A 186-bp, AT-rich repeat was validated as centromeric using both fluorescence in situ hybridization (FISH) and immunofluorescence combined with FISH (IF-FISH) on interphase nuclei and metaphase spreads. This repeat hybridizes strongly to the centromere on all chromosomes, with the exception of weak hybridization to the Y chromosome. Together, our work provides the first validated sequence information for the threespine stickleback centromere.
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Affiliation(s)
- Jennifer N Cech
- Divisions of Human Biology and Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave North, Mailstop C2-023, Seattle, WA, 98109, USA.,Graduate Program in Molecular and Cellular Biology, University of Washington, Seattle, WA, 98195, USA
| | - Catherine L Peichel
- Divisions of Human Biology and Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave North, Mailstop C2-023, Seattle, WA, 98109, USA.
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30
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Catacchio CR, Ragone R, Chiatante G, Ventura M. Organization and evolution of Gorilla centromeric DNA from old strategies to new approaches. Sci Rep 2015; 5:14189. [PMID: 26387916 PMCID: PMC4585704 DOI: 10.1038/srep14189] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 08/18/2015] [Indexed: 11/09/2022] Open
Abstract
The centromere/kinetochore interaction is responsible for the pairing and segregation of replicated chromosomes in eukaryotes. Centromere DNA is portrayed as scarcely conserved, repetitive in nature, quickly evolving and protein-binding competent. Among primates, the major class of centromeric DNA is the pancentromeric α-satellite, made of arrays of 171 bp monomers, repeated in a head-to-tail pattern. α-satellite sequences can either form tandem heterogeneous monomeric arrays or assemble in higher-order repeats (HORs). Gorilla centromere DNA has barely been characterized, and data are mainly based on hybridizations of human alphoid sequences. We isolated and finely characterized gorilla α-satellite sequences and revealed relevant structure and chromosomal distribution similarities with other great apes as well as gorilla-specific features, such as the uniquely octameric structure of the suprachromosomal family-2 (SF2). We demonstrated for the first time the orthologous localization of alphoid suprachromosomal families-1 and −2 (SF1 and SF2) between human and gorilla in contrast to chimpanzee centromeres. Finally, the discovery of a new 189 bp monomer type in gorilla centromeres unravels clues to the role of the centromere protein B, paving the way to solve the significance of the centromere DNA’s essential repetitive nature in association with its function and the peculiar evolution of the α-satellite sequence.
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Affiliation(s)
- C R Catacchio
- University of Bari Aldo Moro, Department of Biology, Via Orabona 4, Bari, 70125, Italy
| | - R Ragone
- University of Bari Aldo Moro, Department of Biology, Via Orabona 4, Bari, 70125, Italy
| | - G Chiatante
- University of Bari Aldo Moro, Department of Biology, Via Orabona 4, Bari, 70125, Italy
| | - M Ventura
- University of Bari Aldo Moro, Department of Biology, Via Orabona 4, Bari, 70125, Italy
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31
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Abstract
Power-law distributions are the main functional form for the distribution of repeat size and repeat copy number in the human genome. When the genome is broken into fragments for sequencing, the limited size of fragments and reads may prevent an unique alignment of repeat sequences to the reference sequence. Repeats in the human genome can be as long as 104 bases, or 105 − 106 bases when allowing for mismatches between repeat units. Sequence reads from these regions are therefore unmappable when the read length is in the range of 103 bases. With a read length of 1000 bases, slightly more than 1% of the assembled genome, and slightly less than 1% of the 1 kb reads, are unmappable, excluding the unassembled portion of the human genome (8% in GRCh37/hg19). The slow decay (long tail) of the power-law function implies a diminishing return in converting unmappable regions/reads to become mappable with the increase of the read length, with the understanding that increasing read length will always move toward the direction of 100% mappability.
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Affiliation(s)
- Wentian Li
- The Robert S. Boas Center for Genomics and Human Genetics, The Feinstein Institute for Medical Research, North Shore LIJ Health System Manhasset, NY, USA
| | - Jan Freudenberg
- The Robert S. Boas Center for Genomics and Human Genetics, The Feinstein Institute for Medical Research, North Shore LIJ Health System Manhasset, NY, USA
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Abstract
Since discovery of the centromere-specific histone H3 variant CENP-A, centromeres have come to be defined as chromatin structures that establish the assembly site for the complex kinetochore machinery. In most organisms, centromere activity is defined epigenetically, rather than by specific DNA sequences. In this review, we describe selected classic work and recent progress in studies of centromeric chromatin with a focus on vertebrates. We consider possible roles for repetitive DNA sequences found at most centromeres, chromatin factors and modifications that assemble and activate CENP-A chromatin for kinetochore assembly, plus the use of artificial chromosomes and kinetochores to study centromere function.
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Affiliation(s)
- Tatsuo Fukagawa
- Department of Molecular Genetics, National Institute of Genetics and Graduate University for Advanced Studies (SOKENDAI), Mishima, Shizuoka 411-8540, Japan.
| | - William C Earnshaw
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, King's Buildings, Mayfield Road, Edinburgh, EH9 3JR, UK.
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Miga KH, Newton Y, Jain M, Altemose N, Willard HF, Kent WJ. Centromere reference models for human chromosomes X and Y satellite arrays. Genome Res 2014; 24:697-707. [PMID: 24501022 PMCID: PMC3975068 DOI: 10.1101/gr.159624.113] [Citation(s) in RCA: 165] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The human genome sequence remains incomplete, with multimegabase-sized gaps representing the endogenous centromeres and other heterochromatic regions. Available sequence-based studies within these sites in the genome have demonstrated a role in centromere function and chromosome pairing, necessary to ensure proper chromosome segregation during cell division. A common genomic feature of these regions is the enrichment of long arrays of near-identical tandem repeats, known as satellite DNAs, which offer a limited number of variant sites to differentiate individual repeat copies across millions of bases. This substantial sequence homogeneity challenges available assembly strategies and, as a result, centromeric regions are omitted from ongoing genomic studies. To address this problem, we utilize monomer sequence and ordering information obtained from whole-genome shotgun reads to model two haploid human satellite arrays on chromosomes X and Y, resulting in an initial characterization of 3.83 Mb of centromeric DNA within an individual genome. To further expand the utility of each centromeric reference sequence model, we evaluate sites within the arrays for short-read mappability and chromosome specificity. Because satellite DNAs evolve in a concerted manner, we use these centromeric assemblies to assess the extent of sequence variation among 366 individuals from distinct human populations. We thus identify two satellite array variants in both X and Y centromeres, as determined by array length and sequence composition. This study provides an initial sequence characterization of a regional centromere and establishes a foundation to extend genomic characterization to these sites as well as to other repeat-rich regions within complex genomes.
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Affiliation(s)
- Karen H Miga
- Duke Institute for Genome Sciences & Policy, Duke University, Durham, North Carolina 27708, USA
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Dai X, Otake K, You C, Cai Q, Wang Z, Masumoto H, Wang Y. Identification of novel α-n-methylation of CENP-B that regulates its binding to the centromeric DNA. J Proteome Res 2013; 12:4167-75. [PMID: 23978223 DOI: 10.1021/pr400498y] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The eukaryotic centromere is an essential chromatin region required for accurate segregation of sister chromatids during cell division. Centromere protein B (CENP-B) is a highly conserved protein which can bind to the 17-bp CENP-B box on the centromeric DNA. In this study, we found that CENP-B could be α-N-methylated in human cells. We also showed that the level of the α-N-methylation was stimulated in cells in response to a variety of extracellular stimuli, including increased cell density, heat shock, and arsenite treatment, although the methylation level was not altered upon metaphase arrest. We identified N-terminal RCC1 methyltransferase (NRMT) as a major enzyme required for the CENP-B methylation. Additionally, we found that chromatin-bound CENP-B was primarily trimethylated and α-N-trimethylation could enhance CENP-B's binding to CENP-B box in cells. Our study also expands the function of protein α-N-methylation that has been known for decades and whose function remains largely unexplored.
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Affiliation(s)
- Xiaoxia Dai
- Department of Chemistry, University of California, Riverside, California 92521-0403, United States
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Prakhongcheep O, Chaiprasertsri N, Terada S, Hirai Y, Srikulnath K, Hirai H, Koga A. Heterochromatin blocks constituting the entire short arms of acrocentric chromosomes of Azara's owl monkey: formation processes inferred from chromosomal locations. DNA Res 2013; 20:461-70. [PMID: 23761219 PMCID: PMC3789557 DOI: 10.1093/dnares/dst023] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Centromeres and telomeres of higher eukaryotes generally contain repetitive sequences, which often form pericentric or subtelomeric heterochromatin blocks. C-banding analysis of chromosomes of Azara's owl monkey, a primate species, showed that the short arms of acrocentric chromosomes consist mostly or solely of constitutive heterochromatin. The purpose of the present study was to determine which category, pericentric, or subtelomeric is most appropriate for this heterochromatin, and to infer its formation processes. We cloned and sequenced its DNA component, finding it to be a tandem repeat sequence comprising 187-bp repeat units, which we named OwlRep. Subsequent hybridization analyses revealed that OwlRep resides in the pericentric regions of a small number of metacentric chromosomes, in addition to the short arms of acrocentric chromosomes. Further, in the pericentric regions of the acrocentric chromosomes, OwlRep was observed on the short-arm side only. This distribution pattern of OwlRep among chromosomes can be simply and sufficiently explained by assuming (i) OwlRep was transferred from chromosome to chromosome by the interaction of pericentric heterochromatin, and (ii) it was amplified there as subtelomeric heterochromatin. OwlRep carries several direct and inverted repeats within its repeat units. This complex structure may lead to a higher frequency of chromosome scission and may thus be a factor in the unique distribution pattern among chromosomes. Neither OwlRep nor similar sequences were found in the genomes of the other New World monkey species we examined, suggesting that OwlRep underwent rapid amplification after the divergence of the owl monkey lineage from lineages of the other species.
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Rubtsov NB. Organization of eukaryotic chromosomes: From Kol’tsov’s studies up to present day. RUSS J GENET+ 2013. [DOI: 10.1134/s1022795413010109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Podgornaya O, Gavrilova E, Stephanova V, Demin S, Komissarov A. Large tandem repeats make up the chromosome bar code: a hypothesis. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2013; 90:1-30. [PMID: 23582200 DOI: 10.1016/b978-0-12-410523-2.00001-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Much of tandem repeats' functional nature in any genome remains enigmatic because there are only few tools available for dissecting and elucidating the functions of repeated DNA. The large tandem repeat arrays (satellite DNA) found in two mouse whole-genome shotgun assemblies were classified into 4 superfamilies, 8 families, and 62 subfamilies. With the simplified variant of chromosome positioning of different tandem repeats, we noticed the nonuniform distribution instead of the positions reported for mouse major and minor satellites. It is visible that each chromosome possesses a kind of unique code made up of different large tandem repeats. The reference genomes allow marking only internal tandem repeats, and even with such a limited data, the colored "bar code" made up of tandem repeats is visible. We suppose that tandem repeats bare the mechanism for chromosomes to recognize the regions to be associated. The associations, initially established via RNA, become fixed by histone modifications (the histone or chromatin code) and specific proteins. In such a way, associations, being at the beginning flexible and regulated, that is, adjustable, appear as irreversible and inheritable in cell generations. Tandem repeat multiformity tunes the developed nuclei 3D pattern by sequential steps of associations. Tandem repeats-based chromosome bar code could be the carrier of the genome structural information; that is, the order of precise tandem repeat association is the DNA morphogenetic program. Tandem repeats are the cores of the distinct 3D structures postulated in "gene gating" hypothesis.
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Abstract
Centromeres, the sites of spindle attachment during mitosis and meiosis, are located in specific positions in the human genome, normally coincident with diverse subsets of alpha satellite DNA. While there is strong evidence supporting the association of some subfamilies of alpha satellite with centromere function, the basis for establishing whether a given alpha satellite sequence is or is not designated a functional centromere is unknown, and attempts to understand the role of particular sequence features in establishing centromere identity have been limited by the near identity and repetitive nature of satellite sequences. Utilizing a broadly applicable experimental approach to test sequence competency for centromere specification, we have carried out a genomic and epigenetic functional analysis of endogenous human centromere sequences available in the current human genome assembly. The data support a model in which functionally competent sequences confer an opportunity for centromere specification, integrating genomic and epigenetic signals and promoting the concept of context-dependent centromere inheritance.
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Abstract
Advances in human genomics have accelerated studies in evolution, disease, and cellular regulation. However, centromere sequences, defining the chromosomal interface with spindle microtubules, remain largely absent from ongoing genomic studies and disconnected from functional, genome-wide analyses. This disparity results from the challenge of predicting the linear order of multi-megabase-sized regions that are composed almost entirely of near-identical satellite DNA. Acknowledging these challenges, the field of human centromere genomics possesses the potential to rapidly advance given the availability of individual, or personalized, genome projects matched with the promise of long-read sequencing technologies. Here I review the current genomic model of human centromeres in consideration of those studies involving functional datasets that examine the role of sequence in centromere identity.
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O'Brien B, Zeng H, Polyzos AA, Lemke KH, Weier JF, Wang M, Zitzelsberger HF, Weier HUG. Bioinformatics tools allow targeted selection of chromosome enumeration probes and aneuploidy detection. J Histochem Cytochem 2012. [PMID: 23204113 PMCID: PMC3636690 DOI: 10.1369/0022155412470955] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Accurate determination of cellular chromosome complements is a highly relevant issue beyond prenatal/pre-implantation genetic analyses or stem cell research, because aneusomy may be an important mechanism by which organisms control the rate of fetal cellular proliferation and the fate of regenerating tissues. Typically, small amounts of individual cells or nuclei are assayed by in situ hybridization using chromosome-specific DNA probes. Careful probe selection is fundamental to successful hybridization experiments. Numerous DNA probes for chromosome enumeration studies are commercially available, but their use in multiplexed hybridization assays is hampered due to differing probe-specific hybridization conditions or a lack of a sufficiently large number of different reporter molecules. Progress in the International Human Genome Project has equipped the scientific community with a wealth of unique resources, among them recombinant DNA libraries, physical maps, and data-mining tools. Here, we demonstrate how bioinformatics tools can become an integral part of simple, yet powerful approaches to devise diagnostic strategies for detection of aneuploidy in interphase cells. Our strategy involving initial in silico optimization steps offers remarkable savings in time and costs during probe generation, while at the same time significantly increasing the assay’s specificity, sensitivity, and reproducibility.
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Affiliation(s)
- Benjamin O'Brien
- William Harvey Research Institute, Queen Mary University London, UK.
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De Rop V, Padeganeh A, Maddox PS. CENP-A: the key player behind centromere identity, propagation, and kinetochore assembly. Chromosoma 2012; 121:527-38. [PMID: 23095988 PMCID: PMC3501172 DOI: 10.1007/s00412-012-0386-5] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 10/01/2012] [Accepted: 10/01/2012] [Indexed: 12/26/2022]
Abstract
Chromosome segregation is the one of the great problems in biology with complexities spanning from biophysics and polymer dynamics to epigenetics. Here, we summarize the current knowledge and highlight gaps in understanding of the mechanisms controlling epigenetic regulation of chromosome segregation.
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Affiliation(s)
- Valérie De Rop
- Institute for Research in Immunology and Cancer (IRIC), Department of Pathology and Cell Biology, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Québec H3C 3J7 Canada
| | - Abbas Padeganeh
- Institute for Research in Immunology and Cancer (IRIC), Department of Pathology and Cell Biology, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Québec H3C 3J7 Canada
| | - Paul S. Maddox
- Institute for Research in Immunology and Cancer (IRIC), Department of Pathology and Cell Biology, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Québec H3C 3J7 Canada
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42
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Marks J. Hominoid cytogenetics and evolution. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2012. [DOI: 10.1002/ajpa.1330260507] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Carbone L, Harris RA, Mootnick AR, Milosavljevic A, Martin DIK, Rocchi M, Capozzi O, Archidiacono N, Konkel MK, Walker JA, Batzer MA, de Jong PJ. Centromere remodeling in Hoolock leuconedys (Hylobatidae) by a new transposable element unique to the gibbons. Genome Biol Evol 2012; 4:648-58. [PMID: 22593550 PMCID: PMC3606032 DOI: 10.1093/gbe/evs048] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Gibbons (Hylobatidae) shared a common ancestor with the other hominoids only 15–18 million years ago. Nevertheless, gibbons show very distinctive features that include heavily rearranged chromosomes. Previous observations indicate that this phenomenon may be linked to the attenuated epigenetic repression of transposable elements (TEs) in gibbon species. Here we describe the massive expansion of a repeat in almost all the centromeres of the eastern hoolock gibbon (Hoolock leuconedys). We discovered that this repeat is a new composite TE originating from the combination of portions of three other elements (L1ME5, AluSz6, and SVA_A) and thus named it LAVA. We determined that this repeat is found in all the gibbons but does not occur in other hominoids. Detailed investigation of 46 different LAVA elements revealed that the majority of them have target site duplications (TSDs) and a poly-A tail, suggesting that they have been retrotransposing in the gibbon genome. Although we did not find a direct correlation between the emergence of LAVA elements and human–gibbon synteny breakpoints, this new composite transposable element is another mark of the great plasticity of the gibbon genome. Moreover, the centromeric expansion of LAVA insertions in the hoolock closely resembles the massive centromeric expansion of the KERV-1 retroelement reported for wallaby (marsupial) interspecific hybrids. The similarity between the two phenomena is consistent with the hypothesis that evolution of the gibbons is characterized by defects in epigenetic repression of TEs, perhaps triggered by interspecific hybridization.
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Affiliation(s)
- Lucia Carbone
- Children's Hospital Oakland Research Institute, Oakland, CA, USA.
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44
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Cellamare A, Catacchio CR, Alkan C, Giannuzzi G, Antonacci F, Cardone MF, Della Valle G, Malig M, Rocchi M, Eichler EE, Ventura M. New insights into centromere organization and evolution from the white-cheeked gibbon and marmoset. Mol Biol Evol 2009; 26:1889-900. [PMID: 19429672 DOI: 10.1093/molbev/msp101] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The evolutionary history of alpha-satellite DNA, the major component of primate centromeres, is hardly defined because of the difficulty in its sequence assembly and its rapid evolution when compared with most genomic sequences. By using several approaches, we have cloned, sequenced, and characterized alpha-satellite sequences from two species representing critical nodes in the primate phylogeny: the white-cheeked gibbon, a lesser ape, and marmoset, a New World monkey. Sequence analyses demonstrate that white-cheeked gibbon and marmoset alpha-satellite sequences are formed by units of approximately 171 and approximately 342 bp, respectively, and they both lack the high-order structure found in humans and great apes. Fluorescent in situ hybridization characterization shows a broad dispersal of alpha-satellite in the white-cheeked gibbon genome including centromeric, telomeric, and chromosomal interstitial localizations. On the other hand, centromeres in marmoset appear organized in highly divergent dimers roughly of 342 bp that show a similarity between monomers much lower than previously reported dimers, thus representing an ancient dimeric structure. All these data shed light on the evolution of the centromeric sequences in Primates. Our results suggest radical differences in the structure, organization, and evolution of alpha-satellite DNA among different primate species, supporting the notion that 1) all the centromeric sequence in Primates evolved by genomic amplification, unequal crossover, and sequence homogenization using a 171 bp monomer as the basic seeding unit and 2) centromeric function is linked to relatively short repeated elements, more than higher-order structure. Moreover, our data indicate that complex higher-order repeat structures are a peculiarity of the hominid lineage, showing the more complex organization in humans.
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Affiliation(s)
- A Cellamare
- Department of Genetics and Microbiology, University of Bari, Bari, Italy
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Paar V, Pavin N, Basar I, Rosandić M, Gluncić M, Paar N. Hierarchical structure of cascade of primary and secondary periodicities in Fourier power spectrum of alphoid higher order repeats. BMC Bioinformatics 2008; 9:466. [PMID: 18980673 PMCID: PMC2661002 DOI: 10.1186/1471-2105-9-466] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2008] [Accepted: 11/03/2008] [Indexed: 11/28/2022] Open
Abstract
Background Identification of approximate tandem repeats is an important task of broad significance and still remains a challenging problem of computational genomics. Often there is no single best approach to periodicity detection and a combination of different methods may improve the prediction accuracy. Discrete Fourier transform (DFT) has been extensively used to study primary periodicities in DNA sequences. Here we investigate the application of DFT method to identify and study alphoid higher order repeats. Results We used method based on DFT with mapping of symbolic into numerical sequence to identify and study alphoid higher order repeats (HOR). For HORs the power spectrum shows equidistant frequency pattern, with characteristic two-level hierarchical organization as signature of HOR. Our case study was the 16 mer HOR tandem in AC017075.8 from human chromosome 7. Very long array of equidistant peaks at multiple frequencies (more than a thousand higher harmonics) is based on fundamental frequency of 16 mer HOR. Pronounced subset of equidistant peaks is based on multiples of the fundamental HOR frequency (multiplication factor n for nmer) and higher harmonics. In general, nmer HOR-pattern contains equidistant secondary periodicity peaks, having a pronounced subset of equidistant primary periodicity peaks. This hierarchical pattern as signature for HOR detection is robust with respect to monomer insertions and deletions, random sequence insertions etc. For a monomeric alphoid sequence only primary periodicity peaks are present. The 1/fβ – noise and periodicity three pattern are missing from power spectra in alphoid regions, in accordance with expectations. Conclusion DFT provides a robust detection method for higher order periodicity. Easily recognizable HOR power spectrum is characterized by hierarchical two-level equidistant pattern: higher harmonics of the fundamental HOR-frequency (secondary periodicity) and a subset of pronounced peaks corresponding to constituent monomers (primary periodicity). The number of lower frequency peaks (secondary periodicity) below the frequency of the first primary periodicity peak reveals the size of nmer HOR, i.e., the number n of monomers contained in consensus HOR.
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Affiliation(s)
- Vladimir Paar
- Faculty of Science, University of Zagreb, Bijenicka 32, Zagreb, Croatia.
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Paar V, Basar I, Rosandić M, Glunčić M. Consensus higher order repeats and frequency of string distributions in human genome. Curr Genomics 2007; 8:93-111. [PMID: 18660848 PMCID: PMC2435359 DOI: 10.2174/138920207780368169] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2007] [Revised: 01/26/2007] [Accepted: 01/30/2007] [Indexed: 02/01/2023] Open
Abstract
Key string algorithm (KSA) could be viewed as robust computational generalization of restriction enzyme method. KSA enables robust and effective identification and structural analyzes of any given genomic sequences, like in the case of NCBI assembly for human genome. We have developed a method, using total frequency distribution of all r-bp key strings in dependence on the fragment length l, to determine the exact size of all repeats within the given genomic sequence, both of monomeric and HOR type. Subsequently, for particular fragment lengths equal to each of these repeat sizes we compute the partial frequency distribution of r-bp key strings; the key string with highest frequency is a dominant key string, optimal for segmentation of a given genomic sequence into repeat units. We illustrate how a wide class of 3-bp key strings leads to a key-string-dependent periodic cell which enables a simple identification and consensus length determinations of HORs, or any other highly convergent repeat of monomeric or HOR type, both tandem or dispersed. We illustrated KSA application for HORs in human genome and determined consensus HORs in the Build 35.1 assembly. In the next step we compute suprachromosomal family classification and CENP-B box / pJalpha distributions for HORs. In the case of less convergent repeats, like for example monomeric alpha satellite (20-40% divergence), we searched for optimal compact key string using frequency method and developed a concept of composite key string (GAAAC--CTTTG) or flexible relaxation (28 bp key string) which provides both monomeric alpha satellites as well as alpha monomer segmentation of internal HOR structure. This method is convenient also for study of R-strand (direct) / S-strand (reverse complement) alpha monomer alternations. Using KSA we identified 16 alternating regions of R-strand and S-strand monomers in one contig in choromosome 7. Use of CENP-B box and/or pJalpha motif as key string is suitable both for identification of HORs and monomeric pattern as well as for studies of CENP-B box / pJalpha distribution. As an example of application of KSA to sequences outside of HOR regions we present our finding of a tandem with highly convergent 3434-bp Long monomer in chromosome 5 (divergence less then 0.3%).
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Affiliation(s)
- Vladimir Paar
- Faculty of Science, University of Zagreb, Bijenička 32, 10000 Zagreb, Croatia
| | - Ivan Basar
- Faculty of Science, University of Zagreb, Bijenička 32, 10000 Zagreb, Croatia
| | - Marija Rosandić
- Department of Internal Medicine,
University Hospital Rebro, Kišpatićeva 12, 10000 Zagreb, Croatia
| | - Matko Glunčić
- Faculty of Science, University of Zagreb, Bijenička 32, 10000 Zagreb, Croatia
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Storlazzi CT, Albano F, Dencić-Fekete M, Djordjević V, Rocchi M. Late-appearing pseudocentric fission event during chronic myeloid leukemia progression. ACTA ACUST UNITED AC 2007; 174:61-7. [PMID: 17350469 DOI: 10.1016/j.cancergencyto.2006.11.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2006] [Revised: 11/13/2006] [Accepted: 11/21/2006] [Indexed: 11/28/2022]
Abstract
Pseudocentric fission is a rare event consisting of the splitting of one functional centromere into two new products, of which only one can give rise to a functionally competent kinetochore. We report here a pseudocentric fission event within the D5Z2 alphoid subset disrupting the centromeric region of chromosome 5 in a case of chronic myeloid leukemia (CML) after treatment with imatinib and interferon. The breakage generated unequal partitioning of alpha-satellite sequences between the two fission products. One product was inserted within the long arm of chromosome 12 at band 14.3, becoming the only functional centromere of chromosome der(5). The other fission product was rearranged to form a sandwich-like dicentric--but functionally monocentric--chromosome der(6), made up of material from chromosomes 5, 12, and 6. The intercentric distance on der(6) was shown to be largely >20 Mb. To our knowledge, this is the first pseudocentric fission event described in CML. Moreover, our results confirm the susceptibility to breakage of the centromeric region of chromosome 5.
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Affiliation(s)
- Clelia Tiziana Storlazzi
- Department of Genetics and Microbiology, University of Bari, Via Amendola 165/A, 70126 Bari, Italy.
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49
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Abstract
Centromeres are the elements of chromosomes that assemble the proteinaceous kinetochore, maintain sister chromatid cohesion, regulate chromosome attachment to the spindle, and direct chromosome movement during cell division. Although the functions of centromeres and the proteins that contribute to their complex structure and function are conserved in eukaryotes, centromeric DNA diverges rapidly. Human centromeres are particularly complicated. Here, we review studies on the organization of homogeneous arrays of chromosome-specific alpha-satellite repeats and evolutionary links among eukaryotic centromeric sequences. We also discuss epigenetic mechanisms of centromere identity that confer structural and functional features of the centromere through DNA-protein interactions and post-translational modifications, producing centromere-specific chromatin signatures. The assembly and organization of human centromeres, the contributions of satellite DNA to centromere identity and diversity, and the mechanism whereby centromeres are distinguished from the rest of the genome reflect ongoing puzzles in chromosome biology.
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Affiliation(s)
- Mary G Schueler
- Genome Technology Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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50
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Abstract
In research as well as in clinical applications, fluorescence in situ hybridization (FISH) has gained increasing popularity as a highly sensitive technique to study cytogenetic changes. Today, hundreds of commercially available DNA probes serve the basic needs of the biomedical research community. Widespread applications, however, are often limited by the lack of appropriately labeled, specific nucleic acid probes. We describe two approaches for an expeditious preparation of chromosome-specific DNAs and the subsequent probe labeling with reporter molecules of choice. The described techniques allow the preparation of highly specific DNA repeat probes suitable for enumeration of chromosomes in interphase cell nuclei or tissue sections. In addition, there is no need for chromosome enrichment by flow cytometry and sorting or molecular cloning. Our PCR-based method uses either bacterial artificial chromosomes or human genomic DNA as templates with alpha-satellite-specific primers. Here we demonstrate the production of fluorochrome-labeled DNA repeat probes specific for human chromosomes 17 and 18 in just a few days without the need for highly specialized equipment and without the limitation to only a few fluorochrome labels.
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Affiliation(s)
- Adolf Baumgartner
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, California, CA 94720, USA
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