scholarly journals The epigenetic regulation of centromeres and telomeres in plants and animals

2020 ◽  
Vol 14 (2) ◽  
pp. 265-311
Author(s):  
Magdalena Achrem ◽  
Izabela Szućko ◽  
Anna Kalinka
Keyword(s):  
Cell Division ◽  
Chromosome Segregation ◽  
Cell Nucleus ◽  
Epigenetic Regulation ◽  
Enzymatic Degradation ◽  
Chromosomal Region ◽  
Epigenetic Mechanisms ◽  
Linear Chromosome ◽  
Proper Functioning

The centromere is a chromosomal region where the kinetochore is formed, which is the attachment point of spindle fibers. Thus, it is responsible for the correct chromosome segregation during cell division. Telomeres protect chromosome ends against enzymatic degradation and fusions, and localize chromosomes in the cell nucleus. For this reason, centromeres and telomeres are parts of each linear chromosome that are necessary for their proper functioning. More and more research results show that the identity and functions of these chromosomal regions are epigenetically determined. Telomeres and centromeres are both usually described as highly condensed heterochromatin regions. However, the epigenetic nature of centromeres and telomeres is unique, as epigenetic modifications characteristic of both eu- and heterochromatin have been found in these areas. This specificity allows for the proper functioning of both regions, thereby affecting chromosome homeostasis. This review focuses on demonstrating the role of epigenetic mechanisms in the functioning of centromeres and telomeres in plants and animals.

fumble Encodes a Pantothenate Kinase Homolog Required for Proper Mitosis and Meiosis in Drosophila melanogaster

Genetics ◽  
2001 ◽  
Vol 157 (3) ◽  
pp. 1267-1276
Author(s):  
Katayoun Afshar ◽  
Pierre Gönczy ◽  
Stephen DiNardo ◽  
Steven A Wasserman
Keyword(s):  
Cell Division ◽  
Chromosome Segregation ◽  
Cell Division Cycle ◽  
Protein Isoforms ◽  
Pantothenate Kinase ◽  
Male Germline ◽  
Dividing Cells ◽  
Mutant Cells ◽  
Mitosis And Meiosis

Abstract A number of fundamental processes comprise the cell division cycle, including spindle formation, chromosome segregation, and cytokinesis. Our current understanding of these processes has benefited from the isolation and analysis of mutants, with the meiotic divisions in the male germline of Drosophila being particularly well suited to the identification of the required genes. We show here that the fumble (fbl) gene is required for cell division in Drosophila. We find that dividing cells in fbl-deficient testes exhibit abnormalities in bipolar spindle organization, chromosome segregation, and contractile ring formation. Cytological analysis of larval neuroblasts from null mutants reveals a reduced mitotic index and the presence of polyploid cells. Molecular analysis demonstrates that fbl encodes three protein isoforms, all of which contain a domain with high similarity to the pantothenate kinases of A. nidulans and mouse. The largest Fumble isoform is dispersed in the cytoplasm during interphase, concentrates around the spindle at metaphase, and localizes to the spindle midbody at telophase. During early embryonic development, the protein localizes to areas of membrane deposition and/or rearrangement, such as the metaphase and cellularization furrows. Given the role of pantothenate kinase in production of Coenzyme A and in phospholipid biosynthesis, this pattern of localization is suggestive of a role for fbl in membrane synthesis. We propose that abnormalities in synthesis and redistribution of membranous structures during the cell division cycle underlie the cell division defects in fbl mutant cells.

The epigenetic regulation of synaptic genes contributes to the etiology of autism

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Annamaria Srancikova ◽  
Zuzana Bacova ◽  
Jan Bakos
Keyword(s):  
Epigenetic Regulation ◽  
Neurodevelopmental Disorders ◽  
Autism Spectrum ◽  
Prader Willi Syndrome ◽  
Epigenetic Mechanisms ◽  
Substantial Evidence ◽  
Autistic Symptoms ◽  
Spectrum Disorders ◽  
The Brain

Abstract Epigenetic mechanisms greatly affect the developing brain, as well as the maturation of synapses with pervasive, long-lasting consequences on behavior in adults. Substantial evidence exists that implicates dysregulation of epigenetic mechanisms in the etiology of neurodevelopmental disorders. Therefore, this review explains the role of enzymes involved in DNA methylation and demethylation in neurodevelopment by emphasizing changes of synaptic genes and proteins. Epigenetic causes of sex-dependent differences in the brain are analyzed in conjunction with the pathophysiology of autism spectrum disorders. Special attention is devoted to the epigenetic regulation of the melanoma-associated antigen-like gene 2 (MAGEL2) found in Prader-Willi syndrome, which is known to be accompanied by autistic symptoms.

Epigenetic regulation of adipogenesis by histone-modifying enzymes

Epigenomics ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 235-251
Author(s):  
Paolo E Macchia ◽  
Immacolata C Nettore ◽  
Fabiana Franchini ◽  
Laura Santana-Viera ◽  
Paola Ungaro
Keyword(s):  
Epigenetic Regulation ◽  
Transcriptional Control ◽  
Metabolic Diseases ◽  
Epigenetic Mechanisms ◽  
Differentiation Process ◽  
Histone Tails ◽  
Histone Modifying Enzymes ◽  
Epigenomic Regulation ◽  
Adipocyte Development

Many studies investigating the transcriptional control of adipogenesis have been published so far; recently the research is focusing on the role of epigenetic mechanisms in regulating the process of adipocyte development. Histone-modifying enzymes and the histone tails post-transcriptional modifications catalyzed by them, are fundamentally involved in the epigenetic regulation of adipogenesis. In our review, we will discuss recent advances in epigenomic regulation of adipogenesis with a focus on histone-modifying enzymes implicated in the various phases of adipocytes differentiation process from mesenchymal stem cells to mature adipocytes. Understanding adipogenesis, may provide new ways to treat obesity and related metabolic diseases.

scholarly journals The Drosophila Kinesin-like Protein KLP67A Is Essential for Mitotic and Male Meiotic Spindle Assembly

2004 ◽  
Vol 15 (1) ◽  
pp. 121-131 ◽  
Author(s):  
Rita Gandhi ◽  
Silvia Bonaccorsi ◽  
Diana Wentworth ◽  
Stephen Doxsey ◽  
Maurizio Gatti ◽  
...  
Keyword(s):  
Cell Division ◽  
Chromosome Segregation ◽  
Mutational Analysis ◽  
Spindle Assembly ◽  
Male Meiosis ◽  
Meiotic Spindle ◽  
Drosophila Cell ◽  
Centrosome Separation ◽  
Mutant Cells

We have performed a mutational analysis together with RNA interference to determine the role of the kinesin-like protein KLP67A in Drosophila cell division. During both mitosis and male meiosis, Klp67A mutations cause an increase in MT length and disrupt discrete aspects of spindle assembly, as well as cytokinesis. Mutant cells exhibit greatly enlarged metaphase spindle as a result of excessive MT polymerization. The analysis of both living and fixed cells also shows perturbations in centrosome separation, chromosome segregation, and central spindle assembly. These data demonstrate that the MT plus end-directed motor KLP67A is essential for spindle assembly during mitosis and male meiosis and suggest that the regulation of MT plus-end polymerization is a key determinant of spindle architecture throughout cell division.

scholarly journals The Possible Role of Epigenetics in Gestational Diabetes: Cause, Consequence, or Both

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
J. L. Fernández-Morera ◽  
S. Rodríguez-Rodero ◽  
E. Menéndez-Torre ◽  
M. F. Fraga
Keyword(s):  
Diabetes Mellitus ◽  
Risk Factors ◽  
Environmental Factors ◽  
Gestational Diabetes ◽  
Gestational Diabetes Mellitus ◽  
Epigenetic Regulation ◽  
Negative Impact ◽  
Epigenetic Mechanisms ◽  
Intrauterine Environment

Gestational diabetes mellitus (GDM) is defined as the glucose intolerance that is not present or recognized prior to pregnancy. Several risk factors of GDM depend on environmental factors that are thought to regulate the genome through epigenetic mechanisms. Thus, epigenetic regulation could be involved in the development of GDM. In addition, the adverse intrauterine environment in patients with GDM could also have a negative impact on the establishment of the epigenomes of the offspring.

scholarly journals CENP-C is a blueprint for constitutive centromere–associated network assembly within human kinetochores

2015 ◽  
Vol 210 (1) ◽  
pp. 11-22 ◽  
Author(s):  
Kerstin Klare ◽  
John R. Weir ◽  
Federica Basilico ◽  
Tomasz Zimniak ◽  
Lucia Massimiliano ◽  
...  
Keyword(s):  
Cell Division ◽  
Chromosome Segregation ◽  
The Other ◽  
Microtubule Binding ◽  
Kinetochore Assembly ◽  
Binding Interface ◽  
Other Hand ◽  
Spindle Microtubules ◽  
Data Point

Kinetochores are multisubunit complexes that assemble on centromeres to bind spindle microtubules and promote faithful chromosome segregation during cell division. A 16-subunit complex named the constitutive centromere–associated network (CCAN) creates the centromere–kinetochore interface. CENP-C, a CCAN subunit, is crucial for kinetochore assembly because it links centromeres with the microtubule-binding interface of kinetochores. The role of CENP-C in CCAN organization, on the other hand, had been incompletely understood. In this paper, we combined biochemical reconstitution and cellular investigations to unveil how CENP-C promotes kinetochore targeting of other CCAN subunits. The so-called PEST domain in the N-terminal half of CENP-C interacted directly with the four-subunit CCAN subcomplex CENP-HIKM. We identified crucial determinants of this interaction whose mutation prevented kinetochore localization of CENP-HIKM and of CENP-TW, another CCAN subcomplex. When considered together with previous observations, our data point to CENP-C as a blueprint for kinetochore assembly.

scholarly journals Stable inheritance of Sinorhizobium meliloti cell growth polarity requires an FtsN-like protein and an amidase

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Elizaveta Krol ◽  
Lisa Stuckenschneider ◽  
Joana M. Kästle Silva ◽  
Peter L. Graumann ◽  
Anke Becker
Keyword(s):  
Cell Division ◽  
Cell Polarity ◽  
Chromosome Segregation ◽  
Cell Elongation ◽  
Sinorhizobium Meliloti ◽  
Growth Zone ◽  
Cell Pole ◽  
Growth Polarity ◽  
Selection Of

AbstractIn Rhizobiales bacteria, such as Sinorhizobium meliloti, cell elongation takes place only at new cell poles, generated by cell division. Here, we show that the role of the FtsN-like protein RgsS in S. meliloti extends beyond cell division. RgsS contains a conserved SPOR domain known to bind amidase-processed peptidoglycan. This part of RgsS and peptidoglycan amidase AmiC are crucial for reliable selection of the new cell pole as cell elongation zone. Absence of these components increases mobility of RgsS molecules, as well as abnormal RgsS accumulation and positioning of the growth zone at the old cell pole in about one third of the cells. These cells with inverted growth polarity are able to complete the cell cycle but show partially impaired chromosome segregation. We propose that amidase-processed peptidoglycan provides a landmark for RgsS to generate cell polarity in unipolarly growing Rhizobiales.

scholarly journals Repetitive centromeric satellite RNA is essential for kinetochore formation and cell division

2014 ◽  
Vol 207 (3) ◽  
pp. 335-349 ◽  
Author(s):  
Silvana Rošić ◽  
Florian Köhler ◽  
Sylvia Erhardt
Keyword(s):  
Cell Division ◽  
Chromosome Segregation ◽  
Noncoding Rna ◽  
Genome Stability ◽  
Sex Chromosome ◽  
Epigenetic Mark ◽  
Epigenetic Mechanisms ◽  
Satellite Rna ◽  
Centromeric Dna ◽  
In Trans

Chromosome segregation requires centromeres on every sister chromatid to correctly form and attach the microtubule spindle during cell division. Even though centromeres are essential for genome stability, the underlying centromeric DNA is highly variable in sequence and evolves quickly. Epigenetic mechanisms are therefore thought to regulate centromeres. Here, we show that the 359-bp repeat satellite III (SAT III), which spans megabases on the X chromosome of Drosophila melanogaster, produces a long noncoding RNA that localizes to centromeric regions of all major chromosomes. Depletion of SAT III RNA causes mitotic defects, not only of the sex chromosome but also in trans of all autosomes. We furthermore find that SAT III RNA binds to the kinetochore component CENP-C, and is required for correct localization of the centromere-defining proteins CENP-A and CENP-C, as well as outer kinetochore proteins. In conclusion, our data reveal that SAT III RNA is an integral part of centromere identity, adding RNA to the complex epigenetic mark at centromeres in flies.

scholarly journals Recurrent loss of CenH3 is associated with independent transitions to holocentricity in insects

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Ines A Drinnenberg ◽  
Dakota deYoung ◽  
Steven Henikoff ◽  
Harmit Singh Malik
Keyword(s):  
Cell Division ◽  
Chromosome Segregation ◽  
Chromosomal Region ◽  
Histone H3 ◽  
The Other ◽  
Spindle Attachment ◽  
Histone H3 Variant ◽  
Transcriptome Analyses ◽  
Almost All ◽  
Chromosomal Length

Faithful chromosome segregation in all eukaryotes relies on centromeres, the chromosomal sites that recruit kinetochore proteins and mediate spindle attachment during cell division. The centromeric histone H3 variant, CenH3, is the defining chromatin component of centromeres in most eukaryotes, including animals, fungi, plants, and protists. In this study, using detailed genomic and transcriptome analyses, we show that CenH3 was lost independently in at least four lineages of insects. Each of these lineages represents an independent transition from monocentricity (centromeric determinants localized to a single chromosomal region) to holocentricity (centromeric determinants extended over the entire chromosomal length) as ancient as 300 million years ago. Holocentric insects therefore contain a CenH3-independent centromere, different from almost all the other eukaryotes. We propose that ancient transitions to holocentricity in insects obviated the need to maintain CenH3, which is otherwise essential in most eukaryotes, including other holocentrics.

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