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Articles 1 - 8 of 8
Full-Text Articles in Life Sciences
The Role Of Centromeric Chromatin And Kinetochore-Associated Factors In Chromosome Segregation, Wesley Williamson
The Role Of Centromeric Chromatin And Kinetochore-Associated Factors In Chromosome Segregation, Wesley Williamson
Graduate Theses and Dissertations
Previous work in our lab has identified a point mutation in HTA1, one of the genes encoding histone H2A, which causes an increase-in-ploidy phenotype in Saccharomyces cerevisiae. This histone mutant strain was used to carry out a transposon insertion screen to identify suppressors of the increase-in-ploidy phenotype. This screen identified all three subunits of the Hda histone deacetylase complex, HDA1, HDA2, and HDA3. This study aims to elucidate the function of the Hda complex in chromosome segregation by exploring interactions among the members of the complex, as well as interactions between Hda complex and kinetochore components. …
Controls Of Nucleosome Positioning In The Human Genome, Daniel J. Gaffney, Graham Mcvicker, Athma A. Pai, Yvonne N. Fondufe-Mittendorf, Noah Lewellen, Katelyn Michelini, Jonathan Widom, Yoav Gilad, Jonathan K. Pritchard
Controls Of Nucleosome Positioning In The Human Genome, Daniel J. Gaffney, Graham Mcvicker, Athma A. Pai, Yvonne N. Fondufe-Mittendorf, Noah Lewellen, Katelyn Michelini, Jonathan Widom, Yoav Gilad, Jonathan K. Pritchard
Molecular and Cellular Biochemistry Faculty Publications
Nucleosomes are important for gene regulation because their arrangement on the genome can control which proteins bind to DNA. Currently, few human nucleosomes are thought to be consistently positioned across cells; however, this has been difficult to assess due to the limited resolution of existing data. We performed paired-end sequencing of micrococcal nuclease-digested chromatin (MNase-seq) from seven lymphoblastoid cell lines and mapped over 3.6 billion MNase-seq fragments to the human genome to create the highest-resolution map of nucleosome occupancy to date in a human cell type. In contrast to previous results, we find that most nucleosomes have more consistent positioning …
Condensin Ii Promotes The Formation Of Chromosome Territories By Inducing Axial Compaction Of Polyploid Interphase Chromosomes, Christopher R. R. Bauer, Tom A. Hartl, Giovanni Bosco
Condensin Ii Promotes The Formation Of Chromosome Territories By Inducing Axial Compaction Of Polyploid Interphase Chromosomes, Christopher R. R. Bauer, Tom A. Hartl, Giovanni Bosco
Dartmouth Scholarship
The eukaryotic nucleus is both spatially and functionally partitioned. This organization contributes to the maintenance, expression, and transmission of genetic information. Though our ability to probe the physical structure of the genome within the nucleus has improved substantially in recent years, relatively little is known about the factors that regulate its organization or the mechanisms through which specific organizational states are achieved. Here, we show that Drosophila melanogaster Condensin II induces axial compaction of interphase chromosomes, globally disrupts interchromosomal interactions, and promotes the dispersal of peri-centric heterochromatin. These Condensin II activities compartmentalize the nucleus into discrete chromosome territories and indicate …
Mecp2 Binds To Nucleosome Free (Linker Dna) Regions And To H3k9/H3k27 Methylated Nucleosomes In The Brain, Anita A. Thambirajah, Marlee K. Ng, Lindsay J. Frehlick, Andra Li, Jason J. Serpa, Evgeniy V. Petrotchenko, Begonia Silva-Moreno, Kristal K. Missiaen, Christoph H. Borchers, J. Adam Hall, Ryan Mackie, Frank Lutz, Brent E. Gowen, Michael Hendzel, Philippe T. Georgel, Juan Ausió
Mecp2 Binds To Nucleosome Free (Linker Dna) Regions And To H3k9/H3k27 Methylated Nucleosomes In The Brain, Anita A. Thambirajah, Marlee K. Ng, Lindsay J. Frehlick, Andra Li, Jason J. Serpa, Evgeniy V. Petrotchenko, Begonia Silva-Moreno, Kristal K. Missiaen, Christoph H. Borchers, J. Adam Hall, Ryan Mackie, Frank Lutz, Brent E. Gowen, Michael Hendzel, Philippe T. Georgel, Juan Ausió
Biological Sciences Faculty Research
Methyl-CpG-binding protein 2 (MeCP2) is a chromatin-binding protein that mediates transcriptional regulation, and is highly abundant in brain. The nature of its binding to reconstituted templates has been well characterized in vitro. However, its interactions with native chromatin are less understood. Here we show that MeCP2 displays a distinct distribution within fractionated chromatin from various tissues and cell types. Artificially induced global changes in DNA methylation by 3-aminobenzamide or 5-aza-2′-deoxycytidine, do not significantly affect the distribution or amount of MeCP2 in HeLa S3 or 3T3 cells. Most MeCP2 in brain is chromatin-bound and localized within highly nuclease-accessible regions. We …
Examination Of The Chromatin Structure Of Xlr3b Using The Chromosome Conformation Capture Assay, Sarah Elise Conderino
Examination Of The Chromatin Structure Of Xlr3b Using The Chromosome Conformation Capture Assay, Sarah Elise Conderino
Honors Scholar Theses
Imprinted genes contain epigenetic modifications that influence expression patterns based on parent-of-origin. Recent studies have shown that imprinted genes contribute to numerous human diseases and disorders. Xlr3b, an imprinted gene on the X chromosome, has been implicated in social and behavioral deficits characteristic of disorders such as Turner syndrome and autism. The imprinting mechanism of this gene is still unknown, and this study analyzed the native chromatin structure of Xlr3b through the chromosome conformation capture assay to determine if there are any long-range interactions that regulate the expression of this gene. Brain tissue from a mouse model of Turner …
Characterization Of Novel Histone H2b Mutants Associated With Chromosome Segregation Defects In Saccharomyces Cerevisiae, Thiruchelvam Rajagopal
Characterization Of Novel Histone H2b Mutants Associated With Chromosome Segregation Defects In Saccharomyces Cerevisiae, Thiruchelvam Rajagopal
Graduate Theses and Dissertations
Histones are small basic proteins that associate with DNA to form the basic unit of chromatin, the nucleosome. Histones H3 and H4 form a tetramer that is bound by two H2A-H2B dimers to form the histone octamer, to which approximately 146 bp of DNA wrap around to form the nucleosome. High resolution structural information and recent advances in the understanding of histone post-translational modifications have illuminated the many regulatory functions chromatin exerts in the cell, from the transcriptional control of gene expression to chromosome segregation. However, the specific role that histones play in these processes is not well understood. Previous …
Dissecting Mammalian Replication-Independent Chromatin Assembly €“ Biochemical And Structural Studies On The H3.3-Specific Histone Chaperones Hira And Daxx, Simon Elsässer
Student Theses and Dissertations
Histones are architectural proteins that wrap approximately two turns of DNA around their octameric core structure, constituting the fundamental packaging unit of eukaryotic chromatin – the nucleosome. Beyond their structural role, they regulate virtually all processes that act on or depend on DNA, such as replication, gene expression and maintenance of centromeres and telomeres. Despite the high conservation of the four core histones, H3, H4, H2A and H2B, throughout all eukaryotes, histone variants have emerged with variable degree of divergence from their canonical counterparts. These variants are thought to expand the regulatory repertoire of chromatin. The histone replacement variant H3.3 …
The Role Of Chromatin And Cofactors In The Transcriptional Memory Effect Exerted In Saccharomyces Cerevisiae, Emily Leigh Paul
The Role Of Chromatin And Cofactors In The Transcriptional Memory Effect Exerted In Saccharomyces Cerevisiae, Emily Leigh Paul
Legacy Theses & Dissertations (2009 - 2024)
Abf1 and Rap1 are functionally similar general regulatory factors (GRFs) found in Saccharomyces cerevisiae . Abf1, in its role as a transcriptional activator, exerts a memory effect on some genes under its control. This effect results in transcription levels remaining steady when Abf1 dissociates from its binding site in a conditional mutant. In contrast, Rap1 fails to elicit the same effect on its regulatory targets. Transcriptional memory effects have been observed in many fields of study, including immunology, cancer, and stem cells, and conservation of transcription machinery will allow studies in yeast to be applied to higher organisms.