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Updated: Jun 15, 2026
08:49
A Multilabel Single Molecule Localization Microscopy Protocol for Investigation of Chromatin in the Dense Nuclear Environment
Published on: June 5, 2026
Positional variations among heterogeneous nucleosome maps give dynamical information on chromatin
Yoshiaki Tanaka1, Itsuki Yoshimura, Kenta Nakai
1Department of Medical Genome Sciences, University of Tokyo, Minato-ku, Japan.
Chromosoma
|March 13, 2010
Summary
This study maps genome-wide nucleosome remodeling in yeast using existing data. Higher variability in nucleosome positioning correlates with gene expression variety, offering insights into transcriptional regulation.
Area of Science:
- Molecular Biology
- Genetics
- Epigenetics
Background:
- Nucleosome remodeling is crucial for eukaryotic gene transcription.
- Genome-wide understanding of nucleosome remodeling dynamics remains limited.
- Recent advancements in nucleosome positioning mapping provide new opportunities.
Purpose of the Study:
- To develop a genome-wide profile of nucleosome remodeling by analyzing existing yeast nucleosome positioning maps.
- To investigate the relationship between nucleosome dynamics, transcription factor binding, and gene expression.
- To explore correlations between nucleosome dynamics, gene function, and histone modifications.
Main Methods:
- Comparative analysis of seven yeast nucleosome positioning maps.
- Calculation of local nucleosome variability using entropy.
- Quantification of linker DNA length (linker ratio).
- Correlation analysis between nucleosome dynamics and gene expression, function, and histone modification data.
Main Results:
- Significantly higher nucleosome variability (entropy) was observed in reported unstable nucleosomes.
- Transcription factor binding sites associated with remodeling factors showed high entropy and linker ratio.
- Binding sites of Yhp1, a potential inhibitor, exhibited the lowest entropy and linker ratio.
- A novel 'nucleosome dynamics' map correlated with the degree of expression variety, not intensity.
Conclusions:
- The developed map effectively represents genome-wide nucleosome dynamics.
- Nucleosome remodeling and dynamics are strongly linked to the variability of gene expression.
- This approach offers a valuable tool for studying transcriptional regulation and epigenetic modifications.
Related Concept Videos
02:32Position-effect Variegation
In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread out in the interphase nucleus, others do not. He termed them euchromatin and heterochromatin, respectively. He proposed that the heterochromatin regions reflect a functionally inactive state of the genome. It was later confirmed that heterochromatin is transcriptionally repressed, and euchromatin is transcriptionally active chromatin.
02:54Nucleosome Remodeling
Nucleosomes are the basic units of chromatin compaction. Each nucleosome consists of the DNA bound tightly around a histone core, which makes the DNA inaccessible to DNA binding proteins such as DNA polymerase and RNA polymerase. Hence, the fundamental problem is to ensure access to DNA when appropriate, despite the compact and protective chromatin structure.
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
02:35Chromatin Position Affects Gene Expression
Chromatin is the massive complex of DNA and proteins packaged inside the nucleus. The complexity of chromatin folding and how it is packaged inside the nucleus greatly influences access to genetic information. Generally, the nucleus' periphery is considered transcriptionally repressive, while the cell's interior is considered a transcriptionally active area.
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01:12The Nucleosome Core Particle
Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins.
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during...
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during...
02:10The Nucleosome Core Particle
Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins.
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Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...
The paradox
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...
02:38Heterochromatin
The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions that take up more dye are called heterochromatin. Heterochromatin is further classified into two forms – constitutive heterochromatin and facultative heterochromatin.
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th...
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th...