On the basis of chromatin condensation
Abstract/Contents
- Abstract
- The basis for the remarkable structural plasticity of chromosomes has been an unresolved question since Flemming's elucidation of mitosis in the late nineteenth century. As the eukaryotic cell prepares for division, its chromatin, dispersed throughout the interphase nucleus, transforms into a set of compact, discrete, cylindrical bodies (chromatids) through which the vertical transmission of genetic information is accomplished. The formation of metaphase chromatids involves three key steps: axialization, lengthwise contraction, and condensation. Axialization has been attributed to the formation of a scaffold, long suspected on the basis of observations of denatured chromosomes and demonstrated here for the first time in native specimens without assumptions as to molecular composition. Lengthwise contraction is likely mediated by the formation of chromatin loops, as recently demonstrated by several groups. Condensation, whose basis has remained obscure, is shown to involve a volume phase transition of the chromosomal gel. The gel nature of the chromosome is rigorously demonstrated through a comparison of condensation behavior with theoretical predictions for polyelectrolyte gels. Finally, the gel nature of the chromosome is exploited to allow direct observation of chromatin fibers within a native context. Analysis of isotropically expanded chromosomes by cryo-electron tomography reveals the trajectories of chromatin fibers, over distances of ten kilobases or more, at subnucleosome resolution. The trajectories are shown to be irregular, with almost no evidence of short- or long-range order.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2021; ©2021 |
| Publication date | 2021; 2021 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Beel, Andrew John |
|---|---|
| Degree supervisor | Kornberg, Roger D |
| Thesis advisor | Kornberg, Roger D |
| Thesis advisor | Geiduschek, Peter |
| Thesis advisor | Levitt, Michael, 1947- |
| Degree committee member | Geiduschek, Peter |
| Degree committee member | Levitt, Michael, 1947- |
| Associated with | Stanford University, Biophysics Program |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Andrew John Beel. |
|---|---|
| Note | Submitted to the Biophysics Program. |
| Thesis | Thesis Ph.D. Stanford University 2021. |
| Location | https://purl.stanford.edu/bt118qq7827 |
Access conditions
- Copyright
- © 2021 by Andrew John Beel
- License
- This work is licensed under a Creative Commons Attribution Non Commercial No Derivatives 3.0 Unported license (CC BY-NC-ND).
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