Imaging the dynamics of transcription loops in living chromosomes
When in the lampbrush configuration chromosomes display thousands of visible DNA loops that are transcribed at exceptionally high rates by RNA polymerase II (pol II). These transcription loops provide unique opportunities to investigate not only the detailed architecture of pol II transcription site...
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| Format: | Article |
| Language: | English |
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Springer
2018
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| Online Access: | https://eprints.nottingham.ac.uk/50672/ |
| _version_ | 1848798311084982272 |
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| author | Morgan, Gary T. |
| author_facet | Morgan, Gary T. |
| author_sort | Morgan, Gary T. |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | When in the lampbrush configuration chromosomes display thousands of visible DNA loops that are transcribed at exceptionally high rates by RNA polymerase II (pol II). These transcription loops provide unique opportunities to investigate not only the detailed architecture of pol II transcription sites but also the structural dynamics of chromosome looping, which is receiving fresh attention as the organizational principle underpinning the higher order structure of all chromosome states. The approach described here allows for extended imaging of individual transcription loops and transcription units under conditions in which loop RNA synthesis continues. In intact nuclei from lampbrush-stage Xenopus oocytes isolated under mineral oil, highly-specific targeting of fluorescent fusions of the RNA-binding protein CELF1 to nascent transcripts allowed functional transcription loops to be observed and their longevity assessed over time. Some individual loops remained extended and essentially static structures over time courses of up to an hour. However others were less stable and shrank markedly over periods of 30-60 minutes in a manner that suggested loop extension requires continued dense coverage with nascent transcripts. In stable loops and loop-derived structures the molecular dynamics of the visible nascent RNP component were addressed using photokinetic approaches. The results suggested that CELF1 exchanges freely between the accumulated nascent RNP and the surrounding nucleoplasm, and that it exits RNP with similar kinetics to its entrance. Overall it appears that on transcription loops nascent transcripts contribute to a dynamic self-organizing structure that exemplifies a phase-separated nuclear compartment. |
| first_indexed | 2025-11-14T20:17:45Z |
| format | Article |
| id | nottingham-50672 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T20:17:45Z |
| publishDate | 2018 |
| publisher | Springer |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-506722018-04-14T12:45:57Z https://eprints.nottingham.ac.uk/50672/ Imaging the dynamics of transcription loops in living chromosomes Morgan, Gary T. When in the lampbrush configuration chromosomes display thousands of visible DNA loops that are transcribed at exceptionally high rates by RNA polymerase II (pol II). These transcription loops provide unique opportunities to investigate not only the detailed architecture of pol II transcription sites but also the structural dynamics of chromosome looping, which is receiving fresh attention as the organizational principle underpinning the higher order structure of all chromosome states. The approach described here allows for extended imaging of individual transcription loops and transcription units under conditions in which loop RNA synthesis continues. In intact nuclei from lampbrush-stage Xenopus oocytes isolated under mineral oil, highly-specific targeting of fluorescent fusions of the RNA-binding protein CELF1 to nascent transcripts allowed functional transcription loops to be observed and their longevity assessed over time. Some individual loops remained extended and essentially static structures over time courses of up to an hour. However others were less stable and shrank markedly over periods of 30-60 minutes in a manner that suggested loop extension requires continued dense coverage with nascent transcripts. In stable loops and loop-derived structures the molecular dynamics of the visible nascent RNP component were addressed using photokinetic approaches. The results suggested that CELF1 exchanges freely between the accumulated nascent RNP and the surrounding nucleoplasm, and that it exits RNP with similar kinetics to its entrance. Overall it appears that on transcription loops nascent transcripts contribute to a dynamic self-organizing structure that exemplifies a phase-separated nuclear compartment. Springer 2018-04-03 Article PeerReviewed application/pdf en cc_by https://eprints.nottingham.ac.uk/50672/9/s00412-018-0667-8.pdf Morgan, Gary T. (2018) Imaging the dynamics of transcription loops in living chromosomes. Chromosoma . ISSN 1432-0886 Lampbrush chromosomes; CELF1; Nascent RNP; Transcription unit; Nuclear compartment https://link.springer.com/article/10.1007%2Fs00412-018-0667-8 doi:10.1007/s00412-018-0667-8 doi:10.1007/s00412-018-0667-8 |
| spellingShingle | Lampbrush chromosomes; CELF1; Nascent RNP; Transcription unit; Nuclear compartment Morgan, Gary T. Imaging the dynamics of transcription loops in living chromosomes |
| title | Imaging the dynamics of transcription loops in living chromosomes |
| title_full | Imaging the dynamics of transcription loops in living chromosomes |
| title_fullStr | Imaging the dynamics of transcription loops in living chromosomes |
| title_full_unstemmed | Imaging the dynamics of transcription loops in living chromosomes |
| title_short | Imaging the dynamics of transcription loops in living chromosomes |
| title_sort | imaging the dynamics of transcription loops in living chromosomes |
| topic | Lampbrush chromosomes; CELF1; Nascent RNP; Transcription unit; Nuclear compartment |
| url | https://eprints.nottingham.ac.uk/50672/ https://eprints.nottingham.ac.uk/50672/ https://eprints.nottingham.ac.uk/50672/ |