Super-resolution in situ analysis of active ribosomal DNA chromatin organization in the nucleolus
Ribosomal RNA (rRNA) transcription by RNA polymerase I (Pol I) is the frst key step of ribosome biogenesis. While the molecular mechanisms of rRNA transcription regulation have been elucidated in great detail, the functional organization of the multicopy rRNA gene clusters (rDNA) in the nucleolus is...
| Main Authors: | , , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
Nature Research
2020
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| _version_ | 1797058929274912768 |
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| author | Maiser, A Dillinger, S Längst, G Schermelleh, L Leonhardt, H Németh, A |
| author_facet | Maiser, A Dillinger, S Längst, G Schermelleh, L Leonhardt, H Németh, A |
| author_sort | Maiser, A |
| collection | OXFORD |
| description | Ribosomal RNA (rRNA) transcription by RNA polymerase I (Pol I) is the frst key step of ribosome
biogenesis. While the molecular mechanisms of rRNA transcription regulation have been elucidated in
great detail, the functional organization of the multicopy rRNA gene clusters (rDNA) in the nucleolus
is less well understood. Here we apply super-resolution 3D structured illumination microscopy (3DSIM) to investigate the spatial organization of transcriptionally competent active rDNA chromatin at
size scales well below the difraction limit by optical microscopy. We identify active rDNA chromatin
units exhibiting uniformly ring-shaped conformations with diameters of ~240nm in mouse and
~170nm in human fbroblasts, consistent with rDNA looping. The active rDNA chromatin units are
clearly separated from each other and from the surrounding areas of rRNA processing. Simultaneous
imaging of all active genes bound by Pol I and the architectural chromatin protein Upstream Binding
Transcription Factor (UBF) reveals a random spatial orientation of regular repeats of rDNA coding
sequences within the nucleoli. These observations imply rDNA looping and exclude potential formation
of systematic spatial assemblies of the well-ordered repetitive arrays of transcription units. Collectively,
this study uncovers key features of the 3D organization of active rDNA chromatin units and their
nucleolar clusters providing a spatial framework of nucleolar chromatin organization at unprecedented
detail. |
| first_indexed | 2024-03-06T19:57:00Z |
| format | Journal article |
| id | oxford-uuid:25f5d03e-64f1-41f8-806a-476a1140d9b7 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T19:57:00Z |
| publishDate | 2020 |
| publisher | Nature Research |
| record_format | dspace |
| spelling | oxford-uuid:25f5d03e-64f1-41f8-806a-476a1140d9b72022-03-26T11:58:23ZSuper-resolution in situ analysis of active ribosomal DNA chromatin organization in the nucleolusJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:25f5d03e-64f1-41f8-806a-476a1140d9b7EnglishSymplectic ElementsNature Research2020Maiser, ADillinger, SLängst, GSchermelleh, LLeonhardt, HNémeth, ARibosomal RNA (rRNA) transcription by RNA polymerase I (Pol I) is the frst key step of ribosome biogenesis. While the molecular mechanisms of rRNA transcription regulation have been elucidated in great detail, the functional organization of the multicopy rRNA gene clusters (rDNA) in the nucleolus is less well understood. Here we apply super-resolution 3D structured illumination microscopy (3DSIM) to investigate the spatial organization of transcriptionally competent active rDNA chromatin at size scales well below the difraction limit by optical microscopy. We identify active rDNA chromatin units exhibiting uniformly ring-shaped conformations with diameters of ~240nm in mouse and ~170nm in human fbroblasts, consistent with rDNA looping. The active rDNA chromatin units are clearly separated from each other and from the surrounding areas of rRNA processing. Simultaneous imaging of all active genes bound by Pol I and the architectural chromatin protein Upstream Binding Transcription Factor (UBF) reveals a random spatial orientation of regular repeats of rDNA coding sequences within the nucleoli. These observations imply rDNA looping and exclude potential formation of systematic spatial assemblies of the well-ordered repetitive arrays of transcription units. Collectively, this study uncovers key features of the 3D organization of active rDNA chromatin units and their nucleolar clusters providing a spatial framework of nucleolar chromatin organization at unprecedented detail. |
| spellingShingle | Maiser, A Dillinger, S Längst, G Schermelleh, L Leonhardt, H Németh, A Super-resolution in situ analysis of active ribosomal DNA chromatin organization in the nucleolus |
| title | Super-resolution in situ analysis of active ribosomal DNA chromatin organization in the nucleolus |
| title_full | Super-resolution in situ analysis of active ribosomal DNA chromatin organization in the nucleolus |
| title_fullStr | Super-resolution in situ analysis of active ribosomal DNA chromatin organization in the nucleolus |
| title_full_unstemmed | Super-resolution in situ analysis of active ribosomal DNA chromatin organization in the nucleolus |
| title_short | Super-resolution in situ analysis of active ribosomal DNA chromatin organization in the nucleolus |
| title_sort | super resolution in situ analysis of active ribosomal dna chromatin organization in the nucleolus |
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