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Santinello B, Sun R, Amjad A, Hoyt SJ, Ouyang L, Courret C, Drennan R, Leo L, Larracuente AM, Core LM, O’Neill RJ, Mellone BG. A centromere-derived retroelement RNA localizes in cis and is a core element of the transcriptional landscape of Drosophila centromeres. bioRxiv 2024:2024.01.14.574223. [PMID: 38293134 PMCID: PMC10827089 DOI: 10.1101/2024.01.14.574223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Centromeres are essential chromosomal landmarks that dictate the point of attachment between chromosomes and spindle microtubules during cell division. The stable transmission of the centromere site through generations is ensured by a unique chromatin containing the histone H3 variant CENP-A. Previous studies have highlighted the impact of transcription on promoting CENP-A deposition. However, the specific sequences undergoing this transcription and their contribution to centromere function in metazoan systems remain elusive. In this study, we unveil the centromeric transcriptional landscape and explore its correlation with CENP-A in D. melanogaster, currently the only in vivo model with assembled centromeres. We find that the centromere-enriched retroelement G2/Jockey-3 (hereafter referred to as Jockey-3) is a major driver of centromere transcription, producing RNAs that localize to all mitotic centromeres, with the Y centromere showing the most transcription. Taking advantage of the polymorphism of Jockey-3, we show that these RNAs remain associated with their cognate DNA sequences in cis. Using a LacI/lacO system to generate de novo centromeres, we find that Jockey-3 transcripts do not localize to ectopic sites, suggesting they are unlikely to function as non-coding RNAs with a structural role at centromeres. At de novo centromeres on the lacO array, the presence of CENP-A augments the detection of exogenous lacO-derived transcripts specifically in metaphase. We propose that Jockey-3 contributes to the epigenetic maintenance of the centromere by promoting chromatin transcription, while inserting in a region that permits its continuous transmission. Given the conservation of retroelements as centromere components across taxa, our findings have broad implications in understanding this widespread association.
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Affiliation(s)
- B Santinello
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, US
| | - R Sun
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, US
| | - A Amjad
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, US
| | - SJ Hoyt
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, US
| | - L Ouyang
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, US
| | - C Courret
- Department of Biology, University of Rochester, Rochester, NY, US
| | - R Drennan
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, US
| | - L Leo
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, US
- Dipartimento di Biologia e Biotecnologie “Charles Darwin”, “Sapienza” University of Rome, 00185 Rome, Italy
- Present address: RNA editing Lab, Onco-Haematology Department, Genetics and Epigenetics of Pediatric Cancers, Bambino Gesù Children Hospital, IRCCS, 00146 Rome, Italy
| | - AM Larracuente
- Department of Biology, University of Rochester, Rochester, NY, US
| | - LM Core
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, US
- Institute for Systems Genomics, University of Connecticut, Storrs CT, US
| | - RJ O’Neill
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, US
- Institute for Systems Genomics, University of Connecticut, Storrs CT, US
- Department of Genetics and Genome Sciences, UConn Health, Farmington, CT, US
| | - BG Mellone
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT, US
- Institute for Systems Genomics, University of Connecticut, Storrs CT, US
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O’Neill RJ, Cleere EF, Elsafty N, Gaffney R. Zenker’s diverticulitis: a bitter pill to swallow. J Surg Case Rep 2022; 2022:rjac258. [PMID: 35783242 PMCID: PMC9246281 DOI: 10.1093/jscr/rjac258] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 05/16/2022] [Indexed: 01/24/2023] Open
Abstract
Acute oesophageal obstruction from food bolus impaction is often triggered by underlying oesophageal pathology, both benign and malignant. These can be readily detected with standard investigations such as oesophagoscopy or computed tomography. Zenker’s diverticulum (ZD) is a benign condition frequently presenting with chronic dysphagia or may be asymptomatic. We report the case of an 81-year-old man with a previously undiagnosed 1-cm ZD causing complete oesophageal obstruction secondary to localized oedema from an impacted ibuprofen tablet. Although initial clinical, endoscopic and radiological findings were equivocal and suspicious for upper oesophageal malignancy, symptoms rapidly settled in response to systemic corticosteroids. The diagnosis was later confirmed on barium swallow with no other clinical, radiological or histopathological abnormalities identified. In conclusion, ZD is an uncommon cause of acute oesophageal obstruction which may occur in diverticula of all sizes. Surgery should be performed in patients with recurrent symptoms or large diverticula.
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Affiliation(s)
- R J O’Neill
- Beaumont Hospital , Dublin , Ireland
- Royal College of Surgeons , Dublin , Ireland
| | | | - N Elsafty
- Beaumont Hospital , Dublin , Ireland
- Royal College of Surgeons , Dublin , Ireland
| | - R Gaffney
- Beaumont Hospital , Dublin , Ireland
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