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Shao Z, Hu J, Jandura A, Wilk R, Jachimowicz M, Ma L, Hu C, Sundquist A, Das I, Samuel-Larbi P, Brill JA, Krause HM. Spatially revealed roles for lncRNAs in Drosophila spermatogenesis, Y chromosome function and evolution. Nat Commun 2024; 15:3806. [PMID: 38714658 PMCID: PMC11076287 DOI: 10.1038/s41467-024-47346-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 03/25/2024] [Indexed: 05/10/2024] Open
Abstract
Unlike coding genes, the number of lncRNA genes in organism genomes is relatively proportional to organism complexity. From plants to humans, the tissues with highest numbers and levels of lncRNA gene expression are the male reproductive organs. To learn why, we initiated a genome-wide analysis of Drosophila lncRNA spatial expression patterns in these tissues. The numbers of genes and levels of expression observed greatly exceed those previously reported, due largely to a preponderance of non-polyadenylated transcripts. In stark contrast to coding genes, the highest numbers of lncRNAs expressed are in post-meiotic spermatids. Correlations between expression levels, localization and previously performed genetic analyses indicate high levels of function and requirement. More focused analyses indicate that lncRNAs play major roles in evolution by controlling transposable element activities, Y chromosome gene expression and sperm construction. A new type of lncRNA-based particle found in seminal fluid may also contribute to reproductive outcomes.
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Affiliation(s)
- Zhantao Shao
- Donnelly Ctr., 160 College St., University of Toronto, Toronto, ON, Canada
| | - Jack Hu
- Donnelly Ctr., 160 College St., University of Toronto, Toronto, ON, Canada
| | - Allison Jandura
- Donnelly Ctr., 160 College St., University of Toronto, Toronto, ON, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada
| | - Ronit Wilk
- Donnelly Ctr., 160 College St., University of Toronto, Toronto, ON, Canada
| | - Matthew Jachimowicz
- Donnelly Ctr., 160 College St., University of Toronto, Toronto, ON, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada
| | - Lingfeng Ma
- Donnelly Ctr., 160 College St., University of Toronto, Toronto, ON, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada
| | - Chun Hu
- Donnelly Ctr., 160 College St., University of Toronto, Toronto, ON, Canada
| | - Abby Sundquist
- Donnelly Ctr., 160 College St., University of Toronto, Toronto, ON, Canada
| | - Indrani Das
- Donnelly Ctr., 160 College St., University of Toronto, Toronto, ON, Canada
| | | | - Julie A Brill
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada.
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada.
| | - Henry M Krause
- Donnelly Ctr., 160 College St., University of Toronto, Toronto, ON, Canada.
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada.
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2
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Koestler SA, Ball ML, Muresan L, Dinakaran V, White R. Transcriptionally active chromatin loops contain both 'active' and 'inactive' histone modifications that exhibit exclusivity at the level of nucleosome clusters. Epigenetics Chromatin 2024; 17:8. [PMID: 38528624 DOI: 10.1186/s13072-024-00535-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Accepted: 03/14/2024] [Indexed: 03/27/2024] Open
Abstract
Chromatin state is thought to impart regulatory function to the underlying DNA sequence. This can be established through histone modifications and chromatin organisation, but exactly how these factors relate to one another to regulate gene expression is unclear. In this study, we have used super-resolution microscopy to image the Y loops of Drosophila melanogaster primary spermatocytes, which are enormous transcriptionally active chromatin fibres, each representing single transcription units that are individually resolvable in the nuclear interior. We previously found that the Y loops consist of regular clusters of nucleosomes, with an estimated median of 54 nucleosomes per cluster with wide variation.In this study, we report that the histone modifications H3K4me3, H3K27me3, and H3K36me3 are also clustered along the Y loops, with H3K4me3 more associated with diffuse chromatin compared to H3K27me3. These histone modifications form domains that can be stretches of Y loop chromatin micrometres long, or can be in short alternating domains. The different histone modifications are associated with different sizes of chromatin clusters and unique morphologies. Strikingly, a single chromatin cluster almost always only contains only one type of the histone modifications that were labelled, suggesting exclusivity, and therefore regulation at the level of individual chromatin clusters. The active mark H3K36me3 is more associated with actively elongating RNA polymerase II than H3K27me3, with polymerase often appearing on what are assumed to be looping regions on the periphery of chromatin clusters.These results provide a foundation for understanding the relationship between chromatin state, chromatin organisation, and transcription regulation - with potential implications for pause-release dynamics, splicing complex organisation and chromatin dynamics during polymerase progression along a gene.
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Affiliation(s)
- Stefan A Koestler
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, CB2 3DY, UK
| | - Madeleine L Ball
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, CB2 3DY, UK
| | - Leila Muresan
- Cambridge Advanced Imaging Centre, University of Cambridge, Downing Site, Cambridge, CB2 3DY, UK
| | - Vineet Dinakaran
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, CB2 3DY, UK
| | - Robert White
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, CB2 3DY, UK.
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3
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Ball ML, Koestler SA, Muresan L, Rehman SA, O’Holleran K, White R. The anatomy of transcriptionally active chromatin loops in Drosophila primary spermatocytes using super-resolution microscopy. PLoS Genet 2023; 19:e1010654. [PMID: 36867662 PMCID: PMC10016678 DOI: 10.1371/journal.pgen.1010654] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 03/15/2023] [Accepted: 02/04/2023] [Indexed: 03/04/2023] Open
Abstract
While the biochemistry of gene transcription has been well studied, our understanding of how this process is organised in 3D within the intact nucleus is less well understood. Here we investigate the structure of actively transcribed chromatin and the architecture of its interaction with active RNA polymerase. For this analysis, we have used super-resolution microscopy to image the Drosophila melanogaster Y loops which represent huge, several megabases long, single transcription units. The Y loops provide a particularly amenable model system for transcriptionally active chromatin. We find that, although these transcribed loops are decondensed they are not organised as extended 10nm fibres, but rather they largely consist of chains of nucleosome clusters. The average width of each cluster is around 50nm. We find that foci of active RNA polymerase are generally located off the main fibre axis on the periphery of the nucleosome clusters. Foci of RNA polymerase and nascent transcripts are distributed around the Y loops rather than being clustered in individual transcription factories. However, as the RNA polymerase foci are considerably less prevalent than the nucleosome clusters, the organisation of this active chromatin into chains of nucleosome clusters is unlikely to be determined by the activity of the polymerases transcribing the Y loops. These results provide a foundation for understanding the topological relationship between chromatin and the process of gene transcription.
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Affiliation(s)
- Madeleine L. Ball
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, United Kingdom
| | - Stefan A. Koestler
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, United Kingdom
| | - Leila Muresan
- Cambridge Advanced Imaging Centre, University of Cambridge, Downing Site, Cambridge, United Kingdom
| | - Sohaib Abdul Rehman
- Cambridge Advanced Imaging Centre, University of Cambridge, Downing Site, Cambridge, United Kingdom
| | - Kevin O’Holleran
- Cambridge Advanced Imaging Centre, University of Cambridge, Downing Site, Cambridge, United Kingdom
| | - Robert White
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Site, Cambridge, United Kingdom
- * E-mail:
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4
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Fingerhut JM, Yamashita YM. The regulation and potential functions of intronic satellite DNA. Semin Cell Dev Biol 2022; 128:69-77. [PMID: 35469677 DOI: 10.1016/j.semcdb.2022.04.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 04/11/2022] [Accepted: 04/12/2022] [Indexed: 12/15/2022]
Abstract
Satellite DNAs are arrays of tandem repeats found in the eukaryotic genome. They are mainly found in pericentromeric heterochromatin and have been believed to be mostly inert, leading satellite DNAs to be erroneously regarded as junk. Recent studies have started to elucidate the function of satellite DNA, yet little is known about the peculiar case where satellite DNA is found within the introns of protein coding genes, resulting in incredibly large introns, a phenomenon termed intron gigantism. Studies in Drosophila demonstrated that satellite DNA-containing introns are transcribed with the gene and require specialized mechanisms to overcome the burdens imposed by the extremely long stretches of repetitive DNA. Whether intron gigantism confers any benefit or serves any functional purpose for cells and/or organisms remains elusive. Here we review our current understanding of intron gigantism: where it is found, the challenges it imposes, how it is regulated and what purpose it may serve.
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Affiliation(s)
- Jaclyn M Fingerhut
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA; Howard Hughes Medical Institute, Cambridge, MA, USA.
| | - Yukiko M Yamashita
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA; Howard Hughes Medical Institute, Cambridge, MA, USA.
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5
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Kotov AA, Bazylev SS, Adashev VE, Shatskikh AS, Olenina LV. Drosophila as a Model System for Studying of the Evolution and Functional Specialization of the Y Chromosome. Int J Mol Sci 2022; 23:4184. [PMID: 35457001 PMCID: PMC9031259 DOI: 10.3390/ijms23084184] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/06/2022] [Accepted: 04/07/2022] [Indexed: 02/07/2023] Open
Abstract
The Y chromosome is one of the sex chromosomes found in males of animals of different taxa, including insects and mammals. Among all chromosomes, the Y chromosome is characterized by a unique chromatin landscape undergoing dynamic evolutionary change. Being entirely heterochromatic, the Y chromosome as a rule preserves few functional genes, but is enriched in tandem repeats and transposons. Due to difficulties in the assembly of the highly repetitive Y chromosome sequence, deep analyses of Y chromosome evolution, structure, and functions are limited to a few species, one of them being Drosophila melanogaster. Despite Y chromosomes exhibiting high structural divergence between even closely related species, Y-linked genes have evolved convergently and are mainly associated with spermatogenesis-related activities. This indicates that male-specific selection is a dominant force shaping evolution of Y chromosomes across species. This review presents our analysis of current knowledge concerning Y chromosome functions, focusing on recent findings in Drosophila. Here we dissect the experimental and bioinformatics data about the Y chromosome accumulated to date in Drosophila species, providing comparative analysis with mammals, and discussing the relevance of our analysis to a wide range of eukaryotic organisms, including humans.
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Affiliation(s)
| | | | | | | | - Ludmila V. Olenina
- Institute of Molecular Genetics of National Research Center «Kurchatov Institute», 123182 Moscow, Russia; (A.A.K.); (S.S.B.); (V.E.A.); (A.S.S.)
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6
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Chang CH, Gregory LE, Gordon KE, Meiklejohn CD, Larracuente AM. Unique structure and positive selection promote the rapid divergence of Drosophila Y chromosomes. eLife 2022; 11:e75795. [PMID: 34989337 PMCID: PMC8794474 DOI: 10.7554/elife.75795] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 12/18/2021] [Indexed: 02/06/2023] Open
Abstract
Y chromosomes across diverse species convergently evolve a gene-poor, heterochromatic organization enriched for duplicated genes, LTR retrotransposons, and satellite DNA. Sexual antagonism and a loss of recombination play major roles in the degeneration of young Y chromosomes. However, the processes shaping the evolution of mature, already degenerated Y chromosomes are less well-understood. Because Y chromosomes evolve rapidly, comparisons between closely related species are particularly useful. We generated de novo long-read assemblies complemented with cytological validation to reveal Y chromosome organization in three closely related species of the Drosophila simulans complex, which diverged only 250,000 years ago and share >98% sequence identity. We find these Y chromosomes are divergent in their organization and repetitive DNA composition and discover new Y-linked gene families whose evolution is driven by both positive selection and gene conversion. These Y chromosomes are also enriched for large deletions, suggesting that the repair of double-strand breaks on Y chromosomes may be biased toward microhomology-mediated end joining over canonical non-homologous end-joining. We propose that this repair mechanism contributes to the convergent evolution of Y chromosome organization across organisms.
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Affiliation(s)
- Ching-Ho Chang
- Department of Biology, University of RochesterRochesterUnited States
| | - Lauren E Gregory
- Department of Biology, University of RochesterRochesterUnited States
| | - Kathleen E Gordon
- School of Biological Sciences, University of Nebraska-LincolnLincolnUnited States
| | - Colin D Meiklejohn
- School of Biological Sciences, University of Nebraska-LincolnLincolnUnited States
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7
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Lawlor MA, Cao W, Ellison CE. A transposon expression burst accompanies the activation of Y-chromosome fertility genes during Drosophila spermatogenesis. Nat Commun 2021; 12:6854. [PMID: 34824217 PMCID: PMC8617248 DOI: 10.1038/s41467-021-27136-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 11/04/2021] [Indexed: 11/09/2022] Open
Abstract
Transposable elements (TEs) must replicate in germline cells to pass novel insertions to offspring. In Drosophila melanogaster ovaries, TEs can exploit specific developmental windows of opportunity to evade host silencing and increase their copy numbers. However, TE activity and host silencing in the distinct cell types of Drosophila testis are not well understood. Here, we reanalyze publicly available single-cell RNA-seq datasets to quantify TE expression in the distinct cell types of the Drosophila testis. We develop a method for identification of TE and host gene expression modules and find that a distinct population of early spermatocytes expresses a large number of TEs at much higher levels than other germline and somatic components of the testes. This burst of TE expression coincides with the activation of Y chromosome fertility factors and spermatocyte-specific transcriptional regulators, as well as downregulation of many components of the piRNA pathway. The TEs expressed by this cell population are specifically enriched on the Y chromosome and depleted on the X chromosome, relative to other active TEs. These data suggest that some TEs may achieve high insertional activity in males by exploiting a window of opportunity for mobilization created by the activation of spermatocyte-specific and Y chromosome-specific transcriptional programs.
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Affiliation(s)
- Matthew A Lawlor
- Department of Genetics, Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ, USA
| | - Weihuan Cao
- Department of Genetics, Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ, USA
| | - Christopher E Ellison
- Department of Genetics, Human Genetics Institute of New Jersey, Rutgers University, Piscataway, NJ, USA.
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8
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Zhu L, Fukunaga R. RNA-binding protein Maca is crucial for gigantic male fertility factor gene expression, spermatogenesis, and male fertility, in Drosophila. PLoS Genet 2021; 17:e1009655. [PMID: 34181646 PMCID: PMC8248703 DOI: 10.1371/journal.pgen.1009655] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 07/01/2021] [Accepted: 06/09/2021] [Indexed: 11/19/2022] Open
Abstract
During spermatogenesis, the process in which sperm for fertilization are produced from germline cells, gene expression is spatiotemporally highly regulated. In Drosophila, successful expression of extremely large male fertility factor genes on Y-chromosome spanning some megabases due to their gigantic intron sizes is crucial for spermatogenesis. Expression of such extremely large genes must be challenging, but the molecular mechanism that allows it remains unknown. Here we report that a novel RNA-binding protein Maca, which contains two RNA-recognition motifs, is crucial for this process. maca null mutant male flies exhibited a failure in the spermatid individualization process during spermatogenesis, lacked mature sperm, and were completely sterile, while maca mutant female flies were fully fertile. Proteomics and transcriptome analyses revealed that both protein and mRNA abundance of the gigantic male fertility factor genes kl-2, kl-3, and kl-5 (kl genes) are significantly decreased, where the decreases of kl-2 are particularly dramatic, in maca mutant testes. Splicing of the kl-3 transcripts was also dysregulated in maca mutant testes. All these physiological and molecular phenotypes were rescued by a maca transgene in the maca mutant background. Furthermore, we found that in the control genetic background, Maca is exclusively expressed in spermatocytes in testes and enriched at Y-loop A/C in the nucleus, where the kl-5 primary transcripts are localized. Our data suggest that Maca increases transcription processivity, promotes successful splicing of gigantic introns, and/or protects transcripts from premature degradation, of the kl genes. Our study identified a novel RNA-binding protein Maca that is crucial for successful expression of the gigantic male fertility factor genes, spermatogenesis, and male fertility.
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Affiliation(s)
- Li Zhu
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Ryuya Fukunaga
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- * E-mail:
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9
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Mahadevaraju S, Fear JM, Akeju M, Galletta BJ, Pinheiro MMLS, Avelino CC, Cabral-de-Mello DC, Conlon K, Dell'Orso S, Demere Z, Mansuria K, Mendonça CA, Palacios-Gimenez OM, Ross E, Savery M, Yu K, Smith HE, Sartorelli V, Yang H, Rusan NM, Vibranovski MD, Matunis E, Oliver B. Dynamic sex chromosome expression in Drosophila male germ cells. Nat Commun 2021; 12:892. [PMID: 33563972 PMCID: PMC7873209 DOI: 10.1038/s41467-021-20897-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 12/22/2020] [Indexed: 01/30/2023] Open
Abstract
Given their copy number differences and unique modes of inheritance, the evolved gene content and expression of sex chromosomes is unusual. In many organisms the X and Y chromosomes are inactivated in spermatocytes, possibly as a defense mechanism against insertions into unpaired chromatin. In addition to current sex chromosomes, Drosophila has a small gene-poor X-chromosome relic (4th) that re-acquired autosomal status. Here we use single cell RNA-Seq on fly larvae to demonstrate that the single X and pair of 4th chromosomes are specifically inactivated in primary spermatocytes, based on measuring all genes or a set of broadly expressed genes in testis we identified. In contrast, genes on the single Y chromosome become maximally active in primary spermatocytes. Reduced X transcript levels are due to failed activation of RNA-Polymerase-II by phosphorylation of Serine 2 and 5.
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Affiliation(s)
- Sharvani Mahadevaraju
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Kidney and Digestive Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Justin M Fear
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Kidney and Digestive Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Miriam Akeju
- Department of Cell Biology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD, 21205, USA
| | - Brian J Galletta
- Cell Biology and Physiology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Mara M L S Pinheiro
- Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of São Paulo, SP 05508-090, São Paulo, Brazil
| | - Camila C Avelino
- Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of São Paulo, SP 05508-090, São Paulo, Brazil
| | - Diogo C Cabral-de-Mello
- Instituto de Biociências/IB, Departamento de Biologia Geral e Aplicada, UNESP-Universidade Estadual Paulista, Rio Claro, São Paulo, 13506-900, Brazil
| | - Katie Conlon
- Department of Cell Biology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD, 21205, USA
| | - Stafania Dell'Orso
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Zelalem Demere
- Department of Cell Biology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD, 21205, USA
| | - Kush Mansuria
- Department of Cell Biology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD, 21205, USA
| | - Carolina A Mendonça
- Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of São Paulo, SP 05508-090, São Paulo, Brazil
| | - Octavio M Palacios-Gimenez
- Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of São Paulo, SP 05508-090, São Paulo, Brazil
- Department of Evolutionary Biology and Department of Organismal Biology, Systematic Biology, Evolutionary Biology Centre, Uppsala University, 75236, Uppsala, Sweden
| | - Eli Ross
- Department of Cell Biology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD, 21205, USA
| | - Max Savery
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Kidney and Digestive Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Kevin Yu
- Department of Cell Biology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD, 21205, USA
| | - Harold E Smith
- Genomics Core, National Institute of Diabetes and Kidney and Digestive Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Vittorio Sartorelli
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Haiwang Yang
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Kidney and Digestive Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Nasser M Rusan
- Cell Biology and Physiology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Maria D Vibranovski
- Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of São Paulo, SP 05508-090, São Paulo, Brazil
| | - Erika Matunis
- Department of Cell Biology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD, 21205, USA
| | - Brian Oliver
- Laboratory of Cellular and Developmental Biology, National Institute of Diabetes and Kidney and Digestive Diseases, National Institutes of Health, Bethesda, MD, 20892, USA.
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10
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Satellite DNA-containing gigantic introns in a unique gene expression program during Drosophila spermatogenesis. PLoS Genet 2019; 15:e1008028. [PMID: 31071079 PMCID: PMC6508621 DOI: 10.1371/journal.pgen.1008028] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 02/18/2019] [Indexed: 11/19/2022] Open
Abstract
Intron gigantism, where genes contain megabase-sized introns, is observed across species, yet little is known about its purpose or regulation. Here we identify a unique gene expression program utilized for the proper expression of genes with intron gigantism. We find that two Drosophila genes with intron gigantism, kl-3 and kl-5, are transcribed in a spatiotemporal manner over the course of spermatocyte differentiation, which spans ~90 hours. The introns of these genes contain megabases of simple satellite DNA repeats that comprise over 99% of the gene loci, and these satellite-DNA containing introns are transcribed. We identify two RNA-binding proteins that specifically localize to kl-3 and kl-5 transcripts and are needed for the successful transcription or processing of these genes. We propose that genes with intron gigantism require a unique gene expression program, which may serve as a platform to regulate gene expression during cellular differentiation. Introns are non-coding elements of eukaryotic genes, often containing important regulatory sequences. Curiously, some genes contain introns so large that more than 99% of the gene locus is non-coding. One of the best-studied large genes, Dystrophin, a causative gene for Duchenne Muscular Dystrophy, spans 2.2Mb, only 11kb of which is coding. This phenomenon, ‘intron gigantism’, is observed across species, yet little is known about its purpose or regulation. Here we identify a unique gene expression program utilized for the proper expression of genes with intron gigantism using Drosophila spermatogenic genes as a model system. We show that the gigantic introns of these genes are transcribed in line with the exons, likely as a single transcript. We identify two RNA-binding proteins that specifically localize to the site of transcription and are needed for the successful transcription or processing of these genes. We propose that genes with intron gigantism require a unique gene expression program, which may serve as a platform to regulate gene expression during cellular differentiation.
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11
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Subcellular Specialization and Organelle Behavior in Germ Cells. Genetics 2018; 208:19-51. [PMID: 29301947 DOI: 10.1534/genetics.117.300184] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Accepted: 08/17/2017] [Indexed: 11/18/2022] Open
Abstract
Gametes, eggs and sperm, are the highly specialized cell types on which the development of new life solely depends. Although all cells share essential organelles, such as the ER (endoplasmic reticulum), Golgi, mitochondria, and centrosomes, germ cells display unique regulation and behavior of organelles during gametogenesis. These germ cell-specific functions of organelles serve critical roles in successful gamete production. In this chapter, I will review the behaviors and roles of organelles during germ cell differentiation.
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12
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The Germline Linker Histone dBigH1 and the Translational Regulator Bam Form a Repressor Loop Essential for Male Germ Stem Cell Differentiation. Cell Rep 2018; 21:3178-3189. [PMID: 29241545 DOI: 10.1016/j.celrep.2017.11.060] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 08/31/2017] [Accepted: 11/15/2017] [Indexed: 12/13/2022] Open
Abstract
Drosophila spermatogenesis constitutes a paradigmatic system to study maintenance, proliferation, and differentiation of adult stem cell lineages. Each Drosophila testis contains 6-12 germ stem cells (GSCs) that divide asymmetrically to produce gonialblast cells that undergo four transit-amplifying (TA) spermatogonial divisions before entering spermatocyte differentiation. Mechanisms governing these crucial transitions are not fully understood. Here, we report the essential role of the germline linker histone dBigH1 during early spermatogenesis. Our results suggest that dBigH1 is a general silencing factor that represses Bam, a key regulator of spermatogonia proliferation that is silenced in spermatocytes. Reciprocally, Bam represses dBigH1 during TA divisions. This double-repressor mechanism switches dBigH1/Bam expression from off/on in spermatogonia to on/off in spermatocytes, regulating progression into spermatocyte differentiation. dBigH1 is also required for GSC maintenance and differentiation. These results show the critical importance of germline H1s for male GSC lineage differentiation, unveiling a regulatory interaction that couples transcriptional and translational repression.
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13
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Lakhotia SC. Non-coding RNAs demystify constitutive heterochromatin as essential modulator of epigenotype. THE NUCLEUS 2017. [DOI: 10.1007/s13237-017-0221-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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14
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Lowe N, Rees JS, Roote J, Ryder E, Armean IM, Johnson G, Drummond E, Spriggs H, Drummond J, Magbanua JP, Naylor H, Sanson B, Bastock R, Huelsmann S, Trovisco V, Landgraf M, Knowles-Barley S, Armstrong JD, White-Cooper H, Hansen C, Phillips RG, Lilley KS, Russell S, St Johnston D. Analysis of the expression patterns, subcellular localisations and interaction partners of Drosophila proteins using a pigP protein trap library. Development 2014; 141:3994-4005. [PMID: 25294943 PMCID: PMC4197710 DOI: 10.1242/dev.111054] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 08/13/2014] [Indexed: 01/01/2023]
Abstract
Although we now have a wealth of information on the transcription patterns of all the genes in the Drosophila genome, much less is known about the properties of the encoded proteins. To provide information on the expression patterns and subcellular localisations of many proteins in parallel, we have performed a large-scale protein trap screen using a hybrid piggyBac vector carrying an artificial exon encoding yellow fluorescent protein (YFP) and protein affinity tags. From screening 41 million embryos, we recovered 616 verified independent YFP-positive lines representing protein traps in 374 genes, two-thirds of which had not been tagged in previous P element protein trap screens. Over 20 different research groups then characterized the expression patterns of the tagged proteins in a variety of tissues and at several developmental stages. In parallel, we purified many of the tagged proteins from embryos using the affinity tags and identified co-purifying proteins by mass spectrometry. The fly stocks are publicly available through the Kyoto Drosophila Genetics Resource Center. All our data are available via an open access database (Flannotator), which provides comprehensive information on the expression patterns, subcellular localisations and in vivo interaction partners of the trapped proteins. Our resource substantially increases the number of available protein traps in Drosophila and identifies new markers for cellular organelles and structures.
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Affiliation(s)
- Nick Lowe
- The Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | - Johanna S Rees
- The Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK The Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
| | - John Roote
- The Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
| | - Ed Ryder
- The Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
| | - Irina M Armean
- The Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
| | - Glynnis Johnson
- The Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
| | - Emma Drummond
- The Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
| | - Helen Spriggs
- The Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
| | - Jenny Drummond
- The Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
| | - Jose P Magbanua
- The Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
| | - Huw Naylor
- The Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
| | - Bénédicte Sanson
- The Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
| | - Rebecca Bastock
- The Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | - Sven Huelsmann
- The Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | - Vitor Trovisco
- The Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
| | - Matthias Landgraf
- The Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
| | - Seymour Knowles-Barley
- Institute for Adaptive and Neural Computation, University of Edinburgh, 10 Crichton Street, Edinburgh EH8 9AB, UK
| | - J Douglas Armstrong
- Institute for Adaptive and Neural Computation, University of Edinburgh, 10 Crichton Street, Edinburgh EH8 9AB, UK
| | - Helen White-Cooper
- Cardiff School of Biosciences, The Sir Martin Evans Building, Museum Avenue, Cardiff CF10 3AX, UK
| | - Celia Hansen
- Department of Genetics, University of Leicester, Adrian Building, University Road, Leicester LE1 7RH, UK
| | - Roger G Phillips
- Centre for Advanced Microscopy, University of Sussex, School of Life Sciences, John Maynard Smith Building, Falmer, Brighton and Hove BN1 9QG, UK
| | - Kathryn S Lilley
- The Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QR, UK
| | - Steven Russell
- The Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
| | - Daniel St Johnston
- The Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge CB2 1QN, UK
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15
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El-Sharnouby S, Redhouse J, White RAH. Genome-wide and cell-specific epigenetic analysis challenges the role of polycomb in Drosophila spermatogenesis. PLoS Genet 2013; 9:e1003842. [PMID: 24146626 PMCID: PMC3798269 DOI: 10.1371/journal.pgen.1003842] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Accepted: 08/15/2013] [Indexed: 11/19/2022] Open
Abstract
The Drosophila spermatogenesis cell differentiation pathway involves the activation of a large set of genes in primary spermatocytes. Most of these genes are activated by testis-specific TATA-binding protein associated factors (tTAFs). In the current model for the activation mechanism, Polycomb plays a key role silencing these genes in the germline precursors, and tTAF-dependent activation in primary spermatocytes involves the displacement of Polycomb from gene promoters. We investigated the genome-wide binding of Polycomb in wild type and tTAF mutant testes. According to the model we expected to see a clear enhancement in Polycomb binding at tTAF-dependent spermatogenesis genes in tTAF mutant testes. However, we find little evidence for such an enhancement in tTAF mutant testes compared to wild type. To avoid problems arising from cellular heterogeneity in whole testis analysis, we further tested the model by analysing Polycomb binding in purified germline precursors, representing cells before tTAF-dependent gene activation. Although we find Polycomb associated with its canonical targets, we find little or no evidence of Polycomb at spermatogenesis genes. The lack of Polycomb at tTAF-dependent spermatogenesis genes in precursor cells argues against a model where Polycomb displacement is the mechanism of spermatogenesis gene activation.
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Affiliation(s)
- Sherif El-Sharnouby
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Juliet Redhouse
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Robert A. H. White
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
- * E-mail:
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