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Mahadevaraju S, Pal S, Bhaskar P, McDonald BD, Benner L, Denti L, Cozzi D, Bonizzoni P, Przytycka TM, Oliver B. Diverse somatic Transformer and sex chromosome karyotype pathways regulate gene expression in Drosophila gonad development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.12.607556. [PMID: 39372789 PMCID: PMC11451611 DOI: 10.1101/2024.08.12.607556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/08/2024]
Abstract
The somatic sex determination gene transformer (tra) is required for the highly sexually dimorphic development of most somatic cells, including those of the gonads. In addition, somatic tra is required for the germline development even though it is not required for sex determination within germ cells. Germ cell autonomous gene expression is also necessary for their sex determination. To understand the interplay between these signals, we compared the phenotype and gene expression of larval wild-type gonads and the sex-transformed tra gonads. XX larval ovaries transformed into testes were dramatically smaller than wild-type, with significant reductions in germ cell number, likely due to altered geometry of the stem cell niche. Additionally, there was a defect in progression into spermatocyte stages. XY larval testes transformed into ovaries had excessive germ cells, possibly due to the earlier onset of cell division. We suggest that germ cells are neither fully female nor male following somatic sex transformation, with certain pathways characteristic of each sex expressed in tra mutants. We found multiple patterns of somatic and germline gene expression control exclusively due to tra, exclusively due to sex chromosome karyotype, but usually due to a combination of these factors showing tra and sex chromosome karyotype pathways regulate gene expression during Drosophila gonad development.
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Affiliation(s)
- Sharvani Mahadevaraju
- Section of Developmental Genomics, Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
- Department of Biology. St. Mary’s College of Maryland, St. Mary’s City, Maryland, USA
| | - Soumitra Pal
- National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
- Neurobiology Neurodegeneration and Repair Lab, National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Pradeep Bhaskar
- Section of Developmental Genomics, Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Brennan D. McDonald
- Section of Developmental Genomics, Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
- Department of Biology, Stanford University, Stanford, California, USA
| | - Leif Benner
- Section of Developmental Genomics, Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Luca Denti
- Department of Informatics, Systems, and Communication, University of Milano - Bicocca, Milan, Italy
| | - Davide Cozzi
- Department of Informatics, Systems, and Communication, University of Milano - Bicocca, Milan, Italy
| | - Paola Bonizzoni
- Department of Informatics, Systems, and Communication, University of Milano - Bicocca, Milan, Italy
| | - Teresa M. Przytycka
- National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - Brian Oliver
- Section of Developmental Genomics, Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
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Kotb NM, Ulukaya G, Chavan A, Nguyen SC, Proskauer L, Joyce EF, Hasson D, Jagannathan M, Rangan P. Genome organization regulates nuclear pore complex formation and promotes differentiation during Drosophila oogenesis. Genes Dev 2024; 38:436-454. [PMID: 38866556 PMCID: PMC11216175 DOI: 10.1101/gad.351402.123] [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: 12/10/2023] [Accepted: 05/21/2024] [Indexed: 06/14/2024]
Abstract
Genome organization can regulate gene expression and promote cell fate transitions. The differentiation of germline stem cells (GSCs) to oocytes in Drosophila involves changes in genome organization mediated by heterochromatin and the nuclear pore complex (NPC). Heterochromatin represses germ cell genes during differentiation, and NPCs anchor these silenced genes to the nuclear periphery, maintaining silencing to allow for oocyte development. Surprisingly, we found that genome organization also contributes to NPC formation, mediated by the transcription factor Stonewall (Stwl). As GSCs differentiate, Stwl accumulates at boundaries between silenced and active gene compartments. Stwl at these boundaries plays a pivotal role in transitioning germ cell genes into a silenced state and activating a group of oocyte genes and nucleoporins (Nups). The upregulation of these Nups during differentiation is crucial for NPC formation and further genome organization. Thus, cross-talk between genome architecture and NPCs is essential for successful cell fate transitions.
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Affiliation(s)
- Noor M Kotb
- Department of Biomedical Sciences/Wadsworth Center, University at Albany State University of New York (SUNY), Albany, New York 12202, USA
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, New York 12202, USA
- Department of Cell, Developmental, and Regenerative Biology, Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NewYork 10029, USA
| | - Gulay Ulukaya
- Department of Cell, Developmental, and Regenerative Biology, Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NewYork 10029, USA
- Bioinformatics for Next-Generation Sequencing (BiNGS) Core, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Ankita Chavan
- Institute of Biochemistry, Department of Biology, Eidgenössische Technische Hochschule (ETH) Zürich, 8092 Zürich, Switzerland
| | - Son C Nguyen
- Department of Genetics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Lydia Proskauer
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, New York 12202, USA
| | - Eric F Joyce
- Department of Genetics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Dan Hasson
- Department of Cell, Developmental, and Regenerative Biology, Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NewYork 10029, USA
- Bioinformatics for Next-Generation Sequencing (BiNGS) Core, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
- Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Madhav Jagannathan
- Institute of Biochemistry, Department of Biology, Eidgenössische Technische Hochschule (ETH) Zürich, 8092 Zürich, Switzerland
| | - Prashanth Rangan
- Department of Cell, Developmental, and Regenerative Biology, Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NewYork 10029, USA;
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3
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Sarkar K, Kotb NM, Lemus A, Martin ET, McCarthy A, Camacho J, Iqbal A, Valm AM, Sammons MA, Rangan P. A feedback loop between heterochromatin and the nucleopore complex controls germ-cell-to-oocyte transition during Drosophila oogenesis. Dev Cell 2023; 58:2580-2596.e6. [PMID: 37673064 PMCID: PMC11301765 DOI: 10.1016/j.devcel.2023.08.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 04/12/2023] [Accepted: 08/09/2023] [Indexed: 09/08/2023]
Abstract
Germ cells differentiate into oocytes that launch the next generation upon fertilization. How the highly specialized oocyte acquires this distinct cell fate is poorly understood. During Drosophila oogenesis, H3K9me3 histone methyltransferase SETDB1 translocates from the cytoplasm to the nucleus of germ cells concurrently with oocyte specification. Here, we discovered that nuclear SETDB1 is required for silencing a cohort of differentiation-promoting genes by mediating their heterochromatinization. Intriguingly, SETDB1 is also required for upregulating 18 of the ∼30 nucleoporins (Nups) that compose the nucleopore complex (NPC), promoting NPC formation. NPCs anchor SETDB1-dependent heterochromatin at the nuclear periphery to maintain H3K9me3 and gene silencing in the egg chambers. Aberrant gene expression due to the loss of SETDB1 or Nups results in the loss of oocyte identity, cell death, and sterility. Thus, a feedback loop between heterochromatin and NPCs promotes transcriptional reprogramming at the onset of oocyte specification, which is critical for establishing oocyte identity.
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Affiliation(s)
- Kahini Sarkar
- Department of Biological Sciences and RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Noor M Kotb
- Department of Biological Sciences and RNA Institute, University at Albany SUNY, Albany, NY 12222, USA; Department of Biomedical Sciences, School of Public Health, University at Albany SUNY, Albany, NY 12222, USA
| | - Alex Lemus
- Department of Biological Sciences and RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Elliot T Martin
- Department of Biological Sciences and RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Alicia McCarthy
- Department of Biological Sciences and RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Justin Camacho
- Department of Biological Sciences and RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Ayman Iqbal
- Department of Biological Sciences and RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Alex M Valm
- Department of Biological Sciences and RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Morgan A Sammons
- Department of Biological Sciences and RNA Institute, University at Albany SUNY, Albany, NY 12222, USA
| | - Prashanth Rangan
- Department of Biological Sciences and RNA Institute, University at Albany SUNY, Albany, NY 12222, USA.
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4
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Kotb NM, Ulukaya G, Chavan A, Nguyen SC, Proskauer L, Joyce E, Hasson D, Jagannathan M, Rangan P. Genome organization regulates nuclear pore complex formation and promotes differentiation during Drosophila oogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.15.567233. [PMID: 38014330 PMCID: PMC10680722 DOI: 10.1101/2023.11.15.567233] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Genome organization can regulate gene expression and promote cell fate transitions. The differentiation of germline stem cells (GSCs) to oocytes in Drosophila involves changes in genome organization mediated by heterochromatin and the nuclear pore complex (NPC). Heterochromatin represses germ-cell genes during differentiation and NPCs anchor these silenced genes to the nuclear periphery, maintaining silencing to allow for oocyte development. Surprisingly, we find that genome organization also contributes to NPC formation, mediated by the transcription factor Stonewall (Stwl). As GSCs differentiate, Stwl accumulates at boundaries between silenced and active gene compartments. Stwl at these boundaries plays a pivotal role in transitioning germ-cell genes into a silenced state and activating a group of oocyte genes and Nucleoporins (Nups). The upregulation of these Nups during differentiation is crucial for NPC formation and further genome organization. Thus, crosstalk between genome architecture and NPCs is essential for successful cell fate transitions.
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Affiliation(s)
- Noor M. Kotb
- Department of Biomedical Sciences/Wadsworth Center, University at Albany SUNY, Albany, NY 12202
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202
- Department of Cell, Developmental, and Regenerative Biology, Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Gulay Ulukaya
- Department of Cell, Developmental, and Regenerative Biology, Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Tisch Cancer Institute Bioinformatics for Next Generation Sequencing (BiNGS) core
| | - Ankita Chavan
- Department of Biology, Institute of Biochemistry, ETH Zurich, 8092 Zurich
| | - Son C. Nguyen
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104
| | - Lydia Proskauer
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202
- Current address: Biochemistry and Molecular Biology Department, University of Massachusetts Amherst, Amherst, MA 01003
| | - Eric Joyce
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104
| | - Dan Hasson
- Department of Cell, Developmental, and Regenerative Biology, Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Tisch Cancer Institute Bioinformatics for Next Generation Sequencing (BiNGS) core
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Madhav Jagannathan
- Department of Biology, Institute of Biochemistry, ETH Zurich, 8092 Zurich
| | - Prashanth Rangan
- Department of Cell, Developmental, and Regenerative Biology, Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
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Carro MDLM, Grimson A, Cohen PE. Small RNAs and their protein partners in animal meiosis. Curr Top Dev Biol 2022; 151:245-279. [PMID: 36681472 DOI: 10.1016/bs.ctdb.2022.06.001] [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] [Indexed: 01/25/2023]
Abstract
Meiosis is characterized by highly regulated transitions in gene expression that require diverse mechanisms of gene regulation. For example, in male mammals, transcription undergoes a global shut-down in early prophase I of meiosis, followed by increasing transcriptional activity into pachynema. Later, as spermiogenesis proceeds, the histones bound to DNA are replaced with transition proteins, which are themselves replaced with protamines, resulting in a highly condensed nucleus with repressed transcriptional activity. In addition, two specialized gene silencing events take place during prophase I: meiotic silencing of unsynapsed chromatin (MSUC), and the sex chromatin specific mechanism, meiotic sex chromosome inactivation (MSCI). Notably, conserved roles for the RNA binding protein (RBP) machinery that functions with small non-coding RNAs have been described as participating in these meiosis-specific mechanisms, suggesting that RNA-mediated gene regulation is critical for fertility in many species. Here, we review roles of small RNAs and their associated RBPs in meiosis-related processes such as centromere function, silencing of unpaired chromatin and meiotic recombination. We will discuss the emerging evidence of non-canonical functions of these components in meiosis.
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Affiliation(s)
- María de Las Mercedes Carro
- Department of Biomedical Sciences, Cornell University, Ithaca, NY, United States; Cornell Reproductive Sciences Center (CoRe), Cornell University, Ithaca, NY, United States
| | - Andrew Grimson
- Cornell Reproductive Sciences Center (CoRe), Cornell University, Ithaca, NY, United States; Department of Molecular Biology & Genetics, Cornell University, Ithaca, NY, United States.
| | - Paula E Cohen
- Department of Biomedical Sciences, Cornell University, Ithaca, NY, United States; Cornell Reproductive Sciences Center (CoRe), Cornell University, Ithaca, NY, United States.
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6
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Blatt P, Wong-Deyrup SW, McCarthy A, Breznak S, Hurton MD, Upadhyay M, Bennink B, Camacho J, Lee MT, Rangan P. RNA degradation is required for the germ-cell to maternal transition in Drosophila. Curr Biol 2021; 31:2984-2994.e7. [PMID: 33989522 PMCID: PMC8319052 DOI: 10.1016/j.cub.2021.04.052] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 03/26/2021] [Accepted: 04/20/2021] [Indexed: 10/21/2022]
Abstract
In sexually reproducing animals, the oocyte contributes a large supply of RNAs that are essential to launch development upon fertilization. The mechanisms that regulate the composition of the maternal RNA contribution during oogenesis are unclear. Here, we show that a subset of RNAs expressed during the early stages of oogenesis is subjected to regulated degradation during oocyte specification. Failure to remove these RNAs results in oocyte dysfunction and death. We identify the RNA-degrading Super Killer complex and No-Go Decay factor Pelota as key regulators of oogenesis via targeted degradation of specific RNAs expressed in undifferentiated germ cells. These regulators target RNAs enriched for cytidine sequences that are bound by the polypyrimidine tract binding protein Half pint. Thus, RNA degradation helps orchestrate a germ cell-to-maternal transition that gives rise to the maternal contribution to the zygote.
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Affiliation(s)
- Patrick Blatt
- University at Albany, Department of Biological Sciences, RNA Institute; 1400 Washington Avenue, LSRB 2033D, Albany, NY 12222
| | - Siu Wah Wong-Deyrup
- University at Albany, Department of Biological Sciences, RNA Institute; 1400 Washington Avenue, LSRB 2033D, Albany, NY 12222
| | - Alicia McCarthy
- University at Albany, Department of Biological Sciences, RNA Institute; 1400 Washington Avenue, LSRB 2033D, Albany, NY 12222; 10x Genomics, Inc., 6230 Stoneridge Mall Road, Pleasanton, CA, 94588
| | - Shane Breznak
- University at Albany, Department of Biological Sciences, RNA Institute; 1400 Washington Avenue, LSRB 2033D, Albany, NY 12222
| | - Matthew D Hurton
- University of Pittsburgh, Department of Biological Sciences; 4249 Fifth Avenue, Pittsburgh, PA 15260
| | - Maitreyi Upadhyay
- University at Albany, Department of Biological Sciences, RNA Institute; 1400 Washington Avenue, LSRB 2033D, Albany, NY 12222; Department of Stem Cell and Regenerative Biology, Sherman Fairchild 100, Harvard University, 7 Divinity Avenue, Cambridge, MA 02138
| | - Benjamin Bennink
- University at Albany, Department of Biological Sciences, RNA Institute; 1400 Washington Avenue, LSRB 2033D, Albany, NY 12222
| | - Justin Camacho
- University at Albany, Department of Biological Sciences, RNA Institute; 1400 Washington Avenue, LSRB 2033D, Albany, NY 12222
| | - Miler T Lee
- University of Pittsburgh, Department of Biological Sciences; 4249 Fifth Avenue, Pittsburgh, PA 15260.
| | - Prashanth Rangan
- University at Albany, Department of Biological Sciences, RNA Institute; 1400 Washington Avenue, LSRB 2033D, Albany, NY 12222.
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A comparative genomic approach using mouse and fruit fly data to discover genes involved in testis function in hymenopterans with a focus on Nasonia vitripennis. BMC Ecol Evol 2021; 21:90. [PMID: 34011283 PMCID: PMC8132408 DOI: 10.1186/s12862-021-01825-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 05/12/2021] [Indexed: 11/18/2022] Open
Abstract
Background Spermatogenesis appears to be a relatively well-conserved process even among distantly related animal taxa such as invertebrates and vertebrates. Although Hymenopterans share many characteristics with other organisms, their complex haplodiploid reproduction system is still relatively unknown. However, they serve as a complementary insect model to Drosophila for studying functional male fertility. In this study, we used a comparative method combining taxonomic, phenotypic data and gene expression to identify candidate genes that could play a significant role in spermatogenesis in hymenopterans. Results Of the 546 mouse genes predominantly or exclusively expressed in the mouse testes, 36% had at least one ortholog in the fruit fly. Of these genes, 68% had at least one ortholog in one of the six hymenopteran species we examined. Based on their gene expression profiles in fruit fly testes, 71 of these genes were hypothesized to play a marked role in testis function. Forty-three of these 71 genes had an ortholog in at least one of the six hymenopteran species examined, and their enriched GO terms were related to the G2/M transition or to cilium organization, assembly, or movement. Second, of the 379 genes putatively involved in male fertility in Drosophila, 224 had at least one ortholog in each of the six Hymenoptera species. Finally, we showed that 199 of these genes were expressed in early pupal testis in Nasonia vitripennis; 86 exhibited a high level of expression, and 54 displayed modulated expression during meiosis. Conclusions In this study combining phylogenetic and experimental approaches, we highlighted genes that may have a major role in gametogenesis in hymenopterans; an essential prerequisite for further research on functional importance of these genes. Supplementary Information The online version contains supplementary material available at 10.1186/s12862-021-01825-6.
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Schneider J, Imler JL. Sensing and signalling viral infection in drosophila. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 117:103985. [PMID: 33358662 DOI: 10.1016/j.dci.2020.103985] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 12/16/2020] [Accepted: 12/17/2020] [Indexed: 06/12/2023]
Abstract
The fruitfly Drosophila melanogaster is a valuable model to unravel mechanisms of innate immunity, in particular in the context of viral infections. RNA interference, and more specifically the small interfering RNA pathway, is a major component of antiviral immunity in drosophila. In addition, the contribution of inducible transcriptional responses to the control of viruses in drosophila and other invertebrates is increasingly recognized. In particular, the recent discovery of a STING-IKKβ-Relish signalling cassette in drosophila has confirmed that NF-κB transcription factors play an important role in the control of viral infections, in addition to bacterial and fungal infections. Here, we review recent developments in the field, which begin to shed light on the mechanisms involved in sensing of viral infections and in signalling leading to production of antiviral effectors.
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Affiliation(s)
- Juliette Schneider
- Université de Strasbourg, CNRS UPR9022, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France
| | - Jean-Luc Imler
- Université de Strasbourg, CNRS UPR9022, Institut de Biologie Moléculaire et Cellulaire, Strasbourg, France; Sino-French Hoffmann Institute, School of Basic Medical Science, Guangzhou Medical University, Guangzhou 511436, China.
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Nitschko V, Kunzelmann S, Fröhlich T, Arnold GJ, Förstemann K. Trafficking of siRNA precursors by the dsRBD protein Blanks in Drosophila. Nucleic Acids Res 2020; 48:3906-3921. [PMID: 32025726 PMCID: PMC7144943 DOI: 10.1093/nar/gkaa072] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 01/21/2020] [Accepted: 02/03/2020] [Indexed: 01/03/2023] Open
Abstract
RNA interference targets aberrant transcripts with cognate small interfering RNAs, which derive from double-stranded RNA precursors. Several functional screens have identified Drosophila blanks/lump (CG10630) as a facilitator of RNAi, yet its molecular function has remained unknown. The protein carries two dsRNA binding domains (dsRBD) and blanks mutant males have a spermatogenesis defect. We demonstrate that blanks selectively boosts RNAi triggered by dsRNA of nuclear origin. Blanks binds dsRNA via its second dsRBD in vitro, shuttles between nucleus and cytoplasm and the abundance of siRNAs arising at many sites of convergent transcription is reduced in blanks mutants. Since features of nascent RNAs - such as introns and transcription beyond the polyA site – contribute to the small RNA pool, we propose that Blanks binds dsRNA formed by cognate nascent RNAs in the nucleus and fosters its export to the cytoplasm for dicing. We refer to the resulting small RNAs as blanks exported siRNAs (bepsiRNAs). While bepsiRNAs were fully dependent on RNA binding to the second dsRBD of blanks in transgenic flies, male fertility was not. This is consistent with a previous report that linked fertility to the first dsRBD of Blanks. The role of blanks in spermatogenesis appears thus unrelated to its role in dsRNA export.
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Affiliation(s)
- Volker Nitschko
- Genzentrum & Department Biochemie, Ludwig-Maximilians-Universität, 81377 München, Germany
| | - Stefan Kunzelmann
- Genzentrum & Department Biochemie, Ludwig-Maximilians-Universität, 81377 München, Germany
| | - Thomas Fröhlich
- Laboratory of Functional Genome Analysis, Ludwig-Maximilians-Universität, 81377 München, Germany
| | - Georg J Arnold
- Laboratory of Functional Genome Analysis, Ludwig-Maximilians-Universität, 81377 München, Germany
| | - Klaus Förstemann
- Genzentrum & Department Biochemie, Ludwig-Maximilians-Universität, 81377 München, Germany
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He Z, Zheng Y, Yu WJ, Fang Y, Mao B, Wang YF. How do Wolbachia modify the Drosophila ovary? New evidences support the "titration-restitution" model for the mechanisms of Wolbachia-induced CI. BMC Genomics 2019; 20:608. [PMID: 31340757 PMCID: PMC6657171 DOI: 10.1186/s12864-019-5977-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 07/16/2019] [Indexed: 02/06/2023] Open
Abstract
Background Cytoplasmic incompatibility (CI) is the most common phenotype induced by endosymbiont Wolbachia and results in embryonic lethality when Wolbachia-modified sperm fertilize eggs without Wolbachia. However, eggs carrying the same strain of Wolbachia can rescue this embryonic death, thus producing viable Wolbachia-infected offspring. Hence Wolbachia can be transmitted mainly by hosts’ eggs. One of the models explaining CI is “titration-restitution”, which hypothesized that Wolbachia titrated-out some factors from the sperm and the Wolbachia in the egg would restitute the factors after fertilization. However, how infected eggs rescue CI and how hosts’ eggs ensure the proliferation and transmission of Wolbachia are not well understood. Results By RNA-seq analyses, we first compared the transcription profiles of Drosophila melanogaster adult ovaries with and without the wMel Wolbachia and identified 149 differentially expressed genes (DEGs), of which 116 genes were upregulated and 33 were downregulated by Wolbachia infection. To confirm the results obtained from RNA-seq and to screen genes potentially associated with reproduction, 15 DEGs were selected for quantitative RT-PCR (qRT-PCR). Thirteen genes showed the same changing trend as RNA-seq analyses. To test whether these genes are associated with CI, we also detected their expression levels in testes. Nine of them exhibited different changing trends in testes from those in ovaries. To investigate how these DEGs were regulated, sRNA sequencing was performed and identified seven microRNAs (miRNAs) that were all upregulated in fly ovaries by Wolbachia infection. Matching of miRNA and mRNA data showed that these seven miRNAs regulated 15 DEGs. Wolbachia-responsive genes in fly ovaries were involved in biological processes including metabolism, transportation, oxidation-reduction, immunity, and development. Conclusions Comparisons of mRNA and miRNA data from fly ovaries revealed 149 mRNAs and seven miRNAs that exhibit significant changes in expression due to Wolbachia infection. Notably, most of the DEGs showed variation in opposite directions in ovaries versus testes in the presence of Wolbachia, which generally supports the “titration-restitution” model for CI. Furthermore, genes related to metabolism were upregulated, which may benefit maximum proliferation and transmission of Wolbachia. This provides new insights into the molecular mechanisms of Wolbachia-induced CI and Wolbachia dependence on host ovaries. Electronic supplementary material The online version of this article (10.1186/s12864-019-5977-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Zhen He
- School of Life Sciences, Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, 430079, People's Republic of China
| | - Ya Zheng
- School of Life Sciences, Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, 430079, People's Republic of China
| | - Wen-Juan Yu
- School of Life Sciences, Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, 430079, People's Republic of China
| | - Yang Fang
- School of Life Sciences, Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, 430079, People's Republic of China
| | - Bin Mao
- School of Life Sciences, Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, 430079, People's Republic of China
| | - Yu-Feng Wang
- School of Life Sciences, Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, 430079, People's Republic of China.
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11
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Bateman JR, Anderson DJ. Taming the giant within. PLoS Genet 2019; 15:e1008098. [PMID: 31071083 PMCID: PMC6508613 DOI: 10.1371/journal.pgen.1008098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Jack R. Bateman
- Biology Department, Bowdoin College, Brunswick, Maine, United States of America
- * E-mail:
| | - David J. Anderson
- Biology Department, Bowdoin College, Brunswick, Maine, United States of America
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12
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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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13
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Wester JVWC, Lima CAC, Machado MCR, Zampar PV, Tavares SS, Monesi N. Characterization of a novel Drosophila melanogaster cis-regulatory module that drives gene expression to the larval tracheal system and adult thoracic musculature. Genesis 2018; 56:e23222. [PMID: 30096221 DOI: 10.1002/dvg.23222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 06/10/2018] [Accepted: 06/11/2018] [Indexed: 11/05/2022]
Abstract
In a previous bioinformatics analysis we identified 10 conserved Drosophila melanogaster sequences that reside upstream from protein coding genes (CGs). Here we characterize one of these genomic regions, which constitutes a Drosophila melanogaster cis-regulatory module (CRM) that we denominate TT-CRM. The TT-CRM is 646 bp long and is located in one of the introns of CG32239 and resides about 3,500 bp upstream of CG13711 and about 620 bp upstream of CG12493. Analysis of 646 bp-lacZ lines revealed that TT-CRM drives gene expression not only to the larval, prepupal, and pupal tracheal system but also to the adult dorsal longitudinal muscles. The patterns of mRNA expression of the transgene and of the CGs that lie in the vicinity of TT-CRM were investigated both in dissected trachea and in adult thoraces. Through RT-qPCR we observed that in the tracheal system the pattern of expression of 646 bp-lacZ is similar to the pattern of expression of CG32239 and CG13711, whereas in the thoracic muscles 646 bp-lacZ expression accompanies the expression of CG12493. Together, these results suggest new functions for two previously characterized D. melanogaster genes and also contribute to the initial characterization of a novel CRM that drives a dynamic pattern of expression throughout development.
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Affiliation(s)
- Jorge Victor Wilfredo Cachay Wester
- Programa de Pós-Graduação em Biologia Celular e Molecular, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - Carlos Antonio Couto Lima
- Departamento de Física e Química, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - Maiaro Cabral Rosa Machado
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - Patrícia Vieira Zampar
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - Simone Sakagute Tavares
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
| | - Nadia Monesi
- Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo, Brazil
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14
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An RNA-binding protein Blanks plays important roles in defining small RNA and mRNA profiles in Drosophila testes. Heliyon 2018; 4:e00706. [PMID: 30094376 PMCID: PMC6074722 DOI: 10.1016/j.heliyon.2018.e00706] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 07/10/2018] [Accepted: 07/20/2018] [Indexed: 01/03/2023] Open
Abstract
Drosophila Blanks is a testes-specific RNA-binding protein required for post-meiotic spermiogenesis. However, Blanks's role in regulating RNA populations in the testes remains unknown. We performed small RNA and mRNA high-throughput sequencing in blanks mutant testes and controls. We identified two miRNAs, one siRNA, and hundreds of mRNAs that are significantly upregulated or downregulated in blanks mutant testes. Pathway analysis revealed that differentially expressed mRNAs are involved in catabolic and metabolic processes, anion and cation transport, mating, and reproductive behavior. Our results reveal that Blanks plays important roles in defining testicular small RNA and mRNA profiles.
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15
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Wong JT, Akhbar F, Ng AYE, Tay MLI, Loi GJE, Pek JW. DIP1 modulates stem cell homeostasis in Drosophila through regulation of sisR-1. Nat Commun 2017; 8:759. [PMID: 28970471 PMCID: PMC5624886 DOI: 10.1038/s41467-017-00684-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 07/19/2017] [Indexed: 01/09/2023] Open
Abstract
Stable intronic sequence RNAs (sisRNAs) are by-products of splicing and regulate gene expression. How sisRNAs are regulated is unclear. Here we report that a double-stranded RNA binding protein, Disco-interacting protein 1 (DIP1) regulates sisRNAs in Drosophila. DIP1 negatively regulates the abundance of sisR-1 and INE-1 sisRNAs. Fine-tuning of sisR-1 by DIP1 is important to maintain female germline stem cell homeostasis by modulating germline stem cell differentiation and niche adhesion. Drosophila DIP1 localizes to a nuclear body (satellite body) and associates with the fourth chromosome, which contains a very high density of INE-1 transposable element sequences that are processed into sisRNAs. DIP1 presumably acts outside the satellite bodies to regulate sisR-1, which is not on the fourth chromosome. Thus, our study identifies DIP1 as a sisRNA regulatory protein that controls germline stem cell self-renewal in Drosophila. Stable intronic sequence RNAs (sisRNAs) are by-products of splicing from introns with roles in embryonic development in Drosophila. Here, the authors show that the RNA binding protein DIP1 regulates sisRNAs in Drosophila, which is necessary for germline stem cell homeostasis.
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Affiliation(s)
- Jing Ting Wong
- Ngee Ann Polytechnic, 535 Clementi Road, Singapore, 599489, Singapore
| | - Farzanah Akhbar
- Temasek Polytechnic, 21 Tampines Avenue 1, Singapore, 529757, Singapore
| | - Amanda Yunn Ee Ng
- Temasek Life Sciences Laboratory, 1 Research Link National University of Singapore, Singapore, 117604, Singapore
| | - Mandy Li-Ian Tay
- Temasek Life Sciences Laboratory, 1 Research Link National University of Singapore, Singapore, 117604, Singapore
| | - Gladys Jing En Loi
- National University of Singapore, 21 Lower Kent Ridge Road, Singapore, 119077, Singapore
| | - Jun Wei Pek
- Temasek Life Sciences Laboratory, 1 Research Link National University of Singapore, Singapore, 117604, Singapore.
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16
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Paces J, Nic M, Novotny T, Svoboda P. Literature review of baseline information to support the risk assessment of RNAi‐based GM plants. ACTA ACUST UNITED AC 2017. [PMCID: PMC7163844 DOI: 10.2903/sp.efsa.2017.en-1246] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Jan Paces
- Institute of Molecular Genetics of the Academy of Sciences of the Czech Republic (IMG)
| | | | | | - Petr Svoboda
- Institute of Molecular Genetics of the Academy of Sciences of the Czech Republic (IMG)
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17
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Swenson JM, Colmenares SU, Strom AR, Costes SV, Karpen GH. The composition and organization of Drosophila heterochromatin are heterogeneous and dynamic. eLife 2016; 5:e16096. [PMID: 27514026 PMCID: PMC4981497 DOI: 10.7554/elife.16096] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 07/06/2016] [Indexed: 12/13/2022] Open
Abstract
Heterochromatin is enriched for specific epigenetic factors including Heterochromatin Protein 1a (HP1a), and is essential for many organismal functions. To elucidate heterochromatin organization and regulation, we purified Drosophila melanogaster HP1a interactors, and performed a genome-wide RNAi screen to identify genes that impact HP1a levels or localization. The majority of the over four hundred putative HP1a interactors and regulators identified were previously unknown. We found that 13 of 16 tested candidates (83%) are required for gene silencing, providing a substantial increase in the number of identified components that impact heterochromatin properties. Surprisingly, image analysis revealed that although some HP1a interactors and regulators are broadly distributed within the heterochromatin domain, most localize to discrete subdomains that display dynamic localization patterns during the cell cycle. We conclude that heterochromatin composition and architecture is more spatially complex and dynamic than previously suggested, and propose that a network of subdomains regulates diverse heterochromatin functions.
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Affiliation(s)
- Joel M Swenson
- Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, United States
| | - Serafin U Colmenares
- Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, United States
| | - Amy R Strom
- Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, United States
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
| | - Sylvain V Costes
- Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, United States
| | - Gary H Karpen
- Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, United States
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, United States
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18
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Cugusi S, Li Y, Jin P, Lucchesi JC. The Drosophila Helicase MLE Targets Hairpin Structures in Genomic Transcripts. PLoS Genet 2016; 12:e1005761. [PMID: 26752049 PMCID: PMC4710571 DOI: 10.1371/journal.pgen.1005761] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 12/02/2015] [Indexed: 12/28/2022] Open
Abstract
RNA hairpins are a common type of secondary structures that play a role in every aspect of RNA biochemistry including RNA editing, mRNA stability, localization and translation of transcripts, and in the activation of the RNA interference (RNAi) and microRNA (miRNA) pathways. Participation in these functions often requires restructuring the RNA molecules by the association of single-strand (ss) RNA-binding proteins or by the action of helicases. The Drosophila MLE helicase has long been identified as a member of the MSL complex responsible for dosage compensation. The complex includes one of two long non-coding RNAs and MLE was shown to remodel the roX RNA hairpin structures in order to initiate assembly of the complex. Here we report that this function of MLE may apply to the hairpins present in the primary RNA transcripts that generate the small molecules responsible for RNA interference. Using stocks from the Transgenic RNAi Project and the Vienna Drosophila Research Center, we show that MLE specifically targets hairpin RNAs at their site of transcription. The association of MLE at these sites is independent of sequence and chromosome location. We use two functional assays to test the biological relevance of this association and determine that MLE participates in the RNAi pathway.
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Affiliation(s)
- Simona Cugusi
- Department of Biology, Emory University, Atlanta, Georgia, United States of America
| | - Yujing Li
- Department of Human Genetics, Emory University School of Medicine, Atlanta
| | - Peng Jin
- Department of Human Genetics, Emory University School of Medicine, Atlanta
| | - John C. Lucchesi
- Department of Biology, Emory University, Atlanta, Georgia, United States of America
- * E-mail:
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19
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Loss of the Drosophila melanogaster DEAD box protein Ddx1 leads to reduced size and aberrant gametogenesis. Dev Biol 2015; 407:232-45. [PMID: 26433063 PMCID: PMC7094483 DOI: 10.1016/j.ydbio.2015.09.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 07/31/2015] [Accepted: 09/24/2015] [Indexed: 02/07/2023]
Abstract
Mammalian DDX1 has been implicated in RNA trafficking, DNA double-strand break repair and RNA processing; however, little is known about its role during animal development. Here, we report phenotypes associated with a null Ddx1 (Ddx1AX) mutation generated in Drosophila melanogaster. Ddx1 null flies are viable but significantly smaller than control and Ddx1 heterozygous flies. Female Ddx1 null flies have reduced fertility with egg chambers undergoing autophagy, whereas males are sterile due to disrupted spermatogenesis. Comparative RNA sequencing of control and Ddx1 null third instars identified several transcripts affected by Ddx1 inactivation. One of these, Sirup mRNA, was previously shown to be overexpressed under starvation conditions and implicated in mitochondrial function. We demonstrate that Sirup is a direct binding target of Ddx1 and that Sirup mRNA is differentially spliced in the presence or absence of Ddx1. Combining Ddx1 null mutation with Sirup dsRNA-mediated knock-down causes epistatic lethality not observed in either single mutant. Our data suggest a role for Drosophila Ddx1 in stress-induced regulation of splicing. We describe a new Ddx1 null Drosophila line. Ddx1 null flies are smaller in size and display aberrant gametogenesis. Sirup splicing is altered in Ddx1 null flies. We show both a physical and a genetic interaction between Ddx1 and Sirup.
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20
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Steinhauer J. Separating from the pack: Molecular mechanisms of Drosophila spermatid individualization. SPERMATOGENESIS 2015; 5:e1041345. [PMID: 26413413 PMCID: PMC4581072 DOI: 10.1080/21565562.2015.1041345] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 03/26/2015] [Accepted: 03/26/2015] [Indexed: 12/18/2022]
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21
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dDsk2 regulates H2Bub1 and RNA polymerase II pausing at dHP1c complex target genes. Nat Commun 2015; 6:7049. [PMID: 25916810 DOI: 10.1038/ncomms8049] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2014] [Accepted: 03/26/2015] [Indexed: 12/13/2022] Open
Abstract
dDsk2 is a conserved extraproteasomal ubiquitin receptor that targets ubiquitylated proteins for degradation. Here we report that dDsk2 plays a nonproteolytic function in transcription regulation. dDsk2 interacts with the dHP1c complex, localizes at promoters of developmental genes and is required for transcription. Through the ubiquitin-binding domain, dDsk2 interacts with H2Bub1, a modification that occurs at dHP1c complex-binding sites. H2Bub1 is not required for binding of the complex; however, dDsk2 depletion strongly reduces H2Bub1. Co-depletion of the H2Bub1 deubiquitylase dUbp8/Nonstop suppresses this reduction and rescues expression of target genes. RNA polymerase II is strongly paused at promoters of dHP1c complex target genes and dDsk2 depletion disrupts pausing. Altogether, these results suggest that dDsk2 prevents dUbp8/Nonstop-dependent H2Bub1 deubiquitylation at promoters of dHP1c complex target genes and regulates RNA polymerase II pausing. These results expand the catalogue of nonproteolytic functions of ubiquitin receptors to the epigenetic regulation of chromatin modifications.
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22
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Mirkovic-Hösle M, Förstemann K. Transposon defense by endo-siRNAs, piRNAs and somatic pilRNAs in Drosophila: contributions of Loqs-PD and R2D2. PLoS One 2014; 9:e84994. [PMID: 24454776 PMCID: PMC3890300 DOI: 10.1371/journal.pone.0084994] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 11/27/2013] [Indexed: 12/30/2022] Open
Abstract
Transposable elements are a serious threat for genome integrity and their control via small RNA mediated silencing pathways is an ancient strategy. The fruit fly Drosophila melanogaster has two silencing activities that target transposons: endogenous siRNAs (esiRNAs or endo-siRNAs) and Piwi-interacting small RNAs (piRNAs). The biogenesis of endo-siRNAs involves the Dicer-2 co-factors Loqs-PD, which acts predominantly during processing of dsRNA by Dcr-2, and R2D2, which primarily helps to direct siRNAs into the RNA interference effector Ago2. Nonetheless, loss of either protein is not sufficient to produce a phenotype comparable with a dcr-2 mutation. We provide further deep sequencing evidence supporting the notion that R2D2 and Loqs-PD have partially overlapping function. Certain transposons display a preference for either dsRBD-protein during production or loading; this appeared to correlate neither with overall abundance, classification of the transposon or a specific site of genomic origin. The endo-siRNA biogenesis pathway in germline operates according to the same principles as the existing model for the soma, and its impairment does not significantly affect piRNAs. Expanding the analysis, we confirmed the occurrence of somatic piRNA-like RNAs (pilRNAs) that show a ping-pong signature. We detected expression of the Piwi-family protein mRNAs only barely above background, indicating that the somatic pilRNAs may arise from a small sub-population of somatic cells that express a functional piRNA pathway.
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Affiliation(s)
| | - Klaus Förstemann
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität, Munich, Germany
- * E-mail:
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23
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Marques JT, Wang JP, Wang X, de Oliveira KPV, Gao C, Aguiar ERGR, Jafari N, Carthew RW. Functional specialization of the small interfering RNA pathway in response to virus infection. PLoS Pathog 2013; 9:e1003579. [PMID: 24009507 PMCID: PMC3757037 DOI: 10.1371/journal.ppat.1003579] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Accepted: 07/10/2013] [Indexed: 01/04/2023] Open
Abstract
In Drosophila, post-transcriptional gene silencing occurs when exogenous or endogenous double stranded RNA (dsRNA) is processed into small interfering RNAs (siRNAs) by Dicer-2 (Dcr-2) in association with a dsRNA-binding protein (dsRBP) cofactor called Loquacious (Loqs-PD). siRNAs are then loaded onto Argonaute-2 (Ago2) by the action of Dcr-2 with another dsRBP cofactor called R2D2. Loaded Ago2 executes the destruction of target RNAs that have sequence complementarity to siRNAs. Although Dcr-2, R2D2, and Ago2 are essential for innate antiviral defense, the mechanism of virus-derived siRNA (vsiRNA) biogenesis and viral target inhibition remains unclear. Here, we characterize the response mechanism mediated by siRNAs against two different RNA viruses that infect Drosophila. In both cases, we show that vsiRNAs are generated by Dcr-2 processing of dsRNA formed during viral genome replication and, to a lesser extent, viral transcription. These vsiRNAs seem to preferentially target viral polyadenylated RNA to inhibit viral replication. Loqs-PD is completely dispensable for silencing of the viruses, in contrast to its role in silencing endogenous targets. Biogenesis of vsiRNAs is independent of both Loqs-PD and R2D2. R2D2, however, is required for sorting and loading of vsiRNAs onto Ago2 and inhibition of viral RNA expression. Direct injection of viral RNA into Drosophila results in replication that is also independent of Loqs-PD. This suggests that triggering of the antiviral pathway is not related to viral mode of entry but recognition of intrinsic features of virus RNA. Our results indicate the existence of a vsiRNA pathway that is separate from the endogenous siRNA pathway and is specifically triggered by virus RNA. We speculate that this unique framework might be necessary for a prompt and efficient antiviral response. The RNA interference (RNAi) pathway utilizes small non-coding RNAs to silence gene expression. In insects, RNAi regulates endogenous genes and functions as an RNA-based immune system against viral infection. Here we have uncovered details of how RNAi is triggered by RNA viruses. Double-stranded RNA (dsRNA) generated as a replication intermediate or from transcription of the RNA virus can be used as substrate for the biogenesis of virus-derived small interfering RNAs (vsiRNAs). Unlike other dsRNAs, virus RNA processing involves Dicer but not its canonical partner protein Loqs-PD. Thus, vsiRNA biogenesis is mechanistically different from biogenesis of endogenous siRNAs or siRNAs derived from other exogenous RNA sources. Our results suggest a specialization of the pathway dedicated to silencing of RNA viruses versus other types of RNAi silencing. The understanding of RNAi mechanisms during viral infection could have implications for the control of insect-borne viruses and the use of siRNAs to treat viral infections in humans.
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Affiliation(s)
- Joao Trindade Marques
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
- Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
- * E-mail: (JTM); (RWC)
| | - Ji-Ping Wang
- Department of Statistics, Northwestern University, Evanston, Illinois, United States of America
| | - Xiaohong Wang
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Karla Pollyanna Vieira de Oliveira
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
- Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Catherine Gao
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Eric Roberto Guimaraes Rocha Aguiar
- Department of Biochemistry and Immunology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Nadereh Jafari
- Genomics Core, Center for Genetic Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Richard W. Carthew
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
- * E-mail: (JTM); (RWC)
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24
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Hussain S, Tuorto F, Menon S, Blanco S, Cox C, Flores JV, Watt S, Kudo NR, Lyko F, Frye M. The mouse cytosine-5 RNA methyltransferase NSun2 is a component of the chromatoid body and required for testis differentiation. Mol Cell Biol 2013; 33:1561-70. [PMID: 23401851 PMCID: PMC3624257 DOI: 10.1128/mcb.01523-12] [Citation(s) in RCA: 128] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 01/30/2013] [Indexed: 11/20/2022] Open
Abstract
Posttranscriptional regulatory mechanisms are crucial for protein synthesis during spermatogenesis and are often organized by the chromatoid body. Here, we identify the RNA methyltransferase NSun2 as a novel component of the chromatoid body and, further, show that NSun2 is essential for germ cell differentiation in the mouse testis. In NSun2-depleted testes, genes encoding Ddx4, Miwi, and Tudor domain-containing (Tdr) proteins are repressed, indicating that RNA-processing and posttranscriptional pathways are impaired. Loss of NSun2 specifically blocked meiotic progression of germ cells into the pachytene stage, as spermatogonial and Sertoli cells were unaffected in knockout mice. We observed the same phenotype when we simultaneously deleted NSun2 and Dnmt2, the only other cytosine-5 RNA methyltransferase characterized to date, indicating that Dnmt2 was not functionally redundant with NSun2 in spermatogonial stem cells or Sertoli cells. Specific NSun2- and Dnmt2-methylated tRNAs decreased in abundance when both methyltransferases were deleted, suggesting that RNA methylation pathways play an essential role in male germ cell differentiation.
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Affiliation(s)
- Shobbir Hussain
- Wellcome Trust-Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
| | - Francesca Tuorto
- Division of Epigenetics, German Cancer Research Center, Heidelberg, Germany
| | - Suraj Menon
- CR-UK Cambridge Research Institute, Li Ka Shing Centre, Cambridge, United Kingdom
| | - Sandra Blanco
- Wellcome Trust-Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
| | - Claire Cox
- Wellcome Trust-Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
| | - Joana V. Flores
- Wellcome Trust-Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
| | - Stephen Watt
- CR-UK Cambridge Research Institute, Li Ka Shing Centre, Cambridge, United Kingdom
| | - Nobuaki R. Kudo
- IRDB, Department of Surgery and Cancer, Imperial College London, London, United Kingdom
| | - Frank Lyko
- Division of Epigenetics, German Cancer Research Center, Heidelberg, Germany
| | - Michaela Frye
- Wellcome Trust-Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
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25
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Smith G, Fang Y, Liu X, Kenny J, Cossins AR, de Oliveira CC, Etges WJ, Ritchie MG. Transcriptome-wide expression variation associated with environmental plasticity and mating success in cactophilic Drosophila mojavensis. Evolution 2013; 67:1950-63. [PMID: 23815652 DOI: 10.1111/evo.12082] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2012] [Accepted: 01/23/2013] [Indexed: 01/03/2023]
Abstract
Ecological speciation occurs with the adaptation of populations to different environments and concurrent evolution of reproductive isolation. Phenotypic plasticity might influence both ecological adaptation and reproductive traits. We examined environment-specific gene expression and male mating success in cactophilic Drosophila mojavensis using transcriptome sequencing. This species exhibits cactus-dependent mating success across different species of host plants, with genotype-by-environment interactions for numerous traits. We cultured flies from egg to eclosion on two natural cactus hosts and surveyed gene expression in adult males that were either successful or unsuccessful in achieving copulation in courtship trials. We identified gene expression differences that included functions involved with metabolism, most likely related to chemical differences between host cactus species. Several epigenetic-related functions were identified that might play a role in modulating gene expression in adults due to host cactus effects on larvae, and mating success. Cactus-dependent mating success involved expression differences of genes implicated in translation, transcription, and nervous system development. This suggests a role of neurological function genes in the mating success of D. mojavensis males. Together, these results suggest that the influence of environmental variation on mating success via regulation of gene expression might be an important aspect of ecological speciation.
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Affiliation(s)
- Gilbert Smith
- School of Biology, University of St Andrews, St Andrews, Fife KY16 9TH, U.K.
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26
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Sanders C, Smith DP. LUMP is a putative double-stranded RNA binding protein required for male fertility in Drosophila melanogaster. PLoS One 2011; 6:e24151. [PMID: 21912621 PMCID: PMC3166160 DOI: 10.1371/journal.pone.0024151] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Accepted: 07/31/2011] [Indexed: 01/10/2023] Open
Abstract
In animals, male fertility requires the successful development of motile sperm. During Drosophila melanogaster spermatogenesis, 64 interconnected spermatids descended from a single germline stem cell are resolved into motile sperm in a process termed individualization. Here we identify a putative double-stranded RNA binding protein LUMP that is required for male fertility. lump(1) mutants are male-sterile and lack motile sperm due to defects in sperm individualization. We show that one dsRNA binding domains (dsRBD) is essential for LUMP function in male fertility. These findings reveal LUMP is a novel factor required for late stages of male germline differentiation.
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Affiliation(s)
- Charcacia Sanders
- Departments of Pharmacology and Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Dean P. Smith
- Departments of Pharmacology and Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- * E-mail:
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