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Samuels TJ, Gui J, Gebert D, Karam Teixeira F. Two distinct waves of transcriptome and translatome changes drive Drosophila germline stem cell differentiation. EMBO J 2024; 43:1591-1617. [PMID: 38480936 PMCID: PMC11021484 DOI: 10.1038/s44318-024-00070-z] [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: 11/22/2023] [Revised: 02/22/2024] [Accepted: 02/23/2024] [Indexed: 03/18/2024] Open
Abstract
The tight control of fate transitions during stem cell differentiation is essential for proper tissue development and maintenance. However, the challenges in studying sparsely distributed adult stem cells in a systematic manner have hindered efforts to identify how the multilayered regulation of gene expression programs orchestrates stem cell differentiation in vivo. Here, we synchronised Drosophila female germline stem cell (GSC) differentiation in vivo to perform in-depth transcriptome and translatome analyses at high temporal resolution. This characterisation revealed widespread and dynamic changes in mRNA level, promoter usage, exon inclusion, and translation efficiency. Transient expression of the master regulator, Bam, drives a first wave of expression changes, primarily modifying the cell cycle program. Surprisingly, as Bam levels recede, differentiating cells return to a remarkably stem cell-like transcription and translation program, with a few crucial changes feeding into a second phase driving terminal differentiation to form the oocyte. Altogether, these findings reveal that rather than a unidirectional accumulation of changes, the in vivo differentiation of stem cells relies on distinctly regulated and developmentally sequential waves.
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Affiliation(s)
- Tamsin J Samuels
- Department of Genetics, University of Cambridge, Downing Street, CB2 3EH, Cambridge, UK
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, CB2 3DY, Cambridge, UK
| | - Jinghua Gui
- Department of Genetics, University of Cambridge, Downing Street, CB2 3EH, Cambridge, UK
| | - Daniel Gebert
- Department of Genetics, University of Cambridge, Downing Street, CB2 3EH, Cambridge, UK
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, CB2 3DY, Cambridge, UK
| | - Felipe Karam Teixeira
- Department of Genetics, University of Cambridge, Downing Street, CB2 3EH, Cambridge, UK.
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, CB2 3DY, Cambridge, UK.
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2
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Mukherjee A, Nongthomba U. To RNA-binding and beyond: Emerging facets of the role of Rbfox proteins in development and disease. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023:e1813. [PMID: 37661850 DOI: 10.1002/wrna.1813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 07/23/2023] [Accepted: 07/25/2023] [Indexed: 09/05/2023]
Abstract
The RNA-binding Fox-1 homologue (Rbfox) proteins represent an ancient family of splicing factors, conserved through evolution. All members share an RNA recognition motif (RRM), and a particular affinity for the GCAUG signature in target RNA molecules. The role of Rbfox, as a splice factor, deciding the tissue-specific inclusion/exclusion of an exon, depending on its binding position on the flanking introns, is well known. Rbfox often acts in concert with other splicing factors, and forms splicing regulatory networks. Apart from this canonical role, recent studies show that Rbfox can also function as a transcription co-factor, and affects mRNA stability and translation. The repertoire of Rbfox targets is vast, including genes involved in the development of tissue lineages, such as neurogenesis, myogenesis, and erythropoeiesis, and molecular processes, including cytoskeletal dynamics, and calcium handling. A second layer of complexity is added by the fact that Rbfox expression itself is regulated by multiple mechanisms, and, in vertebrates, exhibits tissue-specific expression. The optimum dosage of Rbfox is critical, and its misexpression is etiological to various disease conditions. In this review, we discuss the contextual roles played by Rbfox as a tissue-specific regulator for the expression of many important genes with diverse functions, through the lens of the emerging data which highlights its involvement in many human diseases. Furthermore, we explore the mechanistic details provided by studies in model organisms, with emphasis on the work with Drosophila. This article is categorized under: RNA Processing > Splicing Mechanisms RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications RNA Turnover and Surveillance > Regulation of RNA Stability RNA Processing > Splicing Regulation/Alternative Splicing.
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Affiliation(s)
- Amartya Mukherjee
- Department of Developmental Biology and Genetics, Indian Institute of Science, Bangalore, India
| | - Upendra Nongthomba
- Department of Developmental Biology and Genetics, Indian Institute of Science, Bangalore, India
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3
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Zhang J, Zhang S, Sun Z, Cai Y, Zhong G, Yi X. Camptothecin Effectively Regulates Germline Differentiation through Bam-Cyclin A Axis in Drosophila melanogaster. Int J Mol Sci 2023; 24:ijms24021617. [PMID: 36675143 PMCID: PMC9864452 DOI: 10.3390/ijms24021617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/09/2023] [Accepted: 01/10/2023] [Indexed: 01/18/2023] Open
Abstract
Camptothecin (CPT), first isolated from Chinese tree Camptotheca acuminate, produces rapid and prolonged inhibition of DNA synthesis and induction of DNA damage by targeting topoisomerase I (top1), which is highly activated in cancer cells. CPT thus exhibits remarkable anticancer activities in various cancer types, and is a promising therapeutic agent for the treatment of cancers. However, it remains to be uncovered underlying its cytotoxicity toward germ cells. In this study we found that CPT, a cell cycle-specific anticancer agent, reduced fecundity and exhibited significant cytotoxicity toward GSCs and two-cell cysts. We showed that CPT induced GSC loss and retarded two-cell cysts differentiation in a niche- or apoptosis-independent manner. Instead, CPT induced ectopic expression of a differentiation factor, bag of marbles (Bam), and regulated the expression of cyclin A, which contributed to GSC loss. In addition, CPT compromised two-cell cysts differentiation by decreasing the expression of Bam and inducing cell arrest at G1/S phase via cyclin A, eventually resulting in two-cell accumulation. Collectively, this study demonstrates, for the first time in vivo, that the Bam-cyclin A axis is involved in CPT-mediated germline stem cell loss and two-cell cysts differentiation defects via inducing cell cycle arrest, which could provide information underlying toxicological effects of CPT in the productive system, and feature its potential to develop as a pharmacology-based germline stem cell regulation agent.
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Affiliation(s)
- Jing Zhang
- Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou 510642, China
| | - Shijie Zhang
- Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou 510642, China
| | - Zhipeng Sun
- Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou 510642, China
| | - Yu Cai
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore 119077, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore 119077, Singapore
| | - Guohua Zhong
- Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou 510642, China
- Correspondence: (G.Z.); (X.Y.)
| | - Xin Yi
- Key Laboratory of Crop Integrated Pest Management in South China, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China
- Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou 510642, China
- Correspondence: (G.Z.); (X.Y.)
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4
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Martin ET, Sarkar K, McCarthy A, Rangan P. Oo-site: A dashboard to visualize gene expression during Drosophila oogenesis suggests meiotic entry is regulated post-transcriptionally. Biol Open 2022; 11:275394. [PMID: 35579517 PMCID: PMC9148541 DOI: 10.1242/bio.059286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 04/19/2022] [Indexed: 11/20/2022] Open
Abstract
Determining how stem cell differentiation is controlled has important implications for understanding the etiology of degenerative disease and designing regenerative therapies. In vivo analyses of stem cell model systems have revealed regulatory paradigms for stem cell self-renewal and differentiation. The germarium of the female Drosophila gonad, which houses both germline and somatic stem cells, is one such model system. Bulk mRNA sequencing (RNA-seq), single-cell RNA-seq (scRNA-seq), and bulk translation efficiency (polysome-seq) of mRNAs are available for stem cells and their differentiating progeny within the Drosophila germarium. However, visualizing those data is hampered by the lack of a tool to spatially map gene expression and translational data in the germarium. Here, we have developed Oo-site (https://www.ranganlab.com/Oo-site), a tool for visualizing bulk RNA-seq, scRNA-seq, and translational efficiency data during different stages of germline differentiation, which makes these data accessible to non-bioinformaticians. Using this tool, we recapitulated previously reported expression patterns of developmentally regulated genes and discovered that meiotic genes, such as those that regulate the synaptonemal complex, are regulated at the level of translation.
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Affiliation(s)
- Elliot T Martin
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA
| | - Kahini Sarkar
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA.,Black Family Stem Cell Institute, Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Place, New York, NY 10029, USA
| | - Alicia McCarthy
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA
| | - Prashanth Rangan
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA.,Black Family Stem Cell Institute, Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, 1 Gustave L. Levy Place, New York, NY 10029, USA
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5
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Nikonova E, Mukherjee A, Kamble K, Barz C, Nongthomba U, Spletter ML. Rbfox1 is required for myofibril development and maintaining fiber type-specific isoform expression in Drosophila muscles. Life Sci Alliance 2022; 5:5/4/e202101342. [PMID: 34996845 PMCID: PMC8742874 DOI: 10.26508/lsa.202101342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 12/22/2021] [Accepted: 12/23/2021] [Indexed: 11/24/2022] Open
Abstract
Protein isoform transitions confer muscle fibers with distinct properties and are regulated by differential transcription and alternative splicing. RNA-binding Fox protein 1 (Rbfox1) can affect both transcript levels and splicing, and is known to contribute to normal muscle development and physiology in vertebrates, although the detailed mechanisms remain obscure. In this study, we report that Rbfox1 contributes to the generation of adult muscle diversity in Drosophila Rbfox1 is differentially expressed among muscle fiber types, and RNAi knockdown causes a hypercontraction phenotype that leads to behavioral and eclosion defects. Misregulation of fiber type-specific gene and splice isoform expression, notably loss of an indirect flight muscle-specific isoform of Troponin-I that is critical for regulating myosin activity, leads to structural defects. We further show that Rbfox1 directly binds the 3'-UTR of target transcripts, regulates the expression level of myogenic transcription factors myocyte enhancer factor 2 and Salm, and both modulates expression of and genetically interacts with the CELF family RNA-binding protein Bruno1 (Bru1). Rbfox1 and Bru1 co-regulate fiber type-specific alternative splicing of structural genes, indicating that regulatory interactions between FOX and CELF family RNA-binding proteins are conserved in fly muscle. Rbfox1 thus affects muscle development by regulating fiber type-specific splicing and expression dynamics of identity genes and structural proteins.
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Affiliation(s)
- Elena Nikonova
- Department of Physiological Chemistry, Biomedical Center, Ludwig-Maximilians-Universität München, Martinsried-Planegg, Germany
| | - Amartya Mukherjee
- Department of Molecular Reproduction, Development and Genetics (MRDG), Indian Institute of Science, Bangalore, India
| | - Ketaki Kamble
- Department of Molecular Reproduction, Development and Genetics (MRDG), Indian Institute of Science, Bangalore, India
| | - Christiane Barz
- Muscle Dynamics Group, Max Planck Institute of Biochemistry, Martinsried-Planegg, Germany
| | - Upendra Nongthomba
- Department of Molecular Reproduction, Development and Genetics (MRDG), Indian Institute of Science, Bangalore, India
| | - Maria L Spletter
- Department of Physiological Chemistry, Biomedical Center, Ludwig-Maximilians-Universität München, Martinsried-Planegg, Germany
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6
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McCarthy A, Sarkar K, Martin ET, Upadhyay M, Jang S, Williams ND, Forni PE, Buszczak M, Rangan P. Msl3 promotes germline stem cell differentiation in female Drosophila. Development 2022; 149:dev199625. [PMID: 34878097 PMCID: PMC8783043 DOI: 10.1242/dev.199625] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 11/19/2021] [Indexed: 01/07/2023]
Abstract
Gamete formation from germline stem cells (GSCs) is essential for sexual reproduction. However, the regulation of GSC differentiation is incompletely understood. Set2, which deposits H3K36me3 modifications, is required for GSC differentiation during Drosophila oogenesis. We discovered that the H3K36me3 reader Male-specific lethal 3 (Msl3) and histone acetyltransferase complex Ada2a-containing (ATAC) cooperate with Set2 to regulate GSC differentiation in female Drosophila. Msl3, acting independently of the rest of the male-specific lethal complex, promotes transcription of genes, including a germline-enriched ribosomal protein S19 paralog RpS19b. RpS19b upregulation is required for translation of RNA-binding Fox protein 1 (Rbfox1), a known meiotic cell cycle entry factor. Thus, Msl3 regulates GSC differentiation by modulating translation of a key factor that promotes transition to an oocyte fate.
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Affiliation(s)
- Alicia McCarthy
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA
| | - Kahini Sarkar
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA
| | - Elliot T. Martin
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA
| | - Maitreyi Upadhyay
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA
- Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA 02138, USA
| | - Seoyeon Jang
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Nathan D. Williams
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Paolo E. Forni
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA
| | - Michael Buszczak
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Prashanth Rangan
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202, USA
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7
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Mercer M, Jang S, Ni C, Buszczak M. The Dynamic Regulation of mRNA Translation and Ribosome Biogenesis During Germ Cell Development and Reproductive Aging. Front Cell Dev Biol 2021; 9:710186. [PMID: 34805139 PMCID: PMC8595405 DOI: 10.3389/fcell.2021.710186] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Accepted: 10/07/2021] [Indexed: 01/21/2023] Open
Abstract
The regulation of mRNA translation, both globally and at the level of individual transcripts, plays a central role in the development and function of germ cells across species. Genetic studies using flies, worms, zebrafish and mice have highlighted the importance of specific RNA binding proteins in driving various aspects of germ cell formation and function. Many of these mRNA binding proteins, including Pumilio, Nanos, Vasa and Dazl have been conserved through evolution, specifically mark germ cells, and carry out similar functions across species. These proteins typically influence mRNA translation by binding to specific elements within the 3′ untranslated region (UTR) of target messages. Emerging evidence indicates that the global regulation of mRNA translation also plays an important role in germ cell development. For example, ribosome biogenesis is often regulated in a stage specific manner during gametogenesis. Moreover, oocytes need to produce and store a sufficient number of ribosomes to support the development of the early embryo until the initiation of zygotic transcription. Accumulating evidence indicates that disruption of mRNA translation regulatory mechanisms likely contributes to infertility and reproductive aging in humans. These findings highlight the importance of gaining further insights into the mechanisms that control mRNA translation within germ cells. Future work in this area will likely have important impacts beyond germ cell biology.
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Affiliation(s)
- Marianne Mercer
- Department of Molecular Biology, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Seoyeon Jang
- Department of Molecular Biology, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Chunyang Ni
- Department of Molecular Biology, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Michael Buszczak
- Department of Molecular Biology, The University of Texas Southwestern Medical Center, Dallas, TX, United States
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8
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A Broad-Based Mosquito Yeast Interfering RNA Pesticide Targeting Rbfox1 Represses Notch Signaling and Kills Both Larvae and Adult Mosquitoes. Pathogens 2021; 10:pathogens10101251. [PMID: 34684200 PMCID: PMC8541554 DOI: 10.3390/pathogens10101251] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/21/2021] [Accepted: 09/23/2021] [Indexed: 12/03/2022] Open
Abstract
Prevention of mosquito-borne infectious diseases will require new classes of environmentally safe insecticides and novel mosquito control technologies. Saccharomyces cerevisiae was engineered to express short hairpin RNA (shRNA) corresponding to mosquito Rbfox1 genes. The yeast induced target gene silencing, resulting in larval death that was observed in both laboratory and outdoor semi-field trials conducted on Aedes aegypti. High levels of mortality were also observed during simulated field trials in which adult females consumed yeast delivered through a sugar bait. Mortality correlated with defects in the mosquito brain, in which a role for Rbfox1 as a positive regulator of Notch signaling was identified. The larvicidal and adulticidal activities of the yeast were subsequently confirmed in trials conducted on Aedes albopictus, Anopheles gambiae, and Culex quinquefasciatus, yet the yeast had no impact on survival of select non-target arthropods. These studies indicate that yeast RNAi pesticides targeting Rbfox1 could be further developed as broad-based mosquito larvicides and adulticides for deployment in integrated biorational mosquito control programs. These findings also suggest that the species-specificity of attractive targeted sugar baits, a new paradigm for vector control, could potentially be enhanced through RNAi technology, and specifically through the use of yeast-based interfering RNA pesticides.
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9
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Ote M, Yamamoto D. Impact of Wolbachia infection on Drosophila female germline stem cells. CURRENT OPINION IN INSECT SCIENCE 2020; 37:8-15. [PMID: 31726321 DOI: 10.1016/j.cois.2019.10.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 09/02/2019] [Accepted: 10/06/2019] [Indexed: 06/10/2023]
Abstract
Wolbachia pipientis, one of the most dominant insect-symbiotic bacteria, highjacks the female germline of insects for its own propagation across host generations. Such strict dependence on female gametes in trans-generational propagation has driven Wolbachia to devise ingenious strategies to enhance female fertility. In Drosophila melanogaster females with female-sterile mutant alleles of the master sex-determining gene Sex-lethal (Sxl), Wolbachia colonizing female germline stem cells (GSCs) support the maintenance of GSCs, thereby rescuing the defective ovarian development. In the germ cell cytoplasm, Wolbachia are often found in proximity to ribonucleoprotein-complex processing bodies (P bodies), where the Wolbachia-derived protein TomO interacts with RNAs encoding Nanos and Orb proteins, which support the GSC maintenance and oocyte polarization, respectively. Thus, manipulation of host RNA is the key to successful vertical transmission of Wolbachia.
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Affiliation(s)
- Manabu Ote
- Department of Tropical Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Daisuke Yamamoto
- Neuro-Network Evolution Project, Advanced ICT Research Institute, National Institute of Information and Communications Technology (NICT), Kobe, Japan.
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10
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Bhargava V, Goldstein CD, Russell L, Xu L, Ahmed M, Li W, Casey A, Servage K, Kollipara R, Picciarelli Z, Kittler R, Yatsenko A, Carmell M, Orth K, Amatruda JF, Yanowitz JL, Buszczak M. GCNA Preserves Genome Integrity and Fertility Across Species. Dev Cell 2019; 52:38-52.e10. [PMID: 31839537 DOI: 10.1016/j.devcel.2019.11.007] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 08/07/2019] [Accepted: 11/13/2019] [Indexed: 12/20/2022]
Abstract
The propagation of species depends on the ability of germ cells to protect their genome from numerous exogenous and endogenous threats. While these cells employ ubiquitous repair pathways, specialized mechanisms that ensure high-fidelity replication, chromosome segregation, and repair of germ cell genomes remain incompletely understood. We identified Germ Cell Nuclear Acidic Peptidase (GCNA) as a conserved regulator of genome stability in flies, worms, zebrafish, and human germ cell tumors. GCNA contains an acidic intrinsically disordered region (IDR) and a protease-like SprT domain. In addition to chromosomal instability and replication stress, Gcna mutants accumulate DNA-protein crosslinks (DPCs). GCNA acts in parallel with the SprT domain protein Spartan. Structural analysis reveals that while the SprT domain is needed to limit DNA damage, the IDR imparts significant function. This work shows that GCNA protects germ cells from various sources of damage, providing insights into conserved mechanisms that promote genome integrity across generations.
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Affiliation(s)
- Varsha Bhargava
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Courtney D Goldstein
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Logan Russell
- Magee-Womens Research Institute, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine, PA 15213, USA
| | - Lin Xu
- Quantitative Biomedical Research Center, Department of Population and Data Sciences, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Murtaza Ahmed
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Wei Li
- Magee-Womens Research Institute, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine, PA 15213, USA; Tsinghua University MD Program, School of Medicine, Tsinghua University, Haidian District, Beijing 100084, PR China
| | - Amanda Casey
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Kelly Servage
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Howard Hughes Medical Institute, 6000 Harry Hines Boulevard NA5.120F, Dallas, TX 75235, USA
| | - Rahul Kollipara
- McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Zachary Picciarelli
- Magee-Womens Research Institute, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine, PA 15213, USA
| | - Ralf Kittler
- McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Alexander Yatsenko
- Magee-Womens Research Institute, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine, PA 15213, USA
| | - Michelle Carmell
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA; RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA; Department of Biological Sciences, Wellesley College, Wellesley, MA 02481, USA
| | - Kim Orth
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Howard Hughes Medical Institute, 6000 Harry Hines Boulevard NA5.120F, Dallas, TX 75235, USA
| | - James F Amatruda
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Judith L Yanowitz
- Magee-Womens Research Institute, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh School of Medicine, PA 15213, USA.
| | - Michael Buszczak
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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11
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Teixeira FK, Lehmann R. Translational Control during Developmental Transitions. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a032987. [PMID: 30082467 DOI: 10.1101/cshperspect.a032987] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The many steps of gene expression, from the transcription of a gene to the production of its protein product, are well understood. Yet, transcriptional regulation has been the focal point for the study of gene expression during development. However, quantitative studies reveal that messenger RNA (mRNA) levels are not necessarily good predictors of the respective proteins' levels in a cell. This discrepancy is, at least in part, the result of developmentally regulated, translational mechanisms that control the spatiotemporal regulation of gene expression. In this review, we focus on translational regulatory mechanisms mediating global transitions in gene expression: the shift from the maternal to the embryonic developmental program in the early embryo and the switch from the self-renewal of stem cells to differentiation in the adult.
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Affiliation(s)
| | - Ruth Lehmann
- Howard Hughes Medical Institute (HHMI) and Kimmel Center for Biology and Medicine of the Skirball Institute, Department of Cell Biology, New York University School of Medicine, New York, New York 10016
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12
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McCarthy A, Deiulio A, Martin ET, Upadhyay M, Rangan P. Tip60 complex promotes expression of a differentiation factor to regulate germline differentiation in female Drosophila. Mol Biol Cell 2018; 29:2933-2945. [PMID: 30230973 PMCID: PMC6329907 DOI: 10.1091/mbc.e18-06-0385] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 09/06/2018] [Accepted: 09/13/2018] [Indexed: 01/23/2023] Open
Abstract
Germline stem cells (GSCs) self-renew and differentiate to sustain a continuous production of gametes. In the female Drosophila germ line, two differentiation factors, bag of marbles ( bam) and benign gonial cell neoplasm ( bgcn), work in concert in the stem cell daughter to promote the generation of eggs. In GSCs, bam transcription is repressed by signaling from the niche and is activated in stem cell daughters. In contrast, bgcn is transcribed in both the GSCs and stem cell daughters, but little is known about how bgcn is transcriptionally modulated. Here we find that the conserved protein Nipped-A acts through the Tat interactive protein 60-kDa (Tip60) histone acetyl transferase complex in the germ line to promote GSC daughter differentiation. We find that Nipped-A is required for efficient exit from the gap phase 2 (G2) of cell cycle of the GSC daughter and for expression of a differentiation factor, bgcn. Loss of Nipped-A results in accumulation of GSC daughters . Forced expression of bgcn in Nipped-A germline-depleted ovaries rescues this differentiation defect. Together, our results indicate that Tip60 complex coordinates cell cycle progression and expression of bgcn to help drive GSC daughters toward a differentiation program.
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Affiliation(s)
- Alicia McCarthy
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12222
| | - Aron Deiulio
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12222
| | - Elliot Todd Martin
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12222
| | - Maitreyi Upadhyay
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12222
| | - Prashanth Rangan
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12222
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13
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Abstract
Gametogenesis represents the most dramatic cellular differentiation pathways in both female and male flies. At the genome level, meiosis ensures that diploid germ cells become haploid gametes. At the epigenome level, extensive changes are required to turn on and shut off gene expression in a precise spatiotemporally controlled manner. Research applying conventional molecular genetics and cell biology, in combination with rapidly advancing genomic tools have helped us to investigate (1) how germ cells maintain lineage specificity throughout their adult reproductive lifetime; (2) what molecular mechanisms ensure proper oogenesis and spermatogenesis, as well as protect genome integrity of the germline; (3) how signaling pathways contribute to germline-soma communication; and (4) if such communication is important. In this chapter, we highlight recent discoveries that have improved our understanding of these questions. On the other hand, restarting a new life cycle upon fertilization is a unique challenge faced by gametes, raising questions that involve intergenerational and transgenerational epigenetic inheritance. Therefore, we also discuss new developments that link changes during gametogenesis to early embryonic development-a rapidly growing field that promises to bring more understanding to some fundamental questions regarding metazoan development.
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14
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Nazario-Toole AE, Robalino J, Okrah K, Corrada-Bravo H, Mount SM, Wu LP. The Splicing Factor RNA-Binding Fox Protein 1 Mediates the Cellular Immune Response in Drosophila melanogaster. THE JOURNAL OF IMMUNOLOGY 2018; 201:1154-1164. [PMID: 29997126 DOI: 10.4049/jimmunol.1800496] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 06/14/2018] [Indexed: 12/15/2022]
Abstract
The uptake and destruction of bacteria by phagocytic cells is an essential defense mechanism in metazoans. To identify novel genes involved in the phagocytosis of Staphylococcus aureus, a major human pathogen, we assessed the phagocytic capacity of adult blood cells (hemocytes) of the fruit fly, Drosophila melanogaster, by testing several lines of the Drosophila Genetic Reference Panel. Natural genetic variation in the gene RNA-binding Fox protein 1 (Rbfox1) correlated with low phagocytic capacity in hemocytes, pointing to Rbfox1 as a candidate regulator of phagocytosis. Loss of Rbfox1 resulted in increased expression of the Ig superfamily member Down syndrome adhesion molecule 4 (Dscam4). Silencing of Dscam4 in Rbfox1-depleted blood cells rescued the fly's cellular immune response to S. aureus, indicating that downregulation of Dscam4 by Rbfox1 is critical for S. aureus phagocytosis in Drosophila To our knowledge, this study is the first to demonstrate a link between Rbfox1, Dscam4, and host defense against S. aureus.
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Affiliation(s)
- Ashley E Nazario-Toole
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742.,Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, MD 20742; and
| | - Javier Robalino
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742
| | - Kwame Okrah
- Center for Bioinformatics and Computational Biology, University of Maryland, College Park, MD 20742
| | - Hector Corrada-Bravo
- Center for Bioinformatics and Computational Biology, University of Maryland, College Park, MD 20742
| | - Stephen M Mount
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742.,Center for Bioinformatics and Computational Biology, University of Maryland, College Park, MD 20742
| | - Louisa P Wu
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742; .,Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, MD 20742; and
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15
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Requirement of the Dynein-Adaptor Spindly for Mitotic and Post-Mitotic Functions in Drosophila. J Dev Biol 2018; 6:jdb6020009. [PMID: 29615558 PMCID: PMC6027351 DOI: 10.3390/jdb6020009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 03/20/2018] [Accepted: 03/27/2018] [Indexed: 11/17/2022] Open
Abstract
Spindly was originally identified as a specific regulator of Dynein activity at the kinetochore. In early prometaphase, Spindly recruits the Dynein/Dynactin complex, promoting the establishment of stable kinetochore-microtubule interactions and progression into anaphase. While details of Spindly function in mitosis have been worked out in cultured human cells and in the C. elegans zygote, the function of Spindly within the context of an organism has not yet been addressed. Here, we present loss- and gain-of-function studies of Spindly using transgenic RNAi in Drosophila. Knock-down of Spindly in the female germ line results in mitotic arrest during embryonic cleavage divisions. We investigated the requirements of Spindly protein domains for its localisation and function, and found that the carboxy-terminal region controls Spindly localisation in a cell-type specific manner. Overexpression of Spindly in the female germ line is embryonic lethal and results in altered egg morphology. To determine whether Spindly plays a role in post-mitotic cells, we altered Spindly protein levels in migrating cells and found that ovarian border cell migration is sensitive to the levels of Spindly protein. Our study uncovers novel functions of Spindly and a differential, functional requirement for its carboxy-terminal region in Drosophila.
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16
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Stress-dependent miR-980 regulation of Rbfox1/A2bp1 promotes ribonucleoprotein granule formation and cell survival. Nat Commun 2018; 9:312. [PMID: 29358748 PMCID: PMC5778076 DOI: 10.1038/s41467-017-02757-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 12/21/2017] [Indexed: 12/22/2022] Open
Abstract
Upon stress, profound post-transcriptional adjustments of gene expression occur in spatially restricted, subcellular, membraneless compartments, or ribonucleoprotein (RNP) granules, which are formed by liquid phase separation of RNA-binding proteins with low complexity sequence domains (LCDs). Here, we show that Rbfox1 is an LCD-containing protein that aggregates into liquid droplets and amyloid-like fibers and promiscuously joins different nuclear and cytoplasmic RNP granules. Using Drosophila oogenesis as an in vivo system for stress response, we demonstrate a mechanism by which Rbfox1 promotes cell survival. The stress-dependent miRNA miR-980 acts to buffer Rbfox1 levels, since it targets only those Rbfox1 transcripts that contain extended 3′UTRs. Reduced miR-980 expression during stress leads to increased Rbfox1 levels, widespread formation of various RNP granules, and increased cell viability. We show that human RBFOX proteins also contain multiple LCDs and form membraneless compartments, suggesting that the RNP granule-linked control of cellular adaptive responses may contribute to a wide range of RBFOX-associated pathologies in humans. Rbfox1, a pro-survival RNA-binding protein, is expressed in a complex manner and mediates diverse developmental processes. Here, the authors observe alternative splicing of Rbfox1 and stress-dependent regulation by miR-980 in Drosophila ovaries and Rbfox1 localisation in ribonucleoprotein granules in human cells.
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17
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Salz HK, Dawson EP, Heaney JD. Germ cell tumors: Insights from the Drosophila ovary and the mouse testis. Mol Reprod Dev 2017; 84:200-211. [PMID: 28079292 DOI: 10.1002/mrd.22779] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 01/10/2017] [Indexed: 12/14/2022]
Abstract
Ovarian and testicular germ cell tumors of young adults are thought to arise from defects in germ cell development, but the molecular mechanisms underlying malignant transformation are poorly understood. In this review, we focus on the biology of germ cell tumor formation in the Drosophila ovary and the mouse testis, for which evidence supports common underlying mechanisms, such as blocking initiation into the differentiation pathway, impaired lineage progression, and sexual identity instability. We then discuss how these concepts inform our understanding of the disease in humans. Mol. Reprod. Dev. 84: 200-211, 2017. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Helen K Salz
- Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio
| | - Emily P Dawson
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Jason D Heaney
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
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18
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Ma X, Zhu X, Han Y, Story B, Do T, Song X, Wang S, Zhang Y, Blanchette M, Gogol M, Hall K, Peak A, Anoja P, Xie T. Aubergine Controls Germline Stem Cell Self-Renewal and Progeny Differentiation via Distinct Mechanisms. Dev Cell 2017; 41:157-169.e5. [DOI: 10.1016/j.devcel.2017.03.023] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Revised: 02/10/2017] [Accepted: 03/29/2017] [Indexed: 01/09/2023]
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19
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Shukla JP, Deshpande G, Shashidhara LS. Ataxin 2-binding protein 1 is a context-specific positive regulator of Notch signaling during neurogenesis in Drosophila melanogaster. Development 2017; 144:905-915. [PMID: 28174239 DOI: 10.1242/dev.140657] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 01/18/2017] [Indexed: 12/28/2022]
Abstract
The role of the Notch pathway during the lateral inhibition that underlies binary cell fate choice is extensively studied, but the context specificity that generates diverse outcomes is less well understood. In the peripheral nervous system of Drosophila melanogaster, differential Notch signaling between cells of the proneural cluster orchestrates sensory organ specification. Here we report functional analysis of Drosophila Ataxin 2-binding protein 1 (A2BP1) during this process. Its human ortholog is linked to type 2 spinocerebellar ataxia and other complex neuronal disorders. Downregulation of Drosophila A2BP1 in the proneural cluster increases adult sensory bristle number, whereas its overexpression results in loss of bristles. We show that A2BP1 regulates sensory organ specification by potentiating Notch signaling. Supporting its direct involvement, biochemical analysis shows that A2BP1 is part of the Suppressor of Hairless [Su(H)] complex in the presence and absence of Notch. However, in the absence of Notch signaling, the A2BP1 interacting fraction of Su(H) does not associate with the repressor proteins Groucho and CtBP. We propose a model explaining the requirement of A2BP1 as a positive regulator of context-specific Notch activity.
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Affiliation(s)
- Jay Prakash Shukla
- Indian Institute of Science Education and Research Pune, Dr Homi Bhabha Road, Pune, Maharashtra 411008, India
| | - Girish Deshpande
- Indian Institute of Science Education and Research Pune, Dr Homi Bhabha Road, Pune, Maharashtra 411008, India.,Department of Molecular Biology, Princeton University, Princeton, NJ 08540, USA
| | - L S Shashidhara
- Indian Institute of Science Education and Research Pune, Dr Homi Bhabha Road, Pune, Maharashtra 411008, India
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20
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Guan G, Sun K, Zhang X, Zhao X, Li M, Yan Y, Wang Y, Chen J, Yi M, Hong Y. Developmental tracing of oocyte development in gonadal soma-derived factor deficiency medaka (Oryzias latipes) using a transgenic approach. Mech Dev 2017; 143:53-61. [PMID: 28093265 DOI: 10.1016/j.mod.2016.12.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 12/25/2016] [Accepted: 12/26/2016] [Indexed: 11/21/2022]
Abstract
Gonadal soma-derived factor (gsdf) is reported to be a male initiator in medaka based on loss- and gain- of function via targeted disruption, or transgenic over-expression. However, little is known about how gsdf promotes undifferentiated gonad entry into male pathways or prevents entry into the female pathway. We utilized a visible folliculogenesis system with a reporter cassette of dual-color fluorescence expression to identify difference between oocyte development from wildtype and gsdf deficiency medaka. A red fluorescent protein (RFP) is driven by a major component of the synaptonemal complex (SYCP3) promoter which enables RFP expression solely in oocytes after the onset of meiosis, and a histone 2b-EGFP fused protein (H2BEGFP) under the control of an elongation factor (EF1α) promoter, wildly used as a mitotic reporter of cell cycle. This mitosis-meiosis visible switch revealed that early meiotic oocytes present in gsdf deficiency were more than those in wildtype ovaries, corresponding to the decrease of inhibin expression detected by real-time qPCR analysis, suggesting gsdf is tightly involved in the process of medaka oocyte development at early stage.
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Affiliation(s)
- Guijun Guan
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, College of Fisheries and Life Sciences, Shanghai Ocean University, Shanghai 201306, China.
| | - Kaiqing Sun
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, College of Fisheries and Life Sciences, Shanghai Ocean University, Shanghai 201306, China
| | - Xi Zhang
- Department of Biological Sciences, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore
| | - Xiaomiao Zhao
- Reproductive Endocrinology & Infertility, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Yanjiang Road 107, Guangdong 510120, China
| | - Mingyou Li
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, College of Fisheries and Life Sciences, Shanghai Ocean University, Shanghai 201306, China
| | - Yan Yan
- Department of Biological Sciences, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore
| | - Yunzhi Wang
- Department of Biological Sciences, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore
| | - Jianbin Chen
- Department of Biological Sciences, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore
| | - Meisheng Yi
- Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Zhuhai Key Laboratory of Marine Bioresources and Environment, School of Marine Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yunhan Hong
- Department of Biological Sciences, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore
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21
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Blake AJ, Finger DS, Hardy VL, Ables ET. RNAi-Based Techniques for the Analysis of Gene Function in Drosophila Germline Stem Cells. Methods Mol Biol 2017; 1622:161-184. [PMID: 28674809 DOI: 10.1007/978-1-4939-7108-4_13] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Elucidating the full repertoire of molecular mechanisms that promote stem cell maintenance requires sophisticated techniques for identifying and characterizing gene function in stem cells in their native environment. Ovarian germline stem cells in the fruit fly, Drosophila melanogaster, are an ideal model to study the complex molecular mechanisms driving stem cell function in vivo. A variety of new genetic tools make RNAi a useful complement to traditional genetic mutants for the investigation of the molecular mechanisms guiding ovarian germline stem cell function. Here, we provide a detailed guide for using targeted RNAi knockdown for the discovery of gene function in ovarian germline stem cells and their progeny.
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Affiliation(s)
- Amelia J Blake
- East Carolina University, 1001 E. 10th Street, Mailstop 551, Greenville, NC, 27858, USA
| | - Danielle S Finger
- East Carolina University, 1001 E. 10th Street, Mailstop 551, Greenville, NC, 27858, USA
| | - Victoria L Hardy
- East Carolina University, 1001 E. 10th Street, Mailstop 551, Greenville, NC, 27858, USA
| | - Elizabeth T Ables
- East Carolina University, 1001 E. 10th Street, Mailstop 551, Greenville, NC, 27858, USA.
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22
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Nkiliza A, Mutez E, Simonin C, Leprêtre F, Duflot A, Figeac M, Villenet C, Semaille P, Comptdaer T, Genet A, Sablonnière B, Devos D, Defebvre L, Destée A, Chartier-Harlin MC. RNA-binding disturbances as a continuum from spinocerebellar ataxia type 2 to Parkinson disease. Neurobiol Dis 2016; 96:312-322. [PMID: 27663142 DOI: 10.1016/j.nbd.2016.09.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 09/07/2016] [Accepted: 09/17/2016] [Indexed: 12/13/2022] Open
Abstract
CAG triplet expansions in Ataxin-2 gene (ATXN2) cause spinocerebellar ataxia type 2 and have a role that remains to be clarified in Parkinson's disease (PD). To study the molecular events associated with these expansions, we sequenced them and analyzed the transcriptome from blood cells of controls and three patient groups diagnosed with spinocerebellar ataxia type 2 (herein referred to as SCA2c) or PD with or without ATXN2 triplet expansions (named SCA2p). The transcriptome profiles of these 40 patients revealed three main observations: i) a specific pattern of pathways related to cellular contacts, proliferation and differentiation associated with SCA2p group, ii) similarities between the SCA2p and sporadic PD groups in genes and pathways known to be altered in PD such as Wnt, Ephrin and Leukocyte extravasation signaling iii) RNA metabolism disturbances with "RNA-binding" and "poly(A) RNA-binding" as a common feature in all groups. Remarkably, disturbances of ALS signaling were shared between SCA2p and sporadic PD suggesting common molecular dysfunctions in PD and ALS including CACNA1, hnRNP, DDX and PABPC gene family perturbations. Interestingly, the transcriptome profiles of patients with parkinsonian phenotypes were prevalently associated with alterations of translation while SCA2c and PD patients presented perturbations of splicing. While ATXN2 RNA expression was not perturbed, its protein expression in immortalized lymphoblastoid cells was significantly decreased in SCA2c and SCA2p versus control groups assuming post-transcriptional biological perturbations. In conclusion, the transcriptome data do not exclude the role of ATXN2 mutated alleles in PD but its decrease protein expression in both SCA2c and SCA2p patients suggest a potential involvement of this gene in PD. The perturbations of "RNA-binding" and "poly(A) RNA-binding" molecular functions in the three patient groups as well as gene deregulations of factors not yet described in PD but known to be deleterious in other neurological conditions, suggest the existence of RNA-binding disturbances as a continuum between spinocerebellar ataxia type 2 and Parkinson's disease.
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Affiliation(s)
- Aurore Nkiliza
- Univ. Lille, UMR-S 1172 - JPArc - Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer, F-59000 Lille, France; Inserm, UMR-S 1172, Team "Early stages of Parkinson's disease", F-59000 Lille, France
| | - Eugénie Mutez
- Univ. Lille, UMR-S 1172 - JPArc - Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer, F-59000 Lille, France; Inserm, UMR-S 1172, Team "Early stages of Parkinson's disease", F-59000 Lille, France; CHU Lille, Neurologie et Pathologie du Mouvement, F-59000 Lille, France
| | - Clémence Simonin
- Univ. Lille, UMR-S 1172 - JPArc - Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer, F-59000 Lille, France; Inserm, UMR-S 1172, Team "Early stages of Parkinson's disease", F-59000 Lille, France; CHU Lille, Neurologie et Pathologie du Mouvement, F-59000 Lille, France
| | - Frédéric Leprêtre
- Univ. Lille, UMR-S 1172 - JPArc - Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer, F-59000 Lille, France; Univ. Lille, CHU Lille, IRCL, Structural and Functional Genomics Core Facility, F-59000 Lille, France
| | - Aurélie Duflot
- Univ. Lille, UMR-S 1172 - JPArc - Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer, F-59000 Lille, France; Inserm, UMR-S 1172, Team "Early stages of Parkinson's disease", F-59000 Lille, France
| | - Martin Figeac
- Univ. Lille, CHU Lille, IRCL, Structural and Functional Genomics Core Facility, F-59000 Lille, France
| | - Céline Villenet
- Univ. Lille, CHU Lille, IRCL, Structural and Functional Genomics Core Facility, F-59000 Lille, France
| | - Pierre Semaille
- Univ. Lille, UMR-S 1172 - JPArc - Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer, F-59000 Lille, France; Inserm, UMR-S 1172, Team "Early stages of Parkinson's disease", F-59000 Lille, France; CHU Lille, Neurologie et Pathologie du Mouvement, F-59000 Lille, France
| | - Thomas Comptdaer
- Univ. Lille, UMR-S 1172 - JPArc - Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer, F-59000 Lille, France; Inserm, UMR-S 1172, Team "Early stages of Parkinson's disease", F-59000 Lille, France
| | - Alexandre Genet
- CHU Lille, Centre de Biologie Pathologie, Unité de Neurobiologie, F-59000 Lille, France
| | - Bernard Sablonnière
- Univ. Lille, UMR-S 1172 - JPArc - Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer, F-59000 Lille, France; CHU Lille, Centre de Biologie Pathologie, Unité de Neurobiologie, F-59000 Lille, France
| | - David Devos
- CHU Lille, Neurologie et Pathologie du Mouvement, F-59000 Lille, France
| | - Luc Defebvre
- CHU Lille, Neurologie et Pathologie du Mouvement, F-59000 Lille, France
| | - Alain Destée
- Univ. Lille, UMR-S 1172 - JPArc - Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer, F-59000 Lille, France; Inserm, UMR-S 1172, Team "Early stages of Parkinson's disease", F-59000 Lille, France; CHU Lille, Neurologie et Pathologie du Mouvement, F-59000 Lille, France
| | - Marie-Christine Chartier-Harlin
- Univ. Lille, UMR-S 1172 - JPArc - Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer, F-59000 Lille, France; Inserm, UMR-S 1172, Team "Early stages of Parkinson's disease", F-59000 Lille, France.
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23
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Repression of Pumilio Protein Expression by Rbfox1 Promotes Germ Cell Differentiation. Dev Cell 2016; 36:562-71. [PMID: 26954550 DOI: 10.1016/j.devcel.2016.02.010] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 01/11/2016] [Accepted: 02/08/2016] [Indexed: 11/21/2022]
Abstract
RNA-binding Fox (Rbfox) proteins have well-established roles in regulating alternative splicing, but specific Rbfox isoforms lack nuclear localization signals and accumulate in the cytoplasm. The potential splicing-independent functions of these proteins remain unknown. Here we demonstrate that cytoplasmic Drosophila Rbfox1 regulates germ cell development and represses the translation of mRNAs containing (U)GCAUG elements within their 3'UTRs. During germline cyst differentiation, Rbfox1 targets pumilio mRNA for destabilization and translational silencing, thereby promoting germ cell development. Mis-expression of pumilio results in the formation of germline tumors, which contain cysts that break down and dedifferentiate back to single, mitotically active cells. Together, these results reveal that cytoplasmic Rbfox family members regulate the translation of specific target mRNAs. In the Drosophila ovary, this activity provides a genetic barrier that prevents germ cells from reverting back to an earlier developmental state. The finding that Rbfox proteins regulate mRNA translation has implications for Rbfox-related diseases.
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24
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Yang H, Li M, Hu X, Xin T, Zhang S, Zhao G, Xuan T, Li M. MicroRNA-dependent roles of Drosha and Pasha in the Drosophila larval ovary morphogenesis. Dev Biol 2016; 416:312-23. [DOI: 10.1016/j.ydbio.2016.06.026] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 06/17/2016] [Accepted: 06/17/2016] [Indexed: 01/04/2023]
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25
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Guven-Ozkan T, Busto GU, Schutte SS, Cervantes-Sandoval I, O'Dowd DK, Davis RL. MiR-980 Is a Memory Suppressor MicroRNA that Regulates the Autism-Susceptibility Gene A2bp1. Cell Rep 2016; 14:1698-1709. [PMID: 26876166 DOI: 10.1016/j.celrep.2016.01.040] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 10/26/2015] [Accepted: 01/09/2016] [Indexed: 01/07/2023] Open
Abstract
MicroRNAs have been associated with many different biological functions, but little is known about their roles in conditioned behavior. We demonstrate that Drosophila miR-980 is a memory suppressor gene functioning in multiple regions of the adult brain. Memory acquisition and stability were both increased by miR-980 inhibition. Whole cell recordings and functional imaging experiments indicated that miR-980 regulates neuronal excitability. We identified the autism susceptibility gene, A2bp1, as an mRNA target for miR-980. A2bp1 levels varied inversely with miR-980 expression; memory performance was directly related to A2bp1 levels. In addition, A2bp1 knockdown reversed the memory gains produced by miR-980 inhibition, consistent with A2bp1 being a downstream target of miR-980 responsible for the memory phenotypes. Our results indicate that miR-980 represses A2bp1 expression to tune the excitable state of neurons, and the overall state of excitability translates to memory impairment or improvement.
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Affiliation(s)
- Tugba Guven-Ozkan
- Department of Neuroscience, The Scripps Research Institute Florida, Jupiter, FL 33458, USA
| | - Germain U Busto
- Department of Neuroscience, The Scripps Research Institute Florida, Jupiter, FL 33458, USA
| | - Soleil S Schutte
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA 92697, USA; Department of Anatomy and Neurobiology, University of California, Irvine, Irvine, CA 92697, USA
| | | | - Diane K O'Dowd
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA 92697, USA; Department of Anatomy and Neurobiology, University of California, Irvine, Irvine, CA 92697, USA
| | - Ronald L Davis
- Department of Neuroscience, The Scripps Research Institute Florida, Jupiter, FL 33458, USA.
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26
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Abstract
Programmed cell death (PCD) is essential for health and development. Generally, the last step of PCD is clearance, or engulfment, by phagocytes. Engulfment can be broken down into five basic steps: attraction of the phagocyte, recognition of the dying cell, internalization, phagosome maturation, and acidification of the engulfed material. The Drosophila melanogaster ovary serves as an excellent model to study diverse types of PCD and engulfment by epithelial cells. Here, we describe several methods to detect and analyze multiple steps of engulfment in the Drosophila ovary: recognition, vesicle uptake, phagosome maturation, and acidification. Annexin V detects phosphatidylserine, which is flipped to the outer leaflet of the plasma membrane of apoptotic cells, serving as an "eat me" signal. Several germline markers including tral-GFP, Orb, and cleaved Dcp-1 can all be used to label the germline and visualize its uptake into engulfing follicle cells. Drosophila strains expressing GFP and mCherry protein fusions can enable a detailed analysis of phagosome maturation. LysoTracker labels highly acidified compartments, marking phagolysosomes. Together these labels can be used to mark the progression of engulfment in Drosophila follicle cells.
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Abstract
Drosophila oogenesis is a powerful model for studying a wide spectrum of cellular and developmental processes in vivo. Oogenesis starts in a specialized structure called the germarium, which harbors the stem cells for both germ and somatic cells. The germarium produces egg chambers, each of which will develop into an egg. Active areas of research in Drosophila germaria include stem cell self-renewal, division, and maintenance, cell cycle control and differentiation, oocyte specification, intercellular communication, and signaling, among others. The solid knowledge base, the genetic tractability of the Drosophila model, as well as the availability and fast development of tools and imaging techniques for oogenesis research ensure that studies in this model will keep being instrumental for novel discoveries within cell and developmental biology also in the future. This chapter focuses on antibody staining in Drosophila germaria and provides a protocol for immunostaining as well as an overview of commonly used antibodies for visualization of different cell types and cellular structures. The protocol is well-suited for subsequent confocal microscopy analyses, and in addition we present key adaptations of the protocol that are useful when performing structured illumination microscopy (SIM) super-resolution imaging.
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Affiliation(s)
- Anette Lie-Jensen
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, N-0379, Oslo, Norway
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, N-0379, Oslo, Norway
| | - Kaisa Haglund
- Department of Molecular Cell Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, N-0379, Oslo, Norway.
- Centre for Cancer Biomedicine, Faculty of Medicine, University of Oslo, Montebello, N-0379, Oslo, Norway.
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Fu Z, Geng C, Wang H, Yang Z, Weng C, Li H, Deng L, Liu L, Liu N, Ni J, Xie T. Twin Promotes the Maintenance and Differentiation of Germline Stem Cell Lineage through Modulation of Multiple Pathways. Cell Rep 2015; 13:1366-1379. [DOI: 10.1016/j.celrep.2015.10.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Revised: 08/12/2015] [Accepted: 10/05/2015] [Indexed: 11/28/2022] Open
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Li C, Kan L, Chen Y, Zheng X, Li W, Zhang W, Cao L, Lin X, Ji S, Huang S, Zhang G, Liu X, Tao Y, Wu S, Chen D. Ci antagonizes Hippo signaling in the somatic cells of the ovary to drive germline stem cell differentiation. Cell Res 2015; 25:1152-70. [PMID: 26403189 DOI: 10.1038/cr.2015.114] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 08/02/2015] [Accepted: 08/06/2015] [Indexed: 12/17/2022] Open
Abstract
Many stem cell populations are tightly regulated by their local microenvironment (niche), which comprises distinct types of stromal cells. However, little is known about mechanisms by which niche subgroups coordinately determine the stem cell fate. Here we identify that Yki, the key Hippo pathway component, is essential for escort cell (EC) function in promoting germline differentiation in Drosophila ovary. We found that Hedgehog (Hh) signals emanating primarily from cap cells support the function of ECs, where Cubitus interruptus (Ci), the Hh signaling effector, acts to inhibit Hippo kinase cascade activity. Mechanistically, we found that Ci competitively interacts with Hpo and impairs the Hpo-Wts signaling complex formation, thereby promoting Yki nuclear localization. The actions of Ci ensure effective Yki signaling to antagonize Sd/Tgi/Vg-mediated default repression in ECs. This study uncovers a mechanism explaining how subgroups of niche cells coordinate to determine the stem cell fate via Hh-Hippo signaling crosstalk, and enhances our understanding of mechanistic regulations of the oncogenic Yki/YAP signaling.
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Affiliation(s)
- Chaoyi Li
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Datun Road, Chaoyang, Beijing 100101, China
| | - Lijuan Kan
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Datun Road, Chaoyang, Beijing 100101, China
| | - Yan Chen
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Xiudeng Zheng
- Centre for Computational and Evolutionary Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Weini Li
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Datun Road, Chaoyang, Beijing 100101, China
| | - Wenxin Zhang
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Datun Road, Chaoyang, Beijing 100101, China
| | - Lei Cao
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Xiaohui Lin
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Shanming Ji
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Datun Road, Chaoyang, Beijing 100101, China
| | - Shoujun Huang
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Datun Road, Chaoyang, Beijing 100101, China
| | - Guoqiang Zhang
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Datun Road, Chaoyang, Beijing 100101, China
| | - Xiaohui Liu
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Yi Tao
- Centre for Computational and Evolutionary Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Shian Wu
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Dahua Chen
- State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Datun Road, Chaoyang, Beijing 100101, China
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Mukai M, Hira S, Nakamura K, Nakamura S, Kimura H, Sato M, Kobayashi S. H3K36 Trimethylation-Mediated Epigenetic Regulation is Activated by Bam and Promotes Germ Cell Differentiation During Early Oogenesis in Drosophila. Biol Open 2015; 4:119-24. [PMID: 25572421 PMCID: PMC4365480 DOI: 10.1242/bio.201410850] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Epigenetic silencing is critical for maintaining germline stem cells in Drosophila ovaries. However, it remains unclear how the differentiation factor, Bag-of-marbles (Bam), counteracts transcriptional silencing. We found that the trimethylation of lysine 36 on histone H3 (H3K36me3), a modification that is associated with gene activation, is enhanced in Bam-expressing cells. H3K36me3 levels were reduced in flies deficient in Bam. Inactivation of the Set2 methyltransferase, which confers the H3K36me3 modification, in germline cells markedly reduced H3K36me3 and impaired differentiation. Genetic analyses revealed that Set2 acts downstream of Bam. Furthermore, orb expression, which is required for germ cell differentiation, was activated by Set2, probably through direct H3K36me3 modification of the orb locus. Our data indicate that H3K36me3-mediated epigenetic regulation is activated by bam, and that this modification facilitates germ cell differentiation, probably through transcriptional activation. This work provides a novel link between Bam and epigenetic transcriptional control.
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Affiliation(s)
- Masanori Mukai
- Department of Biology, Faculty of Science and Engineering, Konan University, Okamoto, Higashinada, Kobe 658-8501, Japan Graduate School of Natural Science, Konan University, Okamoto, Higashinada, Kobe 658-8501, Japan Institute for Integrative Neurobiology, Konan University, Okamoto, Higashinada, Kobe 658-8501, Japan
| | - Seiji Hira
- Graduate School of Natural Science, Konan University, Okamoto, Higashinada, Kobe 658-8501, Japan Research Fellow of Japan Society for the Promotion of Science, Tokyo 102-0083, Japan
| | - Katsuhiro Nakamura
- Graduate School of Natural Science, Konan University, Okamoto, Higashinada, Kobe 658-8501, Japan
| | - Shoichi Nakamura
- Department of Biology, Faculty of Science and Engineering, Konan University, Okamoto, Higashinada, Kobe 658-8501, Japan
| | - Hiroshi Kimura
- Department of Biological Sciences, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, 226-8501, Japan
| | - Masanao Sato
- Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, Higashiyama, Myodaiji, Okazaki 444-8787, Japan
| | - Satoru Kobayashi
- Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, Higashiyama, Myodaiji, Okazaki 444-8787, Japan Life Science Center, Tsukuba Advanced Research Alliance, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
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31
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Laws KM, Sampson LL, Drummond-Barbosa D. Insulin-independent role of adiponectin receptor signaling in Drosophila germline stem cell maintenance. Dev Biol 2015; 399:226-36. [PMID: 25576925 DOI: 10.1016/j.ydbio.2014.12.033] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 12/02/2014] [Accepted: 12/29/2014] [Indexed: 10/24/2022]
Abstract
Adipocytes have key endocrine roles, mediated in large part by secreted protein hormones termed adipokines. The adipokine adiponectin is well known for its role in sensitizing peripheral tissues to insulin, and several lines of evidence suggest that adiponectin might also modulate stem cells/precursors. It remains unclear, however, how adiponectin signaling controls stem cells and whether this role is secondary to its insulin-sensitizing effects or distinct. Drosophila adipocytes also function as an endocrine organ and, although no obvious adiponectin homolog has been identified, Drosophila AdipoR encodes a well-conserved homolog of mammalian adiponectin receptors. Here, we generate a null AdipoR allele and use clonal analysis to demonstrate an intrinsic requirement for AdipoR in germline stem cell (GSC) maintenance in the Drosophila ovary. AdipoR null GSCs are not fully responsive to bone morphogenetic protein ligands from the niche and have a slight reduction in E-cadherin levels at the GSC-niche junction. Conversely, germline-specific overexpression of AdipoR inhibits natural GSC loss, suggesting that reduction in adiponectin signaling might contribute to the normal decline in GSC numbers observed over time in wild-type females. Surprisingly, AdipoR is not required for insulin sensitization of the germline, leading us to speculate that insulin sensitization is a more recently acquired function than stem cell regulation in the evolutionary history of adiponectin signaling. Our findings establish Drosophila female GSCs as a new system for future studies addressing the molecular mechanisms whereby adiponectin receptor signaling modulates stem cell fate.
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Affiliation(s)
- Kaitlin M Laws
- Department of Biochemistry and Molecular Biology, Division of Reproductive Biology, Baltimore, MD, USA
| | - Leesa L Sampson
- Department of Biochemistry and Molecular Biology, Division of Reproductive Biology, Baltimore, MD, USA
| | - Daniela Drummond-Barbosa
- Department of Biochemistry and Molecular Biology, Division of Reproductive Biology, Baltimore, MD, USA; Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA.
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32
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He J, Xuan T, Xin T, An H, Wang J, Zhao G, Li M. Evidence for chromatin-remodeling complex PBAP-controlled maintenance of the Drosophila ovarian germline stem cells. PLoS One 2014; 9:e103473. [PMID: 25068272 PMCID: PMC4113433 DOI: 10.1371/journal.pone.0103473] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 06/30/2014] [Indexed: 11/19/2022] Open
Abstract
In the Drosophila oogenesis, germline stem cells (GSCs) continuously self-renew and differentiate into daughter cells for consecutive germline lineage commitment. This developmental process has become an in vivo working platform for studying adult stem cell fate regulation. An increasing number of studies have shown that while concerted actions of extrinsic signals from the niche and intrinsic regulatory machineries control GSC self-renewal and germline differentiation, epigenetic regulation is implicated in the process. Here, we report that Brahma (Brm), the ATPase subunit of the Drosophila SWI/SNF chromatin-remodeling complexes, is required for maintaining GSC fate. Removal or knockdown of Brm function in either germline or niche cells causes a GSC loss, but does not disrupt normal germline differentiation within the germarium evidenced at the molecular and morphological levels. There are two Drosophila SWI/SNF complexes: the Brm-associated protein (BAP) complex and the polybromo-containing BAP (PBAP) complex. More genetic studies reveal that mutations in polybromo/bap180, rather than gene encoding Osa, the BAP complex-specific subunit, elicit a defect in GSC maintenance reminiscent of the brm mutant phenotype. Further genetic interaction test suggests a functional association between brm and polybromo in controlling GSC self-renewal. Taken together, studies in this paper provide the first demonstration that Brm in the form of the PBAP complex functions in the GSC fate regulation.
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Affiliation(s)
- Jie He
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, P R China
| | - Tao Xuan
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, P R China
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, P R China
- * E-mail: (TX); (ML)
| | - Tianchi Xin
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, P R China
| | - Hongbo An
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, P R China
| | - Jinye Wang
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, P R China
| | - Gengchun Zhao
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, P R China
| | - Mingfa Li
- School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, P R China
- * E-mail: (TX); (ML)
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Zhang Q, Shalaby NA, Buszczak M. Changes in rRNA transcription influence proliferation and cell fate within a stem cell lineage. Science 2014; 343:298-301. [PMID: 24436420 DOI: 10.1126/science.1246384] [Citation(s) in RCA: 145] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Ribosome biogenesis drives cell growth and proliferation, but mechanisms that modulate this process within specific lineages remain poorly understood. Here, we identify a Drosophila RNA polymerase I (Pol I) regulatory complex composed of Under-developed (Udd), TAF1B, and a TAF1C-like factor. Disruption of udd or TAF1B results in reduced ovarian germline stem cell (GSC) proliferation. Female GSCs display high levels of ribosomal RNA (rRNA) transcription, and Udd becomes enriched in GSCs relative to their differentiating daughters. Increasing Pol I transcription delays differentiation, whereas reducing rRNA production induces both morphological changes that accompany multicellular cyst formation and specific decreased expression of the bone morphogenetic protein (BMP) pathway component Mad. These findings demonstrate that modulating rRNA synthesis fosters changes in the cell fate, growth, and proliferation of female Drosophila GSCs and their daughters.
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Affiliation(s)
- Qiao Zhang
- Department of Molecular Biology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-9148, USA
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Xin T, Xuan T, Tan J, Li M, Zhao G, Li M. The Drosophila putative histone acetyltransferase Enok maintains female germline stem cells through regulating Bruno and the niche. Dev Biol 2013; 384:1-12. [PMID: 24120347 DOI: 10.1016/j.ydbio.2013.10.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 09/29/2013] [Accepted: 10/02/2013] [Indexed: 12/16/2022]
Abstract
Maintenance of adult stem cells is largely dependent on the balance between their self-renewal and differentiation. The Drosophila ovarian germline stem cells (GSCs) provide a powerful in vivo system for studying stem cell fate regulation. It has been shown that maintaining the GSC population involves both genetic and epigenetic mechanisms. Although the role of epigenetic regulation in this process is evident, the underlying mechanisms remain to be further explored. In this study, we find that Enoki mushroom (Enok), a Drosophila putative MYST family histone acetyltransferase controls GSC maintenance in the ovary at multiple levels. Removal or knockdown of Enok in the germline causes a GSC maintenance defect. Further studies show that the cell-autonomous role of Enok in maintaining GSCs is not dependent on the BMP/Bam pathway. Interestingly, molecular studies reveal an ectopic expression of Bruno, an RNA binding protein, in the GSCs and their differentiating daughter cells elicited by the germline Enok deficiency. Misexpression of Bruno in GSCs and their immediate descendants results in a GSC loss that can be exacerbated by incorporating one copy of enok mutant allele. These data suggest a role for Bruno in Enok-controlled GSC maintenance. In addition, we observe that Enok is required for maintaining GSCs non-autonomously. Compromised expression of enok in the niche cells impairs the niche maintenance and BMP signal output, thereby causing defective GSC maintenance. This is the first demonstration that the niche size control requires an epigenetic mechanism. Taken together, studies in this paper provide new insights into the GSC fate regulation.
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Affiliation(s)
- Tianchi Xin
- MoE Key Laboratory of Developmental Genetics and Neuropsychiatric Diseases, Bio-X Institutes, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, 200240 Shanghai, PR China
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Soshnev AA, Baxley RM, Manak JR, Tan K, Geyer PK. The insulator protein Suppressor of Hairy-wing is an essential transcriptional repressor in the Drosophila ovary. Development 2013; 140:3613-23. [PMID: 23884443 DOI: 10.1242/dev.094953] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Suppressor of Hairy-wing [Su(Hw)] is a DNA-binding factor required for gypsy insulator function and female germline development in Drosophila. The insulator function of the gypsy retrotransposon depends on Su(Hw) binding to clustered Su(Hw) binding sites (SBSs) and recruitment of the insulator proteins Centrosomal Protein 190 kD (CP190) and Modifier of mdg4 67.2 kD (Mod67.2). By contrast, the Su(Hw) germline function involves binding to non-clustered SBSs and does not require CP190 or Mod67.2. Here, we identify Su(Hw) target genes, using genome-wide analyses in the ovary to uncover genes with an ovary-bound SBS that are misregulated upon Su(Hw) loss. Most Su(Hw) target genes demonstrate enriched expression in the wild-type CNS. Loss of Su(Hw) leads to increased expression of these CNS-enriched target genes in the ovary and other tissues, suggesting that Su(Hw) is a repressor of neural genes in non-neural tissues. Among the Su(Hw) target genes is RNA-binding protein 9 (Rbp9), a member of the ELAV/Hu gene family. Su(Hw) regulation of Rbp9 appears to be insulator independent, as Rbp9 expression is unchanged in a genetic background that compromises the functions of the CP190 and Mod67.2 insulator proteins, even though both localize to Rbp9 SBSs. Rbp9 misregulation is central to su(Hw)(-/-) sterility, as Rbp9(+/-), su(Hw)(-/-) females are fertile. Eggs produced by Rbp9(+/-), su(Hw)(-/-) females show patterning defects, revealing a somatic requirement for Su(Hw) in the ovary. Our studies demonstrate that Su(Hw) is a versatile transcriptional regulatory protein with an essential developmental function involving transcriptional repression.
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Affiliation(s)
- Alexey A Soshnev
- Interdisciplinary Graduate Program in Molecular and Cellular Biology, University of Iowa, Iowa City, IA 52242, USA
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Li Y, Zhang Q, Carreira-Rosario A, Maines JZ, McKearin DM, Buszczak M. Mei-p26 cooperates with Bam, Bgcn and Sxl to promote early germline development in the Drosophila ovary. PLoS One 2013; 8:e58301. [PMID: 23526974 PMCID: PMC3603962 DOI: 10.1371/journal.pone.0058301] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Accepted: 02/01/2013] [Indexed: 01/17/2023] Open
Abstract
In the Drosophila female germline, spatially and temporally specific translation of mRNAs governs both stem cell maintenance and the differentiation of their progeny. However, the mechanisms that control and coordinate different modes of translational repression within this lineage remain incompletely understood. Here we present data showing that Mei-P26 associates with Bam, Bgcn and Sxl and nanos mRNA during early cyst development, suggesting that this protein helps to repress the translation of nanos mRNA. Together with recently published studies, these data suggest that Mei-P26 mediates both GSC self-renewal and germline differentiation through distinct modes of translational repression depending on the presence of Bam.
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Affiliation(s)
- Yun Li
- Department of Molecular Biology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, United States of America
| | - Qiao Zhang
- Department of Molecular Biology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, United States of America
| | - Arnaldo Carreira-Rosario
- Department of Molecular Biology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, United States of America
| | - Jean Z. Maines
- Department of Molecular Biology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, United States of America
| | - Dennis M. McKearin
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | - Michael Buszczak
- Department of Molecular Biology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, United States of America
- * E-mail:
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37
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Li Y, Maines JZ, Tastan OY, McKearin DM, Buszczak M. Mei-P26 regulates the maintenance of ovarian germline stem cells by promoting BMP signaling. Development 2012; 139:1547-56. [PMID: 22438571 DOI: 10.1242/dev.077412] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
In the Drosophila ovary, bone morphogenetic protein (BMP) ligands maintain germline stem cells (GSCs) in an undifferentiated state. The activation of the BMP pathway within GSCs results in the transcriptional repression of the differentiation factor bag of marbles (bam). The Nanos-Pumilio translational repressor complex and the miRNA pathway also help to promote GSC self-renewal. How the activities of different transcriptional and translational regulators are coordinated to keep the GSC in an undifferentiated state remains uncertain. Data presented here show that Mei-P26 cell-autonomously regulates GSC maintenance in addition to its previously described role of promoting germline cyst development. Within undifferentiated germ cells, Mei-P26 associates with miRNA pathway components and represses the translation of a shared target mRNA, suggesting that Mei-P26 can enhance miRNA-mediated silencing in specific contexts. In addition, disruption of mei-P26 compromises BMP signaling, resulting in the inappropriate expression of bam in germ cells immediately adjacent to the cap cell niche. Loss of mei-P26 results in premature translation of the BMP antagonist Brat in germline stem cells. These data suggest that Mei-P26 has distinct functions in the ovary and participates in regulating the fates of both GSCs and their differentiating daughters.
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Affiliation(s)
- Yun Li
- Department of Molecular Biology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-9148, USA
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Perinthottathil S, Kim C. Bam and Bgcn in Drosophila germline stem cell differentiation. VITAMINS AND HORMONES 2011; 87:399-416. [PMID: 22127253 DOI: 10.1016/b978-0-12-386015-6.00038-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The female Drosophila reproductive organ, the ovary, has provided researchers with an incisive genetic system with which principle regulation of stem cell maintenance and differentiation has been delineated. An environmental niche regulates a stem cell's asymmetric self-renewal division that produces a daughter stem cell and a differentiated daughter cell, which further differentiate into eggs. A number of extrinsic and intrinsic factors have been identified that are required either for stem cell maintenance or differentiation. Bam/Bgcn complex plays a pivotal role in promoting stem cell differentiation. Recent papers suggest that Bam/Bgcn complex regulates translation of important maintenance factors and is also involved in the regulation of microRNA-dependent translational repression. Here, we focus on Bam and Bgcn repression of stem cell maintenance factors in the differentiation of germline stem cells (GSCs).
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Affiliation(s)
- Sreejith Perinthottathil
- Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju, South Korea
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