1
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Kong R, Zhao H, Li J, Ma Y, Li N, Shi L, Li Z. A regulatory loop of JAK/STAT signalling and its downstream targets represses cell fate conversion and maintains male germline stem cell niche homeostasis. Cell Prolif 2024:e13648. [PMID: 38987866 DOI: 10.1111/cpr.13648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 04/03/2024] [Accepted: 04/11/2024] [Indexed: 07/12/2024] Open
Abstract
A specialised microenvironment, termed niche, provides extrinsic signals for the maintenance of residential stem cells. However, how residential stem cells maintain niche homeostasis and whether stromal niche cells could convert their fate into stem cells to replenish lost stem cells upon systemic stem cell loss remain largely unknown. Here, through systemic identification of JAK/STAT downstream targets in adult Drosophila testis, we show that Escargot (Esg), a member of the Snail family of transcriptional factors, is a putative JAK/STAT downstream target. esg is intrinsically required in cyst stem cells (CySCs) but not in germline stem cells (GSCs). esg depletion in CySCs results in CySC loss due to differentiation and non-cell autonomous GSC loss. Interestingly, hub cells are gradually lost by delaminating from the hub and converting into CySCs in esg-defective testes. Mechanistically, esg directly represses the expression of socs36E, the well-known downstream target and negative regulator of JAK/STAT signalling. Finally, further depletion of socs36E completely rescues the defects observed in esg-defective testes. Collectively, JAK/STAT target Esg suppresses SOCS36E to maintain CySC fate and repress niche cell conversion. Thus, our work uncovers a regulatory loop between JAK/STAT signalling and its downstream targets in controlling testicular niche homeostasis under physiological conditions.
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Affiliation(s)
- Ruiyan Kong
- Laboratory of Stem Cell Biology, College of Life Sciences, Capital Normal University, Beijing, China
| | - Hang Zhao
- Laboratory of Stem Cell Biology, College of Life Sciences, Capital Normal University, Beijing, China
| | - Juan Li
- Laboratory of Stem Cell Biology, College of Life Sciences, Capital Normal University, Beijing, China
| | - Yankun Ma
- Laboratory of Stem Cell Biology, College of Life Sciences, Capital Normal University, Beijing, China
| | - Ningfang Li
- Laboratory of Stem Cell Biology, College of Life Sciences, Capital Normal University, Beijing, China
| | - Lin Shi
- Laboratory of Stem Cell Biology, College of Life Sciences, Capital Normal University, Beijing, China
| | - Zhouhua Li
- Laboratory of Stem Cell Biology, College of Life Sciences, Capital Normal University, Beijing, China
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2
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Sreejith P, Kim C. Lin28 is Required for Single Niche Development in the Drosophila Male Gonad. Dev Reprod 2023; 27:221-226. [PMID: 38292237 PMCID: PMC10824566 DOI: 10.12717/dr.2023.27.4.221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 10/22/2023] [Accepted: 11/23/2023] [Indexed: 02/01/2024]
Abstract
A stem cell niche provides an environment that governs stem cell maintenance and division. Thus, the development of a proper niche is of prime importance to stem cell behaviors. Mechanisms of niche development are beginning to be revealed in the Drosophila male gonad. Niche cells are initially dispersed throughout the gonad, then assemble at its apical tip through the anterior migration of posteriorly located niche cells. The molecular mechanisms of this migration and assembly are still poorly understood. Here we show evidence suggesting that Lin28, an RNA-binding protein and regulator of let7 genesis, might be an intrinsic factor for the anterior migration of niche cells. We found that a dispersed, ectopic niche, a phenotype observed with anterior migration defects, occurs in lin28 mutant gonads. This phenotype is rescued by expression of lin28 in the niche cells. These findings suggest that Lin28 might be required for the anterior migration of niche cells.
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Affiliation(s)
- Perinthottathil Sreejith
- Department of Biomedical Genetics,
University of Rochester Medical Center, Rochester,
NY 14642, USA
| | - Changsoo Kim
- School of Biological Sciences and
Technology, Chonnam National University, Gwangju
61186, Korea
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3
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Raz AA, Vida GS, Stern SR, Mahadevaraju S, Fingerhut JM, Viveiros JM, Pal S, Grey JR, Grace MR, Berry CW, Li H, Janssens J, Saelens W, Shao Z, Hu C, Yamashita YM, Przytycka T, Oliver B, Brill JA, Krause H, Matunis EL, White-Cooper H, DiNardo S, Fuller MT. Emergent dynamics of adult stem cell lineages from single nucleus and single cell RNA-Seq of Drosophila testes. eLife 2023; 12:e82201. [PMID: 36795469 PMCID: PMC9934865 DOI: 10.7554/elife.82201] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 01/19/2023] [Indexed: 02/17/2023] Open
Abstract
Proper differentiation of sperm from germline stem cells, essential for production of the next generation, requires dramatic changes in gene expression that drive remodeling of almost all cellular components, from chromatin to organelles to cell shape itself. Here, we provide a single nucleus and single cell RNA-seq resource covering all of spermatogenesis in Drosophila starting from in-depth analysis of adult testis single nucleus RNA-seq (snRNA-seq) data from the Fly Cell Atlas (FCA) study. With over 44,000 nuclei and 6000 cells analyzed, the data provide identification of rare cell types, mapping of intermediate steps in differentiation, and the potential to identify new factors impacting fertility or controlling differentiation of germline and supporting somatic cells. We justify assignment of key germline and somatic cell types using combinations of known markers, in situ hybridization, and analysis of extant protein traps. Comparison of single cell and single nucleus datasets proved particularly revealing of dynamic developmental transitions in germline differentiation. To complement the web-based portals for data analysis hosted by the FCA, we provide datasets compatible with commonly used software such as Seurat and Monocle. The foundation provided here will enable communities studying spermatogenesis to interrogate the datasets to identify candidate genes to test for function in vivo.
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Affiliation(s)
- Amelie A Raz
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Howard Hughes Medical InstituteCambridgeUnited States
| | - Gabriela S Vida
- Department of Cell and Developmental Biology, The Perelman School of Medicine and The Penn Institute for Regenerative MedicinePhiladelphiaUnited States
| | - Sarah R Stern
- Department of Developmental Biology, Stanford University School of MedicineStanfordUnited States
| | - Sharvani Mahadevaraju
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of HealthBethesdaUnited States
| | - Jaclyn M Fingerhut
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Howard Hughes Medical InstituteCambridgeUnited States
| | - Jennifer M Viveiros
- Department of Cell Biology, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Soumitra Pal
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of HealthBethesdaUnited States
| | - Jasmine R Grey
- Department of Cell Biology, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Mara R Grace
- Department of Cell Biology, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Cameron W Berry
- Department of Developmental Biology, Stanford University School of MedicineStanfordUnited States
| | - Hongjie Li
- Huffington Center on Aging and Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
| | - Jasper Janssens
- JVIB Center for Brain & Disease Research, and the Department of Human Genetics, KU LeuvenLeuvenBelgium
| | - Wouter Saelens
- Data Mining and Modeling for Biomedicine, VIB Center for Inflammation Research, and Department of Applied Mathematics, Computer Science and Statistics, Ghent UniversityGhentBelgium
| | - Zhantao Shao
- Donnelly Centre for Cellular and Biomolecular Research, University of TorontoTorontoCanada
| | - Chun Hu
- Donnelly Centre for Cellular and Biomolecular Research, University of TorontoTorontoCanada
| | - Yukiko M Yamashita
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Howard Hughes Medical InstituteCambridgeUnited States
| | - Teresa Przytycka
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of HealthBethesdaUnited States
| | - Brian Oliver
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of HealthBethesdaUnited States
| | - Julie A Brill
- Cell Biology Program, The Hospital for Sick ChildrenTorontoCanada
- Department of Molecular Genetics, University of TorontoTorontoCanada
- Institute of Medical Science, University of TorontoTorontoCanada
| | - Henry Krause
- Donnelly Centre for Cellular and Biomolecular Research, University of TorontoTorontoCanada
- Department of Molecular Genetics, University of TorontoTorontoCanada
| | - Erika L Matunis
- Department of Cell Biology, Johns Hopkins University School of MedicineBaltimoreUnited States
| | | | - Stephen DiNardo
- Department of Cell and Developmental Biology, The Perelman School of Medicine and The Penn Institute for Regenerative MedicinePhiladelphiaUnited States
| | - Margaret T Fuller
- Department of Developmental Biology, Stanford University School of MedicineStanfordUnited States
- Department of Genetics, Stanford UniversityStanfordUnited States
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4
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Hétié P, de Cuevas M, Matunis EL. The adult Drosophila testis lacks a mechanism to replenish missing niche cells. Development 2023; 150:dev201148. [PMID: 36503989 PMCID: PMC10110489 DOI: 10.1242/dev.201148] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 11/29/2022] [Indexed: 12/14/2022]
Abstract
The adult Drosophila testis contains a well-defined niche created by a cluster of hub cells, which secrete signals that maintain adjacent germline stem cells and somatic cyst stem cells (CySCs). Hub cells are normally quiescent in adult flies but can exit quiescence, delaminate from the hub and convert into CySCs after ablation of all CySCs. The opposite event, CySC conversion into hub cells, was proposed to occur under physiological conditions, but the frequency of this event is debated. Here, to probe further the question of whether or not hub cells can be regenerated, we developed methods to genetically ablate some or all hub cells. Surprisingly, when flies were allowed to recover from ablation, the missing hub cells were not replaced. Hub cells did not exit quiescence after partial ablation of hub cells, and labeled cells from outside the hub did not enter the hub during or after ablation. Despite its ability to exit quiescence in response to CySC ablation, we conclude that the hub in the adult Drosophila testis does not have a mechanism to replenish missing hub cells.
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Affiliation(s)
- Phylis Hétié
- Department of Cell Biology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA
| | - Margaret de Cuevas
- Department of Cell Biology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA
| | - Erika L. Matunis
- Department of Cell Biology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA
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5
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Ranjan R, Snedeker J, Wooten M, Chu C, Bracero S, Mouton T, Chen X. Differential condensation of sister chromatids acts with Cdc6 to ensure asynchronous S-phase entry in Drosophila male germline stem cell lineage. Dev Cell 2022; 57:1102-1118.e7. [PMID: 35483360 PMCID: PMC9134767 DOI: 10.1016/j.devcel.2022.04.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 01/16/2022] [Accepted: 04/05/2022] [Indexed: 01/06/2023]
Abstract
During Drosophila melanogaster male germline stem cell (GSC) asymmetric division, preexisting old versus newly synthesized histones H3 and H4 are asymmetrically inherited. However, the biological outcomes of this phenomenon have remained unclear. Here, we tracked old and new histones throughout the GSC cell cycle through the use of high spatial and temporal resolution microscopy. We found unique features that differ between old and new histone-enriched sister chromatids, including differences in nucleosome density, chromosomal condensation, and H3 Ser10 phosphorylation. These distinct chromosomal features lead to their differential association with Cdc6, a pre-replication complex component, and subsequent asynchronous DNA replication initiation in the resulting daughter cells. Disruption of asymmetric histone inheritance abolishes differential Cdc6 association and asynchronous S-phase entry, demonstrating that histone asymmetry acts upstream of these critical cell-cycle progression events. Furthermore, disruption of these GSC-specific chromatin features leads to GSC defects, indicating a connection between histone inheritance, cell-cycle progression, and cell fate determination.
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Affiliation(s)
- Rajesh Ranjan
- Howard Hughes Medical Institute, Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA; Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA.
| | - Jonathan Snedeker
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Matthew Wooten
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Carolina Chu
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Sabrina Bracero
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Taylar Mouton
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Xin Chen
- Howard Hughes Medical Institute, Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA; Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA.
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6
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Nagai H, Miura M, Nakajima YI. Cellular mechanisms underlying adult tissue plasticity in Drosophila. Fly (Austin) 2022; 16:190-206. [PMID: 35470772 PMCID: PMC9045823 DOI: 10.1080/19336934.2022.2066952] [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] [Indexed: 11/26/2022] Open
Abstract
Adult tissues in Metazoa dynamically remodel their structures in response to environmental challenges including sudden injury, pathogen infection, and nutritional fluctuation, while maintaining quiescence under homoeostatic conditions. This characteristic, hereafter referred to as adult tissue plasticity, can prevent tissue dysfunction and improve the fitness of organisms in continuous and/or severe change of environments. With its relatively simple tissue structures and genetic tools, studies using the fruit fly Drosophila melanogaster have provided insights into molecular mechanisms that control cellular responses, particularly during regeneration and nutrient adaptation. In this review, we present the current understanding of cellular mechanisms, stem cell proliferation, polyploidization, and cell fate plasticity, all of which enable adult tissue plasticity in various Drosophila adult organs including the midgut, the brain, and the gonad, and discuss the organismal strategy in response to environmental changes and future directions of the research.
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Affiliation(s)
- Hiroki Nagai
- Graduate School of Pharmaceutical Sciences, the University of Tokyo, Tokyo, Japan
| | - Masayuki Miura
- Graduate School of Pharmaceutical Sciences, the University of Tokyo, Tokyo, Japan
| | - Yu-Ichiro Nakajima
- Graduate School of Pharmaceutical Sciences, the University of Tokyo, Tokyo, Japan
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7
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Greenspan LJ, de Cuevas M, Le KH, Viveiros JM, Matunis EL. Activation of the EGFR/MAPK pathway drives transdifferentiation of quiescent niche cells to stem cells in the Drosophila testis niche. eLife 2022; 11:e70810. [PMID: 35468055 PMCID: PMC9038189 DOI: 10.7554/elife.70810] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 03/31/2022] [Indexed: 12/28/2022] Open
Abstract
Adult stem cells are maintained in niches, specialized microenvironments that regulate their self-renewal and differentiation. In the adult Drosophila testis stem cell niche, somatic hub cells produce signals that regulate adjacent germline stem cells (GSCs) and somatic cyst stem cells (CySCs). Hub cells are normally quiescent, but after complete genetic ablation of CySCs, they can proliferate and transdifferentiate into new CySCs. Here we find that Epidermal growth factor receptor (EGFR) signaling is upregulated in hub cells after CySC ablation and that the ability of testes to recover from ablation is inhibited by reduced EGFR signaling. In addition, activation of the EGFR pathway in hub cells is sufficient to induce their proliferation and transdifferentiation into CySCs. We propose that EGFR signaling, which is normally required in adult cyst cells, is actively inhibited in adult hub cells to maintain their fate but is repurposed to drive stem cell regeneration after CySC ablation.
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Affiliation(s)
- Leah J Greenspan
- Department of Cell Biology, Johns Hopkins University School of MedicineBaltimoreUnited States
- Division of Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of HealthBethesdaUnited States
| | - Margaret de Cuevas
- Department of Cell Biology, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Kathy H Le
- Department of Cell Biology, Johns Hopkins University School of MedicineBaltimoreUnited States
- Graduate Program in Biophysics, Stanford UniversityStanfordUnited States
| | - Jennifer M Viveiros
- Department of Cell Biology, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Erika L Matunis
- Department of Cell Biology, Johns Hopkins University School of MedicineBaltimoreUnited States
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8
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To V, Kim HJ, Jang W, Sreejith P, Kim C. Lin28 and Imp are Required for Stability of Bowl Transcripts in Hub
Cells of the Drosophila Testis. Dev Reprod 2021; 25:313-319. [PMID: 35141457 PMCID: PMC8807131 DOI: 10.12717/dr.2021.25.4.313] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/28/2021] [Accepted: 12/15/2021] [Indexed: 11/24/2022]
Abstract
Hub cells comprise a niche for germline stem cells and cyst stem cells in the
Drosophila testis. Hub cells arise from common somatic
gonadal precursors in embryos, but the mechanism of their specification is still
poorly understood. Here we find that RNA binding proteins Lin28 and Imp mediate
transcript stability of Bowl, a known hub specification factor; Bowl transcripts
were reduced in the testis of Lin28 and Imp mutants, and also when RNA-mediated
interference against Lin28 or Imp was expressed in hub cells. In tissue culture
Luciferase assays involving the Bowl 3’UTR, stability of Luc reporter
transcripts depended on the Bowl 3’UTR and required Lin28 and Imp. Our
findings suggest that proper Bowl function during hub cell specification
requires Lin28 and Imp in the testis hub cells.
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Affiliation(s)
- Van To
- School of Biological Sciences and
Technology, Chonnam National University, Gwangju
61186, Korea
| | - Hyun Ju Kim
- School of Biological Sciences and
Technology, Chonnam National University, Gwangju
61186, Korea
| | - Wijeong Jang
- School of Biological Sciences and
Technology, Chonnam National University, Gwangju
61186, Korea
| | | | - Changsoo Kim
- School of Biological Sciences and
Technology, Chonnam National University, Gwangju
61186, Korea
- Corresponding author Changsoo Kim, School of
Biological Sciences and Technology, Chonnam National University, Gwangju 61186,
Korea. Tel: +82-62-530-5201, E-mail:
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9
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Herrera SC, Sainz de la Maza D, Grmai L, Margolis S, Plessel R, Burel M, O'Connor M, Amoyel M, Bach EA. Proliferative stem cells maintain quiescence of their niche by secreting the Activin inhibitor Follistatin. Dev Cell 2021; 56:2284-2294.e6. [PMID: 34363758 PMCID: PMC8387025 DOI: 10.1016/j.devcel.2021.07.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 05/14/2021] [Accepted: 07/15/2021] [Indexed: 12/20/2022]
Abstract
Aging causes stem cell dysfunction as a result of extrinsic and intrinsic changes. Decreased function of the stem cell niche is an important contributor to this dysfunction. We use the Drosophila testis to investigate what factors maintain niche cells. The testis niche comprises quiescent “hub” cells and supports two mitotic stem cell pools: germline stem cells and somatic cyst stem cells (CySCs). We identify the cell-cycle-responsive Dp/E2f1 transcription factor as a crucial non-autonomous regulator required in CySCs to maintain hub cell quiescence. Dp/E2f1 inhibits local Activin ligands through production of the Activin antagonist Follistatin (Fs). Inactivation of Dp/E2f1 or Fs in CySCs or promoting Activin receptor signaling in hub cells causes transdifferentiation of hub cells into fully functional CySCs. This Activin-dependent communication between CySCs and hub regulates the physiological decay of the niche with age and demonstrates that hub cell quiescence results from signals from surrounding stem cells. Dp/E2f1 is required in stem cells to non-autonomously maintain niche quiescence Dp/E2f1 promotes niche quiescence through Fs, an Activin antagonist Activin signaling in niche cells causes transdifferentiation into functional stem cells Fs in stem cells regulates the physiological decay of the niche with age
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Affiliation(s)
- Salvador C Herrera
- Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY 10016, USA; Centro Andaluz de Biología del Desarrollo, CSIC/Universidad Pablo de Olavide/JA, Carretera de Utrera km 1, 41013 Sevilla, Spain
| | - Diego Sainz de la Maza
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Lydia Grmai
- Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Shally Margolis
- Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Rebecca Plessel
- Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Michael Burel
- Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Michael O'Connor
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Marc Amoyel
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK.
| | - Erika A Bach
- Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY 10016, USA.
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10
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Arias Padilla LF, Castañeda-Cortés DC, Rosa IF, Moreno Acosta OD, Hattori RS, Nóbrega RH, Fernandino JI. Cystic proliferation of germline stem cells is necessary to reproductive success and normal mating behavior in medaka. eLife 2021; 10:62757. [PMID: 33646121 PMCID: PMC7946426 DOI: 10.7554/elife.62757] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 02/28/2021] [Indexed: 12/11/2022] Open
Abstract
The production of an adequate number of gametes is necessary for normal reproduction, for which the regulation of proliferation from early gonadal development to adulthood is key in both sexes. Cystic proliferation of germline stem cells is an especially important step prior to the beginning of meiosis; however, the molecular regulators of this proliferation remain elusive in vertebrates. Here, we report that ndrg1b is an important regulator of cystic proliferation in medaka. We generated mutants of ndrg1b that led to a disruption of cystic proliferation of germ cells. This loss of cystic proliferation was observed from embryogenic to adult stages, impacting the success of gamete production and reproductive parameters such as spawning and fertilization. Interestingly, the depletion of cystic proliferation also impacted male sexual behavior, with a decrease of mating vigor. These data illustrate why it is also necessary to consider gamete production capacity in order to analyze reproductive behavior.
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Affiliation(s)
| | - Diana C Castañeda-Cortés
- Reproductive and Molecular Biology Group, Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University (UNESP), Botucatu, Brazil
| | - Ivana F Rosa
- Reproductive and Molecular Biology Group, Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University (UNESP), Botucatu, Brazil
| | - Omar D Moreno Acosta
- Salmonid Experimental Station at Campos do Jordão, UPD-CJ, Sao Paulo Fisheries Institute (APTA/SAA), Campos do Jordao, Brazil
| | - Ricardo S Hattori
- Reproductive and Molecular Biology Group, Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University (UNESP), Botucatu, Brazil
| | - Rafael H Nóbrega
- Instituto Tecnológico de Chascomús, INTECH (CONICET-UNSAM), Chascomús, Argentina
| | - Juan I Fernandino
- Instituto Tecnológico de Chascomús, INTECH (CONICET-UNSAM), Chascomús, Argentina
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11
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Bazylev SS, Adashev VE, Shatskikh AS, Olenina LV, Kotov AA. Somatic Cyst Cells as a Microenvironment for the Maintenance and Differentiation of Germline Cells in Drosophila Spermatogenesis. Russ J Dev Biol 2021. [DOI: 10.1134/s1062360421010021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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12
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Sreejith P, Jang W, To V, Hun Jo Y, Biteau B, Kim C. Lin28 is a critical factor in the function and aging of Drosophila testis stem cell niche. Aging (Albany NY) 2020; 11:855-873. [PMID: 30713156 PMCID: PMC6382437 DOI: 10.18632/aging.101765] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 01/05/2019] [Indexed: 12/21/2022]
Abstract
Age-related decline in stem cell function is observed in many tissues from invertebrates to humans. While cell intrinsic alterations impair stem cells, aging of the stem cell niche also significantly contributes to the loss of tissue homeostasis associated with reduced regenerative capacity. Hub cells, which constitute the stem cell niche in the Drosophila testis, exhibit age-associated decline in number and activities, yet underlying mechanisms are not fully understood. Here we show that Lin28, a highly conserved RNA binding protein, is expressed in hub cells and its expression dramatically declines in old testis. lin28 mutant testes exhibit hub cell loss and defective hub architecture, recapitulating the normal aging process. Importantly, maintained expression of Lin28 prolongs hub integrity and function in aged testes, suggesting that Lin28 decline is a driver of hub cell aging. Mechanistically, the level of unpaired (upd), a stem cell self-renewal factor, is reduced in lin28 mutant testis and Lin28 protein directly binds and stabilizes upd transcripts, in a let-7 independent manner. Altogether, our results suggest that Lin28 acts to protect upd transcripts in hub cells, and reduction of Lin28 in old testis leads to decreased upd levels, hub cell aging and loss of the stem cell niche.
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Affiliation(s)
- Perinthottathil Sreejith
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Republic of Korea.,Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Wijeong Jang
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Van To
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Yong Hun Jo
- Division of Plant Biotechnology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Benoit Biteau
- Department of Biomedical Genetics, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Changsoo Kim
- School of Biological Sciences and Technology, Chonnam National University, Gwangju 61186, Republic of Korea
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13
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Muthusamy B, Bellad A, Prasad P, Bandari AK, Bhuvanalakshmi G, Kiragasur RM, Girimaj SC, Pandey A. A Novel LINS1 Truncating Mutation in Autosomal Recessive Nonsyndromic Intellectual Disability. Front Psychiatry 2020; 11:354. [PMID: 32499722 PMCID: PMC7247441 DOI: 10.3389/fpsyt.2020.00354] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The large majority of cases with intellectual disability are syndromic (i.e. occur with other well-defined clinical phenotypes) and have been studied extensively. Autosomal recessive nonsyndromic intellectual disability is a group of genetically heterogeneous disorders for which a number of potentially causative genes have been identified although the molecular basis of most of them remains unexplored. Here, we report the clinical characteristics and genetic findings of a family with two male siblings affected with autosomal recessive nonsyndromic intellectual disability. Whole exome sequencing was carried out on two affected male siblings and unaffected parents. A potentially pathogenic variant identified in this study was confirmed by Sanger sequencing to be inherited in an autosomal recessive fashion. We identified a novel nonsense mutation (p.Gln368Ter) in the LINS1 gene which leads to loss of 389 amino acids in the C-terminus of the encoded protein. The truncation mutation causes a complete loss of LINES_C domain along with loss of three known phosphorylation sites and a known ubiquitylation site in addition to other evolutionarily conserved regions of LINS1. LINS1 has been reported to cause MRT27 (mental retardation, autosomal recessive 27), a rare autosomal recessive nonsyndromic intellectual disability, with limited characterization of the phenotype. Identification of a potentially pathogenic truncating mutation in LINS1 in two profoundly intellectually impaired patients also confirms its role in cognition.
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Affiliation(s)
- Babylakshmi Muthusamy
- Institute of Bioinformatics, Bangalore, India.,Center for Molecular Medicine, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India.,Manipal Academy of Higher Education, Manipal, India
| | - Anikha Bellad
- Institute of Bioinformatics, Bangalore, India.,Center for Molecular Medicine, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India.,Manipal Academy of Higher Education, Manipal, India
| | - Pramada Prasad
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India
| | - Aravind K Bandari
- Institute of Bioinformatics, Bangalore, India.,Center for Molecular Medicine, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India.,Manipal Academy of Higher Education, Manipal, India
| | | | - R M Kiragasur
- Department of Child and Adolescent Psychiatry, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India
| | - Satish Chandra Girimaj
- Department of Child and Adolescent Psychiatry, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India
| | - Akhilesh Pandey
- Center for Molecular Medicine, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India.,Manipal Academy of Higher Education, Manipal, India.,Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States.,Center for Individualized Medicine, Mayo Clinic, Rochester, MN, United States
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14
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Asymmetric Centromeres Differentially Coordinate with Mitotic Machinery to Ensure Biased Sister Chromatid Segregation in Germline Stem Cells. Cell Stem Cell 2019; 25:666-681.e5. [PMID: 31564548 DOI: 10.1016/j.stem.2019.08.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 06/25/2019] [Accepted: 08/19/2019] [Indexed: 12/29/2022]
Abstract
Many stem cells utilize asymmetric cell division (ACD) to produce a self-renewed stem cell and a differentiating daughter cell. How non-genic information could be inherited differentially to establish distinct cell fates is not well understood. Here, we report a series of spatiotemporally regulated asymmetric components, which ensure biased sister chromatid attachment and segregation during ACD of Drosophila male germline stem cells (GSCs). First, sister centromeres are differentially enriched with proteins involved in centromere specification and kinetochore function. Second, temporally asymmetric microtubule activities and polarized nuclear envelope breakdown allow for the preferential recognition and attachment of microtubules to asymmetric sister kinetochores and sister centromeres. Abolishment of either the asymmetric sister centromeres or the asymmetric microtubule activities results in randomized sister chromatid segregation. Together, these results provide the cellular basis for partitioning epigenetically distinct sister chromatids during stem cell ACDs, which opens new directions to study these mechanisms in other biological contexts.
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15
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Anllo L, Plasschaert LW, Sui J, DiNardo S. Live imaging reveals hub cell assembly and compaction dynamics during morphogenesis of the Drosophila testis niche. Dev Biol 2018; 446:102-118. [PMID: 30553808 DOI: 10.1016/j.ydbio.2018.12.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 11/19/2018] [Accepted: 12/12/2018] [Indexed: 01/23/2023]
Abstract
Adult stem cells are often found in specialized niches, where the constituent cells direct self-renewal of their stem cell pool. The niche is therefore crucial for both normal homeostasis and tissue regeneration. In many mammalian tissues, niche cells have classically been difficult to identify, which has hampered any understanding of how tissues first construct niches during development. Fortunately, the Drosophila germline stem cell (GSC) niche is well defined, allowing for unambiguous identification of both niche cells and resident stem cells. The testis niche first forms in the early embryo, during a late stage of gonadogenesis. Here, using live-imaging both in vivo and ex vivo, we follow pro-niche cells as they assemble and assume their final form. We show that after ex vivo culture the niche appears fully functional, as judged by enrichment of adhesion proteins, the ability to activate STAT in adjacent GSCs, and to direct GSCs to divide orthogonally to the niche, just as they would in situ. Collectively, our imaging has generated several novel insights on niche morphogenesis that could not be inferred from fixed images alone. We identify dynamic processes that constitute an assembly phase and a compaction phase during morphogenesis. The compaction phase correlates with cell neighbor exchange among the assembled pro-niche cells, as well as a burst of divisions among newly recruited stem cells. Before compaction, an assembly phase involves the movement of pro-niche cells along the outer periphery of the gonad, using the extracellular matrix (ECM) to assemble at the anterior of the gonad. Finally, live-imaging in integrin mutants allows us to define the role of pro-niche cell-ECM interaction with regard to the new assembly and compaction dynamics revealed here.
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Affiliation(s)
- Lauren Anllo
- The Perelman School of Medicine at the University of Pennsylvania, 421 Curie Blvd, Philadelphia, PA 19104, United States; The Penn Institute for Regenerative Medicine, 421 Curie Blvd, Philadelphia, PA 19104, United States.
| | - Lindsey W Plasschaert
- The Perelman School of Medicine at the University of Pennsylvania, 421 Curie Blvd, Philadelphia, PA 19104, United States; The Penn Institute for Regenerative Medicine, 421 Curie Blvd, Philadelphia, PA 19104, United States.
| | - Justin Sui
- The Perelman School of Medicine at the University of Pennsylvania, 421 Curie Blvd, Philadelphia, PA 19104, United States; The Penn Institute for Regenerative Medicine, 421 Curie Blvd, Philadelphia, PA 19104, United States.
| | - Stephen DiNardo
- The Perelman School of Medicine at the University of Pennsylvania, 421 Curie Blvd, Philadelphia, PA 19104, United States; The Penn Institute for Regenerative Medicine, 421 Curie Blvd, Philadelphia, PA 19104, United States.
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16
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Regulatory Mechanisms of the Germline Stem Cell Niche in Drosophila melanogaster. DIVERSITY AND COMMONALITY IN ANIMALS 2018. [DOI: 10.1007/978-4-431-56609-0_2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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17
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Inaba M, Sorenson DR, Kortus M, Salzmann V, Yamashita YM. Merlin is required for coordinating proliferation of two stem cell lineages in the Drosophila testis. Sci Rep 2017; 7:2502. [PMID: 28566755 PMCID: PMC5451480 DOI: 10.1038/s41598-017-02768-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 04/18/2017] [Indexed: 11/29/2022] Open
Abstract
Although the mechanisms that balance self-renewal and differentiation of a stem cell lineage have been extensively studied, it remains poorly understood how tissues that contain multiple stem cell lineages maintain balanced proliferation among distinct lineages: when stem cells of a particular lineage proliferate, how do the other lineages respond to maintain the correct ratio of cells among linages? Here, we show that Merlin (Mer), a homolog of the human tumor suppressor neurofibromatosis 2, is required to coordinate proliferation of germline stem cells (GSCs) and somatic cyst stem cells (CySCs) in the Drosophila testis. Mer mutant CySCs fail to coordinate their proliferation with that of GSCs in multiple settings, and can be triggered to undergo tumorous overproliferation. Mer executes its function by stabilizing adherens junctions. Given the known role of Mer in contact-dependent inhibition of proliferation, we propose that the proliferation of CySCs are regulated by crowdedness, or confluency, of cells in their lineage with respect to that of germline, thereby coordinating the proliferation of two lineages.
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Affiliation(s)
- Mayu Inaba
- Life Sciences Institute, Center for Stem Cell Biology, Ann Arbor, Michigan, United States.,Department of Cell and Developmental Biology, School of Medicine, Ann Arbor, Michigan, United States.,Howard Hughes Medical Institute, University of Michigan, Ann Arbor, Michigan, United States.,263 Farmington Ave. E6053, Department of Cell Biology, UConn Health, Farmington, CT, 06030, USA
| | - Dorothy R Sorenson
- Department of Cell and Developmental Biology, School of Medicine, Ann Arbor, Michigan, United States
| | - Matt Kortus
- Department of Cell and Developmental Biology, School of Medicine, Ann Arbor, Michigan, United States
| | - Viktoria Salzmann
- Life Sciences Institute, Center for Stem Cell Biology, Ann Arbor, Michigan, United States.,Department of Cell and Developmental Biology, School of Medicine, Ann Arbor, Michigan, United States
| | - Yukiko M Yamashita
- Life Sciences Institute, Center for Stem Cell Biology, Ann Arbor, Michigan, United States. .,Department of Cell and Developmental Biology, School of Medicine, Ann Arbor, Michigan, United States. .,Howard Hughes Medical Institute, University of Michigan, Ann Arbor, Michigan, United States.
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18
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Fairchild MJ, Yang L, Goodwin K, Tanentzapf G. Occluding Junctions Maintain Stem Cell Niche Homeostasis in the Fly Testes. Curr Biol 2016; 26:2492-2499. [PMID: 27546574 DOI: 10.1016/j.cub.2016.07.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 05/23/2016] [Accepted: 07/08/2016] [Indexed: 12/16/2022]
Abstract
Stem cells can be controlled by their local microenvironment, known as the stem cell niche. The Drosophila testes contain a morphologically distinct niche called the hub, composed of a cluster of between 8 and 20 cells known as hub cells, which contact and regulate germline stem cells (GSCs) and somatic cyst stem cells (CySCs). Both hub cells and CySCs originate from somatic gonadal precursor cells during embryogenesis, but whereas hub cells, once specified, cease all mitotic activity, CySCs remain mitotic into adulthood [1, 2]. Cyst cells, derived from the CySCs, first encapsulate the germline and then, using occluding junctions, form an isolating permeability barrier [3]. This barrier promotes germline differentiation by excluding niche-derived stem cell maintenance factors. Here, we show that the somatic permeability barrier is also required to regulate stem cell niche homeostasis. Loss of occluding junction components in the somatic cells results in hub overgrowth. Enlarged hubs are active and recruit more GSCs and CySCs to the niche. Surprisingly, hub growth results from depletion of occluding junction components in cyst cells, not from depletion in the hub cells themselves. Moreover, hub growth is caused by incorporation of cells that previously expressed markers for cyst cells and not by hub cell proliferation. Importantly, depletion of occluding junctions disrupts Notch and mitogen-activated protein kinase (MAPK) signaling, and hub overgrowth defects are partially rescued by modulation of either signaling pathway. Overall, these data show that occluding junctions shape the signaling environment between the soma and the germline in order to maintain niche homeostasis.
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Affiliation(s)
- Michael J Fairchild
- Department of Cellular and Physiological Sciences, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Lulu Yang
- Department of Cellular and Physiological Sciences, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Katharine Goodwin
- Department of Cellular and Physiological Sciences, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Guy Tanentzapf
- Department of Cellular and Physiological Sciences, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada.
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19
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Lee JY, Chen JY, Shaw JL, Chang KT. Maintenance of Stem Cell Niche Integrity by a Novel Activator of Integrin Signaling. PLoS Genet 2016; 12:e1006043. [PMID: 27191715 PMCID: PMC4871447 DOI: 10.1371/journal.pgen.1006043] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 04/19/2016] [Indexed: 01/22/2023] Open
Abstract
Stem cells depend critically on the surrounding microenvironment, or niche, for their maintenance and self-renewal. While much is known about how the niche regulates stem cell self-renewal and differentiation, mechanisms for how the niche is maintained over time are not well understood. At the apical tip of the Drosophila testes, germline stem cells (GSCs) and somatic stem cells share a common niche formed by hub cells. Here we demonstrate that a novel protein named Shriveled (Shv) is necessary for the maintenance of hub/niche integrity. Depletion of Shv protein results in age-dependent deterioration of the hub structure and loss of GSCs, whereas upregulation of Shv preserves the niche during aging. We find Shv is a secreted protein that modulates DE-cadherin levels through extracellular activation of integrin signaling. Our work identifies Shv as a novel activator of integrin signaling and suggests a new integration model in which crosstalk between integrin and DE-cadherin in niche cells promote their own preservation by maintaining the niche architecture. Stem cells are vital for development and for regeneration and repair of tissues in an organism. The ability of adult stem cells to maintain their “stemness” depends critically on the localized microenvironment, or niche. While much is known about how the niche regulates stem cell self-renewal and differentiation, mechanisms for how the niche is maintained during aging are not well understood. Using Drosophila testis as a model system, here we demonstrate that a protein we named Shriveled is a secreted protein that activates integrin signaling to preserve niche architecture. We also show that Shriveled-dependent activation of integrin maintains normal E-cadherin levels in the niche cells, providing a mechanism for niche maintenance. Interestingly, upregulation of Shriveled retards the loss of niche and stem cells seen during normal aging. Together, our work identifies Shriveled as a novel molecule required for preservation of the niche structure in the Drosophila testis.
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Affiliation(s)
- Joo Yeun Lee
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Neuroscience Graduate Program, University of Southern California, Los Angeles, California, United States of America
| | - Jessica Y. Chen
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Jillian L. Shaw
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Neuroscience Graduate Program, University of Southern California, Los Angeles, California, United States of America
| | - Karen T. Chang
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Neuroscience Graduate Program, University of Southern California, Los Angeles, California, United States of America
- Department of Cell and Neurobiology, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- * E-mail:
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20
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Loza-Coll MA, Jones DL. Simultaneous control of stemness and differentiation by the transcription factor Escargot in adult stem cells: How can we tease them apart? Fly (Austin) 2016; 10:53-9. [PMID: 27077690 DOI: 10.1080/19336934.2016.1176650] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
The homeostatic turnover of adult organs and their regenerative capacity following injury depend on a careful balance between stem cell self-renewal (to maintain or enlarge the stem cell pool) and differentiation (to replace lost tissue). We have recently characterized the role of the Drosophila Snail family transcription factor escargot (esg) in testis cyst stem cells (CySCs) (1,2) and intestinal stem cells (ISCs). (3,4) CySCs mutant for esg are not maintained as stem cells, but they remain capable of differentiating normally along the cyst cell lineage. In contrast, esg mutant CySCs that give rise to a closely related lineage, the apical hub cells, cannot maintain hub cell identity. Similarly, Esg maintains stemness of ISCs while regulating the terminal differentiation of progenitor cells into absorptive enterocytes or secretory enteroendocrine cells. Therefore, our findings suggest that Esg may play a conserved and pivotal regulatory role in adult stem cells, controlling both their maintenance and terminal differentiation. Here we propose that this dual regulatory role is due to simultaneous control by Esg of overlapping genetic programs and discuss the exciting challenges and opportunities that lie ahead to explore the underlying mechanisms experimentally.
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Affiliation(s)
- Mariano A Loza-Coll
- a Department of Biology , California State University , Northridge , CA , USA
| | - D Leanne Jones
- b Molecular, Cell and Developmental Biology, University of California , Los Angeles , CA , USA.,c Eli and Edythe Broad Center of Regenerative Medicine, University of California , Los Angeles , CA , USA
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21
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Xie J, Wooten M, Tran V, Chen BC, Pozmanter C, Simbolon C, Betzig E, Chen X. Histone H3 Threonine Phosphorylation Regulates Asymmetric Histone Inheritance in the Drosophila Male Germline. Cell 2015; 163:920-33. [PMID: 26522592 DOI: 10.1016/j.cell.2015.10.002] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 08/08/2015] [Accepted: 09/22/2015] [Indexed: 12/11/2022]
Abstract
A long-standing question concerns how stem cells maintain their identity through multiple divisions. Previously, we reported that pre-existing and newly synthesized histone H3 are asymmetrically distributed during Drosophila male germline stem cell (GSC) asymmetric division. Here, we show that phosphorylation at threonine 3 of H3 (H3T3P) distinguishes pre-existing versus newly synthesized H3. Converting T3 to the unphosphorylatable residue alanine (H3T3A) or to the phosphomimetic aspartate (H3T3D) disrupts asymmetric H3 inheritance. Expression of H3T3A or H3T3D specifically in early-stage germline also leads to cellular defects, including GSC loss and germline tumors. Finally, compromising the activity of the H3T3 kinase Haspin enhances the H3T3A but suppresses the H3T3D phenotypes. These studies demonstrate that H3T3P distinguishes sister chromatids enriched with distinct pools of H3 in order to coordinate asymmetric segregation of "old" H3 into GSCs and that tight regulation of H3T3 phosphorylation is required for male germline activity.
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Affiliation(s)
- Jing Xie
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Matthew Wooten
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Vuong Tran
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Bi-Chang Chen
- HHMI, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Caitlin Pozmanter
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Christine Simbolon
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Eric Betzig
- HHMI, Janelia Research Campus, 19700 Helix Drive, Ashburn, VA 20147, USA
| | - Xin Chen
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA.
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22
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Tarayrah L, Li Y, Gan Q, Chen X. Epigenetic regulator Lid maintains germline stem cells through regulating JAK-STAT signaling pathway activity. Biol Open 2015; 4:1518-27. [PMID: 26490676 PMCID: PMC4728359 DOI: 10.1242/bio.013961] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Signaling pathways and epigenetic mechanisms have both been shown to play essential roles in regulating stem cell activity. While the role of either mechanism in this regulation is well established in multiple stem cell lineages, how the two mechanisms interact to regulate stem cell activity is not as well understood. Here we report that in the Drosophila testis, an H3K4me3-specific histone demethylase encoded by little imaginal discs (lid) maintains germline stem cell (GSC) mitotic index and prevents GSC premature differentiation. Lid is required in germ cells for proper expression of the Stat92E transcription factor, the downstream effector of the Janus kinase signal transducer and activator of transcription (JAK-STAT) signaling pathway. Our findings support a germ cell autonomous role for the JAK-STAT pathway in maintaining GSCs and place Lid as an upstream regulator of this pathway. Our study provides new insights into the biological functions of a histone demethylase in vivo and sheds light on the interaction between epigenetic mechanisms and signaling pathways in regulating stem cell activities. Summary: This study provides new insights into the biological functions of a histone demethylase and sheds light on the interaction between epigenetic mechanisms and signaling pathways in regulating stem cell activities.
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Affiliation(s)
- Lama Tarayrah
- Department of Biology, 3400 North Charles Street, The Johns Hopkins University, Baltimore, MD 21218-2685, USA
| | - Yuping Li
- Department of Biology, 3400 North Charles Street, The Johns Hopkins University, Baltimore, MD 21218-2685, USA
| | - Qiang Gan
- Department of Biology, 3400 North Charles Street, The Johns Hopkins University, Baltimore, MD 21218-2685, USA
| | - Xin Chen
- Department of Biology, 3400 North Charles Street, The Johns Hopkins University, Baltimore, MD 21218-2685, USA
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23
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Abstract
Stem cells are necessary for the maintenance of many adult tissues. Signals within the stem cell microenvironment, or niche, regulate the self-renewal and differentiation capability of these cells. Misregulation of these signals through mutation or damage can lead to overgrowth or depletion of different stem cell pools. In this review, we focus on the Drosophila testis and ovary, both of which contain well-defined niches, as well as the mouse testis, which has become a more approachable stem cell system with recent technical advances. We discuss the signals that regulate gonadal stem cells in their niches, how these signals mediate self-renewal and differentiation under homeostatic conditions, and how stress, whether from mutations or damage, can cause changes in cell fate and drive stem cell competition.
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Affiliation(s)
- Leah Joy Greenspan
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205; , ,
| | - Margaret de Cuevas
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205; , ,
| | - Erika Matunis
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205; , ,
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24
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Schardt L, Ander JJ, Lohmann I, Papagiannouli F. Stage-specific control of niche positioning and integrity in the Drosophila testis. Mech Dev 2015; 138 Pt 3:336-48. [PMID: 26226434 DOI: 10.1016/j.mod.2015.07.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 06/23/2015] [Accepted: 07/24/2015] [Indexed: 12/11/2022]
Abstract
A fundamental question is how complex structures are maintained after their initial specification. Stem cells reside in a specialized microenvironment, called niche, which provides essential signals controlling stem cell behavior. We addressed this question by studying the Drosophila male stem cell niche, called the hub. Once specified, the hub cells need to maintain their position and architectural integrity through embryonic, larval and pupal stages of testis organogenesis and during adult life. The Hox gene Abd-B, in addition to its described role in male embryonic gonads, maintains the architecture and positioning of the larval hub from the germline by affecting integrin localization in the neighboring somatic cyst cells. We find that the AbdB-Boss/Sev cascade affects integrin independent of Talin, while genetic interactions depict integrin as the central downstream player in this system. Focal adhesion and integrin-adaptor proteins within the somatic stem cells and cyst cells, such as Paxillin, Pinch and Vav, also contribute to proper hub integrity and positioning. During adult stages, hub positioning is controlled by Abd-B activity in the outer acto-myosin sheath, while Abd-B expression in adult spermatocytes exerts no effect on hub positioning and integrin localization. Our data point at a cell- and stage-specific function of Abd-B and suggest that the occurrence of new cell types and cell interactions in the course of testis organogenesis made it necessary to adapt the whole system by reusing the same players for male stem cell niche positioning and integrity in an alternative manner.
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Affiliation(s)
- Lisa Schardt
- Centre for Organismal Studies (COS) Heidelberg, Cell Networks - Cluster of Excellence, University of Heidelberg, D-69120, Germany; Deutsches Krebsforschungszentrum (DKFZ), D-69120, Germany
| | - Janina-Jacqueline Ander
- Centre for Organismal Studies (COS) Heidelberg, Cell Networks - Cluster of Excellence, University of Heidelberg, D-69120, Germany
| | - Ingrid Lohmann
- Centre for Organismal Studies (COS) Heidelberg, Cell Networks - Cluster of Excellence, University of Heidelberg, D-69120, Germany.
| | - Fani Papagiannouli
- Centre for Organismal Studies (COS) Heidelberg, Cell Networks - Cluster of Excellence, University of Heidelberg, D-69120, Germany.
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25
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Wingert L, DiNardo S. Traffic jam functions in a branched pathway from Notch activation to niche cell fate. Development 2015; 142:2268-77. [PMID: 26092848 DOI: 10.1242/dev.124230] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 05/15/2015] [Indexed: 12/19/2022]
Abstract
The niche directs key behaviors of its resident stem cells, and is thus crucial for tissue maintenance, repair and longevity. However, little is known about the genetic pathways that guide niche specification and development. The male germline stem cell niche in Drosophila houses two stem cell populations and is specified within the embryonic gonad, thus making it an excellent model for studying niche development. The hub cells that form the niche are specified early by Notch activation. Over the next few hours, these individual cells then cluster together and take up a defined position before expressing markers of hub cell differentiation. This timing suggests that there are other factors for niche development yet to be defined. Here, we have identified a role for the large Maf transcription factor Traffic jam (Tj) in hub cell specification downstream of Notch. Tj downregulation is the first detectable effect of Notch activation in hub cells. Furthermore, Tj depletion is sufficient to generate ectopic hub cells that can recruit stem cells. Surprisingly, ectopic niche cells in tj mutants remain dispersed in the absence of Notch activation. This led us to uncover a branched pathway downstream of Notch in which Bowl functions to direct hub cell assembly in parallel to Tj downregulation.
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Affiliation(s)
- Lindsey Wingert
- Department of Cell & Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Stephen DiNardo
- Department of Cell & Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
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26
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Bonfini A, Wilkin MB, Baron M. Reversible regulation of stem cell niche size associated with dietary control of Notch signalling. BMC DEVELOPMENTAL BIOLOGY 2015; 15:8. [PMID: 25637382 PMCID: PMC4320563 DOI: 10.1186/s12861-015-0059-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 01/21/2015] [Indexed: 01/08/2023]
Abstract
Background Stem cells can respond to environmental and physiological inputs to adaptively remodel tissues. Little is known about whether stem cell niches are similarly responsive. The Drosophila ovary germline stem cell (GSC) niche is a well-studied model, which is comprised of cap cells that provide anchorage and maintenance signals for GSCs to maintain oogenesis. Previous studies have shown a strong link between diet and the regulation of oogenesis, making this a useful model system in which to investigate dietary regulation of the niche and its associated stem cells. Results We show that the Drosophila ovary GSC cap cell niche is a dynamic structure, which can contract and expand in fluctuating dietary conditions. Cap cells are lost when adult flies are shifted to nutrient poor diet and are restored after returning flies to nutrient-rich medium. Notch signalling in cap and escort cells is similarly reduced and restored by dietary shifts to nutrient poor and rich media. In old flies decreased Notch signalling is associated with decreased robustness of the niche to dietary changes. We demonstrated using a Notch temperature sensitive allele that removal and restoration of Notch signalling also leads to a reduction and re-expansion of the niche. Changes in niche size were not associated with apoptosis or cell division. We identified two distinct roles for Notch in the adult germarium. Notch can act in cap cells to prevent their loss while activation of Notch in the flanking escort cells results in expansion of the niche. Conclusions We provide evidence that dietary changes alone are sufficient to alter Notch signalling and reversibly change niche size in the adult in wild type flies. We show Notch acts in different cells to maintain and re-expand the niche and propose a model in which cell fate transitions between cap cells and flanking somatic cells accounts for niche dynamics. These findings reveal an unexpected reversible plasticity of the GSC niche whose responses provide an integrated read out of the physiological status of the fly that is modulated by diet and age. Electronic supplementary material The online version of this article (doi:10.1186/s12861-015-0059-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Alessandro Bonfini
- Faculty of Life Sciences, Michael Smith Building, Oxford Road, University of Manchester, Manchester, M13 9PT, UK.
| | - Marian B Wilkin
- Faculty of Life Sciences, Michael Smith Building, Oxford Road, University of Manchester, Manchester, M13 9PT, UK.
| | - Martin Baron
- Faculty of Life Sciences, Michael Smith Building, Oxford Road, University of Manchester, Manchester, M13 9PT, UK.
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Papagiannouli F, Lohmann I. Stage-specific control of stem cell niche architecture in the Drosophila testis by the posterior Hox gene Abd-B. Comput Struct Biotechnol J 2015; 13:122-30. [PMID: 25750700 PMCID: PMC4348433 DOI: 10.1016/j.csbj.2015.01.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 01/12/2015] [Accepted: 01/15/2015] [Indexed: 11/30/2022] Open
Abstract
A fundamental question in biology is how complex structures are maintained after their initial specification. We address this question by reviewing the role of the Hox gene Abd-B in Drosophila testis organogenesis, which proceeds through embryonic, larval and pupal stages to reach maturation in adult stages. The data presented in this review highlight a cell- and stage-specific function of Abd-B, since the mechanisms regulating stem cell niche positioning and architecture at different stages seem to be different despite the employment of similar factors. In addition to its described role in the male embryonic gonads, sustained activity of Abd-B in the pre-meiotic germline spermatocytes during larval stages is required to maintain the architecture of the stem cell niche by regulating βPS-integrin localization in the neighboring somatic cyst cells. Loss of Abd-B is associated with cell non-autonomous effects within the niche, leading to a dramatic reduction of pre-meiotic cell populations in adult testes. Identification of Abd-B target genes revealed that Abd-B mediates its effects by controlling the activity of the sevenless ligand Boss via its direct targets Src42A and Sec63. During adult stages, when testis morphogenesis is completed with the addition of the acto-myosin sheath originating from the genital disc, stem cell niche positioning and integrity are regulated by Abd-B activity in the acto-myosin sheath whereas integrin acts in an Abd-B independent way. It seems that the occurrence of new cell types and cell interactions in the course of testis organogenesis made it necessary to adapt the system to the new cellular conditions by reusing the same players for testis stem cell niche positioning in an alternative manner.
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Affiliation(s)
- Fani Papagiannouli
- Centre for Organismal Studies (COS) Heidelberg, Cell Networks - Cluster of Excellence, University of Heidelberg, D-69120, Germany
| | - Ingrid Lohmann
- Centre for Organismal Studies (COS) Heidelberg, Cell Networks - Cluster of Excellence, University of Heidelberg, D-69120, Germany
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28
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Zoller R, Schulz C. The Drosophila cyst stem cell lineage: Partners behind the scenes? SPERMATOGENESIS 2014; 2:145-157. [PMID: 23087834 PMCID: PMC3469438 DOI: 10.4161/spmg.21380] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In all animals, germline cells differentiate in intimate contact with somatic cells and interactions between germline and soma are particularly important for germline development and function. In the male gonad of Drosophila melanogaster, the developing germline cells are enclosed by somatic cyst cells. The cyst cells are derived from cyst stem cells (CySCs) of somatic origin and codifferentiate with the germline cells. The fast generation cycle and the genetic tractability of Drosophila has made the Drosophila testis an excellent model for studying both the roles of somatic cells in guiding germline development and the interdependence of two separate stem cell lineages. This review focuses on our current understanding of CySC specification, CySC self-renewing divisions, cyst cell differentiation, and soma-germline interactions. Many of the mechanisms guiding these processes in Drosophila testes are similarly essential for the development and function of tissues in other organisms, most importantly for gametogenesis in mammals.
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Affiliation(s)
- Richard Zoller
- Department of Cellular Biology; University of Georgia; Athens, GA USA
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29
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Whitworth C, Jimenez E, Van Doren M. Development of sexual dimorphism in the Drosophila testis. SPERMATOGENESIS 2014; 2:129-136. [PMID: 23087832 PMCID: PMC3469436 DOI: 10.4161/spmg.21780] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The creation of sexual dimorphism in the gonads is essential for producing the male and female gametes required for sexual reproduction. Sexual development of the gonads involves both somatic cells and germ cells, which often undergo sex determination by different mechanisms. While many sex-specific characteristics evolve rapidly and are very different between animal species, gonad function and the formation of sperm and eggs appear more similar and may be more conserved. Consistent with this, the doublesex/mab3 Related Transcription factors (DMRTs) are important for gonad sexual dimorphism in a wide range of animals, including flies, worms and mammals. Here we explore how sexual dimorphism is regulated in the Drosophila gonad, focusing on recent discoveries relating to testis development. We will discuss how sex determination in both the germline and the soma are utilized to create a testis, including the role of the key somatic sex determination factor doublesex.
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Affiliation(s)
- Cale Whitworth
- Department of Biology; The Johns Hopkins University; Baltimore, MD USA
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30
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Amoyel M, Simons BD, Bach EA. Neutral competition of stem cells is skewed by proliferative changes downstream of Hh and Hpo. EMBO J 2014; 33:2295-313. [PMID: 25092766 PMCID: PMC4253521 DOI: 10.15252/embj.201387500] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Neutral competition, an emerging feature of stem cell homeostasis, posits that individual stem cells can be lost and replaced by their neighbors stochastically, resulting in chance dominance of a clone at the niche. A single stem cell with an oncogenic mutation could bias this process and clonally spread the mutation throughout the stem cell pool. The Drosophila testis provides an ideal system for testing this model. The niche supports two stem cell populations that compete for niche occupancy. Here, we show that cyst stem cells (CySCs) conform to the paradigm of neutral competition and that clonal deregulation of either the Hedgehog (Hh) or Hippo (Hpo) pathway allows a single CySC to colonize the niche. We find that the driving force behind such behavior is accelerated proliferation. Our results demonstrate that a single stem cell colonizes its niche through oncogenic mutation by co-opting an underlying homeostatic process.
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Affiliation(s)
- Marc Amoyel
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - Benjamin D Simons
- Cavendish Laboratory, Department of Physics, University of Cambridge, Cambridge, UK Wellcome Trust-CRUK Gurdon Institute, University of Cambridge, Cambridge, UK Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Erika A Bach
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA The Helen L. and Martin S. Kimmel Center for Stem Cell Biology, New York University School of Medicine, New York, NY, USA
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31
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Voog J, Sandall SL, Hime GR, Resende LPF, Loza-Coll M, Aslanian A, Yates JR, Hunter T, Fuller MT, Jones DL. Escargot restricts niche cell to stem cell conversion in the Drosophila testis. Cell Rep 2014; 7:722-34. [PMID: 24794442 DOI: 10.1016/j.celrep.2014.04.025] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2012] [Revised: 02/05/2013] [Accepted: 04/17/2014] [Indexed: 01/08/2023] Open
Abstract
Stem cells reside within specialized microenvironments, or niches, that control many aspects of stem cell behavior. Somatic hub cells in the Drosophila testis regulate the behavior of cyst stem cells (CySCs) and germline stem cells (GSCs) and are a primary component of the testis stem cell niche. The shutoff (shof) mutation, characterized by premature loss of GSCs and CySCs, was mapped to a locus encoding the evolutionarily conserved transcription factor Escargot (Esg). Hub cells depleted of Esg acquire CySC characteristics and differentiate as cyst cells, resulting in complete loss of hub cells and eventually CySCs and GSCs, similar to the shof mutant phenotype. We identified Esg-interacting proteins and demonstrate an interaction between Esg and the corepressor C-terminal binding protein (CtBP), which was also required for maintenance of hub cell fate. Our results indicate that niche cells can acquire stem cell properties upon removal of a single transcription factor in vivo.
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Affiliation(s)
- Justin Voog
- Department of Biomedical Sciences, University of California, San Diego, La Jolla, CA, 92037, USA; Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Sharsti L Sandall
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - Gary R Hime
- ARC Centre of Excellence in Biotechnology and Development, University of Melbourne, VIC 3010, Australia; Department of Anatomy and Neuroscience, University of Melbourne, VIC 3010, Australia
| | - Luís Pedro F Resende
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA 92037, USA; GABBA, Instituto Ciências Biomédicas Abel Salazar, University of Porto, Portugal
| | - Mariano Loza-Coll
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Aaron Aslanian
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - John R Yates
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Tony Hunter
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Margaret T Fuller
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA, 94305, USA; Department of Genetics, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - D Leanne Jones
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA 92037, USA; Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, 90095, USA.
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Hétié P, de Cuevas M, Matunis E. Conversion of quiescent niche cells to somatic stem cells causes ectopic niche formation in the Drosophila testis. Cell Rep 2014; 7:715-21. [PMID: 24746819 DOI: 10.1016/j.celrep.2014.03.058] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 01/29/2014] [Accepted: 03/28/2014] [Indexed: 11/25/2022] Open
Abstract
Adult stem cells reside in specialized regulatory microenvironments, or niches, where local signals ensure stem cell maintenance. The Drosophila testis contains a well-characterized niche wherein signals from postmitotic hub cells promote maintenance of adjacent germline stem cells and somatic cyst stem cells (CySCs). Hub cells were considered to be terminally differentiated; here, we show that they can give rise to CySCs. Genetic ablation of CySCs triggers hub cells to transiently exit quiescence, delaminate from the hub, and convert into functional CySCs. Ectopic Cyclin D-Cdk4 expression in hub cells is also sufficient to trigger their conversion into CySCs. In both cases, this conversion causes the formation of multiple ectopic niches over time. Therefore, our work provides a model for understanding how oncogenic mutations in quiescent niche cells could promote loss of quiescence, changes in cell fate, and aberrant niche expansion.
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Affiliation(s)
- Phylis Hétié
- Department of Cell Biology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA
| | - Margaret de Cuevas
- Department of Cell Biology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA
| | - Erika Matunis
- Department of Cell Biology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA.
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Pancratov R, Peng F, Smibert P, Yang JS, Olson ER, Guha-Gilford C, Kapoor AJ, Liang FX, Lai EC, Flaherty MS, DasGupta R. The miR-310/13 cluster antagonizes β-catenin function in the regulation of germ and somatic cell differentiation in the Drosophila testis. Development 2013; 140:2904-16. [PMID: 23821034 PMCID: PMC3699279 DOI: 10.1242/dev.092817] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/12/2013] [Indexed: 12/19/2022]
Abstract
MicroRNAs (miRNAs) are regulators of global gene expression and function in a broad range of biological processes. Recent studies have suggested that miRNAs can function as tumor suppressors or oncogenes by modulating the activities of evolutionarily conserved signaling pathways that are commonly dysregulated in cancer. We report the identification of the miR-310 to miR-313 (miR-310/13) cluster as a novel antagonist of Wingless (Drosophila Wnt) pathway activity in a functional screen for Drosophila miRNAs. We demonstrate that miR-310/13 can modulate Armadillo (Arm; Drosophila β-catenin) expression and activity by directly targeting the 3'-UTRs of arm and pangolin (Drosophila TCF) in vivo. Notably, the miR-310/13-deficient flies exhibit abnormal germ and somatic cell differentiation in the male gonad, which can be rescued by reducing Arm protein levels or activity. Our results implicate a previously unrecognized function for miR-310/13 in dampening the activity of Arm in early somatic and germline progenitor cells, whereby inappropriate/sustained activation of Arm-mediated signaling or cell adhesion may impact normal differentiation in the Drosophila male gonad.
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Affiliation(s)
- Raluca Pancratov
- New York University Langone Medical Center, Department of Pharmacology and the NYU Cancer Institute, 522 First Avenue, SRB #1211, New York, NY 10016, USA
| | - Felix Peng
- New York University Langone Medical Center, Department of Pharmacology and the NYU Cancer Institute, 522 First Avenue, SRB #1211, New York, NY 10016, USA
| | - Peter Smibert
- Sloan-Kettering Institute, Department of Developmental Biology, 1275 York Avenue Box 252, New York, NY 10065, USA
| | - Jr-Shiuan Yang
- Sloan-Kettering Institute, Department of Developmental Biology, 1275 York Avenue Box 252, New York, NY 10065, USA
| | - Emily Ruth Olson
- New York University Langone Medical Center, Department of Pharmacology and the NYU Cancer Institute, 522 First Avenue, SRB #1211, New York, NY 10016, USA
| | - Ciaran Guha-Gilford
- New York University Langone Medical Center, Department of Pharmacology and the NYU Cancer Institute, 522 First Avenue, SRB #1211, New York, NY 10016, USA
| | - Amol J. Kapoor
- New York University Langone Medical Center, Department of Pharmacology and the NYU Cancer Institute, 522 First Avenue, SRB #1211, New York, NY 10016, USA
| | - Feng-Xia Liang
- New York University Langone Medical Center, Office of Collaborative Science, Microscopy Core, 550 First Avenue, New York, NY 10016, USA
| | - Eric C. Lai
- Sloan-Kettering Institute, Department of Developmental Biology, 1275 York Avenue Box 252, New York, NY 10065, USA
| | - Maria Sol Flaherty
- New York University Langone Medical Center, Department of Pharmacology and the NYU Cancer Institute, 522 First Avenue, SRB #1211, New York, NY 10016, USA
- City University of New York, New York City College of Technology, Biological Sciences Department, 300 Jay Street, Brooklyn, NY 11201, USA
| | - Ramanuj DasGupta
- New York University Langone Medical Center, Department of Pharmacology and the NYU Cancer Institute, 522 First Avenue, SRB #1211, New York, NY 10016, USA
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Akawi NA, Al-Jasmi F, Al-Shamsi AM, Ali BR, Al-Gazali L. LINS, a modulator of the WNT signaling pathway, is involved in human cognition. Orphanet J Rare Dis 2013; 8:87. [PMID: 23773660 PMCID: PMC3847167 DOI: 10.1186/1750-1172-8-87] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 06/12/2013] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Inherited intellectual disability (ID) conditions are a group of genetically heterogeneous disorders that lead to variable degrees of cognition deficits. It has been shown that inherited ID can be caused by mutations in over 100 different genes and there is evidence for the presence of as yet unidentified genes in a significant proportion of patients. We aimed at identifying the defective gene underlying an autosomal recessive ID in two sibs of an Emirati family. METHODS A combined approach involving homozygosity mapping and whole-exome sequencing was used to identify the causative mutation. RNA analysis was performed to gain further insight into the pathogenic effect of the detected mutation. RESULTS We have identified a homozygous splicing mutation (c.1219_1222+1delAAAGG) in the LINS gene in the affected children. LINS is the human homologue of the Drosophila segment polarity gene lin that encodes an essential regulator of the wingless/Wnt signaling. The identified mutation alters the first consensus nucleotide of the 5' donor splice junction of intron 5 and the 3' end of exon 5. Transcript analysis revealed that this change leads to an exon skipping event resulting in direct splicing of exon 4 to exon 6. Another mutation in LINS has been described very briefly in an Iranian family with autosomal recessive ID and microcephaly. CONCLUSION Our study confirms that LINS, a modulator of the WNT pathway, is an indispensable gene to human cognition and this finding sheds further light on the importance of WNT signaling in human brain development and/or function.
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Affiliation(s)
- Nadia A Akawi
- Department of Pathology, College of Medicine and Health Sciences United Arab Emirates University, P,O, Box 17666, Al-Ain, United Arab Emirates.
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35
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Stem Cell Niche. Regen Med 2013. [DOI: 10.1007/978-94-007-5690-8_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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36
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Singh SR, Liu Y, Kango-Singh M, Nevo E. Genetic, immunofluorescence labeling, and in situ hybridization techniques in identification of stem cells in male and female germline niches. Methods Mol Biol 2013; 1035:9-23. [PMID: 23959978 DOI: 10.1007/978-1-62703-508-8_2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Stem cells have an enormous capacity of self-renewal, as well as the ability to differentiate into specialized cell types. Proper control of these two properties of stem cells is crucial for animal development, growth control, and reproduction. Germline stem cells (GSCs) are a self-renewing population of germ cells, which generate haploid gametes (sperms or oocyte) that transmit genetic information from generation to generation. In Drosophila testis and ovary, GSCs are anchored around the niche cells. The cap cells cluster in females and hub cells in males act as a niche to control GSC behavior. With highly sophisticated genetic techniques in Drosophila, tremendous progress has been made in understanding the interactions between stem cells and niches at cellular and molecular levels. Here, we provide details of genetic, immunofluorescence labeling, and in situ hybridization techniques in identification and characterization of stem cells in Drosophila male and female germline niches.
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Affiliation(s)
- Shree Ram Singh
- Mouse Cancer Genetics Program, National Cancer Institute, NIH, Frederick, MD, USA
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37
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Morillo Prado JR, Chen X, Fuller MT. Polycomb group genes Psc and Su(z)2 maintain somatic stem cell identity and activity in Drosophila. PLoS One 2012; 7:e52892. [PMID: 23285219 PMCID: PMC3528704 DOI: 10.1371/journal.pone.0052892] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2012] [Accepted: 11/23/2012] [Indexed: 11/27/2022] Open
Abstract
Adult stem cells are essential for the proper function of many tissues, yet the mechanisms that maintain the proper identity and regulate proliferative capacity in stem cell lineages are not well understood. Polycomb group (PcG) proteins are transcriptional repressors that have recently emerged as important regulators of stem cell maintenance and differentiation. Here we describe the role of Polycomb Repressive Complex 1 (PRC1) genes Posterior sex combs (Psc) and Suppressor of zeste two (Su(z)2) in restricting the proliferation and maintaining the identity of the Cyst Stem Cell (CySC) lineage in the Drosophila testis. In contrast, Psc and Su(z)2 seem to be dispensable for both germline stem cell (GSC) maintenance and germ cell development. We show that loss of Psc and Su(z)2 function in the CySC lineage results in the formation of aggregates of mutant cells that proliferate abnormally, and display abnormal somatic identity correlated with derepression of the Hox gene Abdominal-B. Furthermore, we show that tumorigenesis in the CySC lineage interferes non-cell autonomously with maintenance of GSCs most likely by displacing them from their niche.
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Affiliation(s)
- Jose Rafael Morillo Prado
- Department of Developmental Biology, School of Medicine, Stanford University, Stanford, California, United States of America
| | - Xin Chen
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Margaret T. Fuller
- Department of Developmental Biology, School of Medicine, Stanford University, Stanford, California, United States of America
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38
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Amoyel M, Sanny J, Burel M, Bach EA. Hedgehog is required for CySC self-renewal but does not contribute to the GSC niche in the Drosophila testis. Development 2012; 140:56-65. [PMID: 23175633 DOI: 10.1242/dev.086413] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The Drosophila testis harbors two types of stem cells: germ line stem cells (GSCs) and cyst stem cells (CySCs). Both stem cell types share a physical niche called the hub, located at the apical tip of the testis. The niche produces the JAK/STAT ligand Unpaired (Upd) and BMPs to maintain CySCs and GSCs, respectively. However, GSCs also require BMPs produced by CySCs, and as such CySCs are part of the niche for GSCs. Here we describe a role for another secreted ligand, Hedgehog (Hh), produced by niche cells, in the self-renewal of CySCs. Hh signaling cell-autonomously regulates CySC number and maintenance. The Hh and JAK/STAT pathways act independently and non-redundantly in CySC self-renewal. Finally, Hh signaling does not contribute to the niche function of CySCs, as Hh-sustained CySCs are unable to maintain GSCs in the absence of Stat92E. Therefore, the extended niche function of CySCs is solely attributable to JAK/STAT pathway function.
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Affiliation(s)
- Marc Amoyel
- Department of Biochemistry and Molecular Biology, New York University School of Medicine, New York, NY 10016, USA
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39
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Sinden D, Badgett M, Fry J, Jones T, Palmen R, Sheng X, Simmons A, Matunis E, Wawersik M. Jak-STAT regulation of cyst stem cell development in the Drosophila testis. Dev Biol 2012; 372:5-16. [PMID: 23010510 DOI: 10.1016/j.ydbio.2012.09.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 09/15/2012] [Accepted: 09/16/2012] [Indexed: 10/27/2022]
Abstract
Establishment and maintenance of functional stem cells is critical for organ development and tissue homeostasis. Little is known about the mechanisms underlying stem establishment during organogenesis. Drosophila testes are among the most thoroughly characterized systems for studying stem cell behavior, with germline stem cells (GSCs) and somatic cyst stem cells (CySCs) cohabiting a discrete stem cell niche at the testis apex. GSCs and CySCs are arrayed around hub cells that also comprise the niche and communication between hub cells, GSCs, and CySCs regulates the balance between stem cell maintenance and differentiation. Recent data has shown that functional, asymmetrically dividing GSCs are first established at ∼23 h after egg laying during Drosophila testis morphogenesis (Sheng et al., 2009). This process correlates with coalescence of the hub, but development of CySCs from somatic gonadal precursors (SGPs) was not examined. Here, we show that functional CySCs are present at the time of GSC establishment, and that Jak-STAT signaling is necessary and sufficient for CySC maintenance shortly thereafter. Furthermore, hyper-activation of Jak in CySCs promotes expansion of the GSC population, while ectopic Jak activation in the germline induces GSC gene expression in GSC daughter cells but does not prevent spermatogenic differentiation. Together, these observations indicate that, similar to adult testes, Jak-STAT signaling from the hub acts on both GSCs and CySC to regulate their development and differentiation, and that additional signaling from CySCs to the GSCs play a dominant role in controlling GSC maintenance during niche formation.
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Affiliation(s)
- D Sinden
- College of William & Mary, Biology Department, Williamsburg, VA 23185, USA
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40
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Michel M, Kupinski AP, Raabe I, Bökel C. Hh signalling is essential for somatic stem cell maintenance in the Drosophila testis niche. Development 2012; 139:2663-9. [PMID: 22745310 DOI: 10.1242/dev.075242] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In the Drosophila testis, germline stem cells (GSCs) and somatic cyst stem cells (CySCs) are arranged around a group of postmitotic somatic cells, termed the hub, which produce a variety of growth factors contributing to the niche microenvironment that regulates both stem cell pools. Here we show that CySC but not GSC maintenance requires Hedgehog (Hh) signalling in addition to Jak/Stat pathway activation. CySC clones unable to transduce the Hh signal are lost by differentiation, whereas pathway overactivation leads to an increase in proliferation. However, unlike cells ectopically overexpressing Jak/Stat targets, the additional cells generated by excessive Hh signalling remain confined to the testis tip and retain the ability to differentiate. Interestingly, Hh signalling also controls somatic cell populations in the fly ovary and the mammalian testis. Our observations might therefore point towards a higher degree of organisational homology between the somatic components of gonads across the sexes and phyla than previously appreciated.
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Del Signore SJ, Hayashi T, Hatini V. odd-skipped genes and lines organize the notum anterior-posterior axis using autonomous and non-autonomous mechanisms. Mech Dev 2012; 129:147-61. [PMID: 22613630 DOI: 10.1016/j.mod.2012.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 04/27/2012] [Accepted: 05/06/2012] [Indexed: 10/28/2022]
Abstract
The growth and patterning of Drosophila wing and notum primordia depend on their subdivision into progressively smaller domains by secreted signals that emanate from localized sources termed organizers. While the mechanisms that organize the wing primordium have been studied extensively, those that organize the notum are incompletely understood. The genes odd-skipped (odd), drumstick (drm), sob, and bowl comprise the odd-skipped family of C(2)H(2) zinc finger genes, which has been implicated in notum growth and patterning. Here we show that drm, Bowl, and eyegone (eyg), a gene required for notum patterning, accumulate in nested domains in the anterior notum. Ectopic drm organized the nested expression of these anterior notum genes and downregulated the expression of posterior notum genes. The cell-autonomous induction of Bowl and Eyg required bowl, while the non-autonomous effects were independent of bowl. The homeodomain protein Bar is expressed along the anterior border of the notum adjacent to cells expressing the Notch (N) ligand Delta (Dl). bowl was required to promote Bar and repress Dl expression to pattern the anterior notum in a cell-autonomous manner, while lines acted antagonistically to bowl posterior to the Bowl domain. Our data suggest that the odd-skipped genes act at the anterior notum border to organize the notum anterior-posterior (AP) axis using both autonomous and non-autonomous mechanisms.
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Affiliation(s)
- Steven J Del Signore
- Department of Anatomy & Cellular Biology, Tufts University School of Medicine, USA
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Papagiannouli F, Lohmann I. Shaping the niche: lessons from the Drosophila testis and other model systems. Biotechnol J 2012; 7:723-36. [PMID: 22488937 DOI: 10.1002/biot.201100352] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2011] [Revised: 01/31/2012] [Accepted: 02/27/2012] [Indexed: 11/12/2022]
Abstract
Stem cells are fascinating, as they supply the cells that construct our adult bodies and replenish, as we age, worn out, damaged, and diseased tissues. Stem cell regulation relies on intrinsic signals but also on inputs emanating from the neighbouring niche. The Drosophila testis provides an excellent system for studying such processes. Although recent advances have uncovered several signalling, cytoskeletal and other factors affecting niche homeostasis and testis differentiation, many aspects of niche regulation and maintenance remain unsolved. In this review, we discuss aspects of niche establishment and integrity not yet fully understood and we compare it to the current knowledge in other model systems such as vertebrates and plants. We also address specific questions on stem cell maintenance and niche regulation in the Drosophila testis under the control of Hox genes. Finally, we provide insights on the striking functional conservation of homologous genes in plants and animals and their respective stem cell niches. Elucidating conserved mechanisms of stem cell control in both lineages could reveal the importance underlying this conservation and justify the evolutionary pressure to adapt homologous molecules for performing the same task.
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Affiliation(s)
- Fani Papagiannouli
- Centre for Organismal Studies (COS) Heidelberg and CellNetworks - Cluster of Excellence, Heidelberg, Germany.
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A family business: stem cell progeny join the niche to regulate homeostasis. Nat Rev Mol Cell Biol 2012; 13:103-14. [PMID: 22266760 DOI: 10.1038/nrm3272] [Citation(s) in RCA: 205] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Stem cell niches, the discrete microenvironments in which the stem cells reside, play a dominant part in regulating stem cell activity and behaviours. Recent studies suggest that committed stem cell progeny become indispensable components of the niche in a wide range of stem cell systems. These unexpected niche inhabitants provide versatile feedback signals to their stem cell parents. Together with other heterologous cell types that constitute the niche, they contribute to the dynamics of the microenvironment. As progeny are often located in close proximity to stem cell niches, similar feedback regulations may be the underlying principles shared by different stem cell systems.
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Losick VP, Morris LX, Fox DT, Spradling A. Drosophila stem cell niches: a decade of discovery suggests a unified view of stem cell regulation. Dev Cell 2011; 21:159-71. [PMID: 21763616 PMCID: PMC6894370 DOI: 10.1016/j.devcel.2011.06.018] [Citation(s) in RCA: 236] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2011] [Revised: 06/03/2011] [Accepted: 06/10/2011] [Indexed: 12/28/2022]
Abstract
The past decade of research on Drosophila stem cells and niches has provided key insights. Fly stem cells do not occupy a special "state" based on novel "stem cell genes" but resemble transiently arrested tissue progenitors. Moreover, individual stem cells and downstream progenitors are highly dynamic and dispensable, not tissue bulwarks. Niches, rather than fixed cell lineages, ensure tissue health by holding stem cells and repressing cell differentiation inside, but not outside. We review the five best-understood adult Drosophila stem cells and argue that the fundamental biology of stem cells and niches is conserved between Drosophila and mice.
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Affiliation(s)
- Vicki P Losick
- Howard Hughes Medical Institute Research Laboratories, Department of Embryology, Carnegie Institution for Science, 3520 San Martin Drive, Baltimore, MD 21218, USA
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Abstract
In metazoans, tissue maintenance and regeneration depend on adult stem cells, which are characterized by their ability to self-renew and generate differentiating progeny in response to the needs of the tissues in which they reside. In the Drosophila testis, germline and somatic stem cells are housed together in a common niche, where they are regulated by local signals, epigenetic mechanisms and systemic factors. These stem cell populations in the Drosophila testis have the unique advantage of being easy to identify and manipulate, and hence much progress has been made in understanding how this niche operates. Here, we summarize recent work on stem cells in the adult Drosophila testis and discuss the remarkable ability of these stem cells to respond to change within the niche.
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Affiliation(s)
- Margaret de Cuevas
- Department of Cell Biology, Johns Hopkins School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA.
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