1
|
Faerberg DF, Aprison EZ, Ruvinsky I. Accelerated hermaphrodite maturation on male pheromones suggests a general principle of coordination between larval behavior and development. Development 2024; 151:dev202961. [PMID: 38975828 PMCID: PMC11266794 DOI: 10.1242/dev.202961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Accepted: 06/04/2024] [Indexed: 07/09/2024]
Abstract
Environment in general and social signals in particular could alter development. In Caenorhabditis elegans, male pheromones hasten development of hermaphrodite larvae. We show that this involves acceleration of growth and both somatic and germline development during the last larval stage (L4). Larvae exposed to male pheromones spend more time in L3 and less in the quiescent period between L3 and L4. This behavioral alteration improves provision in early L4, likely allowing for faster development. Larvae must be exposed to male pheromones in late L3 for behavioral and developmental effects to occur. Latter portions of other larval stages also contain periods of heightened sensitivity to environmental signals. Behavior during the early part of the larval stages is biased toward exploration, whereas later the emphasis shifts to food consumption. We argue that this organization allows assessment of the environment to identify the most suitable patch of resources, followed by acquisition of sufficient nutrition and salient information for the developmental events in the next larval stage. Evidence from other species indicates that such coordination of behavior and development may be a general feature of larval development.
Collapse
Affiliation(s)
- Denis F. Faerberg
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Erin Z. Aprison
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Ilya Ruvinsky
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| |
Collapse
|
2
|
Qiu C, Crittenden SL, Carrick BH, Dillard LB, Costa Dos Santos SJ, Dandey VP, Dutcher RC, Viverette EG, Wine RN, Woodworth J, Campbell ZT, Wickens M, Borgnia MJ, Kimble J, Tanaka Hall TM. A higher order PUF complex is central to regulation of C. elegans germline stem cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.14.599074. [PMID: 38915480 PMCID: PMC11195197 DOI: 10.1101/2024.06.14.599074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
PUF RNA-binding proteins are broadly conserved stem cell regulators. Nematode PUF proteins maintain germline stem cells (GSCs) and, with key partner proteins, repress differentiation mRNAs, including gld-1. Here we report that PUF protein FBF-2 and its partner LST-1 form a ternary complex that represses gld-1 via a pair of adjacent FBF-2 binding elements (FBEs) in its 3ÚTR. One LST-1 molecule links two FBF-2 molecules via motifs in the LST-1 intrinsically-disordered region; the gld-1 FBE pair includes a well-established 'canonical' FBE and a newly-identified noncanonical FBE. Remarkably, this FBE pair drives both full RNA repression in GSCs and full RNA activation upon differentiation. Discovery of the LST-1-FBF-2 ternary complex, the gld-1 adjacent FBEs, and their in vivo significance predicts an expanded regulatory repertoire of different assemblies of PUF-partner complexes in nematode germline stem cells. It also suggests analogous PUF controls may await discovery in other biological contexts and organisms.
Collapse
Affiliation(s)
- Chen Qiu
- Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | | | - Brian H. Carrick
- Department of Biochemistry, University of Wisconsin, Madison, WI 53706, USA
- Current address: MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK
| | - Lucas B. Dillard
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
- Current address: Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Stephany J. Costa Dos Santos
- Department of Biochemistry, University of Wisconsin, Madison, WI 53706, USA
- These authors contributed equally to the manuscript and are listed in alphabetical order
| | - Venkata P. Dandey
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
- These authors contributed equally to the manuscript and are listed in alphabetical order
| | - Robert C. Dutcher
- Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
- These authors contributed equally to the manuscript and are listed in alphabetical order
| | - Elizabeth G. Viverette
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
- These authors contributed equally to the manuscript and are listed in alphabetical order
- Current address: Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Robert N. Wine
- Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
- These authors contributed equally to the manuscript and are listed in alphabetical order
| | - Jennifer Woodworth
- Department of Biochemistry, University of Wisconsin, Madison, WI 53706, USA
- These authors contributed equally to the manuscript and are listed in alphabetical order
| | - Zachary T. Campbell
- Department of Anesthesiology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792, USA
| | - Marvin Wickens
- Department of Biochemistry, University of Wisconsin, Madison, WI 53706, USA
| | - Mario J. Borgnia
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Judith Kimble
- Department of Biochemistry, University of Wisconsin, Madison, WI 53706, USA
| | - Traci M. Tanaka Hall
- Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
- Lead contact
| |
Collapse
|
3
|
Carrick BH, Crittenden SL, Chen F, Linsley M, Woodworth J, Kroll-Conner P, Ferdous AS, Keleş S, Wickens M, Kimble J. PUF partner interactions at a conserved interface shape the RNA-binding landscape and cell fate in Caenorhabditis elegans. Dev Cell 2024; 59:661-675.e7. [PMID: 38290520 PMCID: PMC11253550 DOI: 10.1016/j.devcel.2024.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 11/10/2023] [Accepted: 01/08/2024] [Indexed: 02/01/2024]
Abstract
Protein-RNA regulatory networks underpin much of biology. C. elegans FBF-2, a PUF-RNA-binding protein, binds over 1,000 RNAs to govern stem cells and differentiation. FBF-2 interacts with multiple protein partners via a key tyrosine, Y479. Here, we investigate the in vivo significance of partnerships using a Y479A mutant. Occupancy of the Y479A mutant protein increases or decreases at specific sites across the transcriptome, varying with RNAs. Germline development also changes in a specific fashion: Y479A abolishes one FBF-2 function-the sperm-to-oocyte cell fate switch. Y479A's effects on the regulation of one mRNA, gld-1, are critical to this fate change, though other network changes are also important. FBF-2 switches from repression to activation of gld-1 RNA, likely by distinct FBF-2 partnerships. The role of RNA-binding protein partnerships in governing RNA regulatory networks will likely extend broadly, as such partnerships pervade RNA controls in virtually all metazoan tissues and species.
Collapse
Affiliation(s)
- Brian H Carrick
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
| | - Sarah L Crittenden
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Fan Chen
- Department of Statistics, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - MaryGrace Linsley
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Jennifer Woodworth
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Peggy Kroll-Conner
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Ahlan S Ferdous
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Sündüz Keleş
- Department of Statistics, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Marvin Wickens
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
| | - Judith Kimble
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
| |
Collapse
|
4
|
Urman MA, John NS, Jung T, Lee C. Aging disrupts spatiotemporal regulation of germline stem cells and niche integrity. Biol Open 2024; 13:bio060261. [PMID: 38156664 PMCID: PMC10810562 DOI: 10.1242/bio.060261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 12/13/2023] [Indexed: 01/03/2024] Open
Abstract
A major factor driving stem cell decline is stem cell niche aging, but its molecular mechanism remains elusive. We use the Caenorhabditis elegans distal tip cell (DTC), the mesenchymal niche that employs Notch signaling to regulate germline stem cells (GSCs), as an in vivo niche aging model and delineate the molecular details of the DTC/niche aging process. Here, we demonstrate that a drastic decrease in C. elegans germline fecundity, which begins even in early adulthood, is mainly due to an age-induced disruption in spatial regulation of Notch-dependent transcription in the germline combined with a moderate reduction in Notch transcription at both tissue and cellular levels. Consequently, the Notch-responsive GSC pool shifts from the distal end of the gonad to a more proximal region, disrupting the distal-to-proximal germline polarity. We find that this GSC pool shift is due to a dislocation of the DTC/niche nucleus, which is associated with age-induced changes in the structure and morphology of the DTC/niche. Our findings reveal a critical link between physiological changes in the aging niche, their consequences in stem cell regulation, and germline tissue functions.
Collapse
Affiliation(s)
- Michelle A. Urman
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY, 12222, USA
- The RNA Institute, University at Albany, State University of New York, Albany, NY, 12222, USA
| | - Nimmy S. John
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY, 12222, USA
- The RNA Institute, University at Albany, State University of New York, Albany, NY, 12222, USA
| | - Tyler Jung
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY, 12222, USA
| | - ChangHwan Lee
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY, 12222, USA
- The RNA Institute, University at Albany, State University of New York, Albany, NY, 12222, USA
| |
Collapse
|
5
|
Robert VJ, Caron M, Gely L, Adrait A, Pakulska V, Couté Y, Chevalier M, Riedel CG, Bedet C, Palladino F. SIN-3 acts in distinct complexes to regulate the germline transcriptional program in Caenorhabditis elegans. Development 2023; 150:dev201755. [PMID: 38771303 PMCID: PMC10617626 DOI: 10.1242/dev.201755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 09/18/2023] [Indexed: 10/12/2023]
Abstract
The transcriptional co-regulator SIN3 influences gene expression through multiple interactions that include histone deacetylases. Haploinsufficiency and mutations in SIN3 are the underlying cause of Witteveen-Kolk syndrome and related intellectual disability and autism syndromes, emphasizing its key role in development. However, little is known about the diversity of its interactions and functions in developmental processes. Here, we show that loss of SIN-3, the single SIN3 homolog in Caenorhabditis elegans, results in maternal-effect sterility associated with de-regulation of the germline transcriptome, including de-silencing of X-linked genes. We identify at least two distinct SIN3 complexes containing specific histone deacetylases and show that they differentially contribute to fertility. Single-cell, single-molecule fluorescence in situ hybridization reveals that in sin-3 mutants the X chromosome becomes re-expressed prematurely and in a stochastic manner in individual germ cells, suggesting a role for SIN-3 in its silencing. Furthermore, we identify histone residues whose acetylation increases in the absence of SIN-3. Together, this work provides a powerful framework for the in vivo study of SIN3 and associated proteins.
Collapse
Affiliation(s)
- Valerie J. Robert
- Laboratory of Biology and Modeling of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, Université de Lyon, 69007 Lyon, France
| | - Matthieu Caron
- Laboratory of Biology and Modeling of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, Université de Lyon, 69007 Lyon, France
| | - Loic Gely
- Laboratory of Biology and Modeling of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, Université de Lyon, 69007 Lyon, France
| | - Annie Adrait
- Grenoble Alpes, CEA, Inserm, UA13 BGE, CNRS, CEA, FR2048, 38000 Grenoble, France
| | - Victoria Pakulska
- Grenoble Alpes, CEA, Inserm, UA13 BGE, CNRS, CEA, FR2048, 38000 Grenoble, France
| | - Yohann Couté
- Grenoble Alpes, CEA, Inserm, UA13 BGE, CNRS, CEA, FR2048, 38000 Grenoble, France
| | - Manon Chevalier
- Department of Biosciences and Nutrition, Karolinska Institutet, Blickagången 16, 14157 Huddinge, Sweden
| | - Christian G. Riedel
- Department of Biosciences and Nutrition, Karolinska Institutet, Blickagången 16, 14157 Huddinge, Sweden
| | - Cecile Bedet
- Laboratory of Biology and Modeling of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, Université de Lyon, 69007 Lyon, France
| | - Francesca Palladino
- Laboratory of Biology and Modeling of the Cell, UMR5239 CNRS/Ecole Normale Supérieure de Lyon, INSERM U1210, UMS 3444 Biosciences Lyon Gerland, Université de Lyon, 69007 Lyon, France
| |
Collapse
|
6
|
Faerberg DF, Aprison EZ, Ruvinsky I. Periods of environmental sensitivity couple larval behavior and development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.04.552015. [PMID: 37609125 PMCID: PMC10441318 DOI: 10.1101/2023.08.04.552015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
The typical life cycle in most animal phyla includes a larval period that bridges embryogenesis and adulthood1. Despite the great diversity of larval forms, all larvae grow, acquire adult morphology and function, while navigating their habitats to obtain resources necessary for development. How larval development is coordinated with behavior remains substantially unclear. Here, we describe features of the iterative organization of larval stages that serve to assess the environment and procure resources prior to costly developmental commitments. We found that male-excreted pheromones accelerate2-4 the onset of adulthood in C. elegans hermaphrodites by coordinately advancing multiple developmental events and growth during the last larval stage. The larvae are sensitive to the accelerating male pheromones only at the end of the penultimate larval stage, just before the acceleration begins. Other larval stages also contain windows of sensitivity to environmental inputs. Importantly, behaviors associated with search and consumption of food are distinct between early and late portions of larval stages. We infer that each larval stage in C. elegans is subdivided into two epochs: A) global assessment of the environment to identify the most suitable patch and B) consumption of sufficient food and acquisition of salient information for developmental events in the next stage. We predict that in larvae of other species behavior is also divided into distinct epochs optimized either for assessing the habitat or obtaining the resources. Thus, a major role of larval behavior is to coordinate the orderly progression of development in variable environments.
Collapse
Affiliation(s)
- Denis F. Faerberg
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Erin Z. Aprison
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Ilya Ruvinsky
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| |
Collapse
|
7
|
Aprison EZ, Dzitoyeva S, Ruvinsky I. Serotonergic signaling plays a deeply conserved role in improving oocyte quality. Dev Biol 2023; 499:24-30. [PMID: 37121310 PMCID: PMC10247452 DOI: 10.1016/j.ydbio.2023.04.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 04/21/2023] [Accepted: 04/27/2023] [Indexed: 05/02/2023]
Abstract
Declining germline quality is a major cause of reproductive senescence. Potential remedies could be found by studying regulatory pathways that promote germline quality. Several lines of evidence, including a C. elegans male pheromone ascr#10 that counteracts the effects of germline aging in hermaphrodites, suggest that the nervous system plays an important role in regulating germline quality. Inspired by the fact that serotonin mediates ascr#10 signaling, here we show that serotonin reuptake inhibitors recapitulate the effects of ascr#10 on the germline and promote healthy oocyte aging in C. elegans. Surprisingly, we found that pharmacological increase of serotonin signaling stimulates several developmental processes in D. melanogaster, including improved oocyte quality, although underlying mechanisms appear to be different between worms and flies. Our results reveal a plausibly conserved role for serotonin in maintaining germline quality and identify a class of therapeutic interventions using available compounds that could efficiently forestall reproductive aging.
Collapse
Affiliation(s)
- Erin Z Aprison
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, 60208, USA
| | - Svetlana Dzitoyeva
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, 60208, USA
| | - Ilya Ruvinsky
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, 60208, USA.
| |
Collapse
|
8
|
Gleason RJ, Guo Y, Semancik CS, Ow C, Lakshminarayanan G, Chen X. Developmentally programmed histone H3 expression regulates cellular plasticity at the parental-to-early embryo transition. SCIENCE ADVANCES 2023; 9:eadh0411. [PMID: 37027463 PMCID: PMC10081851 DOI: 10.1126/sciadv.adh0411] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 03/08/2023] [Indexed: 06/19/2023]
Abstract
During metazoan development, the marked change in developmental potential from the parental germline to the embryo raises an important question regarding how the next life cycle is reset. As the basic unit of chromatin, histones are essential for regulating chromatin structure and function and, accordingly, transcription. However, the genome-wide dynamics of the canonical, replication-coupled (RC) histones during gametogenesis and embryogenesis remain unknown. In this study, we use CRISPR-Cas9-mediated gene editing in Caenorhabditis elegans to investigate the expression pattern and role of individual RC histone H3 genes and compare them to the histone variant, H3.3. We report a tightly regulated epigenome landscape change from the germline to embryos that are regulated through differential expression of distinct histone gene clusters. Together, this study reveals that a change from a H3.3- to H3-enriched epigenome during embryogenesis restricts developmental plasticity and uncovers distinct roles for individual H3 genes in regulating germline chromatin.
Collapse
Affiliation(s)
- Ryan J. Gleason
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | - Yanrui Guo
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
| | | | - Cindy Ow
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
- University of California, San Francisco, San Francisco, CA 94143, USA
| | - Gitanjali Lakshminarayanan
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
- Dana-Farber Cancer Institute, Boston, MA 02215 USA
| | - Xin Chen
- Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA
- Howard Hughes Medical Institute, Department of Biology, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA
| |
Collapse
|
9
|
Ferdous AS, Costa Dos Santos SJ, Kanzler CR, Shin H, Carrick BH, Crittenden SL, Wickens M, Kimble J. Functional significance of PUF partnerships in C. elegans germline stem cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.15.528708. [PMID: 36824876 PMCID: PMC9949348 DOI: 10.1101/2023.02.15.528708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/26/2023]
Abstract
PUF RNA-binding proteins are conserved stem cell regulators. Four PUF proteins govern self-renewal of C. elegans germline stem cells together with two intrinsically disordered proteins, LST-1 and SYGL-1. Based on yeast two-hybrid results, we proposed a composite self-renewal hub in the stem cell regulatory network, with eight PUF partnerships and extensive redundancy. Here, we investigate LST-1-PUF and SYGL-1-PUF partnerships and their molecular activities in their natural context - nematode stem cells. We confirm LST-1-PUF partnerships and their specificity to self-renewal PUFs by co-immunoprecipitation and show that an LST-1(A m B m ) mutant defective for PUF-interacting motifs does not complex with PUFs in nematodes. LST-1(A m B m ) is used to explore the functional significance of the LST-1-PUF partnership. Tethered LST-1 requires the partnership to repress expression of a reporter RNA, and LST-1 requires the partnership to co-immunoprecipitate with NTL-1/Not1 of the CCR4-NOT complex. We suggest that the partnership provides multiple molecular interactions that work together to form an effector complex on PUF target RNAs. Comparison of PUF-LST-1 and Pumilio-Nanos reveals fundamental molecular differences, making PUF-LST-1 a distinct paradigm for PUF partnerships. Summary statement Partnerships between PUF RNA-binding proteins and intrinsically disordered proteins are essential for stem cell maintenance and RNA repression.
Collapse
Affiliation(s)
- Ahlan S Ferdous
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | | | - Charlotte R Kanzler
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Heaji Shin
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Brian H Carrick
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Sarah L Crittenden
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Marvin Wickens
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Judith Kimble
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| |
Collapse
|
10
|
Aprison EZ, Dzitoyeva S, Ruvinsky I. The serotonin circuit that coordinates germline proliferation and egg laying with other reproductive functions in Caenorhabditis elegans. Proc Biol Sci 2022; 289:20220913. [PMID: 36448283 PMCID: PMC9709507 DOI: 10.1098/rspb.2022.0913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 11/10/2022] [Indexed: 12/03/2022] Open
Abstract
Behaviour and physiology are altered in reproducing animals, but neuronal circuits that regulate these changes remain largely unknown. Insights into mechanisms that regulate and possibly coordinate reproduction-related traits could be gleaned from the study of sex pheromones that can improve the reproductive success of potential mating partners. In Caenorhabditis elegans, the prominent male pheromone, ascr#10, modifies reproductive behaviour and several aspects of reproductive physiology in hermaphrodite recipients, including improving oocyte quality. Here we show that a circuit that contains serotonin-producing and serotonin-uptaking neurons plays a key role in mediating effects of ascr#10 on germline development and egg laying behaviour. We also demonstrate that increased serotonin signalling promotes proliferation of germline progenitors in adult hermaphrodites. Our results establish a role for serotonin in maintaining germline quality and highlight a simple neuronal circuit that acts as a linchpin that couples food intake, mating behaviour, reproductive output, and germline renewal and provisioning.
Collapse
Affiliation(s)
- Erin Z. Aprison
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Svetlana Dzitoyeva
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Ilya Ruvinsky
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| |
Collapse
|
11
|
Mechanisms of germ cell survival and plasticity in Caenorhabditis elegans. Biochem Soc Trans 2022; 50:1517-1526. [PMID: 36196981 PMCID: PMC9704514 DOI: 10.1042/bst20220878] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 09/20/2022] [Accepted: 09/21/2022] [Indexed: 11/17/2022]
Abstract
Animals constantly encounter environmental and physiological stressors that threaten survival and fertility. Somatic stress responses and germ cell arrest/repair mechanisms are employed to withstand such challenges. The Caenorhabditis elegans germline combats stress by initiating mitotic germ cell quiescence to preserve genome integrity, and by removing meiotic germ cells to prevent inheritance of damaged DNA or to tolerate lack of germline nutrient supply. Here, we review examples of germline recovery from distinct stressors - acute starvation and defective splicing - where quiescent mitotic germ cells resume proliferation to repopulate a germ line following apoptotic removal of meiotic germ cells. These protective mechanisms reveal the plastic nature of germline stem cells.
Collapse
|
12
|
Abstract
Pheromones exchanged by conspecifics are a major class of chemical signals that can alter behavior, physiology, and development. In particular, males and females communicate with potential mating partners via sex pheromones to promote reproductive success. Physiological and developmental mechanisms by which pheromones facilitate progeny production remain largely enigmatic. Here, we describe how a Caenorhabditis elegans male pheromone, ascr#10, improves the oogenic germline. Before most signs of aging become evident, C. elegans hermaphrodites start producing lower-quality gametes characterized by abnormal morphology, increased rates of chromosomal nondisjunction, and higher penetrance of deleterious alleles. We show that exposure to the male pheromone substantially ameliorates these defects and reduces embryonic lethality. ascr#10 stimulates proliferation of germline precursor cells in adult hermaphrodites. Coupled to the greater precursor supply is increased physiological germline cell death, which is required to improve oocyte quality in older mothers. The hermaphrodite germline is sensitive to the pheromone only during a time window, comparable in duration to a larval stage, in early adulthood. During this period, prereproductive adults assess the suitability of the environment for reproduction. Our results identify developmental events that occur in the oogenic germline in response to a male pheromone. They also suggest that the opposite effects of the pheromone on gamete quality and maternal longevity arise from competition over resource allocation between soma and the germline.
Collapse
|
13
|
Cao W, Tran C, Archer SK, Gopal S, Pocock R. Functional recovery of the germ line following splicing collapse. Cell Death Differ 2022; 29:772-787. [PMID: 34663906 PMCID: PMC8991207 DOI: 10.1038/s41418-021-00891-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 09/30/2021] [Accepted: 10/04/2021] [Indexed: 11/09/2022] Open
Abstract
Splicing introns from precursor-messenger RNA (pre-mRNA) transcripts is essential for translating functional proteins. Here, we report that the previously uncharacterized Caenorhabditis elegans protein MOG-7 acts as a pre-mRNA splicing factor. Depleting MOG-7 from the C. elegans germ line causes intron retention in most germline-expressed genes, impeding the germ cell cycle, and causing defects in nuclear morphology, germ cell identity and sterility. Despite the deleterious consequences caused by MOG-7 loss, the adult germ line can functionally recover to produce viable and fertile progeny when MOG-7 is restored. Germline recovery is dependent on a burst of apoptosis that likely clears defective germ cells, and viable gametes generated from the proliferation of germ cells in the progenitor zone. Together, these findings reveal that MOG-7 is essential for germ cell development, and that the germ line can functionally recover after a collapse in RNA splicing.
Collapse
Affiliation(s)
- Wei Cao
- grid.1002.30000 0004 1936 7857Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC 3800 Australia
| | - Christopher Tran
- grid.1002.30000 0004 1936 7857Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC 3800 Australia
| | - Stuart K. Archer
- grid.1002.30000 0004 1936 7857Monash Bioinformatics Platform, Monash University, Melbourne, VIC 3800 Australia
| | - Sandeep Gopal
- grid.1002.30000 0004 1936 7857Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC 3800 Australia
| | - Roger Pocock
- grid.1002.30000 0004 1936 7857Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, VIC 3800 Australia
| |
Collapse
|
14
|
Lynch TR, Xue M, Czerniak CW, Lee C, Kimble J. Notch-dependent DNA cis-regulatory elements and their dose-dependent control of C. elegans stem cell self-renewal. Development 2022; 149:274985. [PMID: 35394007 PMCID: PMC9058496 DOI: 10.1242/dev.200332] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 02/16/2022] [Indexed: 11/20/2022]
Abstract
A long-standing biological question is how DNA cis-regulatory elements shape transcriptional patterns during metazoan development. Reporter constructs, cell culture assays and computational modeling have made major contributions to answering this question, but analysis of elements in their natural context is an important complement. Here, we mutate Notch-dependent LAG-1 binding sites (LBSs) in the endogenous Caenorhabditis elegans sygl-1 gene, which encodes a key stem cell regulator, and analyze the consequences on sygl-1 expression (nascent transcripts, mRNA, protein) and stem cell maintenance. Mutation of one LBS in a three-element cluster approximately halved both expression and stem cell pool size, whereas mutation of two LBSs essentially abolished them. Heterozygous LBS mutant clusters provided intermediate values. Our results lead to two major conclusions. First, both LBS number and configuration impact cluster activity: LBSs act additively in trans and synergistically in cis. Second, the SYGL-1 gradient promotes self-renewal above its functional threshold and triggers differentiation below the threshold. Our approach of coupling CRISPR/Cas9 LBS mutations with effects on both molecular and biological readouts establishes a powerful model for in vivo analyses of DNA cis-regulatory elements. Summary: Notch-dependent DNA cis-regulatory elements work together in their developmental context in C. elegans to shape a transcriptional gradient, control stem cell pool size, and govern differentiation onset.
Collapse
Affiliation(s)
- Tina R. Lynch
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
- Integrated Program in Biochemistry, Madison, WI 53706, USA
| | - Mingyu Xue
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
- Department of Life Sciences, Imperial College London, South Kensington, London, SW7 2AZ, UK
| | - Cazza W. Czerniak
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
- Joint Department of Biomedical Engineering, Marquette University and Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - ChangHwan Lee
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Judith Kimble
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
- Integrated Program in Biochemistry, Madison, WI 53706, USA
| |
Collapse
|
15
|
Robinson-Thiewes S, Kershner AM, Shin H, Haupt KA, Kroll-Connor P, Kimble J. A sensitized genetic screen to identify regulators of Caenorhabditis elegans germline stem cells. G3 (BETHESDA, MD.) 2022; 12:jkab439. [PMID: 35100350 PMCID: PMC9210287 DOI: 10.1093/g3journal/jkab439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 12/08/2021] [Indexed: 11/26/2022]
Abstract
GLP-1/Notch signaling and a downstream RNA regulatory network maintain germline stem cells in Caenorhabditis elegans. In mutants lacking the GLP-1 receptor, all germline stem cells enter the meiotic cell cycle precociously and differentiate into sperm. This dramatic germline stem cell defect is called the "Glp" phenotype. The lst-1 and sygl-1 genes are direct targets of Notch transcriptional activation and functionally redundant. Whereas single lst-1 and sygl-1 mutants are fertile, lst-1 sygl-1 double mutants are sterile with a Glp phenotype. We set out to identify genes that function redundantly with either lst-1 or sygl-1 to maintain germline stem cells. To this end, we conducted forward genetic screens for mutants with a Glp phenotype in genetic backgrounds lacking functional copies of either lst-1 or sygl-1. The screens generated 9 glp-1 alleles, 2 lst-1 alleles, and 1 allele of pole-1, which encodes the catalytic subunit of DNA polymerase ε. Three glp-1 alleles reside in Ankyrin repeats not previously mutated. pole-1 single mutants have a low penetrance Glp phenotype that is enhanced by loss of sygl-1. Thus, the screen uncovered 1 locus that interacts genetically with sygl-1 and generated useful mutations for further studies of germline stem cell regulation.
Collapse
Affiliation(s)
| | | | - Heaji Shin
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Kimberly A Haupt
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Peggy Kroll-Connor
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Judith Kimble
- Department of Genetics, University of Wisconsin-Madison, Madison, WI 53706, USA
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| |
Collapse
|
16
|
Aoki ST, Lynch TR, Crittenden SL, Bingman CA, Wickens M, Kimble J. C. elegans germ granules require both assembly and localized regulators for mRNA repression. Nat Commun 2021; 12:996. [PMID: 33579952 PMCID: PMC7881195 DOI: 10.1038/s41467-021-21278-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 01/14/2021] [Indexed: 02/07/2023] Open
Abstract
Cytoplasmic RNA-protein (RNP) granules have diverse biophysical properties, from liquid to solid, and play enigmatic roles in RNA metabolism. Nematode P granules are paradigmatic liquid droplet granules and central to germ cell development. Here we analyze a key P granule scaffolding protein, PGL-1, to investigate the functional relationship between P granule assembly and function. Using a protein-RNA tethering assay, we find that reporter mRNA expression is repressed when recruited to PGL-1. We determine the crystal structure of the PGL-1 N-terminal region to 1.5 Å, discover its dimerization, and identify key residues at the dimer interface. Mutations of those interface residues prevent P granule assembly in vivo, de-repress PGL-1 tethered mRNA, and reduce fertility. Therefore, PGL-1 dimerization lies at the heart of both P granule assembly and function. Finally, we identify the P granule-associated Argonaute WAGO-1 as crucial for repression of PGL-1 tethered mRNA. We conclude that P granule function requires both assembly and localized regulators.
Collapse
Affiliation(s)
- Scott Takeo Aoki
- grid.257413.60000 0001 2287 3919Department of Biochemistry and Molecular Biology, School of Medicine, Indiana University, Indianapolis, IN USA ,grid.14003.360000 0001 2167 3675Department of Biochemistry, University of Wisconsin-Madison, Madison, WI USA
| | - Tina R. Lynch
- grid.14003.360000 0001 2167 3675Department of Biochemistry, University of Wisconsin-Madison, Madison, WI USA
| | - Sarah L. Crittenden
- grid.14003.360000 0001 2167 3675Department of Biochemistry, University of Wisconsin-Madison, Madison, WI USA ,grid.14003.360000 0001 2167 3675Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, WI USA
| | - Craig A. Bingman
- grid.14003.360000 0001 2167 3675Department of Biochemistry, University of Wisconsin-Madison, Madison, WI USA
| | - Marvin Wickens
- grid.14003.360000 0001 2167 3675Department of Biochemistry, University of Wisconsin-Madison, Madison, WI USA
| | - Judith Kimble
- grid.14003.360000 0001 2167 3675Department of Biochemistry, University of Wisconsin-Madison, Madison, WI USA ,grid.14003.360000 0001 2167 3675Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, WI USA
| |
Collapse
|
17
|
Haupt KA, Law KT, Enright AL, Kanzler CR, Shin H, Wickens M, Kimble J. A PUF Hub Drives Self-Renewal in Caenorhabditis elegans Germline Stem Cells. Genetics 2020; 214:147-161. [PMID: 31740451 PMCID: PMC6944405 DOI: 10.1534/genetics.119.302772] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 11/05/2019] [Indexed: 01/12/2023] Open
Abstract
Stem cell regulation relies on extrinsic signaling from a niche plus intrinsic factors that respond and drive self-renewal within stem cells. A priori, loss of niche signaling and loss of the intrinsic self-renewal factors might be expected to have equivalent stem cell defects. Yet this simple prediction has not been borne out for most stem cells, including Caenorhabditis elegans germline stem cells (GSCs). The central regulators of C. elegans GSCs include extrinsically acting GLP-1/Notch signaling from the niche; intrinsically acting RNA-binding proteins in the PUF family, termed FBF-1 and FBF-2 (collectively FBF); and intrinsically acting PUF partner proteins that are direct Notch targets. Abrogation of either GLP-1/Notch signaling or its targets yields an earlier and more severe GSC defect than loss of FBF-1 and FBF-2, suggesting that additional intrinsic regulators must exist. Here, we report that those missing regulators are two additional PUF proteins, PUF-3 and PUF-11 Remarkably, an fbf-1fbf-2 ; puf-3puf-11 quadruple null mutant has a GSC defect virtually identical to that of a glp-1/Notch null mutant. PUF-3 and PUF-11 both affect GSC maintenance, both are expressed in GSCs, and epistasis experiments place them at the same position as FBF within the network. Therefore, action of PUF-3 and PUF-11 explains the milder GSC defect in fbf-1fbf-2 mutants. We conclude that a "PUF hub," comprising four PUF proteins and two PUF partners, constitutes the intrinsic self-renewal node of the C. elegans GSC RNA regulatory network. Discovery of this hub underscores the significance of PUF RNA-binding proteins as key regulators of stem cell maintenance.
Collapse
Affiliation(s)
- Kimberly A Haupt
- Department of Biochemistry, University of Wisconsin-Madison, Wisconsin 53706
| | - Kimberley T Law
- Department of Biochemistry, University of Wisconsin-Madison, Wisconsin 53706
| | - Amy L Enright
- Department of Biochemistry, University of Wisconsin-Madison, Wisconsin 53706
| | - Charlotte R Kanzler
- Department of Biochemistry, University of Wisconsin-Madison, Wisconsin 53706
| | - Heaji Shin
- Department of Biochemistry, University of Wisconsin-Madison, Wisconsin 53706
| | - Marvin Wickens
- Department of Biochemistry, University of Wisconsin-Madison, Wisconsin 53706
| | - Judith Kimble
- Department of Biochemistry, University of Wisconsin-Madison, Wisconsin 53706
| |
Collapse
|
18
|
Aoki ST, Porter DF, Prasad A, Wickens M, Bingman CA, Kimble J. An RNA-Binding Multimer Specifies Nematode Sperm Fate. Cell Rep 2019; 23:3769-3775. [PMID: 29949762 PMCID: PMC6066285 DOI: 10.1016/j.celrep.2018.05.095] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 04/26/2018] [Accepted: 05/30/2018] [Indexed: 11/27/2022] Open
Abstract
FOG-3 is a master regulator of sperm fate in Caenorhabditis elegans and homologous to Tob/BTG proteins, which in mammals are monomeric adaptors that recruit enzymes to RNA binding proteins. Here, we determine the FOG-3 crystal structure and in vitro demonstrate that FOG-3 forms dimers that can multi-merize. The FOG-3 multimeric structure has a basic surface potential, suggestive of binding nucleic acid. Consistent with that prediction, FOG-3 binds directly to nearly 1,000 RNAs in nematode spermatogenic germ cells. Most binding is to the 3′ UTR, and most targets (94%) are oogenic mRNAs, even though assayed in spermatogenic cells. When tethered to a reporter mRNA, FOG-3 represses its expression. Together these findings elucidate the molecular mechanism of sperm fate specification and reveal the evolution of a protein from monomeric to multimeric form with acquisition of a distinct mode of mRNA repression. The mechanism of the sperm or oocyte fate decision has been elusive. Aoki et al. report that nematode FOG-3, a Tob/BTG protein driving sperm fate, has evolved from monomeric to multimeric form with acquisition of a divergent Tob/BTG mechanism for mRNA repression.
Collapse
Affiliation(s)
- Scott T Aoki
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Douglas F Porter
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Aman Prasad
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Marvin Wickens
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Craig A Bingman
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Judith Kimble
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA; Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, WI 53706, USA.
| |
Collapse
|
19
|
Hubbard EJA, Schedl T. Biology of the Caenorhabditis elegans Germline Stem Cell System. Genetics 2019; 213:1145-1188. [PMID: 31796552 PMCID: PMC6893382 DOI: 10.1534/genetics.119.300238] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Accepted: 09/09/2019] [Indexed: 12/14/2022] Open
Abstract
Stem cell systems regulate tissue development and maintenance. The germline stem cell system is essential for animal reproduction, controlling both the timing and number of progeny through its influence on gamete production. In this review, we first draw general comparisons to stem cell systems in other organisms, and then present our current understanding of the germline stem cell system in Caenorhabditis elegans In contrast to stereotypic somatic development and cell number stasis of adult somatic cells in C. elegans, the germline stem cell system has a variable division pattern, and the system differs between larval development, early adult peak reproduction and age-related decline. We discuss the cell and developmental biology of the stem cell system and the Notch regulated genetic network that controls the key decision between the stem cell fate and meiotic development, as it occurs under optimal laboratory conditions in adult and larval stages. We then discuss alterations of the stem cell system in response to environmental perturbations and aging. A recurring distinction is between processes that control stem cell fate and those that control cell cycle regulation. C. elegans is a powerful model for understanding germline stem cells and stem cell biology.
Collapse
Affiliation(s)
- E Jane Albert Hubbard
- Skirball Institute of Biomolecular Medicine, Departments of Cell Biology and Pathology, New York University School of Medicine, New York 10016
| | - Tim Schedl
- and Department of Genetics, Washington University School of Medicine, St. Louis, Missouri 63110
| |
Collapse
|
20
|
Haupt KA, Enright AL, Ferdous AS, Kershner AM, Shin H, Wickens M, Kimble J. The molecular basis of LST-1 self-renewal activity and its control of stem cell pool size. Development 2019; 146:dev.181644. [PMID: 31515205 DOI: 10.1242/dev.181644] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 09/05/2019] [Indexed: 01/01/2023]
Abstract
PUF RNA-binding proteins have diverse roles in animal development, with a broadly conserved role in stem cells. Two paradigmatic PUF proteins, FBF-1 and FBF-2, promote both self-renewal and differentiation in the C. elegans germline. The LST-1 protein is a pivotal regulator of self-renewal and is oncogenic when mis-expressed. Here, we demonstrate that LST-1 self-renewal activity resides within a predicted disordered region that harbors two KXXL motifs. We find that the KXXL motifs mediate the binding of LST-1 to FBF, and that point mutations of these motifs abrogate LST-1 self-renewal activity. The LST-1-FBF partnership is therefore crucial to stem cell maintenance and is a key element in the FBF regulatory network. A distinct region within LST-1 determines its spatial expression and size of the GSC pool. Most importantly, the molecular understanding of how an IDR-rich protein works in an essential partnership with a conserved stem cell regulator and RNA-binding protein suggests broad new avenues for combinatorial control.
Collapse
Affiliation(s)
- Kimberly A Haupt
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Amy L Enright
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Ahlan S Ferdous
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Aaron M Kershner
- Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Heaji Shin
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Marvin Wickens
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Judith Kimble
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA .,Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, WI 53706, USA
| |
Collapse
|
21
|
Lee C, Shin H, Kimble J. Dynamics of Notch-Dependent Transcriptional Bursting in Its Native Context. Dev Cell 2019; 50:426-435.e4. [PMID: 31378588 PMCID: PMC6724715 DOI: 10.1016/j.devcel.2019.07.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 05/23/2019] [Accepted: 07/01/2019] [Indexed: 12/16/2022]
Abstract
Transcription is well known to be inherently stochastic and episodic, but the regulation of transcriptional dynamics is not well understood. Here, we analyze how Notch signaling modulates transcriptional bursting during animal development. Our focus is Notch regulation of transcription in germline stem cells of the nematode C. elegans. Using the MS2 system to visualize nascent transcripts and live imaging to record dynamics, we analyze bursting as a function of position within the intact animal. We find that Notch-dependent transcriptional activation is indeed "bursty"; that wild-type Notch modulates burst duration (ON-time) rather than duration of pauses between bursts (OFF-time) or mean burst intensity; and that a mutant Notch receptor, which is compromised for assembly into the Notch transcription factor complex, primarily modifies burst size (duration × intensity). These analyses thus visualize the effect of a canonical signaling pathway on metazoan transcriptional bursting in its native context.
Collapse
Affiliation(s)
- ChangHwan Lee
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Heaji Shin
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Judith Kimble
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA; Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, WI 53706, USA.
| |
Collapse
|
22
|
Crittenden SL, Lee C, Mohanty I, Battula S, Knobel K, Kimble J. Sexual dimorphism of niche architecture and regulation of the Caenorhabditis elegans germline stem cell pool. Mol Biol Cell 2019; 30:1757-1769. [PMID: 31067147 PMCID: PMC6727753 DOI: 10.1091/mbc.e19-03-0164] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 04/24/2019] [Accepted: 05/02/2019] [Indexed: 01/08/2023] Open
Abstract
Stem cell maintenance by niche signaling is a common theme across phylogeny. In the Caenorhabditis elegans gonad, the broad outlines of germline stem cell (GSC) regulation are the same for both sexes: GLP-1/Notch signaling from the mesenchymal distal tip cell niche maintains GSCs in the distal gonad of both sexes and does so via two key stem cell regulators, SYGL-1 and LST-1. Yet most recent analyses of niche signaling and GSC regulation have focused on XX hermaphrodites, an essentially female sex making sperm in larvae and oocytes in adults. Here we focus on GSC regulation in XO males. Sexual dimorphism of niche architecture, reported previously, suggested that the molecular responses to niche signaling or numbers of GSCs might also be sexually distinct. Remarkably, this is not the case. This work extends our understanding of the sexually dimorphic niche architecture, but also demonstrates that the dimorphic niches drive a similar molecular response and maintain a similar number of GSCs in their stem cell pools.
Collapse
Affiliation(s)
- Sarah L. Crittenden
- Howard Hughes Medical Institute, University of Wisconsin–Madison, Madison, WI 53706
- Department of Biochemistry, University of Wisconsin–Madison, Madison, WI 53706
| | - ChangHwan Lee
- Howard Hughes Medical Institute, University of Wisconsin–Madison, Madison, WI 53706
- Department of Biochemistry, University of Wisconsin–Madison, Madison, WI 53706
| | - Ipsita Mohanty
- Department of Biochemistry, University of Wisconsin–Madison, Madison, WI 53706
| | - Sindhu Battula
- Department of Biochemistry, University of Wisconsin–Madison, Madison, WI 53706
| | - Karla Knobel
- Department of Biochemistry, University of Wisconsin–Madison, Madison, WI 53706
| | - Judith Kimble
- Howard Hughes Medical Institute, University of Wisconsin–Madison, Madison, WI 53706
- Department of Biochemistry, University of Wisconsin–Madison, Madison, WI 53706
| |
Collapse
|
23
|
Seidel HS, Smith TA, Evans JK, Stamper JQ, Mast TG, Kimble J. C. elegans germ cells divide and differentiate in a folded tissue. Dev Biol 2018; 442:173-187. [DOI: 10.1016/j.ydbio.2018.07.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Revised: 07/08/2018] [Accepted: 07/16/2018] [Indexed: 12/18/2022]
|
24
|
McManus CE, Reinke V. The Germline-Specific Factor OEF-1 Facilitates Coordinated Progression Through Germ Cell Development in Caenorhabditis elegans. Genetics 2018; 208:549-563. [PMID: 29167199 PMCID: PMC5788521 DOI: 10.1534/genetics.117.1123] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 11/19/2017] [Indexed: 11/18/2022] Open
Abstract
The purpose of germ cells is to ensure the faithful transmission of genetic material to the next generation. To develop into mature gametes, germ cells must pass through cell cycle checkpoints while maintaining totipotency and genomic integrity. How germ cells coordinate developmental events while simultaneously protecting their unique fate is not well understood. Here, we characterize a novel nuclear protein, Oocyte-Excluded Factor-1 (OEF-1), with highly specific germline expression in Caenorhabditis elegans OEF-1 is initially detected early in embryogenesis and is expressed in the nuclei of all germ cells during larval stages. In adults, OEF-1 expression abruptly decreases just prior to oocyte differentiation. In oef-1 mutants, the developmental progression of germ cells is accelerated, resulting in subtle defects at multiple stages of germ cell development. Lastly, OEF-1 is primarily associated with the bodies of germline-expressed genes, and as such is excluded from the X chromosome. We hypothesize that OEF-1 may regulate the rate of progression through germ cell development, providing insight into how these critical maturation events are coordinated.
Collapse
Affiliation(s)
- Catherine E McManus
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06520
| | - Valerie Reinke
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06520
| |
Collapse
|
25
|
Shin H, Haupt KA, Kershner AM, Kroll-Conner P, Wickens M, Kimble J. SYGL-1 and LST-1 link niche signaling to PUF RNA repression for stem cell maintenance in Caenorhabditis elegans. PLoS Genet 2017; 13:e1007121. [PMID: 29232700 PMCID: PMC5741267 DOI: 10.1371/journal.pgen.1007121] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 12/22/2017] [Accepted: 11/20/2017] [Indexed: 01/14/2023] Open
Abstract
Central questions in regenerative biology include how stem cells are maintained and how they transition from self-renewal to differentiation. Germline stem cells (GSCs) in Caeno-rhabditis elegans provide a tractable in vivo model to address these questions. In this system, Notch signaling and PUF RNA binding proteins, FBF-1 and FBF-2 (collectively FBF), maintain a pool of GSCs in a naïve state. An open question has been how Notch signaling modulates FBF activity to promote stem cell self-renewal. Here we report that two Notch targets, SYGL-1 and LST-1, link niche signaling to FBF. We find that SYGL-1 and LST-1 proteins are cytoplasmic and normally restricted to the GSC pool region. Increasing the distribution of SYGL-1 expands the pool correspondingly, and vast overexpression of either SYGL-1 or LST-1 generates a germline tumor. Thus, SYGL-1 and LST-1 are each sufficient to drive "stemness" and their spatial restriction prevents tumor formation. Importantly, SYGL-1 and LST-1 can only drive tumor formation when FBF is present. Moreover, both proteins interact physically with FBF, and both are required to repress a signature FBF mRNA target. Together, our results support a model in which SYGL-1 and LST-1 form a repressive complex with FBF that is crucial for stem cell maintenance. We further propose that progression from a naïve stem cell state to a state primed for differentiation relies on loss of SYGL-1 and LST-1, which in turn relieves FBF target RNAs from repression. Broadly, our results provide new insights into the link between niche signaling and a downstream RNA regulatory network and how this circuitry governs the balance between self-renewal and differentiation.
Collapse
Affiliation(s)
- Heaji Shin
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Kimberly A. Haupt
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Aaron M. Kershner
- Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Peggy Kroll-Conner
- Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Marvin Wickens
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Judith Kimble
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| |
Collapse
|
26
|
Abstract
Many stem cell niches contain support cells that increase contact with stem cells by enwrapping them in cellular processes. One example is the germ stem cell niche in C. elegans, which is composed of a single niche cell termed the distal tip cell (DTC) that extends cellular processes, constructing an elaborate plexus that enwraps germ stem cells. To identify genes required for plexus formation and to explore the function of this specialized enwrapping behavior, a series of targeted and tissue-specific RNAi screens were performed. Here we identify genes that promote stem cell enwrapment by the DTC plexus, including a set that specifically functions within the DTC, such as the chromatin modifier lin-40/MTA1, and others that act within the germline, such as the 14-3-3 signaling protein par-5. Analysis of genes that function within the germline to mediate plexus development reveal that they are required for expansion of the germ progenitor zone, supporting the emerging idea that germ stem cells signal to the niche to stimulate enwrapping behavior. Examination of wild-type animals with asymmetric plexus formation and animals with reduced DTC plexus elaboration via loss of two candidates including lin-40 indicate that cellular enwrapment promotes GLP-1/Notch signaling and germ stem cell fate. Together, our work identifies novel regulators of cellular enwrapment and suggests that reciprocal signaling between the DTC niche and the germ stem cells promotes enwrapment behavior and stem cell fate.
Collapse
|
27
|
Lee C, Seidel HS, Lynch TR, Sorensen EB, Crittenden SL, Kimble J. Single-molecule RNA Fluorescence in situ Hybridization (smFISH) in Caenorhabditis elegans. Bio Protoc 2017; 7:e2357. [PMID: 34541104 DOI: 10.21769/bioprotoc.2357] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 01/30/2017] [Accepted: 05/18/2017] [Indexed: 11/02/2022] Open
Abstract
Single-molecule RNA fluorescence in situ hybridization (smFISH) is a technique to visualize individual RNA molecules using multiple fluorescently-labeled oligonucleotide probes specific to the target RNA ( Raj et al., 2008 ; Lee et al., 2016a ). We adapted this technique to visualize RNAs in the C. elegans whole adult worm or its germline, which enabled simultaneous recording of nascent transcripts at active transcription sites and mature mRNAs in the cytoplasm ( Lee et al., 2013 and 2016b). Here we describe each step of the smFISH procedure, reagents, and microscope settings optimized for C. elegans extruded gonads.
Collapse
Affiliation(s)
- ChangHwan Lee
- Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA.,Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Hannah S Seidel
- Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA.,Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA.,Current address: Department of Biology, Eastern Michigan University, Ypsilanti, Michigan, USA
| | - Tina R Lynch
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Erika B Sorensen
- Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA.,Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA.,Current address: Department of Biology, Wabash College, Crawfordsville, Indiana, USA
| | - Sarah L Crittenden
- Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Judith Kimble
- Howard Hughes Medical Institute, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA.,Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| |
Collapse
|