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Abe K, Hashimura H, Hiraoka H, Fujishiro S, Kameya N, Taoka K, Kuwana S, Fukuzawa M, Sawai S. Cell-cell heterogeneity in phosphoenolpyruvate carboxylase biases early cell fate priming in Dictyostelium discoideum. Front Cell Dev Biol 2025; 12:1526795. [PMID: 39968235 PMCID: PMC11832675 DOI: 10.3389/fcell.2024.1526795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2024] [Accepted: 12/31/2024] [Indexed: 02/20/2025] Open
Abstract
Glucose metabolism is a key factor characterizing the cellular state during multicellular development. In metazoans, the metabolic state of undifferentiated cells correlates with growth/differentiation transition and cell fate determination. Notably, the cell fate of the Amoebozoa species Dictyostelium discoideum is biased by the presence of glucose and is also correlated with early differences in intracellular ATP. However, the relationship between early cell-cell heterogeneity, cell differentiation, and the metabolic state is unclear. To address the link between glucose metabolism and cell differentiation in D. discoideum, we studied the role of phosphoenolpyruvate carboxylase (PEPC), a key enzyme in the PEP-oxaloacetate-pyruvate node, a core junction that dictates the metabolic flux of glycolysis, the TCA cycle, and gluconeogenesis. We demonstrate that there is cell-cell heterogeneity in PEPC promoter activity in vegetative cells, which depends on nutrient conditions, and that cells with high PEPC promoter activity differentiate into spores. The PEPC null mutant exhibited an aberrantly high prestalk/prespore ratio, and the spore mass of the fruiting body was glassy and consisted of immature spores. Furthermore, the PEPC null mutant had high ATP levels and low mitochondrial membrane potential. Our results suggest the importance of cell-cell heterogeneity in the levels of metabolic enzymes during early cell fate priming.
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Affiliation(s)
- Kenichi Abe
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyō, Japan
| | - Hidenori Hashimura
- Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Meguro, Japan
| | - Haruka Hiraoka
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Shoko Fujishiro
- Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Meguro, Japan
| | - Narufumi Kameya
- Department of Biology, Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, Japan
| | - Kazuteru Taoka
- Department of Biology, Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, Japan
| | - Satoshi Kuwana
- Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Meguro, Japan
| | - Masashi Fukuzawa
- Department of Biology, Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki, Japan
| | - Satoshi Sawai
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyō, Japan
- Department of Basic Science, Graduate School of Arts and Sciences, The University of Tokyo, Meguro, Japan
- Research Center for Complex Systems Biology, Universal Biology Institute, The University of Tokyo, Meguro, Japan
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2
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Wang Y, Papayova M, Warren E, Pears CJ. mTORC1 pathway activity biases cell fate choice. Sci Rep 2024; 14:20832. [PMID: 39242621 PMCID: PMC11379915 DOI: 10.1038/s41598-024-71298-2] [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: 05/15/2024] [Accepted: 08/27/2024] [Indexed: 09/09/2024] Open
Abstract
Pluripotent stem cells can differentiate into distinct cell types but the intracellular pathways controlling cell fate choice are not well understood. The social amoeba Dictyostelium discoideum is a simplified system to study choice preference as proliferating amoebae enter a developmental cycle upon starvation and differentiate into two major cell types, stalk and spores, organised in a multicellular fruiting body. Factors such as acidic vesicle pH predispose amoebae to one fate. Here we show that the mechanistic target of rapamycin complex 1 (mTORC1) pathway has a role in cell fate bias in Dictyostelium. Inhibiting the mTORC1 pathway activity by disruption of Rheb (activator Ras homolog enriched in brain), or treatment with the mTORC1 inhibitor rapamycin prior to development, biases cells to a spore cell fate. Conversely activation of the pathway favours stalk cell differentiation. The Set1 histone methyltransferase, responsible for histone H3 lysine4 methylation, in Dictyostelium cells regulates transcription at the onset of development. Disruption of Set1 leads to high mTORC1 pathway activity and stalk cell predisposition. The ability of the mTORC1 pathway to regulate cell fate bias of cells undergoing differentiation offers a potential target to increase the efficiency of stem cell differentiation into a particular cell type.
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Affiliation(s)
- Yuntao Wang
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Monika Papayova
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Eleanor Warren
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Catherine J Pears
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK.
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3
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Ricci-Tam C, Kuipa S, Kostman MP, Aronson MS, Sgro AE. Microbial models of development: Inspiration for engineering self-assembled synthetic multicellularity. Semin Cell Dev Biol 2023; 141:50-62. [PMID: 35537929 DOI: 10.1016/j.semcdb.2022.04.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 04/13/2022] [Indexed: 10/18/2022]
Abstract
While the field of synthetic developmental biology has traditionally focused on the study of the rich developmental processes seen in metazoan systems, an attractive alternate source of inspiration comes from microbial developmental models. Microbes face unique lifestyle challenges when forming emergent multicellular collectives. As a result, the solutions they employ can inspire the design of novel multicellular systems. In this review, we dissect the strategies employed in multicellular development by two model microbial systems: the cellular slime mold Dictyostelium discoideum and the biofilm-forming bacterium Bacillus subtilis. Both microbes face similar challenges but often have different solutions, both from metazoan systems and from each other, to create emergent multicellularity. These challenges include assembling and sustaining a critical mass of participating individuals to support development, regulating entry into development, and assigning cell fates. The mechanisms these microbial systems exploit to robustly coordinate development under a wide range of conditions offer inspiration for a new toolbox of solutions to the synthetic development community. Additionally, recreating these phenomena synthetically offers a pathway to understanding the key principles underlying how these behaviors are coordinated naturally.
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Affiliation(s)
- Chiara Ricci-Tam
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA; Biological Design Center, Boston University, Boston, MA 02215, USA
| | - Sophia Kuipa
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA; Biological Design Center, Boston University, Boston, MA 02215, USA
| | - Maya Peters Kostman
- Biological Design Center, Boston University, Boston, MA 02215, USA; Molecular Biology, Cell Biology & Biochemistry Program, Boston University, Boston, MA 02215, USA
| | - Mark S Aronson
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA; Biological Design Center, Boston University, Boston, MA 02215, USA
| | - Allyson E Sgro
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA; Biological Design Center, Boston University, Boston, MA 02215, USA; Molecular Biology, Cell Biology & Biochemistry Program, Boston University, Boston, MA 02215, USA.
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4
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Kohrman AQ, Kim-Yip RP, Posfai E. Imaging developmental cell cycles. Biophys J 2021; 120:4149-4161. [PMID: 33964274 PMCID: PMC8516676 DOI: 10.1016/j.bpj.2021.04.035] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/14/2021] [Accepted: 04/30/2021] [Indexed: 01/05/2023] Open
Abstract
The last decade has seen a major expansion in development of live biosensors, the tools needed to genetically encode them into model organisms, and the microscopic techniques used to visualize them. When combined, these offer us powerful tools with which to make fundamental discoveries about complex biological processes. In this review, we summarize the availability of biosensors to visualize an essential cellular process, the cell cycle, and the techniques for single-cell tracking and quantification of these reporters. We also highlight studies investigating the connection of cellular behavior to the cell cycle, particularly through live imaging, and anticipate exciting discoveries with the combination of these technologies in developmental contexts.
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Affiliation(s)
- Abraham Q Kohrman
- Department of Molecular Biology, Princeton University, Princeton, New Jersey
| | - Rebecca P Kim-Yip
- Department of Molecular Biology, Princeton University, Princeton, New Jersey
| | - Eszter Posfai
- Department of Molecular Biology, Princeton University, Princeton, New Jersey.
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5
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Gruenheit N, Baldwin A, Stewart B, Jaques S, Keller T, Parkinson K, Salvidge W, Baines R, Brimson C, Wolf JB, Chisholm R, Harwood AJ, Thompson CRL. Mutant resources for functional genomics in Dictyostelium discoideum using REMI-seq technology. BMC Biol 2021; 19:172. [PMID: 34429112 PMCID: PMC8386026 DOI: 10.1186/s12915-021-01108-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Accepted: 07/22/2021] [Indexed: 01/26/2023] Open
Abstract
Background Genomes can be sequenced with relative ease, but ascribing gene function remains a major challenge. Genetically tractable model systems are crucial to meet this challenge. One powerful model is the social amoeba Dictyostelium discoideum, a eukaryotic microbe widely used to study diverse questions in the cell, developmental and evolutionary biology. Results We describe REMI-seq, an adaptation of Tn-seq, which allows high throughput, en masse, and quantitative identification of the genomic site of insertion of a drug resistance marker after restriction enzyme-mediated integration. We use REMI-seq to develop tools which greatly enhance the efficiency with which the sequence, transcriptome or proteome variation can be linked to phenotype in D. discoideum. These comprise (1) a near genome-wide resource of individual mutants and (2) a defined pool of ‘barcoded’ mutants to allow large-scale parallel phenotypic analyses. These resources are freely available and easily accessible through the REMI-seq website that also provides comprehensive guidance and pipelines for data analysis. We demonstrate that integrating these resources allows novel regulators of cell migration, phagocytosis and macropinocytosis to be rapidly identified. Conclusions We present methods and resources, generated using REMI-seq, for high throughput gene function analysis in a key model system. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-021-01108-y.
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Affiliation(s)
- Nicole Gruenheit
- Centre for Life's Origins and Evolution, Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London, WC1E 6BT, UK
| | - Amy Baldwin
- Cardiff School of Biosciences, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ, UK
| | - Balint Stewart
- Centre for Life's Origins and Evolution, Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London, WC1E 6BT, UK
| | - Sarah Jaques
- Cardiff School of Biosciences, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ, UK
| | - Thomas Keller
- Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, The University of Manchester, Michael Smith Building, Oxford Road, Manchester, M13 9PT, UK
| | - Katie Parkinson
- Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, The University of Manchester, Michael Smith Building, Oxford Road, Manchester, M13 9PT, UK
| | - William Salvidge
- Centre for Life's Origins and Evolution, Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London, WC1E 6BT, UK
| | - Robert Baines
- Centre for Life's Origins and Evolution, Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London, WC1E 6BT, UK
| | - Chris Brimson
- Centre for Life's Origins and Evolution, Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London, WC1E 6BT, UK
| | - Jason B Wolf
- Milner Centre for Evolution and Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - Rex Chisholm
- Feinberg School of Medicine, Northwestern University, Chicago, Illinois, 60611, USA
| | - Adrian J Harwood
- Cardiff School of Biosciences, Cardiff University, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ, UK.
| | - Christopher R L Thompson
- Centre for Life's Origins and Evolution, Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London, WC1E 6BT, UK.
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6
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Dhakshinamoorthy R, Singh SP. Evolution of Reproductive Division of Labor - Lessons Learned From the Social Amoeba Dictyostelium discoideum During Its Multicellular Development. Front Cell Dev Biol 2021; 9:599525. [PMID: 33748102 PMCID: PMC7969725 DOI: 10.3389/fcell.2021.599525] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 02/12/2021] [Indexed: 11/13/2022] Open
Abstract
The origin of multicellular life from unicellular beings is an epochal step in the evolution of eukaryotes. There are several factors influencing cell fate choices during differentiation and morphogenesis of an organism. Genetic make-up of two cells that unite and fertilize is the key factor to signal the formation of various cell-types in due course of development. Although ploidy of the cell-types determines the genetics of an individual, the role of ploidy in cell fate decisions remains unclear. Dictyostelium serves as a versatile model to study the emergence of multicellular life from unicellular life forms. In this work, we investigate the role played by ploidy status of a cell on cell fate commitments during Dictyostelium development. To answer this question, we created Dictyostelium cells of different ploidy: haploid parents and derived isogenic diploids, allowing them to undergo development. The diploid strains used in this study were generated using parasexual genetics. The ploidy status of the haploids and diploids were confirmed by microscopy, flow cytometry, and karyotyping. Prior to reconstitution, we labeled the cells by two methods. First, intragenic expression of red fluorescent protein (RFP) and second, staining the amoebae with a vital, fluorescent dye carboxyfluorescein succinimidyl ester (CFSE). RFP labeled haploid cells allowed us to track the haploids in the chimeric aggregates, slugs, and fruiting bodies. The CFSE labeling method allowed us to track both the haploids and the diploids in the chimeric developmental structures. Our findings illustrate that the haploids demonstrate sturdy cell fate commitment starting from the aggregation stage. The haploids remain crowded at the aggregation centers of the haploid-diploid chimeric aggregates. At the slug stage haploids are predominantly occupying the slug posterior, and are visible in the spore population in the fruiting bodies. Our findings show that cell fate decisions during D. discoideum development are highly influenced by the ploidy status of a cell, adding a new aspect to already known factors Here, we report that ploidy status of a cell could also play a crucial role in regulating the cell fate commitments.
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Affiliation(s)
- Ranjani Dhakshinamoorthy
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, India
| | - Shashi P Singh
- Cell Migration and Chemotaxis Group, Cancer Research UK Beatson Institute, Glasgow, United Kingdom
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7
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Saiz N, Hadjantonakis AK. Coordination between patterning and morphogenesis ensures robustness during mouse development. Philos Trans R Soc Lond B Biol Sci 2020; 375:20190562. [PMID: 32829684 PMCID: PMC7482220 DOI: 10.1098/rstb.2019.0562] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/01/2020] [Indexed: 12/11/2022] Open
Abstract
The mammalian preimplantation embryo is a highly tractable, self-organizing developmental system in which three cell types are consistently specified without the need for maternal factors or external signals. Studies in the mouse over the past decades have greatly improved our understanding of the cues that trigger symmetry breaking in the embryo, the transcription factors that control lineage specification and commitment, and the mechanical forces that drive morphogenesis and inform cell fate decisions. These studies have also uncovered how these multiple inputs are integrated to allocate the right number of cells to each lineage despite inherent biological noise, and as a response to perturbations. In this review, we summarize our current understanding of how these processes are coordinated to ensure a robust and precise developmental outcome during early mouse development. This article is part of a discussion meeting issue 'Contemporary morphogenesis'.
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Affiliation(s)
- Néstor Saiz
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA
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8
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Conditional expression explains molecular evolution of social genes in a microbe. Nat Commun 2019; 10:3284. [PMID: 31337766 PMCID: PMC6650454 DOI: 10.1038/s41467-019-11237-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 06/25/2019] [Indexed: 12/30/2022] Open
Abstract
Conflict is thought to play a critical role in the evolution of social interactions by promoting diversity or driving accelerated evolution. However, despite our sophisticated understanding of how conflict shapes social traits, we have limited knowledge of how it impacts molecular evolution across the underlying social genes. Here we address this problem by analyzing the genome-wide impact of social interactions using genome sequences from 67 Dictyostelium discoideum strains. We find that social genes tend to exhibit enhanced polymorphism and accelerated evolution. However, these patterns are not consistent with conflict driven processes, but instead reflect relaxed purifying selection. This pattern is most likely explained by the conditional nature of social interactions, whereby selection on genes expressed only in social interactions is diluted by generations of inactivity. This dilution of selection by inactivity enhances the role of drift, leading to increased polymorphism and accelerated evolution, which we call the Red King process.
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9
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Gruenheit N, Parkinson K, Brimson CA, Kuwana S, Johnson EJ, Nagayama K, Llewellyn J, Salvidge WM, Stewart B, Keller T, van Zon W, Cotter SL, Thompson CRL. Cell Cycle Heterogeneity Can Generate Robust Cell Type Proportioning. Dev Cell 2018; 47:494-508.e4. [PMID: 30473004 PMCID: PMC6251973 DOI: 10.1016/j.devcel.2018.09.023] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 07/27/2018] [Accepted: 09/26/2018] [Indexed: 01/01/2023]
Abstract
Cell-cell heterogeneity can facilitate lineage choice during embryonic development because it primes cells to respond to differentiation cues. However, remarkably little is known about the origin of heterogeneity or whether intrinsic and extrinsic variation can be controlled to generate reproducible cell type proportioning seen in vivo. Here, we use experimentation and modeling in D. discoideum to demonstrate that population-level cell cycle heterogeneity can be optimized to generate robust cell fate proportioning. First, cell cycle position is quantitatively linked to responsiveness to differentiation-inducing signals. Second, intrinsic variation in cell cycle length ensures cells are randomly distributed throughout the cell cycle at the onset of multicellular development. Finally, extrinsic perturbation of optimal cell cycle heterogeneity is buffered by compensatory changes in global signal responsiveness. These studies thus illustrate key regulatory principles underlying cell-cell heterogeneity optimization and the generation of robust and reproducible fate choice in development. Dictyostelium cells break symmetry in a stochastic salt and pepper fashion Cell cycle position affects responsiveness to differentiation inducing signals Cell cycle length variation ensures cells are distributed in different cycle phases Perturbation of cell cycle dynamics is buffered by changes in signal responsiveness
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Affiliation(s)
- Nicole Gruenheit
- Centre for Life's Origins and Evolution, Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK; Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, The University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Katie Parkinson
- Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, The University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Christopher A Brimson
- Centre for Life's Origins and Evolution, Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Satoshi Kuwana
- Centre for Life's Origins and Evolution, Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Edward J Johnson
- Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, The University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Koki Nagayama
- Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, The University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Jack Llewellyn
- Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, The University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK; School of Mathematics, Faculty of Science and Engineering, The University of Manchester, Alan Turing Building, Manchester M13 9PL, UK
| | - William M Salvidge
- Centre for Life's Origins and Evolution, Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK
| | - Balint Stewart
- Centre for Life's Origins and Evolution, Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK; Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, The University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Thomas Keller
- Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, The University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Wouter van Zon
- Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, The University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
| | - Simon L Cotter
- School of Mathematics, Faculty of Science and Engineering, The University of Manchester, Alan Turing Building, Manchester M13 9PL, UK
| | - Christopher R L Thompson
- Centre for Life's Origins and Evolution, Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK; Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, The University of Manchester, Michael Smith Building, Oxford Road, Manchester M13 9PT, UK.
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10
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Abstract
Life in seasonally changing environments is challenging. Biological systems have to not only respond directly to the environment, but also schedule life history events in anticipation of seasonal changes. The cellular and molecular basis of how these events are scheduled is unknown. Cellular decision-making processes in response to signals above certain thresholds regularly occur i.e. cellular fate determination, apoptosis and firing of action potentials. Binary switches, the result of cellular decision-making processes, are defined as a change in phenotype between two stable states. A recent study presents evidence of a binary switch operating in the pars tuberalis (PT) of the pituitary, seemingly timing seasonal reproduction in sheep. Though, how a binary switch would allow for anticipation of seasonal environmental changes, not just direct responsiveness, is unclear. The purpose of this review is to assess the evidence for a binary switching mechanism timing seasonal reproduction and to hypothesize how a binary switch would allow biological processes to be timed over weeks to years. I draw parallels with mechanisms used in development, cell fate determination and seasonal timing in plants. I propose that the adult PT is a plastic tissue, showing a seasonal cycle of cellular differentiation, and that the underlying processes are likely to be epigenetic. Therefore, considering the mechanisms behind adult cellular plasticity offers a framework to hypothesize how a long-term timer functions within the PT.
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Affiliation(s)
- Shona H Wood
- Department of Arctic and Marine Biology, UiT – The Arctic University of Norway, Tromsø, Norway
- Faculty of Biology, Medicine and Health, School of Medical Sciences, University of Manchester, Manchester, UK
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11
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Strategic investment explains patterns of cooperation and cheating in a microbe. Proc Natl Acad Sci U S A 2018; 115:E4823-E4832. [PMID: 29735672 DOI: 10.1073/pnas.1716087115] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Contributing to cooperation is typically costly, while its rewards are often available to all members of a social group. So why should individuals be willing to pay these costs, especially if they could cheat by exploiting the investments of others? Kin selection theory broadly predicts that individuals should invest more into cooperation if their relatedness to group members is high (assuming they can discriminate kin from nonkin). To better understand how relatedness affects cooperation, we derived the ‟Collective Investment" game, which provides quantitative predictions for patterns of strategic investment depending on the level of relatedness. We then tested these predictions by experimentally manipulating relatedness (genotype frequencies) in mixed cooperative aggregations of the social amoeba Dictyostelium discoideum, which builds a stalk to facilitate spore dispersal. Measurements of stalk investment by natural strains correspond to the predicted patterns of relatedness-dependent strategic investment, wherein investment by a strain increases with its relatedness to the group. Furthermore, if overall group relatedness is relatively low (i.e., no strain is at high frequency in a group) strains face a scenario akin to the "Prisoner's Dilemma" and suffer from insufficient collective investment. We find that strains employ relatedness-dependent segregation to avoid these pernicious conditions. These findings demonstrate that simple organisms like D. discoideum are not restricted to being ‟cheaters" or ‟cooperators" but instead measure their relatedness to their group and strategically modulate their investment into cooperation accordingly. Consequently, all individuals will sometimes appear to cooperate and sometimes cheat due to the dynamics of strategic investing.
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12
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Dunn JD, Bosmani C, Barisch C, Raykov L, Lefrançois LH, Cardenal-Muñoz E, López-Jiménez AT, Soldati T. Eat Prey, Live: Dictyostelium discoideum As a Model for Cell-Autonomous Defenses. Front Immunol 2018; 8:1906. [PMID: 29354124 PMCID: PMC5758549 DOI: 10.3389/fimmu.2017.01906] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 12/13/2017] [Indexed: 12/11/2022] Open
Abstract
The soil-dwelling social amoeba Dictyostelium discoideum feeds on bacteria. Each meal is a potential infection because some bacteria have evolved mechanisms to resist predation. To survive such a hostile environment, D. discoideum has in turn evolved efficient antimicrobial responses that are intertwined with phagocytosis and autophagy, its nutrient acquisition pathways. The core machinery and antimicrobial functions of these pathways are conserved in the mononuclear phagocytes of mammals, which mediate the initial, innate-immune response to infection. In this review, we discuss the advantages and relevance of D. discoideum as a model phagocyte to study cell-autonomous defenses. We cover the antimicrobial functions of phagocytosis and autophagy and describe the processes that create a microbicidal phagosome: acidification and delivery of lytic enzymes, generation of reactive oxygen species, and the regulation of Zn2+, Cu2+, and Fe2+ availability. High concentrations of metals poison microbes while metal sequestration inhibits their metabolic activity. We also describe microbial interference with these defenses and highlight observations made first in D. discoideum. Finally, we discuss galectins, TNF receptor-associated factors, tripartite motif-containing proteins, and signal transducers and activators of transcription, microbial restriction factors initially characterized in mammalian phagocytes that have either homologs or functional analogs in D. discoideum.
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Affiliation(s)
- Joe Dan Dunn
- Faculty of Sciences, Department of Biochemistry, University of Geneva, Geneva, Switzerland
| | - Cristina Bosmani
- Faculty of Sciences, Department of Biochemistry, University of Geneva, Geneva, Switzerland
| | - Caroline Barisch
- Faculty of Sciences, Department of Biochemistry, University of Geneva, Geneva, Switzerland
| | - Lyudmil Raykov
- Faculty of Sciences, Department of Biochemistry, University of Geneva, Geneva, Switzerland
| | - Louise H Lefrançois
- Faculty of Sciences, Department of Biochemistry, University of Geneva, Geneva, Switzerland
| | - Elena Cardenal-Muñoz
- Faculty of Sciences, Department of Biochemistry, University of Geneva, Geneva, Switzerland
| | | | - Thierry Soldati
- Faculty of Sciences, Department of Biochemistry, University of Geneva, Geneva, Switzerland
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13
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Kuwana S, Senoo H, Sawai S, Fukuzawa M. A novel, lineage-primed prestalk cell subtype involved in the morphogenesis of D. discoideum. Dev Biol 2016; 416:286-99. [PMID: 27373689 DOI: 10.1016/j.ydbio.2016.06.032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 05/07/2016] [Accepted: 06/21/2016] [Indexed: 11/26/2022]
Abstract
Dictyostelium morphogenesis requires the tip, which acts as an organizer and conducts orchestrated cell movement and cell differentiation. At the slug stage the tip region contains prestalk A (pstA) cells, which are usually recognized by their expression of reporter constructs that utilize a fragment of the promoter of the ecmA gene. Here, using the promoter region of the o-methyl transferase 12 gene (omt12) to drive reporter expression, we demonstrate the presence, also within the pstA region, of a novel prestalk cell subtype: the pstV(A) cells. Surprisingly, a sub-population of the vegetative cells express a pstV(A): GFP marker and, sort out to the tip, both when developing alone and when co-developed with an excess of unmarked cells. The development of such a purified GFP-marked population is greatly accelerated: by precocious cell aggregation and tip formation with accompanying precocious elevation of developmental gene transcription. We therefore suggest that the tip contains at least two prestalk cell subtypes: the developmentally-specified pstA cells and the lineage-primed pstV(A) cells. It is presumably the pstV(A) cells that play the dominant role in morphogenesis during the earlier stages of development. The basis for the lineage priming is, however, unclear because we can find no correlation between pstV(A) differentiation and nutrient status during growth or cell cycle position at the time of starvation, the two known determinants of probable cell fate.
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Affiliation(s)
- Satoshi Kuwana
- Department of Biology, Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki 036-8561, Japan
| | - Hiroshi Senoo
- Department of Cell Biology, The Johns Hopkins University School of Medicine, Baltimore, USA
| | - Satoshi Sawai
- Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan
| | - Masashi Fukuzawa
- Department of Biology, Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki 036-8561, Japan.
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Loomis WF. Genetic control of morphogenesis in Dictyostelium. Dev Biol 2015; 402:146-61. [PMID: 25872182 PMCID: PMC4464777 DOI: 10.1016/j.ydbio.2015.03.016] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 03/12/2015] [Accepted: 03/25/2015] [Indexed: 01/06/2023]
Abstract
Cells grow, move, expand, shrink and die in the process of generating the characteristic shapes of organisms. Although the structures generated during development of the social amoeba Dictyostelium discoideum look nothing like the structures seen in metazoan embryogenesis, some of the morphogenetic processes used in their making are surprisingly similar. Recent advances in understanding the molecular basis for directed cell migration, cell type specific sorting, differential adhesion, secretion of matrix components, pattern formation, regulation and terminal differentiation are reviewed. Genes involved in Dictyostelium aggregation, slug formation, and culmination of fruiting bodies are discussed.
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Affiliation(s)
- William F Loomis
- Cell and Developmental Biology, Division of Biological Sciences, University of California San Diego, La Jolla, CA 92093, United States.
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15
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Fritzsch B, Jahan I, Pan N, Elliott KL. Evolving gene regulatory networks into cellular networks guiding adaptive behavior: an outline how single cells could have evolved into a centralized neurosensory system. Cell Tissue Res 2014; 359:295-313. [PMID: 25416504 DOI: 10.1007/s00441-014-2043-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Accepted: 10/20/2014] [Indexed: 12/18/2022]
Abstract
Understanding the evolution of the neurosensory system of man, able to reflect on its own origin, is one of the major goals of comparative neurobiology. Details of the origin of neurosensory cells, their aggregation into central nervous systems and associated sensory organs and their localized patterning leading to remarkably different cell types aggregated into variably sized parts of the central nervous system have begun to emerge. Insights at the cellular and molecular level have begun to shed some light on the evolution of neurosensory cells, partially covered in this review. Molecular evidence suggests that high mobility group (HMG) proteins of pre-metazoans evolved into the definitive Sox [SRY (sex determining region Y)-box] genes used for neurosensory precursor specification in metazoans. Likewise, pre-metazoan basic helix-loop-helix (bHLH) genes evolved in metazoans into the group A bHLH genes dedicated to neurosensory differentiation in bilaterians. Available evidence suggests that the Sox and bHLH genes evolved a cross-regulatory network able to synchronize expansion of precursor populations and their subsequent differentiation into novel parts of the brain or sensory organs. Molecular evidence suggests metazoans evolved patterning gene networks early, which were not dedicated to neuronal development. Only later in evolution were these patterning gene networks tied into the increasing complexity of diffusible factors, many of which were already present in pre-metazoans, to drive local patterning events. It appears that the evolving molecular basis of neurosensory cell development may have led, in interaction with differentially expressed patterning genes, to local network modifications guiding unique specializations of neurosensory cells into sensory organs and various areas of the central nervous system.
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Affiliation(s)
- Bernd Fritzsch
- Department of Biology, University of Iowa, CLAS, 143 BB, Iowa City, IA, 52242, USA,
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16
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Abstract
Experiments on the social amoeba Dictyostelium discoideum show that the origins of lineage bias in this system lie in the nutritional history of individual cells. Clues to the molecular basis for this process suggest similar forces may be at work in early mammalian development.
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Affiliation(s)
- Sophie M Morgani
- Sophie M Morgani is in the Danish Stem Cell Center (DanStem), University of Copenhagen, Copenhagen, Denmark
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