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Yellow polyketide pigment suppresses premature hatching in social amoeba. Proc Natl Acad Sci U S A 2022; 119:e2116122119. [PMID: 36252029 PMCID: PMC9618038 DOI: 10.1073/pnas.2116122119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Low-molecular-weight natural products from microbes are indispensable in the development of potent drugs. However, their biological roles within an ecological context often remain elusive. Here, we shed light on natural products from eukaryotic microorganisms that have the ability to transition from single cells to multicellular organisms: the social amoebae. These eukaryotes harbor a large number of polyketide biosynthetic genes in their genomes, yet virtually none of the corresponding products can be isolated or characterized. Using complementary molecular biology approaches, including CRISPR-Cas9, we generated polyketide synthase (pks5) inactivation and overproduction strains of the social amoeba Dictyostelium discoideum. Differential, untargeted metabolomics of wild-type versus mutant fruiting bodies allowed us to pinpoint candidate metabolites derived from the amoebal PKS5. Extrachromosomal expression of the respective gene led to the identification of a yellow polyunsaturated fatty acid. Analysis of the temporospatial production pattern of this compound in conjunction with detailed bioactivity studies revealed the polyketide to be a spore germination suppressor.
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Kufs JE, Reimer C, Stallforth P, Hillmann F, Regestein L. The potential of amoeba-based processes for natural product syntheses. Curr Opin Biotechnol 2022; 77:102766. [PMID: 35944344 DOI: 10.1016/j.copbio.2022.102766] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 07/11/2022] [Accepted: 07/12/2022] [Indexed: 11/18/2022]
Abstract
The identification of novel platform organisms for the production and discovery of small molecules is of high interest for the pharmaceutical industry. In particular, the structural complexity of most natural products with therapeutic potential restricts an industrial production since chemical syntheses often require complex multistep routes. The amoeba Dictyostelium discoideum can be easily cultivated in bioreactors due to its planktonic growth behavior and contains numerous polyketide and terpene synthase genes with only a few compounds being already elucidated. Hence, the amoeba both bears a wealth of hidden natural products and allows for the development of new bioprocesses for existing pharmaceuticals. In this mini review, we present D. discoideum as a novel platform for the production of complex secondary metabolites and discuss its suitability for industrial processes. We also provide initial insights into future bioprocesses, both involving bacterial coculture setups and for the production of plant-based pharmaceuticals.
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Affiliation(s)
- Johann E Kufs
- Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (Leibniz-HKI), Jena, Germany
| | - Christin Reimer
- Evolution of Microbial Interactions, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (Leibniz-HKI), Jena, Germany; Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany
| | - Pierre Stallforth
- Paleobiotechnology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (Leibniz-HKI), Jena, Germany; Friedrich Schiller University Jena, Institute for Organic Chemistry and Macromolecular Chemistry, Jena, Germany
| | - Falk Hillmann
- Evolution of Microbial Interactions, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (Leibniz-HKI), Jena, Germany
| | - Lars Regestein
- Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (Leibniz-HKI), Jena, Germany.
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3
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Wen J, Li M, Zhang W, Wang H, Bai Y, Hao J, Liu C, Deng K, Zhao Y. Role of Higenamine in Heart Diseases: A Mini-Review. Front Pharmacol 2022; 12:798495. [PMID: 35082678 PMCID: PMC8784381 DOI: 10.3389/fphar.2021.798495] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 11/29/2021] [Indexed: 01/22/2023] Open
Abstract
Higenamine, a natural product with multiple targets in heart diseases, is originally derived from Aconitum, which has been traditionally used in China for the treatment of heart disease, including heart failure, arrhythmia, bradycardia, cardiac ischemia/reperfusion injury, cardiac fibrosis, etc. This study is aimed to clarify the role of higenamine in heart diseases. Higenamine has effects on improving energy metabolism of cardiomyocytes, anti-cardiac fibroblast activation, anti-oxidative stress and anti-apoptosis. Accumulating evidence from various studies has shown that higenamine exerts a wide range of cardiovascular pharmacological effects in vivo and in vitro, including alleviating heart failure, reducing cardiac ischemia/reperfusion injury, attenuating pathological cardiac fibrosis and dysfunction. In addition, several clinical studies have reported that higenamine could continuously increase the heart rate levels of healthy volunteers as well as patients with heart disease, but there are variable effects on systolic blood pressure and diastolic blood pressure. Moreover, the heart protection and therapeutic effects of higenamine on heart disease are related to regulating LKB1/AMPKα/Sirt1, mediating the β2-AR/PI3K/AKT cascade, induction of heme oxygenase-1, suppressing TGF-β1/Smad signaling, and targeting ASK1/MAPK (ERK, P38)/NF-kB signaling pathway. However, the interventional effects of higenamine on heart disease and its underlying mechanisms based on experimental studies have not yet been systematically reviewed. This paper reviewed the potential pharmacological mechanisms of higenamine on the prevention, treatment, and diagnosis of heart disease and clarified its clinical applications. The literature shows that higenamine may have a potent effect on complex heart diseases, and proves the profound medicinal value of higenamine in heart disease.
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Affiliation(s)
- Jianxia Wen
- School of Food and Bioengineering, Xihua University, Chengdu, China
| | - Mingjie Li
- Department of Pathology, First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Wenwen Zhang
- School of Food and Bioengineering, Xihua University, Chengdu, China
| | - Haoyu Wang
- School of Food and Bioengineering, Xihua University, Chengdu, China
| | - Yan Bai
- School of Food and Bioengineering, Xihua University, Chengdu, China
| | - Junjie Hao
- College of Pharmaceutical Science, Yunnan University of Chinese Medicine, Kunming, China
| | - Chuan Liu
- School of Food and Bioengineering, Xihua University, Chengdu, China
| | - Ke Deng
- School of Food and Bioengineering, Xihua University, Chengdu, China
| | - Yanling Zhao
- Department of Pharmacy, Chinese PLA General Hospital, Beijing, China
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4
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Reimer C, Kufs JE, Rautschek J, Regestein L, Valiante V, Hillmann F. Engineering the amoeba Dictyostelium discoideum for biosynthesis of a cannabinoid precursor and other polyketides. Nat Biotechnol 2022; 40:751-758. [PMID: 34992245 DOI: 10.1038/s41587-021-01143-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 10/29/2021] [Indexed: 02/07/2023]
Abstract
Aromatic polyketides are natural polyphenolic compounds with a broad spectrum of pharmacological activities. Production of those metabolites in the model organisms Escherichia coli and Saccharomyces cerevisiae has been limited by the extensive cellular engineering needed for the coordinated biosynthesis of polyketides and their precursors. In contrast, the amoeba Dictyostelium discoideum is a native producer of secondary metabolites and harbors a wide, but largely unexplored, repertoire of genes for the biosynthesis of polyketides and terpenoids. Here we present D. discoideum as an advantageous chassis for the production of aromatic polyketides. By expressing its native and cognate plant polyketide synthase genes in D. discoideum, we demonstrate production of phlorocaprophenone, methyl-olivetol, resveratrol and olivetolic acid (OA), which is the central intermediate in the biosynthesis of cannabinoids. To facilitate OA synthesis, we further engineered an amoeba/plant inter-kingdom hybrid enzyme that produced OA from primary metabolites in two enzymatic steps, providing a shortcut in a synthetic cannabinoid pathway using the D. discoideum host system.
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Affiliation(s)
- Christin Reimer
- Evolution of Microbial Interactions, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (Leibniz-HKI), Jena, Germany.,Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany
| | - Johann E Kufs
- Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany.,Biobricks of Microbial Natural Product Syntheses, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (Leibniz-HKI), Jena, Germany.,Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (Leibniz-HKI), Jena, Germany
| | - Julia Rautschek
- Biobricks of Microbial Natural Product Syntheses, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (Leibniz-HKI), Jena, Germany
| | - Lars Regestein
- Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (Leibniz-HKI), Jena, Germany
| | - Vito Valiante
- Biobricks of Microbial Natural Product Syntheses, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (Leibniz-HKI), Jena, Germany.
| | - Falk Hillmann
- Evolution of Microbial Interactions, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (Leibniz-HKI), Jena, Germany.
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Scherlach K, Hertweck C. Mining and unearthing hidden biosynthetic potential. Nat Commun 2021; 12:3864. [PMID: 34162873 PMCID: PMC8222398 DOI: 10.1038/s41467-021-24133-5] [Citation(s) in RCA: 107] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 06/04/2021] [Indexed: 12/11/2022] Open
Abstract
Genetically encoded small molecules (secondary metabolites) play eminent roles in ecological interactions, as pathogenicity factors and as drug leads. Yet, these chemical mediators often evade detection, and the discovery of novel entities is hampered by low production and high rediscovery rates. These limitations may be addressed by genome mining for biosynthetic gene clusters, thereby unveiling cryptic metabolic potential. The development of sophisticated data mining methods and genetic and analytical tools has enabled the discovery of an impressive array of previously overlooked natural products. This review shows the newest developments in the field, highlighting compound discovery from unconventional sources and microbiomes. Natural products are an important source of bioactive compounds and have versatile applications in different fields, but their discovery is challenging. Here, the authors review the recent developments in genome mining for discovery of natural products, focusing on compounds from unconventional microorganisms and microbiomes.
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Affiliation(s)
- Kirstin Scherlach
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, HKI, Jena, Germany
| | - Christian Hertweck
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology, HKI, Jena, Germany. .,Faculty of Biological Sciences, Friedrich Schiller University Jena, Jena, Germany.
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Liu C, Kakeya H. Cryptic Chemical Communication: Secondary Metabolic Responses Revealed by Microbial Co‐culture. Chem Asian J 2020; 15:327-337. [DOI: 10.1002/asia.201901505] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 12/15/2019] [Indexed: 02/06/2023]
Affiliation(s)
- Chao Liu
- Department of System Chemotherapy and Molecular SciencesDivision of Bioinformatics and Chemical GenomicsGraduate School of Pharmaceutical SciencesKyoto University Sakyo-ku Kyoto 606-8501 Japan
| | - Hideaki Kakeya
- Department of System Chemotherapy and Molecular SciencesDivision of Bioinformatics and Chemical GenomicsGraduate School of Pharmaceutical SciencesKyoto University Sakyo-ku Kyoto 606-8501 Japan
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Temperini A, Lanari D, Colognese F, Piazzolla F. Scalable Multicomponent Synthesis of (Hetero)aryl-Substituted Phenyls: Focus on Metal-Free Halogenated Biaryls, 3-Arylindoles, and Isourolithine A Synthesis. European J Org Chem 2019. [DOI: 10.1002/ejoc.201901551] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Andrea Temperini
- Dipartimento di Scienze Farmaceutiche; Università di Perugia; Via del Liceo 1 06123 Perugia Italy
| | - Daniela Lanari
- Dipartimento di Scienze Farmaceutiche; Università di Perugia; Via del Liceo 1 06123 Perugia Italy
| | - Francesco Colognese
- Dipartimento di Scienze Farmaceutiche; Università di Perugia; Via del Liceo 1 06123 Perugia Italy
| | - Francesca Piazzolla
- School of Chemistry and Biochemistry; University of Geneva; 1211 Geneva Switzerland
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8
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Chen X, Luck K, Rabe P, Dinh CQ, Shaulsky G, Nelson DR, Gershenzon J, Dickschat JS, Köllner TG, Chen F. A terpene synthase-cytochrome P450 cluster in Dictyostelium discoideum produces a novel trisnorsesquiterpene. eLife 2019; 8:44352. [PMID: 31063135 PMCID: PMC6524965 DOI: 10.7554/elife.44352] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 05/03/2019] [Indexed: 12/14/2022] Open
Abstract
Terpenoids are enormously diverse, but our knowledge of their biosynthesis and functions is limited. Here we report on a terpene synthase (DdTPS8)-cytochrome P450 (CYP521A1) gene cluster that produces a novel C12 trisnorsesquiterpene and affects the development of Dictyostelium discoideum. DdTPS8 catalyzes the formation of a sesquiterpene discoidol, which is undetectable from the volatile bouquet of wild type D. discoideum. Interestingly, a DdTPS8 knockout mutant lacks not only discoidol, but also a putative trisnorsesquiterpene. This compound was hypothesized to be derived from discoidol via cytochrome P450 (CYP)-catalyzed oxidative cleavage. CYP521A1, which is clustered with DdTPS8, was identified as a top candidate. Biochemical assays demonstrated that CYP521A1 catalyzes the conversion of discoidol to a novel trisnorsesquiterpene named discodiene. The DdTPS8 knockout mutant exhibited slow progression in development. This study points to the untapped diversity of natural products made by D. discoideum, which may have diverse roles in its development and chemical ecology.
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Affiliation(s)
- Xinlu Chen
- Department of Plant Sciences, University of Tennessee, Knoxville, United States
| | - Katrin Luck
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Patrick Rabe
- Kekulé-Institute of Organic Chemistry and Biochemistry, University of Bonn, Bonn, Germany
| | - Christopher Qd Dinh
- Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, United States
| | - Gad Shaulsky
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, United States
| | - David R Nelson
- Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, United States
| | - Jonathan Gershenzon
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Jeroen S Dickschat
- Kekulé-Institute of Organic Chemistry and Biochemistry, University of Bonn, Bonn, Germany
| | - Tobias G Köllner
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Feng Chen
- Department of Plant Sciences, University of Tennessee, Knoxville, United States
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9
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Antimicrobial Activities of Dictyostelium Differentiation-Inducing Factors and Their Derivatives. Biomolecules 2019; 9:biom9050163. [PMID: 31035614 PMCID: PMC6571789 DOI: 10.3390/biom9050163] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 04/25/2019] [Accepted: 04/25/2019] [Indexed: 01/22/2023] Open
Abstract
At the end of its life cycle, the cellular slime mold Dictyostelium discoideum forms a fruiting body consisting of spores and a multicellular stalk. Originally, the chlorinated alkylphenone differentiation-inducing factors (DIFs) -1 and -3 were isolated as stalk cell inducers in D. discoideum. Later, DIFs and their derivatives were shown to possess several biologic activities including antitumor and anti-Trypanosoma properties. In this study, we examined the antibacterial activities of approximately 30 DIF derivatives by using several bacterial species. Several of the DIF derivatives strongly suppressed the growth of the Gram-positive bacteria Staphylococcus aureus, Bacillus subtilis, and Enterococcus faecalis and Enterococcus faecium, at minimum inhibitory concentrations (MICs) in the sub-micromolar to low-micromolar range. In contrast, none of the DIF derivatives evaluated had any noteworthy effect on the growth of the Gram-negative bacterium Escherichia coli (MIC, >100 µM). Most importantly, several of the DIF derivatives strongly inhibited the growth of methicillin-resistant S. aureus and vancomycin-resistant E. faecalis and E. faecium. Transmission electron microscopy revealed that treatment with DIF derivatives led to the formation of distinct multilayered structures consisting of cell wall or plasma membrane in S. aureus. The present results suggest that DIF derivatives are good lead compounds for developing novel antimicrobials.
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Kubohara Y, Kikuchi H. Dictyostelium: An Important Source of Structural and Functional Diversity in Drug Discovery. Cells 2018; 8:E6. [PMID: 30583484 PMCID: PMC6356392 DOI: 10.3390/cells8010006] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 12/19/2018] [Accepted: 12/19/2018] [Indexed: 12/12/2022] Open
Abstract
The cellular slime mold Dictyostelium discoideum is an excellent model organism for the study of cell and developmental biology because of its simple life cycle and ease of use. Recent findings suggest that Dictyostelium and possibly other genera of cellular slime molds, are potential sources of novel lead compounds for pharmacological and medical research. In this review, we present supporting evidence that cellular slime molds are an untapped source of lead compounds by examining the discovery and functions of polyketide differentiation-inducing factor-1, a compound that was originally isolated as an inducer of stalk-cell differentiation in D. discoideum and, together with its derivatives, is now a promising lead compound for drug discovery in several areas. We also review other novel compounds, including secondary metabolites, that have been isolated from cellular slime molds.
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Affiliation(s)
- Yuzuru Kubohara
- Laboratory of Health and Life Science, Graduate School of Health and Sports Science, Juntendo University, Inzai, Chiba 270-1695, Japan.
| | - Haruhisa Kikuchi
- Laboratory of Natural Product Chemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aza-aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan.
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11
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Chen X, Köllner TG, Shaulsky G, Jia Q, Dickschat JS, Gershenzon J, Chen F. Diversity and Functional Evolution of Terpene Synthases in Dictyostelid Social Amoebae. Sci Rep 2018; 8:14361. [PMID: 30254228 PMCID: PMC6156593 DOI: 10.1038/s41598-018-32639-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 09/12/2018] [Indexed: 11/23/2022] Open
Abstract
Dictyostelids, or social amoebae, have a unique life style in forming multicellular fruiting bodies from unicellular amoeboids upon starvation. Recently, dictyostelids were found to contain terpene synthase (TPS) genes, a gene type of secondary metabolism previously known to occur only in plants, fungi and bacteria. Here we report an evolutionary functional study of dictyostelid TPS genes. The number of TPS genes in six species of dictyostelids examined ranges from 1 to 19; and the model species Dictyostelium purpureum contains 12 genes. Using in vitro enzyme assays, the 12 TPS genes from D. purpureum were shown to encode functional enzymes with distinct product profiles. The expression of the 12 TPS genes in D. purpureum is developmentally regulated. During multicellular development, D. purpureum releases a mixture of volatile terpenes dominated by sesquiterpenes that are the in vitro products of a subset of the 12 TPS genes. The quality and quantity of the terpenes released from D. purpureum, however, bear little resemblance to those of D. discoideum, a closely related dictyostelid. Despite these variations, the conserved clade of dictyostelid TPSs, which have an evolutionary distance of more than 600 million years, has the same biochemical function, catalyzing the formation of a sesquiterpene protoillud-7-ene. Taken together, our results indicate that the dynamic evolution of dictyostelid TPS genes includes both purifying selection of an orthologous group and species-specific expansion with functional divergence. Consequently, the terpenes produced by these TPSs most likely have conserved as well as species-adaptive biological functions as chemical languages in dictyostelids.
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Affiliation(s)
- Xinlu Chen
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA
| | - Tobias G Köllner
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Gad Shaulsky
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Qidong Jia
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA
| | - Jeroen S Dickschat
- Kekulé-Institute of Organic Chemistry and Biochemistry, University of Bonn, Gerhard-Domagk-Straße 1, 53121, Bonn, Germany
| | - Jonathan Gershenzon
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Feng Chen
- Department of Plant Sciences, University of Tennessee, Knoxville, TN, 37996, USA.
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12
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Shu L, Zhang B, Queller DC, Strassmann JE. Burkholderia bacteria use chemotaxis to find social amoeba Dictyostelium discoideum hosts. THE ISME JOURNAL 2018; 12:1977-1993. [PMID: 29795447 PMCID: PMC6052080 DOI: 10.1038/s41396-018-0147-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 02/05/2018] [Accepted: 03/28/2018] [Indexed: 12/15/2022]
Abstract
A key question in cooperation is how to find the right partners and maintain cooperative relationships. This is especially challenging for horizontally transferred bacterial symbionts where relationships must be repeatedly established anew. In the social amoeba Dictyostelium discoideum farming symbiosis, two species of inedible Burkholderia bacteria (Burkholderia agricolaris and Burkholderia hayleyella) initiate stable associations with naive D. discoideum hosts and cause carriage of additional bacterial species. However, it is not clear how the association between D. discoideum and its carried Burkholderia is formed and maintained. Here, we look at precisely how Burkholderia finds its hosts. We found that both species of Burkholderia clones isolated from D. discoideum, but not other tested Burkholderia species, are attracted to D. discoideum supernatant, showing that the association is not simply the result of haphazard engulfment by the amoebas. The chemotactic responses are affected by both partners. We find evidence that B. hayleyella prefers D. discoideum clones that currently or previously carried Burkholderia, while B. agricolaris does not show this preference. However, we find no evidence of Burkholderia preference for their own host clone or for other hosts of their own species. We further investigate the chemical differences of D. discoideum supernatants that might explain the patterns shown above using a mass spectrometry based metabolomics approach. These results show that these bacterial symbionts are able to preferentially find and to some extent choose their unicellular partners. In addition, this study also suggests that bacteria can actively search for and target phagocytic cells, which may help us better understand how bacteria interact with immune systems.
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Affiliation(s)
- Longfei Shu
- Department of Biology, Washington University in St. Louis, St. Louis, MO, 63130, USA.
| | - Bojie Zhang
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - David C Queller
- Department of Biology, Washington University in St. Louis, St. Louis, MO, 63130, USA
| | - Joan E Strassmann
- Department of Biology, Washington University in St. Louis, St. Louis, MO, 63130, USA
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