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Coppinger M, Yang L, Popham DL, Ruby E, Stabb EV. Transient infection of Euprymna scolopes with an engineered D-alanine auxotroph of Vibrio fischeri. Appl Environ Microbiol 2024:e0129824. [PMID: 39235243 DOI: 10.1128/aem.01298-24] [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: 07/01/2024] [Accepted: 08/10/2024] [Indexed: 09/06/2024] Open
Abstract
The symbiosis between Vibrio fischeri and the Hawaiian bobtail squid, Euprymna scolopes, is a tractable and well-studied model of bacteria-animal mutualism. Here, we developed a method to transiently colonize E. scolopes using D-alanine (D-ala) auxotrophy of the symbiont, controlling the persistence of viable infection by supplying or withholding D-ala. We generated alanine racemase (alr) mutants of V. fischeri that lack avenues for mutational suppression of auxotrophy or reversion to prototrophy. Surprisingly, an ∆alr mutant did not require D-ala to grow in a minimal medium, a phenomenon requiring metC, which encodes cystathionine β-lyase. Likewise, overexpression of metC suppressed D-ala auxotrophy in a rich medium. To block potential mechanisms of suppression, we combined the ∆alr mutation with deletions of metC and/or bsrF, which encodes a broad-spectrum racemase and investigated the suppression rates of four D-ala auxotrophic strains. We then focused on ∆alr ∆bsrF mutant MC13, which has a suppression rate of <10-9. When D-ala was removed from a growing culture of MC13, cells rounded and lysed within 40 minutes. Transient colonization of E. scolopes was achieved by inoculating squid in seawater containing MC13 and D-ala, and then transferring the squid into water lacking D-ala, which resulted in loss of viable symbionts within hours. Interestingly, the symbionts within crypt 3 persisted longer than those of crypt 1, suggesting a difference in bacterial growth rate in distinct crypt environments. Our study highlights a new approach for inducing transient colonization and provides insight into the biogeography of the E. scolopes light organ.IMPORTANCEThe importance of this study is multi-faceted, providing a valuable methodological tool and insight into the biology of the symbiosis between Vibrio fischeri and Euprymna scolopes. First, the study sheds light on the critical role of D-ala for bacterial growth, and the underpinnings of D-ala synthesis. Our observations that metC obviates the need for D-ala supplementation of an alr mutant in minimal medium and that MetC-dependent growth correlates with D-ala in peptidoglycan, corroborate and extend previous findings in Escherichia coli regarding a role of MetC in D-ala production. Second, our isolation of robust D-ala auxotrophs led us to a novel method for studying the squid-Vibrio symbiosis, allowing for transient colonization without the use of antibiotics, and revealed intriguing differences in symbiont growth parameters in distinct light organ crypts. This work and the methodology developed will contribute to our understanding of the persistence and dynamics of V. fischeri within its host.
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Affiliation(s)
- Macey Coppinger
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Liu Yang
- Division of Biosphere Sciences and Engineering, California Institute of Technology, Pasadena, California, USA
| | - David L Popham
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, USA
| | - Edward Ruby
- Division of Biosphere Sciences and Engineering, California Institute of Technology, Pasadena, California, USA
| | - Eric V Stabb
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
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2
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de Visser PJ, Karagrigoriou D, Nguindjel AC, Korevaar PA. Quorum Sensing in Emulsion Droplet Swarms Driven by a Surfactant Competition System. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2307919. [PMID: 38887869 PMCID: PMC11321703 DOI: 10.1002/advs.202307919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 04/23/2024] [Indexed: 06/20/2024]
Abstract
Quorum sensing enables unicellular organisms to probe their population density and perform behavior that exclusively occurs above a critical density. Quorum sensing is established in emulsion droplet swarms that float at a water surface and cluster above a critical density. The design involves competition between 1) a surface tension gradient that is generated upon release of a surfactant from the oil droplets, and thereby drives their mutual repulsion, and 2) the release of a surfactant precursor from the droplets, that forms a strong imine surfactant which suppresses the surface tension gradient and thereby causes droplet clustering upon capillary (Cheerios) attraction. The production of the imine-surfactant depends on the population density of the droplets releasing the precursor so that the clustering only occurs above a critical population density. The pH-dependence of the imine-surfactant formation is exploited to trigger quorum sensing upon a base stimulus: dynamic droplet swarms are generated that cluster and spread upon spatiotemporally varying acid and base conditions. Next, the clustering of two droplet subpopulations is coupled to a chemical reaction that generates a fluorescent signal. It is foreseen that quorum sensing enables control mechanisms in droplet-based systems that display collective responses in contexts of, e.g., sensing, optics, or dynamically controlled droplet-reactors.
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Affiliation(s)
- Pieter J. de Visser
- Institute for Molecules and MaterialsRadboud UniversityHeyendaalseweg 135Nijmegen6525 AJThe Netherlands
| | - Dimitrios Karagrigoriou
- Institute for Molecules and MaterialsRadboud UniversityHeyendaalseweg 135Nijmegen6525 AJThe Netherlands
| | - Anne‐Déborah C. Nguindjel
- Institute for Molecules and MaterialsRadboud UniversityHeyendaalseweg 135Nijmegen6525 AJThe Netherlands
| | - Peter A. Korevaar
- Institute for Molecules and MaterialsRadboud UniversityHeyendaalseweg 135Nijmegen6525 AJThe Netherlands
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3
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Pawlowska TE. Symbioses between fungi and bacteria: from mechanisms to impacts on biodiversity. Curr Opin Microbiol 2024; 80:102496. [PMID: 38875733 PMCID: PMC11323152 DOI: 10.1016/j.mib.2024.102496] [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: 07/10/2023] [Revised: 05/20/2024] [Accepted: 05/31/2024] [Indexed: 06/16/2024]
Abstract
Symbiotic interactions between fungi and bacteria range from positive to negative. They are ubiquitous in free-living as well as host-associated microbial communities worldwide. Yet, the impact of fungal-bacterial symbioses on the organization and dynamics of microbial communities is uncertain. There are two reasons for this uncertainty: (1) knowledge gaps in the understanding of the genetic mechanisms underpinning fungal-bacterial symbioses and (2) prevailing interpretations of ecological theory that favor antagonistic interactions as drivers stabilizing biological communities despite the existence of models emphasizing contributions of positive interactions. This review synthesizes information on fungal-bacterial symbioses common in the free-living microbial communities of the soil as well as in host-associated polymicrobial biofilms. The interdomain partnerships are considered in the context of the relevant community ecology models, which are discussed critically.
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Affiliation(s)
- Teresa E Pawlowska
- School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, USA.
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4
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Wilde J, Slack E, Foster KR. Host control of the microbiome: Mechanisms, evolution, and disease. Science 2024; 385:eadi3338. [PMID: 39024451 DOI: 10.1126/science.adi3338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 05/29/2024] [Indexed: 07/20/2024]
Abstract
Many species, including humans, host communities of symbiotic microbes. There is a vast literature on the ways these microbiomes affect hosts, but here we argue for an increased focus on how hosts affect their microbiomes. Hosts exert control over their symbionts through diverse mechanisms, including immunity, barrier function, physiological homeostasis, and transit. These mechanisms enable hosts to shape the ecology and evolution of microbiomes and generate natural selection for microbial traits that benefit the host. Our microbiomes result from a perpetual tension between host control and symbiont evolution, and we can leverage the host's evolved abilities to regulate the microbiota to prevent and treat disease. The study of host control will be central to our ability to both understand and manipulate microbiotas for better health.
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Affiliation(s)
- Jacob Wilde
- Department of Biology, University of Oxford, Oxford, UK
| | - Emma Slack
- Institute for Food, Nutrition and Health, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
- Basel Institute for Child Health, Basel, Switzerland
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Kevin R Foster
- Department of Biology, University of Oxford, Oxford, UK
- Department of Biochemistry, University of Oxford, Oxford, UK
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5
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McAtamney A, Ferranti A, Ludvik DA, Yildiz FH, Mandel MJ, Hayward T, Sanchez LM. Microbial metabolomics' latest SICRIT: Soft ionization by Chemical Reaction in-Transfer mass spectrometry. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.17.604007. [PMID: 39071417 PMCID: PMC11275794 DOI: 10.1101/2024.07.17.604007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
Microbial metabolomics studies are a common approach to identifying microbial strains that have a capacity to produce new chemistries both in vitro and in situ. A limitation to applying microbial metabolomics to the discovery of new chemical entities is the rediscovery of known compounds, or "known unknowns." One contributing factor to this rediscovery is the majority of laboratories use one ionization source-electrospray ionization (ESI)-to conduct metabolomics studies. Although ESI is an efficient, widely adopted ionization method, its widespread use may contribute to the re-identification of known metabolites. Here, we present the use of a dielectric barrier discharge ionization (DBDI) for microbial metabolomics applications through the use of soft ionization chemical reaction in-transfer (SICRIT). Additionally, we compared SICRIT to ESI using two different Vibrio species-Vibrio fischeri, a symbiotic marine bacterium, and Vibrio cholerae, a pathogenic bacterium. Overall, we found that the SICRIT source ionizes a different set of metabolites than ESI, and it has the ability to ionize lipids more efficiently than ESI in positive mode. This work highlights the value of using more than one ionization source for the detection of metabolites.
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Affiliation(s)
- Allyson McAtamney
- 1156 High St, Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | | | - Denise A. Ludvik
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706
| | - Fitnat H. Yildiz
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, Santa Cruz, CA 95064
| | - Mark J. Mandel
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706
| | | | - Laura M. Sanchez
- 1156 High St, Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
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6
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Yang L, Lawhorn S, Bongrand C, Kosmopoulos JC, Kuwabara J, VanNieuwenhze M, Mandel MJ, McFall-Ngai M, Ruby E. Bacterial growth dynamics in a rhythmic symbiosis. Mol Biol Cell 2024; 35:ar79. [PMID: 38598294 PMCID: PMC11238090 DOI: 10.1091/mbc.e24-01-0044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 04/01/2024] [Accepted: 04/04/2024] [Indexed: 04/12/2024] Open
Abstract
The symbiotic relationship between the bioluminescent bacterium Vibrio fischeri and the bobtail squid Euprymna scolopes serves as a valuable system to investigate bacterial growth and peptidoglycan (PG) synthesis within animal tissues. To better understand the growth dynamics of V. fischeri in the crypts of the light-emitting organ of its juvenile host, we showed that, after the daily dawn-triggered expulsion of most of the population, the remaining symbionts rapidly proliferate for ∼6 h. At that point the population enters a period of extremely slow growth that continues throughout the night until the next dawn. Further, we found that PG synthesis by the symbionts decreases as they enter the slow-growing stage. Surprisingly, in contrast to the most mature crypts (i.e., Crypt 1) of juvenile animals, most of the symbiont cells in the least mature crypts (i.e., Crypt 3) were not expelled and, instead, remained in the slow-growing state throughout the day, with almost no cell division. Consistent with this observation, the expression of the gene encoding the PG-remodeling enzyme, L,D-transpeptidase (LdtA), was greatest during the slowly growing stage of Crypt 1 but, in contrast, remained continuously high in Crypt 3. Finally, deletion of the ldtA gene resulted in a symbiont that grew and survived normally in culture, but was increasingly defective in competing against its parent strain in the crypts. This result suggests that remodeling of the PG to generate additional 3-3 linkages contributes to the bacterium's fitness in the symbiosis, possibly in response to stresses encountered during the very slow-growing stage.
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Affiliation(s)
- Liu Yang
- Carnegie Institution for Science, Pasadena, CA 91101
- Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, HI 96848
| | - Susannah Lawhorn
- Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, HI 96848
| | - Clotilde Bongrand
- Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, HI 96848
| | - James C. Kosmopoulos
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, WI 53706
| | - Jill Kuwabara
- Carnegie Institution for Science, Pasadena, CA 91101
- Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, HI 96848
| | | | - Mark J. Mandel
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, WI 53706
- Department of Medical Microbiology & Immunology, University of Wisconsin-Madison, Madison, WI 53706
| | - Margaret McFall-Ngai
- Carnegie Institution for Science, Pasadena, CA 91101
- Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, HI 96848
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA 91125
| | - Edward Ruby
- Carnegie Institution for Science, Pasadena, CA 91101
- Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, HI 96848
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA 91125
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7
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Septer AN, Visick KL. Lighting the way: how the Vibrio fischeri model microbe reveals the complexity of Earth's "simplest" life forms. J Bacteriol 2024; 206:e0003524. [PMID: 38695522 PMCID: PMC11112999 DOI: 10.1128/jb.00035-24] [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] [Indexed: 05/05/2024] Open
Abstract
Vibrio (Aliivibrio) fischeri's initial rise to fame derived from its alluring production of blue-green light. Subsequent studies to probe the mechanisms underlying this bioluminescence helped the field discover the phenomenon now known as quorum sensing. Orthologs of quorum-sensing regulators (i.e., LuxR and LuxI) originally identified in V. fischeri were subsequently uncovered in a plethora of bacterial species, and analogous pathways were found in yet others. Over the past three decades, the study of this microbe has greatly expanded to probe the unique role of V. fischeri as the exclusive symbiont of the light organ of the Hawaiian bobtail squid, Euprymna scolopes. Buoyed by this optically amenable host and by persistent and insightful researchers who have applied novel and cross-disciplinary approaches, V. fischeri has developed into a robust model for microbe-host associations. It has contributed to our understanding of how bacteria experience and respond to specific, often fluxing environmental conditions and the mechanisms by which bacteria impact the development of their host. It has also deepened our understanding of numerous microbial processes such as motility and chemotaxis, biofilm formation and dispersal, and bacterial competition, and of the relevance of specific bacterial genes in the context of colonizing an animal host. Parallels in these processes between this symbiont and bacteria studied as pathogens are readily apparent, demonstrating functional conservation across diverse associations and permitting a reinterpretation of "pathogenesis." Collectively, these advances built a foundation for microbiome studies and have positioned V. fischeri to continue to expand the frontiers of our understanding of the microbial world inside animals.
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Affiliation(s)
- Alecia N. Septer
- Department of Earth, Marine and Environmental Sciences, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Karen L. Visick
- Department of Microbiology and Immunology, Loyola University Chicago, Maywood, Illinois, USA
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8
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Mishra A, Kim HS, Kumar R, Srivastava V. Advances in Vibrio-related infection management: an integrated technology approach for aquaculture and human health. Crit Rev Biotechnol 2024:1-28. [PMID: 38705837 DOI: 10.1080/07388551.2024.2336526] [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: 08/03/2023] [Accepted: 11/25/2023] [Indexed: 05/07/2024]
Abstract
Vibrio species pose significant threats worldwide, causing mortalities in aquaculture and infections in humans. Global warming and the emergence of worldwide strains of Vibrio diseases are increasing day by day. Control of Vibrio species requires effective monitoring, diagnosis, and treatment strategies at the global scale. Despite current efforts based on chemical, biological, and mechanical means, Vibrio control management faces limitations due to complicated implementation processes. This review explores the intricacies and challenges of Vibrio-related diseases, including accurate and cost-effective diagnosis and effective control. The global burden due to emerging Vibrio species further complicates management strategies. We propose an innovative integrated technology model that harnesses cutting-edge technologies to address these obstacles. The proposed model incorporates advanced tools, such as biosensing technologies, the Internet of Things (IoT), remote sensing devices, cloud computing, and machine learning. This model offers invaluable insights and supports better decision-making by integrating real-time ecological data and biological phenotype signatures. A major advantage of our approach lies in leveraging cloud-based analytics programs, efficiently extracting meaningful information from vast and complex datasets. Collaborating with data and clinical professionals ensures logical and customized solutions tailored to each unique situation. Aquaculture biotechnology that prioritizes sustainability may have a large impact on human health and the seafood industry. Our review underscores the importance of adopting this model, revolutionizing the prognosis and management of Vibrio-related infections, even under complex circumstances. Furthermore, this model has promising implications for aquaculture and public health, addressing the United Nations Sustainable Development Goals and their development agenda.
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Affiliation(s)
- Anshuman Mishra
- Department of Biological Sciences, College of Natural Sciences, Pusan National University, Busan, South Korea
| | - Heui-Soo Kim
- Department of Biological Sciences, College of Natural Sciences, Pusan National University, Busan, South Korea
| | - Rajender Kumar
- Division of Glycoscience, Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, AlbaNova University Center, Stockholm, Sweden
| | - Vaibhav Srivastava
- Division of Glycoscience, Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, AlbaNova University Center, Stockholm, Sweden
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9
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Coppinger MN, Laramore K, Popham DL, Stabb EV. A prototrophic suppressor of a Vibrio fischeri D-glutamate auxotroph reveals a member of the periplasmic broad-spectrum racemase family (BsrF). J Bacteriol 2024; 206:e0033323. [PMID: 38411059 PMCID: PMC10955857 DOI: 10.1128/jb.00333-23] [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: 12/08/2023] [Accepted: 02/04/2024] [Indexed: 02/28/2024] Open
Abstract
Although bacterial peptidoglycan (PG) is highly conserved, some natural variations in PG biosynthesis and structure have evolved. Understanding the mechanisms and limits of such variation will inform our understanding of antibiotic resistance, innate immunity, and the evolution of bacteria. We have explored the constraints on PG evolution by blocking essential steps in PG biosynthesis in Vibrio fischeri and then selecting mutants with restored prototrophy. Here, we attempted to select prototrophic suppressors of a D-glutamate auxotrophic murI racD mutant. No suppressors were isolated on unsupplemented lysogeny broth salts (LBS), despite plating >1011 cells, nor were any suppressors generated through mutagenesis with ethyl methanesulfonate. A single suppressor was isolated on LBS supplemented with iso-D-gln, although the iso-D-gln subsequently appeared irrelevant. This suppressor has a genomic amplification formed by the creation of a novel junction that fuses proB to a gene encoding a putative broad-spectrum racemase of V. fischeri, bsrF. An engineered bsrF allele lacking the putative secretion signal (ΔSS-bsrF) also suppressed D-glu auxotrophy, resulting in PG that was indistinguishable from the wild type. The ΔSS-bsrF allele similarly suppressed the D-alanine auxotrophy of an alr mutant and restored prototrophy to a murI alr double mutant auxotrophic for both D-ala and D-glu. The ΔSS-bsrF allele increased resistance to D-cycloserine but had no effect on sensitivity to PG-targeting antibiotics penicillin, ampicillin, or vancomycin. Our work helps define constraints on PG evolution and reveals a periplasmic broad-spectrum racemase in V. fischeri that can be co-opted for PG biosynthesis, with concomitant D-cycloserine resistance. IMPORTANCE D-Amino acids are used and produced by organisms across all domains of life, but often, their origins and roles are not well understood. In bacteria, D-ala and D-glu are structural components of the canonical peptidoglycan cell wall and are generated by dedicated racemases Alr and MurI, respectively. The more recent discovery of additional bacterial racemases is broadening our view and deepening our understanding of D-amino acid metabolism. Here, while exploring alternative PG biosynthetic pathways in Vibrio fischeri, we unexpectedly shed light on an unusual racemase, BsrF. Our results illustrate a novel mechanism for the evolution of antibiotic resistance and provide a new avenue for exploring the roles of non-canonical racemases and D-amino acids in bacteria.
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Affiliation(s)
- Macey N. Coppinger
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
- Department of Biological Sciences, University of Illinois, Chicago, Illinois, USA
| | - Kathrin Laramore
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
| | - David L. Popham
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, USA
| | - Eric V. Stabb
- Department of Biological Sciences, University of Illinois, Chicago, Illinois, USA
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10
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Vijayan N, McAnulty SJ, Sanchez G, Jolly J, Ikeda Y, Nishiguchi MK, Réveillac E, Gestal C, Spady BL, Li DH, Burford BP, Kerwin AH, Nyholm SV. Evolutionary history influences the microbiomes of a female symbiotic reproductive organ in cephalopods. Appl Environ Microbiol 2024; 90:e0099023. [PMID: 38315021 PMCID: PMC10952459 DOI: 10.1128/aem.00990-23] [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: 06/14/2023] [Accepted: 12/09/2023] [Indexed: 02/07/2024] Open
Abstract
Many female squids and cuttlefishes have a symbiotic reproductive organ called the accessory nidamental gland (ANG) that hosts a bacterial consortium involved with egg defense against pathogens and fouling organisms. While the ANG is found in multiple cephalopod families, little is known about the global microbial diversity of these ANG bacterial symbionts. We used 16S rRNA gene community analysis to characterize the ANG microbiome from different cephalopod species and assess the relationship between host and symbiont phylogenies. The ANG microbiome of 11 species of cephalopods from four families (superorder: Decapodiformes) that span seven geographic locations was characterized. Bacteria of class Alphaproteobacteria, Gammaproteobacteria, and Flavobacteriia were found in all species, yet analysis of amplicon sequence variants by multiple distance metrics revealed a significant difference between ANG microbiomes of cephalopod families (weighted/unweighted UniFrac, Bray-Curtis, P = 0.001). Despite being collected from widely disparate geographic locations, members of the family Sepiolidae (bobtail squid) shared many bacterial taxa including (~50%) Opitutae (Verrucomicrobia) and Ruegeria (Alphaproteobacteria) species. Furthermore, we tested for phylosymbiosis and found a positive correlation between host phylogenetic distance and bacterial community dissimilarity (Mantel test r = 0.7). These data suggest that closely related sepiolids select for distinct symbionts from similar bacterial taxa. Overall, the ANGs of different cephalopod species harbor distinct microbiomes and thus offer a diverse symbiont community to explore antimicrobial activity and other functional roles in host fitness.IMPORTANCEMany aquatic organisms recruit microbial symbionts from the environment that provide a variety of functions, including defense from pathogens. Some female cephalopods (squids, bobtail squids, and cuttlefish) have a reproductive organ called the accessory nidamental gland (ANG) that contains a bacterial consortium that protects eggs from pathogens. Despite the wide distribution of these cephalopods, whether they share similar microbiomes is unknown. Here, we studied the microbial diversity of the ANG in 11 species of cephalopods distributed over a broad geographic range and representing 15-120 million years of host divergence. The ANG microbiomes shared some bacterial taxa, but each cephalopod species had unique symbiotic members. Additionally, analysis of host-symbiont phylogenies suggests that the evolutionary histories of the partners have been important in shaping the ANG microbiome. This study advances our knowledge of cephalopod-bacteria relationships and provides a foundation to explore defensive symbionts in other systems.
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Affiliation(s)
- Nidhi Vijayan
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Sarah J. McAnulty
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Gustavo Sanchez
- Molecular Genetics Unit, Okinawa Institute of Science and Technology, Okinawa, Japan
- Graduate School of Integrated Science for Life, Hiroshima University, Hiroshima, Japan
| | - Jeffrey Jolly
- Molecular Genetics Unit, Okinawa Institute of Science and Technology, Okinawa, Japan
- Marine Climate Change Unit, Okinawa Institute of Science and Technology, Okinawa, Japan
| | - Yuzuru Ikeda
- Department of Chemistry, Biology and Marine Science, Faculty of Science, University of Ryukyus, Ryukyus, Japan
| | - Michele K. Nishiguchi
- Department of Molecular and Cell Biology, University of California, Merced, California, USA
| | - Elodie Réveillac
- Littoral, Environnement et Sociétés (LIENSs), UMR 7266 CNRS–La Rochelle Université, La Rochelle, France
| | - Camino Gestal
- Institute of Marine Research (IIM), CSIC, Vigo, Spain
| | - Blake L. Spady
- College of Science and Engineering, James Cook University, Townsville, Queensland, Australia
- U.S. National Oceanic and Atmospheric Administration, National Environmental Satellite Data and Information Service, Center for Satellite Applications and Research, Coral Reef Watch, College Park, Maryland, USA
| | - Diana H. Li
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, New York, USA
| | - Benjamin P. Burford
- Institute of Marine Sciences, University of California, affiliated with the National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Southwest Fisheries Science Center, Santa Cruz, California, USA
| | - Allison H. Kerwin
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
- Department of Biology, McDaniel College, Westminster, Maryland, USA
| | - Spencer V. Nyholm
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
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11
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Fung BL, Esin JJ, Visick KL. Vibrio fischeri: a model for host-associated biofilm formation. J Bacteriol 2024; 206:e0037023. [PMID: 38270381 PMCID: PMC10882983 DOI: 10.1128/jb.00370-23] [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] [Indexed: 01/26/2024] Open
Abstract
Multicellular communities of adherent bacteria known as biofilms are often detrimental in the context of a human host, making it important to study their formation and dispersal, especially in animal models. One such model is the symbiosis between the squid Euprymna scolopes and the bacterium Vibrio fischeri. Juvenile squid hatch aposymbiotically and selectively acquire their symbiont from natural seawater containing diverse environmental microbes. Successful pairing is facilitated by ciliary movements that direct bacteria to quiet zones on the surface of the squid's symbiotic light organ where V. fischeri forms a small aggregate or biofilm. Subsequently, the bacteria disperse from that aggregate to enter the organ, ultimately reaching and colonizing deep crypt spaces. Although transient, aggregate formation is critical for optimal colonization and is tightly controlled. In vitro studies have identified a variety of polysaccharides and proteins that comprise the extracellular matrix. Some of the most well-characterized matrix factors include the symbiosis polysaccharide (SYP), cellulose polysaccharide, and LapV adhesin. In this review, we discuss these components, their regulation, and other less understood V. fischeri biofilm contributors. We also highlight what is currently known about dispersal from these aggregates and host cues that may promote it. Finally, we briefly describe discoveries gleaned from the study of other V. fischeri isolates. By unraveling the complexities involved in V. fischeri's control over matrix components, we may begin to understand how the host environment triggers transient biofilm formation and dispersal to promote this unique symbiotic relationship.
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Affiliation(s)
- Brittany L. Fung
- Department of Microbiology and Immunology, Loyola University Chicago, Maywood, Illinois, USA
| | - Jeremy J. Esin
- Department of Microbiology and Immunology, Loyola University Chicago, Maywood, Illinois, USA
| | - Karen L. Visick
- Department of Microbiology and Immunology, Loyola University Chicago, Maywood, Illinois, USA
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12
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Brealey JC, Kodama M, Rasmussen JA, Hansen SB, Santos-Bay L, Lecaudey LA, Hansen M, Fjære E, Myrmel LS, Madsen L, Bernhard A, Sveier H, Kristiansen K, Gilbert MTP, Martin MD, Limborg MT. Host-gut microbiota interactions shape parasite infections in farmed Atlantic salmon. mSystems 2024; 9:e0104323. [PMID: 38294254 PMCID: PMC10886447 DOI: 10.1128/msystems.01043-23] [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: 09/27/2023] [Accepted: 12/19/2023] [Indexed: 02/01/2024] Open
Abstract
Animals and their associated microbiota share long evolutionary histories. However, it is not always clear how host genotype and microbiota interact to affect phenotype. We applied a hologenomic approach to explore how host-microbiota interactions shape lifetime growth and parasite infection in farmed Atlantic salmon (Salmo salar). Multi-omics data sets were generated from the guts of 460 salmon, 82% of which were naturally infected with an intestinal cestode. A single Mycoplasma bacterial strain, MAG01, dominated the gut metagenome of large, non-parasitized fish, consistent with previous studies showing high levels of Mycoplasma in the gut microbiota of healthy salmon. While small and/or parasitized salmon also had high abundance of MAG01, we observed increased alpha diversity in these individuals, driven by increased frequency of low-abundance Vibrionaceae and other Mycoplasma species that carried known virulence genes. Colonization by one of these cestode-associated Mycoplasma strains was associated with host individual genomic variation in long non-coding RNAs. Integrating the multi-omic data sets revealed coordinated changes in the salmon gut mRNA transcriptome and metabolome that correlated with shifts in the microbiota of smaller, parasitized fish. Our results suggest that the gut microbiota of small and/or parasitized fish is in a state of dysbiosis that partly depends on the host genotype, highlighting the value of using a hologenomic approach to incorporate the microbiota into the study of host-parasite dynamics.IMPORTANCEStudying host-microbiota interactions through the perspective of the hologenome is gaining interest across all life sciences. Intestinal parasite infections are a huge burden on human and animal health; however, there are few studies investigating the role of the hologenome during parasite infections. We address this gap in the largest multi-omics fish microbiota study to date using natural cestode infection of farmed Atlantic salmon. We find a clear association between cestode infection, salmon lifetime growth, and perturbation of the salmon gut microbiota. Furthermore, we provide the first evidence that the genetic background of the host may partly determine how the gut microbiota changes during parasite-associated dysbiosis. Our study therefore highlights the value of a hologenomic approach for gaining a more in-depth understanding of parasitism.
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Affiliation(s)
- Jaelle C Brealey
- Department of Natural History, NTNU University Museum, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Miyako Kodama
- Center for Evolutionary Hologenomics, Globe Institute, Faculty of Health and Medical Sciences,University of Copenhagen, Copenhagen, Denmark
| | - Jacob A Rasmussen
- Center for Evolutionary Hologenomics, Globe Institute, Faculty of Health and Medical Sciences,University of Copenhagen, Copenhagen, Denmark
- Department of Biology, Laboratory of Genomics and Molecular Biomedicine, University of Copenhagen, Copenhagen, Denmark
| | - Søren B Hansen
- Center for Evolutionary Hologenomics, Globe Institute, Faculty of Health and Medical Sciences,University of Copenhagen, Copenhagen, Denmark
| | - Luisa Santos-Bay
- Center for Evolutionary Hologenomics, Globe Institute, Faculty of Health and Medical Sciences,University of Copenhagen, Copenhagen, Denmark
| | - Laurène A Lecaudey
- Department of Natural History, NTNU University Museum, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
- Aquaculture Department, SINTEF Ocean, Trondheim, Norway
| | - Martin Hansen
- Department of Environmental Science, Environmental Metabolomics Lab, Aarhus University, Roskilde, Denmark
| | - Even Fjære
- Institute of Marine Research, Bergen, Norway
| | | | - Lise Madsen
- Institute of Marine Research, Bergen, Norway
- Department of Clinical Medicine, University of Bergen, Norway, Bergen, Norway
| | | | | | - Karsten Kristiansen
- Department of Biology, Laboratory of Genomics and Molecular Biomedicine, University of Copenhagen, Copenhagen, Denmark
| | - M Thomas P Gilbert
- Department of Natural History, NTNU University Museum, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
- Center for Evolutionary Hologenomics, Globe Institute, Faculty of Health and Medical Sciences,University of Copenhagen, Copenhagen, Denmark
| | - Michael D Martin
- Department of Natural History, NTNU University Museum, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Morten T Limborg
- Center for Evolutionary Hologenomics, Globe Institute, Faculty of Health and Medical Sciences,University of Copenhagen, Copenhagen, Denmark
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13
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Rogers TF, Yalçın G, Briseno J, Vijayan N, Nyholm SV, Simakov O. Gene modelling and annotation for the Hawaiian bobtail squid, Euprymna scolopes. Sci Data 2024; 11:40. [PMID: 38184621 PMCID: PMC10771462 DOI: 10.1038/s41597-023-02903-8] [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: 08/15/2023] [Accepted: 12/28/2023] [Indexed: 01/08/2024] Open
Abstract
Coleoid cephalopods possess numerous complex, species-specific morphological and behavioural adaptations, e.g., a uniquely structured nervous system that is the largest among the invertebrates. The Hawaiian bobtail squid (Euprymna scolopes) is one of the most established cephalopod species. With its recent publication of the chromosomal-scale genome assembly and regulatory genomic data, it also emerges as a key model for cephalopod gene regulation and evolution. However, the latest genome assembly has been lacking a native gene model set. Our manuscript describes the generation of new long-read transcriptomic data and, made using this combined with a plethora of publicly available transcriptomic and protein sequence data, a new reference annotation for E. scolopes.
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Affiliation(s)
- Thea F Rogers
- Department of Neuroscience and Developmental Biology, Division of Molecular Evolution and Development, University of Vienna, Vienna, Austria.
| | - Gözde Yalçın
- Department of Neuroscience and Developmental Biology, Division of Molecular Evolution and Development, University of Vienna, Vienna, Austria
| | - John Briseno
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Nidhi Vijayan
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Spencer V Nyholm
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, Connecticut, USA
| | - Oleg Simakov
- Department of Neuroscience and Developmental Biology, Division of Molecular Evolution and Development, University of Vienna, Vienna, Austria
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14
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Baden T, Briseño J, Coffing G, Cohen-Bodénès S, Courtney A, Dickerson D, Dölen G, Fiorito G, Gestal C, Gustafson T, Heath-Heckman E, Hua Q, Imperadore P, Kimbara R, Król M, Lajbner Z, Lichilín N, Macchi F, McCoy MJ, Nishiguchi MK, Nyholm SV, Otjacques E, Pérez-Ferrer PA, Ponte G, Pungor JR, Rogers TF, Rosenthal JJC, Rouressol L, Rubas N, Sanchez G, Santos CP, Schultz DT, Seuntjens E, Songco-Casey JO, Stewart IE, Styfhals R, Tuanapaya S, Vijayan N, Weissenbacher A, Zifcakova L, Schulz G, Weertman W, Simakov O, Albertin CB. Cephalopod-omics: Emerging Fields and Technologies in Cephalopod Biology. Integr Comp Biol 2023; 63:1226-1239. [PMID: 37370232 PMCID: PMC10755191 DOI: 10.1093/icb/icad087] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 06/09/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023] Open
Abstract
Few animal groups can claim the level of wonder that cephalopods instill in the minds of researchers and the general public. Much of cephalopod biology, however, remains unexplored: the largest invertebrate brain, difficult husbandry conditions, and complex (meta-)genomes, among many other things, have hindered progress in addressing key questions. However, recent technological advancements in sequencing, imaging, and genetic manipulation have opened new avenues for exploring the biology of these extraordinary animals. The cephalopod molecular biology community is thus experiencing a large influx of researchers, emerging from different fields, accelerating the pace of research in this clade. In the first post-pandemic event at the Cephalopod International Advisory Council (CIAC) conference in April 2022, over 40 participants from all over the world met and discussed key challenges and perspectives for current cephalopod molecular biology and evolution. Our particular focus was on the fields of comparative and regulatory genomics, gene manipulation, single-cell transcriptomics, metagenomics, and microbial interactions. This article is a result of this joint effort, summarizing the latest insights from these emerging fields, their bottlenecks, and potential solutions. The article highlights the interdisciplinary nature of the cephalopod-omics community and provides an emphasis on continuous consolidation of efforts and collaboration in this rapidly evolving field.
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Affiliation(s)
- Tom Baden
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, UK
| | - John Briseño
- Molecular and Cell Biology Department, University of Connecticut, Storrs, CT 06269, USA
| | - Gabrielle Coffing
- Biology Department: Institute of Ecology and Evolution, University of Oregon, Eugene, OR 97403-5289, USA
| | - Sophie Cohen-Bodénès
- Laboratoire des Systèmes Perceptifs, Département d'Etudes Cognitives, Ecole Normale Supérieure, PSL University, CNRS, 75005 Paris, France
| | - Amy Courtney
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Dominick Dickerson
- Friday Harbor Laboratory, University of Washington, Seattle, WA 98250, USA
| | - Gül Dölen
- Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Graziano Fiorito
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, 80121 Napoli, Italy
| | - Camino Gestal
- Laboratory of Marine Molecular Pathobiology, Institute of Marine Research (IIM), Spanish National Research Council (CSIC), Vigo 36208, Spain
| | | | - Elizabeth Heath-Heckman
- Departments of Integrative Biology and Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA
| | - Qiaz Hua
- Department of Ecology and Evolution, University of Adelaide, Adelaide, South Australia 5000, Australia
| | - Pamela Imperadore
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, 80121 Napoli, Italy
| | - Ryosuke Kimbara
- Misaki Marine Biological Station, School of Science, The University of Tokyo, Miura, Kanagawa 238-0225, Japan
| | - Mirela Król
- Adam Mickiewicz University in Poznań, Poznań 61-712, Poland
| | - Zdeněk Lajbner
- Physics and Biology Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna, Kunigami District, Okinawa 904-0495, Japan
| | - Nicolás Lichilín
- Department of Neurosciences and Developmental Biology, University of Vienna, Vienna 1010, Austria
| | - Filippo Macchi
- Program in Biology, New York University Abu Dhabi, P.O. Box 129188 Abu Dhabi, United Arab Emirates
| | - Matthew J McCoy
- Department of Pathology, Stanford University, Stanford, CA 94305, USA
| | - Michele K Nishiguchi
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, 5200 N. Lake Blvd., Merced, CA 95343, USA
| | - Spencer V Nyholm
- Molecular and Cell Biology Department, University of Connecticut, Storrs, CT 06269, USA
| | - Eve Otjacques
- MARE—Marine and Environmental Sciences Centre & ARNET—Aquatic Research Network, Laboratório Marítimo da Guia, Faculdade de Ciências, Universidade de Lisboa, Av. Nossa Senhora do Cabo, 939, 2750-374 Cascais, Portugal
- Division of Biosphere Sciences and Engineering, Carnegie Institution for Science, 1200 E. California Blvd, Pasadena, CA 91125, USA
| | - Pedro Antonio Pérez-Ferrer
- Department of Molecular and Cell Biology, School of Natural Sciences, University of California, Merced, 5200 N. Lake Blvd., Merced, CA 95343, USA
| | - Giovanna Ponte
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, 80121 Napoli, Italy
| | - Judit R Pungor
- Biology Department: Institute of Ecology and Evolution, University of Oregon, Eugene, OR 97403-5289, USA
| | - Thea F Rogers
- Department of Neurosciences and Developmental Biology, University of Vienna, Vienna 1010, Austria
| | - Joshua J C Rosenthal
- Marine Biological Laboratory, The Eugene Bell Center for Regenerative Biology and Tissue Engineering, Woods Hole, MA 02543-1015, USA
| | - Lisa Rouressol
- Department of Neurosciences and Developmental Biology, University of Vienna, Vienna 1010, Austria
| | - Noelle Rubas
- Department of Molecular Biosciences and Bioengineering, University of Hawaii Manoa, Honolulu, HI 96822, USA
| | - Gustavo Sanchez
- Molecular Genetics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
| | - Catarina Pereira Santos
- MARE—Marine and Environmental Sciences Centre & ARNET—Aquatic Research Network, Laboratório Marítimo da Guia, Faculdade de Ciências, Universidade de Lisboa, Av. Nossa Senhora do Cabo, 939, 2750-374 Cascais, Portugal
| | - Darrin T Schultz
- Department of Neurosciences and Developmental Biology, University of Vienna, Vienna 1010, Austria
| | - Eve Seuntjens
- Laboratory of Developmental Neurobiology, Department of Biology, KU Leuven, Leuven 3000, Belgium
| | - Jeremea O Songco-Casey
- Biology Department: Institute of Ecology and Evolution, University of Oregon, Eugene, OR 97403-5289, USA
| | - Ian Erik Stewart
- Neural Circuits and Behaviour Lab, Max‐Delbrück‐Center for Molecular Medicine in the Helmholtz Association (MDC), Berlin 13125, Germany
| | - Ruth Styfhals
- Laboratory of Developmental Neurobiology, Department of Biology, KU Leuven, Leuven 3000, Belgium
| | - Surangkana Tuanapaya
- Laboratory of genetics and applied breeding of molluscs, Fisheries College, Ocean University of China, Qingdao 266100, China
| | - Nidhi Vijayan
- Molecular and Cell Biology Department, University of Connecticut, Storrs, CT 06269, USA
| | | | - Lucia Zifcakova
- Physics and Biology Unit, Okinawa Institute of Science and Technology Graduate University, 1919-1 Tancha, Onna, Kunigami District, Okinawa 904-0495, Japan
| | | | - Willem Weertman
- Friday Harbor Laboratory, University of Washington, Seattle, WA 98250, USA
| | - Oleg Simakov
- Department of Neurosciences and Developmental Biology, University of Vienna, Vienna 1010, Austria
| | - Caroline B Albertin
- Marine Biological Laboratory, The Eugene Bell Center for Regenerative Biology and Tissue Engineering, Woods Hole, MA 02543-1015, USA
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15
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Bongrand C, Foster JS. Modelled microgravity impacts Vibrio fischeri population structure in a mutualistic association with an animal host. Environ Microbiol 2023; 25:3269-3279. [PMID: 37828645 DOI: 10.1111/1462-2920.16522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 09/28/2023] [Indexed: 10/14/2023]
Abstract
Perturbations to host-microbe interactions, such as environmental stress, can alter and disrupt homeostasis. In this study, we examined the effects of a stressor, simulated microgravity, on beneficial bacteria behaviours when colonising their host. We studied the bacterium Vibrio fischeri, which establishes a mutualistic association in a symbiosis-specific organ within the bobtail squid, Euprymna scolopes. To elucidate how animal-microbe interactions are affected by the stress of microgravity, squid were inoculated with different bacterial strains exhibiting either a dominant- or sharing-colonisation behaviour in High Aspect Ratio Vessels, which simulate the low-shear environment of microgravity. The colonisation behaviours of the sharing and dominant strains under modelled microgravity conditions were determined by counting light-organ homogenate of squids as well as confocal microscopy to assess the partitioning of different strains within the light organ. The results indicated that although the colonisation behaviours of the strains did not change, the population levels of the sharing strains were at lower relative abundance in single-colonised animals exposed to modelled microgravity compared to unit gravity; in addition, there were shifts in the relative abundance of strains in co-colonised squids. Together these results suggest that the initiation of beneficial interactions between microbes and animals can be altered by environmental stress, such as simulated microgravity.
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Affiliation(s)
- Clotilde Bongrand
- Department of Microbiology and Cell Science, Space Life Sciences Lab, University of Florida, Merritt Island, Florida, USA
| | - Jamie S Foster
- Department of Microbiology and Cell Science, Space Life Sciences Lab, University of Florida, Merritt Island, Florida, USA
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16
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Steele MI, Peiser JM, Shreenidhi PM, Strassmann JE, Queller DC. Predation-resistant Pseudomonas bacteria engage in symbiont-like behavior with the social amoeba Dictyostelium discoideum. THE ISME JOURNAL 2023; 17:2352-2361. [PMID: 37884792 PMCID: PMC10689837 DOI: 10.1038/s41396-023-01535-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 10/04/2023] [Accepted: 10/06/2023] [Indexed: 10/28/2023]
Abstract
The soil amoeba Dictyostelium discoideum acts as both a predator and potential host for diverse bacteria. We tested fifteen Pseudomonas strains that were isolated from transiently infected wild D. discoideum for ability to escape predation and infect D. discoideum fruiting bodies. Three predation-resistant strains frequently caused extracellular infections of fruiting bodies but were not found within spores. Furthermore, infection by one of these species induces secondary infections and suppresses predation of otherwise edible bacteria. Another strain can persist inside of amoebae after being phagocytosed but is rarely taken up. We sequenced isolate genomes and discovered that predation-resistant isolates are not monophyletic. Many Pseudomonas isolates encode secretion systems and toxins known to improve resistance to phagocytosis in other species, as well as diverse secondary metabolite biosynthetic gene clusters that may contribute to predation resistance. However, the distribution of these genes alone cannot explain why some strains are edible and others are not. Each lineage may employ a unique mechanism for resistance.
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Affiliation(s)
- Margaret I Steele
- Biology Department, Washington University in St. Louis, St. Louis, MO, USA.
| | - Jessica M Peiser
- Biology Department, Washington University in St. Louis, St. Louis, MO, USA
| | - P M Shreenidhi
- Biology Department, Washington University in St. Louis, St. Louis, MO, USA
| | - Joan E Strassmann
- Biology Department, Washington University in St. Louis, St. Louis, MO, USA
| | - David C Queller
- Biology Department, Washington University in St. Louis, St. Louis, MO, USA
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17
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Greenwich JL, Fleming D, Banin E, Häussler S, Kjellerup BV, Sauer K, Visick KL, Fuqua C. The biofilm community resurfaces: new findings and post-pandemic progress. J Bacteriol 2023; 205:e0016623. [PMID: 37756166 PMCID: PMC10601713 DOI: 10.1128/jb.00166-23] [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] [Indexed: 09/29/2023] Open
Abstract
The ninth American Society for Microbiology Conference on Biofilms was convened in-person on 13-17 November 2022 in Charlotte, NC. As the first of these conferences since prior to the start of the COVID-19 pandemic, the energy among the participants of the conference was clear, and the meeting was a tremendous success. The mixture of >330 oral and poster presentations resoundingly embodied the vitality of biofilm research across a wide range of topics and multiple scientific disciplines. Special activities, including a pre-conference symposium for early career researchers, further enhanced the attendee experience. As a general theme, the conference was deliberately structured to provide high levels of participation and engagement among early career scientists.
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Affiliation(s)
| | - Derek Fleming
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA
| | - Ehud Banin
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | | | - Birthe V. Kjellerup
- Department of Civil and Environmental Engineering, University of Maryland, College Park, Maryland, USA
| | - Karin Sauer
- Department of Biological Sciences, University of Binghamton, Binghamton, New York, USA
| | - Karen L. Visick
- Department of Microbiology and Immunology, Loyola University Chicago, Maywood, Illinois, USA
| | - Clay Fuqua
- Department of Biology, Indiana University, Bloomington, Indiana, USA
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18
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Abstract
The first discovered and well-characterized bacterial quorum sensing (QS) system belongs to Vibrio fischeri, which uses N-acyl homo-serine lactones (AHLs) for cell-cell signaling. AHL QS cell-cell communication is often regarded as a cell density-dependent regulatory switch. Since the discovery of QS, it has been known that AHL concentration (which correlates imperfectly with cell density) is not necessarily the only QS trigger. Additionally, not all cells respond to a QS signal. Bacteria could, via QS, exhibit phenotypic heterogeneity, resulting in sub-populations with unique phenotypes. It is time to ascribe greater importance to QS-dependent phenotypic heterogeneity, and its potential purpose in natura, with emphasis on the division of labor, specialization, and "bet-hedging". We hope that this perspective article will stimulate the awareness that QS can be more than just a cell-density switch. This basic mechanism could result in "bacterial civilizations", thus forcing us to reconsider the way bacterial communities are envisioned in natura.
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Affiliation(s)
- Mihael Spacapan
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy
| | - Cristina Bez
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy
| | - Vittorio Venturi
- International Centre for Genetic Engineering and Biotechnology, Padriciano 99, 34149 Trieste, Italy
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19
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Guckes KR, Yount TA, Steingard CH, Miyashiro TI. Quorum sensing inhibits interference competition among bacterial symbionts within a host. Curr Biol 2023; 33:4244-4251.e4. [PMID: 37689064 PMCID: PMC10592073 DOI: 10.1016/j.cub.2023.08.051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 06/20/2023] [Accepted: 08/16/2023] [Indexed: 09/11/2023]
Abstract
The symbioses that animals form with bacteria play important roles in health and disease, but the molecular details underlying how bacterial symbionts initially assemble within a host remain unclear.1,2,3 The bioluminescent bacterium Vibrio fischeri establishes a light-emitting symbiosis with the Hawaiian bobtail squid Euprymna scolopes by colonizing specific epithelium-lined crypt spaces within a symbiotic organ called the light organ.4 Competition for these colonization sites occurs between different strains of V. fischeri, with the lancet-like type VI secretion system (T6SS) facilitating strong competitive interference that results in strain incompatibility within a crypt space.5,6 Although recent studies have identified regulators of this T6SS, how the T6SS is controlled as symbionts assemble in vivo remains unknown.7,8 Here, we show that T6SS activity is suppressed by N-octanoyl-L-homoserine lactone (C8 HSL), which is a signaling molecule that facilitates quorum sensing in V. fischeri and is important for efficient symbiont assembly.9,10 We find that this signaling depends on the quorum-sensing regulator LitR, which lowers expression of the needle subunit Hcp, a key component of the T6SS, by repressing transcription of the T6SS regulator VasH. We show that LitR-dependent quorum sensing inhibits strain incompatibility within the squid light organ. Collectively, these results provide new insights into the mechanisms by which regulatory networks that promote symbiosis also control competition among symbionts, which in turn may affect the overall symbiont diversity that assembles within a host.
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Affiliation(s)
- Kirsten R Guckes
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Taylor A Yount
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Caroline H Steingard
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Tim I Miyashiro
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA; The One Health Microbiome Center, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA.
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20
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Alker AT, Farrell MV, Aspiras AE, Dunbar TL, Fedoriouk A, Jones JE, Mikhail SR, Salcedo GY, Moore BS, Shikuma NJ. A modular plasmid toolkit applied in marine bacteria reveals functional insights during bacteria-stimulated metamorphosis. mBio 2023; 14:e0150223. [PMID: 37530556 PMCID: PMC10470607 DOI: 10.1128/mbio.01502-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 06/17/2023] [Indexed: 08/03/2023] Open
Abstract
A conspicuous roadblock to studying marine bacteria for fundamental research and biotechnology is a lack of modular synthetic biology tools for their genetic manipulation. Here, we applied, and generated new parts for, a modular plasmid toolkit to study marine bacteria in the context of symbioses and host-microbe interactions. To demonstrate the utility of this plasmid system, we genetically manipulated the marine bacterium Pseudoalteromonas luteoviolacea, which stimulates the metamorphosis of the model tubeworm, Hydroides elegans. Using these tools, we quantified constitutive and native promoter expression, developed reporter strains that enable the imaging of host-bacteria interactions, and used CRISPR interference (CRISPRi) to knock down a secondary metabolite and a host-associated gene. We demonstrate the broader utility of this modular system for testing the genetic tractability of marine bacteria that are known to be associated with diverse host-microbe symbioses. These efforts resulted in the successful conjugation of 12 marine strains from the Alphaproteobacteria and Gammaproteobacteria classes. Altogether, the present study demonstrates how synthetic biology strategies enable the investigation of marine microbes and marine host-microbe symbioses with potential implications for environmental restoration and biotechnology. IMPORTANCE Marine Proteobacteria are attractive targets for genetic engineering due to their ability to produce a diversity of bioactive metabolites and their involvement in host-microbe symbioses. Modular cloning toolkits have become a standard for engineering model microbes, such as Escherichia coli, because they enable innumerable mix-and-match DNA assembly and engineering options. However, such modular tools have not yet been applied to most marine bacterial species. In this work, we adapt a modular plasmid toolkit for use in a set of 12 marine bacteria from the Gammaproteobacteria and Alphaproteobacteria classes. We demonstrate the utility of this genetic toolkit by engineering a marine Pseudoalteromonas bacterium to study their association with its host animal Hydroides elegans. This work provides a proof of concept that modular genetic tools can be applied to diverse marine bacteria to address basic science questions and for biotechnology innovations.
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Affiliation(s)
- Amanda T. Alker
- Department of Biology, San Diego State University, San Diego, California, USA
| | - Morgan V. Farrell
- Department of Biology, San Diego State University, San Diego, California, USA
| | - Alpher E. Aspiras
- Department of Biology, San Diego State University, San Diego, California, USA
| | - Tiffany L. Dunbar
- Department of Biology, San Diego State University, San Diego, California, USA
| | - Andriy Fedoriouk
- Department of Biology, San Diego State University, San Diego, California, USA
| | - Jeffrey E. Jones
- Department of Biology, San Diego State University, San Diego, California, USA
| | - Sama R. Mikhail
- Department of Biology, San Diego State University, San Diego, California, USA
| | | | - Bradley S. Moore
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, California, USA
| | - Nicholas J. Shikuma
- Department of Biology, San Diego State University, San Diego, California, USA
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21
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Ingham CS, Engl T, Matarrita-Carranza B, Vogler P, Huettel B, Wielsch N, Svatoš A, Kaltenpoth M. Host hydrocarbons protect symbiont transmission from a radical host defense. Proc Natl Acad Sci U S A 2023; 120:e2302721120. [PMID: 37487102 PMCID: PMC10400980 DOI: 10.1073/pnas.2302721120] [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: 02/16/2023] [Accepted: 06/06/2023] [Indexed: 07/26/2023] Open
Abstract
Symbioses with microbes play a pivotal role in the evolutionary success of insects, and can lead to intimate host-symbiont associations. However, how the host maintains a stable symbiosis with its beneficial partners while keeping antagonistic microbes in check remains incompletely understood. Here, we uncover a mechanism by which a host protects its symbiont from the host's own broad-range antimicrobial defense during transmission. Beewolves, a group of solitary digger wasps (Hymenoptera: Crabronidae), provide their brood cells with symbiotic Streptomyces bacteria that are later transferred to the cocoon and protect the offspring from opportunistic pathogens by producing antibiotics. In the brood cell, however, the symbiont-containing secretion is exposed to a toxic burst of nitric oxide (NO) released by the beewolf egg, which effectively kills antagonistic microorganisms. How the symbiont survives this lethal NO burst remained unknown. Here, we report that upon NO exposure in vitro, the symbionts mount a global stress response, but this is insufficient to ensure survival at brood cell-level NO concentrations. Instead, in vivo bioassays demonstrate that the host's antennal gland secretion (AGS) surrounding the symbionts in the brood cell provides an effective diffusion barrier against NO. This physicochemical protection can be reconstituted in vitro by beewolf hydrocarbon extracts and synthetic hydrocarbons, indicating that the host-derived long-chain alkenes and alkanes in the AGS are responsible for shielding the symbionts from NO. Our results reveal how host adaptations can protect a symbiont from host-generated oxidative and nitrosative stress during transmission, thereby efficiently balancing pathogen defense and mutualism maintenance.
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Affiliation(s)
- Chantal Selina Ingham
- Department of Evolutionary Ecology, Institute of Organismic and Molecular Evolution, Johannes Gutenberg-University Mainz, Mainz55128, Germany
| | - Tobias Engl
- Department of Evolutionary Ecology, Institute of Organismic and Molecular Evolution, Johannes Gutenberg-University Mainz, Mainz55128, Germany
- Department of Insect Symbiosis, Max-Planck-Institute for Chemical Ecology, Jena07745, Germany
| | | | - Paul Vogler
- Department of Evolutionary Ecology, Institute of Organismic and Molecular Evolution, Johannes Gutenberg-University Mainz, Mainz55128, Germany
| | - Bruno Huettel
- Max Planck Genome Centre Cologne, Max Planck Institute for Plant Breeding Research, Cologne50829, Germany
| | - Natalie Wielsch
- Research Group Mass Spectrometry/Proteomics, Max-Planck-Institute for Chemical Ecology, Jena07745, Germany
| | - Aleš Svatoš
- Research Group Mass Spectrometry/Proteomics, Max-Planck-Institute for Chemical Ecology, Jena07745, Germany
| | - Martin Kaltenpoth
- Department of Evolutionary Ecology, Institute of Organismic and Molecular Evolution, Johannes Gutenberg-University Mainz, Mainz55128, Germany
- Department of Insect Symbiosis, Max-Planck-Institute for Chemical Ecology, Jena07745, Germany
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22
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Bapteste E, Huneman P, Keller L, Teulière J, Lopez P, Teeling EC, Lindner AB, Baudisch A, Ludington WB, Franceschi C. Expanding evolutionary theories of ageing to better account for symbioses and interactions throughout the Web of Life. Ageing Res Rev 2023; 89:101982. [PMID: 37321383 PMCID: PMC10771319 DOI: 10.1016/j.arr.2023.101982] [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: 04/14/2023] [Revised: 05/26/2023] [Accepted: 06/11/2023] [Indexed: 06/17/2023]
Abstract
How, when, and why organisms age are fascinating issues that can only be fully addressed by adopting an evolutionary perspective. Consistently, the main evolutionary theories of ageing, namely the Mutation Accumulation theory, the Antagonistic Pleiotropy theory, and the Disposable Soma theory, have formulated stimulating hypotheses that structure current debates on both the proximal and ultimate causes of organismal ageing. However, all these theories leave a common area of biology relatively under-explored. The Mutation Accumulation theory and the Antagonistic Pleiotropy theory were developed under the traditional framework of population genetics, and therefore are logically centred on the ageing of individuals within a population. The Disposable Soma theory, based on principles of optimising physiology, mainly explains ageing within a species. Consequently, current leading evolutionary theories of ageing do not explicitly model the countless interspecific and ecological interactions, such as symbioses and host-microbiomes associations, increasingly recognized to shape organismal evolution across the Web of Life. Moreover, the development of network modelling supporting a deeper understanding on the molecular interactions associated with ageing within and between organisms is also bringing forward new questions regarding how and why molecular pathways associated with ageing evolved. Here, we take an evolutionary perspective to examine the effects of organismal interactions on ageing across different levels of biological organisation, and consider the impact of surrounding and nested systems on organismal ageing. We also apply this perspective to suggest open issues with potential to expand the standard evolutionary theories of ageing.
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Affiliation(s)
- Eric Bapteste
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Sorbonne Université, CNRS, Museum National d'Histoire Naturelle, EPHE, Université des Antilles, Paris, France.
| | - Philippe Huneman
- Institut d'Histoire et de Philosophie des Sciences et des Techniques (CNRS/ Université Paris I Sorbonne), Paris, France
| | - Laurent Keller
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland
| | - Jérôme Teulière
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Sorbonne Université, CNRS, Museum National d'Histoire Naturelle, EPHE, Université des Antilles, Paris, France
| | - Philippe Lopez
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Sorbonne Université, CNRS, Museum National d'Histoire Naturelle, EPHE, Université des Antilles, Paris, France
| | - Emma C Teeling
- School of Biology and Environmental Science, University College Dublin, Ireland
| | - Ariel B Lindner
- Université de Paris, INSERM U1284, Center for Research and Interdisciplinarity (CRI), Paris, France
| | - Annette Baudisch
- Interdisciplinary Centre on Population Dynamics, University of Southern Denmark, 5230 Odense M, Denmark
| | - William B Ludington
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA; Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Claudio Franceschi
- Department of Medical and Surgical Sciences, Alma Mater Studiorum University of Bologna, 40138 Bologna, Italy; Department of Applied Mathematics and Laboratory of Systems Medicine of Aging, Lobachevsky University, Nizhny Novgorod 603950, Russia
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23
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Rouressol L, Briseno J, Vijayan N, Chen GY, Ritschard EA, Sanchez G, Nyholm SV, McFall-Ngai MJ, Simakov O. Emergence of novel genomic regulatory regions associated with light-organ development in the bobtail squid. iScience 2023; 26:107091. [PMID: 37426346 PMCID: PMC10329180 DOI: 10.1016/j.isci.2023.107091] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 03/25/2023] [Accepted: 06/07/2023] [Indexed: 07/11/2023] Open
Abstract
Light organs (LO) with symbiotic bioluminescent bacteria are hallmarks of many bobtail squid species. These organs possess structural and functional features to modulate light, analogous to those found in coleoid eyes. Previous studies identified four transcription factors and modulators (SIX, EYA, PAX6, DAC) associated with both eyes and light organ development, suggesting co-option of a highly conserved gene regulatory network. Using available topological, open chromatin, and transcriptomic data, we explore the regulatory landscape around the four transcription factors as well as genes associated with LO and shared LO/eye expression. This analysis revealed several closely associated and putatively co-regulated genes. Comparative genomic analyses identified distinct evolutionary origins of these putative regulatory associations, with the DAC locus showing a unique topological and evolutionarily recent organization. We discuss different scenarios of modifications to genome topology and how these changes may have contributed to the evolutionary emergence of the light organ.
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Affiliation(s)
- Lisa Rouressol
- Department for Neurosciences and Developmental Biology, University of Vienna, Vienna 1030, Austria
- Department of Biosphere Sciences and Engineering, Carnegie Institution for Science, Pasadena, CA 91125, USA
| | - John Briseno
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA
| | - Nidhi Vijayan
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA
| | - Grischa Y. Chen
- Department of Biosphere Sciences and Engineering, Carnegie Institution for Science, Pasadena, CA 91125, USA
| | - Elena A. Ritschard
- Department for Neurosciences and Developmental Biology, University of Vienna, Vienna 1030, Austria
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, 80121 Napoli, NA, Italy
| | - Gustavo Sanchez
- Molecular Genetics Unit, Okinawa Institute of Science and Technology, Okinawa 904-0495, Japan
| | - Spencer V. Nyholm
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA
| | - Margaret J. McFall-Ngai
- Department of Biosphere Sciences and Engineering, Carnegie Institution for Science, Pasadena, CA 91125, USA
| | - Oleg Simakov
- Department for Neurosciences and Developmental Biology, University of Vienna, Vienna 1030, Austria
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24
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Donnelly AR, Giacobe EJ, Cook RA, Francis GM, Buddle GK, Beaubrun CL, Cecere AG, Miyashiro TI. Quantification of the capacity of vibrio fischeri to establish symbiosis with Euprymna scolopes. PLoS One 2023; 18:e0287519. [PMID: 37440554 PMCID: PMC10343157 DOI: 10.1371/journal.pone.0287519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 06/01/2023] [Indexed: 07/15/2023] Open
Abstract
Most animals establish long-term symbiotic associations with bacteria that are critical for normal host physiology. The symbiosis that forms between the Hawaiian squid Euprymna scolopes and the bioluminescent bacterium Vibrio fischeri serves as an important model system for investigating the molecular mechanisms that promote animal-bacterial symbioses. E. scolopes hatch from their eggs uncolonized, which has led to the development of squid-colonization assays that are based on introducing culture-grown V. fischeri cells to freshly hatched juvenile squid. Recent studies have revealed that strains often exhibit large differences in how they establish symbiosis. Therefore, we sought to develop a simplified and reproducible protocol that permits researchers to determine appropriate inoculum levels and provides a platform to standardize the assay across different laboratories. In our protocol, we adapt a method commonly used for evaluating the infectivity of pathogens to quantify the symbiotic capacity of V. fischeri strains. The resulting metric, the symbiotic dose-50 (SD50), estimates the inoculum level that is necessary for a specific V. fischeri strain to establish a light-emitting symbiosis. Relative to other protocols, our method requires 2-5-fold fewer animals. Furthermore, the power analysis presented here suggests that the protocol can detect up to a 3-fold change in the SD50 between different strains.
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Affiliation(s)
- Aidan R. Donnelly
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Elizabeth J. Giacobe
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Rachel A. Cook
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Gareth M. Francis
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Grace K. Buddle
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Christina L. Beaubrun
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Andrew G. Cecere
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
| | - Tim I. Miyashiro
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, United States of America
- The One Health Microbiome Center, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, United States of America
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25
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Lin YL, Smith SN, Kanso E, Septer AN, Rycroft CH. A subcellular biochemical model for T6SS dynamics reveals winning competitive strategies. PNAS NEXUS 2023; 2:pgad195. [PMID: 37441614 PMCID: PMC10335733 DOI: 10.1093/pnasnexus/pgad195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 05/30/2023] [Accepted: 06/01/2023] [Indexed: 07/15/2023]
Abstract
The type VI secretion system (T6SS) is a broadly distributed interbacterial weapon that can be used to eliminate competing bacterial populations. Although unarmed target populations are typically used to study T6SS function in vitro, bacteria most likely encounter other T6SS-armed competitors in nature. However, the connection between subcellular details of the T6SS and the outcomes of such mutually lethal battles is not well understood. Here, we incorporate biological data derived from natural competitors of Vibrio fischeri light organ symbionts to build a biochemical model for T6SS at the single-cell level, which we then integrate into an agent-based model (ABM). Using the ABM, we isolate and experiment with strain-specific physiological differences between competitors in ways not possible with biological samples to identify winning strategies for T6SS-armed populations. Through in vitro experiments, we discover that strain-specific differences exist in T6SS activation speed. ABM simulations corroborate that faster activation is dominant in determining survival during competition. Once competitors are fully activated, the energy required for T6SS creates a tipping point where increased weapon building and firing becomes too costly to be advantageous. Through ABM simulations, we identify the threshold where this transition occurs in the T6SS parameter space. We also find that competitive outcomes depend on the geometry of the battlefield: unarmed target cells survive at the edges of a range expansion where unlimited territory can be claimed. Alternatively, competitions within a confined space, much like the light organ crypts where natural V. fischeri compete, result in the rapid elimination of the unarmed population.
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Affiliation(s)
| | | | - Eva Kanso
- Department of Aerospace and Mechanical Engineering, University of Southern California, 3650 McClintock Ave, Los Angeles, CA 90089, USA
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26
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Wollmuth EM, Angert ER. Microbial circadian clocks: host-microbe interplay in diel cycles. BMC Microbiol 2023; 23:124. [PMID: 37161348 PMCID: PMC10173096 DOI: 10.1186/s12866-023-02839-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 03/28/2023] [Indexed: 05/11/2023] Open
Abstract
BACKGROUND Circadian rhythms, observed across all domains of life, enable organisms to anticipate and prepare for diel changes in environmental conditions. In bacteria, a circadian clock mechanism has only been characterized in cyanobacteria to date. These clocks regulate cyclical patterns of gene expression and metabolism which contribute to the success of cyanobacteria in their natural environments. The potential impact of self-generated circadian rhythms in other bacterial and microbial populations has motivated extensive research to identify novel circadian clocks. MAIN TEXT Daily oscillations in microbial community composition and function have been observed in ocean ecosystems and in symbioses. These oscillations are influenced by abiotic factors such as light and the availability of nutrients. In the ocean ecosystems and in some marine symbioses, oscillations are largely controlled by light-dark cycles. In gut systems, the influx of nutrients after host feeding drastically alters the composition and function of the gut microbiota. Conversely, the gut microbiota can influence the host circadian rhythm by a variety of mechanisms including through interacting with the host immune system. The intricate and complex relationship between the microbiota and their host makes it challenging to disentangle host behaviors from bacterial circadian rhythms and clock mechanisms that might govern the daily oscillations observed in these microbial populations. CONCLUSIONS While the ability to anticipate the cyclical behaviors of their host would likely be enhanced by a self-sustained circadian rhythm, more evidence and further studies are needed to confirm whether host-associated heterotrophic bacteria possess such systems. In addition, the mechanisms by which heterotrophic bacteria might respond to diel cycles in environmental conditions has yet to be uncovered.
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Affiliation(s)
- Emily M Wollmuth
- Department of Microbiology, Cornell University, 123 Wing Drive, Ithaca, NY, 14853, USA
| | - Esther R Angert
- Department of Microbiology, Cornell University, 123 Wing Drive, Ithaca, NY, 14853, USA.
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27
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Surrett ED, Guckes KR, Cousins S, Ruskoski TB, Cecere AG, Ludvik DA, Okafor CD, Mandel MJ, Miyashiro TI. Two enhancer binding proteins activate σ 54-dependent transcription of a quorum regulatory RNA in a bacterial symbiont. eLife 2023; 12:e78544. [PMID: 37145113 PMCID: PMC10162802 DOI: 10.7554/elife.78544] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Accepted: 04/20/2023] [Indexed: 05/06/2023] Open
Abstract
To colonize a host, bacteria depend on an ensemble of signaling systems to convert information about the various environments encountered within the host into specific cellular activities. How these signaling systems coordinate transitions between cellular states in vivo remains poorly understood. To address this knowledge gap, we investigated how the bacterial symbiont Vibrio fischeri initially colonizes the light organ of the Hawaiian bobtail squid Euprymna scolopes. Previous work has shown that the small RNA Qrr1, which is a regulatory component of the quorum-sensing system in V. fischeri, promotes host colonization. Here, we report that transcriptional activation of Qrr1 is inhibited by the sensor kinase BinK, which suppresses cellular aggregation by V. fischeri prior to light organ entry. We show that Qrr1 expression depends on the alternative sigma factor σ54 and the transcription factors LuxO and SypG, which function similar to an OR logic gate, thereby ensuring Qrr1 is expressed during colonization. Finally, we provide evidence that this regulatory mechanism is widespread throughout the Vibrionaceae family. Together, our work reveals how coordination between the signaling pathways underlying aggregation and quorum-sensing promotes host colonization, which provides insight into how integration among signaling systems facilitates complex processes in bacteria.
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Affiliation(s)
- Ericka D Surrett
- Department of Biochemistry and Molecular Biology, Pennsylvania State UniversityUniversity ParkUnited States
| | - Kirsten R Guckes
- Department of Biochemistry and Molecular Biology, Pennsylvania State UniversityUniversity ParkUnited States
| | - Shyan Cousins
- Department of Biochemistry and Molecular Biology, Pennsylvania State UniversityUniversity ParkUnited States
| | - Terry B Ruskoski
- Department of Biochemistry and Molecular Biology, Pennsylvania State UniversityUniversity ParkUnited States
| | - Andrew G Cecere
- Department of Biochemistry and Molecular Biology, Pennsylvania State UniversityUniversity ParkUnited States
| | - Denise A Ludvik
- Department of Medical Microbiology and Immunology, University of Wisconsin-MadisonMadisonUnited States
| | - C Denise Okafor
- Department of Biochemistry and Molecular Biology, Pennsylvania State UniversityUniversity ParkUnited States
- Department of Chemistry, Pennsylvania State UniversityUniversity ParkUnited States
| | - Mark J Mandel
- Department of Medical Microbiology and Immunology, University of Wisconsin-MadisonMadisonUnited States
| | - Tim I Miyashiro
- Department of Biochemistry and Molecular Biology, Pennsylvania State UniversityUniversity ParkUnited States
- The Microbiome Center, Huck Institutes of the Life Sciences, Pennsylvania State UniversityUniversity ParkUnited States
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28
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Oliveira RA, Cabral V, Torcato I, Xavier KB. Deciphering the quorum-sensing lexicon of the gut microbiota. Cell Host Microbe 2023; 31:500-512. [PMID: 37054672 DOI: 10.1016/j.chom.2023.03.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/15/2023]
Abstract
The enduring coexistence between the gut microbiota and the host has led to a symbiotic relationship that benefits both parties. In this complex, multispecies environment, bacteria can communicate through chemical molecules to sense and respond to the chemical, physical, and ecological properties of the surrounding environment. One of the best-studied cell-to-cell communication mechanisms is quorum sensing. Chemical signaling through quorum sensing is involved in regulating the bacterial group behaviors, often required for host colonization. However, most microbial-host interactions regulated by quorum sensing are studied in pathogens. Here, we will focus on the latest reports on the emerging studies of quorum sensing in the gut microbiota symbionts and on group behaviors adopted by these bacteria to colonize the mammalian gut. Moreover, we address the challenges and approaches to uncover molecule-mediated communication mechanisms, which will allow us to unravel the processes that drive the establishment of gut microbiota.
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Affiliation(s)
| | - Vitor Cabral
- Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal
| | - Inês Torcato
- Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal
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29
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Essock-Burns T, Lawhorn S, Wu L, McClosky S, Moriano-Gutierrez S, Ruby EG, McFall-Ngai MJ. Maturation state of colonization sites promotes symbiotic resiliency in the Euprymna scolopes-Vibrio fischeri partnership. MICROBIOME 2023; 11:68. [PMID: 37004104 PMCID: PMC10064550 DOI: 10.1186/s40168-023-01509-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Accepted: 03/05/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND Many animals and plants acquire their coevolved symbiotic partners shortly post-embryonic development. Thus, during embryogenesis, cellular features must be developed that will promote both symbiont colonization of the appropriate tissues, as well as persistence at those sites. While variation in the degree of maturation occurs in newborn tissues, little is unknown about how this variation influences the establishment and persistence of host-microbe associations. RESULTS The binary symbiosis model, the squid-vibrio (Euprymna scolopes-Vibrio fischeri) system, offers a way to study how an environmental gram-negative bacterium establishes a beneficial, persistent, extracellular colonization of an animal host. Here, we show that bacterial symbionts occupy six different colonization sites in the light-emitting organ of the host that have both distinct morphologies and responses to antibiotic treatment. Vibrio fischeri was most resilient to antibiotic disturbance when contained within the smallest and least mature colonization sites. We show that this variability in crypt development at the time of hatching allows the immature sites to act as a symbiont reservoir that has the potential to reseed the more mature sites in the host organ when they have been cleared by antibiotic treatment. This strategy may produce an ecologically significant resiliency to the association. CONCLUSIONS The data presented here provide evidence that the evolution of the squid-vibrio association has been selected for a nascent organ with a range of host tissue maturity at the onset of symbiosis. The resulting variation in physical and chemical environments results in a spectrum of host-symbiont interactions, notably, variation in susceptibility to environmental disturbance. This "insurance policy" provides resiliency to the symbiosis during the critical period of its early development. While differences in tissue maturity at birth have been documented in other animals, such as along the infant gut tract of mammals, the impact of this variation on host-microbiome interactions has not been studied. Because a wide variety of symbiosis characters are highly conserved over animal evolution, studies of the squid-vibrio association have the promise of providing insights into basic strategies that ensure successful bacterial passage between hosts in horizontally transmitted symbioses. Video Abstract.
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Affiliation(s)
- Tara Essock-Burns
- Kewalo Marine Laboratory, Pacific Biosciences Research Center, University of Hawai'i, Mānoa, Honolulu, HI, USA
- Present address: Carnegie Institution for Science, Division of Biosphere Sciences and Engineering, Pasadena, CA, USA
| | - Susannah Lawhorn
- Kewalo Marine Laboratory, Pacific Biosciences Research Center, University of Hawai'i, Mānoa, Honolulu, HI, USA
| | - Leo Wu
- Kewalo Marine Laboratory, Pacific Biosciences Research Center, University of Hawai'i, Mānoa, Honolulu, HI, USA
| | - Sawyer McClosky
- Kewalo Marine Laboratory, Pacific Biosciences Research Center, University of Hawai'i, Mānoa, Honolulu, HI, USA
| | - Silvia Moriano-Gutierrez
- Kewalo Marine Laboratory, Pacific Biosciences Research Center, University of Hawai'i, Mānoa, Honolulu, HI, USA
- Present address: Department of Fundamental Biology, University of Lausanne, Lausanne, Switzerland
| | - Edward G Ruby
- Kewalo Marine Laboratory, Pacific Biosciences Research Center, University of Hawai'i, Mānoa, Honolulu, HI, USA
- Present address: Carnegie Institution for Science, Division of Biosphere Sciences and Engineering, Pasadena, CA, USA
| | - Margaret J McFall-Ngai
- Kewalo Marine Laboratory, Pacific Biosciences Research Center, University of Hawai'i, Mānoa, Honolulu, HI, USA.
- Present address: Carnegie Institution for Science, Division of Biosphere Sciences and Engineering, Pasadena, CA, USA.
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30
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Septer AN, Sharpe G, Shook EA. The Vibrio fischeri type VI secretion system incurs a fitness cost under host-like conditions. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.07.529561. [PMID: 36945377 PMCID: PMC10028907 DOI: 10.1101/2023.03.07.529561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
Abstract
The type VI secretion system (T6SS) is an interbacterial weapon composed of thousands of protein subunits and predicted to require significant cellular energy to deploy, yet a fitness cost from T6SS use is rarely observed. Here, we identify host-like conditions where the T6SS incurs a fitness cost using the beneficial symbiont, Vibrio fischeri, which uses its T6SS to eliminate competitors in the natural squid host. We hypothesized that a fitness cost for the T6SS could be dependent on the cellular energetic state and used theoretical ATP cost estimates to predict when a T6SS-dependent fitness cost may be apparent. Theoretical energetic cost estimates predicted a minor relative cost for T6SS use in fast-growing populations (0.4-0.45% of total ATP used cell-1), and a higher relative cost (3.1-13.6%) for stationary phase cells. Consistent with these predictions, we observed no significant T6SS-dependent fitness cost for fast-growing populations typically used for competition assays. However, the stationary phase cell density was significantly lower in the wild-type strain, compared to a regulator mutant that does not express the T6SS, and this T6SS-dependent fitness cost was between 11 and 23%. Such a fitness cost could influence the prevalence and biogeography of T6SSs in animal-associated bacteria. While the T6SS may be required in kill or be killed scenarios, once the competitor is eliminated there is no longer selective pressure to maintain the weapon. Our findings indicate an evolved genotype lacking the T6SS would have a growth advantage over its parent, resulting in the eventual dominance of the unarmed population.
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Affiliation(s)
- Alecia N. Septer
- Department of Earth, Marine & Environmental Sciences, University of North Carolina, Chapel Hill, NC 27599
| | - Garrett Sharpe
- Department of Earth, Marine & Environmental Sciences, University of North Carolina, Chapel Hill, NC 27599
- Environment, Ecology & Energy Program, University of North Carolina, Chapel Hill, NC 27599
| | - Erika A. Shook
- Department of Earth, Marine & Environmental Sciences, University of North Carolina, Chapel Hill, NC 27599
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31
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Rossetto V, Moore-Machacek A, Woods DF, Galvão HM, Shanahan RM, Hickey A, O'Leary N, O'Gara F, McGlacken GP, Reen FJ. Structural modification of the Pseudomonas aeruginosa alkylquinoline cell-cell communication signal, HHQ, leads to benzofuranoquinolines with anti-virulence behaviour in ESKAPE pathogens. MICROBIOLOGY (READING, ENGLAND) 2023; 169. [PMID: 36862576 DOI: 10.1099/mic.0.001303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Abstract
Microbial populations have evolved intricate networks of negotiation and communication through which they can coexist in natural and host ecosystems. The nature of these systems can be complex and they are, for the most part, poorly understood at the polymicrobial level. The Pseudomonas Quinolone Signal (PQS) and its precursor 4-hydroxy-2-heptylquinoline (HHQ) are signal molecules produced by the important nosocomial pathogen
Pseudomonas aeruginosa
. They are known to modulate the behaviour of co-colonizing bacterial and fungal pathogens such as Bacillus atropheaus, Candida albicans and Aspergillus fumigatus. While the structural basis for alkyl-quinolone signalling within
P. aeruginosa
has been studied extensively, less is known about how structural derivatives of these molecules can influence multicellular behaviour and population-level decision-making in other co-colonizing organisms. In this study, we investigated a suite of small molecules derived initially from the HHQ framework, for anti-virulence activity against ESKAPE pathogens, at the species and strain levels. Somewhat surprisingly, with appropriate substitution, loss of the alkyl chain (present in HHQ and PQS) did not result in a loss of activity, presenting a more easily accessible synthetic framework for investigation. Virulence profiling uncovered significant levels of inter-strain variation among the responses of clinical and environmental isolates to small-molecule challenge. While several lead compounds were identified in this study, further work is needed to appreciate the extent of strain-level tolerance to small-molecule anti-infectives among pathogenic organisms.
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Affiliation(s)
- Veronica Rossetto
- Faculty of Science and Technology, Universidade do Algarve, Algarve, Portugal.,School of Microbiology, University College Cork, Cork, Ireland
| | | | - David F Woods
- School of Microbiology, University College Cork, Cork, Ireland
| | - Helena M Galvão
- Faculty of Science and Technology, Universidade do Algarve, Algarve, Portugal
| | - Rachel M Shanahan
- School of Chemistry and Analytical and Biological Chemistry Research Facility, University College Cork, Cork, Ireland
| | - Aobha Hickey
- School of Chemistry and Analytical and Biological Chemistry Research Facility, University College Cork, Cork, Ireland
| | - Niall O'Leary
- School of Microbiology, University College Cork, Cork, Ireland
| | - Fergal O'Gara
- School of Microbiology, University College Cork, Cork, Ireland.,Biomerit Research Centre, School of Microbiology, University College Cork, Cork, Ireland.,Wal-yan Respiratory Research Centre, Telethon Kids Institute, Perth, WA, Australia
| | - Gerard P McGlacken
- School of Chemistry and Analytical and Biological Chemistry Research Facility, University College Cork, Cork, Ireland.,Synthesis and Solid State Pharmaceutical Centre, University College Cork, Cork, Ireland
| | - F Jerry Reen
- School of Microbiology, University College Cork, Cork, Ireland.,Synthesis and Solid State Pharmaceutical Centre, University College Cork, Cork, Ireland
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32
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Dalwadi MP, Pearce P. Universal dynamics of biological pattern formation in spatio-temporal morphogen variations. Proc Math Phys Eng Sci 2023. [DOI: 10.1098/rspa.2022.0829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/31/2023] Open
Abstract
In biological systems, chemical signals termed morphogens self-organize into patterns that are vital for many physiological processes. As observed by Turing in 1952, these patterns are in a state of continual development, and are usually transitioning from one pattern into another. How do cells robustly decode these spatio-temporal patterns into signals in the presence of confounding effects caused by unpredictable or heterogeneous environments? Here, we answer this question by developing a general theory of pattern formation in spatio-temporal variations of ‘pre-pattern’ morphogens, which determine gene-regulatory network parameters. Through mathematical analysis, we identify universal dynamical regimes that apply to wide classes of biological systems. We apply our theory to two paradigmatic pattern-forming systems, and predict that they are robust with respect to non-physiological morphogen variations. More broadly, our theoretical framework provides a general approach to classify the emergent dynamics of pattern-forming systems based on how the bifurcations in their governing equations are traversed.
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33
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Abstract
Developmental processes in animals are influenced by colonization and/or signaling from microbial symbionts. Here, we show that bacteria from the environment are linked to development of a symbiotic organ that houses a bacterial consortium in female Hawaiian bobtail squid, Euprymna scolopes. In addition to the well-characterized light organ association with the bioluminescent bacterium Vibrio fischeri, female E. scolopes house a simple bacterial community in a reproductive organ, the accessory nidamental gland (ANG). In order to understand the influences of bacteria on ANG development, squid were raised in the laboratory under conditions where exposure to environmental microorganisms was experimentally manipulated. Under conditions where hosts were exposed to depleted environmental bacteria, ANGs were completely absent or stunted, a result independent of the presence of the light organ symbiont V. fischeri. When squid were raised in the laboratory with substrate from the host's natural environment containing the native microbiota, normal ANG development was observed, and the bacterial communities were similar to wild-caught animals. Analysis of the bacterial communities from ANGs and substrates of wild-caught and laboratory-raised animals suggests that certain bacterial groups, namely, the Verrucomicrobia, are linked to ANG development. The ANG community composition was also experimentally manipulated. Squid raised with natural substrate supplemented with a specific ANG bacterial strain, Leisingera sp. JC1, had high proportions of this strain in the ANG, suggesting that once ANG development is initiated, specific strains can be introduced and subsequently colonize the organ. Overall, these data suggest that environmental bacteria are required for development of the ANG in E. scolopes. IMPORTANCE Microbiota have profound effects on animal and plant development. Hosts raised axenically or without symbionts often suffer negative outcomes resulting in developmental defects or reduced organ function. Using defined experimental conditions, we demonstrate that environmental bacteria are required for the formation of a female-specific symbiotic organ in the Hawaiian bobtail squid, Euprymna scolopes. Although nascent tissues from this organ that are involved with bacterial recruitment formed initially, the mature organ failed to develop and was absent or severely reduced in sexually mature animals that were not exposed to microbiota from the host's natural environment. This is the first example of complete organ development relying on exposure to symbiotic bacteria in an animal host. This study broadens the use of E. scolopes as a model organism for studying the influence of beneficial bacteria on animal development.
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Guckes KR, Miyashiro TI. The type-VI secretion system of the beneficial symbiont Vibrio fischeri. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001302. [PMID: 36809081 PMCID: PMC9972734 DOI: 10.1099/mic.0.001302] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 01/23/2023] [Indexed: 02/23/2023]
Abstract
The mutualistic symbiosis between the Hawaiian bobtail squid Euprymna scolopes and the marine bacterium Vibrio fischeri is a powerful experimental system for determining how intercellular interactions impact animal-bacterial associations. In nature, this symbiosis features multiple strains of V. fischeri within each adult animal, which indicates that different strains initially colonize each squid. Various studies have demonstrated that certain strains of V. fischeri possess a type-VI secretion system (T6SS), which can inhibit other strains from establishing symbiosis within the same host habitat. The T6SS is a bacterial melee weapon that enables a cell to kill adjacent cells by translocating toxic effectors via a lancet-like apparatus. This review describes the progress that has been made in understanding the factors that govern the structure and expression of the T6SS in V. fischeri and its effect on the symbiosis.
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Affiliation(s)
- Kirsten R. Guckes
- The Microbiome Center, Huck Institutes of the Life Sciences, Pennsylvania State University, PA, USA
| | - Tim I. Miyashiro
- The Microbiome Center, Huck Institutes of the Life Sciences, Pennsylvania State University, PA, USA
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35
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Alker AT, Aspiras AE, Dunbar TL, Farrell MV, Fedoriouk A, Jones JE, Mikhail SR, Salcedo GY, Moore BS, Shikuma NJ. A modular plasmid toolkit applied in marine Proteobacteria reveals functional insights during bacteria-stimulated metamorphosis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.31.526474. [PMID: 36778221 PMCID: PMC9915575 DOI: 10.1101/2023.01.31.526474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A conspicuous roadblock to studying marine bacteria for fundamental research and biotechnology is a lack of modular synthetic biology tools for their genetic manipulation. Here, we applied, and generated new parts for, a modular plasmid toolkit to study marine bacteria in the context of symbioses and host-microbe interactions. To demonstrate the utility of this plasmid system, we genetically manipulated the marine bacterium Pseudoalteromonas luteoviolacea , which stimulates the metamorphosis of the model tubeworm, Hydroides elegans . Using these tools, we quantified constitutive and native promoter expression, developed reporter strains that enable the imaging of host-bacteria interactions, and used CRISPR interference (CRISPRi) to knock down a secondary metabolite and a host-associated gene. We demonstrate the broader utility of this modular system for rapidly creating and iteratively testing genetic tractability by modifying marine bacteria that are known to be associated with diverse host-microbe symbioses. These efforts enabled the successful transformation of twelve marine strains across two Proteobacteria classes, four orders and ten genera. Altogether, the present study demonstrates how synthetic biology strategies enable the investigation of marine microbes and marine host-microbe symbioses with broader implications for environmental restoration and biotechnology.
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36
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Goffredi SK, Appy RG, Hildreth R, deRogatis J. Marine vampires: Persistent, internal associations between bacteria and blood-feeding marine annelids and crustaceans. Front Microbiol 2023; 13:1113237. [PMID: 36713196 PMCID: PMC9876621 DOI: 10.3389/fmicb.2022.1113237] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 12/21/2022] [Indexed: 01/13/2023] Open
Abstract
Persistent bacterial presence is believed to play an important role in host adaptation to specific niches that would otherwise be unavailable, including the exclusive consumption of blood by invertebrate parasites. Nearly all blood-feeding animals examined so far host internal bacterial symbionts that aid in some essential aspect of their nutrition. Obligate blood-feeding (OBF) invertebrates exist in the oceans, yet symbiotic associations between them and beneficial bacteria have not yet been explored. This study describes the microbiome of 6 phylogenetically-diverse species of marine obligate blood-feeders, including leeches (both fish and elasmobranch specialists; e.g., Pterobdella, Ostreobdella, and Branchellion), isopods (e.g., Elthusa and Nerocila), and a copepod (e.g., Lernanthropus). Amplicon sequencing analysis revealed the blood-feeding invertebrate microbiomes to be low in diversity, compared to host fish skin surfaces, seawater, and non-blood-feeding relatives, and dominated by only a few bacterial genera, including Vibrio (100% prevalence and comprising 39%-81% of the average total recovered 16S rRNA gene sequences per OBF taxa). Vibrio cells were localized to the digestive lumen in and among the blood meal for all taxa examined via fluorescence microscopy. For Elthusa and Branchellion, Vibrio cells also appeared intracellularly within possible hemocytes, suggesting an interaction with the immune system. Additionally, Vibrio cultivated from four of the obligate blood-feeding marine taxa matched the dominant amplicons recovered, and all but one was able to effectively lyse vertebrate blood cells. Bacteria from 2 additional phyla and 3 families were also regularly recovered, albeit in much lower abundances, including members of the Oceanospirillaceae, Flavobacteriacea, Porticoccaceae, and unidentified members of the gamma-and betaproteobacteria, depending on the invertebrate host. For the leech Pterobdella, the Oceanospirillaceae were also detected in the esophageal diverticula. For two crustacean taxa, Elthusa and Lernanthropus, the microbial communities associated with brooded eggs were very similar to the adults, indicating possible direct transmission. Virtually nothing is known about the influence of internal bacteria on the success of marine blood-feeders, but this evidence suggests their regular presence in marine parasites from several prominent groups.
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Affiliation(s)
- Shana K. Goffredi
- Department of Biology, Occidental College, Los Angeles, CA, United States
| | - Ralph G. Appy
- Cabrillo Marine Aquarium, San Pedro, CA, United States
| | - Rebecca Hildreth
- Department of Biology, Occidental College, Los Angeles, CA, United States
| | - Julia deRogatis
- Department of Biology, Occidental College, Los Angeles, CA, United States
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37
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Dunn AK. Alternative oxidase in bacteria. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2023; 1864:148929. [PMID: 36265564 DOI: 10.1016/j.bbabio.2022.148929] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 09/20/2022] [Accepted: 10/12/2022] [Indexed: 11/06/2022]
Abstract
While alternative oxidase (AOX) was discovered in bacteria in 2003, the expression, function, and evolutionary history of this protein in these important organisms is largely unexplored. To date, expression and functional analysis is limited to studies in the Proteobacteria Novosphingobium aromaticivorans and Vibrio fischeri, where AOX likely plays roles in maintenance of cellular energy homeostasis and supporting responses to cellular stress. This review describes the history of the study of AOX in bacteria, details current knowledge of the predicted biochemical and structural characteristics, distribution, and function of bacterial AOX, and highlights interesting areas for the future study of AOX in bacteria.
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Affiliation(s)
- Anne K Dunn
- Department of Microbiology and Plant Biology, University of Oklahoma, 770 Van Vleet Oval, Norman, OK 73019, USA.
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38
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Ganesan R, Wierz JC, Kaltenpoth M, Flórez LV. How It All Begins: Bacterial Factors Mediating the Colonization of Invertebrate Hosts by Beneficial Symbionts. Microbiol Mol Biol Rev 2022; 86:e0012621. [PMID: 36301103 PMCID: PMC9769632 DOI: 10.1128/mmbr.00126-21] [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] [Indexed: 01/01/2023] Open
Abstract
Beneficial associations with bacteria are widespread across animals, spanning a range of symbiont localizations, transmission routes, and functions. While some of these associations have evolved into obligate relationships with permanent symbiont localization within the host, the majority require colonization of every host generation from the environment or via maternal provisions. Across the broad diversity of host species and tissue types that beneficial bacteria can colonize, there are some highly specialized strategies for establishment yet also some common patterns in the molecular basis of colonization. This review focuses on the mechanisms underlying the early stage of beneficial bacterium-invertebrate associations, from initial contact to the establishment of the symbionts in a specific location of the host's body. We first reflect on general selective pressures that can drive the transition from a free-living to a host-associated lifestyle in bacteria. We then cover bacterial molecular factors for colonization in symbioses from both model and nonmodel invertebrate systems where these have been studied, including terrestrial and aquatic host taxa. Finally, we discuss how interactions between multiple colonizing bacteria and priority effects can influence colonization. Taking the bacterial perspective, we emphasize the importance of developing new experimentally tractable systems to derive general insights into the ecological factors and molecular adaptations underlying the origin and establishment of beneficial symbioses in animals.
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Affiliation(s)
- Ramya Ganesan
- Department of Evolutionary Ecology, Institute of Organismic and Molecular Evolution, Johannes Gutenberg University, Mainz, Germany
- Department of Insect Symbiosis, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Jürgen C. Wierz
- Department of Evolutionary Ecology, Institute of Organismic and Molecular Evolution, Johannes Gutenberg University, Mainz, Germany
- Department of Insect Symbiosis, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Martin Kaltenpoth
- Department of Evolutionary Ecology, Institute of Organismic and Molecular Evolution, Johannes Gutenberg University, Mainz, Germany
- Department of Insect Symbiosis, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Laura V. Flórez
- Department of Evolutionary Ecology, Institute of Organismic and Molecular Evolution, Johannes Gutenberg University, Mainz, Germany
- Department of Plant and Environmental Sciences, Section for Organismal Biology, University of Copenhagen, Copenhagen, Denmark
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Schmittmann L, Rahn T, Busch K, Fraune S, Pita L, Hentschel U. Stability of a dominant sponge-symbiont in spite of antibiotic-induced microbiome disturbance. Environ Microbiol 2022; 24:6392-6410. [PMID: 36250983 DOI: 10.1111/1462-2920.16249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 10/13/2022] [Indexed: 01/12/2023]
Abstract
Marine sponges are known for their complex and stable microbiomes. However, the lack of a gnotobiotic sponge-model and experimental methods to manipulate both the host and the microbial symbionts currently limit our mechanistic understanding of sponge-microbial symbioses. We have used the North Atlantic sponge species Halichondria panicea to evaluate the use of antibiotics to generate gnotobiotic sponges. We further asked whether the microbiome can be reestablished via recolonization with the natural microbiome. Experiments were performed in marine gnotobiotic facilities equipped with a custom-made, sterile, flow-through aquarium system. Bacterial abundance dynamics were monitored qualitatively and quantitatively by 16 S rRNA gene amplicon sequencing and qPCR, respectively. Antibiotics induced dysbiosis by favouring an increase of opportunistic, antibiotic-resistant bacteria, resulting in more complex, but less specific bacteria-bacteria interactions than in untreated sponges. The abundance of the dominant symbiont, Candidatus Halichondribacter symbioticus, remained overall unchanged, reflecting its obligately symbiotic nature. Recolonization with the natural microbiome could not reverse antibiotic-induced dysbiosis. However, single bacterial taxa that were transferred, successfully recolonized the sponge and affected bacteria-bacteria interactions. By experimentally manipulating microbiome composition, we could show the stability of a sponge-symbiont clade despite microbiome dysbiosis. This study contributes to understanding both host-bacteria and bacteria-bacteria interactions in the sponge holobiont.
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Affiliation(s)
- Lara Schmittmann
- GEOMAR Helmholtz Centre for Ocean Research Kiel, RD3 Marine Ecology, RU Marine Symbioses, Kiel, Germany
| | - Tanja Rahn
- GEOMAR Helmholtz Centre for Ocean Research Kiel, RD3 Marine Ecology, RU Marine Symbioses, Kiel, Germany
| | - Kathrin Busch
- GEOMAR Helmholtz Centre for Ocean Research Kiel, RD3 Marine Ecology, RU Marine Symbioses, Kiel, Germany
| | - Sebastian Fraune
- Heinrich-Heine-University, Zoology and Organismic Interactions, Düsseldorf, Germany
| | - Lucía Pita
- GEOMAR Helmholtz Centre for Ocean Research Kiel, RD3 Marine Ecology, RU Marine Symbioses, Kiel, Germany.,Institut de Ciències del Mar - CSIC, Marine Biology and Oceanography, Marine Biogeochemistry, Atmosphere and Climate, Barcelona, Spain
| | - Ute Hentschel
- GEOMAR Helmholtz Centre for Ocean Research Kiel, RD3 Marine Ecology, RU Marine Symbioses, Kiel, Germany.,Christian-Albrechts-University Kiel, Kiel, Germany
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40
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Gundlach KA, Nawroth J, Kanso E, Nasrin F, Ruby EG, McFall-Ngai M. Ciliated epithelia are key elements in the recruitment of bacterial partners in the squid-vibrio symbiosis. Front Cell Dev Biol 2022; 10:974213. [PMID: 36340026 PMCID: PMC9632347 DOI: 10.3389/fcell.2022.974213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 10/07/2022] [Indexed: 11/28/2022] Open
Abstract
The Hawaiian bobtail squid, Euprymna scolopes, harvests its luminous symbiont, Vibrio fischeri, from the surrounding seawater within hours of hatching. During embryogenesis, the host animal develops a nascent light organ with ciliated fields on each lateral surface. We hypothesized that these fields function to increase the efficiency of symbiont colonization of host tissues. Within minutes of hatching from the egg, the host’s ciliated fields shed copious amounts of mucus in a non-specific response to bacterial surface molecules, specifically peptidoglycan (PGN), from the bacterioplankton in the surrounding seawater. Experimental manipulation of the system provided evidence that nitric oxide in the mucus drives an increase in ciliary beat frequency (CBF), and exposure to even small numbers of V. fischeri cells for short periods resulted in an additional increase in CBF. These results indicate that the light-organ ciliated fields respond specifically, sensitively, and rapidly, to the presence of nonspecific PGN as well as symbiont cells in the ambient seawater. Notably, the study provides the first evidence that this induction of an increase in CBF occurs as part of a thus far undiscovered initial phase in colonization of the squid host by its symbiont, i.e., host recognition of V. fischeri cues in the environment within minutes. Using a biophysics-based mathematical analysis, we showed that this rapid induction of increased CBF, while accelerating bacterial advection, is unlikely to be signaled by V. fischeri cells interacting directly with the organ surface. These overall changes in CBF were shown to significantly impact the efficiency of V. fischeri colonization of the host organ. Further, once V. fischeri has fully colonized the host tissues, i.e., about 12–24 h after initial host-symbiont interactions, the symbionts drove an attenuation of mucus shedding from the ciliated fields, concomitant with an attenuation of the CBF. Taken together, these findings offer a window into the very first interactions of ciliated surfaces with their coevolved microbial partners.
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Affiliation(s)
- Katrina A. Gundlach
- Kewalo Marine Laboratory, University of Hawaiʻi at Mānoa, Honolulu, HI, United States
| | - Janna Nawroth
- Helmholtz Pioneer Campus, Helmholtz Zentrum München, Neuherberg, Germany
| | - Eva Kanso
- Department of Aerospace and Mechanical Engineering, University of Southern California, Los Angeles, CA, United States
| | - Farzana Nasrin
- Department of Mathematics, University of Hawaiʻi at Mānoa, Honolulu, HI, United States
| | - Edward G. Ruby
- Kewalo Marine Laboratory, University of Hawaiʻi at Mānoa, Honolulu, HI, United States
| | - Margaret McFall-Ngai
- Kewalo Marine Laboratory, University of Hawaiʻi at Mānoa, Honolulu, HI, United States
- *Correspondence: Margaret McFall-Ngai,
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41
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Suria AM, Smith S, Speare L, Chen Y, Chien I, Clark EG, Krueger M, Warwick AM, Wilkins H, Septer AN. Prevalence and diversity of type VI secretion systems in a model beneficial symbiosis. Front Microbiol 2022; 13:988044. [PMID: 36187973 PMCID: PMC9515649 DOI: 10.3389/fmicb.2022.988044] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 08/24/2022] [Indexed: 11/13/2022] Open
Abstract
The type VI secretion system (T6SS) is widely distributed in diverse bacterial species and habitats where it is required for interbacterial competition and interactions with eukaryotic cells. Previous work described the role of a T6SS in the beneficial symbiont, Vibrio fischeri, during colonization of the light organ of Euprymna scolopes squid. However, the prevalence and diversity of T6SSs found within the distinct symbiotic structures of this model host have not yet been determined. Here, we analyzed 73 genomes of isolates from squid light organs and accessory nidamental glands (ANGs) and 178 reference genomes. We found that the majority of these bacterial symbionts encode diverse T6SSs from four distinct classes, and most share homology with T6SSs from more distantly related species, including pathogens of animals and humans. These findings indicate that T6SSs with shared evolutionary histories can be integrated into the cellular systems of host-associated bacteria with different effects on host health. Furthermore, we found that one T6SS in V. fischeri is located within a genomic island with high genomic plasticity. Five distinct genomic island genotypes were identified, suggesting this region encodes diverse functional potential that natural selection can act on. Finally, analysis of newly described T6SSs in roseobacter clade ANG isolates revealed a novel predicted protein that appears to be a fusion of the TssB-TssC sheath components. This work underscores the importance of studying T6SSs in diverse organisms and natural habitats to better understand how T6SSs promote the propagation of bacterial populations and impact host health.
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Affiliation(s)
- Andrea M. Suria
- Department of Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Stephanie Smith
- Department of Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Lauren Speare
- Department of Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States,Department of Microbiology, Oregon State University, Corvallis, OR, United States
| | - Yuzhou Chen
- Department of Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Iris Chien
- Department of Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Emily Grace Clark
- Department of Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Madelyn Krueger
- Department of Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Alexander M. Warwick
- Department of Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Hannah Wilkins
- Department of Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Alecia N. Septer
- Department of Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States,*Correspondence: Alecia N. Septer,
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42
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A peptidoglycan-recognition protein orchestrates the first steps of symbiont recruitment in the squid-vibrio symbiosis. Symbiosis 2022; 87:31-43. [DOI: 10.1007/s13199-022-00855-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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43
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Drerup C. The behavioural ecology of Sepiolidae (Cephalopoda: Sepiolida): a review. MOLLUSCAN RESEARCH 2022. [DOI: 10.1080/13235818.2022.2107503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Affiliation(s)
- Christian Drerup
- Marine Behavioural Ecology Group, Department of Zoology, University of Cambridge, Cambridge, United Kingdom
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Impact of transit time on the reproductive capacity of Euprymna scolopes as a laboratory animal. Lab Anim Res 2022; 38:25. [PMID: 35908064 PMCID: PMC9338615 DOI: 10.1186/s42826-022-00135-2] [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: 04/06/2022] [Accepted: 07/21/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The Hawaiian bobtail squid Euprymna scolopes hosts various marine bacterial symbionts, and these symbioses have served as models for the animal-microbe relationships that are important for host health. Within a light organ, E. scolopes harbors populations of the bacterium Vibrio fischeri, which produce low levels of bioluminescence that the squid uses for camouflage. The symbiosis is initially established after a juvenile squid hatches from its egg and acquires bacterial symbionts from the ambient marine environment. The relative ease with which a cohort of wild-caught E. scolopes can be maintained in a mariculture facility has facilitated over 3 decades of research involving juvenile squid. However, because E. scolopes is native to the Hawaiian archipelago, their transport from Hawaii to research facilities often represents a stress that has the potential to impact their physiology. RESULTS Here, we describe animal survival and reproductive capacity associated with a cohort of squid assembled from two shipments with markedly different transit times. We found that the lower juvenile squid counts generated by animals with the longer transit time were not due to the discrepancy in shipment but instead to fewer female squid that produced egg clutches at an elevated rate, which we term hyper-reproductivity. We find that hyper-reproductive females were responsible for 58% of the egg clutches laid. CONCLUSIONS The significance of these findings for E. scolopes biology and husbandry is discussed, thereby providing a platform for future investigation and further development of this cephalopod as a valuable lab animal for microbiology research.
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Shrestha P, Razvi A, Fung BL, Eichinger SJ, Visick KL. Mutational Analysis of Vibrio fischeri c-di-GMP-Modulating Genes Reveals Complex Regulation of Motility. J Bacteriol 2022; 204:e0010922. [PMID: 35758751 PMCID: PMC9295575 DOI: 10.1128/jb.00109-22] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 06/04/2022] [Indexed: 12/30/2022] Open
Abstract
The symbiont Vibrio fischeri uses motility to colonize its host. In numerous bacterial species, motility is negatively controlled by cyclic-di-GMP (c-di-GMP), which is produced by diguanylate cyclases (DGCs) with GGDEF domains and degraded by phosphodiesterases with either EAL or HD-GYP domains. To begin to decode the functions of the 50 Vibrio fischeri genes with GGDEF, EAL, and/or HD-GYP domains, we deleted each gene and assessed each mutant's migration through tryptone broth salt (TBS) soft agar medium containing or lacking magnesium (Mg) and calcium (Ca), which are known to influence V. fischeri motility. We identified 6, 13, and 16 mutants with altered migration in TBS-Mg, TBS, and TBS-Ca soft agar, respectively, a result that underscores the importance of medium conditions in assessing gene function. A biosensor-based assay revealed that Mg and Ca affected c-di-GMP levels negatively and positively, respectively; the severe decrease in c-di-GMP caused by Mg addition correlates with its strong positive impact on bacterial migration. A mutant defective for VF_0494, a homolog of V. cholerae rocS, exhibited a severe defect in migration across all conditions. Motility of a VF_1603 VF_2480 double mutant was also severely defective and could be restored by expression of "c-di-GMP-blind" alleles of master flagellar regulator flrA. Together, this work sheds light on the genes and conditions that influence c-di-GMP-mediated control over motility in V. fischeri and provides a foundation for (i) assessing roles of putative c-di-GMP-binding proteins, (ii) evaluating other c-di-GMP-dependent phenotypes in V. fischeri, (iii) uncovering potential redundancy, and (iv) deciphering signal transduction mechanisms. IMPORTANCE Critical bacterial processes, including motility, are influenced by c-di-GMP, which is controlled by environment-responsive synthetic and degradative enzymes. Because bacteria such as Vibrio fischeri use motility to colonize their hosts, understanding the roles of c-di-GMP-modulating enzymes in controlling motility has the potential to inform on microbe-host interactions. We leveraged recent advances in genetic manipulation to generate 50 mutants defective for putative c-di-GMP synthetic and degradative enzymes. We then assessed the consequences on motility, manipulating levels of magnesium and calcium, which inversely influenced motility and levels of c-di-GMP. Distinct subsets of the 50 genes were required under the different conditions. Our data thus provide needed insight into the functions of these enzymes and environmental factors that influence them.
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Affiliation(s)
| | - Ali Razvi
- Loyola University Chicago, Maywood, Illinois, USA
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46
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Abstract
Acetobacter species are a major component of the gut microbiome of the fruit fly Drosophila melanogaster, a widely used model organism. While a range of studies have illuminated impacts of Acetobacter on their hosts, less is known about how association with the host impacts bacteria. A previous study identified that a purine salvage locus was commonly found in Acetobacter associated with Drosophila. In this study, we sought to verify the functions of predicted purine salvage genes in Acetobacter fabarum DsW_054 and to test the hypothesis that these bacteria can utilize host metabolites as a sole source of nitrogen. Targeted gene deletion and complementation experiments confirmed that genes encoding xanthine dehydrogenase (xdhB), urate hydroxylase (urhA), and allantoinase (puuE) were required for growth on their respective substrates as the sole source of nitrogen. Utilization of urate by Acetobacter is significant because this substrate is the major nitrogenous waste product of Drosophila, and its accumulation in the excretory system is detrimental to both flies and humans. The potential significance of our findings for host purine homeostasis and health are discussed, as are the implications for interactions among microbiota members, which differ in their capacity to utilize host metabolites for nitrogen. IMPORTANCEAcetobacter are commonly found in the gut microbiota of fruit flies, including Drosophila melanogaster. We evaluated the function of purine salvage genes in Acetobacter fabarum to test the hypothesis that this bacterium can utilize host metabolites as a source of nitrogen. Our results identify functions for three genes required for growth on urate, a major host waste product. The utilization of this and other Drosophila metabolites by gut bacteria may play a role in their survival in the host environment. Future research into how microbial metabolism impacts host purine homeostasis may lead to therapies because urate accumulation in the excretory system is detrimental to flies and humans.
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47
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Gundlach KA, Briegel A. Zooming in on host-symbiont interactions: advances in cryo-EM sample processing methods and future application to symbiotic tissues. Symbiosis 2022. [DOI: 10.1007/s13199-022-00859-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AbstractAnimals, plants, and fungi live in a microbe-dominated world. Investigating the interactions and processes at the host-microbe interface offers insight to how bacteria influence the development, health, and disease of the host. Optimization of existing imaging technologies and development of novel instrumentation will provide the tools needed to fully understand the dynamic relationship that occurs at the host-microbe interface throughout the lifetime of the host. In this review, we describe the current methods used in cryo-electron microscopy (cryo-EM) including cryo-fixation, sample processing, FIB-SEM, and cryotomography. Further, we highlight the new advances associated with these methods that open the cryo-EM discipline to large, complex multicellular samples, like symbiotic tissues. We describe the advantages and challenges associated with correlative imaging techniques and sample thinning methods like lift-out. By highlighting recent pioneering studies in the large-volume or symbiotic sample workflows, we provide insight into how symbiotic model systems will benefit from cryo-EM methods to provide artefact-free, near-native, macromolecular-scale resolution imaging at the host-microbe interface throughout the development and maintenance of symbiosis. Cryo-EM methods have brought a deep fundamental understanding of prokaryotic biology since its conception. We propose the application of existing and novel cryo-EM techniques to symbiotic systems is the logical next step that will bring an even greater understanding how microbes interact with their host tissues.
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48
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Abstract
Animal development is an inherently complex process that is regulated by highly conserved genomic networks, and the resulting phenotype may remain plastic in response to environmental signals. Despite development having been studied in a more natural setting for the past few decades, this framework often precludes the role of microbial prokaryotes in these processes. Here, we address how microbial symbioses impact animal development from the onset of gametogenesis through adulthood. We then provide a first assessment of which developmental processes may or may not be influenced by microbial symbioses and, in doing so, provide a holistic view of the budding discipline of developmental symbiosis.
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Affiliation(s)
- Tyler J Carrier
- GEOMAR Helmholtz Centre for Ocean Research, Kiel 24105, Germany.,Zoological Institute, Christian-Albrechts University of Kiel, Kiel 24118, Germany
| | - Thomas C G Bosch
- Zoological Institute, Christian-Albrechts University of Kiel, Kiel 24118, Germany
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49
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Fronk DC, Sachs JL. Symbiotic organs: the nexus of host-microbe evolution. Trends Ecol Evol 2022; 37:599-610. [PMID: 35393155 DOI: 10.1016/j.tree.2022.02.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 02/14/2022] [Accepted: 02/28/2022] [Indexed: 02/07/2023]
Abstract
Diverse plants and animals have evolved specialized structures to filter and house beneficial microbes. These symbiotic organs form crucial points of exchange between host and symbiont, are often shaped by both partners, and exhibit features that facilitate a suite of microbial services. While symbiotic organs exhibit varied function, morphology, and developmental plasticity, they share core features linked to the evolutionary maintenance of beneficial symbiosis. Moreover, these organs can have a significant role in altering the demographic forces that shape microbial genomes, driving population bottlenecks and horizontal gene transfer (HGT). To advance our understanding of these 'joint phenotypes' across varied systems, future research must consider the emergent forces that can shape symbiotic organs, including fitness feedbacks and conflicts between interacting genomes.
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Affiliation(s)
- David C Fronk
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA 92521, USA
| | - Joel L Sachs
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA 92521, USA; Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA; Institute for Integrative Genome Biology, University of California, Riverside, CA 92521, USA.
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50
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Abstract
A huge number of bacterial species are motile by flagella, which allow them to actively move toward favorable environments and away from hazardous areas and to conquer new habitats. The general perception of flagellum-mediated movement and chemotaxis is dominated by the Escherichia coli paradigm, with its peritrichous flagellation and its famous run-and-tumble navigation pattern, which has shaped the view on how bacteria swim and navigate in chemical gradients. However, a significant amount-more likely the majority-of bacterial species exhibit a (bi)polar flagellar localization pattern instead of lateral flagella. Accordingly, these species have evolved very different mechanisms for navigation and chemotaxis. Here, we review the earlier and recent findings on the various modes of motility mediated by polar flagella. Expected final online publication date for the Annual Review of Microbiology, Volume 76 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Kai M Thormann
- Institute of Microbiology and Molecular Biology, Justus Liebig University Gießen, Gießen, Germany;
| | - Carsten Beta
- Institute of Physics and Astronomy, University of Potsdam, Potsdam, Germany;
| | - Marco J Kühn
- Institute of Bioengineering and Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland;
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