1
|
Gilkes JM, Frampton RA, Board AJ, Hudson AO, Price TG, Morris VK, Crittenden DL, Muscroft‐Taylor AC, Sheen CR, Smith GR, Dobson RCJ. A new lysine biosynthetic enzyme from a bacterial endosymbiont shaped by genetic drift and genome reduction. Protein Sci 2024; 33:e5083. [PMID: 38924211 PMCID: PMC11201819 DOI: 10.1002/pro.5083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 05/16/2024] [Accepted: 06/03/2024] [Indexed: 06/28/2024]
Abstract
The effect of population bottlenecks and genome reduction on enzyme function is poorly understood. Candidatus Liberibacter solanacearum is a bacterium with a reduced genome that is transmitted vertically to the egg of an infected psyllid-a population bottleneck that imposes genetic drift and is predicted to affect protein structure and function. Here, we define the function of Ca. L. solanacearum dihydrodipicolinate synthase (CLsoDHDPS), which catalyzes the committed branchpoint reaction in diaminopimelate and lysine biosynthesis. We demonstrate that CLsoDHDPS is expressed in Ca. L. solanacearum and expression is increased ~2-fold in the insect host compared to in planta. CLsoDHDPS has decreased thermal stability and increased aggregation propensity, implying mutations have destabilized the enzyme but are compensated for through elevated chaperone expression and a stabilized oligomeric state. CLsoDHDPS uses a ternary-complex kinetic mechanism, which is to date unique among DHDPS enzymes, has unusually low catalytic ability, but an unusually high substrate affinity. Structural studies demonstrate that the active site is more open, and the structure of CLsoDHDPS with both pyruvate and the substrate analogue succinic-semialdehyde reveals that the product is both structurally and energetically different and therefore evolution has in this case fashioned a new enzyme. Our study suggests the effects of genome reduction and genetic drift on the function of essential enzymes and provides insights on bacteria-host co-evolutionary associations. We propose that bacteria with endosymbiotic lifestyles present a rich vein of interesting enzymes useful for understanding enzyme function and/or informing protein engineering efforts.
Collapse
Affiliation(s)
- Jenna M. Gilkes
- Biomolecular Interaction CentreSchool of Biological Sciences, University of CanterburyChristchurchNew Zealand
- The New Zealand Institute for Plant and Food Research LimitedLincolnNew Zealand
- Callaghan Innovation, University of CanterburyChristchurchNew Zealand
| | - Rebekah A. Frampton
- The New Zealand Institute for Plant and Food Research LimitedLincolnNew Zealand
| | - Amanda J. Board
- Biomolecular Interaction CentreSchool of Biological Sciences, University of CanterburyChristchurchNew Zealand
| | - André O. Hudson
- Rochester Institute of Technology, Thomas H. Gosnell School of Life SciencesRochesterNew YorkUSA
| | - Thomas G. Price
- Biomolecular Interaction CentreSchool of Chemical and Physical Sciences, University of CanterburyChristchurchNew Zealand
| | - Vanessa K. Morris
- Biomolecular Interaction CentreSchool of Biological Sciences, University of CanterburyChristchurchNew Zealand
| | - Deborah L. Crittenden
- Biomolecular Interaction CentreSchool of Chemical and Physical Sciences, University of CanterburyChristchurchNew Zealand
| | | | - Campbell R. Sheen
- Callaghan Innovation, University of CanterburyChristchurchNew Zealand
| | - Grant R. Smith
- The New Zealand Institute for Plant and Food Research LimitedLincolnNew Zealand
| | - Renwick C. J. Dobson
- Biomolecular Interaction CentreSchool of Biological Sciences, University of CanterburyChristchurchNew Zealand
- Bio21 Molecular Science and Biotechnology Institute, Department of Biochemistry and Molecular BiologyUniversity of MelbourneParkvilleVictoriaAustralia
| |
Collapse
|
2
|
Mies US, Hervé V, Kropp T, Platt K, Sillam-Dussès D, Šobotník J, Brune A. Genome reduction and horizontal gene transfer in the evolution of Endomicrobia-rise and fall of an intracellular symbiosis with termite gut flagellates. mBio 2024; 15:e0082624. [PMID: 38742878 DOI: 10.1128/mbio.00826-24] [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] [Received: 03/19/2024] [Accepted: 04/09/2024] [Indexed: 05/16/2024] Open
Abstract
Bacterial endosymbionts of eukaryotic hosts typically experience massive genome reduction, but the underlying evolutionary processes are often obscured by the lack of free-living relatives. Endomicrobia, a family-level lineage of host-associated bacteria in the phylum Elusimicrobiota that comprises both free-living representatives and endosymbionts of termite gut flagellates, are an excellent model to study evolution of intracellular symbionts. We reconstructed 67 metagenome-assembled genomes (MAGs) of Endomicrobiaceae among more than 1,700 MAGs from the gut microbiota of a wide range of termites. Phylogenomic analysis confirmed a sister position of representatives from termites and ruminants, and allowed to propose eight new genera in the radiation of Endomicrobiaceae. Comparative genome analysis documented progressive genome erosion in the new genus Endomicrobiellum, which comprises all flagellate endosymbionts characterized to date. Massive gene losses were accompanied by the acquisition of new functions by horizontal gene transfer, which led to a shift from a glucose-based energy metabolism to one based on sugar phosphates. The breakdown of glycolysis and many anabolic pathways for amino acids and cofactors in several subgroups was compensated by the independent acquisition of new uptake systems, including an ATP/ADP antiporter, from other gut microbiota. The putative donors are mostly flagellate endosymbionts from other bacterial phyla, including several, hitherto unknown lineages of uncultured Alphaproteobacteria, documenting the importance of horizontal gene transfer in the convergent evolution of these intracellular symbioses. The loss of almost all biosynthetic capacities in some lineages of Endomicrobiellum suggests that their originally mutualistic relationship with flagellates is on its decline.IMPORTANCEUnicellular eukaryotes are frequently colonized by bacterial and archaeal symbionts. A prominent example are the cellulolytic gut flagellates of termites, which harbor diverse but host-specific bacterial symbionts that occur exclusively in termite guts. One of these lineages, the so-called Endomicrobia, comprises both free-living and endosymbiotic representatives, which offers the unique opportunity to study the evolutionary processes underpinning the transition from a free-living to an intracellular lifestyle. Our results revealed a progressive gene loss in energy metabolism and biosynthetic pathways, compensated by the acquisition of new functions via horizontal gene transfer from other gut bacteria, and suggest the eventual breakdown of an initially mutualistic symbiosis. Evidence for convergent evolution of unrelated endosymbionts reflects adaptations to the intracellular environment of termite gut flagellates.
Collapse
Affiliation(s)
- Undine S Mies
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Vincent Hervé
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Tom Kropp
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Katja Platt
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - David Sillam-Dussès
- Laboratory of Experimental and Comparative Ethology LEEC, UR 4443, University Sorbonne Paris Nord, Villetaneuse, France
| | - Jan Šobotník
- Faculty of Tropical AgriSciences, Czech University of Life Sciences, Prague, Czechia
- Biology Centre, Czech Academy of Sciences, Institute of Entomology, České Budějovice, Czechia
| | - Andreas Brune
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| |
Collapse
|
3
|
Bennett GM, Kwak Y, Maynard R. Endosymbioses Have Shaped the Evolution of Biological Diversity and Complexity Time and Time Again. Genome Biol Evol 2024; 16:evae112. [PMID: 38813885 PMCID: PMC11154151 DOI: 10.1093/gbe/evae112] [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: 04/23/2024] [Revised: 05/17/2024] [Accepted: 05/17/2024] [Indexed: 05/31/2024] Open
Abstract
Life on Earth comprises prokaryotes and a broad assemblage of endosymbioses. The pages of Molecular Biology and Evolution and Genome Biology and Evolution have provided an essential window into how these endosymbiotic interactions have evolved and shaped biological diversity. Here, we provide a current perspective on this knowledge by drawing on decades of revelatory research published in Molecular Biology and Evolution and Genome Biology and Evolution, and insights from the field at large. The accumulated work illustrates how endosymbioses provide hosts with novel phenotypes that allow them to transition between adaptive landscapes to access environmental resources. Such endosymbiotic relationships have shaped and reshaped life on Earth. The early serial establishment of mitochondria and chloroplasts through endosymbioses permitted massive upscaling of cellular energetics, multicellularity, and terrestrial planetary greening. These endosymbioses are also the foundation upon which all later ones are built, including everything from land-plant endosymbioses with fungi and bacteria to nutritional endosymbioses found in invertebrate animals. Common evolutionary mechanisms have shaped this broad range of interactions. Endosymbionts generally experience adaptive and stochastic genome streamlining, the extent of which depends on several key factors (e.g. mode of transmission). Hosts, in contrast, adapt complex mechanisms of resource exchange, cellular integration and regulation, and genetic support mechanisms to prop up degraded symbionts. However, there are significant differences between endosymbiotic interactions not only in how partners have evolved with each other but also in the scope of their influence on biological diversity. These differences are important considerations for predicting how endosymbioses will persist and adapt to a changing planet.
Collapse
Affiliation(s)
- Gordon M Bennett
- Department of Life and Environmental Sciences, University of California, Merced, CA, USA
- National Science Foundation Biological Integration Institute—INSITE, University of California, Merced, CA, USA
| | - Younghwan Kwak
- Department of Life and Environmental Sciences, University of California, Merced, CA, USA
- National Science Foundation Biological Integration Institute—INSITE, University of California, Merced, CA, USA
| | - Reo Maynard
- Department of Life and Environmental Sciences, University of California, Merced, CA, USA
| |
Collapse
|
4
|
Khalaf A, Francis O, Blaxter ML. Genome evolution in intracellular parasites: Microsporidia and Apicomplexa. J Eukaryot Microbiol 2024:e13033. [PMID: 38785208 DOI: 10.1111/jeu.13033] [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: 02/14/2024] [Revised: 03/29/2024] [Accepted: 05/02/2024] [Indexed: 05/25/2024]
Abstract
Microsporidia and Apicomplexa are eukaryotic, single-celled, intracellular parasites with huge public health and economic importance. Typically, these parasites are studied separately, emphasizing their uniqueness and diversity. In this review, we explore the huge amount of genomic data that has recently become available for the two groups. We compare and contrast their genome evolution and discuss how their transitions to intracellular life may have shaped it. In particular, we explore genome reduction and compaction, genome expansion and ploidy, gene shuffling and rearrangements, and the evolution of centromeres and telomeres.
Collapse
Affiliation(s)
- Amjad Khalaf
- Tree of Life, Wellcome Sanger Institute, Cambridge, UK
| | - Ore Francis
- Tree of Life, Wellcome Sanger Institute, Cambridge, UK
| | | |
Collapse
|
5
|
Zhang B, Xiao L, Lyu L, Zhao F, Miao M. Exploring the landscape of symbiotic diversity and distribution in unicellular ciliated protists. MICROBIOME 2024; 12:96. [PMID: 38790063 PMCID: PMC11127453 DOI: 10.1186/s40168-024-01809-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 04/04/2024] [Indexed: 05/26/2024]
Abstract
BACKGROUND The eukaryotic-bacterial symbiotic system plays an important role in various physiological, developmental, and evolutionary processes. However, our current understanding is largely limited to multicellular eukaryotes without adequate consideration of diverse unicellular protists, including ciliates. RESULTS To investigate the bacterial profiles associated with unicellular organisms, we collected 246 ciliate samples spanning the entire Ciliophora phylum and conducted single-cell based metagenome sequencing. This effort has yielded the most extensive collection of bacteria linked to unicellular protists to date. From this dataset, we identified 883 bacterial species capable of cohabiting with ciliates, unveiling the genomes of 116 novel bacterial cohabitants along with 7 novel archaeal cohabitants. Highlighting the intimate relationship between ciliates and their cohabitants, our study unveiled that over 90% of ciliates coexist with bacteria, with individual hosts fostering symbiotic relationships with multiple bacteria concurrently, resulting in the observation of seven distinct symbiotic patterns among bacteria. Our exploration of symbiotic mechanisms revealed the impact of host digestion on the intracellular diversity of cohabitants. Additionally, we identified the presence of eukaryotic-like proteins in bacteria as a potential contributing factor to their resistance against host digestion, thereby expanding their potential host range. CONCLUSIONS As the first large-scale analysis of prokaryotic associations with ciliate protists, this study provides a valuable resource for future research on eukaryotic-bacterial symbioses. Video Abstract.
Collapse
Affiliation(s)
- Bing Zhang
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Institute of Zoology, Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, 100101, China
- Key Laboratory of Systems Biology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, China
| | - Liwen Xiao
- Institute of Zoology, Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, 100101, China
| | - Liping Lyu
- Key Laboratory of Evolution & Marine Biodiversity (Ministry of Education), and Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, 266003, China
| | - Fangqing Zhao
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Institute of Zoology, Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, 100101, China.
- Key Laboratory of Systems Biology, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, China.
| | - Miao Miao
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Institute of Zoology, Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, 100101, China.
| |
Collapse
|
6
|
McCutcheon JP, Garber AI, Spencer N, Warren JM. How do bacterial endosymbionts work with so few genes? PLoS Biol 2024; 22:e3002577. [PMID: 38626194 PMCID: PMC11020763 DOI: 10.1371/journal.pbio.3002577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/18/2024] Open
Abstract
The move from a free-living environment to a long-term residence inside a host eukaryotic cell has profound effects on bacterial function. While endosymbioses are found in many eukaryotes, from protists to plants to animals, the bacteria that form these host-beneficial relationships are even more diverse. Endosymbiont genomes can become radically smaller than their free-living relatives, and their few remaining genes show extreme compositional biases. The details of how these reduced and divergent gene sets work, and how they interact with their host cell, remain mysterious. This Unsolved Mystery reviews how genome reduction alters endosymbiont biology and highlights a "tipping point" where the loss of the ability to build a cell envelope coincides with a marked erosion of translation-related genes.
Collapse
Affiliation(s)
- John P. McCutcheon
- Biodesign Institute and School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | - Arkadiy I. Garber
- Biodesign Institute and School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | - Noah Spencer
- Biodesign Institute and School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | - Jessica M. Warren
- Biodesign Institute and School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| |
Collapse
|
7
|
Bhattacharya D, Stephens TG, Chille EE, Benites LF, Chan CX. Facultative lifestyle drives diversity of coral algal symbionts. Trends Ecol Evol 2024; 39:239-247. [PMID: 37953106 DOI: 10.1016/j.tree.2023.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 10/11/2023] [Accepted: 10/12/2023] [Indexed: 11/14/2023]
Abstract
The photosynthetic symbionts of corals sustain biodiverse reefs in nutrient-poor, tropical waters. Recent genomic data illuminate the evolution of coral symbionts under genome size constraints and suggest that retention of the facultative lifestyle, widespread among these algae, confers a selective advantage when compared with a strict symbiotic existence. We posit that the coral symbiosis is analogous to a 'bioreactor' that selects winner genotypes and allows them to rise to high numbers in a sheltered habitat prior to release by the coral host. Our observations lead to a novel hypothesis, the 'stepping-stone model', which predicts that local adaptation under both the symbiotic and free-living stages, in a stepwise fashion, accelerates coral alga diversity and the origin of endemic strains and species.
Collapse
Affiliation(s)
- Debashish Bhattacharya
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ 08901, USA.
| | - Timothy G Stephens
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ 08901, USA
| | - Erin E Chille
- Ecology and Evolution Graduate Program, Rutgers University, New Brunswick, NJ 08901, USA
| | - L Felipe Benites
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ 08901, USA
| | - Cheong Xin Chan
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, 4072, QLD, Australia.
| |
Collapse
|
8
|
Zhang H, Hellweger FL, Luo H. Genome reduction occurred in early Prochlorococcus with an unusually low effective population size. THE ISME JOURNAL 2024; 18:wrad035. [PMID: 38365237 PMCID: PMC10837832 DOI: 10.1093/ismejo/wrad035] [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: 11/22/2023] [Revised: 12/14/2023] [Accepted: 12/20/2023] [Indexed: 02/18/2024]
Abstract
In the oligotrophic sunlit ocean, the most abundant free-living planktonic bacterial lineages evolve convergently through genome reduction. The cyanobacterium Prochlorococcus responsible for 10% global oxygen production is a prominent example. The dominant theory known as "genome streamlining" posits that they have extremely large effective population sizes (Ne) such that selection for metabolic efficiency acts to drive genome reduction. Because genome reduction largely took place anciently, this theory builds on the assumption that their ancestors' Ne was similarly large. Constraining Ne for ancient ancestors is challenging because experimental measurements of extinct organisms are impossible and alternatively reconstructing ancestral Ne with phylogenetic models gives large uncertainties. Here, we develop a new strategy that leverages agent-based modeling to simulate the changes in the genome-wide ratio of radical to conservative nonsynonymous nucleotide substitution rate (dR/dC) in a possible range of Ne in ancestral populations. This proxy shows expected increases with decreases of Ne only when Ne falls to about 10 k - 100 k or lower, magnitudes characteristic of Ne of obligate endosymbiont species where drift drives genome reduction. Our simulations therefore strongly support a scenario where the primary force of Prochlorococcus genome reduction is drift rather than selection.
Collapse
Affiliation(s)
- Hao Zhang
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, 999077, Hong Kong SAR
- Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, 518000, China
| | - Ferdi L Hellweger
- Water Quality Engineering, Technical University of Berlin, Berlin, 10623, Germany
| | - Haiwei Luo
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, 999077, Hong Kong SAR
- Institute of Environment, Energy and Sustainability, The Chinese University of Hong Kong, Shatin, 999077, Hong Kong SAR
| |
Collapse
|
9
|
Espada‐Hinojosa S, Karthäuser C, Srivastava A, Schuster L, Winter T, de Oliveira AL, Schulz F, Horn M, Sievert S, Bright M. Comparative genomics of a vertically transmitted thiotrophic bacterial ectosymbiont and its close free-living relative. Mol Ecol Resour 2024; 24:e13889. [PMID: 38010882 PMCID: PMC10952691 DOI: 10.1111/1755-0998.13889] [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: 01/09/2023] [Revised: 08/31/2023] [Accepted: 10/20/2023] [Indexed: 11/29/2023]
Abstract
Thiotrophic symbioses between sulphur-oxidizing bacteria and various unicellular and metazoan eukaryotes are widespread in reducing marine environments. The giant colonial ciliate Zoothamnium niveum, however, is the only host of thioautotrophic symbionts that has been cultivated along with its symbiont, the vertically transmitted ectosymbiont Candidatus Thiobius zoothamnicola (short Thiobius). Because theoretical predictions posit a smaller genome in vertically transmitted endosymbionts compared to free-living relatives, we investigated whether this is true also for an ectosymbiont. We used metagenomics to recover the high-quality draft genome of this bacterial symbiont. For comparison we have also sequenced a closely related free-living cultured but not formally described strain Milos ODIII6 (short ODIII6). We then performed comparative genomics to assess the functional capabilities at gene, metabolic pathway and trait level. 16S rRNA gene trees and average amino acid identity confirmed the close phylogenetic relationship of both bacteria. Indeed, Thiobius has about a third smaller genome than its free-living relative ODIII6, with reduced metabolic capabilities and fewer functional traits. The functional capabilities of Thiobius were a subset of those of the more versatile ODIII6, which possessed additional genes for oxygen, sulphur and hydrogen utilization and for the acquisition of phosphorus illustrating features that may be adaptive for the unstable environmental conditions at hydrothermal vents. In contrast, Thiobius possesses genes potentially enabling it to utilize lactate and acetate heterotrophically, compounds that may be provided as byproducts by the host. The present study illustrates the effect of strict host-dependence of a bacterial ectosymbiont on genome evolution and host adaptation.
Collapse
Affiliation(s)
| | - Clarissa Karthäuser
- Biology DepartmentWoods Hole Oceanographic InstitutionWoods HoleMassachusettsUSA
| | - Abhishek Srivastava
- Department of Functional and Evolutionary EcologyUniversity of ViennaViennaAustria
| | - Lukas Schuster
- Department of Functional and Evolutionary EcologyUniversity of ViennaViennaAustria
- Present address:
Deakin UniversityBurwoodAustralia
| | - Teresa Winter
- Department of Functional and Evolutionary EcologyUniversity of ViennaViennaAustria
| | - André Luiz de Oliveira
- Department of Functional and Evolutionary EcologyUniversity of ViennaViennaAustria
- Present address:
Max Planck Institute for Marine MicrobiologyBremenGermany
| | - Frederik Schulz
- Center for Microbiology and Environmental Systems ScienceUniversity of ViennaViennaAustria
- Present address:
DOE Joint Genome InstituteBerkeleyCaliforniaUSA
| | - Matthias Horn
- Center for Microbiology and Environmental Systems ScienceUniversity of ViennaViennaAustria
| | - Stefan Sievert
- Biology DepartmentWoods Hole Oceanographic InstitutionWoods HoleMassachusettsUSA
| | - Monika Bright
- Department of Functional and Evolutionary EcologyUniversity of ViennaViennaAustria
| |
Collapse
|
10
|
Amses K, Desiró A, Bryson A, Grigoriev I, Mondo S, Lipzen A, LaButti K, Riley R, Singan V, Salazar-Hamm P, King J, Ballou E, Pawlowska T, Adeleke R, Bonito G, Uehling J. Convergent reductive evolution and host adaptation in Mycoavidus bacterial endosymbionts of Mortierellaceae fungi. Fungal Genet Biol 2023; 169:103838. [PMID: 37716699 DOI: 10.1016/j.fgb.2023.103838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 09/06/2023] [Accepted: 09/11/2023] [Indexed: 09/18/2023]
Abstract
Intimate associations between fungi and intracellular bacterial endosymbionts are becoming increasingly well understood. Phylogenetic analyses demonstrate that bacterial endosymbionts of Mucoromycota fungi are related either to free-living Burkholderia or Mollicutes species. The so-called Burkholderia-related endosymbionts or BRE comprise Mycoavidus, Mycetohabitans and Candidatus Glomeribacter gigasporarum. These endosymbionts are marked by genome contraction thought to be associated with intracellular selection. However, the conclusions drawn thus far are based on a very small subset of endosymbiont genomes, and the mechanisms leading to genome streamlining are not well understood. The purpose of this study was to better understand how intracellular existence shapes Mycoavidus and BRE functionally at the genome level. To this end we generated and analyzed 14 novel draft genomes for Mycoavidus living within the hyphae of Mortierellomycotina fungi. We found that our novel Mycoavidus genomes were significantly reduced compared to free-living Burkholderiales relatives. Using a genome-scale phylogenetic approach including the novel and available existing genomes of Mycoavidus, we show that the genus is an assemblage composed of two independently derived lineages including three well supported clades of Mycoavidus. Using a comparative genomic approach, we shed light on the functional implications of genome reduction, documenting shared and unique gene loss patterns between the three Mycoavidus clades. We found that many endosymbiont isolates demonstrate patterns of vertical transmission and host-specificity, but others are present in phylogenetically disparate hosts. We discuss how reductive evolution and host specificity reflect convergent adaptation to the intrahyphal selective landscape, and commonalities of eukaryotic endosymbiont genome evolution.
Collapse
Affiliation(s)
- Kevin Amses
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97333, USA
| | - Alessandro Desiró
- Department of Plant Soil and Microbial Sciences, Michigan State University, East Lansing MI 48824, USA
| | - Abigail Bryson
- Department of Plant Soil and Microbial Sciences, Michigan State University, East Lansing MI 48824, USA
| | - Igor Grigoriev
- United States Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Stephen Mondo
- United States Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Department of Agricultural Biology, Colorado State University, Fort Collins, CO, USA
| | - Anna Lipzen
- United States Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Kurt LaButti
- United States Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Robert Riley
- United States Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Vasanth Singan
- United States Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Paris Salazar-Hamm
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97333, USA
| | - Jason King
- Department of Agricultural Biology, Colorado State University, Fort Collins, CO, USA
| | - Elizabeth Ballou
- School of Biosciences, University of Sheffield, Western Bank S10 2TN, UK
| | - Teresa Pawlowska
- MRC Centre for Medical Mycology, University of Exeter, Exeter EX4 4QD, UK
| | - Rasheed Adeleke
- School of Integrative Plant Science, Cornell University, Ithaca, NY 14853-5904, USA; Unit for Environmental Sciences and Management, North-West University, Potchefstroom, Private bag X6001, 2520, South Africa
| | - Gregory Bonito
- Department of Plant Soil and Microbial Sciences, Michigan State University, East Lansing MI 48824, USA
| | - Jessie Uehling
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97333, USA.
| |
Collapse
|
11
|
Chen X, Fang D, Xu Y, Duan K, Yoshida S, Yang S, Sahu SK, Fu H, Guang X, Liu M, Wu C, Liu Y, Mu W, Chen Y, Fan Y, Wang F, Peng S, Shi D, Wang Y, Yu R, Zhang W, Bai Y, Liu ZJ, Yan Q, Liu X, Xu X, Yang H, Wu J, Graham SW, Liu H. Balanophora genomes display massively convergent evolution with other extreme holoparasites and provide novel insights into parasite-host interactions. NATURE PLANTS 2023; 9:1627-1642. [PMID: 37735254 DOI: 10.1038/s41477-023-01517-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Accepted: 08/18/2023] [Indexed: 09/23/2023]
Abstract
Parasitic plants have evolved to be subtly or severely dependent on host plants to complete their life cycle. To provide new insights into the biology of parasitic plants in general, we assembled genomes for members of the sandalwood order Santalales, including a stem hemiparasite (Scurrula) and two highly modified root holoparasites (Balanophora) that possess chimaeric host-parasite tubers. Comprehensive genome comparisons reveal that hemiparasitic Scurrula has experienced a relatively minor degree of gene loss compared with autotrophic plants, consistent with its moderate degree of parasitism. Nonetheless, patterns of gene loss appear to be substantially divergent across distantly related lineages of hemiparasites. In contrast, Balanophora has experienced substantial gene loss for the same sets of genes as an independently evolved holoparasite lineage, the endoparasitic Sapria (Malpighiales), and the two holoparasite lineages experienced convergent contraction of large gene families through loss of paralogues. This unprecedented convergence supports the idea that despite their extreme and strikingly divergent life histories and morphology, the evolution of these and other holoparasitic lineages can be shaped by highly predictable modes of genome reduction. We observe substantial evidence of relaxed selection in retained genes for both hemi- and holoparasitic species. Transcriptome data also document unusual and novel interactions between Balanophora and host plants at the host-parasite tuber interface tissues, with evidence of mRNA exchange, substantial and active hormone exchange and immune responses in parasite and host.
Collapse
Affiliation(s)
- Xiaoli Chen
- State Key Laboratory of Agricultural Genomics, BGI Research, Shenzhen, China
| | - Dongming Fang
- State Key Laboratory of Agricultural Genomics, BGI Research, Shenzhen, China
| | - Yuxing Xu
- Department of Economic Plants and Biotechnology, Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Kunyu Duan
- BGI College and Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
| | - Satoko Yoshida
- Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
| | - Shuai Yang
- State Key Laboratory of Agricultural Genomics, BGI Research, Shenzhen, China
| | - Sunil Kumar Sahu
- State Key Laboratory of Agricultural Genomics, BGI Research, Shenzhen, China
| | - Hui Fu
- BGI College and Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
| | - Xuanmin Guang
- State Key Laboratory of Agricultural Genomics, BGI Research, Shenzhen, China
| | - Min Liu
- State Key Laboratory of Agricultural Genomics, BGI Research, Shenzhen, China
| | - Chenyu Wu
- State Key Laboratory of Agricultural Genomics, BGI Research, Shenzhen, China
| | - Yang Liu
- State Key Laboratory of Agricultural Genomics, BGI Research, Shenzhen, China
- Key Laboratory of Southern Subtropical Plant Diversity, Fairy Lake Botanical Garden, Shenzhen and Chinese Academy of Sciences, Shenzhen, China
| | - Weixue Mu
- State Key Laboratory of Agricultural Genomics, BGI Research, Shenzhen, China
| | - Yewen Chen
- State Key Laboratory of Agricultural Genomics, BGI Research, Shenzhen, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yannan Fan
- State Key Laboratory of Agricultural Genomics, BGI Research, Shenzhen, China
| | - Fang Wang
- State Key Laboratory of Agricultural Genomics, BGI Research, Shenzhen, China
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Shufeng Peng
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
- China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Dishen Shi
- BGI College and Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
| | - Yayu Wang
- State Key Laboratory of Agricultural Genomics, BGI Research, Shenzhen, China
| | - Runxian Yu
- State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Wen Zhang
- China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Yuqing Bai
- Administrative Office of Wutong Mountain National Park, Shenzhen, China
| | - Zhong-Jian Liu
- Key Laboratory of National Forestry and Grassland Administration for Orchid Conservation and Utilization at College of Landscape Architecture and Art, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Qiaoshun Yan
- Ailaoshan Station for Subtropical Forest Ecosystem Studies, Chinese Academy of Sciences, Jingdong, China
| | - Xin Liu
- State Key Laboratory of Agricultural Genomics, BGI Research, Shenzhen, China
| | - Xun Xu
- State Key Laboratory of Agricultural Genomics, BGI Research, Shenzhen, China
- Guangdong Provincial Key Laboratory of Genome Read and Write, Shenzhen, China
| | - Huanming Yang
- State Key Laboratory of Agricultural Genomics, BGI Research, Shenzhen, China
- Key Laboratory of Southern Subtropical Plant Diversity, Fairy Lake Botanical Garden, Shenzhen and Chinese Academy of Sciences, Shenzhen, China
- James D. Watson Institute of Genome Sciences, Hangzhou, China
| | - Jianqiang Wu
- Department of Economic Plants and Biotechnology, Yunnan Key Laboratory for Wild Plant Resources, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, China
| | - Sean W Graham
- Department of Botany, University of British Columbia, Vancouver, BC, Canada.
- Biodiversity Research Centre, University of British Columbia, Vancouver, BC, Canada.
| | - Huan Liu
- State Key Laboratory of Agricultural Genomics, BGI Research, Shenzhen, China.
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China.
| |
Collapse
|
12
|
Žárský V, Karnkowska A, Boscaro V, Trznadel M, Whelan TA, Hiltunen-Thorén M, Onut-Brännström I, Abbott CL, Fast NM, Burki F, Keeling PJ. Contrasting outcomes of genome reduction in mikrocytids and microsporidians. BMC Biol 2023; 21:137. [PMID: 37280585 DOI: 10.1186/s12915-023-01635-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 05/26/2023] [Indexed: 06/08/2023] Open
Abstract
BACKGROUND Intracellular symbionts often undergo genome reduction, losing both coding and non-coding DNA in a process that ultimately produces small, gene-dense genomes with few genes. Among eukaryotes, an extreme example is found in microsporidians, which are anaerobic, obligate intracellular parasites related to fungi that have the smallest nuclear genomes known (except for the relic nucleomorphs of some secondary plastids). Mikrocytids are superficially similar to microsporidians: they are also small, reduced, obligate parasites; however, as they belong to a very different branch of the tree of eukaryotes, the rhizarians, such similarities must have evolved in parallel. Since little genomic data are available from mikrocytids, we assembled a draft genome of the type species, Mikrocytos mackini, and compared the genomic architecture and content of microsporidians and mikrocytids to identify common characteristics of reduction and possible convergent evolution. RESULTS At the coarsest level, the genome of M. mackini does not exhibit signs of extreme genome reduction; at 49.7 Mbp with 14,372 genes, the assembly is much larger and gene-rich than those of microsporidians. However, much of the genomic sequence and most (8075) of the protein-coding genes code for transposons, and may not contribute much of functional relevance to the parasite. Indeed, the energy and carbon metabolism of M. mackini share several similarities with those of microsporidians. Overall, the predicted proteome involved in cellular functions is quite reduced and gene sequences are extremely divergent. Microsporidians and mikrocytids also share highly reduced spliceosomes that have retained a strikingly similar subset of proteins despite having reduced independently. In contrast, the spliceosomal introns in mikrocytids are very different from those of microsporidians in that they are numerous, conserved in sequence, and constrained to an exceptionally narrow size range (all 16 or 17 nucleotides long) at the shortest extreme of known intron lengths. CONCLUSIONS Nuclear genome reduction has taken place many times and has proceeded along different routes in different lineages. Mikrocytids show a mix of similarities and differences with other extreme cases, including uncoupling the actual size of a genome with its functional reduction.
Collapse
Affiliation(s)
- Vojtečh Žárský
- Department of Botany, University of British Columbia, V6T 1Z4, Vancouver, 3529-6270 University Boulevard, BC, Canada
| | - Anna Karnkowska
- Department of Botany, University of British Columbia, V6T 1Z4, Vancouver, 3529-6270 University Boulevard, BC, Canada
- Institute of Evolutionary Biology, Faculty of Biology, University of Warsaw, 02-089, Warsaw, Poland
| | - Vittorio Boscaro
- Department of Botany, University of British Columbia, V6T 1Z4, Vancouver, 3529-6270 University Boulevard, BC, Canada.
| | - Morelia Trznadel
- Department of Botany, University of British Columbia, V6T 1Z4, Vancouver, 3529-6270 University Boulevard, BC, Canada
| | - Thomas A Whelan
- Department of Botany, University of British Columbia, V6T 1Z4, Vancouver, 3529-6270 University Boulevard, BC, Canada
| | - Markus Hiltunen-Thorén
- Department of Organismal Biology, Uppsala University, Norbyv. 18D, 752 36, Uppsala, Sweden
- Department of Ecology, Environment and Plant Sciences, Stockholm University, SE-106 91, Stockholm, Sweden
| | - Ioana Onut-Brännström
- Department of Organismal Biology, Uppsala University, Norbyv. 18D, 752 36, Uppsala, Sweden
- Department of Ecology and Genetics, Uppsala University, 752 36, Uppsala, Sweden
- Natural History Museum, University of Oslo, 0562, Oslo, Norway
| | - Cathryn L Abbott
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC, V9T 6N7, Canada
| | - Naomi M Fast
- Department of Botany, University of British Columbia, V6T 1Z4, Vancouver, 3529-6270 University Boulevard, BC, Canada
| | - Fabien Burki
- Department of Organismal Biology, Uppsala University, Norbyv. 18D, 752 36, Uppsala, Sweden
| | - Patrick J Keeling
- Department of Botany, University of British Columbia, V6T 1Z4, Vancouver, 3529-6270 University Boulevard, BC, Canada.
| |
Collapse
|
13
|
From Pathogens to Cancer: Are Cancer Cells Evolved Mitochondrial Super Cells? Diagnostics (Basel) 2023; 13:diagnostics13040813. [PMID: 36832301 PMCID: PMC9954806 DOI: 10.3390/diagnostics13040813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/07/2023] [Accepted: 02/19/2023] [Indexed: 02/23/2023] Open
Abstract
Life is based on a highly specific combination of atoms, metabolism, and genetics which eventually reflects the chemistry of the Universe which is composed of hydrogen, oxygen, nitrogen, sulfur, phosphorus, and carbon. The interaction of atomic, metabolic, and genetic cycles results in the organization and de-organization of chemical information of that which we consider as living entities, including cancer cells. In order to approach the problem of the origin of cancer it is therefore reasonable to start from the assumption that the sub-molecular level, the atomic structure, should be the considered starting point on which metabolism, genetics, and external insults eventually emanate. Second, it is crucial to characterize which of the entities and parts composing human cells may live a separate life; certainly, this theoretical standpoint would consider mitochondria, an organelle of "bacteria" origin embedded in conditions favorable for the onset of both. This organelle has not only been tolerated by immunity but has also been placed as a central regulator of cell defense. Virus, bacteria, and mitochondria are also similar in the light of genetic and metabolic elements; they share not only equivalent DNA and RNA features but also many basic biological activities. Thus, it is important to finalize that once the cellular integrity has been constantly broken down, the mitochondria like any other virus or bacteria return to their original autonomy to simply survive. The Warburg's law that states the ability of cancers to ferment glucose in the presence of oxygen, indicates mitochondria respiration abnormalities may be the underlying cause of this transformation towards super cancer cells. Though genetic events play a key part in altering biochemical metabolism, inducing aerobic glycolysis, this is not enough to impair mitochondrial function since mitochondrial biogenesis and quality control are constantly upregulated in cancers. While some cancers have mutations in the nuclear-encoded mitochondrial tricarboxylic acid (TCA) cycle, enzymes that produce oncogenic metabolites, there is also a bio-physic pathway for pathogenic mitochondrial genome mutations. The atomic level of all biological activities can be considered the very beginning, marked by the electron abnormal behavior that consequently affects DNA of both cells and mitochondria. Whilst the cell's nucleus DNA after a certain number of errors and defection tends to gradually switch off, the mitochondria DNA starts adopting several escape strategies, switching-on a few important genes that belong back at their original roots as independent beings. The ability to adopt this survival trick, by becoming completely immune to current life-threatening events, is probably the beginning of a differentiation process towards a "super-power cell", the cancer cells that remind many pathogens, including virus, bacteria, and fungi. Thus, here, we present a hypothesis regarding those changes that first begin at the mitochondria atomic level to steadily involve molecular, tissue and organ levels in response to the virus or bacteria constant insults that drive a mitochondria itself to become an "immortal cancer cell". Improved insights into this interplay between these pathogens and mitochondria progression may disclose newly epistemological paradigms as well as innovative procedures in targeting cancer cell progressive invasion.
Collapse
|
14
|
Pawlak K, Błażej P, Mackiewicz D, Mackiewicz P. The Influence of the Selection at the Amino Acid Level on Synonymous Codon Usage from the Viewpoint of Alternative Genetic Codes. Int J Mol Sci 2023; 24:ijms24021185. [PMID: 36674703 PMCID: PMC9866869 DOI: 10.3390/ijms24021185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 12/19/2022] [Accepted: 12/30/2022] [Indexed: 01/11/2023] Open
Abstract
Synonymous codon usage can be influenced by mutations and/or selection, e.g., for speed of protein translation and correct folding. However, this codon bias can also be affected by a general selection at the amino acid level due to differences in the acceptance of the loss and generation of these codons. To assess the importance of this effect, we constructed a mutation-selection model model, in which we generated almost 90,000 stationary nucleotide distributions produced by mutational processes and applied a selection based on differences in physicochemical properties of amino acids. Under these conditions, we calculated the usage of fourfold degenerated (4FD) codons and compared it with the usage characteristic of the pure mutations. We considered both the standard genetic code (SGC) and alternative genetic codes (AGCs). The analyses showed that a majority of AGCs produced a greater 4FD codon bias than the SGC. The mutations producing more thymine or adenine than guanine and cytosine increased the differences in usage. On the other hand, the mutational pressures generating a lot of cytosine or guanine with a low content of adenine and thymine decreased this bias because the nucleotide content of most 4FD codons stayed in the compositional equilibrium with these pressures. The comparison of the theoretical results with those for real protein coding sequences showed that the influence of selection at the amino acid level on the synonymous codon usage cannot be neglected. The analyses indicate that the effect of amino acid selection cannot be disregarded and that it can interfere with other selection factors influencing codon usage, especially in AT-rich genomes, in which AGCs are usually used.
Collapse
|
15
|
Mahajan S, Agashe D. Evolutionary jumps in bacterial GC content. G3 GENES|GENOMES|GENETICS 2022; 12:6586800. [PMID: 35579351 PMCID: PMC9339322 DOI: 10.1093/g3journal/jkac108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 04/20/2022] [Indexed: 11/29/2022]
Abstract
Genomic GC (Guanine-Cytosine) content is a fundamental molecular trait linked with many key genomic features such as codon and amino acid use. Across bacteria, GC content is surprisingly diverse and has been studied for many decades; yet its evolution remains incompletely understood. Since it is difficult to observe GC content evolve on laboratory time scales, phylogenetic comparative approaches are instrumental; but this dimension is rarely studied systematically in the case of bacterial GC content. We applied phylogenetic comparative models to analyze GC content evolution in multiple bacterial groups across 2 major bacterial phyla. We find that GC content diversifies via a combination of gradual evolution and evolutionary “jumps.” Surprisingly, unlike prior reports that solely focused on reductions in GC, we found a comparable number of jumps with both increased and decreased GC content. Overall, many of the identified jumps occur in lineages beyond the well-studied peculiar examples of endosymbiotic and AT-rich marine bacteria and do not support the predicted role of oxygen dependence. Our analysis of rapid and large shifts in GC content thus identifies new clades and novel contexts to further understand the ecological and evolutionary drivers of this important genomic trait.
Collapse
Affiliation(s)
- Saurabh Mahajan
- National Centre for Biological Sciences, Tata Institute of Fundamental Research , Bengaluru 560065, India
- Atria University , Bengaluru 560024, India
| | - Deepa Agashe
- National Centre for Biological Sciences, Tata Institute of Fundamental Research , Bengaluru 560065, India
| |
Collapse
|
16
|
Vasquez YM, Bennett GM. A complex interplay of evolutionary forces continues to shape ancient co-occurring symbiont genomes. iScience 2022; 25:104786. [PMID: 35982793 PMCID: PMC9379567 DOI: 10.1016/j.isci.2022.104786] [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: 03/27/2022] [Revised: 06/03/2022] [Accepted: 07/13/2022] [Indexed: 01/03/2023] Open
Abstract
Many insects depend on ancient associations with intracellular bacteria for essential nutrition. The genomes of these bacteria are often highly reduced. Although drift is a major driver of symbiont evolution, other evolutionary forces continue to influence them. To understand how ongoing molecular evolution and gene loss shape symbiont genomes, we sequenced two of the most ancient symbionts known, Sulcia and Nasuia, from 20 Hawaiian Nesophrosyne leafhoppers. We leveraged the parallel divergence of Nesophrosyne lineages throughout Hawaii as a natural experimental framework. Sulcia and Nasuia experience ongoing-but divergent-gene loss, often in a convergent fashion. Although some genes are under relaxed selection, purifying and positive selection are also important drivers of genome evolution, particularly in maintaining certain nutritional and cellular functions. Our results further demonstrate that symbionts experience dramatically different evolutionary environments, as evidenced by the finding that Sulcia and Nasuia have one of the slowest and fastest rates of molecular evolution known.
Collapse
Affiliation(s)
- Yumary M. Vasquez
- Department of Life and Environmental Sciences, University of California, Merced, CA, USA,Corresponding author
| | - Gordon M. Bennett
- Department of Life and Environmental Sciences, University of California, Merced, CA, USA,Corresponding author
| |
Collapse
|
17
|
Renoz F, Ambroise J, Bearzatto B, Fakhour S, Parisot N, Ribeiro Lopes M, Gala JL, Calevro F, Hance T. The Di-Symbiotic Systems in the Aphids Sipha maydis and Periphyllus lyropictus Provide a Contrasting Picture of Recent Co-Obligate Nutritional Endosymbiosis in Aphids. Microorganisms 2022; 10:microorganisms10071360. [PMID: 35889078 PMCID: PMC9317480 DOI: 10.3390/microorganisms10071360] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 07/01/2022] [Accepted: 07/04/2022] [Indexed: 11/25/2022] Open
Abstract
Dependence on multiple nutritional bacterial symbionts forming a metabolic unit has repeatedly evolved in many insect species that feed on nutritionally unbalanced diets such as plant sap. This is the case for aphids of the subfamilies Lachninae and Chaitophorinae, which have evolved di-symbiotic systems in which the ancient obligate nutritional symbiont Buchnera aphidicola is metabolically complemented by an additional nutritional symbiont acquired more recently. Deciphering how different symbionts integrate both metabolically and anatomically in such systems is crucial to understanding how complex nutritional symbiotic systems function and evolve. In this study, we sequenced and analyzed the genomes of the symbionts B. aphidicola and Serratia symbiotica associated with the Chaitophorinae aphids Sipha maydis and Periphyllus lyropictus. Our results show that, in these two species, B. aphidicola and S. symbiotica complement each other metabolically (and their hosts) for the biosynthesis of essential amino acids and vitamins, but with distinct metabolic reactions supported by each symbiont depending on the host species. Furthermore, the S. symbiotica symbiont associated with S. maydis appears to be strictly compartmentalized into the specialized host cells housing symbionts in aphids, the bacteriocytes, whereas the S. symbiotica symbiont associated with P. lyropictus exhibits a highly invasive phenotype, presumably because it is capable of expressing a larger set of virulence factors, including a complete flagellum for bacterial motility. Such contrasting levels of metabolic and anatomical integration for two S. symbiotica symbionts that were recently acquired as nutritional co-obligate partners reflect distinct coevolutionary processes specific to each association.
Collapse
Affiliation(s)
- François Renoz
- Biodiversity Research Centre, Earth and Life Institute, Université Catholique de Louvain (UCLouvain), 1348 Louvain-la-Neuve, Belgium;
- Univ Lyon, INSA Lyon, INRAE, BF2I, UMR203, F-69621 Villeurbanne, France; (N.P.); (M.R.L.); (F.C.)
- Correspondence:
| | - Jérôme Ambroise
- Center for Applied Molecular Technologies, Institute of Experimental and Clinical Research, Université Catholique de Louvain (UCLouvain), 1200 Woluwe-Saint-Lambert, Belgium; (J.A.); (B.B.); (J.-L.G.)
| | - Bertrand Bearzatto
- Center for Applied Molecular Technologies, Institute of Experimental and Clinical Research, Université Catholique de Louvain (UCLouvain), 1200 Woluwe-Saint-Lambert, Belgium; (J.A.); (B.B.); (J.-L.G.)
| | - Samir Fakhour
- Department of Plant Protection, National Institute of Agricultural Research, Avenue Ennasr, BP 415 Rabat Principale, Rabat 10090, Morocco;
| | - Nicolas Parisot
- Univ Lyon, INSA Lyon, INRAE, BF2I, UMR203, F-69621 Villeurbanne, France; (N.P.); (M.R.L.); (F.C.)
| | - Mélanie Ribeiro Lopes
- Univ Lyon, INSA Lyon, INRAE, BF2I, UMR203, F-69621 Villeurbanne, France; (N.P.); (M.R.L.); (F.C.)
| | - Jean-Luc Gala
- Center for Applied Molecular Technologies, Institute of Experimental and Clinical Research, Université Catholique de Louvain (UCLouvain), 1200 Woluwe-Saint-Lambert, Belgium; (J.A.); (B.B.); (J.-L.G.)
| | - Federica Calevro
- Univ Lyon, INSA Lyon, INRAE, BF2I, UMR203, F-69621 Villeurbanne, France; (N.P.); (M.R.L.); (F.C.)
| | - Thierry Hance
- Biodiversity Research Centre, Earth and Life Institute, Université Catholique de Louvain (UCLouvain), 1348 Louvain-la-Neuve, Belgium;
| |
Collapse
|
18
|
Lajoie G, Parfrey LW. Beyond specialization: re-examining routes of host influence on symbiont evolution. Trends Ecol Evol 2022; 37:590-598. [PMID: 35466020 DOI: 10.1016/j.tree.2022.03.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 03/15/2022] [Accepted: 03/20/2022] [Indexed: 11/17/2022]
Abstract
Our understanding of host influence on microbial evolution has focused on symbiont specialization and the genomic streamlining that often accompanies it. However, a vast diversity of symbiotic lineages facultatively interact with hosts or associate with multiple hosts. Yet, there are no clear expectations for how host association influences the niche of these symbionts or their evolution. Here, we discuss how weak or variable selection on microbial symbiotic associations, horizontal transmission, and low costs of adaptation to novel host habitats are predicted to promote the expansion or maintenance of microbial niches. This broad perspective will aid in developing better and more general predictions for evolution in microbial symbioses.
Collapse
Affiliation(s)
- Geneviève Lajoie
- Botany Department, University of British Columbia, 6270 University Boulevard, Vancouver, BC, Canada, V6T 1Z4.
| | - Laura Wegener Parfrey
- Botany Department, University of British Columbia, 6270 University Boulevard, Vancouver, BC, Canada, V6T 1Z4
| |
Collapse
|
19
|
Amandine C, Ebert D, Stukenbrock E, Rodríguez de la Vega RC, Tiffin P, Croll D, Tellier A. Unraveling coevolutionary dynamics using ecological genomics. Trends Genet 2022; 38:1003-1012. [PMID: 35715278 DOI: 10.1016/j.tig.2022.05.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 05/08/2022] [Accepted: 05/10/2022] [Indexed: 11/27/2022]
Abstract
Coevolutionary interactions, from the delicate co-dependency in mutualistic interactions to the antagonistic relationship of hosts and parasites, are a ubiquitous driver of adaptation. Surprisingly, little is known about the genomic processes underlying coevolution in an ecological context. However, species comprise genetically differentiated populations that interact with temporally variable abiotic and biotic environments. We discuss the recent advances in coevolutionary theory and genomics as well as shortcomings, to identify coevolving genes that take into account this spatial and temporal variability of coevolution, and propose a practical guide to understand the dynamic of coevolution using an ecological genomics lens.
Collapse
Affiliation(s)
- Cornille Amandine
- Université Paris Saclay, INRAE, CNRS, AgroParisTech, GQE - Le Moulon, 91190 Gif-sur-Yvette, France.
| | - Dieter Ebert
- Department of Environmental Sciences, Zoology, University of Basel, Vesalgasse 1, 4051 Basel, Switzerland
| | - Eva Stukenbrock
- Max Planck Institute for Terrestrial Microbiology, Max Planck Research Group, Fungal Biodiversity, Marburg, Germany
| | | | - Peter Tiffin
- Department of Plant and Microbial Biology, 250 Biological Sciences, 1445 Gortner Ave., University of Minnesota, Saint Paul, MN 55108, USA
| | - Daniel Croll
- Laboratory of Evolutionary Genetics, Institute of Biology, University of Neuchâtel, 2000 Neuchâtel, Switzerland.
| | - Aurélien Tellier
- Population Genetics, Department of Life Science Systems, Technical University of Munich, Liesel-Beckman-Str. 2, 85354 Freising, Germany.
| |
Collapse
|
20
|
Rafiqi AM, Polo PG, Milat NS, Durmuş ZÖ, Çolak-Al B, Alarcón ME, Çağıl FZ, Rajakumar A. Developmental Integration of Endosymbionts in Insects. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.846586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In endosymbiosis, two independently existing entities are inextricably intertwined such that they behave as a single unit. For multicellular hosts, the endosymbiont must be integrated within the host developmental genetic network to maintain the relationship. Developmental integration requires innovations in cell type, gene function, gene regulation, and metabolism. These innovations are contingent upon the existing ecological interactions and may evolve mutual interdependence. Recent studies have taken significant steps toward characterizing the proximate mechanisms underlying interdependence. However, the study of developmental integration is only in its early stages of investigation. Here, we review the literature on mutualistic endosymbiosis to explore how unicellular endosymbionts developmentally integrate into their multicellular hosts with emphasis on insects as a model. Exploration of this process will help gain a more complete understanding of endosymbiosis. This will pave the way for a better understanding of the endosymbiotic theory of evolution in the future.
Collapse
|
21
|
Chen Z, Wang X, Song Y, Zeng Q, Zhang Y, Luo H. Prochlorococcus have low global mutation rate and small effective population size. Nat Ecol Evol 2022; 6:183-194. [PMID: 34949817 DOI: 10.1038/s41559-021-01591-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 10/14/2021] [Indexed: 12/27/2022]
Abstract
Prochlorococcus are the most abundant free-living photosynthetic carbon-fixing organisms in the ocean. Prochlorococcus show small genome sizes, low genomic G+C content, reduced DNA repair gene pool and fast evolutionary rates, which are typical features of endosymbiotic bacteria. Nevertheless, their evolutionary mechanisms are believed to be different. Evolution of endosymbiotic bacteria is dominated by genetic drift owing to repeated population bottlenecks, whereas Prochlorococcus are postulated to have extremely large effective population sizes (Ne) and thus drift has rarely been considered. However, accurately extrapolating Ne requires measuring an unbiased global mutation rate through mutation accumulation, which is challenging for Prochlorococcus. Here, we managed this experiment over 1,065 days using Prochlorococcus marinus AS9601, sequenced genomes of 141 mutant lines and determined its mutation rate to be 3.50 × 10-10 per site per generation. Extrapolating Ne additionally requires identifying population boundaries, which we defined using PopCOGenT and over 400 genomes related to AS9601. Accordingly, we calculated its Ne to be 1.68 × 107, which is only reasonably greater than that of endosymbiotic bacteria but surprisingly smaller than that of many free-living bacteria extrapolated using the same approach. Our results therefore suggest that genetic drift is a key driver of Prochlorococcus evolution.
Collapse
Affiliation(s)
- Zhuoyu Chen
- State Key Laboratory of Marine Environmental Science and College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Xiaojun Wang
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR.,Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China
| | - Yu Song
- State Key Laboratory of Marine Environmental Science and College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Qinglu Zeng
- Department of Ocean Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong SAR.,Hong Kong Branch of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Clear Water Bay, Hong Kong SAR
| | - Yao Zhang
- State Key Laboratory of Marine Environmental Science and College of Ocean and Earth Sciences, Xiamen University, Xiamen, China.
| | - Haiwei Luo
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR. .,Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, China. .,Hong Kong Branch of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Clear Water Bay, Hong Kong SAR.
| |
Collapse
|
22
|
Uthanumallian K, Iha C, Repetti SI, Chan CX, Bhattacharya D, Duchene S, Verbruggen H. Tightly Constrained Genome Reduction and Relaxation of Purifying Selection during Secondary Plastid Endosymbiosis. Mol Biol Evol 2022; 39:msab295. [PMID: 34613411 PMCID: PMC8763093 DOI: 10.1093/molbev/msab295] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Endosymbiosis, the establishment of a former free-living prokaryotic or eukaryotic cell as an organelle inside a host cell, can dramatically alter the genomic architecture of the endosymbiont. Plastids or chloroplasts, the light-harvesting organelle of photosynthetic eukaryotes, are excellent models to study this phenomenon because plastid origin has occurred multiple times in evolution. Here, we investigate the genomic signature of molecular processes acting through secondary plastid endosymbiosis-the origination of a new plastid from a free-living eukaryotic alga. We used phylogenetic comparative methods to study gene loss and changes in selective regimes on plastid genomes, focusing on green algae that have given rise to three independent lineages with secondary plastids (euglenophytes, chlorarachniophytes, and Lepidodinium). Our results show an overall increase in gene loss associated with secondary endosymbiosis, but this loss is tightly constrained by the retention of genes essential for plastid function. The data show that secondary plastids have experienced temporary relaxation of purifying selection during secondary endosymbiosis. However, this process is tightly constrained, with selection relaxed only relative to the background in primary plastids. Purifying selection remains strong in absolute terms even during the endosymbiosis events. Selection intensity rebounds to pre-endosymbiosis levels following endosymbiosis events, demonstrating the changes in selection efficiency during different origin phases of secondary plastids. Independent endosymbiosis events in the euglenophytes, chlorarachniophytes, and Lepidodinium differ in their degree of relaxation of selection, highlighting the different evolutionary contexts of these events. This study reveals the selection-drift interplay during secondary endosymbiosis and evolutionary parallels during organellogenesis.
Collapse
Affiliation(s)
| | - Cintia Iha
- School of BioSciences, University of Melbourne, Melbourne, VIC, Australia
| | - Sonja I Repetti
- School of BioSciences, University of Melbourne, Melbourne, VIC, Australia
| | - Cheong Xin Chan
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | | | - Sebastian Duchene
- Deptartment of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC, Australia
| | - Heroen Verbruggen
- School of BioSciences, University of Melbourne, Melbourne, VIC, Australia
| |
Collapse
|
23
|
Szabó G, Schulz F, Manzano-Marín A, Toenshoff ER, Horn M. Evolutionarily recent dual obligatory symbiosis among adelgids indicates a transition between fungus- and insect-associated lifestyles. THE ISME JOURNAL 2022; 16:247-256. [PMID: 34294881 PMCID: PMC8692619 DOI: 10.1038/s41396-021-01056-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 06/28/2021] [Accepted: 07/01/2021] [Indexed: 02/07/2023]
Abstract
Adelgids (Insecta: Hemiptera: Adelgidae) form a small group of insects but harbor a surprisingly diverse set of bacteriocyte-associated endosymbionts, which suggest multiple replacement and acquisition of symbionts over evolutionary time. Specific pairs of symbionts have been associated with adelgid lineages specialized on different secondary host conifers. Using a metagenomic approach, we investigated the symbiosis of the Adelges laricis/Adelges tardus species complex containing betaproteobacterial ("Candidatus Vallotia tarda") and gammaproteobacterial ("Candidatus Profftia tarda") symbionts. Genomic characteristics and metabolic pathway reconstructions revealed that Vallotia and Profftia are evolutionary young endosymbionts, which complement each other's role in essential amino acid production. Phylogenomic analyses and a high level of genomic synteny indicate an origin of the betaproteobacterial symbiont from endosymbionts of Rhizopus fungi. This evolutionary transition was accompanied with substantial loss of functions related to transcription regulation, secondary metabolite production, bacterial defense mechanisms, host infection, and manipulation. The transition from fungus to insect endosymbionts extends our current framework about evolutionary trajectories of host-associated microbes.
Collapse
Affiliation(s)
- Gitta Szabó
- Department of Microbiology and Ecosystem Science, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria.
- Department of Internal Medicine and Oncology, Semmelweis University, Budapest, Hungary.
| | - Frederik Schulz
- Department of Microbiology and Ecosystem Science, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
- US Department of Energy (DOE) Joint Genome Institute, Berkeley, CA, USA
| | - Alejandro Manzano-Marín
- Department of Microbiology and Ecosystem Science, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Elena Rebecca Toenshoff
- Department of Microbiology and Ecosystem Science, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
- Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| | - Matthias Horn
- Department of Microbiology and Ecosystem Science, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| |
Collapse
|
24
|
Rosenberg E, Zilber-Rosenberg I. Reconstitution and Transmission of Gut Microbiomes and Their Genes between Generations. Microorganisms 2021; 10:microorganisms10010070. [PMID: 35056519 PMCID: PMC8780831 DOI: 10.3390/microorganisms10010070] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/26/2021] [Accepted: 12/28/2021] [Indexed: 12/13/2022] Open
Abstract
Microbiomes are transmitted between generations by a variety of different vertical and/or horizontal modes, including vegetative reproduction (vertical), via female germ cells (vertical), coprophagy and regurgitation (vertical and horizontal), physical contact starting at birth (vertical and horizontal), breast-feeding (vertical), and via the environment (horizontal). Analyses of vertical transmission can result in false negatives (failure to detect rare microbes) and false positives (strain variants). In humans, offspring receive most of their initial gut microbiota vertically from mothers during birth, via breast-feeding and close contact. Horizontal transmission is common in marine organisms and involves selectivity in determining which environmental microbes can colonize the organism's microbiome. The following arguments are put forth concerning accurate microbial transmission: First, the transmission may be of functions, not necessarily of species; second, horizontal transmission may be as accurate as vertical transmission; third, detection techniques may fail to detect rare microbes; lastly, microbiomes develop and reach maturity with their hosts. In spite of the great variation in means of transmission discussed in this paper, microbiomes and their functions are transferred from one generation of holobionts to the next with fidelity. This provides a strong basis for each holobiont to be considered a unique biological entity and a level of selection in evolution, largely maintaining the uniqueness of the entity and conserving the species from one generation to the next.
Collapse
|
25
|
Osuna-Mascaró C, Doña J, Johnson KP, de Rojas M. Genome-Resolved Metagenomic Analyses Reveal the Presence of a Putative Bacterial Endosymbiont in an Avian Nasal Mite (Rhinonyssidae; Mesostigmata). Microorganisms 2021; 9:microorganisms9081734. [PMID: 34442816 PMCID: PMC8398770 DOI: 10.3390/microorganisms9081734] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 08/09/2021] [Accepted: 08/10/2021] [Indexed: 11/16/2022] Open
Abstract
Rhinonyssidae (Mesostigmata) is a family of nasal mites only found in birds. All species are hematophagous endoparasites, which may damage the nasal cavities of birds, and also could be potential reservoirs or vectors of other infections. However, the role of members of Rhinonyssidae as disease vectors in wild bird populations remains uninvestigated, with studies of the microbiomes of Rhinonyssidae being almost non-existent. In the nasal mite (Tinaminyssus melloi) from rock doves (Columba livia), a previous study found evidence of a highly abundant putatively endosymbiotic bacteria from Class Alphaproteobacteria. Here, we expanded the sample size of this species (two different hosts- ten nasal mites from two independent samples per host), incorporated contamination controls, and increased sequencing depth in shotgun sequencing and genome-resolved metagenomic analyses. Our goal was to increase the information regarding this mite species and its putative endosymbiont. We obtained a metagenome assembled genome (MAG) that was estimated to be 98.1% complete and containing only 0.9% possible contamination. Moreover, the MAG has characteristics typical of endosymbionts (namely, small genome size an AT bias). Overall, our results support the presence of a potential endosymbiont, which is the first described for avian nasal mites to date, and improve the overall understanding of the microbiota inhabiting these mites.
Collapse
Affiliation(s)
- Carolina Osuna-Mascaró
- Department of Biology, University of Nevada, 1664 N Virginia St, Reno, NV 89557, USA
- Correspondence: (C.O.-M.); (M.d.R.)
| | - Jorge Doña
- Illinois Natural History Survey, Prairie Research Institute, University of Illinois at Urbana-Champaign, Champaign, IL 61820, USA; (J.D.); (K.P.J.)
- Departamento de Biología Animal, Universitario de Cartuja, Calle Prof. Vicente Callao, 3, 18011 Granada, Spain
| | - Kevin P. Johnson
- Illinois Natural History Survey, Prairie Research Institute, University of Illinois at Urbana-Champaign, Champaign, IL 61820, USA; (J.D.); (K.P.J.)
| | - Manuel de Rojas
- Department of Microbiology and Parasitology, Faculty of Pharmacy, Universidad de Sevilla, Calle San Fernando, 4, 41004 Sevilla, Spain
- Correspondence: (C.O.-M.); (M.d.R.)
| |
Collapse
|
26
|
Álvarez-Lugo A, Becerra A. The Role of Gene Duplication in the Divergence of Enzyme Function: A Comparative Approach. Front Genet 2021; 12:641817. [PMID: 34335678 PMCID: PMC8318041 DOI: 10.3389/fgene.2021.641817] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 06/21/2021] [Indexed: 11/13/2022] Open
Abstract
Gene duplication is a crucial process involved in the appearance of new genes and functions. It is thought to have played a major role in the growth of enzyme families and the expansion of metabolism at the biosphere's dawn and in recent times. Here, we analyzed paralogous enzyme content within each of the seven enzymatic classes for a representative sample of prokaryotes by a comparative approach. We found a high ratio of paralogs for three enzymatic classes: oxidoreductases, isomerases, and translocases, and within each of them, most of the paralogs belong to only a few subclasses. Our results suggest an intricate scenario for the evolution of prokaryotic enzymes, involving different fates for duplicated enzymes fixed in the genome, where around 20-40% of prokaryotic enzymes have paralogs. Intracellular organisms have a lesser ratio of duplicated enzymes, whereas free-living enzymes show the highest ratios. We also found that phylogenetically close phyla and some unrelated but with the same lifestyle share similar genomic and biochemical traits, which ultimately support the idea that gene duplication is associated with environmental adaptation.
Collapse
Affiliation(s)
- Alejandro Álvarez-Lugo
- Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Mexico City, Mexico.,Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Arturo Becerra
- Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| |
Collapse
|
27
|
Skalický T, Alves JMP, Morais AC, Režnarová J, Butenko A, Lukeš J, Serrano MG, Buck GA, Teixeira MMG, Camargo EP, Sanders M, Cotton JA, Yurchenko V, Kostygov AY. Endosymbiont Capture, a Repeated Process of Endosymbiont Transfer with Replacement in Trypanosomatids Angomonas spp. Pathogens 2021; 10:pathogens10060702. [PMID: 34200026 PMCID: PMC8229890 DOI: 10.3390/pathogens10060702] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 05/31/2021] [Accepted: 06/01/2021] [Indexed: 11/16/2022] Open
Abstract
Trypanosomatids of the subfamily Strigomonadinae bear permanent intracellular bacterial symbionts acquired by the common ancestor of these flagellates. However, the cospeciation pattern inherent to such relationships was revealed to be broken upon the description of Angomonas ambiguus, which is sister to A. desouzai, but bears an endosymbiont genetically close to that of A. deanei. Based on phylogenetic inferences, it was proposed that the bacterium from A. deanei had been horizontally transferred to A. ambiguus. Here, we sequenced the bacterial genomes from two A. ambiguus isolates, including a new one from Papua New Guinea, and compared them with the published genome of the A. deanei endosymbiont, revealing differences below the interspecific level. Our phylogenetic analyses confirmed that the endosymbionts of A. ambiguus were obtained from A. deanei and, in addition, demonstrated that this occurred more than once. We propose that coinfection of the same blowfly host and the phylogenetic relatedness of the trypanosomatids facilitate such transitions, whereas the drastic difference in the occurrence of the two trypanosomatid species determines the observed direction of this process. This phenomenon is analogous to organelle (mitochondrion/plastid) capture described in multicellular organisms and, thereafter, we name it endosymbiont capture.
Collapse
Affiliation(s)
- Tomáš Skalický
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, 370 05 České Budějovice (Budweis), Czech Republic; (T.S.); (A.B.); (J.L.)
| | - João M. P. Alves
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-000, Brazil; (J.M.P.A.); (A.C.M.); (M.M.G.T.); (E.P.C.)
| | - Anderson C. Morais
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-000, Brazil; (J.M.P.A.); (A.C.M.); (M.M.G.T.); (E.P.C.)
| | - Jana Režnarová
- Life Science Research Centre, Faculty of Science, University of Ostrava, 710 00 Ostrava, Czech Republic; (J.R.); (V.Y.)
| | - Anzhelika Butenko
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, 370 05 České Budějovice (Budweis), Czech Republic; (T.S.); (A.B.); (J.L.)
- Life Science Research Centre, Faculty of Science, University of Ostrava, 710 00 Ostrava, Czech Republic; (J.R.); (V.Y.)
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, 370 05 České Budějovice (Budweis), Czech Republic; (T.S.); (A.B.); (J.L.)
- Faculty of Sciences, University of South Bohemia, 370 05 České Budějovice (Budweis), Czech Republic
| | - Myrna G. Serrano
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA 23298-0678, USA; (M.G.S.); (G.A.B.)
| | - Gregory A. Buck
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA 23298-0678, USA; (M.G.S.); (G.A.B.)
| | - Marta M. G. Teixeira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-000, Brazil; (J.M.P.A.); (A.C.M.); (M.M.G.T.); (E.P.C.)
| | - Erney P. Camargo
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-000, Brazil; (J.M.P.A.); (A.C.M.); (M.M.G.T.); (E.P.C.)
| | - Mandy Sanders
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SA, UK; (M.S.); (J.A.C.)
| | - James A. Cotton
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge CB10 1SA, UK; (M.S.); (J.A.C.)
| | - Vyacheslav Yurchenko
- Life Science Research Centre, Faculty of Science, University of Ostrava, 710 00 Ostrava, Czech Republic; (J.R.); (V.Y.)
- Martsinovsky Institute of Medical Parasitology, Sechenov University, 119435 Moscow, Russia
| | - Alexei Y. Kostygov
- Life Science Research Centre, Faculty of Science, University of Ostrava, 710 00 Ostrava, Czech Republic; (J.R.); (V.Y.)
- Zoological Institute of the Russian Academy of Sciences, 199034 St. Petersburg, Russia
- Correspondence:
| |
Collapse
|
28
|
Schrader L, Pan H, Bollazzi M, Schiøtt M, Larabee FJ, Bi X, Deng Y, Zhang G, Boomsma JJ, Rabeling C. Relaxed selection underlies genome erosion in socially parasitic ant species. Nat Commun 2021; 12:2918. [PMID: 34006882 PMCID: PMC8131649 DOI: 10.1038/s41467-021-23178-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 04/06/2021] [Indexed: 02/03/2023] Open
Abstract
Inquiline ants are highly specialized and obligate social parasites that infiltrate and exploit colonies of closely related species. They have evolved many times convergently, are often evolutionarily young lineages, and are almost invariably rare. Focusing on the leaf-cutting ant genus Acromyrmex, we compared genomes of three inquiline social parasites with their free-living, closely-related hosts. The social parasite genomes show distinct signatures of erosion compared to the host lineages, as a consequence of relaxed selective constraints on traits associated with cooperative ant colony life and of inquilines having very small effective population sizes. We find parallel gene losses, particularly in olfactory receptors, consistent with inquiline species having highly reduced social behavioral repertoires. Many of the genomic changes that we uncover resemble those observed in the genomes of obligate non-social parasites and intracellular endosymbionts that branched off into highly specialized, host-dependent niches.
Collapse
Affiliation(s)
- Lukas Schrader
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany.
| | | | - Martin Bollazzi
- Entomología, Facultad de Agronomía, Universidad de la República, Montevideo, Uruguay
| | - Morten Schiøtt
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Fredrick J Larabee
- Department of Entomology, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA
| | | | | | - Guojie Zhang
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark
- BGI-Shenzhen, Shenzhen, China
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Jacobus J Boomsma
- Centre for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
| | - Christian Rabeling
- Department of Biology, University of Rochester, Rochester, NY, USA.
- School of Life Sciences, Arizona State University, Tempe, AZ, USA.
| |
Collapse
|
29
|
Doña J, Virrueta Herrera S, Nyman T, Kunnasranta M, Johnson KP. Patterns of Microbiome Variation Among Infrapopulations of Permanent Bloodsucking Parasites. Front Microbiol 2021; 12:642543. [PMID: 33935998 PMCID: PMC8085356 DOI: 10.3389/fmicb.2021.642543] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 03/26/2021] [Indexed: 12/22/2022] Open
Abstract
While interspecific variation in microbiome composition can often be readily explained by factors such as host species identity, there is still limited knowledge of how microbiomes vary at scales lower than the species level (e.g., between individuals or populations). Here, we evaluated variation in microbiome composition of individual parasites among infrapopulations (i.e., populations of parasites of the same species living on a single host individual). To address this question, we used genome-resolved and shotgun metagenomic data of 17 infrapopulations (balanced design) of the permanent, bloodsucking seal louse Echinophthirius horridus sampled from individual Saimaa ringed seals Pusa hispida saimensis. Both genome-resolved and read-based metagenomic classification approaches consistently show that parasite infrapopulation identity is a significant factor that explains both qualitative and quantitative patterns of microbiome variation at the intraspecific level. This study contributes to the general understanding of the factors driving patterns of intraspecific variation in microbiome composition, especially of bloodsucking parasites, and has implications for understanding how well-known processes occurring at higher taxonomic levels, such as phylosymbiosis, might arise in these systems.
Collapse
Affiliation(s)
- Jorge Doña
- Illinois Natural History Survey, Prairie Research Institute, University of Illinois at Urbana-Champaign, Champaign, IL, United States.,Departamento de Biología Animal, Universidad de Granada, Granada, Spain
| | - Stephany Virrueta Herrera
- Illinois Natural History Survey, Prairie Research Institute, University of Illinois at Urbana-Champaign, Champaign, IL, United States
| | - Tommi Nyman
- Department of Ecosystems in the Barents Region, Norwegian Institute of Bioeconomy Research, Svanvik, Norway
| | - Mervi Kunnasranta
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland.,Natural Resources Institute Finland, Joensuu, Finland
| | - Kevin P Johnson
- Illinois Natural History Survey, Prairie Research Institute, University of Illinois at Urbana-Champaign, Champaign, IL, United States
| |
Collapse
|
30
|
Finding Needles in Haystacks and Inferring Their Function: Challenges and Successes in Beneficial Symbiosis Research. mSystems 2021; 6:6/2/e00243-21. [PMID: 33824196 PMCID: PMC8546974 DOI: 10.1128/msystems.00243-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Symbioses between hosts and beneficial microbes are key drivers of biological innovation and diversity. While a range of systems have emerged that provide foundational insights into how symbioses function and evolve, we still have a limited understanding of the vast diversity of organisms that engage in such interactions. Recent advances in molecular tools, theory, and interdisciplinary approaches now permit researchers to expand our knowledge and to press forward the frontiers of symbiosis research. As described in a recent issue of mSystems, Myers and colleagues (K. N. Myers, D. Conn, and A. M. V. Brown, mSystems, 6:e01048-20, 2021, https://doi.org/10.1128/mSystems.01048-20) conducted a genome skimming approach to understand the role of obligate beneficial symbionts in plant-parasitic dagger nematodes. Nematodes are extraordinarily abundant and key players in ecosystem function and health. However, they are difficult to harness in the lab. The approach used by Myers et al. ameliorates these challenges to illustrate a relatively complete picture of a poorly understood beneficial symbiosis.
Collapse
|
31
|
Goodrich-Blair H. Interactions of host-associated multispecies bacterial communities. Periodontol 2000 2021; 86:14-31. [PMID: 33690897 DOI: 10.1111/prd.12360] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The oral microbiome comprises microbial communities colonizing biotic (epithelia, mucosa) and abiotic (enamel) surfaces. Different communities are associated with health (eg, immune development, pathogen resistance) and disease (eg, tooth loss and periodontal disease). Like any other host-associated microbiome, colonization and persistence of both beneficial and dysbiotic oral microbiomes are dictated by successful utilization of available nutrients and defense against host and competitor assaults. This chapter will explore these general features of microbe-host interactions through the lens of symbiotic (mutualistic and antagonistic/pathogenic) associations with nonmammalian animals. Investigations in such systems across a broad taxonomic range have revealed conserved mechanisms and processes that underlie the complex associations among microbes and between microbes and hosts.
Collapse
Affiliation(s)
- Heidi Goodrich-Blair
- Department of Microbiology, University of Tennessee-Knoxville, Knoxville, Tennessee, USA
| |
Collapse
|
32
|
Waneka G, Vasquez YM, Bennett GM, Sloan DB. Mutational Pressure Drives Differential Genome Conservation in Two Bacterial Endosymbionts of Sap-Feeding Insects. Genome Biol Evol 2020; 13:6020258. [PMID: 33275136 PMCID: PMC7952229 DOI: 10.1093/gbe/evaa254] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/28/2020] [Indexed: 11/16/2022] Open
Abstract
Compared with free-living bacteria, endosymbionts of sap-feeding insects have tiny and rapidly evolving genomes. Increased genetic drift, high mutation rates, and relaxed selection associated with host control of key cellular functions all likely contribute to genome decay. Phylogenetic comparisons have revealed massive variation in endosymbiont evolutionary rate, but such methods make it difficult to partition the effects of mutation versus selection. For example, the ancestor of Auchenorrhynchan insects contained two obligate endosymbionts, Sulcia and a betaproteobacterium (BetaSymb; called Nasuia in leafhoppers) that exhibit divergent rates of sequence evolution and different propensities for loss and replacement in the ensuing ∼300 Ma. Here, we use the auchenorrhynchan leafhopper Macrosteles sp. nr. severini, which retains both of the ancestral endosymbionts, to test the hypothesis that differences in evolutionary rate are driven by differential mutagenesis. We used a high-fidelity technique known as duplex sequencing to measure and compare low-frequency variants in each endosymbiont. Our direct detection of de novode novo mutations reveals that the rapidly evolving endosymbiont (Nasuia) has a much higher frequency of single-nucleotide variants than the more stable endosymbiont (Sulcia) and a mutation spectrum that is potentially even more AT-biased than implied by the 83.1% AT content of its genome. We show that indels are common in both endosymbionts but differ substantially in length and distribution around repetitive regions. Our results suggest that differences in long-term rates of sequence evolution in Sulcia versus BetaSymb, and perhaps the contrasting degrees of stability of their relationships with the host, are driven by differences in mutagenesis.
Collapse
Affiliation(s)
- Gus Waneka
- Department of Biology, Colorado State University, Fort Collins, CO, USA
| | - Yumary M Vasquez
- Department of Life and Environmental Sciences, University of California, Merced, CA, USA
| | - Gordon M Bennett
- Department of Life and Environmental Sciences, University of California, Merced, CA, USA
| | - Daniel B Sloan
- Department of Biology, Colorado State University, Fort Collins, CO, USA
| |
Collapse
|
33
|
Santos-Garcia D, Mestre-Rincon N, Ouvrard D, Zchori-Fein E, Morin S. Portiera Gets Wild: Genome Instability Provides Insights into the Evolution of Both Whiteflies and Their Endosymbionts. Genome Biol Evol 2020; 12:2107-2124. [PMID: 33049039 PMCID: PMC7821994 DOI: 10.1093/gbe/evaa216] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/09/2020] [Indexed: 12/12/2022] Open
Abstract
Whiteflies (Hemiptera: Sternorrhyncha: Aleyrodidae) are a superfamily of small phloem-feeding insects. They rely on their primary endosymbionts "Candidatus Portiera aleyrodidarum" to produce essential amino acids not present in their diet. Portiera has been codiverging with whiteflies since their origin and therefore reflects its host's evolutionary history. Like in most primary endosymbionts, the genome of Portiera stays stable across the Aleyrodidae superfamily after millions of years of codivergence. However, Portiera of the whitefly Bemisia tabaci has lost the ancestral genome order, reflecting a rare event in the endosymbiont evolution: the appearance of genome instability. To gain a better understanding of Portiera genome evolution, identify the time point in which genome instability appeared and contribute to the reconstruction of whitefly phylogeny, we developed a new phylogenetic framework. It targeted five Portiera genes and determined the presence of the DNA polymerase proofreading subunit (dnaQ) gene, previously associated with genome instability, and two alternative gene rearrangements. Our results indicated that Portiera gene sequences provide a robust tool for studying intergenera phylogenetic relationships in whiteflies. Using these new framework, we found that whitefly species from the Singhiella, Aleurolobus, and Bemisia genera form a monophyletic tribe, the Aleurolobini, and that their Portiera exhibit genome instability. This instability likely arose once in the common ancestor of the Aleurolobini tribe (at least 70 Ma), drawing a link between the appearance of genome instability in Portiera and the switch from multibacteriocyte to a single-bacteriocyte mode of inheritance in this tribe.
Collapse
Affiliation(s)
- Diego Santos-Garcia
- Department of Entomology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Natividad Mestre-Rincon
- Department of Entomology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - David Ouvrard
- Department of Life Sciences, Natural History Museum, London, United Kingdom.,Entomology and Invasive Plants Unit, Plant Health Laboratory, ANSES, Montferrier-sur-Lez, France
| | - Einat Zchori-Fein
- Department of Entomology, Newe-Ya'ar Research Center, ARO, Ramat-Yishai, Israel
| | - Shai Morin
- Department of Entomology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| |
Collapse
|
34
|
|
35
|
Russell SL, Pepper-Tunick E, Svedberg J, Byrne A, Ruelas Castillo J, Vollmers C, Beinart RA, Corbett-Detig R. Horizontal transmission and recombination maintain forever young bacterial symbiont genomes. PLoS Genet 2020; 16:e1008935. [PMID: 32841233 PMCID: PMC7473567 DOI: 10.1371/journal.pgen.1008935] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 09/04/2020] [Accepted: 06/16/2020] [Indexed: 12/30/2022] Open
Abstract
Bacterial symbionts bring a wealth of functions to the associations they participate in, but by doing so, they endanger the genes and genomes underlying these abilities. When bacterial symbionts become obligately associated with their hosts, their genomes are thought to decay towards an organelle-like fate due to decreased homologous recombination and inefficient selection. However, numerous associations exist that counter these expectations, especially in marine environments, possibly due to ongoing horizontal gene flow. Despite extensive theoretical treatment, no empirical study thus far has connected these underlying population genetic processes with long-term evolutionary outcomes. By sampling marine chemosynthetic bacterial-bivalve endosymbioses that range from primarily vertical to strictly horizontal transmission, we tested this canonical theory. We found that transmission mode strongly predicts homologous recombination rates, and that exceedingly low recombination rates are associated with moderate genome degradation in the marine symbionts with nearly strict vertical transmission. Nonetheless, even the most degraded marine endosymbiont genomes are occasionally horizontally transmitted and are much larger than their terrestrial insect symbiont counterparts. Therefore, horizontal transmission and recombination enable efficient natural selection to maintain intermediate symbiont genome sizes and substantial functional genetic variation.
Collapse
Affiliation(s)
- Shelbi L. Russell
- Department of Molecular Cellular and Developmental Biology. University of California Santa Cruz, Santa Cruz, California, United States of America
- Department of Biomolecular Engineering. University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Evan Pepper-Tunick
- Department of Biomolecular Engineering. University of California Santa Cruz, Santa Cruz, California, United States of America
- Genomics Institute, University of California, Santa Cruz, California, United States of America
| | - Jesper Svedberg
- Department of Biomolecular Engineering. University of California Santa Cruz, Santa Cruz, California, United States of America
- Genomics Institute, University of California, Santa Cruz, California, United States of America
| | - Ashley Byrne
- Department of Molecular Cellular and Developmental Biology. University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Jennie Ruelas Castillo
- Department of Molecular Cellular and Developmental Biology. University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Christopher Vollmers
- Department of Biomolecular Engineering. University of California Santa Cruz, Santa Cruz, California, United States of America
- Genomics Institute, University of California, Santa Cruz, California, United States of America
| | - Roxanne A. Beinart
- Graduate School of Oceanography. University of Rhode Island, Narragansett, Rhode Island, United States of America
| | - Russell Corbett-Detig
- Department of Biomolecular Engineering. University of California Santa Cruz, Santa Cruz, California, United States of America
- Genomics Institute, University of California, Santa Cruz, California, United States of America
| |
Collapse
|
36
|
Bohlin J, Rose B, Brynildsrud O, Birgitte Freiesleben De Blasio. A simple stochastic model describing genomic evolution over time of GC content in microbial symbionts. J Theor Biol 2020; 503:110389. [PMID: 32634385 DOI: 10.1016/j.jtbi.2020.110389] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 04/21/2020] [Accepted: 06/24/2020] [Indexed: 11/29/2022]
Abstract
An organism's genomic base composition is usually summarized by its AT or GC content due to Chargaff's parity laws. Variation in prokaryotic GC content can be substantial between taxa but is generally small within microbial genomes. This variation has been found to correlate with both phylogeny and environmental factors. Since novel single-nucleotide polymorphisms (SNPs) within genomes are at least partially linked to the environment through natural selection, SNP GC content can be considered a compound measure of an organism's environmental influences, lifestyle, phylogeny as well as other more or less random processes. While there are several models describing genomic GC content few, if any, consider AT/GC mutation rates subjected to random perturbations. We present a mathematical model that describes how GC content in microbial genomes evolves over time as a function of the AT → GC and GC → AT mutation rates with Gaussian white noise disturbances. The model, which is suited specifically to non-recombining vertically transmitted prokaryotic symbionts, suggests that small differences in the AT/GC mutation rates can lead to profound differences in outcome due to the ensuing stochastic process. In other words, the model indicates that time to extinction could be a consequence of the mutation rate trajectory on which the symbiont embarked early on in its evolutionary history.
Collapse
Affiliation(s)
- Jon Bohlin
- Division of Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway; Centre for Fertility and Health, Norwegian Institute of Public Health, Oslo, Norway; Department of Production Animals, Faculty of Veterinary Medicine, Norwegian University of Life Science, Oslo, Norway
| | - Brittany Rose
- Division of Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway; Department of Biostatistics, Oslo Centre for Biostatistics and Epidemiology, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Ola Brynildsrud
- Division of Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway; Department of Production Animals, Faculty of Veterinary Medicine, Norwegian University of Life Science, Oslo, Norway
| | - Birgitte Freiesleben De Blasio
- Division of Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway; Department of Biostatistics, Oslo Centre for Biostatistics and Epidemiology, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| |
Collapse
|
37
|
Boguszewska K, Szewczuk M, Kaźmierczak-Barańska J, Karwowski BT. The Similarities between Human Mitochondria and Bacteria in the Context of Structure, Genome, and Base Excision Repair System. Molecules 2020; 25:E2857. [PMID: 32575813 PMCID: PMC7356350 DOI: 10.3390/molecules25122857] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 06/17/2020] [Accepted: 06/19/2020] [Indexed: 02/06/2023] Open
Abstract
Mitochondria emerged from bacterial ancestors during endosymbiosis and are crucial for cellular processes such as energy production and homeostasis, stress responses, cell survival, and more. They are the site of aerobic respiration and adenosine triphosphate (ATP) production in eukaryotes. However, oxidative phosphorylation (OXPHOS) is also the source of reactive oxygen species (ROS), which are both important and dangerous for the cell. Human mitochondria contain mitochondrial DNA (mtDNA), and its integrity may be endangered by the action of ROS. Fortunately, human mitochondria have repair mechanisms that allow protecting mtDNA and repairing lesions that may contribute to the occurrence of mutations. Mutagenesis of the mitochondrial genome may manifest in the form of pathological states such as mitochondrial, neurodegenerative, and/or cardiovascular diseases, premature aging, and cancer. The review describes the mitochondrial structure, genome, and the main mitochondrial repair mechanism (base excision repair (BER)) of oxidative lesions in the context of common features between human mitochondria and bacteria. The authors present a holistic view of the similarities of mitochondria and bacteria to show that bacteria may be an interesting experimental model for studying mitochondrial diseases, especially those where the mechanism of DNA repair is impaired.
Collapse
Affiliation(s)
| | | | | | - Bolesław T. Karwowski
- DNA Damage Laboratory of Food Science Department, Faculty of Pharmacy, Medical University of Lodz, ul. Muszynskiego 1, 90-151 Lodz, Poland; (K.B.); (M.S.); (J.K.-B.)
| |
Collapse
|
38
|
Xue CX, Zhang H, Lin HY, Sun Y, Luo D, Huang Y, Zhang XH, Luo H. Ancestral niche separation and evolutionary rate differentiation between sister marine flavobacteria lineages. Environ Microbiol 2020; 22:3234-3247. [PMID: 32390223 DOI: 10.1111/1462-2920.15065] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 05/05/2020] [Accepted: 05/07/2020] [Indexed: 12/30/2022]
Abstract
Marine flavobacteria are specialists for polysaccharide degradation. They dominate in habitats enriched with polysaccharides, but are also prevalent in pelagic environments where polysaccharides are less available. These niches are likely occupied by distinct lineages, but evolutionary processes underlying their niche differentiation remain elusive. Here, genomic analyses and physiological assays indicate that the sister flavobacteria lineages Leeuwenhoekiella and Nonlabens likely explore polysaccharide-rich macroalgae and polysaccharide-poor pelagic niches respectively. Phylogenomic analyses inferred that the niche separation likely occurred anciently and coincided with increased sequence evolutionary rate in Nonlabens compared with Leeuwenhoekiella. Further analyses ruled out the known mechanisms likely driving evolutionary rate acceleration, including reduced selection efficiency, decreased generation time and increased mutation rate. In particular, the mutation rates were determined using an unbiased experimental method, which measures the present-day populations and may not reflect ancestral populations. These data collectively lead to a new hypothesis that an ancestral and transient mutation rate increase resulted in evolutionary rate increase in Nonlabens. This hypothesis was supported by inferring that gains and losses of genes involved in SOS response, a mechanism known to drive transiently increased mutation rate, coincided with evolutionary rate acceleration. Our analyses highlight the evolutionary mechanisms underlying niche differentiation of flavobacteria lineages.
Collapse
Affiliation(s)
- Chun-Xu Xue
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China.,Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Hao Zhang
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - He-Yu Lin
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Ying Sun
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Danli Luo
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Yongjie Huang
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR
| | - Xiao-Hua Zhang
- College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China
| | - Haiwei Luo
- Simon F. S. Li Marine Science Laboratory, School of Life Sciences and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, Hong Kong SAR.,Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, 518000, China
| |
Collapse
|
39
|
Chlamydia psittaci in fulmars on the Faroe Islands: a causative link to South American psittacines eight decades after a severe epidemic. Microbes Infect 2020; 22:356-359. [PMID: 32135200 DOI: 10.1016/j.micinf.2020.02.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 01/21/2020] [Accepted: 02/21/2020] [Indexed: 11/20/2022]
Abstract
A psittacosis epidemic linked to fulmar hunting occurred on the Faroe Islands in the 1930s. This study investigates a plausible explanation to the 20% human mortality in this outbreak. Phylogenetic analysis showed that Chlamydia psittaci isolated from fulmars were closely related to the highly virulent 6BC strains from psittacines and are compatible with an acquisition by fulmars of an ancestor of the 6BC clade in the 1930s. This supports the hypothesis that the outbreak on the Faroe Islands started after naïve fulmars acquired C. psittaci from infected dead parrots thrown overboard when shipped to Europe in the 1930s.
Collapse
|
40
|
Symbiont replacements reset the co-evolutionary relationship between insects and their heritable bacteria. ISME JOURNAL 2020; 14:1384-1395. [PMID: 32076126 DOI: 10.1038/s41396-020-0616-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 01/31/2020] [Accepted: 02/07/2020] [Indexed: 01/03/2023]
Abstract
Auchenorrhynchan insects (Hemiptera) generally depend on two bacterial symbionts for nutrition. These bacteria experience extreme genome reduction and loss of essential cell functions that require direct host support, or the replacement of failing symbionts with more capable ones. However, it remains unclear how hosts adapt to integrate symbionts into their systems, particularly when they are replaced. Here, we comparatively investigated the evolution of host-support mechanisms in the glassy-winged sharpshooter, Homalodisca vitripennis (GWSS), and the aster leafhopper, Macrosteles quadrilineatus (ALF). ALF harbors the ancestral co-symbionts of the Auchenorrhyncha that have tiny genomes, Sulcia (190 kb) and Nasuia (112 kb). In GWSS, Sulcia retains an expanded genome (245 kb), but Nasuia was replaced by the more capable Baumannia (686 kb). To support their symbionts, GWSS and ALF have evolved novel mechanisms via horizontal gene transfer, gene duplication, and co-option of mitochondrial support genes. However, GWSS has fewer support systems targeting essential bacterial processes. In particular, although both hosts use ancestral mechanisms to support Sulcia, GWSS does not encode all of the same support genes required to sustain Sulcia-ALF or Nasuia. Moreover, GWSS support of Baumannia is far more limited and tailored to its expanded capabilities. Our results demonstrate how symbiont replacements shape host genomes and the co-evolutionary process.
Collapse
|
41
|
Romero Picazo D, Dagan T, Ansorge R, Petersen JM, Dubilier N, Kupczok A. Horizontally transmitted symbiont populations in deep-sea mussels are genetically isolated. THE ISME JOURNAL 2019; 13:2954-2968. [PMID: 31395952 PMCID: PMC6863903 DOI: 10.1038/s41396-019-0475-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 05/22/2019] [Accepted: 06/16/2019] [Indexed: 02/07/2023]
Abstract
Eukaryotes are habitats for bacterial organisms where the host colonization and dispersal among individual hosts have consequences for the bacterial ecology and evolution. Vertical symbiont transmission leads to geographic isolation of the microbial population and consequently to genetic isolation of microbiotas from individual hosts. In contrast, the extent of geographic and genetic isolation of horizontally transmitted microbiota is poorly characterized. Here we show that chemosynthetic symbionts of individual Bathymodiolus brooksi mussels constitute genetically isolated subpopulations. The reconstruction of core genome-wide strains from high-resolution metagenomes revealed distinct phylogenetic clades. Nucleotide diversity and strain composition vary along the mussel life span and individual hosts show a high degree of genetic isolation. Our results suggest that the uptake of environmental bacteria is a restricted process in B. brooksi, where self-infection of the gill tissue results in serial founder effects during symbiont evolution. We conclude that bacterial colonization dynamics over the host life cycle is thus an important determinant of population structure and genome evolution of horizontally transmitted symbionts.
Collapse
Affiliation(s)
- Devani Romero Picazo
- Genomic Microbiology Group, Institute of General Microbiology, Christian-Albrechts University, Kiel, Germany.
| | - Tal Dagan
- Genomic Microbiology Group, Institute of General Microbiology, Christian-Albrechts University, Kiel, Germany
| | - Rebecca Ansorge
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Jillian M Petersen
- Division of Microbiology and Ecosystem Science, University of Vienna, Wien, Austria
| | - Nicole Dubilier
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Anne Kupczok
- Genomic Microbiology Group, Institute of General Microbiology, Christian-Albrechts University, Kiel, Germany.
| |
Collapse
|
42
|
Reis AC, Kolvenbach BA, Chami M, Gales L, Egas C, Corvini PFX, Nunes OC. Comparative genomics reveals a novel genetic organization of the sad cluster in the sulfonamide-degrader 'Candidatus Leucobacter sulfamidivorax' strain GP. BMC Genomics 2019; 20:885. [PMID: 31752666 PMCID: PMC6868719 DOI: 10.1186/s12864-019-6206-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 10/21/2019] [Indexed: 02/01/2023] Open
Abstract
Background Microbial communities recurrently establish metabolic associations resulting in increased fitness and ability to perform complex tasks, such as xenobiotic degradation. In a previous study, we have described a sulfonamide-degrading consortium consisting of a novel low-abundant actinobacterium, named strain GP, and Achromobacter denitrificans PR1. However, we found that strain GP was unable to grow independently and could not be further purified. Results Previous studies suggested that strain GP might represent a new putative species within the Leucobacter genus (16S rRNA gene similarity < 97%). In this study, we found that average nucleotide identity (ANI) with other Leucobacter spp. ranged between 76.8 and 82.1%, further corroborating the affiliation of strain GP to a new provisional species. The average amino acid identity (AAI) and percentage of conserved genes (POCP) values were near the lower edge of the genus delimitation thresholds (65 and 55%, respectively). Phylogenetic analysis of core genes between strain GP and Leucobacter spp. corroborated these findings. Comparative genomic analysis indicates that strain GP may have lost genes related to tetrapyrrole biosynthesis and thiol transporters, both crucial for the correct assembly of cytochromes and aerobic growth. However, supplying exogenous heme and catalase was insufficient to abolish the dependent phenotype. The actinobacterium harbors at least two copies of a novel genetic element containing a sulfonamide monooxygenase (sadA) flanked by a single IS1380 family transposase. Additionally, two homologs of sadB (4-aminophenol monooxygenase) were identified in the metagenome-assembled draft genome of strain GP, but these were not located in the vicinity of sadA nor of mobile or integrative elements. Conclusions Comparative genomics of the genus Leucobacter suggested the absence of some genes encoding for important metabolic traits in strain GP. Nevertheless, although media and culture conditions were tailored to supply its potential metabolic needs, these conditions were insufficient to isolate the PR1-dependent actinobacterium further. This study gives important insights regarding strain GP metabolism; however, gene expression and functional studies are necessary to characterize and further isolate strain GP. Based on our data, we propose to classify strain GP in a provisional new species within the genus Leucobacter, ‘Candidatus Leucobacter sulfamidivorax‘.
Collapse
Affiliation(s)
- Ana C Reis
- Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering - LEPABE, Department of Chemical Engineering, University of Porto, Rua Dr. Roberto Frias s/n, 4200-465, Porto, Portugal.,Institute for Ecopreneurship, School of Life Sciences, University of Applied Sciences Northwestern Switzerland, Gruendenstrasse 40, 4132, Muttenz, Switzerland
| | - Boris A Kolvenbach
- Institute for Ecopreneurship, School of Life Sciences, University of Applied Sciences Northwestern Switzerland, Gruendenstrasse 40, 4132, Muttenz, Switzerland
| | - Mohamed Chami
- BioEM lab, C-Cina, Biozentrum, University of Basel, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - Luís Gales
- Instituto de Investigação e Inovação em Saúde - i3S, Rua Alfredo Allen 208, 4200-135, Porto, Portugal.,Instituto de Biologia Molecular e Celular - IBMC, Rua Alfredo Allen 208, 4200-135, Porto, Portugal.,Instituto de Ciências Biomédicas Abel Salazar - ICBAS, Rua de Jorge Viterbo Ferreira 228, 4050-313, Porto, Portugal
| | - Conceição Egas
- Next Generation Sequencing Unit, Biocant, BiocantPark, Núcleo 04, Lote 8, 3060-197, Cantanhede, Portugal.,Center for Neuroscience and Cell Biology, University of Coimbra, Faculty of Medicine, Rua Larga, Pólo I, 3004-504, Coimbra, Portugal
| | - Philippe F-X Corvini
- Institute for Ecopreneurship, School of Life Sciences, University of Applied Sciences Northwestern Switzerland, Gruendenstrasse 40, 4132, Muttenz, Switzerland
| | - Olga C Nunes
- Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering - LEPABE, Department of Chemical Engineering, University of Porto, Rua Dr. Roberto Frias s/n, 4200-465, Porto, Portugal.
| |
Collapse
|
43
|
Watanabe K, Suzuki H, Nishida T, Mishima M, Tachibana M, Fujishima M, Shimizu T, Watarai M. Identification of novel Legionella genes required for endosymbiosis in Paramecium based on comparative genome analysis with Holospora spp. FEMS Microbiol Ecol 2019; 94:5074368. [PMID: 30124811 DOI: 10.1093/femsec/fiy162] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 08/11/2018] [Indexed: 12/20/2022] Open
Abstract
The relationship between Legionella and protist hosts has a huge impact when considering the infectious risk in humans because it facilitates the long-term replication and survival of Legionella in the environment. The ciliate Paramecium is considered to be a protist host for Legionella in natural environments, but the details of their endosymbiosis are largely unknown. In this study, we determined candidate Legionella pneumophila genes that are likely to be involved in the establishment of endosymbiosis in Paramecium caudatum by comparing the genomes of Legionella spp. and Holospora spp. that are obligate endosymbiotic bacteria in Paramecium spp. Among the candidate genes, each single deletion mutant for five genes (lpg0492, lpg0522, lpg0523, lpg2141 and lpg2398) failed to establish endosymbiosis in P. caudatum despite showing intracellular growth in human macrophages. The mutants exhibited no characteristic changes in terms of their morphology, multiplication rate or capacity for modulating the phagosomes in which they were contained, but their resistance to lysozyme decreased significantly. This study provides insights into novel factors required by L. pneumophila for endosymbiosis in P. caudatum, and suggests that endosymbiotic organisms within conspecific hosts may have shared genes related to effective endosymbiosis establishment.
Collapse
Affiliation(s)
- Kenta Watanabe
- The United Graduate School of Veterinary Science, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan.,Joint Faculty of Veterinary Medicine, Laboratory of Veterinary Public Health, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
| | - Haruo Suzuki
- Institute for Advanced Biosciences, Keio University, 5322 Endo, Fujisawa, Kanagawa 252-0882, Japan
| | - Takashi Nishida
- The United Graduate School of Veterinary Science, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
| | - Manami Mishima
- Joint Faculty of Veterinary Medicine, Laboratory of Veterinary Public Health, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
| | - Masato Tachibana
- Graduate School of Medicine, Dentistry and Pharmaceutical Science, Okayama University, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan
| | - Masahiro Fujishima
- Department of Sciences, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan.,Department of Research Infrastructure, National BioResource Project of Japan Agency for Medical Research and Development, Chiyoda-ku, Tokyo 100-0004, Japan
| | - Takashi Shimizu
- The United Graduate School of Veterinary Science, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan.,Joint Faculty of Veterinary Medicine, Laboratory of Veterinary Public Health, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
| | - Masahisa Watarai
- The United Graduate School of Veterinary Science, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan.,Joint Faculty of Veterinary Medicine, Laboratory of Veterinary Public Health, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
| |
Collapse
|
44
|
Otero-Bravo A, Goffredi S, Sabree ZL. Cladogenesis and Genomic Streamlining in Extracellular Endosymbionts of Tropical Stink Bugs. Genome Biol Evol 2019; 10:680-693. [PMID: 29420776 PMCID: PMC5822708 DOI: 10.1093/gbe/evy033] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/05/2018] [Indexed: 01/21/2023] Open
Abstract
Phytophagous stink bugs are globally distributed and many harbor vertically inherited bacterial symbionts that are extracellular, yet little is known about how the symbiont’s genomes have evolved under this transmission strategy. Genome reduction is common in insect intracellular symbionts but limited genome sampling of the extracellular symbionts of distantly related stink bugs has precluded inferring patterns of extracellular symbiont genome evolution. To address this knowledge gap, we completely sequenced the genomes of the uncultivable bacterial symbionts of four neotropical stink bugs of the Edessa genus. Phylogenetic and comparative analyses indicated that the symbionts form a clade within the Pantoea genus and their genomes are highly reduced (∼0.8 Mb). Furthermore, genome synteny analysis and a jackknife approach for phylogenetic reconstruction, which corrected for long branch attraction artifacts, indicated that the Edessa symbionts were the result of a single symbiotic event that was distinct from the symbiosis event giving rise to Candidatus “Pantoea carbekii,” the extracellular symbiont of the invasive pentatomid stink bug, Halyomorpha halys. Metabolic functions inferred from the Edessa symbiont genomes suggests a shift in genomic composition characteristic of its lifestyle in that they retained many host-supportive functions while undergoing dramatic gene loss and establishing a stable relationship with their host insects. Given the undersampled nature of extracellular insect symbionts, this study is the first comparative analysis of these symbiont genomes from four distinct Edessa stink bug species. Finally, we propose the candidate name “Candidatus Pantoea edessiphila” for the species of these symbionts with strain designations according to their host species.
Collapse
Affiliation(s)
| | - Shana Goffredi
- Department of Biology, Occidental College, Los Angeles, California
| | - Zakee L Sabree
- Department of Evolution, Ecology and Organismal Biology, Ohio State University
| |
Collapse
|
45
|
Gilkes JM, Sheen CR, Frampton RA, Smith GR, Dobson RCJ. The First Purification of Functional Proteins from the Unculturable, Genome-Reduced, Bottlenecked α-Proteobacterium ' Candidatus Liberibacter solanacearum'. PHYTOPATHOLOGY 2019; 109:1141-1148. [PMID: 30887888 DOI: 10.1094/phyto-12-18-0486-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
'Candidatus Liberibacter solanacearum' is an unculturable α-proteobacterium that is the causal agent of zebra chip disease of potato-a major problem in potato-growing areas, because it affects growth and yield. Developing effective treatments for 'Ca. L. solanacearum' has been hampered by the difficulty in functionally characterizing the proteins of this organism, largely because they are not easily expressed and purified in standard expression systems. 'Ca. L. solanacearum' has a reduced genome and its proteins are predicted to be prone to instability and aggregation. Among intracellular-dwelling bacteria, chaperone proteins are conserved and overexpressed to buffer against problems in protein folding. We mimicked this approach for expressing and purifying 'Ca. L. solanacearum' proteins in Escherichia coli by coexpressing them with chaperones. Neither of the representative 'Ca. L. solanacearum' enzymes, dihydrodipicolinate synthase (key in lysine biosynthesis) and pyruvate kinase (involved in glycolysis), were overexpressed in standard E. coli expression plasmids or strains. However, soluble dihydrodipicolinate synthase was successfully coexpressed with GroEL/GroES, while soluble pyruvate kinase was successfully coexpressed with either GroEL/GroES, dnaK/dnaJ/grpE, or a trigger factor. Both enzymes, believed to be key proteins for the organism, were purified by a combination of affinity chromatography and size-exclusion chromatography. Additionally, both 'Ca. L. solanacearum' enzymes are active and have the canonical tetrameric oligomeric structure in solution, consistent with other bacterial orthologs. This is the first study to successfully isolate and functionally characterize proteins from 'Ca. L. solanacearum'. Thus, we provide a general strategy for characterizing its proteins, enabling new research and drug discovery programs to study and manage the pathogenicity of the organism.
Collapse
Affiliation(s)
- Jenna M Gilkes
- 1 Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Christchurch 8041, New Zealand
- 2 The New Zealand Institute for Plant & Food Research Limited, Lincoln 7608, New Zealand
| | - Campbell R Sheen
- 3 Callaghan Innovation, University of Canterbury, Christchurch 8041, New Zealand; and
| | - Rebekah A Frampton
- 2 The New Zealand Institute for Plant & Food Research Limited, Lincoln 7608, New Zealand
| | - Grant R Smith
- 2 The New Zealand Institute for Plant & Food Research Limited, Lincoln 7608, New Zealand
| | - Renwick C J Dobson
- 1 Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Christchurch 8041, New Zealand
- 4 Bio21 Molecular Science and Biotechnology Institute, Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria 3010, Australia
| |
Collapse
|
46
|
Dietel AK, Merker H, Kaltenpoth M, Kost C. Selective advantages favour high genomic AT-contents in intracellular elements. PLoS Genet 2019; 15:e1007778. [PMID: 31034469 PMCID: PMC6519830 DOI: 10.1371/journal.pgen.1007778] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 05/15/2019] [Accepted: 03/27/2019] [Indexed: 12/27/2022] Open
Abstract
Extrachromosomal genetic elements such as bacterial endosymbionts and plasmids generally exhibit AT-contents that are increased relative to their hosts’ DNA. The AT-bias of endosymbiotic genomes is commonly explained by neutral evolutionary processes such as a mutational bias towards increased A+T. Here we show experimentally that an increased AT-content of host-dependent elements can be selectively favoured. Manipulating the nucleotide composition of bacterial cells by introducing A+T-rich or G+C-rich plasmids, we demonstrate that cells containing GC-rich plasmids are less fit than cells containing AT-rich plasmids. Moreover, the cost of GC-rich elements could be compensated by providing precursors of G+C, but not of A+T, thus linking the observed fitness effects to the cytoplasmic availability of nucleotides. Accordingly, introducing AT-rich and GC-rich plasmids into other bacterial species with different genomic GC-contents revealed that the costs of G+C-rich plasmids decreased with an increasing GC-content of their host’s genomic DNA. Taken together, our work identifies selection as a strong evolutionary force that drives the genomes of intracellular genetic elements toward higher A+T contents. Genomes of endosymbiotic bacteria are commonly more AT-rich than the ones of their free-living relatives. Interestingly, genomes of other intracellular elements like plasmids or bacteriophages also tend to be richer in AT than the genomes of their hosts. The AT-bias of endosymbiotic genomes is commonly explained by neutral evolutionary processes. However, since A+T nucleotides are both more abundant and energetically less expensive than G+C nucleotides, an alternative explanation is that selective advantages drive the nucleotide composition of intracellular elements. Here we provide strong experimental evidence that intracellular elements, whose genome is more AT-rich than the genome of the host, are selectively favoured on the host level. Thus, our results emphasize the importance of selection for shaping the DNA base composition of extrachromosomal genetic elements.
Collapse
Affiliation(s)
- Anne-Kathrin Dietel
- Experimental Ecology and Evolution Research Group, Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Holger Merker
- Experimental Ecology and Evolution Research Group, Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Martin Kaltenpoth
- Insect Symbiosis Research Group, Max Planck Institute for Chemical Ecology, Jena, Germany
- * E-mail: (MK); (CK)
| | - Christian Kost
- Experimental Ecology and Evolution Research Group, Department of Bioorganic Chemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
- * E-mail: (MK); (CK)
| |
Collapse
|
47
|
Evolutionary dynamics of the chromatophore genome in three photosynthetic Paulinella species. Sci Rep 2019; 9:2560. [PMID: 30796245 PMCID: PMC6384880 DOI: 10.1038/s41598-019-38621-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 01/04/2019] [Indexed: 11/21/2022] Open
Abstract
The thecate amoeba Paulinella is a valuable model for understanding plastid organellogenesis because this lineage has independently gained plastids (termed chromatophores) of alpha-cyanobacterial provenance. Plastid primary endosymbiosis in Paulinella occurred relatively recently (90–140 million years ago, Mya), whereas the origin of the canonical Archaeplastida plastid occurred >1,500 Mya. Therefore, these two events provide independent perspectives on plastid formation on vastly different timescales. Here we generated the complete chromatophore genome sequence from P. longichromatophora (979,356 bp, GC-content = 38.8%, 915 predicted genes) and P. micropora NZ27 (977,190 bp, GC-content = 39.9%, 911 predicted genes) and compared these data to that from existing chromatophore genomes. Our analysis suggests that when a basal split occurred among photosynthetic Paulinella species ca. 60 Mya, only 35% of the ancestral orthologous gene families from the cyanobacterial endosymbiont remained in chromatophore DNA. Following major gene losses during the early stages of endosymbiosis, this process slowed down significantly, resulting in a conserved gene content across extant taxa. Chromatophore genes faced relaxed selection when compared to homologs in free-living alpha-cyanobacteria, likely reflecting the homogeneous intracellular environment of the Paulinella host. Comparison of nucleotide substitution and insertion/deletion events among different P. micropora strains demonstrates that increases in AT-content and genome reduction are ongoing and dynamic processes in chromatophore evolution.
Collapse
|
48
|
Fueled by methane: deep-sea sponges from asphalt seeps gain their nutrition from methane-oxidizing symbionts. ISME JOURNAL 2019; 13:1209-1225. [PMID: 30647460 PMCID: PMC6474228 DOI: 10.1038/s41396-019-0346-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 12/16/2018] [Accepted: 12/20/2018] [Indexed: 01/26/2023]
Abstract
Sponges host a remarkable diversity of microbial symbionts, however, the benefit their microbes provide is rarely understood. Here, we describe two new sponge species from deep-sea asphalt seeps and show that they live in a nutritional symbiosis with methane-oxidizing (MOX) bacteria. Metagenomics and imaging analyses revealed unusually high amounts of MOX symbionts in hosts from a group previously assumed to have low microbial abundances. These symbionts belonged to the Marine Methylotrophic Group 2 clade. They are host-specific and likely vertically transmitted, based on their presence in sponge embryos and streamlined genomes, which lacked genes typical of related free-living MOX. Moreover, genes known to play a role in host–symbiont interactions, such as those that encode eukaryote-like proteins, were abundant and expressed. Methane assimilation by the symbionts was one of the most highly expressed metabolic pathways in the sponges. Molecular and stable carbon isotope patterns of lipids confirmed that methane-derived carbon was incorporated into the hosts. Our results revealed that two species of sponges, although distantly related, independently established highly specific, nutritional symbioses with two closely related methanotrophs. This convergence in symbiont acquisition underscores the strong selective advantage for these sponges in harboring MOX bacteria in the food-limited deep sea.
Collapse
|
49
|
Abstract
The streamlining hypothesis is usually used to explain the genomic reduction events in free-living bacteria like SAR11. However, we find that the genomic reduction phenomenon in the bacterial genus Idiomarina is different from that in SAR11. Therefore, we propose a new hypothesis to explain genomic reduction in this genus based on trophic specialization that could result in genomic reduction, which would be not uncommon in nature. Not only can the trophic specialization hypothesis explain the genomic reduction in the genus Idiomarina, but it also sheds new light on our understanding of the genomic reduction processes in other free-living bacterial lineages. The streamlining hypothesis is generally used to explain the genomic reduction events related to the small genome size of free-living bacteria like marine bacteria SAR11. However, our current understanding of the correlation between bacterial genome size and environmental adaptation relies on too few species. It is still unclear whether there are other paths leading to genomic reduction in free-living bacteria. The genome size of marine free-living bacteria of the genus Idiomarina belonging to the order Alteromonadales (Gammaproteobacteria) is much smaller than the size of related genomes from bacteria in the same order. Comparative genomic and physiological analyses showed that the genomic reduction pattern in this genus is different from that of the classical SAR11 lineage. Genomic reduction reconstruction and substrate utilization profile showed that Idiomarina spp. lost a large number of genes related to carbohydrate utilization, and instead they specialized on using proteinaceous resources. Here we propose a new hypothesis to explain genomic reduction in this genus; we propose that trophic specialization increasing the metabolic efficiency for using one kind of substrate but reducing the substrate utilization spectrum could result in bacterial genomic reduction, which would be not uncommon in nature. This hypothesis was further tested in another free-living genus, Kangiella, which also shows dramatic genomic reduction. These findings highlight that trophic specialization is potentially an important path leading to genomic reduction in some marine free-living bacteria, which is distinct from the classical lineages like SAR11.
Collapse
|
50
|
Mao M, Yang X, Bennett GM. Evolution of host support for two ancient bacterial symbionts with differentially degraded genomes in a leafhopper host. Proc Natl Acad Sci U S A 2018; 115:E11691-E11700. [PMID: 30463949 PMCID: PMC6294904 DOI: 10.1073/pnas.1811932115] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Plant sap-feeding insects (Hemiptera) rely on bacterial symbionts for nutrition absent in their diets. These bacteria experience extreme genome reduction and require genetic resources from their hosts, particularly for basic cellular processes other than nutrition synthesis. The host-derived mechanisms that complete these processes have remained poorly understood. It is also unclear how hosts meet the distinct needs of multiple bacterial partners with differentially degraded genomes. To address these questions, we investigated the cell-specific gene-expression patterns in the symbiotic organs of the aster leafhopper (ALF), Macrosteles quadrilineatus (Cicadellidae). ALF harbors two intracellular symbionts that have two of the smallest known bacterial genomes: Nasuia (112 kb) and Sulcia (190 kb). Symbionts are segregated into distinct host cell types (bacteriocytes) and vary widely in their basic cellular capabilities. ALF differentially expresses thousands of genes between the bacteriocyte types to meet the functional needs of each symbiont, including the provisioning of metabolites and support of cellular processes. For example, the host highly expresses genes in the bacteriocytes that likely complement gene losses in nucleic acid synthesis, DNA repair mechanisms, transcription, and translation. Such genes are required to function in the bacterial cytosol. Many host genes comprising these support mechanisms are derived from the evolution of novel functional traits via horizontally transferred genes, reassigned mitochondrial support genes, and gene duplications with bacteriocyte-specific expression. Comparison across other hemipteran lineages reveals that hosts generally support the incomplete symbiont cellular processes, but the origins of these support mechanisms are generally specific to the host-symbiont system.
Collapse
Affiliation(s)
- Meng Mao
- Department of Life and Environmental Sciences, University of California, Merced, CA 95343;
- Department of Plant and Environmental Protection Sciences, University of Hawaii at Manoa, Honolulu, HI 96822
| | - Xiushuai Yang
- Department of Plant and Environmental Protection Sciences, University of Hawaii at Manoa, Honolulu, HI 96822
| | - Gordon M Bennett
- Department of Life and Environmental Sciences, University of California, Merced, CA 95343
- Department of Plant and Environmental Protection Sciences, University of Hawaii at Manoa, Honolulu, HI 96822
| |
Collapse
|