1
|
Fournier GP. Stem Life: A Framework for Understanding the Prebiotic-Biotic Transition. J Mol Evol 2024; 92:539-549. [PMID: 39244680 PMCID: PMC11458642 DOI: 10.1007/s00239-024-10201-z] [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: 01/31/2024] [Accepted: 08/27/2024] [Indexed: 09/10/2024]
Abstract
Abiogenesis is frequently envisioned as a linear, ladder-like progression of increasingly complex chemical systems, eventually leading to the ancestors of extant cellular life. This "pre-cladistics" view is in stark contrast to the well-accepted principles of organismal evolutionary biology, as informed by paleontology and phylogenetics. Applying this perspective to origins, I explore the paradigm of "Stem Life," which embeds abiogenesis within a broader continuity of diversification and extinction of both hereditary lineages and chemical systems. In this new paradigm, extant life's ancestral lineage emerged alongside and was dependent upon many other complex prebiotic chemical systems, as part of a diverse and fecund prebiosphere. Drawing from several natural history analogies, I show how this shift in perspective enriches our understanding of Origins and directly informs debates on defining Life, the emergence of the Last Universal Common Ancestor (LUCA), and the implications of prebiotic chemical experiments.
Collapse
Affiliation(s)
- Gregory P Fournier
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA.
| |
Collapse
|
2
|
Kloub L, Gosselin S, Graf J, Gogarten JP, Bansal MS. Investigating Additive and Replacing Horizontal Gene Transfers Using Phylogenies and Whole Genomes. Genome Biol Evol 2024; 16:evae180. [PMID: 39163267 PMCID: PMC11375855 DOI: 10.1093/gbe/evae180] [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: 04/21/2024] [Revised: 07/29/2024] [Accepted: 08/12/2024] [Indexed: 08/22/2024] Open
Abstract
Horizontal gene transfer (HGT) is fundamental to microbial evolution and adaptation. When a gene is horizontally transferred, it may either add itself as a new gene to the recipient genome (possibly displacing nonhomologous genes) or replace an existing homologous gene. Currently, studies do not usually distinguish between "additive" and "replacing" HGTs, and their relative frequencies, integration mechanisms, and specific roles in microbial evolution are poorly understood. In this work, we develop a novel computational framework for large-scale classification of HGTs as either additive or replacing. Our framework leverages recently developed phylogenetic approaches for HGT detection and classifies HGTs inferred between terminal edges based on gene orderings along genomes and phylogenetic relationships between the microbial species under consideration. The resulting method, called DART, is highly customizable and scalable and can classify a large fraction of inferred HGTs with high confidence and statistical support. Our application of DART to a large dataset of thousands of gene families from 103 Aeromonas genomes provides insights into the relative frequencies, functional biases, and integration mechanisms of additive and replacing HGTs. Among other results, we find that (i) the relative frequency of additive HGT increases with increasing phylogenetic distance, (ii) replacing HGT dominates at shorter phylogenetic distances, (iii) additive and replacing HGTs have strikingly different functional profiles, (iv) homologous recombination in flanking regions of a novel gene may be a frequent integration mechanism for additive HGT, and (v) phages and mobile genetic elements likely play an important role in facilitating additive HGT.
Collapse
Affiliation(s)
- Lina Kloub
- School of Computing, University of Connecticut, 371 Fairfield Way, Unit 4155, Storrs, CT 06269-4155, USA
| | - Sophia Gosselin
- Department of Molecular and Cell Biology, University of Connecticut, 91 North Eagleville Road, Unit 3125, Storrs, CT 06269-3125, USA
| | - Joerg Graf
- Department of Molecular and Cell Biology, University of Connecticut, 91 North Eagleville Road, Unit 3125, Storrs, CT 06269-3125, USA
- Pacific Biosciences Research Center, University of Hawaii, Honolulu, HI 96822, USA
| | - Johann Peter Gogarten
- Department of Molecular and Cell Biology, University of Connecticut, 91 North Eagleville Road, Unit 3125, Storrs, CT 06269-3125, USA
- The Institute for Systems Genomics, University of Connecticut, Storrs, CT 06269, USA
| | - Mukul S Bansal
- School of Computing, University of Connecticut, 371 Fairfield Way, Unit 4155, Storrs, CT 06269-4155, USA
- The Institute for Systems Genomics, University of Connecticut, Storrs, CT 06269, USA
| |
Collapse
|
3
|
Daakour S, Nelson DR, Fu W, Jaiswal A, Dohai B, Alzahmi AS, Koussa J, Huang X, Shen Y, Twizere JC, Salehi-Ashtiani K. Adaptive Evolution Signatures in Prochlorococcus: Open Reading Frame (ORF)eome Resources and Insights from Comparative Genomics. Microorganisms 2024; 12:1720. [PMID: 39203562 PMCID: PMC11357015 DOI: 10.3390/microorganisms12081720] [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: 05/07/2024] [Revised: 07/30/2024] [Accepted: 08/13/2024] [Indexed: 09/03/2024] Open
Abstract
Prochlorococcus, a cyanobacteria genus of the smallest and most abundant oceanic phototrophs, encompasses ecotype strains adapted to high-light (HL) and low-light (LL) niches. To elucidate the adaptive evolution of this genus, we analyzed 40 Prochlorococcus marinus ORFeomes, including two cornerstone strains, MED4 and NATL1A. Employing deep learning with robust statistical methods, we detected new protein family distributions in the strains and identified key genes differentiating the HL and LL strains. The HL strains harbor genes (ABC-2 transporters) related to stress resistance, such as DNA repair and RNA processing, while the LL strains exhibit unique chlorophyll adaptations (ion transport proteins, HEAT repeats). Additionally, we report the finding of variable, depth-dependent endogenous viral elements in the 40 strains. To generate biological resources to experimentally study the HL and LL adaptations, we constructed the ORFeomes of two representative strains, MED4 and NATL1A synthetically, covering 99% of the annotated protein-coding sequences of the two species, totaling 3976 cloned, sequence-verified open reading frames (ORFs). These comparative genomic analyses, paired with MED4 and NATL1A ORFeomes, will facilitate future genotype-to-phenotype mappings and the systems biology exploration of Prochlorococcus ecology.
Collapse
Affiliation(s)
- Sarah Daakour
- Center for Genomics and Systems Biology (CGSB), New York University-Abu Dhabi, Abu Dhabi P.O. Box 129188, United Arab Emirates; (S.D.); (D.R.N.); (W.F.); (A.J.); (B.D.); (A.S.A.); (J.K.); (J.-C.T.)
- Division of Science and Math, New York University-Abu Dhabi, Abu Dhabi P.O. Box 129188, United Arab Emirates
| | - David R. Nelson
- Center for Genomics and Systems Biology (CGSB), New York University-Abu Dhabi, Abu Dhabi P.O. Box 129188, United Arab Emirates; (S.D.); (D.R.N.); (W.F.); (A.J.); (B.D.); (A.S.A.); (J.K.); (J.-C.T.)
- Division of Science and Math, New York University-Abu Dhabi, Abu Dhabi P.O. Box 129188, United Arab Emirates
| | - Weiqi Fu
- Center for Genomics and Systems Biology (CGSB), New York University-Abu Dhabi, Abu Dhabi P.O. Box 129188, United Arab Emirates; (S.D.); (D.R.N.); (W.F.); (A.J.); (B.D.); (A.S.A.); (J.K.); (J.-C.T.)
- Division of Science and Math, New York University-Abu Dhabi, Abu Dhabi P.O. Box 129188, United Arab Emirates
- Department of Marine Science, Ocean College, Zhejiang University, Zhoushan 316021, China
| | - Ashish Jaiswal
- Center for Genomics and Systems Biology (CGSB), New York University-Abu Dhabi, Abu Dhabi P.O. Box 129188, United Arab Emirates; (S.D.); (D.R.N.); (W.F.); (A.J.); (B.D.); (A.S.A.); (J.K.); (J.-C.T.)
- Division of Science and Math, New York University-Abu Dhabi, Abu Dhabi P.O. Box 129188, United Arab Emirates
| | - Bushra Dohai
- Center for Genomics and Systems Biology (CGSB), New York University-Abu Dhabi, Abu Dhabi P.O. Box 129188, United Arab Emirates; (S.D.); (D.R.N.); (W.F.); (A.J.); (B.D.); (A.S.A.); (J.K.); (J.-C.T.)
- Division of Science and Math, New York University-Abu Dhabi, Abu Dhabi P.O. Box 129188, United Arab Emirates
- Helmholtz Center Munich, Institute of Network Biology (INET), German Research Center for Environmental Health, 85764 Munich, Germany
| | - Amnah Salem Alzahmi
- Center for Genomics and Systems Biology (CGSB), New York University-Abu Dhabi, Abu Dhabi P.O. Box 129188, United Arab Emirates; (S.D.); (D.R.N.); (W.F.); (A.J.); (B.D.); (A.S.A.); (J.K.); (J.-C.T.)
- Division of Science and Math, New York University-Abu Dhabi, Abu Dhabi P.O. Box 129188, United Arab Emirates
- Laboratory of Viral Interactomes Networks, Unit of Molecular & Computational Biology, Interdisciplinary Cluster for Applied Genoproteomics (GIGA Institute), University of Liège, 4000 Liège, Belgium
| | - Joseph Koussa
- Center for Genomics and Systems Biology (CGSB), New York University-Abu Dhabi, Abu Dhabi P.O. Box 129188, United Arab Emirates; (S.D.); (D.R.N.); (W.F.); (A.J.); (B.D.); (A.S.A.); (J.K.); (J.-C.T.)
- Division of Science and Math, New York University-Abu Dhabi, Abu Dhabi P.O. Box 129188, United Arab Emirates
- Department of Biology, New York University, New York, NY 10012, USA
- Department of Chemical and Biological Sciences, Montgomery College, Germantown, MD 20850, USA
| | - Xiaoluo Huang
- Genome Synthesis and Editing Platform, China National GeneBank (CNGB), BGI-Research, Shenzhen 518120, China; (X.H.); (Y.S.)
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Beijing 100045, China
| | - Yue Shen
- Genome Synthesis and Editing Platform, China National GeneBank (CNGB), BGI-Research, Shenzhen 518120, China; (X.H.); (Y.S.)
| | - Jean-Claude Twizere
- Center for Genomics and Systems Biology (CGSB), New York University-Abu Dhabi, Abu Dhabi P.O. Box 129188, United Arab Emirates; (S.D.); (D.R.N.); (W.F.); (A.J.); (B.D.); (A.S.A.); (J.K.); (J.-C.T.)
- Division of Science and Math, New York University-Abu Dhabi, Abu Dhabi P.O. Box 129188, United Arab Emirates
- Laboratory of Viral Interactomes Networks, Unit of Molecular & Computational Biology, Interdisciplinary Cluster for Applied Genoproteomics (GIGA Institute), University of Liège, 4000 Liège, Belgium
| | - Kourosh Salehi-Ashtiani
- Center for Genomics and Systems Biology (CGSB), New York University-Abu Dhabi, Abu Dhabi P.O. Box 129188, United Arab Emirates; (S.D.); (D.R.N.); (W.F.); (A.J.); (B.D.); (A.S.A.); (J.K.); (J.-C.T.)
- Division of Science and Math, New York University-Abu Dhabi, Abu Dhabi P.O. Box 129188, United Arab Emirates
| |
Collapse
|
4
|
Li T, Ma Z, Ding T, Yang Y, Wang F, Wan X, Liang F, Chen X, Yao H. Codon usage bias and phylogenetic analysis of chloroplast genome in 36 gracilariaceae species. Funct Integr Genomics 2024; 24:45. [PMID: 38429550 DOI: 10.1007/s10142-024-01316-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 02/11/2024] [Accepted: 02/13/2024] [Indexed: 03/03/2024]
Abstract
Gracilariaceae is a group of marine large red algae and main source of agar with important economic and ecological value. The codon usage patterns of chloroplast genomes in 36 species from Graciliaceae show that GC range from 0.284 to 0.335, the average GC3 range from 0.135 to 0.243 and the value of ENC range from 35.098 to 42.327, which indicates these genomes are rich in AT and prefer to use codons ending with AT in these species. Nc plot, PR2 plot, neutrality plot analyses and correlation analysis indicate that these biases may be caused by multiple factors, such as natural selection and mutation pressure, but prolonged natural selection is the main driving force influencing codon usage preference. The cluster analysis and phylogenetic analysis show that the differentiation relationship of them is different and indicate that codons with weak or unbiased preferences may also play an irreplaceable role in these species' evolution. In addition, we identified 26 common high-frequency codons and 8-18 optimal codons all ending in A/U in these 36 species. Our results will not only contribute to carrying out transgenic work in Gracilariaceae species to maximize the protein yield in the future, but also lay a theoretical foundation for further exploring systematic classification of them.
Collapse
Affiliation(s)
- Tingting Li
- College of Life Science, Sichuan Agriculture University, Ya'an, 625014, Sichuan, People's Republic of China
| | - Zheng Ma
- College of Life Science, Sichuan Agriculture University, Ya'an, 625014, Sichuan, People's Republic of China
| | - Tiemei Ding
- College of Life Science, Sichuan Agriculture University, Ya'an, 625014, Sichuan, People's Republic of China
| | - Yanxin Yang
- College of Life Science, Sichuan Agriculture University, Ya'an, 625014, Sichuan, People's Republic of China
| | - Fei Wang
- College of Life Science, Sichuan Agriculture University, Ya'an, 625014, Sichuan, People's Republic of China
| | - Xinjing Wan
- College of Life Science, Sichuan Agriculture University, Ya'an, 625014, Sichuan, People's Republic of China
| | - Fangyun Liang
- College of Life Science, Sichuan Agriculture University, Ya'an, 625014, Sichuan, People's Republic of China
| | - Xi Chen
- College of Life Science, Sichuan Agriculture University, Ya'an, 625014, Sichuan, People's Republic of China
| | - Huipeng Yao
- College of Life Science, Sichuan Agriculture University, Ya'an, 625014, Sichuan, People's Republic of China.
| |
Collapse
|
5
|
Stanojković A, Skoupý S, Škaloud P, Dvořák P. High genomic differentiation and limited gene flow indicate recent cryptic speciation within the genus Laspinema (cyanobacteria). Front Microbiol 2022; 13:977454. [PMID: 36160208 PMCID: PMC9500459 DOI: 10.3389/fmicb.2022.977454] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 08/15/2022] [Indexed: 11/18/2022] Open
Abstract
The sympatric occurrence of closely related lineages displaying conserved morphological and ecological traits is often characteristic of free-living microbes. Gene flow, recombination, selection, and mutations govern the genetic variability between these cryptic lineages and drive their differentiation. However, sequencing conservative molecular markers (e.g., 16S rRNA) coupled with insufficient population-level sampling hindered the study of intra-species genetic diversity and speciation in cyanobacteria. We used phylogenomics and a population genomic approach to investigate the extent of local genomic diversity and the mechanisms underlying sympatric speciation of Laspinema thermale. We found two cryptic lineages of Laspinema. The lineages were highly genetically diverse, with recombination occurring more frequently within than between them. That suggests the existence of a barrier to gene flow, which further maintains divergence. Genomic regions of high population differentiation harbored genes associated with possible adaptations to high/low light conditions and stress stimuli, although with a weak diversifying selection. Overall, the diversification of Laspinema species might have been affected by both genomic and ecological processes.
Collapse
Affiliation(s)
| | - Svatopluk Skoupý
- Department of Botany, Faculty of Science, Palacký University Olomouc, Olomouc, Czechia
| | - Pavel Škaloud
- Department of Botany, Faculty of Science, Charles University in Prague, Prague, Czechia
| | - Petr Dvořák
- Department of Botany, Faculty of Science, Palacký University Olomouc, Olomouc, Czechia
| |
Collapse
|
6
|
Smith JT, Andam CP. Extensive Horizontal Gene Transfer within and between Species of Coagulase-Negative Staphylococcus. Genome Biol Evol 2021; 13:evab206. [PMID: 34498042 PMCID: PMC8462280 DOI: 10.1093/gbe/evab206] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/01/2021] [Indexed: 01/10/2023] Open
Abstract
Members of the gram-positive bacterial genus Staphylococcus have historically been classified into coagulase-positive Staphylococcus (CoPS) and coagulase-negative Staphylococcus (CoNS) based on the diagnostic presentation of the coagulase protein. Previous studies have noted the importance of horizontal gene transfer (HGT) and recombination in the more well-known CoPS species Staphylococcus aureus, yet little is known of the contributions of these processes in CoNS evolution. In this study, we aimed to elucidate the phylogenetic relationships, genomic characteristics, and frequencies of HGT in CoNS, which are now being recognized as major opportunistic pathogens of humans. We compiled a data set of 1,876 publicly available named CoNS genomes. These can be delineated into 55 species based on allele differences in 462 core genes and variation in accessory gene content. CoNS species are a reservoir of transferrable genes associated with resistance to diverse classes of antimicrobials. We also identified nine types of the mobile genetic element SCCmec, which carries the methicillin resistance determinant mecA. Other frequently transferred genes included those associated with resistance to heavy metals, surface-associated proteins related to virulence and biofilm formation, type VII secretion system, iron capture, recombination, and metabolic enzymes. The highest frequencies of receipt and donation of recombined DNA fragments were observed in Staphylococcus capitis, Staphylococcus caprae, Staphylococcus hominis, Staphylococcus haemolyticus, and members of the Saprophyticus species group. The variable rates of recombination and biases in transfer partners imply that certain CoNS species function as hubs of gene flow and major reservoir of genetic diversity for the entire genus.
Collapse
Affiliation(s)
- Joshua T Smith
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire, USA
| | - Cheryl P Andam
- Department of Biological Sciences, University at Albany, State University of New York, New York, USA
| |
Collapse
|
7
|
Occurrence and diversity of viruses associated with cyanobacterial communities in a Brazilian freshwater reservoir. Braz J Microbiol 2021; 52:773-785. [PMID: 33791954 DOI: 10.1007/s42770-021-00473-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 03/25/2021] [Indexed: 02/06/2023] Open
Abstract
As part of the phytoplankton of marine and freshwater environments around the world, cyanobacteria interact with viruses (cyanophages) that affect their abundance and diversity. Investigations focusing on cyanophages co-occurring with freshwater cyanobacteria are scarce, particularly in Brazil. The aim of this study was to assess the diversity of cyanophages associated with a Microcystis-dominated cyanobacterial bloom in a tropical reservoir. Samples were processed as viral fractions of water and cellular fractions, and temporal fluctuations in the abundance of Ma-LMM01-type cyanophages and their Microcystis hosts were determined by qPCR. We applied shotgun metagenomics to obtain a wider characterization of the cyanophage community. During the study period, Microcystis gene copies were quantified in all cellular fractions, and the copy number of the Ma-LMM01 phage gene tended to increase with host abundance. Metagenomic analysis demonstrated that Caudovirales was the major viral order associated with the cyanophage families Myoviridae (34-88%), Podoviridae (3-42%), and Siphoviridae (6-23%). The metagenomic analysis results confirmed the presence of Microcystis cyanophages in both viral and cellular fractions and demonstrated a high relative abundance of picocyanobacteria-related viruses and Prochlorococcus (36-52%) and Synechococcus (37-50%) phages. For other main cyanobacterial genera, no related cyanophages were identified, which was probably due to the scarce representation of cyanophage sequences in databanks. Thus, the studied reservoir hosted a diverse cyanophage community with a remarkable contribution of phages related to picoplanktonic cyanobacteria. These results provide insights that motivate future sequencing efforts to assess cyanophage diversity and recover complete genomes.
Collapse
|
8
|
Kim A, Rosenberg NA, Degnan JH. Probabilities of Unranked and Ranked Anomaly Zones under Birth-Death Models. Mol Biol Evol 2021; 37:1480-1494. [PMID: 31860090 DOI: 10.1093/molbev/msz305] [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] [Indexed: 01/23/2023] Open
Abstract
A labeled gene tree topology that is more probable than the labeled gene tree topology matching a species tree is called "anomalous." Species trees that can generate such anomalous gene trees are said to be in the "anomaly zone." Here, probabilities of "unranked" and "ranked" gene tree topologies under the multispecies coalescent are considered. A ranked tree depicts not only the topological relationship among gene lineages, as an unranked tree does, but also the sequence in which the lineages coalesce. In this article, we study how the parameters of a species tree simulated under a constant-rate birth-death process can affect the probability that the species tree lies in the anomaly zone. We find that with more than five taxa, it is possible for species trees to have both anomalous unranked and ranked gene trees. The probability of being in either type of anomaly zone increases with more taxa. The probability of anomalous gene trees also increases with higher speciation rates. We observe that the probabilities of unranked anomaly zones are higher and grow much faster than those of ranked anomaly zones as the speciation rate increases. Our simulation shows that the most probable ranked gene tree is likely to have the same unranked topology as the species tree. We design the software PRANC, which computes probabilities of ranked gene tree topologies given a species tree under the coalescent model.
Collapse
Affiliation(s)
- Anastasiia Kim
- Department of Mathematics and Statistics, University of New Mexico, Albuquerque, NM
| | | | - James H Degnan
- Department of Mathematics and Statistics, University of New Mexico, Albuquerque, NM
| |
Collapse
|
9
|
Hammerschmidt K, Landan G, Domingues Kümmel Tria F, Alcorta J, Dagan T. The Order of Trait Emergence in the Evolution of Cyanobacterial Multicellularity. Genome Biol Evol 2020; 13:5999801. [PMID: 33231627 PMCID: PMC7937182 DOI: 10.1093/gbe/evaa249] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/19/2020] [Indexed: 01/31/2023] Open
Abstract
The transition from unicellular to multicellular organisms is one of the most significant events in the history of life. Key to this process is the emergence of Darwinian individuality at the higher level: Groups must become single entities capable of reproduction for selection to shape their evolution. Evolutionary transitions in individuality are characterized by cooperation between the lower level entities and by division of labor. Theory suggests that division of labor may drive the transition to multicellularity by eliminating the trade off between two incompatible processes that cannot be performed simultaneously in one cell. Here, we examine the evolution of the most ancient multicellular transition known today, that of cyanobacteria, where we reconstruct the sequence of ecological and phenotypic trait evolution. Our results show that the prime driver of multicellularity in cyanobacteria was the expansion in metabolic capacity offered by nitrogen fixation, which was accompanied by the emergence of the filamentous morphology and succeeded by a reproductive life cycle. This was followed by the progression of multicellularity into higher complexity in the form of differentiated cells and patterned multicellularity.
Collapse
Affiliation(s)
- Katrin Hammerschmidt
- Genomic Microbiology Group, Institute of Microbiology, Kiel University, Germany,Corresponding author: E-mail:
| | - Giddy Landan
- Genomic Microbiology Group, Institute of Microbiology, Kiel University, Germany
| | | | - Jaime Alcorta
- Department of Molecular Genetics and Microbiology, Biological Sciences Faculty, Pontifical Catholic University of Chile, Santiago, Chile
| | - Tal Dagan
- Genomic Microbiology Group, Institute of Microbiology, Kiel University, Germany
| |
Collapse
|
10
|
Bauer KM, Dicovitsky R, Pellegrini M, Zhaxybayeva O, Ragusa MJ. The structure of a highly-conserved picocyanobacterial protein reveals a Tudor domain with an RNA-binding function. J Biol Chem 2019; 294:14333-14344. [PMID: 31391250 DOI: 10.1074/jbc.ra119.007938] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 08/06/2019] [Indexed: 11/06/2022] Open
Abstract
Cyanobacteria of the Prochlorococcus and marine Synechococcus genera are the most abundant photosynthetic microbes in the ocean. Intriguingly, the genomes of these bacteria are strongly divergent even within each genus, both in gene content and at the amino acid level of the encoded proteins. One striking exception to this is a 62-amino-acid protein, termed Prochlorococcus/ Synechococcus hyper-conserved protein (PSHCP). PSHCP is not only found in all sequenced Prochlorococcus and marine Synechococcus genomes, but it is also nearly 100% identical in its amino acid sequence across all sampled genomes. Such universal distribution and sequence conservation suggest an essential cellular role of PSHCP in these bacteria. However, its function is unknown. Here, we used NMR spectroscopy to determine its structure, finding that 53 of the 62 amino acids in PSHCP form a Tudor domain, whereas the remainder of the protein is disordered. NMR titration experiments revealed that PSHCP has only a weak affinity for DNA, but an 18.5-fold higher affinity for tRNA, hinting at an involvement of PSHCP in translation. Isothermal titration calorimetry experiments further revealed that PSHCP also binds single-stranded, double-stranded, and hairpin RNAs. These results provide the first insight into the structure and function of PSHCP, suggesting that PSHCP appears to be an RNA-binding protein that can recognize a broad array of RNA molecules.
Collapse
Affiliation(s)
- Katherine M Bauer
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire 03755
| | - Rose Dicovitsky
- Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755
| | - Maria Pellegrini
- Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755
| | - Olga Zhaxybayeva
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755.,Department of Computer Science, Dartmouth College, Hanover, New Hampshire 03755
| | - Michael J Ragusa
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire 03755 .,Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755
| |
Collapse
|
11
|
Park CJ, Andam CP. Within-Species Genomic Variation and Variable Patterns of Recombination in the Tetracycline Producer Streptomyces rimosus. Front Microbiol 2019; 10:552. [PMID: 30949149 PMCID: PMC6437091 DOI: 10.3389/fmicb.2019.00552] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 03/04/2019] [Indexed: 01/09/2023] Open
Abstract
Streptomyces rimosus is best known as the primary source of the tetracycline class of antibiotics, most notably oxytetracycline, which have been widely used against many gram-positive and gram-negative pathogens and protozoan parasites. However, despite the medical and agricultural importance of S. rimosus, little is known of its evolutionary history and genome dynamics. In this study, we aim to elucidate the pan-genome characteristics and phylogenetic relationships of 32 S. rimosus genomes. The S. rimosus pan-genome contains more than 22,000 orthologous gene clusters, and approximately 8.8% of these genes constitutes the core genome. A large part of the accessory genome is composed of 9,646 strain-specific genes. S. rimosus exhibits an open pan-genome (decay parameter α = 0.83) and high gene diversity between strains (genomic fluidity φ = 0.12). We also observed strain-level variation in the distribution and abundance of biosynthetic gene clusters (BGCs) and that each individual S. rimosus genome has a unique repertoire of BGCs. Lastly, we observed variation in recombination, with some strains donating or receiving DNA more often than others, strains that tend to frequently recombine with specific partners, genes that often experience recombination more than others, and variable sizes of recombined DNA sequences. We conclude that the high levels of inter-strain genomic variation in S. rimosus is partly explained by differences in recombination among strains. These results have important implications on current efforts for natural drug discovery, the ecological role of strain-level variation in microbial populations, and addressing the fundamental question of why microbes have pan-genomes.
Collapse
Affiliation(s)
- Cooper J Park
- Department of Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, NH, United States
| | - Cheryl P Andam
- Department of Molecular, Cellular, and Biomedical Sciences, University of New Hampshire, Durham, NH, United States
| |
Collapse
|
12
|
Abstract
Microbial populations exchange genetic material through a process called homologous recombination. Although this process has been studied in particular organisms, we lack an understanding of its differential impact over the genome and across microbes with different life-styles. We used a common analytical framework to assess this process in a representative set of microorganisms. Our results uncovered important trends. First, microbes with different lifestyles are differentially impacted, with endosymbionts and obligate pathogens being those less prone to undergo this process. Second, certain genetic elements such as restriction-modification systems seem to be associated with higher rates of recombination. Most importantly, recombined genomes show the footprints of natural selection in which recombined regions preferentially contain genes that can be related to specific ecological adaptations. Taken together, our results clarify the relative contributions of factors modulating homologous recombination and show evidence for a clear a role of this process in shaping microbial genomes and driving ecological adaptations. Homologous recombination (HR) enables the exchange of genetic material between and within species. Recent studies suggest that this process plays a major role in the microevolution of microbial genomes, contributing to core genome homogenization and to the maintenance of cohesive population structures. However, we still have a very poor understanding of the possible adaptive roles of intraspecific HR and of the factors that determine its differential impact across clades and lifestyles. Here we used a unified methodological framework to assess HR in 338 complete genomes from 54 phylogenetically diverse and representative prokaryotic species, encompassing different lifestyles and a broad phylogenetic distribution. Our results indicate that lifestyle and presence of restriction-modification (RM) machineries are among the main factors shaping HR patterns, with symbionts and intracellular pathogens having the lowest HR levels. Similarly, the size of exchanged genomic fragments correlated with the presence of RM and competence machineries. Finally, genes exchanged by HR showed functional enrichments which could be related to adaptations to different environments and ecological strategies. Taken together, our results clarify the factors underlying HR impact and suggest important adaptive roles of genes exchanged through this mechanism. Our results also revealed that the extent of genetic exchange correlated with lifestyle and some genomic features. Moreover, the genes in exchanged regions were enriched for functions that reflected specific adaptations, supporting identification of HR as one of the main evolutionary mechanisms shaping prokaryotic core genomes.
Collapse
|
13
|
Bobay LM, Ochman H. Factors driving effective population size and pan-genome evolution in bacteria. BMC Evol Biol 2018; 18:153. [PMID: 30314447 PMCID: PMC6186134 DOI: 10.1186/s12862-018-1272-4] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 10/04/2018] [Indexed: 02/07/2023] Open
Abstract
Background Knowledge of population-level processes is essential to understanding the efficacy of selection operating within a species. However, attempts at estimating effective population sizes (Ne) are particularly challenging in bacteria due to their extremely large census populations sizes, varying rates of recombination and arbitrary species boundaries. Results In this study, we estimated Ne for 153 species (152 bacteria and one archaeon) defined under a common framework and found that ecological lifestyle and growth rate were major predictors of Ne; and that contrary to theoretical expectations, Ne was unaffected by recombination rate. Additionally, we found that Ne shapes the evolution and diversity of total gene repertoires of prokaryotic species. Conclusion Together, these results point to a new model of genome architecture evolution in prokaryotes, in which pan-genome sizes, not individual genome sizes, are governed by drift-barrier evolution. Electronic supplementary material The online version of this article (10.1186/s12862-018-1272-4) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Louis-Marie Bobay
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, 78712, USA. .,Department of Biology, University of North Carolina at Greensboro, 321 McIver Street, PO Box 26170, Greensboro, NC, 27402, USA.
| | - Howard Ochman
- Department of Integrative Biology, University of Texas at Austin, Austin, TX, 78712, USA
| |
Collapse
|
14
|
Degnan JH, Rhodes JA. There are no caterpillars in a wicked forest. Theor Popul Biol 2015; 105:17-23. [DOI: 10.1016/j.tpb.2015.08.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 08/26/2015] [Accepted: 08/28/2015] [Indexed: 10/23/2022]
|
15
|
Co-occurring Synechococcus ecotypes occupy four major oceanic regimes defined by temperature, macronutrients and iron. ISME JOURNAL 2015. [PMID: 26208139 DOI: 10.1038/ismej.2015.115] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Marine picocyanobacteria, comprised of the genera Synechococcus and Prochlorococcus, are the most abundant and widespread primary producers in the ocean. More than 20 genetically distinct clades of marine Synechococcus have been identified, but their physiology and biogeography are not as thoroughly characterized as those of Prochlorococcus. Using clade-specific qPCR primers, we measured the abundance of 10 Synechococcus clades at 92 locations in surface waters of the Atlantic and Pacific Oceans. We found that Synechococcus partition the ocean into four distinct regimes distinguished by temperature, macronutrients and iron availability. Clades I and IV were prevalent in colder, mesotrophic waters; clades II, III and X dominated in the warm, oligotrophic open ocean; clades CRD1 and CRD2 were restricted to sites with low iron availability; and clades XV and XVI were only found in transitional waters at the edges of the other biomes. Overall, clade II was the most ubiquitous clade investigated and was the dominant clade in the largest biome, the oligotrophic open ocean. Co-occurring clades that occupy the same regime belong to distinct evolutionary lineages within Synechococcus, indicating that multiple ecotypes have evolved independently to occupy similar niches and represent examples of parallel evolution. We speculate that parallel evolution of ecotypes may be a common feature of diverse marine microbial communities that contributes to functional redundancy and the potential for resiliency.
Collapse
|
16
|
Inter-phylum HGT has shaped the metabolism of many mesophilic and anaerobic bacteria. ISME JOURNAL 2015; 9:958-67. [PMID: 25314320 DOI: 10.1038/ismej.2014.193] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 07/12/2014] [Accepted: 08/25/2014] [Indexed: 11/08/2022]
Abstract
Genome sequencing has revealed that horizontal gene transfer (HGT) is a major evolutionary process in bacteria. Although it is generally assumed that closely related organisms engage in genetic exchange more frequently than distantly related ones, the frequency of HGT among distantly related organisms and the effect of ecological relatedness on the frequency has not been rigorously assessed. Here, we devised a novel bioinformatic pipeline, which minimized the effect of over-representation of specific taxa in the available databases and other limitations of homology-based approaches by analyzing genomes in standardized triplets, to quantify gene exchange between bacterial genomes representing different phyla. Our analysis revealed the existence of networks of genetic exchange between organisms with overlapping ecological niches, with mesophilic anaerobic organisms showing the highest frequency of exchange and engaging in HGT twice as frequently as their aerobic counterparts. Examination of individual cases suggested that inter-phylum HGT is more pronounced than previously thought, affecting up to ∼ 16% of the total genes and ∼ 35% of the metabolic genes in some genomes (conservative estimation). In contrast, ribosomal and other universal protein-coding genes were subjected to HGT at least 150 times less frequently than genes encoding the most promiscuous metabolic functions (for example, various dehydrogenases and ABC transport systems), suggesting that the species tree based on the former genes may be reliable. These results indicated that the metabolic diversity of microbial communities within most habitats has been largely assembled from preexisting genetic diversity through HGT and that HGT accounts for the functional redundancy among phyla.
Collapse
|
17
|
Zorz JK, Allanach JR, Murphy CD, Roodvoets MS, Campbell DA, Cockshutt AM. The RUBISCO to Photosystem II Ratio Limits the Maximum Photosynthetic Rate in Picocyanobacteria. Life (Basel) 2015; 5:403-17. [PMID: 25658887 PMCID: PMC4390859 DOI: 10.3390/life5010403] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2014] [Revised: 01/12/2015] [Accepted: 01/22/2015] [Indexed: 01/22/2023] Open
Abstract
Marine Synechococcus and Prochlorococcus are picocyanobacteria predominating in subtropical, oligotrophic marine environments, a niche predicted to expand with climate change. When grown under common low light conditions Synechococcus WH 8102 and Prochlorococcus MED 4 show similar Cytochrome b6f and Photosystem I contents normalized to Photosystem II content, while Prochlorococcus MIT 9313 has twice the Cytochrome b6f content and four times the Photosystem I content of the other strains. Interestingly, the Prochlorococcus strains contain only one third to one half of the RUBISCO catalytic subunits compared to the marine Synechococcus strain. The maximum Photosystem II electron transport rates were similar for the two Prochlorococcus strains but higher for the marine Synechococcus strain. Photosystem II electron transport capacity is highly correlated to the molar ratio of RUBISCO active sites to Photosystem II but not to the ratio of cytochrome b6f to Photosystem II, nor to the ratio of Photosystem I: Photosystem II. Thus, the catalytic capacity for the rate-limiting step of carbon fixation, the ultimate electron sink, appears to limit electron transport rates. The high abundance of Cytochrome b6f and Photosystem I in MIT 9313, combined with the slower flow of electrons away from Photosystem II and the relatively low level of RUBISCO, are consistent with cyclic electron flow around Photosystem I in this strain.
Collapse
Affiliation(s)
- Jackie K Zorz
- Department of Chemistry & Biochemistry, Mount Allison University, Sackville, New Brunswick, E4L 1G8, Canada.
| | - Jessica R Allanach
- Department of Chemistry & Biochemistry, Mount Allison University, Sackville, New Brunswick, E4L 1G8, Canada.
| | - Cole D Murphy
- Department of Chemistry & Biochemistry, Mount Allison University, Sackville, New Brunswick, E4L 1G8, Canada.
| | - Mitchell S Roodvoets
- Department of Chemistry & Biochemistry, Mount Allison University, Sackville, New Brunswick, E4L 1G8, Canada.
| | - Douglas A Campbell
- Department of Chemistry & Biochemistry, Mount Allison University, Sackville, New Brunswick, E4L 1G8, Canada.
| | - Amanda M Cockshutt
- Department of Chemistry & Biochemistry, Mount Allison University, Sackville, New Brunswick, E4L 1G8, Canada.
| |
Collapse
|
18
|
|
19
|
Whidden CE, DeZeeuw KG, Zorz JK, Joy AP, Barnett DA, Johnson MS, Zhaxybayeva O, Cockshutt AM. Quantitative and functional characterization of the hyper-conserved protein of Prochlorococcus and marine Synechococcus. PLoS One 2014; 9:e109327. [PMID: 25360678 PMCID: PMC4215834 DOI: 10.1371/journal.pone.0109327] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 09/11/2014] [Indexed: 11/26/2022] Open
Abstract
A large fraction of any bacterial genome consists of hypothetical protein-coding open reading frames (ORFs). While most of these ORFs are present only in one or a few sequenced genomes, a few are conserved, often across large phylogenetic distances. Such conservation provides clues to likely uncharacterized cellular functions that need to be elucidated. Marine cyanobacteria from the Prochlorococcus/marine Synechococcus clade are dominant bacteria in oceanic waters and are significant contributors to global primary production. A Hyper Conserved Protein (PSHCP) of unknown function is 100% conserved at the amino acid level in genomes of Prochlorococcus/marine Synechococcus, but lacks homologs outside of this clade. In this study we investigated Prochlorococcus marinus strains MED4 and MIT 9313 and Synechococcus sp. strain WH 8102 for the transcription of the PSHCP gene using RT-Q-PCR, for the presence of the protein product through quantitative immunoblotting, and for the protein's binding partners in a pull down assay. Significant transcription of the gene was detected in all strains. The PSHCP protein content varied between 8±1 fmol and 26±9 fmol per ug total protein, depending on the strain. The 50 S ribosomal protein L2, the Photosystem I protein PsaD and the Ycf48-like protein were found associated with the PSHCP protein in all strains and not appreciably or at all in control experiments. We hypothesize that PSHCP is a protein associated with the ribosome, and is possibly involved in photosystem assembly.
Collapse
Affiliation(s)
- Caroline E. Whidden
- Department of Chemistry & Biochemistry, Mount Allison University, Sackville, NB, Canada
| | - Katrina G. DeZeeuw
- Department of Chemistry & Biochemistry, Mount Allison University, Sackville, NB, Canada
| | - Jackie K. Zorz
- Department of Chemistry & Biochemistry, Mount Allison University, Sackville, NB, Canada
| | - Andrew P. Joy
- Atlantic Cancer Research Institute, Moncton, NB, Canada
| | | | - Milo S. Johnson
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, United States of America
| | - Olga Zhaxybayeva
- Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire, United States of America
- Department of Computer Science, Dartmouth College, Hanover, New Hampshire, United States of America
- * E-mail: (OZ); (AMC)
| | - Amanda M. Cockshutt
- Department of Chemistry & Biochemistry, Mount Allison University, Sackville, NB, Canada
- * E-mail: (OZ); (AMC)
| |
Collapse
|
20
|
Biller SJ, Berube PM, Berta-Thompson JW, Kelly L, Roggensack SE, Awad L, Roache-Johnson KH, Ding H, Giovannoni SJ, Rocap G, Moore LR, Chisholm SW. Genomes of diverse isolates of the marine cyanobacterium Prochlorococcus. Sci Data 2014; 1:140034. [PMID: 25977791 PMCID: PMC4421930 DOI: 10.1038/sdata.2014.34] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 08/19/2014] [Indexed: 11/30/2022] Open
Abstract
The marine cyanobacterium Prochlorococcus is the numerically dominant photosynthetic organism in the oligotrophic oceans, and a model system in marine microbial ecology. Here we report 27 new whole genome sequences (2 complete and closed; 25 of draft quality) of cultured isolates, representing five major phylogenetic clades of Prochlorococcus. The sequenced strains were isolated from diverse regions of the oceans, facilitating studies of the drivers of microbial diversity—both in the lab and in the field. To improve the utility of these genomes for comparative genomics, we also define pre-computed clusters of orthologous groups of proteins (COGs), indicating how genes are distributed among these and other publicly available Prochlorococcus genomes. These data represent a significant expansion of Prochlorococcus reference genomes that are useful for numerous applications in microbial ecology, evolution and oceanography.
Collapse
Affiliation(s)
- Steven J Biller
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts, USA
| | - Paul M Berube
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts, USA
| | - Jessie W Berta-Thompson
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts, USA ; Microbiology Graduate Program, Massachusetts Institute of Technology , Cambridge, Massachusetts, USA
| | - Libusha Kelly
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts, USA
| | - Sara E Roggensack
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts, USA
| | - Lana Awad
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts, USA
| | | | - Huiming Ding
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts, USA ; Department of Biology, Massachusetts Institute of Technology , Cambridge, Massachusetts, USA
| | | | - Gabrielle Rocap
- School of Oceanography, Center for Environmental Genomics, University of Washington , Seattle, Washington, USA
| | - Lisa R Moore
- Department of Biological Sciences, University of Southern Maine , Portland, Maine, USA
| | - Sallie W Chisholm
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts, USA ; Department of Biology, Massachusetts Institute of Technology , Cambridge, Massachusetts, USA
| |
Collapse
|
21
|
Ochoa de Alda JAG, Esteban R, Diago ML, Houmard J. The plastid ancestor originated among one of the major cyanobacterial lineages. Nat Commun 2014; 5:4937. [PMID: 25222494 DOI: 10.1038/ncomms5937] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Accepted: 08/08/2014] [Indexed: 12/15/2022] Open
Abstract
The primary endosymbiotic origin of chloroplasts is now well established but the identification of the present cyanobacteria most closely related to the plastid ancestor remains debated. We analyse the evolutionary trajectory of a subset of highly conserved cyanobacterial proteins (core) along the plastid lineage, those which were not lost after the endosymbiosis. We concatenate the sequences of 33 cyanobacterial core proteins that share a congruent evolutionary history, with their eukaryotic counterparts to reconstruct their phylogeny using sophisticated evolutionary models. We perform an independent reconstruction using concatenated 16S and 23S rRNA sequences. These complementary approaches converge to a plastid origin occurring during the divergence of one of the major cyanobacterial lineages that include N2-fixing filamentous cyanobacteria and species able to differentiate heterocysts.
Collapse
Affiliation(s)
- Jesús A G Ochoa de Alda
- 1] Grupo Hortofruenol, INTAEX-CICYTEX, Avenida Adolfo Suárez, s/n, 06071 Badajoz, Spain [2] School of Biology, IE University, Cardenal Zúñiga 12, 40003 Segovia, Spain [3]
| | - Rocío Esteban
- School of Biology, IE University, Cardenal Zúñiga 12, 40003 Segovia, Spain
| | - María Luz Diago
- School of Biology, IE University, Cardenal Zúñiga 12, 40003 Segovia, Spain
| | | |
Collapse
|
22
|
Reductive genome evolution at both ends of the bacterial population size spectrum. Nat Rev Microbiol 2014; 12:841-50. [DOI: 10.1038/nrmicro3331] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
23
|
Prabha R, Singh DP, Gupta SK, Rai A. Whole genome phylogeny of Prochlorococcus marinus group of cyanobacteria: genome alignment and overlapping gene approach. Interdiscip Sci 2014; 6:149-57. [PMID: 25172453 DOI: 10.1007/s12539-013-0024-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 10/21/2013] [Accepted: 01/10/2014] [Indexed: 11/29/2022]
Abstract
Prochlorococcus is the smallest known oxygenic phototrophic marine cyanobacterium dominating the mid-latitude oceans. Physiologically and genetically distinct P. marinus isolates from many oceans in the world were assigned two different groups, a tightly clustered high-light (HL)-adapted and a divergent low-light (LL-) adapted clade. Phylogenetic analysis of this cyanobacterium on the basis of 16S rRNA and other conserved genes did not show consistency with its phenotypic behavior. We analyzed phylogeny of this genus on the basis of complete genome sequences through genome alignment, overlapping-gene content and gene-order approach. Phylogenetic tree of P. marinus obtained by comparing whole genome sequences in contrast to that based on 16S rRNA gene, corresponded well with the HL/LL ecotypic distinction of twelve strains and showed consistency with phenotypic classification of P. marinus. Evidence for the horizontal descent and acquisition of genes within and across the genus was observed. Many genes involved in metabolic functions were found to be conserved across these genomes and many were continuously gained by different strains as per their needs during the course of their evolution. Consistency in the physiological and genetic phylogeny based on whole genome sequence is established. These observations improve our understanding about the adaptation and diversification of these organisms under evolutionary pressure.
Collapse
Affiliation(s)
- Ratna Prabha
- National Bureau of Agriculturally Important Microorganisms, Indian Council of Agricultural Research, Kushmaur, Maunath Bhanjan, 275103, India
| | | | | | | |
Collapse
|
24
|
Matzke NJ, Shih PM, Kerfeld CA. Bayesian analysis of congruence of core genes in Prochlorococcus and Synechococcus and implications on horizontal gene transfer. PLoS One 2014; 9:e85103. [PMID: 24465485 PMCID: PMC3897415 DOI: 10.1371/journal.pone.0085103] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 11/22/2013] [Indexed: 01/28/2023] Open
Abstract
It is often suggested that horizontal gene transfer is so ubiquitous in microbes that the concept of a phylogenetic tree representing the pattern of vertical inheritance is oversimplified or even positively misleading. "Universal proteins" have been used to infer the organismal phylogeny, but have been criticized as being only the "tree of one percent." Currently, few options exist for those wishing to rigorously assess how well a universal protein phylogeny, based on a relative handful of well-conserved genes, represents the phylogenetic histories of hundreds of genes. Here, we address this problem by proposing a visualization method and a statistical test within a Bayesian framework. We use the genomes of marine cyanobacteria, a group thought to exhibit substantial amounts of HGT, as a test case. We take 379 orthologous gene families from 28 cyanobacteria genomes and estimate the Bayesian posterior distributions of trees - a "treecloud" - for each, as well as for a concatenated dataset based on putative "universal proteins." We then calculate the average distance between trees within and between all treeclouds on various metrics and visualize this high-dimensional space with non-metric multidimensional scaling (NMMDS). We show that the tree space is strongly clustered and that the universal protein treecloud is statistically significantly closer to the center of this tree space than any individual gene treecloud. We apply several commonly-used tests for incongruence/HGT and show that they agree HGT is rare in this dataset, but make different choices about which genes were subject to HGT. Our results show that the question of the representativeness of the "tree of one percent" is a quantitative empirical question, and that the phylogenetic central tendency is a meaningful observation even if many individual genes disagree due to the various sources of incongruence.
Collapse
Affiliation(s)
- Nicholas J. Matzke
- Department of Integrative Biology, University of California, Berkeley, California, United States of America
| | - Patrick M. Shih
- Department of Plant and Microbial Biology, University of California, Berkeley, California, United States of America
| | - Cheryl A. Kerfeld
- Department of Plant and Microbial Biology, University of California, Berkeley, California, United States of America
- US Department of Energy-Joint Genome Institute, Walnut Creek, California, United States of America
- * E-mail:
| |
Collapse
|
25
|
Saw JHW, Schatz M, Brown MV, Kunkel DD, Foster JS, Shick H, Christensen S, Hou S, Wan X, Donachie SP. Cultivation and complete genome sequencing of Gloeobacter kilaueensis sp. nov., from a lava cave in Kīlauea Caldera, Hawai'i. PLoS One 2013; 8:e76376. [PMID: 24194836 PMCID: PMC3806779 DOI: 10.1371/journal.pone.0076376] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 08/24/2013] [Indexed: 02/05/2023] Open
Abstract
The ancestor of Gloeobacter violaceus PCC 7421(T) is believed to have diverged from that of all known cyanobacteria before the evolution of thylakoid membranes and plant plastids. The long and largely independent evolutionary history of G. violaceus presents an organism retaining ancestral features of early oxygenic photoautotrophs, and in whom cyanobacteria evolution can be investigated. No other Gloeobacter species has been described since the genus was established in 1974 (Rippka et al., Arch Microbiol 100:435). Gloeobacter affiliated ribosomal gene sequences have been reported in environmental DNA libraries, but only the type strain's genome has been sequenced. However, we report here the cultivation of a new Gloeobacter species, G. kilaueensis JS1(T), from an epilithic biofilm in a lava cave in Kīlauea Caldera, Hawai'i. The strain's genome was sequenced from an enriched culture resembling a low-complexity metagenomic sample, using 9 kb paired-end 454 pyrosequences and 400 bp paired-end Illumina reads. The JS1(T) and G. violaceus PCC 7421(T) genomes have little gene synteny despite sharing 2842 orthologous genes; comparing the genomes shows they do not belong to the same species. Our results support establishing a new species to accommodate JS1(T), for which we propose the name Gloeobacter kilaueensis sp. nov. Strain JS1(T) has been deposited in the American Type Culture Collection (BAA-2537), the Scottish Marine Institute's Culture Collection of Algae and Protozoa (CCAP 1431/1), and the Belgian Coordinated Collections of Microorganisms (ULC0316). The G. kilaueensis holotype has been deposited in the Algal Collection of the US National Herbarium (US# 217948). The JS1(T) genome sequence has been deposited in GenBank under accession number CP003587. The G+C content of the genome is 60.54 mol%. The complete genome sequence of G. kilaueensis JS1(T) may further understanding of cyanobacteria evolution, and the shift from anoxygenic to oxygenic photosynthesis.
Collapse
Affiliation(s)
- Jimmy H. W. Saw
- Department of Microbiology, University of Hawai'i at Mānoa, Honolulu, Hawai'i, United States of America
| | - Michael Schatz
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, United States of America
| | - Mark V. Brown
- NASA Astrobiology Institute, University of Hawai'i, Honolulu, Hawai'i, United States of America
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, New South Wales, Australia
| | - Dennis D. Kunkel
- Dennis Kunkel Microscopy, Inc., Kailua, Hawai'i, United States of America
| | - Jamie S. Foster
- Department of Microbiology and Cell Science, University of Florida Space Life Science Laboratory, Kennedy Space Center, Kennedy, Florida, United States of America
| | | | - Stephanie Christensen
- Department of Oceanography, School of Ocean and Earth Science and Technology, University of Hawai'i at Mānoa, Honolulu, Hawai'I, United States of America
| | - Shaobin Hou
- Department of Microbiology, University of Hawai'i at Mānoa, Honolulu, Hawai'i, United States of America
- Advanced Studies of Genomics, Proteomics and Bioinformatics, University of Hawai'i at Mānoa, Honolulu, Hawai'i, United States of America
| | - Xuehua Wan
- Department of Microbiology, University of Hawai'i at Mānoa, Honolulu, Hawai'i, United States of America
- Advanced Studies of Genomics, Proteomics and Bioinformatics, University of Hawai'i at Mānoa, Honolulu, Hawai'i, United States of America
| | - Stuart P. Donachie
- Department of Microbiology, University of Hawai'i at Mānoa, Honolulu, Hawai'i, United States of America
| |
Collapse
|
26
|
Skippington E, Ragan MA. Phylogeny rather than ecology or lifestyle biases the construction of Escherichia coli-Shigella genetic exchange communities. Open Biol 2013; 2:120112. [PMID: 23091700 PMCID: PMC3472396 DOI: 10.1098/rsob.120112] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 08/20/2012] [Indexed: 11/12/2022] Open
Abstract
Genetic material can be transmitted not only vertically from parent to offspring, but also laterally (horizontally) from one bacterial lineage to another. Lateral genetic transfer is non-uniform; biases in its nature or frequency construct communities of genetic exchange. These biases have been proposed to arise from phylogenetic relatedness, shared ecology and/or common lifestyle. Here, we test these hypotheses using a graph-based abstraction of inferred genetic-exchange relationships among 27 Escherichia coli and Shigella genomes. We show that although barriers to inter-phylogenetic group lateral transfer are low, E. coli and Shigella are more likely to have exchanged genetic material with close relatives. We find little evidence of bias arising from shared environment or lifestyle. More than one-third of donor-recipient pairs in our analysis show some level of fragmentary gene transfer. Thus, within the E. coli-Shigella clade, intact genes and gene fragments have been disseminated non-uniformly and at appreciable frequency, constructing communities that transgress environmental and lifestyle boundaries.
Collapse
Affiliation(s)
- Elizabeth Skippington
- Institute for Molecular Bioscience and Australian Research Council Centre of Excellence in Bioinformatics, The University of Queensland, Brisbane, Queensland 4072, Australia
| | | |
Collapse
|
27
|
Williams D, Gogarten JP, Papke RT. Quantifying homologous replacement of loci between haloarchaeal species. Genome Biol Evol 2013; 4:1223-44. [PMID: 23160063 PMCID: PMC3542582 DOI: 10.1093/gbe/evs098] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
In vitro studies of the haloarchaeal genus Haloferax have demonstrated
their ability to frequently exchange DNA between species, whereas rates of homologous
recombination estimated from natural populations in the genus Halorubrum
are high enough to maintain random association of alleles between five loci. To quantify
the effects of gene transfer and recombination of commonly held (relaxed core) genes
during the evolution of the class Halobacteria (haloarchaea), we reconstructed the history
of 21 genomes representing all major groups. Using a novel algorithm and a concatenated
ribosomal protein phylogeny as a reference, we created a directed horizontal genetic
transfer (HGT) network of contemporary and ancestral genomes. Gene order analysis revealed
that 90% of testable HGTs were by direct homologous replacement, rather than
nonhomologous integration followed by a loss. Network analysis revealed an inverse
log-linear relationship between HGT frequency and ribosomal protein evolutionary distance
that is maintained across the deepest divergences in Halobacteria. We use this
mathematical relationship to estimate the total transfers and amino acid substitutions
delivered by HGTs in each genome, providing a measure of chimerism. For the relaxed core
genes of each genome, we conservatively estimate that 11–20% of their
evolution occurred in other haloarchaea. Our findings are unexpected, because the transfer
and homologous recombination of relaxed core genes between members of the class
Halobacteria disrupts the coevolution of genes; however, the generation of new
combinations of divergent but functionally related genes may lead to adaptive phenotypes
not available through cumulative mutations and recombination within a single
population.
Collapse
Affiliation(s)
- David Williams
- Department of Molecular and Cell Biology, University of Connecticut, CT, USA
| | | | | |
Collapse
|
28
|
Stolzer M, Lai H, Xu M, Sathaye D, Vernot B, Durand D. Inferring duplications, losses, transfers and incomplete lineage sorting with nonbinary species trees. ACTA ACUST UNITED AC 2013; 28:i409-i415. [PMID: 22962460 PMCID: PMC3436813 DOI: 10.1093/bioinformatics/bts386] [Citation(s) in RCA: 218] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Motivation: Gene duplication (D), transfer (T), loss (L) and incomplete lineage sorting (I) are crucial to the evolution of gene families and the emergence of novel functions. The history of these events can be inferred via comparison of gene and species trees, a process called reconciliation, yet current reconciliation algorithms model only a subset of these evolutionary processes. Results: We present an algorithm to reconcile a binary gene tree with a nonbinary species tree under a DTLI parsimony criterion. This is the first reconciliation algorithm to capture all four evolutionary processes driving tree incongruence and the first to reconcile non-binary species trees with a transfer model. Our algorithm infers all optimal solutions and reports complete, temporally feasible event histories, giving the gene and species lineages in which each event occurred. It is fixed-parameter tractable, with polytime complexity when the maximum species outdegree is fixed. Application of our algorithms to prokaryotic and eukaryotic data show that use of an incomplete event model has substantial impact on the events inferred and resulting biological conclusions. Availability: Our algorithms have been implemented in Notung, a freely available phylogenetic reconciliation software package, available at http://www.cs.cmu.edu/~durand/Notung. Contact:mstolzer@andrew.cmu.edu
Collapse
Affiliation(s)
- Maureen Stolzer
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
| | | | | | | | | | | |
Collapse
|
29
|
Bansal MS, Banay G, Harlow TJ, Gogarten JP, Shamir R. Systematic inference of highways of horizontal gene transfer in prokaryotes. ACTA ACUST UNITED AC 2013; 29:571-9. [PMID: 23335015 DOI: 10.1093/bioinformatics/btt021] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
MOTIVATION Horizontal gene transfer (HGT) plays a crucial role in the evolution of prokaryotic species. Typically, no more than a few genes are horizontally transferred between any two species. However, several studies identified pairs of species (or linages) between which many different genes were horizontally transferred. Such a pair is said to be linked by a highway of gene sharing. Inferring such highways is crucial to understanding the evolution of prokaryotes and for inferring past symbiotic and ecological associations among different species. RESULTS We present a new improved method for systematically detecting highways of gene sharing. As we demonstrate using a variety of simulated datasets, our method is highly accurate and efficient, and robust to noise and high rates of HGT. We further validate our method by applying it to a published dataset of >22 000 gene trees from 144 prokaryotic species. Our method makes it practical, for the first time, to perform accurate highway analysis quickly and easily even on large datasets with high rates of HGT. AVAILABILITY AND IMPLEMENTATION An implementation of the method can be freely downloaded from: http://acgt.cs.tau.ac.il/hide.
Collapse
Affiliation(s)
- Mukul S Bansal
- The Blavatnik School of Computer Science, Tel-Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | | | | | | | | |
Collapse
|
30
|
Dagan T, Roettger M, Stucken K, Landan G, Koch R, Major P, Gould SB, Goremykin VV, Rippka R, Tandeau de Marsac N, Gugger M, Lockhart PJ, Allen JF, Brune I, Maus I, Pühler A, Martin WF. Genomes of Stigonematalean cyanobacteria (subsection V) and the evolution of oxygenic photosynthesis from prokaryotes to plastids. Genome Biol Evol 2013; 5:31-44. [PMID: 23221676 PMCID: PMC3595030 DOI: 10.1093/gbe/evs117] [Citation(s) in RCA: 154] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/04/2012] [Indexed: 01/12/2023] Open
Abstract
Cyanobacteria forged two major evolutionary transitions with the invention of oxygenic photosynthesis and the bestowal of photosynthetic lifestyle upon eukaryotes through endosymbiosis. Information germane to understanding those transitions is imprinted in cyanobacterial genomes, but deciphering it is complicated by lateral gene transfer (LGT). Here, we report genome sequences for the morphologically most complex true-branching cyanobacteria, and for Scytonema hofmanni PCC 7110, which with 12,356 proteins is the most gene-rich prokaryote currently known. We investigated components of cyanobacterial evolution that have been vertically inherited, horizontally transferred, and donated to eukaryotes at plastid origin. The vertical component indicates a freshwater origin for water-splitting photosynthesis. Networks of the horizontal component reveal that 60% of cyanobacterial gene families have been affected by LGT. Plant nuclear genes acquired from cyanobacteria define a lower bound frequency of 611 multigene families that, in turn, specify diazotrophic cyanobacterial lineages as having a gene collection most similar to that possessed by the plastid ancestor.
Collapse
Affiliation(s)
- Tal Dagan
- Institute of Genomic Microbiology, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Henley WJ, Litaker RW, Novoveská L, Duke CS, Quemada HD, Sayre RT. Initial risk assessment of genetically modified (GM) microalgae for commodity-scale biofuel cultivation. ALGAL RES 2013. [DOI: 10.1016/j.algal.2012.11.001] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
|
32
|
Lapierre P, Lasek-Nesselquist E, Gogarten JP. The impact of HGT on phylogenomic reconstruction methods. Brief Bioinform 2012; 15:79-90. [DOI: 10.1093/bib/bbs050] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
|
33
|
Gupta RS. Origin and Spread of Photosynthesis Based upon Conserved Sequence Features in Key Bacteriochlorophyll Biosynthesis Proteins. Mol Biol Evol 2012; 29:3397-412. [DOI: 10.1093/molbev/mss145] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
34
|
Mao F, Williams D, Zhaxybayeva O, Poptsova M, Lapierre P, Gogarten JP, Xu Y. Quartet decomposition server: a platform for analyzing phylogenetic trees. BMC Bioinformatics 2012; 13:123. [PMID: 22676320 PMCID: PMC3447714 DOI: 10.1186/1471-2105-13-123] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Accepted: 06/07/2012] [Indexed: 11/11/2022] Open
Abstract
Background The frequent exchange of genetic material among prokaryotes means that extracting a majority or plurality phylogenetic signal from many gene families, and the identification of gene families that are in significant conflict with the plurality signal is a frequent task in comparative genomics, and especially in phylogenomic analyses. Decomposition of gene trees into embedded quartets (unrooted trees each with four taxa) is a convenient and statistically powerful technique to address this challenging problem. This approach was shown to be useful in several studies of completely sequenced microbial genomes. Results We present here a web server that takes a collection of gene phylogenies, decomposes them into quartets, generates a Quartet Spectrum, and draws a split network. Users are also provided with various data download options for further analyses. Each gene phylogeny is to be represented by an assessment of phylogenetic information content, such as sets of trees reconstructed from bootstrap replicates or sampled from a posterior distribution. The Quartet Decomposition server is accessible at http://quartets.uga.edu. Conclusions The Quartet Decomposition server presented here provides a convenient means to perform Quartet Decomposition analyses and will empower users to find statistically supported phylogenetic conflicts.
Collapse
Affiliation(s)
- Fenglou Mao
- Department of Biochemistry and Molecular Biology, University of Georgia, 120 Green St, Athens, GA 30622, USA
| | | | | | | | | | | | | |
Collapse
|
35
|
Temporal orchestration of glycogen synthase (GlgA) gene expression and glycogen accumulation in the oceanic picoplanktonic cyanobacterium Synechococcus sp. strain WH8103. Appl Environ Microbiol 2012; 78:4744-7. [PMID: 22522678 DOI: 10.1128/aem.00254-12] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Glycogen is accumulated during the latter half of the diel cycle in Synechococcus sp. strain WH8103 following a midday maximum in glgA (encoding glycogen synthase) mRNA abundance. This temporal pattern is quite distinct from that of Prochlorococcus and may highlight divergent regulatory control of carbon/nitrogen metabolism in these closely related picocyanobacteria.
Collapse
|
36
|
Affiliation(s)
- R Thane Papke
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269-3125, USA.
| | | |
Collapse
|
37
|
Morrissey J, Bowler C. Iron utilization in marine cyanobacteria and eukaryotic algae. Front Microbiol 2012; 3:43. [PMID: 22408637 PMCID: PMC3296057 DOI: 10.3389/fmicb.2012.00043] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Accepted: 01/27/2012] [Indexed: 12/21/2022] Open
Abstract
Iron is essential for aerobic organisms. Additionally, photosynthetic organisms must maintain the iron-rich photosynthetic electron transport chain, which likely evolved in the iron-replete Proterozoic ocean. The subsequent rise in oxygen since those times has drastically decreased the levels of bioavailable iron, indicating that adaptations have been made to maintain sufficient cellular iron levels in the midst of scarcity. In combination with physiological studies, the recent sequencing of marine microorganism genomes and transcriptomes has begun to reveal the mechanisms of iron acquisition and utilization that allow marine microalgae to persist in iron limited environments.
Collapse
Affiliation(s)
- Joe Morrissey
- Ecole Normale Supérieur, Institut de Biologie de l'ENS Paris, France Inserm U1024, Paris, France CNRS UMR 8197, Paris, France
| | | |
Collapse
|
38
|
de la Haba RR, Márquez MC, Papke RT, Ventosa A. Multilocus sequence analysis of the family Halomonadaceae. Int J Syst Evol Microbiol 2012; 62:520-538. [DOI: 10.1099/ijs.0.032938-0] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Multilocus sequence analysis (MLSA) protocols have been developed for species circumscription for many taxa. However, at present, no studies based on MLSA have been performed within any moderately halophilic bacterial group. To test the usefulness of MLSA with these kinds of micro-organisms, the family Halomonadaceae, which includes mainly halophilic bacteria, was chosen as a model. This family comprises ten genera with validly published names and 85 species of environmental, biotechnological and clinical interest. In some cases, the phylogenetic relationships between members of this family, based on 16S rRNA gene sequence comparisons, are not clear and a deep phylogenetic analysis using several housekeeping genes seemed appropriate. Here, MLSA was applied using the 16S rRNA, 23S rRNA, atpA, gyrB, rpoD and secA genes for species of the family Halomonadaceae. Phylogenetic trees based on the individual and concatenated gene sequences revealed that the family Halomonadaceae formed a monophyletic group of micro-organisms within the order Oceanospirillales. With the exception of the genera Halomonas and Modicisalibacter, all other genera within this family were phylogenetically coherent. Five of the six studied genes (16S rRNA, 23S rRNA, gyrB, rpoD and secA) showed a consistent evolutionary history. However, the results obtained with the atpA gene were different; thus, this gene may not be considered useful as an individual gene phylogenetic marker within this family. The phylogenetic methods produced variable results, with those generated from the maximum-likelihood and neighbour-joining algorithms being more similar than those obtained by maximum-parsimony methods. Horizontal gene transfer (HGT) plays an important evolutionary role in the family Halomonadaceae; however, the impact of recombination events in the phylogenetic analysis was minimized by concatenating the six loci, which agreed with the current taxonomic scheme for this family. Finally, the findings of this study also indicated that the 16S rRNA, gyrB and rpoD genes were the most suitable genes for future taxonomic studies using MLSA within the family Halomonadaceae.
Collapse
Affiliation(s)
- Rafael R. de la Haba
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, 41012 Sevilla, Spain
| | - M. Carmen Márquez
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, 41012 Sevilla, Spain
| | - R. Thane Papke
- Department of Molecular and Cell Biology, University of Connecticut, 06269 Storrs, CT, USA
| | - Antonio Ventosa
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Sevilla, 41012 Sevilla, Spain
| |
Collapse
|
39
|
Mazard S, Ostrowski M, Partensky F, Scanlan DJ. Multi-locus sequence analysis, taxonomic resolution and biogeography of marine Synechococcus. Environ Microbiol 2012; 14:372-86. [PMID: 21651684 DOI: 10.1111/j.1462-2920.2011.02514.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Conserved markers such as the 16S rRNA gene do not provide sufficient molecular resolution to identify spatially structured populations of marine Synechococcus, or 'ecotypes' adapted to distinct ecological niches. Multi-locus sequence analysis targeting seven 'core' genes was employed to taxonomically resolve Synechococcus isolates and correlate previous phylogenetic analyses encompassing a range of markers. Despite the recognized importance of lateral gene transfer in shaping the genomes of marine cyanobacteria, multi-locus sequence analysis of more than 120 isolates reflects a clonal population structure of major lineages and subgroups. A single core genome locus, petB, encoding the cytochrome b(6) subunit of the cytochrome b(6) f complex, was selected to expand our understanding of the diversity and ecology of marine Synechococcus populations. Environmental petB sequences cloned from contrasting sites highlight numerous genetically and ecologically distinct clusters, some of which represent novel, environmentally abundant clades without cultured representatives. With a view to scaling ecological analyses, the short sequence, taxonomic resolution and accurate automated alignment of petB is ideally suited to high-throughput and high-resolution sequencing projects to explore links between the ecology, evolution and biology of marine Synechococcus.
Collapse
Affiliation(s)
- Sophie Mazard
- School of Life Sciences, University of Warwick, Gibbet Hill Road, Coventry, UK
| | | | | | | |
Collapse
|
40
|
Bansal MS, Banay G, Gogarten JP, Shamir R. Detecting highways of horizontal gene transfer. J Comput Biol 2012; 18:1087-114. [PMID: 21899418 DOI: 10.1089/cmb.2011.0066] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In a horizontal gene transfer (HGT) event, a gene is transferred between two species that do not have an ancestor-descendant relationship. Typically, no more than a few genes are horizontally transferred between any two species. However, several studies identified pairs of species between which many different genes were horizontally transferred. Such a pair is said to be linked by a highway of gene sharing. We present a method for inferring such highways. Our method is based on the fact that the evolutionary histories of horizontally transferred genes disagree with the corresponding species phylogeny. Specifically, given a set of gene trees and a trusted rooted species tree, each gene tree is first decomposed into its constituent quartet trees and the quartets that are inconsistent with the species tree are identified. Our method finds a pair of species such that a highway between them explains the largest (normalized) fraction of inconsistent quartets. For a problem on n species and m input quartet trees, we give an efficient O(m + n(2))-time algorithm for detecting highways, which is optimal with respect to the quartets input size. An application of our method to a dataset of 1128 genes from 11 cyanobacterial species, as well as to simulated datasets, illustrates the efficacy of our method.
Collapse
Affiliation(s)
- Mukul S Bansal
- The Blavatnik School of Computer Science, Tel-Aviv University, Tel-Aviv, Israel
| | | | | | | |
Collapse
|
41
|
Bay RA, Bielawski JP. Recombination Detection Under Evolutionary Scenarios Relevant to Functional Divergence. J Mol Evol 2012; 73:273-86. [DOI: 10.1007/s00239-011-9473-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Accepted: 11/07/2011] [Indexed: 12/01/2022]
|
42
|
Yu T, Li J, Yang Y, Qi L, Chen B, Zhao F, Bao Q, Wu J. Codon usage patterns and adaptive evolution of marine unicellular cyanobacteria Synechococcus and Prochlorococcus. Mol Phylogenet Evol 2012; 62:206-13. [DOI: 10.1016/j.ympev.2011.09.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2011] [Revised: 09/03/2011] [Accepted: 09/23/2011] [Indexed: 10/16/2022]
|
43
|
Narechania A, Baker RH, Sit R, Kolokotronis SO, DeSalle R, Planet PJ. Random Addition Concatenation Analysis: a novel approach to the exploration of phylogenomic signal reveals strong agreement between core and shell genomic partitions in the cyanobacteria. Genome Biol Evol 2011; 4:30-43. [PMID: 22094860 PMCID: PMC3267395 DOI: 10.1093/gbe/evr121] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/12/2011] [Indexed: 11/14/2022] Open
Abstract
Recent whole-genome approaches to microbial phylogeny have emphasized partitioning genes into functional classes, often focusing on differences between a stable core of genes and a variable shell. To rigorously address the effects of partitioning and combining genes in genome-level analyses, we developed a novel technique called Random Addition Concatenation Analysis (RADICAL). RADICAL operates by sequentially concatenating randomly chosen gene partitions starting with a single-gene partition and ending with the entire genomic data set. A phylogenetic tree is built for every successive addition, and the entire process is repeated creating multiple random concatenation paths. The result is a library of trees representing a large variety of differently sized random gene partitions. This library can then be mined to identify unique topologies, assess overall agreement, and measure support for different trees. To evaluate RADICAL, we used 682 orthologous genes across 13 cyanobacterial genomes. Despite previous assertions of substantial differences between a core and a shell set of genes for this data set, RADICAL reveals the two partitions contain congruent phylogenetic signal. Substantial disagreement within the data set is limited to a few nodes and genes involved in metabolism, a functional group that is distributed evenly between the core and the shell partitions. We highlight numerous examples where RADICAL reveals aspects of phylogenetic behavior not evident by examining individual gene trees or a "'total evidence" tree. Our method also demonstrates that most emergent phylogenetic signal appears early in the concatenation process. The software is freely available at http://desalle.amnh.org.
Collapse
Affiliation(s)
- Apurva Narechania
- Sackler Institute for Comparative Genomics, American Museum of Natural History
| | - Richard H. Baker
- Sackler Institute for Comparative Genomics, American Museum of Natural History
| | - Ryan Sit
- Sackler Institute for Comparative Genomics, American Museum of Natural History
| | - Sergios-Orestis Kolokotronis
- Sackler Institute for Comparative Genomics, American Museum of Natural History
- Present address: Department of Biology, Barnard College, Columbia University
| | - Rob DeSalle
- Sackler Institute for Comparative Genomics, American Museum of Natural History
| | - Paul J. Planet
- Sackler Institute for Comparative Genomics, American Museum of Natural History
- Department of Pediatrics, College of Physicians and Surgeons, Columbia University
| |
Collapse
|
44
|
Mühling M. On the culture-independent assessment of the diversity and distribution of Prochlorococcus. Environ Microbiol 2011; 14:567-79. [DOI: 10.1111/j.1462-2920.2011.02589.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
45
|
Tai V, Poon AFY, Paulsen IT, Palenik B. Selection in coastal Synechococcus (cyanobacteria) populations evaluated from environmental metagenomes. PLoS One 2011; 6:e24249. [PMID: 21931665 PMCID: PMC3170327 DOI: 10.1371/journal.pone.0024249] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Accepted: 08/05/2011] [Indexed: 11/19/2022] Open
Abstract
Environmental metagenomics provides snippets of genomic sequences from all organisms in an environmental sample and are an unprecedented resource of information for investigating microbial population genetics. Current analytical methods, however, are poorly equipped to handle metagenomic data, particularly of short, unlinked sequences. A custom analytical pipeline was developed to calculate dN/dS ratios, a common metric to evaluate the role of selection in the evolution of a gene, from environmental metagenomes sequenced using 454 technology of flow-sorted populations of marine Synechococcus, the dominant cyanobacteria in coastal environments. The large majority of genes (98%) have evolved under purifying selection (dN/dS<1). The metagenome sequence coverage of the reference genomes was not uniform and genes that were highly represented in the environment (i.e. high read coverage) tended to be more evolutionarily conserved. Of the genes that may have evolved under positive selection (dN/dS>1), 77 out of 83 (93%) were hypothetical. Notable among annotated genes, ribosomal protein L35 appears to be under positive selection in one Synechococcus population. Other annotated genes, in particular a possible porin, a large-conductance mechanosensitive channel, an ATP binding component of an ABC transporter, and a homologue of a pilus retraction protein had regions of the gene with elevated dN/dS. With the increasing use of next-generation sequencing in metagenomic investigations of microbial diversity and ecology, analytical methods need to accommodate the peculiarities of these data streams. By developing a means to analyze population diversity data from these environmental metagenomes, we have provided the first insight into the role of selection in the evolution of Synechococcus, a globally significant primary producer.
Collapse
Affiliation(s)
- Vera Tai
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, United States of America
| | - Art F. Y. Poon
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, British Columbia, Canada
| | - Ian T. Paulsen
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - Brian Palenik
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, California, United States of America
| |
Collapse
|
46
|
Rae BD, Förster B, Badger MR, Price GD. The CO2-concentrating mechanism of Synechococcus WH5701 is composed of native and horizontally-acquired components. PHOTOSYNTHESIS RESEARCH 2011; 109:59-72. [PMID: 21384181 DOI: 10.1007/s11120-011-9641-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Accepted: 02/24/2011] [Indexed: 05/30/2023]
Abstract
The cyanobacterial CO(2)-concentrating mechanism (CCM) is an effective adaptation that increases the carbon dioxide (CO(2)) concentration around the primary photosynthetic enzyme Ribulose-1,5-bisphosphate Carboxylase/Oxygenase (RuBisCO). α-Cyanobacteria (those containing Form1-A RuBisCO within cso-type α-carboxysomes) have a limited CCM composed of a small number of Ci-transporters whereas β-cyanobacteria (those species containing Form-1B RuBisCO within ccm-type β-carboxysomes) exhibit a more diverse CCM with a greater variety in Ci-transporter complement and regulation. In the coastal species Synechococcus sp. WH5701 (α-cyanobacteria), the minimal α-cyanobacterial CCM has been supplemented with β-cyanobacterial Ci transporters through the process of horizontal gene transfer (HGT). These transporters are transcriptionally regulated in response to external Ci-depletion however this change in transcript abundance is not correlated with a physiological induction. WH5701 exhibits identical physiological responses grown at 4% CO(2) (K (1/2) ≈ 31 μM Ci) and after induction with 0.04% CO(2) (K (1/2) ≈ 29 μM Ci). Insensitivity to external Ci concentration is an unusual characteristic of the WH5701 CCM which is a result of evolution by HGT. Our bioinformatic and physiological data support the hypothesis that WH5701 represents a clade of α-cyanobacterial species in transition from the marine/oligotrophic environment to a coastal/freshwater environment.
Collapse
Affiliation(s)
- Benjamin D Rae
- Division of Plant Science, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University, Canberra, ACT, Australia
| | | | | | | |
Collapse
|
47
|
Beauregard-Racine J, Bicep C, Schliep K, Lopez P, Lapointe FJ, Bapteste E. Of woods and webs: possible alternatives to the tree of life for studying genomic fluidity in E. coli. Biol Direct 2011; 6:39; discussion 39. [PMID: 21774799 PMCID: PMC3160433 DOI: 10.1186/1745-6150-6-39] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Accepted: 07/20/2011] [Indexed: 12/26/2022] Open
Abstract
Background We introduce several forest-based and network-based methods for exploring microbial evolution, and apply them to the study of thousands of genes from 30 strains of E. coli. This case study illustrates how additional analyses could offer fast heuristic alternatives to standard tree of life (TOL) approaches. Results We use gene networks to identify genes with atypical modes of evolution, and genome networks to characterize the evolution of genetic partnerships between E. coli and mobile genetic elements. We develop a novel polychromatic quartet method to capture patterns of recombination within E. coli, to update the clanistic toolkit, and to search for the impact of lateral gene transfer and of pathogenicity on gene evolution in two large forests of trees bearing E. coli. We unravel high rates of lateral gene transfer involving E. coli (about 40% of the trees under study), and show that both core genes and shell genes of E. coli are affected by non-tree-like evolutionary processes. We show that pathogenic lifestyle impacted the structure of 30% of the gene trees, and that pathogenic strains are more likely to transfer genes with one another than with non-pathogenic strains. In addition, we propose five groups of genes as candidate mobile modules of pathogenicity. We also present strong evidence for recent lateral gene transfer between E. coli and mobile genetic elements. Conclusions Depending on which evolutionary questions biologists want to address (i.e. the identification of modules, genetic partnerships, recombination, lateral gene transfer, or genes with atypical evolutionary modes, etc.), forest-based and network-based methods are preferable to the reconstruction of a single tree, because they provide insights and produce hypotheses about the dynamics of genome evolution, rather than the relative branching order of species and lineages. Such a methodological pluralism - the use of woods and webs - is to be encouraged to analyse the evolutionary processes at play in microbial evolution. This manuscript was reviewed by: Ford Doolittle, Tal Pupko, Richard Burian, James McInerney, Didier Raoult, and Yan Boucher
Collapse
|
48
|
Dreher TW, Brown N, Bozarth CS, Schwartz AD, Riscoe E, Thrash C, Bennett SE, Tzeng SC, Maier CS. A freshwater cyanophage whose genome indicates close relationships to photosynthetic marine cyanomyophages. Environ Microbiol 2011; 13:1858-74. [PMID: 21605306 PMCID: PMC4185292 DOI: 10.1111/j.1462-2920.2011.02502.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Bacteriophage S-CRM01 has been isolated from a freshwater strain of Synechococcus and shown to be present in the upper Klamath River valley in northern California and Oregon. The genome of this lytic T4-like phage has a 178,563 bp circular genetic map with 297 predicted protein-coding genes and 33 tRNA genes that represent all 20-amino-acid specificities. Analyses based on gene sequence and gene content indicate a close phylogenetic relationship to the 'photosynthetic' marine cyanomyophages infecting Synechococcus and Prochlorococcus. Such relatedness suggests that freshwater and marine phages can draw on a common gene pool. The genome can be considered as being comprised of three regions. Region 1 is populated predominantly with structural genes, recognized as such by homology to other T4-like phages and by identification in a proteomic analysis of purified virions. Region 2 contains most of the genes with roles in replication, recombination, nucleotide metabolism and regulation of gene expression, as well as 5 of the 6 signature genes of the photosynthetic cyanomyophages (hli03, hsp20, mazG, phoH and psbA; cobS is present in Region 3). Much of Regions 1 and 2 are syntenic with marine cyanomyophage genomes, except that a segment encompassing Region 2 is inverted. Region 3 contains a high proportion (85%) of genes that are unique to S-CRM01, as well as most of the tRNA genes. Regions 1 and 2 contain many predicted late promoters, with a combination of CTAAATA and ATAAATA core sequences. Two predicted genes that are unusual in phage genomes are homologues of cellular spoT and nusG.
Collapse
Affiliation(s)
- Theo W Dreher
- Department of Microbiology, Oregon State University, Corvallis, Oregon 97331, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
49
|
O'Malley MA, Koonin EV. How stands the Tree of Life a century and a half after The Origin? Biol Direct 2011; 6:32. [PMID: 21714936 PMCID: PMC3158114 DOI: 10.1186/1745-6150-6-32] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Accepted: 06/30/2011] [Indexed: 12/21/2022] Open
Abstract
We examine the Tree of Life (TOL) as an evolutionary hypothesis and a heuristic. The original TOL hypothesis has failed but a new "statistical TOL hypothesis" is promising. The TOL heuristic usefully organizes data without positing fundamental evolutionary truth.
Collapse
Affiliation(s)
- Maureen A O'Malley
- Department of Philosophy, Quadrangle A14, University of Sydney, NSW 2006, Australia
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda MD20894, USA
| |
Collapse
|
50
|
Klatt CG, Wood JM, Rusch DB, Bateson MM, Hamamura N, Heidelberg JF, Grossman AR, Bhaya D, Cohan FM, Kühl M, Bryant DA, Ward DM. Community ecology of hot spring cyanobacterial mats: predominant populations and their functional potential. ISME JOURNAL 2011; 5:1262-78. [PMID: 21697961 DOI: 10.1038/ismej.2011.73] [Citation(s) in RCA: 137] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Phototrophic microbial mat communities from 60°C and 65°C regions in the effluent channels of Mushroom and Octopus Springs (Yellowstone National Park, WY, USA) were investigated by shotgun metagenomic sequencing. Analyses of assembled metagenomic sequences resolved six dominant chlorophototrophic populations and permitted the discovery and characterization of undescribed but predominant community members and their physiological potential. Linkage of phylogenetic marker genes and functional genes showed novel chlorophototrophic bacteria belonging to uncharacterized lineages within the order Chlorobiales and within the Kingdom Chloroflexi. The latter is the first chlorophototrophic member of Kingdom Chloroflexi that lies outside the monophyletic group of chlorophototrophs of the Order Chloroflexales. Direct comparison of unassembled metagenomic sequences to genomes of representative isolates showed extensive genetic diversity, genomic rearrangements and novel physiological potential in native populations as compared with genomic references. Synechococcus spp. metagenomic sequences showed a high degree of synteny with the reference genomes of Synechococcus spp. strains A and B', but synteny declined with decreasing sequence relatedness to these references. There was evidence of horizontal gene transfer among native populations, but the frequency of these events was inversely proportional to phylogenetic relatedness.
Collapse
Affiliation(s)
- Christian G Klatt
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT 59717, USA.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|