101
|
Abstract
Most phylogenetic methods are model-based and depend on models of evolution designed to approximate the evolutionary processes. Several methods have been developed to identify suitable models of evolution for phylogenetic analysis of alignments of nucleotide or amino acid sequences and some of these methods are now firmly embedded in the phylogenetic protocol. However, in a disturbingly large number of cases, it appears that these models were used without acknowledgement of their inherent shortcomings. In this chapter, we discuss the problem of model selection and show how some of the inherent shortcomings may be identified and overcome.
Collapse
Affiliation(s)
| | - Vivek Jayaswal
- School of Biomedical Sciences, Queensland University of Technology, Brisbane, QLD, Australia
| | - Faisal M Ababneh
- Department of Mathematics & Statistics, Al-Hussein Bin Talal University, Ma'an, Jordan
| | - John Robinson
- School of Mathematics & Statistics, University of Sydney, Sydney, NSW, Australia
| |
Collapse
|
102
|
Lombard J. Early evolution of polyisoprenol biosynthesis and the origin of cell walls. PeerJ 2016; 4:e2626. [PMID: 27812422 PMCID: PMC5088576 DOI: 10.7717/peerj.2626] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Accepted: 09/27/2016] [Indexed: 11/30/2022] Open
Abstract
After being a matter of hot debate for years, the presence of lipid membranes in the last common ancestor of extant organisms (i.e., the cenancestor) now begins to be generally accepted. By contrast, cenancestral cell walls have attracted less attention, probably owing to the large diversity of cell walls that exist in the three domains of life. Many prokaryotic cell walls, however, are synthesized using glycosylation pathways with similar polyisoprenol lipid carriers and topology (i.e., orientation across the cell membranes). Here, we provide the first systematic phylogenomic report on the polyisoprenol biosynthesis pathways in the three domains of life. This study shows that, whereas the last steps of the polyisoprenol biosynthesis are unique to the respective domain of life of which they are characteristic, the enzymes required for basic unsaturated polyisoprenol synthesis can be traced back to the respective last common ancestor of each of the three domains of life. As a result, regardless of the topology of the tree of life that may be considered, the most parsimonious hypothesis is that these enzymes were inherited in modern lineages from the cenancestor. This observation supports the presence of an enzymatic mechanism to synthesize unsaturated polyisoprenols in the cenancestor and, since these molecules are notorious lipid carriers in glycosylation pathways involved in the synthesis of a wide diversity of prokaryotic cell walls, it provides the first indirect evidence of the existence of a hypothetical unknown cell wall synthesis mechanism in the cenancestor.
Collapse
Affiliation(s)
- Jonathan Lombard
- Biosciences, University of Exeter, Exeter, United Kingdom; National Evolutionary Synthesis Center, Durham, NC, United States of America
| |
Collapse
|
103
|
Fernández R, Edgecombe GD, Giribet G. Exploring Phylogenetic Relationships within Myriapoda and the Effects of Matrix Composition and Occupancy on Phylogenomic Reconstruction. Syst Biol 2016; 65:871-89. [PMID: 27162151 PMCID: PMC4997009 DOI: 10.1093/sysbio/syw041] [Citation(s) in RCA: 74] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Accepted: 04/28/2016] [Indexed: 11/14/2022] Open
Abstract
Myriapods, including the diverse and familiar centipedes and millipedes, are one of the dominant terrestrial arthropod groups. Although molecular evidence has shown that Myriapoda is monophyletic, its internal phylogeny remains contentious and understudied, especially when compared to those of Chelicerata and Hexapoda. Until now, efforts have focused on taxon sampling (e.g., by including a handful of genes from many species) or on maximizing matrix size (e.g., by including hundreds or thousands of genes in just a few species), but a phylogeny maximizing sampling at both levels remains elusive. In this study, we analyzed 40 Illumina transcriptomes representing 3 of the 4 myriapod classes (Diplopoda, Chilopoda, and Symphyla); 25 transcriptomes were newly sequenced to maximize representation at the ordinal level in Diplopoda and at the family level in Chilopoda. Ten supermatrices were constructed to explore the effect of several potential phylogenetic biases (e.g., rate of evolution, heterotachy) at 3 levels of gene occupancy per taxon (50%, 75%, and 90%). Analyses based on maximum likelihood and Bayesian mixture models retrieved monophyly of each myriapod class, and resulted in 2 alternative phylogenetic positions for Symphyla, as sister group to Diplopoda + Chilopoda, or closer to Diplopoda, the latter hypothesis having been traditionally supported by morphology. Within centipedes, all orders were well supported, but 2 deep nodes remained in conflict in the different analyses despite dense taxon sampling at the family level. Relationships among centipede orders in all analyses conducted with the most complete matrix (90% occupancy) are at odds not only with the sparser but more gene-rich supermatrices (75% and 50% supermatrices) and with the matrices optimizing phylogenetic informativeness or most conserved genes, but also with previous hypotheses based on morphology, development, or other molecular data sets. Our results indicate that a high percentage of ribosomal proteins in the most complete matrices, in conjunction with distance from the root, can act in concert to compromise the estimated relationships within the ingroup. We discuss the implications of these findings in the context of the ever more prevalent quest for completeness in phylogenomic studies.
Collapse
Affiliation(s)
- Rosa Fernández
- Museum of Comparative Zoology & Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
| | - Gregory D Edgecombe
- Department of Earth Sciences, The Natural History Museum, Cromwell Road, London SW7 5BD, UK
| | - Gonzalo Giribet
- Museum of Comparative Zoology & Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
| |
Collapse
|
104
|
Derelle R, López-García P, Timpano H, Moreira D. A Phylogenomic Framework to Study the Diversity and Evolution of Stramenopiles (=Heterokonts). Mol Biol Evol 2016; 33:2890-2898. [PMID: 27512113 DOI: 10.1093/molbev/msw168] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Stramenopiles or heterokonts constitute one of the most speciose and diverse clades of protists. It includes ecologically important algae (such as diatoms or large multicellular brown seaweeds), as well as heterotrophic (e.g., bicosoecids, MAST groups) and parasitic (e.g., Blastocystis, oomycetes) species. Despite their evolutionary and ecological relevance, deep phylogenetic relationships among stramenopile groups, inferred mostly from small-subunit rDNA phylogenies, remain unresolved, especially for the heterotrophic taxa. Taking advantage of recently released stramenopile transcriptome and genome sequences, as well as data from the genomic assembly of the MAST-3 species Incisomonas marina generated in our laboratory, we have carried out the first extensive phylogenomic analysis of stramenopiles, including representatives of most major lineages. Our analyses, based on a large data set of 339 widely distributed proteins, strongly support a root of stramenopiles lying between two clades, Bigyra and Gyrista (Pseudofungi plus Ochrophyta). Additionally, our analyses challenge the Phaeista-Khakista dichotomy of photosynthetic stramenopiles (ochrophytes) as two groups previously considered to be part of the Phaeista (Pelagophyceae and Dictyochophyceae), branch with strong support with the Khakista (Bolidophyceae and Diatomeae). We propose a new classification of ochrophytes within the two groups Chrysista and Diatomista to reflect the new phylogenomic results. Our stramenopile phylogeny provides a robust phylogenetic framework to investigate the evolution and diversification of this group of ecologically relevant protists.
Collapse
Affiliation(s)
- Romain Derelle
- Unité d'Ecologie, Systématique et Evolution, Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud/Paris-Saclay, AgroParisTech, Orsay, France
| | - Purificación López-García
- Unité d'Ecologie, Systématique et Evolution, Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud/Paris-Saclay, AgroParisTech, Orsay, France
| | - Hélène Timpano
- Unité d'Ecologie, Systématique et Evolution, Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud/Paris-Saclay, AgroParisTech, Orsay, France
| | - David Moreira
- Unité d'Ecologie, Systématique et Evolution, Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud/Paris-Saclay, AgroParisTech, Orsay, France
| |
Collapse
|
105
|
Lombard J. The multiple evolutionary origins of the eukaryotic N-glycosylation pathway. Biol Direct 2016; 11:36. [PMID: 27492357 PMCID: PMC4973528 DOI: 10.1186/s13062-016-0137-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 07/26/2016] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND The N-glycosylation is an essential protein modification taking place in the membranes of the endoplasmic reticulum (ER) in eukaryotes and the plasma membranes in archaea. It shares mechanistic similarities based on the use of polyisoprenol lipid carriers with other glycosylation pathways involved in the synthesis of bacterial cell wall components (e.g. peptidoglycan and teichoic acids). Here, a phylogenomic analysis was carried out to examine the validity of rival hypotheses suggesting alternative archaeal or bacterial origins to the eukaryotic N-glycosylation pathway. RESULTS The comparison of several polyisoprenol-based glycosylation pathways from the three domains of life shows that most of the implicated proteins belong to a limited number of superfamilies. The N-glycosylation pathway enzymes are ancestral to the eukaryotes, but their origins are mixed: Alg7, Dpm and maybe also one gene of the glycosyltransferase 1 (GT1) superfamily and Stt3 have proteoarchaeal (TACK superphylum) origins; alg2/alg11 may have resulted from the duplication of the original GT1 gene; the lumen glycosyltransferases were probably co-opted and multiplied through several gene duplications during eukaryogenesis; Alg13/Alg14 are more similar to their bacterial homologues; and Alg1, Alg5 and a putative flippase have unknown origins. CONCLUSIONS The origin of the eukaryotic N-glycosylation pathway is not unique and less straightforward than previously thought: some basic components likely have proteoarchaeal origins, but the pathway was extensively developed before the eukaryotic diversification through multiple gene duplications, protein co-options, neofunctionalizations and even possible horizontal gene transfers from bacteria. These results may have important implications for our understanding of the ER evolution and eukaryogenesis. REVIEWERS This article was reviewed by Pr. Patrick Forterre and Dr. Sergei Mekhedov (nominated by Editorial Board member Michael Galperin).
Collapse
Affiliation(s)
- Jonathan Lombard
- National Evolutionary Synthesis Center, 2024 W. Main Street Suite A200, Durham, NC, 27705, USA.
- Biosciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK.
| |
Collapse
|
106
|
Mingrone J, Susko E, Bielawski J. Smoothed Bootstrap Aggregation for Assessing Selection Pressure at Amino Acid Sites. Mol Biol Evol 2016; 33:2976-2989. [PMID: 27486222 DOI: 10.1093/molbev/msw160] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
To detect positive selection at individual amino acid sites, most methods use an empirical Bayes approach. After parameters of a Markov process of codon evolution are estimated via maximum likelihood, they are passed to Bayes formula to compute the posterior probability that a site evolved under positive selection. A difficulty with this approach is that parameter estimates with large errors can negatively impact Bayesian classification. By assigning priors to some parameters, Bayes Empirical Bayes (BEB) mitigates this problem. However, as implemented, it imposes uniform priors, which causes it to be overly conservative in some cases. When standard regularity conditions are not met and parameter estimates are unstable, inference, even under BEB, can be negatively impacted. We present an alternative to BEB called smoothed bootstrap aggregation (SBA), which bootstraps site patterns from an alignment of protein coding DNA sequences to accommodate the uncertainty in the parameter estimates. We show that deriving the correction for parameter uncertainty from the data in hand, in combination with kernel smoothing techniques, improves site specific inference of positive selection. We compare BEB to SBA by simulation and real data analysis. Simulation results show that SBA balances accuracy and power at least as well as BEB, and when parameter estimates are unstable, the performance gap between BEB and SBA can widen in favor of SBA. SBA is applicable to a wide variety of other inference problems in molecular evolution.
Collapse
Affiliation(s)
- Joseph Mingrone
- Department of Mathematics and Statistics, Dalhousie University, Halifax, NS, Canada Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, NS, Canada
| | - Edward Susko
- Department of Mathematics and Statistics, Dalhousie University, Halifax, NS, Canada Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, NS, Canada
| | - Joseph Bielawski
- Department of Mathematics and Statistics, Dalhousie University, Halifax, NS, Canada Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, NS, Canada Department of Biology, Dalhousie University, Halifax, NS, Canada
| |
Collapse
|
107
|
Irisarri I, Meyer A. The Identification of the Closest Living Relative(s) of Tetrapods: Phylogenomic Lessons for Resolving Short Ancient Internodes. Syst Biol 2016; 65:1057-1075. [PMID: 27425642 DOI: 10.1093/sysbio/syw057] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 06/08/2016] [Indexed: 01/08/2023] Open
Abstract
Identifying the closest living relative(s) of tetrapods is an important, yet still contested question in vertebrate phylogenetics. Three hypotheses are possible and ruling out alternatives has proven difficult even with large molecular data sets due to weak phylogenetic signal coupled nonphylogenetic noise resulting from relatively rapid speciation events that occurred a long time ago ([Formula: see text]400 Ma). Here, we revisit the identity of the closest living relative of land vertebrates from a phylogenomic perspective and include new genomic data for all extant lungfish genera. RNA-seq proves to be a great alternative to genomic sequencing, which currently is technically not feasible in lungfishes due to their huge (50-130 Gb) and repetitive genomes. We examined the most important sources of systematic error, namely long-branch attraction (LBA), compositional heterogeneity and distribution of missing data and applied different correction techniques. A multispecies coalescent approach is used to account for deep coalescence that might come from the short and deep internodes separating early sarcopterygian splits. Concatenation methods favored lungfishes as the closest living relatives of tetrapods with strong statistical support. Amino acid profile mixture models can unambiguously resolve this difficult internode thanks to their ability to avoid systematic error. We assessed the performance of different site-heterogeneous models and data partitioning and compared the ability of different strategies designed to overcome LBA, including taxon manipulation, reduction of among-lineage rate heterogeneity and removal of fast-evolving or compositionally heterogeneous positions. The identification of lungfish as sister group of tetrapods is robust regarding the effects of nonstationary composition and distribution of missing data. The multispecies coalescent method reconstructed strongly supported topologies that were congruent with concatenation, despite pervasive gene tree heterogeneity. We reject alternative topologies for early sarcopterygian relationships by increasing the signal-to-noise ratio in our alignments. The analytical pipeline outlined here combines probabilistic phylogenomic inference with methods for evaluating data quality, model adequacy, and assessing systematic error, and thus is likely to help resolve similarly difficult internodes in the tree of life. [Coalescence; coelacanth; compositional heterogeneity; gene tree; long-branch attraction; lungfish; missing data; model misspecification; phylogenomic; species tree; systematic error.].
Collapse
Affiliation(s)
- Iker Irisarri
- Laboratory for Zoology and Evolutionary Biology, Department of Biology, University of Konstanz, 78464 Konstanz, Germany
| | - Axel Meyer
- Laboratory for Zoology and Evolutionary Biology, Department of Biology, University of Konstanz, 78464 Konstanz, Germany
| |
Collapse
|
108
|
Abstract
Mitochondrion-related organelles (MROs) have arisen independently in a wide range of anaerobic protist lineages. Only a few of these organelles and their functions have been investigated in detail, and most of what is known about MROs comes from studies of parasitic organisms such as the parabasalid Trichomonas vaginalis. Here, we describe the MRO of a free-living anaerobic jakobid excavate, Stygiella incarcerata. We report an RNAseq-based reconstruction of S. incarcerata’s MRO proteome, with an associated biochemical map of the pathways predicted to be present in this organelle. The pyruvate metabolism and oxidative stress response pathways are strikingly similar to those found in the MROs of other anaerobic protists, such as Pygsuia and Trichomonas. This elegant example of convergent evolution is suggestive of an anaerobic biochemical ‘module’ of prokaryotic origins that has been laterally transferred among eukaryotes, enabling them to adapt rapidly to anaerobiosis. We also identified genes corresponding to a variety of mitochondrial processes not found in Trichomonas, including intermembrane space components of the mitochondrial protein import apparatus, and enzymes involved in amino acid metabolism and cardiolipin biosynthesis. In this respect, the MROs of S. incarcerata more closely resemble those of the much more distantly related free-living organisms Pygsuia biforma and Cantina marsupialis, likely reflecting these organisms’ shared lifestyle as free-living anaerobes.
Collapse
Affiliation(s)
- Michelle M Leger
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada
| | - Laura Eme
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada
| | - Laura A Hug
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada
| | - Andrew J Roger
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, Canada
| |
Collapse
|
109
|
Cenci U, Moog D, Curtis BA, Tanifuji G, Eme L, Lukeš J, Archibald JM. Heme pathway evolution in kinetoplastid protists. BMC Evol Biol 2016; 16:109. [PMID: 27193376 PMCID: PMC4870792 DOI: 10.1186/s12862-016-0664-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Accepted: 04/21/2016] [Indexed: 01/09/2023] Open
Abstract
Background Kinetoplastea is a diverse protist lineage composed of several of the most successful parasites on Earth, organisms whose metabolisms have coevolved with those of the organisms they infect. Parasitic kinetoplastids have emerged from free-living, non-pathogenic ancestors on multiple occasions during the evolutionary history of the group. Interestingly, in both parasitic and free-living kinetoplastids, the heme pathway—a core metabolic pathway in a wide range of organisms—is incomplete or entirely absent. Indeed, Kinetoplastea investigated thus far seem to bypass the need for heme biosynthesis by acquiring heme or intermediate metabolites directly from their environment. Results Here we report the existence of a near-complete heme biosynthetic pathway in Perkinsela spp., kinetoplastids that live as obligate endosymbionts inside amoebozoans belonging to the genus Paramoeba/Neoparamoeba. We also use phylogenetic analysis to infer the evolution of the heme pathway in Kinetoplastea. Conclusion We show that Perkinsela spp. is a deep-branching kinetoplastid lineage, and that lateral gene transfer has played a role in the evolution of heme biosynthesis in Perkinsela spp. and other Kinetoplastea. We also discuss the significance of the presence of seven of eight heme pathway genes in the Perkinsela genome as it relates to its endosymbiotic relationship with Paramoeba. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0664-6) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Ugo Cenci
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada.,Centre for Comparative Genomics and Evolutionary Bioinformatics, Halifax, Nova Scotia, Canada
| | - Daniel Moog
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada.,Centre for Comparative Genomics and Evolutionary Bioinformatics, Halifax, Nova Scotia, Canada
| | - Bruce A Curtis
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada.,Centre for Comparative Genomics and Evolutionary Bioinformatics, Halifax, Nova Scotia, Canada
| | - Goro Tanifuji
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
| | - Laura Eme
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada.,Centre for Comparative Genomics and Evolutionary Bioinformatics, Halifax, Nova Scotia, Canada
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, and Faculty of Sciences, University of South Bohemia, České Budӗjovice, Czech Republic.,Canadian Institute for Advanced Research, Toronto, Canada
| | - John M Archibald
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada. .,Centre for Comparative Genomics and Evolutionary Bioinformatics, Halifax, Nova Scotia, Canada. .,Canadian Institute for Advanced Research, Toronto, Canada.
| |
Collapse
|
110
|
Trifinopoulos J, Nguyen LT, von Haeseler A, Minh BQ. W-IQ-TREE: a fast online phylogenetic tool for maximum likelihood analysis. Nucleic Acids Res 2016; 44:W232-5. [PMID: 27084950 PMCID: PMC4987875 DOI: 10.1093/nar/gkw256] [Citation(s) in RCA: 2373] [Impact Index Per Article: 296.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This article presents W-IQ-TREE, an intuitive and user-friendly web interface and server for IQ-TREE, an efficient phylogenetic software for maximum likelihood analysis. W-IQ-TREE supports multiple sequence types (DNA, protein, codon, binary and morphology) in common alignment formats and a wide range of evolutionary models including mixture and partition models. W-IQ-TREE performs fast model selection, partition scheme finding, efficient tree reconstruction, ultrafast bootstrapping, branch tests, and tree topology tests. All computations are conducted on a dedicated computer cluster and the users receive the results via URL or email. W-IQ-TREE is available at http://iqtree.cibiv.univie.ac.at. It is free and open to all users and there is no login requirement.
Collapse
Affiliation(s)
- Jana Trifinopoulos
- Center for Integrative Bioinformatics, Max F. Perutz Laboratories, University of Vienna, Medical University of Vienna, 1030 Vienna, Austria
| | - Lam-Tung Nguyen
- Center for Integrative Bioinformatics, Max F. Perutz Laboratories, University of Vienna, Medical University of Vienna, 1030 Vienna, Austria
| | - Arndt von Haeseler
- Center for Integrative Bioinformatics, Max F. Perutz Laboratories, University of Vienna, Medical University of Vienna, 1030 Vienna, Austria Bioinformatics and Computational Biology, Faculty of Computer Science, University of Vienna, 1090 Vienna, Austria
| | - Bui Quang Minh
- Center for Integrative Bioinformatics, Max F. Perutz Laboratories, University of Vienna, Medical University of Vienna, 1030 Vienna, Austria
| |
Collapse
|
111
|
Cannon JT, Vellutini BC, Smith J, Ronquist F, Jondelius U, Hejnol A. Xenacoelomorpha is the sister group to Nephrozoa. Nature 2016; 530:89-93. [PMID: 26842059 DOI: 10.1038/nature16520] [Citation(s) in RCA: 197] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2015] [Accepted: 12/07/2015] [Indexed: 01/06/2023]
Abstract
The position of Xenacoelomorpha in the tree of life remains a major unresolved question in the study of deep animal relationships. Xenacoelomorpha, comprising Acoela, Nemertodermatida, and Xenoturbella, are bilaterally symmetrical marine worms that lack several features common to most other bilaterians, for example an anus, nephridia, and a circulatory system. Two conflicting hypotheses are under debate: Xenacoelomorpha is the sister group to all remaining Bilateria (= Nephrozoa, namely protostomes and deuterostomes) or is a clade inside Deuterostomia. Thus, determining the phylogenetic position of this clade is pivotal for understanding the early evolution of bilaterian features, or as a case of drastic secondary loss of complexity. Here we show robust phylogenomic support for Xenacoelomorpha as the sister taxon of Nephrozoa. Our phylogenetic analyses, based on 11 novel xenacoelomorph transcriptomes and using different models of evolution under maximum likelihood and Bayesian inference analyses, strongly corroborate this result. Rigorous testing of 25 experimental data sets designed to exclude data partitions and taxa potentially prone to reconstruction biases indicates that long-branch attraction, saturation, and missing data do not influence these results. The sister group relationship between Nephrozoa and Xenacoelomorpha supported by our phylogenomic analyses implies that the last common ancestor of bilaterians was probably a benthic, ciliated acoelomate worm with a single opening into an epithelial gut, and that excretory organs, coelomic cavities, and nerve cords evolved after xenacoelomorphs separated from the stem lineage of Nephrozoa.
Collapse
Affiliation(s)
| | - Bruno Cossermelli Vellutini
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgate 55, 5008 Bergen, Norway
| | - Julian Smith
- Department of Biology, Winthrop University, 701 Oakland Avenue, Rock Hill, South Carolina 29733, USA
| | - Fredrik Ronquist
- Naturhistoriska Riksmuseet, PO Box 50007, SE-104 05 Stockholm, Sweden
| | - Ulf Jondelius
- Naturhistoriska Riksmuseet, PO Box 50007, SE-104 05 Stockholm, Sweden
| | - Andreas Hejnol
- Sars International Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgate 55, 5008 Bergen, Norway
| |
Collapse
|
112
|
Echave J, Spielman SJ, Wilke CO. Causes of evolutionary rate variation among protein sites. Nat Rev Genet 2016; 17:109-21. [PMID: 26781812 DOI: 10.1038/nrg.2015.18] [Citation(s) in RCA: 176] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
It has long been recognized that certain sites within a protein, such as sites in the protein core or catalytic residues in enzymes, are evolutionarily more conserved than other sites. However, our understanding of rate variation among sites remains surprisingly limited. Recent progress to address this includes the development of a wide array of reliable methods to estimate site-specific substitution rates from sequence alignments. In addition, several molecular traits have been identified that correlate with site-specific mutation rates, and novel mechanistic biophysical models have been proposed to explain the observed correlations. Nonetheless, current models explain, at best, approximately 60% of the observed variance, highlighting the limitations of current methods and models and the need for new research directions.
Collapse
Affiliation(s)
- Julian Echave
- Escuela de Ciencia y Tecnología, Universidad Nacional de San Martín, 1650 San Martín, Buenos Aires, Argentina
| | - Stephanie J Spielman
- Department of Integrative Biology, Center for Computational Biology and Bioinformatics, and Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Claus O Wilke
- Department of Integrative Biology, Center for Computational Biology and Bioinformatics, and Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas 78712, USA
| |
Collapse
|
113
|
Cannon JT, Kocot KM. Phylogenomics Using Transcriptome Data. Methods Mol Biol 2016; 1452:65-80. [PMID: 27460370 DOI: 10.1007/978-1-4939-3774-5_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This chapter presents a generalized protocol for conducting phylogenetic analyses using large-scale molecular datasets, specifically using transcriptome data from the Illumina sequencing platform. The general molecular lab bench protocol consists of RNA extraction, cDNA synthesis, and sequencing, in this case via Illumina. After sequences have been obtained, bioinformatics methods are used to assemble raw reads, identify coding regions, and categorize sequences from different species into groups of orthologous genes (OGs). The specific OGs to be used for phylogenetic inference are selected using a custom shell script. Finally, the selected orthologous groups are concatenated into a supermatrix. Generalized methods for phylogenomic inference using maximum likelihood and Bayesian inference software are presented.
Collapse
Affiliation(s)
- Johanna Taylor Cannon
- Department of Zoology, Naturhistoriska Riksmuseet, 50007, SE-104 05, Stockholm, Sweden.
| | - Kevin Michael Kocot
- Department of Biological Sciences and Alabama Museum of Natural History, The University of Alabama, 307 Mary Harmon Bryant Hall, Tuscaloosa, AL, 35487, USA
| |
Collapse
|
114
|
Lartillot N. Probabilistic models of eukaryotic evolution: time for integration. Philos Trans R Soc Lond B Biol Sci 2015; 370:20140338. [PMID: 26323768 PMCID: PMC4571576 DOI: 10.1098/rstb.2014.0338] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/03/2015] [Indexed: 11/12/2022] Open
Abstract
In spite of substantial work and recent progress, a global and fully resolved picture of the macroevolutionary history of eukaryotes is still under construction. This concerns not only the phylogenetic relations among major groups, but also the general characteristics of the underlying macroevolutionary processes, including the patterns of gene family evolution associated with endosymbioses, as well as their impact on the sequence evolutionary process. All these questions raise formidable methodological challenges, calling for a more powerful statistical paradigm. In this direction, model-based probabilistic approaches have played an increasingly important role. In particular, improved models of sequence evolution accounting for heterogeneities across sites and across lineages have led to significant, although insufficient, improvement in phylogenetic accuracy. More recently, one main trend has been to move away from simple parametric models and stepwise approaches, towards integrative models explicitly considering the intricate interplay between multiple levels of macroevolutionary processes. Such integrative models are in their infancy, and their application to the phylogeny of eukaryotes still requires substantial improvement of the underlying models, as well as additional computational developments.
Collapse
Affiliation(s)
- Nicolas Lartillot
- Laboratoire de Biométrie et Biologie Evolutive, UMR CNRS 5558, Université Claude Bernard Lyon 1, F-69622 Villeurbanne Cedex, France
| |
Collapse
|
115
|
Ankarklev J, Franzén O, Peirasmaki D, Jerlström-Hultqvist J, Lebbad M, Andersson J, Andersson B, Svärd SG. Comparative genomic analyses of freshly isolated Giardia intestinalis assemblage A isolates. BMC Genomics 2015; 16:697. [PMID: 26370391 PMCID: PMC4570179 DOI: 10.1186/s12864-015-1893-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 09/01/2015] [Indexed: 12/31/2022] Open
Abstract
Background The diarrhea-causing protozoan Giardia intestinalis makes up a species complex of eight different assemblages (A-H), where assemblage A and B infect humans. Comparative whole-genome analyses of three of these assemblages have shown that there is significant divergence at the inter-assemblage level, however little is currently known regarding variation at the intra-assemblage level. We have performed whole genome sequencing of two sub-assemblage AII isolates, recently axenized from symptomatic human patients, to study the biological and genetic diversity within assemblage A isolates. Results Several biological differences between the new and earlier characterized assemblage A isolates were identified, including a difference in growth medium preference. The two AII isolates were of different sub-assemblage types (AII-1 [AS175] and AII-2 [AS98]) and showed size differences in the smallest chromosomes. The amount of genetic diversity was characterized in relation to the genome of the Giardia reference isolate WB, an assemblage AI isolate. Our analyses indicate that the divergence between AI and AII is approximately 1 %, represented by ~100,000 single nucleotide polymorphisms (SNP) distributed over the chromosomes with enrichment in variable genomic regions containing surface antigens. The level of allelic sequence heterozygosity (ASH) in the two AII isolates was found to be 0.25–0.35 %, which is 25–30 fold higher than in the WB isolate and 10 fold higher than the assemblage AII isolate DH (0.037 %). 35 protein-encoding genes, not found in the WB genome, were identified in the two AII genomes. The large gene families of variant-specific surface proteins (VSPs) and high cysteine membrane proteins (HCMPs) showed isolate-specific divergences of the gene repertoires. Certain genes, often in small gene families with 2 to 8 members, localize to the variable regions of the genomes and show high sequence diversity between the assemblage A isolates. One of the families, Bactericidal/Permeability Increasing-like protein (BPIL), with eight members was characterized further and the proteins were shown to localize to the ER in trophozoites. Conclusions Giardia genomes are modular with highly conserved core regions mixed up by variable regions containing high levels of ASH, SNPs and variable surface antigens. There are significant genomic variations in assemblage A isolates, in terms of chromosome size, gene content, surface protein repertoire and gene polymorphisms and these differences mainly localize to the variable regions of the genomes. The large genetic differences within one assemblage of G. intestinalis strengthen the argument that the assemblages represent different Giardia species. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1893-6) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Johan Ankarklev
- Department of Cell and Molecular Biology, Science for Life Laboratory, BMC, Uppsala University, Box 596, SE-751 24, Uppsala, Sweden.
| | - Oscar Franzén
- Department of Cell and Molecular Biology, Karolinska Institutet, Box 285, SE-171 77, Stockholm, Sweden. .,Science for Life Laboratory, KISP, Tomtebodavägen 23A, 171 65, Solna, Sweden.
| | - Dimitra Peirasmaki
- Department of Cell and Molecular Biology, Science for Life Laboratory, BMC, Uppsala University, Box 596, SE-751 24, Uppsala, Sweden.
| | - Jon Jerlström-Hultqvist
- Department of Cell and Molecular Biology, Science for Life Laboratory, BMC, Uppsala University, Box 596, SE-751 24, Uppsala, Sweden.
| | - Marianne Lebbad
- Department of Microbiology, Public Health Agency of Sweden, SE-171 82, Solna, Sweden.
| | - Jan Andersson
- Department of Cell and Molecular Biology, Science for Life Laboratory, BMC, Uppsala University, Box 596, SE-751 24, Uppsala, Sweden.
| | - Björn Andersson
- Department of Cell and Molecular Biology, Karolinska Institutet, Box 285, SE-171 77, Stockholm, Sweden. .,Science for Life Laboratory, KISP, Tomtebodavägen 23A, 171 65, Solna, Sweden.
| | - Staffan G Svärd
- Department of Cell and Molecular Biology, Science for Life Laboratory, BMC, Uppsala University, Box 596, SE-751 24, Uppsala, Sweden.
| |
Collapse
|
116
|
Bauer R, Garnica S, Oberwinkler F, Riess K, Weiß M, Begerow D. Entorrhizomycota: A New Fungal Phylum Reveals New Perspectives on the Evolution of Fungi. PLoS One 2015. [PMID: 26200112 PMCID: PMC4511587 DOI: 10.1371/journal.pone.0128183] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Entorrhiza is a small fungal genus comprising 14 species that all cause galls on roots of Cyperaceae and Juncaceae. Although this genus was established 130 years ago, crucial questions on the phylogenetic relationships and biology of this enigmatic taxon are still unanswered. In order to infer a robust hypothesis about the phylogenetic position of Entorrhiza and to evaluate evolutionary trends, multiple gene sequences and morphological characteristics of Entorrhiza were analyzed and compared with respective findings in Fungi. In our comprehensive five-gene analyses Entorrhiza appeared as a highly supported monophyletic lineage representing the sister group to the rest of the Dikarya, a phylogenetic placement that received but moderate maximum likelihood and maximum parsimony bootstrap support. An alternative maximum likelihood tree with the constraint that Entorrhiza forms a monophyletic group with Basidiomycota could not be rejected. According to the first phylogenetic hypothesis, the teliospore tetrads of Entorrhiza represent the prototype of the dikaryan meiosporangium. The alternative hypothesis is supported by similarities in septal pore structure, cell wall and spindle pole bodies. Based on the isolated phylogenetic position of Entorrhiza and its peculiar combination of features related to ultrastructure and reproduction mode, we propose a new phylum Entorrhizomycota, for the genus Entorrhiza, which represents an apparently widespread group of inconspicuous fungi.
Collapse
Affiliation(s)
- Robert Bauer
- University of Tübingen, Plant Evolutionary Ecology, Institute of Evolution and Ecology, Auf der Morgenstelle 1, 72076, Tübingen, Germany
| | - Sigisfredo Garnica
- University of Tübingen, Plant Evolutionary Ecology, Institute of Evolution and Ecology, Auf der Morgenstelle 1, 72076, Tübingen, Germany
| | - Franz Oberwinkler
- University of Tübingen, Plant Evolutionary Ecology, Institute of Evolution and Ecology, Auf der Morgenstelle 1, 72076, Tübingen, Germany
| | - Kai Riess
- University of Tübingen, Plant Evolutionary Ecology, Institute of Evolution and Ecology, Auf der Morgenstelle 1, 72076, Tübingen, Germany
- * E-mail: (KR); (DB)
| | - Michael Weiß
- University of Tübingen, Department of Biology, Auf der Morgenstelle 1, 72076, Tübingen, Germany
- Institute of Organismal Mycology and Microbiology, Vor dem Kreuzberg 17, 72076, Tübingen, Germany
| | - Dominik Begerow
- University of Bochum, AG Geobotanik, Universitätsstraße 150, 44780, Bochum, Germany
- * E-mail: (KR); (DB)
| |
Collapse
|
117
|
Woo YH, Ansari H, Otto TD, Klinger CM, Kolisko M, Michálek J, Saxena A, Shanmugam D, Tayyrov A, Veluchamy A, Ali S, Bernal A, del Campo J, Cihlář J, Flegontov P, Gornik SG, Hajdušková E, Horák A, Janouškovec J, Katris NJ, Mast FD, Miranda-Saavedra D, Mourier T, Naeem R, Nair M, Panigrahi AK, Rawlings ND, Padron-Regalado E, Ramaprasad A, Samad N, Tomčala A, Wilkes J, Neafsey DE, Doerig C, Bowler C, Keeling PJ, Roos DS, Dacks JB, Templeton TJ, Waller RF, Lukeš J, Oborník M, Pain A. Chromerid genomes reveal the evolutionary path from photosynthetic algae to obligate intracellular parasites. eLife 2015; 4:e06974. [PMID: 26175406 PMCID: PMC4501334 DOI: 10.7554/elife.06974] [Citation(s) in RCA: 143] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 06/16/2015] [Indexed: 12/18/2022] Open
Abstract
The eukaryotic phylum Apicomplexa encompasses thousands of obligate intracellular parasites of humans and animals with immense socio-economic and health impacts. We sequenced nuclear genomes of Chromera velia and Vitrella brassicaformis, free-living non-parasitic photosynthetic algae closely related to apicomplexans. Proteins from key metabolic pathways and from the endomembrane trafficking systems associated with a free-living lifestyle have been progressively and non-randomly lost during adaptation to parasitism. The free-living ancestor contained a broad repertoire of genes many of which were repurposed for parasitic processes, such as extracellular proteins, components of a motility apparatus, and DNA- and RNA-binding protein families. Based on transcriptome analyses across 36 environmental conditions, Chromera orthologs of apicomplexan invasion-related motility genes were co-regulated with genes encoding the flagellar apparatus, supporting the functional contribution of flagella to the evolution of invasion machinery. This study provides insights into how obligate parasites with diverse life strategies arose from a once free-living phototrophic marine alga. DOI:http://dx.doi.org/10.7554/eLife.06974.001 Single-celled parasites cause many severe diseases in humans and animals. The apicomplexans form probably the most successful group of these parasites and include the parasites that cause malaria. Apicomplexans infect a broad range of hosts, including humans, reptiles, birds, and insects, and often have complicated life cycles. For example, the malaria-causing parasites spread by moving from humans to female mosquitoes and then back to humans. Despite significant differences amongst apicomplexans, these single-celled parasites also share a number of features that are not seen in other living species. How and when these features arose remains unclear. It is known from previous work that apicomplexans are closely related to single-celled algae. But unlike apicomplexans, which depend on a host animal to survive, these algae live freely in their environment, often in close association with corals. Woo et al. have now sequenced the genomes of two photosynthetic algae that are thought to be close living relatives of the apicomplexans. These genomes were then compared to each other and to the genomes of other algae and apicomplexans. These comparisons reconfirmed that the two algae that were studied were close relatives of the apicomplexans. Further analyses suggested that thousands of genes were lost as an ancient free-living algae evolved into the apicomplexan ancestor, and further losses occurred as these early parasites evolved into modern species. The lost genes were typically those that are important for free-living organisms, but are either a hindrance to, or not needed in, a parasitic lifestyle. Some of the ancestor's genes, especially those that coded for the building blocks of flagella (structures which free-living algae use to move around), were repurposed in ways that helped the apicomplexans to invade their hosts. Understanding this repurposing process in greater detail will help to identify key molecules in these deadly parasites that could be targeted by drug treatments. It will also offer answers to one of the most fascinating questions in evolutionary biology: how parasites have evolved from free-living organisms. DOI:http://dx.doi.org/10.7554/eLife.06974.002
Collapse
Affiliation(s)
- Yong H Woo
- Pathogen Genomics Laboratory, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Hifzur Ansari
- Pathogen Genomics Laboratory, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Thomas D Otto
- Parasite Genomics, Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Cambridge, United Kingdom
| | | | - Martin Kolisko
- Canadian Institute for Advanced Research, Department of Botany, University of British Columbia, Vancouver, Canada
| | - Jan Michálek
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Alka Saxena
- Pathogen Genomics Laboratory, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | | | - Annageldi Tayyrov
- Pathogen Genomics Laboratory, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Alaguraj Veluchamy
- Ecology and Evolutionary Biology Section, Institut de Biologie de l'Ecole Normale Supérieure, CNRS UMR8197 INSERM U1024, Paris, France
| | - Shahjahan Ali
- Bioscience Core Laboratory, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Axel Bernal
- Department of Biology, University of Pennsylvania, Philadelphia, United States
| | - Javier del Campo
- Canadian Institute for Advanced Research, Department of Botany, University of British Columbia, Vancouver, Canada
| | - Jaromír Cihlář
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Pavel Flegontov
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | | | - Eva Hajdušková
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Aleš Horák
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Jan Janouškovec
- Canadian Institute for Advanced Research, Department of Botany, University of British Columbia, Vancouver, Canada
| | | | - Fred D Mast
- Seattle Biomedical Research Institute, Seattle, United States
| | - Diego Miranda-Saavedra
- Centro de Biología Molecular Severo Ochoa, CSIC/Universidad Autónoma de Madrid, Madrid, Spain
| | - Tobias Mourier
- Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark
| | - Raeece Naeem
- Pathogen Genomics Laboratory, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Mridul Nair
- Pathogen Genomics Laboratory, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Aswini K Panigrahi
- Bioscience Core Laboratory, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Neil D Rawlings
- European Bioinformatics Institute (EMBL-EBI), Wellcome Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Eriko Padron-Regalado
- Pathogen Genomics Laboratory, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Abhinay Ramaprasad
- Pathogen Genomics Laboratory, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Nadira Samad
- School of Botany, University of Melbourne, Parkville, Australia
| | - Aleš Tomčala
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Jon Wilkes
- Wellcome Trust Centre For Molecular Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Daniel E Neafsey
- Broad Genome Sequencing and Analysis Program, Broad Institute of MIT and Harvard, Cambridge, United States
| | - Christian Doerig
- Department of Microbiology, Monash University, Clayton, Australia
| | - Chris Bowler
- Ecology and Evolutionary Biology Section, Institut de Biologie de l'Ecole Normale Supérieure, CNRS UMR8197 INSERM U1024, Paris, France
| | - Patrick J Keeling
- Canadian Institute for Advanced Research, Department of Botany, University of British Columbia, Vancouver, Canada
| | - David S Roos
- Department of Biology, University of Pennsylvania, Philadelphia, United States
| | - Joel B Dacks
- Department of Cell Biology, University of Alberta, Edmonton, Canada
| | - Thomas J Templeton
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, United States
| | - Ross F Waller
- School of Botany, University of Melbourne, Parkville, Australia
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Miroslav Oborník
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Arnab Pain
- Pathogen Genomics Laboratory, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| |
Collapse
|
118
|
Sharma PP, Fernández R, Esposito LA, González-Santillán E, Monod L. Phylogenomic resolution of scorpions reveals multilevel discordance with morphological phylogenetic signal. Proc Biol Sci 2015; 282:20142953. [PMID: 25716788 PMCID: PMC4375871 DOI: 10.1098/rspb.2014.2953] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 01/26/2015] [Indexed: 01/22/2023] Open
Abstract
Scorpions represent an iconic lineage of arthropods, historically renowned for their unique bauplan, ancient fossil record and venom potency. Yet, higher level relationships of scorpions, based exclusively on morphology, remain virtually untested, and no multilocus molecular phylogeny has been deployed heretofore towards assessing the basal tree topology. We applied a phylogenomic assessment to resolve scorpion phylogeny, for the first time, to our knowledge, sampling extensive molecular sequence data from all superfamilies and examining basal relationships with up to 5025 genes. Analyses of supermatrices as well as species tree approaches converged upon a robust basal topology of scorpions that is entirely at odds with traditional systematics and controverts previous understanding of scorpion evolutionary history. All analyses unanimously support a single origin of katoikogenic development, a form of parental investment wherein embryos are nurtured by direct connections to the parent's digestive system. Based on the phylogeny obtained herein, we propose the following systematic emendations: Caraboctonidae is transferred to Chactoidea new superfamilial assignment: ; superfamily Bothriuroidea revalidated: is resurrected and Bothriuridae transferred therein; and Chaerilida and Pseudochactida are synonymized with Buthida new parvordinal synonymies: .
Collapse
Affiliation(s)
- Prashant P Sharma
- Division of Invertebrate Zoology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024, USA
| | - Rosa Fernández
- Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
| | - Lauren A Esposito
- Essig Museum of Entomology, University of California at Berkeley, 130 Mulford Hall, Berkeley, CA 94720, USA
| | - Edmundo González-Santillán
- Laboratorio Nacional de Genómica para la Biodiversidad, Centro de Investigaciones y de Estudios Avanzados del Instituto Politecnico Nacional, and Laboratorio de Aracnología, Departamento de Biología Comparada, Facultad de Ciencias, Universidad Nacional Autónoma de México, Coyoacán, C.P. 04510, México DF, México
| | - Lionel Monod
- Département des Arthropodes et d'Entomologie I, Muséum d'Histoire Naturelle de la Ville de Genève, Route de Malagnou 1, Genève 1208, Switzerland
| |
Collapse
|
119
|
Havird JC, Kocot KM, Brannock PM, Cannon JT, Waits DS, Weese DA, Santos SR, Halanych KM. Reconstruction of cyclooxygenase evolution in animals suggests variable, lineage-specific duplications, and homologs with low sequence identity. J Mol Evol 2015; 80:193-208. [PMID: 25758350 DOI: 10.1007/s00239-015-9670-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 03/02/2015] [Indexed: 11/30/2022]
Abstract
Cyclooxygenase (COX) enzymatically converts arachidonic acid into prostaglandin G/H in animals and has importance during pregnancy, digestion, and other physiological functions in mammals. COX genes have mainly been described from vertebrates, where gene duplications are common, but few studies have examined COX in invertebrates. Given the increasing ease in generating genomic data, as well as recent, although incomplete descriptions of potential COX sequences in Mollusca, Crustacea, and Insecta, assessing COX evolution across Metazoa is now possible. Here, we recover 40 putative COX orthologs by searching publicly available genomic resources as well as ~250 novel invertebrate transcriptomic datasets. Results suggest the common ancestor of Cnidaria and Bilateria possessed a COX homolog similar to those of vertebrates, although such homologs were not found in poriferan and ctenophore genomes. COX was found in most crustaceans and the majority of molluscs examined, but only specific taxa/lineages within Cnidaria and Annelida. For example, all octocorallians appear to have COX, while no COX homologs were found in hexacorallian datasets. Most species examined had a single homolog, although species-specific COX duplications were found in members of Annelida, Mollusca, and Cnidaria. Additionally, COX genes were not found in Hemichordata, Echinodermata, or Platyhelminthes, and the few previously described COX genes in Insecta lacked appreciable sequence homology (although structural analyses suggest these may still be functional COX enzymes). This analysis provides a benchmark for identifying COX homologs in future genomic and transcriptomic datasets, and identifies lineages for future studies of COX.
Collapse
Affiliation(s)
- Justin C Havird
- Department of Biological Sciences & Molette Biology Laboratory for Environmental and Climate Change Studies, Auburn University, Auburn, USA,
| | | | | | | | | | | | | | | |
Collapse
|
120
|
Kozlov AM, Aberer AJ, Stamatakis A. ExaML version 3: a tool for phylogenomic analyses on supercomputers. Bioinformatics 2015; 31:2577-9. [PMID: 25819675 PMCID: PMC4514929 DOI: 10.1093/bioinformatics/btv184] [Citation(s) in RCA: 144] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 03/24/2015] [Indexed: 01/17/2023] Open
Abstract
Motivation: Phylogenies are increasingly used in all fields of medical and biological research. Because of the next generation sequencing revolution, datasets used for conducting phylogenetic analyses grow at an unprecedented pace. We present ExaML version 3, a dedicated production-level code for inferring phylogenies on whole-transcriptome and whole-genome alignments using supercomputers. Results: We introduce several improvements and extensions to ExaML: Extensions of substitution models and supported data types, the integration of a novel load balance algorithm as well as a parallel I/O optimization that significantly improve parallel efficiency, and a production-level implementation for Intel MIC-based hardware platforms. Availability and implementation: The code is available under GNU GPL at https://github.com/stamatak/ExaML. Contact:Alexandros.Stamatakis@h-its.org Supplementary information:Supplementary data are available at Bioinformatics online.
Collapse
Affiliation(s)
- Alexey M Kozlov
- Scientific Computing Group, Heidelberg Institute for Theoretical Studies, Heidelberg, Germany and
| | - Andre J Aberer
- Scientific Computing Group, Heidelberg Institute for Theoretical Studies, Heidelberg, Germany and
| | - Alexandros Stamatakis
- Scientific Computing Group, Heidelberg Institute for Theoretical Studies, Heidelberg, Germany and Department of informatics, Institute of Theoretical Informatics, Karlsruhe Institute of Technology, Karlsruhe, Germany
| |
Collapse
|
121
|
An ancestral bacterial division system is widespread in eukaryotic mitochondria. Proc Natl Acad Sci U S A 2015; 112:10239-46. [PMID: 25831547 DOI: 10.1073/pnas.1421392112] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Bacterial division initiates at the site of a contractile Z-ring composed of polymerized FtsZ. The location of the Z-ring in the cell is controlled by a system of three mutually antagonistic proteins, MinC, MinD, and MinE. Plastid division is also known to be dependent on homologs of these proteins, derived from the ancestral cyanobacterial endosymbiont that gave rise to plastids. In contrast, the mitochondria of model systems such as Saccharomyces cerevisiae, mammals, and Arabidopsis thaliana seem to have replaced the ancestral α-proteobacterial Min-based division machinery with host-derived dynamin-related proteins that form outer contractile rings. Here, we show that the mitochondrial division system of these model organisms is the exception, rather than the rule, for eukaryotes. We describe endosymbiont-derived, bacterial-like division systems comprising FtsZ and Min proteins in diverse less-studied eukaryote protistan lineages, including jakobid and heterolobosean excavates, a malawimonad, stramenopiles, amoebozoans, a breviate, and an apusomonad. For two of these taxa, the amoebozoan Dictyostelium purpureum and the jakobid Andalucia incarcerata, we confirm a mitochondrial localization of these proteins by their heterologous expression in Saccharomyces cerevisiae. The discovery of a proteobacterial-like division system in mitochondria of diverse eukaryotic lineages suggests that it was the ancestral feature of all eukaryotic mitochondria and has been supplanted by a host-derived system multiple times in distinct eukaryote lineages.
Collapse
|
122
|
Laumer CE, Hejnol A, Giribet G. Nuclear genomic signals of the 'microturbellarian' roots of platyhelminth evolutionary innovation. eLife 2015; 4:e05503. [PMID: 25764302 PMCID: PMC4398949 DOI: 10.7554/elife.05503] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 03/06/2015] [Indexed: 12/25/2022] Open
Abstract
Flatworms number among the most diverse invertebrate phyla and represent the most biomedically significant branch of the major bilaterian clade Spiralia, but to date, deep evolutionary relationships within this group have been studied using only a single locus (the rRNA operon), leaving the origins of many key clades unclear. In this study, using a survey of genomes and transcriptomes representing all free-living flatworm orders, we provide resolution of platyhelminth interrelationships based on hundreds of nuclear protein-coding genes, exploring phylogenetic signal through concatenation as well as recently developed consensus approaches. These analyses robustly support a modern hypothesis of flatworm phylogeny, one which emphasizes the primacy of the often-overlooked 'microturbellarian' groups in understanding the major evolutionary transitions within Platyhelminthes: perhaps most notably, we propose a novel scenario for the interrelationships between free-living and vertebrate-parasitic flatworms, providing new opportunities to shed light on the origins and biological consequences of parasitism in these iconic invertebrates.
Collapse
Affiliation(s)
- Christopher E Laumer
- Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, United States
| | - Andreas Hejnol
- Sars International Centre for Marine Molecular Biology, University of Bergen, Bergen, Norway
| | - Gonzalo Giribet
- Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, United States
| |
Collapse
|
123
|
Nývltová E, Stairs CW, Hrdý I, Rídl J, Mach J, Pačes J, Roger AJ, Tachezy J. Lateral gene transfer and gene duplication played a key role in the evolution of Mastigamoeba balamuthi hydrogenosomes. Mol Biol Evol 2015; 32:1039-55. [PMID: 25573905 DOI: 10.1093/molbev/msu408] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Lateral gene transfer (LGT) is an important mechanism of evolution for protists adapting to oxygen-poor environments. Specifically, modifications of energy metabolism in anaerobic forms of mitochondria (e.g., hydrogenosomes) are likely to have been associated with gene transfer from prokaryotes. An interesting question is whether the products of transferred genes were directly targeted into the ancestral organelle or initially operated in the cytosol and subsequently acquired organelle-targeting sequences. Here, we identified key enzymes of hydrogenosomal metabolism in the free-living anaerobic amoebozoan Mastigamoeba balamuthi and analyzed their cellular localizations, enzymatic activities, and evolutionary histories. Additionally, we characterized 1) several canonical mitochondrial components including respiratory complex II and the glycine cleavage system, 2) enzymes associated with anaerobic energy metabolism, including an unusual D-lactate dehydrogenase and acetyl CoA synthase, and 3) a sulfate activation pathway. Intriguingly, components of anaerobic energy metabolism are present in at least two gene copies. For each component, one copy possesses an mitochondrial targeting sequence (MTS), whereas the other lacks an MTS, yielding parallel cytosolic and hydrogenosomal extended glycolysis pathways. Experimentally, we confirmed that the organelle targeting of several proteins is fully dependent on the MTS. Phylogenetic analysis of all extended glycolysis components suggested that these components were acquired by LGT. We propose that the transformation from an ancestral organelle to a hydrogenosome in the M. balamuthi lineage involved the lateral acquisition of genes encoding extended glycolysis enzymes that initially operated in the cytosol and that established a parallel hydrogenosomal pathway after gene duplication and MTS acquisition.
Collapse
Affiliation(s)
- Eva Nývltová
- Department of Parasitology, Faculty of Science, Charles University in Prague, Viničná, Prague, Czech Republic
| | - Courtney W Stairs
- Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, NS, Canada
| | - Ivan Hrdý
- Department of Parasitology, Faculty of Science, Charles University in Prague, Viničná, Prague, Czech Republic
| | - Jakub Rídl
- Laboratory of Genomics and Bioinformatics, Institute of Molecular Genetics AV CR, Vídeňská, Prague, Czech Republic
| | - Jan Mach
- Department of Parasitology, Faculty of Science, Charles University in Prague, Viničná, Prague, Czech Republic
| | - Jan Pačes
- Laboratory of Genomics and Bioinformatics, Institute of Molecular Genetics AV CR, Vídeňská, Prague, Czech Republic
| | - Andrew J Roger
- Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, NS, Canada
| | - Jan Tachezy
- Department of Parasitology, Faculty of Science, Charles University in Prague, Viničná, Prague, Czech Republic
| |
Collapse
|
124
|
Celis AI, Geeraerts Z, Ngmenterebo D, Machovina MM, Kurker RC, Rajakumar K, Ivancich A, Rodgers KR, Lukat-Rodgers GS, DuBois JL. A dimeric chlorite dismutase exhibits O2-generating activity and acts as a chlorite antioxidant in Klebsiella pneumoniae MGH 78578. Biochemistry 2014; 54:434-46. [PMID: 25437493 PMCID: PMC4303309 DOI: 10.1021/bi501184c] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
![]()
Chlorite
dismutases (Clds) convert chlorite to O2 and
Cl–, stabilizing heme in the presence of strong
oxidants and forming the O=O bond with high efficiency. The
enzyme from the pathogen Klebsiella pneumoniae (KpCld) represents a subfamily of Clds that share most of
their active site structure with efficient O2-producing
Clds, even though they have a truncated monomeric structure, exist
as a dimer rather than a pentamer, and come from Gram-negative bacteria
without a known need to degrade chlorite. We hypothesized that KpCld, like others in its subfamily, should be able to make
O2 and may serve an in vivo antioxidant
function. Here, it is demonstrated that it degrades chlorite with
limited turnovers relative to the respiratory Clds, in part because
of the loss of hypochlorous acid from the active site and destruction
of the heme. The observation of hypochlorous acid, the expected leaving
group accompanying transfer of an oxygen atom to the ferric heme,
is consistent with the more open, solvent-exposed heme environment
predicted by spectroscopic measurements and inferred from the crystal
structures of related proteins. KpCld is more susceptible
to oxidative degradation under turnover conditions than the well-characterized
Clds associated with perchlorate respiration. However, wild-type K. pneumoniae has a significant growth advantage in the
presence of chlorate relative to a Δcld knockout
strain, specifically under nitrate-respiring conditions. This suggests
that a physiological function of KpCld may be detoxification
of endogenously produced chlorite.
Collapse
Affiliation(s)
- Arianna I Celis
- Department of Chemistry and Biochemistry, Montana State University , Bozeman, Montana 59715, United States
| | | | | | | | | | | | | | | | | | | |
Collapse
|
125
|
Lemieux C, Otis C, Turmel M. Six newly sequenced chloroplast genomes from prasinophyte green algae provide insights into the relationships among prasinophyte lineages and the diversity of streamlined genome architecture in picoplanktonic species. BMC Genomics 2014; 15:857. [PMID: 25281016 PMCID: PMC4194372 DOI: 10.1186/1471-2164-15-857] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 09/25/2014] [Indexed: 12/01/2022] Open
Abstract
Background Because they represent the earliest divergences of the Chlorophyta, the morphologically diverse unicellular green algae making up the prasinophytes hold the key to understanding the nature of the first viridiplants and the evolutionary patterns that accompanied the radiation of chlorophytes. Nuclear-encoded 18S rDNA phylogenies unveiled nine prasinophyte clades (clades I through IX) but their branching order is still uncertain. We present here the newly sequenced chloroplast genomes of Nephroselmis astigmatica (clade III) and of five picoplanktonic species from clade VI (Prasinococcus sp. CCMP 1194, Prasinophyceae sp. MBIC 106222 and Prasinoderma coloniale) and clade VII (Picocystis salinarum and Prasinophyceae sp. CCMP 1205). These chloroplast DNAs (cpDNAs) were compared with those of the six previously sampled prasinophytes (clades I, II, III and V) in order to gain information both on the relationships among prasinophyte lineages and on chloroplast genome evolution. Results Varying from 64.3 to 85.6 kb in size and encoding 100 to 115 conserved genes, the cpDNAs of the newly investigated picoplanktonic species are substantially smaller than those observed for larger-size prasinophytes, are economically packed and contain a reduced gene content. Although the Nephroselmis and Picocystis cpDNAs feature a large inverted repeat encoding the rRNA operon, gene partitioning among the single copy regions is remarkably different. Unexpectedly, we found that all three species from clade VI (Prasinococcales) harbor chloroplast genes not previously documented for chlorophytes (ndhJ, rbcR, rpl21, rps15, rps16 and ycf66) and that Picocystis contains a trans-spliced group II intron. The phylogenies inferred from cpDNA-encoded proteins are essentially congruent with 18S rDNA trees, resolving with robust support all six examined prasinophyte lineages, with the exception of the Pycnococcaceae. Conclusions Our results underscore the high variability in genome architecture among prasinophyte lineages, highlighting the strong pressure to maintain a small and compact chloroplast genome in picoplanktonic species. The unique set of six chloroplast genes found in the Prasinococcales supports the ancestral status of this lineage within the prasinophytes. The widely diverging traits uncovered for the clade-VII members (Picocystis and Prasinophyceae sp. CCMP 1205) are consistent with their resolution as separate lineages in the chloroplast phylogeny.
Collapse
Affiliation(s)
- Claude Lemieux
- Institut de biologie intégrative et des systèmes, Département de biochimie, de microbiologie et de bio-informatique, Université Laval, Québec, QC G1V 0A6, Canada.
| | | | | |
Collapse
|
126
|
Lemieux C, Otis C, Turmel M. Chloroplast phylogenomic analysis resolves deep-level relationships within the green algal class Trebouxiophyceae. BMC Evol Biol 2014; 14:211. [PMID: 25270575 PMCID: PMC4189289 DOI: 10.1186/s12862-014-0211-2] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 09/24/2014] [Indexed: 11/13/2022] Open
Abstract
Background The green algae represent one of the most successful groups of photosynthetic eukaryotes, but compared to their land plant relatives, surprisingly little is known about their evolutionary history. This is in great part due to the difficulty of recognizing species diversity behind morphologically similar organisms. The Trebouxiophyceae is a species-rich class of the Chlorophyta that includes symbionts (e.g. lichenized algae) as well as free-living green algae. Members of this group display remarkable ecological variation, occurring in aquatic, terrestrial and aeroterrestrial environments. Because a reliable backbone phylogeny is essential to understand the evolutionary history of the Trebouxiophyceae, we sought to identify the relationships among the major trebouxiophycean lineages that have been previously recognized in nuclear-encoded 18S rRNA phylogenies. To this end, we used a chloroplast phylogenomic approach. Results We determined the sequences of 29 chlorophyte chloroplast genomes and assembled amino acid and nucleotide data sets derived from 79 chloroplast genes of 61 chlorophytes, including 35 trebouxiophyceans. The amino acid- and nucleotide-based phylogenies inferred using maximum likelihood and Bayesian methods and various models of sequence evolution revealed essentially the same relationships for the trebouxiophyceans. Two major groups were identified: a strongly supported clade of 29 taxa (core trebouxiophyceans) that is sister to the Chlorophyceae + Ulvophyceae and a clade comprising the Chlorellales and Pedinophyceae that represents a basal divergence relative to the former group. The core trebouxiophyceans form a grade of strongly supported clades that include a novel lineage represented by the desert crust alga Pleurastrosarcina brevispinosa. The assemblage composed of the Oocystis and Geminella clades is the deepest divergence of the core trebouxiophyceans. Like most of the chlorellaleans, early-diverging core trebouxiophyceans are predominantly planktonic species, whereas core trebouxiophyceans occupying more derived lineages are mostly terrestrial or aeroterrestrial algae. Conclusions Our phylogenomic study provides a solid foundation for addressing fundamental questions related to the biology and ecology of the Trebouxiophyceae. The inferred trees reveal that this class is not monophyletic; they offer new insights not only into the internal structure of the class but also into the lifestyle of its founding members and subsequent adaptations to changing environments.
Collapse
Affiliation(s)
- Claude Lemieux
- Département de Biochimie, de Microbiologie et de Bio-informatique, Institut de Biologie Intégrative et des Systèmes, Université Laval, 1030 avenue de la Medicine, Pavillon Marchand, Québec, G1V 0A6, Canada.
| | | | | |
Collapse
|
127
|
Cooper ED. Overly simplistic substitution models obscure green plant phylogeny. TRENDS IN PLANT SCIENCE 2014; 19:576-582. [PMID: 25023343 DOI: 10.1016/j.tplants.2014.06.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 05/25/2014] [Accepted: 06/05/2014] [Indexed: 06/03/2023]
Abstract
Phylogenetic analysis is an increasingly common and valuable component of plant science. Knowledge of the phylogenetic relationships between plant groups is a prerequisite for understanding the origin and evolution of important plant features, and phylogenetic analysis of individual genes and gene families provides fundamental insights into how those genes and their functions evolved. However, despite an active research community exploring and improving phylogenetic methods, the analytical methods commonly used, and the phylogenetic results they produce, are accorded far more confidence than they warrant. In this opinion article, I emphasise that important parts of the green plant phylogeny are inconsistently resolved and I argue that the lack of consistency arises due to inadequate modelling of changes in the substitution process.
Collapse
Affiliation(s)
- Endymion D Cooper
- CMNS-Cell Biology and Molecular Genetics, 2107 Bioscience Research Building, University of Maryland, College Park, MD 20742-4407, USA.
| |
Collapse
|
128
|
Andrade SCS, Montenegro H, Strand M, Schwartz ML, Kajihara H, Norenburg JL, Turbeville JM, Sundberg P, Giribet G. A Transcriptomic Approach to Ribbon Worm Systematics (Nemertea): Resolving the Pilidiophora Problem. Mol Biol Evol 2014; 31:3206-15. [DOI: 10.1093/molbev/msu253] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
|
129
|
Sharma PP, Kaluziak ST, Pérez-Porro AR, González VL, Hormiga G, Wheeler WC, Giribet G. Phylogenomic Interrogation of Arachnida Reveals Systemic Conflicts in Phylogenetic Signal. Mol Biol Evol 2014; 31:2963-84. [DOI: 10.1093/molbev/msu235] [Citation(s) in RCA: 215] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
130
|
Reid AJ, Blake DP, Ansari HR, Billington K, Browne HP, Bryant J, Dunn M, Hung SS, Kawahara F, Miranda-Saavedra D, Malas TB, Mourier T, Naghra H, Nair M, Otto TD, Rawlings ND, Rivailler P, Sanchez-Flores A, Sanders M, Subramaniam C, Tay YL, Woo Y, Wu X, Barrell B, Dear PH, Doerig C, Gruber A, Ivens AC, Parkinson J, Rajandream MA, Shirley MW, Wan KL, Berriman M, Tomley FM, Pain A. Genomic analysis of the causative agents of coccidiosis in domestic chickens. Genome Res 2014; 24:1676-85. [PMID: 25015382 PMCID: PMC4199364 DOI: 10.1101/gr.168955.113] [Citation(s) in RCA: 150] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Global production of chickens has trebled in the past two decades and they are now the most important source of dietary animal protein worldwide. Chickens are subject to many infectious diseases that reduce their performance and productivity. Coccidiosis, caused by apicomplexan protozoa of the genus Eimeria, is one of the most important poultry diseases. Understanding the biology of Eimeria parasites underpins development of new drugs and vaccines needed to improve global food security. We have produced annotated genome sequences of all seven species of Eimeria that infect domestic chickens, which reveal the full extent of previously described repeat-rich and repeat-poor regions and show that these parasites possess the most repeat-rich proteomes ever described. Furthermore, while no other apicomplexan has been found to possess retrotransposons, Eimeria is home to a family of chromoviruses. Analysis of Eimeria genes involved in basic biology and host-parasite interaction highlights adaptations to a relatively simple developmental life cycle and a complex array of co-expressed surface proteins involved in host cell binding.
Collapse
Affiliation(s)
- Adam J Reid
- Wellcome Trust Sanger Institute, Genome Campus, Hinxton, Cambridgeshire CB10 1SA, United Kingdom
| | - Damer P Blake
- Royal Veterinary College, North Mymms, Hertfordshire AL9 7TA, United Kingdom; The Pirbright Institute, Compton Laboratory, Newbury, Berkshire RG20 7NN, United Kingdom
| | - Hifzur R Ansari
- Computational Bioscience Research Center, Biological Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Jeddah 23955-6900, Kingdom of Saudi Arabia
| | - Karen Billington
- The Pirbright Institute, Compton Laboratory, Newbury, Berkshire RG20 7NN, United Kingdom
| | - Hilary P Browne
- Wellcome Trust Sanger Institute, Genome Campus, Hinxton, Cambridgeshire CB10 1SA, United Kingdom
| | - Josephine Bryant
- Wellcome Trust Sanger Institute, Genome Campus, Hinxton, Cambridgeshire CB10 1SA, United Kingdom
| | - Matt Dunn
- Wellcome Trust Sanger Institute, Genome Campus, Hinxton, Cambridgeshire CB10 1SA, United Kingdom
| | - Stacy S Hung
- Program in Molecular Structure and Function, Hospital for Sick Children and Departments of Biochemistry and Molecular Genetics, University of Toronto, Toronto, Ontario M5G 1X8, Canada
| | - Fumiya Kawahara
- Nippon Institute for Biological Science, Ome, Tokyo 198-0024, Japan
| | - Diego Miranda-Saavedra
- Fibrosis Laboratories, Institute of Cellular Medicine, Newcastle University Medical School, Framlington Place, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Tareq B Malas
- Computational Bioscience Research Center, Biological Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Jeddah 23955-6900, Kingdom of Saudi Arabia
| | - Tobias Mourier
- Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen, 1350 Copenhagen, Denmark
| | - Hardeep Naghra
- Wellcome Trust Sanger Institute, Genome Campus, Hinxton, Cambridgeshire CB10 1SA, United Kingdom; School of Life Sciences, Centre for Biomolecular Sciences, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Mridul Nair
- Computational Bioscience Research Center, Biological Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Jeddah 23955-6900, Kingdom of Saudi Arabia
| | - Thomas D Otto
- Wellcome Trust Sanger Institute, Genome Campus, Hinxton, Cambridgeshire CB10 1SA, United Kingdom
| | - Neil D Rawlings
- European Bioinformatics Institute, Genome Campus, Hinxton, Cambridgeshire CB10 1SA, United Kingdom
| | - Pierre Rivailler
- The Pirbright Institute, Compton Laboratory, Newbury, Berkshire RG20 7NN, United Kingdom; Division of Viral Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA
| | - Alejandro Sanchez-Flores
- Unidad Universitaria de Apoyo Bioinformático, Institute of Biotechnology, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, Mexico
| | - Mandy Sanders
- Wellcome Trust Sanger Institute, Genome Campus, Hinxton, Cambridgeshire CB10 1SA, United Kingdom
| | - Chandra Subramaniam
- The Pirbright Institute, Compton Laboratory, Newbury, Berkshire RG20 7NN, United Kingdom
| | - Yea-Ling Tay
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor DE, Malaysia; Malaysia Genome Institute, Jalan Bangi, 43000 Kajang, Selangor DE, Malaysia
| | - Yong Woo
- Computational Bioscience Research Center, Biological Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Jeddah 23955-6900, Kingdom of Saudi Arabia
| | - Xikun Wu
- The Pirbright Institute, Compton Laboratory, Newbury, Berkshire RG20 7NN, United Kingdom; Amgen Limited, Uxbridge UB8 1DH, United Kingdom
| | - Bart Barrell
- Wellcome Trust Sanger Institute, Genome Campus, Hinxton, Cambridgeshire CB10 1SA, United Kingdom
| | - Paul H Dear
- MRC Laboratory of Molecular Biology, Cambridge CB2 0QH, United Kingdom
| | - Christian Doerig
- Department of Microbiology, Monash University, Clayton VIC 3800, Australia
| | - Arthur Gruber
- Departament of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP 05508-000, Brazil
| | - Alasdair C Ivens
- Centre for Immunity, Infection and Evolution, Ashworth Laboratories, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JT, United Kingdom
| | - John Parkinson
- Program in Molecular Structure and Function, Hospital for Sick Children and Departments of Biochemistry and Molecular Genetics, University of Toronto, Toronto, Ontario M5G 1X8, Canada
| | - Marie-Adèle Rajandream
- Wellcome Trust Sanger Institute, Genome Campus, Hinxton, Cambridgeshire CB10 1SA, United Kingdom
| | - Martin W Shirley
- The Pirbright Institute, Pirbright Laboratory, Pirbright, Surrey GU24 0NF, United Kingdom
| | - Kiew-Lian Wan
- School of Biosciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor DE, Malaysia; Malaysia Genome Institute, Jalan Bangi, 43000 Kajang, Selangor DE, Malaysia
| | - Matthew Berriman
- Wellcome Trust Sanger Institute, Genome Campus, Hinxton, Cambridgeshire CB10 1SA, United Kingdom
| | - Fiona M Tomley
- Royal Veterinary College, North Mymms, Hertfordshire AL9 7TA, United Kingdom; The Pirbright Institute, Compton Laboratory, Newbury, Berkshire RG20 7NN, United Kingdom;
| | - Arnab Pain
- Computational Bioscience Research Center, Biological Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Jeddah 23955-6900, Kingdom of Saudi Arabia;
| |
Collapse
|
131
|
A novel papillomavirus isolated from a nasal neoplasia in an Italian free-ranging chamois (Rupicapra r. rupicapra). Vet Microbiol 2014; 172:108-19. [PMID: 24910075 DOI: 10.1016/j.vetmic.2014.05.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Revised: 04/30/2014] [Accepted: 05/04/2014] [Indexed: 11/22/2022]
Abstract
Most amniotes are the hosts of many, distantly related papillomaviruses (PVs). Infection by PVs can be asymptomatic, or lead instead to benign or malignant lesions. However, PVs infecting animals and associated with malignancies are still largely understudied. In the present study, we communicate the complete genome of a novel PV found in a nasal neoplasia of a free-ranging alpine chamois (Rupicapra r. rupicapra) in an Italian national park. Long-PCR and cloning approaches followed for Sanger sequencing were used to identify the first PV found in chamois. The genome of the novel virus - RrupPV1 - of 7256 bp in length, presents the classical PV structure, and lacks the interE2-L2 region that hosts the E5 gene in AlphaPVs and in DeltaPVs. The nucleotide identity percentage of the L1 ORF, places RrupPV1 together with OaPV3 in the same genus. The latter is a PV isolated from a squamous cell carcinoma in sheep in Sardinia. Full-genome phylogenetic reconstructions suggest that these two viruses are sister taxa, and that both of them are very distantly related to any other known PV. Many cetartiodactyl species are infected by non-monophyletic PVs. Our results exemplify further the multiple links between the infection by certain, distantly related PVs and the development of diverse cancers in animals and highlight the need of a systematic search of oncogenic and non-oncogenic animal PVs.
Collapse
|
132
|
Palpitomonas bilix represents a basal cryptist lineage: insight into the character evolution in Cryptista. Sci Rep 2014; 4:4641. [PMID: 24717814 PMCID: PMC3982174 DOI: 10.1038/srep04641] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Accepted: 03/21/2014] [Indexed: 12/19/2022] Open
Abstract
Phylogenetic position of the marine biflagellate Palpitomonas bilix is intriguing, since several ultrastructural characteristics implied its evolutionary connection to Archaeplastida or Hacrobia. The origin and early evolution of these two eukaryotic assemblages have yet to be fully elucidated, and P. bilix may be a key lineage in tracing those groups' early evolution. In the present study, we analyzed a 'phylogenomic' alignment of 157 genes to clarify the position of P. bilix in eukaryotic phylogeny. In the 157-gene phylogeny, P. bilix was found to be basal to a clade of cryptophytes, goniomonads and kathablepharids, collectively known as Cryptista, which is proposed to be a part of the larger taxonomic assemblage Hacrobia. We here discuss the taxonomic assignment of P. bilix, and character evolution in Cryptista.
Collapse
|
133
|
Fernández R, Laumer CE, Vahtera V, Libro S, Kaluziak S, Sharma PP, Pérez-Porro AR, Edgecombe GD, Giribet G. Evaluating topological conflict in centipede phylogeny using transcriptomic data sets. Mol Biol Evol 2014; 31:1500-13. [PMID: 24674821 DOI: 10.1093/molbev/msu108] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Relationships between the five extant orders of centipedes have been considered solved based on morphology. Phylogenies based on samples of up to a few dozen genes have largely been congruent with the morphological tree apart from an alternative placement of one order, the relictual Craterostigmomorpha, consisting of two species in Tasmania and New Zealand. To address this incongruence, novel transcriptomic data were generated to sample all five orders of centipedes and also used as a test case for studying gene-tree incongruence. Maximum likelihood and Bayesian mixture model analyses of a data set composed of 1,934 orthologs with 45% missing data, as well as the 389 orthologs in the least saturated, stationary quartile, retrieve strong support for a sister-group relationship between Craterostigmomorpha and all other pleurostigmophoran centipedes, of which the latter group is newly named Amalpighiata. The Amalpighiata hypothesis, which shows little gene-tree incongruence and is robust to the influence of among-taxon compositional heterogeneity, implies convergent evolution in several morphological and behavioral characters traditionally used in centipede phylogenetics, such as maternal brood care, but accords with patterns of first appearances in the fossil record.
Collapse
Affiliation(s)
- Rosa Fernández
- Museum of Comparative Zoology & Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA
| | - Christopher E Laumer
- Museum of Comparative Zoology & Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA
| | - Varpu Vahtera
- Museum of Comparative Zoology & Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MAZoological Museum, Department of Biology, University of Turku, Turku, Finland
| | - Silvia Libro
- Marine Science Center, Northeastern University, Nahant, MA
| | | | - Prashant P Sharma
- Division of Invertebrate Zoology, American Museum of Natural History, New York, NY
| | - Alicia R Pérez-Porro
- Museum of Comparative Zoology & Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MACentre d'Estudis Avançats de Blanes (CEAB-CSIC), Catalonia, Spain
| | - Gregory D Edgecombe
- Department of Earth Sciences, The Natural History Museum, London, United Kingdom
| | - Gonzalo Giribet
- Museum of Comparative Zoology & Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA
| |
Collapse
|
134
|
Stamatakis A. RAxML version 8: a tool for phylogenetic analysis and post-analysis of large phylogenies. ACTA ACUST UNITED AC 2014; 30:1312-3. [PMID: 24451623 PMCID: PMC3998144 DOI: 10.1093/bioinformatics/btu033] [Citation(s) in RCA: 19440] [Impact Index Per Article: 1944.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Motivation: Phylogenies are increasingly used in all fields of medical and biological research. Moreover, because of the next-generation sequencing revolution, datasets used for conducting phylogenetic analyses grow at an unprecedented pace. RAxML (Randomized Axelerated Maximum Likelihood) is a popular program for phylogenetic analyses of large datasets under maximum likelihood. Since the last RAxML paper in 2006, it has been continuously maintained and extended to accommodate the increasingly growing input datasets and to serve the needs of the user community. Results: I present some of the most notable new features and extensions of RAxML, such as a substantial extension of substitution models and supported data types, the introduction of SSE3, AVX and AVX2 vector intrinsics, techniques for reducing the memory requirements of the code and a plethora of operations for conducting post-analyses on sets of trees. In addition, an up-to-date 50-page user manual covering all new RAxML options is available. Availability and implementation: The code is available under GNU GPL at https://github.com/stamatak/standard-RAxML. Contact:alexandros.stamatakis@h-its.org Supplementary information:Supplementary data are available at Bioinformatics online.
Collapse
Affiliation(s)
- Alexandros Stamatakis
- Scientific Computing Group, Heidelberg Institute for Theoretical Studies, 69118 Heidelberg and Department of Informatics, Institute of Theoretical Informatics, Karlsruhe Institute of Technology, 76128 Karlsruhe, Germany
| |
Collapse
|
135
|
Miyazawa S. Superiority of a mechanistic codon substitution model even for protein sequences in phylogenetic analysis. BMC Evol Biol 2013; 13:257. [PMID: 24256155 PMCID: PMC4225520 DOI: 10.1186/1471-2148-13-257] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2013] [Accepted: 11/14/2013] [Indexed: 11/25/2022] Open
Abstract
Background Nucleotide and amino acid substitution tendencies are characteristic of each species, organelle, and protein family. Hence, various empirical amino acid substitution rate matrices have needed to be estimated for phylogenetic analysis: JTT, WAG, and LG for nuclear proteins, mtREV for mitochondrial proteins, cpREV10 and cpREV64 for chloroplast-encoded proteins, and FLU for influenza proteins. On the other hand, in a mechanistic codon substitution model, in which each codon substitution rate is proportional to the product of a codon mutation rate and the ratio of fixation depending on the type of amino acid replacement, mutation rates and the strength of selective constraint on amino acids can be tailored to each protein family with additional 11 parameters. As a result, in the evolutionary analysis of codon sequences it outperforms codon substitution models equivalent to empirical amino acid substitution matrices. Is it superior even for amino acid sequences, among which synonymous substitutions cannot be identified? Results Nucleotide mutations are assumed to occur independently of codon positions but multiple nucleotide changes in infinitesimal time are allowed. Selective constraints on the respective types of amino acid replacements are tailored to each gene with a linear function of a given estimate of selective constraints, which were estimated by maximizing the likelihood of an empirical amino acid or codon substitution frequency matrix, each of JTT, WAG, LG, and KHG. It is shown that the mechanistic codon substitution model with the assumption of equal codon usage yields better values of Akaike and Bayesian information criteria for all three phylogenetic trees of mitochondrial, chloroplast, and influenza-A hemagglutinin proteins than the empirical amino acid substitution models with mtREV, cpREV64, and FLU, which were designed specifically for those protein families, respectively. The variation of selective constraint across sites fits the datasets significantly better than variable codon mutation rates, confirming that substitution rate variations across sites detected by amino acid substitution models are caused primarily by the variation of selective constraint against amino acid substitutions rather than the variation of codon mutation rate. Conclusions The mechanistic codon substitution model is superior to amino acid substitution models even in the evolutionary analysis of protein sequences.
Collapse
|
136
|
Increased sequence coverage through combined targeting of variant and conserved epitopes correlates with control of HIV replication. J Virol 2013; 88:1354-65. [PMID: 24227851 DOI: 10.1128/jvi.02361-13] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A major challenge in the development of an HIV vaccine is that of contending with the extensive sequence variability found in circulating viruses. Induction of HIV-specific T-cell responses targeting conserved regions and induction of HIV-specific T-cell responses recognizing a high number of epitope variants have both been proposed as strategies to overcome this challenge. We addressed the ability of cytotoxic T lymphocytes from 30 untreated HIV-infected subjects with and without control of virus replication to recognize all clade B Gag sequence variants encoded by at least 5% of the sequences in the Los Alamos National Laboratory HIV database (1,300 peptides) using gamma interferon and interleukin-2 (IFN-γ/IL-2) FluoroSpot analysis. While targeting of conserved regions was similar in the two groups (P = 0.47), we found that subjects with control of virus replication demonstrated marginally lower recognition of Gag epitope variants than subjects with normal progression (P = 0.05). In viremic controllers and progressors, we found variant recognition to be associated with viral load (r = 0.62, P = 0.001). Interestingly, we show that increased overall sequence coverage, defined as the overall proportion of HIV database sequences targeted through the Gag-specific repertoire, is inversely associated with viral load (r = -0.38, P = 0.03). Furthermore, we found that sequence coverage, but not variant recognition, correlated with increased recognition of a panel of clade B HIV founder viruses (r = 0.50, P = 0.004). We propose sequence coverage by HIV Gag-specific immune responses as a possible correlate of protection that may contribute to control of virus replication. Additionally, sequence coverage serves as a valuable measure by which to evaluate the protective potential of future vaccination strategies.
Collapse
|
137
|
Lasek-Nesselquist E, Gogarten JP. The effects of model choice and mitigating bias on the ribosomal tree of life. Mol Phylogenet Evol 2013; 69:17-38. [PMID: 23707703 DOI: 10.1016/j.ympev.2013.05.006] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Revised: 04/26/2013] [Accepted: 05/08/2013] [Indexed: 01/03/2023]
Abstract
Deep-level relationships within Bacteria, Archaea, and Eukarya as well as the relationships of these three domains to each other require resolution. The ribosomal machinery, universal to all cellular life, represents a protein repertoire resistant to horizontal gene transfer, which provides a largely congruent signal necessary for reconstructing a tree suitable as a backbone for life's reticulate history. Here, we generate a ribosomal tree of life from a robust taxonomic sampling of Bacteria, Archaea, and Eukarya to elucidate deep-level intra-domain and inter-domain relationships. Lack of phylogenetic information and systematic errors caused by inadequate models (that cannot account for substitution rate or compositional heterogeneities) or improper model selection compound conflicting phylogenetic signals from HGT and/or paralogy. Thus, we tested several models of varying sophistication on three different datasets, performed removal of fast-evolving or long-branched Archaea and Eukarya, and employed three different strategies to remove compositional heterogeneity to examine their effects on the topological outcome. Our results support a two-domain topology for the tree of life, where Eukarya emerges from within Archaea as sister to a Korarchaeota/Thaumarchaeota (KT) or Crenarchaeota/KT clade for all models under all or at least one of the strategies employed. Taxonomic manipulation allows single-matrix and certain mixture models to vacillate between two-domain and three-domain phylogenies. We find that models vary in their ability to resolve different areas of the tree of life, which does not necessarily correlate with model complexity. For example, both single-matrix and some mixture models recover monophyletic Crenarchaeota and Euryarchaeota archaeal phyla. In contrast, the most sophisticated model recovers a paraphyletic Euryarchaeota but detects two large clades that comprise the Bacteria, which were recovered separately but never together in the other models. Overall, models recovered consistent topologies despite dataset modifications due to the removal of compositional bias, which reflects either ineffective bias reduction or robust datasets that allow models to overcome reconstruction artifacts. We recommend a comparative approach for evolutionary models to identify model weaknesses as well as consensus relationships.
Collapse
|
138
|
Netti F, Malgieri G, Esposito S, Palmieri M, Baglivo I, Isernia C, Omichinski JG, Pedone PV, Lartillot N, Fattorusso R. An Experimentally Tested Scenario for the Structural Evolution of Eukaryotic Cys2His2 Zinc Fingers from Eubacterial Ros Homologs. Mol Biol Evol 2013; 30:1504-13. [DOI: 10.1093/molbev/mst068] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
139
|
Dunn KA, Jiang W, Field C, Bielawski JP. Improving evolutionary models for mitochondrial protein data with site-class specific amino acid exchangeability matrices. PLoS One 2013; 8:e55816. [PMID: 23383286 PMCID: PMC3561347 DOI: 10.1371/journal.pone.0055816] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Accepted: 01/02/2013] [Indexed: 11/24/2022] Open
Abstract
Adequate modeling of mitochondrial sequence evolution is an essential component of mitochondrial phylogenomics (comparative mitogenomics). There is wide recognition within the field that lineage-specific aspects of mitochondrial evolution should be accommodated through lineage-specific amino-acid exchangeability matrices (e.g., mtMam for mammalian data). However, such a matrix must be applied to all sites and this implies that all sites are subject to the same, or largely similar, evolutionary constraints. This assumption is unjustified. Indeed, substantial differences are expected to arise from three-dimensional structures that impose different physiochemical environments on individual amino acid residues. The objectives of this paper are (1) to investigate the extent to which amino acid evolution varies among sites of mitochondrial proteins, and (2) to assess the potential benefits of explicitly modeling such variability. To achieve this, we developed a novel method for partitioning sites based on amino acid physiochemical properties. We apply this method to two datasets derived from complete mitochondrial genomes of mammals and fish, and use maximum likelihood to estimate amino acid exchangeabilities for the different groups of sites. Using this approach we identified large groups of sites evolving under unique physiochemical constraints. Estimates of amino acid exchangeabilities differed significantly among such groups. Moreover, we found that joint estimates of amino acid exchangeabilities do not adequately represent the natural variability in evolutionary processes among sites of mitochondrial proteins. Significant improvements in likelihood are obtained when the new matrices are employed. We also find that maximum likelihood estimates of branch lengths can be strongly impacted. We provide sets of matrices suitable for groups of sites subject to similar physiochemical constraints, and discuss how they might be used to analyze real data. We also discuss how the general approach might be employed to improve a variety of mitogenomic-based research activities.
Collapse
Affiliation(s)
- Katherine A Dunn
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada.
| | | | | | | |
Collapse
|
140
|
Zoller S, Schneider A. Improving phylogenetic inference with a semiempirical amino acid substitution model. Mol Biol Evol 2012; 30:469-79. [PMID: 23002090 DOI: 10.1093/molbev/mss229] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Amino acid substitution matrices describe the rates by which amino acids are replaced during evolution. In contrast to nucleotide or codon models, amino acid substitution matrices are in general parameterless and empirically estimated, probably because there is no obvious parametrization for amino acid substitutions. Principal component analysis has previously been used to improve codon substitution models by empirically finding the most relevant parameters. Here, we apply the same method to amino acid substitution matrices, leading to a semiempirical substitution model that can adjust the transition rates to the protein sequences under investigation. Our new model almost invariably achieves the best likelihood values in large-scale comparisons with established amino acid substitution models (JTT, WAG, and LG). In particular for longer alignments, these likelihood gains are considerably larger than what could be expected from simply having more parameters. The application of our model differs from that of mixture models (such as UL2 or UL3), as we optimize one rate matrix per alignment, whereas mixture models apply the variation per alignments site. This makes our model computationally more efficient, while the performance is comparable to that of UL3. Applied to the phylogenetic problem of the origin of placental mammals, our new model and the UL3 mixed model are the only ones of the tested models that cluster Afrotheria and Xenarthra into a clade called Atlantogenata, which would be in correspondence with recent findings using more sophisticated phylogenetic methods.
Collapse
Affiliation(s)
- Stefan Zoller
- Computational Biochemistry Research Group, ETH Zürich, Zürich, Switzerland.
| | | |
Collapse
|