New Phylogenomic Analysis of the Enigmatic Phylum Telonemia Further Resolves the Eukaryote Tree of Life

AbstractThe resolution of the broad-scale tree of eukaryotes is constantly improving, but the evolutionary origin of several major groups remains unknown. Resolving the phylogenetic position of these “orphan” groups is important, especially those that originated early in evolution, because they represent missing evolutionary links between established groups. Telonemia is one such orphan taxon for which little is known. The group is composed of molecularly diverse biflagellated protists, often prevalent although not abundant in aquatic environments. Telonemia has been hypothesized to represent a deeply diverging eukaryotic phylum but no consensus exists as to where it is placed in the tree. Here, we established cultures and report the phylogenomic analyses of three new transcriptome data sets for divergent telonemid lineages. All our phylogenetic reconstructions, based on 248 genes and using site-heterogeneous mixture models, robustly resolve the evolutionary origin of Telonemia as sister to the Sar supergroup. This grouping remains well supported when as few as 60% of the genes are randomly subsampled, thus is not sensitive to the sets of genes used but requires a minimal alignment length to recover enough phylogenetic signal. Telonemia occupies a crucial position in the tree to examine the origin of Sar, one of the most lineage-rich eukaryote supergroups. We propose the moniker “TSAR” to accommodate this new mega-assemblage in the phylogeny of eukaryotes.

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New phylogenomic analysis of the enigmatic phylum Telonemia further resolves the eukaryote tree of life

10.1101/403329 ◽

2018 ◽

Cited By ~ 1

Author(s):

Jürgen F. H. Strassert ◽

Mahwash Jamy ◽

Alexander P. Mylnikov ◽

Denis V. Tikhonenkov ◽

Fabien Burki

Keyword(s):

Phylogenetic Signal ◽

Evolutionary Origin ◽

Phylogenetic Position ◽

Aquatic Environments ◽

Phylogenomic Analysis ◽

Heterogeneous Mixture ◽

Phylogenetic Reconstructions ◽

Phylogenomic Analyses ◽

Alignment Length ◽

Broad Scale

AbstractThe broad-scale tree of eukaryotes is constantly improving, but the evolutionary origin of several major groups remains unknown. Resolving the phylogenetic position of these ‘orphan’ groups is important, especially those that originated early in evolution, because they represent missing evolutionary links between established groups. Telonemia is one such orphan taxon for which little is known. The group is composed of molecularly diverse biflagellated protists, often prevalent although not abundant in aquatic environments. Telonemia has been hypothesized to represent a deeply diverging eukaryotic phylum but no consensus exists as to where it is placed in the tree. Here, we established cultures and report the phylogenomic analyses of three new transcriptome datasets for divergent telonemid lineages. All our phylogenetic reconstructions, based on 248 genes and using site-heterogeneous mixture models, robustly resolve the evolutionary origin of Telonemia as sister to the Sar supergroup. This grouping remains well supported when as few as 60% of the genes are randomly subsampled, thus is not sensitive to the sets of genes used but requires a minimal alignment length to recover enough phylogenetic signal. Telonemia occupies a crucial position in the tree to examine the origin of Sar, one of the most lineage-rich eukaryote supergroups. We propose the moniker ‘TSAR’ to accommodate this new mega-assemblage in the phylogeny of eukaryotes.

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Transcriptomics provides a robust framework for the relationships of the major clades of cladobranch sea slugs (Mollusca, Gastropoda, Heterobranchia), but fails to resolve the position of the enigmatic genus Embletonia

BMC Ecology and Evolution ◽

10.1186/s12862-021-01944-0 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Dario Karmeinski ◽

Karen Meusemann ◽

Jessica A. Goodheart ◽

Michael Schroedl ◽

Alexander Martynov ◽

...

Keyword(s):

Phylogenetic Relationships ◽

Evolutionary History ◽

Phylogenetic Signal ◽

Set Covering ◽

Phylogenetic Position ◽

Data Sets ◽

Transcriptome Data ◽

Data Set ◽

Sea Slugs ◽

History Of

Abstract Background The soft-bodied cladobranch sea slugs represent roughly half of the biodiversity of marine nudibranch molluscs on the planet. Despite their global distribution from shallow waters to the deep sea, from tropical into polar seas, and their important role in marine ecosystems and for humans (as targets for drug discovery), the evolutionary history of cladobranch sea slugs is not yet fully understood. Results To enlarge the current knowledge on the phylogenetic relationships, we generated new transcriptome data for 19 species of cladobranch sea slugs and two additional outgroup taxa (Berthella plumula and Polycera quadrilineata). We complemented our taxon sampling with previously published transcriptome data, resulting in a final data set covering 56 species from all but one accepted cladobranch superfamilies. We assembled all transcriptomes using six different assemblers, selecting those assemblies that provided the largest amount of potentially phylogenetically informative sites. Quality-driven compilation of data sets resulted in four different supermatrices: two with full coverage of genes per species (446 and 335 single-copy protein-coding genes, respectively) and two with a less stringent coverage (667 genes with 98.9% partition coverage and 1767 genes with 86% partition coverage, respectively). We used these supermatrices to infer statistically robust maximum-likelihood trees. All analyses, irrespective of the data set, indicate maximal statistical support for all major splits and phylogenetic relationships at the family level. Besides the questionable position of Noumeaella rubrofasciata, rendering the Facelinidae as polyphyletic, the only notable discordance between the inferred trees is the position of Embletonia pulchra. Extensive testing using Four-cluster Likelihood Mapping, Approximately Unbiased tests, and Quartet Scores revealed that its position is not due to any informative phylogenetic signal, but caused by confounding signal. Conclusions Our data matrices and the inferred trees can serve as a solid foundation for future work on the taxonomy and evolutionary history of Cladobranchia. The placement of E. pulchra, however, proves challenging, even with large data sets and various optimization strategies. Moreover, quartet mapping results show that confounding signal present in the data is sufficient to explain the inferred position of E. pulchra, again leaving its phylogenetic position as an enigma.

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Exploration of Plastid Phylogenomic Conflict Yields New Insights into the Deep Relationships of Leguminosae

Systematic Biology ◽

10.1093/sysbio/syaa013 ◽

2020 ◽

Vol 69 (4) ◽

pp. 613-622 ◽

Cited By ~ 15

Author(s):

Rong Zhang ◽

Yin-Huan Wang ◽

Jian-Jun Jin ◽

Gregory W Stull ◽

Anne Bruneau ◽

...

Keyword(s):

Phylogenetic Signal ◽

Strong Support ◽

Molecular Data ◽

Data Sets ◽

Plastome Evolution ◽

The Family ◽

Phylogenetic Resolution ◽

History Of ◽

Phylogenomic Analyses ◽

Almost All

Abstract Phylogenomic analyses have helped resolve many recalcitrant relationships in the angiosperm tree of life, yet phylogenetic resolution of the backbone of the Leguminosae, one of the largest and most economically and ecologically important families, remains poor due to generally limited molecular data and incomplete taxon sampling of previous studies. Here, we resolve many of the Leguminosae’s thorniest nodes through comprehensive analysis of plastome-scale data using multiple modified coding and noncoding data sets of 187 species representing almost all major clades of the family. Additionally, we thoroughly characterize conflicting phylogenomic signal across the plastome in light of the family’s complex history of plastome evolution. Most analyses produced largely congruent topologies with strong statistical support and provided strong support for resolution of some long-controversial deep relationships among the early diverging lineages of the subfamilies Caesalpinioideae and Papilionoideae. The robust phylogenetic backbone reconstructed in this study establishes a framework for future studies on legume classification, evolution, and diversification. However, conflicting phylogenetic signal was detected and quantified at several key nodes that prevent the confident resolution of these nodes using plastome data alone. [Leguminosae; maximum likelihood; phylogenetic conflict; plastome; recalcitrant relationships; stochasticity; systematic error.]

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Transcriptomics provides a robust framework for the relationships of the major clades of cladobranch sea slugs (Mollusca, Gastropoda, Heterobranchia), but fails to resolve the position of the enigmatic genus Embletonia

10.1101/2020.09.22.307728 ◽

2020 ◽

Author(s):

Dario Karmeinski ◽

Karen Meusemann ◽

Jessica A. Goodheart ◽

Michael Schroedl ◽

Alexander Martynov ◽

...

Keyword(s):

Phylogenetic Relationships ◽

Evolutionary History ◽

Transcriptome Assembly ◽

Phylogenetic Signal ◽

Taxon Sampling ◽

Data Sets ◽

Transcriptome Data ◽

Data Set ◽

Sea Slugs ◽

History Of

AbstractBackgroundCladobranch sea slugs represent roughly half of the biodiversity of soft-bodied, marine gastropod molluscs (Nudibranchia) on the planet. Despite their global distribution from shallow waters to the deep sea, from tropical into polar seas, and their important role in marine ecosystems and for humans (as bioindicators and providers of medical drug leads), the evolutionary history of cladobranch sea slugs is not yet fully understood. Here, we amplify the current knowledge on the phylogenetic relationships by extending the cladobranch and outgroup taxon sampling using transcriptome data.ResultsWe generated new transcriptome data for 19 species of cladobranch sea slugs and two additional outgroup taxa. We complemented our taxon sampling with previously published transcriptome data, resulting in a final supermatrix covering 56 species from all but one accepted cladobranch superfamilies. Transcriptome assembly using six different assemblers, selection of those assemblies providing the largest amount of potentially phylogenetically informative sites, and quality-driven compilation of data sets resulted in three different supermatrices: one with a full coverage of genes per species (446 single-copy protein-coding genes) and two with a less stringent coverage (667 genes with 98.9% partition coverage and 1,767 genes with 86% partition coverage, respectively). We used these supermatrices to infer statistically robust maximum-likelihood trees. All analyses, irrespective of the data set, indicate maximum statistical support for all major splits and phylogenetic relationships on family level. The only discordance between the inferred trees is the position of Embletonia pulchra. Extensive testing using Four-cluster Likelihood Mapping, Approximately Unbiased tests, and Quartet Scores revealed that its position is not due to any informative phylogenetic signal, but caused by confounding signal.ConclusionsOur data matrices and the inferred trees inferred can serve as a solid foundation for future work on the taxonomy and evolutionary history of Cladobranchia. The correct placement of E. pulchra, however, proves challenging, even with large data sets. Moreover, quartet mapping shows that confounding signal present in the data is sufficient to explain the inferred position of E. pulchra, again leaving its phylogenetic position as an enigma.

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A 250 plastome phylogeny of the grass family (Poaceae): topological support under different data partitions

PeerJ ◽

10.7717/peerj.4299 ◽

2018 ◽

Vol 6 ◽

pp. e4299 ◽

Cited By ~ 53

Author(s):

Jeffery M. Saarela ◽

Sean V. Burke ◽

William P. Wysocki ◽

Matthew D. Barrett ◽

Lynn G. Clark ◽

...

Keyword(s):

High Throughput Sequencing ◽

Sequence Data ◽

Phylogenetic Signal ◽

Purifying Selection ◽

Bootstrap Support ◽

Phylogenomic Analysis ◽

Branch Points ◽

Protein Coding ◽

Selective Forces ◽

Phylogenomic Analyses

The systematics of grasses has advanced through applications of plastome phylogenomics, although studies have been largely limited to subfamilies or other subgroups of Poaceae. Here we present a plastome phylogenomic analysis of 250 complete plastomes (179 genera) sampled from 44 of the 52 tribes of Poaceae. Plastome sequences were determined from high throughput sequencing libraries and the assemblies represent over 28.7 Mbases of sequence data. Phylogenetic signal was characterized in 14 partitions, including (1) complete plastomes; (2) protein coding regions; (3) noncoding regions; and (4) three loci commonly used in single and multi-gene studies of grasses. Each of the four main partitions was further refined, alternatively including or excluding positively selected codons and also the gaps introduced by the alignment. All 76 protein coding plastome loci were found to be predominantly under purifying selection, but specific codons were found to be under positive selection in 65 loci. The loci that have been widely used in multi-gene phylogenetic studies had among the highest proportions of positively selected codons, suggesting caution in the interpretation of these earlier results. Plastome phylogenomic analyses confirmed the backbone topology for Poaceae with maximum bootstrap support (BP). Among the 14 analyses, 82 clades out of 309 resolved were maximally supported in all trees. Analyses of newly sequenced plastomes were in agreement with current classifications. Five of seven partitions in which alignment gaps were removed retrieved Panicoideae as sister to the remaining PACMAD subfamilies. Alternative topologies were recovered in trees from partitions that included alignment gaps. This suggests that ambiguities in aligning these uncertain regions might introduce a false signal. Resolution of these and other critical branch points in the phylogeny of Poaceae will help to better understand the selective forces that drove the radiation of the BOP and PACMAD clades comprising more than 99.9% of grass diversity.

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Plastid phylogenomics resolves ambiguous relationships within the orchid family and provides a solid timeframe for biogeography and macroevolution

Scientific Reports ◽

10.1038/s41598-021-83664-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Maria Alejandra Serna-Sánchez ◽

Oscar A. Pérez-Escobar ◽

Diego Bogarín ◽

María Fernanda Torres-Jimenez ◽

Astrid Catalina Alvarez-Yela ◽

...

Keyword(s):

Phylogenetic Relationships ◽

Divergence Times ◽

Molecular Clocks ◽

Phylogenetic Placement ◽

Plastid Genomes ◽

Phylogenetic Reconstructions ◽

A Genome ◽

Tree Models ◽

Phylogenomic Analyses ◽

First Time

AbstractRecent phylogenomic analyses based on the maternally inherited plastid organelle have enlightened evolutionary relationships between the subfamilies of Orchidaceae and most of the tribes. However, uncertainty remains within several subtribes and genera for which phylogenetic relationships have not ever been tested in a phylogenomic context. To address these knowledge-gaps, we here provide the most extensively sampled analysis of the orchid family to date, based on 78 plastid coding genes representing 264 species, 117 genera, 18 tribes and 28 subtribes. Divergence times are also provided as inferred from strict and relaxed molecular clocks and birth–death tree models. Our taxon sampling includes 51 newly sequenced plastid genomes produced by a genome skimming approach. We focus our sampling efforts on previously unplaced clades within tribes Cymbidieae and Epidendreae. Our results confirmed phylogenetic relationships in Orchidaceae as recovered in previous studies, most of which were recovered with maximum support (209 of the 262 tree branches). We provide for the first time a clear phylogenetic placement for Codonorchideae within subfamily Orchidoideae, and Podochilieae and Collabieae within subfamily Epidendroideae. We also identify relationships that have been persistently problematic across multiple studies, regardless of the different details of sampling and genomic datasets used for phylogenetic reconstructions. Our study provides an expanded, robust temporal phylogenomic framework of the Orchidaceae that paves the way for biogeographical and macroevolutionary studies.

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Comparative Cladistics: Fossils, Morphological Data Partitions and Lost Branches in the Fossil Tree of Life

10.31237/osf.io/7sa6d ◽

2017 ◽

Author(s):

Ross Mounce

Keyword(s):

Large Scale ◽

Phylogenetic Signal ◽

Scientific Progress ◽

Molecular Data ◽

Morphological Data ◽

Data Sets ◽

Phylogenetic Groups ◽

Use Of Data ◽

Wide Range ◽

Cladistic Analyses

In this thesis I attempt to gather together a wide range of cladistic analyses of fossil and extant taxa representing a diverse array of phylogenetic groups. I use this data to quantitatively compare the effect of fossil taxa relative to extant taxa in terms of support for relationships, number of most parsimonious trees (MPTs) and leaf stability. In line with previous studies I find that the effects of fossil taxa are seldom different to extant taxa – although I highlight some interesting exceptions. I also use this data to compare the phylogenetic signal within vertebrate morphological data sets, by choosing to compare cranial data to postcranial data. Comparisons between molecular data and morphological data have been previously well explored, as have signals between different molecular loci. But comparative signal within morphological data sets is much less commonly characterized and certainly not across a wide array of clades. With this analysis I show that there are many studies in which the evidence provided by cranial data appears to be be significantly incongruent with the postcranial data – more than one would expect to see just by the effect of chance and noise alone. I devise and implement a modification to a rarely used measure of homoplasy that will hopefully encourage its wider usage. Previously it had some undesirable bias associated with the distribution of missing data in a dataset, but my modification controls for this. I also take an in-depth and extensive review of the ILD test, noting it is often misused or reported poorly, even in recent studies. Finally, in attempting to collect data and metadata on a large scale, I uncovered inefficiencies in the research publication system that obstruct re-use of data and scientific progress. I highlight the importance of replication and reproducibility – even simple reanalysis of high profile papers can turn up some very different results. Data is highly valuable and thus it must be retained and made available for further re-use to maximize the overall return on research investment.

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Agromyces humi sp. nov., actinobacterium isolated from farm soil

INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY ◽

10.1099/ijsem.0.004376 ◽

2020 ◽

Vol 70 (9) ◽

pp. 5032-5039 ◽

Cited By ~ 3

Author(s):

Jae-Chan Lee ◽

Kyung-Sook Whang

Keyword(s):

Type Species ◽

Phylogenomic Analysis ◽

Rrna Gene ◽

Content Type ◽

Link Type ◽

Gene Sequence Analysis ◽

Phyletic Line ◽

Phylogenomic Analyses ◽

The 16S Rrna Gene ◽

Sequence Similarities

A Gram-stain-positive actinobacterial strain, designated ANK073T, was isolated from rhizosphere soil sampled at a spinach farming field in Shinan, Republic of Korea. Cells of strain ANK073T were found to be aerobic, non-motile, non-spore-forming rods which could grow at 20–40 °C (optimum, 30 °C), at pH 6.0–10.0 (optimum, pH 6.5–7.5) and at salinities of 0–4 % (w/v) NaCl (optimum, 0 % NaCl). The 16S rRNA gene sequence analysis showed that strain ANK073T belongs to the genus Agromyces with high sequence similarities to Agromyces humatus CD5T (98.8 %), Agromyces tardus SJ-23T (98.5 %) and Agromyces iriomotensis IY07-20T (98.4 %). The phylogenetic analysis indicated that strain ANK073T formed a distinct phyletic line in the genus Agromyces and the results of DNA–DNA relatedness and phylogenomic analysis based on whole genome sequences demonstrated that strain ANK073T could be separated from its closest relatives in the genus Agromyces . The strain contained 2,4-diaminobutylic acid, glycine, d-glutamic acid and d-alanine in the peptidoglycan. The predominant menaquinones were identified as MK-12 and MK-11, and the major fatty acids were anteiso-C17 : 0, anteiso-C15 : 0 and iso-C15:0. The major polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The G+C content of the genome was determined to be 70.2 mol%. On the basis of its phenotypic and chemotaxonomic properties and the results of phylogenetic and phylogenomic analyses, strain ANK073T is considered to represent a novel species in the genus Agromyces , for which the name Agromyces humi sp. nov. is proposed. The type strain is ANK073T (=KACC 18683T=NBRC 111825T).

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Importance of the postcranial skeleton in eusuchian phylogeny: Reassessing the systematics of allodaposuchid crocodylians

PLoS ONE ◽

10.1371/journal.pone.0251900 ◽

2021 ◽

Vol 16 (6) ◽

pp. e0251900

Author(s):

Alejandro Blanco

Keyword(s):

Current Knowledge ◽

Phylogenetic Signal ◽

Morphological Data ◽

Phylogenetic Position ◽

Postcranial Skeleton ◽

Skull Morphology ◽

Taxonomic Descriptions ◽

The Family ◽

Phylogenetic Hypotheses ◽

Internal Relationships

Our current knowledge on the crocodyliform evolution is strongly biased towards the skull morphology, and the postcranial skeleton is usually neglected in many taxonomic descriptions. However, it is logical to expect that it can contribute with its own phylogenetic signal. In this paper, the changes in the tree topology caused by the addition of the postcranial information are analysed for the family Allodaposuchidae, the most representative eusuchians in the latest Cretaceous of Europe. At present, different phylogenetic hypotheses have been proposed for this group without reaching a consensus. The results of this paper evidence a shift in the phylogenetic position when the postcranium is included in the dataset, pointing to a relevant phylogenetic signal in the postcranial elements. Finally, the phylogenetic relationships of allodaposuchids within Eusuchia are reassessed; and the internal relationships within Allodaposuchidae are also reconsidered after an exhaustive revision of the morphological data. New and improved diagnoses for each species are here provided.

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Segeticoccus rhizosphaerae gen. nov., sp. nov., an actinobacterium isolated from soil of a farming field

INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY ◽

10.1099/ijsem.0.003973 ◽

2020 ◽

Vol 70 (3) ◽

pp. 1785-1792 ◽

Cited By ~ 6

Author(s):

Jae-Chan Lee ◽

Kyung-Sook Whang

Keyword(s):

16S Rrna ◽

16S Rrna Gene ◽

Phylogenomic Analysis ◽

Rrna Gene ◽

Content Type ◽

Link Type ◽

The Family ◽

Diamino Acid ◽

Phylogenomic Analyses ◽

Sequence Similarities

A Gram-stain-positive actinobacterial strain, designated YJ01T, was isolated from a spinach farming field soil at Shinan in Korea. Strain YJ01T was aerobic, non-motile, non-spore-forming cocci with diameters of 1.5–1.9 µm, and was able to grow at 10–37 °C (optimum, 28–30 °C), at pH 4.5–9.0 (optimum, pH 7.0–8.0) and at salinities of 0–7.5 % (w/v) NaCl (optimum, 1.0 % NaCl). Sequence similarities of the 16S rRNA gene of strain YJ01T with closely related relatives were in the range 96.2–92.8 %, and the results of phylogenomic analysis indicated that strain YJ01T was clearly separated from species of genera in the family Intrasporangiaceae showing average nucleotide identity values of 84.2–83.4 %. The predominant isoprenoid quinone was identified as MK-8(H4) and the major fatty acids were iso-C15 : 0, iso-C16:1 h, iso-C16 : 0 and anteiso-C17 : 1ω9c. The diagnostic diamino acid of the peptidoglycan was ornithine, and the interpeptide bridge was l-Orn–Gly2–d-Glu. The major polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylserine, an unidentified phosphatidylglycolipid, two unidentified phosphoaminolipids and an unidentified phosphoglycoaminolipid. The G+C content of the genome was 70.1 mol%. On the basis of phenotypic and chemotaxonomic properties and phylogenetic and phylogenomic analyses using 16S rRNA gene sequences and whole-genome sequences, strain YJ01T is considered to represent a novel species of a new genus in the family Intrasporangiaceae , for which the name Segeticoccus rhizosphaerae gen. nov. sp. nov. is proposed. The type strain of Segeticoccus rhizosphaerae is YJ01T (=KACC 19547T=NBRC 113173T).

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