phylogenetics
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Ants in the genera Anochetus and Odontomachus belong to one of the largest clades in the subfamily Ponerinae, and are one of four lineages of ants possessing spring-loaded "trap-jaws." Here we present results from the first global species-level molecular phylogenetic analysis of these trap-jaw ants, reconstructed from one mitochondrial, one ribosomal RNA, and three nuclear protein-coding genes. Bayesian and likelihood analyses strongly support reciprocal monophyly for the genera Anochetus and Odontomachus. Additionally, we found strong support for seven trap-jaw ant clades (four in Anochetus and three in Odontomachus) mostly concordant with geographic distribution. Ambiguity remains concerning the closest living non-trap-jaw ant relative of the Anochetus+Odontomachus clade, but Bayes factor hypothesis testing strongly suggests that trap-jaw ants evolved from a short mandible ancestor. Ponerine trap-jaw ants originated in the early Eocene (52.5Mya) in either South America or Southeast Asia, where they have radiated rapidly in the last 30million years, and subsequently dispersed multiple times to Africa and Australia. These results will guide future taxonomic work on the group and act as a phylogenetic framework to study the macroevolution of extreme ant mouthpart specialization.
- Klíčová slova
- Anochetus, Ants, Odontomachus, Phylogenetics, Trap-jaw ants,
- MeSH
- Bayesova věta MeSH
- cytochromy b klasifikace genetika metabolismus MeSH
- Formicidae klasifikace genetika MeSH
- fylogeneze MeSH
- fylogeografie MeSH
- genetická variace MeSH
- RNA ribozomální 28S klasifikace genetika metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Afrika MeSH
- Austrálie MeSH
- jihovýchodní Asie MeSH
- Jižní Amerika MeSH
- Názvy látek
- cytochromy b MeSH
- RNA ribozomální 28S MeSH
Euglenids are a well-known group of single-celled eukaryotes, with phototrophic, osmotrophic and phagotrophic members. Phagotrophs represent most of the phylogenetic diversity of euglenids, and gave rise to the phototrophs and osmotrophs, but their evolutionary relationships are poorly understood. Symbiontids, in contrast, are anaerobes that are alternatively inferred to be derived euglenids, or a separate euglenozoan group. Most phylogenetic studies of euglenids have examined the SSU rDNA only, which is often highly divergent. Also, many phagotrophic euglenids (and symbiontids) are uncultured, restricting collection of other molecular data. We generated transcriptome data for 28 taxa, mostly using a single-cell approach, and conducted the first multigene phylogenetic analyses of euglenids to include phagotrophs and symbiontids. Euglenids are recovered as monophyletic, with symbiontids forming an independent branch within Euglenozoa. Spirocuta, the clade of flexible euglenids that contains both the phototrophs (Euglenophyceae) and osmotrophs (Aphagea), is robustly resolved, with the ploeotid Olkasia as its sister group, forming the new taxon Olkaspira. Ploeotids are paraphyletic, although Ploeotiidae (represented by Ploeotia spp.), Lentomonas, and Keelungia form a robust clade (new taxon Alistosa). Petalomonadida branches robustly as sister to other euglenids in outgroup-rooted analyses. Within Spirocuta, Euglenophyceae is a robust clade that includes Rapaza, and Anisonemia is a well-supported monophyletic group containing Anisonemidae (Anisonema and Dinema spp.), 'Heteronema II' (represented by H. vittatum), and a clade of Neometanema plus Aphagea. Among 'peranemid' phagotrophs, Chasmostoma branches with included Urceolus, and Peranema with the undescribed 'Jenningsia II', while other relationships are weakly supported and consequently the closest sister group to Euglenophyceae remains unresolved. Our results are inconsistent with recent inferences that Entosiphon is the evolutionarily pivotal sister either to other euglenids, or to Spirocuta. At least three transitions between posterior and anterior flagellar gliding occurred in euglenids, with the phylogenetic positions and directions of those transitions remaining ambiguous.
- Klíčová slova
- Cell motility, Euglenozoa, Phylogenomics, Protozoa, Spirocuta, Symbiontida,
- MeSH
- biologická evoluce MeSH
- Euglenida klasifikace genetika MeSH
- fylogeneze * MeSH
- transkriptom * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Broad tapeworms (Diphyllobothriidea) are parasites whose adults are capable of infecting a wide range of freshwater, marine and terrestrial tetrapods including humans. Previous works examining the evolution of habitat and host use in this group have been hampered by the lack of a well-resolved phylogeny. In order to produce a robust phylogenetic framework for diphyllobothriideans, we sequenced the complete mitochondrial genome of 13 representatives, carefully chosen to cover the major clades, and two outgroup species representing the Spathebothriidea and Haplobothriidea. In addition, complementary data from the nuclear ribosomal operon was sequenced for 10 representative taxa. Mitogenomes and ssrDNA and lsrDNA were used towards elucidating the phylogenetic framework for the Diphyllobothriidea. The Cephalochlamydidae is confirmed as the earliest diverging diphyllobothriidean lineage, and Solenophoridae and Diphyllobothriidae are sister groups. We infer a probable freshwater origin of the diphyllobothriideans. The ancestral condition for life cycle complexity could not be unambiguously resolved. However, we infer exclusive use of a three-host life cycle following the origin of the Solenophoridae + Diphyllobothriidae. Regarding definitive host use, although we infer reptiles as the most likely ancestral condition, this result should be revisited with a more densely sampled phylogeny in future studies. Freshwater habitat is used by the early diverging lineages within the Solenophoridae + Diphyllobothriidae clade. For the latter, habitat use shifts between freshwater and marine environments, and definitive host use includes marine and terrestrial mammals and birds. We use mitochondrial genomes to distinguish Schistocephalus species occurring in different species of sticklebacks and demonstrate conspecificity of Ligula cf. intestinalis specimens collected from two Fennoscandian ringed seal subspecies.
- Klíčová slova
- 18S rDNA, 28S rDNA, Ancestral character estimation, Diphyllobothriosis, Genome-skimming, Sparganosis, Systematics,
- MeSH
- Cestoda * genetika MeSH
- fylogeneze MeSH
- genom mitochondriální * MeSH
- lidé MeSH
- operon MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Mitochondrial genomes are readily sequenced with recent technology and thus evolutionary lineages can be densely sampled. This permits better phylogenetic estimates and assessment of potential biases resulting from heterogeneity in nucleotide composition and rate of change. We gathered 245 mitochondrial sequences for the Coleoptera representing all 4 suborders, 15 superfamilies of Polyphaga, and altogether 97 families, including 159 newly sequenced full or partial mitogenomes. Compositional heterogeneity greatly affected 3rd codon positions, and to a lesser extent the 1st and 2nd positions, even after RY coding. Heterogeneity also affected the encoded protein sequence, in particular in the nad2, nad4, nad5, and nad6 genes. Credible tree topologies were obtained with the nhPhyML ("nonhomogeneous") algorithm implementing a model for branch-specific equilibrium frequencies. Likelihood searches using RAxML were improved by data partitioning by gene and codon position. Finally, the PhyloBayes software, which allows different substitution processes for amino acid replacement at various sites, produced a tree that best matched known higher level taxa and defined basal relationships in Coleoptera. After rooting with Neuropterida outgroups, suborder relationships were resolved as (Polyphaga (Myxophaga (Archostemata + Adephaga))). The infraorder relationships in Polyphaga were (Scirtiformia (Elateriformia ((Staphyliniformia + Scarabaeiformia) (Bostrichiformia (Cucujiformia))))). Polyphagan superfamilies were recovered as monophyla except Staphylinoidea (paraphyletic for Scarabaeiformia) and Cucujoidea, which can no longer be considered a valid taxon. The study shows that, although compositional heterogeneity is not universal, it cannot be eliminated for some mitochondrial genes, but dense taxon sampling and the use of appropriate Bayesian analyses can still produce robust phylogenetic trees.
- Klíčová slova
- PhyloBayes, RY coding, long-range PCR, mitogenomes, mixture models, rogue taxa,
- MeSH
- brouci klasifikace genetika MeSH
- fylogeneze * MeSH
- genetická heterogenita * MeSH
- genom hmyzu * MeSH
- genom mitochondriální * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Phylogenetic relationships of sub-Saharan African natricine snakes are understudied and poorly understood, which in turn has precluded analyses of the historical biogeography of the Seychelles endemic Lycognathophis seychellensis. We inferred the phylogenetic relationships of Seychelles and mainland sub-Saharan natricines by analysing a multilocus DNA sequence dataset for three mitochondrial (mt) and four nuclear (nu) genes. The mainland sub-Saharan natricines and L. seychellensis comprise a well-supported clade. Two maximally supported sets of relationships within this clade are (Limnophis,Natriciteres) and (Afronatrix,(Hydraethiops,Helophis)). The relationships of L. seychellensis with respect to these two lineages are not clearly resolved by analysing concatenated mt and nu data. Analysed separately, nu data best support a sister relationship of L. seychellensis with (Afronatrix,(Hydraethiops,Helophis)) and mt data best support a sister relationship with all mainland sub-Saharan natricines. Methods designed to cope with incomplete lineage sorting strongly favour the former hypothesis. Genetic variation among up to 33 L. seychellensis from five Seychelles islands is low. Fossil calibrated divergence time estimates support an overseas dispersal of the L. seychellensis lineage to the Seychelles from mainland Africa ca. 43-25 million years before present (Ma), rather than this taxon being a Gondwanan relic.
- Klíčová slova
- Biogeography, Gondwana, Natricidae, Natricinae, Overseas dispersal, Systematics,
- MeSH
- Colubridae genetika MeSH
- fylogeneze * MeSH
- fylogeografie * MeSH
- molekulární evoluce * MeSH
- sekvenční analýza DNA MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Seychely MeSH
- subsaharská Afrika MeSH
Phylogenetic inference has become a standard technique in integrative taxonomy and systematics, as well as in biogeography and ecology. DNA barcodes are often used for phylogenetic inference, despite being strongly limited due to their low number of informative sites. Also, because current DNA barcodes are based on a fraction of a single, fast-evolving gene, they are highly unsuitable for resolving deeper phylogenetic relationships due to saturation. In recent years, methods that analyse hundreds and thousands of loci at once have improved the resolution of the Tree of Life, but these methods require resources, experience and molecular laboratories that most taxonomists do not have. This paper introduces a PCR-based protocol that produces long amplicons of both slow- and fast-evolving unlinked mitochondrial and nuclear gene regions, which can be sequenced by the affordable and portable ONT MinION platform with low infrastructure or funding requirements. As a proof of concept, we inferred a phylogeny of a sample of 63 spider species from 20 families using our proposed protocol. The results were overall consistent with the results from approaches based on hundreds and thousands of loci, while requiring just a fraction of the cost and labour of such approaches, making our protocol accessible to taxonomists worldwide.
- Klíčová slova
- DNA barcoding, Nanopore sequencing, PCR primers, Phylogeny, Spider, Taxonomy,
- MeSH
- analýza nákladů a výnosů MeSH
- DNA * chemie MeSH
- fylogeneze MeSH
- lidé MeSH
- sekvenční analýza DNA metody MeSH
- taxonomické DNA čárové kódování * metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- DNA * MeSH
The presence of a nucleus and other membrane-bounded intracellular compartments is the defining feature of eukaryotic cells. Endosymbiosis accounts for the origins of mitochondria and plastids, but the evolutionary ancestry of the remaining cellular compartments is incompletely documented. Resolving the evolutionary history of organelle-identity encoding proteins within the endomembrane system is a necessity for unravelling the origins and diversification of the endogenously derived organelles. Comparative genomics reveals events after the last eukaryotic common ancestor (LECA), but resolution of events prior to LECA, and a full account of the intracellular compartments present in LECA, has proved elusive. We have devised and exploited a new phylogenetic strategy to reconstruct the history of the Rab GTPases, a key family of endomembrane-specificity proteins. Strikingly, we infer a remarkably sophisticated organellar composition for LECA, which we predict possessed as many as 23 Rab GTPases. This repertoire is significantly greater than that present in many modern organisms and unexpectedly indicates a major role for secondary loss in the evolutionary diversification of the endomembrane system. We have identified two Rab paralogues of unknown function but wide distribution, and thus presumably ancient nature; RabTitan and RTW. Furthermore, we show that many Rab paralogues emerged relatively suddenly during early metazoan evolution, which is in stark contrast to the lack of significant Rab family expansions at the onset of most other major eukaryotic groups. Finally, we reconstruct higher-order ancestral clades of Rabs primarily linked with endocytic and exocytic process, suggesting the presence of primordial Rabs associated with the establishment of those pathways and giving the deepest glimpse to date into pre-LECA history of the endomembrane system.
- MeSH
- eukaryotické buňky klasifikace enzymologie MeSH
- fylogeneze MeSH
- intracelulární membrány enzymologie MeSH
- klasifikace metody MeSH
- lidé MeSH
- molekulární evoluce MeSH
- molekulární sekvence - údaje MeSH
- Rab proteiny vázající GTP genetika metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
- Názvy látek
- Rab proteiny vázající GTP MeSH
Peridinialean dinophytes include a unique evolutionary group of algae harboring a diatom as an endosymbiont (Kryptoperidiniaceae), whose phylogenetic origin and internal relationships are not fully resolved at present. Several interpretations of the thecal plate pattern present in Durinskia oculata currently compete and lead to considerable taxonomic confusion. Moreover, it is unclear at present whether the species is restricted to freshwater habitats, or occurs in the marine environment as well. We collected material at the type locality of D. oculata in the Czech Republic and established monoclonal strains. Dinophyte cells were studied using light and electron microscopy, and we also determined DNA sequences of several rRNA regions (including the Internal Transcribed Spacers) for molecular characterization and phylogenetics. The morphology of strain GeoM∗662 indicated a plate formula of Po, X, 4', 2a, 6″, 5c, 5s, 5‴, 2⁗, which was sustained also in form of a microscopic slide serving as an epitype. In the molecular DNA tree based on a matrix composed of concatenated rRNA sequences, strain GeoM∗662 showed a close relationship to other species of Durinskia, and the freshwater species clearly differs from the marine members. Two independent colonization events from the marine into the freshwater environment can be inferred within the Kryptoperidiniaceae. We provide a summarizing cladogram of dinophytes harboring a diatom as endosymbiont with evolutionary novelties indicated as well as a morphological key to the 6 species of Durinskia that are currently accepted.
- Klíčová slova
- Epitype, Molecular sequence diagnostics, Morphology, Ribosomal RNA, Sequence comparison, Taxonomy,
- MeSH
- fylogeneze MeSH
- pravděpodobnostní funkce MeSH
- RNA ribozomální chemie genetika MeSH
- rozsivky cytologie genetika MeSH
- sekvenční analýza DNA MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
- Názvy látek
- RNA ribozomální MeSH
We have revisited the mtDNA phylogeny of the bank vole Clethrionomys glareolus based on Sanger and next-generation Illumina sequencing of 32 complete mitochondrial genomes. The bank vole is a key study species for understanding the response of European fauna to the climate change following the Last Glacial Maximum (LGM) and one of the most convincing examples of a woodland mammal surviving in cryptic northern glacial refugia in Europe. The genomes sequenced included multiple representatives of each of the eight bank vole clades previously described based on cytochrome b (cob) sequences. All clades with the exception of the Basque - likely a misidentified pseudogene clade - were highly supported in all phylogenetic analyses and the relationships between the clades were resolved with high confidence. Our data extend the distribution of the Carpathian clade, the marker of a northern glacial refugium in the Carpathian Mountains, to include Britain and Fennoscandia (but not adjacent areas of continental Europe). The Carpathian sub-clade that colonized Britain and Fennoscandia had a somewhat different history from the sub-clade currently found in or close to the Carpathians and may have derived from a more north-westerly refugial area. The two bank vole populations that colonized Britain at the end of the last glaciation are for the first time linked with particular continental clades, the first colonists with the Carpathian clade and the second colonists with the western clade originating in a more southerly refugium in the vicinity of the Alps. We however found no evidence that a functional divergence of proteins encoded in the mitochondrial genome promoted the partial genetic replacement of the first colonists by the second colonists detected previously in southern Britain. We did identify one codon site that changed more often and more radically in the tree than expected and where the observed amino acid change may affect the reductase activity of the cytochrome bc1 complex, but the change was not specific to a particular clade. We also found an excess of radical changes to the primary protein structure for geographically restricted clades from southern Italy and Norway, respectively, possibly related to stronger selective pressure at the latitudinal extremes of the bank vole distribution. However, overall, we find little evidence of pervasive effects of deviation from neutrality on bank vole mtDNA phylogeography.
- Klíčová slova
- Adaptation, Glacial refugia, Mitogenome, Myodes glareolus, Numt, mtDNA,
- MeSH
- Arvicolinae klasifikace genetika MeSH
- Bayesova věta MeSH
- biologická evoluce * MeSH
- cytochromy b genetika MeSH
- fylogeneze * MeSH
- fylogeografie MeSH
- genetická variace MeSH
- genom mitochondriální MeSH
- klimatické změny MeSH
- mitochondriální DNA genetika MeSH
- modely genetické MeSH
- pravděpodobnostní funkce MeSH
- sekvenční analýza DNA MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Evropa MeSH
- Názvy látek
- cytochromy b MeSH
- mitochondriální DNA MeSH
Views on myxosporean phylogeny and systematics have recently undergone substantial changes resulting from analyses of SSU rDNA. Here, we further investigate the evolutionary trends within myxosporean lineages by using 35 new sequences of the LSU rDNA. We show a good agreement between the two rRNA genes and confirm the main phylogenetic split between the freshwater and marine lineages. The informative superiority of the LSU data is shown by an increase of the resolution, nodal supports and tree indexes in the LSU rDNA and combined analyses. We determine the most suitable part of LSU for the myxosporean phylogeny by comparing informative content in various regions of the LSU sequences. Based on this comparison, we propose the D5-3'-end part of the LSU rRNA gene as the most informative region which provides in concatenation with the complete SSU a well resolved and robust tree. To allow for simple amplification of the marker, we design specific primer set for this part of LSU rDNA.
- MeSH
- Bayesova věta MeSH
- DNA primery MeSH
- fylogeneze * MeSH
- geny rRNA MeSH
- molekulární evoluce * MeSH
- Myxozoa klasifikace genetika MeSH
- pravděpodobnostní funkce MeSH
- ribozomální DNA genetika MeSH
- sekvenční analýza DNA MeSH
- sekvenční seřazení MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- DNA primery MeSH
- ribozomální DNA MeSH