phylogenetic analyses
Dotaz
Zobrazit nápovědu
Apicomplexan protozoa contain a single mitochondrion and a multimembranous plastid-like organelle termed apicoplast. The size of the apicomplexan plastid genome is extremely small (35 kb) thus offering a limited number of genes for phylogenetic analysis. Moreover, the sequences of apicoplast genes are highly adenosine+thymidine-rich and rapidly evolving. Due to these facts, phylogenetic analyses based on different genes or the structure of the ribosomal operon show conflicting results and the evolutionary history of this exciting organelle remains unclear. Although it is evident that the apicoplast and its genome is plastid-derived, our detailed phylogenetic analysis of amino acid and nucleotide sequences of selected apicoplast ribosomal protein genes rpl2, rpl14 and rps12 show their possible mitochondrial origin. The affinity of apicoplast ribosomal proteins to their mitochondrial homologs is very stable and well supported. Based on our results we propose that apicoplasts might contain both plastid and mitochondrial genes, thus constituting a hybrid assembly.
- MeSH
- fylogeneze * MeSH
- mitochondriální DNA genetika MeSH
- molekulární evoluce MeSH
- organely genetika MeSH
- Plasmodium falciparum genetika MeSH
- plastidy genetika MeSH
- protozoální DNA genetika MeSH
- protozoální geny genetika MeSH
- protozoální proteiny genetika MeSH
- ribozomální proteiny genetika MeSH
- Toxoplasma genetika MeSH
- zastoupení bazí MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- mitochondriální DNA MeSH
- protozoální DNA MeSH
- protozoální proteiny MeSH
- ribosomal protein L14 MeSH Prohlížeč
- ribosomal protein L2 MeSH Prohlížeč
- ribosomal protein S12 MeSH Prohlížeč
- ribozomální proteiny MeSH
Despite the importance of ticks as vectors of disease very little is known about their immune system. Antimicrobial peptides, including defensins (phylogenetically ancient antibacterial peptides) are major components of innate immunity in ticks that have been shown to provide protection against gram-negative and gram-positive bacteria, fungi, viruses and protozoan parasites. With the aim of studying the evolution of the genes involved in tick defense, we identified the preprodefensin genes from four Ornithodoros tick species (O. papillipes: isoforms A, B, and D; O. tartakovskyi and O. puertoricensis: isoforms A and B; O. rostratus: isoform A) and from two Dermacentor tick species (D. reticulatus and D. marginatus: one isoform) not previously described. Phylogenetic analyses revealed that Ornithodoros defensin isoforms (A, B, C, and D) form 4 separate clades, while hard tick defensins are divided into several branches based on particular tick species.
- MeSH
- defensiny chemie genetika metabolismus MeSH
- fylogeneze * MeSH
- klíšťata genetika metabolismus MeSH
- molekulární sekvence - údaje MeSH
- sekvence aminokyselin MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- defensiny MeSH
The genus Cheiromycina is one of the few genera of lichenized hyphomycetes for which no sexual reproductive stages have been observed. The genus includes species from boreal to temperate regions of the Northern Hemisphere where it is found growing on bark or wood. Congeners in Cheiromycina are characterized by a noncorticate thallus, nearly immersed in the substrate and presenting powdery unpigmented sporodochia, and containing chlorococcoid photobionts. The relationships of members of Cheiromycina with other fungi are not known. Here we inferred the phylogenetic placement of Cheiromycina using three loci (nuSSU, nuLSU, and mtSSU) representing C. flabelliformis, the type species for the genus, C. petri, and C. reimeri. Our results revealed that the genus Cheiromycina is found within the family Malmideaceae (Lecanorales) where members formed a monophyletic clade sister to the genera Savoronala and Malmidea. This phylogenetic placement and the relationships of Cheiromycina with other lichenized hyphomycetous taxa are here discussed.
- Klíčová slova
- Cheiroid conidia, Lecanorales, Malmideaceae, mycobiont, ribosomal DNA, symbiosis,
- MeSH
- Ascomycota klasifikace cytologie genetika MeSH
- DNA fungální genetika MeSH
- fylogeneze * MeSH
- kůra rostlin mikrobiologie MeSH
- lišejníky mikrobiologie MeSH
- mitosporické houby klasifikace cytologie genetika MeSH
- RNA ribozomální 18S genetika MeSH
- RNA ribozomální 28S genetika MeSH
- RNA ribozomální genetika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Evropa MeSH
- Spojené státy americké MeSH
- Názvy látek
- DNA fungální MeSH
- RNA ribozomální 18S MeSH
- RNA ribozomální 28S MeSH
- RNA ribozomální MeSH
- RNA, ribosomal, 12S MeSH Prohlížeč
Multigene, genus-wide phylogenetic studies have uncovered the limited taxonomic resolution power of commonly used gene markers, particularly of rRNA genes, to discriminate closely related species of the nematode genus Heterorhabditis. In addition, conflicting tree topologies are often obtained using the different gene markers, which limits our understanding of the phylo- and co-phylogenetic relationships and biogeography of the entomopathogenic nematode genus Heterorhabditis. Here we carried out phylogenomic reconstructions using whole nuclear and mitochondrial genomes, and whole ribosomal operon sequences, as well as multiple phylogenetic reconstructions using various single nuclear and mitochondrial genes. Using the inferred phylogenies, we then investigated co-phylogenetic relationships between Heterorhabditis and their Photorhabdus bacterial symbionts and biogeographical patterns. Robust, well-resolved, and highly congruent phylogenetic relationships were reconstructed using both whole nuclear and mitochondrial genomes. Similarly, whole ribosomal operon sequences proved valuable for phylogenomic reconstructions, though they have limited value to discriminate closely related species. In addition, two mitochondrial genes, the cytochrome c oxidase subunit I (cox-1) and the NADH dehydrogenase subunit 4 (nad-4), and two housekeeping genes, the fanconi-associated nuclease 1 (fan-1) and the serine/threonine-protein phosphatase 4 regulatory subunit 1 (ppfr-1), provided the most robust phylogenetic reconstructions compared to other individual genes. According to our findings, whole nuclear and/or mitochondrial genomes are strongly recommended for reconstructing phylogenetic relationships of the genus Heterorhabditis. If whole nuclear and/or mitochondrial genomes are unavailable, a combination of nuclear and mitochondrial genes can be used as an alternative. Under these circumstances, sequences of multiple conspecific isolates in a genus-wide phylogenetic context should be analyzed to avoid artefactual species over-splitting driven by the high intraspecific sequence divergence of mitochondrial genes and to avoid artefactual species lumping driven by the low interspecific sequence divergence of some nuclear genes. On the other hand, we observed that the genera Heterorhabditis and Photorhabdus exhibit diverse biogeographic patterns, ranging from cosmopolitan species to potentially endemic species, and show high phylogenetic congruence, although host switches have also occurred. Our study contributes to a better understanding of the biodiversity and phylo- and co-phylogenetic relationships of an important group of biological control agents and advances our efforts to develop more tools that are compatible with sustainable and eco-friendly agricultural practices.
- Klíčová slova
- Biological control, Molecular systematics, Phylogenetic species concept, Phylogenetics, Phylogenomics, Sustainable agriculture, Taxonomy,
- MeSH
- buněčné jádro genetika MeSH
- celogenomová asociační studie MeSH
- fylogeneze * MeSH
- fylogeografie * metody MeSH
- genetická variace * MeSH
- genom mitochondriální MeSH
- genom u helmintů * MeSH
- pravděpodobnostní funkce MeSH
- Strongyloidea * genetika MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The ARF family of regulatory GTPases is ancient, with 16 members predicted to have been present in the last eukaryotic common ancestor. Our phylogenetic profiling of paralogues in diverse species identified four family members whose presence correlates with that of a cilium/flagellum: ARL3, ARL6, ARL13, and ARL16. No prior evidence links ARL16 to cilia or other cell functions, despite its presence throughout eukaryotes. Deletion of ARL16 in mouse embryonic fibroblasts (MEFs) results in decreased ciliogenesis yet increased ciliary length. We also found Arl16 knockout (KO) in MEFs to alter ciliary protein content, including loss of ARL13B, ARL3, INPP5E, and the IFT-A core component IFT140. Instead, both INPP5E and IFT140 accumulate at the Golgi in Arl16 KO lines, while other intraflagellar transport (IFT) proteins do not, suggesting a specific defect in traffic from Golgi to cilia. We propose that ARL16 regulates a Golgi-cilia traffic pathway and is required specifically in the export of IFT140 and INPP5E from the Golgi.
- MeSH
- cilie metabolismus MeSH
- fibroblasty * metabolismus MeSH
- fosfatasy * metabolismus MeSH
- fylogeneze MeSH
- myši MeSH
- proteiny metabolismus MeSH
- transport proteinů MeSH
- transportní proteiny genetika metabolismus MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Názvy látek
- fosfatasy * MeSH
- IFT140 protein, mouse MeSH Prohlížeč
- phosphoinositide 5-phosphatase MeSH Prohlížeč
- proteiny MeSH
- transportní proteiny MeSH
Polydiscidium is an enigmatic, monotypic, and rarely reported genus of Ascomycota of uncertain placement. The morphologically unique Polydiscidium martynii grows on dead wood and forms compound ascomata composed of thick, black, gelatinous somatic tissue that branches out from a common base. Multiple apothecia are located on the branches, mostly toward the tips, and are composed of 8-spored asci and paraphyses embedded in a gelatinous matrix that turns blue in Melzer's reagent. The species was previously known from only three collections from Guyana (holotype), Trinidad, and the Democratic Republic of the Congo and no sequences exist. Due to its peculiar morphology, taxonomic affinities of Polydiscidium have been debated, with different authors having placed it in Helotiaceae, Leotiaceae, or Leotiomycetes incertae sedis. Recent collections of this species resulting from long-term field work in Guyana and Cameroon led us to revisit the morphology and phylogenetic position of this fungus. Newly generated sequences of P. martynii were added to an Ascomycota-wide six-locus data set. The resulting phylogeny showed Polydiscidium to be a member of order Sclerococcales (Eurotiomycetes). Next, a four-locus (18S, ITS, 28S, mtSSU) phylogenetic reconstruction revealed that Polydiscidium is congeneric with Sclerococcum. A new combination is proposed for this species, Sclerococcum martynii. Micromorphological features, including the gelatinous hymenium composed of asci with amyloid gel cap and septate brown ascospores, are in agreement with Sclerococcum. New combinations are proposed for two additional species: Sclerococcum chiangraiensis and S. fusiformis. Finally, Dactylosporales is considered a later synonym of Sclerococcales.
- Klíčová slova
- 3 new taxa, Cameroon, Guiana Shield, Sclerococcaceae, multilocus phylogeny, rare fungi, systematics, taxonomy,
- MeSH
- Ascomycota * genetika MeSH
- dřevo mikrobiologie MeSH
- fylogeneze MeSH
- spory hub MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
- Geografické názvy
- Guyana MeSH
Clades that have undergone episodes of rapid cladogenesis are challenging from a phylogenetic point of view. They are generally characterised by short or missing internal branches in phylogenetic trees and by conflicting topologies among individual gene trees. This may be the case of the subfamily Trematominae, a group of marine teleosts of coastal Antarctic waters, which is considered to have passed through a period of rapid diversification. Despite much phylogenetic attention, the relationships among Trematominae species remain unclear. In contrast to previous studies that were mostly based on concatenated datasets of mitochondrial and/or single nuclear loci, we applied various single-locus and multilocus phylogenetic approaches to sequences from 11 loci (eight nuclear) and we also used several methods to assess the hypothesis of a radiation event in Trematominae evolution. Diversification rate analyses support the hypothesis of a period of rapid diversification during Trematominae history and only a few nodes in the hypothetical species tree were consistently resolved with various phylogenetic methods. We detected significant discrepancies among trees from individual genes of these species, most probably resulting from incomplete lineage sorting, suggesting that concatenation of loci is not the most appropriate way to investigate Trematominae species interrelationships. These data also provide information about the possible effects of historic climate changes on the diversification rate of this group of fish.
- MeSH
- Bayesova věta MeSH
- fylogeneze * MeSH
- ryby klasifikace genetika MeSH
- sekvenční analýza DNA MeSH
- vznik druhů (genetika) * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Antarktida MeSH
Cyphellophora and Phialophora (Chaetothyriales, Pezizomycota) comprise species known from skin infections of humans and animals and from a variety of environmental sources. These fungi were studied based on the comparison of cultural and morphological features and phylogenetic analyses of five nuclear loci, i.e., internal transcribed spacer rDNA operon (ITS), large and small subunit nuclear ribosomal DNA (nuc28S rDNA, nuc18S rDNA), β-tubulin, DNA replication licensing factor (mcm7) and second largest subunit of RNA polymerase II (rpb2). Phylogenetic results were supported by comparative analysis of ITS1 and ITS2 secondary structure of representatives of the Chaetothyriales and the identification of substitutions among the taxa analyzed. Base pairs with non-conserved, co-evolving nucleotides that maintain base pairing in the RNA transcript and unique evolutionary motifs in the ITS2 that characterize whole clades or individual taxa were mapped on predicted secondary structure models. Morphological characteristics, structural data and phylogenetic analyses of three datasets, i.e., ITS, ITS-β-tubulin and 28S-18S-rpb2-mcm7, define a robust clade containing eight species of Cyphellophora (including the type) and six species of Phialophora. These taxa are now accommodated in the Cyphellophoraceae, a novel evolutionary lineage within the Chaetothyriales. Cyphellophora is emended and expanded to encompass species with both septate and nonseptate conidia formed on discrete, intercalary, terminal or lateral phialides. Six new combinations in Cyphellophora are proposed and a dichotomous key to species accepted in the genus is provided. Cyphellophora eugeniae and C. hylomeconis, which grouped in the Chaetothyriaceae, represent another novel lineage and are introduced as the type species of separate genera.
- MeSH
- Ascomycota genetika MeSH
- fylogeneze * MeSH
- genetické lokusy genetika MeSH
- geny hub genetika MeSH
- konformace nukleové kyseliny * MeSH
- konsenzuální sekvence MeSH
- mezerníky ribozomální DNA chemie genetika MeSH
- molekulární evoluce * MeSH
- molekulární sekvence - údaje MeSH
- nukleotidové motivy genetika MeSH
- RNA ribozomální chemie genetika MeSH
- sekvence nukleotidů MeSH
- spory hub cytologie MeSH
- tubulin genetika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Názvy látek
- mezerníky ribozomální DNA MeSH
- RNA ribozomální MeSH
- tubulin MeSH
Photosynthetic euglenids acquired chloroplasts by secondary endosymbiosis, which resulted in changes to their mode of nutrition and affected the evolution of their morphological characters. Mapping morphological characters onto a reliable molecular tree could elucidate major trends of those changes. We analyzed nucleotide sequence data from regions of three nuclear-encoded genes (nSSU, nLSU, hsp90), one chloroplast-encoded gene (cpSSU) and one nuclear-encoded chloroplast gene (psbO) to estimate phylogenetic relationships among 59 photosynthetic euglenid species. Our results were consistent with previous works; most genera were monophyletic, except for the polyphyletic genus Euglena, and the paraphyletic genus Phacus. We also analyzed character evolution in photosynthetic euglenids using our phylogenetic tree and eight morphological traits commonly used for generic and species diagnoses, including: characters corresponding to well-defined clades, apomorphies like presence of lorica and mucilaginous stalks, and homoplastic characters like rigid cells and presence of large paramylon grains. This research indicated that pyrenoids were lost twice during the evolution of phototrophic euglenids, and that mucocysts, which only occur in the genus Euglena, evolved independently at least twice. In contrast, the evolution of cell shape and chloroplast morphology was difficult to elucidate, and could not be unambiguously reconstructed in our analyses.
- Klíčová slova
- Algae, Euglenea, Euglenida, LSU rDNA, SSU rDNA, hsp90, molecular phylogeny, protists, psbO,
- MeSH
- Euglenida klasifikace cytologie genetika MeSH
- fotosystém II (proteinový komplex) genetika MeSH
- fylogeneze * MeSH
- molekulární evoluce * MeSH
- proteiny tepelného šoku HSP90 genetika MeSH
- protozoální geny * MeSH
- RNA ribozomální 18S genetika MeSH
- RNA ribozomální genetika MeSH
- sekvenční analýza DNA MeSH
- výpočetní biologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- fotosystém II (proteinový komplex) MeSH
- proteiny tepelného šoku HSP90 MeSH
- RNA ribozomální 18S MeSH
- RNA ribozomální MeSH
- RNA, ribosomal, 26S MeSH Prohlížeč
Two key biological features distinguish Trypanosoma evansi from the T. brucei group: independence from the tsetse fly as obligatory vector, and independence from the need for functional mitochondrial DNA (kinetoplast or kDNA). In an effort to better understand the molecular causes and consequences of these differences, we sequenced the genome of an akinetoplastic T. evansi strain from China and compared it to the T. b. brucei reference strain. The annotated T. evansi genome shows extensive similarity to the reference, with 94.9% of the predicted T. b. brucei coding sequences (CDS) having an ortholog in T. evansi, and 94.6% of the non-repetitive orthologs having a nucleotide identity of 95% or greater. Interestingly, several procyclin-associated genes (PAGs) were disrupted or not found in this T. evansi strain, suggesting a selective loss of function in the absence of the insect life-cycle stage. Surprisingly, orthologous sequences were found in T. evansi for all 978 nuclear CDS predicted to represent the mitochondrial proteome in T. brucei, although a small number of these may have lost functionality. Consistent with previous results, the F1FO-ATP synthase γ subunit was found to have an A281 deletion, which is involved in generation of a mitochondrial membrane potential in the absence of kDNA. Candidates for CDS that are absent from the reference genome were identified in supplementary de novo assemblies of T. evansi reads. Phylogenetic analyses show that the sequenced strain belongs to a dominant group of clonal T. evansi strains with worldwide distribution that also includes isolates classified as T. equiperdum. At least three other types of T. evansi or T. equiperdum have emerged independently. Overall, the elucidation of the T. evansi genome sequence reveals extensive similarity of T. brucei and supports the contention that T. evansi should be classified as a subspecies of T. brucei.
- MeSH
- analýza hlavních komponent MeSH
- fylogeneze * MeSH
- genom protozoální * MeSH
- jednonukleotidový polymorfismus MeSH
- mikrosatelitní repetice MeSH
- protozoální proteiny genetika metabolismus MeSH
- regulace genové exprese MeSH
- Trypanosoma klasifikace genetika MeSH
- trypanosomové variantní povrchové glykoproteiny genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Názvy látek
- protozoální proteiny MeSH
- trypanosomové variantní povrchové glykoproteiny MeSH