scholarly journals The origin and evolution of antistasin-like proteins in leeches (Hirudinida, Clitellata)

2020 ◽  
Author(s):  
Rafael Eiji Iwama ◽  
Michael Tesser ◽  
Mark E Siddall ◽  
Sebastian Kvist
Keyword(s):  
Phylogenetic Analyses ◽  
Gene Tree ◽  
Factor Xa ◽  
Protein Family ◽  
Orthologous Group ◽  
Sequence Motifs ◽  
Leukocyte Elastase ◽  
Elastase Inhibitor ◽  
Origin And Evolution ◽  
Molecular Features

Abstract Bloodfeeding is employed by many parasitic animals and requires specific innovations for efficient feeding. Some of these innovations are molecular features that are related to the inhibition of hemostasis. For example, bloodfeeding insects, bats and leeches release proteins with anticoagulatory activity through their salivary secretions. The antistasin-like protein family, composed of serine protease inhibitors with one or more antistasin-like domains, is tightly linked to inhibition of hemostasis in leeches. However, this protein family has been recorded also in non-bloodfeeding invertebrates, such as cnidarians, molluscs, polychaetes and oligochaetes. The present study aims to: (1) root the antistasin-like gene tree and delimit the major orthologous groups, (2) identify potential independent origins of salivary proteins secreted by leeches and (3) identify major changes in domain and/or motif structure within each orthologous group. Five clades containing leech antistasin-like proteins are distinguishable through rigorous phylogenetic analyses based on nine new transcriptomes and a diverse set of comparative data: the trypsin + leukocyte elastase inhibitors clade, the antistasin clade, the therostasin clade and two additional, unnamed clades. The antistasin-like gene tree supports multiple origins of leech antistasin-like proteins due to the presence of both leech and non-leech sequences in one of the unnamed clades, but a single origin of factor Xa and trypsin + leukocyte elastase inhibitors. This is further supported by three sequence motifs that are exclusive to antistasins, the trypsin + leukocyte elastase inhibitor clade and the therostasin clade, respectively. We discuss the implications of our findings for the evolution of this diverse family of leech anticoagulants.

scholarly journals Multilocus phylogenies reveal three new truffle-like taxa and the traces of interspecific hybridization in Octaviania (Boletaceae, Boletales)

IMA Fungus ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Takamichi Orihara ◽  
Rosanne Healy ◽  
Adriana Corrales ◽  
Matthew E. Smith
Keyword(s):  
Rna Polymerase Ii ◽  
Phylogenetic Analyses ◽  
Large Subunit ◽  
Gene Tree ◽  
Phylogenetic Network ◽  
Elongation Factor ◽  
Morphological Observation ◽  
Tree Comparison ◽  
Unknown Species ◽  
The Usa

ABSTRACTAmong many convergently evolved sequestrate fungal genera in Boletaceae (Boletales, Basidiomycota), the genus Octaviania is the most diverse. We recently collected many specimens of Octaviania subg. Octaviania, including several undescribed taxa, from Japan and the Americas. Here we describe two new species in subgenus Octaviania, O. tenuipes and O. tomentosa, from temperate to subtropical evergreen Fagaceae forests in Japan based on morphological observation and robust multilocus phylogenetic analyses (nrDNA ITS and partial large subunit [LSU], translation elongation factor 1-α gene [TEF1] and the largest subunit of RNA polymerase II gene [RPB1]). Based on specimens from the Americas as well as studies of the holotype, we also taxonomically re-evaluate O. asterosperma var. potteri. Our analysis suggests that O. asterosperma var. potteri is a distinct taxon within the subgenus Octaviania so we recognize this as O. potteri stat. nov. We unexpectedly collected O. potteri specimens from geographically widespread sites in the USA, Japan and Colombia. This is the first verified report of Octaviania from the South American continent. Our molecular analyses also revealed that the RPB1 sequence of one O. tenuipes specimen was identical to that of a closely related species, O. japonimontana, and that one O. potteri specimen from Minnesota had an RPB1 sequence of an unknown species of O. subg. Octaviania. Additionally, one O. japonimontana specimen had an unusually divergent TEF1 sequence. Gene-tree comparison and phylogenetic network analysis of the multilocus dataset suggest that these heterogenous sequences are most likely the result of previous inter- and intra-specific hybridization. We hypothesize that frequent hybridization events in Octaviania may have promoted the high genetic and species diversity found within the genus.

scholarly journals Complete WO Phage Sequences Reveal Their Dynamic Evolutionary Trajectories and Putative Functional Elements Required for Integration into the Wolbachia Genome

2009 ◽  
Vol 75 (17) ◽  
pp. 5676-5686 ◽  
Author(s):  
Kohjiro Tanaka ◽  
Seiichi Furukawa ◽  
Naruo Nikoh ◽  
Tetsuhiko Sasaki ◽  
Takema Fukatsu
Keyword(s):  
Genetic Transformation ◽  
Protein Interactions ◽  
Phylogenetic Analyses ◽  
Attachment Site ◽  
Host Bacterium ◽  
Sequence Motifs ◽  
Integrase Gene ◽  
Bacterial Phyla ◽  
Genetic Elements ◽  
Evolutionary Trajectories

ABSTRACT Wolbachia endosymbionts are ubiquitously found in diverse insects including many medical and hygienic pests, causing a variety of reproductive phenotypes, such as cytoplasmic incompatibility, and thereby efficiently spreading in host insect populations. Recently, Wolbachia-mediated approaches to pest control and management have been proposed, but the application of these approaches has been hindered by the lack of genetic transformation techniques for symbiotic bacteria. Here, we report the genome and structure of active bacteriophages from a Wolbachia endosymbiont. From the Wolbachia strain wCauB infecting the moth Ephestia kuehniella two closely related WO prophages, WOcauB2 of 43,016 bp with 47 open reading frames (ORFs) and WOcauB3 of 45,078 bp with 46 ORFs, were characterized. In each of the prophage genomes, an integrase gene and an attachment site core sequence were identified, which are putatively involved in integration and excision of the mobile genetic elements. The 3′ region of the prophages encoded genes with sequence motifs related to bacterial virulence and protein-protein interactions, which might represent effector molecules that affect cellular processes and functions of their host bacterium and/or insect. Database searches and phylogenetic analyses revealed that the prophage genes have experienced dynamic evolutionary trajectories. Genes similar to the prophage genes were found across divergent bacterial phyla, highlighting the active and mobile nature of the genetic elements. We suggest that the active WO prophage genomes and their constituent sequence elements would provide a clue to development of a genetic transformation vector for Wolbachia endosymbionts.

scholarly journals Mosaic Genomes of the Six Major Primate Lentivirus Lineages Revealed by Phylogenetic Analyses

2003 ◽  
Vol 77 (13) ◽  
pp. 7202-7213 ◽  
Author(s):  
Marco Salemi ◽  
Tulio De Oliveira ◽  
Valerie Courgnaud ◽  
Vincent Moulton ◽  
Barbara Holland ◽  
...  
Keyword(s):  
Phylogenetic Relationships ◽  
Statistical Tests ◽  
Phylogenetic Analyses ◽  
Decomposition Analysis ◽  
Phylogeny Reconstruction ◽  
Origin And Evolution ◽  
Immunodeficiency Virus ◽  
Primate Lentiviruses ◽  
Recombinant Fragments ◽  
Clustering Patterns

ABSTRACT To clarify the origin and evolution of the primate lentiviruses (PLVs), which include human immunodeficiency virus types 1 and 2 as well as their simian relatives, simian immunodeficiency viruses (SIVs), isolated from several host species, we investigated the phylogenetic relationships among the six supposedly nonrecombinant PLV lineages for which the full genome sequences are available. Employing bootscanning as an exploratory tool, we located several regions in the PLV genome that seem to have uncertain or conflicting phylogenetic histories. Phylogeny reconstruction based on distance and maximum-likelihood algorithms followed by a number of statistical tests confirms the existence of at least five putative recombinant fragments in the PLV genome with different clustering patterns. Split decomposition analysis also shows that phylogenetic relationships among PLVs may be better represented by network-based graphs, such as the ones produced by SplitsTree. Our findings not only imply that the six so-called pure PLV lineages have in fact mosaic genomes but also make more unlikely the hypothesis of cospeciation of SIVs and their simian hosts.

scholarly journals Dissecting the basis of novel trait evolution in a radiation with widespread phylogenetic discordance

2017 ◽  
Author(s):  
Meng Wu ◽  
Jamie L. Kostyun ◽  
Matthew W. Hahn ◽  
Leonie Moyle
Keyword(s):  
De Novo ◽  
Incomplete Lineage Sorting ◽  
Phylogenetic Analyses ◽  
Gene Tree ◽  
Fruit Color ◽  
Species Tree ◽  
Color Variation ◽  
Lineage Sorting ◽  
Floral Character ◽  
Trait Evolution

ABSTRACTPhylogenetic analyses of trait evolution can provide insight into the evolutionary processes that initiate and drive phenotypic diversification. However, recent phylogenomic studies have revealed extensive gene tree-species tree discordance, which can lead to incorrect inferences of trait evolution if only a single species tree is used for analysis. This phenomenon—dubbed “hemiplasy”—is particularly important to consider during analyses of character evolution in rapidly radiating groups, where discordance is widespread. Here we generate whole-transcriptome data for a phylogenetic analysis of 14 species in the plant genus Jaltomata (the sister clade to Solanum), which has experienced rapid, recent trait evolution, including in fruit and nectar color, and flower size and shape. Consistent with other radiations, we find evidence for rampant gene tree discordance due to incomplete lineage sorting (ILS) and several introgression events among the well-supported subclades. Since both ILS and introgression increase the probability of hemiplasy, we perform several analyses that take discordance into account while identifying genes that might contribute to phenotypic evolution. Despite discordance, the history of fruit color evolution in Jaltomata can be inferred with high confidence, and we find evidence of de novo adaptive evolution at individual genes associated with fruit color variation. In contrast, hemiplasy appears to strongly affect inferences about floral character transitions in Jaltomata, and we identify candidate loci that could arise either from multiple lineage-specific substitutions or standing ancestral polymorphisms. Our analysis provides a generalizable example of how to manage discordance when identifying loci associated with trait evolution in a radiating lineage.

scholarly journals Characterization and Establishment of a Novel EBV Strain Simultaneously Associated With Nasopharyngeal Carcinoma and B-Cell Lymphoma

2021 ◽  
Vol 11 ◽  
Author(s):  
Fenggang Yu ◽  
Nicholas L. Syn ◽  
Yanan Lu ◽  
Qing Yun Chong ◽  
Junyun Lai ◽  
...  
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Phylogenetic Analyses ◽  
Human Tumor ◽  
B Cell Lymphoma ◽  
Asia Pacific ◽  
B Lymphoma ◽  
Barr Virus ◽  
Molecular Features ◽  
Geographical Regions ◽  
Epstein Barr

Epstein-Barr virus (EBV)—the prototypical human tumor virus—is responsible for 1–2% of the global cancer burden, but divergent strains seem to exist in different geographical regions with distinct predilections for causing lymphoid or epithelial malignancies. Here we report the establishment and characterization of Yu103, an Asia Pacific EBV strain with a highly remarkable provenance of being derived from nasopharyngeal carcinoma biopsy but subsequently propagated in human B-lymphoma cells and xenograft models. Unlike previously characterized EBV strains which are either predominantly B-lymphotropic or epitheliotropic, Yu103 evinces an uncanny capacity to infect and transform both B-lymphocytes and nasopharyngeal epithelial cells. Genomic and phylogenetic analyses indicated that Yu103 EBV lies midway along the spectrum of EBV strains known to drive lymphomagenesis or carcinogenesis, and harbors molecular features which likely account for its unusual properties. To our knowledge, Yu103 EBV is currently the only EBV isolate shown to drive human nasopharyngeal carcinoma and B-lymphoma, and should therefore provide a powerful novel platform for research on EBV-driven hematological and epithelial malignancies.

scholarly journals Molecular fossils illuminate the evolution of retroviruses following a macroevolutionary transition from land to water

2021 ◽  
Vol 17 (7) ◽  
pp. e1009730
Author(s):  
Jialu Zheng ◽  
Jianhua Wang ◽  
Zhen Gong ◽  
Guan-Zhu Han
Keyword(s):  
Phylogenetic Analyses ◽  
Endogenous Retroviruses ◽  
Integration Time ◽  
Aquatic Environments ◽  
Ongoing Activity ◽  
Aquatic Life ◽  
Origin And Evolution ◽  
Molecular Fossils ◽  
Retroviral Infections

The ancestor of cetaceans underwent a macroevolutionary transition from land to water early in the Eocene Period >50 million years ago. However, little is known about how diverse retroviruses evolved during this shift from terrestrial to aquatic environments. Did retroviruses transition into water accompanying their hosts? Did retroviruses infect cetaceans through cross-species transmission after cetaceans invaded the aquatic environments? Endogenous retroviruses (ERVs) provide important molecular fossils for tracing the evolution of retroviruses during this macroevolutionary transition. Here, we use a phylogenomic approach to study the origin and evolution of ERVs in cetaceans. We identify a total of 8,724 ERVs within the genomes of 25 cetaceans, and phylogenetic analyses suggest these ERVs cluster into 315 independent lineages, each of which represents one or more independent endogenization events. We find that cetacean ERVs originated through two possible routes. 298 ERV lineages may derive from retrovirus endogenization that occurred before or during the transition from land to water of cetaceans, and most of these cetacean ERVs were reaching evolutionary dead-ends. 17 ERV lineages are likely to arise from independent retrovirus endogenization events that occurred after the split of mysticetes and odontocetes, indicating that diverse retroviruses infected cetaceans through cross-species transmission from non-cetacean mammals after the transition to aquatic life of cetaceans. Both integration time and synteny analyses support the recent or ongoing activity of multiple retroviral lineages in cetaceans, some of which proliferated into hundreds of copies within the host genomes. Although ERVs only recorded a proportion of past retroviral infections, our findings illuminate the complex evolution of retroviruses during one of the most marked macroevolutionary transitions in vertebrate history.

scholarly journals Genomic Characterization and Curation of UCEs Improves Species Tree Reconstruction

2020 ◽  
Author(s):  
Matthew H Van Dam ◽  
James B Henderson ◽  
Lauren Esposito ◽  
Michelle Trautwein
Keyword(s):  
Marine Invertebrates ◽  
Phylogenetic Analyses ◽  
Single Gene ◽  
Gene Tree ◽  
Single Copy ◽  
Species Tree ◽  
Bootstrap Support ◽  
Gene Trees ◽  
Species Trees ◽  
Tree Reconstruction

Abstract Ultraconserved genomic elements (UCEs) are generally treated as independent loci in phylogenetic analyses. The identification pipeline for UCE probes does not require prior knowledge of genetic identity, only selecting loci that are highly conserved, single copy, without repeats, and of a particular length. Here, we characterized UCEs from 11 phylogenomic studies across the animal tree of life, from birds to marine invertebrates. We found that within vertebrate lineages, UCEs are mostly intronic and intergenic, while in invertebrates, the majority are in exons. We then curated four different sets of UCE markers by genomic category from five different studies including: birds, mammals, fish, Hymenoptera (ants, wasps, and bees), and Coleoptera (beetles). Of genes captured by UCEs, we find that many are represented by two or more UCEs, corresponding to nonoverlapping segments of a single gene. We considered these UCEs to be nonindependent, merged all UCEs that belonged to a particular gene, constructed gene and species trees, and then evaluated the subsequent effect of merging cogenic UCEs on gene and species tree reconstruction. Average bootstrap support for merged UCE gene trees was significantly improved across all data sets apparently driven by the increase in loci length. Additionally, we conducted simulations and found that gene trees generated from merged UCEs were more accurate than those generated by unmerged UCEs. As loci length improves gene tree accuracy, this modest degree of UCE characterization and curation impacts downstream analyses and demonstrates the advantages of incorporating basic genomic characterizations into phylogenomic analyses. [Anchored hybrid enrichment; ants; ASTRAL; bait capture; carangimorph; Coleoptera; conserved nonexonic elements; exon capture; gene tree; Hymenoptera; mammal; phylogenomic markers; songbird; species tree; ultraconserved elements; weevils.]

scholarly journals SAND, a New Protein Family: From Nucleic Acid to Protein Structure and Function Prediction

2001 ◽  
Vol 2 (4) ◽  
pp. 226-235 ◽  
Author(s):  
Amanda Cottage ◽  
Yvonne J. K. Edwards ◽  
Greg Elgar
Keyword(s):  
Genomic Sequence ◽  
Protein Family ◽  
Sequence Motifs ◽  
Est Database ◽  
Computational Tools ◽  
Conserved Sequence ◽  
Conserved Sequence Motifs ◽  
And Function ◽  
New Protein ◽  
Genomic Organisation

As a result of genome, EST and cDNA sequencing projects, there are huge numbers of predicted and/or partially characterised protein sequences compared with a relatively small number of proteins with experimentally determined function and structure. Thus, there is a considerable attention focused on the accurate prediction of gene function and structure from sequence by using bioinformatics. In the course of our analysis of genomic sequence fromFugu rubripes, we identified a novel gene,SAND, with significant sequence identity to hypothetical proteins predicted inSaccharomyces cerevisiae, Schizosaccharomyces pombe, Caenorhabditis elegans, aDrosophila melanogastergene, and mouse and human cDNAs. Here we identify a furtherSANDhomologue in human andArabidopsis thalianaby use of standard computational tools. We describe the genomic organisation ofSANDin these evolutionarily divergent species and identify sequence homologues from EST database searches confirming the expression of SAND in over 20 different eukaryotes. We confirm the expression of two different SAND paralogues in mammals and determine expression of one SAND in other vertebrates and eukaryotes. Furthermore, we predict structural properties of SAND, and characterise conserved sequence motifs in this protein family.

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