scholarly journals Corallimorpharians are not “naked corals”: insights into relationships between Scleractinia and Corallimorpharia from phylogenomic analyses

2016 ◽  
Author(s):  
Mei Fang Lin ◽  
Wen Hwa Chou ◽  
Marcelo V Kitahara ◽  
Chao Lun Allen Chen ◽  
David John Miller ◽  
...  
Keyword(s):  
Evolutionary Relationship ◽  
Single Copy ◽  
Scleractinian Corals ◽  
Amino Acid Sequences ◽  
Compositional Bias ◽  
Nuclear Markers ◽  
Protein Coding ◽  
Mitochondrial Sequences ◽  
Phylogenomic Analyses ◽  
Close Relatives

Calcification is one of the most distinctive traits of scleractinian corals. Their hard skeletons form the substratum of reef ecosystems and confer on corals their remarkable diversity of shapes. Corallimorpharians are non-calcifying, close relatives of scleractinian corals, and the evolutionary relationship between these two groups is key to understanding the evolution of calcification in the coral lineage. One pivotal question is whether scleractinians are a monophyletic group, paraphyly being an alternative possibility if corallimorpharians are corals that have lost their ability to calcify, as is implied by the “naked-coral” hypothesis. Despite major efforts, relationships between scleractinians and corallimorpharians remain equivocal and controversial. Although the complete mitochondrial genomes of a range of scleractinians and corallimorpharians have been obtained, heterogeneity in composition and evolutionary rates means that mitochondrial sequences are insufficient to understand the relationship between these two groups. To overcome these limitations, transcriptome data were generated for three representative corallimorpharians. These were used in combination with sequences available for a representative range of scleractinians to identify 291 orthologous single copy protein-coding nuclear markers. Unlike the mitochondrial sequences, these nuclear markers do not display any distinct compositional bias in their nucleotide or amino-acid sequences. A range of phylogenomic approaches congruently reveal a topology consistent with scleractinian monophyly and corallimorpharians as the sister clade of scleractinians.

scholarly journals Corallimorpharians are not “naked corals”: insights into relationships between Scleractinia and Corallimorpharia from phylogenomic analyses

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2463 ◽  
Author(s):  
Mei Fang Lin ◽  
Wen Hwa Chou ◽  
Marcelo V. Kitahara ◽  
Chao Lun Allen Chen ◽  
David John Miller ◽  
...  
Keyword(s):  
Evolutionary Relationship ◽  
Single Copy ◽  
Scleractinian Corals ◽  
Amino Acid Sequences ◽  
Compositional Bias ◽  
Nuclear Markers ◽  
Protein Coding ◽  
Mitochondrial Sequences ◽  
Phylogenomic Analyses ◽  
Close Relatives

Calcification is one of the most distinctive traits of scleractinian corals. Their hard skeletons form the substratum of reef ecosystems and confer on corals their remarkable diversity of shapes. Corallimorpharians are non-calcifying, close relatives of scleractinian corals, and the evolutionary relationship between these two groups is key to understanding the evolution of calcification in the coral lineage. One pivotal question is whether scleractinians are a monophyletic group, paraphyly being an alternative possibility if corallimorpharians are corals that have lost their ability to calcify, as is implied by the “naked-coral” hypothesis. Despite major efforts, relationships between scleractinians and corallimorpharians remain equivocal and controversial. Although the complete mitochondrial genomes of a range of scleractinians and corallimorpharians have been obtained, heterogeneity in composition and evolutionary rates means that mitochondrial sequences are insufficient to understand the relationship between these two groups. To overcome these limitations, transcriptome data were generated for three representative corallimorpharians. These were used in combination with sequences available for a representative range of scleractinians to identify 291 orthologous single copy protein-coding nuclear markers. Unlike the mitochondrial sequences, these nuclear markers do not display any distinct compositional bias in their nucleotide or amino-acid sequences. A range of phylogenomic approaches congruently reveal a topology consistent with scleractinian monophyly and corallimorpharians as the sister clade of scleractinians.

scholarly journals Corallimorpharians are not “naked corals”: insights into relationships between Scleractinia and Corallimorpharia from phylogenomic analyses

2016 ◽  
Author(s):  
Mei Fang Lin ◽  
Wen Hwa Chou ◽  
Marcelo V Kitahara ◽  
Chao Lun Allen Chen ◽  
David John Miller ◽  
...  
Keyword(s):  
Evolutionary Relationship ◽  
Single Copy ◽  
Scleractinian Corals ◽  
Amino Acid Sequences ◽  
Compositional Bias ◽  
Nuclear Markers ◽  
Protein Coding ◽  
Mitochondrial Sequences ◽  
Phylogenomic Analyses ◽  
Close Relatives

Calcification is one of the most distinctive traits of scleractinian corals. Their hard skeletons form the substratum of reef ecosystems and confer on corals their remarkable diversity of shapes. Corallimorpharians are non-calcifying, close relatives of scleractinian corals, and the evolutionary relationship between these two groups is key to understanding the evolution of calcification in the coral lineage. One pivotal question is whether scleractinians are a monophyletic group, paraphyly being an alternative possibility if corallimorpharians are corals that have lost their ability to calcify, as is implied by the “naked-coral” hypothesis. Despite major efforts, relationships between scleractinians and corallimorpharians remain equivocal and controversial. Although the complete mitochondrial genomes of a range of scleractinians and corallimorpharians have been obtained, heterogeneity in composition and evolutionary rates means that mitochondrial sequences are insufficient to understand the relationship between these two groups. To overcome these limitations, transcriptome data were generated for three representative corallimorpharians. These were used in combination with sequences available for a representative range of scleractinians to identify 291 orthologous single copy protein-coding nuclear markers. Unlike the mitochondrial sequences, these nuclear markers do not display any distinct compositional bias in their nucleotide or amino-acid sequences. A range of phylogenomic approaches congruently reveal a topology consistent with scleractinian monophyly and corallimorpharians as the sister clade of scleractinians.

scholarly journals The unresolved phylogenomic tree of butterflies and moths (Lepidoptera): assessing the potential causes and consequences

2021 ◽  
Author(s):  
Jadranka Rota ◽  
Victoria Gwendoline Twort ◽  
Andrea Chiocchio ◽  
Carlos Pena ◽  
Christopher W. Wheat ◽  
...  
Keyword(s):  
Amino Acid ◽  
Molecular Phylogenetics ◽  
Phylogenetic Signal ◽  
Tree Of Life ◽  
Amino Acid Sequences ◽  
Model Organisms ◽  
Compositional Bias ◽  
Sequencing Technologies ◽  
Phylogenetic Hypotheses ◽  
Phylogenomic Analyses

The field of molecular phylogenetics is being revolutionised with next-generation sequencing technologies making it possible to sequence large numbers of genomes for non-model organisms ushering us into the era of phylogenomics. The current challenge is no longer how to get enough data, but rather how to analyse the data and how to assess the support for the inferred phylogeny. We focus on one of the largest animal groups on the planet - butterflies and moths (order Lepidoptera). We clearly demonstrate that there are unresolved issues in the inferred phylogenetic relationships of the major lineages, despite several recent phylogenomic studies of the group. We assess the potential causes and consequences of the conflicting phylogenetic hypotheses. With a dataset consisting of 331 protein-coding genes and the alignment length over 290 000 base pairs, including 200 taxa representing 81% of lepidopteran superfamilies, we compare phylogenetic hypotheses inferred from amino acid and nucleotide alignments. The resulting two phylogenies are discordant, especially with respect to the placement of the superfamily Gelechioidea, which is likely due to compositional bias of both the nucleotide and amino acid sequences. With a series of analyses, we dissect our dataset and demonstrate that there is sufficient phylogenetic signal to resolve much of the lepidopteran tree of life. Overall, the results from the nucleotide alignment are more robust to the various perturbations of the data that we carried out. However, the lack of support for much of the backbone within Ditrysia makes the current butterfly and moth tree of life still unresolved. We conclude that taxon sampling remains an issue even in phylogenomic analyses, and recommend that poorly sampled highly diverse groups, such as Gelechioidea in Lepidoptera, should receive extra attention in the future.

scholarly journals PhyloFisher: A phylogenomic package for resolving eukaryotic relationships

PLoS Biology ◽  
2021 ◽  
Vol 19 (8) ◽  
pp. e3001365
Author(s):  
Alexander K. Tice ◽  
David Žihala ◽  
Tomáš Pánek ◽  
Robert E. Jones ◽  
Eric D. Salomaki ◽  
...  
Keyword(s):  
Single Copy ◽  
Protein Coding ◽  
Eukaryotic Diversity ◽  
Protein Coding Genes ◽  
Markov Cluster Algorithm ◽  
Pruning Algorithms ◽  
Phylogenomic Analyses ◽  
Diverse Groups ◽  
Tree Pruning ◽  
Markov Cluster

Phylogenomic analyses of hundreds of protein-coding genes aimed at resolving phylogenetic relationships is now a common practice. However, no software currently exists that includes tools for dataset construction and subsequent analysis with diverse validation strategies to assess robustness. Furthermore, there are no publicly available high-quality curated databases designed to assess deep (>100 million years) relationships in the tree of eukaryotes. To address these issues, we developed an easy-to-use software package, PhyloFisher (https://github.com/TheBrownLab/PhyloFisher), written in Python 3. PhyloFisher includes a manually curated database of 240 protein-coding genes from 304 eukaryotic taxa covering known eukaryotic diversity, a novel tool for ortholog selection, and utilities that will perform diverse analyses required by state-of-the-art phylogenomic investigations. Through phylogenetic reconstructions of the tree of eukaryotes and of the Saccharomycetaceae clade of budding yeasts, we demonstrate the utility of the PhyloFisher workflow and the provided starting database to address phylogenetic questions across a large range of evolutionary time points for diverse groups of organisms. We also demonstrate that undetected paralogy can remain in phylogenomic “single-copy orthogroup” datasets constructed using widely accepted methods such as all vs. all BLAST searches followed by Markov Cluster Algorithm (MCL) clustering and application of automated tree pruning algorithms. Finally, we show how the PhyloFisher workflow helps detect inadvertent paralog inclusions, allowing the user to make more informed decisions regarding orthology assignments, leading to a more accurate final dataset.

scholarly journals Evolution of Rosaceae Plastomes Highlights Unique Cerasus Diversification and Independent Origins of Fruiting Cherry

2021 ◽  
Vol 12 ◽  
Author(s):  
Jing Zhang ◽  
Yan Wang ◽  
Tao Chen ◽  
Qing Chen ◽  
Lei Wang ◽  
...  
Keyword(s):  
Single Copy ◽  
Genomic Variation ◽  
Molecular Dating ◽  
Divergent Evolution ◽  
Comparative Genomic ◽  
Evolutionary Patterns ◽  
Protein Coding ◽  
Longmenshan Fault ◽  
Plastid Protein ◽  
Phylogenomic Analyses

Rosaceae comprises numerous types of economically important fruits, ornamentals, and timber. The lack of plastome characteristics has blocked our understanding of the evolution of plastome and plastid genes of Rosaceae crops. Using comparative genomics and phylogenomics, we analyzed 121 Rosaceae plastomes of 54 taxa from 13 genera, predominantly including Cerasus (true cherry) and its relatives. To our knowledge, we generated the first comprehensive map of genomic variation across Rosaceae plastomes. Contraction/expansion of inverted repeat regions and sequence losses of the two single-copy regions underlie large genomic variations in size among Rosaceae plastomes. Plastid protein-coding genes were characterized with a high proportion (over 50%) of synonymous variants and insertion-deletions with multiple triplets. Five photosynthesis-related genes were specially selected in perennial woody trees. Comparative genomic analyses implied divergent evolutionary patterns between pomaceous and drupaceous trees. Across all examined plastomes, unique and divergent evolution was detected in Cerasus plastomes. Phylogenomic analyses and molecular dating highlighted the relatively distant phylogenetic relationship between Cerasus and relatives (Microcerasus, Amygdalus, Prunus, and Armeniaca), which strongly supported treating the monophyletic true cherry group as a separate genus excluding dwarf cherry. High genetic differentiation and distinct phylogenetic relationships implied independent origins and domestication between fruiting cherries, particularly between Prunus pseudocerasus (Cerasus pseudocerasus) and P. avium (C. avium). Well-resolved maternal phylogeny suggested that cultivated P. pseudocerasus originated from Longmenshan Fault zone, the eastern edge of Himalaya-Hengduan Mountains, where it was subjected to frequent genomic introgression between its presumed wild ancestors and relatives.

scholarly journals Phylogenomic Analyses of Hepatica Species and Comparative Analyses Within Tribe Anemoneae (Ranunculaceae)

2021 ◽  
Vol 12 ◽  
Author(s):  
Kyu Tae Park ◽  
SeonJoo Park
Keyword(s):  
Phylogenetic Analyses ◽  
Single Copy ◽  
Rrna Genes ◽  
Large Single Copy ◽  
Protein Coding ◽  
Comparative Analyses ◽  
Phylogenomic Analyses ◽  
Small Genus ◽  
Small Single Copy ◽  
Large Single Copy Region

Hepatica is a small genus of Ranunculaceae with medicinal and horticultural value. We characterized nine complete chloroplast (cp) genomes of Hepatica, which ranged from 159,549 to 161,081 bp in length and had a typical quadripartite structure with a large single-copy region (LSC; 80,270–81,249 bp), a small single-copy region (SSC; 17,029–17,838 bp), and two copies of inverted repeat (IR; 31,008–31,100 bp). The cp genomes of Hepatica possess 76 protein-coding genes (PCGs), 29 tRNAs, and four rRNA genes. Comparative analyses revealed a conserved ca. 5-kb IR expansion in Hepatica and other Anemoneae; moreover, multiple inversion events occurred in Hepatica and its relatives. Analyses of selection pressure (dN/dS) showed that most of the PCGs are highly conserved except for rpl20 and rpl22 in Hepatica falconeri, Hepatica americana, and Hepatica acutiloba. Two genes (rps16 and infA) were identified as pseudogenes in Hepatica. In contrast, rpl32 gene was completely lost. The phylogenetic analyses based on 76 PCGs resolved the phylogeny of Hepatica and its related genera. Non-monophyly of Anemone s.l. indicates that Hepatica should be reclassified as an independent genus. In addition, Hepatica nobilis var. japonica is not closely related to H. nobilis.

scholarly journals Extensive sequence divergence of non-coding regions between Aspergillus fumigatus, a major fungal pathogen of humans, and its relatives

2021 ◽  
Author(s):  
Alec Brown ◽  
Matthew E Mead ◽  
Jacob L. Steenwyk ◽  
Gustavo Goldman ◽  
Antonis Rokas
Keyword(s):  
Aspergillus Fumigatus ◽  
Sequence Variation ◽  
Sequence Divergence ◽  
Single Copy ◽  
Orthologous Genes ◽  
Sequence Alignments ◽  
Protein Coding ◽  
Extensive Sequence ◽  
Coding Regions ◽  
Close Relatives

Invasive aspergillosis is a deadly fungal disease; more than 400,000 patients are infected worldwide each year and the mortality rate can be as high as 50-95%. Of the ~450 species in the genus Aspergillus only a few are known to be clinically relevant, with the major pathogen Aspergillus fumigatus being responsible for ~50% of all invasive mold infections. Genomic comparisons of A. fumigatu to other Aspergillus species have historically focused on protein-coding regions. However, most A. fumigatus genes, including those that modulate its virulence, are also present in non-pathogenic close relatives of A. fumigatus. Our hypothesis is that differential gene regulation - mediated through the non-coding regions upstream of genes' transcription start sites - contributes to A. fumigatus pathogenicity. To begin testing this, we compared non-coding regions up to 500 base pairs upstream of the first codon of single-copy orthologous genes from the two A. fumigatus reference strains Af293 and A1163 and eight closely related Aspergillus section Fumigati species. We found that non-coding regions showed extensive sequence variation and lack of homology across species. By examining the evolutionary rates of both protein-coding and non-coding regions in a subset of orthologous genes with highly conserved non-coding regions across the phylogeny, we identified 418 genes, including 25 genes known to modulate A. fumigatus virulence, whose non-coding regions exhibit a different rate of evolution in A. fumigatus. Examination of sequence alignments of these non-coding regions revealed numerous instances of insertions, deletions, and other types of mutations of at least a few nucleotides in A. fumigatus compared to its close relatives. These results show that closely related Aspergillus species that vary greatly in their pathogenicity exhibit extensive non-coding sequence variation and identify numerous changes in non-coding regions of A. fumigatus genes known to contribute to virulence.

scholarly journals Degenerative Minimalism in the Genome of a Psyllid Endosymbiont

2001 ◽  
Vol 183 (6) ◽  
pp. 1853-1861 ◽  
Author(s):  
Marta A. Clark ◽  
Linda Baumann ◽  
MyLo Ly Thao ◽  
Nancy A. Moran ◽  
Paul Baumann
Keyword(s):  
Amino Acids ◽  
Extreme Case ◽  
Amino Acid Sequences ◽  
Compositional Bias ◽  
Buchnera Aphidicola ◽  
Homologous Proteins ◽  
Protein Coding ◽  
Phloem Sap ◽  
Promoter Sequences ◽  
Genes Encoding

ABSTRACT Psyllids, like aphids, feed on plant phloem sap and are obligately associated with prokaryotic endosymbionts acquired through vertical transmission from an ancestral infection. We have sequenced 37 kb of DNA of the genome of Carsonella ruddii, the endosymbiont of psyllids, and found that it has a number of unusual properties revealing a more extreme case of degeneration than was previously reported from studies of eubacterial genomes, including that of the aphid endosymbiont Buchnera aphidicola. Among the unusual properties are an exceptionally low guanine-plus-cytosine content (19.9%), almost complete absence of intergenic spaces, operon fusion, and lack of the usual promoter sequences upstream of 16S rDNA. These features suggest the synthesis of long mRNAs and translational coupling. The most extreme instances of base compositional bias occur in the genes encoding proteins that have less highly conserved amino acid sequences; the guanine-plus-cytosine content of some protein-coding sequences is as low as 10%. The shift in base composition has a large effect on proteins: in polypeptides of C. ruddii, half of the residues consist of five amino acids with codons low in guanine plus cytosine. Furthermore, the proteins ofC. ruddii are reduced in size, with an average of about 9% fewer amino acids than in homologous proteins of related bacteria. These observations suggest that the C. ruddii genome is not subject to constraints that limit the evolution of other known eubacteria.

scholarly journals Combined cultivation and single-cell approaches to the phylogenomics of nucleariid amoebae, close relatives of fungi

2019 ◽  
Vol 374 (1786) ◽  
pp. 20190094 ◽  
Author(s):  
Luis Javier Galindo ◽  
Guifré Torruella ◽  
David Moreira ◽  
Yana Eglit ◽  
Alastair G. B. Simpson ◽  
...  
Keyword(s):  
Single Cell ◽  
Single Copy ◽  
Last Common Ancestor ◽  
Ecological Specialization ◽  
Evolutionary Relatedness ◽  
Cell Genome ◽  
Phylogenomic Analyses ◽  
Cell Transcriptome ◽  
Close Relatives ◽  
Single Cell Transcriptome

Nucleariid amoebae (Opisthokonta) have been known since the nineteenth century but their diversity and evolutionary history remain poorly understood. To overcome this limitation, we have obtained genomic and transcriptomic data from three Nuclearia , two Pompholyxophrys and one Lithocolla species using traditional culturing and single-cell genome (SCG) and single-cell transcriptome amplification methods. The phylogeny of the complete 18S rRNA sequences of Pompholyxophrys and Lithocolla confirmed their suggested evolutionary relatedness to nucleariid amoebae, although with moderate support for internal splits. SCG amplification techniques also led to the identification of probable bacterial endosymbionts belonging to Chlamydiales and Rickettsiales in Pompholyxophrys . To improve the phylogenetic framework of nucleariids, we carried out phylogenomic analyses based on two datasets of, respectively, 264 conserved proteins and 74 single-copy protein domains. We obtained full support for the monophyly of the nucleariid amoebae, which comprise two major clades: (i) Parvularia–Fonticula and (ii) Nuclearia with the scaled genera Pompholyxophrys and Lithocolla . Based on these findings, the evolution of some traits of the earliest-diverging lineage of Holomycota can be inferred. Our results suggest that the last common ancestor of nucleariids was a freshwater, bacterivorous, non-flagellated filose and mucilaginous amoeba. From the ancestor, two groups evolved to reach smaller ( Parvularia–Fonticula ) and larger ( Nuclearia and related scaled genera) cell sizes, leading to different ecological specialization. The Lithocolla + Pompholyxophrys clade developed exogenous or endogenous cell coverings from a Nuclearia -like ancestor. This article is part of a discussion meeting issue ‘Single cell ecology’.

scholarly journals Analyses of Chloroplast Genome of Eutrema japonicum Provide New Insights into the Evolution of Eutrema Species

Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2546
Author(s):  
Mengyao Li ◽  
Ran Zhang ◽  
Jie Li ◽  
Kaiming Zheng ◽  
Jiachang Xiao ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Genetic Relationships ◽  
Evolutionary Relationship ◽  
Single Copy ◽  
Rrna Genes ◽  
Genetic Profile ◽  
Trna Genes ◽  
Protein Coding ◽  
Close Relationship ◽  
Cp Genome

Wasabi (Eutrema japonicum) is a vegetable of Brassicaceae family, currently cultivated in Southwest Asia. It is rich in nutritional and has a spicy flavour. It is regarded as a rare condiment worldwide. Its genetic profile for yield improvement and the development of E. japonicum germplasm resources remains unknown. Cognizant of this, this study sequenced and assembled the chloroplast (cp) genome of E. japonicum to enrich our genomic information of wasabi and further understand genetic relationships within the Eutrema species. The structural characteristics, phylogeny, and evolutionary relationship of cp genomes among other Brassicaceae plants were analyzed and compared to those of Eutrema species. The cp genome of E. japonicum has 153,851 bp with a typical quadripartite structure, including 37 tRNA genes, 8 rRNA genes, and 87 protein-coding genes. It contains 290 simple sequence repeats and prefers to end their codons with an A or T, which is the same as other Brassicaceae species. Moreover, the cp genomes of the Eutrema species had a high degree of collinearity and conservation during the evolution process. Nucleotide diversity analysis revealed that genes in the IR regions had higher Pi values than those in LSC (Large single copy) and SSC (Small single copy) regions, making them potential molecular markers for wasabi diversity studies. The analysis of genetic distance between Eutrema plants and other Brassicacea plants showed that intraspecies variation was found to be low, while large differences were found between genera and species. Phylogenetic analysis based on 29 cp genomes revealed the existence of a close relationship amongst the Eutrema species. Overall, this study provides baseline information for cp genome-based molecular breeding and genetic transformation studies of Eutrema plants.

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