scholarly journals UFBoot2: Improving the Ultrafast Bootstrap Approximation

2017 ◽  
Author(s):  
Diep Thi Hoang ◽  
Olga Chernomor ◽  
Arndt von Haeseler ◽  
Bui Quang Minh ◽  
Le Sy Vinh

AbstractThe standard bootstrap (SBS), despite being computationally intensive, is widely used in maximum likelihood phylogenetic analyses. We recently proposed the ultrafast bootstrap approximation (UFBoot) to reduce computing time while achieving more unbiased branch supports than SBS under mild model violations. UFBoot has been steadily adopted as an efficient alternative to SBS and other bootstrap approaches.Here, we present UFBoot2, which substantially accelerates UFBoot and reduces the risk of overestimating branch supports due to polytomies or severe model violations. Additionally, UFBoot2 provides suitable bootstrap resampling strategies for phylogenomic data. UFBoot2 is 778 and 8.4 times (median) faster than SBS and RAxML rapid bootstrap on tested datasets, respectively. UFBoot2 is implemented in the IQ-TREE software package version 1.6 and freely available at http://www.iqtree.org.

2019 ◽  
Author(s):  
Bui Quang Minh ◽  
Heiko Schmidt ◽  
Olga Chernomor ◽  
Dominik Schrempf ◽  
Michael Woodhams ◽  
...  

AbstractIQ-TREE (http://www.iqtree.org) is a user-friendly and widely used software package for phylogenetic inference using maximum likelihood. Since the release of version 1 in 2014, we have continuously expanded IQ-TREE to integrate a plethora of new models of sequence evolution and efficient computational approaches of phylogenetic inference to deal with genomic data. Here, we describe notable features of IQ-TREE version 2 and highlight the key advantages over other software.


Author(s):  
Bahareh Nowruzi ◽  
Fabiana Soares

In Iran, polyphasic studies of unicellular cyanobacteria are still scarce, with more emphasis being placed on filamentous cyanobacteria in paddy fields and fresh water regions. In an effort to increase the knowledge of the diversity of unicellular cyanobacteria from paddy fields in Iran, we have isolated and characterized a new unicellular cyanobacterium strain. The strain was studied using a polyphasic approach based on morphological, ecological and phylogenetic analyses of the 16S–23S ITS rRNA gene region. Complementarily, we have searched for the presence of cyanotoxin genes and analysed the pigment content of the strain. Results showed that the strain was morphologically indistinguishable from the genus Chroococcus , but phylogenetic analyses based on the Bayesian inference and maximum-likelihood methods placed the strain in a separated monophyletic and highly supported (0.99/98, posterior probability/maximum-likelihood) genus-level cluster, distant from Chroococcus sensu stricto and with Chalicogloea cavernicola as sister taxa. The calculated p-distance for the 16S rRNA gene also reinforced the presence of a new genus, by showing 92 % similarity to C. cavernicola . The D1–D1′, Box-B and V3 ITS secondary structures showed the uniqueness of this strain, as it shared no similar pattern with closest genera within the Chroococcales. For all these reasons, and in accordance with the International Code of Nomenclature for Algae, Fungi and Plants, we here proposed the description of a new genus with the name Alborzia gen. nov. along with the description of a new species, Alborzia kermanshahica sp. nov. (holotype: CCC1399-a; reference strains CCC1399-b; MCC 4116).


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Juan C. Muñoz-Escalante ◽  
Andreu Comas-García ◽  
Sofía Bernal-Silva ◽  
Daniel E. Noyola

AbstractRespiratory syncytial virus (RSV) is a major cause of respiratory infections and is classified in two main groups, RSV-A and RSV-B, with multiple genotypes within each of them. For RSV-B, more than 30 genotypes have been described, without consensus on their definition. The lack of genotype assignation criteria has a direct impact on viral evolution understanding, development of viral detection methods as well as vaccines design. Here we analyzed the totality of complete RSV-B G gene ectodomain sequences published in GenBank until September 2018 (n = 2190) including 478 complete genome sequences using maximum likelihood and Bayesian phylogenetic analyses, as well as intergenotypic and intragenotypic distance matrices, in order to generate a systematic genotype assignation. Individual RSV-B genes were also assessed using maximum likelihood phylogenetic analyses and multiple sequence alignments were used to identify molecular markers associated to specific genotypes. Analyses of the complete G gene ectodomain region, sequences clustering patterns, and the presence of molecular markers of each individual gene indicate that the 37 previously described genotypes can be classified into fifteen distinct genotypes: BA, BA-C, BA-CC, CB1-THB, GB1-GB4, GB6, JAB1-NZB2, SAB1, SAB2, SAB4, URU2 and a novel early circulating genotype characterized in the present study and designated GB0.


2015 ◽  
Vol 65 (Pt_2) ◽  
pp. 516-521 ◽  
Author(s):  
Gaiyun Zhang ◽  
Yubian Zhang ◽  
Xijie Yin ◽  
Shuang Wang

A Gram-staining-positive, aerobic, motile and non-spore-forming actinobacteria, designated strain F10T, was isolated from a deep-sea sediment of the western Pacific Ocean. Phylogenetic and phenotypic properties of the organism supported that it belonged to the genus Nesterenkonia . Strain F10T shared highest 16S rRNA gene sequence similarity of 96.8 % with Nesterenkonia aethiopica DSM 17733T, followed by Nesterenkonia xinjiangensis YIM 70097T (96.7 %) and Nesterenkonia alba CAAS 252T (96.6 %). The organism grew at 4–50 °C, at pH 7.0–12.0 and in the presence of 0–12 % (w/v) NaCl, with optimal growth occurring at 40 °C, at pH 9.0 and in the presence of 1 % (w/v) NaCl. The peptidoglycan type was A4(alpha), l-Lys–Gly–l-Glu. The polar lipid profile of strain F10T consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, two unknown glycolipids and two unknown lipids. The isolate contained MK-9 (92 %) and MK-8 (5.8 %) as the major components of the menaquinone system, and anteiso-C17 : 0 (50.9 %) and anteiso-C15 : 0 (29.8 %) as the predominant fatty acids. The G+C content of the genomic DNA of strain F10T was 66.2 mol%. Based on phenotypic, genotypic and phylogenetic analyses, strain F10T represents a novel species of the genus Nesterenkonia for which the name Nesterenkonia alkaliphila sp. nov. is proposed. The type strain is F10T ( = LMG 28112T = CGMCC 1.12781T = JCM 19766T = MCCC 1A09946T).


Nematology ◽  
2003 ◽  
Vol 5 (5) ◽  
pp. 699-711 ◽  
Author(s):  
Peter Mullin ◽  
Timothy Harris ◽  
Thomas Powers

AbstractThe systematic position of Campydora Cobb, 1920, which possesses many unique morphological features, especially in pharyngeal structure and stomatal armature, has long been a matter of uncertainty with the 'position of the Campydorinae' (containing only Campydora) being questionable. A review of the morphology of C. demonstrans, the only nominal species of Campydora concluded that the species warranted placement as the sole member of a monotypic suborder, Campydorina, in the order Dorylaimida. Others placed Campydorina in the order Enoplida. We conducted phylogenetic analyses, using 18s small subunit ribosomal DNA sequences generated from a number of taxa in the subclasses Enoplia and Dorylaimia, to evaluate these competing hypotheses. Although precise taxonomic placement of the genus Campydora and the identity of its closest living relatives is in need of further investigation, our analyses, under maximum parsimony, distance, and maximum likelihood criteria, unambiguously indicate that Campydora shares a common, more recent, ancestry with genera such as Alaimus, Pontonema, Tripyla and Ironus (Enoplida), rather than with any members of Dorylaimida, Mononchida or Triplonchida.


2013 ◽  
Vol 63 (Pt_5) ◽  
pp. 1766-1770 ◽  
Author(s):  
Joon Yong Kim ◽  
Jina Lee ◽  
Na-Ri Shin ◽  
Ji-Hyun Yun ◽  
Tae Woong Whon ◽  
...  

A novel Gram-stain-negative, facultatively anaerobic, non-motile and coccus-shaped bacterium, strain C7T, was isolated from the gut of the butterfly Sasakia charonda. Strain C7T grew optimally at 20–25 °C, at pH 7–8 and with 1 % (w/v) NaCl. The strain was negative for oxidase activity but positive for catalase activity. The 16S rRNA gene sequences of strain C7T and Orbus hercynius CN3T shared 96.8 % similarity. The major fatty acids identified were C14 : 0, C16 : 0, C18 : 1ω7c and summed feature 2 (comprising C14 : 0 3-OH/iso-C16 : 1). The major respiratory quinone was ubiquinone-8 (Q-8). The polar lipids of strain C7T were phosphatidylethanolamine, phosphatidylglycerol, an unidentified phospholipid and two unidentified aminophospholipids. The G+C content of the genomic DNA extracted from strain C7T was 32.1 mol%. Taken together, the phenotypic, genotypic and phylogenetic analyses indicate that strain C7T represents a novel species of the genus Orbus , for which the name Orbus sasakiae sp. nov. is proposed. The type strain is C7T ( = KACC 16544T = JCM 18050T). An emended description of the genus Orbus is provided.


2014 ◽  
Vol 64 (Pt_1) ◽  
pp. 122-127 ◽  
Author(s):  
Tong Yu ◽  
Zenghu Zhang ◽  
Xiaoyang Fan ◽  
Xiaochong Shi ◽  
Xiao-Hua Zhang

A novel Gram-stain-negative, rod-shaped, non-flagellated, strictly aerobic strain with gliding motility, designated XH134T, was isolated from surface seawater of the South Pacific Gyre (45° 58′ S 163° 11′ W) during the Integrated Ocean Drilling Program Expedition 329. The major respiratory quinone of strain XH134T was MK-6. The dominant fatty acids of strain XH134T were iso-C15 : 0, iso-C15 : 1 G, C16 : 1ω6c and/or C16 : 1ω7c, iso-C17 : 0 3-OH, iso-C15 : 0 3-OH and 10-methyl C16 : 0 and/or iso-C17 : 1ω9c. The polar lipids of strain XH134T comprised phosphatidylethanolamine, one unknown aminolipid and three unknown polar lipids. The DNA G+C content of strain XH134T was 32.4 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that the novel strain was related most closely to Aquimarina macrocephali JAMB N27T with 96.9 % sequence similarity. A number of phenotypic characteristics distinguished strain XH134T from described members of the genus Aquimarina . On the basis of combined phenotypic and phylogenetic analyses, strain XH134T represents a novel species of the genus Aquimarina , for which the name Aquimarina megaterium sp. nov. is proposed. The type strain is XH134T ( = CGMCC 1.12186T = JCM 18215T).


2013 ◽  
Vol 63 (Pt_3) ◽  
pp. 934-938 ◽  
Author(s):  
Wen-Ming Chen ◽  
Rey-Chang Chang ◽  
Chih-Yu Cheng ◽  
Yu-Wen Shiau ◽  
Shih-Yi Sheu

A novel bacterium, designated strain JchiT, was isolated from soil in Taiwan and characterized using a polyphasic approach. Cells of strain JchiT were aerobic, Gram-stain-negative, motile and rod-shaped. They contained poly-β-hydroxybutyrate granules and formed dark-yellow colonies. Growth occurred at 20–37 °C (optimum between 25 and 30 °C), at pH 6.0–8.0 (optimum between pH 7.0 and pH 8.0) and with 0–2 % NaCl (optimum between 0 and 1 %). Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain JchiT belonged to the genus Jeongeupia and that its closest neighbour was Jeongeupia naejangsanensis BIO-TAS4-2T (98.0 % sequence similarity). The major fatty acids (>10 %) of strain JchiT were summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and C18 : 1ω7c. The major cellular hydroxy fatty acid was C12 : 0 3-OH. The isoprenoid quinone was Q-8 and the genomic DNA G+C content was 66.1 mol%. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylserine and two unidentified phospholipids. The DNA–DNA relatedness value between strain JchiT and J. naejangsanensis BIO-TAS4-2T was about 41.0 %. On the basis of the genotypic and phenotypic data, strain JchiT represents a novel species in the genus Jeongeupia , for which the name Jeongeupia chitinilytica sp. nov. is proposed. The type strain is JchiT ( = BCRC 80367T  = KCTC 23701T).


Author(s):  
Fenfa Li ◽  
Qingyi Xie ◽  
Shuangqing Zhou ◽  
Fandong Kong ◽  
Yun Xu ◽  
...  

Strain HNM0947T, representing a novel actinobacterium, was isolated from the coral Galaxea astreata collected from the coast of Wenchang, Hainan, China. The strain was found to have morphological and chemotaxonomic characteristics consistent with the genus Nocardiopsis . The organism formed abundant fragmented substrate mycelia and aerial mycelia which differentiated into non-motile, rod-shaped spores. Whole-cell hydrolysates contained meso-diaminopimelic acid and no diagnostic sugars. The major menaquinones were MK-10(H8), MK-10(H6) and MK-10(H4). The major phospholipids were phosphatidylcholine, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannosides. The major fatty acids were iso-C16:0, anteiso-C17:0, C18:0, C18:0 10-methyl (TBSA) and anteiso-C15:0. The G+C content was 71.3 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain HNM0947T belonged to the genus Nocardiopsis and shared highest sequence similarity to Nocardiopsis salina YIM 90010T (98.8%), Nocardiopsis xinjiangensis YIM 90004T(98.5%) and Nocardiopsis kunsanensis DSM 44524T (98.3%). The strain HNM0947T was distinguished from its closest type strain by low average nucleotide identity (90.8%) and dDDH values (60.4%) respectively. Based on genotypic, chemotaxonomic and phenotypic characteristics, it was concluded that strain HNM0947T represents a novel species of the genus Nocardiopsis whose name was proposed as Nocardiopsis coralli sp. nov. The type strain was HNM0947T (=CCTCC AA 2020015 T=KCTC 49525 T).


Author(s):  
Shan Jiang ◽  
Feng-Bai Lian ◽  
You-Yang Sun ◽  
Xiao-Kui Zhang ◽  
Zong-Jun Du

A Gram-stain-negative, rod-shaped and facultatively aerobic bacterial strain, designated F7430T, was isolated from coastal sediment collected at Jingzi Wharf in Weihai, PR China. Cells of strain F7430T were 0.3–0.4 µm wide, 2.0–2.6 µm long, non-flagellated, non-motile and formed pale-beige colonies. Growth was observed at 4–40 °C (optimum, 30 °C), pH 6.0–9.0 (optimum, pH 7.5–8.0) and at NaCl concentrations of 1.0–10.0 % (w/v; optimum, 1.0 %). The sole respiratory quinone of strain F7430T was ubiquinone 8 and the predominant cellular fatty acids were summed feature 8 (C18 : 1  ω7c / C18 : 1  ω6c; 60.7 %), summed feature 3 (C16 : 1  ω7c/C16 : 1  ω6c; 30.2 %) and C15 : 0 iso (13.9 %). The polar lipids of strain F7430T consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, one unidentified phospholipid and three unidentified lipids. Results of 16S rRNA gene sequences analyses indicated that this strain belonged to the family Halieaceae and had high sequence similarities to Parahaliea aestuarii JCM 51547T (95.3 %) and Halioglobus pacificus DSM 27932T (95.2 %) followed by 92.9–95.0 % sequence similarities to other type species within the aforementioned family. The rpoB gene sequences analyses indicated that the novel strain had the highest sequence similarities to Parahaliea aestuarii JCM 51547T (82.2 %) and Parahaliea mediterranea DSM 21924T (82.2 %) followed by 75.2–80.5 % sequence similarities to other type species within this family. Phylogenetic analyses showed that strain F7430T constituted a monophyletic branch clearly separated from the other genera of family Halieaceae . Whole-genome sequencing of strain F7430T revealed a 3.3 Mbp genome size with a DNA G+C content of 52.6 mol%. The genome encoded diverse metabolic pathways including the Entner–Doudoroff pathway, assimilatory sulphate reduction and biosynthesis of dTDP-l-rhamnose. Based on results from the current polyphasic study, strain F7430T is proposed to represent a novel species of a new genus within the family Halieaceae , for which the name Sediminihaliea albiluteola gen. nov., sp. nov. is proposed. The type strain of the type species is F7430T (=KCTC 72873T=MCCC 1H00420T).


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