scholarly journals Magnus Representation of Genome Sequences

2019 ◽  
Author(s):  
Chengyuan Wu ◽  
Shiquan Ren ◽  
Jie Wu ◽  
Kelin Xia

AbstractWe introduce an alignment-free method, the Magnus Representation, to analyze genome sequences. The Magnus Representation captures higher-order information in genome sequences. We combine our approach with the idea ofk-mers to define an effectively computable Mean Magnus Vector. We perform phylogenetic analysis on three datasets: mosquito-borne viruses, filoviruses, and bacterial genomes. Our results on ebolaviruses are consistent with previous phylogenetic analyses, and confirm the modern viewpoint that the 2014 West African Ebola outbreak likely originated from Central Africa. Our analysis also confirms the close relationship betweenBundibugyo ebolavirusandTaï Forest ebolavirus. For bacterial genomes, our method is able to classify relatively well at the family and genus level, as well as at higher levels such as phylum level. The bacterial genomes are also separated well into Gram-positive and Gram-negative subgroups.


2019 ◽  
Vol 8 (34) ◽  
Author(s):  
Hazuki Yamashita ◽  
Takayuki Wada ◽  
Yusuke Kato ◽  
Takuji Ikeda ◽  
Masayuki Imajoh

Flavobacterium psychrophilum is a Gram-negative, psychrophilic bacterium within the family Flavobacteriaceae. Here, we report the draft genome sequences of three F. psychrophilum strains isolated from skin ulcers of diseased ayu caught by tomozuri angling at three sites in the Kagami River in Japan.



Phytotaxa ◽  
2017 ◽  
Vol 319 (1) ◽  
pp. 84 ◽  
Author(s):  
XUDONG LIU ◽  
HUAN ZHU ◽  
BENWEN LIU ◽  
GUOXIANG LIU ◽  
ZHENGYU HU

The genus Nephrocytium Nägeli is a common member of phytoplankton communities that has a distinctive morphology. Its taxonomic position is traditionally considered to be within the family Oocystaceae (Trebouxiophyceae). However, research on its ultrastructure is rare, and the phylogenetic position has not yet been determined. In this study, two strains of Nephrocytium, N. agardhianum Nägeli and N. limneticum (G.M.Smith) G.M.Smith, were identified and successfully cultured in the laboratory. Morphological inspection by light and electron microscopy and molecular phylogenetic analyses were performed to explore the taxonomic position. Ultrastructure implied a likely irregular network of dense and fine ribs on the surface of the daughter cell wall that resembled that of the genus Chromochloris Kol & Chodat (Chromochloridaceae). Phylogenetic analyses revealed that Nephrocytium formed an independent lineage in the order Sphaeropleales (Chlorophyceae) with high support values and a close phylogenetic relationship with Chromochloris. Based on combined morphological, ultrastructural and phylogenetic data, we propose a re-classification of Nephrocytium into Sphaeropleales, sharing a close relationship with Chromochloris.



2014 ◽  
Vol 89 (2) ◽  
pp. 1456-1460 ◽  
Author(s):  
Nadine N′Dilimabaka ◽  
Nicolas Berthet ◽  
Virginie Rougeron ◽  
Joa Braïthe Mangombi ◽  
Patrick Durand ◽  
...  

Lymphocytic choriomeningitis virus (LCMV) can cause acute fatal disease on all continents but was never detected in Africa. We report the first detection of LCMV RNA in a common European house mouse (Mus musculusdomesticus) in Africa. Phylogenetic analyses show a close relationship with North American strains. These findings suggest that there is a risk of the appearance of LCMV acute encephalitis cases. This is a perfect example of virus dissemination by its natural host that may have dramatic public health consequences.



1994 ◽  
Vol 72 (9) ◽  
pp. 1250-1263 ◽  
Author(s):  
G. W. Saunders ◽  
G. T. Kraft

Nucleotide sequences of the nuclear, small-subunit (SSU) ribosomal RNAs, as inferred from polymerase chain reaction (PCR)-amplified products, are presented for Areschougia congesta (Turner) J. Agardh (Solieriaceae), Dasyphloea insignis Montagne (Dumontiaceae), Sarcothalia crassifolia (C. Agardh) Edyvane & Womersley (Gigartinaceae), Nizymenia australis Sonder (Nizymeniaceae), Phacelocarpus peperocarpos (Poiret) Wynne, Ardré & Silva (Phacelocarpaceae), Plocamiocolax pulvinata Setchell, Plocamium angustum (J. Agardh) J.D. Hooker, Plocamium cartilagineum (Linnaeus) Dixon (Plocamiaceae), Rhodymenia linearis J. Agardh (Rhodymeniaceae), and Sphaerococcus coronopifolius Stackhouse (Sphaerococcaceae). Phylogenetic analyses of the SSU sequences between the Plocamiaceae and members of the Sphaerococcaceae, Phacelocarpaceae, and Nizymeniaceae, with which the Plocamiaceae has been associated historically, show SSU differences of between 87 and 105 nucleotides and do not indicate a close relationship. A review of anatomical knowledge of the Plocamiaceae and Pseudoanemoniaceae and new information on vegetative and tetrasporangial development in Plocamium and Plocamiocolax are presented to buttress a case for the Plocamiales ord.nov. Representatives of the Nizymeniaceae and Phacelocarpaceae differ from one another by only nine nucleotides, suggesting that these two taxa are very closely related and perhaps not distinct at the family rank. Key words: Gigartinales, PCR, phylogeny, Plocamiales ord.nov., Pseudoanemoniaceae, Rhodophyta, small-subunit rRNA, systematics.



Holzforschung ◽  
2018 ◽  
Vol 72 (4) ◽  
pp. 337-345 ◽  
Author(s):  
Yu Song ◽  
Xin Yao ◽  
Bing Liu ◽  
Yunhong Tan ◽  
Richard T. Corlett

AbstractAlseodaphneis a genus of timber trees (ca. 40 spp.) belonging to thePerseagroup of the Lauraceae. It is widely distributed in tropical Asia, but is often confused withDehaasiaandNothaphoebe, and the systematics of the genus is unclear. Here, the complete chloroplast genome sequences ofA. semecarpifoliawill be reported, the type species ofAlseodaphne, and two China-endemic species,A. gracilisandA. huanglianshanensis. The three plastomes were 153 051 bp, 153 099 bp and 153 070 bp, respectively. Comparative genomic analyses indicate that the threeAlseodaphneplastomes have similar genome size and those are very different with previously published plastomes of Lauraceae in length. The length difference is directly caused by inverted repeats expansion/contraction. Four highly variable loci includingpsbD-trnM,ndhF-rpl32,rpl32-trnLandycf1among the threeAlseodaphnespecies were identified as useful plastid candidate barcodes forAlseodaphneand Lauraceae species. Phylogenetic analyses based on 12 complete plastomes of Lauraceae species confirm a monophyleticPerseagroup comprising species ofAlseodaphne,Phoebe,PerseaandMachilus.



1998 ◽  
Vol 30 (4-5) ◽  
pp. 463-472 ◽  
Author(s):  
Jan-Eric Mattsson ◽  
Mats Wedin

AbstractIn order to identify monophyletic groups within the family Parmeliaceae, eleven taxa (Bryoria capillaris, Cetraria islandica, Evernia pruniastri, Hypogymnia physodes, Parmelia saxatilis, Platismatia glauca, Pleurosticta acetabulum, Usneaflorida, Vulpicida juniperina, V. pinastri, and Xanthoparmelia conspersa) were studied using newly produced nuclear rDNA sequence data from the ITS and 5·8S regions. The resulting evolutionary hypothesis was compared with results from previous phylogenetic analyses based on anatomy, morphology, and chemistry. The outcome of this comparison does not support the earlier proposed phylogenies but is not stable enough for identifying monophyletic groups, with one exception. The results indicate a close relationship between Cetraria and Vulpicida, which is contradictory to previous published analyses. The variation in ascus structures in the Parmeliaceae is discussed and it is questioned whether the earlier distinguished ‘ forms ’ of ascus types represent synapomorphies, if they are based on poorly supported analyses, or if they are exaggerations of relatively slight variation in shape. Further interpretations of the results are discussed and areas of future studies based on DNA-data are suggested.



PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e6032 ◽  
Author(s):  
Zhenyu Zhao ◽  
Xin Wang ◽  
Yi Yu ◽  
Subo Yuan ◽  
Dan Jiang ◽  
...  

Dioscorea L., the largest genus of the family Dioscoreaceae with over 600 species, is not only an important food but also a medicinal plant. The identification and classification of Dioscorea L. is a rather difficult task. In this study, we sequenced five Dioscorea chloroplast genomes, and analyzed with four other chloroplast genomes of Dioscorea species from GenBank. The Dioscorea chloroplast genomes displayed the typical quadripartite structure of angiosperms, which consisted of a pair of inverted repeats separated by a large single-copy region, and a small single-copy region. The location and distribution of repeat sequences and microsatellites were determined, and the rapidly evolving chloroplast genome regions (trnK-trnQ, trnS-trnG, trnC-petN, trnE-trnT, petG-trnW-trnP, ndhF, trnL-rpl32, and ycf1) were detected. Phylogenetic relationships of Dioscorea inferred from chloroplast genomes obtained high support even in shortest internodes. Thus, chloroplast genome sequences provide potential molecular markers and genomic resources for phylogeny and species identification.



Zootaxa ◽  
2012 ◽  
Vol 3451 (1) ◽  
pp. 1 ◽  
Author(s):  
RICARDO BELMONTE-LOPES ◽  
GUSTAVO A. BRAVO ◽  
MARCOS R. BORNSCHEIN ◽  
GIOVANNI N. MAURÍCIO ◽  
MARCIO R. PIE ◽  
...  

Recent DNA-based phylogenetic analyses of the family Thamnophilidae have shown that the genus Myrmotherula is polyphyletic. Traditional plumage-based taxonomy has been misleading in terms of identifying independently evolving lineages within the complex. Here, we integrate a molecular phylogeny with morphometric information and ancestral reconstruction of syringeal character states of the Musculi vocales ventrales, to investigate the taxonomic position of M. gularis, a species for which phylogenetic affinities have long been uncertain. We show that M. gularis represents a long branch in the tribe Thamnophilini that is not closely related to any other member of the Myrmotherula complex. Its relationships within the tribe remain uncertain because of the lack of phylogenetic resolution at the base of the tribe. M. gularis shares a derived character state of the M. vocalis ventralis with Taraba, Hypoedaleus, and Mackenziaena, which supports a close relationship between M. gularis and the large antshrikes. M. gularis can be diagnosed from Myrmotherula and Epinecrophylla by this condition of its M. vocalis ventralis, and from Isleria by plumage and other morphological traits. The phylogenetic and morphological distinctiveness of M. gularis does not warrant merging it into any other genus. We propose that this species be placed in a monotypic genus, for which the available name Rhopias applies.



Plant Disease ◽  
2019 ◽  
Vol 103 (6) ◽  
pp. 1302-1308 ◽  
Author(s):  
Nomatter Chingandu ◽  
Lelia Dongo ◽  
Osman A. Gutierrez ◽  
Judith K. Brown

Cacao swollen shoot disease (CSSD) of Theobroma cacao was reported in Nigeria in 1944; however, no badnaviral genome sequences have been found associated with the symptomatic trees. In 2017, leaf samples (n = 18) were collected from cacao trees from Osun and Oyo, Nigeria showing foliar symptoms that included red vein-banding and shoot swelling, and variable secondary mosaic, mottling, and fern-like pattern symptoms. Abutting primers designed around previously determined 500-bp intergenic region sequences were used for polymerase chain reaction (PCR) amplification. Of the 18 samples, 9 yielded an approximately 7,000-bp, apparently genome-size product. The nine genomes were sequenced and found to encode four open reading frames, and to share 86 to 99% nucleotide identity. Pairwise analysis of the Nigerian genomes with 21 previously reported CSSD badnaviruses, at the complete genome and reverse-transcription ribonuclease H (1,230 bp) sequence levels, indicated 71 to 75 and 72 to 76% nucleotide identity, respectively. Phylogenetic analysis of the nine complete genomes indicated that the closest relatives of the divergent Nigerian isolates were previously described West African CSSD badnaviruses. Based on pairwise comparisons and phylogenetic analyses, the Nigerian CSSD isolates constitute a previously unrecognized Badnavirus sp., herein named Cacao red vein-banding virus (CRVBV). Primers designed based on the CRVBV genome sequences amplified a 1,068-bp fragment from 16 of 18 field samples tested by PCR, suggesting the possible existence of additional CRVBV variants.



2009 ◽  
Vol 83 (21) ◽  
pp. 11233-11243 ◽  
Author(s):  
Stephanie D. Friedman ◽  
Fred J. Genthner ◽  
Jennifer Gentry ◽  
Mark D. Sobsey ◽  
Jan Vinjé

ABSTRACT Male-specific single-stranded RNA (FRNA) coliphages belong to the family Leviviridae. They are classified into two genera (Levivirus and Allolevivirus), which can be subdivided into four genogroups (genogroups I and II in Levivirus and genogroups III and IV in Allolevivirus). Relatively few strains have been completely characterized, and hence, a detailed knowledge of this virus family is lacking. In this study, we sequenced and characterized the complete genomes of 19 FRNA strains (10 Levivirus strains and 9 Allolevivirus strains) and compared them to the 11 complete genome sequences available in GenBank. Nucleotide similarities among strains of Levivirus genogroups I and II were 75% to 99% and 83 to 94%, respectively, whereas similarities among strains of Allolevivirus genogroups III and IV ranged from 70 to 96% and 75 to 95%, respectively. Although genogroup I strain fr and genogroup III strains MX1 and M11 share only 70 to 78% sequence identity with strains in their respective genogroups, phylogenetic analyses of the complete genome and the individual genes suggest that strain fr should be grouped in Levivirus genogroup I and that the MX1 and M11 strains belong in Allolevivirus genogroup III. Strains within each genus share >50% sequence identity, whereas between the two genera, strains have <40% nucleotide sequence identity. Overall, amino acid composition, nucleotide similarities, and replicase catalytic domain location contributed to phylogenetic assignments. A conserved eight-nucleotide signature at the 3′ end of the genome distinguishes leviviruses (5′ ACCACCCA 3′) from alloleviviruses (5′ TCCTCCCA 3′).



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