scholarly journals Phylogenetic analysis of isolates of Beet necrotic yellow vein virus collected worldwide

2005 ◽  
Vol 86 (10) ◽  
pp. 2897-2911 ◽  
Author(s):  
Audrey Schirmer ◽  
Didier Link ◽  
Valérie Cognat ◽  
Benoît Moury ◽  
Monique Beuve ◽  
...  
Keyword(s):  
Amino Acid ◽  
Phylogenetic Trees ◽  
Molecular Diversity ◽  
Synonymous Substitution ◽  
Plant Viruses ◽  
Yellow Vein ◽  
Sugar Beets ◽  
Selective Constraints ◽  
Geographic Origins ◽  
Synonymous Substitution Rates

A study of molecular diversity was carried out on 136 sugar beets infected with Beet necrotic yellow vein virus (BNYVV, Benyvirus) collected worldwide. The nucleotide sequences of the RNA-2-encoded CP, RNA-3-encoded p25 and RNA-5-encoded p26 proteins were analysed. The resulting phylogenetic trees allowed BNYVV to be classified into groups that show correlations between the virus clusters and geographic origins. The selective constraints on these three sequences were measured by estimating the ratio between synonymous and non-synonymous substitution rates (ω) with maximum-likelihood models. The results suggest that selective constraints are exerted differently on the proteins. CP was the most conserved, with mean ω values ranging from 0·12 to 0·15, while p26 was less constrained, with mean ω values ranging from 0·20 to 0·33. Selection was detected in three amino acid positions of p26, with ω values of about 5·0. The p25 sequences presented the highest mean ω values (0·36–1·10), with strong positive selection (ω=4·7–54·7) acting on 14 amino acids, and particularly on amino acid 68, where the ω value was the highest so far encountered in plant viruses.

scholarly journals Potent Antibody-Mediated Neutralization and Evolution of Antigenic Escape Variants of Simian Immunodeficiency Virus Strain SIVmac239 In Vivo

2008 ◽  
Vol 82 (19) ◽  
pp. 9739-9752 ◽  
Author(s):  
Shuji Sato ◽  
Eloisa Yuste ◽  
William A. Lauer ◽  
Eun Hyuk Chang ◽  
Jennifer S. Morgan ◽  
...  
Keyword(s):  
Amino Acid ◽  
Time Course ◽  
Neutralizing Antibody ◽  
Synonymous Substitution ◽  
Viral Envelope ◽  
Single Amino Acid ◽  
Nucleotide Substitutions ◽  
Recombinant Viruses ◽  
Synonymous Substitution Rates

ABSTRACT Here, we describe the evolution of antigenic escape variants in a rhesus macaque that developed unusually high neutralizing antibody titers to SIVmac239. By 42 weeks postinfection, 50% neutralization of SIVmac239 was achieved with plasma dilutions of 1:1,000. Testing of purified immunoglobulin confirmed that the neutralizing activity was antibody mediated. Despite the potency of the neutralizing antibody response, the animal displayed a typical viral load profile and progressed to terminal AIDS with a normal time course. Viral envelope sequences from week 16 and week 42 plasma contained an excess of nonsynonymous substitutions, predominantly in V1 and V4, including individual sites with ratios of nonsynonymous to synonymous substitution rates (dN/dS) highly suggestive of strong positive selection. Recombinant viruses encoding envelope sequences isolated from these time points remained resistant to neutralization by all longitudinal plasma samples, revealing the failure of the animal to mount secondary responses to the escaped variants. Substitutions at two sites with significant dN/dS values, one in V1 and one in V4, were independently sufficient to confer nearly complete resistance to neutralization. Substitutions at three additional sites, one in V4 and two in gp41, conferred moderate to high levels of resistance when tested individually. All the amino acid changes leading to escape resulted from single nucleotide substitutions. The observation that antigenic escape resulted from individual, single amino acid replacements at sites well separated in current structural models of Env indicates that the virus can utilize multiple independent pathways to rapidly achieve similar levels of resistance.

scholarly journals Cross-Protection Against Bean yellow mosaic virus (BYMV) and Clover yellow vein virus by Attenuated BYMV Isolate M11

2009 ◽  
Vol 99 (3) ◽  
pp. 251-257 ◽  
Author(s):  
Eiko Nakazono-Nagaoka ◽  
Tsubasa Takahashi ◽  
Takumi Shimizu ◽  
Yoshitaka Kosaka ◽  
Tomohide Natsuaki ◽  
...  
Keyword(s):  
Amino Acid ◽  
Mosaic Virus ◽  
Phylogenetic Trees ◽  
Amino Acid Sequences ◽  
Cross Protection ◽  
Bean Yellow Mosaic Virus ◽  
Yellow Vein ◽  
Yellow Mosaic Virus ◽  
Challenge Virus ◽  
Clover Yellow Vein Virus

Attenuated isolate M11 of Bean yellow mosaic virus (BYMV), obtained after exposing BYMV-infected plants to low temperature, and its efficacy in cross-protecting against infection by BYMV isolates from gladiolus, broad bean (Vicia faba) and white clover (Trifolium repens) was assessed with western blotting and reverse transcription-polymerase chain reaction. The level of cross-protection varied depending on the challenge virus isolates. Cross-protection was complete against BYMV isolates from gladiolus, but incomplete against BYMV isolates from other hosts. M11 also partially cross-protected against an isolate of Clover yellow vein virus. A comparison of the nucleotide sequence of M11 and those of BYMV isolates from gladiolus and from other hosts showed higher homology among gladiolus isolates than the homology between gladiolus isolates and nongladiolus isolates. In the phylogenetic trees, constructed using the nucleotide sequences of an overall polyprotein of the genomes, five gladiolus isolates clustered together, completely separated from the three BYMV isolates from other hosts. A comparison of the amino acid sequences between M11 and its parental isolate IbG, and analysis of recombinant infectious clones between M11 and IbG revealed that an amino acid at position 314 was involved in the attenuation of BYMV.

scholarly journals A double-stranded RNA from a Phytophthora species is related to the plant endornaviruses and contains a putative UDP glycosyltransferase gene

2005 ◽  
Vol 86 (5) ◽  
pp. 1561-1570 ◽  
Author(s):  
Caroline V. Hacker ◽  
Clive M. Brasier ◽  
Kenneth W. Buck
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Phylogenetic Trees ◽  
Sequence Similarity ◽  
Plant Viruses ◽  
Terminal Region ◽  
Bootstrap Support ◽  
Amino Acid Sequence Similarity ◽  
Sequence Motifs ◽  
Rna Helicases

A new dsRNA was isolated from a Phytophthora isolate from Douglas fir. Sequence analysis showed the dsRNA to consist of 13 883 bp and to contain a single open reading frame with the potential to encode a polyprotein of 4548 aa. This polyprotein contained amino acid sequence motifs characteristic of virus RNA-dependent RNA polymerases (RdRps) in its C-terminal region and motifs characteristic of RNA helicases in its N-terminal region. These sequence motifs were related to corresponding motifs in plant viruses in the genus Endornavirus. In phylogenetic trees constructed from the RdRp and helicase motifs of a range of ssRNA and dsRNA viruses, the Phytophthora RdRp and helicase sequences clustered with those of the plant endornaviruses with good bootstrap support. The properties of the Phytophthora dsRNA are consistent with its being classified as the first non-plant member of the genus Endornavirus, for which we propose the name phytophthora endornavirus 1 (PEV1). A region between the RdRp and helicase domains of the PEV1 protein had significant amino acid sequence similarity to UDP glycosyltransferases (UGTs). Two sequence motifs were identified, one characteristic of all UGTs and the other characteristic of sterol UGTs. The PEV1 UGT would be the first for an RNA virus, although ecdysteroid UGT genes have been found in many baculoviruses. The PEV1 UGT was only distantly related to baculovirus ecdysteroid UGTs, which belong to a family distinct from the sterol UGTs.

Pseudogenized Amelogenin Reveals Early Tooth Loss in True Toads (Anura: Bufonidae)

2021 ◽  
Author(s):  
John Shaheen ◽  
Austin B Mudd ◽  
Thomas G H Diekwisch ◽  
John Abramyan
Keyword(s):  
Tooth Loss ◽  
Tooth Enamel ◽  
Synonymous Substitution ◽  
Bufo Bufo ◽  
Molecular Dating ◽  
Bufo Gargarizans ◽  
The Family ◽  
Synonymous Substitution Rates ◽  
Mandibular Teeth ◽  
Early Tooth Loss

Abstract Extant anurans (frogs and toads) exhibit reduced dentition, ranging from a lack of mandibular teeth to complete edentulation, as observed in the true toads of the family Bufonidae. The evolutionary timeline of these reductions remains vague due to a poor fossil record. Previous studies have demonstrated an association between the lack of teeth in edentulous vertebrates and the pseudogenization of the major tooth enamel gene amelogenin (AMEL) through accumulation of deleterious mutations and the disruption of its coding sequence. In the present study we have harnessed the pseudogenization of AMEL as a molecular dating tool to correlate loss of dentition with genomic mutation patterns during the rise of the family Bufonidae. Specifically, we have utilized AMEL pseudogenes in three members of the family as a tool to estimate the putative date of edentulation in true toads. Comparison of AMEL sequences from Rhinella marina, Bufo gargarizans and Bufo bufo, with nine extant, dentulous frogs, revealed mutations confirming AMEL inactivation in Bufonidae. AMEL pseudogenes in modern bufonids also exhibited remarkably high 86–93% sequence identity among each other, with only a slight increase in substitution rate and relaxation of selective pressure, in comparison to functional copies in other anurans. Moreover, using selection intensity estimates and synonymous substitution rates, analysis of functional and pseudogenized AMEL resulted in an estimated inactivation window of 46-60 MYA in the lineage leading to modern true toads, a timeline that coincides with the rise of the family Bufonidae.

scholarly journals Comparing Patterns of Nucleotide Substitution Rates Among Chloroplast Loci Using the Relative Ratio Test

Genetics ◽  
1997 ◽  
Vol 146 (1) ◽  
pp. 393-399 ◽  
Author(s):  
Spencer V Muse ◽  
Brandon S Gaut
Keyword(s):  
Nucleotide Substitution ◽  
Nonsynonymous Substitution ◽  
Synonymous Substitution ◽  
Joint Analysis ◽  
Ratio Test ◽  
Substitution Rates ◽  
Chloroplast Genomes ◽  
Synonymous Substitution Rates ◽  
Nucleotide Substitution Rates ◽  
Evolutionary Lineages

Even when several genetic loci are used in molecular evolutionary studies, each locus is typically analyzed independently of the others. This type of approach makes it difficult to study mechanisms and processes that affect multiple genes. In this work we develop a statistical approach for the joint analysis of two or more loci. The tests we propose examine whether or not nucleotide substitution rates across evolutionary lineages have the same relative proportions at two loci. Theses procedures are applied to 33 genes from the chloroplast genomes of rice, tobacco, pine, and liverwort. With the exception of five clearly distinct loci, we find that synonymous substitution rates tend to change proportionally across genes. We interpret these results to be consistent with a “lineage effect” acting on the entire chloroplast genome. In contrast, nonsynonymous rates do not change proportionally across genes, suggesting that locus-specific evolutionary effects dominate patterns of nonsynonymous substitution.

scholarly journals Techniques for the verification of minimal phylogenetic trees illustrated with ten mammalian haemoglobin sequences

1980 ◽  
Vol 187 (1) ◽  
pp. 65-74 ◽  
Author(s):  
D Penny ◽  
M D Hendy ◽  
L R Foulds
Keyword(s):  
Amino Acid ◽  
Phylogenetic Tree ◽  
Protein Sequence ◽  
Phylogenetic Trees ◽  
Sequence Data ◽  
Protein Sequences ◽  
Nucleotide Sequences ◽  
Amino Acid Sequences ◽  
Minimal Tree ◽  
Protein Sequence Data

We have recently reported a method to identify the shortest possible phylogenetic tree for a set of protein sequences [Foulds Hendy & Penny (1979) J. Mol. Evol. 13. 127–150; Foulds, Penny & Hendy (1979) J. Mol. Evol. 13, 151–166]. The present paper discusses issues that arise during the construction of minimal phylogenetic trees from protein-sequence data. The conversion of the data from amino acid sequences into nucleotide sequences is shown to be advantageous. A new variation of a method for constructing a minimal tree is presented. Our previous methods have involved first constructing a tree and then either proving that it is minimal or transforming it into a minimal tree. The approach presented in the present paper progressively builds up a tree, taxon by taxon. We illustrate this approach by using it to construct a minimal tree for ten mammalian haemoglobin alpha-chain sequences. Finally we define a measure of the complexity of the data and illustrate a method to derive a directed phylogenetic tree from the minimal tree.

scholarly journals MOLECULAR AND GENETIC CHARACTERISTICS OF SURFACE AND NONSTRUCTURE PROTEINS OF PANDEMIC INFLUENZA VIRUSES A(H1N1)PDM09 IN 2015-2016 EPIDEMIC SEASON

2016 ◽  
Vol 72 (2) ◽  
pp. 44-48
Author(s):  
O. Smutko ◽  
L. Radchenko ◽  
A. Mironenko
Keyword(s):  
Amino Acid ◽  
Pandemic Influenza ◽  
Influenza A ◽  
Phylogenetic Trees ◽  
Influenza Viruses ◽  
Amino Acid Substitutions ◽  
Ns1 Protein ◽  
Genetic Characteristics ◽  
Epidemic Season ◽  
Influenza A H1n1

The aim of the present study was identifying of molecular and genetic changes in hemaglutinin (HA), neuraminidase (NA) and non-structure protein (NS1) genes of pandemic influenza A(H1N1)pdm09 strains, that circulated in Ukraine during 2015-2016 epidemic season. Samples (nasopharyngeal swabs from patients) were analyzed using real-time polymerase chain reaction (RTPCR). Phylogenetic trees were constructed using MEGA 7 software. 3D structures were constructed in Chimera 1.11.2rc software. Viruses were collected in 2015-2016 season fell into genetic group 6B and in two emerging subgroups, 6B.1 and 6B.2 by gene of HA and NA. Subgroups 6B.1 and 6B.2 are defined by the following amino acid substitutions. In the NS1 protein were identified new amino acid substitutions D2E, N48S, and E125D in 2015-2016 epidemic season. Specific changes were observed in HA protein antigenic sites, but viruses saved similarity to vaccine strain. NS1 protein acquired substitution associated with increased virulence of the influenza virus.

scholarly journals Rapid screening of RNA silencing suppressors by using a recombinant virus derived from beet necrotic yellow vein virus

2009 ◽  
Vol 90 (10) ◽  
pp. 2536-2541 ◽  
Author(s):  
H. Guilley ◽  
D. Bortolamiol ◽  
G. Jonard ◽  
S. Bouzoubaa ◽  
V. Ziegler-Graff
Keyword(s):  
Rna Silencing ◽  
Plant Defence ◽  
Plant Viruses ◽  
Yellow Vein ◽  
Rapid Screening ◽  
Silencing Suppressor ◽  
Defence Mechanisms ◽  
Simple Method ◽  
Yellow Dwarf Virus ◽  
Plant Defence Mechanisms

To counteract plant defence mechanisms, plant viruses have evolved to encode RNA silencing suppressor (RSS) proteins. These proteins can be identified by a range of silencing suppressor assays. Here, we describe a simple method using beet necrotic yellow vein virus (BNYVV) that allows a rapid screening of RSS activity. The viral inoculum consisted of BNYVV RNA1, which encodes proteins involved in viral replication, and two BNYVV-derived replicons: rep3–P30, which expresses the movement protein P30 of tobacco mosaic virus, and rep5–X, which allows the expression of a putative RSS (X). This approach has been validated through the use of several known RSSs. Two potential candidates have been tested and we show that, in our system, the P13 protein of burdock mottle virus displays RSS activity while the P0 protein of cereal yellow dwarf virus-RPV does not.

scholarly journals Ampelographic and molecular diversity among grapevine (Vitis spp.) cultivars

2009 ◽  
Vol 45 (No. 4) ◽  
pp. 160-168 ◽  
Author(s):  
A. Sabir ◽  
S. Tangolar ◽  
S. Buyukalaca ◽  
S. Kafkas
Keyword(s):  
Molecular Characterization ◽  
Molecular Diversity ◽  
Genetic Distances ◽  
Mean Values ◽  
Issr Analysis ◽  
Geographic Origins ◽  
The Mean ◽  
Vitis Spp

This study presents the ampelographic and molecular characterization of 44 grapevine cultivars. Ampelographic data were obtained during two vegetation periods using the latest version of the descriptors. Based on the mean values transformed by the method indicated in IBPGR publications, a dendrogram was constructed. ISSR analysis was also employed to characterize the genotypes at the DNA level. Twenty primers, selected on the basis of their discriminating potential, generated a total of 157 bands, of which 140 were polymorphic. The dendrograms constructed by the two approaches were largely similar in both the clustering position and divergence of varietal groups. The least distance was observed between Yuvarlak Cekirdeksiz and Superior Seedless. The clustering position of cultivars throughout the dendrograms was basically related to the genetic distances and main uses, as well as to geographic origins.

scholarly journals Metagenomic Next-Generation Sequencing Reveal Presence of a Novel Ungulate Bocaparvovirus in Alpacas

Viruses ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 701 ◽  
Author(s):  
Kumar ◽  
Chaudhary ◽  
Lu ◽  
Duff ◽  
Heffel ◽  
...  
Keyword(s):  
Next Generation Sequencing ◽  
Amino Acid ◽  
Phylogenetic Trees ◽  
Neurological Diseases ◽  
Virus Infectivity ◽  
Whole Genome ◽  
Ns1 Protein ◽  
Next Generation ◽  
Percent Identity ◽  
Generation Sequencing

Viruses belonging to the genus Bocaparvovirus (BoV) are a genetically diverse group of DNA viruses known to cause respiratory, enteric, and neurological diseases in animals, including humans. An intestinal sample from an alpaca (Vicugna pacos) herd with reoccurring diarrhea and respiratory disease was submitted for next-generation sequencing, revealing the presence of a BoV strain. The alpaca BoV strain (AlBoV) had a 58.58% whole genome nucleotide percent identity to a camel BoV from Dubai, belonging to a tentative ungulate BoV 8 species (UBoV8). Recombination events were lacking with other UBoV strains. The AlBoV genome was comprised of the NS1, NP1, and VP1 proteins. The NS1 protein had the highest amino acid percent identity range (57.89–67.85%) to the members of UBoV8, which was below the 85% cut-off set by the International Committee on Taxonomy of Viruses. The low NS1 amino acid identity suggests that AlBoV is a tentative new species. The whole genome, NS1, NP1, and VP1 phylogenetic trees illustrated distinct branching of AlBoV, sharing a common ancestor with UBoV8. Walker loop and Phospholipase A2 (PLA2) motifs that are vital for virus infectivity were identified in NS1 and VP1 proteins, respectively. Our study reports a novel BoV strain in an alpaca intestinal sample and highlights the need for additional BoV research.

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