Search results for "Tree"
showing 10 items of 1841 documents
Genetic diversity ofMelon necrotic spot virusandOlpidiumisolates from different origins
2010
The geographic incidence, genetic diversity and phylogenetic relationships of Melon necrotic spot virus (MNSV) and Olpidium isolates were studied in three cucurbit species from several Latin American and European countries on different collecting dates. Of the 112 cucurbit samples analysed, 69 from Guatemala, Honduras, Mexico, Panama and Spain were DAS-ELISA-positive for MNSV. Olpidium bornovanus and O. virulentus infections, and MNSV infections mixed with these Olpidium species, were observed for all these countries. Twenty-nine MNSV isolates from all the origins where the virus was detected were selected and amplified by RT-PCR. The resulting RT-PCR of the p29, p89, p7A, p7B and p42 prote…
Gene encoding capsid protein VP1 of foot-and-mouth disease virus A quasispecies model of molecular evolution
1988
A phylogenetic tree relating the VP1 gene of 15 isolates of foot-and-mouth disease virus (FMDV) of serotypes A, C, and O has been constructed. The most parsimonious tree shows that FMDV subtypes and isolates within subtypes constitute sets of related, nonidentical genomes, in agreement with a quasispecies mode of evolution of this virus. The average number of nucleotide replacements per site for all possible pairs of VP1 coding segments is higher among representatives of serotype A than serotype C or O. In comparing amino acid sequences, the values of dispersion index (variance/mean value) are greater than 1, with the highest values scored when all sequences are considered. This indicates a…
Sampling and repeatability in the evaluation of hepatitis C virus genetic variability.
2003
Among the experimental techniques available to study the genetic variability of RNA virus populations, the most informative involve reverse transcription (RT), amplification, cloning and sequencing. The effects of several aspects of these techniques on the estimation of genetic variability in a virus population were analysed. Hepatitis C virus populations from four patients were examined. For each patient, ten series of data derived from independent PCR amplifications of a single RT reaction were obtained. The sample size of each data set was 10 sequences (in nine series) and 100 sequences (in one series). An additional data set derived from an independent RT reaction (about 10 sequences) p…
Exploring Evolution in Ceboidea (Platyrrhini, Primates) by Williams-Beuren Probe (HSA 7q11.23) Chromosome Mapping
2007
The ancestral platyrrhine karyotype was characterised by a syntenic association of human 5 and a small segment of human 7 orthologues. This large syntenic association has undergone numerous rearrangements in various phylogenetic lines. We used a locus-specific molecular cytogenetic approach to study the chromosomal evolution of the human 7q11.23 orthologous sequences (William-Beuren syndrome, WS) in various Ceboidea (Platyrrhini) species. The fluorescent in situ hybridisation of the WS probe revealed a two-way pattern of chromosomal organisation that suggests various evolutionary scenarios. The first pattern (seen in Callimico and Saimiri ) includes a fairly simple disruption of the 7/5 syn…
Phylogenetic signal and functional categories in Proteobacteria genomes
2007
Abstract Background A comprehensive evolutionary analysis of bacterial genomes implies to identify the hallmark of vertical and non-vertical signals and to discriminate them from the presence of mere phylogenetic noise. In this report we have addressed the impact of factors like the universal distribution of the genes, their essentiality or their functional role in the cell on the inference of vertical signal through phylogenomic methods. Results We have established that supermatrices derived from data sets composed mainly by genes suspected to be essential for bacterial cellular life perform better on the recovery of vertical signal than those composed by widely distributed genes. In addit…
Tracking evolutionary trends towards increasing complexity: a case study in Cyanobacteria
2020
AbstractProgressive evolution, the tendency towards increasing complexity, is a controversial issue in Biology, whose resolution requires a proper measurement of complexity. Genomes are the best entities to address this challenge, as they record the history and information gaining of organisms in their ongoing biotic and environmental interactions. Using six metrics of genome complexity, none of which is primarily associated to biological function, we measure genome complexity in 91 genomes from the phylum Cyanobacteria. Several phylogenetic analyses reveal the existence of progressive evolution towards higher genome complexity: 1) all the metrics detect strong phylogenetic signals; 2) ridg…
Phylogenomic Analysis Reveals Deep Divergence and Recombination in an Economically Important Grapevine Virus
2015
The evolutionary history of the exclusively grapevine (Vitis spp.) infecting, grapevine leafroll-associated virus 3 (GLRaV-3) has not been studied extensively, partly due to limited available sequence data. In this study we trace the evolutionary history of GLRaV-3, focussing on isolate GH24, a newly discovered variant. GH24 was discovered through the use of next-generation sequencing (NGS) and the whole genome sequence determined and validated with Sanger sequencing. We assembled an alignment of all 13 available whole genomes of GLRaV-3 isolates and all other publicly available GLRaV-3 sequence data. Using multiple recombination detection methods we identified a clear signal for recombinat…
Deep metazoan phylogeny: When different genes tell different stories
2013
11 páginas, 4 figuras, 1 tabla.
Homologous recombination as a mechanism of genetic changes in bovine parainfluenza-3 virus
2021
Bovine parainfluenza-3 virus (BPIV-3) is one of the main viruses associated with bovine respiratory disease complex (BRDC) worldwide. BPIV-3 infect the bovine respiratory tract causing from subclinical infections to severe pneumonia with significant economic losses in the cattle industry. BPIV-3 is a RNA virus with high genetic variability, nevertheless, the contribution of recombination events to its variability has not been assessed so far. In this study the 25 complete genome sequences (CGS) reported so far and 215 partial sequences of different viral genes of BPIV-3 were analyzed to determine their genotypes and subgenotypes, distribution, and the existence of potential recombination ev…
Lactobacillus rennini sp. nov., isolated from rennin and associated with cheese spoilage.
2006
Two bacterial strains, DSM 20253T and DSM 20254, isolated from rennin and regarded as causing cheese spoilage, were deposited in the DSMZ as Lactobacillus sp. by J. Stadhouders. The strains show 99·9 % 16S rRNA gene sequence similarity and have less than 94·3 % similarity with any other species of the genus. Lactobacillus coryniformis is their closest phylogenetic neighbour. DNA–DNA hybridization experiments confirmed that the two strains are members of the same species with separate status within the genus Lactobacillus. The strains are homofermentative lactic acid bacteria and can be phenotypically and genotypically distinguished from their closest relatives. 16S rRNA gene-targeted specif…