Search results for "Molecular sequence"
showing 10 items of 1972 documents
Epidemic dynamics of two coexisting hepatitis C virus subtypes.
2006
Hepatitis C virus (HCV) infection affects about 3 % of the human population. Phylogenetic analyses have grouped its variants into six major genotypes, which have a star-like distribution and several minor subtypes. The most abundant genotype in Europe is the so-called genotype 1, with two prevalent subtypes, 1a and 1b. In order to explain the higher prevalence of subtype 1b over 1a, a large-scale sequence analysis (100 virus clones) has been carried out over 25 patients of both subtypes in two regions of the HCV genome: one comprising hypervariable region 1 and another including the interferon sensitivity-determining region. Neither polymorphism analysis nor molecular variance analysis (att…
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…
Nucleotide sequence of plasmid p4028, a cryptic plasmid from Leuconostoc oenos.
1996
Abstract TheLeuconostoc oenosplasmid p4028 was cloned in pBlueScript (SK+), and its complete nucleotide sequence was determined. The analysis of the nucleotide sequence revealed five open reading frames, all of them located on the same strand and grouped in two clusters separated by a short noncoding stretch. A similarity search against the other sequences deposited in the EMBL and GenBank databases showed that p4028 has no significant similarity with any of the sequences checked. Nevertheless, a putative ATP-binding motif was found in ORF2. A more detailed analysis of this ORF suggests that it could encode for a DNA-dependent ATPase.
Recombination drives genome evolution in outbreak-related Legionella pneumophila isolates.
2014
Legionella pneumophila is a strictly environmental pathogen and the etiological agent of legionellosis. It is known that non-vertical processes have a major role in the short-term evolution of pathogens, but little is known about the relevance of these and other processes in environmental bacteria. We report the whole-genome sequencing of 69 L. pneumophila strains linked to recurrent outbreaks in a single location (Alcoy, Spain) over 11 years. We found some examples where the genome sequences of isolates of the same sequence type and outbreak did not cluster together and were more closely related to sequences from different outbreaks. Our analyses identify 16 recombination events responsibl…
A new subtype of hepatitis C virus genotype 1: complete genome and phylogenetic relationships of an Equatorial Guinea isolate.
2006
Hepatitis C virus (HCV) is the leading cause of chronic liver disease and is associated with hepatocellular carcinoma. However, there have been few studies on the distribution and genetic diversity of HCV isolates in non-developed countries. Here, the complete genome sequence of an HCV genotype 1 isolate from Equatorial Guinea is reported, the first complete HCV-1 genome of African origin. Phylogenetic analysis revealed that this sequence always grouped with sequences of genotype 1, but did not group clearly with any subtype described so far. An analysis of partial NS5B gene sequences with additional sequences of African origin also failed to find close similarities between the new sequenc…
Yunis-Varón Syndrome Is Caused by Mutations in FIG4, Encoding a Phosphoinositide Phosphatase
2013
Yunis-Varón syndrome (YVS) is an autosomal-recessive disorder with cleidocranial dysplasia, digital anomalies, and severe neurological involvement. Enlarged vacuoles are found in neurons, muscle, and cartilage. By whole-exome sequencing, we identified frameshift and missense mutations of FIG4 in affected individuals from three unrelated families. FIG4 encodes a phosphoinositide phosphatase required for regulation of PI(3,5)P(2) levels, and thus endosomal trafficking and autophagy. In a functional assay, both missense substitutions failed to correct the vacuolar phenotype of Fig4-null mouse fibroblasts. Homozygous Fig4-null mice exhibit features of YVS, including neurodegeneration and enlarg…
Genotypic analysis at multiple loci across Kaposi's sarcoma herpesvirus (KSHV) DNA molecules: clustering patterns, novel variants and chimerism
2001
Abstract Background: the genomes of human Kaposi's sarcoma-associated herpesvirus (KSHV) display several levels of DNA sequence heterogeneity and subgrouping that show distinctive clustering patterns in related human populations. The four major subtype patterns for the hypervariable ORF-K1 protein correlate closely with the principal diasporas resulting from the migration of modern humans out of East Africa and suggest that KSHV is an ancient human virus that is transmitted primarily in a familial fashion with consequent very low recombination rates. However, chimeric genomes have also been detected, especially with regard to the presence of P versus M alleles of the ORF-K15 gene. Objective…
Molecular Characterization of New Natural Hybrids of Saccharomyces cerevisiae and S. kudriavzevii in Brewing▿ †
2008
ABSTRACT We analyzed 24 beer strains from different origins by using PCR-restriction fragment length polymorphism analysis of different gene regions, and six new Saccharomyces cerevisiae × Saccharomyces kudriavzevii hybrid strains were found. This is the first time that the presence in brewing of this new type of hybrid has been demonstrated. From the comparative molecular analysis of these natural hybrids with respect to those described in wines, it can be concluded that these originated from at least two hybridization events and that some brewing hybrids share a common origin with wine hybrids. Finally, a reduction of the S. kudriavzevii fraction of the hybrid genomes was observed, but th…
Lactobacillus rossii sp. nov. isolated from wheat sourdough
2005
Screening of sourdough lactic acid bacteria for bacteriocin production resulted in the isolation of a Gram-positive, catalase-negative, non-spore-forming, non-motile rod bacterium (strain CS1T) that could not be associated with any previously described species. Comparative 16S rRNA gene sequence analysis recognized strain CS1T as a distinct member of the genus Lactobacillus. By a species-specific PCR strategy, five additional strains previously isolated from sourdoughs were found to belong to the same species as strain CS1T, as confirmed by 16S rRNA gene sequence analysis. The closest related species were Lactobacillus durianis, Lactobacillus malefermentans and Lactobacillus suebicus, with …
Acanthamoeba isolates belonging to T1, T2, T3, T4 and T7 genotypes from environmental freshwater samples in the Nile Delta region, Egypt.
2006
The free-living amoebae of the genus Acanthamoeba include non-pathogenic and pathogenic species and has been recently classified into 15 different genotypes, T1–T15. In this study, a survey was conducted in order to determine the presence and pathogenic potential of free-living amoebae of Acanthamoeba genus in freshwater sources associated with human activities in the Nile Delta region, Egypt. Identification of Acanthamoeba was based on the morphology of cyst and trophozoite forms and PCR amplification with a genus specific primer pair. The pathogenic potential of Acanthamoeba isolates was characterized using temperature and osmotolerance assays and PCR reactions with two primer pairs speci…