Search results for "genetic analysi"
showing 10 items of 150 documents
Changing distribution of norovirus genotypes and genetic analysis of recombinant GIIb among infants and children with diarrhea in Japan
2006
A total of 402 fecal specimens collected during July 2003-June 2004 from infants and children with acute gastroenteritis, encompassing five localities (Maizuru, Tokyo, Sapporo, Saga, and Osaka) of Japan, were tested for the presence of norovirus by RT-PCR. It was found that 58 (14.4%) fecal specimens were positive for norovirus. Norovirus infection was detected throughout the year with the highest prevalence in December. Norovirus GII was the most predominant genogroup (98.3%; 57 of 58). The genotypes detected in this study were GI/4, GII/2, GII/3, GII/4, and GII/6. Of these, NoV GII/3 (known as the Arg320 virus cluster) was the most predominant genotype (43.9%), followed by NoV GII/4 (the …
Genetic structure of Tunisian sheep breeds as inferred from genome-wide SNP markers
2020
Abstract Assessing the status of genetic variability of native sheep breeds could provide important clues for research and policy makers to devise better strategies for the conservation and management of genetic resources. In this study, a genetic investigation of Tunisian sheep breeds using a genome-wide scan of approximately 50,000 SNPs was performed. To reconstruct genetic structure and relationships among four sheep breeds, 40 samples belonging to fat-tailed Barbarine, Queue Fine de l’Ouest, Noire de Thibar and D’Man breeds were genotyped using Illumina Ovine SNP50 BeadChip. Tunisian breeds averaged 96 % polymorphic loci with an expected heterozygosity (He = 0.36). Genetic analysis of r…
Comparative genomic and phylogenetic analyses of gammaproteobacterial glg genes traced the origin of the Escherichia coli glycogen glgBXCAP operon to…
2015
© 2015 Almagro et al. Production of branched α-glucan, glycogen-like polymers is widely spread in the Bacteria domain. The glycogen pathway of synthesis and degradation has been fairly well characterized in the model enterobacterial species Escherichia coli (order Enterobacteriales, class Gammaproteobacteria), in which the cognate genes (branching enzyme glgB, debranching enzyme glgX, ADP-glucose pyrophosphorylase glgC, glycogen synthase glgA, and glycogen phosphorylase glgP) are clustered in a glgBXCAP operon arrangement. However, the evolutionary origin of this particular arrangement and of its constituent genes is unknown. Here, by using 265 complete gammaproteobacterial genomes we have …
Quantitative genetic analysis of Cry1Ab tolerance in Ostrinia nubilalis Spanish populations
2013
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On the complexity of the Saccharomyces bayanus taxon: Hybridization and potential hybrid speciation
2014
Although the genus Saccharomyces has been thoroughly studied, some species in the genus has not yet been accurately resolved; an example is S. bayanus, a taxon that includes genetically diverse lineages of pure and hybrid strains. This diversity makes the assignation and classification of strains belonging to this species unclear and controversial. They have been subdivided by some authors into two varieties (bayanus and uvarum), which have been raised to the species level by others. In this work, we evaluate the complexity of 46 different strains included in the S. bayanus taxon by means of PCR-RFLP analysis and by sequencing of 34 gene regions and one mitochondrial gene. Using the sequenc…
Phylogenetic analyses of Fusarium graminearum strains from cereals in Italy, and characterisation of their molecular and chemical chemotypes
2014
The Fusarium graminearum species complex (FGSC) is a pathogen of durum wheat and other cereals worldwide. The complex consists of at least 15 species that can produce various mycotoxins, including trichothecenes, associated with human and animals toxicoses. In particular, deoxynivalenol (DON), nivalenol (NIV) and their different acetylated derivatives can be produced by the different chemotypes of the complex. In this study, 90 strains, isolated mainly from wheat in Italy and belonging to the FGSC, were assessed for their phylogeny and their chemotype and trichothecene genotype. Almost all strains of the FGSC belonged to F. graminearum sensu stricto, whereas two strains were F. cortaderiae…
Genetic diversity of two perch Perca fluviatilis populations of the Latgale region
2015
Molecular markers based on retrotransposons possibility of integration into genomes of many organisms are commonly used for genetic analysis of different species. The aim of this study was to test possibility of use those markers in perch and detect genetic diversity of populations of two lakes of the Latgale region of Latvia: Cirišs and Sventes. The distance between the lakes is nearly 60 km, they belong to the same Daugava river basin but are different from ecological point of view. Forty two blood samples of <em>Perca fluviatilis </em>were collected altogether. Extracted DNA was analyzed using inter-PBS amplification technique with specifically selected retrotransposon-based …
A novel methodology for large-scale phylogeny partition
2011
Understanding the determinants of virus transmission is a fundamental step for effective design of screening and intervention strategies to control viral epidemics. Phylogenetic analysis can be a valid approach for the identification of transmission chains, and very-large data sets can be analysed through parallel computation. Here we propose and validate a new methodology for the partition of large-scale phylogenies and the inference of transmission clusters. This approach, on the basis of a depth-first search algorithm, conjugates the evaluation of node reliability, tree topology and patristic distance analysis. The method has been applied to identify transmission clusters of a phylogeny …
An operon for histidine biosynthesis in Streptomyces coelicolor
1973
On the assumption that a cluster of five his genes (eight cistrons) in S. coelicolor corresponds to an operon, a genetic analysis of a constitutive mutant was carried out. This strain has a multi-site mutation localized at the (conventional) right end of the his cluster and is derepressed for at least two enzymes coded by genes of the cluster. The study of suitable heterozygous clones (heteroclones), showed the mutation to be cis-dominant, suggesting that the operator region is affected. Most likely the strain has a deletion connecting the his operon to an adjacent amm (ammonium requirement) operon as demonstrated by its inability to utilize nitrate as nitrogen source and to complement or r…
Screening and identification ofvipgenes inBacillus thuringiensisstrains
2009
Aims: To identify known vip genes and to detect potentially novel vip genes in a collection of 507 strains of Bacillus thuringiensis. Methods and Results: Following a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) strategy, four restriction patterns were found within the vip1 family: vip1Aa1, vip1Ba1/vip1Ba2 and vip1Ca. In the screening of vip2 genes, patterns similar to those of vip2Aa1, vip2Ba1/vip2Ba2 and vip2Ac1 genes were observed. Patterns for vip3Aa1, vip3Ae2 and vip3Af1 were found among vip3 genes. Two new patterns revealed novel vip1 and vip3A genes. The observed frequency of genes belonging to vip1 and vip2 families was around 10%, whereas 48·9% of…