Search results for "Restriction Fragment Length"
showing 10 items of 200 documents
Repetitive nucleotide sequencing of a dispensable DNA segment in a clonal population of African swine fever virus
1991
Abstract Repetitive nucleotide sequencing of a dispensable genomic segment of a clonal population of African swine fever (ASF) virus has been carried out to estimate the mutant frequency to neutral alleles. Since no mutations have been detected in a total of 54026 nucleotides screened, the maximum mutant frequency is 5.5 × 10 −5 substitutions/nucleotide (95% confidence level). The result renders very unlikely the occurrence of hypermutational events during ASF virus DNA replication, at least within the selected DNA fragment.
Human papillomavirus frequency in oral epithelial lesions
2005
BACKGROUND: Oral human papillomavirus (HPV) prevalence varies according to geographical occurrence, the type of lesion, and the method of diagnosis. The polymerase chain reaction method (PCR) appears to be more sensitive and can be easily applicable to epidemiologic studies. OBJECTIVES: To determine the frequency of HPV and its genotypes in oral lesions among patients attending a reference clinic of a university hospital. METHODS: PCR was performed to identify HPV DNA from samples of oral epithelial lesions in 80 patients. For HPV DNA amplification, MY09/MY11 consensus primers were used and specific genotypes were identified through restriction fragment of length polymorphism (RFLP) pattern…
Risultati di un test RFLP su ceppi vaccinali di Canine Distemper Virus in Italia
2013
Canine Distemper (CD) is a highly contagious and multisystemic viral disease of domestic and wild carnivores. A published Restriction Fragment Length Polymorphism (RFLP) test, based on the presence of a PsiI cleavage site on hemagglutinin (H) gene, allows a rapid differentiation of all currently used vaccine strains by virulent field strains. The present study describes the results of this test carried out on different CD vaccines available in Italy in 2010. RFLP has also revealed that the CD strain present in the Vanguard (Pfizer Animal Health) vaccine reacts as a wild-type strain. Moreover, genetic analysis of H gene sequence has showed that Vanguard vaccine strain does not cluster in the…
Conflict between parasites with different transmission strategies infecting an amphipod host
2005
Competition between parasites within a host can influence the evolution of parasite virulence and host resistance, but few studies examine the effects of unrelated parasites with conflicting transmission strategies infecting the same host. Vertically transmitted (VT) parasites, transmitted from mother to offspring, are in conflict with virulent, horizontally transmitted (HT) parasites, because healthy hosts are necessary to maximize VT parasite fitness. Resolution of the conflict between these parasites should lead to the evolution of one of two strategies: avoidance, or sabotage of HT parasite virulence by the VT parasite. We investigated two co-infecting parasites in the amphipod host, G…
Impact of crop species on bacterial community structure during anaerobic co-digestion of crops and cow manure
2008
The bacterial communities in three continuously stirred tank reactors co-digesting cow manure with grass silage, oat straw, and sugar beet tops, respectively, were investigated by 16S rRNA gene-based fingerprints and clone libraries. The analyses revealed both clearly distinct and similar phylotypes in the bacterial communities between the reactors. The major groups represented in the three reactors were Clostridia, unclassified Bacteria, and Bacteroidetes. Phylotypes affiliated with Bacilli or Deltaproteobacteria were unique to the sugar beet and straw reactor, respectively. Unclassified Bacteria dominated in sugar beet reactor while in the straw and grass reactor Clostridia was the domina…
Molecular Identification of Yeasts Associated with Traditional Egyptian Dairy Products
2009
This study aimed to examine the diversity and ecology of yeasts associated with traditional Egyptian dairy products employing molecular techniques in yeast identification. A total of 120 samples of fresh and stored Domiati cheese, kariesh cheese, and "Matared" cream were collected from local markets and examined. Forty yeast isolates were cultured from these samples and identified using the restriction-fragment length polymorphism (RFLPs) of 5.8S-ITS rDNA region and sequencing of the domains D1 and D2 of the 26S rRNA gene. Yeasts were identified as Issatchenkia orientalis (13 isolates), Candida albicans (4 isolates), Clavispora lusitaniae (Candida lusitaniae) (9 isolates), Kodamaea ohmeri (…
Study of the Evolutionary Relationships among Limonium Species (Plumbaginaceae) Using Nuclear and Cytoplasmic Molecular Markers
2000
The genus Limonium, due to the patchiness of the natural habitats of its species as well as the high frequency of hybridization and polyploidy and the possibility of reproduction by apomixis, provides an example of all the principal mechanisms of rapid speciation of plants. As an initial study of evolution in this genus, we have analyzed intra- and interspecific variability in 17 species from section Limonium, the largest in the genus, based on RFLPs of cpDNA and nuclear rDNA ITS sequences. In the cpDNA analysis, 21 restriction enzymes were used, resulting in 779 fragments, 490 of which were variable and 339 parsimony informative. L. furfuraceum exhibited two relatively divergent cpDNA hapl…
Direct conjugal transfers of Ti plasmid to soil microflora
2002
The bacterial species in soil that can receive a Ti plasmid by conjugation from Agrobacterium spp. were investigated. In order to have direct access to the potential reservoir of Ti plasmid amongst soil microflora, the conjugal system consisting of a multiply auxotrophic derivative of C58 (ST-96-4) and a derivative of pTiC58Delta(acc)R (pSTiEGK) containing a triple antibiotic-resistance cassette in traM was used to transfer the Ti plasmid in a complex soil microflora used as the recipient. Numerous transconjugants were obtained by this method but none was identified as Agrobacterium. This could be explained by the low density of Agrobacterium in the tested soil. As indicated by analysis of …
Molecular analysis of the catechol-degrading bacterial community in a coal wasteland heavily contaminated with PAHs
2010
International audience; A PCR-based molecular tool was developed to estimate the diversity of the catechol-degrading bacterial community in a coal wasteland heavily contaminated with PAHS. A degenerate primer pair specific to catA sequences was designed by multiple alignment of known sequences coding a key intermediate of the β-ketoadiapate pathway degrading catechol, namely catechol 1,2-dioxygenase. The specificity of this primer pair was assessed in 21 pure strains by PCR and sequencing. Comparison of the 16S rDNA and catA phylogenies revealed an absence of congruence between these two genes. The primer set was able to amplify catA sequences in DNA extracts from an industrial soil highly …
Evidence of Genomic Instability in Campylobacter jejuni Isolated from Poultry
1998
ABSTRACT Poultry isolates of Campylobacter jejuni derived from a survey of meat processing batches were genotyped by pulsed-field gel electrophoresis (PFGE) of chromosomal DNA to establish the clonal relationships between single-colony isolates. In the majority of batches studied, one or two genotype patterns predominated. However, in one batch (batch A), 21 single-colony isolates gave 14 different PFGE genotypes. The banding patterns obtained with Sma I were sufficiently different to distinguish between genotypes, although the patterns also produced many common bands. The question of whether these isolates represented different clones or had a common clonal ancestry was addressed by additi…