Search results for "Restriction"
showing 10 items of 527 documents
A chromosome map of the Flavescence dorée phytoplasma
2008
International audience; The Flavescence dorée phytoplasma (FD-P), a non-cultivable, plant-pathogenic bacterium of the class Mollicutes, is the causal agent of a quarantine disease affecting vineyards of southern Europe, mainly in southern France and northern Italy. To investigate FD-P diversity and phytoplasma genetic determinants governing the FD-P life cycle, a genome project has been initiated. A physical map of the chromosome of FD-P strain FD92, purified from infected broad beans, was constructed by performing restriction digests of the chromosome and resolving the fragments by PFGE. Single and double digestions of the chromosome with the enzymes SalI, BssHII, MluI and EagI were perfor…
Yeast Population Dynamics during the Fermentation and Biological Aging of Sherry Wines
2001
ABSTRACTMolecular and physiological analyses were used to study the evolution of the yeast population, from alcoholic fermentation to biological aging in the process of “fino” sherry wine making. The four races of “flor”Saccharomyces cerevisiae (beticus, cheresiensis, montuliensis, androuxii) exhibited identical restriction patterns for the region spanning the internal transcribed spacers 1 and 2 (ITS-1 and ITS-2) and the 5.8S rRNA gene, but this pattern was different, from those exhibited by non-florS. cerevisiaestrains. This flor-specific pattern was detected only after wines were fortified, never during alcoholic fermentation, and all the strains isolated from the velum exhibited the typ…
DNA extraction from soils: old bias for new microbial diversity analysis methods.
2001
ABSTRACT The impact of three different soil DNA extraction methods on bacterial diversity was evaluated using PCR-based 16S ribosomal DNA analysis. DNA extracted directly from three soils showing contrasting physicochemical properties was subjected to amplified ribosomal DNA restriction analysis and ribosomal intergenic spacer analysis (RISA). The obtained RISA patterns revealed clearly that both the phylotype abundance and the composition of the indigenous bacterial community are dependent on the DNA recovery method used. In addition, this effect was also shown in the context of an experimental study aiming to estimate the impact on soil biodiversity of the application of farmyard manure o…
Shifts in diversity and microscale distribution of the adapted bacterial phenotypes due to Hg(II) spiking in soil.
2003
In a previous experiment [Ranjard et al. (2000) FEMS Microbiol Ecol 31:107–115], the spatial heterogeneity of a mercury impact on soil bacterial community was revealed by an increase of mercury-resistant (HgR) bacterial numbers in the outer fraction and the sand fractions when compared to those in the silt fractions. The objectives of the present study were (i) to investigate whether mercury exposure affects the diversity and the distribution within the various fractions of the HgR populations and (ii) to evaluate the contribution of the HgR populations to the overall community adaptation. A total of 236 strains isolated before (104 isolates) and 30 days (132 isolates) after spiking were ch…
Use of nodulation pattern, stress tolerance, nodC gene amplification, RAPD-PCR and RFLP-16S rDNA analysis to discriminate genotypes of Rhizobium legu…
2005
Twenty-seven new Rhizobium isolates were obtained from root nodules of wild and crop legumes belonging to the genera Vicia, Lathyrus and Pisum from different agroecological areas in central and southern Italy. A polyphasic approach including phenotypic and genotypic techniques was used to study their diversity and their relationships with other biovars and species of rhizobia. Analysis of symbiotic properties and stress tolerance tests revealed that wild isolates, showed a wide spectrum of nodulation and a marked variation in stress tolerance compared with reference strains tested in this study. All rhizobial isolates (except for the isolate CG4 from Galega officinalis) were presumptively i…
Comparative sequence analysis of the Clostridium difficile toxins A and B.
1992
The six clones pTB112, pTB324, pTBs12, pCd122, pCd14 and pCd13 cover the tox locus of Clostridium difficile VPI 10463. This region of 19 kb of chromosomal DNA contains four open reading frames including the complete toxB and toxA genes. The two toxins show 63% amino acid (aa) homology, a relatedness that had been predicted by the cross-reactivity of some monoclonal antibodies (mAb) but that is in contrast to the toxin specificity of polyclonal antisera. A special feature of ToxA and ToxB is their repetitive C-termini. We define herein 19 individual CROPs (combined repetitive oligopeptides of 20-50 aa length) in the ToxB C-terminus, which are separable into five homologous groups. Comparison…
rDNA fingerprinting as a tool in epidemiological analysis of Salmonella typhi infections
1991
SUMMARYCharacterization of 169 strainsof Salmonella typhiof phage types C1, C4, D1and D9isolated in 1975–88 was carried out by rDNA gene restriction pattern analysis. Twenty-four isolates had been recovered during four large waterbone outbreaks in the last 20 years in Sicily; 145 strains, isolated from apparently sporadic cases of infection in Southern Italy in the same period of time, were also examined.Application of rRNA–DNA hybridization technique after digestion of chromosomal DNA withClaI showed the identity of patterns of the epidemic strains of phage types C1and D1, confirming attribution of the outbreaks to single bacterial clones. Patterns of the two available strains of lysotype …
Clostridium difficile toxin A carries a C-terminal repetitive structure homologous to the carbohydrate binding region of streptococcal glycosyltransf…
1990
A detailed analysis of the 8130-bp open reading frame (ORF) of gene toxA and of an upstream ORF designated utxA, indicates the presence of a transcription terminator stem-loop for toxA, promoter sequences, and Shine-Dalgarno boxes for toxA and utxA. No transcription terminator between toxA and utxA is suggested by the sequence. ToxA contains two domains, one-third (C-terminal) with a repetitive structure and the residual two-thirds with no repetitions. The 2499-bp sequence encoding the repetitive structure is composed of nine groups of different short repetitive oligodeoxyribonucleotides (SRONs). A combination of these SRONs codes for five groups of combined repetitive oligopeptides (CROPs)…
Whole genome sequencing analysis of intrapatient microevolution in Mycobacterium tuberculosis: potential impact on the inference of tuberculosis tran…
2013
Background. It has been accepted that the infection by Mycobacterium tuberculosis (M. tuberculosis) can be more heterogeneous than considered. The emergence of clonal variants caused by microevolution events leading to population heterogeneity is a phenomenon largely unexplored. Until now, we could only superficially analyze this phenomenon by standard fingerprinting (RFLP and VNTR).Methods. In this study we applied whole genome sequencing for a more in-depth analysis of the scale of microevolution both at the intrapatient and interpatient scenarios.Results. We found that the amount of variation accumulated within a patient can be as high as that observed between patients along a chain of t…
Identification of a novel Drosophila melanogaster gene, angel, a member of a nested gene cluster at locus 59F4,5.
1996
The identification of a novel Drosophila melanogaster gene, angel, is presented in this study. angel is located on the right arm of the second chromosome at locus 59F5, close to the nested genes l(2)tid, l(2)not, l(2)rot and l(2)dtl. We describe the genetic and molecular localization of angel and present its temporal expression in the wild-type. The deduced amino acid sequence of the ANG39 protein is characterized by a nuclear localization signal. Furthermore, the central part of the predicted ANG39 protein shows significant homology to the C-terminal portion of the yeast transcriptional effector CCR4.