Search results for "rRNA"
showing 10 items of 133 documents
Identification of Colletotrichum species responsible for anthracnose of strawberry based on the internal transcribed spacers of the ribosomal region.
2000
In recent years, different molecular techniques have led to an important progress in the characterisation of Colletotrichum species, but there are no available methods which permit the easy identification of Colletotrichum strains and their assignation to classical species. In the present work, the restriction patterns generated from the region spanning the internal transcribed spacers (ITS1 and ITS2) and the 5.8S rRNA gene, were used to identify a total of 80 strains of Colletotrichum, the majority of them isolated from strawberry. One of the most interesting results derived from this study was the easy and reliable distinction, using the endonuclease MvnI, between Colletotrichum fragariae…
Mites of the genus Typhlodromus (Acari: Phytoseiidae) from Southern France: combined morphological and molecular approaches for species identification
2019
Mites of the family Phytoseiidae are important predators for biological control applications. They occur naturally in ecosystems but their overall distribution is not completely known. This study presents results of surveys carried out in the south of France. It proposes the use of a combination of morphological and molecular approaches for species diagnosis. Eighteen species of the genus Typhlodromus are reported from southern France, of which nine belong to Typhlodromus (Anthoseius) and nine to Typhlodromus (Typhlodromus). Eight of these species are new to the French fauna. The mitochondrial DNA CytB gene from 85 specimens (18 species) and the 12S rRNA gene from 30 specimens (9 species) w…
Mitochondrial simple sequenze repeats and 12s – rRNA gene reveal two distinct lineages of Crocidura russula (Mammalia, Sorcidae)
2004
A short segment (135 bp) of the control region and a partial sequence (394 bp) of the 12S-rRNA gene in the mitochondrial DNA of Crocidura russula were analyzed in order to test a previous hypothesis regarding the presence of a gene flow disruption in northern Africa. This breakpoint would have separated northeast-African C. russula populations from the European (plus the northwest-African) populations. The analysis was carried out on specimens from Tunisia (C. r. cf agilis), Sardinia (C. r. ichnusae), and Pantelleria (C. r. cossyrensis), and on C. r. russula from Spain and Belgium. Two C. russula lineages were identified; they both shared R2 tandem repeated motifs of the same length (12 bp)…
Functional variants of 5S rRNA in the ribosomes of common sea urchin Paracentrotus lividus
2012
Abstract We have previously reported a molecular and cytogenetic characterization of three different 5S rDNA clusters in the sea urchin Paracentrotus lividus ; this study, performed at DNA level only, lends itself as starting point to verify that these clusters could contain transcribed genes, then, to demonstrate the presence of heterogeneity at functional RNA level, also. In the present work we report in P. lividus ribosomes the existence of several transcribed variants of the 5S rRNA and we associate all transcribed variants to the cluster to which belong. Our finding is the first demonstration of the presence of high heterogeneity in functional 5S rRNA molecules in animal ribosomes, a f…
Isolation and Characterization of Novosphingobium sp. Strain MT1, a Dominant Polychlorophenol-Degrading Strain in a Groundwater Bioremediation System
2002
ABSTRACT A high-rate fluidized-bed bioreactor has been treating polychlorophenol-contaminated groundwater in southern Finland at 5 to 8°C for over 6 years. We examined the microbial diversity of the bioreactor using three 16S ribosomal DNA (rDNA)-based methods: denaturing gradient gel electrophoresis, length heterogeneity-PCR analysis, and restriction fragment length polymorphism analysis. The molecular study revealed that the process was dependent on a stable bacterial community with low species diversity. The dominant organism, Novosphingobium sp. strain MT1, was isolated and characterized. Novosphingobium sp. strain MT1 degraded the main contaminants of the groundwater, 2,4,6-trichloroph…
Pythium ornacarpum: a new species with ornamented oogonia isolated from soil in France
1999
Pythium ornacarpum sp. nov. was isolated from a soil sample taken from Genlis in the Burgundy region of France. This species is unique because of its ornamented oogonia which are completely surrounded by antheridial filaments. The fungus is closely related to Pythium echinulatum Matthews. Morphological and reproductive aspects of this species as well as a study by PCR of the sequence of the internal transcribed spacer (ITS1) of the nuclear ribosomal gene and its comparison with related species are described here. The nucleotide sequence of the ITS1 region flaking the 5.8S rRNA of this species and other related species are also given here.
A new species of Pythium with ornamented oogonia: morphology, taxonomy, internal transcribed spacer region of its ribosomal RNA, and its comparison w…
2006
Pythium spiculum sp. nov. was isolated from soil samples taken in a vineyard in the Burgundian region of France and from different locations in Spain and Portugal. The oomycete has spiny oogonia and does not sporulate readily. It resembles Pythium mamillatum Meurs, but has its own distinguishing characteristics. It also exhibits sickle-shaped as well as spherical appressoria which at times are associated with sex organs like those found in Pythium abappressorium Paulitz and Pythium contiguanum Paul. Sequencing of the internal transcribed spacer region of its nuclear ribosomal DNA and a close look at its morphological characters have now enabled us to describe it as a new species. The intern…
Lactobacillus uvarum sp. nov. - A new lactic acid bacterium isolated from Spanish Bobal grape must
2008
Five strains isolated from grape musts in Spain in 1997, have been characterized by several molecular techniques, and three of them have been identified as pertaining to a new species. All strains are Gram-positive rods, aerotolerant and homofermentative bacteria that do not exhibit catalase activity. Phylogenetic analysis based on 16S rRNA gene sequences placed these strains within the genus Lactobacillus, closely related to Lactobacillus mali. DNA-DNA hybridization experiments confirmed that strain 71 belongs to the lately described species L. satsumensis, strain 88 belongs to L. mali and the other three isolates have an independent status at species level. Restriction analysis of the amp…
Morphological determination of the phototrophic community composition of biological soil crusts in coastal sand dunes in northern Germany
2022
This dataset comprises the microbial community composition of biological soil crusts in north-German sand dunes. For this we obtained enrichment cultures of phototrophic microorganisms, by placing fragments of biocrusts of the same Petri dishes as used for sequencing, in Petri dishes with Bold Basal (1N BBM) agarized medium (Bischoff and Bold 1963). Cultures were grown under standard laboratory conditions: with a 12-hour alteration of light and dark phases and irradiation of 25 μmol photons m-2 s-1 at a temperature 20 ± 5 ºС. Microscopic study of these raw cultures began in the third week of cultivation. Morphological examinations were performed using Olympus BX53 light microscope with Noma…
Vertical stratification patterns of methanotrophs and their genetic controllers in water columns of oxygen-stratified boreal lakes
2021
ABSTRACT The vertical structuring of methanotrophic communities and its genetic controllers remain understudied in the water columns of oxygen-stratified lakes. Therefore, we used 16S rRNA gene sequencing to study the vertical stratification patterns of methanotrophs in two boreal lakes, Lake Kuivajärvi and Lake Lovojärvi. Furthermore, metagenomic analyses were performed to assess the genomic characteristics of methanotrophs in Lovojärvi and the previously studied Lake Alinen Mustajärvi. The methanotroph communities were vertically structured along the oxygen gradient. Alphaproteobacterial methanotrophs preferred oxic water layers, while Methylococcales methanotrophs, consisting of putative…