Home  About us  Contact
 

Small Subunit rRNA (small + subunit_rrna)

Distribution by Scientific Domains
Life Sciences100%

Terms modified by Small Subunit rRNA

  • small subunit rrna gene
    		•

    Selected Abstracts

    Morphological, Small Subunit rRNA, and Physiological Characterization of Trimyema minutum (Kahl, 1931), an Anaerobic Ciliate from Submarine Hydrothermal Vents Growing from 28°C to 52°C

    THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 3 2002
    MANUELA BAUMGARTNER
    ABSTRACT. A thermophilic strain of Trimyema minutum was isolated from the hydrothermally heated sea floor at Vulcano Island (Italy) and cultivated monoxenically on Marinobaaer sp. and Methanococcus thermolithotrophicus. It can be propagated strictly an aerobically and is sensitive to oxygen: if exposed to air at 48°C all cells die within 60 min. It grows from 0.45,7.2% (w/v) salt and at pH 6.0,8.0. The isolate is the most extreme thermophilic ciliate which ever has been cultivated, exhibiting an optimal growth temperature of 48°C (doubling time 6 h). Growth occurs between 28°C and 52°C. Trimyema minutum is redescribed using live observation and silver impregnation. Its morphology and the small subunit ribosomal RNA sequence is distinctly different from that of T. compressum, but morphology is highly similar to that of T. shoalsiaNerad et al. 1995, which is thus probably a junior synonym of T. minutum. To stabilize the bewildering species taxonomy in Trimyema. we suggest to recognize our population as a neotype of T. minutum. [source]

    Ticks have R2 retrotransposons but not the consensus transposon target site of other arthropods

    INSECT MOLECULAR BIOLOGY, Issue 5 2005
    J. Bunikis
    Abstract Some copies of the large subunit rRNA genes (LSU rDNA) of most arthropods studied to date are inactivated by R-element retrotransposons at a specific target region that is highly conserved in sequence across all kingdoms of organisms. Here we report finding R2 elements in low copy numbers in the LSU rDNA of hard and soft ticks. Although the elements were inserted at the same LSU rDNA location as in insects, there were substitutions in the consensus R2 endonuclease cleavage site in the ticks and some other parasitiform mites. The substituted region comprises a critical contact point with small subunit rRNA, but in vitro structure probing analysis revealed novel, presumably stabilizing base-pairing. [source]

    Morphology, Ultrastructure, Molecular Phylogeny, and Autecology of Euplotes elegans Kahl, 1932 (Hypotrichida; Euplotidae) Isolated from the Anoxic Mariager Fjord, Denmark

    THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 2 2007
    M. V. JULIAN SCHWARZ
    ABSTRACT. The morphology, autecology, and molecular phylogeny of an euryhaline Euplotes isolate collected from the anoxic water column of the Mariager Fjord in Denmark were investigated. The isolate matches the original description of Euplotes elegans Kahl, 1932 very well. However, its dorsal silverline system is clearly distinct from the redescription of this species by Tuffrau. Thus, a neotypification is proposed for E. elegans Kahl, 1932. The oval-shaped cell has a mean size of 107 × 51 ,m and is characterized by 9.4 dorsolateral kineties, seven prominent dorsal ridges, large elongated ampullae, which encircle the dorsal kinetids, 18 kinetids in the middorsal row, nine frontoventral cirri, five transversal cirri, and three caudal cirri (two right caudal cirri and one left marginal cirrus). The dorsal silverline system is of the double type with the narrow polygons located on the right side of the dorsal kinetids. The ecological tolerances of this species to pH, salinity, temperature, and oxygen match the ambient environmental conditions of the sampling site. Molecular phylogeny was studied using small subunit rRNA (SSU rRNA) gene sequences. The molecular data cluster E. elegans with Euplotes raikovi, a member of the Euplotopsis group. The data suggest that the E. elegans,E. raikovi clade represents an isolated and deep branch at the base of the Euplotes tree. [source]

    Reevaluation of the Phylogenetic Relationship between Mobilid and Sessilid Peritrichs (Ciliophora, Oligohymenophorea) Based on Small Subunit rRNA Genes Sequences

    THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 5 2006
    YING-CHUN GONG
    ABSTRACT. Based on morphological characters, peritrich ciliates (Class Olygohymenophorea, Subclass Peritrichia) have been subdivided into the Orders Sessilida and Mobilida. Molecular phylogenetic studies on peritrichs have been restricted to members of the Order Sessilida. In order to shed more light into the evolutionary relationships within peritrichs, the complete small subunit rRNA (SSU rRNA) sequences of four mobilid species, Trichodina nobilis, Trichodina heterodentata, Trichodina reticulata, and Trichodinella myakkae were used to construct phylogenetic trees using maximum parsimony, neighbor joining, and Bayesian analyses. Whatever phylogenetic method used, the peritrichs did not constitute a monophyletic group: mobilid and sessilid species did not cluster together. Similarity in morphology but difference in molecular data led us to suggest that the oral structures of peritrichs are the result of evolutionary convergence. In addition, Trichodina reticulata, a Trichodina species with granules in the center of the adhesive disc, branched separately from its congeners, Trichodina nobilis and Trichodina heterodentata, trichodinids without such granules. This indicates that granules in the adhesive disc might be a phylogenetic character of high importance within the Family Trichodinidae. [source]

    Cryptosporidium Species and Genotypes in HIV-Positive Patients in Lima, Peru

    THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 2003
    Vitaliano A. Cama
    ABSTRACT: Cryptosporidium parasites from a cross-sectional study conducted in two national hospitals in Lima, Peru were genetically characterized to deteimine the diversity of Cryptosporidium spp. in HIV-positive people. A total of 2,672 patients participated in this study and provided 13,937 specimens. Cryptosporidium oocysts were detected by microscopy in 354 (13.3%) of the patients. Analysis of 951 Cryptosporidium - positive specimens from 300 patients using a small subunit rRNA-based PCR-RFLP tool identified 6 genotypes; Cryptosporidium hominis was the species most frequently detected (67.5%), followed by C. meleagridis (12.6%) and C. parvum (11.3%). Cryptosporidium canis (4.0%), C. felis (3.3%), and Cryptosporidium pig genotype (0.5%) were also found. These findings indicate that C. hominis is the predominant species in Peruvian HIV-positive persons, and that zoonotic Cryptosporidium spp. account for about 30% of cryptosporidiosis in these patients. [source]