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Dominant Bands (dominant + bands)

Distribution by Scientific Domains

Medical Sciences	50%
Life Sciences	50%

Selected Abstracts

Fungal endophytes in potato roots studied by traditional isolation and cultivation-independent DNA-based methods

FEMS MICROBIOLOGY ECOLOGY, Issue 3 2006
Monika Götz
Abstract The composition and relative abundance of endophytic fungi in roots of field-grown transgenic T4-lysozyme producing potatoes and the parental line were assessed by classical isolation from root segments and cultivation-independent techniques to test the hypothesis that endophytic fungi are affected by T4-lysozyme. Fungi were isolated from the majority of root segments of both lines and at least 63 morphological groups were obtained with Verticillium dahliae, Cylindrocarpon destructans, Colletotrichum coccodes and Plectosporium tabacinum as the most frequently isolated species. Dominant bands in the fungal fingerprints obtained by denaturing gradient gel electrophoresis analysis of 18S rRNA gene fragments amplified from total community DNA corresponded to the electrophoretic mobility of the 18S rRNA gene fragments of the three most abundant fungal isolates, V. dahliae, C. destructans and Col. coccodes, but not to P. tabacinum. The assignment of the bands to these isolates was confirmed for V. dahliae and Col. coccodes by sequencing of clones. Verticillium dahliae was the most abundant endophytic fungus in the roots of healthy potato plants. Differences in the relative abundance of endophytic fungi colonizing the roots of T4-lysozyme producing potatoes and the parental line could be detected by both methods. [source]

Cultivation-independent analysis of Pseudomonas species in soil and in the rhizosphere of field-grown Verticillium dahliae host plants

ENVIRONMENTAL MICROBIOLOGY, Issue 12 2006
Rodrigo Costa
Summary Despite their importance for rhizosphere functioning, rhizobacterial Pseudomonas spp. have been mainly studied in a cultivation-based manner. In this study a cultivation-independent method was used to determine to what extent the factors plant species, sampling site and year-to-year variation influence Pseudomonas community structure in bulk soil and in the rhizosphere of two Verticillium dahliae host plants, oilseed rape and strawberry. Community DNA was extracted from bulk and rhizosphere soil samples of flowering plants collected at three different sites in Germany in two consecutive years. Pseudomonas community structure and diversity were assessed using a polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) system to fingerprint Pseudomonas -specific 16S rRNA gene fragments amplified from community DNA. Dominant and differentiating DGGE bands were excised from the gels, cloned and sequenced. The factors sampling site, plant species and year-to-year variation were shown to significantly influence the community structure of Pseudomonas in rhizosphere soils. The composition of Pseudomonas 16S rRNA gene fragments in the rhizosphere differed from that in the adjacent bulk soil and the rhizosphere effect tended to be plant-specific. The clone sequences of most dominant bands analysed belonged to the Pseudomonas fluorescens lineage and showed closest similarity to culturable Pseudomonas known for displaying antifungal properties. This report provides a better understanding of how different factors drive Pseudomonas community structure and diversity in bulk and rhizosphere soils. [source]

Sequence and expression analyses of , and , transcripts in patients with waldenström's macroglobulinemia

AMERICAN JOURNAL OF HEMATOLOGY, Issue 3 2001
Satoshi Shiokawa
Abstract Waldenström's macroglobulinemia (WM) is a malignant lymphoplasmo-proliferative disorder with monoclonal pentameric immunoglobulin (Ig)M production. The most consistent feature of clonal B cells in the bone marrow (BM) and/or lymph nodes of patients with WM is the presence of pleomorphic B-lineage cells at different stages of maturation, such as small lymphocytes, lymphoplasmacytoid cells, and plasma cells. Monoclonal lymphocytes express , chains with or without , chains. A recent DNA analysis of WM tumor clones showed WM to be derived from B cells that have been selected by antigen at a relatively late stage of differentiation. To further clarify the origin of WM tumor cells, we analyzed the variable (V) domain sequences of tumor derived , and , transcripts. The expression of , transcripts was also examined in peripheral blood (PB) and BM using the reverse transcriptase polymerase chain reaction (RT-PCR) combined with a single-strand conformation polymorphism (SSCP) analysis. The sequences were identical among the , and , transcripts in each patient and the level of somatic mutation in the VH regions expressed by tumor cells was in the same range as that of IgM-only B cells and IgM+IgD+ memory B cells. In our previous RT-PCR-SSCP analysis, a single dominant band of the , isotype was observed in BM and PB in all patients. However, common dominant bands in BM and PB were detected in only one patient in a , transcript analysis. In the rest of the patients, monoclonal , transcripts were only detected in BM. Our results suggest that a normal counterpart of WM cells is somatically mutated IgM+IgD+ and/or IgM-only B cells and the expression patterns of monoclonal , and , transcripts differ between BM and PB in some cases of WM. Am. J. Hematol. 68:139,143, 2001. © 2001 Wiley-Liss, Inc. [source]

Modified implant surfaces show different biofilm compositions under in vivo conditions

CLINICAL ORAL IMPLANTS RESEARCH, Issue 8 2009
Birte Größner-Schreiber
Abstract Objective: Plaque accumulation on implant surfaces can result in peri-implantitis with potential implant loss. The aim of the present study was to examine the influence of zirconium nitride (ZrN) as a potential implant surface on the biofilm composition and diversity in vivo. Material and methods: ZrN- or titanium (Ti)-coated glass specimens and ZrN or roughened Ti discs were used as substrates. Pure glass and polished titanium served as controls. The specimens were mounted on removable intraoral splints in five adults. After 24 h of intraoral exposure, the biofilms were analyzed applying single-strand conformation polymorphism (SSCP analysis) of 16S rRNA genes. Sequence analysis of the dominant bands excised from the SSCP fingerprints allowed to taxonomically describe bacteria derived from biofilm samples. Results: The highest number of bands was counted on pure glass and Ti 800. ZrN-coated glass and ZrN-coated titanium discs showed the lowest values for species richness. However, no significant differences were observed regarding the diversity of the identified bacterial species among all the surfaces examined. A total of 46 different bacteria were identified. The dominant bands within the fingerprints indicated bacteria belonging to the Streptococcus group as identified by their 16S rDNA sequence. Conclusion: A coating of glass surfaces with ZrN significantly reduced the species richness in early bacterial colonization but the diversity was not significantly changed. In consideration of the results obtained by this and former studies a ZrN coating appears to rather modify the quantity of early bacterial adherence than the quality of the microbial community structure. [source]