scholarly journals A new fluorescent oligonucleotide probe for in-situ identification of Microcystis aeruginosa in freshwater

2019 ◽  
Vol 148 ◽  
pp. 503-513 ◽  
Author(s):  
A. Barra Caracciolo ◽  
L. Dejana ◽  
C. Fajardo ◽  
P. Grenni ◽  
M. Martin ◽  
...  
Keyword(s):  
Microcystis Aeruginosa ◽  
Oligonucleotide Probe

scholarly journals Expression and localization of the mRNA for DNA (cytosine-5)- methyltransferase in mouse seminiferous tubules.

1994 ◽  
Vol 42 (9) ◽  
pp. 1271-1276 ◽  
Author(s):  
M Numata ◽  
T Ono ◽  
S Iseki
Keyword(s):  
In Situ Hybridization ◽  
Significant Role ◽  
Meiotic Prophase ◽  
Oligonucleotide Probe ◽  
Mouse Testis ◽  
Seminiferous Tubules ◽  
Hybridization Histochemistry ◽  
In Situ Hybridization Histochemistry

DNA (cytosine-5)-methyltransferase (DNA MTase) is the only enzyme known to be involved in the methylation of mammalian DNA. Although the expression of DNA MTase gene is abundant in the testis, little is known about the role of this enzyme during spermatogenesis. We examined the distribution of DNA MTase mRNA in mouse testis by in situ hybridization histochemistry with an oligonucleotide probe. The mRNA signal was observed in the seminiferous tubules and was localized predominantly in spermatogonia and spermatocytes, particularly during the earlier steps of meiotic prophase I, with maximal intensity in the early pachytene cells. These results suggest some significant role for DNA MTase in spermatogenesis.

scholarly journals In situ hybridisation for the detection of Leishmania species in paraffin wax-embedded canine tissues using a digoxigenin-labelled oligonucleotide probe

2011 ◽  
Vol 169 (20) ◽  
pp. 525-525 ◽  
Author(s):  
N. Dinhopl ◽  
M. M. Mostegl ◽  
B. Richter ◽  
N. Nedorost ◽  
A. Maderner ◽  
...  
Keyword(s):  
Oligonucleotide Probe ◽  
In Situ Hybridisation ◽  
Leishmania Species ◽  
Paraffin Wax

Counting and Size Classification of Active Soil Bacteria by Fluorescence In Situ Hybridization with an rRNA Oligonucleotide Probe

1999 ◽  
Vol 65 (4) ◽  
pp. 1753-1761 ◽  
Author(s):  
Henrik Christensen ◽  
Michael Hansen ◽  
Jan Sørensen
Keyword(s):  
In Situ Hybridization ◽  
Nucleotide Sequence ◽  
Fluorescence In Situ Hybridization ◽  
Soil Bacteria ◽  
Oligonucleotide Probe ◽  
A Value ◽  
Nonspecific Staining ◽  
Dry Soil ◽  
Active Bacteria

ABSTRACT A fluorescence in situ hybridization (FISH) technique based on binding of a rhodamine-labelled oligonucleotide probe to 16S rRNA was used to estimate the numbers of ribosome-rich bacteria in soil samples. Such bacteria, which have high cellular rRNA contents, were assumed to be active (and growing) in the soil. Hybridization to an rRNA probe, EUB338, for the domain Bacteria was performed with a soil slurry, and this was followed by collection of the bacteria by membrane filtration (pore size, 0.2 μm). A nonsense probe, NONEUB338 (which has a nucleotide sequence complementary to the nucleotide sequence of probe EUB338), was used as a control for nonspecific staining. Counting and size classification into groups of small, medium, and large bacteria were performed by fluorescence microscopy. To compensate for a difference in the relative staining intensities of the probes and for binding by the rhodamine part of the probe, control experiments in which excess unlabelled probe was added were performed. This resulted in lower counts with EUB338 but not with NONEUB338, indicating that nonspecific staining was due to binding of rhodamine to the bacteria. A value of 4.8 × 108 active bacteria per g of dry soil was obtained for bulk soil incubated for 2 days with 0.3% glucose. In comparison, a value of 3.8 × 108 active bacteria per g of dry soil was obtained for soil which had been air dried and subsequently rewetted. In both soils, the majority (68 to 77%) of actively growing bacteria were members of the smallest size class (cell width, 0.25 to 0.5 μm), but the active (and growing) bacteria still represented only approximately 5% of the total bacterial population determined by DAPI (4′,6-diamidino-2-phenylindole) staining. The FISH technique in which slurry hybridization is used holds great promise for use with phylogenetic probes and for automatic counting of soil bacteria.

scholarly journals Expression of growth hormone-releasing hormone in human primary endometrial carcinomas

2002 ◽  
pp. 381-386 ◽  
Author(s):  
I Chatzistamou ◽  
AV Schally ◽  
A Pafiti ◽  
H Kiaris ◽  
H Koutselini
Keyword(s):  
In Situ Hybridization ◽  
Mixed Type ◽  
Oligonucleotide Probe ◽  
Rabbit Antibody ◽  
Cytoplasmic Staining ◽  
Releasing Hormone ◽  
Ectopic Production ◽  
Endometrial Carcinomas ◽  
Mullerian Tumor

BACKGROUND: Hypothalamic GH-releasing hormone (GHRH) regulates GH release from the pituitary, but an ectopic production of GHRH has been detected in various non-hypothalamic tissues, especially cancers. OBJECTIVE: To investigate whether endometrial tumors produce GHRH. METHODS: Twenty-four endometrioid, three serous papillary (SP), three mixed type endometrioid/serous papillary adenocarcinomas and one malignant mixed Mullerian tumor (MMMT) were assessed for GHRH immunoreactivity by the polyclonal anti-rabbit antibody SV95 and for the expression of GHRH mRNA by in situ hybridization using an oligonucleotide probe. RESULTS: Increased GHRH immunoreactivity was detected in 15 out of 24 (63%) of the endometrioid tumors, including two out of three (66%) of the mixed type endometrioid/serous adenocarcinomas but not in the three SP or the MMMT tumor. Cytoplasmic staining was detected in all positive cases, while in three of them strong nuclear localization of GHRH was also revealed. In situ hybridization indicated the presence of GHRH mRNA in six cases, all characterized as positive for GHRH immunoreactivity. CONCLUSION: GHRH is expressed in a subset of endometrial tumors, of the endometrioid type in particular. A paracrine/autocrine role for GHRH in the development of the disease should be considered.

Grazing of the copepod Cyclops vicinus on toxic Microcystis aeruginosa: potential for controlling cyanobacterial blooms and transfer of toxins

2018 ◽  
Vol 47 (3) ◽  
pp. 296-302 ◽  
Author(s):  
Zakaria A. Mohamed ◽  
Asmaa A. Bakr ◽  
Hamed A. Ghramh
Keyword(s):  
Microcystis Aeruginosa ◽  
Grazing Rate ◽  
Cyanobacterial Blooms ◽  
Feeding Experiments ◽  
Cyclops Vicinus ◽  
Ankistrodesmus Falcatus ◽  
Toxic Cyanobacteria ◽  
Study Laboratory ◽  
Grazer Species

Abstract Grazing of zooplankton on phytoplankton may contribute to a reduction of harmful cyanobacteria in eutrophic waters. However, the feeding capacity and interaction between zooplankton and toxic cyanobacteria vary among grazer species. In this study, laboratory feeding experiments were designed to measure the grazing rate of the copepod Cyclops vicinus on Microcystis aeruginosa and the potential microcystin (MC) accumulation in the grazer. Copepods were fed a mixed diet of the edible green alga Ankistrodesmus falcatus and toxic M. aeruginosa for 10 days. The results showed that C. vicinus efficiently ingested toxic Microcystis cells with high grazing rates, varying during the feeding period (68.9–606.3 Microcystis cells animal-1 d-1) along with Microcystis cell density. Microcystis cells exhibited a remarkable induction in MC production under grazing conditions with concentrations 1.67–12.5 times higher than those in control cultures. Furthermore, C. vicinus was found to accumulate MCs in its body with concentrations increasing during the experiment (0.05–3.21 μg MC animal-1). Further in situ studies are needed to investigate the ability of Cyclops and other copepods to assimilate and detoxify MCs at environmentally relevant concentrations before deciding on the biocontrol of Microcystis blooms by copepods.

Application of oligonucleotide probes for the detection of Thiothrix spp. in activated sludge plants treating paper and board mill wastes

2002 ◽  
Vol 46 (1-2) ◽  
pp. 559-564 ◽  
Author(s):  
S.B. Kim ◽  
M. Goodfellow ◽  
J. Kelly ◽  
G.S. Saddler ◽  
A.C. Ward
Keyword(s):  
Activated Sludge ◽  
Bacterial Population ◽  
Oligonucleotide Probe ◽  
In Situ Hybridisation ◽  
Filamentous Bacteria ◽  
Phylogenetic Groups ◽  
Investigation Period ◽  
Mixed Populations ◽  
Conventional Microscopy

Filamentous bacteria belonging to the genus Thiothrix were detected in activated sludge samples using the fluorescent in situ hybridisation (FISH) technique. A 16S rRNA-targeted oligonucleotide probe was developed for the detection of members of the T. fructosivorans group, and the performance of probe TNI for the detection of Thiothrix nivea group was enhanced by using an unlabeled competitor. A set of 5 probes covering all phylogenetic groups of Thiothrix were used to examine samples taken from selected activated sludge plants treating paper and board mill wastes. Members of the T. eikelboomii group formed the predominant filamentous bacterial population in plants experiencing poor sludge settleability, whereas members of the T. nivea group were commonly found but not dominantly in the remaining plants. Members of the T. fructosivorans group were not detected at any significant level in any of the samples. The distribution of the main Thiothrix types remained unchanged throughout the investigation period. It was evident that mixed populations of Thiothrix spp. were present in all activated sludge samples investigated, the observed differences were in the relative abundance of the various groups. These findings were supported by the results obtained using conventional microscopy.

scholarly journals Phylogenetic Analysis of and Oligonucleotide Probe Development for Eikelboom Type 021N Filamentous Bacteria Isolated from Bulking Activated Sludge

2000 ◽  
Vol 66 (11) ◽  
pp. 5043-5052 ◽  
Author(s):  
Takahiro Kanagawa ◽  
Yoichi Kamagata ◽  
Shinobu Aruga ◽  
Tetsuro Kohno ◽  
Matthias Horn ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Oligonucleotide Probe ◽  
Sequence Similarity ◽  
Rdna Sequence ◽  
Filamentous Bacteria ◽  
16S Rdna Sequence ◽  
Monophyletic Cluster ◽  
16S Ribosomal Dna ◽  
In Situ Detection

ABSTRACT Fifteen filamentous strains, morphologically classified as Eikelboom type 021N bacteria, were isolated from bulking activated sludges. Based on comparative 16S ribosomal DNA (rDNA) sequence analysis, all strains form a monophyletic cluster together with all recognized Thiothrix species (88.3 to 98.7% 16S rDNA sequence similarity) within the gamma-subclass ofProteobacteria. The investigated Eikelboom type 021N isolates were subdivided into three distinct groups (I to III) demonstrating a previously unrecognized genetic diversity hidden behind the uniform morphology of the filaments. For in situ detection of these bacteria, 16S rRNA-targeted oligonucleotide probes specific for the entire Eikelboom type 021N-Thiothrix cluster and the Eikelboom type 021N groups I, II, and III, respectively, were designed, evaluated, and successfully applied in activated sludge.

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