scholarly journals Interactions of U2 Gene Loci and Their Nuclear Transcripts with Cajal (Coiled) Bodies: Evidence for PreU2 within Cajal Bodies

2000 ◽  
Vol 11 (9) ◽  
pp. 2987-2998 ◽  
Author(s):  
Kelly P. Smith ◽  
Jeanne Bentley Lawrence
Keyword(s):  
Potential Role ◽  
Coiled Body ◽  
Oligonucleotide Probes ◽  
Primary Transcript ◽  
U2 Snrna ◽  
Rna Foci ◽  
Coiled Bodies ◽  
Snrna Gene

The Cajal (coiled) body (CB) is a structure enriched in proteins involved in mRNA, rRNA, and snRNA metabolism. CBs have been shown to interact with specific histone and snRNA gene loci. To examine the potential role of CBs in U2 snRNA metabolism, we used a variety of genomic and oligonucleotide probes to visualize in situ newly synthesized U2 snRNA relative to U2 loci and CBs. Results demonstrate that long spacer sequences between U2 coding repeats are transcribed, supporting other recent evidence that U2 transcription proceeds past the 3′ box. The presence of bright foci of this U2 locus RNA differed between alleles within the same nucleus; however, this did not correlate with the loci's association with a CB. Experiments with specific oligonucleotide probes revealed signal for preU2 RNA within CBs. PreU2 was also detected in the locus-associated RNA foci, whereas sequences 3′ of preU2 were found only in these foci, not in CBs. This suggests that a longer primary transcript is processed before entry into CBs. Although this work shows that direct contact of a U2 locus with a CB is not simply correlated with RNA at that locus, it provides the first evidence of new preU2 transcripts within CBs. We also show that, in contrast to CBs, SMN gems do not associate with U2 gene loci and do not contain preU2. Because other evidence indicates that preU2 is processed in the cytoplasm before assembly into snRNPs, results point to an involvement of CBs in modification or transport of preU2 RNA.

scholarly journals Identification of Type VI Collagen Synthesizing Cells in Human Diabetic Glomerulosclerosis Using Renal Biopsy Sections

1997 ◽  
Vol 15 (3) ◽  
pp. 175-181 ◽  
Author(s):  
Mohammed Shawkat Razzaque ◽  
Takehiko Koji ◽  
Takashi Harada ◽  
Takashi Taguchi
Keyword(s):  
Renal Biopsy ◽  
Cellular Localization ◽  
Oligonucleotide Probes ◽  
Diabetic Glomerulosclerosis ◽  
Type Vi Collagen ◽  
Cellular Origin ◽  
Collagen Mrna ◽  
Nodular Lesions

Although the role of extracellular matrices in the development of glomerulosclerosis has been discussed widely, the cellular origin of type VI collagen in diabetic nephropathy (DN) has remained relatively unexplored. This study reports the distribution and cellular origin of type VI collagen in DN. Type VI collagen‐specific oligonucleotide probes and monoclonal antibody were used to assess the relative expression of mRNA for \alpha1 (VI) chain and its translated protein in paraffin‐embedded renal biopsy sections of DN. By immunohistochemistry, compared to the control, increased deposition of type VI collagen was noted in the diffuse and nodular lesions of diabetic glomeruli. For cellular localization of type VI collagen mRNA, paraffin‐embedded renal sections of the control and DN were hybridizedin situwith digoxigenin (Dig)‐labeled antisense oligo‐DNA probe complementary to a part of \alpha1 (VI) mRNA. In comparison to the control kidney sections, increased numbers of intraglomerular cells (both mesangial and epithelial cells) were positive forα1 (VI) mRNA in renal biopsy sections of DN. From the results, we conclude that overexpression of type VI collagen by intraglomerular cells with its increased deposition might significantly contribute to the glomerulosclerosis found in DN.

scholarly journals Cryptic role of tetrathionate in the sulfur cycle: A study from Arabian Sea oxygen minimum zone sediments

2019 ◽  
Author(s):  
Subhrangshu Mandal ◽  
Sabyasachi Bhattacharya ◽  
Chayan Roy ◽  
Moidu Jameela Rameez ◽  
Jagannath Sarkar ◽  
...  
Keyword(s):  
Arabian Sea ◽  
Potential Role ◽  
Sediment Cores ◽  
Oxygen Minimum Zone ◽  
Sulfur Cycle ◽  
Metagenome Analysis ◽  
Minimum Zone ◽  
Oxygen Minimum

ABSTRACTTo explore the potential role of tetrathionate in the sulfur cycle of marine sediments, the population ecology of tetrathionate-forming, oxidizing, and respiring microorganisms was revealed at 15-30 cm resolution along two, ∼3-m-long, cores collected from 530- and 580-mbsl water-depths of Arabian Sea, off India’s west coast, within the oxygen minimum zone (OMZ). Metagenome analysis along the two sediment-cores revealed widespread occurrence of the structural genes that govern these metabolisms; high diversity and relative-abundance was also detected for the bacteria known to render these processes. Slurry-incubation of the sediment-samples, pure-culture isolation, and metatranscriptome analysis, corroborated thein situfunctionality of all the three metabolic-types. Geochemical analyses revealed thiosulfate (0-11.1 μM), pyrite (0.05-1.09 wt %), iron (9232-17234 ppm) and manganese (71-172 ppm) along the two sediment-cores. Pyrites (via abiotic reaction with MnO2) and thiosulfate (via oxidation by chemolithotrophic bacteria prevalentin situ) are apparently the main sources of tetrathionate in this ecosystem. Tetrathionate, in turn, can be either converted to sulfate (via oxidation by the chemolithotrophs present) or reduced back to thiosulfate (via respiration by native bacteria); 0-2.01 mM sulfide present in the sediment-cores may also reduce tetrathionate abiotically to thiosulfate and elemental sulfur. Notably tetrathionate was not detectedin situ- high microbiological and geochemical reactivity of this polythionate is apparently instrumental in the cryptic nature of its potential role as a central sulfur cycle intermediate. Biogeochemical roles of this polythionate, albeit revealed here in the context of OMZ sediments, may well extend to the sulfur cycles of other geomicrobiologically-distinct marine sediment horizons.

scholarly journals Cryptic role of tetrathionate in the sulfur cycle: A study from Arabian Sea oxygen minimum zone sediments

2019 ◽  
Author(s):  
Subhrangshu Mandal ◽  
Sabyasachi Bhattacharya ◽  
Chayan Roy ◽  
Moidu Jameela Rameez ◽  
Jagannath Sarkar ◽  
...  
Keyword(s):  
Arabian Sea ◽  
Potential Role ◽  
Sediment Cores ◽  
Oxygen Minimum Zone ◽  
Sulfur Cycle ◽  
Metagenome Analysis ◽  
Minimum Zone ◽  
Oxygen Minimum

Abstract. To explore the potential role of tetrathionate in the sulfur cycle of marine sediments, the population ecology of tetrathionate-forming, oxidizing, and respiring microorganisms was revealed at 15–30 cm resolution along two, ~ 3-m-long, cores collected from 530- and 580-mbsl water-depths of Arabian Sea, off India’s west coast, within the oxygen minimum zone (OMZ). Metagenome analysis along the two sediment-cores revealed widespread occurrence of the structural genes that govern these metabolisms; high diversity and relative-abundance was also detected for the bacteria known to render these processes. Slurry-incubation of the sediment-samples, pure-culture isolation, and metatranscriptome analysis, corroborated the in situ functionality of all the three metabolic-types. Geochemical analyses revealed thiosulfate (0–11.1 µM), pyrite (0.05–1.09 wt %), iron (9232–17234 ppm) and manganese (71–172 ppm) along the two sediment-cores. Pyrites (via abiotic reaction with MnO2) and thiosulfate (via oxidation by chemolithotrophic bacteria prevalent in situ) are apparently the main sources of tetrathionate in this ecosystem. Tetrathionate, in turn, can be either converted to sulfate (via oxidation by the chemolithotrophs present) or reduced back to thiosulfate (via respiration by native bacteria); 0–2.01 mM sulfide present in the sediment-cores may also reduce tetrathionate abiotically to thiosulfate and elemental sulfur. Notably tetrathionate was not detected in situ – high microbiological and geochemical reactivity of this polythionate is apparently instrumental in the cryptic nature of its potential role as a central sulfur cycle intermediate. Biogeochemical roles of this polythionate, albeit revealed here in the context of OMZ sediments, may well extend to the sulfur cycles of other geomicrobiologically-distinct marine sediment horizons.

Role of leukocytes in ethanol-induced microvascular injury in the rat brain in situ: potential role in alcohol brain pathology and stroke

2002 ◽  
Vol 448 (1) ◽  
pp. 89-94 ◽  
Author(s):  
Burton M. Altura ◽  
Asefa Gebrewold ◽  
Aimin Zhang ◽  
Bella T. Altura
Keyword(s):  
Rat Brain ◽  
Potential Role ◽  
Brain Pathology ◽  
Microvascular Injury

Why does convection weaken over Sumatra Island in an active phase of the MJO?

2022 ◽  
Keyword(s):  
Potential Role ◽  
Sea Breeze ◽  
Active Phase ◽  
Maritime Continent ◽  
Sea Temperature ◽  
Sumatra Island ◽  
Temperature Contrast ◽  
Convection Initiation

Abstract This study investigated the diurnal cycle of convection over Sumatra Island in an active phase of the Madden-Julian Oscillation (MJO) during the Pre-Years of the Maritime Continent (YMC) observation campaign in December 2015 based on in-situ and satellite observations and a convection-permitting numerical model. Observations suggest that before the active phase of the MJO in early December, convection occurred frequently over the island during the afternoon and at midnight. By contrast, during the active phase of the MJO in mid-December, afternoon convection over the island was delayed and suppressed, and midnight convection was suppressed. Numerical experiments also successfully replicated the main features of the observed modulations. In general, during the active phase of the MJO, the troposphere became drier in the Sumatra region. While the clouds reduced the solar radiation over the land, the sea breeze was also found to be delayed and weakened. As a result, the afternoon convection initiation was delayed and weakened. Further analyses suggested that the sea breeze was weakened mainly due to the orographic stagnation effect rather than the slightly reduced land-sea temperature contrast. On the other hand, the increased stratiform-anvil clouds induced the anomalous evaporative cooling in the mid-troposphere and generated island-scale subsidence during the nighttime, which finally led to the suppression of inland convection. Overall, our study reveals the modulation of diurnal convection over Sumatra Island by an active phase of the MJO and also shows the potential role of land-sea interaction in convection initiation and maintenance.

Molecular Biology and the Major Psychoses

1997 ◽  
Vol 31 (1) ◽  
pp. 12-16 ◽  
Author(s):  
Andrew Lloyd ◽  
Gavin Dixon ◽  
Xu Feng Huang ◽  
Phillip Ward ◽  
Stan Catts ◽  
...  
Keyword(s):  
Brain Tissue ◽  
Messenger Rna ◽  
Potential Role ◽  
In Situ Hybridisation ◽  
Northern Analysis ◽  
Expression Of Genes ◽  
Expression Studies ◽  
Biological Studies

Objective:To highlight the potential role of molecular biological studies in examining the expression of genes of interest in brain tissue to elucidate the pathophysiological basis of the major psychoses. Method:To review the principles underlying the available techniques for expression studies. Results:Detection of messenger RNA by in situ hybridisation and quantitation by Northern analysis are powerful tools to detect abnormalities in gene expression in brain tissue. Conclusion:The availability of simple techniques to examine the expression of RNA and protein products of individual genes, including examination at the level of individual cells, offers a clear opportunity to define the molecular basis of the major psychoses.

scholarly journals Transcription on lampbrush chromosome loops in the absence of U2 snRNA.

1992 ◽  
Vol 3 (3) ◽  
pp. 249-261 ◽  
Author(s):  
A Tsvetkov ◽  
M Jantsch ◽  
Z Wu ◽  
C Murphy ◽  
J G Gall
Keyword(s):  
Physiological Saline ◽  
Lampbrush Chromosome ◽  
Antisense Oligodeoxynucleotides ◽  
Lampbrush Chromosomes ◽  
U2 Snrna ◽  
Complete Destruction ◽  
Small Nuclear Rnas ◽  
Cytological Changes

The five small nuclear RNAs (snRNAs) involved in splicing occur on the loops of amphibian lampbrush chromosomes and in hundreds to thousands of extrachromosomal granules called B snurposomes. To assess the role of these snRNAs during transcription and to explore possible relationships between the loops and B snurposomes, we injected single-stranded antisense oligodeoxynucleotides (oligos) against U1 and U2 snRNA into toad and newt oocytes. As shown before, antisense U1 and U2 oligos caused truncation of U1 and complete destruction of U2 snRNAs, respectively. However, injection of any oligo, regardless of sequence, brought on dramatic cytological changes, including shortening of the chromosomes and retraction of the lateral loops, with concomitant shutdown of polymerase II transcription, as well as disappearance of some or all of the B snurposomes. When injected oocytes were incubated for 12 h or longer in physiological saline, these changes were reversible; that is, the chromosomes lengthened, transcription (detected by 3H-UTP incorporation) resumed on newly extended lateral loops, and B snurposomes reappeared. In situ hybridization showed that loops and B snurposomes had negligible amounts of U2 snRNA after recovery from injection of the anti-U2 oligo, whereas these structures had normal levels of U2 snRNA after recovery from a control oligo. Thus, the morphological integrity of B snurposomes and lampbrush chromosome loops is not dependent on the presence of U2 snRNA. Because transcription occurs in the absence of U2 snRNA, we conclude that splicing is not required for transcription on lampbrush chromosome loops.

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