Nucleolar organization in the euglenoid Astasia longa as disclosed by selective staining, actinomycin D treatment, and cold shock

1979 ◽  
Vol 57 (19) ◽  
pp. 2031-2043 ◽  
Author(s):  
N. Chaly ◽  
A. Lord ◽  
J. G. Lafontaine
Keyword(s):  
Low Temperature ◽  
Cold Shock ◽  
Actinomycin D ◽  
Peripheral Region ◽  
Prolonged Treatment ◽  
Filamentous Structure ◽  
Normal Cells ◽  
Selective Staining ◽  
Nucleolar Organization ◽  
Astasia Longa

Nucleolar ultrastructure in Astasia longa (Jahn) was examined in normal cells as well as in cells treated with actinomycin D or subjected to low temperature. Selective staining for ribonucleo-proteins (RNP) revealed that, in normal cells, the fibrillar nucleolar zones consisted of a rather homogeneous, moderately dense material within which were observed circular and elongate areas having a noticeably greater density. These denser areas were interpreted as corresponding to cross and oblique sections of a coarse filamentous structure, or nucleolonema, which constitutes the main component of the fibrillar zones. Following staining with Moyne's Feulgen-like technique, the nucleolonemal profiles appeared denser than the remaining regions of the nucleolar mass, thus indicating that DNA is associated with this filamentous structure. This conclusion was supported by the observation that actinomycin D, a substance known to react with DNA, rapidly induced a transformation of the fibrillar nucleolar zones. After 1 h of such treatment and staining for RNP, the nucleolus was observed to be homogeneously dense except for the presence of a number of small, circular, lighter areas presumably representing cross sections of the transformed nucleolonema. Staining for DNA revealed similar masses which were now denser than the remaining portion of the nucleolus. As a result of prolonged treatment with actinomycin D, the Feulgen-positive material often appeared as a coarse network segregated within a crescent-shaped and peripheral region of the nucleolar body.After exposure of cells to low temperature (14.5 °C) for 1 h the granular zones of the nucleolus became looser and the nucleolonemal core appeared less distinct. Nucleolar organization reverted almost to normal when the cold shock treatment was prolonged for a 3-h period.

scholarly journals Adaptation of flocculent anammox culture to low temperature by cold shock: long-term response of microbial population

2021 ◽  
pp. 1-19
Author(s):  
Vojtech Kouba ◽  
Juan Camilo Gerlein ◽  
Andrea Benakova ◽  
Marco Antonio Lopez Marin ◽  
Eva Rysava ◽  
...  
Keyword(s):  
Low Temperature ◽  
Cold Shock ◽  
Microbial Population ◽  
Term Response

scholarly journals Cold Shock Proteins of Lactococcus lactis MG1363 Are Involved in Cryoprotection and in the Production of Cold-Induced Proteins

2001 ◽  
Vol 67 (11) ◽  
pp. 5171-5178 ◽  
Author(s):  
Jeroen A. Wouters ◽  
Hélène Frenkiel ◽  
Willem M. de Vos ◽  
Oscar P. Kuipers ◽  
Tjakko Abee
Keyword(s):  
Low Temperature ◽  
Lactococcus Lactis ◽  
Type Strain ◽  
Wild Type Strain ◽  
Cold Shock ◽  
Transcriptional Level ◽  
Wild Type ◽  
Cold Shock Proteins ◽  
Shock Proteins ◽  
Induced Proteins

ABSTRACT Members of the group of 7-kDa cold-shock proteins (CSPs) are the proteins with the highest level of induction upon cold shock in the lactic acid bacterium Lactococcus lactis MG1363. By using double-crossover recombination, two L. lactis strains were generated in which genes encoding CSPs are disrupted: L. lactis NZ9000ΔAB lacks the tandemly orientatedcspA and cspB genes, and NZ9000ΔABE lackscspA, cspB, and cspE. Both strains showed no differences in growth at normal and at low temperatures compared to that of the wild-type strain, L. lactis NZ9000. Two-dimensional gel electrophoresis showed that upon disruption of thecspAB genes, the production of remaining CspE at low temperature increased, and upon disruption of cspA, cspB, and cspE, the production of CspD at normal growth temperatures increased. Northern blot analysis showed that control is most likely at the transcriptional level. Furthermore, it was established by a proteomics approach that some (non-7-kDa) cold-induced proteins (CIPs) are not cold induced in the csp-lacking strains, among others the histon-like protein HslA and the signal transduction protein LlrC. This supports earlier observations (J. A. Wouters, M. Mailhes, F. M. Rombouts, W. M. De Vos, O. P. Kuipers, and T. Abee, Appl. Environ. Microbiol. 66:3756–3763, 2000). that the CSPs of L. lactis might be directly involved in the production of some CIPs upon low-temperature exposure. Remarkably, the adaptive response to freezing by prior exposure to 10°C was significantly reduced in strain NZ9000ΔABE but not in strain NZ9000ΔAB compared to results with wild-type strain NZ9000, indicating a notable involvement of CspE in cryoprotection.

scholarly journals Effect of Thermal Processing on Antioxidant Activity and Cytotoxicity of Waste Potato Juice

2019 ◽  
Vol 14 (1) ◽  
pp. 150-157 ◽  
Author(s):  
Przemysław Łukasz Kowalczewski ◽  
Anna Olejnik ◽  
Wojciech Białas ◽  
Piotr Kubiak ◽  
Aleksander Siger ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Low Temperature ◽  
Cytotoxic Activity ◽  
Spray Drying ◽  
Cell Lines ◽  
Freeze Drying ◽  
Cytotoxic Activities ◽  
Normal Cells ◽  
Stabilization Methods ◽  
The Impact

AbstractPotato juice (PJ), commonly considered a burdensome waste, is rich in various compounds with bioactive properties. It has long been considered a remedy for gastric problems in traditional folk medicine. If valorization of PJ through implementation in the production of functional foods is to be considered, stabilization methods must be developed to allow long-term storage of this seasonal product. It is important that such methods are chosen with regard to their effect on the bioactive value of the obtained product. In this study, the impact of four stabilization methods on the antioxidant and cytotoxic activities of PJ was investigated. Elevated temperatures were used in thermal deproteinization used to obtain DPJW (deproteinated potato juice water) and spray-drying of FPJ (fresh potato juice) that resulted in SDPJ. Freeze drying and cryoconcentration were the low temperature processing methods that yielded PJL (potato juice lyophilisate) and CPJ (cryocorncentrated potato juice), respectively. All processed materials were characterized chemically and compared with raw materials in terms of phenolic compounds content, antioxidant activity as well as cytotoxicity to human tumor cells isolated from the gastric mucosa (Hs476T cell line), colon (Caco-2 and HT-29 cell lines), and normal cells isolated from the small intestine and colon epithelium (IEC-6 and NCM460 cell lines). It was stated that high-temperature processes – thermal deproteinization and spray-drying – yielded products with increased antioxidant potential (TEAC) that also showed increased cytotoxic activity towards intestinal cancer cells. At the same time the cytotoxicity towards normal cells remained on par with that of fresh PJ (IEC-6 cells) or decreased (NCM460 cells). Thermal deproteinization significantly decreased the content of glycoalcaloids in the juice, while spray drying did not have such an effect. The two low-temperature processes investigated – cryoconcentration and freeze drying – did not affect the PJ cytotoxic activity towards any of the cell lines used in the tests, whereas they did affect the antioxidant properties and glycoalcaloids content of PJ.

scholarly journals Role of ςB in Adaptation ofListeria monocytogenes to Growth at Low Temperature

2000 ◽  
Vol 182 (24) ◽  
pp. 7083-7087 ◽  
Author(s):  
Lynne A. Becker ◽  
Stefanie N. Evans ◽  
Robert W. Hutkins ◽  
Andrew K. Benson
Keyword(s):  
Listeria Monocytogenes ◽  
Low Temperature ◽  
Growth Phase ◽  
Cold Shock ◽  
Dependent Manner ◽  
High Osmolarity ◽  
Efficient Uptake ◽  
Oflisteria Monocytogenes

ABSTRACT The activity of ςB in Listeria monocytogenes is stimulated by high osmolarity and is necessary for efficient uptake of osmoprotectants. Here we demonstrate that, during cold shock, ςB contributes to adaptation in a growth phase-dependent manner and is necessary for efficient accumulation of betaine and carnitine as cryoprotectants.

scholarly journals Understanding the early cold response mechanism in IR64 indica rice variety through comparative transcriptome analysis

2020 ◽  
Author(s):  
Pratiti Dasgupta ◽  
Abhishek Das ◽  
Sambit Datta New ◽  
Ishani Banerjee New ◽  
Sucheta Tripathy ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Low Temperature ◽  
Cold Stress ◽  
Cold Shock ◽  
Indica Rice ◽  
Cellular Reprogramming ◽  
Early Gene ◽  
Signaling Proteins ◽  
Cold Response

Abstract Background Cellular reprogramming in response to environmental stress involves alteration of gene expression, changes in the protein and metabolite profile for ensuring better stress management in plants. Similar to other plant species originating in tropical and sub-tropical areas, indica rice is highly sensitive to low temperature that adversely affects its growth and grain productivity. Substantial work has been done to understand cold induced changes in gene expression in rice plants. However, adequate information is not available for early gene expression, especially in indica variety. Therefore, a transcriptome profile was generated for cold shock treated seedlings of IR64 variety to identify early responsive genes. Results The functional annotation of early DEGs shows enrichment of genes involved in altered membrane rigidity and electrolytic leakage, the onset of calcium signaling, ROS generation and activation of stress responsive transcription factors in IR64. Gene regulatory network suggests that cold shock induces Ca 2+ signaling to activate DREB/CBF pathway and other groups of transcription factors such as MYB, NAC and ZFP; for activating various cold-responsive genes. The analysis also indicates that cold induced signaling proteins like RLKs, RLCKs, CDPKs and MAPKK and ROS signaling proteins. Further, several LEA, dehydrins and Low temperature-induced-genes were upregulated under early cold shock condition, indicating the onset of water-deficit conditions. Expression profiling in different high yielding cultivars shows high expression of cold-responsive genes in Heera and CB1 indica varieties, These varieties show low levels of cold induced ROS production, electrolytic leakage and high germination rate post-cold stress, compared to IR36 and IR64. Collectively, these results suggest that these varieties may have improved adaptability to cold stress. Conclusions The results of this study provide insights about early responsive events in Oryza sativa L.ssp. indica cv IR64 in response to cold stress. Our data shows the onset of cold response is associated with upregulation of stress responsive TFs, hydrophilic proteins and signaling molecules, whereas, the genes coding for cellular biosynthetic enzymes, cell cycle control and growth-related TFs are downregulated. This study reports that the generation of ROS is integral to the early response to trigger the ROS mediated signaling events during later stages.

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