scholarly journals Influence of temperature on the development, reproduction and regeneration in the flatworm model organism Macrostomum lignano

2018 ◽  
Author(s):  
Jakub Wudarski ◽  
Kirill Ustyantsev ◽  
Lisa Glazenburg ◽  
Eugene Berezikov
Keyword(s):  
Heat Shock ◽  
Heat Shock Response ◽  
Elevated Temperatures ◽  
Model Organism ◽  
Response Threshold ◽  
Reproduction Rate ◽  
Negative Consequences ◽  
Time Reproduction ◽  
Shock Response ◽  
Macrostomum Lignano

AbstractThe free-living marine flatworm Macrostomum lignano is a powerful model organism to study mechanisms of regeneration and stem cell regulation due to its convenient combination of biological and experimental properties, including the availability of transgenesis methods, which is unique among flatworm models. However, due to its relatively recent introduction in research, there are still many biological aspects of the animal that are not known. One of such questions is the influence of the culturing temperature on Macrostomum biology. Here we systematically investigated how different culturing temperatures affect the development time, reproduction rate, regeneration, heat shock response, and gene knockdown efficiency by RNA interference in M. lignano. We used marker transgenic lines of the flatworm to accurately measure the regeneration endpoint and to establish the stress response threshold for temperature shock. We found that compared to the culturing temperature of 20°C commonly used for M. lignano, elevated temperatures of 25°C-30°C substantially speed-up the development and regeneration time and increase reproduction rate without detectable negative consequences for the animal, while temperatures above 30°C elicit a heat shock response.We show that altering the temperature conditions can be used to shorten the time required to establish M. lignano cultures, store important lines and optimize the microinjection procedures for transgenesis. Our findings will help to optimize the design of experiments in M. lignano and thus facilitate future research in this model organism.

Mitochondrial activity and heat-shock response during morphogenesis in the pathogenic fungus Histoplasma capsulatum

1992 ◽  
Vol 70 (3-4) ◽  
pp. 207-214 ◽  
Author(s):  
Eduardo J. Patriarca ◽  
George S. Kobayashi ◽  
Bruno Maresca
Keyword(s):  
Heat Shock ◽  
Heat Shock Response ◽  
Elevated Temperatures ◽  
Histoplasma Capsulatum ◽  
Pathogenic Fungus ◽  
Temperature Shift ◽  
Mitochondrial Activity ◽  
Mitochondrial Atpase ◽  
Heat Shock Genes ◽  
Shock Response

Changes in temperature and a variety of other stimuli coordinately induce transcription of a specific set of heat-shock genes in all organisms. In the human fungal pathogen Histoplasma capsulatum, a temperature shift from 25 to 37 °C acts not only as a signal that causes transcription of heat-shock genes, but also triggers a morphological mycelium-to yeast-phase transition. The temperature-induced morphological transition may be viewed as a heat-shock response followed by cellular adaptation to a higher temperature. We have found that by inducing thermotolerance, i.e., an initial incubation at 34 °C, the thermosensitive attenuated Downs strain of H. capsulatum can be made to resemble those of the more temperature-tolerant G222B strain with respect to mitochondrial ATPase activity and electron transport efficiency at elevated temperatures. Furthermore, if the heat-shock response is first elicited by preincubation at milder temperatures or stress, transcription of heat-shock mRNA in mycelial cells of Downs strain that shifted to 37 °C proceeds at rates comparable to those of the virulent strains.Key words: heat shock, thermotolerance, ATPase, 70-kilodalton heat-shock protein, fungal morphogenesis.

scholarly journals Molecular Basis of the Defective Heat Stress Response in Mycobacterium leprae

2007 ◽  
Vol 189 (24) ◽  
pp. 8818-8827 ◽  
Author(s):  
Diana L. Williams ◽  
Tana L. Pittman ◽  
Mike Deshotel ◽  
Sandra Oby-Robinson ◽  
Issar Smith ◽  
...  
Keyword(s):  
Heat Stress ◽  
Stress Response ◽  
Heat Shock ◽  
Heat Shock Response ◽  
Elevated Temperatures ◽  
Transcriptional Response ◽  
Mycobacterium Leprae ◽  
Heat Stress Response ◽  
Regulatory Circuits ◽  
Shock Response

ABSTRACT Mycobacterium leprae, a major human pathogen, grows poorly at 37°C. The basis for its inability to survive at elevated temperatures was investigated. We determined that M. leprae lacks a protective heat shock response as a result of the lack of transcriptional induction of the alternative sigma factor genes sigE and sigB and the major heat shock operons, HSP70 and HSP60, even though heat shock promoters and regulatory circuits for these genes appear to be intact. M. leprae sigE was found to be capable of complementing the defective heat shock response of mycobacterial sigE knockout mutants only in the presence of a functional mycobacterial sigH, which orchestrates the mycobacterial heat shock response. Since the sigH of M. leprae is a pseudogene, these data support the conclusion that a key aspect of the defective heat shock response in M. leprae is the absence of a functional sigH. In addition, 68% of the genes induced during heat shock in M. tuberculosis were shown to be either absent from the M. leprae genome or were present as pseudogenes. Among these is the hsp/acr2 gene, whose product is essential for M. tuberculosis survival during heat shock. Taken together, these results suggest that the reduced ability of M. leprae to survive at elevated temperatures results from the lack of a functional transcriptional response to heat shock and the absence of a full repertoire of heat stress response genes, including sigH.

scholarly journals Heat shock response of thermophilic fungi: membrane lipids and soluble carbohydrates under elevated temperatures

Microbiology ◽  
2016 ◽  
Vol 162 (6) ◽  
pp. 989-999 ◽  
Author(s):  
Elena A. Ianutsevich ◽  
Olga A. Danilova ◽  
Natalia V. Groza ◽  
Ekaterina R. Kotlova ◽  
Vera M. Tereshina
Keyword(s):  
Heat Shock ◽  
Heat Shock Response ◽  
Elevated Temperatures ◽  
Membrane Lipids ◽  
Soluble Carbohydrates ◽  
Thermophilic Fungi ◽  
Shock Response

scholarly journals Convergence of Molecular, Modeling, and Systems Approaches for an Understanding of the Escherichia coli Heat Shock Response

2008 ◽  
Vol 72 (3) ◽  
pp. 545-554 ◽  
Author(s):  
Eric Guisbert ◽  
Takashi Yura ◽  
Virgil A. Rhodius ◽  
Carol A. Gross
Keyword(s):  
Escherichia Coli ◽  
Heat Shock ◽  
Heat Shock Response ◽  
Feedback Loop ◽  
Model Organism ◽  
Central Component ◽  
E Coli ◽  
Functional Aspects ◽  
Shock Response ◽  
Homeostatic Response

SUMMARY The heat shock response (HSR) is a homeostatic response that maintains the proper protein-folding environment in the cell. This response is universal, and many of its components are well conserved from bacteria to humans. In this review, we focus on the regulation of one of the most well-characterized HSRs, that of Escherichia coli. We show that even for this simple model organism, we still do not fully understand the central component of heat shock regulation, a chaperone-mediated negative feedback loop. In addition, we review other components that contribute to the regulation of the HSR in E. coli and discuss how these additional components contribute to regulation. Finally, we discuss recent genomic experiments that reveal additional functional aspects of the HSR.

scholarly journals Dynamical modelling of the heat shock response inChlamydomonas reinhardtii

2016 ◽  
Author(s):  
Stefano Magni ◽  
Antonella Succurro ◽  
Alexander Skupin ◽  
Oliver Ebenhöh
Keyword(s):  
Steady State ◽  
Heat Shock ◽  
Heat Shock Response ◽  
Model Organism ◽  
Mass Action ◽  
Large Temperature ◽  
System Response ◽  
Yield Reduction ◽  
Mass Action Kinetics ◽  
Shock Response

AbstractGlobal warming is exposing plants to more frequent heat stress, with consequent crop yield reduction. Organisms exposed to large temperature increases protect themselves typically with a heat shock response (HSR). To study the HSR in photosynthetic organisms we present here a data driven mathematical model describing the dynamics of the HSR in the model organismChlamydomonas reinhartii. Temperature variations are sensed by the accumulation of unfolded proteins, which activates the synthesis of heat shock proteins (HSP) mediated by the heat shock transcription factor HSF1. Our dynamical model employs a system of ordinary differential equations mostly based on mass-action kinetics to study the time evolution of the involved species. The signalling network is inferred from data in the literature, and the multiple experimental data-sets available are used to calibrate the model, which allows to reproduce their qualitative behaviour. With this model we show the ability of the system to adapt to temperatures higher than usual during heat shocks longer than three hours by shifting to a new steady state. We study how the steady state concentrations depend on the temperature at which the steady state is reached. We systematically investigate how the accumulation of HSPs depends on the combination of temperature and duration of the heat shock. We finally investigate the system response to a smooth variation in temperature simulating a hot day.

Conventional and novel PKC isoenzymes modify the heat-induced stress response but are not activated by heat shock

1998 ◽  
Vol 111 (22) ◽  
pp. 3357-3365 ◽  
Author(s):  
C.I. Holmberg ◽  
P.M. Roos ◽  
J.M. Lord ◽  
J.E. Eriksson ◽  
L. Sistonen
Keyword(s):  
Stress Response ◽  
Heat Shock ◽  
Heat Shock Response ◽  
Mammalian Cells ◽  
Elevated Temperatures ◽  
Heat Shock Element ◽  
Post Translational Modifications ◽  
Induced Stress ◽  
Shock Response

In mammalian cells, the heat-induced stress response is mediated by the constitutively expressed heat shock transcription factor 1 (HSF1). Upon exposure to elevated temperatures, HSF1 undergoes several post-translational modifications, including inducible phosphorylation or hyperphosphorylation. To date, neither the role of HSF1 hyperphosphorylation in regulation of the transcriptional activity of HSF1 nor the signaling pathways involved have been characterized. We have previously shown that the protein kinase C (PKC) activator, 12-O-tetradecanoylphorbol 13-acetate (TPA), markedly enhances the heat-induced stress response, and in the present study we elucidate the mechanism by which PKC activation affects the heat shock response in human cells. Our results show that several conventional and novel PKC isoenzymes are activated during the TPA-mediated enhancement of the heat shock response and that the enhancement can be inhibited by the specific PKC inhibitor bisindolylmaleimide I. Furthermore, the potentiating effect of TPA on the heat-induced stress response requires an intact heat shock element in the hsp70 promoter, indicating that PKC-responsive pathways are able to modulate the activity of HSF1. We also demonstrate that PKC is not activated by heat stress per se. These results reveal that PKC exhibits a significant modulatory role of the heat-induced stress response, but is not directly involved in regulation of the heat shock response.

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