scholarly journals Thermal sensitivity of the Spiroplasma – Drosophila hydei protective symbiosis: The best of climes, the worst of climes

2021 ◽  
Vol 30 (5) ◽  
pp. 1336-1344
Author(s):  
Chris Corbin ◽  
Jordan E. Jones ◽  
Ewa Chrostek ◽  
Andy Fenton ◽  
Gregory D. D. Hurst
Keyword(s):  
Thermal Sensitivity ◽  
Drosophila Hydei

scholarly journals Thermal sensitivity of the Spiroplasma-Drosophila hydei protective symbiosis: The best of climes, the worst of climes

2020 ◽  
Author(s):  
Chris Corbin ◽  
Jordan E. Jones ◽  
Ewa Chrostek ◽  
Andy Fenton ◽  
Gregory D. D. Hurst
Keyword(s):  
Vertical Transmission ◽  
Evolutionary Ecology ◽  
Thermal Environment ◽  
Thermal Sensitivity ◽  
Natural Populations ◽  
Parasitoid Wasp ◽  
Natural Environments ◽  
Protective Capacity ◽  
Drosophila Hydei ◽  
The Impact

AbstractThe outcome of natural enemy attack in insects has commonly been found to be influenced by the presence of protective symbionts in the host. The degree to which protection functions in natural populations, however, will depend on the robustness of the phenotype to variation in the abiotic environment. We studied the impact of a key environmental parameter – temperature – on the efficacy of the protective effect of the symbiont Spiroplasma on its host Drosophila hydei, against attack by the parasitoid wasp Leptopilina heterotoma. In addition, we investigated the thermal sensitivity of the symbiont’s vertical transmission, which may be a key determinant of the ability of the symbiont to persist. We found that vertical transmission was more robust than previously considered, with Spiroplasma being maintained at 25 °C, 18 °C and with 18/15 °C diurnal cycles, with rates of segregational loss only increasing at 15 °C. Protection against wasp attack was ablated before symbiont transmission was lost, with the symbiont failing to rescue the fly host at 18 °C. We conclude that the presence of a protective symbiosis in natural populations cannot be simply inferred from presence of a symbiont whose protective capacity has been tested under narrow controlled conditions. More broadly, we argue that the thermal environment is likely to represent an important determinant of the evolutionary ecology of defensive symbioses in natural environments, potentially driving seasonal, latitudinal and altitudinal variation in symbiont frequency, and modulating the strength of selection for symbiotic protective systems compared to defensive systems encoded in the nuclear genomes.

scholarly journals Patients with Minimal Hepatic Encephalopathy Show Altered Thermal Sensitivity and Autonomic Function

2021 ◽  
Vol 10 (2) ◽  
pp. 239
Author(s):  
Dalia Rega ◽  
Mika Aiko ◽  
Nicolás Peñaranda ◽  
Amparo Urios ◽  
Juan-José Gallego ◽  
...  
Keyword(s):  
Nervous System ◽  
Hepatic Encephalopathy ◽  
Quantitative Sensory Testing ◽  
Autonomic Function ◽  
Thermal Sensitivity ◽  
Somatosensory System ◽  
Minimal Hepatic Encephalopathy ◽  
Heat Pain ◽  
Sensory Testing ◽  
Cirrhotic Patients

Cirrhotic patients may experience alterations in the peripheral nervous system and in somatosensory perception. Impairment of the somatosensory system could contribute to cognitive and motor alterations characteristic of minimal hepatic encephalopathy (MHE), which affects up to 40% of cirrhotic patients. We assessed the relationship between MHE and alterations in thermal, vibration, and/or heat pain sensitivity in 58 cirrhotic patients (38 without and 20 with MHE according to Psychometric Hepatic Encephalopathy Score) and 39 controls. All participants underwent attention and coordination tests, a nerve conduction study, autonomic function testing, and evaluation of sensory thresholds (vibration, cooling, and heat pain detection) by electromyography and quantitative sensory testing. The detection thresholds for cold and heat pain on the foot were higher in patients with, than those without MHE. This hyposensitivity was correlated with attention deficits. Reaction times in the foot were longer in patients with, than without MHE. Patients with normal sural nerve amplitude showed altered thermal sensitivity and autonomic function, with stronger alterations in patients with, than in those without MHE. MHE patients show a general decrease in cognitive and sensory abilities. Small fibers of the autonomic nervous system and thermal sensitivity are altered early on in MHE, before large sensory fibers. Quantitative sensory testing could be used as a marker of MHE.

scholarly journals Genomic variation in the American pika: signatures of geographic isolation and implications for conservation

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Kelly B. Klingler ◽  
Joshua P. Jahner ◽  
Thomas L. Parchman ◽  
Chris Ray ◽  
Mary M. Peacock
Keyword(s):  
Genetic Variation ◽  
Genetic Structure ◽  
Sierra Nevada ◽  
Spatial Genetic Structure ◽  
Spatial Scales ◽  
Thermal Sensitivity ◽  
Genomic Variation ◽  
Genome Wide ◽  
A Genome ◽  
American Pika

Abstract Background Distributional responses by alpine taxa to repeated, glacial-interglacial cycles throughout the last two million years have significantly influenced the spatial genetic structure of populations. These effects have been exacerbated for the American pika (Ochotona princeps), a small alpine lagomorph constrained by thermal sensitivity and a limited dispersal capacity. As a species of conservation concern, long-term lack of gene flow has important consequences for landscape genetic structure and levels of diversity within populations. Here, we use reduced representation sequencing (ddRADseq) to provide a genome-wide perspective on patterns of genetic variation across pika populations representing distinct subspecies. To investigate how landscape and environmental features shape genetic variation, we collected genetic samples from distinct geographic regions as well as across finer spatial scales in two geographically proximate mountain ranges of eastern Nevada. Results Our genome-wide analyses corroborate range-wide, mitochondrial subspecific designations and reveal pronounced fine-scale population structure between the Ruby Mountains and East Humboldt Range of eastern Nevada. Populations in Nevada were characterized by low genetic diversity (π = 0.0006–0.0009; θW = 0.0005–0.0007) relative to populations in California (π = 0.0014–0.0019; θW = 0.0011–0.0017) and the Rocky Mountains (π = 0.0025–0.0027; θW = 0.0021–0.0024), indicating substantial genetic drift in these isolated populations. Tajima’s D was positive for all sites (D = 0.240–0.811), consistent with recent contraction in population sizes range-wide. Conclusions Substantial influences of geography, elevation and climate variables on genetic differentiation were also detected and may interact with the regional effects of anthropogenic climate change to force the loss of unique genetic lineages through continued population extirpations in the Great Basin and Sierra Nevada.

scholarly journals Inhibition of HDAC4 by GSK3β leads to downregulation of KLF5 and ASK1 and prevents the progression of intravertebral disc degeneration

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Lin Xiao ◽  
Dongping Gong ◽  
Loufeng Liang ◽  
Anwei Liang ◽  
Huaxin Liang ◽  
...  
Keyword(s):  
Intervertebral Disc ◽  
Disc Degeneration ◽  
Cell Apoptosis ◽  
Thermal Sensitivity ◽  
Downstream Signaling ◽  
Thermal Pain ◽  
Histone Deacetylase 4 ◽  
Staining Methods ◽  
Hematoxylin And Eosin ◽  
Safranin O

Abstract Background Intervertebral disc degeneration (IDD) is a major cause of lower back pain. This study aimed at exploring the effects of histone deacetylase 4 (HDAC4) and its upstream and downstream signaling molecules on IDD development. Methods A murine IDD model was established by inducing a needle puncture injury to the vertebrate, whereupon we isolated and transfected of nucleus pulposus (NP) cells. Disc height index (DHI) of the mice was determined by X-ray tomography, while the pain experienced by the IDD mice was evaluated by mechanical and thermal sensitivity tests. Next, the interaction between GSK3β and HDAC4 as well as that between HDAC4 and KLF5 acetylation was assessed by co-immunoprecipitation, while the promoter region binding was assessed identified by chromatin immunoprecipitation. By staining methods with TUNEL, Safranin O fast green, and hematoxylin and eosin, the NP cell apoptosis, degradation of extracellular matrix, and morphology of intervertebral disc tissues were measured. Furthermore, mRNA and protein expressions of GSK3β, HDAC4, KLF5, and ASK1, as well as the extent of HDAC4 phosphorylation, were determined by RT-qPCR and Western blotting. Results GSK3β was identified to be downregulated in the intervertebral disc tissues obtained from IDD mice, while HDAC4, KLF5, and ASK1 were upregulated. HDAC4 silencing alleviated IDD symptoms. It was also found that GSK3β promoted the phosphorylation of HDAC4 to increase its degradation, while HDAC4 promoted ASK1 expression through upregulating the expression of KLF5. In IDD mice, GSK3β overexpression resulted in increased DHI, inhibition of NP cell apoptosis, alleviation of disc degeneration, and promoted mechanical and thermal pain thresholds. However, HDAC4 overexpression reversed these effects by promoting ASK1 expression. Conclusion Based on the key findings of the current study, we conclude that GSK3β can promote degradation of HDAC4, which lead to an overall downregulation of the downstream KLF5/ASK1 axis, thereby alleviating the development of IDD.

The initial reaction mechanism and thermal sensitivity of a fluoropolymer-containing energetic molecular system: the coupling effect of interfacial interactions and free radical reactions

CrystEngComm ◽  
2021 ◽  
Vol 23 (16) ◽  
pp. 3006-3014
Author(s):  
Wen Qian
Keyword(s):  
Free Radical ◽  
Coupling Effect ◽  
Molecular System ◽  
Thermal Sensitivity ◽  
Radical Reactions ◽  
Initial Reaction ◽  
Interfacial Interactions ◽  
Free Radical Reactions ◽  
Molecular Systems ◽  
Reactive Molecular Dynamics

A strategy combining classic and reactive molecular dynamics is applied to find the coupling effect of interfacial interactions and free radical reactions during the initial thermal decomposition of fluoropolymer-containing molecular systems.

scholarly journals SUR1, newly expressed in astrocytes, mediates neuropathic pain in a mouse model of peripheral nerve injury

2021 ◽  
Vol 17 ◽  
pp. 174480692110066
Author(s):  
Orest Tsymbalyuk ◽  
Volodymyr Gerzanich ◽  
Aaida Mumtaz ◽  
Sanketh Andhavarapu ◽  
Svetlana Ivanova ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Neuropathic Pain ◽  
Sciatic Nerve ◽  
Peripheral Nerve ◽  
Dorsal Horn ◽  
Nerve Injury ◽  
Peripheral Nerve Injury ◽  
Thermal Sensitivity ◽  
Gradual Improvement ◽  
Pain Behaviors

Background Neuropathic pain following peripheral nerve injury (PNI) is linked to neuroinflammation in the spinal cord marked by astrocyte activation and upregulation of interleukin 6 (IL -6 ), chemokine (C-C motif) ligand 2 (CCL2) and chemokine (C-X-C motif) ligand 1 (CXCL1), with inhibition of each individually being beneficial in pain models. Methods Wild type (WT) mice and mice with global or pGfap-cre- or pGFAP-cre/ERT2-driven Abcc8/SUR1 deletion or global Trpm4 deletion underwent unilateral sciatic nerve cuffing. WT mice received prophylactic (starting on post-operative day [pod]-0) or therapeutic (starting on pod-21) administration of the SUR1 antagonist, glibenclamide (10 µg IP) daily. We measured mechanical and thermal sensitivity using von Frey filaments and an automated Hargreaves method. Spinal cord tissues were evaluated for SUR1-TRPM4, IL-6, CCL2 and CXCL1. Results Sciatic nerve cuffing in WT mice resulted in pain behaviors (mechanical allodynia, thermal hyperalgesia) and newly upregulated SUR1-TRPM4 in dorsal horn astrocytes. Global and pGfap-cre-driven Abcc8 deletion and global Trpm4 deletion prevented development of pain behaviors. In mice with Abcc8 deletion regulated by pGFAP-cre/ERT2, after pain behaviors were established, delayed silencing of Abcc8 by tamoxifen resulted in gradual improvement over the next 14 days. After PNI, leakage of the blood-spinal barrier allowed entry of glibenclamide into the affected dorsal horn. Daily repeated administration of glibenclamide, both prophylactically and after allodynia was established, prevented or reduced allodynia. The salutary effects of glibenclamide on pain behaviors correlated with reduced expression of IL-6, CCL2 and CXCL1 by dorsal horn astrocytes. Conclusion SUR1-TRPM4 may represent a novel non-addicting target for neuropathic pain.

Estimation of channel temperature and thermal sensitivity for a 0.15 μm GaN HEMT

2021 ◽  
pp. 111595
Author(s):  
Abu Zahed Chowdhury ◽  
Mohammad Abdul Alim ◽  
Shariful Islam ◽  
Christophe Gaquiere
Keyword(s):  
Thermal Sensitivity ◽  
Gan Hemt ◽  
Channel Temperature

Thermal sensitivity of Bullfrog's immune response kept at different temperatures

2020 ◽  
Author(s):  
Alan S. Lima ◽  
Letícia de F. Ferreira ◽  
Diego P. Silva ◽  
Fernando R. Gomes ◽  
Stefanny C. M. Titon
Keyword(s):  
Immune Response ◽  
Thermal Sensitivity ◽  
Different Temperatures
Sign in / Sign up

Export Citation Format

Share Document