Algal symbionts increase oxidative damage and death in coral larvae at high temperatures

Many marine invertebrates provide their offspring with symbionts. Yet the consequences of maternally inherited symbionts on larval fitness remain largely unexplored. In the stony coral Favia fragum (Esper 1797), mothers produce larvae with highly variable amounts of endosymbiotic algae, and we examined the implications of this variation in symbiont density on the performance of F. fragum larvae under different environmental scenarios. High symbiont densities prolonged the period that larvae actively swam and searched for suitable settlement habitats. Thermal stress reduced survival and settlement success in F. fragum larvae, whereby larvae with high symbiont densities suffered more from non-lethal stress and were five times more likely to die compared with larvae with low symbiont densities. These results show that maternally inherited algal symbionts can be either beneficial or harmful to coral larvae depending on the environmental conditions at hand, and suggest that F. fragum mothers use a bet-hedging strategy to minimize risks associated with spatio-temporal variability in their offspring's environment.

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Antioxidant Enzymes and Heat Shock Protein Genes from Liposcelis bostrychophila Are Involved in Stress Defense upon Heat Shock

Insects ◽

10.3390/insects11120839 ◽

2020 ◽

Vol 11 (12) ◽

pp. 839

Author(s):

Ze Qing Miao ◽

Yan Qing Tu ◽

Peng Yu Guo ◽

Wang He ◽

Tian Xing Jing ◽

...

Keyword(s):

Antioxidant Enzymes ◽

Heat Stress ◽

Thermal Stress ◽

Heat Shock ◽

Oxidative Damage ◽

High Temperatures ◽

Defense Mechanisms ◽

Molecular Mechanisms ◽

Instar Nymph ◽

Liposcelis Bostrychophila

Psocids are a new risk for global food security and safety because they are significant worldwide pests of stored products. Among these psocids, Liposcelis bostrychophila has developed high levels of resistance or tolerance to heat treatment in grain storage systems, and thus has led to investigation of molecular mechanisms underlying heat tolerance in this pest. In this study, the time-related effects of thermal stress treatments at relatively high temperatures on the activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), peroxidases (POD), glutathione-S-transferases (GST) and malondialdehyde (MDA), of L. bostrychophila were determined. Thermal stress resulted that L. bostrychophila had a significantly higher MDA concentration at 42.5 °C, which indicated that the heat stress increased lipid peroxidation (LPO) contents and oxidative stress in this psocid pest. Heat stress also resulted in significant elevation of SOD, CAT and GST activities but decreased POD activity. Our data indicates that different antioxidant enzymes contribute to defense mechanisms, counteracting oxidative damage in varying levels. POD play minor roles in scavenging deleterious LPO, while enhanced SOD, CAT and GST activities in response to thermal stress likely play a more important role against oxidative damage. Here, we firstly identified five LbHsps (four LbHsp70s and one LbHsp110) from psocids, and most of these LbHsps (except LbHsp70-1) are highly expressed at fourth instar nymph and adults, and LbHsp70-1 likely presents as a cognate form of HSP due to its non-significant changes of expression. Most LbHsp70s (except LbHsp70-4) are significantly induced at moderate high temperatures (<40 °C) and decreased at extreme high temperatures (40–45 °C), but LbHsp110-1 can be significantly induced at all high temperatures. Results of this study suggest that the LbHsp70s and LbHsp110 genes are involved in tolerance to thermal stress in L. bostrychophila, and antioxidant enzymes and heat shock proteins may be coordinately involved in the tolerance to thermal stress in psocids.

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Response of antioxidant enzymes in Mythimna separata (Lepidoptera: Noctuidae) exposed to thermal stress

Bulletin of Entomological Research ◽

10.1017/s0007485316001000 ◽

2016 ◽

Vol 107 (3) ◽

pp. 382-390 ◽

Cited By ~ 17

Author(s):

A. Ali ◽

M. A. Rashid ◽

Q. Y. Huang ◽

C. Wong ◽

C.-L. Lei

Keyword(s):

Antioxidant Enzymes ◽

Thermal Stress ◽

Oxidative Damage ◽

High Temperatures ◽

Stress Responses ◽

Physiological Stress ◽

Southern China ◽

Northern China ◽

Mythimna Separata ◽

Lepidoptera Noctuidae

AbstractThe oriental army worm Mythimna separata (Lepidoptera: Noctuidae) is a migratory pest in Eastern Asia and China. Seasonal high temperatures in Southern China and low temperatures in Northern China are pressures favouring the annual migration of this species, while cold tolerance determines the northern limit of its overwintering range. A number of physiological stress responses occur in insects as a result of variations in temperature. One reaction to thermal stress is the generation of reactive oxygen species (ROS), which can be harmful by causing oxidative damage. The time-related effects (durations of 1, 4 and 7 h) of thermal stress treatments of M. separata at comparatively low (5, 10, 15 and 20°C) and high (30, 35, 40 and 45°C) temperatures on the activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), peroxidase (POX) and glutathione S-transferases (GSTs), and total antioxidant capacity (T-AOC) were determined. Thermal stress resulted in significant elevation of the activities of SOD, CAT and GSTs, indicating that these enzymes contribute to defence mechanisms counteracting oxidative damage caused by an increase in ROS. However, at high-temperatures, POX and T-AOC were also found to contribute to scavenging ROS. Our results also indicate that extreme temperatures lead to elevated ROS production in M. separata. The present study confirms that thermal stress can be responsible for oxidative damage. To overcome such stress, antioxidant enzymes play key roles in diminishing oxidative damage in M. separata.

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First instance of settlement by cryopreserved coral larvae in symbiotic association with dinoflagellates

Scientific Reports ◽

10.1038/s41598-019-55374-6 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 1

Author(s):

Luca Cirino ◽

Zhi-Hong Wen ◽

Kevin Hsieh ◽

Cheng-Liang Huang ◽

Qi Lun Leong ◽

...

Keyword(s):

Pulse Width ◽

Human Impacts ◽

Marine Species ◽

Global Scale ◽

Final Concentration ◽

Symbiotic Association ◽

Beam Diameter ◽

Coral Larvae ◽

Algal Symbionts ◽

Characteristic Wavelength

AbstractCoral reefs are suffering on a global scale due to human impacts, thereby necessitating cryopreservation efforts. The objective of this study was to develop a suitable vitrification and laser warming protocol for larvae of the scleractinian coral Seriatopora caliendrum, which inherit their dinoflagellate algal symbionts vertically. Toxicity experiments were conducted with the cryoprotectants (CPAs) ethylene glycol (EG), propylene glycol (PG), dimethyl sulfoxide (DMSO), glycerol (GLY), and methanol (METH; listed in order from least to most toxic), and larvae were subjected to vitrification and laser warming using 2 M EG + 1 M PG and 2 M EG + 1 M DMSO. Vitrification and laser warming (300 V, 10 ms pulse width, 2 mm beam diameter) using a vitrification solution of 2 M EG + 1 M PG, 40% w/v Ficoll, and 10% v/v gold nanobars (GNB) at a final concentration of 1.2 × 1018 GNB/mL and a characteristic wavelength of 535 nm resulted in larvae with vitality and settlement percentages of 55 and 9%, respectively. This represents the first successful instance of cryopreservation of coral larvae that proceeded to settle upon warming, and suggests that the vitrification and ultra-fast laser warming approach may be applicable to other threatened marine species.

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Erythrophagocytosis in the Liver in Hemolytic Anemias

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100100664 ◽

1968 ◽

Vol 26 ◽

pp. 184-185

Author(s):

O. T. Minick ◽

E. Orfei ◽

F. Volini ◽

G. Kent

Keyword(s):

Acid Phosphatase ◽

Oxidative Damage ◽

Phosphatase Activity ◽

Kupffer Cells ◽

Acid Phosphatase Activity ◽

Common Type ◽

Red Cell ◽

Cell Fragments ◽

Reticulo Endothelial System ◽

Important Site

Hemolytic anemias were produced in rats by administering phenylhydrazine or anti-erythrocytic (rooster) serum, the latter having agglutinin and hemolysin titers exceeding 1:1000.Following administration of phenylhydrazine, the erythrocytes undergo oxidative damage and are removed from the circulation by the cells of the reticulo-endothelial system, predominantly by the spleen. With increasing dosage or if animals are splenectomized, the Kupffer cells become an important site of sequestration and are greatly hypertrophied. Whole red cells are the most common type engulfed; they are broken down in digestive vacuoles, as shown by the presence of acid phosphatase activity (Fig. 1). Heinz body material and membranes persist longer than native hemoglobin. With larger doses of phenylhydrazine, erythrocytes undergo intravascular fragmentation, and the particles phagocytized are now mainly red cell fragments of varying sizes (Fig. 2).

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In situ REM imaging of surface processes on ceramic bulk crystals from 300 to 1670 K in a conventional TEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100087616 ◽

1991 ◽

Vol 49 ◽

pp. 660-661

Author(s):

Z. L. Wang ◽

J. Bentley

Keyword(s):

High Temperatures ◽

Image Resolution ◽

Atomic Processes ◽

Crystal Surfaces ◽

Beam Radiation ◽

Surface Areas ◽

Transmission Electron ◽

Reflection Electron Microscopy ◽

Gas Reactions

Studying the behavior of surfaces at high temperatures is of great importance for understanding the properties of ceramics and associated surface-gas reactions. Atomic processes occurring on bulk crystal surfaces at high temperatures can be recorded by reflection electron microscopy (REM) in a conventional transmission electron microscope (TEM) with relatively high resolution, because REM is especially sensitive to atomic-height steps.Improved REM image resolution with a FEG: Cleaved surfaces of a-alumina (012) exhibit atomic flatness with steps of height about 5 Å, determined by reference to a screw (or near screw) dislocation with a presumed Burgers vector of b = (1/3)<012> (see Fig. 1). Steps of heights less than about 0.8 Å can be clearly resolved only with a field emission gun (FEG) (Fig. 2). The small steps are formed by the surface oscillating between the closely packed O and Al stacking layers. The bands of dark contrast (Fig. 2b) are the result of beam radiation damage to surface areas initially terminated with O ions.

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Protective effect of chitooligosaccharides on hydrogen peroxide-induced PC-12 cells death by inhibition of oxidative damage

Cell Biology International ◽

10.1042/cbi034s027d ◽

2010 ◽

Vol 34 (8) ◽

pp. S27-S27

Author(s):

Xueling Dai ◽

Ping Chang ◽

Ke Xu ◽

Changjun Lin ◽

Hanchang Huang ◽

...

Keyword(s):

Hydrogen Peroxide ◽

Oxidative Damage ◽

Protective Effect ◽

Pc 12 Cells ◽

Cells Death

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Aging and Oxidative Damage: Are Telomeres the Target?

Comments® on Theoretical Biology ◽

10.1080/08948550214391 ◽

2002 ◽

Vol 7 (5) ◽

pp. 295-313 ◽

Cited By ~ 1

Author(s):

Patricia A. McChesney ◽

Lynne W. Elmore ◽

Shawn E. Holt

Keyword(s):

Oxidative Damage

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Melatonin reduces high levels of lipid peroxidation induced by potassium iodate in porcine thyroid

International Journal for Vitamin and Nutrition Research ◽

10.1024/0300-9831/a000628 ◽

2019 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Paulina Iwan ◽

Jan Stepniak ◽

Malgorzata Karbownik-Lewinska

Keyword(s):

Lipid Peroxidation ◽

Oxidative Damage ◽

Membrane Lipids ◽

Chemical Properties ◽

Iodine Concentration ◽

Free Radical Scavenger ◽

Radical Scavenger ◽

Protective Effects ◽

Potassium Iodate ◽

Hormone Synthesis

Abstract. Iodine is essential for thyroid hormone synthesis. Under normal iodine supply, calculated physiological iodine concentration in the thyroid is approx. 9 mM. Either potassium iodide (KI) or potassium iodate (KIO3) are used in iodine prophylaxis. KI is confirmed as absolutely safe. KIO3 possesses chemical properties suggesting its potential toxicity. Melatonin (N-acetyl-5-methoxytryptamine) is an effective antioxidant and free radical scavenger. Study aims: to evaluate potential protective effects of melatonin against oxidative damage to membrane lipids (lipid peroxidation, LPO) induced by KI or KIO3 in porcine thyroid. Homogenates of twenty four (24) thyroids were incubated in presence of either KI or KIO3 without/with melatonin (5 mM). As melatonin was not effective against KI-induced LPO, in the next step only KIO3 was used. Homogenates were incubated in presence of KIO3 (200; 100; 50; 25; 20; 15; 10; 7.5; 5.0; 2.5; 1.25 mM) without/with melatonin or 17ß-estradiol. Five experiments were performed with different concentrations of melatonin (5.0; 2.5; 1.25; 1.0; 0.625 mM) and one with 17ß-estradiol (1.0 mM). Malondialdehyde + 4-hydroxyalkenals (MDA + 4-HDA) concentration (LPO index) was measured spectrophotometrically. KIO3 increased LPO with the strongest damaging effect (MDA + 4-HDA level: ≈1.28 nmol/mg protein, p < 0.05) revealed at concentrations of around 15 mM, thus corresponding to physiological iodine concentrations in the thyroid. Melatonin reduced LPO (MDA + 4-HDA levels: from ≈0.97 to ≈0,76 and from ≈0,64 to ≈0,49 nmol/mg protein, p < 0.05) induced by KIO3 at concentrations of 10 mM or 7.5 mM. Conclusion: Melatonin can reduce very strong oxidative damage to membrane lipids caused by KIO3 used in doses resulting in physiological iodine concentrations in the thyroid.

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