Influence Of Thermal Acclimation Research Articles

温度驯化对红耳滑龟幼龟选择体温、热耐受性和抗氧化酶活性的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 温度驯化对红耳滑龟幼龟选择体温、热耐受性和抗氧化酶活性的影响 DOI: 10.5846/stxb201408101597 作者: 作者单位: 温州大学 生命与环境科学学院,温州大学 生命与环境科学学院,温州大学 生命与环境科学学院,温州大学 生命与环境科学学院,温州大学 生命与环境科学学院,温州大学 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目(31170376);浙江省大学生科技创新活动计划(2013R424029);温州大学实验室开放项目(12SK56A) Influence of temperature acclimation on selected body temperature, thermal tolerance, and antioxidant enzyme activity of juvenile red-eared slider turtles (Trachemys scripta elegans) Author: Affiliation: College of Life and Environmental Sciences,Wenzhou University,College of Life and Environmental Sciences,Wenzhou University,College of Life and Environmental Sciences,Wenzhou University,College of Life and Environmental Sciences,Wenzhou University,College of Life and Environmental Sciences,Wenzhou University,College of Life and Environmental Sciences,Wenzhou University Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:温度驯化对变温动物的生理和行为表现会产生重要影响,不同物种的驯化反应不尽相同。红耳滑龟(Trachemys scripta elegans)为外来入侵种,在中国许多地区发现了野外种群,对当地生物多样性产生了一定程度的威胁。为了探讨红耳滑龟幼体的热适应表现,在5个恒定温度(16,20,26,32℃和36℃)下驯化幼龟30d后,检验幼龟的选择体温(Tsel),耐受低温(CTMin)、耐受高温(CTMax)和耐受温度范围(TRR),以及骨骼肌、心肌和肝脏的过氧化物岐化酶(SOD)活力、过氧化氢酶(CAT)活力和丙二醛(MDA)含量是否受驯化温度影响。结果显示:驯化温度显著影响幼龟的Tsel、CTMin和CTMax,并随驯化温度的升高而升高,但对TRR无显著影响。驯化温度显著影响骨骼肌、心肌和肝脏的SOD活力。驯化温度显著影响肝脏的MDA含量,而对骨骼肌和心肌的MDA含量无显著影响。驯化温度显著影响心肌和肝脏的CAT活力,对骨骼肌CAT活力无显著影响。以上结果表明:温度驯化会影响红耳滑龟幼体选择体温和热耐受能力,符合越热越好假设;同时会影响组织的抗氧化能力。 Abstract:As an important environmental factor, temperature affects the growth, reproduction, physiology, behavior, and offspring phenotype of reptiles. The influence of thermal acclimation on physiological and behavioral performance has been documented in many ectotherm animals, although the acclimation responses of different species may be not identical. The red-eared slider turtle (Trachemys scripta elegans) is an alien invasive species found in China. Wild populations have been found to be a threat to local biodiversity in many areas. In this paper, critical thermal minima (CTMin) and critical thermal maxima (CTMax) are used to assess the thermal resistance of juvenile red-eared slider turtles. In addition, the selected body temperature (Tsel) is used to determine the species' preferred temperature. Our study aimed to determine whether acclimation temperature would affect the Tsel, CTMin, CTMax, thermal resistance range (TRR), the activity of superoxide dismutase (SOD) and catalase (CAT), and the malondialdehyde (MDA) content of the skeletal muscles, cardiac muscles, and liver. In order to examine their thermal adaptive performance at different temperatures, we selected 90 juvenile turtles weighing between 40.0 and 44.3 g, randomly divided them into 5 groups with similar average weights (P=0.141), and acclimated them to five thermal conditions (16, 20, 26, 32℃ and 36℃) for 30 days. After acclimation, Tsel were measured using a thermometer (UT-325) in thermal gradient groove, while CTMin and CTMax were measured in binder incubators. SOD and CAT activity, as well as the MDA content were measured using commercial kits produced by Jiancheng Biotech Co. Ltd., Nanjing, China, according to the manufacturer's instructions. Then, a one-way ANOVA was used to test the effects of acclimation temperature on Tsel, CTMin, CTMax, TRR, SOD and CAT activity, and the MDA content of different tissues. The results showed that acclimation temperature had significant effects on the Tsel (P < 0.0001), CTMin (P < 0.0001), and CTMax (P < 0.01) of juvenile turtles, but had no significant effect on the TRR (P=0.212). Tsel, CTMin, and CTMax increased with acclimation temperature. Acclimation temperature had a significant impact on SOD activity in the skeletal muscles, cardiac muscles, and liver, as well as on the MDA content of the liver (all P < 0.05). However, it had no effect on the MDA content of the skeletal and cardiac muscles (all P > 0.05). There was higher SOD activity in the skeletal and cardiac muscles at high temperatures (26-36℃) than at low temperatures (16-20℃); meanwhile, in the liver, higher SOD activity and MDA content were observed at medium temperatures (20-32℃). Acclimation temperature had a significant effect on CAT activity in the cardiac muscles and liver (all P < 0.05), but no effect on that in skeletal muscles (P=0.55). In cardiac muscles, CAT activity was significantly lower at 36℃ than at other temperatures, while in the liver CAT activity peaked at 16℃. This indicates that acclimation temperature affects the selected body temperature and thermal tolerance of juvenile red-eared slider turtles, with higher temperatures generally having more favorable effects. The antioxidant activity in the tissues was also affected by differences in acclimation temperature. 参考文献 相似文献 引证文献

The Influence of Acclimation Temperature on the Lipid Composition of the Larval Lamprey,Petromyzon marinus, Depends on Tissue and Lipid Class

This study was designed to examine the effect of thermal acclimation on the lipid composition of fat depot organs the liver and kidneys of larval sea lamprey, Petromyzon marinus. We found that 21 °C-acclimated larvae possessed lower total lipid amounts in the liver (39% lower) and kidneys (30% lower) than 13 °C-acclimated larvae. Relatively lower lipid contents in the liver and kidneys of 21 °C-acclimated lamprey primarily resulted from a reduction in stored lipid reserve, triacylglycerol, but not the structural lipid, phospholipid. Compared to 21 °C-acclimated larvae, 13 °C-acclimated larvae were found to possess fewer saturated fatty acids (SFAs) and more unsaturated fatty acids (USFAs) in renal triacylglycerol and phospholipid classes, while there were no significant differences in the SFAs and USFAs of hepatic triacylglycerol, phospholipid, cholesteryl ester, fatty acid, and monoacylglycerol classes. Fewer SFAs, found in the kidney triacylglycerol of 13 °C-acclimated lamprey, were due to lower 12:0 and 14:0 fatty acids, but those in the renal phospholipid class were characterized by fewer 14:0, 15:0, and 16:0 fatty acids. More USFAs in renal triacylglycerol, as indicated by a higher unsaturation index, primarily resulted from higher polyunsaturated fatty acids (18:2ω6, 18:3ω3, and 18:4ω3); whereas, in the renal phospholipid class, this was a result of higher monoenes (18:1, 20:1, and 22:1ω9) and ω3 polyunsaturated fatty acids (18:4ω3). These data suggest that the influence of thermal acclimation on the lipid composition of lamprey fat depot organs depends on tissue and lipid class.

Consequences of thermal acclimation for the mating behaviour and swimming performance of female mosquito fish

The mating system of eastern mosquito fish (Gambusia holbrooki) is dominated by male sexual coercion, where all matings are forced and females never appear to cooperate and actively avoid all attempts. Previous research has shown that male G. holbrooki offer a model system for examining the benefits of reversible thermal acclimation for reproductive success, but examining the benefits to female avoidance behaviour has been difficult. In this study, we examined the ability of non-male-deprived female G. holbrooki to avoid forced-coercive matings following acclimation to either 18 or 30 degrees C for six weeks (12h light:12h dark photoperiod). Thermal acclimation of burst and sustained swimming performance was also assessed, as these traits are likely to underlie their ability to avoid forced matings. There was no influence of thermal acclimation on the burst swimming performance of female G. holbrooki over the range 18-30 degrees C; however, sustained swimming performance was significantly lower in the warm- than the cool-acclimation group. For mating behaviour, we tested the hypothesis that acclimation would enhance the ability of female G. holbrooki to avoid forced matings at their host acclimation temperature relative to females acclimated to another environment. However, our hypothesis was not supported. The rate of copulations was almost three times greater for females acclimated to 30 degrees C than 18 degrees C when tested at 30 degrees C, indicating that they possess the ability to alter their avoidance behaviour to 'allow' more copulations in some environments. Coupled with previous studies, female G. holbrooki appear to have greater control on the outcome of coercive mating attempts than previously considered and can alter their propensity to receive forced matings following thermal acclimation. The significance of this change in female mating-avoidance behaviours with thermal acclimation remains to be explored.

The influence of thermal acclimation on power production during swimming. II. Mechanics of scup red muscle under in vivo conditions.

We have previously shown that the power output of red muscle from warm-acclimated scup is greatly reduced when the fish swim at low temperatures. This reduction occurs primarily because, despite the slowing of muscle relaxation rate at cold temperatures, warm-acclimated scup swim with the same tail-beat frequency and the same stimulation durations, thereby not affording the slower-relaxing muscle any extra time to relax. We hypothesize that power output during swimming could be increased if the stimulus duration were reduced or if the relaxation rate of the red muscle were increased during cold acclimation. Scup were acclimated to 10 degrees C (cold-acclimated) and 20 degrees C (warm-acclimated) for at least 6 weeks. Cold acclimation dramatically increased the ability of scup red muscle to produce power at 10 degrees C. Power output measured from cold-acclimated muscle bundles driven through in vivo conditions measured from cold-acclimated scup swimming at 10 degrees C (i.e. work loops) was generally much greater than that from warm-acclimated muscle driven through its respective in vivo conditions at 10 degrees C. The magnitude of the increase depended both on the anatomical location of the muscle and on swimming speed. Integrated over the length of the fish, the red musculature from cold-acclimated fish generated 2.7, 8.9 and 5.8 times more power than the red musculature from warm-acclimated fish while swimming at 30 cm s(-)(1), 40 cm s(-)(1) and 50 cm s(-)(1), respectively. Our analysis suggests that the cold-acclimated fish should be able to swim in excess of 40 cm s(-)(1) with just their red muscle whereas the warm-acclimated fish must recruit their pink muscle well below this speed. Because the red muscle is more aerobic than the pink muscle, cold acclimation may increase the sustained swimming speed at which scup perform their long seasonal migrations at cool temperatures. We then explored the underlying mechanisms for the increase in muscle power output in cold-acclimated fish. Contrary to our expectations, cold-acclimated muscle did not have a faster relaxation rate; instead, it had an approximately 50 % faster activation rate. Our work-loop studies showed that this faster activation rate, alone, can increase the mechanical power production during cyclical contractions to a surprising extent. By driving cold-acclimated muscle through warm- and cold-acclimated in vivo conditions, we were able to partition the improvement in power production associated with increased activation rate and the approximately 20 % reduction in the duration of electromyographic activity found in the accompanying study. Depending on the position and swimming speed, approximately 60 % of the increase in power output was due to the change in the red muscle's contractile properties (i.e. faster activation); the remainder was due to the shorter stimulus duty cycle of cold-acclimated scup. Thus, by both shortening the in vivo stimulation duration and speeding up the rate of muscle activation as part of cold-acclimation, scup achieve a very large increase in the power output of their red muscle during swimming at low temperature. This increase in power output probably results in an increase in muscle efficiency and, hence, a reduction in the energetic cost of swimming. This increase in power output also reduces reliance on the less aerobic and less fatigue-resistant pink muscle. Both these abilities may increase the swimming speed at which prolonged aerobic muscle activity can occur and thus reduce the travel time for the long seasonal migrations in which scup engage.

The influence of thermal acclimation on power production during swimming. I. In vivo stimulation and length change pattern of scup red muscle.

Ectothermal animals are able to locomote in a kinematically similar manner over a wide range of temperatures. It has long been recognized that there can be a significant reduction in the power output of muscle during swimming at low temperatures because of the reduced steady-state (i.e. constant activation and shortening velocity) power-generating capabilities of muscle. However, an additional reduction in power involves the interplay between the non-steady-state contractile properties of the muscles (i.e. the rates of activation and relaxation) and the in vivo stimulation and length change pattern the muscle undergoes during locomotion. In particular, it has been found that isolated scup (Stenotomus chrysops) red muscle working under in vivo stimulus and length change conditions (measured in warm-acclimated scup swimming at low temperatures) generates very little power for swimming. Even though the relaxation of the muscle has slowed greatly, warm-acclimated fish swim with the same tail-beat frequencies and the same stimulus duty cycles at cold temperatures, thereby not affording the slow-relaxing muscle any extra time to relax. We hypothesize that considerable improvement in the power output of the red muscle at low temperatures could be achieved if cold acclimation resulted in either a faster muscle relaxation rate or in the muscle being given more time to relax (e.g. by shortening the stimulus duration or reducing the tail-beat frequency). We test these hypotheses in this paper and the accompanying paper. Scup were acclimated to 10 degrees C (cold-acclimated) and 20 degrees C (warm-acclimated) for at least 6 weeks. Electromyograms (EMGs) and high-speed cine films were taken of fish swimming steadily at 10 degrees C and 20 degrees C. At 10 degrees C, we found that, although there were no differences in tail-beat frequency, muscle strain or stimulation phase between acclimation groups, cold-acclimated scup had EMG duty cycles approximately 20 % shorter than warm-acclimated scup. In contrast at 20 degrees C, there was no difference between acclimation groups in EMG duty cycle, nor in any other muscle length change or stimulation parameter. Thus, in response to cold acclimation, there appears to be a reduction in EMG duty cycle at low swimming temperatures that is probably due to an alteration in the operation of the pattern generator. This novel acclimation probably improves muscle power output at low temperatures compared with that of warm-acclimated fish, an expectation we test in the accompanying paper using the work-loop technique.

Influence of thermal acclimation on glucose production and ketogenesis in isolated eel hepatocytes.

Hepatocytes were isolated by collagenase perfusion of the liver from adult eels (Anguilla anguilla L.) acclimated to different temperatures. Whereas the relative weight of the liver increased in cold-acclimated fish, hepatocytes from 10- and 20 degrees C-acclimated animals did not differ in cellular weight, dry weight, or protein content. Endogenous rates of oxygen consumption and respiratory control ratios were independent of acclimation temperature. There was no effect of temperature on triacylglycerol content, but glycogen concentration was significantly higher in hepatocytes of cold-acclimated fish. Liver cells from cold-acclimated eels exhibited higher rates of glucose release and ketogenesis than those from warm-acclimated animals. It is concluded that the increase in acetoacetate production induced by cold acclimation results primarily from a higher rate of lipolysis. Cellular interactions between ketogenesis and gluconeogenesis are demonstrated and discussed.

Influence of thermal acclimation on membrane lipid composition of rainbow trout liver

Rainbow trout (Salmo gairdneri) acclimated to 5 degrees C possessed larger livers and less neutral lipid per gram of liver than 20 degrees C-acclimated animals; quantities of liver glycolipid, phospholipid, and cholesterol did not vary significantly with acclimation temperature. The relative proportions of phosphatidylethanolamine increased significantly following cold exposure, whereas the quantities of sphingomyelin and cardiolipin declined. For all phosphatides examined (phosphatidylethanolamine, phosphatidylcholine, phosphatidylserine, phosphatidylinositol, lysolecithin, cardiolipin, sphingomyelin) cold acclimation resulted in 1) an increase in the quantity of polyunsaturated fatty acids, 2) a reduction in the level of saturated fatty acids, and 3) little change in the total content of monoenes and dienes. The increased content of polyunsaturated fatty acids in choline and ethanolamine phosphatides following cold acclimation was confined to the 2-position and occurred at the expense of monoenes and dienes. The relative proportions of n - 3 fatty acids, and less frequently n - 6 fatty acids, increased in phosphatides of cold-acclimated trout, whereas the relative proportions of n - 9 fatty acids declined. These data suggest a preferential incorporation of fatty acids belonging to the linolenic acid family at reduced temperatures. Temperature-induced changes in the chemical composition of trout liver phospholipids counteracted the effects of acute temperature change on nonelectrolyte permeability of isolated liposomes.

Influence of thermal acclimation on oxygen consumption in the agamid garden lizard,Calotes nemoricola jerdon, with reference to size, sex, temperature, season and climatic conditions

1. Oxygen consumption of the tropical agamid species of lizard,Calotes nemoricola was measured at 15, 20, 25, 30, 35 and 40° C using different sized animals in Warburg’s respirometer. It was found that the metabolism increases with weight and temperature but the rate of increase was different at different temperatures.

Effects of thermal acclimation on cable constants of the earthworm median giant axon

1. 1. The influence of thermal acclimation on cable constants of the median giant axon of earthworms, Lumbricus terrestris L., has been studied using standard intracellular stimulating and recording techniques. 2. 2. Acute cooling of axons from warm-acclimated worms resulted in changes in cable constants, some of which were partially compensated for (reversed) after cold acclimation. 3. 3. Of special interest is the relative behavior of specific axoplasm resistance in response to acute temperature change in warm- and cold-acclimated worms. 4. 4. The results suggest that thermal acclimation alters the properties of the axoplasm and that the resulting changes in cable constants contribute to compensatory adjustments in nerve conduction velocity after acclimation.

The influence of thermal acclimation on the relation between oxygen consumption and temperature in Littorina littorea (L.) and Mytilus edulis L.

1. 1. Storage of winkles at raised temperatures results in an increase in the temperature at which the thermal optima of the active and standard rates of oxygen consumption occurs. 2. 2. The temperature range over which metabolic compensation of the standard rate occurs is also controlled by the acclimation temperature. 3. 3. At least two phenomena accompany the process of thermal acclimation in cell-free homogenates of winkles and mussels. 4. 4. The first, occuring after 2 days, involves alteration in the thermal tolerance or a point beyond which a decline in oxygen consumption occurs. After 7 days a Q 10 of <1.2 is developed.