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Effects of Simulated Heat Wave on Oxidative Physiology and Immunity in Asian Yellow Pond turtle (Mauremys mutica)

FRONTIERS IN ECOLOGY AND EVOLUTION 2021年 9卷

作者： Li, Shuran Li, Jinhuan Chen, Wei Xu, Zhiwang Xie, Lei Zhang, Yongpu Wenzhou Univ Coll Life & Environm Sci Wenzhou Peoples R China

Global warming has led to an increase in the frequency, duration, and intensity of heat waves in the summer, which can cause frequent and acute heat stress on ectotherms. Thus, determining how ectothermic animals respond to heat waves has been attracting growing interest among ecologists. However, the physiological and biochemical responses to heat waves in reptiles, especially aquatic reptiles, are still poorly understood. The current study investigated the oxidant physiology, immunity, and expression levels of heat shock proteins (HSP) mRNA after exposure to a simulated heat wave (1 week, 35 +/- 4 degrees C), followed by a recovery period (1 week, 28 +/- 4 degrees C) in juvenile Asian yellow pond turtle (Mauremys mutica), a widely farmed aquatic turtle in East Asia. The contents of malondialdehyde (MDA) in the liver and muscle were not significantly affected by the heat wave or recovery. Of all antioxidant enzymes, only the activity of glutathione peroxidase (GSH-Px) in muscles increased after heat wave, while the total superoxide dismutase (T-SOD), catalase activity (CAT), and total antioxidant capacity (T-AOC) did not change during the study. The organo-somatic index for the liver and spleen of M. mutica decreased after the heat wave but increased to the initial level after recovery. In contrast, plasma lysozyme activity and serum complement C4 levels increased after the heat wave, returning to the control level after recovery. In addition, heat waves did not alter the relative expression of HSP60, HSP70, and HSP90 mRNA in the liver. Eventually, heat wave slightly increased the IBR/n index. Therefore, our results suggested that heat waves did not lead to oxidative damage to lipids in M. mutica, but deleteriously affected the turtles' immune organs. Meanwhile, the constitutive levels of most antioxidative enzyme activities, HSPs and enhanced blood immune functions might protect the turtles from the threat of heat waves under the current climate scenarios.

关键词： climate warming heat wave turtle oxidative stress immune function heat shock proteins

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Ecological effects of major injuries in diamondback terrapins: implications for conservation and management

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AQUATIC CONSERVATION-MARINE AND FRESHWATER ECOSYSTEMS 2009年第4期19卷 421-427页

作者： Cecala, K. K. Gibbons, J. W. Dorcas, M. E. Davidson Coll Dept Biol Davidson NC 28035 USA Univ Georgia Savannah River Ecol Lab Aiken SC 29802 USA

1. Many turtle species frequently suffer major injuries due to attempted predation or anthropogenic factors. Diamondback terrapins (Malaclemys terrapin) are one species known to be affected by anthropogenic activity, but little is known about the Causes of injuries. In declining diamondback terrapin populations, learning more about causes and results of injuries can be helpful in developing sound management plans. 2. Patterns of limb loss and major shell injuries;were examined in a population of terrapins Studied for 24 years at Kiawah Island, South Carolina to infer the causes and effects of injuries and possible predators on terrapins. 3. The rate of Shell injuries increased temporally, possibly as a result of increased watercraft activity. Because no differences in rates of limb loss were found between males and females, limb loss probably results from aquatic encounters (i.e. limb loss does not appear to be the result of terrestrial predation during nesting). Furthermore, males experienced reduced body condition When injured, and terrapins with a major injury had lower survivorship than uninjured terrapins. 4. Therefore, in addition to reducing sources of mortality and protecting nesting habitat, measures to Protect terrapins from watereraft activity may increase the survivorship of adult terrapins. Copyright (c) 2008 by John Wiley & Sons, Ltd.

关键词： Malaclemys terrapin limb loss shell injury turtle salt marsh survivorship

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Dynamics and sources of response variability and its coordination in visual cortex

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VISUAL NEUROSCIENCE 2019年 36卷 E013-E013页

作者： Hoseini, Mahmood S. Wright, Nathaniel C. Xia, Ji Clawson, Wesley Shew, Woodrow Wessel, Ralf Washington Univ Dept Phys St Louis MO 63130 USA Univ Arkansas Dept Elect Engn Fayetteville AR 72701 USA Univ Arkansas Dept Phys Fayetteville AR 72701 USA Univ Calif San Francisco Ctr Integrat Neurosci Dept Physiol 675 Nelson Rising Lane San Francisco CA 94143 USA

The trial-to-trial response variability in sensory cortices and the extent to which this variability can be coordinated among cortical units have strong implications for cortical signal processing. Yet, little is known about the relative contributions and dynamics of defined sources to the cortical response variability and their correlations across cortical units. To fill this knowledge gap, here we obtained and analyzed multisite local field potential (LFP) recordings from visual cortex of turtles in response to repeated naturalistic movie clips and decomposed cortical across-trial LFP response variability into three defined sources, namely, input, network, and local fluctuations. We found that input fluctuations dominate cortical response variability immediately following stimulus onset, whereas network fluctuations dominate the response variability in the steady state during continued visual stimulation. Concurrently, we found that the network fluctuations dominate the correlations of the variability during the ongoing and steady-state epochs, but not immediately following stimulus onset. Furthermore, simulations of various model networks indicated that (i) synaptic time constants, leading to oscillatory activity, and (ii) synaptic clustering and synaptic depression, leading to spatially constrained pockets of coherent activity, are both essential features of cortical circuits to mediate the observed relative contributions and dynamics of input, network, and local fluctuations to the cortical LFP response variability and their correlations across recording sites. In conclusion, these results show how a melange of multiscale thalamocortical circuit features mediate a complex stimulus-modulated cortical activity that, when naively related to the visual stimulus alone, appears disguised as high and coordinated across-trial response variability.

关键词： Response variability Visual cortex turtle Correlation Local field potential

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Levels of organochlorine pesticides in Amazon turtle (Podocnemis unifilis) in the Xingu River, Brazil

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JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH PART B-PESTICIDES FOOD CONTAMINANTS AND AGRICULTURAL WASTES 2018年第12期53卷 810-816页

作者： Pignati, Marina Teofilo De Souza, Larissa Costa Mendes, Rosivaldo de Alcantara Lima, Marcelo de Oliveira Pignati, Wanderlei Antonio Brito Pezzuti, Juarez Carlos Univ Fed Para Programa Posgrad Zool BR-66077530 Belem Para Brazil Museu Paraense Emilio Goeldi CZO BR-66077530 Belem Para Brazil Inst Evandro Chagas Secao Meio Ambinte Lab Toxicol Ananindeua Brazil Univ Fed Mato Grosso Inst Saude Colet Cuiaba Brazil Univ Fed Para Nucleo Altos Estudos Amazon Belem Para Brazil

Due to the toxicity and high environmental persistence of organochlorine pesticides in aquatic organisms, turtles have been studied as environment biomonitors. These animals are important sources of protein for the riverside and indigenous peoples of the Brazilian amazon. In the present study, organochlorine pesticide contamination was investigated in Podocnemis unifilis. Liver, muscle and fatty tissue samples were removed from 50 specimens collected from five sampling points located in the Xingu River basin. Fourteen organochlorine pesticides were analysed via gas chromatography with an electron capture detector (CG-ECD). Eight organochlorine pesticides were detected with average concentrations of n-ary sumation DDT, n-ary sumation Endossulfan and n-ary sumation HCH which were 26.17 +/- 26.35, 14.38 +/- 23.77 and 1.39 +/- 8.46 ng g(-1) in moisture content, respectively. DDT compounds were the most predominant, with a greater concentration of pp '-DDT in the liver and pp '-DDD in the muscle. Significant differences were noted between the types of tissues studied, and the concentration of OCPs varied between sampling sites.

关键词： Contamination organochlorine pesticide toxicity Podocnemis unifilis turtle Xingu River

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Temperature fluctuations and maternal estrogens as critical factors for understanding temperature-dependent sex determination in nature

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JOURNAL OF EXPERIMENTAL ZOOLOGY PART A-ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2018年第4-5期329卷 177-184页

作者： Bowden, Rachel M. Paitz, Ryan T. Illinois State Univ Sch Biol Sci Normal IL 61790 USA

Vertebrates with temperature-dependent sex determination (TSD) have justifiably received a lot of attention when it comes to the potential effects of climate change. Freshwater turtles have long been used to characterize the physiological and genetic mechanisms underlying TSD and provide a great system to investigate how changing climatic conditions will affect vertebrates with TSD. Unfortunately, most of what we know about the mechanisms underlying TSD comes from laboratory conditions that do not accurately mimic natural conditions (i.e., constant incubation temperatures and supraphysiological steroid manipulations). In this paper, we review recent advances in our understanding of how TSD operates in nature that arose from studies using more natural fluctuating incubation temperatures and natural variation in maternal estrogens within the yolk. By incorporating more natural conditions into laboratory studies, we are better able to use these studies to predict how changing climatic conditions will affect species with TSD.

关键词： estrogens sex ratios temperature fluctuations turtle

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GABA-mediated component in the feedback response of turtle retinal cones

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VISUAL NEUROSCIENCE 2005年第3期22卷 317-324页

作者： Tatsukawa, T Hirasawa, H Kaneko, A Kaneda, M Keio Univ Sch Med Dept Physiol Shinjuku Ku Tokyo 1608582 Japan

The negative feedback from horizontal cells to cone photoreceptors contributes to the formation of the receptive-field surround in cone photoreceptors. Recently, studies on the modulation of voltage-gated Ca2+ currents in cone photoreceptors have led to great progress in our understanding of the mechanism of horizontal-cone feedback. Another highly probable hypothesis is that GABA mediates this feedback. This hypothesis is supported by the facts that cone photoreceptors respond to GABA and that horizontal cells release GABA. However, GABA-mediated synaptic inputs from horizontal cells to cone photoreceptors have not been demonstrated. In the present study, we examined whether cone photoreceptors receive GABAergic inputs from horizontal cells using a slice patch technique in the turtle retina. When I mM of GABA was applied to the cone photoreceptors, GABA-induced currents were activated. GABA-induced currents reversed their polarity at the equilibrium potential of Cl-. The application of 30 mu M of SR95531, an antagonist of GABA(A) receptors, alone did not produce any change in the holding currents. When 200 mu M of pentobarbital was introduced to potentiate the GABAergic inputs to the cone photoreceptors, however, the inhibitory action of SR95531 on GABAergic inputs became detectable. The amplitude of the GABAergic inputs, potentiated by pentobarbital, increased when the horizontal cells were depolarized by the application of 20 mu M of kainate, while the amplitude decreased when the horizontal cells were hyperpolarized by the application of 10 mu M of CNQX. When the cone photoreceptors were voltage clamped at a potential at which the voltage-gated Ca2+ current was inactive, horizontal-cone feedback was not observed. However, the horizontal-cone feedback became detectable when the GABAergic inputs to the cone photoreceptors were potentiated by pentobarbital. We concluded that the contribution of GABAergic inputs from horizontal cells to cone pedicles in the formatio

关键词： GABA cone photoreceptor horizontal cell retina turtle

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Does predator swamping promote synchronous emergence of turtle hatchlings among nests?

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BEHAVIORAL ECOLOGY 2008年第1期19卷 35-40页

作者： Tucker, John K. Paukstis, Gary L. Janzen, Fredric J. Illinois Nat Hist Survey Great Rivers Field Stn Brighton IL 62012 USA Iowa State Univ Dept Ecol Evolut & Organismal Biol Ames IA 50011 USA

The spatial and temporal synchrony observed for many behaviors is often viewed as deriving from selection to swamp predators, ensuring that at least some individual prey survive. However, this adaptive explanation has rarely been put to experimental test. We conducted 2 field experiments to evaluate the importance of alternative mechanisms (predator swamping and prey switching) to explain synchronous emergence among nests by red-eared slider turtle hatchlings (Trachemys scripta elegans) that initiates the critical migration from nests to water. In the 1998 experiment, we released 1400 hatchlings simultaneously and allowed another 1400 hatchlings to emerge independently from artificial nests. Hatchlings emerging from nests were just as likely to be recaptured as those in the mass release. Moreover, survivorship was highest among nests whose hatchlings began emerging early compared with hatchlings that emerged from nests later during migration. In the 2006 experiment, we released 2 groups of 100 hatchlings 8 days apart and a third group of 300 hatchlings 13 days later. We recaptured more than twice as many hatchlings from the first group as from the similar sized second group and from the larger third group. If the predator swamping mechanism had been important, we should have seen improved survivorship for the hatchlings in the mass release in the first experiment and for hatchlings in the third group in the second experiment. Overall, the results reject predator swamping as an explanation. Our findings instead suggest that synchronous emergence of turtle hatchlings from nests across a population maximizes individual survival by minimizing exposure to prey-switching predators.

关键词： body size hatchling behavior natural selection predation risk survivorship synchrony turtle

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Aural abscesses in wild-caught box turtles (Terapene carolina):: Possible role of organochlorine-induced hypovitaminosis A

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ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2001年第1期48卷 99-106页

作者： Holladay, SD Wolf, JC Smith, SA Jones, DE Robertson, JL Virginia Polytech Inst & State Univ Virginia Maryland Reg Coll Vet Med Dept Biomed Sci & Pathobiol Blacksburg VA 24061 USA

Wild-caught box turtles (Terapene carolina carolina) with aural abscesses were observed over a period of several years. Histopathologic evaluation of epithelial tissues (conjunctiva, pharynx, trachea, auditory tube) revealed mucosal hyperplasia and squamous metaplasia, and accumulated keratin-like material in the middle ear cavity. These manifestations suggested the possibility of vitamin A deficiency. A nonsignificant trend toward reduced serum and hepatic vitamin A levels was observed in turtles with abscesses (mean serum and hepatic vitamin A levels 71 and 49% of respective levels in turtles without abscesses). Three organochlorine (OC) compounds (alpha -benzene hexachloride, heptachlor epoxide, and oxychlordane) and total (mug/g) OC compounds were significantly higher in turtles with abscesses compared with turtles without abscesses. No OC compounds were higher in turtles without abscesses compared with turtles with abscesses, These data suggest a possible effect of environmental chemicals on metabolism or utilization of vitamin A in wild box turtles, resulting in hypovitaminosis A. (C) 2001 academic Press.

关键词： turtle organochlorine aural abscess squamous metaplasia vitamin A

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New Number One Predator of turtle Eggs

Australian marine science bulletin

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Australian marine science bulletin 2018年第TN.202期 47-47页

Goannas have overtaken foxes as the number one predator of the endangered loggerhead turtle at its second-largest Queensland nesting beach, according to new research published in Austral Ecology . University of Queensland researchers Juan Lei and Dr David Booth worked with turtle Care Queensland Inc to monitor predator disturbance of nests at Wreck Rock beach, south of Agnes Waters. They found that predators disturb up to 400 nests at the beach in a single year. “We discovered that only large male yellow-spotted goannas dug open sea turtle nests, but once the nest was opened other lizards, such as lace monitors and smaller yellow-spotted goannas, raided them,” said Dr Booth.

关键词： Caretta caretta turtle Sea turtles nests beach Queensland Fox Lizard turtles Predators

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PRIMARY AFFERENT-PROJECTIONS TO THE SPINAL-CORD AND THE DORSAL COLUMN NUCLEAR-COMPLEX IN THE turtle PSEUDEMYS

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ANATOMY AND EMBRYOLOGY 1983年第2期166卷 229-245页

作者： KUNZLE, H WOODSON, W 1. Institute for Brain Research University of Zürich CH-8029 Zürich Switzerland

Primary afferent projections from cervical and lumbar levels were studied in the turtle Pseudemys scripta elegans. Injections of radioactive amino acids, wheat germ agglutinin and horseradish peroxidase were made into the dorsal root ganglia or the spinal cord. Previous reports on the terminal distribution of primary afferents within the ipsilateral segment of entry were confirmed (Kusuma and ten Donkelaar 1979, 1980) and additional dorsal root projections were demonstrated to the contralateral side and to several neighboring spinal segments. The primary afferent projections to the brainstem were essentially restricted to a dorsolateral area that appears to be homologous to the main dorsal column nuclei (n. gracilis and n. cuneatus medialis) in mammals. While exhibiting a similarly extensive rostro-caudal span, the projections originating from lumbar injections terminated more medially, those from cervical injections more laterally. The labeling pattern suggested that terminations are mainly on dorsally extending dendrites.

关键词： Dorsal root projections Spinal cord Dorsal column nuclear complex Vestibular complex turtle

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