Publications

anoxia tolerance and freeze tolerance in hatchling turtles.	freezing survival in hatchling turtles may be limited by ischemic anoxia in frozen tissues and the associated accumulation of lactate and reactive oxygen species (ros). to determine whether mechanisms for coping with anoxia are also important in freeze tolerance, we examined the association between capacities for freezing survival and anoxia tolerance in hatchlings of seven species of turtles. tolerance to freezing (-2.5 degrees c) was high in emydoidea blandingii, chrysemys picta, terrapene orn ...	2005	15739066
thalamocortical connections in the pond turtle pseudemys scripta elegans.	thalamocortical connections are a neuroanatomical feature shared among vertebrates, although the extent and organization of these connections vary among species. from an evolutionary standpoint, reptiles represent early stages of the pattern of connectivity between the thalamus and cortex, and elucidation of these pathways may help to reveal the biological significance of these projections. the present tract tracing study was performed to examine the organization of thalamocortical projections i ...	2005	15761219
androgen receptor in the oviduct of the turtle, trachemys scripta.	circulating androgens reach high concentrations in females of some reptiles and amphibians. we are testing the hypothesis that androgens can act directly in female reptilian reproductive tissues, via the androgen receptor. in this study, we sought to determine if androgen receptors are present in the oviduct of the turtle, trachemys scripta, using radioligand-binding assays and immunological assays. an androgen-binding site was detected in turtle oviductal cytosol and oviductal nuclear extract b ...	2005	15820135
purification and properties of the glutathione s-transferases from the anoxia-tolerant turtle, trachemys scripta elegans.	glutathione s-transferases (gsts) play critical roles in detoxification, response to oxidative stress, regeneration of s-thiolated proteins, and catalysis of reactions in nondetoxification metabolic pathways. liver gsts were purified from the anoxia-tolerant turtle, trachemys scripta elegans. purification separated a homodimeric (subunit relative molecular mass =34 kda) and a heterodimeric (subunit relative molecular mass = 32.6 and 36.8 kda) form of gst. the enzymes were purified 23-69-fold and ...	2005	16008560
the bioconcentration factor of perfluorooctane sulfonate is significantly larger than that of perfluorooctanoate in wild turtles (trachemys scripta elegans and chinemys reevesii): an ai river ecological study in japan.	turtles rank high in the river food chain, and are suitable for predicting the bioconcentrations of chemicals through the food chain. trachemys scripta elegans (n=46) and chinemys reevesii (n=51) were captured in a river in japan, from september to october 2003 and april to june 2004. surface water samples were collected simultaneously from the same sites at which the turtles were caught. serum perfluorooctane sulfonate (pfos) ranged from 2.4 to 486 microg/l, while water pfos levels ranged from ...	2006	16040121
temperature, genes, and sex: a comparative view of sex determination in trachemys scripta and mus musculus.	sex determination, the step at which differentiation of males and females is initiated in the embryo, is of central importance to the propagation of species. there is a remarkable diversity of mechanisms by which sex determination is accomplished. in general these mechanisms fall into two categories: genetic sex determination (gsd), which depends on genetic differences between the sexes, and environmental sex determination (esd), which depends on extrinsic cues. in this review we will consider t ...	2005	16046442
spinal cord injury-induced changes in breathing are not due to supraspinal plasticity in turtles (pseudemys scripta).	after occurrence of spinal cord injury, it is not known whether the respiratory rhythm generator undergoes plasticity to compensate for respiratory insufficiency. to test this hypothesis, respiratory variables were measured in adult semiaquatic turtles using a pneumotachograph attached to a breathing chamber on a water-filled tank. turtles breathed room air (2 h) before being challenged with two consecutive 2-h bouts of hypercapnia (2 and 6% co2 or 4 and 8% co2). turtles were spinalized at dorsa ...	2005	16099823
production of monoclonal antibodies against chinemys reevesii turtle vitellogenin and their usage for comparison of biochemical and immunological characters of vitellogenins and yolk proteins of freshwater turtles.	four hybridoma clones (acv-1, -3, -4, and -5) were established for chinemys reevesii (reeves' turtle) vitellogenin (vtg) as a precursor protein of egg yolk and a biomarker of environmental pollution. binding-inhibition experiments indicated that the epitopes of four mabs were distinct. no binding of acv-4 to c. reevesii vtg in the western blot suggests that the epitope of acv-4 would be dependent on the three-dimensional structure. acv-1, -3, and -5 bound to c. reevesii vtg in the western blot. ...	2005	16122960
endocrine and behavioral response to a decline in habitat quality: effects of pond drying on the slider turtle, trachemys scripta.	the effect of the simulated drying of a pond on the behavior and corticosterone secretion of trachemys scripta was measured in a field situation. slider turtles were held in experimental and control ponds (12 x 15 m) enclosed with a drift fence integrated with spring-triggered livetraps. the experimental pond water level was dropped 10 cm per day for 8 d, until water was completely drained. slider turtles responded to the draining of the pond by the emigration of the majority (75%) of the experi ...	2005	16161015
endothelin-1 causes systemic vasodilatation in anaesthetised turtles (trachemys scripta) through activation of etb-receptors.	the effects of endothelin-1 (et-1) on systemic and pulmonary circulation were investigated in anaesthetised freshwater turtles (trachemys scripta) instrumented with arterial catheters and blood flow probes. bolus intra-arterial injections of et-1 (0.4-400 pmol kg(-1)) caused a dose-dependent systemic vasodilatation that was associated with a decrease in systemic pressure (p(sys)) and a rise in systemic blood flow (q(sys)), causing systemic conductance (g(sys)) to increase. et-1 had no significan ...	2005	16169951
hair bundle heights in the utricle: differences between macular locations and hair cell types.	hair bundle structure is a major determinant of bundle mechanics and thus of a hair cell's ability to encode sound and head movement stimuli. little quantitative information about bundle structure is available for vestibular organs. here we characterize hair bundle heights in the utricle of a turtle, trachemys scripta. we visualized bundles from the side using confocal images of utricular slices. we measured kinocilia and stereocilia heights and array length (distance from tall to short end of b ...	2006	16177175
metal accumulation in eggs of the red-eared slider (trachemys scripta elegans) in the lower illinois river.	the illinois river is a highly utilized navigable waterway in the us midwest, and has historically been contaminated with metal toxicants from various industrial and municipal pollution sources. little information on metal contamination is available in the lower illinois river, and in particular, in the habitat of the red-eared slider (trachemys scripta elegans) at the southern end of the river near grafton, il. this study was conducted to determine current levels of metal contamination in water ...	2006	16216308
dmrt1 expression in response to estrogen treatment in a reptile with temperature-dependent sex determination.	dmrt1 has been implicated as an important factor in sex determination in all classes of vertebrates, including reptiles with temperature-dependent sex determination (tsd). specifically, early embryonic expression of dmrt1 appears to be an integral part of normal testicular development in vertebrates. recently, a number of tsd studies have placed dmrt1 expression at the top of a short list of putative temperature-sensitive events for tsd. dmrt1 expression has been shown to be up-regulated at male ...	2006	16217798
vitellogenin detection in caiman latirostris (crocodylia: alligatoridae): a tool to assess environmental estrogen exposure in wildlife.	environmental pollution with endocrine disrupting compounds (edcs) has adverse effects on the ecosystem's health. caiman latirostris are widely distributed in south american aquatic ecosystems. caimans have physiological and ecological characteristics that make them particularly vulnerable to edcs exposure and suitable candidate as a sentinel species. vitellogenin (vtg) is a yolk pre-cursor protein synthesized by the liver of non-mammalian vertebrates and induced in response to estrogen. purifie ...	2006	16292562
housing density and growth in juvenile red-eared turtles.	growth rates in juvenile turtles relate strongly to their health and welfare, both in the wild and in captivity. newly hatched turtles in the wild are subject to such high levels of predation that, in some cases, as few as i % survive their first year of life. juvenile turtles in captivity succumb more quickly to the effects of poor housing conditions and poor diets than do older adults. in both the wild and in captivity, turtles who grow quickly during their first year of life stand a better ch ...	1999	16363952
ontogenetic diet shifts and digestive constraints in the omnivorous freshwater turtle trachemys scripta.	many reptiles undergo an ontogenetic diet shift from carnivory to herbivory. in this study, we used the yellow-bellied slider turtle, trachemys scripta, as a model to evaluate whether juvenile turtles are carnivorous because physiological constraints preclude herbivory. we conducted feeding trials in which we fed juvenile and adult turtles a duckweed plant, lemna valdiviana, or a freshwater grass shrimp, palaemontes paludosus, for 5 wk. during the trials, we measured mass-specific intake, digest ...	2006	16380936
nonadditive interactions between animal and plant diet items in an omnivorous freshwater turtle trachemys scripta.	nonadditive interactions occur when diet items interact with one another such that the net energy or nutrient gain from a mixed diet differs from that predicted by summing the gains from individual diet components. we quantified nonadditive effects between duckweed, lemma valdiviana, and grass shrimp, palaemontes paludosus, in the freshwater turtle trachemys scripta. we fed turtles 100% duckweed, 100% shrimp, and two mixed diets containing 67% duckweed, 33% shrimp and 14% duckweed, 86% shrimp (d ...	2006	16503179
a severe salmonella enterica serotype paratyphi b infection in a child related to a pet turtle, trachemys scripta elegans.	our report highlights a case of severe childhood salmonellosis related to a pet turtle, a red-eared slider (trachemys scripta elegans). a 6-year-old girl had gastroenteritis complicated with sepsis caused by serotype paratyphi b, which shared the same pulsed-field gel electrophoresis profiles with the organism isolated from a pet turtle. based on our literature survey on childhood invasive salmonellosis acquired from reptiles, this case is the first documented reptile-associated salmonellosis in ...	2006	16632917
gene transcription of neuroglobin is upregulated by hypoxia and anoxia in the brain of the anoxia-tolerant turtle trachemys scripta.	neuroglobin is a heme protein expressed in the vertebrate brain in mammals, fishes, and birds. the physiological role of neuroglobin is not completely understood but possibilities include serving as an intracellular oxygen-carrier or oxygen-sensor, as a terminal oxidase to regenerate nad(+) under anaerobic conditions, or involvement in no or ros metabolism. as the vertebrate nervous system is particularly sensitive to hypoxia, an intracellular protein that helps sustain cellular respiration woul ...	2006	16636779
quantitative genetics of plastron shape in slider turtles (trachemys scripta).	shape variation is widespread in nature and embodies both a response to and a source for evolution and natural selection. to detect patterns of shape evolution, one must assess the quantitative genetic underpinnings of shape variation as well as the selective environment that the organisms have experienced. here we used geometric morphometrics to assess variation in plastron shell shape in 1314 neonatal slider turtles (trachemys scripta) from 162 clutches of laboratory-incubated eggs from two ne ...	2006	16637501
the role of the sarcoplasmic reticulum in the generation of high heart rates and blood pressures in reptiles.	the functional significance of the sarcoplasmic reticulum (sr) in the generation of high heart rates and blood pressures was investigated in four species of reptile; the turtle, trachemys scripta; the python, python regius, the tegu lizard, tupinanvis merianae, and the varanid lizard, varanus exanthematicus. force-frequency trials and imposed pauses were performed on ventricular and atrial tissue from each species with and without the sr inhibitor ryanodine, and in the absence and presence of ad ...	2006	16651560
physiological responses to freezing in hatchlings of freeze-tolerant and -intolerant turtles.	freeze tolerance is a complex cold-hardiness adaptation that has independently evolved in a diverse group of organisms, including several ectothermic vertebrates. because little is known about the mechanistic basis for freeze tolerance in reptiles, we compared responses to experimental freezing in winter-acclimatized hatchlings representing nine taxa of temperate north american turtles, including ones that tolerated freezing and others that did not. viability rates of hatchlings frozen to -3 deg ...	2006	16758216
tissue glycogen and extracellular buffering limit the survival of red-eared slider turtles during anoxic submergence at 3 degrees c.	the goal of this study was to identify the factors that limit the survival of the red-eared slider turtle trachemys scripta during long-term anoxic submergence at 3 degrees c. we measured blood acid-base status and tissue lactate and glycogen contents after 13, 29, and 44 d of submergence from ventricle, liver, carapace (lactate only), and four skeletal muscles. we also measured plasma ca(2+), mg(2+), na(+), k(+), cl(-), inorganic phosphate (p(i)), lactate, and glucose. after 44 d, one of the si ...	2016	16826499
benign ovarian teratoma in a red-eared slider turtle (trachemys scripta elegans).		2006	16861392
comparative gene expression of steroidogenic factor 1 in chrysemys picta and apalone mutica turtles with temperature-dependent and genotypic sex determination.	characterizing the molecular network underlying temperature-dependent (tsd) and genotypic (gsd) sex determination, including patterns across closely related taxa, is crucial to elucidate the still enigmatic evolution of sex determining mechanisms in vertebrates. here we examined the expression of an important gene for sexual differentiation common to both systems, sf1, at male- and female-producing temperatures, in tsd (chrysemys picta) and gsd turtles (apalone mutica). we tested the hypotheses ...	2010	16925678
force development at elevated [mg2+]o and [k+]o in myocardium from the freshwater turtle (trachemys scripta) and influence of factors associated with hibernation.	the effects of high [mg(2+)](o) on force development were examined for heart muscle of freshwater turtle. plasma [mg(2+)] during hibernation may increase drastically and like plasma [k(+)] approach values as high as 10 mm. each experiment performed at either 20 or 5 degrees c involved four ventricular preparations of which one pair was exposed to 10, and one to 1 mmmg(2+). one preparation of each pair was furthermore exposed to 10 mm k(+), whereas the other was maintained at 2.5 mm k(+). during ...	2006	16928457
estrogen response system in the reproductive tract of the male turtle: an immunocytochemical study.	portions of the reproductive tract of the male (trachemys scripta) turtle were examined by immunocytochemistry for evidence of the capacity to produce and respond to estrogen hormones (via the expression of p450 aromatase and estrogen receptors). aromatase was detected in both the sertoli and leydig cells of the testis and was expressed at different levels during the spermatogenic cycle, being highest in the quiescent testis and lowest during germ cell meiosis. eralpha was found in the leydig ce ...	2007	16935286
comparative shell buffering properties correlate with anoxia tolerance in freshwater turtles.	freshwater turtles as a group are more resistant to anoxia than other vertebrates, but some species, such as painted turtles, for reasons not fully understood, can remain anoxic at winter temperatures far longer than others. because buffering of lactic acid by the shell of the painted turtle is crucial to its long-term anoxic survival, we have tested the hypothesis that previously described differences in anoxia tolerance of five species of north american freshwater turtles may be explained at l ...	2007	17008457
toxicity of glyphosate as glypro and li700 to red-eared slider (trachemys scripta elegans) embryos and early hatchlings.	more than 8.2 billion ha of cropland, gardens, and forests are treated with the herbicide glyphosate each year. whereas the toxicity of glyphosate and associated adjuvants has been measured in other vertebrates, few, if any, studies have looked at their effects in reptiles. in some instances, management of turtle habitat requires control of successional stages through application of herbicides. adults and juvenile turtles may be exposed directly, whereas embryos may contact the chemicals through ...	2006	17022419
germ cell depletion does not alter the morphogenesis of the fetal testis or ovary in the red-eared slider turtle (trachemys scripta).	in the red-eared slider turtle, trachemys scripta, both prospective male and female gonads contain primitive cord structures at the time when the gonad first forms. primordial germ cells arrive in the gonad and accumulate on the coelomic surface. if testis development is initiated, these cords develop further at the same time that germ cells migrate from the coelomic surface and become sequestered in the interior of the cords. in contrast, in the developing ovary germ cells proliferate in a defi ...	2007	17041961
beyond anoxia: the physiology of metabolic downregulation and recovery in the anoxia-tolerant turtle.	the freshwater turtle trachemys scripta is among the most anoxia-tolerant of vertebrates, a true facultative anaerobe able to survive without oxygen for days at room temperature to weeks or months during winter hibernation. our good friend and colleague peter lutz devoted nearly 25 years to the study of the physiology of anoxia tolerance in these and other model organisms, promoting not just the basic science but also the idea that understanding the physiology and molecular mechanisms behind ano ...	2007	17049896
purification and properties of glutathione reductase from liver of the anoxia-tolerant turtle, trachemys scripta elegans.	glutathione reductase (gr) is a homodimeric flavoprotein that catalyzes the reduction of oxidized glutathione (gssg) using nadph as a cofactor. the enzyme is a major component of cellular defense mechanisms against oxidative injury. in this study, gr was purified from the liver of the anoxia-tolerant turtle, trachemys scripta elegans. the overall fold purifications were 13.3- and 12.1-fold with final specific activities of 5.5 and 1.44 u/mg of protein for control and anoxic turtle gr, respective ...	2007	17075686
effects of ultraviolet radiation on 25-hydroxyvitamin d3 synthesis in red-eared slider turtles (trachemys scripta elegans).	to determine whether there are increased concentrations of 25-hydroxyvitaminn d(3) in red-eared slider turtles (trachemys scripta elegans) after exposure to uv radiation.	2006	17144809
lactate uptake by skeletal bone in anoxic turtles, trachemys scripta.	previous studies have shown that freshwater turtle shells can accumulate lactate during periods of anoxic submergence. our objective in this study was to determine lactate uptake in other parts of the turtle's skeleton. we measured lactate concentration of 7 skeletal elements and 4 shell samples of red-eared slider turtles, trachemys scripta, in control animals (n=12) and in animals following submergence for 4-5 days in n(2)-equilibrated water at 10 degrees c (n=8). we also collected blood sampl ...	2007	17188012
immunohistochemical and hodological characterization of calbindin-d28k-containing neurons in the spinal cord of the turtle, pseudemys scripta elegans.	neurons and fibers containing the calcium-binding protein calbindin-d28k (cb) were studied by immunohistochemical techniques in the spinal cord of adult and juvenile turtles, pseudemys scripta elegans. abundant cell bodies and fibers immunoreactive for cb were widely and distinctly distributed throughout the spinal cord. most neurons and fibers were labeled in the superficial dorsal horn, but numerous cells were also located in the intermediate gray and ventral horn. in the dorsal horn, most cb- ...	2007	17203484
effects of extracellular changes on spontaneous heart rate of normoxia- and anoxia-acclimated turtles (trachemys scripta).	heart rate (f(h)) of the anoxia-tolerant freshwater turtle (trachemys scripta) during prolonged anoxia exposure is 2.5- to 5-times lower than the normoxic rate, but whether alterations in blood composition that accompany prolonged anoxia contribute to this bradycardia is unknown. we examined how temperature acclimation, oxygen deprivation, acidosis, hyperkalemia, hypercalcemia and adrenaline affect chronotropy in the turtle myocardium. we monitored spontaneous contraction rates of right-atrial p ...	2007	17234611
formation of the chondrocranium of trachemys scripta (reptilia: testudines: emydidae) and a comparison with other described turtle taxa.	few descriptions of the formation of the chelonian chondrocranium exist. herein, developmental stages critical to the formation of the chondrocranium of the red-eared slider, trachemys scripta (testudines: emydidae), are described and illustrated, with particular attention given to ontogenetic changes that take place in the orbitotemporal region of the skull. morphological descriptions are based on cleared and double-stained and serially-sectioned embryos. these specimens allowed for a detailed ...	2007	17236189
evaluation of a combination of sodium hypochlorite and polyhexamethylene biguanide as an egg wash for red-eared slider turtles (trachemys scripta elegans) to suppress or eliminate salmonella organisms on egg surfaces and in hatchlings.	to evaluate a combination of 2 nonantibiotic microbicide compounds, sodium hypochlorite (naocl) and polyhexamethylene biguanide (phmb), as a treatment to suppress or eliminate salmonella spp from red-eared slider (res) turtle (trachemys scripta elegans) eggs and hatchlings.	2007	17269881
parasympathetic control of the pupillary light response in the red-eared slider turtle (pseudemys scripta elegans).	we investigated effects of both vecuronium bromide, a nicotinic cholinergic antagonist, and atropine, a muscarinic cholinergic antagonist, on the pupil of the turtle to determine whether responses to light are controlled by parasympathetic innervations acting on the iris.	2013	17324166
expression of sox9, mis, and dmrt1 in the gonad of a species with temperature-dependent sex determination.	sex determination in vertebrates, the process of forming an ovary or testis from a bipotential gonad, can be initiated by genetic or environmental factors. elements of the downstream molecular pathways underlying these different sex-determining mechanisms have been evolutionarily conserved. we find the first evidence that sox9 expression is preferentially organized in the testis early in the temperature-sensitive period in a species with temperature-dependent sex determination (trachemys scripta ...	2007	17326219
suppression of reactive oxygen species production enhances neuronal survival in vitro and in vivo in the anoxia-tolerant turtle trachemys scripta.	hypoxia-ischemia with reperfusion is known to cause reactive oxygen species-related damage in mammalian systems, yet, the anoxia tolerant freshwater turtle is able to survive repeated bouts of anoxia/reoxygenation without apparent damage. although the physiology of anoxia tolerance has been much studied, the adaptations that permit survival of reoxygenation stress have been largely ignored. in this study, we examine ros production in the turtle striatum and in primary neuronal cultures, and exam ...	2007	17326763
pharmacokinetics of metronidazole in the red-eared slider turtle (trachemys scripta elegans) after single intracoelomic injection.		2007	17348904
analyzing the evolution of beta-endorphin post-translational processing events: studies on reptiles.	in many cartilaginous fishes, most ray-finned fishes, lungfishes, and amphibians, the post-translational processing of pomc includes the monobasic cleavage of beta-endorphin to yield an opioid that is eight to ten amino acids in length. the amino acid motif within the beta-endorphin sequence required for a monobasic cleavage event is -e-r-(s/g)-q-. mammals and birds lack this motif and as a result beta-endorphin(1-8) is a not an end-product in either group. since both mammals and birds were deri ...	2007	17353011
[reproductive ecology and hunting of the turtle tachemys scropta (testudinata: emydidae) in the "momposine depression", northern colombia].	we studied the reproductive ecology of the slider turtle. trachemys scripta callirostris, during the reproductive season of the year 2000, in an area of the mompós depression, northern colombia. we examined the number of nests ovoposited in locations with different characteristics, their hatching success rates and the natural causes of egg mortality. we also determined the effects of exploitation of nesting females, in two populations with different levels of harvesting. the results showed that ...	2004	17357421
flow cytometric analysis of red-eared slider turtles (trachemys scripta) from tar creek superfund site.	tar creek superfund site (tcsfs) was heavily mined from the 1890s to 1970 and currently is contaminated with lead, zinc, and cadmium. flow cytometry (fcm) was used to measure variation in nuclear dna content of red blood cells collected from trachemys scripta living within tcsfs and reference sites, lake carl blackwell (lcb) and sequoyah national wildlife refuge (snwr). we also used atomic absorption spectrometry to measure pb in blood and carapace and cd in blood samples of turtles from tcsfs a ...	2007	17364238
experimental test of the effects of fluctuating incubation temperatures on hatchling phenotype.	in the painted turtle (chrysemys picta) and red-eared slider turtle (trachemys scripta), the temperature that eggs are exposed to during incubation determines the sex of the developing embryo. constant temperature incubation experiments have shown that for each of these species there is a pivotal temperature that produces a 1:1 sex ratio; higher temperatures bias sex ratios toward females, and lower temperatures toward males. few studies have examined how fluctuating temperatures, as would be ex ...	2007	17377950
effects of temperature on anoxic submergence: skeletal buffering, lactate distribution, and glycogen utilization in the turtle, trachemys scripta.	to test the hypothesis that submergence temperature affects the distribution of the lactate load and glycogen utilization during anoxia in turtles, we sampled a variety of tissues after 7 days, 24 h, and 4 h of anoxic submergence at 5, 15, and 25 degrees c, respectively. these anoxic durations were chosen because we found that they produced similar decreases in plasma hco(3)(-) ( approximately 18-22 meq/l). the sampled tissues included ventricle, liver, small intestine, carapace, and the followi ...	2007	17395788
coelioscopic-assisted prefemoral oophorectomy in chelonians.	to describe a coelioscopic-assisted prefemoral oophorectomy technique for use in chelonians.	2007	17397348
adenosine does not save the heart of anoxia-tolerant vertebrates during prolonged oxygen deprivation.	despite adenosine being regarded as an important signaling molecule capable of coordinating atp supply and demand during periods of oxygen deprivation in anoxia-intolerant mammals, the importance of adenosinergic cardiovascular control in anoxia-tolerant vertebrates is poorly understood. here, we report on adenosinergic cardiovascular control during normoxia and prolonged (hours to days) oxygen deprivation for three vertebrate species tolerant of severe hypoxia/anoxia, the closely related common ...	2007	17433747
effect of temperature and prolonged anoxia exposure on electrophysiological properties of the turtle (trachemys scripta) heart.	cardiac activity of the turtle (trachemys scripta) is greatly depressed with cold acclimation and anoxia. we examined what electrophysiological modifications accompany and perhaps facilitate this depression of cardiac activity. turtles were first acclimated to 21 degrees c or 5 degrees c and held under either normoxic or anoxic (6 h at 21 degrees c; 14 days at 5 degrees c) conditions. we then measured cardiac action potentials (aps) using spontaneously contracting whole heart preparations and wh ...	2007	17442785
tracking the evolution of the proenkephalin gene in tetrapods.	in gnathostomes there is remarkable consistency in the organization of the proenkephalin gene. this opioid precursor encodes seven opioid (yggf) sequences: five pentapeptide sequences, a met-enkephalin-7 sequence and a met-enkephalin-8 sequence. yet, within vertebrate lineages there can be distinct sets of pentapeptide opioids (yggfm or yggfl). in the sarcopterygii, the sixth opioid position in lungfishes and anuran amphibian proenkephalin genes encodes a met-enkephalin (yggfm) sequence. however ...	2007	17449037
distribution and characteristics of endogenous digestive enzymes in the red-eared slider turtle, trachemys scripta elegans.	distribution and properties of the main digestive enzymes including protease and amylase, from stomach, pancreas and the anterior, middle and posterior intestine of the adult red-eared slider turtle trachemys scripta elegans were studied at various phs and temperatures. the optimum temperature and ph for protease in stomach, pancreas and the anterior, middle and posterior intestine were 40 degrees c, 2.5; 50 degrees c, 8.0; 50 degrees c, 7.0; 50 degrees c, 8.0; and 50 degrees c, 8.5; respectivel ...	2007	17462929
analgesic efficacy and respiratory effects of butorphanol and morphine in turtles.	to test the hypothesis that butorphanol or morphine induces antinociception with minimal respiratory depression in conscious red-eared slider turtles.	2007	17472564
gonadal expression of sf1 and aromatase during sex determination in the red-eared slider turtle (trachemys scripta), a reptile with temperature-dependent sex determination.	many egg-laying reptiles have temperature-dependent sex determination (tsd), where the offspring sex is determined by incubation temperature during a temperature-sensitive period (tsp) in the middle third of development. the underlying mechanism transducing a temperature cue into an ovary or testis is unknown, but it is known that steroid hormones play an important role. during the tsp, exogenous application of estrogen can override a temperature cue and produce females, while blocking the activ ...	2007	17490415
experimental transmission and induction of ranaviral disease in western ornate box turtles (terrapene ornata ornata) and red-eared sliders (trachemys scripta elegans).	an experimental transmission study was designed to determine whether a causal relationship exists between a ranavirus (bstrv) isolated from a burmese star tortoise that died and the lesions observed in that tortoise. a pilot study was performed with 3 box turtles (terrapene ornata ornata) and 3 red-eared sliders (ress; trachemys scripta elegans) to assess their suitability in a larger study. based on the outcome of this study, ress were selected, and 2 groups of 4 ress received either an oral (p ...	2007	17491069
characterization of a novel reptilian tolloid-like gene in the pond turtle, pseudemys scripta elegans.	the tolloid metalloproteases are pleiotropic enzymes that are important for many developmental processes. this study describes the isolation and characterization of a novel tolloid family member from the pond turtle pseudemys scripta elegans. the turtle tolloid, designated ttll, is found in two forms. the first, ttlls, contains a signal sequence which may provide a mechanism for secretion. the second, ttllc, does not contain a signal sequence and is likely cytoplasmic. sequence analysis of ttll ...	2007	17493594
evidence that a late-emerging population of trunk neural crest cells forms the plastron bones in the turtle trachemys scripta.	the origin of the turtle plastron is not known, but these nine bones have been homologized to the exoskeletal components of the clavicles, the interclavicular bone, and gastralia. earlier evidence from our laboratory showed that the bone-forming cells of the plastron were positive for hnk-1 and pdgfralpha, two markers of the skeletogenic neural crest. this study looks at the embryonic origin of these plastron-forming cells. we show that the hnk-1+ cells are also positive for p75 and foxd3, confi ...	2017	17501750
adrenal-kidney-gonad complex measurements may not predict gonad-specific changes in gene expression patterns during temperature-dependent sex determination in the red-eared slider turtle (trachemys scripta elegans).	many turtles, including the red-eared slider turtle (trachemys scripta elegans) have temperature-dependent sex determination in which gonadal sex is determined by temperature during the middle third of incubation. the gonad develops as part of a heterogenous tissue complex that comprises the developing adrenal, kidney, and gonad (akg complex). owing to the difficulty in excising the gonad from the adjacent tissues, the akg complex is often used as tissue source in assays examining gene expressio ...	2007	17592622
regulation of extracellular glutamate levels in the long-term anoxic turtle striatum: coordinated activity of glutamate transporters, adenosine, k (atp) (+) channels and gaba.	early in anoxia the mammalian brain experiences an uncontrolled release of glutamate, which combined with the failure of glutamate reuptake mechanisms, leads to massive neurotoxic increases in extracellular glutamate. by contrast, the anoxia tolerant turtle (trachemys scripta) shows no increase in extracellular glutamate levels over many hours of anoxia. during the first hours of anoxia extracellular glutamate levels are maintained by a reduction in glutamate release (mainly due to the inhibitio ...	2007	17629717
life history and ecology of the slider turtle. j. whitfield gibbons, with contributions by harold w. avery et al. smithsonian institution press, washington, dc, 1990. xiv, 368 pp., illus. $60.		1990	17840206
molecular cloning and characterization of estrogen, androgen, and progesterone nuclear receptors from a freshwater turtle (pseudemys nelsoni).	steroid hormones are essential for the normal function of many organ systems in vertebrates. reproductive activity in females and males, such as the differentiation, growth, and maintenance of the reproductive system, requires signaling by the sex steroids. although extensively studied in mammals and a few fish, amphibians, and bird species, the molecular mechanisms of sex steroid hormone (estrogens, androgens, and progestins) action are poorly understood in reptiles. here we evaluate hormone re ...	2008	17916628
estuarine fish and turtles as intermediate and paratenic hosts of gnathostoma binucleatum in nayarit, mexico.	human gnathostomosis is a severe public health problem in the state of nayarit, mexico. between 1995 and 2005, the registration of human cases numbered 6,328, which makes it one of the largest focal points of the disease in the country. the present study determined the presence of natural hosts of gnathostoma binucleatum larvae at the laguna de agua brava in nayarit, mexico. a total of 5,450 fish and 247 turtles were sampled. muscular tissue was ground and observed against the light using a 100- ...	2007	17924145
dendritic properties of turtle pyramidal neurons.	the six-layered mammalian neocortex evolved from the three-layered paleocortex, which is retained in present-day reptiles such as the turtle. thus the turtle offers an opportunity to examine which cellular and circuit properties are fundamental to cortical function. we characterized the dendritic properties of pyramidal neurons in different cortical regions of mature turtles, pseudemys scripta elegans, using whole cell recordings and calcium imaging from the axon, soma, and dendrites in a slice ...	2008	18045998
effect of cadmium on gonadal development in freshwater turtle (trachemys scripta, chrysemys picta) embryos.	prior studies on painted turtle (chrysemys picta) sub-populations near the massachusetts military reservation (mmr), a superfund site on cape cod, massachusetts, usa, suggest several reproductive deficits which may be related to xenobiotics. several heavy metals, including cadmium, have been detected in cape cod surface water and sediments. the present study was carried out to investigate the effect of an environmentally relevant dose of cadmium on gonadal development during the end of the germ ...	2008	18205057
immunohistochemical localization of neuropeptide ff-like in the brain of the turtle: relation to catecholaminergic structures.	a previous study in the lizard gekko gecko has revealed that neuropeptide ff (npff, a neuropeptide involved in nociception, cardiovascular regulation, and endocrine function) is widely distributed throughout the brain and spinal cord. although the distribution of npff immunoreactivity shares many features with that found in other vertebrates, it was noted that gekko shared more features with anamniotes in terms of number of cell groups, more elaborate networks of fibers, and lack of colocalizati ...	2008	18331881
steroid signaling system responds differently to temperature and hormone manipulation in the red-eared slider turtle (trachemys scripta elegans), a reptile with temperature-dependent sex determination.	many reptiles, including the red-eared slider turtle (trachemys scripta elegans), exhibit temperature-dependent sex determination (tsd). temperature determines gonadal sex during the middle of embryogenesis, or the temperature-sensitive period (tsp), when gonadal sex is labile to both temperature and hormones--particularly estrogen. the biological actions of steroid hormones are mediated by their receptors as defined here as the classic transcriptional regulation of target genes. to elucidate es ...	2007	18391529
varying hydric conditions during incubation influence egg water exchange and hatchling phenotype in the red-eared slider turtle.	environmental conditions within the nest, notably temperature and moisture of substrate, exert a powerful influence during embryogenesis in oviparous reptiles. the influence of fluctuating nest temperatures has been experimentally examined in different reptile species; however, similar experiments using moisture as the key variable are lacking. in this article, we examine the effect of various substrate moisture regimes during incubation on different traits (egg mass, incubation length, and hatc ...	2013	18419559
minimal volume regulation after shrinkage of red blood cells from five species of reptiles.	red blood cells (rbcs) from most vertebrates restore volume upon hypertonic shrinkage and the mechanisms underlying this regulatory volume increase (rvi) have been studied extensively in these cells. despite the phylogenetically interesting position of reptiles, very little is known about their red cell function. the present study demonstrates that oxygenated rbcs in all major groups of reptiles exhibit no or a very reduced rvi upon approximately 25% calculated hyperosmotic shrinkage. thus, rbcs ...	2008	18424207
detection of salmonellae in different turtle species within a headwater spring ecosystem.	sediments and water from the slough arm of spring lake, the headwaters of the san marcos river, texas, usa, as well as swabs from biofilms on carapaces and from the cloacae of 18 common musk turtles (sternotherus odoratus), 21 red-eared sliders (trachemys scripta elegans), nine texas river cooters (pseudemys texana), one snapping turtle (chelydra serpentina serpentina), and three guadalupe spiny soft-shell turtles (apalone spinifera guadalupensis), caught at the same site, were analyzed for salm ...	2008	18436690
estrogen inhibits caudal progression but stimulates proliferation of developing müllerian ducts in a turtle with temperature-dependent sex determination.	müllerian duct development appears to be similar in many vertebrate groups, and previous studies have shown that this development is estrogen sensitive. for example, embryonic exposure to diethylstilbestrol (des) in humans and mice, and estrogen exposure in chickens, can have multiple, usually adverse, effects on müllerian duct differentiation and growth. the current study investigates 17beta-estradiol's effects on müllerian duct development in a reptile, the turtle trachemys scripta. in t. scri ...	2008	18485773
adenosine modulates erk1/2, pi3k/akt, and p38mapk activation in the brain of the anoxia-tolerant turtle trachemys scripta.	the fate of cells under anoxic or ischemic stress is determined by intracellular signaling pathways including the mitogen-activated protein kinases (mapks) and phosphatidylinositol 3-kinase (pi3k/akt), which affect downstream members of the apoptotic cascade. the freshwater turtle trachemys scripta is extremely tolerant of anoxia, surviving up to 48 h at room temperature and for weeks at 3 degrees c in the complete absence of oxygen. we investigated the relationship between the neuroprotective p ...	2008	18506199
dependence of myosin-atpase on structure bound creatine kinase in cardiac myofibrils from rainbow trout and freshwater turtle.	the influence of myofibrillar creatine kinase on the myosin-atpase activity was examined in cardiac ventricular myofibrils isolated from rainbow trout (oncorhynchus mykiss) and freshwater turtle (trachemys scripta). the atpase rate was assessed by recording the rephosphorylation of adp by the pyruvate kinase reaction alone or together with the amount of creatine formed, when myofibrillar bound creatine kinase was activated with phosphocreatine. the steady-state concentration of adp in the soluti ...	2008	18515165
layer thickness and curvature effects on otoconial membrane deformation in the utricle of the red-ear slider turtle: static and modal analysis.	finite element models of otoconial membrane (om) were developed to investigate the effects of three geometric variables on static and modal response of the om: (1) curvature of the macular surface, (2) spatial variation in thicknesses of three om layers, and (3) shape of the macular perimeter. a geometrically accurate model of a turtle utricle was constructed from confocal images. modifying values for each variable formed variants of this model: modeling the macula surface as flat, om layer thic ...	2007	18525141
effect of anoxia on the electroretinogram of three anoxia-tolerant vertebrates.	to survive anoxia, neural atp levels have to be defended. reducing electrical activity, which accounts for 50% or more of neural energy consumption, should be beneficial for anoxic survival. the retina is a hypoxia sensitive part of the central nervous system. here, we quantify the in vivo retinal light response (electroretinogram; erg) in three vertebrates that exhibit varying degrees of anoxia tolerance: freshwater turtle (trachemys scripta), epaulette shark (hemiscyllium ocellatum) and leopar ...	2008	18579424
actin filaments associated with the basal sertoli cell surface in the alligator and turtle.	we have studied, using electron microscopy, the basal cytoplasm of sertoli cells in the alligator (alligator mississippiensis) and the turtle (pseudemys scripta). filament bundles occur immediately adjacent to the basal plasma membrane. the diameter of these filaments is smaller than that of perinuclear intermediate filaments, but is similar to that of filaments present in peritubular cells. in the alligator, the filament bundles appear to form a branching network over the base of the cell and a ...	1992	18621219
lung ventilation during treadmill locomotion in a semi-aquatic turtle, trachemys scripta.	it is reasonable to presume that locomotion should have a mechanical effect on breathing in turtles. the turtle shell is rigid, and when the limbs protract and retract, air in the lungs should be displaced. this expectation was met in a previous study of the green sea turtle, chelonia mydas; breathing completely ceased during terrestrial locomotion (jackson and prange, 1979. j comp physiol 134:315-319). in contrast, another study found no direct effect of locomotion on ventilation in the terrest ...	2009	18623107
formation and ossification of limb elements in trachemys scripta and a discussion of autopodial elements in turtles.	though sequences of formation and ossification of bony elements have been described for many taxa, controversy surrounds the formation of limb elements in turtles. three hypotheses for patterns of formation of autopodial elements have been proposed, differing primarily in the origin of distal carpal/tarsal 3, the digital arch, and centrale 4. patterns of formation and ossification of limb elements are described for trachemys scripta. these patterns are compared to similar data for representative ...	2008	18624573
coordinate action of pre- and postsynaptic brain-derived neurotrophic factor is required for ampar trafficking and acquisition of in vitro classical conditioning.	brain-derived neurotrophic factor (bdnf) has been implicated in mechanisms of synaptic plasticity such as long-term potentiation (ltp), but its role in associative learning remains largely unknown. in the present study, we investigated the function of bdnf and its receptor tropomyosin-related kinase b (trkb) in an in vitro model of classical conditioning using pond turtles, pseudemys scripta elegans. conditioning resulted in a significant increase in bdnf and phospho (p)-trk expression. bath app ...	2008	18639615
cloning and expression of r-spondin1 in different vertebrates suggests a conserved role in ovarian development.	r-spondin1 (rspo1) is a novel regulator of the wnt/beta-catenin signalling pathway. loss-of-function mutations in human rspo1 cause testicular differentiation in 46, xx females, pointing to a role in ovarian development. here we report the cloning and comparative expression analysis of r-spondin1 orthologues in the mouse, chicken and red-eared slider turtle, three species with different sex-determining mechanisms. evidence is presented that this gene is an ancient component of the vertebrate ova ...	2008	18651984
immunohistochemical localization of thyrotropin-releasing hormone in the brain of reptiles.	to gain insight into the evolution of the thyrotropin-releasing hormone (trh) system in the brain of vertebrates we have conducted a comparative analysis of the distribution of trh immunoreactive cell bodies and fibers in two reptiles, the turtle pseudemys scripta elegans and the lizard gekko gecko. double labeling for trh and tyrosine hydroxylase, the main catecholamine marker, was made to help the correct localization of the labeled structures and to evaluate the possible interaction of these ...	2008	18674611
inability to induce tympanic squamous metaplasia using organochlorine compounds in vitamin a-deficient red-eared sliders (trachemys scripta elegans).	previously, we reported that wild eastern box turtles (terrapene carolina carolina) with aural abscesses contained higher body burdens of organochlorine (oc) compounds than those without the lesion. this lesion in captive chelonians is associated with turtles that are fed diets deficient in vitamin a. to examine the pathophysiology of this lesion and evaluate the relationship between oc burdens and vitamin a metabolism, we maintained red-eared sliders (trachemys scripta elegans) under different ...	2008	18689652
inhibitory and excitatory effects of micro-, delta-, and kappa-opioid receptor activation on breathing in awake turtles, trachemys scripta.	for ectothermic vertebrates, such as reptiles, the effects of opioid receptor subtype activation on breathing are poorly understood. on the basis of previous studies on mammals and lampreys, we hypothesized that mu- and delta-opioid receptor (mor and dor, respectively) activation would cause respiratory depression, whereas kappa-opioid receptor (kor) activation would have no effect. to address this question, we measured respiration in awake, freely swimming adult red-eared slider turtles (trache ...	2008	18784338
helminth communities of the exotic introduced turtle, trachemys scripta elegans in southwestern spain: transmission from native turtles.	we report the prevalence and diversity of helminth parasites found in native turtles mauremys leprosa and emys orbicularis from three localities in southwestern spain and we describe the helminth communities of exotic turtles trachemys scripta elegans coexisting in the wild with both native turtle species. five nematodes species were identified, of which serpinema microcephalus was the only species common between two localities, although infection parameters were different between them. this is ...	2009	18799176
protein kinase c-dependent and independent signaling pathways regulate synaptic glur1 and glur4 ampar subunits during in vitro classical conditioning.	protein kinase c (pkc) signal transduction pathways have been implicated in mechanisms of synaptic plasticity and learning, however, the roles of the different pkc family isoforms remain to be clarified. previous studies showed that nmdar-mediated trafficking of glur4-containing ampars supports conditioning and that the mitogen-activated protein kinases (mapks) have a central role in the synaptic delivery of glur4 subunits. here, an in vitro model of classical conditioning in pond turtles, pseud ...	2008	18809472
myxidium scripta n. sp. identified in urinary and biliary tract of louisiana-farmed red-eared slider turtles trachemys scripta elegans.	during a necropsy investigation of a mortality event occurring at a turtle farm in assumption parish, louisiana, spores of a myxozoan were identified in the renal tubules in 3 of 6, the gall bladder lumen in 2 of 6, and the bile ductule in 1 of 6 red eared slider turtles trachemys scripta elegans. in total, myxozoa were identified in 4 of 6 turtles. in 1 turtle, renal tubules contained numerous mature spores, had epithelial hyperplasia, granulomatous transformation, compression of adjacent tubul ...	2008	18814545
fasting and postprandial serum bile acid concentrations in 10 healthy female red-eared terrapins (trachemys scripta elegans).	the fasting and postprandial serum concentrations of bile acids and other blood constituents were measured in a group of 10 clinically healthy, female, six-year-old captive red-eared terrapins (trachemys scripta elegans). the terrapins were housed in a temperate room and maintained in four aquaria in which the water temperature ranged from 24 to 27 degrees c and the temperature above the basking site ranged from 27 to 30 degrees c. the serum concentrations of bile acids were measured four times ...	2008	18953075
steroid signaling and temperature-dependent sex determination-reviewing the evidence for early action of estrogen during ovarian determination in turtles.	the developmental processes underlying gonadal differentiation are conserved across vertebrates, but the triggers initiating these trajectories are extremely variable. the red-eared slider turtle (trachemys scripta elegans) exhibits temperature-dependent sex determination (tsd), a system where incubation temperature during a temperature-sensitive period of development determines offspring sex. however, gonadal sex is sensitive to both temperature and hormones during this period-particularly estr ...	2009	18992835
recoding of translation in turtle mitochondrial genomes: programmed frameshift mutations and evidence of a modified genetic code.	a +1 frameshift insertion has been documented in the mitochondrial gene nad3 in some birds and reptiles. by sequencing polyadenylated mrna of the chicken (gallus gallus), we have shown that the extra nucleotide is transcribed and is present in mature mrna. evidence from other animal mitochondrial genomes has led us to hypothesize that certain mitochondrial translation systems have the ability to tolerate frameshift insertions using programmed translational frameshifting. to investigate this, we ...	2008	19030769
sympathetic influence on the pupillary light response in three red-eared slider turtles (trachemys scripta elegans).	we investigated the effects of phenylephrine and its combination with vecuronium bromide on the iris of turtles to determine if the pupillary light response is affected by sympathetic innervation.	2013	19046290
pharmacokinetics of buprenorphine after single-dose subcutaneous administration in red-eared sliders (trachemys scripta elegans).	buprenorphine, a mu opioid receptor agonist, is expected to be a suitable analgesic drug for use in reptiles. however, to date, dosage recommendations have been based on anecdotal observations. the aim of this study was to provide baseline pharmacokinetic data in red-eared sliders (trachemys scripta elegans) targeting a plasma level of 1 ng/ml reported effective for analgesia in humans. serial blood samples were taken after subcutaneous injection of buprenorphine, and plasma buprenorphine levels ...	2008	19110701
localization and regulation of a facilitative urea transporter in the kidney of the red-eared slider turtle (trachemys scripta elegans).	urea is the major excretory end product of nitrogen metabolism in most chelonian reptiles. in the present study, we report the isolation of a 1632 base pair cdna from turtle kidney with one open reading frame putatively encoding a 403-residue protein, the turtle urea transporter (turtle ut). the first cloned reptilian ut has high homology with uts (facilitated urea transporters) cloned from vertebrates, and most closely resembles the ut-a subfamily. injection of turtle ut crna into xenopus oocyt ...	2009	19112144
the distal forelimb musculature in aquatic and terrestrial turtles: phylogeny or environmental constraints?	we compared the muscular anatomy of the distal front limb in terrestrial and aquatic chelonians to test whether observed differences between the two groups are associated with their divergent lifestyles and locomotor modes. given the different use of the forelimb in the two environments (body support and propulsion on land vs. mainly propulsion in water) we expected that: (1) aquatic and terrestrial turtles would show differences in their muscular anatomy, with aquatic species having more indivi ...	2008	19172731
a modified yolk biopsy technique improves survivorship of turtle eggs.	nongenetic maternal contributions, such as steroid hormones, have received much attention in recent years because they have the potential to influence offspring phenotype. research in oviparous taxa has demonstrated that there is among-species variability in their response to these maternal contributions. however, studies in chelonians and crocodilians have been hampered by the fact that techniques involving egg manipulations that breach the eggshell routinely result in massive egg mortality. in ...	2009	19193061
living at extremes: development at the edges of viable temperature under constant and fluctuating conditions.	in the painted turtle (chrysemys picta) and the red-eared slider (trachemys scripta), the temperature that eggs are exposed to during incubation influences many traits of the developing embryo. we tested the effect of fluctuating- versus constant-temperature incubation regimes at the high and low ends of the viable developmental temperature range to assess the effect of incubation environment on offspring development. eggs were incubated in four treatments: 23 degrees c constant, 23 degrees +/- ...	2009	19199555
effects of propofol administered via the supravertebral sinus in red-eared sliders.	to characterize the effects of propofol administered at 10 and 20 mg/kg (4.5 and 9 mg/lb) via the supravertebral venous sinus in red-eared sliders (trachemys scripta).	2009	19210263
nitric oxide increases myocardial efficiency in the hypoxia-tolerant turtle trachemys scripta.	nitric oxide (no) may influence cardiac mechanical performance relative to o2 consumption by depressing respiration rate and by affecting the excitation-contraction coupling. such effects of no should be particularly important during hypoxia in species such as the hypoxia-tolerant turtle trachemys scripta. in heart ventricle preparations from this species, the ratio of twitch force to o2 consumption increased by approximately 15% during full oxygenation and by approximately 60% during hypoxia in ...	2009	19282492
circadian and circannual rhythms in the metabolism and ventilation of red-eared sliders (trachemys scripta elegans).	endogenous circadian and circannual rhythms may exist in the metabolism, ventilation, and breathing pattern of turtles that could further prolong dive times during daily and seasonal periods of reduced activity. to test this hypothesis, turtles were held under seasonal or constant environmental conditions over a 1-yr period, and in each season, v(o)(2) and respiratory variables were measured in all animals under both the prevailing seasonal conditions and the constant conditions for 24 h. endoge ...	2010	19358691
concentrations of persistent organic pollutants in plasma from two species of turtle from the tennessee river gorge.	persistent organic pollutants (pops) are characterized by their resistance to degradation, biomagnification, global transport, and adverse toxicological effects. the goal of this study was to determine baseline concentrations of several classes of pops, including polychlorinated biphenyls (pcbs), organochlorine pesticides, and polybrominated diphenyl ethers (pbdes) in two turtle species, the cumberland slider (trachemys scripta troosti) and the common musk turtle (sternotherus odoratus) from the ...	2009	19406450
role of neuroglobin in regulating reactive oxygen species in the brain of the anoxia-tolerant turtle trachemys scripta.	neuroglobin (ngb) is an oxygen binding heme protein found in nervous tissue with a yet unclear physiological and protective role in the hypoxia-sensitive mammalian brain. here we utilized in vivo and in vitro studies to examine the role of ngb in anoxic and post-anoxic neuronal survival in the freshwater turtle. we employed semiquantitative rt-pcr and western blotting to analyze ngb mrna and protein levels in turtle brain and neuronally enriched cultures. ngb expression is strongly up-regulated ...	2009	19457091
the chelonian spinal nerve ganglia are a conglomerate of the spinal nerve ganglia proper and the sympathetic ganglia.	a tyrosine hydroxylase-immunoreactive cell mass is found in the caudal portion of the dorsal nerve ganglion of the red-eared slider, trachemys scripta elegans. the ganglion appears as a flat oval structure in the horizontal plane, where the major axis runs latero-medially, and the minor axis rostro-caudally in the ventral view. a communicating branch to the sympathetic chain diverges from the top of each tubercle which lies on the caudo-lateral side of the ganglion. a tyrosine hydroxylase- immun ...	2009	19468213