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polycystic kidney-like disease in a red-ear slider turtle (trachemys scripta elegans).a 14-year-old red-ear slider turtle (trachemys scripta elegans) with no history of pre-existing clinical disease died and was referred for necropsy examination. grossly, oesophageal prolapse, bilateral renal cysts and a paraduodenal cystic mass were detected. tissues were processed routinely for histology and immunohistochemistry (ihc) with primary antibodies specific for wilm's tumour suppressor gene-1 (wt-1), insulin, glucagon and pancytokeratins. microscopically, renal medullary cysts and med ...201830360912
a new slider turtle (testudines: emydidae: deirochelyinae:trachemys) from the late hemphillian (late miocene/early pliocene) of eastern tennessee and the evolution of the deirochelyines.trachemys(testudines: emydidae) represents one of the most well-known turtle genera today. the evolution oftrachemys, while being heavily documented with fossil representatives, is not well understood. numerous fossils from the late hemphillian gray fossil site (gfs) in northeastern tennessee help to elucidate its evolution. the fossiltrachemysat the gfs represent a new species. the new taxon,trachemys haugrudi, is described, and currently represents the most thoroughly described fossil emydid s ...201829456887
identification of hemotropic mycoplasmas in an eastern box turtle ( terrapene carolina carolina) and a yellow-bellied slider ( trachemys scripta scripta) from north carolina.mycoplasma spp. are known from several chelonian and other reptilian species. we determined if turtles obtained by the turtle rescue team at north carolina state university are carriers of hemotropic mycoplasma or bartonella spp. spleen samples were collected at necropsy during may through july, 2014 from 53 turtles of seven species. all turtles were dead or were euthanized upon arrival due to severe traumatic injuries, or they died shortly after beginning treatment. we used pcr amplification fo ...201829369724
melanin deposition ruled out as cause of color changes in the red-eared sliders (trachemys scripta elegans).animal coloration primarily depends on the presence of pigments and the mixing ratio of eumelanin and pheomelanin. the color of red-eared slider's carapace varies with age, from an olive green to a yellow green, and then to a yellow brown in juveniles, generally. the purpose of the present study was to investigate whether this color change is related to the difference in melanin expression. melanin deposition levels were examined in the carapace, skin, eye and muscle of the three color-types usi ...201829269034
mitochondrial responses to anoxia exposure in red eared sliders (trachemys scripta).when deprived oxygen, mitochondria from most vertebrates transform from the main site of atp production to the dominant site of cellular atp use due to the reverse functioning of the f1fo-atpase (complex v). the anoxia-tolerant freshwater turtle trachemys scripta however, has previously been shown to inhibit complex v activity in heart and brain in response to anoxia exposure, but the regulatory mechanism is unknown. to gain insight into the putative regulatory mechanisms underlying the anoxia-i ...201829402754
dynamic regulation of six histone h3 lysine (k) methyltransferases in response to prolonged anoxia exposure in a freshwater turtle.the importance of histone lysine methylation is well established in health, disease, early development, aging, and cancer related-research. however, the potential role of epigenetics in regulating gene expression in response to extended periods of oxygen deprivation (anoxia) in a natural anoxia-tolerant model system is underexplored. red-eared sliders (trachemys scripta elegans) can tolerate and survive three months of absolute anoxia and recover without incurring detrimental cellular damage, ma ...201829382574
pharmacokinetics of cefquinome in red-eared slider turtles (trachemys scripta elegans) after single intravenous and intramuscular injections.the purpose of this study was to evaluate the pharmacokinetics of cefquinome (cfq) following single intravenous (iv) or intramuscular (im) injections of 2 mg/kg body weight in red-eared slider turtles. plasma concentrations of cfq were determined by high-performance liquid chromatography and analyzed using noncompartmental methods. the pharmacokinetic parameters following iv injection were as follows: elimination half-life (t1/2λz) 21.73 ± 4.95 hr, volume of distribution at steady-state (vdss) 0 ...201828833214
short heatwaves during fluctuating incubation regimes produce females under temperature-dependent sex determination with implications for sex ratios in nature.patterns of temperature fluctuations in nature affect numerous biological processes, yet, empirical studies often utilize constant temperature treatments. this can limit our understanding of how thermally sensitive species respond to ecologically relevant temperatures. research on turtles with temperature-dependent sex determination (tsd) provides good examples of this, since nest temperatures from many populations rarely exceed those necessary to produce females under constant laboratory condit ...201829311550
hemoglobin polymerization via disulfide bond formation in the hypoxia-tolerant turtle trachemys scripta: implications for antioxidant defense and o2transport.the ability of many reptilian hemoglobins (hbs) to form high-molecular weight polymers, albeit known for decades, has not been investigated in detail. given that turtle hbs often contain a high number of cysteine (cys), potentially contributing to the red blood cell defense against reactive oxygen species, we have examined whether polymerization of hb could occur via intermolecular disulfide bonds in red blood cells of freshwater turtle trachemys scripta, a species that is highly tolerant of hyp ...201828877869
prevalence of salmonella enterica subspecies enterica in red-eared sliders trachemys scripta elegans retailed in pet shops in japan.we investigated the prevalence of salmonella in 227 small red-eared sliders (trachemys scripta elegans) from 2006 to 2008. a total of 130 turtles (57.3%) tested positive for s. enterica subsp. enterica. twenty-two serotypes including s. montevideo, s. newport, s. pomona, s. braenderup, s. sandiego, and s. litchfield were identified. salmonella strains with closely related pulsed field gel electrophoresis (pfge) patterns were isolated from several shops located in different areas from 2006 to 200 ...201930270249
thermal physiological performance of two freshwater turtles acclimated to different temperatures.the thermal physiological performance of invasive species may play a crucial role in determining their invasion success. in this study, we acclimated two cohorts of hatchlings of freshwater turtles (native mauremys reevesii and invasive trachemys scripta elegans) from low and high-latitude collection sites, respectively, to different thermal conditions (20 and 30 °c) for 4 weeks, and then compared their thermal tolerance and locomotor performance. t. scripta elegans hatchlings could swim faster ...201930478602
the expression of genes involved in excitatory and inhibitory neurotransmission in turtle (trachemys scripta) brain during anoxic submergence at 21 °c and 5 °c reveals the importance of cold as a preparatory cue for anoxia survival.we investigated if transcriptional responses are consistent with the arrest of synaptic activity in the anoxic turtle (trachemys scripta) brain. thirty-nine genes of key receptors, transporters, enzymes and regulatory proteins of inhibitory and excitatory neurotransmission were partially cloned and their expression in telencephalon of 21 °c- and 5 °c-acclimated normoxic, anoxic (24 h at 21 °c; 1 and 14 days at 5 °c) and reoxygenated (24 h at 21 °c; 13 days at 5 °c) turtles quantified by real-tim ...201930780100
antioxidant responses to salinity stress in an invasive species, the red-eared slider (trachemys scripta elegans) and involvement of a tor-nrf2 signaling pathway.the red-eared slider (trachemys scripta elegans), a freshwater turtle, is an invasive species in many parts of the world where it survives in both freshwater and coastal saline habitats. high salinity can induce reactive oxygen species (ros) production and lead to oxidative damage. in this study, we investigate the antioxidant defense mechanisms of t. s. elegans in response to salinity stress. the results showed that the mrna expression levels of superoxide dismutase (sods), catalase (cat) and g ...201930738853
contraction of atrial smooth muscle reduces cardiac output in perfused turtle hearts.unusual undulations in resting tension (tonus waves) were described in isolated atria from freshwater turtles more than a century ago. these tonus waves were soon after married with the histological demonstration of a rich layer of smooth muscle on the luminal side of the atrial wall. research thereafter waned and the functional significance of this smooth muscle has remained obscure. here, we provide evidence that contraction of the smooth muscle in the atria may be able to change cardiac outpu ...201930787139
comparative analysis of the liver transcriptome in the red-eared slider trachemys scripta elegans under chronic salinity stress.the red-eared slider (trachemys scripta elegans), identified as one of the 100 most invasive species in the world, is a freshwater turtle originally from the eastern united states and northeastern mexico. field investigations have shown that t. s. elegans can survive and lay eggs in saline habitats. in order to understand the molecular mechanisms of salinity adaptation, high-throughput rna-seq was utilized to identify the changes in gene expression profiles in the liver of t. s. elegans in respo ...201930923649
increase in morbidity and mortality in a shipment of red-eared slider turtles (trachemys scripta elegans).a cohort of captive-bred red-eared slider turtles, trachemys scripta, was received from a commercial vendor. shortly after arrival, several turtles presented as lethargic with subjectively pale skin and multifocal areas of cotton-like tufts in the mouth area and distal extremities. the water was treated with a commercial anti-fungal and anti-bacterial preparation of victoria green b and acriflavine. despite treatment, 10 turtles were euthanized and others demonstrated persistent clinical signs. ...201931238811
learning and behavior in hatchling trachemys scripta exposed to bisphenol-a during embryonic development.steroids play an integral role in orchestrating embryonic development, and they can affect a suite of phenotypic traits, including learning and behavior. endocrine disrupting compounds (edcs) can alter steroid-dependent phenotypic traits during embryonic development. bisphenol-a (bpa) is an edc that disrupts the action of estrogen, and recent work indicates that bpa can affect learning and behavior similarly to estrogen. we exposed red-eared slider turtle (trachemys scripta) eggs to bpa during e ...201931301326
pharmacokinetics of subcutaneously administered hydromorphone in bearded dragons (pogona vitticeps) and red-eared slider turtles (trachemys scripta elegans).to determine pharmacokinetic dosing strategy in bearded dragons (pogona vitticeps) and red-eared sliders (trachemys scripta elegans) based on two subcutaneously (sc) administered doses of hydromorphone (0.5 and 1.0 mg kg-1).201930827804
tissue-dependent variation of hydrogen sulfide homeostasis in anoxic freshwater turtles.hydrogen sulfide (h2s) controls numerous physiological responses. to understand its proposed role in metabolic suppression, we measured free h2s and bound sulfane sulfur (bss) in tissues of the freshwater turtle trachemys scriptaelegans, a species undergoing strong metabolic suppression when cold and anoxic. in warm normoxic turtles, free h2s was higher in red blood cells (rbcs) and kidney (∼9-10 µmol l-1) than in brain, liver and lung (∼1-2 µmol l-1). these values overall aligned with the tissu ...201931109970
the devil is in the details: identifying aspects of temperature variation that underlie sex determination in species with tsd.most organisms experience thermal variability in their environment; however, our understanding of how organisms cope with this variation is under-developed. for example, in organisms with temperature-dependent sex determination (tsd), an inability to predict sex ratios under fluctuating incubation temperatures in the field hinders predictions of how species with tsd will fare in a changing climate. to better understand how sex determination is affected by thermal variation, we incubated trachemy ...201931095337
regulation of p53 in the red-eared slider (trachemys scripta elegans) in response to salinity stress.the freshwater red-eared slider (trachemys scripta elegans) is found not only in freshwater but also in coastal saline habitats. hyperosmotic salinity can induce cell damage. p53, regarded as the guardian of the genome, is very important and versatile in response to the change of environment. in this study, the role of p53 in t. s. elegans under environmental salinity change will be explored. the results indicated that amino acid sequence of p53 showed high similarity to p53 of other species. in ...201930940557
immune function in trachemys scripta following exposure to a predominant brevetoxin congener, pbtx-3, as a model for potential health impacts for sea turtles naturally exposed to brevetoxins.many species of marine life in southwestern florida, including sea turtles, are impacted by blooms of the toxic dinoflagellate, karenia brevis. sublethal exposure to toxins produced by k. brevis has been shown to impact sea turtle health. since all sea turtles in the gulf of mexico have protected status, a freshwater turtle, trachemys scripta, was used as a model for immune system effects following experimental exposure to a predominant brevetoxin congener in k. brevis blooms, pbtx-3. exposure t ...201931559558
effects of chlorella vulgaris polysaccharides accumulation on growth characteristics of trachemys scripta elegans.the present study investigated the effects of the accumulated polysaccharides in chlorella vulgaris microalgae on the growth characteristics of trachemys scripta elegans. sodium alginate was used to prepare immobilized c. vulgaris, and the antioxidant effects of the accumulated polysaccharides in it were determined using caenorhabditis elegans as a model. we determined the specific growth rates of t. s. elegans (10 in each group) and their levels of non-specific immune-related indexes (including ...201931493454
red-eared slider hatchlings (trachemys scripta) show a seasonal shift in behavioral types.correlated and repeatable patterns of behavior, termed behavioral types, can affect individual fitness. the most advantageous behavioral type may differ across predictable environments (e.g., seasonally), and maternally mediated effects may match hatchling behavior to the environment. we measured righting response, an indicator of behavioral type, of juvenile red-eared slider turtles (trachemys scripta) emerging from early and late season clutches to understand if the production of behavioral ty ...201931436909
adenosine monophosphate-activated protein kinase signaling regulates lipid metabolism in response to salinity stress in the red-eared slider turtle trachemys scripta elegans.aquatic animals have developed various mechanisms to live in either hyperionic or hypoionic environments, and, as such, not many species are capable of surviving in both. the red-eared slider turtle, trachemys scripta elegans, a well-known freshwater species, has recently been found to invade and inhabit brackish water. herein, we focus on some of the metabolic adaptations that are required to survive and cope with salinity stress. the regulation of the adenosine monophosphate (amp)-activated pr ...201931417422
pharmacokinetics of tolfenamic acid in red-eared slider turtles (trachemys scripta elegans).to determine the pharmacokinetics of tolfenamic acid (ta) after different routes of administration [intravenous (iv) and intramuscular (im), 2 mg kg-1] and doses (iv, 2 and 4 mg kg-1) in red-eared slider turtles (trachemys scripta elegans).201931395485
intravenous lipid emulsion treatment reduces symptoms of brevetoxicosis in turtles (trachemys scripta).harmful algal blooms (habs) occur when excess nutrients allow dinoflagellates to reproduce in large numbers. marine animals are affected by blooms when algal toxins are ingested or inhaled. in the gulf of mexico, near annual blooms of karenia brevis release a suite of compounds (brevetoxins) that cause sea turtle morbidity and mortality. the primary treatment at rehabilitation facilities for brevetoxin-exposed sea turtles is supportive care, and it has been difficult to design alternative treatm ...201931120660
twins at conspicuously different developmental stages in a turtle egg.one-egg twins, in general, initiate embryonic development at the same time, and their developmental stages proceed in parallel. here we report a rare case of the embryonic development of the red-eared slider turtle, trachemys scripta, in which twins at conspicuously different developmental stages developed on a single yolk. one of the twins appeared to have developed at the normal developmental rate, whereas the development of the other was markedly delayed, despite the absence of any overt anom ...201931116532
pharmacokinetics of levamisole in the red-eared slider turtles (trachemys scripta elegans).the pharmacokinetics and bioavailability of levamisole were determined in red-eared slider turtles after single intravenous (iv), intramuscular (im), and subcutaneous (sc) administration. nine turtles received levamisole (10 mg/kg) by each route in a three-way crossover design with a washout period of 30 days. blood samples were collected at time 0 (pretreatment), and at 0.25, 0.5, 1, 1.5, 3, 6, 9, 12, 18, 24, 36, and 48 hr after drug administration. plasma levamisole concentrations were determi ...201930933367
development of reverse-transcriptase quantitative pcr assays for detection of the cytokines il-1β, tnf-α, and il-10 in chelonians.in response to viral pathogens, a host releases pro-inflammatory cytokines such as interleukin-1 beta (il-1β) and tumor necrosis factor alpha (tnf-α) and anti-inflammatory cytokines such as interleukin-10 (il-10). while several approaches exist to measure cytokine responses, evaluating gene transcription through reverse transcription quantitative polymerase chain reaction (rt-qpcr) provides a fast, reproducible, and sensitive method for quantifying this response. the objective of this study was ...201930856601
pharmacokinetics of intravenous and intramuscular danofloxacin in red-eared slider turtles (trachemys scripta elegans).this study aimed to investigate the pharmacokinetics of danofloxacin in red-eared slider turtle (trachemys scripta elegans) following a single intravenous (iv) and intramuscular (im) administrations of 6 mg/kg, using a two-way crossover study with 30-day washout period. eight clinically healthy red-eared slider turtle weighing 410-600 g (mean 490 g) were used for the study. danofloxacin concentrations were measured using the reversed-phase high-performance liquid chromatography. the plasma conce ...201930853667
trophodynamics and parabolic behaviors of polycyclic aromatic hydrocarbons in an urbanized lake food web, shanghai.understanding the trophic movement and trophic magnification factor (tmf) of polycyclic aromatic hydrocarbons (pahs) is an important criterion to assess their fate and potential effects in an aquatic ecosystem. this study investigated concentrations and trophodynamics of 16 priority pahs in food webwb (food web comprising whole bodies) and food webm (food web containing only muscles) of total 14 species ((including plankton, shrimp, whitebait, mussels, snails, red-eared terrapin and seven other ...201930986628
environmental dna detection and quantification of invasive red-eared sliders, trachemy scripta elegans, in ponds and the influence of water quality.environmental dna (edna) is a powerful tool for monitoring the distribution of aquatic macro-organisms. however, environmental factors, including the water temperature and water quality, can affect the inhibition and/or degradation of edna, which complicates accurate estimations of edna concentrations and the detection of the presence/absence of species in natural habitats. further very few edna studies have been conducted for reptiles, especially with respect to estimating their biomass and/or ...201931824768
intestinal b cells in the red-eared slider turtle, trachemys scripta: anatomical distribution and implications for ecological interactions with pathogenic microbes.disease is a significant threat in the global decline of reptile species. many aquatic reptiles live in habitats with high levels of opportunistic microbial pathogens, yet little is known about their immune system. gut-associated lymphoid tissue is vital for protection against ingested pathogens and maintenance of normal gut microbiota. in mammals, gut mucosal immunity is well-characterized and mucosal surfaces are coated in protective antibodies. however, reptiles lack lymph nodes and peyer's p ...201931328906
experimental removal of introduced slider turtles offers new insight into competition with a native, threatened turtle.the red-eared slider turtle (trachemys scripta elegans; res) is often considered one of the world's most invasive species. results from laboratory and mesocosm experiments suggest that introduced res outcompete native turtles for key ecological resources, but such experiments can overestimate the strength of competition. we report on the first field experiment with a wild turtle community, involving introduced res and a declining native species of conservation concern, the western pond turtle (e ...201931435491
body coloration and mechanisms of colour production in archelosauria: the case of deirocheline turtles.animal body coloration is a complex trait resulting from the interplay of multiple mechanisms. while many studies address the functions of animal coloration, the mechanisms of colour production still remain unknown in most taxa. here we compare reflectance spectra, cellular, ultra- and nano-structure of colour-producing elements, and pigment types in two freshwater turtles with contrasting courtship behaviour, trachemys scripta and pseudemys concinna. the two species differ in the distribution o ...201931417734
auditory brainstem responses in the red-eared slider trachemys scripta elegans (testudoformes: emydidae) reveal sexually dimorphic hearing sensitivity.hearing sensitivity is of general interest from the perspective of understanding the functionality and evolution of vertebrate auditory systems. sexual dimorphism of auditory systems has been reported in several species of vertebrates, but little is known about this phenomenon in turtles. some morphological characteristics, such as middle ear and tympanic membrane that influence the hearing sensitivity of animals can result in hearing sexual dimorphism. to examine whether sexual dimorphism in he ...201931654192
fundamental niche unfilling and potential invasion risk of the slider turtle trachemys scripta.how species colonize new environments is still a fundamental question in ecology and evolution, assessable by evaluating range characteristics of invasive species. here we propose a model approach to evaluate environmental conditions and species features to predict niche changes in non-equilibrium contexts. it incorporates potentially range-limiting processes (fundamental niche), hence allowing for better predictions of range shifts, differentiation of analog and non-analog conditions between th ...201931637143
detecting trends in body size: empirical and statistical requirements for intraspecific analyses.attributing biological explanations to observed ecogeographical and ecological patterns require eliminating potential statistical and sampling artifacts as alternative explanations of the observed patterns. here, we assess the role of sample size, statistical power, and geographic inclusivity on the general validity and statistical significance of relationships between body size and latitude for 3 well-studied species of turtles. we extend those analyses to emphasize the importance of using stat ...201931616479
health assessment of free-ranging chelonians in an urban section of the bronx river, new york, usa.the bronx river in bronx, new york, us spans an area of significant human development and has been subject to historic and ongoing industrial contamination. we evaluated the health of freeranging native common snapping turtles ( chelydra serpentina) and nonnative invasive red-eared sliders ( trachemys scripta) in a segment of the bronx river between may and july 2012. in 18 snapping turtles and nine sliders, complete physical examinations were performed, ectoparasites collected, and blood was an ...201930226800
navigating oxygen deprivation: liver transcriptomic responses of the red eared slider turtle to environmental anoxia.the best facultative anaerobes among vertebrates are members of the genera trachemys (pond slider turtles) and chrysemys (painted turtles), and are able to survive without oxygen for up to 12 to 18 weeks at ∼3 °c. in this study, we utilized rnaseq to profile the transcriptomic changes that take place in response to 20 hrs of anoxia at 5 °c in the liver of the red eared slide turtle (trachemys scripta elegans). sequencing reads were obtained from at least 18,169 different genes and represented a ...201931788367
ultrastructural analysis of the yolk processing pattern in embryonic pond slider turtles (trachemys scripta: emydidae).evolution of the large-yolked, amniotic egg required mechanisms by which extracellular yolk could be made available for embryonic development. in birds, the endodermal lining of the yolk sac absorbs and digests the yolk. in contrast, recent studies on lizards and snakes (squamates) have revealed that yolk is processed by means of a proliferating mass of "spaghetti-like" strands formed by endodermal cells attached to anastomosing blood vessels. to clarify the method of yolk processing in chelonia ...201931328905
a comparison of thyroid hormone levels and plasma capillary zone electrophoresis in red-eared sliders (trachemys scripta elegans) and map turtles (graptemys spp.) depending on season and sex.thyroid hormones and capillary zone electrophoresis are rarely studied in reptile medicine.202032237094
morphometric data for five freshwater turtles in south, central, and west texas.from 2008 to 2013, we sampled freshwater turtle populations at 66 sites in south, central, and west texas, usa. sampling sites included ponds, lakes, resacas (oxbow lakes), canals, and rivers. we sampled turtle populations using baited hoop nets (66 sites) and basking traps (3 sites), and captured turtles by hand opportunistically in terrestrial habitat. we measured carapace length and width, plastron length and width, body depth, and weight of captured turtles. excluding recaptures, we measured ...202032195296
using naturalistic incubation temperatures to demonstrate how variation in the timing and continuity of heat wave exposure influences phenotype.most organisms are exposed to bouts of warm temperatures during development, yet we know little about how variation in the timing and continuity of heat exposure influences biological processes. if heat waves increase in frequency and duration as predicted, it is necessary to understand how these bouts could affect thermally sensitive species, including reptiles with temperature-dependent sex determination (tsd). in a multi-year study using fluctuating temperatures, we exposed trachemys scripta ...202032752987
dynamic regulation of histone h3 lysine (k) acetylation and deacetylation during prolonged oxygen deprivation in a champion anaerobe.trachemys scripta elegans can survive up to three months of absolute anoxia at 3 °c and recover with minimal cellular damage. red-eared sliders employ various physiological and biochemical adaptations to survive anoxia with metabolic rate depression (mrd) being the most prominent adaptation. mrd is mediated by epigenetic, transcriptional, post-transcriptional, and post-translational mechanisms aimed at shutting down cellular processes that are not needed for anoxia survival, while reprioritizing ...202032729004
molecular cytogenetic characterization of the sicilian endemic pond turtle emys trinacris and the yellow-bellied slider trachemys scripta scripta (testudines, emydidae).turtles, a speciose group consisting of more than 300 species, demonstrate karyotypes with diploid chromosome numbers ranging from 2n = 26 to 2n = 68. however, cytogenetic analyses have been conducted only to 1/3rd of the turtle species, often limited to conventional staining methods. in order to expand our knowledge of the karyotype evolution in turtles, we examined the topology of the (ttaggg)n telomeric repeats and the rdna loci by fluorescence in situ hybridization (fish) on the karyotypes o ...202032630506
chemical cues of an invasive turtle reduce development time and size at metamorphosis in the common frog.in aquatic systems, chemical cues are one of the major sources of information through which animals can assess local predation risk. non-native red-eared sliders (trachemys scripta elegans) have the potential to disrupt aquatic ecosystems in central europe because of their superior competitive abilities and omnivorous diets. in this study, we examined whether continuous predator-borne cues are tied to changes in the developmental rates, growth rates and sizes at metamorphosis of common frog tadp ...202032409709
identifying sex of neonate turtles with temperature-dependent sex determination via small blood samples.temperature-dependent sex determination, present in most turtle species, is a mechanism that uses temperature to direct the sex of the embryo. the rapid increase of global temperatures highlights the need for a clear assessment of how sex ratios of organisms with tsd are affected. in turtles with tsd, quantifying primary sex ratios is challenging because they lack external dimorphism and heteromorphic sex chromosomes. here we describe a new technique used to identify sex in neonate turtles of tw ...202032193464
karyotypic evolution of sauropsid vertebrates illuminated by optical and physical mapping of the painted turtle and slider turtle genomes.recent sequencing and software enhancements have advanced our understanding of the evolution of genomic structure and function, especially addressing novel evolutionary biology questions. yet fragmentary turtle genome assemblies remain a challenge to fully decipher the genetic architecture of adaptive evolution. here, we use optical mapping to improve the contiguity of the painted turtle (chrysemys picta) genome assembly and use de novo fluorescent in situ hybridization (fish) of bacterial artif ...202032806747
the development of the trunk neural crest in the turtle trachemys scripta.the neural crest is a group of multipotent cells that give rise to a wide variety of cells, especially portion of the peripheral nervous system. neural crest cells (nccs) show evolutionary conserved fate restrictions based on their axial level of origin: cranial, vagal, trunk, and sacral. while much is known about these cells in mammals, birds, amphibians, and fish, relatively little is known in other types of amniotes such as snakes, lizards, and turtles. we attempt here to provide a more detai ...202031587387
pharmacokinetics of injectable marbofloxacin after intravenous and intramuscular administration in red-eared sliders (trachemys scripta elegans).fluoroquinolone antibacterial drugs are currently used in reptilian medicine because of their broad spectrum of activity including the most frequent pathogens of these species. the disposition kinetics of marbofloxacin (mbx) at a single dose of 2 mg/kg were determined in healthy red-eared sliders after intravenous (iv) and intramuscular (im) administration. the influence of renal portal system on the bioavailability of the drug was investigated by using forelimb and hindlimb as im injection site ...202031393637
h2s-producing enzymes in anoxia-tolerant vertebrates: effects of cold acclimation, anoxia exposure and reoxygenation on gene and protein expression.to lend insight into the potential role of the gasotransmitter hydrogen sulfide (h2s) in facilitating anoxia survival of anoxia-tolerant vertebrates, we quantified the gene expression of the primary h2s-synthesizing enzymes, 3-mercaptopyruvate sulfurtransferase (3mst), cystathionine γ-lyase (cse) and cystathionine β-synthase (cbs), in ventricle and brain of normoxic, anoxic and reoxygenated 21 °c- and 5 °c-acclimated freshwater turtles (trachemys scripta) and 10 °c-acclimated crucian carp (caras ...202032105700
early-life intestinal microbiome in trachemys scripta elegans analyzed using 16s rrna sequencing.during the early-life period, the hatchlings of red-eared slider turtles (trachemys scripta elegans) rely on their own post-hatching internal yolk for several days before beginning to feed. the gut microbiome is critical for the adaptation of organisms to new environments, but, to date, how the microbiome taxa are assembled during early life of the turtle is unknown. in this study, the intestinal microbiome of red-eared slider hatchlings (fed on commercial particle food) was systematically analy ...202032071814
a claustrum in reptiles and its role in slow-wave sleep.the mammalian claustrum, owing to its widespread connectivity with other forebrain structures, has been hypothesized to mediate functions that range from decision-making to consciousness1. here we report that a homologue of the claustrum, identified by single-cell transcriptomics and viral tracing of connectivity, also exists in a reptile-the australian bearded dragon pogona vitticeps. in pogona, the claustrum underlies the generation of sharp waves during slow-wave sleep. the sharp waves, toget ...202032051589
induction of foxo3a protects turtle neurons against oxidative stress.the detrimental effects of oxidative stress caused by the accumulation of reactive oxygen species (ros) factor into aging, senescence and several neurodegenerative diseases. mammalian models are extremely susceptible to the stresses that follow the restoration of oxygen after anoxia; however some organisms including the freshwater turtle trachemys scripta can withstand extended anoxia and reoxygenation without apparent pathology. the ability of the turtle to withstand these conditions is thought ...202032044446
distribution of rods and cones in the red-eared turtle retina (trachemys scripta elegans).we have identified the photoreceptors of trachemys scripta elegans, an intensely studied species that is a model for color vision work. to recognize and count the different photoreceptor types, we labeled them with a combination of morphological and immunohistochemistry markers. the counts for the determination of the density of each photoreceptor type were made in wholemount retinas. the percentages found for each cone type were 29, 23, 21, 12, and 6%, respectively, for l (both types), double, ...202031785154
temperature affects the host hematological and cytokine response following experimental ranavirus infection in red-eared sliders (trachemys scripta elegans).pathogen-host interactions are important components of epidemiological research, but are scarcely investigated in chelonians. red-eared sliders (trachemys scripta elegans), are recognized as a model for frog virus-3 infection (fv3), a ranavirus in the family iridoviridae that infects multiple classes of ectothermic vertebrates. previous challenge studies observed differences in disease outcome based on environmental temperature in this species, but the host response was minimally evaluated. we c ...202033119713
do prolonged fasting periods influence the postprandial metabolic responses in turtles? what can trachemys scripta elegans teach us about this?the postprandial period is characterized by a modification of the gastrointestinal activity after food intake, accompanied by an increase in metabolic rate, secretion of acids, and absorption of nutrients. for ectothermic vertebrates, those changes are particularly prominent given the relatively low metabolic cost and the low frequency of food uptake. however, prolonged fasting periods decrease energy reserves and may compromise the upregulation of costly processes, such as the increase in metab ...202032996720
comparison of lateral and dorsal recumbency during endoscope-assisted oophorectomy in mature pond sliders (trachemys scripta).ovariectomy via the prefemoral fossa is a well-described technique for sterilization in chelonians. the choice between lateral and dorsal recumbency is generally left to the surgeon's preference, with no data supporting an objective superiority of one over the other. twenty-four sexually mature female pond sliders (trachemys scripta) were enrolled for elective prefemoral endoscope-assisted oophorectomy, and were randomly divided in two groups: 12 animals were placed in right lateral recumbency w ...202032825061
isolation and genomic characterization of a pathogenic providencia rettgeri strain g0519 in turtle trachemys scripta.providencia rettgeri infection has occurred occasionally in aquaculture, but is rare in turtles. here, a pathogenic p. rettgeri strain g0519 was isolated from a diseased slider turtle (trachemys scripta) in china, and qpcr assay was established for the rtx toxin (rtxd) gene. histopathological examination showed that many inflammatory cells were infiltrated into heart, liver and intestine, as well as the necrosis of liver, kidney and spleen. the genome consisted of one circular chromosome (4.493  ...202032951105
on some structural and evolutionary aspects of rdna amplification in oogenesis of trachemys scripta turtles.the features of rdna amplification have been studied in oocytes of the red-eared slider trachemys scripta using a number of specific histochemical and cytomolecular methods. a single nucleolus in early diplotene oocytes is associated with the nucleolus organizer region (nor). with oocyte growth, the number of nucleoli increases dramatically and reaches hundreds by the lampbrush chromosome stage (pre-vitellogenesis). rna-polymerase i, fibrillarin, and pcna immunodetection in the amplified nucleol ...202032897424
temporal stability of in vitro venous blood gas, ph, and lactate values of cownose rays (rhinoptera bonasus) and red-eared slider turtles (pseudemys scripta elegans).this study assessed the in vitro temporal changes that occur in blood ph and lactate concentrations for an elasmobranch species and a chelonian species, as well as blood gases (partial pressures of carbon dioxide [pco2] and oxygen [po2]) for a chelonian species, with a portable clinical point-of-care analyzer. blood samples were collected from 10 cownose rays (rhinoptera bonasus) and 10 red-eared sliders (pseudemys scripta elegans), stored on ice, and serially analyzed at six time points up to 9 ...202032212553
effect of benzylpenicillin on intravenous pharmacokinetics of acyclovir in red-eared slider turtles (trachemys scripta elegans).the aim of this study was to determine the effect of benzylpenicillin on the pharmacokinetics of acyclovir in red-eared slider turtles (trachemys scripta elegans). six clinically healthy red-eared slider turtles weighing 400 and 580 g were used for the study. acyclovir (40 mg/kg) and benzylpenicillin (30 mg/kg) were administered intravenously to turtles. in the study, the cross-pharmacokinetic design (2 × 2) with a 30-day washout period was performed in two periods. plasma concentrations of acyc ...202032212341
detection of cryptosporidium parvum in a red-eared slider turtle (trachemys scripta elegans), a noted invasive alien species, captured in a rural aquatic ecosystem in eastern poland.little is known about cryptosporidiosis in turtles of invasive alien species (ias) inhabiting european bodies of fresh water. in this article, we report an occurrence of cryptosporidium parvum in a red-eared slider turtle (trachemys scripta elegans) captured in a rural aquatic ecosystem in eastern poland.202032141020
mucosal antibody quantity but not avidity predicts likelihood of salmonella infection in red-eared slider turtles (trachemys scripta).natural antibodies (nabs) are polyreactive, have low avidity, and are a product of b-1 cells. evidence suggests that nabs may play a key role in immune defense in turtles, as increased total mucosal antibodies are associated with a decreased number of extracellular intestinal parasites. however, it is unknown if this trend extends to other types of pathogens and if avidity of the nab to the pathogen is a factor in protection. we examined the relationship between a common intracellular bacteria i ...202031833242
protein lysine methylation in the regulation of anoxia tolerance in the red eared slider turtle, trachemys scripta elegans.the red eared slider turtle (trachemys scripta elegans) is a champion vertebrate facultative anaerobe, capable of surviving for several months under conditions of exceptionally low oxygen availability. the ability of the turtle to facilitate this impressive tolerance to oxygen restriction is accomplished through a dramatic reduction in non-essential cellular processes. this is done in an attempt to conserve limited atp stores and match demand in the anoxic state, with atp supplied primarily thro ...202032066095
population pharmacokinetics of enrofloxacin and its metabolite ciprofloxacin in clinically diseased or injured eastern box turtles (terrapene carolina carolina), yellow-bellied sliders (trachemys scripta scripta), and river cooters (pseudemys concinna).enrofloxacin is frequently administered to turtles in wildlife clinics during rehabilitation due to its wide spectrum of antibacterial activity and availability of injectable formulations. however, sufficient pharmacokinetic data to guide dosing are lacking. the objective of this study was to determine pharmacokinetic parameters of enrofloxacin and its active metabolite, ciprofloxacin, in chelonians presenting injured to a wildlife clinic. thirty-six eastern box turtles (ebt, terrapene carolina ...202032052471
genetic variation and admixture of red-eared sliders (trachemys scripta elegans) in the usa.the most ubiquitous, abundant, and invasive turtle on earth, trachemys scripta elegans (tse, "red-eared slider"), is one of four taxa in a clade that is native to the usa and adjacent mexico (three subspecies of trachemys scripta plus trachemys gaigeae). the present range-wide study of this clade is based on 173 known-locality mtdna sequences combined with ddrad libraries for 43 samples emphasizing the western part of the range of tse, its contact with that of t. gaigeae, and anthropogenic hybri ...202031874235
serum biochemistry of trachemys scripta elegans and trachemys dorbignyi (testudines: emydidae) bred in captivity in the northeastern semiarid region of brazil.this study aimed to assess fundamental biochemical values of healthy animals and to provide useful data on comparative physiologies of testudines, being assessed the serum biochemistry profiles, and body and tail biometry of trachemys scripta elegans and trachemys dorbignyi bred in interaction in the semiarid region of the são francisco river valley.202032801558
temperature-dependent sex determination is mediated by pstat3 repression of kdm6b.in many reptiles, including the red-eared slider turtle trachemys scripta elegans (t. scripta), sex is determined by ambient temperature during embryogenesis. we previously showed that the epigenetic regulator kdm6b is elevated at the male-producing temperature and essential to activate the male pathway. in this work, we established a causal link between temperature and transcriptional regulation of kdm6b we show that signal transducer and activator of transcription 3 (stat3) is phosphorylated a ...202032299951
an annotated chromosome-level reference genome of the red-eared slider turtle (trachemys scripta elegans).among vertebrates, turtles have many unique characteristics providing biologists with opportunities to study novel evolutionary innovations and processes. we present here a high-quality, partially phased, and chromosome-level red-eared slider (trachemys scripta elegans, tse) genome as a reference for future research on turtle and tetrapod evolution. this tse assembly is 2.269 gb in length, has one of the highest scaffold n50 and n90 values of any published turtle genome to date (n50 = 129.68 mb ...202032227195
smooth muscle in cardiac chambers is common in turtles and extensive in the emydid turtle, trachemys scripta.a prominent layer of smooth muscle lining the luminal side of the atria of freshwater turtles (emydidae) was described more than a century ago. we recently demonstrated that this smooth muscle provides a previously unrecognized mechanism to change cardiac output in the emydid red-eared slider (trachemys scripta) that possibly contributes to their tremendous diving capacity. the purpose of the present immunohistochemical study was firstly to screen major groups of vertebrates for the presence of ...202031509333
modulation of the intestinal barrier adaptive functions in red-eared slider (trachemys scripta elegans) invading brackish waters.globally, the increase in sea levels is leading to salinization of freshwater, which might influence the freshwater organisms such as red-eared slider, trachemys scripta elegans. the turtle can invade brackish water environments, in which it must deal with elevated salinity in the gastrointestinal tract that could impact the intestinal function. the intestinal barrier provides a front-line of organismal defense against the chemical and biological environmental insults. in this study, the adaptiv ...202132890802
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