Publications

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algal infection in a corn snake (elaphe guttata guttata). 19751207051
some corrections of coccidian (apicomplexa: protozoa) nomenclature.the following nomenclatural corrections and changes are introduced for the coccidia. new species: cryptosporidium rhesi from the rhesus monkey macaca mulatta; cryptosporidium serpentis from the snakes elaphe guttata, elapha subocularis, crotalus horridus, and sanzinia madagascarensis; eimeria perazae from the lizard cnemidophorus l. lemniscatus; and eimeria tarichae from the salamander taricha toirosa. new combinations: orcheobius carinii for cariniella carinii from the frog leptodactylus ocella ...19807463253
a zygomycotic infection in captive snakes.we report disseminated, fatal fungal disease involving subcutaneous and visceral tissues in 4 captive snakes (1 elaphe guttata, 2 crotalus horridus, and 1 pituophis melanoleucus). the etiologic agent, which was abundant in the lesion, had a rounded form in vivo with a prominent nucleus. these cells averaged 17 microns in diameter and reproduced by fission, forming clusters of two or four daughter cells. the etiologic agent was isolated on sabouraud dextrose agar from one of the snakes. it also g ...19836683876
responses by corn snakes (elaphe guttata) to chemicals from heterospecific snakes.young corn snakes,elaphe guttata, were tested for responses to chemicals from heterospecific snakes. corn snakes exhibited more tongue-flicks to swabs freshly rubbed against the skin of an ophiophagous kingsnake,lampropeltis getulus, than to blank swabs. responses tol. getulus and a nonophiophagous western plains garter snake,thamnophis radix haydeni, did not differ significantly. corn snakes exhibited more tongue-flicks to swabs treated with chloroform extracts of the shed skins ofl. getulus; a ...199024264894
snake aggregation pheromones: source and chemosensory mediation in western ribbon snakes (thamnophis proximus).aggregation with conspecifics is a robust phenomenon among snakes that is mediated by chemical cues, although the source of such cues is unknown. adult western ribbon snakes (thamnophis proximus) discriminated between skin lipid extracts from conspecifics and those from a sympatric heterospecific snake, the corn snake (elaphe guttata). additionally, ribbon snakes were attracted to conspecific skin lipid-marked shelters when paired with control-marked shelters, but no preference was exhibited whe ...19911860308
physicochemical properties and cytopathogenicity of an adenovirus-like agent isolated from corn snake (elaphe guttata).a virus isolated from the internal organs of a moribund corn snake (elaphe guttata) replicated in reptilian cell cultures (igh-2, th-1 cells) between 10 and 30 degrees c. highest infectivity titers of 10(5.5) tcid50/ml were obtained in igh-2 cells at 25 degrees c. infected igh-2 cells showed the development of three morphologically different intranuclear inclusion bodies. during viral assembly the particles formed typical crystalline aggregates in the nucleus. about 64 h after infection progress ...19938517794
experimental infection of elaphid snakes with cryptosporidium serpentis (apicomplexa: cryptosporidiidae).the shedding pattern of fecal cryptosporidium serpentis oocysts, histopathologic changes in the gastric region, and the effect of spiramycin treatment were investigated in 6 experimentally infected, captive black rat (elaphe obsoleta obsoleta), 4 yellow rat (elaphe obsoleta quadrivittata), and 2 corn snakes (elaphe guttata guttata). feces were monitored for up to 2 years postinfection (pi). no significant (p > 0.07) differences were observed between expected and observed numbers of pi oocyst-pos ...19947931919
biliary cryptosporidiosis in two corn snakes (elaphe guttata). 19968844592
afferent connections of the nucleus accumbens of the snake, elaphe guttata, studied by means of in vitro and in vivo tracing techniques in combination with th immunohistochemistry.the aim of the present study was to determine the afferent connections of the nucleus accumbens in snakes, in particular its catecholaminergic input. for that purpose, in vitro and in vivo applications of retrograde tracers in the nucleus accumbens of elaphe guttata were combined with tyrosine hydroxylase (th) immunohistochemistry. both techniques revealed telencephalic inputs to the nucleus accumbens originating from the diagonal band of broca, ventral pallidum, amygdaloid complex, and dorsal c ...19979147384
colonic adenocarcinoma in a corn snake (elaphe guttata guttata).colonic adenocarcinoma was diagnosed by surgical biopsy in a domestically raised 3-yr-old male corn snake (elaphe guttata guttata). the snake presented with a history of constipation. several masses were palpated in the distal coelomic cavity. on proctoscopy, a nodular firm white mass encircled the distal colon proximal to the cloaca. the histologic diagnosis was transmural mucinous colonic adenocarcinoma with scirrhous reaction. resection of the affected region alleviated intestinal obstruction ...19989809612
modulation of snake hepatic cytochrome p450 by 3-methylcholanthrene and phenobarbital.induction mode of the hepatic drug-metabolizing enzymes was studied in corn snake (elaphe guttata emoryi). treatment of snakes with 3-methylcholanthrene or phenobarbital produced no effects on liver weight and total content of cytochromes p450 and b5. treatment with 3-methylcholanthrene significantly induced the activities of arylhydrocarbon hydroxylase, 7-ethoxyresorufin o-deethylase and 7-pentoxyresorufin o-dealkylase, whereas those of ethoxycoumarin o-deethylase, benzphetamine n-demethylase, ...19989669083
molecular analysis of the 18s rrna gene of cryptosporidium serpentis in a wild-caught corn snake (elaphe guttata guttata) and a five-species restriction fragment length polymorphism- based assay that can additionally discern c. parvum from c. wrairi.an adult wild-caught corn snake (elaphe guttata guttata) was presented for humane euthanasia and necropsy because of severe cryptosporidiosis. the animal was lethargic and >5% dehydrated but in good flesh. gastric lavage was performed prior to euthanasia. histopathologic findings included gastric mucosal hypertrophy and a hemorrhagic erosive gastritis. numerous 5- to 7-microm-diameter round extracellular organisms were associated with the mucosal hypertrophy. a pcr, acid-fast stains, giemsa stai ...199910583987
spatial learning of an escape task by young corn snakes, elaphe guttata guttata.spatial learning is critical to most animals for many behaviours necessary to survival. in vertebrates, most studies on spatial learning and memory have been conducted in mammalian and avian species with few studies on reptiles. we examined spatial learning in the corn snake, elaphe guttata guttata by training 17 young snakes to find the one open shelter in an eight-hole arena, where the entrance was not visible from the arena surface. over a 16-trial, 4-day training period, snakes showed (1) a ...199910053071
phylogeographic analysis of the cornsnake (elaphe guttata) complex as inferred from maximum likelihood and bayesian analyses.most phylogeographic studies have used maximum likelihood or maximum parsimony to infer phylogeny and bootstrap analysis to evaluate support for trees. recently, bayesian methods using marlov chain monte carlo to search tree space and simultaneously estimate tree support have become popular due to its fast search speed and ability to create a posterior distribution of parameters of interest. here, i present a study that utilizes bayesian methods to infer phylogenetic relationships of the cornsna ...200212450751
genomic and phylogenetic analyses of an adenovirus isolated from a corn snake (elaphe guttata) imply a common origin with members of the proposed new genus atadenovirus.approximately 60% of the genome of an adenovirus isolated from a corn snake (elaphe guttata) was cloned and sequenced. the results of homology searches showed that the genes of the corn snake adenovirus (snadv-1) were closest to their counterparts in members of the recently proposed new genus atadenovirus: in phylogenetic analyses of the complete hexon and protease genes, snadv-1 indeed clustered together with the atadenoviruses. the characteristic features in the genome organization of snadv-1 ...200212237421
hepatozoon species (apicomplexa: hepatozoidae) of the corn snake, elaphe guttata (serpentes: colubridae) and the pigmy rattlesnake, sistrurus miliarius barbouri (serpentes: viperidae) in south florida.hepatozoon guttata n. sp. is described from the corn snake (elaphe guttata guttata) from south florida. gamonts average 14.6 x 4.6 (13-17 x 3.5-6) and are not recurved, with nucleus situated in the second quarter of the gamont. erythrocyte cytoplasm rarely appears partially dehemoglobinized. the infected cells are usually distorted and are longer than the uninfected erythrocytes but do not differ in width; nuclei are smaller in length and width than those of uninfected cells. sporogony in aedes ...200212197130
histology of the extraembryonic membranes of an oviparous snake: towards a reconstruction of basal squamate patterns.an understanding of the evolutionary morphology of extraembryonic membranes in reptiles requires information about oviparous as well as viviparous species. we are studying histology and ultrastructure of the extraembryonic membranes of snakes to clarify the evolutionary history of reptilian fetal membranes, including determination of basal (ancestral) ophidian and squamate patterns. microscopic anatomy of the membranes of oviparous corn snakes (elaphe guttata) was examined using light and electr ...200312950034
expression of calbindin-d28k by yolk sac and chorioallantoic membranes of the corn snake, elaphe guttata.the yolk splanchnopleure and chorioallantoic membrane of oviparous reptiles transport calcium from the yolk and eggshell to the developing embryo. among oviparous amniotes, the mechanism of calcium mobilization to embryos has been studied only in domestic fowl, in which the mechanism of calcium transport of the yolk splanchnopleure differs from the chorioallantoic membrane. transport of calcium is facilitated by calbindin-d(28k) in endodermal cells of the yolk splanchnopleure of chickens but the ...200415468049
how snakes eat snakes: the biomechanical challenges of ophiophagy for the california kingsnake, lampropeltis getula californiae (serpentes: colubridae).in this study we investigated how ophiophagous snakes are able to ingest prey snakes that equal or exceed their own length. we used x-ray video, standard video, dissection, and still x-rays to document the process of ophiophagy in kingsnakes (lampropeltis getula) feeding on corn snakes (elaphe guttata). most kingsnakes readily accepted the prey snakes, subdued them by constriction, and swallowed them head first. in agreement with previous observations of ophiophagy, we found that the predator sn ...200416351937
sources and timing of calcium mobilization during embryonic development of the corn snake, pantherophis guttatus.embryos of oviparous reptilia (=turtles, lepidosaurs, crocodilians and birds) extract calcium for growth and development from reserves in the yolk and eggshell. yolk provides most of the calcium to embryos of lizards and snakes. in contrast, the eggshell supplies most of the calcium for embryonic development of turtles, crocodilians and birds. the yolk sac and chorioallantoic membrane of birds recover and transport calcium from the yolk and eggshell and homologous membranes of squamates (lizards ...200415556389
snake care and husbandry.the snake has long been a contradictory species; you either love them or hate them. in the united states, these reptiles are popular pets. there is also a significant amount of energy placed into developing captive breeding programs to produce different color morphs for many species. in some cases, such as the ball pythons (pythonregius), these color morphs can sell for 20,000 dollars to 30,000 dollars each. in comparison to domestic mammals, snakes are long-lived. it is not uncommon for corn sn ...200415145397
mice serve as paratenic hosts for the transmission of caryospora duszynskii (apicomplexa: eimeriidae) between snakes of the genus elaphe.caryospora duszynskii upton, current et barnard, 1984 was successfully transmitted to snakes of the genus elaphe by feeding them previously infected mice. fifty thousand oocysts were orally administered to two mouse strains, balb/c and crl:cd-1(icr)br, which were subsequently fed to captive-born coccidia-free elaphe guttata (l.) in two respective independent experiments. both e. guttata expelled c. duszynskii oocysts in their faeces, beginning on day 18 and 26 post infection (p.i.) and shed oocy ...200516270800
organochlorine detection in the shed skins of snakes.lizards and snakes eliminate heavy metals in their shed skins. there are no data with regard to reptilian skin as a depuration route for organochlorine (oc) compounds; however, birds deposit ocs in feathers. corn snakes (elaphe guttata) were therefore fed thawed mice that had been injected with a mixture of alpha-chlordane, aroclor 1254 (a polychlorinated biphenyl (pcb) mixture), and lindane (gamma-hexachlorocyclohexane) at 2, 8, and 4 mg/kg, respectively. feeding of contaminated mice occurred o ...200515590005
snake egg immunoglobulins: biochemical characteristics and adjusted isolation procedure.transmission of specific immunoglobulins from mothers to their offspring via the egg is a common phenomenon in egg-laying vertebrates but the occurrence of this phenomenon in reptiles, especially in colubrid snakes, has not been proven until recently. thus, the essential biochemical characteristics of antibodies deposited in eggs of elaphe guttata (colubridae, serpentes) were studied after isolation of the antibody by precipitation and purification by affinity chromatography and gel filtration, ...200515777947
excretion of three heavy metals in the shed skin of exposed corn snakes (elaphe guttata).three heavy metals of regional environmental concern-lead, cadmium, and mercury-are frequently evaluated as part of wildlife bioaccumulation and health monitoring studies. shed skins of snakes may represent a useful, nonlethal biomarker tissue for such determinations. in the present study, these three heavy metals were injected into thawed mice that were fed to corn snakes (elaphe guttata) such that snakes received 2mg/kg of each metal/month. shed skins were collected over a period of 34 weeks, ...200616406579
undifferentiated tumor in the ovary of a corn snake (elaphe guttata guttata).a 6-year-old intact female corn snake (elaphe guttata guttata) was presented with a 3-week history of anorexia. coelomic radiographs revealed a 9 x 4 cm soft tissue opacity suggestive of a right ovarian enlargement. the mass (9 x 5 x 4 cm) was surgically removed, and multiple smears from tissue sections were stained with diff-quik. multiple tissue samples from the mass were collected and fixed in formalin. cytologic specimens were moderately cellular and contained light pink amorphous background ...200616511798
evaluation of an implanted osmotic pump for delivery of amikacin to corn snakes (elaphe guttata guttata).the risk of accidental envenomation to the handler of venomous snakes during drug administration limits the ability to treat these animals. one commercially available osmotic pump is a miniature self-contained cylindrical implant that operates on the basis of an osmotic pressure difference between the extracellular fluid and the osmotic agent in the pump. osmotic pumps loaded with amikacin were surgically placed into the coelomic cavity of five adult corn snakes (elaphe guttata guttata) (group a ...200617319138
effects of perch diameter and incline on the kinematics, performance and modes of arboreal locomotion of corn snakes (elaphe guttata).animals moving through arboreal habitats face several functional challenges, including fitting onto and moving on cylindrical branches with variable diameters and inclines. in contrast to lizards and primates, the arboreal locomotion of snakes is poorly understood, despite numerous snake species being arboreal. we quantified the kinematics and performance of corn snakes (elaphe guttata) moving on seven cylinders (diameters 1.6-21 cm) with five inclines (horizontal, +/-45 degrees and +/-90 degree ...200717951427
beta-keratins of differentiating epidermis of snake comprise glycine-proline-serine-rich proteins with an avian-like gene organization.beta-keratins of reptilian scales have been recently cloned and characterized in some lizards. here we report for the first time the sequence of some beta-keratins from the snake elaphe guttata. five different cdnas were obtained using 5'- and 3'-race analyses. four sequences differ by only few nucleotides in the coding region, whereas the last cdna shows, in this region, only 84% of identity. the gene corresponding to one of the cdna sequences has a single intron present in the 5'-untranslated ...200717576619
characterization and cooled storage of semen from corn snakes (elaphe guttata).the phylogenetic order squamata has many representatives that could benefit from the use of semen preservation as a tool for assisting conservation. to date, few studies have been made evaluating the potential for collecting and preserving semen from snakes. the objectives of this study were to characterize semen parameters of the corn snake (elaphe guttata), including appearance, volume, concentration, sperm motility, and sperm morphology, and to determine the longevity of corn snake sperm moti ...200717469269
haematopoiesis in snakes (ophidia) in early postnatal development.the occurrence of haematopoiesis has been studied in various parts of the spine and in the ribs in four species of snakes (boa constrictor l., elaphe guttata l., lamprophis fulaginosus boie., bothrops jararaca wied.) from hatching until 150 days of postnatal development. marrow spaces are formed by chondrolysis with various time frames depending on the studied species. marrow cells egress to the general circulation in two ways: via migration through the endothelial cells lining the venous sinuse ...200717225172
molecular identification of a cryptosporidium saurophilum from corn snake (elaphe guttata guttata). 200717497169
stenotrophomonas maltophilia as a part of normal oral bacterial flora in captive snakes and its susceptibility to antibiotics.only little is known about normal oral bacterial flora in captive snakes containing stenotrophomonas maltophilia. this microbe has been reported as a causative agent of numerous infections in reptiles. therefore, the goal of the study was to detect its presence in the mouths of a significant number of healthy captive snakes and determining its susceptibility to antibiotics at 30 and 37 degrees c. the isolates were obtained in 1999-2005 from mouth swabs of 115 snakes of 12 genera and 22 species-m ...200717276020
oviduct adenocarcinoma in some species of captive snakes.this article reports 5 cases of oviduct adenocarcinoma in adult captive snakes from smithsonian's national zoological park. this neoplasm was found in 1 of each of the following species: emerald tree boa (corallus caninus), amazonian tree boa (corallus enydris enydris), burmese rock python (python molurus bivittatus), northern pine snake (pituophis melanoleucus melanoleucus), and corn snake (elaphe guttata). grossly, tan to red firm masses were found within oviducts in 3 cases. in an additional ...200818725476
circulating siderophagocytes and erythrophagocytes in a corn snake (elaphe guttata) after coelomic surgery.leukocytes containing nonheme iron and phagocytosed fragments of erythrocytes were found in blood smears from a corn snake (elaphe guttata) collected 20 and 79 days after coelomic surgery (ovariosalpingectomy). numerous immature and mitotic erythrocytes also were seen in the sample taken 20 days postsurgically. siderophagocytes and erythrophagocytes had not been observed before surgery and were not found in multiple subsequent blood samples collected 112-602 days after surgery. other than these ...200818761524
effects of temperature and perch diameter on arboreal locomotion in the snake elaphe guttata.arboreality is widespread in multiple lineages of snakes and these habitats are important for foraging, escaping predators, and thermoregulation for many species. however, very little is known about factors influencing the arboreal locomotor abilities of snakes. arboreal performance was assessed in a semi-arboreal snake (elaphe guttata) using an artificial perch apparatus. locomotor velocity, body posture, and balance was measured during movement on three perch diameters (3, 6, 10-cm) at three t ...200818257002
effects of ultraviolet radiation on plasma 25-hydroxyvitamin d3 concentrations in corn snakes (elaphe guttata).to determine whether corn snakes exposed to uvb radiation have increased plasma 25-hydroxyvitamin d3 concentrations, compared with control snakes.200818241029
initiation and patterning of the snake dentition are dependent on sonic hedgehog signaling.here we take the first look at cellular dynamics and molecular signaling in the developing snake dentition. we found that tooth formation differs from rodents in several respects. the majority of snake teeth bud off of a deep, ribbon-like dental lamina rather than as separate tooth germs. prior to and after dental lamina ingrowth, we observe asymmetries in cell proliferation and extracellular matrix distribution suggesting that localized signaling by a secreted protein is involved. we cloned son ...200818456251
arboreal habitat structure affects the performance and modes of locomotion of corn snakes (elaphe guttata).arboreal environments pose many functional challenges for animal locomotion including fitting within narrow spaces, balancing on cylindrical surfaces, moving on inclines, and moving around branches that obstruct a straight path. many species of snakes are arboreal and their elongate, flexible bodies appear well-suited to meet many of these demands, but the effects of arboreal habitat structure on the locomotion of snakes are not well understood. we examined the effects of 108 combinations of sur ...200919189381
metabolic turnover rates of carbon and nitrogen stable isotopes in captive juvenile snakes.metabolic turnover rates (m) of delta(15)n and delta(13)c were assessed in different tissues of newly hatched captive-raised corn snakes (elaphe guttata guttata) fed maintenance diets consisting of earthworms (eisenia foetida) that varied substantially in delta(15)n (by 644 per thousand) and delta(13)c (by 5.0 per thousand). three treatments were used during this 144 day experiment that consisted of the same diet throughout (control), shifting from a depleted to an enriched stable isotope signat ...200919089855
detection of polycyclic aromatic hydrocarbons in the shed skins of corn snakes (elaphe guttata).previous work has shown that organochlorine compounds, including chlordane, lindane and polychlorinated biphenyls, and heavy metals, including lead, mercury and cadmium, are readily detected in the shed skins of snakes dosed with these toxicants. this suggested the shed skins may have broad utility as a non-lethal biomarker tissue for environmental contamination. in the present study, two polycyclic aromatic hydrocarbons (pahs), benzo[a]pyrene (b[a]p) and 3-methylcholanthrene (3-mc), were simila ...200919631985
three new hepatozoon species (apicomplexa: hepatozoidae) infecting the florida kingsnake, lampropeltis getula floridana.the florida kingsnake, lampropeltis getula floridana, is host to 3 species of hepatozoon at the type locality, miramar, broward county, florida, and 2, possibly all 3, species at cedar key, levy county, approximately 480 km to the northwest. hepatozoon eurytopis, n. sp. was present also in diadophis punctatus and elaphe guttata in jupiter farms, palm beach county, and in thamnophis sirtalis at gainesville, alachua county. specific identity in d. punctatus was determined from gamont morphology an ...201019685939
Detection of Cryptosporidium species in feces or gastric contents from snakes and lizards as determined by polymerase chain reaction analysis and partial sequencing of the 18S ribosomal RNA gene.Cryptosporidiosis is a well-known gastrointestinal disease of snakes and lizards. In the current study, 672 samples (feces and/or gastric contents or regurgitated food items) of various snakes and lizards were examined for the presence of cryptosporidia by polymerase chain reaction (PCR) assay targeting a part of the 18S ribosomal RNA gene. A consecutive sequencing reaction was used to identify the cryptosporidian species present in PCR-positive samples. Cryptosporidium varanii (saurophilum) was ...201121908271
a unique novel reptilian paramyxovirus, four atadenovirus types and a reovirus identified in a concurrent infection of a corn snake (pantherophis guttatus) collection in germany.in 2009, 26 clinical samples (organs and oral/cloacal swabs) from a total of 24 corn snakes (pantherophis guttatus) from a single owner were sent to our laboratory to be tested for the presence of viruses. paramyxoviruses (pmv), adenoviruses (adv) and reoviruses were detected by rt-pcr, pcr and virus isolation methods. three snakes were infected with all three viruses at the same time, while two other snakes had a double infection (pmv and reo, adv and reo) and nine other snakes had a single inf ...201121316873
coelomic swelling in a spayed female corn snake (elaphe guttata guttata). 201121772348
cardiac hemangioma in a corn snake (pantherophis guttatus).a 3-yr-old female corn snake, pantherophis guttatus guttatus, was presented for clinical examination of anorexia and a coelomic mass. radiographs and ultrasound demonstrated a fluid-filled mass in the cardiac region. surgical exploration revealed an approximately 1.2-cm, round, multilobulated, fluid-filled, nodular lesion firmly attached to the left atrial wall. resection was attempted but proved unsuccessful and the animal was euthanized. histopathological examination of the lesion revealed a l ...201222779242
four additional hepatozoon species (apicomplexa: hepatozoidae) from north florida ratsnakes, genus pantherophis.records from a colubrid host are reported for hepatozoon horridus, described originally from a viperid snake. hepatozoon horridus in pantherophis guttatus (colubridae) has gamonts 14-18.0 by 4.0-5.5 microm, with length by width (lw) 60-99 microm2, and l/w ratio 2.5-3.9. spherical to elongate, usually ovoid oocysts with l/w ratio 1.0-3.7 contain 16-160 spherical to usually ovoid sporocysts 15-31 by 14-26 microm, with l/w ratio 1.0-1.4, that contain 5-24 sporozoites. two additional hepatozoon spec ...201223136796
recovery of aeromonas hydrophila associated with bacteraemia in captive snakes.captive snakes, that is, a jamaican boa (epicrates subflavus) a yellow anaconda (eunectes notaeus) and a corn snake (pantherophis guttatus guttatus), died with signs of bacteraemia including the presence of petechial haemorrhages in the mouth and gums and haemorrhages in the lung, spleen and intestines. the abdomen and anus were swollen with bloody-tinged mucus in the colon. aeromonas hydrophila was recovered in dense virtually pure culture growth from the internal organs. characterization of th ...201222680932
organized emergence of multiple-generations of teeth in snakes is dysregulated by activation of wnt/beta-catenin signalling.in contrast to mammals, most reptiles constantly regenerate their teeth. in the snake, the epithelial dental lamina ends in a successional lamina, which proliferates and elongates forming multiple tooth generations, all linked by a permanent dental lamina. to investigate the mechanisms used to control the initiation of new tooth germs in an ordered sequential pattern we utilized the polyphodont (multiple-generation) corn snake (pantherophis guttatus). we observed that the dental lamina expressed ...201324019968
development of the hearts of lizards and snakes and perspectives to cardiac evolution.birds and mammals both developed high performance hearts from a heart that must have been reptile-like and the hearts of extant reptiles have an unmatched variability in design. yet, studies on cardiac development in reptiles are largely old and further studies are much needed as reptiles are starting to become used in molecular studies. we studied the growth of cardiac compartments and changes in morphology principally in the model organism corn snake (pantherophis guttatus), but also in the ge ...201323755108
three-dimensional locations of destinations have species-dependent effects on the choice of paths and the gap-bridging performance of arboreal snakes.challenges for moving in arboreal environments include sizable gaps and variable three-dimensional locations between the discrete destinations created by branches. different three-dimensional orientations of the body change the mechanical demands of crossing gaps, especially for elongate animals, but these effects on both the maximal gap distance crossed (gapmax ) and the choice of destinations are poorly understood despite many animals frequently encountering these circumstances. we tested and ...201323281077
snake co-occurrence patterns are best explained by habitat and hypothesized effects of interspecific interactions.snakes often occur in species-rich assemblages, and sympatry is thought to be facilitated primarily by low diet overlap, not interspecific interactions. we selected, a priori, three species pairs consisting of species that are morphologically and taxonomically similar and may therefore be likely to engage in interspecific, consumptive competition. we then examined a large-scale database of snake detection/nondetection data and used occupancy modelling to determine whether these species occur tog ...201423998642
presence of a glycine-cysteine-rich beta-protein in the oberhautchen layer of snake epidermis marks the formation of the shedding layer.the complex differentiation of snake epidermis largely depends on the variation in the production of glycine-cysteine-rich versus glycine-rich beta-proteins (beta-keratins) that are deposited on a framework of alpha-keratins. the knowledge of the amino acid sequences of beta-proteins in the snake pantherophis guttatus has allowed the localization of a glycine-cysteine-rich beta-protein in the spinulated oberhautchen layer of the differentiating shedding complex before molting takes place. this p ...201424817366
the corn snake yolk sac becomes a solid tissue filled with blood vessels and yolk-rich endodermal cells.the amniote egg was a key innovation in vertebrate evolution because it supports an independent existence in terrestrial environments. the egg is provisioned with yolk, and development depends on the yolk sac for the mobilization of nutrients. we have examined the yolk sac of the corn snake pantherophis guttatus by the dissection of living eggs. in contrast to the familiar fluid-filled sac of birds, the corn snake yolk sac invades the yolk mass to become a solid tissue. there is extensive prolif ...201424402715
the genome sequence of the corn snake (pantherophis guttatus), a valuable resource for evodevo studies in squamates.squamates (snakes and lizards) exhibit a striking variety of phenotypes, with little known on their generative mechanisms. studies aiming to understand the genetic basis of this wide diversity in morphology, physiology and ecology will greatly benefit from whole genome sequencing initiatives, as they provide the foundation for comparative analyses and improve our understanding of the evolution, development and diversification of traits. here, we present the first draft genome of the corn snake p ...201426154328
determinants and repeatability of the specific dynamic response of the corn snake, pantherophis guttatus.ingesting, digesting, absorbing, and assimilating a meal are all energy consuming processes that accumulate to form the specific dynamic action (sda) of the meal. sensitive to digestive demand, sda is theoretically fixed to a given meal size and type. in this study, we altered relative meal size to explore the effects of digestive demand on the postprandial metabolic profile and sda of the corn snake, pantherophis guttatus. we also examined the effects of body temperature on the sda response whi ...201424361263
amelanism in the corn snake is associated with the insertion of an ltr-retrotransposon in the oca2 gene.the corn snake (pantherophis guttatus) is a new model species particularly appropriate for investigating the processes generating colours in reptiles because numerous colour and pattern mutants have been isolated in the last five decades. using our captive-bred colony of corn snakes, transcriptomic and genomic next-generation sequencing, exome assembly, and genotyping of snps in multiple families, we delimit the genomic interval bearing the causal mutation of amelanism, the oldest colour variant ...201526597053
experimental infection of snakes with ophidiomyces ophiodiicola causes pathological changes that typify snake fungal disease.snake fungal disease (sfd) is an emerging skin infection of wild snakes in eastern north america. the fungus ophidiomyces ophiodiicola is frequently associated with the skin lesions that are characteristic of sfd, but a causal relationship between the fungus and the disease has not been established. we experimentally infected captive-bred corn snakes (pantherophis guttatus) in the laboratory with pure cultures of o. ophiodiicola. all snakes in the infected group (n = 8) developed gross and micro ...201526578676
scanning laser ophthalmoscopy and optical coherence tomography imaging of spectacular ecdysis in the corn snake (pantherophis guttatus) and the california king snake (lampropeltis getulus californiae).one of the singularities of the eyes of snakes is the presence of the spectacle, a transparent and vascularized integument covering the cornea. the spectacle is completely renewed during ecdysis. combined scanning laser ophthalmoscopy (slo), optical coherence tomography (oct), and conventional macrophotography were used to image this phenomenon.201524787982
ultrastructure of the fetal membranes of the oviparous kingsnake, lampropeltis getula (colubridae) as revealed by scanning electron microscopy.in reptilian sauropsids, fetal (extraembryonic) membranes that line the eggshell sustain developing embryos by providing for gas exchange and uptake of water and eggshell calcium. however, a scarcity of morphological studies hinders an understanding of functional specializations and their evolution. in kingsnakes (lampropeltis getula), scanning electron microscopy reveals two major fetal membranes: the chorioallantois and yolk sac omphalopleure. in early development, the chorioallantois contains ...201526335135
consequences of complex environments: temperature and energy intake interact to influence growth and metabolic rate.the field of comparative physiology has a rich history of elegantly examining the effects of individual environmental factors on performance traits linked to fitness (e.g., thermal performance curves for locomotion). however, animals live in complex environments wherein multiple environmental factors co-vary. thus, we investigated the independent and interactive effects of temperature and energy intake on the growth and metabolic rate of juvenile corn snakes (pantherophis guttatus) in the contex ...201525899738
novel parvoviruses in reptiles and genome sequence of a lizard parvovirus shed light on dependoparvovirus genus evolution.here, we report the detection and partial genome characterization of two novel reptilian parvoviruses derived from a short-tailed pygmy chameleon (rampholeon brevicaudatus) and a corn snake (pantherophis guttatus) along with the complete genome analysis of the first lizard parvovirus, obtained from four bearded dragons (pogona vitticeps). both homology searches and phylogenetic tree reconstructions demonstrated that all are members of the genus dependoparvovirus. even though most dependoparvovir ...201526067293
why arboreal snakes should not be cylindrical: body shape, incline and surface roughness have interactive effects on locomotion.depending on animal size, shape, body plan and behaviour, variation in surface structure can affect the speed and ease of locomotion. the slope of branches and the roughness of bark both vary considerably, but their combined effects on the locomotion of arboreal animals are poorly understood. we used artificial branches with five inclines and five peg heights (≤40 mm) to test for interactive effects on the locomotion of three snake species with different body shapes. unlike boa constrictors (boa ...201526677261
heterochrony and early left-right asymmetry in the development of the cardiorespiratory system of snakes.snake lungs show a remarkable diversity of organ asymmetries. the right lung is always fully developed, while the left lung is either absent, vestigial, or well-developed (but smaller than the right). a 'tracheal lung' is present in some taxa. these asymmetries are reflected in the pulmonary arteries. lung asymmetry is known to appear at early stages of development in thamnophis radix and natrix natrix. unfortunately, there is no developmental data on snakes with a well-developed or absent left ...201525555231
cutaneous and subcutaneous soft tissue tumours in snakes: a retrospective study of 33 cases.cutaneous and subcutaneous soft tissue tumours have been rarely described in detail in snakes. several malignant entities show strikingly similar histological patterns and therefore the term soft tissue sarcoma (sts) has become a standard histopathological diagnosis. the present study characterizes soft tissue tumours in 33 snakes. samples included 29 surgically excised masses and four carcasses. additionally, six animals were humanely destroyed and submitted for necropsy examination following t ...201627324744
molecular identification of cryptosporidium species from pet snakes in thailand.cryptosporidium is an important pathogen causing gastrointestinal disease in snakes and is distributed worldwide. the main objectives of this study were to detect and identify cryptosporidium species in captive snakes from exotic pet shops and snake farms in thailand. in total, 165 fecal samples were examined from 8 snake species, boa constrictor (boa constrictor constrictor), corn snake (elaphe guttata), ball python (python regius), milk snake (lampropeltis triangulum), king snake (lampropeltis ...201627658593
a renal adenocarcinoma in a corn snake (pantherophis guttatus) resembling human collecting duct carcinoma.a 5-year-old male captive corn snake (pantherophis guttatus) with caudal coelomic swelling was admitted for surgical treatment. laparotomy revealed a 5 × 4 × 2.5 cm, firm, expansile, irregularly shaped mass arising from the middle portion of the right kidney with a mild lobulated pattern and mottled white-to-tan. microscopically, the mass was composed of numerous bizarre angulated tubules of polygonal neoplastic cells separated by a scirrhous stroma with remarkable heterophilic infiltrates. the ...201627493139
plasticity of immunity in response to eating.following a meal, an animal can exhibit dramatic shifts in physiology and morphology, as well as a substantial increase in metabolic rate associated with the energetic costs of processing a meal (i.e. specific dynamic action, sda). however, little is known about the effects of digestion on another important physiological and energetically costly trait: immune function. thus, we tested two competing hypotheses. (1) digesting animals up-regulate their immune systems (putatively in response to the ...201627099367
eating increases oxidative damage in a reptile.while eating has substantial benefits in terms of both nutrient and energy acquisition, there are physiological costs associated with digesting and metabolizing a meal. frequently, these costs have been documented in the context of energy expenditure while other physiological costs have been relatively unexplored. here, we tested whether the seemingly innocuous act of eating affects either systemic pro-oxidant (reactive oxygen metabolite, rom) levels or antioxidant capacity of corn snakes (panth ...201627099366
virus distribution and detection in corn snakes (pantherophis guttatus) after experimental infection with three different ferlavirus strains.ferlaviruses are important pathogens of snakes. however, factors influencing the pathogenicity of individual isolates as well as optimal protocols for virus detection in tissues of infected snakes have been insufficiently studied. the objectives of this study were to compare virus detection using previously described pcr and cell culture protocols following infection with three genetically distinct ferlaviruses in corn snakes (pantherophis guttatus) as a model species. groups of 12 corn snakes w ...201626711050
preliminary evaluation of 99mtechnetium diethylenetriamine pentaacetic acid, 99mtechnetium dimercaptosuccinic acid, and 99mtechnetium mercaptoacetyltriglycine for renal scintigraphy in corn snakes (elaphe guttata guttata).the efficacy of three radiopharmaceuticals, 99mtc-diethylenetriaminepentaacetic acid (99mtc-dtpa), 99mtc-dimercaptosuccinic acid (99mtc-dmsa), and 99mtc-mercaptoacetyltriglycine (99mtc-mag3), for renal imaging was examined in 16 corn snakes (elaphe guttata guttata). all snakes received the radiopharmaceutical via an intracardiac injection. the kidneys could not be visualized in the three snakes that received 99mtc-dtpa or in the three snakes that received 99mtc-dmsa, but were well delineated in ...201616553157
morphological specializations of the yolk sac for yolk processing in embryonic corn snakes (pantherophis guttatus: colubridae).non-avian reptiles commonly are assumed to be like birds in their overall patterns of development. however, colubrid corn snakes (pantherophis guttatus) have mechanisms of yolk cellularization and processing that are entirely different from the avian pattern. in birds, a vascular "yolk sac" surrounds and digests the liquid yolk. in contrast, in corn snakes, the yolk material is converted into vascularized cords of yolk-filled cells. in this study, we used stereomicroscopy, histology, and scannin ...201728333368
morphology and morphometry of the lung in corn snakes (pantherophis guttatus) infected with three different strains of ferlavirus.ophidian paramyxovirus (ferlavirus) is a global threat to reptilian sauropsids in herpetological collections, with occasional but fatal effects. this study characterizes the effects of three different genetic strains of ferlavirus on the dynamic changes of histology and morphometry of the lung of corn snakes (pantherophis guttatus). lungs from 42 corn snakes were either sham-infected or infected experimentally under standardized conditions. from 4 to 49 days after intratracheal inoculation, the ...201728284556
a simulated heat wave has diverse effects on immune function and oxidative physiology in the corn snake (pantherophis guttatus).animals will continue to encounter increasingly warm environments, including more frequent and intense heat waves. yet the physiological consequences of heat waves remain equivocal, potentially because of variation in adaptive plasticity (reversible acclimation) and/or aspects of experimental design. thus, we measured a suite of physiological variables in the corn snake (pantherophis guttatus) after exposure to field-parameterized, fluctuating temperature regimes (moderate temperature and heat w ...201728398156
immunologic responses in corn snakes (pantherophis guttatus) after experimentally induced infection with ferlaviruses.objective to measure immunologic responses of snakes after experimentally induced infection with ferlaviruses. animals 42 adult corn snakes (pantherophis guttatus) of both sexes. procedures snakes were inoculated intratracheally with genogroup a (n = 12), b (12), or c (12) ferlavirus (infected groups) or cell-culture supernatant (6; control group) on day 0. three snakes from each infected group were euthanized on days 4, 16, 28, and 49, and 3 snakes from the control group were euthanized on day ...201728345994
pet snakes illegally marketed in brazil: climatic viability and establishment risk.invasive species are one among many threats to biodiversity. brazil has been spared, generically, of several destructive invasive species. reports of invasive snakes' populations are nonexistent, but the illegal pet trade might change this scenario. despite the brazilian laws forbid to import most animals, illegal trade is frequently observed and propagules are found in the wild. the high species richness within brazilian biomes and accelerated fragmentation of natural reserves are a critical fa ...201728817630
a novel pattern of yolk processing in developing snake eggs (colubridae: lampropeltini) and its functional and evolutionary implications.early amniotic vertebrates evolved large-yolked eggs that permitted production of well-developed, terrestrial hatchlings. this reproductive pattern required new mechanisms for cellularizing the yolk and mobilizing it for embryonic use. in birds, cells that line the yolk sac cavity phagocytose and digest the yolk material, a pattern that is commonly assumed to be universal among oviparous amniotes. however, recent evidence challenges the assumption that all squamate reptiles conform to the avian ...201728544760
the intake of water containing a mix of pollutants at environmentally relevant concentrations leads to defensive response deficit in male c57bl/6j mice.previous studies have individually confirmed the toxic effects from different pollutants on mammals. however, effects resulting from the exposure of these animals to multi-pollutant mixes have not been studied so far. thus, the aim of the current study is to assess the effect from the chronic exposure (105days) of c57bl/6j mice to a mix of pollutants on their response to potential predators. in order to do so, the following groups were formed: "control", "mix 1× [compounds from 15 pollutants ide ...201829432930
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