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At least 37 records · Page 2Linked to original sources
PubMed1985

Prolonged diving and recovery in the freshwater turtle, Pseudemys scripta--IV. Effects of profound acidosis on O2 consumption in turtle vs rat (mammalian) brain and heart slices.

The oxygen consumption of rat versus turtle brain and heart slices was compared as a function of extracellular pH and temperature. At pH = 6.20 rat (mammalian) brain and heart slices show a significant depression of oxygen consumption as compared to pH = 7.50 at temperatures of both 24 degrees and 37 degrees C. In the turtle oxygen consumption in brain and heart slices was not depressed at pH = 6.20 compared to pH = 7.50 at 24 degrees C and brain oxygen consumption was not significantly different at the two pH values at 37 degrees C. Turtle heart QO2 was depressed at 37 degrees C. The results suggest that extracellular acidosis depresses mitochondrial O2 uptake in mammalian brain and heart, playing a role in the bioenergetic manifestations of O2 depletion. Turtle brain mitochondria do not show a depression of QO2 at the acidotic pH. The resistance to acidosis of turtle brain mitochondria presumably enhances the possibility of survival following prolonged diving by maintaining ATP generation during the early diving period and during recovery.

Acidosis↗
PubMed2005

Saving sea turtles: the evolution of the IUCN Marine Turtle Group.

When Peter Scott became chairman of the Survival Service Commission of the International Union for the Conservation of Nature and Natural Resources (IUCN) in 1963, he invited Archie Carr to chair the Marine Turtle Group (MTG). A leading authority on the ecology and conservation of sea turtles, Carr believed that the MTG could be the first international forum for sea turtle research and conservation. The assembly of data for the IUCN Red Data Book revealed which species of turtles were threatened with extinction and the array of risks that they faced. Although Carr and Scott differed on what courses of action should be taken in light of this, the MTG did emerge as an important international congress that remains an inspiration to current marine protection efforts.

Animals↗
PubMed1984

Eradication of Salmonella and Arizona species from turtle hatchlings produced from eggs treated on commercial turtle farms.

On commercial turtle farms more than 40% of the hatchlings excrete detectable levels of Salmonella and Arizona spp. when hatched from nonsanitized eggs incubated in sawdust or dirt-filled chambers. Over a 3-year period on 10 farms, more than 10(6) turtle eggs were treated in an attempt to hatch Salmonella-free turtles. Eggs were sanitized in disinfectant, treated by temperature- or pressure-differential dip methods in solutions containing 500 micrograms or more of gentamicin sulfate per ml, and hatched in sanitized plastic chambers free of bedding material. The Salmonella and Arizona spp. infection levels for turtles produced from treated eggs were 0 and 1.12% for years 1 and 2, respectively, whereas infection levels for hatchlings produced from nontreated eggs during these periods were 47 and 44%, respectively. During year 3, dip solutions were filtered daily, treated at 100 degrees C for 15 min on a weekly basis to free the solution of microbial contaminants and egg protein, charged with gentamicin after 10,000 to 20,000 eggs had been treated to maintain antimicrobial activity at 500 micrograms/ml or more, and maintained at pH 6.0 to preserve optimal antimicrobial activity. The implementation of these measures in year 3 resulted in an infection level of 0.15% when the tissues of 3 of 1,959 hatchlings tested were positive for Salmonella and Arizona spp., whereas the tissues of 66 (49.0%) of 135 hatchlings produced from nontreated eggs were positive.

Animals↗
PubMed1995

Effects of anoxia on protein phosphatase in turtle organs: purification and properties of protein phosphatase type-1 from turtle liver.

Protein phosphatase type 1 (PP-1) was analyzed in organs of the red-eared slider turtle, Trachemys scripta elegans, a species capable of long-term anoxia survival. During anoxic submergence at 7 degrees C, PP-1 activity in liver rapidly decreased to 63% of the control value within the first hour and remained suppressed over the subsequent 20 h of anoxia. PP-1 activity was also suppressed in red skeletal muscle during anoxia and dropped transiently (after 1 h) in brain but did not change in heart or white muscle. PP-1 was purified from turtle liver using polyethylene glycol fractionation and chromatography on DEAE-cellulose, blue dextran, Sephacryl S-200, and ADP-agarose. A 3000-fold purification was achieved with a final specific activity of 3156 nmol released min-1 mg protein-1 using 32P-labeled phosphorylase a as the substrate. Turtle liver PP-1 was a monomer of molecular mass 37 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis or 38 +/- 2 kDa by Sephacryl S-200 gel filtration. The enzyme was inhibited by okadaic acid (Ki 12.6 +/- 1.4 nM) and AMP (Ki 23 +/- 2 microM) as well as by ADP, ATP, and IMP. Regulation of liver PP-1 appears to be an integral part of anoxia-induced changes in liver glycogenolysis and metabolic rate suppression.

Adenosine Monophosphate↗
PubMed1984

Turtle lymphocyte surface antigens in chelydra serpentina as characterized by rabbit anti-turtle thymocyte sera.

Spleen and thymus suspensions from the turtle, Chelydra serpentina were examined by indirect immunofluorescence with a rabbit anti-turtle thymocyte serum (RATT). After the species-specific antibodies had been absorbed out, the antisera labeled all lymphocytes in the thymus and spleen. The specificity of RATT for thymocytes was greater than the specificity for splenic lymphocytes. The presence of two antigens, one thymus specific, TS, and another shared by both thymocytes and splenic lymphocytes, LS, is suggested. The TS antigen was absent from a minor subpopulation of turtle thymocytes and may represent a mature population of T-like cells in the thymus.

Animals↗
PubMed2005

Production of monoclonal antibodies against Chinemys reevesii turtle vitellogenin and their usage for comparison of biochemical and immunological characters of vitellogenins and yolk proteins of freshwater turtles.

Four hybridoma clones (ACV-1, -3, -4, and -5) were established for Chinemys reevesii (Reeves' turtle) vitellogenin (VTG) as a precursor protein of egg yolk and a biomarker of environmental pollution. Binding-inhibition experiments indicated that the epitopes of four mAbs were distinct. No binding of ACV-4 to C. reevesii VTG in the Western blot suggests that the epitope of ACV-4 would be dependent on the three-dimensional structure. ACV-1, -3, and -5 bound to C. reevesii VTG in the Western blot. The signal for ACV-1 and -5 disappeared by reduction of the VTG, suggesting that the construction of the epitopes for ACV-1 and -5 were dependent on the disulfide bridge in the VTG molecule. All four mAbs recognized Trachemys scripta and Mauremys japonica VTGs in the ELISA. The yolk proteins were tested for the binding of the mAbs in the Western blot. ACV-1 being capable to bind to the VTG in the reduced condition did not bind to any protein bands of the yolk. This indicates that ACV-1 recognizes a part of the VTG molecule that is not incorporated in the oocytes. Both ACV-3 and -5 bound to the 32- and 70-kDa yolk proteins. Since a mAb recognizes only one site (epitope) on a protein molecule, the 32-kDa protein originated from the 70-kDa one. An ELISA system using ACV-5 as the capture antibody and ACV-3 as the detecting antibody showed the lower detectable concentration (2 ng/mL) and a wide detectable range to 1000 ng/mL (R2=0.999). The system was used to determine serum VTG levels of juvenile turtles treated with estradiol-17beta or vehicle (corn oil). By the use of the mAbs described in this paper, basic and applied studies for turtle VTGs would be improved.

Animals↗
PubMed2004

The Ozobranchus leech is a candidate mechanical vector for the fibropapilloma-associated turtle herpesvirus found latently infecting skin tumors on Hawaiian green turtles (Chelonia mydas).

Fibropapillomatosis (FP) of marine turtles is a neoplastic disease of ecological concern. A fibropapilloma-associated turtle herpesvirus (FPTHV) is consistently present, usually at loads exceeding one virus copy per tumor cell. DNA from an array of parasites of green turtles (Chelonia mydas) was examined with quantitative PCR (qPCR) to determine whether any carried viral loads are sufficient to implicate them as vectors for FPTHV. Marine leeches (Ozobranchus spp.) were found to carry high viral DNA loads; some samples approached 10 million copies per leech. Isopycnic sucrose density gradient/qPCR analysis confirmed that some of these copies were associated with particles of the density of enveloped viruses. The data implicate the marine leech Ozobranchus as a mechanical vector for FPTHV. Quantitative RT-PCR analysis of FPTHV gene expression indicated that most of the FPTHV copies in a fibropapilloma have restricted DNA polymerase expression, suggestive of latent infection.

Animals↗
PubMed2001

Transmission of Haemogregarina balli from painted turtles to snapping turtles through the leech Placobdella ornata.

Six leeches (Placobdella ornata) were allowed to feed on a painted turtle (Chrysemys picta marginata) infected with Haemogregarina balli and subjected to a period of diapause before being allowed to feed on 2 laboratory-reared snapping turtles (Chelydra serpentina). Weekly examination of thin blood films revealed infections of the turtles at 130 days postfeeding. These observations provide support for broad host specificity of hemogregarine parasites of chelonians.

Animals↗
PubMed1999

Ionic exchanges of turtle shell in vitro and their relevance to shell function in the anoxic turtle

To understand more fully the role of the in vivo turtle shell in buffering lactic acid produced during prolonged anoxia, powdered turtle shell was incubated in vitro at constant pH (6.0, 6.5, 7.0, 7. 5 or 8.0) in electrolyte solutions simulating extracellular fluid. Exchanges of ions and CO2 between the shell and solution were evaluated by measuring pre- and post-incubation solution concentrations of calcium, magnesium, sodium, potassium, chloride, phosphate and lactate. The production of CO2 from the shell and lactate within the shell were also measured. We observed that calcium and magnesium, but not phosphate, were released from the shell in association with CO2 and that the magnitude of release of each increased with solution acidity. The amount of acid titration required to maintain constant pH also increased as solution pH fell. The CO2 loss, in mmol, was approximately half the acid titration (in mmol), indicating that the evolved CO2 derives from carbonate. When the incubating solution contained lactate (50 mmol l-1), lactate entered the shell and again the amount entering the shell increased with solution acidity. Shell samples containing high initial lactate levels lost lactate to the solution and at high pH (7.5) acidified the solution and required NaOH titration for pH-stat control. These results are consistent with observations on anoxic turtles in vivo and confirm the important role of the shell as a source of buffer and as a storage site for lactate.

Journal Article↗
PubMed2003

Msx genes are expressed in the carapacial ridge of turtle shell: a study of the European pond turtle, Emys orbicularis.

The turtle shell forms by extensive ossification of dermis ventrally and dorsally. The carapacial ridge (CR) controls early dorsal shell formation and is thought to play a similar role in shell growth as the apical ectodermal ridge during limb development. However, the molecular mechanisms underlying carapace development are still unknown. Msx genes are involved in the development of limb mesenchyme and of various skeletal structures. In particular, precocious Msx expression is recorded in skeletal precursors that develop close to the ectoderm, such as vertebral spinous processes or skull. Here, we have studied the embryonic expression of Msx genes in the European pond turtle, Emys orbicularis. The overall Msx expression in head, limb, and trunk is similar to what is observed in other vertebrates. We have focused on the CR area and pre-skeletal shell condensations. The CR expresses Msx genes transiently, in a pattern similar to that of fgf10. In the future carapace domain, the dermis located dorsal to the spinal cord expresses Msx genes, as in other vertebrates, but we did not see expansion of this expression in the dermis located more laterally, on top of the dermomyotomes. In the ventral plastron, although the dermal osseous condensations form in the embryonic Msx-positive somatopleura, we did not observe enhanced Msx expression around these elements. These observations may indicate that common mechanisms participate in limb bud and CR early development, but that pre-differentiation steps differ between shell and other skeletal structures and involve other gene activities than that of Msx genes.

Animals↗
PubMed2004

Nucleotide sequence of an ICP18.5 assembly protein (UL28) gene of green turtle herpesvirus pathogenically associated with green turtle fibropapilloma.

Because newly identified green turtle herpesvirus (GTHV) is associated pathogenically with marine turtle fibropapillomatosis (FP) and it has not been isolated in vitro, molecular sequencing and analysis of the genomic DNA of this putative reptilian herpesvirus will enhance the current understanding of GTHV in causing the FP disease. An inverse polymerase chain reaction (IPCR) genomic walking technique was developed to obtain new DNA sequences based on a portion of known genomic sequence. Through two genomic walks, a 2169 bp DNA fragment of GTHV was cloned and sequenced. Sequence analysis shows that this DNA fragment contains the entire gene of the UL28, as well as the partial genomic sequence of the UL27 gene. The UL28 gene is 2250 bp long and encodes a 750-amino acid peptide known as ICP18.5 assembly protein of herpesviruses. Phylogenetic analysis of the GHTV UL28 gene showed a high sequence homology with the UL28 homologs of other herpesviruses and supports the current classification of GTHV to be a member of Alphaherpesvirinae. Identification of the genomic sequences of GTHV provides a molecular base for the development of diagnostic immunoassay and also for the determination of the pathogenic role of GTHV infection.

Alphaherpesvirinae↗
PubMedDate not supplied

The physiology of overwintering in a turtle that occupies multiple habitats, the common snapping turtle (Chelydra serpentina).

Common snapping turtles, Chelydra serpentina (Linnaeus), were submerged in anoxic and normoxic water at 3 degrees C. Periodic blood samples were taken, and PO(2), PCO(2), pH, [Na(+)], [K(+)], [Cl(-)], total Ca, total Mg, [lactate], [glucose], hematocrit, and osmolality were measured; weight gain was determined; and plasma [HCO(3)(-)] was calculated. Submergence in normoxic water caused a decrease in PCO(2) from 10.8 to 6.9 mmHg after 125 d, partially compensating a slight increase in lactate and allowing the turtles to maintain a constant pH. Submergence in anoxic water caused a rapid increase in lactate from 1.8 to 168.1 mmol/L after 100 d. Associated with the increased lactate were decreases in pH from 8.057 to 7.132 and in [HCO(3)(-)] from 51.5 to 4.9 mmol/L and increases in total Ca from 2.0 to 36.6 mmol/L, in total Mg from 1.8 to 12.1 mmol/L, and in [K(+)] from 3.08 to 8.45 mmol/L. We suggest that C. serpentina is tolerant of anoxic submergence and therefore is able to exploit habitats unavailable to some other species in northern latitudes.

Acid-Base Equilibrium↗
PubMed1997

Determination of the entire sequence of turtle CR1: the first open reading frame of the turtle CR1 element encodes a protein with a novel zinc finger motif.

CR1 elements are a family of retroposons. They are classified as long interspersed elements (LINEs) or non-long-terminal-repeat (non-LTR) retrotransposons, and they have been found in the genomes of many vertebrates. However, they have been only partially characterized, and only a 2-kb region of the 3' end of chicken CR1 has been sequenced. In the present study, we determined the entire consensus sequence of CR1 elements in the turtle genome, designated PsCR1. The first open reading frame (ORF1) of PsCR1 has two unusual arrangements of Cys residues. One of them includes a zinc finger motif, CX2CX14CX2C. The putative zinc finger has cysteine residues with identical spacing and a similar amino acid composition to those found in the species-specific transcription initiation factors SL1 and TIF-IB. The 5' untranslated region (5' UTR) of PsCR1 contains a sequence similar to part of the human L1 promoter, L1 site A, and several cis elements of the type found in eukaryotic genes. Within a region of about 500 bp, there are nine "E boxes," cis elements that are recognized by the basic helix-loop-helix (bHLH) family of proteins. This observation raises the possibility that cellular transcription factors that bind to these sequences might act in concert to regulate the expression of PsCR1. The extent of the sequence divergence of the 3' UTR of CR1 between species was found to be lower than the rate of nonsynonymous substitutions per site in ORF2, suggesting that a strict functional constraint must exist for this region. This result strongly suggests that the conserved 3'-end sequence of CR1 is the recognition site for the reverse transcriptase of CR1. A discussion is presented of a possible mechanism for the integration of CR1 elements and also of the intriguing possible recruitment of the reverse transcriptase for the retroposition of SINEs.

Amino Acid Sequence↗
PubMed1998

Parasites of Italian sea turtles. II. Loggerhead turtles (Caretta caretta [Linnaeus, 1758]).

Eleven out of fourteen sea turtles (Caretta caretta) stranded along the coast of the Adriatic sea (Mediterranean sea) were found infected with helminths. Seven trematode species (Rhytidodes gelatinosus, Orchidasma amphiorchis, Enodiotrema megachondrus. Pachypsolus irroratus, Pleurogonius trigonocephalus, Calicodes anthos, Plesiochorus cymbiformis) and one nematode (Sulcascaris sulcata) were found. S. sulcata was the most frequent species in the stomach and R. gelatinosus in the intestine. These species were also the most abundant. The redescriptions of C. anthos (Braun, 1899) and P. trigonocephalus (Rudolphi, 1809) Looss, 1901 are included. The accuracy of Braun's original description is questioned because it refers to specimens studied in dorsal view.

Animals↗
PubMed1996

Parasites in Italian sea turtles. I. The leatherback turtle Dermochelys coriacea (Linnaeus, 1766).

Three species of trematodes (Digenea) were collected from a leatherback turtle (Dermochelys coriacea) stranded on the coast of Lampedusa (Sicily Channel, Mediterranean Sea, Italy). One, Enodiotrema carettae, was found in the liver and two, Enodiotrema instar and Pyelosomum renicapite, in the intestine. E. carettae and E. instar are new host findings, E. carettae is a geographic novelty as well. A description of E. instar, previously reported and described by Looss (1902), is included.

Animals↗