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At least 73 records · Page 4Linked to original sources
PubMed2001

Survey of Florida green turtles for exposure to a disease-associated herpesvirus.

A recently developed enzyme-linked immunosorbent assay (ELISA) was used to assess exposure of Florida wild green turtles Chelonia mydas to LETV, the herpesvirus associated with lung-eye-trachea disease (LETD). Plasma samples from 329 wild juvenile green turtles netted in the Indian River lagoon, along the Sebastian reef, or in the Trident basin (Indian River and Brevard Counties, Florida) were tested by ELISA for the presence of antibodies to LETV. Plasma samples from 180 wild juvenile green turtles were tested from these study sites to compare the prevalence of anti-LETV antibodies. While some plasma samples from each site contained anti-LETV antibodies (confirmed by Western blot analysis), plasma samples collected from the Indian River lagoon had statistically higher optical density values measured in the ELISA. No statistical differences were observed when these same plasma samples were analyzed for changes in the level of anti-LETV antibodies over 3 years (1997, 1998, and 1999). To explore the relationship between anti-LETV antibodies and fibropapillomatosis (FP), plasma from 133 green turtles scored for fibropapilloma tumor severity were tested by ELISA. There was no correlation between tumor severity and the presence of antibodies against LETV. Additional plasma samples collected from 16 tagged green turtles captured and sampled more than once (recaptures) were also tested to monitor antibody levels to LETV relative to the FP status of individual turtles over time. Again there was no clear relationship between FP tumor status and the presence of antibodies to LETV. Finally, ELISA tests on plasma from 13 nesting female turtles (9 green and 4 loggerhead) revealed high levels of anti-LETV antibodies in 11 individuals, including 2 loggerhead turtles. These results provide strong evidence that wild Florida green turtle populations at these 3 study sites are exposed to LETV or a closely related virus and that loggerhead turtles may be exposed as well. Based on a cutoff optical density value of 0.310, 71 out of the 329 wild Florida green turtles tested were seropositive for LETV antibodies (seroprevalence = 21.6%). In addition, no relationship between FP tumor severity or status and the presence of anti-LETV antibodies was found, further supporting the hypothesis that LETV and the FP-associated herpesvirus (FPHV) are separate infections of marine turtles.

Animals↗
PubMed1996

Plasma corticosterone concentrations associated with acute captivity stress in wild loggerhead sea turtles (Caretta caretta).

Plasma corticosterone concentrations were measured in wild loggerhead sea turtles (Caretta caretta) in response to acute captivity (capture, serial bleeding, and restraint up to 6 hr). In general, concentrations of corticosterone dramatically increased 1 hr after capture, peaked at 3 hr, and decreased by 6 hr. Initial corticosterone concentrations were significantly lower in animals captured by tangle net than in those captured by trawl and were thought to more closely represent baseline levels. Significant effects of season and size class on corticosterone concentrations were found for turtles captured by trawl. Corticosterone concentrations of small turtles captured in summer were higher than those of large turtles captured in the same season and of all turtles captured during winter. In winter, corticosterone concentrations for small turtles were higher than those for large turtles at 3 hr after capture. Large turtles captured during winter experienced the slowest rate of increase in plasma corticosterone and a decline at 3 hr after capture. Although cloacal temperatures were significantly higher in summer samples, corticosterone concentrations of large turtles did not differ between seasons until 1 hr after capture. In addition, several large turtles during summer did not experience an increase in corticosterone concentrations 1 hr after capture. It is possible that the lower corticosterone response of large turtles captured during summer may be associated with reproductive condition.

Animals↗
PubMed1998

Three closely related herpesviruses are associated with fibropapillomatosis in marine turtles.

Green turtle fibropapillomatosis is a neoplastic disease of increasingly significant threat to the survivability of this species. Degenerate PCR primers that target highly conserved regions of genes encoding herpesvirus DNA polymerases were used to amplify a DNA sequence from fibropapillomas and fibromas from Hawaiian and Florida green turtles. All of the tumors tested (n = 23) were found to harbor viral DNA, whereas no viral DNA was detected in skin biopsies from tumor-negative turtles. The tissue distribution of the green turtle herpesvirus appears to be generally limited to tumors where viral DNA was found to accumulate at approximately two to five copies per cell and is occasionally detected, only by PCR, in some tissues normally associated with tumor development. In addition, herpesviral DNA was detected in fibropapillomas from two loggerhead and four olive ridley turtles. Nucleotide sequencing of a 483-bp fragment of the turtle herpesvirus DNA polymerase gene determined that the Florida green turtle and loggerhead turtle sequences are identical and differ from the Hawaiian green turtle sequence by five nucleotide changes, which results in two amino acid substitutions. The olive ridley sequence differs from the Florida and Hawaiian green turtle sequences by 15 and 16 nucleotide changes, respectively, resulting in four amino acid substitutions, three of which are unique to the olive ridley sequence. Our data suggest that these closely related turtle herpesviruses are intimately involved in the genesis of fibropapillomatosis.

Amino Acid Sequence↗
PubMed2006

Purification and properties of glutathione reductase from liver of the anoxia-tolerant turtle, Trachemys scripta elegans.

Glutathione reductase (GR) is a homodimeric flavoprotein that catalyzes the reduction of oxidized glutathione (GSSG) using NADPH as a cofactor. The enzyme is a major component of cellular defense mechanisms against oxidative injury. In this study, GR was purified from the liver of the anoxia-tolerant turtle, Trachemys scripta elegans. The overall fold purifications were 13.3- and 12.1-fold with final specific activities of 5.5 and 1.44 U/mg of protein for control and anoxic turtle GR, respectively. SDS-PAGE of purified turtle liver GR showed a single protein band at approximately 55 kDa. Reverse phase HPLC of turtle GR revealed a single peak that had the same retention time as yeast GR. No new isoform of GR was detected in liver of T. s. elegans during anoxia. The K (m) values of turtle GR for GSSG and NADPH was 44.6 and 6.82 microM, respectively, suggesting a substantially higher affinity of turtle GR toward GSSG than most other vertebrates. Unlike other human GR, NADP(+ )did not inhibit turtle GR activity. The activation energy of turtle GR, calculated from the slope of the Arrhenius plot, was 32.2 +/- 2.64 kJ/mol. Turtle GR had high activity under a broad pH range (having activity between pHs 4 and 10; optimal activity at pH 6.5) and the enzyme maintains activity under the pH drop that occurs under anoxic conditions. The high affinity of turtle GR suggests that turtles have high redox buffering capacity of tissues to protect against oxidative stress encountered during anoxia/reoxygenation.

Animals↗
PubMed1985

Isolation and properties of sea turtle (Chelonia mydas) pituitary prolactin.

Sea turtle prolactin (PRL) was isolated in a highly purified state from sea turtle pituitary side fractions obtained from other studies and some of its biological, chemical, and immunological properties were determined. Sea turtle PRL is a protein of 22-24 kDa [sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis]. Its sole amino terminal amino acid residue is leucine. The amino acid composition of sea turtle PRL is similar to ovine PRL and is characterized by a high content of aspartic acid (20 residues), glutamic acid (34 residues), serine (19 residues), and leucine (24 residues). It possess three disulfide bonds and 2 tryptophan residues which is also characteristic of many species of PRL. As with PRLs of other species, it displayed multiple stained bands in disc gel electrophoresis, at pH 8.3. Biologically, sea turtle PRL was active in pigeon crop-sac assay but the dose-response characteristics were nonparallel when compared to ovine PRL. An antiserum against sea turtle PRL was raised in rabbit and a homologous radioimmunoassay was developed with a sensitivity of 2.8 ng for sea turtle PRL. Sea turtle gonadotropins did not cross-react, but sea turtle growth hormone showed a 5% cross-reactivity. Pituitary extracts from other species of turtles displayed parallel inhibition curves to the sea turtle PRL. Extracts and prolactin preparations from several birds, snakes, alligator, and marsupials cross-reacted, but in a nonparallel fashion. Bullfrog pituitary extract and Tilapia PRL showed no cross-reaction at high doses. Several purified mammalian PRLs (pig, sheep, human, horse, dog) showed minimal or no ability to cross-react in the RIA.

Amino Acids↗
PubMed1999

Relationship between modulation of the cerebellorubrospinal system in the in vitro turtle brain and changes in motor behavior in rats: effects of novel sigma ligands.

Saturation and competition binding studies showed that the turtle brain contains sigma sites labeled by both [3H]di-o-tolylguanidine (DTG) and [3H](+)-pentazocine. There was a significant correlation between the IC50 values of sigma ligands for [3H]DTG sites in the turtle vs. rat brain, suggesting that the sites are comparable in the two species. In contrast, [3H](+)-pentazocine, which primarily labels sigma1 sites in the rodent brain, labels a heterogeneity of sites in the turtle brain. In extracellular recordings from the in vitro turtle brainstem, some sigma ligands enhanced the burst responses of red nucleus (RN) neurons (DTG, haloperidol, BD1031, BD1052, BD1069) while other sigma ligands decreased the burst responses (BD1047, BD1063). Control compounds (turtle Ringer vehicle control, opiate antagonist naloxone, atypical neuroleptic sulpiride) had no significant effects on the RN burst responses recorded from the in vitro turtle brain. The ED50s of the ligands for altering the burst responses in RN neurons from the turtle brain were correlated with their IC50s for turtle brain sites labeled with [3H]DTG, but not [3H](+)-pentazocine; this pattern is identical to that previously reported in rats, where there is a correlation between the potencies of sigma ligands for producing dystonic postures after microinjection into the rat RN and their binding to rat brain sites labeled with [3H]DTG, but not [3H](+)-pentazocine. When the novel sigma ligands were microinjected into the rat RN, dystonic postures were produced by ligands that increased the burst duration of RN neurons in the turtle brain. Novel sigma ligands that reduced the burst responses in the in vitro turtle brain have previously been reported to have no effects on their own when microinjected into the rat RN, but to block the dystonic postures produced by other sigma ligands. Taken together, the data suggest that the opposite effects of the novel ligands in the turtle electrophysiological studies represent the actions of agonists vs. antagonists, and that the directionality of the effects has predictive value for the expected motor effects of the drugs.

Animals↗
PubMed2003

Testing hypotheses of aging in long-lived painted turtles (Chrysemys picta).

For 38 of the past 50 years, Painted Turtles were studied on the University of Michigan's E.S. George Reserve in southeastern Michigan. We compared age specific body sizes, reproductive traits and survival of Painted Turtles ranging from 9 to 61 years of age to test contrasting predictions of the Relative Reproductive Rate and Senescence Hypotheses of aging. Indeterminate growth (i.e. continued body growth of adults) was important in increasing reproductive output of older turtles; however, growth rate of the oldest age-group was reduced compared to that of younger adults. Although clutch size and among year reproductive frequency did not increase with age, within year reproductive frequency (production of second clutches), egg size, and hatchling size did. Nest predation rates and the proportion of surviving nests that produced hatchlings were similar among age groups, and embryo mortality in nests was not related to age. Survivorship of males was less than that of females, and survivorship of the oldest group of females was not statistically different from that of a younger group of females. No decline in reproductive output or survivorship was detected in the oldest females as predicted by the Senescence Hypothesis. Thus, the majority of data on reproductive traits and survivorship support the Relative Reproductive Rate Hypothesis. We also compared Painted Turtles to Blanding's Turtles, another species studied on the E.S. George Reserve. That Painted Turtles exhibit indeterminate growth whereas Blanding's Turtles do not, appears to be a primary mechanism for some differences between species in the relationships between reproductive traits and age. An important mechanism for increasing reproductive output in both species was increased reproductive frequency in older females. Painted Turtles also increased offspring quality (egg and hatchling size) with age, whereas Blanding's Turtles did not. Compared to younger individuals, there was no reduction in survivorship in the oldest Painted Turtles and survivorship increased in the oldest Blanding's Turtles.

Aging↗
PubMed2004

Force development, energy state and ATP production of cardiac muscle from turtles and trout during normoxia and severe hypoxia.

The effects of hypoxia on energy economy of cardiac muscle were compared between the hypoxia-tolerant freshwater turtle at 20 degrees C and the hypoxia-sensitive rainbow trout at 15 degrees C. Isolated ventricular preparations were left either at rest or stimulated at 30 min(-1) to develop isometric twitch force. Under oxygenated conditions, twitch force and oxygen consumption were similar for the two species. Overall metabolism was reduced during severe hypoxia in both resting and stimulated preparations and under these conditions most of the ATP production was derived from anaerobic metabolism. During hypoxia, a metabolic depression of approximately 2/3 occurred for non-contractile processes in both turtle and trout preparations. During hypoxia, lactate production and residual oxygen consumption were similar in turtle and trout. Cellular energy state and phosphorylation potential decreased during severe hypoxia in both species and this reduction was more severe in preparations stimulated to contraction. However, in turtle ventricular preparations the energy state and phosphorylation potential stabilised at higher levels than in trout, and turtle preparations also maintained a higher twitch force throughout the hypoxic period. Moreover, twitch force relative to total ATP hydrolysis was markedly increased during hypoxia in turtle while this ratio was unchanged for trout. The main findings of this study are: (1) cellular energy liberation and the energy demand of non-contractile processes decreased to similar levels in hypoxic turtle and trout myocardium; (2) turtle myocardium maintained a substantially higher cellular energy state and twitch force development than trout myocardium during hypoxia and (3) the ratio of twitch force to ATP hydrolysis increased during hypoxia in turtle but was unchanged in trout. It is possible that this superior economy of the contracting turtle myocardium contributes to the remarkable hypoxia tolerance of freshwater turtles.

Adenosine Triphosphate↗
PubMed1998

Serological association between spirorchidiasis, herpesvirus infection, and fibropapillomatosis in green turtles from Florida.

Serodiagnostic tests for detecting green turtle (Chelonia mydas) antibody responses were developed to test the strength of association between exposure to spirorchid trematode antigens or herpesvirus antigens and having green turtle fibropapillomatosis (GTFP). Plasma samples from 46 captive-reared green turtles, including paired pre- and 1-yr post-inoculation samples from 12 turtles with experimentally induced GTFP, were found by enzyme-linked immunosorbent assay (ELISA) to be negative for antibodies to adult spirorchid (Learedius learedi) antigens. In contrast, all 12 turtles that developed experimentally induced GTFP converted within 1 yr from having negative to positive antibody reactivity to GTFP-associated herpesvirus antigens, whereas the three controls and four turtles that failed to develop tumors remained negative. Plasma samples from 104 free-ranging green turtles from two Florida (USA) coastal feeding grounds with different GTFP prevalences were tested by ELISA for antibodies to L. learedi adult antigens; and there was no statistically significiant association between antibody prevalence and sampling site. When a low optical density cutoff value (0.15) was used to interpret ELISA results, 98% of the turtles from each site were spirorchid antibody-positive and there was no association between antibody reactivity to spirorchids and GTFP status. When a higher negative cutoff value was used, however, a statistically significant association between antibody reactivity to spirorchids and GTFP-free status was found. These results suggest that spirorchids do not have a role in GTFP pathogenesis. All 20 of the tumor-bearing lagoon turtles had antibodies to herpesvirus antigens whereas only two (10%) of the tumor-free reef turtles had detectable anti-herpesvirus reactivity. The strong association between antibody reactivity to herpesvirus antigens and GTFP status in both captive-reared and free-ranging turtles is consistent with the hypothesis that the transmissible agent that causes GTFP is a herpesvirus.

Animals↗
PubMed2003

Venous blood gases and lactates of wild loggerhead sea turtles (Caretta caretta) following two capture techniques.

During summer of 2001, venous blood gases were determined in loggerhead sea turtles (Caretta caretta) captured by trawl (n = 16) in coastal waters of South Carolina and Georgia (USA) as part of a sea turtle census program and captured in pound nets (n = 6) in coastal North Carolina (USA) during a study of sea turtle population biology. Trawls were towed for 30 min, so turtles captured were forcibly submerged for < or = 30 min. Pound nets are passive gear in which fish and sea turtles are funneled into a concentrated area and removed periodically. Sea turtles in pound nets are free to surface and to feed at will. Blood was obtained from the dorsal cervical sinus as quickly as possible after landing on the boat (range 2-10 min trawl, 1-2 min pound net) and at 30 min after landing just prior to release. Blood gases including pH, partial pressures of O2 and CO2 (pO2, pCO2), and lactate were measured within 10 min. Instrument measurements for pH, pO2, and pCO2 made at 37 C were corrected to cloacal temperature and HCO3- was calculated from temperature-corrected pH and pCO2. Venous blood pH and bicarbonate were higher, and pO2 and lactate were lower from pound net-captured turtles compared to trawl captured turtles at the initial sampling time. In pound net turtles, pH and bicarbonate declined and lactate increased during 30 min on deck. In trawled sea turtles, venous blood pH increased and pCO2 and pO2 decreased during the 30 min on deck. Both capture systems caused perturbations in blood gas, acid-base, and lactate status, though alterations were greater in trawl captured turtles.

Acid-Base Imbalance↗
PubMed1998

Gastrointestinal helminths of loggerhead turtles (Caretta caretta) from the western Mediterranean: constraints on community structure.

Richness and composition of gastrointestinal helminth communities of 54 loggerhead turtles, Caretta caretta, from the western Mediterranean were interpreted from patterns of helminth exchange at 2 host taxonomic scales: exchange between marine turtles and other marine hosts and exchange within turtles. We predicted exchange of the former to be unimportant ecologically and evolutionarily because of the host phylogenetic distance. The absence of records of successful exchange at this host taxonomic scale confirmed that host physiological barriers seem to prevent contemporary parasite transfer between marine turtles and other sympatric hosts. Marine turtles also seem to exhibit an evolutionary association with their parasites largely independent from that of other marine hosts. Therefore, the composition of gastrointestinal helminth communities of marine turtles is predictably restricted to digeneans, nematodes, and aspidogastreans specific to these reptiles. At the scale of host species, helminth exchange among marine turtle species was expected to be significant. This was suggested by reports indicating a high proportion of parasites common to all sea turtle species. Mediterranean C. caretta harbored only 4 digenean species typical of marine turtles, and immature individuals of 1 digenean species accidentally acquired. Further, no relevant parasite exchange with other marine turtles was expected to occur because C. caretta is the only sea turtle species abundant in the western Mediterranean. Therefore, a predictable composition coupled with low species richness in infracommunities might be accounted for partly by constraints on parasite acquisition at both host scales. Host factors limiting parasite recruitment (mainly ectothermy and a wandering behavior) may also contribute to depauperate and isolationist infracommunities.

Animals↗
PubMed2005

Effect of graded hypoxic and acidotic stress on contractile force of heart muscle from hypoxia-tolerant and hypoxia-intolerant turtles.

Previous studies have shown that isometric contractile force of in vitro cardiac muscle from the anoxia-tolerant painted turtle, Chrysemys picta bellii, decreases when anoxic and when acidotic. This study sought to define the thresholds for these responses in the isolated ventricular strips of the painted turtle and in the anoxia-intolerant softshell turtles, Apalone spinifera. The ventricular strips were exposed to HCO3- Ringer's solution equilibrated at P(O2) 156, 74, 37, 19, and 0 mmHg (45 min at each grade), at both pH 7.0 and at pH 7.8. Strips were also exposed to graded lactic acidosis with intervals between pH 6.8 and pH 7.8 at P(O2) 156 mmHg (softshell) or 37 mmHg (painted). In painted turtle strips at pH 7.8, force remained at control levels until it decreased by 30% at P(O2) 19 mmHg. No further significant decrease occurred at P(O2) 0. In contrast, softshell turtle muscle force did not fall significantly until P(O2) reached 0. When graded hypoxia was imposed at pH 7.0, strips from both species were more sensitive to hypoxia, but the softshell force decreased at a higher P(O2) than the painted turtle (P(O2) 156 mmHg vs. 37 mmHg), its force fell to a lower level at P(O2) 0 (22 % of control vs. 40 % of control), and unlike painted turtle heart muscle, softshell muscle did not recover fully. In summary, these data indicate that ventricular strips of the painted turtle are no more tolerant of hypoxia alone than strips from the softshell turtle, but that when hypoxia is combined with acidosis, the painted turtle heart muscle functions significantly better during the exposure and recovers more fully after exposure.

Acidosis, Lactic↗
PubMed1995

Size-dependent, sex-dependent, and seasonal changes in insulin-like growth factor I in the loggerhead sea turtle (Caretta caretta).

This study examines size-dependent, sex-dependent, and seasonal fluctuations in plasma insulin-like growth factor-I (IGF-I) concentrations in loggerhead sea turtles (Caretta caretta). Loggerhead turtles (n = 158) were captured in shrimp trawler nets during a 12-month survey in Cape Canaveral Channel, Florida. Plasma samples were analyzed using a validated heterologous radioimmunoassay. Large turtles (> 75 cm straight-line carapace length) had significantly higher plasma IGF-I concentrations than small turtles (< or = 75 cm; P < 0.0001). Plasma IGF-I concentrations did not vary seasonally in small turtles, but large turtles had significantly higher plasma IGF-I concentrations during the spring and summer months (P < 0.005). Within the large turtles, adult males had significantly lower IGF-I concentrations than females and subadult males (P < 0.05). These results and a review of loggerhead turtle natural history suggest that the seasonal fluctuations in plasma IGF-I of adult turtles are due to elevated IGF-I levels in reproductively active female turtles. Further research is needed to examine correlations between reproductive activities and plasma IGF-I concentrations in reptiles.

Animals↗
PubMed2000

Availability of water affects organ growth in prenatal and neonatal snapping turtles (Chelydra serpentina).

We manipulated the amount of water that was available to prenatal and neonatal snapping turtles (Chelydra serpentina) in order to assess the impact of water on growth by different organs in these animals. Three treatments were used: (1) turtles that completed their incubation on a wet substrate, (2) turtles that completed their incubation on a dry substrate, and (3) turtles that spent a few days in water after completing incubation on a dry substrate. Turtles hatching on a dry substrate (treatment 2) were smaller than animals in the other two treatments (which did not differ in size), so data for mass of different organs were adjusted by ANCOVA to remove effects of body size. Scaled masses of liver, stomach, lungs, kidneys, and small intestine did not differ between turtles emerging in wet environments and those hatching in dry environments, but hearts of turtles hatching in dry settings were substantially larger than those of animals hatching in wet ones. Thus, the mass of most organs in turtles developing in wet and dry environments scaled to body size, whereas the heart was hypertrophied in embryos developing in dry environments. Turtles that spent a few days in water after hatching from eggs in dry environments grew rapidly in size, and the increase in body size was accompanied by disproportionately rapid growth in the liver, stomach, lungs, kidneys, and small intestine. The heart did not increase in size during this period, despite the substantial increase in body mass over that at hatching. The enlarged heart of turtles hatching on dry substrates may have been caused by a circulatory hypovolemia late in incubation; the rapid growth of organs other than the heart when these animals were placed in water may reflect a release from constraints on growth once circulatory volume was restored.

Animals↗
PubMed1995

Sequence of a cDNA encoding turtle riboflavin-binding protein: a comparison with avian riboflavin-binding protein.

To search for the existence and distribution of a riboflavin-binding protein (RfBP), total RNA from estrogen-treated oviparous animals were screened by Northern hybridization using chicken RfBP cDNA as a probe. Besides avian livers and oviducts, RfBP mRNA was found in turtle liver, but not in the turtle oviduct. To elucidate the structure of the RfBP from a reptilian source, we constructed a cDNA library from estrogen-injected turtle liver, and a full-length turtle RfBP-encoding cDNA was cloned and sequenced. The open reading frame (ORF) encoded 242 amino acids (aa) including a signal peptide of 18 aa. There is an overall 71.3% aa identity between the deduced aa sequences of turtle and chicken. The aa sequence of turtle and chicken RfBP also show more than 30% similarity to a fragment of folate-binding protein (FBP). Six Trp and nine pairs of Cys residues are conserved between the two RfBPs with only one pair of Cys residues missing in FBP. The two Asn-linked glycosylation sites found in chicken RfBP are conserved in turtle RfBP, but only one of which is conserved in FBP. However, there is an additional potential N-glycosylation site in the turtle sequence and this may provide a better explanation for the greater molecular weight of the turtle protein than chicken RfBP. Turtle RfBP contains a region of nine Ser and five Glu residues which is present in mature chicken RfBP as eight phosphorylserine clusters forming a highly anionic region at the C terminus, but this region is not found in FBP.

Amino Acid Sequence↗
PubMed2003

Cloning of complimentary deoxyribonucleic acid encoding follicle-stimulating hormone and luteinizing hormone beta subunit precursor molecules in Reeves's turtle (Geoclemys reevesii) and Japanese grass lizard (Takydromus tachydromoides).

Reptilia is the only vertebrate class in which cDNA for the gonadotropin beta subunit precursor molecule has not been cloned. We have isolated the full-length cDNA clone encoding the LH beta subunit precursor molecule and a partial cDNA clone encoding the FSH beta subunit precursor molecule from a pituitary cDNA library of Reeves's turtle. We further clarified the nucleotide sequence of the remaining part of the turtle FSH beta cDNA and that of full-length cDNA encoding the LH beta subunit precursor molecule of the Japanese grass lizard, by means of the 5' rapid amplification of cDNA end (RACE) and 3' RACE. The nucleotide sequence of the turtle FSH beta cDNA we determined was 584 bp long and contained the coding sequence, 5' untranslated region (UTR) and 3' UTR of 396, 34, and 154 bp, respectively. The nucleotide sequence of the turtle LH beta we isolated was 498 bp long and contained the coding sequence, 5' UTR and 3' UTR of 420, 7, and 71 bp, respectively. The nucleotide sequence of the lizard LH beta we determined was 537 bp long and contained the coding sequence, 5' UTR and 3' UTR of 441, 35, and 61 bp, respectively. Amino acid sequences deduced from coding regions of the turtle FSH beta, LH beta and the lizard LH beta were 131, 139, and 146 residues, respectively. Referring to the amino acid sequences of the bullfrog FSH and LH beta subunit molecules determined chemically, we deduced the amino acid sequences of mature peptide. Amino acid sequences of mature peptides of the turtle FSH, turtle LH, and the lizard LH were 111, 112, and 112 residues, respectively. Amino acid sequences of the mature peptides were compared with those of other vertebrates. The amino acid sequence of the turtle FSH beta subunit molecule was 84.7-85.6, 67.8-71.4, and 61.3-62.2% identical to the FSH sequence of birds, mammals, and amphibians, respectively. The amino acid sequence of the turtle LH beta subunit molecule was 51.6-54.6, 36.2-48.7, and 56.3-57.5% identical to the LH sequence of birds, mammals, and amphibians, respectively. The amino acid sequence of the lizard LH beta subunit molecule was 39.1-47.1, 32.9-43.0, and 46.0-47.3% identical to the LH sequence of birds, mammals, and amphibians, respectively. These identity values suggest that the turtle or reptilian FSH beta subunit molecule is more closely related to avian and mammalian FSH beta subunit molecules than to amphibian FSH beta subunit molecules but reptilian LH beta subunit molecules are more closely related to amphibian LH beta subunit molecules than to avian and mammalian LH beta subunit molecules. This discrepancy in the molecular similarity relationship found in the reptilian FSH and LH beta subunit molecules can be interpreted by assuming that evolution speed was not the same among hormone species and also among vertebrate groups.

Amino Acid Sequence↗
PubMed2003

Effects of experimental anemia on blood ion and acid-base status of turtles during submergence in aerated water at 3 degrees C.

The importance of blood hemoglobin to aquatic oxygen uptake by turtles (Chrysemys picta bellii) submerged in aerated water at 3 degrees C was tested by comparing the responses of anemic turtles (hematocrit approximately 6%) to turtles with normal hematocrits (hematocrit approximately 33%). All turtles were submerged for 42 days and blood samples were collected at 0, 7, 21, 32 and 42 days. Blood was analyzed for pH, PCO(2), PO(2), hematocrit, hemoglobin concentration ([Hb]) and plasma was analyzed for concentrations of lactate, glucose, Na(+), K(+), Ca(2+) and Mg(2+). Plasma [HCO(3)(-)] was calculated. [Hb] correlated closely with hematocrit levels. [Lactate] reached higher final values in anemic turtles (34.5+/-5.3 mmol l(-1)) than in normal turtles (14.5+/-4.6 mmol l(-1)) indicating a greater reliance of the anemic animals on anaerobic metabolism. Both groups compensated for acidosis by reduced PCO(2) and anemic turtles also had increased [Ca(2+)] and [Mg(2+)]. Blood pH fell significantly in the anemic turtles but not in the controls. Although the data indicate that the anemic turtles relied more on anaerobic metabolism than the controls, the effect was much less than expected on the basis of the reduced blood O(2) carrying capacity. Possible compensatory mechanisms utilized by the anemic turtles to minimize anaerobic metabolism are discussed.

Acid-Base Equilibrium↗
PubMed2000

Arsenic accumulation in three species of sea turtles.

Arsenic in the liver, kidney and muscle of three species of sea turtles, e.g., green turtles (Chelonia mydas), loggerhead turtles (Caretta caretta) and hawksbill turtles (Eretmochelys imbricata), were determined using HG-AAS, followed by arsenic speciation analysis using HPLC-ICP-MS. The order of arsenic concentration in tissues was muscle > kidney > liver. Unexpectedly, the arsenic concentrations in the hawksbill turtles feeding mainly on sponges were higher than the two other turtles primarily eating algae and mollusk which accumulate a large amount of arsenic. Especially, the muscles of the hawksbill turtles contained remarkably high arsenic concentrations averaging 153 mg kg(-1) dry weight with the range of 23.1-205 mg kg(-1) (n = 4), even in comparison with the data from other organisms. The arsenic concentrations in the tissues of the green turtles were significantly decreased with standard carapace length as an indicator of growth. In arsenic compounds, arsenobetaine was mostly detected in the tissues of all the turtles. Besides arsenobetaine, a small amount of dimethylarsinic acid was also observed in the hawksbill turtles.

Animals↗