WorldWideScience

Sample records for frog sartorius muscle

  1. Effect of acclimation temperature and pH on contraction of frog sartorius muscle.

    Science.gov (United States)

    Renaud, J M; Stevens, E D

    1981-05-01

    The effect of acclimation temperature and pH on the isometric twitch and tetanus of sartorius muscle from frog, Rana pipiens, was studied at different experimental temperatures. Seven variables were measured, namely: tension, latent period, time to maximum tension, half-relaxation time, mean rate, maximum rate, and maximum acceleration of tension development. The effect of experimental temperature was similar to that reported in the literature. The effects of acclimation temperature were small and were not compensatory. Different pH's were obtained by varying CO2 in the gas phase, while the HCO3- concentration was kept constant. The main effects of a decrease in pH on the isometric twitch and tetanus were a reduction in tension and rate of tension development and an increase in latent period. A decrease in pH had no effect on the time to maximum tension or the half-relaxation time. Analysis of variance showed that the test temperature had the greatest effect of all three treatments on each variable, the effects of test and acclimation temperature were dependent on neither the test nor the acclimation temperatures. The in vivo relationships between these three treatments are discussed.

  2. Time-resolved X-ray diffraction studies of myosin head movements in live frog sartorius muscle during isometric and isotonic contractions.

    Science.gov (United States)

    Martin-Fernandez, M L; Bordas, J; Diakun, G; Harries, J; Lowy, J; Mant, G R; Svensson, A; Towns-Andrews, E

    1994-06-01

    Using the facilities at the Daresbury Synchrotron Radiation Source, meridional diffraction patterns of muscles at ca 8 degrees C were recorded with a time resolution of 2 or 4 ms. In isometric contractions tetanic peak tension (P0) is reached in ca 400 ms. Under such conditions, following stimulation from rest, the timing of changes in the major reflections (the 38.2 nm troponin reflection, and the 21.5 and 14.34/14.58 nm myosin reflections) can be explained in terms of four types of time courses: K1, K2, K3 and K4. The onset of K1 occurs immediately after stimulation, but that of K2, K3 and K4 is delayed by a latent period of ca 16 ms. Relative to the end of their own latent periods the half-times for K1, K2, K3 and K4 are 14-16, 16, 32 and 52 ms, respectively. In half-times, K1, K2, K3 lead tension rise by 52, 36 and 20 ms, respectively. K4 parallels the time course of tension rise. From an analysis of the data we conclude that K1 reflects thin filament activation which involves the troponin system; K2 arises from an order-disorder transition during which the register between the filaments is lost; K3 is due to the formation of an acto-myosin complex which (at P0) causes 70% or more of the heads to diffract with actin-based periodicities; and K4 is caused by a change in the axial orientation of the myosin heads (relative to thin filament axis) which is estimated to be from 65-70 degrees at rest to ca 90 degrees at P0. Isotonic contraction experiments showed that during shortening under a load of ca 0.27 P0, at least 85% of the heads (relative to those forming an acto-myosin complex at P0) diffract with actin-based periodicities, whilst their axial orientation does not change from that at rest. During shortening under a negligible load, at most 5-10% of the heads (relative to those forming an acto-myosin complex at P0) diffract with actin-based periodicities, and their axial orientation also remains the same as that at rest. This suggests that in isometric

  3. Classification of the intrafusal muscle fibres in the frog muscle spindle: histochemical and immunofluorescent studies.

    OpenAIRE

    Yoshimura, A; Fujitsuka, N; Sokabe, M; Naruse, K; Nomura, K; Diwan, F H; Ito, F

    1990-01-01

    Intrafusal muscle fibres from bull-frog semitendinosus, iliofibularis and sartorius muscles were classified into three types using the histochemical, immunofluorescent and morphological characteristics, with reference to the extrafusal muscle fibres, which were classified into five types in accordance with Rowlerson & Spurway (1988). Immunofluorescent reactions with antibodies against slow or fast myosins obtained from anterior or posterior latissimus dorsi muscles (ALD or PLD), respectively,...

  4. Regeneration of frog twitch and slow muscle fibers after mincing.

    Science.gov (United States)

    Schmidt, H; Emser, W

    1985-10-01

    Iliofibularis muscles of Rana temporaria were minced and allowed to regenerate in the iliofibularis or the sartorius bed of the same frog. Regenerated muscles were examined for the presence of slow muscle fibers using electrophysiologic, histochemical, and contractile parameters. Muscle regeneration from sartorius mince was also studied. Regeneration was more successful from iliofibularis than from sartorius mince, and the iliofibularis bed was more favorable for regeneration than the sartorius bed for both types of muscle. Twitch fibers regenerated within a few months, but slow fibers could not be identified earlier than 14 months after muscle destruction. Slow muscle fibers regenerated only from iliofibularis mince, both orthotopically and heterotopically. All regenerates capable of maintaining a K-contracture contained histochemically identified slow fibers; the membrane properties of electrophysiologically identified slow fibers were normal. It is concluded that slow muscle fibers regenerate only from the remnants of a muscle that contains slow fibers. The results are discussed with respect to the role of innervating nerve fibers.

  5. Intrafusal muscle fibre types in frog spindles.

    Science.gov (United States)

    Diwan, F H; Ito, F

    1989-04-01

    Muscle spindles from bullfrog semitendinosus, iliofibularis and sartorius muscles were examined with light and electron microscopy. Four types of intrafusal muscle fibre were identified according to their diameter, central nucleation and reticular zone arrangement: a large nuclear bag fibre, a medium nuclear bag fibre, and two types of small nuclear chain fibres with and without a reticular zone, respectively. It is suggested that they are comparable to the nuclear bag1, bag2 and chain fibres in mammalian muscle spindles.

  6. Intrafusal muscle fibre types in frog spindles.

    OpenAIRE

    Diwan, F H; Ito, F

    1989-01-01

    Muscle spindles from bullfrog semitendinosus, iliofibularis and sartorius muscles were examined with light and electron microscopy. Four types of intrafusal muscle fibre were identified according to their diameter, central nucleation and reticular zone arrangement: a large nuclear bag fibre, a medium nuclear bag fibre, and two types of small nuclear chain fibres with and without a reticular zone, respectively. It is suggested that they are comparable to the nuclear bag1, bag2 and chain fibres...

  7. Sparing of the dystrophin-deficient cranial sartorius muscle is associated with classical and novel hypertrophy pathways in GRMD dogs.

    Science.gov (United States)

    Nghiem, Peter P; Hoffman, Eric P; Mittal, Priya; Brown, Kristy J; Schatzberg, Scott J; Ghimbovschi, Svetlana; Wang, Zuyi; Kornegay, Joe N

    2013-11-01

    Both Duchenne and golden retriever muscular dystrophy (GRMD) are caused by dystrophin deficiency. The Duchenne muscular dystrophy sartorius muscle and orthologous GRMD cranial sartorius (CS) are relatively spared/hypertrophied. We completed hierarchical clustering studies to define molecular mechanisms contributing to this differential involvement and their role in the GRMD phenotype. GRMD dogs with larger CS muscles had more severe deficits, suggesting that selective hypertrophy could be detrimental. Serial biopsies from the hypertrophied CS and other atrophied muscles were studied in a subset of these dogs. Myostatin showed an age-dependent decrease and an inverse correlation with the degree of GRMD CS hypertrophy. Regulators of myostatin at the protein (AKT1) and miRNA (miR-539 and miR-208b targeting myostatin mRNA) levels were altered in GRMD CS, consistent with down-regulation of myostatin signaling, CS hypertrophy, and functional rescue of this muscle. mRNA and proteomic profiling was used to identify additional candidate genes associated with CS hypertrophy. The top-ranked network included α-dystroglycan and like-acetylglucosaminyltransferase. Proteomics demonstrated increases in myotrophin and spectrin that could promote hypertrophy and cytoskeletal stability, respectively. Our results suggest that multiple pathways, including decreased myostatin and up-regulated miRNAs, α-dystroglycan/like-acetylglucosaminyltransferase, spectrin, and myotrophin, contribute to hypertrophy and functional sparing of the CS. These data also underscore the muscle-specific responses to dystrophin deficiency and the potential deleterious effects of differential muscle involvement. Copyright © 2013 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  8. Properties of motor units of the frog iliofibularis muscle.

    Science.gov (United States)

    Luff, A R; Proske, U

    1979-01-01

    The tension developed by single motor units of the iliofibularis muscle of the frog Litoria aurea was recorded in response to single-shock and repetitive stimulation of motor axons. The majority of units in each muscle, 13 on the average, were of the twitch type; an additional 4 units were slow or tonic. It appeared that slow units comprised a single homogeneous population, but two types of twitch units could be recognized: small fatigue-resistant units with long twitch times to peak (20--40 ms) and larger, fatigable units with briefer times to peak (16--27 ms). Evidence from a comparison of unit tetanic tensions indicated the presence of polyneuronal innervation of both slow and twitch muscle fibers. The relatively low incidence of polyneuronal innervation of twitch fibers in iliofibularis, when compared with a muscle like sartorius (9), was attributed to the difference in lengths of muscle fibers in the two muscles. It was argued that slow muscle fibers probably receive a multiterminal as well as polyneuronal innervation, with the terminals of any one axon lying widely spaced along the muscle fiber.

  9. A Depolarizing Electrogenic Pump in Frog Muscle

    Science.gov (United States)

    1975-08-01

    mw copy AFRRI SR75-20 AUGUST 1975 AFRRI SCIENTIFIC REPORT O ■ to A DEPOLARIZING ELECTROGENIC PUMP IN FROG MUSCLE D. Geduldig D. R...Academy of Sciences - National Research Council. AFRRI SR75-20 August 1975 A DEPOLARIZING ELECTROGENIC PUMP IN FROG MUSCLE D. GEDULDIG* D. R...INTRODUCTION When Na-enriched frog muscles are bathed in Na- and K-free saline, the small amount of potassium which could accumulate outside of the membrane

  10. Leg for life? The use of sartorius muscle flap for the treatment of an infected vascular reconstructions after VA-ECMO use. A case report

    Directory of Open Access Journals (Sweden)

    George V. Patrut

    2015-01-01

    Conclusion: Although ischemic complications associated with VA-ECMO are accepted by intensivists under the slogan “leg for life”, for the repair of the femoral artery in the presence of groin infection the sartorius muscle remains an efficient solution for limb salvage.

  11. [Role of calcium ions and cyclic nucleotides in neurotrophic control of the membrane properties of muscle fibers in the frog].

    Science.gov (United States)

    Volkov, E M; Kudriavtseva, N V; Nasledov, G A; Poletaev, G I

    1985-06-01

    Subcutaneous injections of caffeine, calcium ionophore X537A or cAMP did not affect the changes of input resistance (R0) and time constant (T) of membrane caused by denervation of the frog m. sartorius but prevented the MP decrease and ACh sensitivity spread. Injections of cGMP did not affect the denervation changes of R0 and MP but increased the ACh sensitivity. The neurotrophic control of frog muscle membrane properties seems to depend on calcium and involve the cyclic nucleotides system.

  12. A comparison of the spindles in two different muscles of the frog.

    Science.gov (United States)

    Brown, M C

    1971-08-01

    1. The responses of spindles in the iliofibularis muscle of frogs to stretch during either small motor nerve fibre stimulation or the application of suxamethonium were compared.2. All spindles which were excited by small motor nerve fibre stimulation were also excited by suxamethonium, and their responses to these two methods of excitation were very similar. The drug dose was usually 5-10 mug/ml. but smaller and larger doses were effective. Large doses (> 100 mug/ml.) could sometimes lead to a reversible partial block of the spindle response to stretch.3. Suxamethonium also caused a prolonged contraction in extrafusal slow muscle fibres. This contraction was not responsible for the effect on the spindle, because the time course of its action on the muscle tension and on the spindle afferent was different.4. It was concluded that suxamethonium stimulated prolonged contraction in the small intrafusal muscle fibres, which are known to be innervated by the small motor nerve fibres.5. Only about half of the spindles in the iliofibularis muscle were excited by suxamethonium.6. In the sartorius muscle which has no slow extrafusal muscle fibres, no spindles were found to be excited by suxamethonium in the way characteristic of that due to small intrafusal muscle fibre contraction.7. It is concluded that, in frog muscles which have no slow extrafusal fibres, the muscle spindles do not have small intrafusal muscle fibres of the kind found in the iliofibularis muscle.

  13. Treatment of femoral neck fracture with muscle-bone flap of both tensor fasciae latae and sartorius

    Institute of Scientific and Technical Information of China (English)

    刘国平; 康斌; 曾晖; 唐嫄科; 唐新宇; 熊奡; 解笑宸; 黄伟

    2003-01-01

    Objective: To evaluate the effect of muscular pedicle bone grafts with sartorius or tensor fasciae latae and sartorius in fresh transcervical or subcapital fractures of the femoral neck. Methods: Thirty cases of fresh transcervical and subcapital fractures of the femoral neck were treated by the tail breakable screws and sartorius pedicle bone grafts (single muscular pedicle, SMP group). The other 23 cases were treated by cannulated pressure screws and bone grafts with the muscular pedicles of both sartorius and tensor fasciae latae (double muscular pedicles, DMP group). Results: Fifty-two cases were followed up for 3 to 5 years (mean, 4 years). In SMP group, ten cases showed poor therapeutic results. Excellent therapeutic effects were achieved in all cases of DMP group. Conclusions: The transcervical or subcapital fractures of the femoral neck can be treated by double muscular pedicles bone graft. The bone graft with double muscular pedicles is more effective than single sartorius muscular pedicles for fresh transcervical and subcapital fractures of the femoral neck during short and medium terms.

  14. Classification of the intrafusal muscle fibres in the frog muscle spindle: histochemical and immunofluorescent studies.

    Science.gov (United States)

    Yoshimura, A; Fujitsuka, N; Sokabe, M; Naruse, K; Nomura, K; Diwan, F H; Ito, F

    1990-10-01

    Intrafusal muscle fibres from bull-frog semitendinosus, iliofibularis and sartorius muscles were classified into three types using the histochemical, immunofluorescent and morphological characteristics, with reference to the extrafusal muscle fibres, which were classified into five types in accordance with Rowlerson & Spurway (1988). Immunofluorescent reactions with antibodies against slow or fast myosins obtained from anterior or posterior latissimus dorsi muscles (ALD or PLD), respectively, of chicken were used as the primary criterion. Histochemical profiles of muscle fibres were classified into nine types of myosin ATPase activity as the secondary criterion. Anti-PLD intrafusal fibres (polar zone) with ATPase profiles of moderate to high acid and alkaline stabilities correspond to large nuclear bag fibres in the classification of Diwan & Ito (1989), whereas anti-ALD fibres (polar zone) with alkaline-labile ATPase profiles correspond to medium nuclear bag fibres. On the basis of diameter, anti-PLD fibres (polar zone) with ATPase profiles of moderate to low acid stability and moderate to high alkaline stability seem to correspond to two types of small nuclear chain fibre. Variations between muscles, between intra- and extrafusal fibres and also between zones along intrafusal fibres are discussed.

  15. 应用缝匠肌治疗伸膝功能障碍%The application of sartorius muscle for treatment of extension disorders of knee

    Institute of Scientific and Technical Information of China (English)

    陈秋生; 李松建; 余斌; 陈霞; 朱立新; 杨建成

    2002-01-01

    Objective Sartorius muscle was applied to treat dislocation or subluxation of patella and extension disorder of knee resulted from poliomyelitis,patellectomy and quadriceps femoris injury.Method The distal one third part or two thirds part of sartorius muscle excluded its insertion was freed,then transposed and threaded to the front surface of patella.Result 30 cases(37 knees)with dislocation or subluxation of patella were treated and 25 cases(28 knees)were followed up(mean followed up time 4 years).pain in the patello femeral joint disappeared without any recurrence of dislocation.75 with weak extensor of knee were treated and 50 were followed up for mean 2 years and 1 month.The extensor strength in the patients with poliomyelitis increased from 0.89 preoperatively to 2.76 postoperatively.The joint movement in the patients with extension stiffness of knee increased from 15° preoperatively to 102° postoperatively.The extensor strength in the patients with patellectomy increased by 2 grades postoperatively,which enable the patients to complete the last 10° to 15° extension movement of knee.Conclusion The authors modified the usual surgery methods,by which the results were far from perfect,in treatment of the lateral displacement of patella and advanced a new treatment for the patients with extension stiffness of knee and the patients with weak extensor strength after patellectomy.

  16. Results of triple muscle (sartorius, tensor fascia latae and part of gluteus medius pedicle bone grafting in neglected femoral neck fracture in physiologically active patients

    Directory of Open Access Journals (Sweden)

    Pankaj Kumar Mishra

    2014-01-01

    Full Text Available Background: Femoral neck fractures are notorious for complications like avascular necrosis and nonunion. In developing countries, various factors such as illiteracy, low socioeconomic status, ignorance are responsible for the delay in surgery. Neglected fracture neck femur always poses a formidable challenge. The purpose of this study was to evaluate the results of triple muscle pedicle bone grafting using sartorius, tensor fasciae latae and part of gluteus medius in neglected femoral neck fracture. Materials and Methods: This is a retrospective study with medical record of 50 patients, who were operated by open reduction, internal fixation along with muscle pedicle bone grafting by the anterior approach. After open reduction, two to three cancellous screws (6.5 mm were used for internal fixation in all cases. A bony chunk of the whole anterior superior iliac spine of 1 cm thickness, 1 cm width and 4.5 cm length, taken from the iliac crest comprised of muscle pedicle of sartorius, tensor fascia latae and part of gluteus medius. Then the graft with all three muscles mobilized and put in the trough made over the anterior or anterosuperior aspect of the femoral head. The graft was fixed with one or two 4.5 mm self-tapping cortical screw in anterior to posterior direction. Results: 14 patients were lost to followup. The results were based on 36 patients. We observed that in our series, there was union in 34, out of 36 (94.4% patients. All patients were within the age group of 15-51 years (average 38 years with displaced neglected femoral neck fracture of ≥30 days. Mean time taken for full clinicoradiological union was 14 weeks (range-10-24 weeks. Conclusion: Triple muscle pedicle bone grafting gives satisfactory results for neglected femoral neck fracture in physiologically active patients.

  17. Opposite effect of ATP on contraction force of tonic and phasic skeletal muscles in frogs.

    Science.gov (United States)

    Grishin, S N; Kamaliev, R R; Teplov, A Yu; Ziganshin, A U

    2011-07-01

    Experiments in vitro showed that ATP and adenosine equally suppressed contractions of frog m. sartorius, which belongs to the phasic type muscles. Adenosine receptors antagonist 8-SPT abolished the effect of adenosine, but did not change the effect of ATP. This fact proves the independence of signaling pathways of these purines. ATP produced an opposite effect on the tonic muscle m. cruralis and increased the force of its contraction. Adenosine produced an inhibitory effect on the force of m. cruralis contration. In this case, 8-SPT also eliminated the effect of adenosine, but did not change the effect of ATP. The potentiating effect of ATP was blocked by suramin, a nonselective antagonist of P2 receptors, which attests to their involvement into the effects of this purine. The opposite effects of purinergic regulation reflect fundamental differences in functional organization of phasic and tonic muscular systems. It was hypothesized that the increase in contraction force under the effect of ATP is a mechanism providing maitenance of the contracted state of tonic muscle without appreciable metabolic costs.

  18. Effect of primycin on some electric properties of the frog skeletal muscle.

    Science.gov (United States)

    Gesztelyi, I; Kónya, L; Kövér, A

    1980-01-01

    The effect of primycin, a guanidine-type antibiotic was studied on the electric properties and 42K+ uptake of the frog sartorius and semitendinosus muscle. Both in normal and choline chloride Ringer solution, primycin evoked a concentration and time dependent depolarization of the surface membrane of the muscle. This depolarization was significantly increased by Na ions. Primycin treatment was shown to evoke a dose-dependent decrease of the depolarization induced by 20 mM K+-Ringer. When the muscles were incubated in a Ringer solution containing choline chloride, during an incubation period of 30 min the uptake of 42K+ was decreased to 12% upon the exposure to 5 x 10(-6) mol primycin as compared to the control value. As the primycin-induced depolarization increased, the shape and amplitude of the action potentials elicited by square-wave electric impulses were altered and decreased, respectively. In sodium isaethionate Ringer 1--2 x 10(-6) M primycin induced a slow depolarization resulting in firing potentials. The results suggest that primycin depolarizes the surface membrane exclusively through the blockade of the resting K+ channels, the other phenomena being the results of this depolarizing effect.

  19. Muscle fatigue in frog semitendinosus: alterations in contractile function

    Science.gov (United States)

    Thompson, L. V.; Balog, E. M.; Riley, D. A.; Fitts, R. H.

    1992-01-01

    The purpose of this study was to characterize the contractile properties of the frog semitendinosus (ST) muscle before and during recovery from fatigue, to relate the observed functional changes to alterations in specific steps in the crossbridge model of muscle contraction, and to determine how fatigue affects the force-frequency relationship. The frog ST (22 degrees C) was fatigued by direct electrical stimulation with 100-ms 150-Hz trains at 1/s for 5 min. The fatigue protocol reduced peak twitch (Pt) and tetanic (Po) force to 32 and 8.5% of initial force, respectively. The decline in Pt was less than Po, in part due to a prolongation in the isometric contraction time (CT), which increased to 300% of the initial value. The isometric twitch duration was greatly prolonged as reflected by the lengthened CT and the 800% increase in the one-half relaxation time (1/2RT). Both Pt and Po showed a biphasic recovery, a rapid initial phase (2 min) followed by a slower (40 min) return to the prefatigue force. CT and 1/2RT also recovered in two phases, returning to 160 and 265% of control in the first 5 min. CT returned to the prefatigue value between 35 and 40 min, whereas even at 60 min 1/2RT was 133% of control. The maximal velocity of shortening, determined by the slack test, was significantly reduced [from 6.7 +/- 0.5 to 2.5 +/- 0.4 optimal muscle length/s] at fatigue. The force-frequency relationship was shifted to the left, so that optimal frequency for generating Po was reduced.(ABSTRACT TRUNCATED AT 250 WORDS).

  20. In vivo muscle force and muscle power during near-maximal frog jumps.

    Science.gov (United States)

    Moo, Eng Kuan; Peterson, Daniel R; Leonard, Timothy R; Kaya, Motoshi; Herzog, Walter

    2017-01-01

    Frogs' outstanding jumping ability has been associated with a high power output from the leg extensor muscles. Two main theories have emerged to explain the high power output of the frog leg extensor muscles, either (i) the contractile conditions of all leg extensor muscles are optimized in terms of muscle length and speed of shortening, or (ii) maximal power is achieved through a dynamic catch mechanism that uncouples fibre shortening from the corresponding muscle-tendon unit shortening. As in vivo instantaneous power generation in frog hind limb muscles during jumping has never been measured directly, it is hard to distinguish between the two theories. In this study, we determined the instantaneous variable power output of the plantaris longus (PL) of Lithobates pipiens (also known as Rana pipiens), by directly measuring the in vivo force, length change, and speed of muscle and fibre shortening in near maximal jumps. Fifteen near maximal jumps (> 50cm in horizontal distance) were analyzed. High instantaneous peak power in PL (536 ± 47 W/kg) was achieved by optimizing the contractile conditions in terms of the force-length but not the force-velocity relationship, and by a dynamic catch mechanism that decouples fascicle shortening from muscle-tendon unit shortening. We also found that the extra-muscular free tendon likely amplifies the peak power output of the PL by modulating fascicle shortening length and shortening velocity for optimum power output, but not by releasing stored energy through recoiling as the tendon only started recoiling after peak PL power had been achieved.

  1. Sexual Dimorphism in Mass of the Hindlimb Muscles of the Piebald Odorous Frog (Odorrana schmackeri)

    Institute of Scientific and Technical Information of China (English)

    Lixia ZHANG; Yunyun ZHAO; Ling SHI Xiaohong CHEN; Youqiang LU; Liang QIAO

    2014-01-01

    Male-biased sexual dimorphism in hind limb muscles is widespread in anuran species where scramble competition is common among males. Such sexual difference is thought to result from sexual selection.In this view, we tested the differences in muscle mass between the sexes and between amplectant and non-amplectant males by quantifying the mass of four hindlimb muscles (triceps femoris, sartorius, gracilis and plantaris longus) of females and males ofOdorrana schmackeri. The results showed that females signiifcantly exceeded males for muscle triceps femoris, gracilis, plantaris longus and total mass when controlled for body size. There are no signiifcant differences between amplectant and non-amplectant males. It is probable that the maintenance of the amplectant position inO. schmackeri may depend on the strength of hindlimb muscles in females to support the pair.

  2. Reconstruction with latissimus dorsi, external abdominal oblique and cranial sartorius muscle flaps for a large defect of abdominal wall in a dog after surgical removal of infiltrative lipoma

    OpenAIRE

    2016-01-01

    This animal was presented with a large-sized infiltrative lipoma in the abdominal wall that had been noted for 4 years. This lipoma was confirmed by histological examination from a previous biopsy, and the infiltrative features were identified by a computerized tomography scan. The surgical removal created a large-sized abdominal defect that was closed by a combination of latissimus dorsi and external abdominal oblique muscle flaps in a pedicle pattern. A small dehiscence at the most distal e...

  3. Connectin filaments in stretched skinned fibers of frog skeletal muscle

    Science.gov (United States)

    1984-01-01

    Indirect immunofluorescence microscopy of highly stretched skinned frog semi-tendinous muscle fibers revealed that connectin, an elastic protein of muscle, is located in the gap between actin and myosin filaments and also in the region of myosin filaments except in their centers. Electron microscopic observations showed that there were easily recognizable filaments extending from the myosin filaments to the I band region and to Z lines in the myofibrils treated with antiserum against connectin. In thin sections prepared with tannic acid, very thin filaments connected myosin filaments to actin filaments. These filaments were also observed in myofibrils extracted with a modified Hasselbach-Schneider solution (0.6 M KCl, 0.1 M phosphate buffer, pH 6.5, 2 mM ATP, 2 mM MgCl2, and 1 mM EGTA) and with 0.6 M Kl. SDS PAGE revealed that connectin (also called titin) remained in extracted myofibrils. We suggest that connectin filaments play an important role in the generation of tension upon passive stretch. A scheme of the cytoskeletal structure of myofibrils of vertebrate skeletal muscle is presented on the basis of our present information of connectin and intermediate filaments. PMID:6384237

  4. Aberrant femoral torsion presenting with frog-leg squatting mimicking gluteal muscle contracture.

    Science.gov (United States)

    Chiang, Chia-Ling; Tsai, Meng-Yuan; Chang, Wei-Ning; Chen, Clement Kuen-Huang

    2012-04-01

    Patients with frog-leg squatting have restricted internal rotation and adduction of the affected hips during sitting or squatting. In the surgical literature, the cause generally has been presumed to arise from and be pathognomonic for gluteal muscle contracture. However, we have encountered patients with frog-leg squatting but without gluteal muscle contracture. We therefore raised the following questions: What are the imaging features of patients with frog-leg squatting? Do conditions other than gluteal muscle contracture manifest frog-leg squatting? We retrospectively reviewed the MR images of 67 patients presenting with frog-leg squatting from April 1998 to July 2010. There were four females and 63 males; their mean age was 22.2 years (range, 4-50 years). During MRI readout, we observed aberrant axes of some femoral necks and obtained additional CT to measure femoral torsion angles in 59 of the 67 patients. MR images of 27 (40%) patients had signs of gluteal muscle contracture. Twenty-two (33%) patients (40 femora) had aberrant femoral torsion, including diminished anteversion (range, 6°-0°; average, 3.9°) in 11 femora of eight patients and femoral retroversion (range, muscle contracture or aberrant femoral torsion. The observation of aberrant femoral torsion was not anticipated before imaging studies. In addition to gluteal muscle contracture, aberrant femoral torsion can be a cause of frog-leg squatting. Level II, diagnostic study. See the guidelines for Authors for a complete description of levels of evidence.

  5. Active tension changes in frog skeletal muscle during and after mechanical extension

    NARCIS (Netherlands)

    Atteveldt, H. van; Crowe, Alan

    1980-01-01

    Isolated frog sartorious muscle at 4°C has been used to study the phenomenon whereby tetanically stimulated muscle, subjected to a mechanical extension, yields an active tension which is greater than that obtained during an isometric contraction in which the muscle is stretched prior to stimulation.

  6. In vivo muscle force and muscle power during near-maximal frog jumps

    Science.gov (United States)

    Leonard, Timothy R.; Kaya, Motoshi; Herzog, Walter

    2017-01-01

    Frogs’ outstanding jumping ability has been associated with a high power output from the leg extensor muscles. Two main theories have emerged to explain the high power output of the frog leg extensor muscles, either (i) the contractile conditions of all leg extensor muscles are optimized in terms of muscle length and speed of shortening, or (ii) maximal power is achieved through a dynamic catch mechanism that uncouples fibre shortening from the corresponding muscle-tendon unit shortening. As in vivo instantaneous power generation in frog hind limb muscles during jumping has never been measured directly, it is hard to distinguish between the two theories. In this study, we determined the instantaneous variable power output of the plantaris longus (PL) of Lithobates pipiens (also known as Rana pipiens), by directly measuring the in vivo force, length change, and speed of muscle and fibre shortening in near maximal jumps. Fifteen near maximal jumps (> 50cm in horizontal distance) were analyzed. High instantaneous peak power in PL (536 ± 47 W/kg) was achieved by optimizing the contractile conditions in terms of the force-length but not the force-velocity relationship, and by a dynamic catch mechanism that decouples fascicle shortening from muscle-tendon unit shortening. We also found that the extra-muscular free tendon likely amplifies the peak power output of the PL by modulating fascicle shortening length and shortening velocity for optimum power output, but not by releasing stored energy through recoiling as the tendon only started recoiling after peak PL power had been achieved. PMID:28282405

  7. Frog tongue acts as muscle-powered adhesive tape

    OpenAIRE

    Kleinteich, Thomas; Gorb, Stanislav N

    2015-01-01

    Frogs are well known to capture fast-moving prey by flicking their sticky tongues out of the mouth. This tongue projection behaviour happens extremely fast which makes frog tongues a biological high-speed adhesive system. The processes at the interface between tongue and prey, and thus the mechanism of adhesion, however, are completely unknown. Here, we captured the contact mechanics of frog tongues by filming tongue adhesion at 2000 frames per second through an illuminated glass. We found th...

  8. Design and Dynamic Model of a Frog-inspired Swimming Robot Powered by Pneumatic Muscles

    Science.gov (United States)

    Fan, Ji-Zhuang; Zhang, Wei; Kong, Peng-Cheng; Cai, He-Gao; Liu, Gang-Feng

    2017-09-01

    Pneumatic muscles with similar characteristics to biological muscles have been widely used in robots, and thus are promising drivers for frog inspired robots. However, the application and nonlinearity of the pneumatic system limit the advance. On the basis of the swimming mechanism of the frog, a frog-inspired robot based on pneumatic muscles is developed. To realize the independent tasks by the robot, a pneumatic system with internal chambers, micro air pump, and valves is implemented. The micro pump is used to maintain the pressure difference between the source and exhaust chambers. The pneumatic muscles are controlled by high-speed switch valves which can reduce the robot cost, volume, and mass. A dynamic model of the pneumatic system is established for the simulation to estimate the system, including the chamber, muscle, and pneumatic circuit models. The robot design is verified by the robot swimming experiments and the dynamic model is verified through the experiments and simulations of the pneumatic system. The simulation results are compared to analyze the functions of the source pressure, internal volume of the muscle, and circuit flow rate which is proved the main factor that limits the response of muscle pressure. The proposed research provides the application of the pneumatic muscles in the frog inspired robot and the pneumatic model to study muscle controller.

  9. Enzyme activity in the aestivating green-striped burrowing frog (Cyclorana alboguttata).

    Science.gov (United States)

    Mantle, Beth L; Guderley, Helga; Hudson, Nicholas J; Franklin, Craig E

    2010-10-01

    Green-striped burrowing frogs (Cyclorana alboguttata) can depress their resting metabolism by more than 80% during aestivation. Previous studies have shown that this species is able to withstand long periods of immobilisation during aestivation while apparently maintaining whole muscle mass and contractile performance. The aim of this study was to determine the effect of prolonged aestivation on the levels of metabolic enzymes (CCO, LDH and CS) in functionally distinct skeletal muscles (cruralis, gastrocnemius, sartorius, iliofibularis and rectus abdominus) and liver of C. alboguttata. CS activity was significantly reduced in all tissues except for the cruralis, gastrocnemius and the liver. LDH activity was significantly reduced in the sartorius and rectus abdominus, but remained at control (active) levels in the other tissues. CCO activity was significantly reduced in the gastrocnemius and rectus abdominus, and unchanged in the remaining tissues. Muscle protein was significantly reduced in the sartorius and iliofibularis during aestivation, and unchanged in the remaining muscles. The results suggest that the energy pathways involved in the production and consumption of ATP are remodelled during prolonged aestivation but selective. Remodelling and subsequent down-regulation of metabolic activity seem to target the smaller non-jumping muscles, while the jumping muscles retain enzyme activities at control levels during aestivation. These results suggest a mechanism by which aestivating C. alboguttata are able to maintain metabolic depression while ensuring that the functional capacity of critical muscles is not compromised upon emergence from aestivation.

  10. Treatment of femoral neck fracture with muscle-bone flap of both musculus tensor fasciae latae and musculus sartorius%阔筋膜张肌缝匠肌骨瓣移植治疗股骨颈骨折

    Institute of Scientific and Technical Information of China (English)

    刘国平; 康斌; 曾辉

    2001-01-01

    Objective To evaluate the effects of bone grafts with muscular pedicles of both musculus tensor fasciae latae and musculus sartorius in treating fresh transcervical or subcapital fractures of femoral neck (TSFFN). Methods 30 cases of TSFFN were treated by tail breakable screws and sartorius muscular pedicles bone grafts. The other 23 cases were treated by hollow pressure screws and bone grafts with muscular pedicles of both musculus tensor fasciae latae and musculus sartorius. Results 52 cases were followed up for 3 to 5 years, 4 years on average. In sartorius muscular pedicles, 8 cases showed the poor therapeutic results. The excellent therapeutic effects were achieved in all cases of musculus sartorius. Conclusion TSFFN can be treated by double muscular pedicles bone graft. The double muscular pedicles bone graft is more effective than single sartorius muscular pedicles in treating TSFFN of short-mid-term.%目的观察阔筋膜张肌和缝匠肌联合双肌蒂骨瓣移植治疗新鲜股骨颈头下型和经颈型骨折的疗效。方法缝匠肌蒂组30例用可折螺钉固定加缝匠肌蒂骨瓣移植;双肌蒂组23例采用可折螺钉或空心加压螺钉固定加阔筋膜张肌和缝匠肌双肌蒂骨瓣移植。结果随访52例,时间3~5年,平均4年,缝匠肌蒂组8例疗效较差,双肌蒂组均愈合良好。结论联合双肌蒂骨瓣治疗股骨颈头下型和经颈型骨折,其近期和中期疗效均较缝匠肌单肌蒂骨瓣移植好。

  11. Myofibrils Bear Most of the Resting Tension in Frog Skeletal Muscle

    Science.gov (United States)

    Magid, Alan; Law, Douglas J.

    1985-12-01

    The tension that develops when relaxed muscles are stretched is the resting (or passive) tension. It has recently been shown that the resting tension of intact skeletal muscle fibers is equivalent to that of mechanically skinned skeletal muscle fibers. Laser diffraction measurements of sarcomere length have now been used to show that the exponential relation between resting tension and sarcomere length for whole frog semitendinosus muscle is similar to that of single fibers. Slack sarcomere lengths and the rates of stress relaxation in these muscles were similar to those in skinned fibers, and sarcomere length remained unchanged during stress relaxation, as in skinned fibers. Thus, in intact semitendinosus muscle of the frog up to a sarcomere length of about 3.8 micrometers, resting tension arises, not in the connective tissue as is commonly thought, but in the elastic resistance of the myofibrils.

  12. Caffeine potentiation of calcium release in frog skeletal muscle fibres.

    Science.gov (United States)

    Delay, M; Ribalet, B; Vergara, J

    1986-06-01

    The effects of caffeine at concentrations up to 3 mM were studied on Ca signals obtained using the metallochromic Ca indicator dyes Arsenazo III and Antipyrylazo III in cut frog skeletal muscle fibres mounted in a triple Vaseline-gap chamber and stimulated by voltage clamp or action potential. The peak amplitude of the transient absorbance change due to Ca2+ release following action potential stimulation is potentiated by an amount dependent on caffeine concentration up to 0.5 mM, and by a concentration-independent amount between 0.5 and 2 mM. At 3 mM-caffeine, the potentiation is reduced, and the Ca signal can have a smaller amplitude than under the control condition. The time course of the rising phase of the Ca signal is preserved by the potentiating effect of caffeine; however, the decay rate of the Ca signal is increasingly slowed at caffeine concentrations greater than 0.5 mM. No substantial change was found in the resting myoplasmic Ca2+ level at caffeine concentrations near 0.5 mM. Even if the free Ca2+ concentration in the presence of this level of caffeine were to increase by 0.04 microM (the threshold of detectability), the calculated potentiation of the Ca signal due to increased partial saturation of intracellular Ca2+ buffers would amount to only about 7%. This value is significantly less than the amount of potentiation observed (up to 40%) following action potentials at caffeine levels of 0.5 mM and above. Experiments made with the impermeant potentiometric dye NK2367 show no alteration by caffeine of the electrical properties of the tubular system. Caffeine at up to moderate concentrations causes a substantial increase in the maximal Ca2+ release obtained following large depolarizations. The voltage dependence of the Ca2+ release is characterized by a caffeine concentration-dependent shift towards more negative membrane potentials. The potentiation of Ca2+ release by caffeine was found to be independent of the external free Ca2+ level. The

  13. Relation between equatorial x-ray intensities and isometric twitch forces in frog skeletal muscle

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Hidehiro; Tameyasu, Tsukasa; Sugi, Haruo (Teikyo Univ., Tokyo (Japan). Faculty of Medicine)

    1983-01-01

    The sartorius muscle of bullfrog (Rana catesbeiana) was mounted vertically in an experimental chamber. The muscle was continuously perfused with Ringer solution, and stimulated with single 2 msec supramaximal current pulses. The equatorial X-ray diffraction pattern (specimen to detector distance, 40 cm) during isometric twitches was recorded with a linear position-sensitive proportional counter, and the data were registered in a computer memory system. With an increase of temperature from 5 to 22/sup 0/C, the magnitude of peak twitch force was reduced by about 50% with a marked decrease in the duration of mechanical response, while the minimum value of Isub(1.0)/Isub(1.1) attained during a twitch increased by more than twofold. On the other hand, the equatorial reflection from resting and fully tetanized muscles showed no appreciable dependence on temperature, though the steady tetanic force P/sub 0/ increased by about 10% with an increase in temperature from 5 to 25/sup 0/C. The intensity ratio is not a linear function of isometric force developed.

  14. Decreased hydrogen peroxide production and mitochondrial respiration in skeletal muscle but not cardiac muscle of the green-striped burrowing frog, a natural model of muscle disuse.

    Science.gov (United States)

    Reilly, Beau D; Hickey, Anthony J R; Cramp, Rebecca L; Franklin, Craig E

    2014-04-01

    Suppression of disuse-induced muscle atrophy has been associated with altered mitochondrial reactive oxygen species (ROS) production in mammals. However, despite extended hindlimb immobility, aestivating animals exhibit little skeletal muscle atrophy compared with artificially immobilised mammalian models. Therefore, we studied mitochondrial respiration and ROS (H2O2) production in permeabilised muscle fibres of the green-striped burrowing frog, Cyclorana alboguttata. Mitochondrial respiration within saponin-permeabilised skeletal and cardiac muscle fibres was measured concurrently with ROS production using high-resolution respirometry coupled to custom-made fluorometers. After 4 months of aestivation, C. alboguttata had significantly depressed whole-body metabolism by ~70% relative to control (active) frogs, and mitochondrial respiration in saponin-permeabilised skeletal muscle fibres decreased by almost 50% both in the absence of ADP and during oxidative phosphorylation. Mitochondrial ROS production showed up to an 88% depression in aestivating skeletal muscle when malate, succinate and pyruvate were present at concentrations likely to reflect those in vivo. The percentage ROS released per O2 molecule consumed was also ~94% less at these concentrations, indicating an intrinsic difference in ROS production capacities during aestivation. We also examined mitochondrial respiration and ROS production in permeabilised cardiac muscle fibres and found that aestivating frogs maintained respiratory flux and ROS production at control levels. These results show that aestivating C. alboguttata has the capacity to independently regulate mitochondrial function in skeletal and cardiac muscles. Furthermore, this work indicates that ROS production can be suppressed in the disused skeletal muscle of aestivating frogs, which may in turn protect against potential oxidative damage and preserve skeletal muscle structure during aestivation and following arousal.

  15. The properties of the extraocular muscles of the frog. I. Mechanical properties of the isolated superior oblique and superior rectus muscles.

    Science.gov (United States)

    Asmussen, G

    1978-01-01

    The mechanical properties of two extraocular muscles (superior oblique and superior rectus muscles) of the frog were studied and compared with those of a frog's skeletal muscle (iliofibularis muscle) which contains the same types of muscle fibres as the oculorotatory muscles. The extraocular muscles are very fast twitching muscles. They exhibit a smaller contraction time, a smaller half-relaxation time, a higher fusion frequency, and a lower twitch-tetanus ratio than the skeletal muscles. The maximum isometric tetanic tension produced per unit cross-sectional area is lower in the extraocular muscles than in skeletal muscles. However, the extraocular muscles show a higher fatigue resistance than the skeletal muscles. With respect to the dynamic properties there are some differences between the various oculorotatory muscles of the frog. The superior rectus muscle exhibits a faster time-course of the contraction, a higher fusion frequency, and a higher fatigability than the superior oblique muscle. An increase of the extracellular K+-concentration evokes sustained contractures not only in the extraocular muscles but also in the iliofibularis muscle; between these muscles there are no striking differences in the mechanical threshold of the whole muscle preparation. The mechanical threshold depends on the Ca++-concentration of the bathing solution and it is found in a range between 12.5 and 17.5 mM K+ in a normal Ringer solution containing 1.8 mM Ca++. The static-mechanical properties of the extraocular muscles of the frog and the dependence of the active developed tension on the muscle extension are very similar to those which are known to exist in the extraocular muscles of other vertebrates. In tetanic activated frog's oculorotatory muscles a linear relationship exists between length and tension. A variation of the stimulation frequency does not change the slope of this curve but causes parallel shifts of the curve. The peculiar properties of the extraocular muscles

  16. The properties of the extraocular muscles of the frog. II. Pharmacological properties of the isolated superior oblique and superior rectus muscles.

    Science.gov (United States)

    Asmussen, G

    1978-01-01

    The pharmacological properties of the superior oblique and the superior rectus muscles of the frog's eye were investigated in comparison with those of a skeletal muscle (iliofibularis muscle) of the same animal. Acetylcholine causes sustained contractures of the extraocular muscles; this effect is increased by physostigmine and decreased or abolished by d-tubocurarine. Also the applications of succinylcholine, choline or caffeine are able to evoke contractures. There are no striking differences in pharmacological properties between extraocular and skeletal muscles of the frog. The time-course of the contractures and the sensitivity of the muscle preparations to the drugs which evoke contractures are identical in extraocular and iliofibularis muscles. In comparison with skeletal muscles there is no higher sensitivity of the extraocular muscles against curare-like drugs. The existence of adrenergic receptors could not be found neither in extraocular nor in skeletal muscles of the frog. It is concluded that in frogs no pharmacological differences exist between the muscle fibre types which compose the extraocular and the skeletal muscles.

  17. Microtransplantation of acetylcholine receptors from normal or denervated rat skeletal muscles to frog oocytes

    Science.gov (United States)

    Bernareggi, Annalisa; Reyes-Ruiz, Jorge Mauricio; Lorenzon, Paola; Ruzzier, Fabio; Miledi, Ricardo

    2011-01-01

    Cell membranes, carrying neurotransmitter receptors and ion channels, can be ‘microtransplanted’ into frog oocytes. This technique allows a direct functional characterization of the original membrane proteins, together with any associated molecules they may have, still embedded in their natural lipid environment. This approach has been previously demonstrated to be very useful to study neurotransmitter receptors and ion channels contained in cell membranes isolated from human brains. Here, we examined the possibility of using the microtransplantation method to study acetylcholine receptors from normal and denervated rat skeletal muscles. We found that the muscle membranes, carrying their fetal or adult acetylcholine receptor isoforms, could be efficiently microtransplanted to the oocyte membrane, making the oocytes become sensitive to acetylcholine. These results show that oocytes injected with skeletal muscle membranes efficiently incorporate functional acetylcholine receptors, thus making the microtransplantation approach a valuable tool to further investigate receptors and ion channels of human muscle diseases. PMID:21224230

  18. PARALYTIC EFFECTS OF "PARALYTIC SHELLFISH POISON" ON FROG NERVE AND MUSCLE.

    Science.gov (United States)

    EVANS, M H

    1964-06-01

    A purified extract of toxic lamellibranchs, Saxidomus giganteus (Deshayes), containing "paralytic shellfish poison," has been tested for its effects on conduction and contraction in frog nerve and muscle. The poison was very toxic and concentrations within the range 0.025 to 0.1 mug/ml. paralysed isolated muscle preparations, with abolition of the muscle action potential. The poison did not readily penetrate the perineurium, but in desheathed sciatic nerves the conduction of nerve impulses was rapidly blocked by concentrations of 0.05 to 0.1 mug/ml. There was no evidence that the poison had any specific curarizing action at the neuromuscular junction, and the paralysis was not accompanied by any appreciable depolarization of the muscle membrane.

  19. Changes in contractile properties by androgen hormones in sexually dimorphic muscles of male frogs (Xenopus laevis).

    Science.gov (United States)

    Regnier, M; Herrera, A A

    1993-02-01

    1. Male frogs (Xenopus laevis) were castrated then given either empty or testosterone-filled implants to produce animals with low or high levels of circulating testosterone. Eight weeks later the contractile properties of an androgen-sensitive forelimb flexor, the flexor carpi radialis muscle (FCR), were measured in vitro. Another forelimb flexor muscle, the coracoradialis, and a hindlimb muscle, the iliofibularis, were analysed similarly. 2. Plasma testosterone levels were 0.9 +/- 0.3 ng/ml (+/- S.E.M.) in castrated frogs with blank implants (C) and 61.3 +/- 4.7 ng/ml in castrates with testosterone implants (CT). Unoperated males, sampled at various times of the year, ranged between 10.8 and 51.0 ng/ml. 3. With direct electrical stimulation of the FCR, contraction time of the isometric twitch was not affected by testosterone levels. Relaxation times were affected, however. Half- and 90% relaxation times were 27 and 42% longer, respectively, for CT compared to C muscles. 4. Testosterone also had no effect on the contraction time of twitches elicited by stimulation of the FCR nerve. Half- and 90% relaxation times were 51 and 76% longer, respectively, for CT compared to C muscles. 5. Tetanus tension, elicited by direct stimulation of the FCR at 50 Hz, was 86% greater in CT compared to C muscles. The average cross-sectional area of FCR muscle fibres was 84% greater in CT muscles. These results implied that testosterone treatment had no effect on specific muscle tension. 6. Stimulation of the FCR nerve at 50 Hz resulted in 53% less tension than the same stimulus applied directly to CT muscles. In C muscles the difference was only 14%. This suggested that testosterone treatment reduced synaptic efficacy. 7. In CT muscles, direct or nerve stimulation of fibres in the shoulder region of the FCR elicited twitches that contracted and relaxed more slowly than fibres in the elbow region. In C muscles there was no difference in contraction or relaxation time between fibres in

  20. EFFECTS OF 2-PAM AND EA 1814 ON NEUROMUSCULAR TRANSMISSION. I. EFFECTS OF 2-PAM AND EA 1814 ON THE FROG RECTUS ABDOMINIS MUSCLE PREPARATION

    Science.gov (United States)

    Contracture of the isolated frog Rectus abdominis muscle was used to study pharmacological properties of 2-PAM (2-pyridine aldoxime methiodide) and...example, concentrations of 2-PAM in excess of 4 x 10 to the -5th power M potentiate contractures of the frog rectus muscle elicited by acetylcholine...2-PAM inhibits the response to the depolarizing agents, decamethonium and carbamylcholine, which are not susceptible to hydrolysis by the ChE of frog

  1. Mechanism of latency relaxation in frog skeletal muscle.

    Science.gov (United States)

    Yagi, N

    2011-05-01

    The latency relaxation is a small drop of tension before skeletal muscle begins to develop active tension. This phenomenon was found nearly one century ago but its origin has not been clarified. In this review, the hypotheses for its mechanism are discussed in terms of the recent experimental results using X-ray diffraction. The latency relaxation takes place almost simultaneously as the structural change of the regulatory protein troponin, an unspecified structural change of the thick filament, and increase in stiffness. It seems difficult to associate all of these with the latency relaxation by assuming a simple mechanism. Copyright © 2010 Elsevier Ltd. All rights reserved.

  2. Frogs and estivation: transcriptional insights into metabolism and cell survival in a natural model of extended muscle disuse.

    Science.gov (United States)

    Reilly, Beau D; Schlipalius, David I; Cramp, Rebecca L; Ebert, Paul R; Franklin, Craig E

    2013-05-15

    Green-striped burrowing frogs (Cyclorana alboguttata) survive in arid environments by burrowing underground and entering into a deep, prolonged metabolic depression known as estivation. Throughout estivation, C. alboguttata is immobilized within a cast-like cocoon of shed skin and ceases feeding and moving. Remarkably, these frogs exhibit very little muscle atrophy despite extended disuse and fasting. Little is known about the transcriptional regulation of estivation or associated mechanisms that may minimize degradative pathways of atrophy. To investigate transcriptional pathways associated with metabolic depression and maintenance of muscle function in estivating burrowing frogs, we assembled a skeletal muscle transcriptome using next-generation short read sequencing and compared gene expression patterns between active and 4 mo estivating C. alboguttata. This identified a complex suite of gene expression changes that occur in muscle during estivation and provides evidence that estivation in burrowing frogs involves transcriptional regulation of genes associated with cytoskeletal remodeling, avoidance of oxidative stress, energy metabolism, the cell stress response, and apoptotic signaling. In particular, the expression levels of genes encoding cell cycle and prosurvival proteins, such as serine/threonine-protein kinase Chk1, cell division protein kinase 2, survivin, and vesicular overexpressed in cancer prosurvival protein 1, were upregulated during estivation. These data suggest that estivating C. alboguttata are able to regulate the expression of genes in several major cellular pathways critical to the survival and viability of cells, thus preserving muscle function while avoiding the deleterious consequences often seen in laboratory models of muscle disuse.

  3. The responses of frog muscle spindles and fast and slow muscle fibres to a variety of mechanical inputs.

    Science.gov (United States)

    Brown, M C

    1971-10-01

    1. The tension in the iliofibularis muscle of frogs was recorded while the muscle was stretched or released. At the same time recordings were made from single spindle afferents in dorsal root filaments. Either large or small motor nerve fibres were stimulated in split ventral root filaments.2. While small motor nerve fibres were stimulated the discharge from muscle spindle afferents was greatly increased by stretching, and greatly reduced by shortening the muscle. This sensitivity to movement was shown even if the movements were small, so that a stretch of 0.2% of the muscle length was sufficient to cause a pronounced increase in the afferent discharge.3. In contrast, during stimulation of the large motor nerve fibres the spindle was much less sensitive to movements with the result that even stretches or releases of the muscle by 1 mm did not cause very large changes in the discharge frequency.4. The tension in slow extrafusal muscle fibres in many ways mirrored the spindle discharge during the stimulation of small motor nerve fibres, for the tension was greatly increased by stretching, even through small distances, and greatly reduced by releasing the muscle. The tension in fast extrafusal muscle fibres was much less changed by such movements, and thus was rather like the spindle discharge during stimulation of large motor nerve fibres.5. As the extrafusal muscle fibres do not directly pull on and excite the spindle afferents, the simplest explanation for the similarities between the muscle tension and the spindle discharge is that the mechanical properties of the intrafusal muscle fibres innervated by the large motor nerve fibres are like those of fast extrafusal muscle fibres, and that the mechanical properties of the small intrafusal fibres are similar to those of slow extrafusal muscle fibres.6. It is shown that the cross-bridge sliding filament mechanism of muscle contraction provides a ready explanation for the differences found between fast and slow muscles

  4. Energy transfer during stress relaxation of contracting frog muscle fibres.

    Science.gov (United States)

    Mantovani, M; Heglund, N C; Cavagna, G A

    2001-12-15

    1. A contracting muscle resists stretching with a force greater than the force it can exert at a constant length, T(o). If the muscle is kept active at the stretched length, the excess tension disappears, at first rapidly and then more slowly (stress relaxation). The present study is concerned with the first, fast tension decay. In particular, it is still debated if and to what extent the fast tension decay after a ramp stretch involves a conservation of the elastic energy stored during stretching into cross-bridge states of higher chemical energy. 2. Single muscle fibres of Rana temporaria and Rana esculenta were subjected to a short ramp stretch (approximately 15 nm per half-sarcomere at either 1.4 or 0.04 sarcomere lengths s(-1)) on the plateau of the force-length relation at temperatures of 4 and 14 degrees C. Immediately after the end of the stretch, or after discrete time intervals of fixed-end contraction and stress relaxation at the stretched length (Delta t(isom) = 0.5-300 ms), the fibre was released against a force ~T(o). Fibre and sarcomere stiffness during the elastic recoil to T(o) (phase 1) and the subsequent transient shortening against T(o) (phase 2), which is expression of the work enhancement by stretch, were measured after different Delta t(isom) and compared with the corresponding fast tension decay during Delta t(isom). 3. The amplitude of fast tension decay is large after the fast stretch, and small or nil after the slow stretch. Two exponential terms are necessary to fit the fast tension decay after the fast stretch at 4 degrees C, whereas one is sufficient in the other cases. The rate constant of the dominant exponential term (0.1-0.2 ms(-1) at 4 degrees C) increases with temperature with a temperature coefficient (Q(10)) of approximately 3. 4. After fast stretch, the fast tension decay during Delta t(isom) is accompanied in both species and at both temperatures by a corresponding increase in the amplitude of phase 2 shortening against T

  5. [Reinnervation of a mixed muscle in the frog Rana temporaria with a regenerating homogeneous nerve].

    Science.gov (United States)

    Radziukevich, T L

    1995-01-01

    Mixed muscle m. iliofibularis from the frog Rana temporaria, consisting of monosynaptically innervated phasic and polysynaptically innervated postural muscle fibers, was reinnervated by homogeneous tailor's nerve having no axons of tonic motor system in its composition. Within 2-7 months after nerves binding treatment phasic muscle fibers were easily identified by subneural apparatus structure revealed at coloration of synaptic acetylcholinesterase. Presynaptic part of neuromuscular apparatus of these fibers after the impregnation by protargol was presented by immature nervous terminals. The identification of tonic Muscular fibers was difficult especially at the late stages of reinnervation as subneural apparatus structure typical for tonic fibers was not revealed. Nonmyelinizated nerve fibers without features of terminal branch were observed in individual regions of nonidentified muscle fibers. The results obtained show that subneural apparatus of tonic muscle fibers depends to a great extent on the influence of inherent tonic motor system. Axons of phasic motor system even at distant reinnervation periods and in the absence of competitive influences of tonic motor system do not form typical "phasic" terminal picture of innervation under the contact with tonic muscle fibers.

  6. Effects of adrenaline on glycogenolysis in resting anaerobic frog muscles studied by 31P-NMR.

    Science.gov (United States)

    Kikuchi, Kimio; Yamada, Takenori; Sugi, Haruo

    2009-11-01

    The effects of adrenaline (also called epinephrine) on glycogenolysis in living anaerobic muscles were examined based on time-dependent changes of (31)P-NMR spectra of resting frog skeletal muscles with and without iodoacetate treatments. The phosphate-metabolite concentration and the intracellular pH determined from the NMR spectra changed with time, reflecting the advancement of various phosphate metabolic reactions coupled with residual ATPase reactions to keep the ATP concentration constant. The results could be explained semi-qualitatively as the ATP regenerative reactions, creatine kinase reaction and glycogenolysis, advanced with time showing the characteristic two phases. Thus, it was clarified for living muscles that adrenaline activates the phosphorylase step of glycogenolysis, and the adrenaline-activated glycogenolysis is further regulated at the phosphofructokinase step by PCr and also possibly by AMP. Associated with the adrenaline-activated glycogenolysis in the examined muscles, the P(i) concentration and the intracellular pH, factors affecting the muscle force, changed significantly, suggesting complicated effects of adrenaline on the muscle contractility.

  7. A comparative study of the membrane structure in different types of muscle fibers in the frog.

    Science.gov (United States)

    Verma, V

    1984-09-01

    The muscle membrane of slow and fast fibers in cruralis and iliofibularis muscles and of intermediate fibers in submaxillaris muscle of the frog is studied in freeze-fracture replicas. A comparison of membrane folds, number, size and distribution of caveolae and of intramembrane particles (IMP) is given. In slow muscle fibers, the membrane folds are systematically present at the level of the I zone with a transversal continuity, whereas in fast and intermediate types the membrane folds are small and are randomly distributed. In slow muscle the caveolae are more numerous at the I zone than in the part corresponding to the center of the sarcomere. In fast muscle, small groups of caveolae form linear patterns, and in intermediate fibers the distribution is random. The number of caveolae in slow muscle fibers is two times more than in fast and intermediate fibers. The mean area of caveolae opening is largest in fast and smallest in slow muscle fibers. The number of IMP is significantly different in the three types of fibers, being highest in slow and lowest in intermediate fibers. The different pattern of folds in slow fibers may correspond to the different contractile properties of this fiber type. The presence of double the number of caveolae in slow fibers correlated to the less elaborate T system in this fiber type shows the possibility that slow fibers may be the result of an arrest during development for the performance of a different function. The difference in IMP density in the three muscle fiber types may be interpreted as the difference in their electrical properties.

  8. Topographical projections of segmental nerves to the frog glutaeus muscle during loss of polyneuronal innervation.

    Science.gov (United States)

    Bennett, M; Lavidis, N

    1986-06-01

    The development of synaptic connexions to the frog (Limnodynastes tasmaniansis) glutaeus muscle from segmental nerves 8 and 9 was determined using glycogen depletion, contraction and electrophysiological methods between stages 54 and 60 (Nieuwkoop & Faber, 1975). There was no change in the number of muscle cells in the glutaeus from stage 55 onwards; the maturation of muscle cells was most advanced at the point of nerve entry on the ventral surface of the glutaeus and least advanced at the dorsal surface. Electrophysiological determination of the segmental innervation of the dorsal surface of the muscle in low calcium (0.5 mM) indicated that the muscle was almost uniquely innervated by nerve 8 at stage 54. Weak nerve 9 terminals were detected at stage 54 only if the calcium concentration was raised to 6.0 mM. Innervation by nerve 9 was first detected in low calcium at stage 55. There was then a progressive decrease in the innervation of the glutaeus muscle by nerve 8 in regions apposed to the iliofibularis muscle, until stage 59 when this part of the glutaeus was almost completely innervated by nerve 9. Glycogen depletion of muscle fibres following tetanic stimulation of either segmental nerve confirmed that the region of the glutaeus muscle apposed by the iliofibularis becomes progressively innervated by nerve 9 during development. Contraction studies of the segmental innervation of the glutaeus muscle in normal calcium (2 mM) indicated that the muscle was predominantly innervated by nerve 8 at stage 54. There was then a progressive increase in the number of nerve 9 motor units up to stage 56. The size of individual motor units declined for both nerves 8 and 9 until stage 59, when the average motor unit size was about 9% of the muscle. It is suggested that the decline in the innervation by nerve 8 of the side of the glutaeus muscle apposing the iliofibularis muscle is due to this region of the muscle selectively favouring synapse formation by nerve 9 over nerve 8.

  9. Effects of cannabinoids on caffeine contractures in slow and fast skeletal muscle fibers of the frog.

    Science.gov (United States)

    Huerta, Miguel; Ortiz-Mesina, Mónica; Trujillo, Xóchitl; Sánchez-Pastor, Enrique; Vásquez, Clemente; Castro, Elena; Velasco, Raymundo; Montoya-Pérez, Rocío; Onetti, Carlos

    2009-05-01

    The effect of cannabinoids on caffeine contractures was investigated in slow and fast skeletal muscle fibers using isometric tension recording. In slow muscle fibers, WIN 55,212-2 (10 and 5 microM) caused a decrease in tension. These doses reduced maximum tension to 67.43 +/- 8.07% (P = 0.02, n = 5) and 79.4 +/- 14.11% (P = 0.007, n = 5) compared to control, respectively. Tension-time integral was reduced to 58.37 +/- 7.17% and 75.10 +/- 3.60% (P = 0.002, n = 5), respectively. Using the CB(1) cannabinoid receptor agonist ACPA (1 microM) reduced the maximum tension of caffeine contractures by 68.70 +/- 11.63% (P = 0.01, n = 5); tension-time integral was reduced by 66.82 +/- 6.89% (P = 0.02, n = 5) compared to controls. When the CB(1) receptor antagonist AM281 was coapplied with ACPA, it reversed the effect of ACPA on caffeine-evoked tension. In slow and fast muscle fibers incubated with the pertussis toxin, ACPA had no effect on tension evoked by caffeine. In fast muscle fibers, ACPA (1 microM) also decreased tension; the maximum tension was reduced by 56.48 +/- 3.4% (P = 0.001, n = 4), and tension-time integral was reduced by 57.81 +/- 2.6% (P = 0.006, n = 4). This ACPA effect was not statistically significant with respect to the reduction in tension in slow muscle fibers. Moreover, we detected the presence of mRNA for the cannabinoid CB(1) receptor on fast and slow skeletal muscle fibers, which was significantly higher in fast compared to slow muscle fiber expression. In conclusion, our results suggest that in the slow and fast muscle fibers of the frog cannabinoids diminish caffeine-evoked tension through a receptor-mediated mechanism.

  10. Mg++ and K+ Distribution in Frog Muscle and Egg: A Disproof of the Donnan Theory of Membrane Equilibrium Applied to the Living Cells,

    Science.gov (United States)

    1979-01-01

    ELECTE! Mg++ and K+ Distribution in Frog Muscle and Egg: B A Disproof of the Donnan Theory of Membrane B Equilibrium Applied to the Living Cells GILBERT...19107 J ABSTRACT 1. We studied the equilibrium distribution of Mg** in the form of chlo- ride and pulfate at two temperatures (5* and 25°C) in frog ...vicinity of 90 jmoles/g/ fresh muscle cells. 4. We observed a similar rectilinear distribution of Mg** in frog ovarian eggs. As in muscle tissues, no major

  11. Reticulospinal actions on primary afferent depolarization of cutaneous and muscle afferents in the isolated frog neuraxis.

    Science.gov (United States)

    González, H; Jiménez, I; Rudomin, P

    1993-01-01

    The effects of the brainstem reticular formation on the intraspinal excitability of low threshold cutaneous and muscle afferents were studied in the frog neuraxis isolated together with the right hindlimb nerves. Stimulation of low threshold fibers (less than two times threshold) in cutaneous nerves produced short latency, negative field potentials in the ipsilateral dorsal neuropil (200-400 microns depth) that reversed to positivity at deeper regions (500-700 microns). Stimulation of low threshold fibers (less than two times threshold) in muscle nerves produced, instead, negative response that acquired their maximum amplitude in the ventral neuropil (700-900 microns depth). These electrophysiological findings suggest, in agreement with observations in the cat, that low threshold cutaneous and muscle afferents end at different sites in the spinal cord. Intraspinal microstimulation applied within the dorsal neuropil produced antidromic responses in low threshold cutaneous afferents that were increased in size following stimulation of the dorsal or ventral roots, as well as of the brainstem reticular formation. This increase in excitability is interpreted as being due to primary afferent depolarization (PAD) of the intraspinal terminals of cutaneous fibers. Antidromic responses recorded in muscle nerves following intraspinal stimulation within the ventral neuropil were also increased following conditioning stimulation of adjacent dorsal or ventral roots. However, stimulation of the bulbar reticular formation produced practically no changes in the antidromic responses, but was able to inhibit the PAD of low threshold muscle afferents elicited by stimulation of the dorsal or ventral roots. It is suggested that the PAD of low threshold cutaneous and muscle afferents is mediated by independent sets of interneurons. Reticulospinal fibers would have excitatory connections with the interneurons mediating the PAD of cutaneous fibers and inhibitory connections with the

  12. Muscle fatigue in frog semitendinosus: role of intracellular pH

    Science.gov (United States)

    Thompson, L. V.; Balog, E. M.; Fitts, R. H.

    1992-01-01

    The purpose of this study was to utilize glass microelectrodes to characterize the intracellular pH (pHi) before and during recovery from fatigue in the frog semitendinosus (ST) muscle. A second objective was to evaluate the relationship between pHi and contractile function. The frog ST muscle (22 degrees C) was fatigued by direct electrical stimulation with 100-ms 150-Hz trains at 1/s for 5 min. Peak tetanic force (Po) was reduced to 8.5% of initial force and recovered in a biphasic manner, returning to the resting value by 40 min. Resting pHi was 7.00 +/- 0.02 (n = 37) and declined with fatigue to an average value of 6.42 at 3 min of recovery. During recovery pHi significantly increased and by 25 min had returned to the prefatigue value. The pHi recovery was highly correlated to the slow phase of Po recovery (r = 0.98, P less than 0.001). The mean resting membrane potential was -78 +/- 1.0 mV (n = 42) and at 3 min of recovery was depolarized to -67 +/- 4 mV. Both the peak rate of twitch force development (+dP/dt) (r = 0.99, P less than 0.001) and decline (-dP/dt) (r = 0.94, P less than 0.014) were highly correlated to pHi during the slow phase of recovery. Contraction time (CT) and one-half relaxation time (1/2RT) increased significantly and recovered exponentially. The recovery of CT and 1/2RT were both significantly correlated to pHi (r = -0.93, P less than 0.001 and r = -0.86, P less than 0.001 for CT and 1/2RT, respectively).(ABSTRACT TRUNCATED AT 250 WORDS).

  13. The formation of synapses in amphibian striated muscle during development.

    Science.gov (United States)

    Bennett, M R; Pettigrew, A G

    1975-10-01

    1. A study has been made of the formation of synapses in developing reinnervated and cross-reinnervated amphibian twitch muscles which receive either a focal (iliofibularis) or a distributed (sartorius) innervation from 'en plaque' nerve terminals using histological, ultrastructural and electrophysiological techniques. 2. During the development of the tadpole through metamorphosis to the adult frog, the sartorius myofibres increased in length at about twice the rate of the iliofibularis myofibres, due to a fast rate of growth at their insertions on to the pelvic tendon. 3. The short iliofibularis and sartorius myofibres of young tadpoles (800 mum long) possessed only a single synapse and the iliofibularis myofibres did not receive any further innervation during development. However the sartorius myofibres received further transient innervation on the new muscle laid down during development at the fast growing pelvic insertion, until the distance between the original synapse formed on the myofibres and the synapse at the pelvic end of the muscle was about 12 mm. 4. During development synapses possessed either skewed, multimodal, or unimodal m.e.p.p. amplitude-frequency distributions; the intervals between m.e.p.p.s. were not distributed randomly according to a Poisson process, as m.e.p.p.s. of similar amplitudes tended to be separated by very short intervals; the unit-size e.p.p. had a similar amplitude-frequency distribution as the m.e.p.p.s. if these had a unimodal distribution. 5. Reinnervation or cross-reinnervation of the sartorius and the iliofibularis muscles in adults or at a late stage of development simply reconstituted the normal focal and distributed innervation patterns of the muscles, as found in the control muscles of the contralateral and unoperated legs. 6. These observations on synapse formation in amphibia are consistent with the hypothesis that during development the axon making the initial synaptic contact on the muscle cells induces a property

  14. Sarcomere lengthening and tension drop in the latent period of isolated frog skeletal muscle fibers.

    Science.gov (United States)

    Haugen, P; Sten-Knudsen, O

    1976-09-01

    A laser diffraction technique has been developed for registering small changes in sarcomere length. The technique is capable of resolving changes as small as 0.2 A in isolated frog skeletal muscle fibers. The small sarcomere lengthening that accompanies the drop in tension in the latent period of contraction was investigated. We suggest this lengthening be named latency elongation (LE). The LE is present in a completely slack fiber and must, therefore, be caused by a forcible lengthening process. Furthermore, the LE is dependent on the existence of an overlap between thin and tick filaments. The rate of elongation and the time interval between stimulation and maximum elongation may vary along the fiber. The maximum elongation was 3-5 A per sarcomere. At any instant the drop in tension is a product of the sum of sarcomere lengthenings along the fiber and the slope stiffness of the series elasticity. The latency relaxation (LR) could be registered in the sarcomere length range from 2.2 mum to 3.6-3.7 mum. The amplitude went through a sharp maximum at 3.0-3.1 mum. In the sarcomere length range from 2.2 to 2.8 mum the delay from onset to maximum LR was nearly proportional to the distance from the Z-line to the overlap zone. A working hypothesis is presented. It is suggested that the LE is caused by a lengthening of the thin filaments.

  15. Calcium channels and intracellular calcium release are pharmacologically different in frog skeletal muscle.

    Science.gov (United States)

    McCleskey, E W

    1985-04-01

    The pharmacology of Ca2+ channels and intracellular Ca2+ release from the sarcoplasmic reticulum (s.r.) were compared by injecting Ca2+ channel blockers into the cytoplasm and observing contraction under voltage clamp of frog skeletal muscle fibres, a preparation that contracts only in response to Ca2+ release from the s.r. A method for quantifying intracellular injections by co-injecting a fluorescent dye is described. Nifedipine injected into cells blocks Ca2+ current through the cell membrane showing that nifedipine is active when applied to the cytoplasmic side of the membrane in which Ca2+ channels are located. Neither the presence of Ca2+ channel blockers in the extracellular medium nor 24 h incubation in nifedipine and D-600 affect contraction. Nifedipine and D-600 injected to intracellular concentrations much greater than necessary to block Ca2+ channels do not affect contraction. The presence of 30 microM-D-600 during K+ contractures caused paralysis but 20 microM-nifedipine did not. Thus, contracture-dependent D-600 paralysis is not due to blockade of the transverse tubule Ca2+ channel. It is concluded that: (a) a functioning Ca2+ channel on the cell membrane is not necessary to trigger Ca2+ release from the s.r.; (b) s.r. Ca2+ release and Ca2+ channels are pharmacologically different.

  16. Changes in sarcomere length during isometric tension development in frog skeletal muscle.

    Science.gov (United States)

    Cleworth, D R; Edman, K A

    1972-12-01

    1. Changes in sarcomere length during isometric contraction of isolated semitendinosus muscle fibres from the frog were studied using laser diffraction techniques. Movements of the first-order diffraction line relative to the zero-order reference were recorded from a screen on continuously moving film. Sarcomere length changes of 50 A could be resolved in this way.2. Following a latent period of approximately 12 msec after the stimulus of a single skeletal muscle fibre at 1-2 degrees C, there appeared to be a simultaneous onset of tension development and sarcomere shortening. Provided that the fibre was uniformly excited along its length, different regions shortened together by approximately the same amount. The extent of the shortening was a function of the total compliance of the tendons and tension measuring device.3. During the plateau of a smooth tetanus no fluctuations of first-order line width or zero- to first-order line spacing were detectable at any point examined along the preparation. This finding provides evidence that, in a functionally intact fibre, no synchronous oscillations of the sarcomeres, at least no length changes exceeding 50 A, occur during a fused tetanus. Furthermore, the fact that the first-order line did not increase in width as the preparation went from rest to full activity indicates that contraction proceeds without appreciable change in distribution of sarcomere lengths.4. The sarcomere movements during relaxation differed along the length of the fibre. As the tension declined smoothly, sarcomeres in some parts of the fibre underwent further shortening, while the end sarcomeres near the tendons and in one or two regions in the middle segment of the fibre were further extended. These data indicate that the duration of the mechanical activity differs in different regions along the length of the fibre. The pattern of relaxation, i.e. the behaviour of the sarcomeres in different fibre segments, is unique to any particular fibre.

  17. Comparison of isometric contractile properties of the tongue muscles in three species of frogs, Litoria caerulea, Dyscophus guinetti, and Bufo marinus.

    Science.gov (United States)

    Peters, S E; Nishikawa, K C

    1999-11-01

    Previous studies show that anurans feed in at least three different ways. Basal frogs have a broad tongue that shortens during protraction and emerges only a short distance from the mouth. Some frogs have long, narrow tongues that elongate dramatically due primarily to inertia from mouth opening, which is transferred to the tongue. A few species have a hydrostatic mechanism that produces tongue elongation during protraction. This functional diversity occurs among frogs that share the same two pairs of tongue muscles. Our study compares the isometric contractile properties of these tongue muscles among three frog species that represent each feeding mechanism. Nerves to the paired protractors and retractors were stimulated electrically in each species to record the force properties, contraction speeds, and fatigabilites of these muscles. Few differences were found in the isometric contractile properties of tongue muscles, and the greatest differences were found in the retractors, not the protractors. We propose that the unique arrangement of the tongue muscles in frogs results in a retractor that may also be coactivated with the protractor in order to produce normal tongue protraction. Inertial effects from body, head, and jaw movements, along with clear differences that we found in passive resistance of the tongues to elongation, may explain much of the behavioral variation in tongue use among species. Copyright 1999 Wiley-Liss, Inc.

  18. Comparison of myoplasmic calcium movements during excitation-contraction coupling in frog twitch and mouse fast-twitch muscle fibers.

    Science.gov (United States)

    Hollingworth, Stephen; Baylor, Stephen M

    2013-05-01

    Single twitch fibers from frog leg muscles were isolated by dissection and micro-injected with furaptra, a rapidly responding fluorescent Ca(2+) indicator. Indicator resting fluorescence (FR) and the change evoked by an action potential (ΔF) were measured at long sarcomere length (16°C); ΔF/FR was scaled to units of ΔfCaD, the change in fraction of the indicator in the Ca(2+)-bound form. ΔfCaD was simulated with a multicompartment model of the underlying myoplasmic Ca(2+) movements, and the results were compared with previous measurements and analyses in mouse fast-twitch fibers. In frog fibers, sarcoplasmic reticulum (SR) Ca(2+) release evoked by an action potential appears to be the sum of two components. The time course of the first component is similar to that of the entire Ca(2+) release waveform in mouse fibers, whereas that of the second component is severalfold slower; the fractional release amounts are ~0.8 (first component) and ~0.2 (second component). Similar results were obtained in frog simulations with a modified model that permitted competition between Mg(2+) and Ca(2+) for occupancy of the regulatory sites on troponin. An anatomical basis for two release components in frog fibers is the presence of both junctional and parajunctional SR Ca(2+) release channels (ryanodine receptors [RyRs]), whereas mouse fibers (usually) have only junctional RyRs. Also, frog fibers have two RyR isoforms, RyRα and RyRβ, whereas the mouse fibers (usually) have only one, RyR1. Our simulations suggest that the second release component in frog fibers functions to supply extra Ca(2+) to activate troponin, which, in mouse fibers, is not needed because of the more favorable location of their triadic junctions (near the middle of the thin filament). We speculate that, in general, parajunctional RyRs permit increased myofilament activation in fibers whose triadic junctions are located at the z-line.

  19. Skeletal muscle-melanocyte association during tadpole tail resorption in a tropical frog, Clinotarsus curtipes Jerdon (Anura, Ranoidea).

    Science.gov (United States)

    Divya, Lekha; Beyo, Reston S; Sreejith, Parameswaran; Akbarsha, Mohammad A; Oommen, Oommen V

    2010-05-01

    We tested the hypothesis that melanin has a role as a molecule within the thyroid-mediated cascade. Light microscopic and ultrastructural changes in the skeletal muscle during tail resorption in tadpoles of the tropical frog Clinotarsus curtipes Jerdon (Anura: Ranoidea) were observed. Light microscopic analysis at metamorphic stage XVIII showed a melanized epidermis. A gradual migration of melanocytes from the epidermis to the dermis and filopodia of melanocytes pervading the skeletal muscle preceded tail resorption. The invasion of melanocytes into the muscle bundles coincided with the breakdown of the muscle bundles into sarcolytes and the arrival of macrophages at this site. This would suggest that the melanocyte-sarcolyte association signals the arrival of macrophages at these sites as metamorphosis progressed. Melanophages, macrophages with melanin granules, were observed at the climax stage of XXIII. The sarcolytes and the melanin granules were phagocytosed by macrophages so as to completely cleanse the exocytic muscle debris and the melanin granules. The presence of large melanomacrophage centers in the tadpole liver at metamorphic climax suggests that these phagocytic macrophages were further processed in the liver and, likely, in the spleen. It is proposed that melanin, a byzantine molecule, has a role in the cascade of events leading to tail resorption in anuran tadpoles.

  20. Enhancement of twitch force by stretch in a nerve-skeletal muscle preparation of the frog Rana porosa brevipoda and the effects of temperature on it.

    Science.gov (United States)

    Ishii, Yoshiki; Watari, Takashi; Tsuchiya, Teizo

    2004-12-01

    We investigated the mechanism of the enhancement of twitch force by stretch and the effects of temperature on it in nerve-skeletal muscle preparations of whole iliofibularis muscles isolated from the frog Rana brevipoda. When a preparation was stimulated indirectly and stretched, the twitch force after the stretch was enhanced remarkably in comparison to that observed before a stretch at low temperature. The enhanced force obtained by a stretch of 20% resting muscle length (l0) at low temperature was as high as the force obtained by direct stimulation. The phenomenon was not dependent on the velocity but on the amplitude of stretch. The enhanced force obeyed the length-force relationship when a stretch was long enough. The above results were observed when the frogs were kept at room temperature (20-22 degrees C). Measurements were also taken at low temperature (4 degrees C); when frogs were kept at low temperature for more than 2 months, twitch force obtained without stretch was considerably higher at l0. The amplitude of the action potential recorded extracellularly from the muscle surface increased remarkably after a stretch, but was same before and after a stretch when recorded from the nerve innervating muscle. The effects of temperature on twitch and tetanic force by direct or indirect stimulation without stretch were also studied as basic data of the stretch experiment. The results from this study suggest that stretch-induced force enhancement in a nerve-muscle preparation is caused by an increase in the transmission rate between nerve and muscle, and the amplitude of the enhanced force is determined by the length-force relationship of the muscle. The phenomenon is also strongly affected by the temperature at which the frogs are kept.

  1. The physical state of potassium in frog skeletal muscle studied by ion-sensitive microelectrodes and by electron microscopy: interpretation of seemingly incompatible results.

    Science.gov (United States)

    Edelmann, L

    2014-01-01

    According to the commonly accepted membrane pump theory most of cellular K+ ions are freely dissolved in free cellular water; the alternative association-induction hypothesis postulates that the bulk of cellular K+ is adsorbed (weakly bound) to cellular proteins that are maintained in a specific labile state in the cytoplasm of a living cell. K+ activities measured with ion-sensitive microelectrodes in the cytoplasm of frog skeletal muscle seem to confirm the claim that most of cellular K+ ions are free in cellular water. On the other hand, it is evident from electron microscopic ion binding studies that in frog skeletal muscle most of cellular K+ ions are adsorbed to cellular proteins. The conflicting results can be explained with the assumption that a damage of the cytoplasm caused by the impaling microelectrode leads to a liberation of adsorbed ions. Using the light microscope tests the possibility that microelectrodes damage the muscle cytoplasm. It is found that microelectrodes produce visible traumas that increase with time. Electron microscopic ion binding studies with damaged muscle support the view that monovalent cations are liberated in the disturbed area of a muscle fiber. It is concluded that a K(+)-sensitive microelectrode is not suited to determine the concentration of free K+ ions in intact frog skeletal muscle.

  2. Monitoring the structural behavior of troponin and myoplasmic free Ca2+ concentration during twitch of frog skeletal muscle.

    Science.gov (United States)

    Matsuo, Tatsuhito; Iwamoto, Hiroyuki; Yagi, Naoto

    2010-07-07

    The interaction of troponin molecules on the thin filament with Ca(2+) plays a key role in regulating muscle contraction. To characterize the structural changes of troponin caused by Ca(2+) and crossbridge formation, we recorded the small-angle x-ray intensity and the myoplasmic free Ca(2+) concentration using fluo-3 AM in the same frog skeletal muscle during twitch elicited by a single electrical pulse at 16 degrees C. In an overstretched muscle, the intensity of the meridional reflection from troponin at 1/38.5 nm(-1) began to change at 4 ms after the stimulus, reached a peak at 10 ms, and returned to the resting level with a halftime of 25 ms. The concentration of troponin-bound Ca(2+) began to increase at 1-2 ms after the stimulus, reached a peak at 5 ms, and returned to the resting level with a halftime of 40 ms, indicating that troponin begins to change conformation only after a sizable amount of Ca(2+) has bound to it, and returns to the resting structure even when there is still some bound Ca(2+). In a muscle with a filament overlap, crossbridge formation appears to slow down Ca(2+) release from troponin and have a large effect on its conformation.

  3. Sarcoplasmic reticulum calcium release in frog skeletal muscle fibres estimated from Arsenazo III calcium transients.

    Science.gov (United States)

    Baylor, S M; Chandler, W K; Marshall, M W

    1983-01-01

    Single twitch fibres, dissected from frog muscle, were injected with the metallochromic dye Arsenazo III. Changes in dye-related absorbance measured at 650 or 660 nm were used to estimate the time course of myoplasmic free [Ca2+] following either action potential stimulation or voltage-clamp depolarization (temperature, 15-17 degrees C). The amplitude of the Ca2+ transient decreased when fibres were stretched to sarcomere spacings approaching 4 microns. The effect appeared to be less marked in H2O Ringer than in D2O Ringer, where a reduction of about 40% was observed in going from 3.0 microns to 3.7-3.9 microns. In fibres heavily injected with dye (1.5-2.2 mM-dye) at least 0.1 mM-Ca2+ was complexed with Arsenazo III following a single action potential, implying that at least 0.1 mM-Ca2+ was released from the sarcoplasmic reticulum (s.r.) into the myoplasm. Computer simulations were carried out to estimate the flux of Ca2+ between the s.r. and myoplasm (in fibres containing no more that 0.8 mM-dye). The amounts and time courses of Ca2+ bound to the Ca2+-regulatory sites on troponin and to the Ca2+, Mg2+ sites on parvalbumin were estimated from the free [Ca2+] wave form and the law of mass action. In the computations the total myoplasmic [Ca2+] was taken as the total amount of Ca2+ existing either as free ion or as ion complexed with dye, troponin or parvalbumin. The time derivative of total myoplasmic [Ca2+] was used as an estimate of net Ca2+ flux (release minus uptake) from the s.r. into myoplasm. Rate constants for formation of cation: receptor complex were taken from published values. For the Ca2+-regulatory sites on troponin, three sets of rate constants, corresponding to two values of dissociation constant (0.2 and 2 microM) were used. Each set of three simulations was carried out both with and without parvalbumin. The simulations show that following action potential stimulation, 0.2-0.3 mM-Ca2+ enters the myoplasm from the s.r. The wave form of s.r. Ca2

  4. Effects of thapsigargin and cyclopiazonic acid on the sarcoplasmic reticulum Ca2+ pump of skinned fibres from frog skeletal muscle.

    Science.gov (United States)

    Du, G G; Ashley, C C; Lea, T J

    1994-12-01

    Thapsigargin has been reported to inhibit ATP-dependent Ca2+ uptake by isolated sarcoplasmic reticulum (SR) vesicles of vertebrate skeletal muscle fibres at nanomolar concentrations. There have been no reports confirming this effect in skinned muscle fibre preparations. We have examined the ability of thapsigargin to inhibit the uptake of Ca2+ by the SR in mechanically skinned fibres of frog iliofibularis muscles, using the size of the caffeine-induced contracture to assess the Ca2+ content of the SR. The SR was first depleted of Ca2+ and then reloaded for 1 min at pCa 6.2 in the presence and absence of thapsigargin. When 5 min were allowed for diffusion, a thapsigargin concentration of at least 131 microM was required to inhibit Ca2+ loading by 50%. In contrast, another SR Ca2+ uptake inhibitor, cyclopiazonic acid, was more effective, producing 50% inhibition at 7.0 microM and total inhibition at 50 microM. When cyclopiazonic acid (100 microM) was applied after, rather than during, Ca2+ loading, the caffeine-induced contracture was not changed. Thapsigargin (300 microM), on the other hand, caused some reduction in the peak amplitude of the caffeine-induced contracture when applied after Ca2+ loading. The poor effectiveness of thapsigargin in the skinned fibres, compared with in SR vesicles, is attributed to its slow diffusion into the skinned fibres, perhaps as a result of binding to myofibrillar components.

  5. Prolonged relaxation after stimulation of the clasping muscle of male frog, Rana japonica, during the breeding season.

    Science.gov (United States)

    Ishii, Yoshiki; Tsuchiya, Teizo

    2010-07-01

    We investigated the mechanical properties of the flexor carpi radialis muscle (FCR), a forelimb muscle used mainly for amplexus in the breeding season (February to March), of the male Japanese brown frog, Rana japonica. In the present experiment, the changes in force and stiffness of the FCR before, during, and after contraction were measured at 4 degrees C. The total time from the end of stimulation to the end of relaxation was about 30 min. The time course of this prolonged relaxation was fitted by two exponential decay processes. Stiffness decreased during prolonged relaxation, but stayed higher than force, when normalized to peak values. These mechanical properties of the FCR were different from those of the glutaeus magnus muscle (GM) in the hindlimb, used for jumping. When a quick release was applied to the FCR during relaxation, the force recovered gradually after a sudden decrease. The time course of this force recovery was fitted by a single exponential term, and the rate constant decreased as the prolonged relaxation proceeded. The possible involvement of active process(es) in the prolonged relaxation is discussed.

  6. Cost-Utility Analysis: Sartorius Flap versus Negative Pressure Therapy for Infected Vascular Groin Graft Managment.

    Science.gov (United States)

    Chatterjee, Abhishek; Macarios, David; Griffin, Leah; Kosowski, Tomasz; Pyfer, Bryan J; Offodile, Anaeze C; Driscoll, Daniel; Maddali, Sirish; Attwood, John

    2015-11-01

    Sartorius flap coverage and adjunctive negative pressure wound therapy (NPWT) have been described in managing infected vascular groin grafts with varying cost and clinical success. We performed a cost-utility analysis comparing sartorius flap with NPWT in managing an infected vascular groin graft. A literature review compiling outcomes for sartorius flap and NPWT interventions was conducted from peer-reviewed journals in MEDLINE (PubMed) and EMBASE. Utility scores were derived from expert opinion and used to estimate quality-adjusted life years (QALYs). Medicare current procedure terminology and diagnosis-related groups codes were used to assess the costs for successful graft salvage with the associated complications. Incremental cost-effectiveness was assessed at $50,000/QALY, and both univariate and probabilistic sensitivity analyses were conducted to assess robustness of the conclusions. Thirty-two studies were used pooling 384 patients (234 sartorius flaps and 150 NPWT). NPWT had better clinical outcomes (86.7% success rate, 0.9% minor complication rate, and 13.3% major complication rate) than sartorius flap (81.6% success rate, 8.0% minor complication rate, and 18.4% major complication rate). NPWT was less costly ($12,366 versus $23,516) and slightly more effective (12.06 QALY versus 12.05 QALY) compared with sartorius flap. Sensitivity analyses confirmed the robustness of the base case findings; NPWT was either cost-effective at $50,000/QALY or dominated sartorius flap in 81.6% of all probabilistic sensitivity analyses. In our cost-utility analysis, use of adjunctive NPWT, along with debridement and antibiotic treatment, for managing infected vascular groin graft wounds was found to be a more cost-effective option when compared with sartorius flaps.

  7. The use of time-resolved X-ray diffraction and sample techniques for studying the muscle structure during relaxation

    Science.gov (United States)

    Vazina, A. A.; Gadzhiev, A. M.; Gerasimov, V. S.; Gorbunova, N. P.; Sergienko, P. M.; Korneev, V. N.; Aulchenko, V. M.; Baru, S. E.

    1995-02-01

    The use of the modern time-resolved X-ray diffraction and sample technique has played an important role in studying muscle structures during contraction at various physiological conditions. We represent time-resolved X-ray data on equatorial diffraction and tension response of the frog sartorius muscle during relaxation. The measurements of the time-course of the intensity change of reflections (1,0), (1,1) and the background under them give a possibility to study the effect of potentiation of contraction by repetitive stimulation in fresh and tired muscles. Model calculations of meridional diffraction patterns for various configurations of cross-bridges in the relaxation phase were carried out.

  8. Activity, abundance and expression of Ca²⁺-activated proteases in skeletal muscle of the aestivating frog, Cyclorana alboguttata.

    Science.gov (United States)

    Reilly, Beau D; Cramp, Rebecca L; Franklin, Craig E

    2015-02-01

    In most mammals, prolonged muscle disuse (e.g. bed-rest, limb casting or spaceflight) results in atrophy of muscle fibres which is largely due to unregulated proteolysis. Although numerous proteolytic pathways are known to participate in muscle disuse atrophy, recent evidence suggests that activation of Ca²⁺-dependent cysteine proteases (calpains) is required for disuse atrophy in limb skeletal muscles. In contrast to typical models of muscle disuse (humans and rodents), animals that experience natural bouts of chronic muscle inactivity, such as hibernating mammals and aestivating frogs, consistently exhibit limited or no change in skeletal muscle size. In the current study, we examined enzyme activity, protein abundance and gene expression levels of calpain isoforms in gastrocnemius muscle of the aestivating frog, Cyclorana alboguttata. We predicted that in aestivating C. alboguttata there would be a downregulation of the abundance, activity and gene expression of calpain 1 and calpain 2. In contrast to our hypothesis, there was no significant decrease in the enzyme activity levels or the relative protein abundances of calpain 1 and calpain 2. Similarly, gene expression assays (both qRT-PCR and RNA Seq data) indicated that calpains were unaffected by aestivation. Western blotting of 'muscle-specific' calpain 3, which is consistently downregulated during atrophic conditions, indicated that this isoform is present in C. alboguttata muscle where it appears to be in its autolysed state. The absence of any increase in enzyme activity, protein and mRNA abundance of calpains in aestivators is consistent with the protection of gastrocnemius muscle against uncontrolled proteolysis throughout aestivation.

  9. The maximum velocity of shortening during the early phases of the contraction in frog single muscle fibres.

    Science.gov (United States)

    Lombardi, V; Menchetti, G

    1984-10-01

    The maximum velocity of shortening (Vmax) was determined at preset times during the development and the plateau of isometric tetani in single fibres isolated from the tibialis anterior muscle of the frog. Experiments were performed at low temperature (3.6-6 degrees C) and at about 2.25 micron sarcomere length. The controlled velocity release method was used. Vmax was measured by determining the lowest velocity of release required to keep the tension at zero. Extreme care was taken in dissection and mounting of the fibres in order to make the passive series compliance very small. The value of Vmax at the end of the latent period for the development of isometric tension (at 4.5 degrees C about 10 ms after the beginning of the stimulus volley) was already the same as later during either the tension rise or at the plateau of isometric tetani. These results show that the value of Vmax of intact fibres is independent of time and activation subsequent to the latent period, and suggest that the cycling rate of the crossbridges may thus attain its steady-state value just at the end of the isometric latent period.

  10. Mechanical, electrical, and morphological characteristics of skeletal muscle fibers from Xenopus and other species of frogs.

    Science.gov (United States)

    Oba, T; Yamamoto, M; Aoki, T; Hotta, K

    1983-01-01

    Mechanical, electrical, and morphological properties of iliofibularis or semitendinosus of Xenopus laevis, Rana catesbeiana, and Rana nigromaculata were investigated in an attempt to find out the differences between them which will give the basic knowledge for the study of excitation-contraction coupling. With application of electrical stimulation, a single muscle fiber from Xenopus contracted at a faster rate of rise than did the other muscles tested. The maximum rate of rise (Tmax) of tension was in the order of Xenopus, R. catesbeiana, and R. nigromaculata. Ca2+ sensitivity and Tmax of mechanically skinned fibers of Xenopus resembled those of R. catesbeiana. Xenopus muscle had a small cross-sectional area of T-tubule compared with that in other species and the action potential exhibited a small positive-going hump. The volume density of the terminal cisternae of sarcoplasmic reticulum (SR) to the myofibril was the largest in the Xenopus muscle, with a statistically significant difference. Therefore, the Xenopus muscle appears to be good material for investigation of mechanisms related to Ca2+ release from SR, as elicited by the excitation of T-tubules.

  11. Ex Vivo Smooth Muscle Pharmacological Effects of a Novel Bradykinin-Related Peptide, and Its Analogue, from Chinese Large Odorous Frog, Odorrana livida Skin Secretions

    Science.gov (United States)

    Xiang, Jie; Wang, Hui; Ma, Chengbang; Zhou, Mei; Wu, Yuxin; Wang, Lei; Guo, Shaodong; Chen, Tianbao; Shaw, Chris

    2016-01-01

    Bradykinin-related peptides (BRPs) are one of the most extensively studied frog secretions-derived peptide families identified from many amphibian species. The diverse primary structures of BRPs have been proven essential for providing valuable information in understanding basic mechanisms associated with drug modification. Here, we isolated, identified and characterized a dodeca-BRP (RAP-L1, T6-BK), with primary structure RAPLPPGFTPFR, from the skin secretions of Chinese large odorous frogs, Odorrana livida. This novel peptide exhibited a dose-dependent contractile property on rat bladder and rat ileum, and increased the contraction frequency on rat uterus ex vivo smooth muscle preparations; it also showed vasorelaxant activity on rat tail artery smooth muscle. In addition, the analogue RAP-L1, T6, L8-BK completely abolished these effects on selected rat smooth muscle tissues, whilst it showed inhibition effect on bradykinin-induced rat tail artery relaxation. By using canonical antagonist for bradykinin B1 or B2 type receptors, we found that RAP-L1, T6-BK -induced relaxation of the arterial smooth muscle was very likely to be modulated by B2 receptors. The analogue RAP-L1, T6, L8-BK further enhanced the bradykinin inhibitory activity only under the condition of co-administration with HOE140 on rat tail artery, suggesting a synergistic inhibition mechanism by which targeting B2 type receptors. PMID:27690099

  12. The Actions of Eserine-Like Compounds upon Frog's Nerve-Muscle Preparations, and the Blocking of Neuromuscular Conduction

    National Research Council Canada - National Science Library

    S. L. Cowan

    1940-01-01

    The actions of prostigmine, eserine, and the dimethylcarbamic ester of 8-hydroxymethylquinolinium methylsulphate upon the frog's isolated nervesartorius preparation have been examined by a method developed by Lucas (1911...

  13. Changes in the maximum speed of shortening of frog muscle fibres early in a tetanic contraction and during relaxation.

    Science.gov (United States)

    Josephson, R K; Edman, K A

    1998-03-01

    1. Isotonic shortening velocities at very light loads were examined in single fibres of the anterior tibialis muscle of the frog, Rana temporaria, using load-clamp recording and slack tests (temperature, 1-3 degrees C; initial sarcomere length, 2.25 microns). 2. Shortening velocities at very light loads (force-clamp recording) were found to be higher early in the rise of a tetanic contraction than during the plateau of the contraction. The upper limit of the load at which there was elevated shortening velocity early in the contraction was 1.5-5.4% of the maximum tetanic tension (Fo) depending on the particular fibre. 3. The maximum shortening velocity determined using the slack test method (Vo) was as much as 30% greater early in a contraction than at the tetanic plateau. Vo was elevated above the plateau level up to about 30 ms after the end of the latent period, which is equivalent to the time required for the force in an isometric contraction to rise to about 30% of Fo. Vo is depressed below the plateau value during relaxation at the cessation of stimulation. 4. Stimulation studies show that the cross-bridge model of Huxley (1957) predicts the maximum shortening velocity to be greater early in a contraction, when new actin binding sites are becoming activated and new cross-bridge connections are being formed rapidly, than during steady-state contraction. The elevated shortening velocity in the model is a consequence of new cross-bridges being formed in the pulling configuration, and there being a delay before the newly added bridges are dragged beyond their equilibrium position so they begin to retard shortening. The model also predicts that maximum shortening velocity should be depressed below the plateau level during early relaxation as cross-bridge binding sites are rapidly removed from the active population.

  14. Intracellular localization of markers within injected or cut frog muscle fibers.

    Science.gov (United States)

    Eisenberg, B R; Mathias, R T; Gilai, A

    1979-07-01

    Many experimental procedures require drastic alterations of muscle fibers, such as cutting the fiber or injecting molecular probes through microelectrodes. We report the ultrastructure of similarly altered muscle fibers and the intracellular distribution of injected horseradish peroxidase (HRP). Cut fibers appear structurally normal at distances greater than 500 microM from the cut end, however, the structure deteriorates nearer to the cut. HRP diffuses longitudinally about 2,000 micrometer from the cut end and the concentration is uniform over the fiber's cross section. If HRP is introduced intracellularly either by pressure injection or through a nick in the sarcolemma, it distributes in a C-shaped annulus extending approximately 2,000 micrometer longitudinally and 1-20 micrometer radially. The ultrastructure of injected or nicked fibers appears normal. The HRP freely entered the junctional gap between T-system and sarcoplasmic reticulum (SR) but was excluded from either structure. Occasionally, a light pillar could be seen between T-system and SR; the space of these pillars suggest they are the central area of the "feet" appearing light against the dark marker.

  15. Effect of Verapamil on Excitation-Contraction Coupling in Frog Single Twitch Muscle Fiber. I. Effect of Verapamil in Low Concentration

    OpenAIRE

    小原, 一男; 鈴木, 稔子; 永井, 寅男

    1981-01-01

    The effects of verapamil in low concentration (0.1 mM) on electrical and mechanical responses in single twitch muscle fiber of the frog were examined and the following results were obtained. 1) Twitch tension was potentiated by verapamil during the first 2 min after application and then declined little by little. 2) Resting and action potentials were not changed by verapamil except for an enhancement of a negative afterpotential. 3) The duration of the active state was prolonged by 1.5 times ...

  16. The effect of length on the relationship between tension and intracellular [Ca2+] in intact frog skeletal muscle fibres.

    Science.gov (United States)

    Claflin, D R; Morgan, D L; Julian, F J

    1998-04-01

    1. The relationship between tension and intracellular calcium concentration ([Ca2+]i) in intact frog skeletal muscle fibres was determined at two fibre lengths, corresponding to mean sarcomere lengths (SL) of 2.2 and 2.9 micron. Tension and [Ca2+]i were recorded during the slow decline of tension following stimulation in the presence of cyclopiazonic acid (CPA), a sarcoplasmic reticulum Ca2+-uptake pump inhibitor. [Ca2+]i was estimated by injecting the K+ salt form of the fluorescent dye fura-2 into the fibres. Experimental temperature was 3.0 C. 2. At a SL of 2.2 micron, where thick and thin filaments fully overlap, the [Ca2+]i corresponding to 50 % tension generation ([Ca2+]50) was 1.09 +/- 0.02 microM (mean +/- S.E.M., n = 61 contractions). At a SL of 2.9 micron, where overlap is approximately 50 %, the [Ca2+]50 was significantly lower, 0.69 +/- 0. 02 microM (n = 22 contractions). This is in agreement with previous results from skinned fibres. 3. The relationship between tension and [Ca2+]i was very steep, as reported previously from experiments at a SL of 2.2 micron in which the membrane permeant acetoxymethyl ester form of fura-2 was used. The fall in tension from 90 to 10 % occurred in 0.12 +/- 0.01 pCa units (mean +/- S.E.M., n = 61) for a SL of 2.2 micron and 0.17 +/- 0.01 pCa units (n = 22) for a SL of 2.9 micron, corresponding to Hill coefficients of 15.4 and 10.9, respectively. 4. We conclude that the increase in sensitivity of tension to [Ca2+] that occurs in skinned skeletal muscle fibres upon stretch also occurs in intact fibres, that the steepness of the relation between tension and [Ca2+]i in intact fibres reported previously cannot be attributed to the use of the acetoxymethyl ester form of fura-2 to report [Ca2+]i, and that the steepness decreases as myofilament overlap decreases.

  17. Effect of the calcium antagonists bepridil (CERM-1978) and verapamil on Ca++-dependent slow action potentials in frog skeletal muscle.

    Science.gov (United States)

    Kerr, L M; Sperelakis, N

    1982-07-01

    The calcium slow channels found in cardiac and smooth muscle are blocked by calcium-antagonistic agents. In the present study, the effects of the Ca++-antagonistic drugs bepridil and verapamil on the slow action potentials (APs) found in the frog skeletal muscle were examined. Slow APs were induced in Cl-- free (acetate substituted), Na+-free (sucrose substituted), high K+ (25 mM)media. A conventional two-microelectrode recording technique was used. Amplitude of the slow APs increases linearly with log [Ca]o with a slope of 28.2 mV/decade, suggesting that Ca++ is the major inward current carrier because this value approaches the theoretical slope of 29 mV/decade (at 21 degrees C) predicted by the Nernst equation for a divalent cation. Duration also increases with increases in [Ca]o. The slow APs were abolished by glycerol shock treatment, which disconnects the T-tubules from the surface membrane, suggesting that the slow APs originate in the T-tubules. Verapamil and bepridil depress the amplitude of the slow APs in a use-dependent manner at concentrations of 5 X 10-9 to 1 X 10-6 M and abolish the slow APs at 5 X 10-6 M. These drugs also decrease the rates of rise of the slow APs. Bepridil decreases the duration of the slow APs, whereas verapamil has little effect, suggesting that bepridil, in addition to blocking the slow channels, might also increase gk. Thus, the slow channels found in the T-tubular system of frog skeletal muscle have some of the same properties of slow channels in vascular smooth muscle and cardiac muscle.

  18. Circuit models of the passive electrical properties of frog skeletal muscle fibers.

    Science.gov (United States)

    Valdiosera, R; Clausen, C; Eisenberg, R S

    1974-04-01

    The relation between the fine structure, electric field equations, and electric circuit models of skeletal muscle fibers is discussed. Experimental evidence illustrates the profound variation of potential with circumferential position, even at low frequencies (100 Hz). Since one-dimensional cable theory cannot account for such variation, three-dimensional cable theory must be used. Several circuit models of a sarcomere are presented and plots are made of the predicted phase angle between sinusoidal applied current and potential. The circuit models are described by equations involving normalized variables, since they affect the phase plot in a relatively simple way. A method is presented for estimating the values of the circuit elements and the standard deviation of the estimates. The reliability of the estimates is discussed. An objective measure of fit, Hamilton's R test, is used to test the significance of different fits to data. Finally, it is concluded that none of the proposed circuit models provides an adequate description of the observed variation of phase angle with circumferential location. It is not clear whether the source of disagreement is inadequate measurements or inadequate theory.

  19. Capsaicin and N-arachidonoyl-dopamine (NADA) decrease tension by activating both cannabinoid and vanilloid receptors in fast skeletal muscle fibers of the frog.

    Science.gov (United States)

    Trujillo, Xóchitl; Ortiz-Mesina, Mónica; Uribe, Tannia; Castro, Elena; Montoya-Pérez, Rocío; Urzúa, Zorayda; Feria-Velasco, Alfredo; Huerta, Miguel

    2015-02-01

    Previous studies have indicated that vanilloid receptor (VR1) mRNA is expressed in muscle fibers. In this study, we evaluated the functional effects of VR1 activation. We measured caffeine-induced contractions in bundles of the extensor digitorum longus muscle of Rana pipiens. Isometric tension measurements showed that two VR1 agonists, capsaicin (CAP) and N-arachidonoyl-dopamine (NADA), reduced muscle peak tension to 57 ± 4 % and 71 ± 3% of control, respectively. The effect of CAP was partially blocked by a VR1 blocker, capsazepine (CPZ), but the effect of NADA was not changed by CPZ. Because NADA is able to act on cannabinoid receptors, which are also present in muscle fibers, we tested the cannabinoid antagonist AM281. We found that AM281 antagonized both CAP and NADA effects. AM281 alone reduced peak tension to 80 ± 6 % of control. With both antagonists, the CAP effect was completely blocked, and the NADA effect was partially blocked. These results provide pharmacological evidence of the functional presence of the VR1 receptor in fast skeletal muscle fibers of the frog and suggest that capsaicin and NADA reduce tension by activating both cannabinoid and vanilloid receptors.

  20. An electrophoretic study of myosin heavy chain expression in skeletal muscles of the toad Bufo marinus.

    Science.gov (United States)

    Nguyen, L T; Stephenson, G M

    1999-10-01

    In this study we developed an SDS-PAGE protocol which for the first time separates effectively all myosin heavy chain (MHC) isoforms expected to be expressed in iliofibularis (IF), pyriformis (PYR), cruralis (CRU) and sartorius (SAR) muscles of the toad Bufo marinus on the basis of previously reported fibre type composition. The main feature of the method is the use of alanine instead of glycine both in the separating gel and in the running buffer. The correlation between the MHC isoform composition of IF, SAR and PYR muscles determined in this study and the previously reported fibre type composition of IF and SAR muscles in the toad and of PYR muscle in the frog was used to tentatively identify the MHC isoforms expressed by twitch fibre types 1, 2 and 3 and by tonic fibres. The alanine-SDS electrophoretic method was employed to examine changes in the MHC composition of IF, PYR, CRU and SAR muscles with the ontogenetic growth of the toad from post-natal life (body weight muscle observed in this study are in very good agreement with those in the fibre type composition of the developing IF muscle reported in the literature.

  1. 缝匠肌和股直肌肌内神经分布研究及其临床意义%The research of distribution of intramuscular nerves in sartorius and rectus femoris and their clinical significance

    Institute of Scientific and Technical Information of China (English)

    张洪武; 薛黔; 杨宇平

    2011-01-01

    Objective: To study the distribution of intramuscular nerve branches, muscle spindles and nerve entering points in human sartorius and rectus femoris (RF) and to provide morphological data for clinical surgery. Methods: The morphological characteristics of sartorius and RF were studied by using the gross-anatomy. The locations of the nerve entering points to muscles were ascertained by measuring. HE staining technique and stereology method were used to study the two muscles' spindle distribution. Modified Sihler's neural staining technique was used to observe the two muscles' intramuscular nerve branch pattern. Results: Sartorius was a kind of ribbon muscle which was composed of long fascicle arranged parallel. RF was a kind of penniform muscle which was composed of short fascicle. The muscle spindle average densities of sartorius and RF were 38.04 number/g and 19.38 number/g, respectively. Sartorius had 2 primary branches entering the muscle and distributed to upper part and middle-lower part, respectively. RF had 2 primary branches and distributed to lateral-upper part and medial-lower part, respectively. The nerve entering points in sartorius laid (9.75 + 1.30) cm, and in RF laid ( 10.23 ± 0.97) cm and ( 14.48 ± 1.12) cm below anterior superior iliac spine, respectively. Conclusion: Sartorius is a ribbon muscle, but RF is a penniform muscle. Sartorius and RF both have two primary branches, respectively. There are less intramuscular nerve branches and less anastomoses and more obvious regional distribution in sartorius. The nerve entering points in sartorius and RF centralize mainly in the No.2 region of the front upper part of thigh.%目的:研究入缝匠肌和股直肌的肌内神经分支分布、肌梭密度和测定神经入肌点,为临床外科提供肌形态学资料.方法:大体解剖法观察20具尸体缝匠肌和股直肌的形态学特点,并以髂前上棘为标志定位缝匠肌和股直肌神经入肌点;H·E染色法研究5具尸体缝匠肌

  2. [Ca2+]i following extrasystoles in guinea-pig trabeculae microinjected with fluo-3 - a comparison with frog skeletal muscle fibres.

    Science.gov (United States)

    Wohlfart, B

    2000-05-01

    Force production of cardiac muscle is highly dependent on the interval between the excitations. The aim was to investigate relations between intracellular calcium ([Ca2+]i) and force when a stimulus protocol, with three extrasystoles (ESs) at various intervals, was used. The relation between [Ca2+]i and force was compared with that in frog skeletal muscle fibre. Fluo-3 was microinjected into thin cardiac trabeculae to monitor [Ca2+]i. During steady-state [Ca2+]i consisted of a rapid rise (phase 1) that lasted until peak dF/dt (rate of force development) and was followed by a slower rise (phase 2) that coincided with the action potential and had a peak after peak force. The decline in [Ca2+]i outlasted the duration of the contraction. As the ES intervals were prolonged, there was a gradual restitution of force and of the amplitude and rate of rise of phase 1 [Ca2+]i. Peak dF/dt was linearly related to the amplitude of phase 1 [Ca2+]i during restitution and potentiation of force. Skeletal muscle fibres were loaded with fluo-3-AM. From [Ca2+]i the amount of calcium bound to troponin ([Ca-T]) as a function of time was estimated. Force production of the skeletal muscle fibre could be predicted from [Ca-T] when the signal was delayed (time constant 36 ms). This finding indicates that the recorded [Ca2+]i in skeletal muscle represents activator calcium. In cardiac muscle probably only phase 1 [Ca2+]i represents activator calcium. Phase 2 [Ca2+]i probably represents calcium entry during the action potential and does not activate the contractile system to any significant extent.

  3. Posteromedial knee friction syndrome: an entity with medial knee pain and edema between the femoral condyle, sartorius and gracilis

    Energy Technology Data Exchange (ETDEWEB)

    Simeone, F.J.; Huang, Ambrose J.; Chang, Connie Y.; Smith, Maximilian; Bredella, Miriam A.; Torriani, Martin [Massachusetts General Hospital and Harvard Medical School, Division of Musculoskeletal Imaging and Intervention, Department of Radiology, Boston, MA (United States); Gill, Thomas J. [Boston Sports Medicine and Research Institute, Boston, MA (United States)

    2014-12-20

    To describe MRI features of an entity consisting of medial knee pain and edema between the posteromedial femoral condyle (PMFC), sartorius and/or gracilis tendons and determine whether reduced tendon-bone distances may account for these findings. We retrospectively identified MRI cases of edema between the PMFC, sartorius and/or gracilis tendons (25 subjects, 26 knees). Two musculoskeletal radiologists independently graded edema and measured the sartorius- and gracilis-PMFC distances and knee flexion angle. Age- and gender-matched subjects with normal knee MRIs (27 subjects, 27 knees) served as controls for measurements. Statistical analyses compared abnormal to control subjects. Sartorius-PMFC and gracilis-PMFC spaces were narrower in abnormal compared to control subjects (1.6 ± 1.0 vs. 2.1 ± 1.2 mm, P = 0.04; 2.3 ± 2.0 vs. 4.6 ± 3.0 mm, P = 0.002, respectively). The knee flexion angle was similar between groups (P > 0.05). In subjects with clinical information, medial knee pain was the main complaint in 58 % (15/26) of abnormal subjects, with 42 % (11/26) having clinical suspicion of medial meniscal tear. Edema between the PMFC, sartorius and/or gracilis was mild in 54 % (14/26), moderate in 35 % (9/26) and severe in 12 % (3/26), and it was most frequent deep to both the sartorius and gracilis (50 %, 13/26). Edema between the PMFC, sartorius and/or gracilis tendons identified on knee MRI may be associated with medial knee pain and may represent a friction syndrome. (orig.)

  4. The effects of temperature on the mechanical performance in fatigued single muscle fibers of the frog induced by twitch and tetanus.

    Science.gov (United States)

    Inamura, N; Fujisige, A; Miyake, S; Ono, A; Tsuchiya, T

    2000-02-01

    Muscle fatigue induced by consecutive twitches or tetani was studied in single skeletal muscle fibers of the frog, Rana japonica. The fatigue by twitch appeared sooner after the start of stimulation at lower temperatures (2-5 degrees C) than at higher ones (15-20 degrees C), while the fatigue by tetanus appeared sooner at higher temperatures. When a twitch-fatigued fiber was bathed in a solution with caffeine (15 mM), the contracture force was much higher than the fatigued force, while in tetanus fatigue, the force by caffeine was not different from the fatigued force. The length-force relation in fatigued fibers was compared with that in pre-fatigue at low and high temperatures. It was noticed that the ascending limb of the length-force curve in fatigued fibers by twitch was lower than that in pre-fatigue at the low temperatures; namely, the fatigue by twitch was more marked in shorter muscle length, while no marked change in the length-force relation was detected in the tetanus fatigue at the low and high temperatures. The maximum shortening velocity, measured by the slack test, decreased in both types of fatigue. These results suggest that the fatigue by twitch may be mainly due to the failure of activation of the contractile system, while in the fatigue by tetanus, the rate of the interaction between actin and myosin may be impaired due to the change in intracellular chemical environment.

  5. Effect of diazepam on calcium translocation during physiological muscle fatigue.

    Science.gov (United States)

    Bianchi, C P; Narayan, S R

    1984-10-01

    Stimulation of frog sartorius muscle at 1 Hz leads to an initial positive staircase during the first 120 twitches and is followed by a negative staircase. There is a net calcium influx into two distinct compartments within the muscle during the positive staircase. The two compartments are separated by measuring the calcium extracted from muscles soaked in strontium-Ringer for 15 min and the calcium remaining in the muscle. A net gain of extractable Ca++ (0.32 mumol/g wet wt.) and residual Ca++ (0.18 mumol/g) is observed during positive staircase. A loss in residual Ca++, a gain in extractable Ca++ and a net loss of Ca++ (0.09 mumol/g) to the bathing medium occur during the period preceding physiological muscle fatigue (60 to 120 twitches). Diazepam (EC50, 5.6 X 10(-6) M) causes a marked reduction in the latent period and increases the rate constant 2.6 times the control value for physiological muscle fatigue. A net loss of 0.31 mumol/g of Ca++ to the bathing medium occurs during the interval between 60 and 120 twitches. Diazepam increases net Ca++ efflux 3.5-fold during this interval when compared to control muscles. Diazepam does not affect the Ca++ gained during the positive staircase but accelerates the loss of calcium from the residual and the extractable compartments during the initial phase of physiological muscle fatigue. Physiological muscle fatigue is attributed to an accumulation of calcium in the transverse tubular network and an uncoupling of the muscle action potential from contraction.

  6. Muscle fiber and motor unit behavior in the longest human skeletal muscle.

    Science.gov (United States)

    Harris, A John; Duxson, Marilyn J; Butler, Jane E; Hodges, Paul W; Taylor, Janet L; Gandevia, Simon C

    2005-09-14

    The sartorius muscle is the longest muscle in the human body. It is strap-like, up to 600 mm in length, and contains five to seven neurovascular compartments, each with a neuromuscular endplate zone. Some of its fibers terminate intrafascicularly, whereas others may run the full length of the muscle. To assess the location and timing of activation within motor units of this long muscle, we recorded electromyographic potentials from multiple intramuscular electrodes along sartorius muscle during steady voluntary contraction and analyzed their activity with spike-triggered averaging from a needle electrode inserted near the proximal end of the muscle. Approximately 30% of sartorius motor units included muscle fibers that ran the full length of the muscle, conducting action potentials at 3.9 +/- 0.1 m/s. Most motor units were innervated within a single muscle endplate zone that was not necessarily near the midpoint of the fiber. As a consequence, action potentials reached the distal end of a unit as late as 100 ms after initiation at an endplate zone. Thus, contractile activity is not synchronized along the length of single sartorius fibers. We postulate that lateral transmission of force from fiber to endomysium and a wide distribution of motor unit endplates along the muscle are critical for the efficient transmission of force from sarcomere to tendon and for the prevention of muscle injury caused by overextension of inactive regions of muscle fibers.

  7. GTP gamma S causes contraction of skinned frog skeletal muscle via the DHP-sensitive Ca2+ channels of sealed T-tubules.

    Science.gov (United States)

    Somasundaram, B; Tregear, R T; Trentham, D R

    1991-03-01

    We have investigated the involvement of G-proteins in excitation-contraction coupling of fast-twitch skeletal muscle, using a fibre preparation designed to retain intact T-tubules and sarcoplasmic reticulum. The nonhydrolysable analogue of guanosine triphosphate, GTP gamma S (50-500 microM) caused a strong, transient isometric contraction in this preparation. Reduction of ethylene-bis(oxonitrilo)tetraacete (EGTA) in the sealed T-tubules from 5 mM to 0.1 mM lowered the threshold to GTP gamma S and removal of sodium reversibly raised it. The dihydropyridine (DHP) calcium channel antagonists nicardipine and nifedipine allowed a first contraction and then blocked subsequent GTP gamma S action. The phenylalkylamine methoxyverapamil (D-600) did likewise, reversibly, at 10 degrees C. The guanosine diphosphate analogue, GDP beta S, and procaine reversibly blocked the action of GTP gamma S; pertussis toxin also blocked it. Photolytic release of 40-100 microM GTP gamma S within 0.1 s from S-caged GTP gamma S caused contraction after a latent period of 0.3-20 s. We conclude that GTP gamma S can activate contraction in frog skeletal muscle via a route requiring both the integrity of the T-tubular DHP-sensitive calcium channel (DHPr) and the presence of sodium in the sealed T-tubules. We propose that in this preparation GTP gamma S activates a G-protein, which in turn activates the DHPr as a calcium channel and releases stored calcium from within the sealed T-tubule. Implications of these results for the excitation-contraction coupling mechanism in skeletal muscle are discussed.

  8. Fantastic Frogs!

    Science.gov (United States)

    Scott, Kym

    2002-01-01

    Number rhymes can be used in many exciting and different ways to support the early learning goals for mathematics. The rhyme "five little speckled frogs" provides the theme for this display, which was set up in Lewisham's professional development center. It provides a range of ideas which would help develop young children's mathematical learning…

  9. Fantastic Frogs!

    Science.gov (United States)

    Scott, Kym

    2002-01-01

    Number rhymes can be used in many exciting and different ways to support the early learning goals for mathematics. The rhyme "five little speckled frogs" provides the theme for this display, which was set up in Lewisham's professional development center. It provides a range of ideas which would help develop young children's mathematical learning…

  10. Sartorius Stedim Biotech推出新Flexsafe生物工艺袋家族

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    Sartorius Stedim Biotech发布全新的可扩展性一次性使用生物工艺袋Flexsafe系列,能够覆盖包括从工艺开发到生产的整个制药生产过程中的所有一次性使用工艺,从上游到下游全部使用同一种聚乙烯膜。Flexsafe系列的创新概念解决了制药行业对永不过日寸的疫苗和药品商业化的一次性生产技术的关键需求。

  11. The Time Course of the Loss and Recovery of Contracture Ability in Frog Striated Muscle Following Exposure to Ca-Free Solutions

    Science.gov (United States)

    Milligan, J. V.

    1965-01-01

    Using area under the contracture curve to quantitate contractures, the diffusion coefficient of calcium ions within the frog toe muscle during washout in a calcium-free solution and subsequent recovery after reintroduction of calcium to the bathing solution was calculated to be about 2 x 10-6 cm2/sec. The diffusion coefficient measured during washout was found to be independent of temperature or initial calcium ion concentration. During recovery it was found to decrease if the temperature was lowered. This was likely due to the repolarization occurring after the depolarizing effect of the calcium-free solution. The relation between contracture area and [Ca]o was found to be useful over a wider range than that between maximum tension and [Ca]o. The normalized contracture areas were larger at lower calcium concentrations if the contractures were produced with cold potassium solutions or if NO3 replaced Cl in the bathing solutions. Decreasing the potassium concentration of the contracture solution to 50 mM from 115 mM did not change the relation between [Ca]o and the normalized area. If the K concentration of the bathing solution was increased, the areas were decreased at lower concentrations of Ca. PMID:14324991

  12. Morphological comparison of five species of poison dart frogs of the genus Ranitomeya (Anura: Dendrobatidae) including the skeleton, the muscle system and inner organs

    Science.gov (United States)

    Krings, Markus; Klein, Benjamin; Heneka, Markus J.

    2017-01-01

    The morphology of larvae stages of most amphibians are often completely different than in adults. Tadpole descriptions have historically been based on external characters like morphometrics, color pattern and oral disc structure. Other papers described anatomical details by the use of dissections. The increase in micro-CT scanning technology provides an opportunity to quantify and describe in detail internal characters like skeleton, musculature and organs. To date, no such tadpole descriptions exist for the well-studied Neotropical poison dart frog genus Ranitomeya (Anura: Dendrobatidae). Here we provide descriptions of the internal skeletal, musculature and organ structures of five Ranitomeya species and then provide morphological comparisons. Contrary to previous observations, closely related species display several morphological differences. For example, we observed considerable variation in chondrocranial characters, the extent of cranial ossifications, the appearance of some cranial muscles and the arrangement of inner organs. Further studies on the tadpole morphology of more species of Ranitomeya and other dendrobatid genera are needed to enable us to understand the complete morphological variation in this group. PMID:28235032

  13. Lbx1 expression and frog limb development.

    Science.gov (United States)

    Sabo, Michelle C; Nath, Kimberly; Elinson, Richard P

    2009-12-01

    In order to identify prospective limb muscle cells in a frog, we cloned Lbx1 from the direct developing frog Eleutherodactylus coqui. Like in embryos of the frog Xenopus laevis but unlike in other vertebrates, EcLbx1 is expressed in all trunk somites. Like in embryos of chick, mouse, and zebrafish, cells expressing EcLbx1 are then found in limb buds, consistent with migration of those cells from somites. EcLbx1 is also expressed in the dorsal spinal cord as in other vertebrates.

  14. Head-head interactions of resting myosin crossbridges in intact frog skeletal muscles, revealed by synchrotron x-ray fiber diffraction.

    Directory of Open Access Journals (Sweden)

    Kanji Oshima

    Full Text Available The intensities of the myosin-based layer lines in the x-ray diffraction patterns from live resting frog skeletal muscles with full thick-thin filament overlap from which partial lattice sampling effects had been removed were analyzed to elucidate the configurations of myosin crossbridges around the thick filament backbone to nanometer resolution. The repeat of myosin binding protein C (C-protein molecules on the thick filaments was determined to be 45.33 nm, slightly longer than that of myosin crossbridges. With the inclusion of structural information for C-proteins and a pre-powerstroke head shape, modeling in terms of a mixed population of regular and perturbed regions of myosin crown repeats along the filament revealed that the myosin filament had azimuthal perturbations of crossbridges in addition to axial perturbations in the perturbed region, producing pseudo-six-fold rotational symmetry in the structure projected down the filament axis. Myosin crossbridges had a different organization about the filament axis in each of the regular and perturbed regions. In the regular region that lacks C-proteins, there were inter-molecular interactions between the myosin heads in axially adjacent crown levels. In the perturbed region that contains C-proteins, in addition to inter-molecular interactions between the myosin heads in the closest adjacent crown levels, there were also intra-molecular interactions between the paired heads on the same crown level. Common features of the interactions in both regions were interactions between a portion of the 50-kDa-domain and part of the converter domain of the myosin heads, similar to those found in the phosphorylation-regulated invertebrate myosin. These interactions are primarily electrostatic and the converter domain is responsible for the head-head interactions. Thus multiple head-head interactions of myosin crossbridges also characterize the switched-off state and have an important role in the regulation

  15. Variation in myoplasmic Ca2+ concentration during contraction and relaxation studied by the indicator fluo-3 in frog muscle fibres.

    Science.gov (United States)

    Caputo, C; Edman, K A; Lou, F; Sun, Y B

    1994-07-01

    1. The fluorescent dye fluo-3, in its permeant acetoxymethyl form, was used to monitor calcium transients during twitch and tetanus of single fibres isolated from the anterior tibialis muscle of Rana temporaria (2-5 degrees C). 2. Fluo-3 was loaded into the muscle fibre by diffusion. Under the experimental conditions used, approximately 45% of maximal fluorescence was reached during a 1 s fused isometric tetanus. Fluo-3 had no detectable effect on the mechanical response of the fibre. 3. The free calcium concentration in the myoplasm, [Ca2+]i, and its variation with time, was calculated from the fluorescence signal by accounting for the on- and off-rate constants for the binding of calcium to the dye. The time course of the calcium transient during twitch and tetanus determined in this way agreed well with previous measurements based on fast-reacting calcium-sensitive dyes. 4. [Ca2+]i declined steeply during the initial phase of force relaxation in both twitch and tetanus, but exhibited a secondary rise that closely coincided with the pseudoexponential fall of tension after the shoulder in the tetanus myogram. The rate of decay of [Ca2+]i during relaxation and the rate of decline of force both became progressively reduced by repetitive stimulation. 5. Stretch and shortening ramps performed during the plateau of an isometric tetanus had no detectable effect upon the calcium transient during the movement. By contrast, shortening and stretch imposed during the linear phase of relaxation both led to an increase of [Ca2+]i and to a steepening of the relaxation phase. 6. The results strongly suggest that the non-uniform length changes that are known to occur along a muscle fibre during relaxation enhance the release of calcium from the contractile system. The calcium mobilized in this way probably accounts for the transitory increase of [Ca2+]i that is observed during the latter part of force relaxation.

  16. Calcium buffering properties of sarcoplasmic reticulum and calcium-induced Ca(2+) release during the quasi-steady level of release in twitch fibers from frog skeletal muscle.

    Science.gov (United States)

    Fénelon, Karine; Lamboley, Cédric R H; Carrier, Nicole; Pape, Paul C

    2012-10-01

    Experiments were performed to characterize the properties of the intrinsic Ca(2+) buffers in the sarcoplasmic reticulum (SR) of cut fibers from frog twitch muscle. The concentrations of total and free calcium ions within the SR ([Ca(T)](SR) and [Ca(2+)](SR)) were measured, respectively, with the EGTA/phenol red method and tetramethylmurexide (a low affinity Ca(2+) indicator). Results indicate SR Ca(2+) buffering was consistent with a single cooperative-binding component or a combination of a cooperative-binding component and a linear binding component accounting for 20% or less of the bound Ca(2+). Under the assumption of a single cooperative-binding component, the most likely resting values of [Ca(2+)](SR) and [Ca(T)](SR) are 0.67 and 17.1 mM, respectively, and the dissociation constant, Hill coefficient, and concentration of the Ca-binding sites are 0.78 mM, 3.0, and 44 mM, respectively. This information can be used to calculate a variable proportional to the Ca(2+) permeability of the SR, namely d[Ca(T)](SR)/dt ÷ [Ca(2+)](SR) (denoted release permeability), in experiments in which only [Ca(T)](SR) or [Ca(2+)](SR) is measured. In response to a voltage-clamp step to -20 mV at 15°C, the release permeability reaches an early peak followed by a rapid decline to a quasi-steady level that lasts ~50 ms, followed by a slower decline during which the release permeability decreases by at least threefold. During the quasi-steady level of release, the release amplitude is 3.3-fold greater than expected from voltage activation alone, a result consistent with the recruitment by Ca-induced Ca(2+) release of 2.3 SR Ca(2+) release channels neighboring each channel activated by its associated voltage sensor. Release permeability at -60 mV increases as [Ca(T)](SR) decreases from its resting physiological level to ~0.1 of this level. This result argues against a release termination mechanism proposed in mammalian muscle fibers in which a luminal sensor of [Ca(2+)](SR) inhibits

  17. Changes in conformation of myosin heads during the development of isometric contraction and rapid shortening in single frog muscle fibres.

    Science.gov (United States)

    Piazzesi, G; Reconditi, M; Dobbie, I; Linari, M; Boesecke, P; Diat, O; Irving, M; Lombardi, V

    1999-01-15

    1. Two-dimensional X-ray diffraction patterns were recorded at the European Synchrotron Radiation Facility from central segments of intact single muscle fibres of Rana temporaria with 5 ms time resolution during the development of isometric contraction. Shortening at ca 0.8 times the maximum velocity was also imposed at the isometric tetanus plateau. 2. The first myosin-based layer line (ML1) and the second myosin-based meridional reflection (M2), which are both strong in resting muscle, were completely abolished at the plateau of the isometric tetanus. The third myosin-based meridional reflection (M3), arising from the axial repeat of the myosin heads along the filaments, remained intense but its spacing changed from 14.34 to 14.56 nm. The intensity change of the M3 reflection, IM3, could be explained as the sum of two components, I14.34 and I14.56, arising from myosin head conformations characteristic of rest and isometric contraction, respectively. 3. The amplitudes (A) of the X-ray reflections, which are proportional to the fraction of myosin heads in each conformation, changed with half-times that were similar to that of isometric force development, which was 33.5 +/- 2. 0 ms (mean +/- s.d., 224 tetani from three fibres, 4 C), measured from the end of the latent period. We conclude that the myosin head conformation changes synchronously with force development, at least within the 5 ms time resolution of these measurements. 4. The changes in the X-ray reflections during rapid shortening have two temporal components. The rapid decrease in intensity of the 14.56 nm reflection at the start of shortening is likely to be due to tilting of myosin heads attached to actin. The slower changes in the other reflections were consistent with a return to the resting conformation of the myosin heads that was about 60 % complete after shortening of 70 nm per half-sarcomere.

  18. 蛙骨骼肌检测紫色甘薯醇提物抗疲劳效应研究%Study on frog skeletal muscle test the anti-fatigue effect of alcohol extract of purple sweet potato

    Institute of Scientific and Technical Information of China (English)

    熊斌; 陶小丹; 王杨科

    2016-01-01

    To investigate extract effect of of purple sweet potato on frog muscle contraction and diastole and filtrate common factor in curve of frog muscle contraction and diastole foranti-fatigue, the most preliminary testing method of fatigue resistance was studied .Connecting the frog nerves-gastrocnemius muscle tension transducer , stimulating the nerve trunk , the curve of muscle contraction and diastole by physiological signal acquisition system.factor analysis is made by TFmax50, Tmax,△T, STI, DTI, DTI50, DTI90, +dT/dtmax,-dT/dtmax , t-dT/dtmax .According to the technical specification for inspection and evaluation of health food , mice experiments on anti-fatigue effect of alcohol extract of purple sweet potato is designed .Factor analysis ex-tract 5 constituent factors, and the cumulative variance is 90.22%, which is a better substitution for the origi-nal 10 indexes to evaluate the anti-fatigue effect of alcohol extract of purple sweet potato by frog skeletal mus-cle.Factor 1 ( DTI50, DTI90, TFmax50 ) can be initially identified as comprehensive factors , mainly for showing the duration of frog muscle diastole .DTI50, DTI90, TFmax50 in frog skeletal muscle reached signifi-cant difference between experimental group and the blank group (P<0.01), suggesting that alcohol extract of purple sweet potato by frog skeletal muscle is of great anti-fatigue effect and in agreement with the experimental conclusion in mice .DTI50 , DTI90 , TFmax50 can reflect of the anti-fatigue effect of alcohol extract of purple sweet potato on frog skeletal muscle .The results showed no difference from the test on mice .%研究紫色甘薯醇提物对蛙骨骼肌收缩舒张的影响,筛选出蛙骨骼肌收缩曲线共性因子作为骨骼肌研究抗疲劳指标,为蛙骨骼肌作为初步检测抗疲劳物方法提供依据。将蛙神经-腓肠肌标本连接到张力换能器,刺激神经干,用生理信号采集系统记录相应的曲线。统

  19. Frog eat frog: exploring variables influencing anurophagy

    Directory of Open Access Journals (Sweden)

    G. John Measey

    2015-08-01

    Full Text Available Background. Frogs are generalist predators of a wide range of typically small prey items. But descriptions of dietary items regularly include other anurans, such that frogs are considered to be among the most important of anuran predators. However, the only existing hypothesis for the inclusion of anurans in the diet of post-metamorphic frogs postulates that it happens more often in bigger frogs. Moreover, this hypothesis has yet to be tested.Methods. We reviewed the literature on frog diet in order to test the size hypothesis and determine whether there are other putative explanations for anurans in the diet of post-metamorphic frogs. In addition to size, we recorded the habitat, the number of other sympatric anuran species, and whether or not the population was invasive. We controlled for taxonomic bias by including the superfamily in our analysis.Results. Around one fifth of the 355 records included anurans as dietary items of populations studied, suggesting that frogs eating anurans is not unusual. Our data showed a clear taxonomic bias with ranids and pipids having a higher proportion of anuran prey than other superfamilies. Accounting for this taxonomic bias, we found that size in addition to being invasive, local anuran diversity, and habitat produced a model that best fitted our data. Large invasive frogs that live in forests with high anuran diversity are most likely to have a higher proportion of anurans in their diet.Conclusions. We confirm the validity of the size hypothesis for anurophagy, but show that there are additional significant variables. The circumstances under which frogs eat frogs are likely to be complex, but our data may help to alert conservationists to the possible dangers of invading frogs entering areas with threatened anuran species.

  20. An Electromyographic Study of Jaw and Tongue Reflexes in Frogs

    OpenAIRE

    熊井, 敏文; 野村, 浩道

    1983-01-01

    Electromyographic activities of jaw and tongue muscles produced reflexly by mechanical and chemical stimulation of various loci of orofacial region were studied in the frog, Rana nigromaculata. Temporal muscle activity occurred when mechanical stimuli were applied to the palatal ridge, lower lip, root of tongue and pharynx. Electromyograms of the masseter muscle were similar to that of the temporal muscle, but the masseter muscle activity was occurred ipsilaterally and was not occurred by the...

  1. [Effect of preparations altering cAMP metabolism on the bioelectrogenesis of the skeletal muscles].

    Science.gov (United States)

    Patrin, I A; Mozzhukhin, A S; Samoĭlov, V O

    1982-07-01

    In the frog isolated m. sartorius, microelectrode technique and in vivo TV microscopy differentiating bioelectrical phenomena in separate fibers of different groups (dark, light, intermediate), revealed that the drugs altering cAMF exchange (adrenaline, caffeine, imidazole) and used in concentration 10(-5) M, affect to different extents the resting potential and the AP. The effect of the drugs is more obvious in respect to excitatory potential. Mechanism of this phenomenon is discussed.

  2. Effects of first exogenous nutrients on the mRNA levels of atrogin-1/MAFbx and GLUT1 in the skeletal muscles of newly hatched chicks.

    Science.gov (United States)

    Ijiri, Daichi; Shimamoto, Saki; Kawaguchi, Mana; Furukawa, Airi; Nakashima, Kazuki; Tada, Osamu; Ohtsuka, Akira

    2017-03-01

    The aim of this study was to examine the effects of first exogenous nutrients on the mRNA levels of muscle atrophy F-box (atrogin-1/MAFbx) and glucose transporters (GLUTs) in the skeletal muscles of newly hatched chicks with no feed experience. In experiment 1, newly hatched chicks had free access to feed or were fasted for the first 24h. The chicks having free access to feed for the first 24h increased their body weight and had decreased atrogin-1/MAFbx mRNA levels in their sartorius and pectoralis major muscles compared with the fasted chicks. In experiment 2, newly hatched chicks received a single feed via intubation into the crop. Three hours after intubation, levels of atrogin-1/MAFbx mRNA in the sartorius muscle were decreased whereas the plasma insulin concentration and phosphorylated AKT levels in the sartorius muscle were increased. In addition, the mRNA levels of GLUT1 and GLUT8 were increased in the sartorius muscle after the intubation. However, in the pectoralis major muscle, AKT phosphorylation and levels of atrogin-1/MAFbx, GLUT1 and GLUT8 mRNA were not affected 3h after intubation. The first exogenous nutrients increased the level of phosphorylated AKT in the sartorius muscle of newly hatched chicks, possibly because of the decrease in atrogin-1/MAFbx mRNA levels. Furthermore, the sartorius muscle in newly hatched chicks appeared to be more susceptible to the first feed compared with the pectoralis major muscle. Copyright © 2016. Published by Elsevier Inc.

  3. Yet More Frogs

    Science.gov (United States)

    Shutler, Paul M. E.

    2011-01-01

    Extending a recent paper by Derek Holton, we show how to represent the algorithm for the Frog Problem diagrammatically. This diagrammatic representation suggests a simpler proof of the symmetrical case (equal numbers of frogs of each colour) by allowing the even and odd cases to be treated together. It also provides a proof in the asymmetrical…

  4. Yet More Frogs

    Science.gov (United States)

    Shutler, Paul M. E.

    2011-01-01

    Extending a recent paper by Derek Holton, we show how to represent the algorithm for the Frog Problem diagrammatically. This diagrammatic representation suggests a simpler proof of the symmetrical case (equal numbers of frogs of each colour) by allowing the even and odd cases to be treated together. It also provides a proof in the asymmetrical…

  5. IMPROVEMENT IN THE METHOD OF PREPARATION FOR NERVE-MUSCLE SPECIMEN OF FROG%蛙坐骨神经-腓肠肌标本制备方法的改进

    Institute of Scientific and Technical Information of China (English)

    华田苗; 刘再群

    2001-01-01

    Nerve-muscle specimens of frogs were prepared by two distinctmethods: First detachment of specimen from the body, and last detachemnt. According to the record of experiments, contracting functions of specimens prepared by the two ways were compared. It was found that single muscle twitch of “Last detachment” specimens showed a higher average of contraction range but a shorter average of time in latent and relaxation periods than that of “First detachment” ones. Some relative reasons were analysed and discussed.%采用“先离体法”和“后离体法”两种方法制备蛙坐骨神经-腓肠肌标本,通过实验记录,对标本的收缩机能进行了比较.结果表明后离体法制备的标本单收缩幅度高,潜伏期和舒张期时程缩短,并对其原因进行了分析与讨论.

  6. POTENTIATION OF CAFFEINE-INDUCED CONTRACTURE BY RAISING EXTRACELLULAR POTASSIUM IN FROG SKELETAL MUSCLE%提高胞外钾引起的蛙骨骼肌咖啡因挛缩增强

    Institute of Scientific and Technical Information of China (English)

    陈克樱; 朱培闳

    1999-01-01

    用蛙胫前肌小束为材料, 研究了提高胞外钾[K+]O对咖啡因挛缩的作用.[K+]O从2 mmol/L提高到10或25 mmol/L, 由3 mmol/L咖啡因引起的挛缩明显增强.以PKC/PC (PKC和PC分别为在高钾和正常钾条件下的咖啡因挛缩)表示的咖啡因挛缩增强, 依赖[K+]O和高钾作用时间.随着10 mmol/L [K+]O作用时间延长, 直至10 min, 增强逐渐增加.但是, 25 mmol/L [K+]O作用1 min时增强达到最大, 然后下降到对照.PKC/PC变化时程不能用高钾引起的去极化解释, 而与由相似[K+]O引起的胞浆自由钙变化时程相符.提示, 至少在蛙骨骼肌, 高钾引起的咖啡因挛缩增强主要是由胞浆自由钙升高引起的.%The effect of raising extracellular potassium ([K+]O) on caffeine contracture was inves~tigated, using small bundles dissected from frog anterior tibialis muscle. Elevating [K+]O from the control of 2 mmol/L to 10 or 25 mmol/L significantly potentiated the contracture induced by 3 mmol/L caffeine. The potentiation represented by PKC/PC, where PKC and PC are the peak tension of the caffeine contracture evoked in high and normal [K+]O respectively, was dependent on [K+]O and the duration of conditioning high K+ exposure. With 10 mmol/L [K+]O, the potentiation was gradually increased by prolonging conditioning exposure up to 10 min. On the contrary, with 25 mmol/L [K+]O the potentiation reached a maximum within only 1 min, and then subsided to the control. These different time courses of PKC/PC could not be accounted for by high K+ induced depolarization, but were in general consistence with the time courses of the change in myoplasmic free calcium induced by corresponding high [K+]O[10]. It is suggested that, at least in frog skeletal muscle, the high [K+]O induced potentiation of caffeine contracture is mainly due to an increase of myoplasmic free calcium.

  7. The association between hip muscle cross-sectional area, muscle strength, and bone mineral density.

    Science.gov (United States)

    Ahedi, Harbeer; Aitken, Dawn; Scott, David; Blizzard, Leigh; Cicuttini, Flavia; Jones, Graeme

    2014-07-01

    Studies examining the association between muscle size, muscle strength, and bone mineral density (BMD) are limited. Thus, this study aimed to describe the association between hip muscles cross-sectional area (CSA), muscle strength, and BMD of the hip and spine. A total of 321 subjects from the Tasmanian Older Adult Cohort study with a right hip MRI scan conducted between 2004 and 2006 were included. Hip muscles were measured on MR images by OsiriX (Geneva) software measuring maximum muscle CSA (cm(2)) of gluteus maximus, obturator externus, gemelli, quadratus femoris, piriformis, pectineus, sartorius, and iliopsoas. Dual-energy X-ray absorptiometry measured total hip, femoral neck, and spine BMD, and lower limb muscle strength was assessed by dynamometer. Muscle CSA of the hip flexors (pectineus, sartorius, and iliopsoas) and the hip rotators, obturator externus, and quadratus femoris were associated with both total hip and femoral neck BMD (all p muscles (except gluteus maximus and gemelli) were positively associated with leg strength (p = 0.02 to strength was weakly associated with BMD (p = 0.11-0.007). Hip muscle CSA, and to a lesser extent muscle strength, were positively associated with hip BMD. These data suggest that both higher muscle mass and strength may contribute to the maintenance of bone mass and prevention of disease progression in older adults.

  8. Skeletal muscle metastasis from uterine leiomyosarcoma

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, J.M.; Brennan, D.D.; Taylor, D.H.; Eustace, S.J. [Cappagh National Orthopaedic Hospital, Department of Radiology, Dublin (Ireland); Holloway, D.P.; O' Keane, J.C. [Cappagh National Orthopaedic Hospital, Department of Pathology, Dublin (Ireland); Hurson, B. [Cappagh National Orthopaedic Hospital, Department of Orthopaedics, Dublin (Ireland)

    2004-11-01

    A case of a 68-year-old woman who presented with a rapidly enlarging painful right thigh mass is presented. She had a known diagnosis of uterine leiomyosarcoma following a hysterectomy for dysfunctional uterine bleeding. She subsequently developed a single hepatic metastatic deposit that responded well to radiofrequency ablation. Whole-body MRI and MRA revealed a vascular mass in the sartorius muscle and a smaller adjacent mass in the gracilis muscle, proven to represent metastatic leiomyosarcoma of uterine origin. To our knowledge, metastatic uterine leiomyosarcoma to the skeletal muscle has not been described previously in the English medical literature. (orig.)

  9. Skeletal muscle metastasis from uterine leiomyosarcoma.

    Science.gov (United States)

    O'Brien, J M; Brennan, D D; Taylor, D H; Holloway, D P; Hurson, B; O'Keane, J C; Eustace, S J

    2004-11-01

    A case of a 68-year-old woman who presented with a rapidly enlarging painful right thigh mass is presented. She had a known diagnosis of uterine leiomyosarcoma following a hysterectomy for dysfunctional uterine bleeding. She subsequently developed a single hepatic metastatic deposit that responded well to radiofrequency ablation. Whole-body MRI and MRA revealed a vascular mass in the sartorius muscle and a smaller adjacent mass in the gracilis muscle, proven to represent metastatic leiomyosarcoma of uterine origin. To our knowledge, metastatic uterine leiomyosarcoma to the skeletal muscle has not been described previously in the English medical literature.

  10. Distribution, structure and projections of the frog intracardiac neurons.

    Science.gov (United States)

    Batulevicius, Darius; Skripkiene, Gertruda; Batuleviciene, Vaida; Skripka, Valdas; Dabuzinskiene, Anita; Pauza, Dainius H

    2012-05-21

    Histochemistry for acetylcholinesterase was used to determine the distribution of intracardiac neurons in the frog Rana temporaria. Seventy-nine intracardiac neurons from 13 frogs were labelled iontophoretically by the intracellular markers Alexa Fluor 568 and Lucifer Yellow CH to determine their structure and projections. Total neuronal number per frog heart was (Mean ± SE) 1374 ± 56. Largest collections of neurons were found in the interatrial septum (46%), atrioventricular junction (25%) and venal sinus (12%). Among the intracellularly labelled neurons, we found the cells of unipolar (71%), multipolar (20%) and bipolar (9%) types. Multiple processes originated from the neuron soma, hillock and proximal axon. These processes projected onto adjacent neuron somata and cardiac muscle fibers within the interatrial septum. Average total length of the processes from proximal axon was 348 ± 50 μm. Average total length of processes from soma and hillock was less, 118 ± 27 μm and 109 ± 24 μm, respectively. The somata of 59% of neurons had bubble- or flake-shaped extensions. Most neurons from the major nerves in the interatrial septum sent their axons towards the ventricle. In contrast, most neurons from the ventral part of the interatrial septum sent their axons towards the atria. Our findings contradict to a view that the frog intracardiac ganglia contain only non-dendritic neurons of the unipolar type. We conclude that the frog intracardiac neurons are structurally complex and diverse. This diversity may account for the complicated integrative functions of the frog intrinsic cardiac ganglia.

  11. Frogs In Danger

    Institute of Scientific and Technical Information of China (English)

    李笑; 岳巧玲

    2005-01-01

    If you go out to the field at ni ght inspring or summer,you can hear frogs croaking and singing joyfully here and there.It seems as if they were performing a fiel dsymphony (交响曲).How pleasant and sweet it sounds!It fills nature with music and vitality.

  12. It's a Frog's Life

    Science.gov (United States)

    Coffey, Audrey L.; Sterling, Donna R.

    2003-01-01

    When a preschool teacher unexpectedly found tadpoles in the school's outdoor baby pool, she recognized an unusual opportunity for her students to study pond life up close. By following the tadpoles' development, students learned about frogs, life cycles, habitats. (Contains 1 resource.)

  13. Different effects of verapamil and low calcium on repetitive contractile activity of frog fatigue-resistant and easily-fatigued muscle fibres.

    Science.gov (United States)

    Lipská, E; Radzyukevich, T

    1999-06-01

    The effects of low calcium and verapamil on contractility of two muscle fibre types (m. iliofibularis, Rana temporaria) upon different stimulation protocols were been compared. Verapamil (0.02 mmol/l) induced temporal excitation-contraction coupling failure during single tetanic stimulation and enhanced the decline of tetanic force during 30 s repetitive tetanic stimulation in both fatigue-resistant fibres and easily-fatigued fibres. In contrast to verapamil, low extracellular calcium (0.02 mmol/l) only enhanced the decline of tetanic force in fatigue-resistant during repetitive tetanic stimulation but had no effect on easily-fatigued fibres. The effect of verapamil on the decline of tetanic force in fatigue-resistant fibres was more profound in low calcium conditions. Both verapamil and low calcium eliminated twitch facilitation that appeared after prolonged contractile activity in fatigue-resistant fibres. 4mmol/l Ni+2, used as calcium channel antagonist, had effects similar to low calcium medium. It could be concluded that (i) extracellular Ca2+-requirements for excitation-contraction coupling are different in fatigue-resistant and easily-fatigued fibres; (ii) the effects of verapamil on force performance are not entirely dependent upon calcium channel blockade.

  14. Active control of ultrasonic hearing in frogs

    Science.gov (United States)

    Gridi-Papp, Marcos; Feng, Albert S.; Shen, Jun-Xian; Yu, Zu-Lin; Rosowski, John J.; Narins, Peter M.

    2008-01-01

    Vertebrates can modulate the sound levels entering their inner ears in the face of intense external sound or during their own vocalizations. Middle ear muscle contractions restrain the motion of the middle ear ossicles, attenuating the transmission of low-frequency sound and thereby protecting the hair cells in the inner ear. Here we show that the Chinese concave-eared torrent frog, Odorrana tormota, can tune its ears dynamically by closing its normally open Eustachian tubes. Contrary to the belief that the middle ear in frogs permanently communicates with the mouth, O. tormota can close this connection by contraction of the submaxillary and petrohyoid muscles, drastically reducing the air volume behind the eardrums. Mathematical modeling and laser Doppler vibrometry revealed that the reduction of this air volume increases the middle ear impedance, resulting in an up to 20 dB gain in eardrum vibration at high frequencies (10–32 kHz) and 26 dB attenuation at low frequencies (3–10 kHz). Eustachian tube closure was observed in the field during calling and swallowing. Besides a potential role in protecting the inner ear from intense low-frequency sound and high buccal air pressure during calling, this previously unrecognized vertebrate mechanism may unmask the high-frequency calls of this species from the low-frequency stream noise which dominates the environment. This mechanism also protects the thin tympanic membranes from injury during swallowing of live arthropod prey. PMID:18658240

  15. Active control of ultrasonic hearing in frogs.

    Science.gov (United States)

    Gridi-Papp, Marcos; Feng, Albert S; Shen, Jun-Xian; Yu, Zu-Lin; Rosowski, John J; Narins, Peter M

    2008-08-05

    Vertebrates can modulate the sound levels entering their inner ears in the face of intense external sound or during their own vocalizations. Middle ear muscle contractions restrain the motion of the middle ear ossicles, attenuating the transmission of low-frequency sound and thereby protecting the hair cells in the inner ear. Here we show that the Chinese concave-eared torrent frog, Odorrana tormota, can tune its ears dynamically by closing its normally open Eustachian tubes. Contrary to the belief that the middle ear in frogs permanently communicates with the mouth, O. tormota can close this connection by contraction of the submaxillary and petrohyoid muscles, drastically reducing the air volume behind the eardrums. Mathematical modeling and laser Doppler vibrometry revealed that the reduction of this air volume increases the middle ear impedance, resulting in an up to 20 dB gain in eardrum vibration at high frequencies (10-32 kHz) and 26 dB attenuation at low frequencies (3-10 kHz). Eustachian tube closure was observed in the field during calling and swallowing. Besides a potential role in protecting the inner ear from intense low-frequency sound and high buccal air pressure during calling, this previously unrecognized vertebrate mechanism may unmask the high-frequency calls of this species from the low-frequency stream noise which dominates the environment. This mechanism also protects the thin tympanic membranes from injury during swallowing of live arthropod prey.

  16. CINRG: Systems Biology of Glucocoricoids in Muscle Disease

    Science.gov (United States)

    2014-12-01

    deficiency causes lethal muscle hypertrophy in cats. J. Neurol. Sci. 110:149–159. http://dx.doi .org/10.1016/0022-510X(92)90022-D Heier, C.R., J.M...J.L. Dow, et al. 2012b. The para- dox of muscle hypertrophy in muscular dystrophy. Phys. Med. Rehabil. Clin. N. Am. 23:149–172. http://dx.doi.org...the dys- trophin-deficient cranial sartorius muscle is associated with classical and novel hypertrophy pathways in GRMD dogs. Am. J. Pathol. 183:1411

  17. Lithobates sylvaticus (wood frog)

    Science.gov (United States)

    Fuller, Pam

    2016-01-01

    A single specimen found southwest of Hattiesburg in Timberton (31.270391oN, 89.327675oW; WGS 84). 23 July 2015. Gary, Kat, and Ron Lukens. Verifi ed by Kenneth Krysko, Florida Museum of Natural History (UF-Herpetology 176455). This species has never been recorded from the state of Mississippi before (Dodd 2013. Frogs of the United States and Canada – Volume 2. John Hopkins University Press, Baltimore, Maryland. 982 pp.). According to Dodd (2013), the closest population is located in east central Alabama, approximately 400 km to the northeast, as documented by Davis and Folkerts (1986. Brimleyana 12:29-50).

  18. Generation of transgenic frogs.

    Science.gov (United States)

    Loeber, Jana; Pan, Fong Cheng; Pieler, Tomas

    2009-01-01

    The possibility of generating transgenic animals is of obvious advantage for the analysis of gene function in development and disease. One of the established vertebrate model systems in developmental biology is the amphibian Xenopus laevis. Different techniques have been successfully applied to create Xenopus transgenics; in this chapter, the so-called meganuclease method is described. This technique is not only technically simple, but also comparably efficient and applicable to both Xenopus laevis and Xenopus tropicalis. The commercially available endonuclease I-SceI (meganuclease) mediates the integration of foreign DNA into the frog genome after coinjection into fertilized eggs. Tissue-specific gene expression, as well as germline transmission, has been observed.

  19. Effect of prolonged bed rest on the anterior hip muscles.

    Science.gov (United States)

    Dilani Mendis, M; Hides, Julie A; Wilson, Stephen J; Grimaldi, Alison; Belavý, Daniel L; Stanton, Warren; Felsenberg, Dieter; Rittweger, Joern; Richardson, Carolyn

    2009-11-01

    Prolonged bed rest and inactivity is known to cause muscular atrophy with previous research indicating that muscles involved in joint stabilisation are more susceptible. The anterior hip muscles are important for hip joint function and stability but little is known about the effects of prolonged inactivity on their function. This study investigated the effect of prolonged bed rest on the size of the anterior hip muscles and their pattern of recovery. The effect of resistive vibration exercise (RVE) as a countermeasure to muscle atrophy was also investigated. 12 male participants, randomly assigned to either a control or an exercise group, underwent 8 weeks of bed rest with 6 months follow-up. Changes in muscle cross-sectional area (CSA) of the iliacus, psoas, iliopsoas, sartorius and rectus femoris muscles were measured by magnetic resonance imaging at regular intervals during bed rest and recovery phases. CSAs of iliopsoas and sartorius decreased at the hip joint (piliacus, psoas, and rectus femoris CSAs were unchanged (p>0.05). No significant difference was found between the two groups for all muscles (all p>0.1), suggesting inefficacy of the countermeasure in this sample. These findings suggest that prolonged bed rest can result in the atrophy of specific muscles across the hip joint which may affect its stability and function.

  20. Landscape resistance to frog movements

    Science.gov (United States)

    Mazerolle, M.J.; Desrochers, A.

    2005-01-01

    An animal's capacity to recolonize a patch depends on at least two components: its ability to detect the patch and its ability to reach it. However, the disruption of such processes by anthropic disturbances could explain low animal abundance patterns observed by many investigators in certain landscapes. Through field experiments, we compared the orientation and homing success of northern green frogs (Rana clamitans melanota Rafinesque, 1820) and northern leopard frogs (Rana pipiens Schreber, 1782) translocated across disturbed or undisturbed surfaces. We also monitored the path selected by individuals when presented with a choice between a short distance over a disturbed surface and a longer, undisturbed route. Finally, we measured the water loss and behaviour of frogs on substrates resulting from anthropogenic disturbances and a control. When presented with a choice, 72% of the frogs avoided disturbed surfaces. Although able to orient towards the pond of capture when translocated on disturbed surfaces, frogs had a lower probability of homing successfully to the pond than when translocated at a similar distance on an undisturbed surface. Frogs lost the most water on substrates associated with disturbance and in the absence of cover. Our data illustrate that anthropically disturbed areas devoid of cover, such as mined peatlands and agricultural fields, disrupt the ability of frogs to reach habitat patches and are likely explanations to their reduced abundance patterns in such environments. ?? 2005 NRC Canada.

  1. DDTs in rice frogs (Rana limnocharis) from an agricultural site, South China: tissue distribution, biomagnification, and potential toxic effects assessment.

    Science.gov (United States)

    Wu, Jiang-Ping; Zhang, Ying; Luo, Xiao-Jun; Chen, She-Jun; Mai, Bi-Xian

    2012-04-01

    Contamination with agricultural pesticides such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD), is among several proposed stressors contributing to the global declines in amphibian populations and species biodiversity. These chemicals were examined in insects and in the muscle, liver, and eggs of rice frogs (Rana limnocharis) from the paddy fields of an agricultural site in South China. The ΣDDT (sum of DDT, DDE, and DDD) concentrations ranged from 154 to 915, 195 to 1,400, and 165 to 1,930 ng/g lipid weight in the muscle, liver, and eggs, respectively. All the DDTs (DDT, DDE, and DDD) showed higher affinity for the liver relative to muscle tissue and can be maternally transferred to eggs in female frogs. The average biomagnification factors for DDTs ranged from 1.6 to 1.9 and 1.5 to 2.9 in female and male frogs, respectively, providing clear evidence of their biomagnification from insects to frogs. Compared with the reported DDT levels demonstrated to have toxic effects on frogs, DDTs in the present frogs are unlikely to constitute an immediate health risk. However, the adverse impacts of high DDT residues in eggs on the hatching success and their potential toxicity to the newly metamorphosed larval frogs should be assessed further.

  2. To Be or Not to Be...a Frog: The Frog Prince and Shifting Paradigms.

    Science.gov (United States)

    Crane, Lisa Marie

    1997-01-01

    Discusses three modern variations of the classic "Frog Prince" folk tale: "Pondlarker" (Fred Gwynne); "The Frog Prince Continued" (Jon Scieszka); and "The Prince of the Pond" (Donna Jo Napoli). Notes that these variants create a world in which frogs can have values, wisdom, and emotion, and in which frogs can influence the ways of humanity. (RS)

  3. A Comparison of V-Frog[C] to Physical Frog Dissection

    Science.gov (United States)

    Lalley, James P.; Piotrowski, Phillip S.; Battaglia, Barbara; Brophy, Keith; Chugh, Kevin

    2010-01-01

    The purpose of the present study was to examine and compare the effectiveness of virtual frog dissection using V-Frog[C] and physical frog dissection on learning, retention, and affect. Subjects were secondary students enrolled in year-long life science classes in a suburban high school (N=102). Virtual dissections were done with V-Frog[C], a…

  4. Active Solute Transport across Frog Skin and Epithelial Cell Systems According to the Association-Induction Hypothesis,

    Science.gov (United States)

    1980-01-01

    AD A136 163 ACTIVE SOLUTE TRANSPORT ACROSS FROG SKIN AND EPITHELIAL 1/1 CELL SYSTEMS ACCO..(U) PENNSYLVANIA HOSPITAL PHILADELPHIA DEPT OF MOLECULAR...TEST CHART fi4TIOtM4. @I*AU OF STA’dAftOS. 43- A ACTIVE SOWTE TRANSPORT ACROSS FROG SKIN AND EPITH-IAL CELL SYSTEMS AC:ORC:NG TO THE ASSOCIATION...taken full account of the difference between unifacial solid cells typified by human red blood cells, frog muscle and squid awn, and bifacial hollow

  5. Structural study of the frog Rana temporaria larval stomach.

    Science.gov (United States)

    Rovira, J; Villaro, A C; Bodegas, M E; Valverde, E; Sesma, P

    1993-10-01

    The gastric wall of Rana temporaria tadpoles consists of a well-developed mucosa and thin muscular and serosa layers. Three cellular types--mucous, ciliated and endocrine cells--make up the lining epithelium. Different types of endocrine cells exist. Argyrophylic endocrine cells can be recognized in semithin sections of plastic-embedded material while non-argyrophylic endocrine cells can only be identified under the electron microscope. Glands are composed mainly of well-differentiated oxyntic cells and, occasionally, scarce endocrine cells. Oxyntic cells show abundant mitochondria and smooth endoplasmic reticulum, but do not contain zymogen granules as do those present in adults. Secretory canaliculi with microvilli are also well-developed. The lamina propria contains numerous vascular sinuses and nerve bundles which innervate the endothelium and some endocrine cells. The neuroendocrine regulation of frog gastric functions seems therefore to have developed in young tadpoles. Nerve fibers also innervate the muscular propria, which is composed of a single layer of smooth muscle cells. Underlying the muscle, connective fibers and a flattened layer of mesothelial cells make up the serosa. In summary, the structure of the frog larval stomach shows a well-differentiated histological pattern, especially referring to surface epithelium and glands. Some of the histological traits will also be present in adult frogs while others are characteristic of the tadpole's stage.

  6. 49 CFR 213.137 - Frogs.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Frogs. 213.137 Section 213.137 Transportation... TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.137 Frogs. (a) The flangeway depth measured from a plane across the wheel-bearing area of a frog on Class 1 track shall not be less than 13/8 inches, or...

  7. Diseases of frogs and toads

    Science.gov (United States)

    Green, D.E.; Converse, K.A.; Majumdar, S.K.; Huffman, J.E.; Brenner, F.J.; Panah, A.I.

    2005-01-01

    This chapter presents information on infectious diseases of free-living frogs and toads that have completed metamorphosis. The diseases discussed in this chapter pertain principally to sub-adult and adult frogs and toads that are at least 60-90 days removed from completion of metamorphosis. The main emphasis of this chapter is the diseases found in amphibians of Canada and the United States. Diseases of recent metamorphs, larvae and amphibian eggs are presented in the chapters Diseases of Amphibian Eggs and Embryos and Diseases of Tadpoles. The smallest disease agents (viruses and bacteria) are presented first, followed by fungi, protozoa, helminths and ectoparasites. Diseases presented in this chapter are Ranaviral (iridovirus) infection Lucke frog herpesvirus (kidney cancer) Frog erythrocytic virus West Nile virus Red-leg disease (bacterial septicemia) Salmonellosis Chytrid fungal infection Basidiobolus fungi Dermosporidiosis Ichthyophoniasis Dermocystidium & Dermomycoides Myxozoa Ribeiroia flukes and Amphibian malformations Clinostomum metacercaria Aspects of each disease are presented to assist the biologist with recognition of diseases in the field. Hence, the major emphases for identification of diseases are the epizootiological aspects (host species, life stage, casualty numbers, etc) and gross findings ('lesions'). Descriptions of the microscopical, ultrastructural and cultural characteristics of each infectious agent were considered beyond the scope of this text. Detailed cultural and microscopical features of these disease agents are available in other reviews (Taylor et al., 2001; Green, 2001). Some diseases, while common in captive and zoo amphibians, are exceptionally rare in free-living frogs and toads, and therefore are omitted from this review. Among the diseases not presented are infections by chlamydia and mycobacteria, which occur principally in captive colonies of African clawed frogs (Xenopus, Hymenochirus, et al.) and northern leopard frogs

  8. Muscle magnetic resonance imaging and histopathology in ACTA1-related congenital nemaline myopathy.

    Science.gov (United States)

    Castiglioni, Claudia; Cassandrini, Denis; Fattori, Fabiana; Bellacchio, Emanuele; D'Amico, Adele; Alvarez, Karin; Gejman, Roger; Diaz, Jorge; Santorelli, Filippo M; Romero, Norma B; Bertini, Enrico; Bevilacqua, Jorge A

    2014-12-01

    Muscle biopsy is usually diagnostic in nemaline myopathy (NM), but some patients may show nonspecific findings, leading to pitfalls in diagnosis. Muscle MRI is a helpful complementary tool. We assessed the clinical, histopathological, MRI, and molecular findings in a 19-year-old patient with NM in whom 2 muscle biopsies with ultrastructural examination showed no nemaline bodies. We analyzed the degree and pattern of muscle MRI involvement of the entire body, including the tongue and pectoral muscles. Muscle MRI abnormalities in sartorius, adductor magnus, and anterior compartment muscles of the leg suggested NM. A previously unreported fatty infiltration of the tongue was found. A third biopsy after the muscle MRI showed scant nemaline bodies. A novel heterozygous de novo ACTA1 c.611C>T/p.Thr204Ile mutation was detected. We highlight the contribution of muscle imaging in addressing the genetic diagnosis of ACTA1-related NM. © 2014 Wiley Periodicals, Inc.

  9. Cryoprotectants and extreme freeze tolerance in a subarctic population of the wood frog.

    Science.gov (United States)

    Costanzo, Jon P; Reynolds, Alice M; do Amaral, M Clara F; Rosendale, Andrew J; Lee, Richard E

    2015-01-01

    Wood frogs (Rana sylvatica) exhibit marked geographic variation in freeze tolerance, with subarctic populations tolerating experimental freezing to temperatures at least 10-13 degrees Celsius below the lethal limits for conspecifics from more temperate locales. We determined how seasonal responses enhance the cryoprotectant system in these northern frogs, and also investigated their physiological responses to somatic freezing at extreme temperatures. Alaskan frogs collected in late summer had plasma urea levels near 10 μmol ml-1, but this level rose during preparation for winter to 85.5 ± 2.9 μmol ml-1 (mean ± SEM) in frogs that remained fully hydrated, and to 186.9 ± 12.4 μmol ml-1 in frogs held under a restricted moisture regime. An osmolality gap indicated that the plasma of winter-conditioned frogs contained an as yet unidentified osmolyte(s) that contributed about 75 mOsmol kg-1 to total osmotic pressure. Experimental freezing to -8°C, either directly or following three cycles of freezing/thawing between -4 and 0°C, or -16°C increased the liver's synthesis of glucose and, to a lesser extent, urea. Concomitantly, organs shed up to one-half (skeletal muscle) or two-thirds (liver) of their water, with cryoprotectant in the remaining fluid reaching concentrations as high as 0.2 and 2.1 M, respectively. Freeze/thaw cycling, which was readily survived by winter-conditioned frogs, greatly increased hepatic glycogenolysis and delivery of glucose (but not urea) to skeletal muscle. We conclude that cryoprotectant accrual in anticipation of and in response to freezing have been greatly enhanced and contribute to extreme freeze tolerance in northern R. sylvatica.

  10. Convergent Substitutions in a Sodium Channel Suggest Multiple Origins of Toxin Resistance in Poison Frogs.

    Science.gov (United States)

    Tarvin, Rebecca D; Santos, Juan C; O'Connell, Lauren A; Zakon, Harold H; Cannatella, David C

    2016-04-01

    Complex phenotypes typically have a correspondingly multifaceted genetic component. However, the genotype-phenotype association between chemical defense and resistance is often simple: genetic changes in the binding site of a toxin alter how it affects its target. Some toxic organisms, such as poison frogs (Anura: Dendrobatidae), have defensive alkaloids that disrupt the function of ion channels, proteins that are crucial for nerve and muscle activity. Using protein-docking models, we predict that three major classes of poison frog alkaloids (histrionicotoxins, pumiliotoxins, and batrachotoxins) bind to similar sites in the highly conserved inner pore of the muscle voltage-gated sodium channel, Nav1.4. We predict that poison frogs are somewhat resistant to these compounds because they have six types of amino acid replacements in the Nav1.4 inner pore that are absent in all other frogs except for a distantly related alkaloid-defended frog from Madagascar, Mantella aurantiaca. Protein-docking models and comparative phylogenetics support the role of these replacements in alkaloid resistance. Taking into account the four independent origins of chemical defense in Dendrobatidae, phylogenetic patterns of the amino acid replacements suggest that 1) alkaloid resistance in Nav1.4 evolved independently at least seven times in these frogs, 2) variation in resistance-conferring replacements is likely a result of differences in alkaloid exposure across species, and 3) functional constraint shapes the evolution of the Nav1.4 inner pore. Our study is the first to demonstrate the genetic basis of autoresistance in frogs with alkaloid defenses.

  11. Cryoprotectants and extreme freeze tolerance in a subarctic population of the wood frog.

    Directory of Open Access Journals (Sweden)

    Jon P Costanzo

    Full Text Available Wood frogs (Rana sylvatica exhibit marked geographic variation in freeze tolerance, with subarctic populations tolerating experimental freezing to temperatures at least 10-13 degrees Celsius below the lethal limits for conspecifics from more temperate locales. We determined how seasonal responses enhance the cryoprotectant system in these northern frogs, and also investigated their physiological responses to somatic freezing at extreme temperatures. Alaskan frogs collected in late summer had plasma urea levels near 10 μmol ml-1, but this level rose during preparation for winter to 85.5 ± 2.9 μmol ml-1 (mean ± SEM in frogs that remained fully hydrated, and to 186.9 ± 12.4 μmol ml-1 in frogs held under a restricted moisture regime. An osmolality gap indicated that the plasma of winter-conditioned frogs contained an as yet unidentified osmolyte(s that contributed about 75 mOsmol kg-1 to total osmotic pressure. Experimental freezing to -8°C, either directly or following three cycles of freezing/thawing between -4 and 0°C, or -16°C increased the liver's synthesis of glucose and, to a lesser extent, urea. Concomitantly, organs shed up to one-half (skeletal muscle or two-thirds (liver of their water, with cryoprotectant in the remaining fluid reaching concentrations as high as 0.2 and 2.1 M, respectively. Freeze/thaw cycling, which was readily survived by winter-conditioned frogs, greatly increased hepatic glycogenolysis and delivery of glucose (but not urea to skeletal muscle. We conclude that cryoprotectant accrual in anticipation of and in response to freezing have been greatly enhanced and contribute to extreme freeze tolerance in northern R. sylvatica.

  12. Mechanics of the frog ear

    NARCIS (Netherlands)

    Van Dijk, Pim; Mason, Matthew J.; Schoffelen, Richard L. M.; Narins, Peter M.; Meenderink, Sebastiaan W. F.

    2011-01-01

    The frog inner ear contains three regions that are sensitive to airborne sound and which are functionally distinct. (1) The responses of nerve fibres innervating the low-frequency, rostral part of the amphibian papilla (AP) are complex. Electrical tuning of hair cells presumably contributes to the f

  13. Guinea Worm in a Frog

    Centers for Disease Control (CDC) Podcasts

    2017-03-09

    Dr. Mark Eberhard, a retired parasitologist and CDC guest researcher, discusses Guinea worm infection in a wild-caught frog.  Created: 3/9/2017 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 3/9/2017.

  14. FROG - Fingerprinting Genomic Variation Ontology.

    Directory of Open Access Journals (Sweden)

    E Abinaya

    Full Text Available Genetic variations play a crucial role in differential phenotypic outcomes. Given the complexity in establishing this correlation and the enormous data available today, it is imperative to design machine-readable, efficient methods to store, label, search and analyze this data. A semantic approach, FROG: "FingeRprinting Ontology of Genomic variations" is implemented to label variation data, based on its location, function and interactions. FROG has six levels to describe the variation annotation, namely, chromosome, DNA, RNA, protein, variations and interactions. Each level is a conceptual aggregation of logically connected attributes each of which comprises of various properties for the variant. For example, in chromosome level, one of the attributes is location of variation and which has two properties, allosomes or autosomes. Another attribute is variation kind which has four properties, namely, indel, deletion, insertion, substitution. Likewise, there are 48 attributes and 278 properties to capture the variation annotation across six levels. Each property is then assigned a bit score which in turn leads to generation of a binary fingerprint based on the combination of these properties (mostly taken from existing variation ontologies. FROG is a novel and unique method designed for the purpose of labeling the entire variation data generated till date for efficient storage, search and analysis. A web-based platform is designed as a test case for users to navigate sample datasets and generate fingerprints. The platform is available at http://ab-openlab.csir.res.in/frog.

  15. Salmonella Infection and Water Frogs

    Centers for Disease Control (CDC) Podcasts

    2010-01-12

    This podcast, featuring lead investigator Shauna Mettee, discusses the first known outbreak of Salmonella in people due to contact with water frogs.  Created: 1/12/2010 by National Center for Zoonotic, Vector-Borne, and Enteric Diseases (NCZVED).   Date Released: 1/12/2010.

  16. Care and Feeding of Frogs

    Science.gov (United States)

    Pan, Margaret; Chiang, Eugene

    2012-01-01

    "Propellers" are features in Saturn's A ring associated with moonlets that open partial gaps. They exhibit non-Keplerian motion (Tiscareno et al.) the longitude residuals of the best-observed propeller, "Blériot," appear consistent with a sinusoid of period ~4 years. Pan & Chiang proposed that propeller moonlets librate in "frog resonances" with co-orbiting ring material. By analogy with the restricted three-body problem, they treated the co-orbital material as stationary in the rotating frame and neglected non-co-orbital material. Here we use simple numerical experiments to extend the frog model, including feedback due to the gap's motion, and drag associated with the Lindblad disk torques that cause Type I migration. Because the moonlet creates the gap, we expect the gap centroid to track the moonlet, but only after a time delay t delay, the time for a ring particle to travel from conjunction with the moonlet to the end of the gap. We find that frog librations can persist only if t delay exceeds the frog libration period P lib, and if damping from Lindblad torques balances driving from co-orbital torques. If t delay Lt P lib, then the libration amplitude damps to zero. In the case of Blériot, the frog resonance model can reproduce the observed libration period P lib ~= 4 yr. However, our simple feedback prescription suggests that Blériot's t delay ~ 0.01P lib, which is inconsistent with the observed libration amplitude of 260 km. We urge more accurate treatments of feedback to test the assumptions of our toy models.

  17. CARE AND FEEDING OF FROGS

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Margaret; Chiang, Eugene, E-mail: mpan@astro.berkeley.edu [Department of Astronomy, University of California, Berkeley, CA 94720 (United States)

    2012-01-15

    'Propellers' are features in Saturn's A ring associated with moonlets that open partial gaps. They exhibit non-Keplerian motion (Tiscareno et al.); the longitude residuals of the best-observed propeller, 'Bleriot', appear consistent with a sinusoid of period {approx}4 years. Pan and Chiang proposed that propeller moonlets librate in 'frog resonances' with co-orbiting ring material. By analogy with the restricted three-body problem, they treated the co-orbital material as stationary in the rotating frame and neglected non-co-orbital material. Here we use simple numerical experiments to extend the frog model, including feedback due to the gap's motion, and drag associated with the Lindblad disk torques that cause Type I migration. Because the moonlet creates the gap, we expect the gap centroid to track the moonlet, but only after a time delay t{sub delay}, the time for a ring particle to travel from conjunction with the moonlet to the end of the gap. We find that frog librations can persist only if t{sub delay} exceeds the frog libration period P{sub lib}, and if damping from Lindblad torques balances driving from co-orbital torques. If t{sub delay} << Pl{sub ib}, then the libration amplitude damps to zero. In the case of Bleriot, the frog resonance model can reproduce the observed libration period P{sub lib} {approx_equal} 4 yr. However, our simple feedback prescription suggests that Bleriot's t{sub delay} {approx} 0.01P{sub lib}, which is inconsistent with the observed libration amplitude of 260 km. We urge more accurate treatments of feedback to test the assumptions of our toy models.

  18. From frog integument to human skin: dermatological perspectives from frog skin biology

    NARCIS (Netherlands)

    Haslam, I.S.; Roubos, E.; Mangoni, M.L.; Yoshizato, K.; Vaudry, H.; Kloepper, J.E.; Pattwell, D.M.; Maderson, P.F.A.; Paus, R.

    2014-01-01

    For over a century, frogs have been studied across various scientific fields, including physiology, embryology, neuroscience, (neuro)endocrinology, ecology, genetics, behavioural science, evolution, drug development, and conservation biology. In some cases, frog skin has proven very successful as a

  19. From frog integument to human skin: dermatological perspectives from frog skin biology

    NARCIS (Netherlands)

    Haslam, I.S.; Roubos, E.; Mangoni, M.L.; Yoshizato, K.; Vaudry, H.; Kloepper, J.E.; Pattwell, D.M.; Maderson, P.F.A.; Paus, R.

    2014-01-01

    For over a century, frogs have been studied across various scientific fields, including physiology, embryology, neuroscience, (neuro)endocrinology, ecology, genetics, behavioural science, evolution, drug development, and conservation biology. In some cases, frog skin has proven very successful as a

  20. Ultrastructure of venom glands in the frog (Rana esculenta).

    Science.gov (United States)

    De Perez, G; Hindelang, C

    1985-01-01

    Electron microscopic study of skin venom glands in the frog, Rana esculenta, revealed the syncytial structure of the inner (secretory) wall which presents two distinct zones: a basal (juxtamuscular) one, which contains nuclei and major cytoplasmic organelles, and an apical one where large electron-dense granules form and accumulate. Granules are seen to arise inside clusters of tightly packed smooth endoplasmic reticulum (SER) elements, which suggests that the SER system is mainly involved in synthesis of this material. A high glutaraldehyde concentration (5%) also reveals a poorly defined material filling the intergranular cytoplasm. No apical limits to the syncytium could be traced, which suggests massive holocrine secretion. Nerves insinuate between the muscle cells and occur all along the internal face of the muscular layer, sometimes in close contact with the syncytium. The gland duct, the wall of which consists of epidermal cells, is blocked, in contact with the gland, by an epidermal bud linked externally to the muscle layer surrounding the gland. Thus, only strong muscle tension such as to expel all or part of the epidermal bud can trigger granule release. This phenomenon can be induced by the subcutaneous injection of epinephrine, but the high and distressing dose needed to provoke appreciable changes in venom glands renders unlikely any natural intense venom release triggered by epinephrine in the frog.

  1. HARDENING FROG POINTS BY EXPLOSIVE ENERGY,

    Science.gov (United States)

    Experiments were made to determine the most efficient method of strain hardening railroad frog points in order to increase their fatigue resistance...Mechanical strain hardening with rolls 40 mm in diameter under a load of 8 tons produced in standard frogs cast from G13L high-manganese steel (AISI...Hadfield steel) a work-hardened surface layer 3-5 mm thick with a hardness of 340 HB. In other experiments, the frogs were hardened by exploding a

  2. The effect of verapamil and diltiazem on cardiac stimulant effect of adrenaline and calcium chloride on isolated frog heart

    Directory of Open Access Journals (Sweden)

    Lakhavat Sudhakar, Naveen Kumar T, Tadvi NA, Venkata Rao Y

    2013-04-01

    Full Text Available Background: Calcium channel blockers block voltage dependent L-type of calcium channel and thus reduce the frequency of opening of these channels in response to depolarization. The result is a marked decrease in transmembrane calcium current associated with long lasting relaxation of vascular smooth muscle, reduction in contractility in cardiac muscle, decrease in pacemaker activity in the SA node and decrease in conduction velocity in the AV node. Among Calcium channel blockers verapamil, is cardio selective, nifedipine is vascular smooth muscle selective, while diltiazem exhibits intermediate selectivity. Methods: In the present study, the effect of two Ca++ channel blocker, Verapamil and Diltiazem were compared on the isolated frog heart by using adrenaline & calcium chloride as standard on frog heart contractility. Results and conclusion: Adrenaline and calcium chloride increased the amplitude of contraction of isolated perfused frog heart. The L- type of Ca2+ channel blockers verapamil and diltiazem produced dose dependent (2mg, 4mg, 8mg, and 16mg reduction in the amplitude of contraction produced by calcium chloride in isolated perfused frog heart. There was no statistical significant difference (p > 0.05 between the inhibitory effect of diltiazem and verapamil on calcium chloride induced contraction of isolated frog heart.

  3. Care and feeding of frogs

    CERN Document Server

    Pan, Margaret; 10.1088/0004-6256/143/1/9

    2012-01-01

    "Propellers" are features in Saturn's A ring associated with moonlets that open partial gaps. They exhibit non-Keplerian motion (Tiscareno 2010); the longitude residuals of the best-observed propeller, "Bl\\'eriot," appear consistent with a sinusoid of period ~4 years. Pan and Chiang (2010) proposed that propeller moonlets librate in "frog resonances" with co-orbiting ring material. By analogy with the restricted three-body problem, they treated the co-orbital material as stationary in the rotating frame and neglected non-co-orbital material. Here we use simple numerical experiments to extend the frog model, including feedback due to the gap's motion, and drag associated with the Lindblad disk torques that cause Type I migration. Because the moonlet creates the gap, we expect the gap centroid to track the moonlet, but only after a time delay t_diff, the time for a ring particle to travel from conjunction with the moonlet to the end of the gap. We find that frog librations can persist only if t_diff exceeds the...

  4. The Ups and Downs of Frogs.

    Science.gov (United States)

    Greene, Janice Schnake; Tamme, Tina

    2001-01-01

    Presents a science activity in which students simulate increases and decreases in frog populations to get a better understanding of different environmental issues affecting animal populations. Includes simulations for both natural frog populations as well as populations affected by human activities. (YDS)

  5. Semi-automated identification of leopard frogs

    Science.gov (United States)

    Petrovska-Delacrétaz, Dijana; Edwards, Aaron; Chiasson, John; Chollet, Gérard; Pilliod, David S.

    2014-01-01

    Principal component analysis is used to implement a semi-automatic recognition system to identify recaptured northern leopard frogs (Lithobates pipiens). Results of both open set and closed set experiments are given. The presented algorithm is shown to provide accurate identification of 209 individual leopard frogs from a total set of 1386 images.

  6. The Ups and Downs of Frogs.

    Science.gov (United States)

    Greene, Janice Schnake; Tamme, Tina

    2001-01-01

    Presents a science activity in which students simulate increases and decreases in frog populations to get a better understanding of different environmental issues affecting animal populations. Includes simulations for both natural frog populations as well as populations affected by human activities. (YDS)

  7. A comparative analysis of frog early development.

    Science.gov (United States)

    del Pino, Eugenia M; Venegas-Ferrín, Michael; Romero-Carvajal, Andrés; Montenegro-Larrea, Paola; Sáenz-Ponce, Natalia; Moya, Iván M; Alarcón, Ingrid; Sudou, Norihiro; Yamamoto, Shinji; Taira, Masanori

    2007-07-17

    The current understanding of Xenopus laevis development provides a comparative background for the analysis of frog developmental modes. Our analysis of development in various frogs reveals that the mode of gastrulation is associated with developmental rate and is unrelated to egg size. In the gastrula of the rapidly developing embryos of the foam-nesting frogs Engystomops coloradorum and Engystomops randi, archenteron and notochord elongation overlapped with involution at the blastopore lip, as in X. laevis embryos. In embryos of dendrobatid frogs and in the frog without tadpoles Eleutherodactylus coqui, which develop somewhat more slowly than X. laevis, involution and archenteron elongation concomitantly occurred during gastrulation; whereas elongation of the notochord and, therefore, dorsal convergence and extension, occurred in the postgastrula. In contrast, in the slow developing embryos of the marsupial frog Gastrotheca riobambae, only involution occurred during gastrulation. The processes of archenteron and notochord elongation and convergence and extension were postgastrulation events. We produced an Ab against the homeodomain protein Lim1 from X. laevis as a tool for the comparative analysis of development. By the expression of Lim1, we were able to identify the dorsal side of the G. riobambae early gastrula, which otherwise was difficult to detect. Moreover, the Lim1 expression in the dorsal lip of the blastopore and notochord differed among the studied frogs, indicating variation in the timing of developmental events. The variation encountered gives evidence of the modular character of frog gastrulation.

  8. Role of calcium and vesicle-docking proteins in remobilising dormant neuromuscular junctions in desert frogs.

    Science.gov (United States)

    Lavidis, Nickolas A; Hudson, Nicholas J; Choy, Peng T; Lehnert, Sigrid A; Franklin, Craig E

    2008-01-01

    Despite prolonged immobility the desert frog, Cyclorana alboguttata, suffers little impairment in muscle function. To determine compensatory mechanisms at neuromuscular junctions, transmitter release was examined along primary terminals in C. alboguttata iliofibularis muscle. Using extracellular recording we found the amplitudes of evoked endplate currents were significantly smaller in dormant frogs. In active frogs we identified two negatively sloping proximal-distal gradients of transmitter frequency and quantal content; a shallow proximal-distal gradient with low probability of transmitter release (0.6). During aestivation, only a shallow gradient was identified. The high probability release sites in control frogs were inhibited during aestivation by a mechanism that could be reversed by (1) increasing the extracellular calcium concentration, and (2) increasing the frequency of stimulation. This suggests that transmitter vesicles are available during aestivation but not released. We quantified expression of messenger RNA transcripts coding for the transmitter vesicle-docking proteins synaptotagmin 1, syntaxin 1B and UNC-13. All three were rare transcripts maintained at control values during aestivation. Neuromuscular remobilisation after dormancy in C. alboguttata is more likely a product of rapidly reversible physiologic mechanisms than reorganisations of the neuromuscular transcriptome.

  9. Antioxidative responses of the tissues of two wild populations of Pelophylax kl. esculentus frogs to heavy metal pollution.

    Science.gov (United States)

    Prokić, Marko D; Borković-Mitić, Slavica S; Krizmanić, Imre I; Mutić, Jelena J; Vukojević, Vesna; Nasia, Mohammed; Gavrić, Jelena P; Despotović, Svetlana G; Gavrilović, Branka R; Radovanović, Tijana B; Pavlović, Slađan Z; Saičić, Zorica S

    2016-06-01

    Heavy metal pollution of the aquatic environment is of great concern worldwide. Heavy metals are capable of inducing oxidative stress by increasing the formation of reactive oxygen species (ROS), and directly affecting the antioxidant defense system (AOS) in living organisms. The frog Pelophylax kl. esculentus is a semiaquatic species with semipermeable skin and a complex lifecycle, and represents a potentially useful bioindicator organism. The aim of this study was to investigate the accumulation of several heavy metals (Cd, Co, Cr, Cu, Fe, Hg, Ni, Pb and Zn), and their effects on selected parameters of the AOS, including the activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR), phase II biotransformation enzyme glutathione-S-transferase (GST), the total glutathione (GSH) contents and sulfhydryl (SH) group concentrations, as well as cholinesterases (ChEs) activities in the liver, skin and muscle of P. kl. esculentus. Frog samples were collected at two sites (the Danube-Tisza-Danube canal (DTDC) and the river Ponjavica) in Serbia, which are characterized by different levels of metal pollution. Differences between the metal contents in different tissues showed that the skin of frogs from the DTDC accumulated statistically higher concentrations of Cd, Cu, Pb and Zn, while only the Fe concentration was lower. No significant differences between metal concentrations in muscle tissues of frogs from the DTDC and Ponjavica were observed. Examination of the parameters of the AOS revealed that frogs from the DTDC had higher concentrations of GSH in the liver and of SH groups in the skin and muscle, whereas the activities of the antioxidative enzymes SOD, GHS-Px and GR in the liver and of GR in the skin were lower than in frogs from the Ponjavica. The relationship between metal concentrations and AOS parameters showed the highest number of correlations with GSH, GR and CAT, and with Ni, Zn, Hg, Cr and Cd. Based

  10. Population density of tropical forest frogs: relation to retreat sites.

    Science.gov (United States)

    Stewart, M M; Pough, F H

    1983-08-05

    The forest frog Eleutherodactylus coqui defends specific sites for retreats and nests in the Luquillo Forest, Puerto Rico. The hypothesis that shortages of nest and retreat sites limit population size was tested by placing 100 bamboo frog houses in plots measuring 100 square meters in areas of high frog density. These new sites were readily adopted by adult frogs. After one year, experimental plots had significantly more nests and frogs of all sizes than did control plots.

  11. Tetranectin in slow intra- and extrafusal chicken muscle fibers

    DEFF Research Database (Denmark)

    Xu, X; Gilpin, B; Iba, K

    2001-01-01

    Tetranectin is a C-type lectin that occurs in the mammalian musculoskeletal system. In the present report we describe the first studies on an avian tetranectin. A full-length chicken tetranectin cDNA was isolated. Comparison of the deduced amino acid sequence of chicken tetranectin with mouse...... and human tetranectin showed an identity of 67 and 68%, respectively. Northern blot analysis demonstrated broad expression of chicken tetranectin mRNA, which was first detected on embryonic day 4. Tetranectin protein was detected in chicken serum and egg yolk. Since muscle is one of few tissues in which...... tetranectin protein is retained, we examined the distribution of tetranectin in various muscle types in chicken. Myofibers strongly positive for tetranectin were observed in several muscles including m. tibialis ant. and m. sartorius (from embryonic day 10 to adult). Using antibodies to fast and slow myosin...

  12. Redescription of the Frog Bladder Fluke Gorgoderina attenuata from the Northern Leopard Frog, Rana pipiens

    National Research Council Canada - National Science Library

    Matthew G. Bolek; Scott D. Snyder; John Janovy Jr

    2009-01-01

    .... Morphological comparisons between gravid G. attenuata recovered from bullfrogs and northern leopard frogs indicated statistically significant differences in 11 of 28 morphological characters examined...

  13. Getting the jump on skeletal muscle disuse atrophy: preservation of contractile performance in aestivating Cyclorana alboguttata (Gunther 1867).

    Science.gov (United States)

    Symonds, Beth L; James, Rob S; Franklin, Craig E

    2007-03-01

    Prolonged immobilisation or unloading of skeletal muscle causes muscle disuse atrophy, which is characterised by a reduction in muscle cross-sectional area and compromised locomotory function. Animals that enter seasonal dormancy, such as hibernators and aestivators, provide an interesting model for investigating atrophy associated with disuse. Previous research on the amphibian aestivator Cyclorana alboguttata (Günther 1867) demonstrated an absence of muscle disuse atrophy after 3 months of aestivation, as measured by gastrocnemius muscle contractile properties and locomotor performance. In this study, we aimed to investigate the effect of aestivation on iliofibularis and sartorius muscle morphology and contractile function of C. alboguttata over a longer, more ecologically relevant time-frame of 9 months. We found that whole muscle mass, muscle cross-sectional area, fibre number and proportions of fibre types remained unchanged after prolonged disuse. There was a significant reduction in iliofibularis fibre cross-sectional area (declined by 36% for oxidative fibre area and 39% for glycolytic fibre area) and sartorius fibre density (declined by 44%). Prolonged aestivation had little effect on the isometric properties of the skeletal muscle of C. alboguttata. There was a significant reduction in the isometric contraction times of the relatively slow-twitch iliofibularis muscle, suggesting that the muscle was becoming slower after 9 months of aestivation (time to peak twitch increased by 25%, time from peak twitch to half relaxation increased by 34% and time from last stimulus to half tetanus relation increased by 20%). However, the results of the work-loop analysis clearly demonstrate that, despite changes to muscle morphology and isometric kinetics, the overall contractile performance and power output levels of muscles from 9-month aestivating C. alboguttata are maintained at control levels.

  14. Evidence for a vertebrate catapult: elastic energy storage in the plantaris tendon during frog jumping.

    Science.gov (United States)

    Astley, Henry C; Roberts, Thomas J

    2012-06-23

    Anuran jumping is one of the most powerful accelerations in vertebrate locomotion. Several species are hypothesized to use a catapult-like mechanism to store and rapidly release elastic energy, producing power outputs far beyond the capability of muscle. Most evidence for this mechanism comes from measurements of whole-body power output; the decoupling of joint motion and muscle shortening expected in a catapult-like mechanism has not been demonstrated. We used high-speed marker-based biplanar X-ray cinefluoroscopy to quantify plantaris muscle fascicle strain and ankle joint motion in frogs in order to test for two hallmarks of a catapult mechanism: (i) shortening of fascicles prior to joint movement (during tendon stretch), and (ii) rapid joint movement during the jump without rapid muscle-shortening (during tendon recoil). During all jumps, muscle fascicles shortened by an average of 7.8 per cent (54% of total strain) prior to joint movement, stretching the tendon. The subsequent period of initial joint movement and high joint angular acceleration occurred with minimal muscle fascicle length change, consistent with the recoil of the elastic tendon. These data support the plantaris longus tendon as a site of elastic energy storage during frog jumping, and demonstrate that catapult mechanisms may be employed even in sub-maximal jumps.

  15. Severe IgE-mediated anaphylaxis following consumption of fried frog legs: definition of alpha-parvalbumin as the allergen in cause.

    Science.gov (United States)

    Hilger, C; Grigioni, F; Thill, L; Mertens, L; Hentges, F

    2002-11-01

    IgE-mediated allergic reactions to bullfrog and edible frog have been reported. The implicated allergens have not been defined so far. The frog material and the patient's serum from a case of severe food-induced anaphylaxis were used to define the implicated allergen at the protein and DNA level. Immunoblotting techniques and N-terminal protein microsequencing were used to define the allergen recognized by the patient's serum. Back translation from the identified protein sequence was used to design degenerated primers to amplify the allergen's cDNA by polymerase chain reaction (PCR). We defined the nucleotide sequence of the allergen from the frog of Indonesian origin that was consumed by the patient, and the homologous cDNA from Rana esculenta. Protein microsequencing revealed that the implicated frog allergen belonged to the parvalbumin family. cDNAs coding for alpha- and beta-parvalbumin of R. esculenta and Rana species were cloned. Recombinant proteins were expressed in Escherichia coli. The patient's serum IgE antibodies recognized parvalbumin prepared from frog muscle and recombinant alpha-parvalbumin from R. species but not from R. esculenta. Recombinant beta-parvalbumin was not recognized by the IgE antibodies. This work defines at the protein and DNA levels alpha-parvalbumin as the allergen implicated in a case of IgE-mediated anaphylaxis to frog muscle. It also shows that a protein belonging to the parvalbumin family is implicated in type I allergies outside the fish species.

  16. Meeting the "Standards" with Vanishing Frogs.

    Science.gov (United States)

    Davidson, Cindy B.; Matthews, Catherine E.; Patrick, Patricia

    2001-01-01

    Explains methods for introducing high school students to the issue of the declining amphibian population. Plays the game Frogs' Futures following a seminar as an instructional strategy. Describes the game, procedures, and rules. (YDS)

  17. Region 6 Northern Leopard Frog Information

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document contains a collection of completed questionnaires and related additional data regarding the status review of the northern leopard frog. On July 1,...

  18. Meeting the "Standards" with Vanishing Frogs.

    Science.gov (United States)

    Davidson, Cindy B.; Matthews, Catherine E.; Patrick, Patricia

    2001-01-01

    Explains methods for introducing high school students to the issue of the declining amphibian population. Plays the game Frogs' Futures following a seminar as an instructional strategy. Describes the game, procedures, and rules. (YDS)

  19. Malformed frog survey Dahomey NWR - 2001

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Report contains field data sheets assoicated with malformed frog survey on Dahomey NWR in 2001. Work was done in support of regional sampling on refuges for...

  20. Frog Call Survey Summary 2002-2006

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Since 2002, Patuxent Research Refuge has conducted frog surveys on South Tract, Central Tract, and North Tract locations. These surveys are conducted by Patuxent...

  1. Internal fertilization in an oviparous frog.

    Science.gov (United States)

    Townsend, D S; Stewart, M M; Pough, F H; Brussard, P F

    1981-04-24

    Eleutherodactylus coqui, an oviparous frog, undergoes internal fertilization. If this mode of fertilization occurs in other species of anurans, interpretations of anuran reproductive strategies based on the assumption of external fertilization must be reviewed.

  2. New genus of diminutive microhylid frogs from Papua New Guinea

    Directory of Open Access Journals (Sweden)

    Fred Kraus

    2010-06-01

    Full Text Available A new genus of diminutive (10.1-11.3 mm microhylid frogs is described from New Guinea that is unique in its combination ofonly seven presacral vertebrae, a reduced phalangeal formula that leaves the first fingers and first toes as vestigial nubs, and reduction of the prepollex and prehallux to single elements. Relationships to other genera are unknown, but overall similarity suggests some relationship to Cophixalus, although that genus also differs in some muscle characters and likely remains paraphyletic. The new genus contains two species, which are among the smallest known frogs in the world. Their miniaturization may be related to their inhabiting leaf litter, exploitation of which may for small size. The new genus is currently known only from one mountaintop in the southeasternmost portion of New Guinea and another on a nearby island. This region is part of the East Papuan Composite Terrane and, should this lineage prove endemic to that region, it may suggest that it originated prior to that geological unit’s docking with mainland New Guinea at 23–29 MY.

  3. Axonal transport of thiamine in frog sciatic nerves in vitro.

    Science.gov (United States)

    Bergquist, J E; Hanson, M

    1983-03-01

    Thiamine has an essential and unknown function in nerve membranes. Administration of thiamine can alleviate symptoms of thiamine deficiency within a few hours. The time course is consistent with a fast axonal transport of the vitamin. Very little is known about axonal transport of low-molecular-weight substances with a preferential localization to the axon membrane. We investigated if labeled thiamine could be transported in the frog sciatic nerve. Radioactivity accumulated proximal to a ligature on the sciatic nerve after supplying the dorsal ganglia with [35S]thiamine in vitro. The accumulation was reduced by inhibition of the energy metabolism with dinitrophenol and by inhibition of protein synthesis in the ganglia with cycloheximide. Vinblastine did not affect the accumulation of thiamine at a concentration which was sufficient to block transport of [3H]leucine-labeled proteins. Accumulation distal to a ligature could be demonstrated in vivo but not in vitro after injecting the gastrocnemius muscle with labeled thiamine. Axonal transport of [3H]leucine-labeled proteins was inhibited by thiamine at millimolar concentrations in the incubation medium. A transient reduction of the compound action potential was obtained at these concentrations. Thiamine was migrating at a fast rate in frog sciatic nerves in both orthograde and retrograde directions. The uptake and/or transport was dependent on energy metabolism and a concomitant protein synthesis. The lack of effect by vinblastine suggests that the transported fraction of thiamine differs in subcellular localization from the bulk of transported [3H]leucine-labeled proteins.

  4. Development of the pseudothumb in frogs

    Science.gov (United States)

    Tokita, Masayoshi; Iwai, Noriko

    2010-01-01

    Frogs have highly conserved hand and foot morphology, possessing four fingers and five toes. As an exception, two Japanese ranid frog species, the Otton frog Babina subaspera and the dagger frog Babina holsti, possess a unique thumb-like structure (the pseudothumb) in the forelimb, giving an appearance of a total of five fingers on the hand. To obtain insights into the developmental mechanisms that generate this novel character, we investigated the hand morphogenesis of the Otton frog. The unique morphological pattern of the pseudothumb was already established in juveniles. Surprisingly, the bud-like structure, which is similar to the area of inductive activity (e.g. feather buds in birds and the carapacial ridge in turtles), was detected over the site where the future prepollex develops in larvae. By contrast, this bud-like structure was not found in larvae of other ranid species. We discuss possible scenarios that would favour the evolution of this very unusual trait in frogs. PMID:20147308

  5. Computed tomographic findings of skeletal muscles in amyotrophic lateral sclerosis (ALS)

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Ryosuke; Imai, Terukuni; Sadashima, Hiromichi; Matsumoto, Sadayuki; Yamamoto, Toru; Kusaka, Hirobumi; Yamasaki, Masahiro; Maya, Kiyomi; Tanabe, Masaya (Kitano Hospital, Osaka (Japan))

    1989-04-01

    We evaluated the Computed Tomographic (CT) findings of skeletal muscles in 12 cases of amyotrophic lateral sclerosis (ALS), 1 case of spinal progressive muscular atrophy (SPMA), and 1 case of Kugelberg-Welander disease. CT examination was performed in the neck, shoulders, abdomen, pelvis, thighs, and lower legs, 15 muscles were selected for evaluation. The following muscles tended to be affected: m. transversospinalis (12 cases were abnormal), m. deltoideus (10), m. subscapularis (10), m. infraspinatus (10), mm. dorsi (12), hamstring muscles (14), m. tibialis anterior (14), and m. triceps surae (14). On the contrary, the following muscles tended to be preserved: m. sternocleidomastoideus (only 7 cases were abnormal), m. psoas major (7), m. gluteus maximus (7), m. rectus femoris (7), m. sartorius (7) and m. gracilis (6). The distribution of the muscles affected showed neither proximal nor distal dominancy. As the disease advanced, however, all the muscles became affected without any severity. CT findings of skeletal muscles in ALS were characterized by muscle atrophy and fat infiltration, which showed a patchy, linear, or moth-eaten appearance. In mildly affected cases, there was muscle atrophy without internal architectual changes. In moderately affected cases, muscle atrophy advanced and internal architectural changes (patchy, linear, and moth-eaten fat infiltration) became evident. In most advanced cases, every muscle showed a ragged appearance because of severe muscle atrophy and internal architectural changes. These findings were well distinguished from those of SPMA, which resembled the CT pattern of primary muscle diseases. (author).

  6. From Virtual Frog to Frog Island: Design Studies in a Development Project.

    Science.gov (United States)

    Dev, Parvati; Walker, Decker F.

    1999-01-01

    Explores the efforts of a curriculum development team who set out to create a virtual frog for use in biology education, but instead, after several design studies, developed a virtual world called Frog Island. Argues for incorporating educational design studies into other educational development projects. (CMK)

  7. Changes in the mechanical properties of human and amphibian muscle after eccentric exercise.

    Science.gov (United States)

    Jones, C; Allen, T; Talbot, J; Morgan, D L; Proske, U

    1997-01-01

    Following a series of eccentric contractions, that is stretching of the muscle while generating active tension, the length-tension relationship of isolated amphibian muscle has been shown to shift towards longer muscle length (Katz 1939; Wood et al. 1993). Here we report observations of electrically stimulated ankle extensor muscles of nine human subjects, demonstrating a similar shift in optimum angle for torque generation [3.9 (1.5) degrees] following exercise on an inclined treadmill that involved eccentric contractions in one leg. (All values are means with the SEMs in parentheses). The shift in the unexercised, control leg was significantly less [mean 0.4 (0.7) degree P post-exercise, while torque took a week to recover. A similar shift in optimum length [12 (1.3)% of rest length] was obtained for five toad (Bufo marinus) sartorius muscles subjected to 25 eccentric contractions. Isometrically contracted control muscles showed a smaller shift [3.5 (1.6)%, n = 5]. Accompanying the shift was a drop in tension of 46 (3)% after the eccentric contractions [control isometric, 23 (6)%, P < 0.0001]. By 5 h after the eccentric contractions the shift had returned to control values, while tension had not recovered. When viewed with an electron microscope, sartorius muscles fixed immediately after the eccentric contractions exhibited many small, and a few larger, regions of myofilament disruption. In muscles fixed 5 h after the contractions, no small regions of disruption were visible, and the number of large regions was no greater than in those muscles fixed immediately after the eccentric contractions. These disruptions are interpreted as the cause of the shift in length-tension relationship.

  8. High-speed cinematography of muscle contraction.

    Science.gov (United States)

    HAUPT, R E; WALL, D M

    1962-07-13

    Motion pictures of the "twitch" of an excised frog gastrocnemius muscle taken at rates of 6000 frames per second provide a means of very accurately timing the phases. The extreme "slow motion" reveals surface phenomena not observable by other techniques. Evidence of "active relaxation" is suggested by results of frame-by-frame analysis.

  9. Measuring parvalbumin levels in fish muscle tissue: relevance of muscle locations and storage conditions.

    Science.gov (United States)

    Lee, Poi-Wah; Nordlee, Julie A; Koppelman, Stef J; Baumert, Joseph L; Taylor, Steve L

    2012-11-15

    Fish is an allergenic food capable of provoking severe anaphylactic reactions. Parvalbumin is the major allergen identified in fish and frog muscles. Antibodies against fish and frog parvalbumin have been used to quantify parvalbumin levels from fish. However, these antibodies react variably with parvalbumin from different fish species. Several factors might be responsible for this variation including instability of parvalbumin in fish muscle as a result of frozen storage and differential parvalbumin expression in muscles from various locations within the whole fish. We aimed to investigate whether these factors contribute to the previously observed variable immunoreactivity of the anti-parvalbumin antibodies. Results showed the detection of parvalbumin by these antibodies was unaffected by frozen storage of muscles for 112 days. However, the parvalbumin content decreased in fish muscles from anterior to posterior positions. This factor may partially explain for the inconsistent reactivity of anti-parvalbumin antibodies to different fish species. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. CT muscle scanning in the evaluation of patients with spinal muscular atrophy (SMA)

    Energy Technology Data Exchange (ETDEWEB)

    Sambrook, P.; Rickards, D.; Cumming, W.J.K.

    1988-12-01

    One hundred with spinal muscular atrophy (SMA) were assessed by CT scanning using a standardised technique. The spectrum of CT abnormality occurring in SMA was observed and by overall analysis the patients were divided into 4 groups. While the CT appearances of these groups correlated well with clinical assessment of severity of disease, the disease process was usually much more widespread than clinical examination suggested. CT abnormality was first observed in the leg and gluteal muscles, progressing to the posterior spinal, thigh, shoulder girdle and sternomastoid muscles. Hypertrophy of sartorius and gracilis was observed in a significant number of patients. Fascial planes were preserved in involved muscles in over half of the patients, even in late-stage disease. Asymmetrical muscle involvement was seen with increasing frequency as the disease process increased in extent as evaluated by CT scanning. There was no discernible difference in the CT appearances in those patients who clinically had limb-girdle, facioscapulohumeral or scapuloperoneal distribution of weakness.

  11. An electromyographic study of the hip muscles of transfemoral amputees in walking.

    Science.gov (United States)

    Jaegers, S M; Arendzen, J H; de Jongh, H J

    1996-07-01

    The aim of this study was to obtain insight into the electromyographic activity of the hip muscles after transfemoral amputation and to determine whether the cleaved hip muscles are still functional in locomotion. The electromyographic activity of the superficial hip muscles of both legs was studied in 11 men who had a unilateral transfemoral amputation. The intact muscles at the intact and amputated side showed the same sequence of activity as did those in healthy subjects, but during a longer period of time. The activity of the cleaved muscles with intact muscle fibers (gluteus maximus, tensor fasciae latae) was dependent on whether the iliotibial tract was reanchored. If the iliotibial tract was fixed, the same activity was found in the muscles of the patients as in those of healthy subjects. The activity of the cleaved, once biarticular, muscles (sartorius, rectus femoris, hamstring muscles, gracilis) was dependent on whether the muscles were reanchored and on the level of amputation. If the cleaved muscles were reanchored correctly, the muscles remained functional in locomotion in patients with an amputation in the distal half of the femur. In patients with high amputation levels, these muscles were almost continuously active; they probably play a role in fixing the socket.

  12. [Bio-acoustic investigations in the green frog, rana esculenta (L.)].

    Science.gov (United States)

    Wahl, Manfred

    1969-07-01

    ; and with mating calls also the repetition-rate of the impulse-groups decreases. 6. The larynx of the green frog consists of 3 elements of cartilage, only one of Cartilago crico-trachealis and the two Cartilagines arytaenoideae, and also 4 pairs of muscles. The muscles are innervated by two branches of the Nervus vagus, named Nervus laryngeus brevis and Nervus laryngeus longus. The larynx of male and female are built the same, but the male larynx is larger. The larynx of Rana ridibunda ridibunda Pallas is little different from that of the green frog. Also in the case of this species the male larynx is larger than the female larynx. 7. The differentiation of the larynx structure in the green frog ends after the completion of the metamorphose. The young frogs emit calls which sound similar to that of the territorial calls of adult frogs.

  13. Effects of chronic heat exposure and protein intake on growth performance, nitrogen retention and muscle development in broiler chickens.

    Science.gov (United States)

    Temim, S; Chagneau, A M; Guillaumin, S; Michel, J; Peresson, R; Geraert, P A; Tesseraud, S

    1999-01-01

    The respective effects of ambient temperature, dietary crude protein and feed intake were investigated in finishing chickens and the consequence of protein supplementation under high temperature conditions was analysed in particular. Heat-related reduction in growth was associated with decreased nitrogen retention (-30 or -35% according to the diet), which could not be explained by the observed lower feed intake alone. Tissue samples performed in 5- to 6-week-old chicks showed varying effects of heat according to the muscles studied: at 32 degrees C, the proportion of Pectoralis major muscle (in percentage of body weight) appeared slightly reduced (reduction lower than 10%), whereas the proportion of two leg muscles were increased (+10 to +15% for the Sartorius muscle; +5% for the gastrocnemius muscle). At 32 degrees C, providing a high protein diet significantly (P < 0.05) increased weight gain and feed efficiency, and slightly improved whole body protein deposition.

  14. 49 CFR 213.139 - Spring rail frogs.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Spring rail frogs. 213.139 Section 213.139..., DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.139 Spring rail frogs. (a) The... wing rail shall be solidly tamped and fully and tightly bolted. (c) Each frog with a bolt hole defect...

  15. 49 CFR 213.141 - Self-guarded frogs.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Self-guarded frogs. 213.141 Section 213.141..., DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.141 Self-guarded frogs. (a) The raised guard on a self-guarded frog shall not be worn more than three-eighths of an inch. (b) If repairs...

  16. Pain perception and anaesthesia in research frogs.

    Science.gov (United States)

    Guénette, Sarah Annie; Giroux, Marie-Chantal; Vachon, Pascal

    2013-01-01

    Frogs possess pain receptors and pathways that support processing and perception of noxious stimuli however the level of organization is less well structured compared to mammals. It was long believed that the experience of pain was limited to 'higher' phylums of the animal kingdom. However, it is now commonly accepted that amphibians possess neuro-anatomical pathways conductive of a complete nociceptive experience. Xenopus laevis frogs have been one of the most popular aquatic research models for developmental studies and genetic research. These frogs have been extensively use in research for their eggs, that can be collected following hormonal stimulation either naturally or by surgical intervention. Many anaesthetics have been used in amphibians such as bath solutions of MS-222, benzocaine and eugenol as well as systemic injections of ketamine or tiletamine, barbiturates, propofol and gas administrations of methoxyflurane, halothane and isoflurane. Most of these anaesthetic drugs produce variability in depth and duration of anaesthesia. MS-222 appears to be one of the most reliable anaesthetics. This review will focus on the evidence of pain perception in frogs and will compare the effectiveness and limitations of different anaesthetics used in Xenopus leavis frogs.

  17. A 3D skeletal muscle model coupled with active contraction of muscle fibres and hyperelastic behaviour.

    Science.gov (United States)

    Tang, C Y; Zhang, G; Tsui, C P

    2009-05-11

    This paper presents a three-dimensional finite element model of skeletal muscle which was developed to simulate active and passive non-linear mechanical behaviours of the muscle during lengthening or shortening under either quasi-static or dynamic condition. Constitutive relation of the muscle was determined by using a strain energy approach, while active contraction behaviour of the muscle fibre was simulated by establishing a numerical algorithm based on the concept of the Hill's three-element muscle model. The proposed numerical algorithm could be used to predict concentric, eccentric, isometric and isotonic contraction behaviours of the muscle. The proposed numerical algorithm and constitutive model for the muscle were derived and implemented into a non-linear large deformation finite element programme ABAQUS by using user-defined material subroutines. A number of scenarios have been used to demonstrate capability of the model for simulating both quasi-static and dynamic response of the muscle. Validation of the proposed model has been performed by comparing the simulated results with the experimental ones of frog gastrocenemius muscle deformation. The effects of the fusiform muscle geometry and fibre orientation on the stress and fibre stretch distributions of frog muscle during isotonic contraction have also been investigated by using the proposed model. The predictability of the present model for dynamic response of the muscle has been demonstrated by simulating the extension of a squid tentacle during a strike to catch prey.

  18. The propeller and the frog

    CERN Document Server

    Pan, Margaret

    2010-01-01

    "Propellers" in planetary rings are disturbances in ring material excited by moonlets that open only partial gaps. We describe a new type of co-orbital resonance that can explain the observed non-Keplerian motions of propellers. The resonance is between the moonlet underlying the propeller, and co-orbiting ring particles downstream of the moonlet where the gap closes. The moonlet librates within the gap about an equilibrium point established by co-orbiting material and stabilized by the Coriolis force. In the limit of small libration amplitude, the libration period scales linearly with the gap azimuthal width and inversely as the square root of the co-orbital mass. The new resonance recalls but is distinct from conventional horseshoe and tadpole orbits; we call it the "frog" resonance, after the relevant term in equine hoof anatomy. For a ring surface density and gap geometry appropriate for the propeller Bl\\'eriot in Saturn's A ring, our theory predicts a libration period of ~4 years, similar to the ~3.7 yea...

  19. FROG The Fast and Realistic OPENGL Displayer

    CERN Document Server

    Quertenmont, Loic

    2009-01-01

    FROG is a generic framework dedicated to visualisation of events in high energy experiment. It is suitable to any particular physics experiment or detector design. The code is light ($<3\\textrm{MB}$) and fast (browsing time ~20 events per second for a large High Energy Physics experiment) and can run on various operating systems, as its object-oriented structure (C++) relies on the cross-platform OPENGL and GLUT libraries. Moreover, FROG does not require installation of third party libraries for the visualisation. This document describes the features and principles of FROG version 1.106, its working scheme and numerous functionalities such as: 3D and 2D visualisations, graphical user interface, mouse interface, configuration files, production of pictures of various format, integration of personal objects, etc. Finally, several examples of its current applications are presented for illustration.

  20. FROG The Fast and Realistic OPENGL Displayer

    CERN Document Server

    Quertenmont, Loic

    2009-01-01

    FROG is a generic framework dedicated to visualisation of events in high energy experiment. It is suitable to any particular physics experiment or detector design. The code is light ($<3\\textrm{MB}$) and fast (browsing time ~20 events per second for a large High Energy Physics experiment) and can run on various operating systems, as its object-oriented structure (C++) relies on the cross-platform OPENGL and GLUT libraries. Moreover, FROG does not require installation of third party libraries for the visualisation. This document describes the features and principles of FROG version 1.106, its working scheme and numerous functionalities such as: 3D and 2D visualisations, graphical user interface, mouse interface, configuration files, production of pictures of various format, integration of personal objects, etc. Finally, several examples of its current applications are presented for illustration.

  1. FROG: The Fast & Realistic OPENGL Displayer

    CERN Document Server

    Quertenmont, Loic

    2009-01-01

    FROG is a generic framework dedicated to visualisation of events in high energy experiment. It is suitable to any particular physics experiment or detector design. The code is light (<3 MB) and fast (browsing time ~20 events per second for a large High Energy Physics experiment) and can run on various operating systems, as its object-oriented structure (C++) relies on the cross-platform OPENGL and GLUT libraries. Moreover, FROG does not require installation of third party libraries for the visualisation. This document describes the features and principles of FROG version 1.106, its working scheme and numerous functionalities such as: 3D and 2D visualisations, graphical user interface, mouse interface, configuration files, production of pictures of various format, integration of personal objects, etc. Finally, several examples of its current applications are presented for illustration.

  2. The Frog Inner Ear: Picture Perfect?

    OpenAIRE

    Mason, Matthew James; Segenhout, Johannes M.; Cobo-Cuan, Ariadna; Quiñones, Patricia M.; van Dijk, Pim

    2015-01-01

    This is the accepted manuscript of a paper published in the Journal of the Association for Research in Otolaryngology (2015) DOI: 10.1007/s10162-015-0506-z Many recent accounts of the frog peripheral auditory system have reproduced Wever’s (1973) schematic cross-section of the ear of a leopard frog. We sought to investigate to what extent this diagram is an accurate and representative depiction of the anuran inner ear, using three-dimensional reconstructions made from serial sections of Ra...

  3. Birds and frogs in mathematics and physics

    Energy Technology Data Exchange (ETDEWEB)

    Dyson, Freeman J [Institute for Advanced Study, Princeton, NJ (United States)

    2010-11-15

    Some scientists are birds, others are frogs. Birds fly high in the air and survey broad vistas of mathematics out to the far horizon. They delight in concepts that unify our thinking and bring together diverse problems from different parts of the landscape. Frogs live in the mud below and see only the flowers that grow nearby. They delight in the details of particular objects, and they solve problems one at a time. A brief history of mathematics and its applications in physics is presented in this article. (from the history of physics)

  4. Effect of prolonged inactivity on skeletal motor nerve terminals during aestivation in the burrowing frog, Cyclorana alboguttata.

    Science.gov (United States)

    Hudson, Nicholas J; Lavidis, Nickolas A; Choy, Peng T; Franklin, Craig E

    2005-04-01

    This study examined the effect of prolonged inactivity, associated with aestivation, on neuromuscular transmission in the green-striped burrowing frog, Cyclorana alboguttata. We compared the structure and function of the neuromuscular junctions on the iliofibularis muscle from active C. alboguttata and from C. alboguttata that had been aestivating for 6 months. Despite the prolonged period of immobility, there was no significant difference in the shape of the terminals (primary, secondary or tertiary branches) or the length of primary terminal branches between aestivators and non-aestivators. Furthermore, there was no significant difference in the membrane potentials of muscle fibres or in miniature end plate potential (EPP) frequency and amplitude. However, there was a significant decrease in evoked transmitter release characterised by a 56% decrease in mean EPP amplitude, and a 29% increase in the failure rate of nerve terminal action potentials to evoke transmitter release. The impact of this suite of neuromuscular characteristics on the locomotor performance of emergent frogs is discussed.

  5. Do all frogs swim alike? The effect of ecological specialization on swimming kinematics in frogs.

    Science.gov (United States)

    Robovska-Havelkova, Pavla; Aerts, Peter; Rocek, Zbynek; Prikryl, Tomas; Fabre, Anne-Claire; Herrel, Anthony

    2014-10-15

    Frog locomotion has attracted wide scientific interest because of the unusual and derived morphology of the frog pelvic girdle and hind limb. Previous authors have suggested that the design of the frog locomotor system evolved towards a specialized jumping morphology early in the radiation of the group. However, data on locomotion in frogs are biased towards a few groups and most of the ecological and functional diversity remains unexplored. Here, we examine the kinematics of swimming in eight species of frog with different ecologies. We use cineradiography to quantify movements of skeletal elements from the entire appendicular skeleton. Our results show that species with different ecologies do differ in the kinematics of swimming, with the speed of limb extension and especially the kinematics of the midfoot being different. Our results moreover suggest that this is not a phylogenetic effect because species from different clades with similar ecologies converge on the same swimming kinematics. We conclude that it is important to analyze frog locomotion in a broader ecological and evolutionary context if one is to understand the evolutionary origins of this behavior.

  6. Heavy metal mediated immunomodulation of the Indian green frog, Euphlyctis hexadactylus (Anura:Ranidae) in urban wetlands.

    Science.gov (United States)

    Priyadarshani, S; Madhushani, W A N; Jayawardena, U A; Wickramasinghe, D D; Udagama, P V

    2015-06-01

    Impacts of heavy metal toxicity on the immune system of the Indian green frog, Euphlyctis hexadactylus, in Bellanwila Attidiya, an urban wetland polluted with high levels of heavy metals, compared to the reference site in Bolgoda, in Sri Lanka was investigated. Significantly higher accumulation of selected heavy metals, copper (Cu), zinc (Zn), lead (Pb), and cadmium (Cd) were detected by AAS in frog liver and gastrocnemius muscle, in the polluted site than in the reference site. Non-functional immunotoxicity tests; total WBC, splenocyte and bone marrow cell counts, spleen weight/body weight ratio, neutrophil/lymphocyte ratio and basal immunoglobulin levels, and phagocytic capacity of peritoneal macrophages (immune functional test) were carried out using standard methodology. Test parameters recorded significantly lower values for frogs of the polluted site compared with their reference site counterparts, indicative of lowered immune response of frogs in the former site. In vitro phagocytic assay based on NBT dye reduction, measured the stimulation index (SI) of E. hexadactylus blood leukocytes, splenocytes and peritoneal macrophages, where SIs of frogs in the polluted site were significantly lower. Also, in vitro exposure of frog phagocytes to Cu, Zn, Pb and Cd at 10(-2)-10(-10)M, showed immunomodulation i.e. low concentrations stimulated phagocytosis while increased concentrations showed a trend towards immunosuppression. IC50 values indicated Cd>Zn>Cu>Pb as the decreasing order of the potential of phagocytosis inhibition. In conclusion, this study clearly demonstrated immunomodulation of E. hexadactylus, stimulated by heavy metals. In-vitro studies evidently suggested the use of phagocytosis as a biomarker in Ecoimmunotoxicology to detect aquatic heavy metal pollution.

  7. Residues of polybrominated diphenyl ethers in frogs (Rana limnocharis) from a contaminated site, South China: tissue distribution, biomagnification, and maternal transfer.

    Science.gov (United States)

    Wu, Jiang-Ping; Luo, Xiao-Jun; Zhang, Ying; Chen, She-Jun; Mai, Bi-Xian; Guan, Yun-Tao; Yang, Zhong-Yi

    2009-07-15

    Environmental pollutants are suspected to be a cause of global declines in amphibian populations, but few data are available on the bioaccumulation of polybrominated diphenyl ethers (PBDEs) in amphibians. To examine the tissue distribution, biomagnification potential, and maternal transfer of PBDEs in frogs, eighteen PBDE congeners were measured in the muscle, liver, and egg tissues of rice frogs (Rana limnocharis) and insects collected from an electronic waste (e-waste) recycling site in South China. PBDE levels in the frogs ranged from 0.63 to 11.6, 4.57 to 56.2, and 10.7 to 125 ng/g wet wt in the muscles, livers, and eggs, respectively. The frogs exhibited a unique congener profile, compared to those in aquatic and terrestrial species, with BDEs 99, 153, 183, 209, and 47 as the dominant congeners, intermediating between aquatic and terrestrial species. Most of the PBDE congeners in general showed higher affinity to liver than to muscle tissue. Except for BDEs 28, 47, 66, 138, and 206, the average biomagnification factors (BMFs) for all PBDE congeners were greater than 1.0, providing clear evidence of their biomagnification from insects to frogs. A parabolic relationship between log BMFs and bromine atom numbers or log Kow of PBDEs was observed, with the maximum BMF values for PBDEs with 6 bromine atoms (or at a log K(ow) of approximately 8.0). Relatively higher levels of 3-MeO-BDE 47 were found in male frogs, suggesting that male frogs in the present study might have higher metabolic capacity for PBDEs compared to female frogs. The ratio of levels in egg/female liver, indicating mother-to-egg transfer capacity, increased with increasing bromine atom numbers up to 7 and then declined as the bromine atom numbers rose. This indicated that the physicochemical properties of the congeners (e.g., K(ow), molecular sizes, and structures), resulting in different affinities to transport proteins, might impact their maternal transfer in frogs.

  8. Water Frogs, Aquariums, and Salmonella -- Oh My!

    Centers for Disease Control (CDC) Podcasts

    2009-12-09

    This CDC Kidtastics podcast discusses how people can get Salmonella from water frogs and aquariums.  Created: 12/9/2009 by National Center for Zoonotic, Vector-Borne, and Enteric Diseases (NCZVED).   Date Released: 12/9/2009.

  9. Frog egg growth, experiment S003

    Science.gov (United States)

    Young, R. S.; Tremor, J. W.

    1971-01-01

    The objective of experiment was to determine the effect of weightlessness on the ability of a fertilized frog egg to divide normally and to differentiate and form a normal embryo. This experiment was first attempted on the Gemini 8 mission and was completed only partially because of the early termination of that mission.

  10. Female frogs send ultrasonic signals for courtship

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ During their studies of Odorrana tormota,a frog species with recessed tympanic membranes,CAS researchers have found that females go ultrasonic during courtship,revealing an amazingly system for communication.The work was reported online on 8 May by Nature.

  11. Tracking Frogs that sing ultrasonic duet

    Institute of Scientific and Technical Information of China (English)

    XIN Ling

    2009-01-01

    @@ In central China, unique frogs talk by emitting ultrasonic calls, male to show their virility and female for courtship, which are received by tunable ears with amazing accuracy. Prof. SHEN Junxian from the CAS Institute of Biophysics and his collaborators are working diligently to explore the mysteries of unique sound communication in animal kingdom.

  12. Anti-apoptotic response during anoxia and recovery in a freeze-tolerant wood frog (Rana sylvatica

    Directory of Open Access Journals (Sweden)

    Victoria E.M. Gerber

    2016-03-01

    Full Text Available The common wood frog, Rana sylvatica, utilizes freeze tolerance as a means of winter survival. Concealed beneath a layer of leaf litter and blanketed by snow, these frogs withstand subzero temperatures by allowing approximately 65–70% of total body water to freeze. Freezing is generally considered to be an ischemic event in which the blood oxygen supply is impeded and may lead to low levels of ATP production and exposure to oxidative stress. Therefore, it is as important to selectively upregulate cytoprotective mechanisms such as the heat shock protein (HSP response and expression of antioxidants as it is to shut down majority of ATP consuming processes in the cell. The objective of this study was to investigate another probable cytoprotective mechanism, anti-apoptosis during oxygen deprivation and recovery in the anoxia tolerant wood frog. In particular, relative protein expression levels of two important apoptotic regulator proteins, Bax and p-p53 (S46, and five anti-apoptotic/pro-survival proteins, Bcl-2, p-Bcl-2 (S70, Bcl-xL, x-IAP, and c-IAP in response to normoxic, 24 Hr anoxic exposure, and 4 Hr recovery stages were assessed in the liver and skeletal muscle using western immunoblotting. The results suggest a tissue-specific regulation of the anti-apoptotic pathway in the wood frog, where both liver and skeletal muscle shows an overall decrease in apoptosis and an increase in cell survival. This type of cytoprotective mechanism could be aimed at preserving the existing cellular components during long-term anoxia and oxygen recovery phases in the wood frog.

  13. Skeletal muscle atrophy occurs slowly and selectively during prolonged aestivation in Cyclorana alboguttata (Gunther 1867).

    Science.gov (United States)

    Mantle, Beth L; Hudson, Nicholas J; Harper, Gregory S; Cramp, Rebecca L; Franklin, Craig E

    2009-11-01

    We investigated the effect of prolonged immobilisation of six and nine months duration on the morphology and antioxidant biochemistry of skeletal muscles in the amphibian aestivator Cyclorana alboguttata. We hypothesised that, in the event of atrophy occurring during aestivation, larger jumping muscles were more likely to be preserved over smaller non-jumping muscles. Whole muscle mass (g), muscle cross-sectional area (CSA) (microm(2)), water content (%) and myofibre number (per mm(2)) remained unchanged in the cruralis muscle after six to nine months of aestivation; however, myofibre area (microm(2)) was significantly reduced. Whole muscle mass, water content, myofibre number and myofibre CSA remained unchanged in the gastrocnemius muscle after six to nine months of aestivation. However, iliofibularis dry muscle mass, whole muscle CSA and myofibre CSA was significantly reduced during aestivation. Similarly, sartorius dry muscle mass, water content and whole muscle CSA was significantly reduced during aestivation. Endogenous antioxidants were maintained at control levels throughout aestivation in all four muscles. The results suggest changes to muscle morphology during aestivation may occur when lipid reserves have been depleted and protein becomes the primary fuel substrate for preserving basal metabolic processes. Muscle atrophy as a result of this protein catabolism may be correlated with locomotor function, with smaller non-jumping muscles preferentially used as a protein source during fasting over larger jumping muscles. Higher levels of endogenous antioxidants in the jumping muscles may confer a protective advantage against oxidative damage during aestivation; however, it is not clear whether they play a role during aestivation or upon resumption of normal metabolic activity.

  14. Identification and characterization of new protein chemoattractants in the frog skin secretome.

    Science.gov (United States)

    Leroy, Baptiste; Toubeau, Gerard; Falmagne, Paul; Wattiez, Ruddy

    2006-11-01

    The vomeronasal organ is a chemosensory organ present in most vertebrates and involved in chemical communication. In the last decade, the deciphering of the signal transduction process of this organ has progressed. However, less is known about the vomeronasal organ ligands and their structure-function relationships. Snakes possess a highly developed vomeronasal system that is used in various behaviors such as mating, predator detection, or prey selection, making this group a suitable model for study of the vomeronasal chemoreception. In this work, we used a proteomics approach to identify and characterize proteins from frog cutaneous mucus proteome involved in prey recognition by snakes of the genus Thamnophis. Herein we report the purification and characterization of two proteins isolated from the frog skin secretome that elicit the vomeronasal organ-mediated predatory behavior of Thamnophis marcianus. These proteins are members of the parvalbumin family, which are calcium-binding proteins generally associated to muscular and nervous tissues. This is the first report that demonstrates parvalbumins are not strictly restricted to intracellular compartments and can also be isolated from exocrine secretions. Purified parvalbumins from frog muscle and mucus revealed identical chemoattractive properties for T. marcianus. Snake bioassay revealed the Ca(2+)/Mg(2+) dependence of the bioactivity of parvalbumins. So parvalbumins appear to be new candidate ligands of the vomeronasal organ.

  15. Effect of intravenous anesthetic propofol on synaptic vesicle exocytosis at the frog neuromuscular junction

    Institute of Scientific and Technical Information of China (English)

    Luciana Ferreira LEITE; Renato Santiago GOMEZ; Matheus de Castro FONSECA; Marcus Vinicius GOMEZ; Cristina GUATIMOSIM

    2011-01-01

    Aim: To investigate the presynaptic effects of propofol, a short-acting intravenous anesthetic, in the frog neuromuscular junction. Methods: Frog cutaneous pectoris nerve muscle preparations were prepared. A fluorescent tool (FM1-43) was used to visualize the effect of propofol on synaptic vesicle exocytosos in the frog neuromuscular junction. Results: Low concentrations of propofol, ranging from 10 to 25 μmol/L, enhanced spontaneous vesicle exocytosis monitored by FM1-43 in a Ca2+-dependent and Na+-independent fashion. Higher concentrations of propofol (50, 100, and 200 μmol/L) had no effect on spontaneous exocytosis. By contrast, higher concentrations of propofol inhibited the Na+-dependent exocytosis evoked by 4-aminopyri-dine but did not affect the Na+-independent exocytosis evoked by KCI. This action was similar and non-additive with that observed by tetrodotoxin, a Na+ channel blocker.Conclusion: Our data suggest that propofol has a dose-dependent presynaptic effect at the neuromuscular transmission which mayhelp to understand some of the clinical effects of this agent on neuromuscular function.

  16. Embryo Development of Tree Frog Polypedates leucomystax at Campus of State University of Malang

    OpenAIRE

    Pearlindah; Emy Kusumawati; Dian Ratri Wulandari; Dwi Listyorini

    2012-01-01

    Tree frogs live in natural places which are unpolluted. Regarding their role as an ecological indicator, the decrease of frogs population in a particular habitat indicates the danger of environment quality decrease. Moreover, this condition can harm the frogs themselves. All kinds of frogs breed in aqueous environment such as ponds, marshes, and farming fields. One of the tree frogs, Polypedates leucomystax, which belongs to Familia Rachophoridae, is widely spread in Indonesia. This frog has ...

  17. The Bear,The Rabbit And The Golden Frog

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Mr. Bear and Mr. Rabbit didn’t like each other very much. One day, while walking through the woods, they came across a golden frog. They were amazed when the frog talked to them. The golden frog admitted that he didn’t often meet anyone, but, when he did, he always gave them six wishes. He told them that they could have 3 wishes each.

  18. Abductor tendon tears are associated with hypertrophy of the tensor fasciae latae muscle.

    Science.gov (United States)

    Sutter, Reto; Kalberer, Fabian; Binkert, Christoph A; Graf, Nicole; Pfirrmann, Christian W A; Gutzeit, Andreas

    2013-05-01

    To evaluate the association between hypertrophy of the tensor fasciae latae muscle and abductor tendon tears. Thirty-five patients who underwent MRI of the abductor tendons of the hip were included in this retrospective study. A subgroup of 18 patients was examined bilaterally. The area of the tensor fasciae latae muscle and the area of the sartorius muscle (size reference) were quantified at the level of the femoral head, and a ratio was calculated. Two radiologists assessed the integrity of the gluteus medius and minimus tendon in consensus. Data were analyzed with a Mann-Whitney U test. Sixteen out of 35 patients (46 %) had a tear of the gluteus medius or minimus tendon. The ratio of the area of the tensor fasciae latae to the sartorius muscle was significantly higher (p = .028) in the group with an abductor tendon tear (median 2.25; Interquartile Range [IQR] = 1.97-3.21) compared to the group without any tears (median 1.91; IQR = 1.52-2.26). The bilateral subanalysis showed that in patients without a tear, the ratio of the two areas did not differ between each side (p = .966), with a median of 1.54 (primary side) and 1.76 (contralateral side). In patients with an abductor tendon tear the ratio was significantly higher (p = .031) on the side with a tear (median 2.81) compared to the contralateral healthy side (1.67). Patients with abductor tendon tears showed hypertrophy of the tensor fasciae latae muscle when compared to the contralateral healthy side and to patients without a tear.

  19. From frog integument to human skin: dermatological perspectives from frog skin biology.

    Science.gov (United States)

    Haslam, Iain S; Roubos, Eric W; Mangoni, Maria Luisa; Yoshizato, Katsutoshi; Vaudry, Hubert; Kloepper, Jennifer E; Pattwell, David M; Maderson, Paul F A; Paus, Ralf

    2014-08-01

    For over a century, frogs have been studied across various scientific fields, including physiology, embryology, neuroscience, (neuro)endocrinology, ecology, genetics, behavioural science, evolution, drug development, and conservation biology. In some cases, frog skin has proven very successful as a research model, for example aiding in the study of ion transport through tight epithelia, where it has served as a model for the vertebrate distal renal tubule and mammalian epithelia. However, it has rarely been considered in comparative studies involving human skin. Yet, despite certain notable adaptations that have enabled frogs to survive in both aquatic and terrestrial environments, frog skin has many features in common with human skin. Here we present a comprehensive overview of frog (and toad) skin ontogeny, anatomy, cytology, neuroendocrinology and immunology, with special attention to its unique adaptations as well as to its similarities with the mammalian integument, including human skin. We hope to provide a valuable reference point and a source of inspiration for both amphibian investigators and mammalian researchers studying the structural and functional properties of the largest organ of the vertebrate body.

  20. The role of extensional viscosity in frog tongue projection

    Science.gov (United States)

    Noel, Alexis; Wagner, Caroline; McKinley, Gareth; Mendelson, Joe; Hu, David

    2014-11-01

    Frogs and other amphibians capture insects through high-speed tongue projection, some achieving tongue accelerations of over fifty times gravity. In this experimental study, we investigate how a frog's sticky saliva enables high-speed prey capture. At the Atlanta zoo, we used high-speed video to film the trajectory of frog tongues during prey capture. We have also designed and built a portable extensional rheometer; by following the capillary-driven thinning in the diameter of a thread of saliva we characterize the relaxation time and extensional viscosity and so infer the adhesive force between the frog tongue and prey.

  1. Muscle magnetic resonance imaging in spinal muscular atrophy type 3: Selective and progressive involvement.

    Science.gov (United States)

    Durmus, Hacer; Yilmaz, Ravza; Gulsen-Parman, Yesim; Oflazer-Serdaroglu, Piraye; Cuttini, Marina; Dursun, Memduh; Deymeer, Feza

    2017-05-01

    In this study we sought to identify magnetic resonance imaging (MRI) signs of selective muscle involvement and disease progression in patients with spinal muscular atrophy type 3b (SMA3b). Twenty-five patients with genetically confirmed SMA3b underwent MRI on a 1.5-Tesla MR scanner. MRI showed significantly more severe involvement of the iliopsoas than of the gluteus maximus muscles, and more severe involvement of the triceps brachii than of the biceps brachii muscles. The quadriceps femoris muscles were severely involved. The deltoid, adductor longus, portions of the hamstrings, gracilis, sartorius, and rectus abdominis muscles were well preserved. We found a significant positive correlation between MRI changes and disease duration for gluteus maximus and triceps brachii. Follow-up MRIs of 4 patients showed disease progression. This study confirms the pattern of selective muscle involvement suggested by previous studies and further refines muscle MRI changes in SMA3b. Progressive muscle involvement is implicated. Muscle Nerve 55: 651-656, 2017. © 2016 Wiley Periodicals, Inc.

  2. Bioavailability and tissue distribution of Dechloranes in wild frogs (Rana limnocharis) from an e-waste recycling area in Southeast China.

    Science.gov (United States)

    Li, Long; Wang, Wenyue; Lv, Quanxia; Ben, Yujie; Li, Xinghong

    2014-03-01

    Dechlorane Plus (DP), a flame retardant used as an alternative to decabromodiphenylether, has been frequently detected in organisms, indicating its bioaccumulation and biomagnification potential in aquatic and terrestrial species. However, little data is available on the bioaccumulation of DP in amphibians. Dechlorane Plus and its analogs (DPs) were detected in the liver, muscle and brain tissues of wild frogs (Rana limnocharis), which were collected from an e-waste recycling site, Southeast China. DP, Mirex, Dec 602 and a dechlorinated compound of DP (anti-Cl11-DP) varied in the range of 2.01-291, 0.650-179, 0.260-12.4, and not detected (nd)-8.67 ng/g lipid weight, respectively. No difference of tissue distribution was found for syn-DP, Mirex and Dec 602 between the liver and muscle tissue (liver/muscle concentration ratio close to 1, p > 0.05). However, higher retention was observed for anti-DP and anti-Cl11-DP in the frog muscle relative to the liver tissue (liver/muscle concentration ratio 1, p frog.

  3. Faint Infrared-Excess Field Galaxies FROGs

    CERN Document Server

    Moustakas, L A; Zepf, S E; Bunker, A J

    1997-01-01

    Deep near-infrared and optical imaging surveys in the field reveal a curious population of galaxies that are infrared-bright (I-K>4), yet with relatively blue optical colors (V-I20, is high enough that if placed at z>1 as our models suggest, their space densities are about one-tenth of phi-*. The colors of these ``faint red outlier galaxies'' (fROGs) may derive from exceedingly old underlying stellar populations, a dust-embedded starburst or AGN, or a combination thereof. Determining the nature of these fROGs, and their relation with the I-K>6 ``extremely red objects,'' has implications for our understanding of the processes that give rise to infrared-excess galaxies in general. We report on an ongoing study of several targets with HST & Keck imaging and Keck/LRIS multislit spectroscopy.

  4. Diffusion-Tensor Imaging of Thigh Muscles in Duchenne Muscular Dystrophy: Correlation of Apparent Diffusion Coefficient and Fractional Anisotropy Values With Fatty Infiltration.

    Science.gov (United States)

    Li, Gui Dian; Liang, Ying Yin; Xu, Ping; Ling, Jian; Chen, Ying Ming

    2016-04-01

    The purpose of this study is to investigate the correlation of apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values with fatty infiltration in the thigh muscles of patients with Duchenne muscular dystrophy (DMD) using diffusion-tensor imaging (DTI). Twenty-one boys with DMD were recruited. The grade of fatty infiltration and the ADC and FA values of four thigh muscles (rectus femoris, semitendinosus, sartorius, and gracilis) were measured, and the FA and ADC values were compared with the grade of fatty infiltration. Twenty age-matched healthy boys were enrolled as the control group. The differences in the ADC and FA values of the thigh muscles between patients with DMD and the control group were compared. The patients with DMD showed lower FA values and higher ADC values in all measured muscles when compared with the control group. The FA and ADC values were correlated with the grade of fatty infiltration. For the rectus femoris muscle, r = -0.753 and p = 0.007 for FA, and r = 0.685 and p = 0.001 for ADC. For the semitendinosus muscle, r = -0.621 and p = 0.041 for FA, and r = 0.705 and p = 0.021 for ADC. For the sartorius muscle, r = -0.662 and p = 0.027 for FA, and r = 0.701 and p = 0.017 for ADC. For the gracilis muscle, r = -0.618 and p = 0.043 for FA, and r = 0.695 and p = 0.022 for ADC. Damage to the thigh muscles in patients with DMD can be detected by ADC and FA values using DTI. DTI can be used to assess the severity of the disease.

  5. Chronic heat exposure alters protein turnover of three different skeletal muscles in finishing broiler chickens fed 20 or 25% protein diets.

    Science.gov (United States)

    Temim, S; Chagneau, A M; Peresson, R; Tesseraud, S

    2000-04-01

    Heat-exposed chickens exhibit a lower growth rate and a depressed protein retention which may result from an alteration in protein metabolism. A high-protein diet seems to be beneficial under hot conditions because it tends to improve growth. Effects of high ambient temperature (32 vs. 22 degrees C) and dietary crude protein (25 vs. 20%) on muscle protein turnover were investigated in finishing broiler chickens. At 5-6 wk of age, protein synthesis was measured in vivo in the Pectoralis major, Sartorius and Gastrocnemius muscles (flooding dose of [(3)H]-phenylalanine). Protein breakdown was determined in the same muscles as the difference between protein synthesis and deposition. Chronic heat stress markedly reduced protein synthesis, irrespective of muscle type (P < 0.05). This was mainly related to the lower capacity for protein synthesis (muscle RNA/Protein) (P < 0.01). Chronic heat exposure also decreased protein breakdown in the P. major and Sartorius; this effect was not observed in the GASTROCNEMIUS: Protein synthesis was more affected than breakdown, leading to reduced protein deposition, at least in the P. major and Gastrocnemius muscles. Increasing dietary protein content had no significant impact on muscle protein turnover. Particularly at 32 degrees C, the high-protein diet did not significantly modify either protein synthesis, ribosomal capacity or translational efficiency. However, it favored muscle protein deposition, which was probably related to reduced proteolysis. In conclusion, we showed that chronic heat exposure decreased muscle protein deposition, mainly by reducing protein synthesis. Under these conditions, the impaired protein synthesis was not restored by a 5% higher protein intake.

  6. A perchlorate sensitive iodide transporter in frogs

    OpenAIRE

    Carr, Deborah L.; James A. Carr; Ray E. Willis; Pressley, Thomas A.

    2008-01-01

    Nucleotide sequence comparisons have identified a gene product in the genome database of African clawed frogs (Xenopus laevis) as a probable member of the solute carrier family of membrane transporters. To confirm its identity as a putative iodide transporter, we examined the function of this sequence after heterologous expression in mammalian cells. A green monkey kidney cell line transfected with the Xenopus nucleotide sequence had significantly greater 125I uptake than sham-transfected con...

  7. Regulation of SMAD transcription factors during freezing in the freeze tolerant wood frog, Rana sylvatica.

    Science.gov (United States)

    Aguilar, Oscar A; Hadj-Moussa, Hanane; Storey, Kenneth B

    2016-11-01

    The wood frog, Rana sylvatica, survives sub-zero winter temperatures by undergoing full body freezing for weeks at a time, during which it displays no measurable brain activity, no breathing, and a flat-lined heart. Freezing is a hypometabolic state characterized by a global suppression of gene expression that is elicited in part by transcription factors that coordinate the activation of vital pro-survival pathways. Smad transcription factors respond to TGF-β signalling and are involved in numerous cellular functions from development to stress. Given the identity of genes they regulate, we hypothesized that they may be involved in coordinating gene expression during freezing. Protein expression of Smad1/2/3/4/5 in response to freezing was examined in 24h frozen and 8h thawed wood frog tissues using western immunoblotting, with the determination of subcellular localization in muscle and liver tissues. Transcript levels of smad2, smad4 and downstream genes (serpine1, myostatin, and tsc22d3) were measured by RT-PCR. Tissue-specific responses were observed during freezing where brain, heart, and liver had elevated levels of pSmad3, and skeletal muscle and kidneys had increased levels of pSmad1/5 and pSmad2 during freeze/thaw cycle, while protein and transcript levels remained constant. There were increases in nuclear levels of pSmad2 in muscle and pSmad3 in liver. Transcript levels of serpine1 were induced in heart, muscle, and liver, myostatin in muscle, and tsc22d3 in heart, and liver during freezing. These results suggest a novel freeze-responsive activation of Smad proteins that may play an important role in coordinating pro-survival gene networks necessary for freeze tolerance.

  8. Modifications of the isolated frog heart preparation in Carl Ludwig's Leipzig Physiological Institute: relevance for cardiovascular research.

    Science.gov (United States)

    Zimmer, H G

    2000-01-01

    Carl Ludwig was the first physiologist to systematically study isolated organs (heart, muscle, kidney, liver, lung). In his Leipzig Physiological Institute, the isolated perfused frog heart preparation was established in 1866 by Elias Cyon. This preparation was subsequently subjected to various modifications, and many important observations were made by scientists such as Joseph Coats, Henry Pickering Bowditch, Luigi Luciani, Michael Joseph Rossbach, Hugo Kronecker and Otto Frank. The influence of filling pressure on contraction amplitude, the all-or-none law of the heart, the absolute refractory period, postextrasystolic potentiation, the staircase ('Treppe') phenomenon and the dependence of heart function on oxidative metabolism were discovered. The negative chronotropic and inotropic effects of vagus nerve stimulation were also first documented, and a model to induce arrhythmias was established. The isolated frog heart preparation became a widely used standard model for teaching and for basic cardiovascular research. Sidney Ringer discovered the essential role of calcium ions for heart function. Otto Loewi discovered the chemical transduction mechanism of the vagus with acetylcholine as transmitter. In more recent times, the cyclical changes in cAMP and cGMP that occur during the cardiac cycle were first described in the frog heart by Wollenberger and associates. Thus, the isolated perfused frog heart established and modified in Carl Ludwig's Leipzig Physiological Institute led not only to the discovery of basic phenomena, but also to observations that became the basis for concepts to be developed and elaborated later. Furthermore, the isolated perfused frog heart was the starting point for the development of the isolated mammalian heart in the retrogradely perfused, nonworking mode in the heart-lung modification and in the working heart preparation.

  9. Mycobacterial Arthritis and Synovitis in Painted Reed Frogs (Hyperolius marmoratus).

    Science.gov (United States)

    Barrows, M; Koeppel, K; Michel, A; Mitchell, E

    2017-02-20

    Several species of atypical mycobacteria have been isolated from wild and captive amphibians. In captive anurans, cutaneous and visceral mycobacteriosis are common and can result in significant mortality, particularly when animals are immunocompromised. Mycobacterial arthritis and synovitis are reported rarely in amphibians. We describe 20 cases in painted reed frogs (Hyperolius marmoratus), which presented with cachexia, limb paresis or paralysis or 'spindly leg syndrome'. Histopathology revealed multifocal histiocytic to granulomatous synovitis affecting appendicular, rib or spinal intervertebral joints. Periarticular granulomata, granulomatous cellulitis and skeletal muscle atrophy, necrosis and degeneration were also present. In one case, granulomatous spinal osteomyelitis was recorded. Ziehl-Neelsen stains showed large numbers of acid-fast bacteria in macrophages and histiocytes. The mycobacterial isolates obtained from culture were identified as members of the Mycobacterium chelonae complex (either M. chelonae or Mycobacteriumabscessus). This was confirmed by 5'-16S ribosomal ribonucleic acid (rRNA) sequencing. In 17 cases mycobacterial lesions were present only in the joints and skeleton, highlighting the importance of not ruling out mycobacterial infection on the basis of absence of cutaneous or visceral lesions.

  10. Structural and biochemical characteristics of locomotory muscles of emperor penguins, Aptenodytes forsteri.

    Science.gov (United States)

    Ponganis, P J; Costello, M L; Starke, L N; Mathieu-Costello, O; Kooyman, G L

    1997-07-01

    Structural and biochemical characteristics of the primary muscles used for swimming (pectoralis, PEC and supracoracoideus, SC) were compared to those of leg muscles in emperor penguins (Aptenodytes forsteri). The mass of PEC-SC was four times that of the leg musculature, and mitochondrial volume density in PEC and SC (4%) was two-thirds that in sartorius (S) and gastrocnemius. The differences in muscle mass and mitochondrial density yielded a 2.2-fold greater total mitochondrial content in PEC-SC than leg muscles, which appears to account for the 1.8-fold greater whole-body highest oxygen consumption previously recorded in emperor penguins during swimming compared to walking. Calculation of maximal mitochondrial O2 consumption in PEC-SC and leg muscle yielded value of 5.8-6.9 ml O2 ml-1 min-1, which are similar to those in locomotory muscles of most mammals and birds. A distinct feature of emperor penguin muscle was its myoglobin content, with concentrations in PEC-SC (6.4 g 100 g-1 among the highest measured in any species. This resulted in a PEC-SC O2 store greater than that of the entire blood. In addition, ratios of myoglobin content to mitochondrial volume density and to citrate synthase activity were 4.4 and 2.5 times greater in PEC than in S, indicative of the significant role of myoglobin in the adaptation of muscle to cardiovascular adjustments during diving.

  11. The organization of primary afferent depolarization in the isolated spinal cord of the frog

    Science.gov (United States)

    Carpenter, D. O.; Rudomin, P.

    1973-01-01

    1. The organization of primary afferent depolarization (PAD) produced by excitation of peripheral sensory and motor nerves was studied in the frog cord isolated with hind limb nerves. 2. Dorsal root potentials from sensory fibres (DR-DRPs) were evoked on stimulation of most sensory nerves, but were largest from cutaneous, joint and flexor muscle afferents. With single shock stimulation the largest cutaneous and joint afferent fibres gave DR-DRPs, but potentials from muscle nerves resulted from activation of sensory fibres with thresholds to electrical stimulation higher than 1·2-1·5 times the threshold of the most excitable fibres in the nerve. This suggests that PAD from muscle afferents is probably due to excitation of extrafusal receptors. 3. Dorsal root potentials produced by antidromic activation of motor fibres (VR-DRPs) were larger from extensor muscles and smaller or absent from flexor muscles. The VR-DRPs were produced by activation of the lowest threshold motor fibres. 4. Three types of interactions were found between test and conditioning DRPs from the same or different nerves. With maximal responses occlusion was usually pronounced. At submaximal levels linear summation occurred. Near threshold the conditioning stimulus frequently resulted in a large facilitation of the test DRP. All three types of interactions were found with two DR-DRPs, two VR-DRPs or one DR-DRP and one VR-DRP. 5. The excitability of sensory nerve terminals from most peripheral nerves was increased during the DR-DRP. The magnitude of the excitability increase varied roughly with the magnitude of the DR-DRP evoked by the conditioning stimulus. 6. There was a marked excitability increase of cutaneous and extensor muscle afferent terminals during the VR-DRP. Flexor muscle afferent terminals often showed no excitability changes to ventral root stimulation. In those experiments where afferent terminals from flexor muscles did show an excitability increase, the effects were smaller than

  12. Frogs and snakes from the island of Morotai (Moluccas)

    NARCIS (Netherlands)

    Brongersma, L.D.

    1948-01-01

    Van Kampen (1924, p. 284) mentions only two species of frogs from Morotai Island; the identification of one of these was considered to be doubtful. Of snakes De Jong (1928, p. 149) records five species from this island. The study of a small collection of frogs and snakes from Morotai, presented to t

  13. Modeling potential river management conflicts between frogs and salmonids

    Science.gov (United States)

    Steven F. Railsback; Bret C. Harvey; Sarah J. Kupferberg; Margaret M. Lang; Scott McBain; Hart H. Welsh

    2016-01-01

    Management of regulated rivers for yellow-legged frogs (Rana boylii) and salmonids exemplifies potential conflicts among species adapted to different parts of the natural flow and temperature regimes. Yellow-legged frogs oviposit in rivers in spring and depend on declining flows and warming temperatures for egg and tadpole survival and growth,...

  14. Coleman Revisited: School Segregation, Peers, and Frog Ponds

    Science.gov (United States)

    Goldsmith, Pat Rubio

    2011-01-01

    Students from minority segregated schools tend to achieve and attain less than similar students from White segregated schools. This study examines whether peer effects can explain this relationship using normative models and frog-pond models. Normative models (where peers become alike) suggest that minority schoolmates are a liability. Frog-pond…

  15. Using a Phototransduction System to Monitor the Isolated Frog Heart

    Science.gov (United States)

    Stephens, Philip J.

    2015-01-01

    A simple and inexpensive method of monitoring the movement of an isolated frog heart provides comparable results to those obtained with a force transducer. A commercially available photoresistor is integrated into a Wheatstone bridge circuit, and the output signal is interfaced directly with a recording device. An excised, beating frog heart is…

  16. Using a Phototransduction System to Monitor the Isolated Frog Heart

    Science.gov (United States)

    Stephens, Philip J.

    2015-01-01

    A simple and inexpensive method of monitoring the movement of an isolated frog heart provides comparable results to those obtained with a force transducer. A commercially available photoresistor is integrated into a Wheatstone bridge circuit, and the output signal is interfaced directly with a recording device. An excised, beating frog heart is…

  17. Photo-Affinity Labeling of Specific Acetylcholine-Binding Sites on Membranes

    Science.gov (United States)

    Kiefer, Hansruedi; Lindstrom, Jon; Lennox, Edwin S.; Singer, S. J.

    1970-01-01

    Acetylcholinesterase of intact red blood cell membranes and the acetylcholine receptor at the neuromuscular junction of whole-frog sartorius muscle have been irreversibly inactivated by photo-affinity labeling with two quaternary ammonium aryl azides. The inactivation requires that the azides, at the time of their photolytic conversion to highly reactive nitrenes, are reversibly bound to the specific acetylcholine-binding sites. PMID:5275370

  18. Hip flexor muscle size, strength and recruitment pattern in patients with acetabular labral tears compared to healthy controls.

    Science.gov (United States)

    Mendis, M Dilani; Wilson, Stephen J; Hayes, David A; Watts, Mark C; Hides, Julie A

    2014-10-01

    Acetabular labral tears are a source of hip pain and are considered to be a precursor to hip osteoarthritis. Hip flexor muscles contribute to hip joint stability and function but it is unknown if their size and function is altered in the presence of labral pathology. This study aimed to investigate hip flexor muscle size, strength and recruitment pattern in patients with hip labral pathology compared to control subjects. 12 subjects diagnosed with an unilateral acetabular labral tear were compared to 12 control subjects matched for age and gender. All subjects underwent magnetic resonance imaging (MRI) of their lumbo-pelvic region. Average muscle cross-sectional area (CSA) of the iliacus, psoas, iliopsoas, sartorius, tensor fascia latae and rectus femoris muscles were measured. Hip flexion strength was measured by an externally fixed dynamometer. Individual muscle recruitment pattern during a resisted hip flexion exercise task was measured by muscle functional MRI. Hip flexor muscle strength was found to be decreased in patients with labral pathology compared to control subjects (p muscle size (all p > 0.17) and recruitment pattern (all p > 0.53). Decreased hip flexor muscle strength may affect physical function in patients with hip labral pathology by contributing to altered gait patterns and functional tasks. Clinical rehabilitation of these patients may need to include strengthening exercises for the hip flexor muscles. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. 49 CFR 213.355 - Frog guard rails and guard faces; gage.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Frog guard rails and guard faces; gage. 213.355... Higher § 213.355 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs... distance between the gage line of a frog to the guard line 1 of its guard rail or guarding face,...

  20. Intramuscular EMG from the hip flexor muscles during human locomotion.

    Science.gov (United States)

    Andersson, E A; Nilsson, J; Thorstensson, A

    1997-11-01

    The purpose was to investigate the activation pattern of five major hip flexor muscles and its adaptation to changing speed and mode of progression. A total of 11 healthy subjects performed walking and running on a motor-driven treadmill at speeds ranging from 1.0 to 6.0 m s-1. Intramuscular fine-wire electrodes were used to record myoelectric signals from the iliacus, psoas, sartorius, rectus femoris and tensor fascia latae muscles. The basic pattern, with respect to number of activation periods, remained the same irrespective of speed and mode of progression. However, differences in the relative duration and timing of onset of activation occurred between individual muscles. Over the speed range in walking, a progressively earlier onset was generally seen for the activation period related to hip flexion. Changes in EMG amplitude were measured in the iliacus and psoas muscles and showed a marked increase and difference between walking and running at speeds above 2.0 m s-1. Thus, the alternating flexion-extension movements at the hip during locomotion appear to be governed by a rather fixed 'neural program' which normally only needs minor modulations to accomplish the adjustments accompanying an increase in speed of progression as well as a change from walking to running.

  1. Progression and variation of fatty infiltration of the thigh muscles in Duchenne muscular dystrophy, a muscle magnetic resonance imaging study.

    Science.gov (United States)

    Li, Wenzhu; Zheng, Yiming; Zhang, Wei; Wang, Zhaoxia; Xiao, Jiangxi; Yuan, Yun

    2015-05-01

    The purpose of this study was to assess the progression and variation of fatty infiltration of the thigh muscles of Duchenne muscular dystrophy patients. Muscle magnetic resonance imaging was used to measure the degree of fatty infiltration of the thigh muscles of 171 boys with Duchenne muscular dystrophy (mean age, 6.09 ± 2.30 years). Fatty infiltration was assigned using a modified Mercuri's scale 0-5 (normal-severe). The gluteus maximus and adductor magnus were affected in patients less than two years old, followed by the biceps femoris. Quadriceps and semimembranosus were first affected at the age of five to six years; the sartorius, gracilis and adductor longus remained apparently unaffected until seven years of age. Fatty infiltration of all the thigh muscles developed rapidly after seven years of age. The standard deviation of the fatty infiltration scores ranged from 2.41 to 4.87 before five years old, and from 6.84 to 11.66 between six and ten years old. This study provides evidence of highly variable degrees of fatty infiltration in children of different ages with Duchenne muscular dystrophy, and indicates that fatty infiltration progresses more quickly after seven years of age. These findings may be beneficial for the selection of therapeutic regimens and the analysis of future clinical trials. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. The Observation of Frog Species at State University of Malang as a Preliminary Effort on Frog Conservation

    Directory of Open Access Journals (Sweden)

    Dian Ratri Wulandari

    2013-04-01

    Full Text Available Frog is an amphibian which is widely spread around the world. Indonesia houses 450 species which represent 11% of frog species in the world. In Java Island alone, there live 42 species of frogs and toads. Frogs can be used as an environment indicator in that the presence of frog in a particular place indicates that the place stays natural and unpolluted. The 1st Campus of State University of Malang, which is located in the heart of Malang District, has been developing rapidly currently. Thus, it requires the construction of new various facilities to support its huge activities. Extensive construction can be destructive even damaging to the habitat of frog, which potentially threats the frog’s life, if it does not take the environmental impact into careful consideration. This study is aimed to identify the species of frog which survives at State University of Malang with, particularly the frog species found in 1995. Species identification was conducted by observing the morphological character. This study found that there were four species with three species remained survived in 1995; those were Duttaphrynus melanostictus, Polypedates leucomystax, and Kaloula baleta; and one new species called Rana chalconota. This study also revealed that there were four species which were extinct; those were Fejervarya cancrivora, Fejervarya limnocharis, Ingerophrynus biporcatus, and Occidoziga lima. This situation shows the decreasing amount of species from 7 to 4 within the last 17 years. This result indicates that there is a serious environmental degradation which causes the losing of frog habitats. Further research is needed to study the ecological condition changing in order to save the frog species.

  3. Organization of lumbosacral motoneuronal cell groups innervating hindlimb, pelvic floor, and axial muscles in the cat.

    Science.gov (United States)

    Vanderhorst, V G; Holstege, G

    1997-05-26

    In a study on descending pathways from the nucleus retroambiguus (NRA) to hindlimb motoneurons (see accompanying paper), it appeared impossible, using data from the literature, to precisely determine which muscles were innervated by the motoneurons receiving the NRA fibers. This lack of data made it necessary to produce a detailed map of the lumbosacral motoneuronal cell groups in the cat. Therefore, 50 different muscles or muscle compartments of hindlimb, pelvic floor and lower back were injected with horseradish peroxidase (HRP) in 135 cases. The respective muscles were divided into ten groups: I, sartorius and iliopsoas; II, quadriceps; III, adductors; IV, hamstrings; V, gluteal and other proximal muscles of the hip; VI, posterior compartment of the distal hindlimb; VII, anterior compartment of the distal hindlimb; VIII, long flexors and intrinsic muscles of the foot; IX, pelvic floor muscles; and X, extensors of the lower back and tail. The L4-S2 segments were cut and incubated, and labeled motoneurons were counted and plotted. A new method was developed that made it possible, despite variations in size and segmental organization between the different cases, to compare the results of different cases. The results show that the spatial interrelationship between the hindlimb and pelvic floor lumbosacral motoneuronal cell groups remains constant. This finding enabled the authors to compose an accurate overall map of the location of lumbosacral motoneuronal cell groups. The general distribution of the motoneuronal cell groups is also discussed in respect to their dorsoventral, mediolateral, and rostrocaudal position within the lumbosacral ventral horn.

  4. Mapping of intramuscular tenderness and muscle fiber orientation of muscles in the beef round.

    Science.gov (United States)

    Senaratne, L S; Calkins, C R; de Mello, A S; Pokharel, S; Hinkle, J B

    2010-09-01

    Intramuscular tenderness variation and muscle fiber orientation of beef M. adductor femoris (AF), M. biceps femoris (BF), M. gracilis (GL), M. pectineus (PT), M. sartorius (SR), M. semimembranosus (SM), M. semitendinosus (SO), M. vastus intermedius (VI), M. vastus medialis (VM), and M. vastus lateralis (VL) were investigated. The USDA Choice boxed beef subprimals were purchased and aged for 14 d from boxed date. The AF, BF, GL, PT, SR, SM, SO, VI, VM, and VL (n = 10 each) were fabricated from subprimals. Crust-frozen AF, BF, SO, SM, and VL were cut into 2.54-cm steaks perpendicular to the long axis and grilled (71 degrees C). The PT, SR, VI, and VM were grilled (71 degrees C) as whole muscles, whereas the GL was grilled after cutting into anterior and posterior regions. Grilled muscles were cut into equal size sections perpendicular to long axis of muscles. Location-specific cores were prepared from each steak/section, and Warner-Bratzler shear force (WBSF) was measured. The muscle fiber orientations of BF, PT, and VI were bipennate, SR and SO were fusiform, and AD, SM, VL, GL, and VM were unipennate. The overall mean WBSF values for BF, SO, AF, SM, PT, SR, GL, VI, VM, and VL were 5.62, 4.86, 4.18, 4.90, 3.76, 4.44, 4.75, 4.78, 4.24, and 6.53 kg, respectively. Based on WBSF values, PT was tender, BF and VL were tough, and VM, VI, SM, GL SR, AF, and SO were intermediate. The first 2 proximal steaks of long head BF were more tender than the rest (P Dry or moist heat oven roasting, as compared with grilling, significantly tenderized SO (P = 0.002) and VL (P beef round.

  5. Strain rate effects on the mechanical properties and fracture mode of skeletal muscle

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, Michael; Tovar, Nick; Yoo, Daniel [Biomaterials and Biomimetics, New York University College of Dentistry (United States); Sobieraj, Micheal [Orthopedic Surgery, Hospital for Joint Diseases (United States); Gupta, Nikhil [Mechanical and Aerospace Engineering, NYU-Poly (United States); Branski, Ryan C. [Dept of Otolaryngology, New York University School of Medicine (United States); Coelho, Paulo G., E-mail: pc92@nyu.edu [Biomaterials and Biomimetics, New York University College of Dentistry (United States)

    2014-06-01

    The present study aimed to characterize the mechanical response of beagle sartorius muscle fibers under strain rates that increase logarithmically (0.1 mm/min, 1 mm/min and 10 mm/min), and provide an analysis of the fracture patterns of these tissues via scanning electron microscopy (SEM). Muscle tissue from dogs' sartorius was excised and test specimens were sectioned with a lancet into sections with nominal length, width, and thickness of 7, 2.5 and 0.6 mm, respectively. Trimming of the tissue was done so that the loading would be parallel to the direction of the muscle fiber. Samples were immediately tested following excision and failures were observed under the SEM. No statistically significant difference was observed in strength between the 0.1 mm/min (2.560 ± 0.37 MPa) and the 1 mm/min (2.702 ± 0.55 MPa) groups. However, the 10 mm/min group (1.545 ± 0.50 MPa) had a statistically significant lower strength than both the 1 mm/min group and the 0.1 mm/min group with p < 0.01 in both cases. At the 0.1 mm/min rate the primary fracture mechanism was that of a shear mode failure of the endomysium with a significant relative motion between fibers. At 1 mm/min this continues to be the predominant failure mode. At the 10 mm/min strain rate there is a significant change in the fracture pattern relative to other strain rates, where little to no evidence of endomysial shear failure nor of significant motion between fibers was detected.

  6. The gastrocoel roof plate in embryos of different frogs.

    Science.gov (United States)

    Sáenz-Ponce, Natalia; Santillana-Ortiz, Juan-Diego; del Pino, Eugenia M

    2012-02-01

    The morphology of the gastrocoel roof plate and the presence of cilia in this structure were examined in embryos of four species of frogs. Embryos of Ceratophrys stolzmanni (Ceratophryidae) and Engystomops randi (Leiuperidae) develop rapidly, provide comparison for the analysis of gastrocoel roof plate development in the slow-developing embryos of Epipedobates machalilla (Dendrobatidae) and Gastrotheca riobambae (Hemiphractidae). Embryos of the analyzed frogs develop from eggs of different sizes, and display different reproductive and developmental strategies. In particular, dorsal convergence and extension and archenteron elongation begin during gastrulation in embryos of rapidly developing frogs, as in Xenopus laevis. In contrast, cells that involute during gastrulation are stored in the large circumblastoporal collar that develops around the closed blastopore in embryos of slow-developing frogs. Dorsal convergence and extension only start after blastopore closure in slow-developing frog embryos. However, in the neurulae, a gastrocoel roof plate develops, despite the accumulation of superficial mesodermal cells in the circumblastoporal collar. Embryos of all four species develop a ciliated gastrocoel roof plate at the beginning of neurulation. Accordingly, fluid-flow across the gastrocoel roof plate is likely the mechanism of left-right asymmetry patterning in these frogs, as in X. laevis and other vertebrates. A ciliated gastrocoel roof plate, with a likely origin as superficial mesoderm, is conserved in frogs belonging to four different families and with different modes of gastrulation.

  7. Frog community responses to recent American bullfrog invasions

    Institute of Scientific and Technical Information of China (English)

    Yiming LI; Zhunwei KE; Yihua WANG; Tim M. BLACKBURN

    2011-01-01

    Native species may decline quickly when confronted with an exotic species to which they are not adapted. The extent of decline may depend on the abundance of an invader and the length of time since it first arrived in the community (residence time), and the interaction between these two variables. We tested these effects using data on the effects of American bullfrog Lithobates catesbeianus invasion on native frog communities in 65 permanent lentic waters on islands in the Zhoushan Archipelago, China. We examined variation in native frog abundance and species richness in relation to features of the American bullfrog invasion, habitat disturbance, characteristics of the water body and fish communities and the presence of red swamp crayfish.Bullfrog invaded sites had lower native frog density and species richness, higher submerged vegetation cover and greater frequency of repairs to the water body than did non-invaded sites. The minimum adequate general linear mixed models showed that both native frog density and species richness were negatively related to post-metamorphosis bullfrog density, and that native frog species richness was also positively related to the vegetation cover. There was no effect on either native frog density or species richness of residence time or its interaction with bullfrog density, or of the abundance of bullfrog tadpoles. The results suggested that post-metamorphosis bullfrogs had impacts on native frog communities in the islands, and that the extents of these impacts are proportional to post-metamorphosis bullfrog density.

  8. Landing on branches in the frog Trachycephalus resinifictrix (Anura: Hylidae).

    Science.gov (United States)

    Bijma, Nienke N; Gorb, Stanislav N; Kleinteich, Thomas

    2016-04-01

    Frogs (Lissamphibia: Anura) are famous for their saltatory or hopping locomotion, which is related to numerous anatomical specialisations that are characteristic for the group. However, while the biomechanics of take-off in frogs have been studied in detail, much less is known on how frogs land after a jump. Besides terrestrial and aquatic species, several lineages of frogs adopted an arboreal lifestyle and especially the biomechanics of landing on challenging, small, and unpredictable substrates, such as leaves or branches, are virtually unknown. Here we studied the landing kinematics of the arboreal frog Trachycephalus resinifictrix (Hylidae) on a wooden stick that was used to mimic a small tree branch. We observed two different landing behaviours: (1) landing on the abdomen and (2) attachment with the toes of either the forelimb or the hindlimb. In the latter case, the frogs performed a cartwheel around the stick, while they were only attached by their adhesive toe pads. We estimated the forces that act on the toes during this behaviour to be up to fourteen times the body weight of the animals. This behaviour demonstrates the remarkable adhesive capabilities of the toe pads and the body control of the frogs.

  9. The wood frog (Rana sylvatica): a technical conservation assessment

    Science.gov (United States)

    Muths, E.; Rittmann, S.; Irwin, J.; Keinath, D.; Scherer, R.

    2005-01-01

    Overall, the wood frog (Rana sylvatica) is ranked G5, secure through most of its range (NatureServe Explorer 2002). However, it is more vulnerable in some states within the USDA Forest Service Region 2: S3 (vulnerable) in Colorado, S2 (imperiled) in Wyoming, and S1 (critically imperiled in South Dakota (NatureServe Explorer 2002); there are no records for wood frogs in Kansas or Nebraska. Primary threats to wood frog populations are habitat fragmentation (loss of area, edge effects, and isolation) and habitat loss due to anthropogenic causes (e.g., wetland draining, grazing) and natural changes as habitat succession occurs. Wood frogs are most conspicuous at breeding sites early in the spring, when snow and ice are often still present at pond margins. They tolerate frezzing and hibernate terrestrially in shallow depressions, under leaf litter, grasses, logs, or rocks (Bagdonas 1968, Bellis 1961a); there are no reports of aquatic hibernation for this species (Licht 1991, Pinder et al. 1992). Wood frogs require semi-permanent and temporary pools of natural origin and adjacent wet meadows, and landscape alterations that shorten the hydroperiod of ponds can result in catastrophic tadpole mortality. Plant communities utilized by wood frogs in the Rocky Mountains are hydric to mesic and include sedge and grass meadows, willow hummocks, aspen groves, lodgepole pine forests, and woodlands with leaf litter and/or herbaceous understory (Maslin 1947, Bellis 1961a, Roberts and Lewin 1979, Haynes and Aird 1981). Wood frogs are likely to disperse into surrounding marsh and woodlands soon after oviposition (Heatwole 1961, Haynes and Aird 1981). In the arly fall, wood frogs begin to seek hibernacula at or just below the ground surface, generally in upland forest habitat (Regosin et al. 2003). Licht (1991) demonstrated shelter-seeking behavior at 1.5 [degrees] C. Once they have concealed themselves for hibernation, wood frogs are very difficult to detecta?|

  10. How frog embryos replicate their DNA reliably

    Science.gov (United States)

    Bechhoefer, John; Marshall, Brandon

    2007-03-01

    Frog embryos contain three billion base pairs of DNA. In early embryos (cycles 2-12), DNA replication is extremely rapid, about 20 min., and the entire cell cycle lasts only 25 min., meaning that mitosis (cell division) takes place in about 5 min. In this stripped-down cell cycle, there are no efficient checkpoints to prevent the cell from dividing before its DNA has finished replication - a disastrous scenario. Even worse, the many origins of replication are laid down stochastically and are also initiated stochastically throughout the replication process. Despite the very tight time constraints and despite the randomness introduced by origin stochasticity, replication is extremely reliable, with cell division failing no more than once in 10,000 tries. We discuss a recent model of DNA replication that is drawn from condensed-matter theories of 1d nucleation and growth. Using our model, we discuss different strategies of replication: should one initiate all origins as early as possible, or is it better to hold back and initiate some later on? Using concepts from extreme-value statistics, we derive the distribution of replication times given a particular scenario for the initiation of origins. We show that the experimentally observed initiation strategy for frog embryos meets the reliability constraint and is close to the one that requires the fewest resources of a cell.

  11. Dystrophin-deficient dogs with reduced myostatin have unequal muscle growth and greater joint contractures.

    Science.gov (United States)

    Kornegay, Joe N; Bogan, Daniel J; Bogan, Janet R; Dow, Jennifer L; Wang, Jiahui; Fan, Zheng; Liu, Naili; Warsing, Leigh C; Grange, Robert W; Ahn, Mihye; Balog-Alvarez, Cynthia J; Cotten, Steven W; Willis, Monte S; Brinkmeyer-Langford, Candice; Zhu, Hongtu; Palandra, Joe; Morris, Carl A; Styner, Martin A; Wagner, Kathryn R

    2016-01-01

    Myostatin (Mstn) is a negative regulator of muscle growth whose inhibition promotes muscle growth and regeneration. Dystrophin-deficient mdx mice in which myostatin is knocked out or inhibited postnatally have a less severe phenotype with greater total mass and strength and less fibrosis and fatty replacement of muscles than mdx mice with wild-type myostatin expression. Dogs with golden retriever muscular dystrophy (GRMD) have previously been noted to have increased muscle mass and reduced fibrosis after systemic postnatal myostatin inhibition. Based partly on these results, myostatin inhibitors are in development for use in human muscular dystrophies. However, persisting concerns regarding the effects of long-term and profound myostatin inhibition will not be easily or imminently answered in clinical trials. To address these concerns, we developed a canine (GRippet) model by crossbreeding dystrophin-deficient GRMD dogs with Mstn-heterozygous (Mstn (+/-)) whippets. A total of four GRippets (dystrophic and Mstn (+/-)), three GRMD (dystrophic and Mstn wild-type) dogs, and three non-dystrophic controls from two litters were evaluated. Myostatin messenger ribonucleic acid (mRNA) and protein levels were downregulated in both GRMD and GRippet dogs. GRippets had more severe postural changes and larger (more restricted) maximal joint flexion angles, apparently due to further exaggeration of disproportionate effects on muscle size. Flexors such as the cranial sartorius were more hypertrophied on magnetic resonance imaging (MRI) in the GRippets, while extensors, including the quadriceps femoris, underwent greater atrophy. Myostatin protein levels negatively correlated with relative cranial sartorius muscle cross-sectional area on MRI, supporting a role in disproportionate muscle size. Activin receptor type IIB (ActRIIB) expression was higher in dystrophic versus control dogs, consistent with physiologic feedback between myostatin and ActRIIB. However, there was no

  12. Biosensor, ELISA, and frog embryo teratogenesis assay: Xenopus (FETAX) analysis of water associated with frog malformations in Minnesota

    Science.gov (United States)

    Garber, Eric A. E.; Erb, Judith L.; Downward, James G.; Priuska, Eric M.; Wittliff, James L.; Feng, Wenke; Magner, Joseph; Larsen, Gerald L.

    2001-03-01

    Between 1995 and 1997 over 62% of the counties in Minnesota reported the presence of malformed frogs. While most sites have recently shown a decline in malformed frog populations, one site in northeastern Minnesota with no prior history of containing malformed frogs was recently discovered to contain > 67% malformed Rana pipiens (northern leopard frogs). As part of an effort to study the presence of hormonally active agents in fresh water sources, water samples were collected from lakes in Minnesota containing malformed frogs and analyzed for the presence of hormonally active compounds using a novel evanescent field fluorometric biosensor and the frog embryo teratogenesis assay: Xenopus (FETAX) bioassay. The waveguide based biosensor developed by ThreeFold Sensors (TFS biosensor, Ann Arbor, MI) detects the presence of estrogenic compounds capable of interacting with free human ER-a and by inhibiting binding to an immobilized estrogen. The FETAX bioassay is a developmental assay, which measures teratogenicity, mortality, and inhibition of growth during the first 96 hours of organogenesis and thereby provides a universal screen for endocrine disruptors. TFS biosensor and FETAX screening of the water samples suggest a relationship between estrogenic activity, mineral supplementation, and the occurrence of malformed frogs.

  13. Muscle Disorders

    Science.gov (United States)

    Your muscles help you move and help your body work. Different types of muscles have different jobs. There are many problems that can affect muscles. Muscle disorders can cause weakness, pain or even ...

  14. Muscle Cramps

    Science.gov (United States)

    Muscle cramps are sudden, involuntary contractions or spasms in one or more of your muscles. They often occur ... minutes. It is a very common muscle problem. Muscle cramps can be caused by nerves that malfunction. Sometimes ...

  15. Frog: The fast and realistic OpenGL event displayer

    Energy Technology Data Exchange (ETDEWEB)

    Quertenmont, Loic, E-mail: loic.quertenmont@cern.c [Center for Particle Physics and Phenomenology CP3, Universite catholique de Louvain, Chemin du cyclotron 2, B-1348-Louvain-la-Neuve (Belgium)

    2010-04-01

    FROG is a generic framework dedicated to visualisation of events in high energy physics experiment. It is suitable to any particular physics experiment or detector design. The code is light (< 3 MB) and fast (browsing time {approx} 20 events per second for a large High Energy Physics experiment) and can run on various operating systems, as its object-oriented structure (C++) relies on the cross-platform OpenGL and Glut libraries. Moreover, Frog does not require installation of heavy third party libraries for the visualisation. This documents describes the features and principles of Frog version 1.106, its working scheme and numerous functionalities such as: 3D and 2D visualisation, graphical user interface, mouse interface, configuration files, production of pictures of various format, integration of personal objects, etc. Finally the application of FROG for physic experiment/environement, such as Gastof, CMS, ILD, Delphes will be presented for illustration.

  16. Frog: The fast & realistic OpenGL event displayer

    Science.gov (United States)

    Quertenmont, Loïc

    2010-04-01

    FROG [1] [2] is a generic framework dedicated to visualisation of events in high energy physics experiment. It is suitable to any particular physics experiment or detector design. The code is light (< 3 MB) and fast (browsing time ~ 20 events per second for a large High Energy Physics experiment) and can run on various operating systems, as its object-oriented structure (C++) relies on the cross-platform OpenGL[3] and Glut [4] libraries. Moreover, Frog does not require installation of heavy third party libraries for the visualisation. This documents describes the features and principles of Frog version 1.106, its working scheme and numerous functionalities such as: 3D and 2D visualisation, graphical user interface, mouse interface, configuration files, production of pictures of various format, integration of personal objects, etc. Finally the application of FROG for physic experiment/environement, such as Gastof, CMS, ILD, Delphes will be presented for illustration.

  17. Dahomey NWR Malformed Frog Survey Data 2003-2004

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Data set contains information concerning surveys for malformed frog collections on Dahomey NWR in MS from 2003-2004. Data were collected as part of the national...

  18. Modeling synchronized calling behavior of Japanese tree frogs

    Science.gov (United States)

    Aihara, Ikkyu

    2009-07-01

    We experimentally observed synchronized calling behavior of male Japanese tree frogs Hyla japonica; namely, while isolated single frogs called nearly periodically, a pair of interacting frogs called synchronously almost in antiphase or inphase. In this study, we propose two types of phase-oscillator models on different degrees of approximations, which can quantitatively explain the phase and frequency properties in the experiment. Moreover, it should be noted that, although the second model is obtained by fitting to the experimental data of the two synchronized states, the model can also explain the transitory dynamics in the interactive calling behavior, namely, the shift from a transient inphase state to a stable antiphase state. We also discuss the biological relevance of the estimated parameter values to calling behavior of Japanese tree frogs and the possible biological meanings of the synchronized calling behavior.

  19. Final Critical Habitat for Oregon Spotted Frog (Rana pretiosa)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify, in general, the areas of FINAL critical habitat for Rana pretiosa (Oregon Spotted Frog). Maps published in the Federal Register 2016.

  20. Final Critical Habitat for Oregon Spotted Frog (Rana pretiosa)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify, in general, the areas of FINAL critical habitat for Rana pretiosa (Oregon Spotted Frog). Maps published in the Federal Register 2016.

  1. California Red-Legged Frogs in coastal dune drainages (2015)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — California Red-legged Frogs (Rana draytonii) are typically regarded as inhabitants of permanent ponds, marshes, and slow-moving streams, but their ecology in other...

  2. FROG: The Fast And Realistic OpenGL Event Displayer

    CERN Document Server

    Quertenmont, Loic

    2009-01-01

    FROG [1] [2] is a generic framework dedicated to visualisation of events in high energy experiment. It is suitable to any particular physics experiment or detector design. The code is light (< 3 MB) and fast (browsing time 20 events per second for a large High Energy Physics experiment) and can run on various operating systems, as its object-oriented structure (C++) relies on the cross-platform OPENGL [3] and GLUT [4] libraries. Moreover, FROG does not require installation of third party libraries for the visualisation. This documents describes the features and principles of FROG version 1.106, its working scheme and numerous functionalities such as: 3D and 2D visualisation, graphical user interface, mouse interface, configuration files, production of pictures of various format, integration of personal objects, etc. Finally the application of FROG for physic experiment/environement, such as Gastof, CMS, ILD, Delphes will be presented for illustration.

  3. Oregon Spotted Frog (Rana pretiosa) Monitoring at Jack Creek 2015

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset contains information from mark-recapture surveys conducted in 2015 by USGS as part of an ongoing Oregon spotted frog (Rana pretiosa) monitoring effort...

  4. Permeabilities of single arterioles and venules in the frog skin: a functional and morphological study.

    Science.gov (United States)

    Olesen, S P; de Saint-Aubain, M L; Bundgaard, M

    1984-07-01

    The permeability of single subcutaneous microvessels in the frog skin was determined with electrophysiological techniques after only minimal surgical intervention. The organization of blood vessels in the frog skin is described at the microscopic level. Transmission electron microscopy showed that the subcutaneous microvessels belong to the class of "continuous" vessels (H. Bennett, J. Luft, and J. Hampton, 1959, Amer. J. Physiol. 196, 381-390). Capillaries in the true sense of the word are rare in this subcutaneous tissue. The electrical resistance of the endothelium in well defined segments of the subcutaneous microvessels was determined by means of current injection and voltage recording microelectrodes using cable theory for the analysis. The average resistances were 70 and 24 omega.cm2 for arterioles and venules, respectively; the mean values of the two groups were significantly different (P less than 0.001). These figures are close to those obtained on microvessels in skeletal muscle (S.-P. Olesen and C. Crone, 1983, Biophys. J. 42, 31-41), but are about one order of magnitude higher than resistances of mesenteric microvessels. The calculated sodium permeabilities were for arterioles: PNa+ = 1.6 x 10(-5) cm sec(-1) and for venules: 4.6 x 10(-5) cm sec(-1).

  5. Exceptional soft tissues preservation in a mummified frog-eating Eocene salamander

    Directory of Open Access Journals (Sweden)

    Jérémy Tissier

    2017-10-01

    Full Text Available Fossils are almost always represented by hard tissues but we present here the exceptional case of a three-dimensionally preserved specimen that was ‘mummified’ (likely between 40 and 34 million years ago in a terrestrial karstic environment. This fossil is the incomplete body of a salamander, Phosphotriton sigei, whose skeleton and external morphology are well preserved, as revealed by phase-contrast synchrotron X-ray microtomography. In addition, internal structures composed of soft tissues preserved in three dimensions are now identified: a lung, the spinal cord, a lumbosacral plexus, the digestive tract, muscles and urogenital organs that may be cloacal glands. These are among the oldest known cases of three-dimensional preservation of these organs in vertebrates and shed light on the ecology of this salamander. Indeed, the digestive tract contains remains of a frog, which represents the only known case of an extinct salamander that fed on a frog, an extremely rare type of predation in extant salamanders. These new data improve our scarce knowledge on soft tissue anatomy of early urodeles and should prove useful for future biologists and palaeontologists working on urodele evolutionary biology. We also suggest that the presence of bat guano and carcasses represented a close source of phosphorus, favouring preservation of soft tissues. Bone microanatomy indicates that P. sigei was likely amphibious or terrestrial, and was probably not neotenic.

  6. Prehibernation Energy Storage in Heilongjiang Brown Frogs (Rana amurensis) from Five Populations in North China

    Institute of Scientific and Technical Information of China (English)

    Wei CHEN; Tianpei GUAN; Lina REN; Dujuan HE; Ying WANG; Xin LU

    2015-01-01

    Energy storage is an important component in the life history of species that directly inlfuences survival and reproduction. The energetic demands of amphibian reproduction can differ between the sexes, with environmental conditions, reproductive pattern or process of the species, and depending upon the timing of breeding, and the reproductive season for a species. Surprisingly, comparative studies of pre-hibernation energy storage for anuran populations from different latitudes are relatively few in Asia, especially in China. Here we investigated the patterns of pre-hibernation energy storage of Heilongjiang brown frogsRana amurensis, based on ifve populations along a ifnely latitudinal gradient in north China (40.7–43.7°N). We found that pre-hibernation energy storage of the frogs did not show a clear latitudinal cline, but differed strongly between the sexes, with males depositing more energy reserves into the muscle and liver, whereas females accumulate more energy in the gonads. The sexual differences in energy storage may result from differential timing of energy allocation for reproduction.

  7. Does lindane (gamma-hexachlorocyclohexane) increase the rapid delayed rectifier outward K+ current (IKr) in frog atrial myocytes?

    OpenAIRE

    Sauviat, Martin-Pierre; Colas, Anthony; Pages, Nicole

    2002-01-01

    BACKGROUND: The effects of lindane, a gamma-isomer of hexachlorocyclohexane, were studied on transmembrane potentials and currents of frog atrial heart muscle using intracellular microelectrodes and the whole cell voltage-clamp technique. RESULTS: Lindane (0.34 microM to 6.8 microM) dose-dependently shortened the action potential duration (APD). Under voltage-clamp conditions, lindane (1.7 microM) increased the amplitude of the outward current (Iout) which developed in Ringer solution contain...

  8. Nondestructive Imaging of Internal Structures of Frog (Xenopus laevis) Embryos by Shadow-Projection X-Ray Microtomography

    Science.gov (United States)

    Aoki, Sadao; Yoneda, Ikuo; Nagai, Takeharu; Ueno, Naoto; Murakami, Kazuo

    1994-04-01

    Nondestructive high-resolution imaging of frog ( Xenopus laevis) embryos has been developed by X-ray microtomography. Shadow-projection X-ray microtomography with a brilliant fine focus laboratory X-ray source could image fine structures of Xenopus embryos which were embedded in paraffin wax. The imaging system enabled us to not only distinguish endoderm from ectoderm at the gastrula stage, but also to obtain a cross-section view of the tail bud embryo showing muscle, notochord and neural tube without staining. Furthermore, the distribution of myosin was also imaged in combination with whole-mount immunohistochemistry.

  9. The need for water quality criteria for frogs.

    OpenAIRE

    Boyer, R; Grue, C. E.

    1995-01-01

    Amphibians are considered reliable indicators of environmental quality. In the western United States, a general decline of frog populations parallels an apparent worldwide decline. The factors thought to be contributing to declines in frog populations include habitat loss, introduction of exotic species, overexploitation, disease, climate change, and decreasing water quality. With respect to water quality, agroecosystems use 80-90% of the water resources in the western United States, frequent...

  10. Association of muscle hardness with muscle tension dynamics: a physiological property.

    Science.gov (United States)

    Murayama, Mitsuyoshi; Watanabe, Kotaro; Kato, Ryoko; Uchiyama, Takanori; Yoneda, Tsugutake

    2012-01-01

    This study aimed to investigate the relationship between muscle hardness and muscle tension in terms of length-tension relationship. A frog gastrocnemius muscle sample was horizontally mounted on the base plate inside a chamber and was stretched from 100 to 150% of the pre-length, in 5% increments. After each step of muscle lengthening, electrical field stimulation for induction of tetanus was applied using platinum-plate electrodes positioned on either side of the muscle submerged in Ringer's solution. The measurement of muscle hardness, i.e., applying perpendicular distortion, was performed whilst maintaining the plateau of passive and tetanic tension. The relationship between normalised tension and normalised muscle hardness was evaluated. The length-hardness diagram could be created from the modification with the length-tension diagram. It is noteworthy that muscle hardness was proportional to passive and total tension. Regression analysis revealed a significant correlation between muscle hardness and passive and total tension, with a significant positive slope (passive tension: r = 0.986, P hardness depends on muscle tension in most ranges of muscle length in the length-tension diagram.

  11. The emergence of Pax7-expressing muscle stem cells during vertebrate head muscle development

    Directory of Open Access Journals (Sweden)

    Julia eMeireles Nogueira

    2015-05-01

    Full Text Available Pax7 expressing muscle stem cells accompany all skeletal muscles in the body and in healthy individuals, efficiently repair muscle after injury. Currently, the in vitro manipulation and culture of these cells is still in its infancy, yet muscle stem cells may be the most promising route towards the therapy of muscle diseases such as muscular dystrophies.It is often overlooked that muscular dystrophies affect head and body skeletal muscle differently. Moreover, these muscles develop differently. Specifically, head muscle and its stem cells develop from the non-somitic head mesoderm which also has cardiac competence. To which extent head muscle stem cells retain properties of the early head mesoderm and might even be able to switch between a skeletal muscle and cardiac fate is not known. This is due to the fact that the timing and mechanisms underlying head muscle stem cell development are still obscure. Consequently, it is not clear at which time point one should compare the properties of head mesodermal cells and head muscle stem cells.To shed light on this, we traced the emergence of head muscle stem cells in the key vertebrate models for myogenesis, chicken, mouse, frog and zebrafish, using Pax7 as key marker. Our study reveals a common theme of head muscle stem cell development that is quite different from the trunk. Unlike trunk muscle stem cells, head muscle stem cells do not have a previous history of Pax7 expression, instead Pax7 expression emerges de-novo. The cells develop late, and well after the head mesoderm has committed to myogenesis. We propose that this unique mechanism of muscle stem cell development is a legacy of the evolutionary history of the chordate head mesoderm.

  12. Frogs Communicate by Means of Ultrasonic Sounds

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ People are always fascinated by ways that some members of mammalian species (such as dolphins, bats and some rodents) communicate using sounds that we cannot hear. But think twice if you say the capacity of producing and detecting ultrasounds (frequencies greater than 20kHz) is limited to mammalians. A study implemented by Prof. SHEN Junxian from the CAS Institute of Biophysics (IBP) and colleagues in CAS and abroad showed that a rare frog species in China should also be added to that list. It is the first documented case of a non-mammalian species being able to use ultrasonic communication. Their work was reported in the March 16 issue of the journal Nature.

  13. Cutaneous acariasis in the African clawed frog (Xenopus laevis).

    Science.gov (United States)

    Ford, Timothy R; Dillehay, Dirck L; Mook, Deborah M

    2004-12-01

    Increased mortality was observed in a single colony of 50 Xenopus laevis. The frogs were used as oocyte donors in developmental biology studies. Necropsy findings included dermal erythema and petechiation consistent with red leg syndrome; dermal ulcerations and white, filamentous growths on the skin were consistent with Saprolegnia sp. Microscopic evaluation of the skin and fungus revealed an astigmatid mite similar to those of the genus Rhizoglyphus. The mite was also found in the water and the biological filter of the tanks housing the frogs. This mite is considered not to be a parasite of X. laevis; instead, it feeds off moss, fungi, and detritus. Subsequent evaluation of the sphagnum moss used for shipping the frogs from the supplier revealed the same mite in the moss. Our hypothesis is that the mite was introduced into the tank with the shipment of new frogs in sphagnum moss. The mites lived within the biological filter, and were only found after the growth of Saprolegnia sp. attracted the mites to the frogs. Laboratory animal care and veterinary personnel should consider non-pathogenic species of mites in the differential diagnosis of acariasis in Xenopus frogs.

  14. Is chytridiomycosis driving Darwin's frogs to extinction?

    Directory of Open Access Journals (Sweden)

    Claudio Soto-Azat

    Full Text Available Darwin's frogs (Rhinoderma darwinii and R. rufum are two species of mouth brooding frogs from Chile and Argentina that have experienced marked population declines. Rhinoderma rufum has not been found in the wild since 1980. We investigated historical and current evidence of Batrachochytrium dendrobatidis (Bd infection in Rhinoderma spp. to determine whether chytridiomycosis is implicated in the population declines of these species. Archived and live specimens of Rhinoderma spp., sympatric amphibians and amphibians at sites where Rhinoderma sp. had recently gone extinct were examined for Bd infection using quantitative real-time PCR. Six (0.9% of 662 archived anurans tested positive for Bd (4/289 R. darwinii; 1/266 R. rufum and 1/107 other anurans, all of which had been collected between 1970 and 1978. An overall Bd-infection prevalence of 12.5% was obtained from 797 swabs taken from 369 extant individuals of R. darwinii and 428 individuals representing 18 other species of anurans found at sites with current and recent presence of the two Rhinoderma species. In extant R. darwinii, Bd-infection prevalence (1.9% was significantly lower than that found in other anurans (7.3%. The prevalence of infection (30% in other amphibian species was significantly higher in sites where either Rhinoderma spp. had become extinct or was experiencing severe population declines than in sites where there had been no apparent decline (3.0%; x(2 = 106.407, P<0.001. This is the first report of widespread Bd presence in Chile and our results are consistent with Rhinoderma spp. declines being due to Bd infection, although additional field and laboratory investigations are required to investigate this further.

  15. Frog Foam Nest Protein Diversity and Synthesis.

    Science.gov (United States)

    Hissa, Denise Cavalcante; Bezerra, Walderly Melgaço; Freitas, Cléverson Diniz Teixeira De; Ramos, Márcio Viana; Lopes, José Luiz De Souza; Beltramini, Leila Maria; Roberto, Igor Joventino; Cascon, Paulo; Melo, Vânia Maria Maciel

    2016-08-01

    Some amphibian species have developed a breeding strategy in which they deposit their eggs in stable foam nests to protect their eggs and larvae. The frog foam nests are rich in proteins (ranaspumin), especially surfactant proteins, involved in the production of the foam nest. Despite the ecological importance of the foam nests for evolution and species conservation, the biochemical composition, the long-term stability and even the origin of the components are still not completely understood. Recently we showed that Lv-RSN-1, a 23.5-kDa surfactant protein isolated from the nest of the frog Leptodacylus vastus, presents a structural conformation distinct from any protein structures yet reported. So, in the current study we aimed to reveal the protein composition of the foam nest of L. vastus and further characterize the Lv-RSN-1. Proteomic analysis showed the foam nest contains more than 100 of proteins, and that Lv-RSN-1 comprises 45% of the total proteins, suggesting a key role in the nest construction and stability. We demonstrated by Western blotting that Lv-RSN-1 is mainly produced only by the female in the pars convoluta dilata, which highlights the importance of the female preservation for conservation of species that depend on the production of foam nests in the early stages of development. Overall, our results showed the foam nest of L. vastus is composed of a great diversity of proteins and that besides Lv-RSN-1, the main protein in the foam, other proteins must have a coadjuvant role in building and stability of the nest.

  16. Frogs on the beach: Ecology of California Red-legged Frogs (Rana draytonii) in coastal dune drainages

    Science.gov (United States)

    Halstead, Brian J.; Kleeman, Patrick M.

    2017-01-01

    California Red-legged Frogs (Rana draytonii) are typically regarded as inhabitants of permanent ponds, marshes, and slow-moving streams, but their ecology in other habitats, such as drainages among coastal dunes, remains obscure. Because coastal dune ecosystems have been degraded by development, off-highway vehicle use, stabilization, and invasive species, these unique ecosystems are the focus of restoration efforts. To better understand the ecology of California Red-legged Frogs in coastal dune ecosystems and to avoid and minimize potential negative effects of dune restoration activities on these rare frogs, we studied their spatial ecology, habitat selection, and survival in coastal dune drainages at Point Reyes National Seashore, California, USA. All 22 radio-marked frogs remained in their home drainages throughout the spring and summer of 2015 and, with some notable exceptions, most remained close to water. Local convex hull home ranges of four out of five California Red-legged Frogs with > 20 observations in dunes were < 1,600 m2 . At the population level, frogs were 1.7 (95% credible interval, 1.2‒4.4) times more likely to select sites 1 m closer to water, and were 83 (2.0‒17,000) times more likely to select sites with 10% greater percentage cover of logs that served as refuges from environmental extremes and predators. On average, California Red-legged Frogs avoided the invasive plants Iceplant (Carpobrotus edulis) and European Beachgrass (Ammophila arenaria). Frogs were 0.68 (0.32‒0.89) and 0.55 (0.24‒0.75) times as likely to select areas that had 10% greater cover of these plants, respectively. Assuming constant risk of mortality, California Redlegged Frogs had an annual survival rate of 0.70 (0.27‒0.96) in coastal dune drainages. Our results indicate that coastal dune drainages provide a locally important habitat for California Red-legged Frogs. Restoration practices that maintain wetted drainages with logjams are likely to benefit California

  17. Potassium Chloride Versus Voltage Clamp Contractures in Ventricular Muscle

    Science.gov (United States)

    Morad, M.; Reeck, S.; Rao, M.

    1981-01-01

    In frog ventricle, developed tension was markedly larger in response to depolarization caused by a voltage clamp step than to depolarization induced by high concentrations of potassium chloride. Measurement of extracellular potassium activity at the surface and at the depth of muscle during the development of contractures showed that the diffusion of potassium is much slower than the spread of depolarization through the cross section of muscle. These two observations suggest that competition between the depolarizing and the negative inotropic effects of an increase in the extracellular potassium ion concentration may determine the time course and magnitude of contractile tension in heart muscle.

  18. Experiment for Development of Simple Escape Countermeasures for Frogs Falling into Concrete Canals

    Science.gov (United States)

    Watabe, Keiji; Mori, Atsushi; Koizumi, Noriyuki; Takemura, Takeshi; Park, Myeong Soo

    Three prototype escape countermeasures for frogs that can be easily installed in U-shaped canals with widths of 30-50 cm and depths of 30-50 cm were experimentally produced because frogs cannot escape from agricultural canals with deep concrete walls after falling into the canal. The differences of effectiveness of the 3 prototypes in places for the countermeasures (1 and 2) and flow conditions (dry and water running) were investigated for 2 frog species (Tokyo Daruma Pond Frog and Japanese Brown Frog). The brown frogs escaped from the canals more easily than the pond frogs. The brown frogs escaped regardless of their body size, but the small pond frogs escaped more easily than the large pond frogs. The prototype with slopes beside both canal walls and a net spread across the center line of the canal enabled frogs to escape from the canal more easily than the prototypes with only slopes or nets beside both canal walls. Increasing the number of places for the countermeasures enhanced frog escape. The differences in frog escape between dry canals and canals with water running were not significant. Therefore, the prototypes were confirmed sufficient as escape countermeasures that is inexpensive and can be easily placed in and removed from agricultural canals.

  19. Correlation between quantal secretion and vesicle loss at the frog neuromuscular junction.

    Science.gov (United States)

    Hurlbut, W P; Iezzi, N; Fesce, R; Ceccarelli, B

    1990-01-01

    1. We measured the rate of occurrence of miniature endplate potentials (MEPPs) at identified endplates in frog cutaneous pectoris muscles treated with crude black widow spider venom (BWSV) or purified alpha-latrotoxin (alpha-LTX) in calcium-free solutions, and we examined the relationship between the length of the nerve terminal and the total number of quanta secreted, and the relationship between the number of quanta secreted and the number of vesicles remaining at different times. 2. The venom, or toxin, was applied in a modified Ringer solution with tetrodotoxin, 1 mM-EGTA and no divalent cations, and quantal secretion was started by applying Ca2(+)-free solutions with Mg2+. This was done to synchronize the quantal discharge at the various junctions in a muscle. Ringer solution was applied after the MEPP rate had declined to low levels, and then the muscle fibre was injected with Lucifer Yellow, the endplate stained for acetylcholinesterase and the length of the nerve terminal and the length of a sarcomere were measured on the fluorescent fibre. 3. The total number of quanta secreted by a terminal was measured under a wide variety of experimental conditions: the weights of the frogs ranged from 13 to 68 g, the temperature from 9 to 28 degrees C, and the concentration of Mg2+ from 2 to 10 mM. In one series of experiments the Mg2+ was withdrawn after 3-4 min and reapplied 35-40 min later in order to divide the total output of quanta into two approximately equal bouts of secretion that were well separated in time. 4. The total number of MEPPs recorded at a junction was loosely correlated with the length of its nerve terminal, but it was not affected by the temperature, the concentration of Mg2+ or the division of secretion into well-separated bouts of quantal release. The average total secretion per unit length was about 3700 quanta/sarcomere or about 1200 quanta/microns. 5. The average time course of quantal secretion per micrometre of terminal was determined at

  20. Resurrecting an Extinct Species: Archival DNA, Taxonomy, and Conservation of the Vegas Valley Leopard Frog

    Science.gov (United States)

    Suggestions that the extinct Vegas Valley leopard frog (Rana fisheri = Lithobates fisheri) may have been synonymous with one of several declining species has complicated recovery planning for imperiled leopard frogs in southwestern North America. To address this concern, we recon...

  1. Prostaglandin E2 release from dermis regulates sodium permeability of frog skin epithelium

    DEFF Research Database (Denmark)

    Rytved, Klaus A.; Brodin, Birger; Nielsen, Robert

    1995-01-01

    Arachidonic acid, cAMP, epithelium, frog skin, intracellular calcium, prostaglandin E*U2, sodium transport, tight epithelium.......Arachidonic acid, cAMP, epithelium, frog skin, intracellular calcium, prostaglandin E*U2, sodium transport, tight epithelium....

  2. Skeletal muscle

    Science.gov (United States)

    There are approximately 650-850 muscles in the human body these include skeletal (striated), smooth and cardiac muscle. The approximation is based on what some anatomists consider separate muscle or muscle systems. Muscles are classified based on their anatomy (striated vs. smooth) and if they are v...

  3. Cystic urolithiasis in captive waxy monkey frogs (Phyllomedusa sauvagii).

    Science.gov (United States)

    Archibald, Kate E; Minter, Larry J; Dombrowski, Daniel S; O'Brien, Jodi L; Lewbart, Gregory A

    2015-03-01

    The waxy monkey frog (Phyllomedusa sauvagii) is an arboreal amphibian native to arid regions of South America, and it has developed behavioral and physiologic adaptations to permit survival in dry environments. These adaptations include a uricotelic nitrogen metabolism and unique cutaneous lipid excretions to prevent evaporative water loss. Uroliths are a rare finding in amphibians. Six adult, presumed wild-caught waxy monkey frogs housed in a museum animal collection were diagnosed with cystic urolithiasis over a 7-yr period, and a single animal was diagnosed with four recurrent cases. Six cases were identified incidentally at routine physical or postmortem examination and four cases were identified during veterinary evaluation for coelomic distension, lethargy, anorexia, and increased soaking behavior. Calculi were surgically removed from three frogs via cystotomy, and a single frog underwent three cystotomies and two cloacotomies for recurrent urolithiasis. Two frogs died within the 24-hr postoperative period. Two representative calculi from a single frog were submitted for component analysis and found to consist of 100% ammonium urate. In the present report, cystic calculi are proposed to be the result of a high-protein diet based on a single invertebrate source, coupled with uricotelism, dehydration, increased cutaneous water loss, body temperature fluctuations facilitating supersaturation of urine, and subsequent accumulation and precipitation of urogenous wastes within the urinary bladder. Surgical cystotomy represents a short-term treatment strategy for this condition. Preventative measures, such as supplying a diversified and balanced diet in addition to environmental manipulation aimed at promoting adequate hydration, are anticipated to be more-rewarding management tools for cystic urolithiasis in the waxy monkey frog.

  4. Panamanian frog species host unique skin bacterial communities

    Directory of Open Access Journals (Sweden)

    Lisa K. Belden

    2015-10-01

    Full Text Available Vertebrates, including amphibians, host diverse symbiotic microbes that contribute to host disease resistance. Globally, and especially in montane tropical systems, many amphibian species are threatened by a chytrid fungus, Batrachochytrium dendrobatidis (Bd, that causes a lethal skin disease. Bd therefore may be a strong selective agent on the diversity and function of the microbial communities inhabiting amphibian skin. In Panamá, amphibian population declines and the spread of Bd have been tracked. In 2012, we completed a field survey in Panamá to examine frog skin microbiota in the context of Bd infection. We focused on three frog species and collected two skin swabs per frog from a total of 136 frogs across four sites that varied from west to east in the time since Bd arrival. One swab was used to assess bacterial community structure using 16S rRNA amplicon sequencing and to determine Bd infection status, and one was used to assess metabolite diversity, as the bacterial production of anti-fungal metabolites is an important disease resistance function. The skin microbiota of the three Panamanian frog species differed in OTU (operational taxonomic unit, ~bacterial species community composition and metabolite profiles, although the pattern was less strong for the metabolites. Comparisons between frog skin bacterial communities from Panamá and the US suggest broad similarities at the phylum level, but key differences at lower taxonomic levels. In our field survey in Panamá, across all four sites, only 35 individuals (~26% were Bd infected. There was no clustering of OTUs or metabolite profiles based on Bd infection status and no clear pattern of west-east changes in OTUs or metabolite profiles across the four sites. Overall, our field survey data suggest that different bacterial communities might be producing broadly similar sets of metabolites across frog hosts and sites. Community structure and function may not be as tightly coupled in

  5. Frog community responses to recent American bullfrog invasions

    Directory of Open Access Journals (Sweden)

    Yiming LI, Zhunwei KE, Yihua WANG, Tim M. BLACKBURN

    2011-02-01

    Full Text Available Native species may decline quickly when confronted with an exotic species to which they are not adapted. The extent of decline may depend on the abundance of an invader and the length of time since it first arrived in the community (residence time, and the interaction between these two variables. We tested these effects using data on the effects of American bullfrog Lithobates catesbeianus invasion on native frog communities in 65 permanent lentic waters on islands in the Zhoushan Archipelago, China. We examined variation in native frog abundance and species richness in relation to features of the American bullfrog invasion, habitat disturbance, characteristics of the water body and fish communities and the presence of red swamp crayfish. Bullfrog invaded sites had lower native frog density and species richness, higher submerged vegetation cover and greater frequency of repairs to the water body than did non-invaded sites. The minimum adequate general linear mixed models showed that both native frog density and species richness were negatively related to post-metamorphosis bullfrog density, and that native frog species richness was also positively related to the vegetation cover. There was no effect on either native frog density or species richness of residence time or its interaction with bullfrog density, or of the abundance of bullfrog tadpoles. The results suggested that post-metamorphosis bullfrogs had impacts on native frog communities in the islands, and that the extents of these impacts are proportional to post-metamorphosis bullfrog density [Current Zoology 57 (1: 83–92, 2011].

  6. Phylogeny and biogeography of South Chinese brown frogs (Ranidae, Anura).

    Science.gov (United States)

    Zhou, Yu; Wang, Sirui; Zhu, Hedan; Li, Pipeng; Yang, Baotian; Ma, Jianzhang

    2017-01-01

    Few studies have explored the role of Cenozoic tectonic evolution in shaping the patterns and processes of extant animal distributions in and around East Asia. In this study, we selected South Chinese brown frogs as a model to examine the phylogenetic and biogeographical consequences of Miocene tectonic events within South China and its margins. We used mitochondrial and nuclear molecular data to reconstruct phylogenetic interrelationships among Chinese brown frogs using Bayesian and maximum likelihood analyses. The phylogeny results show that there are four main clades of Chinese brown frogs. Excepting the three commonly known Chinese brown frog species groups, R. maoershanensis forms an independent clade nearest to the R. japonica group. Phylogeny and P-distance analyses confirmed R. maoershanensis as a valid species. Among South Chinese brown frogs, there are four subclades associated with four geographical areas: (I) R. maoershanensis; (II) R. japonica; (III) R. chaochiaoensis; and (IV) other species of the R. longicrus species group. Divergence times, estimated using mitochondrial sequences, place the vicariance events among the four subclades in the middle to late Miocene epoch. Our results suggest that (1) South Chinese brown frogs originated due to a vicariance event separating them from the R. chensinensis species group at the time of the Geological movement (~18 million years ago, Ma) in southern Tibet and the Himalayan region; (2) the separation and speciation of R. maoershanensis from the R. japonica group occurred due to the dry climate at approximately 16 Ma; (3) South Chinese brown frogs migrated from South China to Japan at the time (~10.8 Ma) that the global sea-level fell and the East China Sea Shelf Basin was swamp facies, when a land gallery may have formed across the sea to connect the two areas; and (4) R. chaochiaoensis separated from other species of the R. longicrus species group during the uplift of the Tibetan Plateau at approximately 9

  7. Complete mitochondrial genome of the Greek marsh frog Pelophylax cretensis (Anura, Ranidae).

    Science.gov (United States)

    Hofman, Sebastian; Pabijan, Maciej; Osikowski, Artur; Szymura, Jacek M

    2016-05-01

    We sequenced the complete mitochondrial genome of the Greek marsh frog Pelophylax cretensis, a water frog species endemic to the island of Crete. The genome sequence was 17,829 bp in size, and the gene order and contents were identical to those of previously reported mitochondrial genomes of other water frog species. This is the first complete mitogenome (i.e. including control region) described for western Palaearctic water frogs.

  8. Muscle Deoxygenation Causes Muscle Fatigue

    Science.gov (United States)

    Murthy, G.; Hargens, A. R.; Lehman, S.; Rempel, D.

    1999-01-01

    Muscle fatigue is a common musculoskeletal disorder in the work place, and may be a harbinger for more disabling cumulative trauma disorders. Although the cause of fatigue is multifactorial, reduced blood flow and muscle oxygenation may be the primary factor in causing muscle fatigue during low intensity muscle exertion. Muscle fatigue is defined as a reduction in muscle force production, and also occurs among astronauts who are subjected to postural constraints while performing lengthy, repetitive tasks. The objectives of this research are to: 1) develop an objective tool to study the role of decreased muscle oxygenation on muscle force production, and 2) to evaluate muscle fatigue during prolonged glovebox work.

  9. 75 FR 8733 - Least Chub and Columbia Spotted Frog Candidate Conservation Agreement With Assurances; Receipt of...

    Science.gov (United States)

    2010-02-25

    ... Fish and Wildlife Service Least Chub and Columbia Spotted Frog Candidate Conservation Agreement With... (CCAA) for the least chub (Iotichthys phlegethontis) and Columbia spotted frog (Rana lutreiventris..., least chub and Columbia spotted frog inhabited a variety of aquatic habitat types throughout...

  10. 49 CFR 236.327 - Switch, movable-point frog or split-point derail.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Switch, movable-point frog or split-point derail..., AND APPLIANCES Interlocking Rules and Instructions § 236.327 Switch, movable-point frog or split-point derail. Switch, movable-point frog, or split-point derail equipped with lock rod shall be maintained...

  11. 49 CFR 213.143 - Frog guard rails and guard faces; gage.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Frog guard rails and guard faces; gage. 213.143... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.143 Frog guard rails and guard faces; gage. The guard check and guard face gages in frogs shall be within the...

  12. Muscle disorder

    Science.gov (United States)

    Myopathic changes; Myopathy; Muscle problem ... Blood tests sometimes show abnormally high muscle enzymes. If a muscle disorder might also affect other family members, genetic testing may be done. When someone has symptoms and signs ...

  13. Sophisticated Communication in the Brazilian Torrent Frog Hylodes japi.

    Science.gov (United States)

    de Sá, Fábio P; Zina, Juliana; Haddad, Célio F B

    2016-01-01

    Intraspecific communication in frogs plays an important role in the recognition of conspecifics in general and of potential rivals or mates in particular and therefore with relevant consequences for pre-zygotic reproductive isolation. We investigate intraspecific communication in Hylodes japi, an endemic Brazilian torrent frog with territorial males and an elaborate courtship behavior. We describe its repertoire of acoustic signals as well as one of the most complex repertoires of visual displays known in anurans, including five new visual displays. Previously unknown in frogs, we also describe a bimodal inter-sexual communication system where the female stimulates the male to emit a courtship call. As another novelty for frogs, we show that in addition to choosing which limb to signal with, males choose which of their two vocal sacs will be used for visual signaling. We explain how and why this is accomplished. Control of inflation also provides additional evidence that vocal sac movement and color must be important for visual communication, even while producing sound. Through the current knowledge on visual signaling in Neotropical torrent frogs (i.e. hylodids), we discuss and highlight the behavioral diversity in the family Hylodidae. Our findings indicate that communication in species of Hylodes is undoubtedly more sophisticated than we expected and that visual communication in anurans is more widespread than previously thought. This is especially true in tropical regions, most likely due to the higher number of species and phylogenetic groups and/or to ecological factors, such as higher microhabitat diversity.

  14. Tourism and the Conservation of Critically Endangered Frogs

    Science.gov (United States)

    Morrison, Clare; Simpkins, Clay; Castley, J. Guy; Buckley, Ralf C.

    2012-01-01

    Protected areas are critical for the conservation of many threatened species. Despite this, many protected areas are acutely underfunded, which reduces their effectiveness significantly. Tourism is one mechanism to promote and fund conservation in protected areas, but there are few studies analyzing its tangible conservation outcomes for threatened species. This study uses the 415 IUCN critically endangered frog species to evaluate the contribution of protected area tourism revenue to conservation. Contributions were calculated for each species as the proportion of geographic range inside protected areas multiplied by the proportion of protected area revenues derived from tourism. Geographic ranges were determined from IUCN Extent of Occurrence maps. Almost 60% (239) of critically endangered frog species occur in protected areas. Higher proportions of total range are protected in Nearctic, Australasian and Afrotopical regions. Tourism contributions to protected area budgets ranged from 5–100%. These financial contributions are highest for developing countries in the Afrotropical, Indomalayan and Neotropical regions. Data for both geographic range and budget are available for 201 critically endangered frog species with proportional contributions from tourism to species protection ranging from 0.8–99%. Tourism's financial contributions to critically endangered frog species protection are highest in the Afrotropical region. This study uses a coarse measure but at the global scale it demonstrates that tourism has significant potential to contribute to global frog conservation efforts. PMID:22984440

  15. Efficacy of frog skin lipids in wound healing

    Directory of Open Access Journals (Sweden)

    Rajaram Rama

    2010-07-01

    Full Text Available Abstract Background Frog skin has been sequentially and scientifically evaluated by our group for its wound healing efficiency. Owing to the complex structure of skin, attempts were being made to analyse the role of individual constituents in different phases of healing. Our earlier papers have shown the significance of frog skin not only in wound healing but also enhancing the proliferating activity of the epidermal and dermal cells which are instrumental for normal healing process. We also have identified for the first time novel antimicrobial peptides from the skin of Rana tigerina and thereby reduce the complications involved in the sepsis. Purpose of the study and Results The current study envisages the role of frog skin lipids in the inflammatory phase of wound healing. The lipid moiety of the frog skin dominated by phospholipids exhibited a dose dependent acceleration of healing irrespective of the mode of application. The efficiency of the extract is attributed partially to the anti-inflammatory activity as observed by the histochemical and immunostimulatory together with plethysmographic studies. Conclusions Thus, frog skin for the first time has been demonstrated to possess lipid components with pharmaceutical and therapeutic potential. The identification and characterization of such natural healing molecules and evaluating their mechanism of action would therefore provide basis for understanding the cues of Nature and hence can be used for application in medicine.

  16. Drainage ditches facilitate frog movements in a hostile landscape

    Science.gov (United States)

    Mazerolle, M.J.

    2005-01-01

    Ditches are common in landscapes influenced by agricultural, forestry, and peat mining activities, and their value as corridors remains unassessed. Pond-breeding amphibians can encounter hostile environments when moving between breeding, summering, or hibernation sites, and are likely to benefit from the presence of ditches in the landscape. Within a system consisting of ditch networks in bogs mined for peat in eastern New Brunswick, Canada, I quantified the breeding, survival, and movements of green frogs (Rana clamitans melanota) in drainage ditches and also surveyed peat fields. Frogs rarely ventured on peat fields and most individuals frequented drainage ditches containing water, particularly in late summer. Though frogs did not breed in ditches, their survival rate in ditches was high (88%). Ditches did not hinder frog movements, as frogs moved independently of the current. Results indicate that drainage ditches containing water enable some movements between habitats isolated by peat mining, in contrast to peat surfaces, and suggest they function as amphibian movement corridors. Thus, such drainage ditches may mitigate the effects of peat extraction on amphibian populations. At the very least, these structures provide an alternative to hostile peat surfaces. This study highlights that small-scale corridors are potentially valuable in population dynamics. ?? Springer 2005.

  17. Frog sound identification using extended k-nearest neighbor classifier

    Science.gov (United States)

    Mukahar, Nordiana; Affendi Rosdi, Bakhtiar; Athiar Ramli, Dzati; Jaafar, Haryati

    2017-09-01

    Frog sound identification based on the vocalization becomes important for biological research and environmental monitoring. As a result, different types of feature extractions and classifiers have been employed to evaluate the accuracy of frog sound identification. This paper presents a frog sound identification with Extended k-Nearest Neighbor (EKNN) classifier. The EKNN classifier integrates the nearest neighbors and mutual sharing of neighborhood concepts, with the aims of improving the classification performance. It makes a prediction based on who are the nearest neighbors of the testing sample and who consider the testing sample as their nearest neighbors. In order to evaluate the classification performance in frog sound identification, the EKNN classifier is compared with competing classifier, k -Nearest Neighbor (KNN), Fuzzy k -Nearest Neighbor (FKNN) k - General Nearest Neighbor (KGNN)and Mutual k -Nearest Neighbor (MKNN) on the recorded sounds of 15 frog species obtained in Malaysia forest. The recorded sounds have been segmented using Short Time Energy and Short Time Average Zero Crossing Rate (STE+STAZCR), sinusoidal modeling (SM), manual and the combination of Energy (E) and Zero Crossing Rate (ZCR) (E+ZCR) while the features are extracted by Mel Frequency Cepstrum Coefficient (MFCC). The experimental results have shown that the EKNCN classifier exhibits the best performance in terms of accuracy compared to the competing classifiers, KNN, FKNN, GKNN and MKNN for all cases.

  18. Occurrence and Distribution of Cave Dwelling Frogs of Peninsular India

    Directory of Open Access Journals (Sweden)

    Jayant Biswas

    2014-10-01

    Full Text Available The life in subterranean caves always needs a high degree of biological adaptability, due to its unusual ecosystem. The cave dwelling species usually get selected from preadapted biological traits for cave life. The cave dwelling tendencies in frog are very uncommon. Majority of reported cave frogs usually prefer cave for temporary shelter. In India, the biospeleological inventory is still in its primary stage. Till date no serious attempt has been taken to understand the cave dwelling habitat for any frog in India. Inspite of it, in India time to time various reports on natural histories of anurans reveal its cave dwelling tendencies. On the basis of personal observations and available literature in this report I have documented the occurrences and distributions of five cave dwelling frogs of India. Common biological traits from all the established cave frogs, which could be referred as preadapted for cave life, have been discussed. Further, the possible threats and IUCN status of each discussed species has been highlighted.

  19. Isoflurane anesthesia in the African clawed frog (Xenopus laevis).

    Science.gov (United States)

    Smith, J M; Stump, K C

    2000-11-01

    Isoflurane is one of the safest and most accepted anesthetic agents for reptiles, birds, and mammals. It has also been used in terrestrial amphibians. The use of inhalation agents in an entirely aquatic frog presents a new dilemma for delivery in contrast to terrestrial species. The African Clawed Frog respires by using both transcutaneous gas exchange and air breathing. These frogs remain submerged for long periods of time, thus making standard inhalation techniques impractical. We tested five methods for delivering isoflurane: 1) bubbling isoflurane and oxygen in the water, 2) intracoelomic injection, 3) subcutaneous injection, 4) intramuscular injection, and 5) topical application. For the topical application, we developed a simple technique by using an absorptive pad with a vapor-barrier backing, saturating the pad with the liquid isoflurane, and placing the pad on the back of the frog while it was confined in a plastic bowl. Although two of the three injectable routes induced anesthesia, only the topical route produced rapid induction with consistent, safe recovery. Bubbling isoflurane with oxygen into water was unsuccessful. Topical application of isoflurane was most successful and appears to be a safe and practical method that can be used as an alternative to tricaine methylsulphonate, hypothermia, or other methods for anesthetizing African Clawed Frogs.

  20. Biological Jumping Mechanism Analysis and Modeling for Frog Robot

    Institute of Scientific and Technical Information of China (English)

    Meng Wang; Xi-zhe Zang; Ji-zhuang Fan; Jie Zhao

    2008-01-01

    This paper presents a mechanical model of jumping robot based on the biological mechanism analysis of frog. By biological observation and kinematic analysis the frog jump is divided into take-off phase, aerial phase and landing phase. We find the similar trajectories of hindlimb joints during jump, the important effect of foot during take-off and the role of forelimb in supporting the body. Based on the observation, the frog jump is simplified and a mechanical model is put forward. The robot leg is represented by a 4-bar spring/linkage mechanism model, which has three Degrees of Freedom (DOF) at hip joint and one DOF (passive) at tarsometatarsal joint on the foot. The shoulder and elbow joints each has one DOF for the balancing function of arm.The ground reaction force of the model is analyzed and compared with that of frog during take-off. The results show that the model has the same advantages of low likelihood of premature lift-off and high efficiency as the frog. Analysis results and the model can be employed to develop and control a robot capable of mimicking the jumping behavior of flog.

  1. Sophisticated Communication in the Brazilian Torrent Frog Hylodes japi

    Science.gov (United States)

    de Sá, Fábio P.; Zina, Juliana; Haddad, Célio F. B.

    2016-01-01

    Intraspecific communication in frogs plays an important role in the recognition of conspecifics in general and of potential rivals or mates in particular and therefore with relevant consequences for pre-zygotic reproductive isolation. We investigate intraspecific communication in Hylodes japi, an endemic Brazilian torrent frog with territorial males and an elaborate courtship behavior. We describe its repertoire of acoustic signals as well as one of the most complex repertoires of visual displays known in anurans, including five new visual displays. Previously unknown in frogs, we also describe a bimodal inter-sexual communication system where the female stimulates the male to emit a courtship call. As another novelty for frogs, we show that in addition to choosing which limb to signal with, males choose which of their two vocal sacs will be used for visual signaling. We explain how and why this is accomplished. Control of inflation also provides additional evidence that vocal sac movement and color must be important for visual communication, even while producing sound. Through the current knowledge on visual signaling in Neotropical torrent frogs (i.e. hylodids), we discuss and highlight the behavioral diversity in the family Hylodidae. Our findings indicate that communication in species of Hylodes is undoubtedly more sophisticated than we expected and that visual communication in anurans is more widespread than previously thought. This is especially true in tropical regions, most likely due to the higher number of species and phylogenetic groups and/or to ecological factors, such as higher microhabitat diversity. PMID:26760304

  2. A perchlorate sensitive iodide transporter in frogs.

    Science.gov (United States)

    Carr, Deborah L; Carr, James A; Willis, Ray E; Pressley, Thomas A

    2008-03-01

    Nucleotide sequence comparisons have identified a gene product in the genome database of African clawed frogs (Xenopus laevis) as a probable member of the solute carrier family of membrane transporters. To confirm its identity as a putative iodide transporter, we examined the function of this sequence after heterologous expression in mammalian cells. A green monkey kidney cell line transfected with the Xenopus nucleotide sequence had significantly greater (125)I uptake than sham-transfected control cells. The uptake in carrier-transfected cells was significantly inhibited in the presence of perchlorate, a competitive inhibitor of mammalian Na(+)/iodide symporter. Tissue distributions of the sequence were also consistent with a role in iodide uptake. The mRNA encoding the carrier was found to be expressed in the thyroid gland, stomach, and kidney of tadpoles from X. laevis, as well as the bullfrog Rana catesbeiana. The ovaries of adult X. laevis also were found to express the carrier. Phylogenetic analysis suggested that the putative X. laevis iodide transporter is orthologous to vertebrate Na(+)-dependent iodide symporters. We conclude that the amphibian sequence encodes a protein that is indeed a functional Na(+)/iodide symporter in X. laevis, as well as R. catesbeiana.

  3. Prevalence of Batrachochytrium dendrobatidis in three species of wild frogs on Prince Edward Island, Canada.

    Science.gov (United States)

    Forzán, M J; Vanderstichel, R; Hogan, N S; Teather, K; Wood, J

    2010-09-02

    Chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), has resulted in the decline or extinction of approximately 200 frog species worldwide. It has been reported throughout much of North America, but its presence on Prince Edward Island (PEI), on the eastern coast of Canada, was unknown. To determine the presence and prevalence of Bd on PEI, skin swabs were collected from 115 frogs from 18 separate sites across the province during the summer of 2009. The swabs were tested through single round end-point PCR for the presence of Bd DNA. Thirty-one frogs were positive, including 25/93 (27%) green frogs Lithobates (Rana) clamitans, 5/20 (25%) northern leopard frogs L. (R.) pipiens, and 1/2 (50%) wood frogs L. sylvaticus (formerly R. sylvatica); 12 of the 18 (67%) sites had at least 1 positive frog. The overall prevalence of Bd infection was estimated at 26.9% (7.2-46.7%, 95% CI). Prevalence amongst green frogs and leopard frogs was similar, but green frogs had a stronger PCR signal when compared to leopard frogs, regardless of age (p frogs, juveniles were more frequently positive than adults (p = 0.001). Green frogs may be the most reliable species to sample when looking for Bd in eastern North America. The 1 wood frog positive for Bd was found dead from chytridiomycosis; none of the other frogs that were positive for Bd by PCR showed any obvious signs of illness. Further monitoring will be required to determine what effect Bd infection has on amphibian population health on PEI.

  4. Sticking under wet conditions: the remarkable attachment abilities of the torrent frog, Staurois guttatus.

    Directory of Open Access Journals (Sweden)

    Thomas Endlein

    Full Text Available Tree frogs climb smooth surfaces utilising capillary forces arising from an air-fluid interface around their toe pads, whereas torrent frogs are able to climb in wet environments near waterfalls where the integrity of the meniscus is at risk. This study compares the adhesive capabilities of a torrent frog to a tree frog, investigating possible adaptations for adhesion under wet conditions. We challenged both frog species to cling to a platform which could be tilted from the horizontal to an upside-down orientation, testing the frogs on different levels of roughness and water flow. On dry, smooth surfaces, both frog species stayed attached to overhanging slopes equally well. In contrast, under both low and high flow rate conditions, the torrent frogs performed significantly better, even adhering under conditions where their toe pads were submerged in water, abolishing the meniscus that underlies capillarity. Using a transparent platform where areas of contact are illuminated, we measured the contact area of frogs during platform rotation under dry conditions. Both frog species not only used the contact area of their pads to adhere, but also large parts of their belly and thigh skin. In the tree frogs, the belly and thighs often detached on steeper slopes, whereas the torrent frogs increased the use of these areas as the slope angle increased. Probing small areas of the different skin parts with a force transducer revealed that forces declined significantly in wet conditions, with only minor differences between the frog species. The superior abilities of the torrent frogs were thus due to the large contact area they used on steep, overhanging surfaces. SEM images revealed slightly elongated cells in the periphery of the toe pads in the torrent frogs, with straightened channels in between them which could facilitate drainage of excess fluid underneath the pad.

  5. Heat production and metabolism during the contraction of mammalian skeletal muscle.

    Science.gov (United States)

    Kretzschmar, K M

    1975-01-01

    Methods are described whereby initial processes of muscular contraction may be investigated in a mammalian preparation, the soleus muscle of the rat. Conditions are chosen so that recovery is avoided. An isometric tetanus is investigated and an energy balance sheet is drawn up. It is found that there is more heat evolved than can be accounted for in terms of measured chemical reaction. This discrepancy is discussed with reference to the similar results that have been obtained using frog muscle.

  6. Prevalence and intensity of Alaria alata (Goeze, 1792) in water frogs and brown frogs in natural conditions.

    Science.gov (United States)

    Patrelle, Cécile; Portier, Julien; Jouet, Damien; Delorme, Daniel; Ferté, Hubert

    2015-12-01

    In the last 15 years, the mesocercariae of Alaria alata have frequently been reported in the wild boar during routine Trichinella inspections made compulsory for the trade of venison meat in Europe. If these studies have focused primarily on mesocercariae isolated from meat, few works have been done so far to understand the circulation of the parasite in natural conditions especially in the intermediate hosts. This study focuses on the second intermediate hosts of this parasite assessing the suitability of two amphibian groups-brown frogs and water frogs sensu lato-for mesocercarial infection on an area where A. alata has already been identified in water snails and wild boars. During this study, both groups showed to be suitable for mesocercarial infection, with high prevalence and parasite burdens. Prevalence was higher in the brown frog group (56.9 versus 11.54 % for water frogs) which would indicate that it is a preferential group for infection on the study area, though reasons for this remain to be investigated. No significant difference among prevalences was observed between tadpoles and frogs. This study, the first focusing on A. alata in these amphibians in Europe, provides further information on circulation of this parasite in natura.

  7. Frog: The Fast & Realistic OpenGL Event Displayer

    CERN Document Server

    Quertenmont, Loic

    2009-01-01

    FROG [1] is a generic framework dedicated to visualisation of events in high energy experiment. It is suitable for any particular physics experiment or detector design. The code is light ($<3~\\textrm{MB}$) and fast (browsing time $\\sim20$ events per second for a large High Energy Physics experiment) and can run on various operating systems, as its object-oriented structure (C++) relies on the cross-platform OpenGL[2] and GLUT [3] libraries. Moreover, \\textsc{Frog} does not require installation of third party libraries for the visualisation. This documents describes the features and principles of FROG version 1.106, its working scheme and numerous functionalities such as: 3D and 2D visualisation, graphical user interface, mouse interface, configuration files, production of pictures of various format, integration of personal objects, etc. Finally, several examples of its current applications are presented for illustration.

  8. Control of rod shedding in the frog retina.

    Science.gov (United States)

    Basinger, S F; Hollyfield, J G

    1980-01-01

    In all vertebrate species examined thus far, rod outer segment shedding follows a cyclic pattern in which the outer segment tips are shed shortly after the onset of light. Work in the rat retina suggests that rod shedding may follow a circadian rhythm which is controlled by one or more circadian oscillators. Our results in the frog retina are significantly different in that: rod shedding can be driven by the onset of light or other environmental cues; shedding does not persist in constant darkness; shedding is unaffected in frogs with chronic unilateral or bilateral optic nerve section; and shedding will rapidly phase shift to the time of light onset on a wide variety of diurnal cycles. Thus, rod shedding in the frog retina does not appear to be a classical circadian rhythm.

  9. Building a robotic link between muscle dynamics and hydrodynamics.

    Science.gov (United States)

    Richards, Christopher T

    2011-07-15

    This study used a novel feedback approach to control a robotic foot using force and length signals transmitted from an isolated Xenopus laevis frog muscle. The foot's environment (inertial versus hydrodynamic), gearing (outlever/inlever) and size were changed to alter the muscle's load. Upon nerve stimulation (250 Hz, 80 ms train duration), variation in loading generated a range of muscle stress (19.8±5.3 to 66.0±22.5 kPa), work (1.89±0.67 to 6.87±2.96 J kg(-1) muscle) and power (12.4±7.5 to 64.8±28.3 W kg(-1) muscle; mean ± s.d., N=6 frogs). Inertial versus hydrodynamic loading dramatically shifted contractile dynamics. With the foot in water, the muscle generated ∼30% higher force, yet shortened slower, producing lower power than inertial loading. Power increased in air from 22.6±5.8 to 63.6±27.2 W kg(-1) muscle in response to doubling the gear ratio, but did not increase in water. Surprisingly, altering foot size diminished muscle performance in water, causing power to drop significantly from 41.6±11.1 to 25.1±8.0 W kg(-1) muscle as foot area was doubled. Thus, morphological modifications influenced muscle dynamics independently of neural control; however, changes in loading environment and gearing affected contractile output more strongly than changes in foot size. Confirming recent theory, these findings demonstrate how muscle contractile output can be modulated solely by altering the mechanical environment.

  10. Effects of dietary spirulina on meat colour in muscle of broiler chickens.

    Science.gov (United States)

    Toyomizu, M; Sato, K; Taroda, H; Kato, T; Akiba, Y

    2001-05-01

    1. The present study was undertaken to determine the effects of dietary spirulina on growth performance and pigmentation in the muscle of growing broiler chickens and to examine the possibility that zeaxanthin in spirulina may affect yellow colour development in the meat. 2. Twenty-four, 21-d-old, male broiler chicks were fed an experimental diet containing spirulina at 0, 40, or 80 g/ kg for 16 d. No significant differences among treatments were observed in body weights, nor weights or yields (as a percentage of body weight) for any of the selected traits, including liver, abdominal fat, kidney and Pectoralis profundus. 3. Spectrocolourimetric analyses revealed that the redness of Pectoralis superficialis, profundus and Sartorius muscles reached a maximum in chicks fed the 40 g/kg spirulina diet, while the yellowness of all fillets, including the Semitendinosus muscle, increased in a sub-linear fashion with increased spirulina in the diet. The overall correlation between the yellowness and zeaxanthin content in the Pectoralis muscle was significant. 4. This study provides the first conclusive evidence that dietary spirulina influences both the yellowness and redness of broiler flesh and that the increments in yellowness with dietary spirulina content may possibly be reflected in the common yellow pigment related to the accumulation of zeaxanthin within the flesh.

  11. Host Defense Peptides from Asian Frogs as Potential Clinical Therapies

    Directory of Open Access Journals (Sweden)

    Vineeth T.V. Kumar

    2015-03-01

    Full Text Available Host defense peptides (HDPs are currently major focal points of medical research as infectious microbes are gaining resistance to existing drugs. They are effective against multi-drug resistant pathogens due to their unique primary target, biological membranes, and their peculiar mode of action. Even though HDPs from 60 Asian frog species belonging to 15 genera have been characterized, research into these peptides is at a very early stage. The purpose of this review is to showcase the status of peptide research in Asia. Here we provide a summary of HDPs from Asian frogs.

  12. Host Defense Peptides from Asian Frogs as Potential Clinical Therapies

    Science.gov (United States)

    Kumar, Vineeth T.V.; Holthausen, David; Jacob, Joshy; George, Sanil

    2015-01-01

    Host defense peptides (HDPs) are currently major focal points of medical research as infectious microbes are gaining resistance to existing drugs. They are effective against multi-drug resistant pathogens due to their unique primary target, biological membranes, and their peculiar mode of action. Even though HDPs from 60 Asian frog species belonging to 15 genera have been characterized, research into these peptides is at a very early stage. The purpose of this review is to showcase the status of peptide research in Asia. Here we provide a summary of HDPs from Asian frogs. PMID:27025618

  13. Determination of age, longevity and age at reproduction of the frog Microhyla ornata by skeletochronology

    Indian Academy of Sciences (India)

    Suresh M Kumbar; Katti Pancharatna

    2001-06-01

    Skeletochronological estimation of age, longevity, age at sexual maturity and breeding of Microhyla ornata was done. Frogs ( = 62) were collected locally in August (rainy season) 1997 and brought to the laboratory. Body mass and snout-vent-length (SVL) of each frog was recorded; the 4th toe of both the hind limbs was clipped under anaesthesia, fixed in 10% formalin, demineralized in 5% nitric acid and processed for histology. Limb bones (femur, humerus, tibiofibula and radioulna) of 6 large sized frogs were also processed for skeletochronology in order to study the rate of resorption. Gonads of 25 frogs (belonging to different body size ranges) were processed for histology in order to ascertain the gametogenic status of individual frogs. One to four growth rings consisting of growth zones and lines of arrested growth (LAGs) were noticed in frogs of different body sizes; the number of LAGs remained identical in all the limb bones and phalanges in 5 out of 6 frogs. Back calculation indicated that the resorption rate is very low in this frog. Male frogs possessed sperm bundles in seminiferous tubules in the 1st year, while females showed yolky follicles in the ovary in the 2nd year. Frogs found in amplexus were 3–5 years old. The results suggest that this frog may live for a maximum of 5 years in the natural population.

  14. Ant and Mite Diversity Drives Toxin Variation in the Little Devil Poison Frog.

    Science.gov (United States)

    McGugan, Jenna R; Byrd, Gary D; Roland, Alexandre B; Caty, Stephanie N; Kabir, Nisha; Tapia, Elicio E; Trauger, Sunia A; Coloma, Luis A; O'Connell, Lauren A

    2016-06-01

    Poison frogs sequester chemical defenses from arthropod prey, although the details of how arthropod diversity contributes to variation in poison frog toxins remains unclear. We characterized skin alkaloid profiles in the Little Devil poison frog, Oophaga sylvatica (Dendrobatidae), across three populations in northwestern Ecuador. Using gas chromatography/mass spectrometry, we identified histrionicotoxins, 3,5- and 5,8-disubstituted indolizidines, decahydroquinolines, and lehmizidines as the primary alkaloid toxins in these O. sylvatica populations. Frog skin alkaloid composition varied along a geographical gradient following population distribution in a principal component analysis. We also characterized diversity in arthropods isolated from frog stomach contents and confirmed that O. sylvatica specialize on ants and mites. To test the hypothesis that poison frog toxin variability reflects species and chemical diversity in arthropod prey, we (1) used sequencing of cytochrome oxidase 1 to identify individual prey specimens, and (2) used liquid chromatography/mass spectrometry to chemically profile consumed ants and mites. We identified 45 ants and 9 mites in frog stomachs, including several undescribed species. We also showed that chemical profiles of consumed ants and mites cluster by frog population, suggesting different frog populations have access to chemically distinct prey. Finally, by comparing chemical profiles of frog skin and isolated prey items, we traced the arthropod source of four poison frog alkaloids, including 3,5- and 5,8-disubstituted indolizidines and a lehmizidine alkaloid. Together, the data show that toxin variability in O. sylvatica reflects chemical diversity in arthropod prey.

  15. Wipe and flexion reflexes of the frog. II. Response to perturbations.

    Science.gov (United States)

    Schotland, J L; Rymer, W Z

    1993-05-01

    1. To evaluate the hypothesis that the neural control of sensorimotor transformations may be simplified by using a single control variable, we compared the movement kinematics and muscle activity patterns [electromyograms (EMGs)] of the frog during flexion withdrawal and the hind limb-hind limb wipe reflex before and after adding an external load. In addition, the flexibility of spinal cord circuitry underlying the hind limb-hind limb wipe reflex was evaluated by comparing wipes before and after removal of one of the contributing muscles by cutting a muscle nerve. 2. The kinematics of the movements were recorded using a WATSMART infrared emitter-detector system and quantified using principal-components analysis to provide a measure of the shape (eigenvalues) and orientation (eigenvector coefficients) of the movement trajectories. The neural pattern coordinating the movements was characterized by the latencies and magnitudes of EMGs of seven muscles acting at the hip, knee, and ankle. These variables were compared 1) during flexion withdrawal and the initial movement segment of the limb during the hind limb-hind limb wipe reflex in both unrestrained movements and in movements executed when a load equal to approximately 10% of the animal's body weight was attached to a distal limb segment and 2) during the initial movement segment of the wipe reflex before and after cutting the nerve to the knee flexor-hip extensor, iliofibularis. 3. Addition of the load had no discernible effect on the end-point position of the foot during either reflex. However, during the loaded flexion reflex, the ankle joint did not move until after the hip and knee joints had moved to their normal positions. This delayed flexion of the ankle was accompanied by large increases in the magnitude of EMG activity in two ankle muscles that exceeded the levels found during unrestrained movements. Significant changes in the temporal organization of the EMG pattern accompanied the change in joint angle

  16. Species-specific loss of sexual dimorphism in vocal effectors accompanies vocal simplification in African clawed frogs (Xenopus).

    Science.gov (United States)

    Leininger, Elizabeth C; Kitayama, Ken; Kelley, Darcy B

    2015-03-01

    Phylogenetic studies can reveal patterns of evolutionary change, including the gain or loss of elaborate courtship traits in males. Male African clawed frogs generally produce complex and rapid courtship vocalizations, whereas female calls are simple and slow. In a few species, however, male vocalizations are also simple and slow, suggesting loss of male-typical traits. Here, we explore features of the male vocal organ that could contribute to loss in two species with simple, slow male calls. In Xenopus boumbaensis, laryngeal morphology is more robust in males than in females. Larynges are larger, have a more complex cartilaginous morphology and contain more muscle fibers. Laryngeal muscle fibers are exclusively fast-twitch in males but are both fast- and slow-twitch in females. The laryngeal electromyogram, a measure of neuromuscular synaptic strength, shows greater potentiation in males than in females. Male-specific physiological features are shared with X. laevis, as well as with a species of the sister clade, Silurana tropicalis, and thus are likely ancestral. In X. borealis, certain aspects of laryngeal morphology and physiology are sexually monomorphic rather than dimorphic. In both sexes, laryngeal muscle fibers are of mixed-twitch type, which limits the production of muscle contractions at rapid intervals. Muscle activity potentiation and discrete tension transients resemble female rather than male X. boumbaensis. The de-masculinization of these laryngeal features suggests an alteration in sensitivity to the gonadal hormones that are known to control the sexual differentiation of the larynx in other Xenopus and Silurana species.

  17. The Maluti Mystery revisited: Taxonomy of African River Frogs (Pyxicephalidae, Amietia) on the Drakensberg Mountains in southern Africa.

    Science.gov (United States)

    Channing, Alan

    2015-02-27

    The taxonomy of two similar frogs from the top of the Drakensberg escarpment, the Maluti River Frog and the Phofung River Frog is not settled. I examine the relevant types and type descriptions, and discover a number of errors in the literature. Some of the recent taxonomic changes were found to be unsupported. The Maluti River Frog is assigned to Amietia vertebralis (Hewitt, 1927), and the Phofung River Frog to Amietia hymenopus (Boulenger, 1920).

  18. Morphometric discrimination of wild from farmed Dybowski's frog (Rana dybowskii) based on hindlimb length

    Institute of Scientific and Technical Information of China (English)

    XIA Rui; HUANG Xiao-ming; YANG Shu-hui; XU Yan-chun; Ying Lu; Thomas D.Dahmer

    2011-01-01

    Commercial farming of anuran species that arc declining in the wild raises a need to discriminate wild from farmed frogs. We hypothesized wild frogs might have extended hindlimbs due to greater frequency or intensity of jumping relative to farmed frogs, highlighting a morphometric approach to discrimination of wild from farmed frogs using hindiimb length. In the present study, Dybowski's frog (Rana dybowskii) was used to test this hypothesis. We measured body mass (Mb)and hindlimb length (Lh) of 2-year old farmed frogs and wild frogs aged 2 to 5 years. Dybowski's frog demonstrated significant dimorphism in Mb and Lh. Mb was significantly greater among farmed 2-year old frogs in both sexes (p=0.000), while only among females w as Lh significantly greater for wild frogs (p=0.000). Lh/Mb was used as an index for origin discrimination to eliminate the influence of Mb due to variation of husbandry conditions among farms. Mean Lh/Mb for fanned frogs was significantly lower than for wild frogs (p=0.000) in the 2-year old age class.Discrimination correctly classified 84.4% of fanned and 96.3% of wild male frogs. Among females, 92.9% of farmed frogs and 90.1% wild frogs were correctly classified. The ovcrall correctness of classification was 92.1% and 90.8% for males and females, respectively. However, Lh/Mb revealed variation with age, resulting in reduced discriminative power for frogs ≥3 years old. We introduced a coefficient Ce to adjust the Lh/Mb of frogs ≥3 years to the level equivalent to 2-year frogs. Thc adjustment achieved 89.5% for overall correctness of origin for wild males and 92.4% for wild females ≥3 years old. These results show that Lh/Mb is an effective index to discriminate wild from fanned Dybowski's frog. Since the physical demands ofjumping are common among anurans, this index is also potentially applicable to other anuran species.

  19. "Target" and "Sandwich" Signs in Thigh Muscles have High Diagnostic Values for Collagen Ⅵ-related Myopathies

    Institute of Scientific and Technical Information of China (English)

    Jun Fu; Yi-Ming Zheng; Su-Qin Jin; Jun-Fei Yi; Xiu-Juan Liu; He Lyn; Zhao-Xia Wang

    2016-01-01

    Background:Collagen Ⅵ-related myopathies are autosomal dominant and recessive hereditary myopathies,mainly including Ullrich congenital muscular dystrophy (UCMD) and Bethlem myopathy (BM).Muscle magnetic resonance imaging (MRI) has been widely used to diagnosis muscular disorders.The purpose of this study was to evaluate the diagnostic value of thigh muscles MRI for collagen Ⅵ-related myopathies.Methods:Eleven patients with collagen Ⅵ gene mutation-related myopathies were enrolled in this study.MRI of the thigh muscles was performed in all patients with collagen Ⅵ gene mutation-related myopathies and in 361 patients with other neuromuscular disorders (disease controls).Tl-weighted images were used to assess fatty infiltration of the muscles using a modified Mercuri's scale.We assessed the sensitivity and specificity of the MRI features of collagen Ⅵ-related myopathies.The relationship between fatty infiltration of muscles and specific collagen Ⅵ gene mutations was also investigated.Results:Eleven patients with collagen Ⅵ gene mutation-related myopathies included six UCMD patients and five BM patients.There was no significant difference between UCMD and BM patients in the fatty infiltration of each thigh muscle except sartorius (P =0.033);therefore,we combined the UCMD and BM data.Mean fatty infiltration scores were 3.1 and 3.0 in adductor magnus and gluteus maximus,while the scores were 1.3,1.3,and 1.5 in gracilis,adductor longus,and sartorius,respectively.A "target" sign in rectus femoris (RF) was present in seven cases,and a "sandwich" sign in vastus lateralis (VL) was present in ten cases.The "target" and "sandwich" signs had sensitivities of 63.6% and 90.9% and specificities of 97.3% and 96.9% for the diagnosis of collagen Ⅵ-related myopathies,respectively.Fatty infiltration scores were 2.0-3.0 in seven patients with mutations in the triple-helical domain,and 1.0-1.5 in three of four patients with mutations in the N-or C-domain of the

  20. Neuronal nitric oxide synthase immunoreactivity in the respiratory tract of the frog, Rana temporaria.

    Science.gov (United States)

    Bodegas, M E; Villaro, A C; Montuenga, L M; Moncada, S; Riveros-Moreno, V; Sesma, P

    1995-10-01

    Physiological and histochemical studies have recently supported the notion that nitric oxide (NO) is the transduction signal responsible for the non-adrenergic, non-cholinergic relaxation of the vasculature as well as the airways of the mammalian lung. We report the presence of immunoreactivity to NO synthase (NOS) in nerve cell bodies and nerve fibres in the neural plexus of the buccal cavity and lungs of the frog, Rana temporaria, using the indirect immunocytochemical technique of avidin-biotin and the NADPH-diaphorase technique. The neural ganglia located next to the muscle layer and within the connective tissue of the buccal cavity were partially immunoreactive for NOS. In the lungs, NOS immunoreactivity occurred in nerve cell bodies, as well as in both myelinated and unmyelinated nerve fibres. Fine nerve fibres immunoreactive to NOS were observed within the muscle fibre bundles and next to the respiratory epithelium. Both the presence of NOS immunoreactivity and the positive histochemical reaction for NADPH-diaphorase in the neural plexus of amphibian respiratory tract suggests a broad evolutionary role for NO as a peripheral neurotransmitter.

  1. Helminths of the two mountain frogs, banded frog, Rana camerani Boulenger, 1886 and Uludağ frog Rana macrocnemis Boulenger, 1885 (Anura: Ranidae), collected from the Antalya province.

    Science.gov (United States)

    Düşen, Serdar

    2007-01-01

    In this study, two mountain frogs (Rana camerani and Rana macrocnemis) were collected in the Antalya Province in south-western Turkey during 2001 and 2002 and were examined for helminths. Out of 15 Rana camerani, 10 (66.7%) were infected with 1 or more helminths and out of 20 Rana macrocnemis, 17 (85%) were infected with 1 or more helminths. The helminth fauna of Rana camerani included 4 species of which were 3 trematode species (Haplometra cylindracea, Pleurogenoides medians, Opisthioglyphe rastellus), and 1 nematode species (Cosmocerca ornata). The helminth fauna of Rana macrocnemis included 3 species with 1 trematode species (H. cylindracea), 1 nematode species (C. ornata), and 1 acanthocephalan species (Acanthocephalus ranae). H. cylindracea and C. ornata were observed in both of the mountain frogs.

  2. Choosing the safest route: frog orientation in an agricultural landscape

    NARCIS (Netherlands)

    Mazerolle, M.J.; Vos, C.C.

    2006-01-01

    Orientation is a key component to successful movements between habitats. We hypothesized that barren agricultural landscapes hinder the ability of frogs to orient and move between habitats. Specifically, we predicted that when presented with a choice between a short route through a hostile environme

  3. Archaeobatrachian paraphyly and pangaean diversification of crown-group frogs.

    Science.gov (United States)

    Roelants, Kim; Bossuyt, Franky

    2005-02-01

    Current models for the early diversification of living frogs inferred from morphological, ontogenetic, or DNA sequence data invoke very different scenarios of character evolution and biogeography. To explore central controversies on the phylogeny of Anura, we analyzed nearly 4000 base pairs of mitochondrial and nuclear DNA for the major frog lineages. Likelihood-based analyses of this data set are congruent with morphological evidence in supporting a paraphyletic arrangement of archaeobatrachian frogs, with an (Ascaphus + Leiopelma) clade as the sister-group of all other living anurans. The stability of this outcome is reinforced by screening for phylogenetic bias resulting from site-specific rate variation, homoplasy, or the obligatory use of distantly related outgroups. Twenty-one alternative branching and rooting hypotheses were evaluated using a nonparametric multicomparison test and parametric bootstrapping. Relaxed molecular clock estimates situate the emergence of crown-group anurans in the Triassic, approximately 55 million years prior to their first appearance in the fossil record. The existence of at least four extant frog lineages on the supercontinent Pangaea before its breakup gains support from the estimation that three early splits between Laurasia- and Gondwana-associated families coincide with the initial rifting of these landmasses. This observation outlines the potential significance of this breakup event in the formation of separate Mesozoic faunal assemblages in both hemispheres.

  4. How Can We Tell if Frogs Jump Further?

    Science.gov (United States)

    Drummond, Gordon B.; Tom, Brian D. M.

    2011-01-01

    How effective is training frogs to jump? This is perhaps the most frequent question in biology that is subjected to statistical analysis: does a treatment make a difference? One can examine whether there is indeed a training effect, by first assuming the opposite. That is, the authors assume that training has no effect on the mean distance jumped.…

  5. Antimicrobial peptides from the skins of North American frogs.

    Science.gov (United States)

    Conlon, J Michael; Kolodziejek, Jolanta; Nowotny, Norbert

    2009-08-01

    North America is home to anuran species belonging to the families Bufonidae, Eleutherodactylidae, Hylidae, Leiopelmatidae, Ranidae, and Scaphiopodidae but antimicrobial peptides have been identified only in skin secretions and/or skin extracts of frogs belonging to the Leiopelmatidae ("tailed frogs") and Ranidae ("true frogs"). Eight structurally-related cationic alpha-helical peptides with broad-spectrum antibacterial activity, termed ascaphins, have been isolated from specimens of Ascaphus truei (Leiopelmatidae) occupying a coastal range. Characterization of orthologous antimicrobial peptides from Ascaphus specimens occupying an inland range supports the proposal that this population should be regarded as a separate species A. montanus. Ascaphin-8 shows potential for development into a therapeutically valuable anti-infective agent. Peptides belonging to the brevinin-1, esculentin-1, esculentin-2, palustrin-1, palustrin-2, ranacyclin, ranatuerin-1, ranatuerin-2, and temporin families have been isolated from North American ranids. It is proposed that "ranalexins" represent brevinin-1 peptides that have undergone a four amino acid residue internal deletion. Current taxonomic recommendations divide North American frogs from the family Ranidae into two genera: Lithobates and Rana. Cladistic analysis based upon the amino acid sequences of the brevinin-1 peptides provides strong support for this assignment.

  6. Natural disturbance reduces disease risk in endangered rainforest frog populations.

    Science.gov (United States)

    Roznik, Elizabeth A; Sapsford, Sarah J; Pike, David A; Schwarzkopf, Lin; Alford, Ross A

    2015-08-21

    Natural disturbances can drive disease dynamics in animal populations by altering the microclimates experienced by hosts and their pathogens. Many pathogens are highly sensitive to temperature and moisture, and therefore small changes in habitat structure can alter the microclimate in ways that increase or decrease infection prevalence and intensity in host populations. Here we show that a reduction of rainforest canopy cover caused by a severe tropical cyclone decreased the risk of endangered rainforest frogs (Litoria rheocola) becoming infected by a fungal pathogen (Batrachochytrium dendrobatidis). Reductions in canopy cover increased the temperatures and rates of evaporative water loss in frog microhabitats, which reduced B. dendrobatidis infection risk in frogs by an average of 11-28% in cyclone-damaged areas, relative to unaffected areas. Natural disturbances to the rainforest canopy can therefore provide an immediate benefit to frogs by altering the microclimate in ways that reduce infection risk. This could increase host survival and reduce the probability of epidemic disease outbreaks. For amphibian populations under immediate threat from this pathogen, targeted manipulation of canopy cover could increase the availability of warmer, drier microclimates and therefore tip the balance from host extinction to coexistence.

  7. Ranavirus in wild edible frogs Pelophylax kl. esculentus in Denmark

    DEFF Research Database (Denmark)

    Ariel, Ellen; Kielgast, Jos; Svart, Hans Erik

    2009-01-01

    interviewed by phone and 10 cases were examined on suspicion of diseaseinduced mortality. All samples were negative for Bd. Ranavirus was isolated from 2 samples of recently dead frogs collected during a mass mortality event in an artificial pond near Slagelse, Denmark. The identity of the virus was confirmed...

  8. Choosing the safest route: frog orientation in an agricultural landscape

    NARCIS (Netherlands)

    Mazerolle, M.J.; Vos, C.C.

    2006-01-01

    Orientation is a key component to successful movements between habitats. We hypothesized that barren agricultural landscapes hinder the ability of frogs to orient and move between habitats. Specifically, we predicted that when presented with a choice between a short route through a hostile environme

  9. BIFURCATION ANALYSIS OF A MITOTIC MODEL OF FROG EGGS

    Institute of Scientific and Technical Information of China (English)

    吕金虎; 张子范; 张锁春

    2003-01-01

    The mitotic model of frog eggs established by Borisuk and Tyson is qualitatively analyzed. The existence and stability of its steady states are further discussed. Furthermore, the bifurcation of above model is further investigated by using theoretical analysis and numerical simulations. At the same time, the numerical results of Tyson are verified by theoretical analysis.

  10. Pesticides and Population Declines of California Alpine Frogs

    Science.gov (United States)

    Airborne pesticides from the Central Valley of California have been implicated as a cause for population declines of several amphibian species, with the strongest evidence for the mountain yellow-legged frog complex (Rana muscosa and R. sierrae) in the Sierra Nevada. We measured ...

  11. How Can We Tell if Frogs Jump Further?

    Science.gov (United States)

    Drummond, Gordon B.; Tom, Brian D. M.

    2011-01-01

    How effective is training frogs to jump? This is perhaps the most frequent question in biology that is subjected to statistical analysis: does a treatment make a difference? One can examine whether there is indeed a training effect, by first assuming the opposite. That is, the authors assume that training has no effect on the mean distance jumped.…

  12. Evidence of auditory insensitivity to vocalization frequencies in two frogs

    DEFF Research Database (Denmark)

    Goutte, Sandra; Mason, Matthew J; Christensen-Dalsgaard, Jakob

    2017-01-01

    The emergence and maintenance of animal communication systems requires the co-evolution of signal and receiver. Frogs and toads rely heavily on acoustic communication for coordinating reproduction and typically have ears tuned to the dominant frequency of their vocalizations, allowing discriminat...

  13. Role of cutaneous surface fluid in frog osmoregulation

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Ramløv, Hans

    2013-01-01

    The study investigated whether evaporative water loss (EWL) in frogs stems from water diffusing through the skin or fluid secreted by mucous glands. Osmolality of cutaneous surface fluid (CSF) of Rana esculenta (Pelophylax kl. esculentus) subjected to isoproterenol or 30 °C–34 °C was 191 ± 9...

  14. AIRBORNE PESTICIDES AND POPULATION DECLINES OF A CALIFORNIA ALPINE FROG

    Science.gov (United States)

    The mountain yellow-legged frog (Rana muscosa) has disappeared from most of its historic localities in the Sierra Nevada of California, and airborne pesticides from the Central Valley have been implicated as a causal agent. To determine the distribution and temporal variation of ...

  15. Pesticides and Population Declines of California Alpine Frogs

    Science.gov (United States)

    Airborne pesticides from the Central Valley of California have been implicated as a cause for population declines of several amphibian species, with the strongest evidence for the mountain yellow-legged frog complex (Rana muscosa and R. sierrae) in the Sierra Nevada. We measured ...

  16. Biophysics of directional hearing in the frog Eleutherodactylus coqui

    DEFF Research Database (Denmark)

    Jørgensen, Morten Buhl; Schmitz, Barbara; Christensen-Dalsgaard, Jakob

    1991-01-01

    ) or closed (GC response) during the measurement. 3. The lateral body wall vibrated with a maximum amplitude close to that of the eardrum and in the same frequency range. 4. Covering the frog's body wall with vaseline reduced the vibration amplitude of the GC response by up to 15 dB. 5. When a closed sound...

  17. Fundamental Experiment to Determine Escape Countermeasures for Frogs Falling into Agricultural Canals

    Science.gov (United States)

    Watabe, Keiji; Mori, Atsushi; Koizumi, Noriyuki; Takemura, Takeshi

    Frogs often drown in agricultural canals with deep concrete walls, which are installed commonly in paddy fields after land improvement projects in Japan, because they cannot escape after falling into the canal. Therefore, countermeasures that enable frogs to escape from canals are required in some rural areas. An experimental canal with partially sloped walls was used as an escape countermeasure to investigate the preferable angle of slope for the walls, water depth and flow velocity that enables Tokyo Daruma Pond Frogs (Rana porosa porosa), which have no adhesive discs, to easily escape. Walls with slopes of 30-45 degrees allowed 50-60% of frogs to escape from the experimental canals, frogs especially easily climbed the 30 degree sloped walls. When the water depth was 5 cm or flow velocity was greater than 20 cm/s, approximately 80% of the frogs moved downstream and reached the sloped walls because the frogs' toes did not reach the bottom of the canal. However, if the depth was 2 cm and the flow velocity was 5 cm/s, only 4% of the frogs climbed the sloped walls because they could move freely. The frogs appeared to not be good at long-distance swimming and could not remain a long-time under running water. Therefore, walls sloped less than 30 degrees and control of both water depth and flow velocity appears important for enabling frogs to easily escape from canals.

  18. Study on the findings of muscle CT in patients with Fukuyama type congenital muscular dystrophy (FCMD)

    Energy Technology Data Exchange (ETDEWEB)

    Sumida, Sawako; Osawa, Makiko; Okada, Noriko and others

    1988-11-01

    This study was carried out to investigate the process of muscle involvement according to age in patients with FCMD (Brain Dev 1981 ; 3:1 - 29) by CT scans. Fourteen patients with FCMD I (age: 5 months-12 years) and two patients with FCMD III or IV (age: 3, 4 years) were studied. The midcalf, midthigh, L3 and shoulder girdle level were the sites chosen. Two types of change were found in FCMD I. One of them was the attenuation of the density in muscle and the other one was decreased area of muscle as a result of low density which started from periphery of the muscle. The latter was found in m. psoas major after age 9, whilst the former was found in other muscles to some degree. The severity of the changes was related to age. In the case which was examined twice, the changes extended even better motor function had been attained. The changes in midcalf preceded those in midthigh, L3, shoulder girdle. The attenuation of density was found early and severely in m. triceps surae, m. adductor magnus, paravertebral muscles and m. subscapularis, whilst those in m. tibialis anterior and posterior, m. gracilis, m. sartorius, m. quadratus lumborum appeared later and relatively mild. The relationship between the process of extension of low density in muscle and joint contractures were also discussed. The changes in CT scan in FCMD III or IV were milder than those of FCMD I and there was no tendency that the change in midcalf preceded those of other scanned level.

  19. COMPARATIVE TOXICITY OF DIURON ON SURVIVAL AND GROWTH OF PACIFIC TREEFROG, BULLFROG, RED-LEGGED FROG, AND AFRICAN CLAWED FROG EMBRYOS AND TADPOLES

    Science.gov (United States)

    The effects of the herbicide diuron on survival and growth of Pacific treefrog (Pseudacris regilla),bullfrog(Rana catesbeiana), red-legged frog(Rana aurora),and African clawed frog(Xenopus laevis)embryos and tadpoles were determined in static-renewal tests. P.regilla and X.laevis...

  20. Muscle biopsy

    Science.gov (United States)

    ... Inflammatory diseases of muscle (such as polymyositis or dermatomyositis ) Diseases of the connective tissue and blood vessels ( ... disease that involves inflammation and a skin rash ( dermatomyositis ) Inherited muscle disorder ( Duchenne muscular dystrophy ) Inflammation of ...

  1. Muscle atrophy

    Science.gov (United States)

    ... atrophy. Exercises may include ones done in a swimming pool to reduce the muscle workload, and other types ... a physical examination and ask about your medical history and symptoms, including: When did the muscle atrophy ...

  2. AcT-2: A Novel Myotropic and Antimicrobial Type 2 Tryptophyllin from the Skin Secretion of the Central American Red-Eyed Leaf Frog, Agalychnis callidryas

    Directory of Open Access Journals (Sweden)

    Lilin Ge

    2014-01-01

    Full Text Available Tryptophyllins are a diverse family of amphibian peptides originally found in extracts of phyllomedusine frog skin by chemical means. Their biological activities remain obscure. Here we describe the isolation and preliminary pharmacological characterization of a novel type 2 tryptophyllin, named AcT-2, from the skin secretion of the red-eyed leaf frog, Agalychnis callidryas. The peptide was initially identified during smooth muscle pharmacological screening of skin secretion HPLC fractions and the unique primary structure—GMRPPWF-NH2—was established by both Edman degradation and electrospray MS/MS fragmentation sequencing. A. cDNA encoding the biosynthetic precursor of AcT-2 was successfully cloned from a skin secretion-derived cDNA library by means of RACE PCR and this contained an open-reading frame consisting of 62 amino acid residues with a single AcT-2 encoding sequence located towards the C-terminus. A synthetic replicate of AcT-2 was found to relax arterial smooth muscle (EC50 = 5.1 nM and to contract rat urinary bladder smooth muscle (EC50 = 9.3 μM. The peptide could also inhibit the growth of the microorganisms, Staphylococcus aureus, (MIC = 256 mg/L Escherichia coli (MIC = 512 mg/L, and Candida albicans (128 mg/L. AcT-2 is thus the first amphibian skin tryptophyllin found to possess both myotropic and antimicrobial activities.

  3. Modelling of gastrocnemius muscle using Hills equation in COMSOL Multiphysics 4.0a

    Directory of Open Access Journals (Sweden)

    S.Vivekanandan

    2012-05-01

    Full Text Available This paper summarizes the force generated by gastrocnemius muscle for the analysis of muscoskeletal simulation in human locomotion using Hills muscle model. Biomechanics of Hills equation describes the study of physical phenomenon by means of mathematical model that relates force and muscle length with the help of a partial differential equation. To calculate maximum fatigue in the muscle and to discriminate strained muscle from the normal one FEM based modelling was done in COMSOL Multiphysics 4.0a. The model parameters were evaluated using similar in vitro experiments performed on frogs gastrocnemius muscle. The biomechanical model was then incorporated into human body for the purpose of predicting force - length response for all the four phases of gait cycle. Evaluating the response for gait cycle will enable the physiotherapist to obtain clues for muscle weakness and fatigue in a rehabilitation program

  4. Your Muscles

    Science.gov (United States)

    ... develops. There they help to push the baby out of the mother's body when it's time to be born. You'll find smooth muscles at work behind the scenes in your eyes, too. These muscles keep the eyes ... thick muscles of the heart contract to pump blood out and then relax to let blood back in ...

  5. Modeling Muscles

    Science.gov (United States)

    Goodwyn, Lauren; Salm, Sarah

    2007-01-01

    Teaching the anatomy of the muscle system to high school students can be challenging. Students often learn about muscle anatomy by memorizing information from textbooks or by observing plastic, inflexible models. Although these mediums help students learn about muscle placement, the mediums do not facilitate understanding regarding integration of…

  6. Skeletal muscle hypertrophy and decreased intramuscular fat after unilateral resistance training in spinal cord injury: case report.

    Science.gov (United States)

    Gorgey, Ashraf S; Shepherd, Collin

    2010-01-01

    Skeletal muscle atrophy is a common adaptation after spinal cord injury (SCI) that results in numerous health-related complications. Neuromuscular electrical stimulation (NMES) has been recognized as an effective tool, which attenuates atrophy and evokes hypertrophy. To investigate the effects of NMES resistance training (RT) on individual muscle groups and adipose tissue of the right thigh after stimulation of the knee extensor muscle group in a man with chronic SCI. A 22-year-old man with a complete SCI sustained in a motorcycle accident 5 years prior to participation in this study. The participant underwent training twice a week for 12 weeks, including unilateral progressive RT of the right knee extensor muscle group using NMES and ankle weights. The stimulation was applied to knee extensors while the participant was sitting in his wheelchair. A series of T1-weighted magnetic resonance images were acquired for the whole right thigh prior to and after training. Skeletal muscle cross-sectional areas were measured of the whole thigh, knee extensors, hip adductors, hamstrings, and sartorius and gracilis muscle groups. Additionally, intramuscular fat and subcutaneous fat of the thigh were measured. At the end of 12 weeks, the participant was able to lift 17 lbs during full knee extension. Average skeletal muscle cross-sectional areas increased in all of the measured muscle groups (12%-43%). Hypertrophy ranging from 30% to 112% was detected in multiaxial slices after the NMES RT protocol. Intramuscular fat decreased by more than 50% and subcutaneous fat increased by 24%. Unilateral NMES RT protocol evoked hypertrophy in the knee extensor and adjacent skeletal muscle groups and was associated with a reduction in intramuscular fat in a person with a chronic SCI. Additionally, subcutaneous adipose tissue cross-sectional areas increased in response to RT.

  7. Glycation of wood frog (Rana sylvatica) hemoglobin and blood proteins: in vivo and in vitro studies

    Science.gov (United States)

    MacDonald, Justin A.; Degenhardt, Thorsten; Baynes, John W.; Storey, Kenneth B.

    2010-01-01

    The effects of in vivo freezing and glucose cryoprotectant on protein glycation were investigated in the wood frog, Rana sylvatica. Our studies revealed no difference in the fructoselysine content of blood plasma sampled from control, 27 h frozen and 18 h thawed wood frogs. Glycated hemoglobin (GHb) decreased slightly with 48 h freezing exposure and was below control levels after 7 d recovery, while glycated serum albumin was unchanged by 48 h freezing but did increase after 7 d of recovery. In vitro exposure of blood lysates to glucose revealed that the GHb production in wood frogs was similar to that of the rat but was lower than in leopard frogs. We conclude that wood frog hemoglobin was glycated in vitro; however, GHb production was not apparent during freezing and recovery when in vivo glucose is highly elevated. It is possible that wood frog blood proteins have different in vivo susceptibilities to glycation. PMID:19540217

  8. Assessment of radiocesium contamination in frogs 18 months after the Fukushima Daiichi nuclear disaster

    Science.gov (United States)

    Matsushima, Noe; Ihara, Sadao; Takase, Minoru; Horiguchi, Toshihiro

    2015-04-01

    We investigated the accumulation of radionuclides in frogs inhabiting radioactively contaminated areas around Fukushima Daiichi Nuclear Power Plant (FDNPP) to search for possible adverse effects due to radionuclides. We collected 5 frog species and soil samples in areas within and outside a 20-km radius from FDNPP in August and September 2012 and determined their radiocesium concentrations (134Cs and 137Cs). There was a positive correlation between radiocesium concentrations in the soil samples and frogs, and the highest concentration in frogs was 47,278.53 Bq/kg-wet. Although we conducted a histological examination of frog ovaries and testes by light microscopy to detect possible effects of radionuclides on the morphology of germ cells, there were no clear abnormalities in the gonadal tissues of frogs collected from sites with different contamination levels.

  9. Adaptive response in frogs chronically exposed to low doses of ionizing radiation in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Audette-Stuart, M., E-mail: stuartm@aecl.ca [Environmental Technologies Branch, Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, Ontario, K0J 1P0 (Canada); Kim, S.B.; McMullin, D.; Festarini, A.; Yankovich, T.L.; Carr, J.; Mulpuru, S. [Environmental Technologies Branch, Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, Ontario, K0J 1P0 (Canada)

    2011-06-15

    Using the micronucleus assay, decreased levels of DNA damage were found after high dose ionizing radiation exposure of liver cells taken from frogs inhabiting a natural environment with above-background levels of ionizing radiation, compared to cells taken from frogs inhabiting background areas. The data obtained from a small number of animals suggest that stress present in the above-background environment could induce an adaptive response to ionizing radiation. This study did not reveal harmful effects of exposure to low levels of radioactivity. On the contrary, stress present in the above-background area may serve to enhance cellular defense mechanisms. - Highlights: > Frogs were collected from background and higher tritium level habitats. > The micronucleus assay was conducted on liver cells obtained from the frogs. > No detrimental effects were noted in frogs exposed to elevated tritium. > Adaptive responses were observed in frogs exposed to elevated tritium.

  10. Pathogenicity of Aeromonas hydrophila, Klebsiella pneumoniae, and Proteus mirabilis to brown tree frogs (Litoria ewingii).

    Science.gov (United States)

    Schadich, Ermin; Cole, Anthony L J

    2010-04-01

    Bacterial dermatosepticemia, a systemic infectious bacterial disease of frogs, can be caused by several opportunistic gram-negative bacterial species including Aeromonas hydrophila, Chryseobacterium indologenes, Chryseobacterium meningosepticum, Citrobacter freundii, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, and Serratia liquifaciens. Here we determined the pathogenicity of 3 bacterial species (Aeromonas hydrophila, Klebsiella pneumoniae, and Proteus mirabilis) associated with an outbreak of fatal dermatosepticemia in New Zealand Litoria ewingii frogs. A bath challenge method was used to expose test frogs to individual bacterial species (2 x 10(7) cfu/mL in pond water); control frogs were exposed to uninfected pond water. None of the control frogs or those exposed to A. hydrophila or P. mirabilis showed any morbidity or mortality. Morbidity and mortality was 40% among frogs exposed to K. pneumonia, and the organism was reisolated from the hearts, spleens, and livers of affected animals.

  11. Glycation of wood frog (Rana sylvatica) hemoglobin and blood proteins: in vivo and in vitro studies.

    Science.gov (United States)

    MacDonald, Justin A; Degenhardt, Thorsten; Baynes, John W; Storey, Kenneth B

    2009-10-01

    The effects of in vivo freezing and glucose cryoprotectant on protein glycation were investigated in the wood frog, Rana sylvatica. Our studies revealed no difference in the fructoselysine content of blood plasma sampled from control, 27 h frozen and 18 h thawed wood frogs. Glycated hemoglobin (GHb) decreased slightly with 48 h freezing exposure and was below control levels after 7d recovery, while glycated serum albumin was unchanged by 48 h freezing but did increase after 7d of recovery. In vitro exposure of blood lysates to glucose revealed that the GHb production in wood frogs was similar to that of the rat but was lower than in leopard frogs. We conclude that wood frog hemoglobin was glycated in vitro; however, GHb production was not apparent during freezing and recovery when in vivo glucose is highly elevated. It is possible that wood frog blood proteins have different in vivo susceptibilities to glycation.

  12. Itraconazole treatment reduces Batrachochytrium dendrobatidis prevalence and increases overwinter field survival in juvenile Cascades frogs.

    Science.gov (United States)

    Hardy, Bennett M; Pope, Karen L; Piovia-Scott, Jonah; Brown, Richard N; Foley, Janet E

    2015-01-15

    The global spread of the fungal pathogen Batrachochytrium dendrobatidis (Bd) has led to widespread extirpation of amphibian populations. During an intervention aimed at stabilizing at-risk populations, we treated wild-caught Cascades frogs Rana cascadae with the antifungal drug itraconazole. In fall 2012, we collected 60 recently metamorphosed R. cascadae from 1 of the 11 remnant populations in the Cascades Mountains (CA, USA). Of these, 30 randomly selected frogs were treated with itraconazole and the other 30 frogs served as experimental controls; all were released at the capture site. Bd prevalence was low at the time of treatment and did not differ between treated frogs and controls immediately following treatment. Following release, Bd prevalence gradually increased in controls but not in treated frogs, with noticeable (but still non-significant) differences 3 wk after treatment (27% [4/15] vs. 0% [0/13]) and strong differences 5 wk after treatment (67% [8/12] vs. 13% [1/8]). We did not detect any differences in Bd prevalence and load between experimental controls and untreated wild frogs during this time period. In spring 2013, we recaptured 7 treated frogs but none of the experimental control frogs, suggesting that over-winter survival was higher for treated frogs. The itraconazole treatment did appear to reduce growth rates: treated frogs weighed 22% less than control frogs 3 wk after treatment (0.7 vs. 0.9 g) and were 9% shorter than control frogs 5 wk after treatment (18.4 vs. 20.2 mm). However, for critically small populations, increased survival of the most at-risk life stage could prevent or delay extinction. Our results show that itraconazole treatment can be effective against Bd infection in wild amphibians, and therefore the beneficial effects on survivorship may outweigh the detrimental effects on growth.

  13. Epidermal Laser Stimulation of Action Potentials in the Frog Sciatic Nerve

    Science.gov (United States)

    2008-10-01

    Laser Stimulation of Action Potentials in the Frog Sciatic Nerve Nichole M. Jindra Robert J. Thomas Human Effectiveness Directorate Directed...in the Frog Sciatic Nerve 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62202F 6. AUTHOR(S) .Nichole M. Jindra, Robert J. Thomas, Douglas N...Alan Rice 14. ABSTRACT Measurements of laser stimulated action potentials in the sciatic nerve of leopard frogs (Rana pipiens) were made using

  14. Increased responsiveness to dietary lysine deficiency of pectoralis major muscle protein turnover in broilers selected on breast development.

    Science.gov (United States)

    Tesseraud, S; Temim, S; Le Bihan-Duval, E; Chagneau, A M

    2001-04-01

    It has been previously established that growth and carcass qualities of chicks are modified by genotype and dietary amino acid supply. In this study, we evaluated the effects of lysine deficiency and genetic selection on muscle protein metabolism. Chicks originating from an experimental line selected for breast development (QL) and its control line (CL) were provided ad libitum access to isoenergetic diets containing 20% crude protein but differing in their lysine content (0.75 or 1.01%). Protein fractional synthesis rates (FSR) were measured in vivo in the pectoralis major and sartorius muscles of 3-wk-old chickens (flooding dose of [3H]phenylalanine). Fractional breakdown rates (FBR) were estimated as the difference between synthesis and deposition. Lysine deficiency reduced (P 0.14). In the pectoralis major muscle, chicks of both lines receiving an adequate lysine intake also exhibited similar protein turnover rates. However, in chicks fed the lysine-deficient (0.75% lysine) diet, FSR and Cs were higher in QL than in CL chicks (P < 0.05), and FBR tended (P = 0.07) to be higher in QL chicks. This increased protein turnover in the QL birds on the lysine-deficient diet suggests that the responsiveness of muscle protein metabolism to amino acid supply is modified by genetic selection for breast development.

  15. Osmolyte regulation by TonEBP/NFAT5 during anoxia-recovery and dehydration–rehydration stresses in the freeze-tolerant wood frog (Rana sylvatica)

    Science.gov (United States)

    Al-attar, Rasha; Zhang, Yichi

    2017-01-01

    Background The wood frog, Rana sylvatica, tolerates freezing as a means of winter survival. Freezing is considered to be an ischemic/anoxic event in which oxygen delivery is significantly impaired. In addition, cellular dehydration occurs during freezing because water is lost to extracellular compartments in order to promote freezing. In order to prevent severe cell shrinkage and cell death, it is important for the wood frog to have adaptive mechanisms for osmoregulation. One important mechanism of cellular osmoregulation occurs through the cellular uptake/production of organic osmolytes like sorbitol, betaine, and myo-inositol. Betaine and myo-inositol are transported by the proteins BGT-1 and SMIT, respectively. Sorbitol on the other hand, is synthesized inside the cell by the enzyme aldose reductase. These three proteins are regulated at the transcriptional level by the transcription factor, NFAT5/TonEBP. Therefore, the objective of this study was to elucidate the role of NFAT5/TonEBP in regulating BGT-1, SMIT, and aldose reductase, during dehydration and anoxia in the wood frog muscle, liver, and kidney tissues. Methods Wood frogs were subjected to 24 h anoxia-4 h recovery and 40% dehydration-full rehydration experiments. Protein levels of NFAT5, BGT-1, SMIT, and aldose reductase were studied using immunoblotting in muscle, liver, and kidney tissues. Results Immunoblotting results demonstrated downregulations in NFAT5 protein levels in both liver and kidney tissues during anoxia (decreases by 41% and 44% relative to control for liver and kidney, respectively). Aldose reductase protein levels also decreased in both muscle and kidney tissues during anoxia (by 37% and 30% for muscle and kidney, respectively). On the other hand, BGT-1 levels increased during anoxia in muscle (0.9-fold compared to control) and kidney (1.1-fold). Under 40% dehydration, NFAT5 levels decreased in liver by 53%. Aldose reductase levels also decreased by 42% in dehydrated muscle, and by

  16. Osmolyte regulation by TonEBP/NFAT5 during anoxia-recovery and dehydration–rehydration stresses in the freeze-tolerant wood frog (Rana sylvatica

    Directory of Open Access Journals (Sweden)

    Rasha Al-attar

    2017-01-01

    Full Text Available Background The wood frog, Rana sylvatica, tolerates freezing as a means of winter survival. Freezing is considered to be an ischemic/anoxic event in which oxygen delivery is significantly impaired. In addition, cellular dehydration occurs during freezing because water is lost to extracellular compartments in order to promote freezing. In order to prevent severe cell shrinkage and cell death, it is important for the wood frog to have adaptive mechanisms for osmoregulation. One important mechanism of cellular osmoregulation occurs through the cellular uptake/production of organic osmolytes like sorbitol, betaine, and myo-inositol. Betaine and myo-inositol are transported by the proteins BGT-1 and SMIT, respectively. Sorbitol on the other hand, is synthesized inside the cell by the enzyme aldose reductase. These three proteins are regulated at the transcriptional level by the transcription factor, NFAT5/TonEBP. Therefore, the objective of this study was to elucidate the role of NFAT5/TonEBP in regulating BGT-1, SMIT, and aldose reductase, during dehydration and anoxia in the wood frog muscle, liver, and kidney tissues. Methods Wood frogs were subjected to 24 h anoxia-4 h recovery and 40% dehydration-full rehydration experiments. Protein levels of NFAT5, BGT-1, SMIT, and aldose reductase were studied using immunoblotting in muscle, liver, and kidney tissues. Results Immunoblotting results demonstrated downregulations in NFAT5 protein levels in both liver and kidney tissues during anoxia (decreases by 41% and 44% relative to control for liver and kidney, respectively. Aldose reductase protein levels also decreased in both muscle and kidney tissues during anoxia (by 37% and 30% for muscle and kidney, respectively. On the other hand, BGT-1 levels increased during anoxia in muscle (0.9-fold compared to control and kidney (1.1-fold. Under 40% dehydration, NFAT5 levels decreased in liver by 53%. Aldose reductase levels also decreased by 42% in

  17. Emerging myxosporean parasites of Australian frogs take a ride with fresh fruit transport

    National Research Council Canada - National Science Library

    Hartigan, Ashlie; Peacock, Lee; Rosenwax, Alex; Phalen, David N; Slapeta, Jan

    2012-01-01

    .... Cystodiscus australis and Cystodiscus axonis are two species of myxosporean parasites infecting Australian frogs and tadpoles that have been recently recognised as important disease agents impacting...

  18. THE DISTRIBUTION OF ICE IN FROZEN TISSUES OF FROGS AND MICE,

    Science.gov (United States)

    and digit free of ice at all temperatures are the stratum corneum in both the frog and the mouse, the stratum compactum in the frog and the fibrous...sheath of the mouse tendon. (4) The epidermis is almost entirely free of ice in frog skin at -1C and in mouse skin at -2C. (5) When ice is formed, the...horizontal connective tissue of the dermis. (6) Ice is present in the tendon of the frog at -5C and -3C, and in that of the mouse at -5C. With excised

  19. Abundance of Green Tree Frogs and Insects in Artificial Canopy Gaps in a Bottomland Hardwood Forest.

    Energy Technology Data Exchange (ETDEWEB)

    Horn, Scott; Hanula, James, L.; Ulyshen, Michael D.; Kilgo, John, C.

    2005-04-01

    ABSTRACT - We found more green tree frogs ( Hyla cinerea) n canopv gaps than in closed canopy forest. Of the 331 green tree frogs observed, 88% were in canopv gaps. Likewise, higher numbers and biomasses of insects were captured in the open gap habitat Flies were the most commonlv collected insect group accounting for 54% of the total capture. These data suggest that one reason green tree frogs were more abundant in canopy gaps was the increased availability of prey and that small canopy gaps provide early successional habitats that are beneficial to green tree frog populations.

  20. [Transfer of the psoas tendon to the, at its origin detached, rectus femoris muscle in infantile cerebral palsy].

    Science.gov (United States)

    Heimkes, B; Engert, K; Stotz, S

    1999-09-01

    Correction of flexion contracture of hip allowing an erect position while standing and walking. The gain in function helps to prevent a neurogenic dislocation of the coxofemoral joint. In infants with cerebral palsy unable to straighten the body before they can stand or walk. In ambulatory spastic children and adolescents with bothersome hip flexion contracture. Severe retardation of motor development in patients with cerebral palsy in whom walking and standing cannot be anticipated. Marked spastic-dystonic muscle weakness. In general, soft tissue releases at hip and knee are performed at the same sitting. Anterior approach to the hip. Detachment of the sartorius from the anterior superior iliac spine and mobilization in a distal direction. Detachment of the rectus femoris from the anterior inferior iliac spine and retraction distally. Exposure of the femoral nerve in the lacuna musculorum. Exposure of the psoas and detachment from the lesser tuberosity. The tendon is mobilized in a proximal direction. Transfer of the rectus tendon on the divided psoas tendon. Reattachment of the sartorius or distal displacement into the fascia of the thigh. A clinical and radiological follow-up of 71 bilaterally operated patients. A pertinent complete radiographic documentation was possible in all but 1 patient. 49.3% (n=35) of patients were able to walk preoperatively compared to 80.3% (n=57) at the time of follow-up. The average migration percentage according to Reimers amounted to 28.4% preoperatively; it had regressed to 18.2% at the time of follow-up. In none of the patients did a subluxation or dislocation occur.

  1. The Genome of the Western Clawed Frog Xenopus tropicalis

    Energy Technology Data Exchange (ETDEWEB)

    Hellsten, Uffe; Harland, Richard M.; Gilchrist, Michael J.; Hendrix, David; Jurka, Jerzy; Kapitonov, Vladimir; Ovcharenko, Ivan; Putnam, Nicholas H.; Shu, Shengqiang; Taher, Leila; Blitz, Ira L.; Blumberg, Bruce; Dichmann, Darwin S.; Dubchak, Inna; Amaya, Enrique; Detter, John C.; Fletcher, Russell; Gerhard, Daniela S.; Goodstein, David; Graves, Tina; Grigoriev, Igor V.; Grimwood, Jane; Kawashima, Takeshi; Lindquist, Erika; Lucas, Susan M.; Mead, Paul E.; Mitros, Therese; Ogino, Hajime; Ohta, Yuko; Poliakov, Alexander V.; Pollet, Nicolas; Robert, Jacques; Salamov, Asaf; Sater, Amy K.; Schmutz, Jeremy; Terry, Astrid; Vize, Peter D.; Warren, Wesley C.; Wells, Dan; Wills, Andrea; Wilson, Richard K.; Zimmerman, Lyle B.; Zorn, Aaron M.; Grainger, Robert; Grammer, Timothy; Khokha, Mustafa K.; Richardson, Paul M.; Rokhsar, Daniel S.

    2009-10-01

    The western clawed frog Xenopus tropicalis is an important model for vertebrate development that combines experimental advantages of the African clawed frog Xenopus laevis with more tractable genetics. Here we present a draft genome sequence assembly of X. tropicalis. This genome encodes over 20,000 protein-coding genes, including orthologs of at least 1,700 human disease genes. Over a million expressed sequence tags validated the annotation. More than one-third of the genome consists of transposable elements, with unusually prevalent DNA transposons. Like other tetrapods, the genome contains gene deserts enriched for conserved non-coding elements. The genome exhibits remarkable shared synteny with human and chicken over major parts of large chromosomes, broken by lineage-specific chromosome fusions and fissions, mainly in the mammalian lineage.

  2. Vocal acrobatics in a Chinese frog, Amolops tormotus

    Science.gov (United States)

    Feng, Albert; Narins, Peter; Xu, Chun-He

    2002-06-01

    Although amphibians are highly vocal, they generally emit only a limited number of acoustic communication signals. We report here the extraordinarily rich vocal repertoire of Amolops tormotus, a ranid species in China. These frogs produce countless vocalizations, some of which share features of birdsong or primate calls, e.g., ultrasonic frequency components, multiple upward and downward FM sweeps, and sudden onset and offset of selective harmonic components within a call note. Frame-by-frame video analysis of the frog's calling behavior suggests the presence of two pairs of vocal sacs that may contribute to the remarkable call-note complexity in this species. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00114-002-0335-x.

  3. The rediscovered Hula painted frog is a living fossil.

    Science.gov (United States)

    Biton, Rebecca; Geffen, Eli; Vences, Miguel; Cohen, Orly; Bailon, Salvador; Rabinovich, Rivka; Malka, Yoram; Oron, Talya; Boistel, Renaud; Brumfeld, Vlad; Gafny, Sarig

    2013-01-01

    Amphibian declines are seen as an indicator of the onset of a sixth mass extinction of life on earth. Because of a combination of factors such as habitat destruction, emerging pathogens and pollutants, over 156 amphibian species have not been seen for several decades, and 34 of these were listed as extinct by 2004. Here we report the rediscovery of the Hula painted frog, the first amphibian to have been declared extinct. We provide evidence that not only has this species survived undetected in its type locality for almost 60 years but also that it is a surviving member of an otherwise extinct genus of alytid frogs, Latonia, known only as fossils from Oligocene to Pleistocene in Europe. The survival of this living fossil is a striking example of resilience to severe habitat degradation during the past century by an amphibian.

  4. Contractile reaction of isolated frog aorta after X-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Michailov, M.C.; Prechter, I.; Greimel, H.; Welscher, U.E.

    1983-07-01

    The action of X-rays (50 kV, filtered by 0.3 mm Al) on helical strip of frog aorta (rana esculenta) has been investigated. The isolated preparations have a stable basal tone and are radio-sensitive to X-rays which induce reversible, dose-dependent, contractile responses. After repeated irradiational tachyphylaxis appears. The threshold doses are about 250 R at 3 to 6 kR/min, antiadrenergic (phentolamine, propranolol), anticholinergic (atropin), antihistaminic (Neo-Bridal) and serotoninergic (Deseril) drugs have no visible influence on the X-ray induced reaction, i.e. these action mechanisms of the irradiation-induced contraction do not seem probable. Theophylline and cAMP inhibit the X-ray contraction probably non-specifically. Indometacin also inhibits the X-ray contraction: this suggests participation of prostaglandin-mechanism on the contraction of frog aorta after irradiation.

  5. The genome of the Western clawed frog Xenopus tropicalis.

    Science.gov (United States)

    Hellsten, Uffe; Harland, Richard M; Gilchrist, Michael J; Hendrix, David; Jurka, Jerzy; Kapitonov, Vladimir; Ovcharenko, Ivan; Putnam, Nicholas H; Shu, Shengqiang; Taher, Leila; Blitz, Ira L; Blumberg, Bruce; Dichmann, Darwin S; Dubchak, Inna; Amaya, Enrique; Detter, John C; Fletcher, Russell; Gerhard, Daniela S; Goodstein, David; Graves, Tina; Grigoriev, Igor V; Grimwood, Jane; Kawashima, Takeshi; Lindquist, Erika; Lucas, Susan M; Mead, Paul E; Mitros, Therese; Ogino, Hajime; Ohta, Yuko; Poliakov, Alexander V; Pollet, Nicolas; Robert, Jacques; Salamov, Asaf; Sater, Amy K; Schmutz, Jeremy; Terry, Astrid; Vize, Peter D; Warren, Wesley C; Wells, Dan; Wills, Andrea; Wilson, Richard K; Zimmerman, Lyle B; Zorn, Aaron M; Grainger, Robert; Grammer, Timothy; Khokha, Mustafa K; Richardson, Paul M; Rokhsar, Daniel S

    2010-04-30

    The western clawed frog Xenopus tropicalis is an important model for vertebrate development that combines experimental advantages of the African clawed frog Xenopus laevis with more tractable genetics. Here we present a draft genome sequence assembly of X. tropicalis. This genome encodes more than 20,000 protein-coding genes, including orthologs of at least 1700 human disease genes. Over 1 million expressed sequence tags validated the annotation. More than one-third of the genome consists of transposable elements, with unusually prevalent DNA transposons. Like that of other tetrapods, the genome of X. tropicalis contains gene deserts enriched for conserved noncoding elements. The genome exhibits substantial shared synteny with human and chicken over major parts of large chromosomes, broken by lineage-specific chromosome fusions and fissions, mainly in the mammalian lineage.

  6. Effects of Dimethoate on Tree Frog (Hyla arborea) Larvae

    OpenAIRE

    Ferah SAYIM; Kaya, Uğur

    2006-01-01

    Considering the global decline of amphibian populations, the present study aimed to investigate the sensitivity of tree frogs to a common pesticide, dimethoate. Our study reports the effects of dimethoate on 21st- and 25th-stage Hyla arborea larvae under standardized laboratory conditions in an acute toxicity test using the static system. Specimens used for testing were obtained from the eggs of mating pairs collected at a local natural pond. Each experimental group contained 10 healthy larva...

  7. Effect of Krebs cycle metabolites on frog heart.

    Science.gov (United States)

    Chopde, C T; Dorle, A K; Brahmankar, D M

    1975-01-01

    All the Krebs metabolites except pyruvate, lactate, acetate and succinate reduced the force and rate of myocardial contractions and also decreased cardiac output in frog. Succinate on the contrary was found to augment the rate and force of heart. The cardiac stimulation produced by epinephrine was reduced by fumarate, malate, oxaloacetate and alpha-oxoglutarate, whereas transaconitate and citrate produced only a slight inhibition. Pyruvate, lactate, acetate and succinate did not alter cardiac response to epinephrine.

  8. Muscle MRI findings in patients with limb girdle muscular dystrophy with calpain 3 deficiency (LGMD2A) and early contractures.

    Science.gov (United States)

    Mercuri, Eugenio; Bushby, Kate; Ricci, Enzo; Birchall, Daniel; Pane, Marika; Kinali, Maria; Allsop, Joanna; Nigro, Vincenzo; Sáenz, Amets; Nascimbeni, Annachiara; Fulizio, Luigi; Angelini, Corrado; Muntoni, Francesco

    2005-02-01

    Limb girdle muscular dystrophy 2A is a common variant secondary to mutations in the calpain 3 gene. A proportion of patients has early and severe contractures, which can cause diagnostic difficulties with other conditions. We report clinical and muscle magnetic resonance imaging findings in seven limb girdle muscular dystrophy 2A patients (four sporadic and three familial) who had prominent and early contractures. All patients showed a striking involvement of the posterior thigh muscles. The involvement of the other thigh muscles was variable and was related to clinical severity. Young patients with minimal functional motor impairment showed a predominant involvement of the adductors and semimembranosus muscles while patients with restricted ambulation had a more diffuse involvement of the posterolateral muscles of the thigh and of the vastus intermedius with relative sparing of the vastus lateralis, sartorius and gracilis. At calf level all patients showed involvement of the soleus muscle and of the medial head of the gastrocnemius with relative sparing of the lateral head. MRI findings were correlated to those found in two patients with the phenotype of limb girdle muscular dystrophy 2A without early contractures and the pattern observed was quite similar. However, the pattern observed in limb girdle muscular dystrophy 2A is different from that reported in other muscle diseases such as Emery-Dreifuss muscular dystrophy and Bethlem myopathy which have a significant clinical overlap with limb girdle muscular dystrophy 2A once early contractures are present. Our results suggest that muscle MRI may help in recognising patients with limb girdle muscular dystrophy 2A even when the clinical presentation overlaps with other conditions, and may therefore, be used as an additional investigation to target the appropriate biochemical and genetic tests.

  9. Develop Inventory Protocols for frogs within the Region 1 Great Northern and Great Basin LCC, Protocol Development & Remote Audial Inventory

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Many refuges lack basic information on distribution of frogs, but conducting inventory surveys for frogs can be problematic. Different species breed at different...

  10. Correlation between chloride flux via the mitochondria-rich cells and transepithelial water movement in isolated frog skin (Rana esculenta)

    DEFF Research Database (Denmark)

    Nielsen, Robert

    1995-01-01

    Antidiuretic hormone; chloride transport; electroosmosis; Frog skin; Intercalated cells; Local osmosis; Mitochondria-rich cells.......Antidiuretic hormone; chloride transport; electroosmosis; Frog skin; Intercalated cells; Local osmosis; Mitochondria-rich cells....

  11. Electrophysiological evidence for an ATP-gated ion channel in the principal cells of the frog skin epithelium

    DEFF Research Database (Denmark)

    Brodin, Birger; Nielsen, Robert

    2000-01-01

    P2X receptor, Na+ absorption, Short circuit current, Cell potential, Microelectrodes, Frog skin, Cytosolic Ca2+......P2X receptor, Na+ absorption, Short circuit current, Cell potential, Microelectrodes, Frog skin, Cytosolic Ca2+...

  12. Effects of the herbicide imazapyr on juvenile Oregon spotted frogs.

    Science.gov (United States)

    Yahnke, Amy E; Grue, Christian E; Hayes, Marc P; Troiano, Alexandra T

    2013-01-01

    Conflict between native amphibians and aquatic weed management in the Pacific Northwest is rarely recognized because most native stillwater-breeding amphibian species move upland during summer, when herbicide application to control weeds in aquatic habitats typically occurs. However, aquatic weed management may pose a risk for aquatic species present in wetlands through the summer, such as the Oregon spotted frog (OSF, Rana pretiosa), a state endangered species in Washington. Acute toxicity of herbicides used to control aquatic weeds tends to be low, but the direct effects of herbicide tank mixes on OSFs have remained unexamined. We exposed juvenile OSFs to tank mixes of the herbicide imazapyr, a surfactant, and a marker dye in a 96-h static-renewal test. The tank mix was chosen because of its low toxicity to fish and its effectiveness in aquatic weed control. Concentrations were those associated with low-volume (3.5 L/ha) and high-volume (7.0 L/ha) applications of imazapyr and a clean-water control. Following exposure, frogs were reared for two months in clean water to identify potential latent effects on growth. Endpoints evaluated included feeding behavior, growth, and body and liver condition indices. We recorded no mortalities and found no significant differences for any end point between the herbicide-exposed and clean-water control frogs. The results suggest that imazapyr use in wetland restoration poses a low risk of direct toxic effects on juvenile OSFs. Copyright © 2012 SETAC.

  13. Effects of the herbicide imazapyr on juvenile Oregon spotted frogs

    Science.gov (United States)

    Yahnke, Amy E.; Grue, Christian E.; Hayes, Marc P.; Troiano, Alexandra T.

    2013-01-01

    Conflict between native amphibians and aquatic weed management in the Pacific Northwest is rarely recognized because most native stillwater-breeding amphibian species move upland during summer, when herbicide application to control weeds in aquatic habitats typically occurs. However, aquatic weed management may pose a risk for aquatic species present in wetlands through the summer, such as the Oregon spotted frog (OSF, Rana pretiosa), a state endangered species in Washington. Acute toxicity of herbicides used to control aquatic weeds tends to be low, but the direct effects of herbicide tank mixes on OSFs have remained unexamined. We exposed juvenile OSFs to tank mixes of the herbicide imazapyr, a surfactant, and a marker dye in a 96-h static-renewal test. The tank mix was chosen because of its low toxicity to fish and its effectiveness in aquatic weed control. Concentrations were those associated with low-volume (3.5 L/ha) and high-volume (7.0 L/ha) applications of imazapyr and a clean-water control. Following exposure, frogs were reared for two months in clean water to identify potential latent effects on growth. Endpoints evaluated included feeding behavior, growth, and body and liver condition indices. We recorded no mortalities and found no significant differences for any end point between the herbicide-exposed and clean-water control frogs. The results suggest that imazapyr use in wetland restoration poses a low risk of direct toxic effects on juvenile OSFs.

  14. Chronic exposures to monomethyl phthalate in Western clawed frogs.

    Science.gov (United States)

    Mathieu-Denoncourt, Justine; de Solla, Shane R; Langlois, Valerie S

    2015-08-01

    Polymer flexibility and elasticity is enhanced by plasticizers. However, plasticizers are often not covalently bound to plastics and thus can leach from products into the environment. Much research effort has focused on their effects in mammalian species, but data on aquatic species are scarce. In this study, Western clawed frog (Silurana tropicalis) embryos were exposed to 1.3, 12.3, and 128.7mg/L monomethyl phthalate (MMP) until the juvenile stage (11weeks) and to 1.3mg/L MMP until the adult stage (51weeks). MMP decreased survival, hastened metamorphosis, and biased the sex ratio toward males (2M:1F) at the juvenile stage without altering the expression of a subset of thyroid hormone-, sex steroid-, cellular stress- or transcription regulation-related genes in the juvenile frog livers. At the adult stage, exposure to MMP did not have significant adverse health effects, except that females had larger interocular distance and the expression of the heat shock protein 70 was decreased by 60% in the adult liver. In conclusion, this study shows that MMP is unlikely to threaten amphibian populations as only concentrations four orders of magnitude higher than the reported environmental concentrations altered the animal physiology. This is the first complete investigation of the effects of phthalates in a frog species, encompassing the entire life cycle of the organisms. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

  15. Polyandry, Predation, and the Evolution of Frog Reproductive Modes.

    Science.gov (United States)

    Zamudio, Kelly R; Bell, Rayna C; Nali, Renato C; Haddad, Célio F B; Prado, Cynthia P A

    2016-09-01

    Frog reproductive modes are complex phenotypes that include egg/clutch characteristics, oviposition site, larval development, and sometimes, parental care. Two evident patterns in the evolution of these traits are the higher diversity of reproductive modes in the tropics and the apparent progression from aquatic to terrestrial reproduction, often attributed to higher fitness resulting from decreased predation on terrestrial eggs and tadpoles. Here, we propose that sexual selection-and not only natural selection due to predation-favors terrestrial breeding by reducing the loss of fitness due to polyandry. To examine this novel selective mechanism, we reconstructed the evolution of reproductive diversity in two frog families (Hylidae and Leptodactylidae) and tested for concerted evolution of egg and tadpole development sites with specific mating behaviors. We found that oviposition and tadpole development sites are evolving independently, do not show the same diversity and/or directionality in terms of terrestriality, and thus may be diversifying due to different selective mechanisms. In both families, terrestrial egg deposition is correlated with amplexus that is hidden from competing males, and in hylids, testes mass was significantly larger and more variable in males with exposed amplexus that are vulnerable to polyandry. Our results indicate that intrasexual selection has been an underappreciated mechanism promoting diversification of frog reproductive modes.

  16. Eugenol for anesthesia of African clawed frogs (Xenopus laevis).

    Science.gov (United States)

    Guénette, Sarah A; Hélie, Pierre; Beaudry, Francis; Vachon, Pascal

    2007-05-01

    To determine the level of anesthesia attained in Xenopus laevis frogs with eugenol at different doses and by different routes of administration. Prospective experimental trial. Sixty X. laevis nonbreeding female frogs weighing between 90 and 140 g. Three different routes of administration were tested - subcutaneous injections into the dorsal lymph sacs, topical administration using a gauze patch, and immersion in a bath containing eugenol. Following the determination of the best route of administration, the acetic acid test, the withdrawal reflex, righting reflex, heart rate, and respiratory frequency were used to evaluate central nervous system depression following eugenol bath administration. In an additional group, the response to a surgical incision of the abdominal wall was evaluated. The pharmacokinetics of eugenol were determined following bath immersion administration, and pharmacokinetic parameters were calculated following blood concentration determination by tandem liquid chromatography/mass spectrometry analyses. It was not possible to induce anethesia with subcutaneous and patch administration, independent of the eugenol dose administered. The immersion bath was the only efficacious route for anesthesia inducing surgical anesthesia for at least 30 minutes with postoperative analgesia. Histopathology of selected tissues (heart, lung, liver, kidneys, eyes) showed no evidence of lesions 24 hours following bath immersion. The elimination half-life (T(1/2)) was 4 hours. When administered as a single-bath immersion (dose 350 mg L(-1)) for 15 minutes, eugenol may serve as an effective anesthetic in X. laevis frogs for short surgical procedures.

  17. Frog meat microbiota (Lithobates catesbeianus used in infant food

    Directory of Open Access Journals (Sweden)

    Eliane Rodrigues

    2014-03-01

    Full Text Available Captive breeding of bullfrog (Lithobates catesbeianus is of great economic potential, mainly for its thighs and leather. The nutritional quality of frog meat includes properly balanced amino acids with a protein profile of high biological value, low fat and low cholesterol, and high digestibility due to its short chain molecule structure. It is recommended by doctors and nutritionists, especially for protein restricted children or malnourished children. Aiming to aggregate value to the segment and offer a product with nutritional properties that meet the need of children aged six months and above, a meat product based on the composition of frog meat was developed experimentally. To ensure raw material quality after bleaching and deboning, the microbiota present in the frog meat was determined. The analyses were performed according to Brazilian laws. It was observed that the resident and transient microbiota met the standards set by regulations. The results found were: mesophyll 4.5 x 10(4 CFU/g; Staphylococcus coagulase positive 2.0 x 10² CFU/g; negative for Salmonella sp. and Aeromonas spp. The findings indicate that the raw material showed satisfactory sanitation even in terms of family industry.

  18. Developmental aspects of the direct-developing frog Adelophryne maranguapensis.

    Science.gov (United States)

    de Lima, Ana V P; Reis, Alice H; Amado, Nathália G; Cassiano-Lima, Daniel; Borges-Nojosa, Diva M; Oriá, Reinaldo B; Abreu, José G

    2016-05-01

    Direct development in amphibians is characterized by the loss of aquatic breeding. The anuran Adelophryne maranguapensis is one example of a species with direct development, and it is endemic to the state of Ceará, Brazil. Detailed morphological features of A. maranguapensis embryos and the stages of sequential development have not been described before. Here, we analyzed all available genetic sequence tags in A. maranguapensis (tyr exon 1, pomc and rag1) and compared them with sequences from other species of Adelophryne frogs. We describe the A. maranguapensis reproductive tract and embryonic body development, with a focus on the limbs, tail, ciliated cells of the skin, and the egg tooth, which were analyzed using scanning electron microscopy. Histological analyses revealed ovaries containing oocytes surrounded by follicular cells, displaying large nuclei with nucleoli inside. Early in development, the body is unpigmented, and the neural tube forms dorsally to the yolk vesicle, typical of a direct-developing frog embryo. The hindlimbs develop earlier than the forelimbs. Ciliated cells are abundant during the early stages of skin development and are less common during later stages. The egg tooth appears in the later stages and develops as a keratinized microridge structure. The developmental profile of A. maranguapensis presented here will contribute to our understanding of the direct-development model and may help preserve this endangered native Brazilian frog. genesis 54:257-271, 2016. © 2016 Wiley Periodicals, Inc.

  19. Hot and steady: Elevated temperatures do not enhance muscle disuse atrophy during prolonged aestivation in the ectotherm Cyclorana alboguttata.

    Science.gov (United States)

    Young, K M; Cramp, R L; Franklin, C E

    2013-02-01

    Animals that undergo prolonged dormancy experience minimal muscle disuse atrophy (MDA) compared to animals subjected to artificial immobilisation over shorter timeframes. An association between oxidative stress and MDA suggests that metabolic depression presumably affords dormant animals some protection against muscle disuse. Because aerobic metabolism is temperature sensitive, we proposed that MDA in dormant (aestivating) ectotherms would be enhanced at elevated temperatures. In the green-striped burrowing frog, Cyclorana alboguttata, the thermal sensitivity of skeletal muscle metabolic rate is muscle-specific. We proposed that the degree of atrophy experienced during aestivation would correlate with the thermal sensitivity of muscle metabolic rate such that muscles with a relatively high metabolic rate at high temperatures would experience more disuse atrophy. To test this hypothesis, we examined the effect of temperature and aestivation on the extent of MDA in two functionally different muscles: the M. gastrocnemius (jumping muscle) and M. iliofibularis (non-jumping muscle), in C. alboguttata aestivating at 24 or 30 °C for 6 months. We compared a range of morphological parameters from muscle cross-sections stained with succinic dehydrogenase to show that muscle-specific patterns of disuse atrophy were consistent with the relative rates of oxygen consumption of those muscle types. However, despite muscle-specific differences in thermal sensitivity of metabolic rate, aestivation temperature did not influence the extent of atrophy in either muscle. Our results suggest that the muscles of frogs aestivating at high temperatures are defended against additional atrophy ensuring protection of muscle function during long periods of immobilisation.

  20. An Effective Hybrid Cuckoo Search Algorithm with Improved Shuffled Frog Leaping Algorithm for 0-1 Knapsack Problems

    OpenAIRE

    2014-01-01

    An effective hybrid cuckoo search algorithm (CS) with improved shuffled frog-leaping algorithm (ISFLA) is put forward for solving 0-1 knapsack problem. First of all, with the framework of SFLA, an improved frog-leap operator is designed with the effect of the global optimal information on the frog leaping and information exchange between frog individuals combined with genetic mutation with a small probability. Subsequently, in order to improve the ...

  1. An addition to the diversity of dendrobatid frogs in Venezuela: description of three new collared frogs (Anura: Dendrobatidae: Mannophryne

    Directory of Open Access Journals (Sweden)

    César Luis Barrio-Amorós

    2010-07-01

    Full Text Available Three new species of collared frogs of the genus Mannophryne are described from Venezuela. Two are newly discovered taxa from the Venezuelan Andes, whereas the third species, previously confused with M. trinitatis, is from the Caracas area in the Cordillera de la Costa. The call of the three new species and that of Mannophryne collaris are described. Taxonomic, zoogeographic, and conservation issues are discussed.

  2. Amphibian (Xenopus laevis) tadpoles and adult frogs mount distinct interferon responses to the Frog Virus 3 ranavirus.

    Science.gov (United States)

    Wendel, Emily S; Yaparla, Amulya; Koubourli, Daphne V; Grayfer, Leon

    2017-03-01

    Infections of amphibians by Frog Virus 3 (FV3) and other ranavirus genus members are significantly contributing to the amphibian declines, yet much remains unknown regarding amphibian antiviral immunity. Notably, amphibians represent an important step in the evolution of antiviral interferon (IFN) cytokines as they are amongst the first vertebrates to possess both type I and type III IFNs. Accordingly, we examined the roles of type I and III IFNs in the skin of FV3-challenged amphibian Xenopus laevis) tadpoles and adult frogs. Interestingly, FV3-infected tadpoles mounted type III IFN responses, whereas adult frogs relied on type I IFN immunity. Subcutaneous administration of type I or type III IFNs offered short-term protection of tadpoles against FV3 and these type I and type III IFNs induced the expression of distinct antiviral genes in the tadpole skin. Moreover, subcutaneous injection of tadpoles with type III IFN significantly extended their survival and reduced FV3 dissemination. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. 76 FR 45602 - Proposed Safe Harbor Agreement for California Red-Legged Frog, at Swallow Creek Ranch, San Luis...

    Science.gov (United States)

    2011-07-29

    ... Fish and Wildlife Service Proposed Safe Harbor Agreement for California Red-Legged Frog, at Swallow... the Federally threatened California red-legged frog (Rana draytonii), under the Endangered Species Act... California red-legged frog on the property subject to the Agreement (Enrolled Property), which is owned...

  4. Establishment of a recording method for surface electromyography in the iliopsoas muscle.

    Science.gov (United States)

    Jiroumaru, Takumi; Kurihara, Toshiyuki; Isaka, Tadao

    2014-08-01

    We examined the availability and reliability of surface electromyography (EMG) signals from the iliopsoas muscle (IL). Using serial magnetic resonance images from fifty healthy young males, we evaluated whether the superficial region of IL was adequate for attaching surface EMG electrodes. Subsequently, we assessed EMG cross-talk from the sartorius muscle (SA)-the nearest to IL-using a selective cooling method in fourteen subjects. The skin above SA was cooled, and the median frequencies of EMG signals from IL and SA were determined. The maximum voluntary contraction during isometric hip flexion was measured before and after selective cooling, and surface EMG signals from SA and IL were measured. The superficial area of IL was adequately large (13.2±2.7cm(2)) for recording surface EMG in all fifty subjects. The maximum perimeter for the medial-lateral skin facing IL was noted at a level 3-5cm distal to the anterior superior iliac spine. Following cooling, the median frequency for SA decreased significantly (from 70.1 to 51.9Hz, pEMG cross-talk from SA was negligible for surface EMG signals from IL during hip flexion.

  5. Phylogeography of Declining Relict and Lowland Leopard Frogs in the Desert Southwest of North America

    Science.gov (United States)

    We investigated the phylogeography of the closely related relict leopard frog (Rana onca) and lowland leopard frog (R. yavapaiensis) – two declining anurans from the warm-desert regions of southwestern North America. We used sequence data from two mitochondrial DNA genes to asses...

  6. Complex and transitive synchronization in a frustrated system of calling frogs

    Science.gov (United States)

    Aihara, Ikkyu; Takeda, Ryu; Mizumoto, Takeshi; Otsuka, Takuma; Takahashi, Toru; Okuno, Hiroshi G.; Aihara, Kazuyuki

    2011-03-01

    This letter reports synchronization phenomena and mathematical modeling on a frustrated system of living beings, or Japanese tree frogs (Hyla japonica). While an isolated male Japanese tree frog calls nearly periodically, he can hear sounds including calls of other males. Therefore, the spontaneous calling behavior of interacting males can be understood as a system of coupled oscillators. We construct a simple but biologically reasonable model based on the experimental results of two frogs, extend the model to a system of three frogs, and theoretically predict the occurrence of rich synchronization phenomena, such as triphase synchronization and 1:2 antiphase synchronization. In addition, we experimentally verify the theoretical prediction by ethological experiments on the calling behavior of three frogs and time series analysis on recorded sound data. Note that the calling behavior of three male Japanese tree frogs is frustrated because almost perfect antiphase synchronization is robustly observed in a system of two male frogs. Thus, nonlinear dynamics of the three-frogs system should be far from trivial.

  7. The toxicity of Poison Dart Frog alkaloids against the Fire Ant (Solenopsis invicta)

    Science.gov (United States)

    Hundreds of alkaloids, representing over 20 structural classes, have been identified from the skin of neotropical poison frogs (Dendrobatidae). These alkaloids are derived from arthropod prey of the frogs, and are generally are believed to deter vertebrate predators. We developed a method to put ind...

  8. Population estimates for the Toiyabe population of the Columbia spotted frog (Rana luteiventris), 2004–10

    Science.gov (United States)

    Adams, Michael J.; Mellison, Chad; Galvan, Stephanie K.

    2013-01-01

    The Toiyabe population of Columbia spotted frogs (Rana luteiventris, hereafter "Toiyabe frogs") is a geographically isolated population located in central Nevada (fig. 1). The Toiyabe population is part of the Great Basin Distinct Population Segment of Columbia spotted frogs, and is a candidate for listing under the Endangered Species Act (U.S. Fish and Wildlife Service, 2011). The cluster of breeding sites in central Nevada represents the southernmost extremity of the Columbia spotted frogs' known range (Funk and others, 2008). Toiyabe frogs are known to occur in seven drainages in Nye County, Nevada: Reese River, Cow Canyon Creek, Ledbetter Canyon Creek, Cloverdale Creek, Stewart Creek, Illinois Creek, and Indian Valley Creek. Most of the Toiyabe frog population resides in the Reese River, Indian Valley Creek, and Cloverdale Creek drainages (fig. 1; Nevada Department of Wildlife, 2003). Approximately 90 percent of the Toiyabe frogs' habitat is on public land. Most of the public land habitat (95 percent) is managed by the U.S. Forest Service (USFS), while the Bureau of Land Management (BLM) manages the remainder. Additional Toiyabe frog habitat is under Yomba Shoshone Tribal management and in private ownership (Nevada Department of Wildlife, 2003). The BLM, USFS, Nevada Department of Wildlife (NDOW), Nevada Natural Heritage Program (NNHP), Nye County, and U.S Fish and Wildlife Service (USFWS) have monitored the Toiyabe population since 2004 using mark and recapture surveys (Nevada Department of Wildlife, 2004). The USFWS contracted with the U.S. Geological Survey (USGS) to produce population estimates using these data.

  9. Propulsive force calculations in swimming frogs II. Application of a vortex ring model to DPIV data

    NARCIS (Netherlands)

    Stamhuis, EJ; Nauwelaerts, S

    2005-01-01

    Frogs propel themselves by kicking water backwards using a synchronised extension of their hind limbs and webbed feet. To understand this propulsion process, we quantified the water movements and displacements resulting from swimming in the green frog Rana esculenta, applying digital particle image

  10. Rate of protein synthesis and polyribosome formation in the frog pancreas after fasting and feeding

    NARCIS (Netherlands)

    Venrooij, W.J. van; Poort, C.

    1972-01-01

    1. 1. The rate of incorporation of [14C]leucine into the proteins of the frog pancreas was measured after the animals had been fasted or fed. The incorporation rate increased after feeding, being maximal at about 4 h after the meal. 2. 2. In homogenates of pancreases from fasted frogs only monoribo

  11. Comparison of RABITT and FROG measurements in the temporal characterization of attosecond pulse trains

    CERN Document Server

    Kim, Kyung Taec; Park, Mi Na; Imran, Tayyab; Umesh, G; Nam, Chang Hee

    2007-01-01

    The attosecond high harmonic pulses obtained from a long Ar-filled gas cell were characterized by two techniques - the reconstruction of attosecond beating by interference of two-photon transition (RABITT) and frequency-resolved optical gating (FROG) methods. The pulse durations obtained by RABITT and FROG methods agreed within 10 %.

  12. Bacterial flora on Cascades frogs in the Klamath Mountains of California

    Science.gov (United States)

    Karen Pope

    2013-01-01

    Amphibians are experiencing global declines due in part to the infectious disease chytridiomycosis. Some symbiotic bacteria residents on frog skin have been shown to inhibit the growth of Batrachochytrium dendrobatitis (Bd) but few studies have attempted to fully describe the resident bacterial flora of frog skin. We cultured and sequenced 130...

  13. Oregon spotted frog (Rana pretiosa) monitoring at Jack Creek 2015-2016

    Science.gov (United States)

    Adams, Michael J.; Pearl, Christopher A.; Mccreary, Brome; Galvan, Stephanie; Rowe, Jennifer

    2017-01-01

    This dataset contains information from mark-recapture and egg mass surveys conducted 2015-2016 by USGS as part of an ongoing Oregon spotted frog (Rana pretiosa) monitoring effort at Jack Creek, Klamath County, Oregon. Data consist of spotted frog counts aggregated by date, location, life stage, and sex, as well as data on environmental conditions at the time each survey.

  14. Multistate outbreak of human Salmonella typhimurium infections associated with aquatic frogs - United States, 2009.

    Science.gov (United States)

    2010-01-08

    During April-July 2009, the Utah Department of Health identified five cases of Salmonella Typhimurium infection with indistinguishable pulsed-field gel electrophoresis (PFGE) patterns, predominantly among children. In August, CDC began a multistate outbreak investigation to determine the source of the infections. This report summarizes the results of this ongoing investigation, which, as of December 30, had identified 85 S. Typhimurium human isolates with the outbreak strain from 31 states. In a multistate case-control study, exposure to frogs was found to be significantly associated with illness (63% of cases versus 3% of controls; matched odds ratio [mOR] = 24.4). Among 14 case-patients who knew the type of frog, all had exposure to an exclusively aquatic frog species, the African dwarf frog. Environmental samples from aquariums containing aquatic frogs in four homes of case-patients yielded S. Typhimurium isolates matching the outbreak strain. Preliminary traceback information has indicated these frogs likely came from the same breeder in California. Reptiles (e.g., turtles) and amphibians (e.g., frogs) have long been recognized as Salmonella carriers, and three multistate outbreaks of human Salmonella infections associated with turtle contact have occurred since 2006. However, this is the first reported multistate outbreak of Salmonella infections associated with amphibians. Educational materials aimed at preventing salmonellosis from contact with reptiles should be expanded to include amphibians, such as aquatic frogs.

  15. BIOSENSING TECHNICS FOR HUMAN DETECTION. 1. THE FROG SKIN TRANSDUCER: PRELIMINARY EXPERIMENT

    Science.gov (United States)

    Isolated frog skin used as a transducer whose bioelectrical potential is measured as a function of chemical species and concentration, is shown to...log units. A high degree of variability of response between frog skins, and a lack of data on ultimate sensitivities at usefully low levels for selected substances, are major problems that remain to be examined.

  16. SOME PROPERTIES OF THE AFFERENT PATHWAY IN THE FROG CORNEAL REFLEX,

    Science.gov (United States)

    evidence on the neurological basis of stimulus specificity. The frog corneal reflex is particularly well suited for this type of study, since the stimulus...conducted on normal adult frogs . The results provide a new basis for study of animals with transplanted sensory tissue. (Author)

  17. Phylogeography of Declining Relict and Lowland Leopard Frogs in the Desert Southwest of North America

    Science.gov (United States)

    We investigated the phylogeography of the closely related relict leopard frog (Rana onca) and lowland leopard frog (R. yavapaiensis) – two declining anurans from the warm-desert regions of southwestern North America. We used sequence data from two mitochondrial DNA genes to asses...

  18. Flesh fly myiasis (Diptera, Sarcophagidae in Peruvian poison frogs genus Epipedobates (Anura, Dendrobatidae

    Directory of Open Access Journals (Sweden)

    Mattias Hagman

    2005-10-01

    Full Text Available In this note we review records of myiasis in poison frogs collected in various locations in Peru during 1982-2005 and present evidence that larger and medium-sized poison frogs (Epipedobates are infected with sarcophagid fly larvae.

  19. Propulsive force calculations in swimming frogs I. A momentum-impulse approach

    NARCIS (Netherlands)

    Nauwelaerts, S; Stamhuis, EJ; Aerts, P

    Frogs are animals that are capable of locomotion in two physically different media, aquatic and terrestrial. A comparison of the kinematics of swimming frogs in a previous study revealed a difference in propulsive impulse between jumping and swimming. To explore this difference further, we

  20. Hematological, Biochemical and Histopathological Studies on Marsh Frog, Rana ridibunda, Naturally Infected with Waltonella duboisi

    Directory of Open Access Journals (Sweden)

    A.M. Al-Attar

    2010-01-01

    Full Text Available The present study was aimed to evaluate the impact of Waltonella duboisi naturally infection in the marsh frog, Rana ridibunda. Healthy and infected frogs of both sexes were collected from Al-Qatif and Al-Hassa farms, Eastern Province, Saudi Arabia. The hematological, biochemical and histopathological changes were estimated in infected male and female frogs compared with healthy frogs. The values of red blood cell count, hemoglobin concentration, hematocrit, mean cell volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration and white blood cell count were statistically decreased in infected frogs. Infection with Waltonella duboisi induced significant reduction in the levels of serum glucose and total proteins, while the values of triglycerides cholesterol, creatinine, glutamic pyruvic acid transaminase and glutamic oxaloacetic acid transaminase were significantly elevated. Histopathological examination of stomach, small intestine, liver showed the larval developmental stages of Waltonella duboisi. A partially abnormal of testis and ovary structures with pronounced disturbance in quantity and quality of spermatogenesis and oogenesis processes were noted in infected of both sexes of frogs. From the present study, it is obviously that Waltonella duboisi caused many severe physiological and histopathological alterations in both sexes of the marsh frogs. Thus, more sincere ecological and scientific efforts are required to rescue the marsh frog population from parasitic infection, pathogenic factors and increases of mortality rate.

  1. Species-specific loss of sexual dimorphism in vocal effectors accompanies vocal simplification in African clawed frogs (Xenopus)

    Science.gov (United States)

    Leininger, Elizabeth C.; Kitayama, Ken; Kelley, Darcy B.

    2015-01-01

    ABSTRACT Phylogenetic studies can reveal patterns of evolutionary change, including the gain or loss of elaborate courtship traits in males. Male African clawed frogs generally produce complex and rapid courtship vocalizations, whereas female calls are simple and slow. In a few species, however, male vocalizations are also simple and slow, suggesting loss of male-typical traits. Here, we explore features of the male vocal organ that could contribute to loss in two species with simple, slow male calls. In Xenopus boumbaensis, laryngeal morphology is more robust in males than in females. Larynges are larger, have a more complex cartilaginous morphology and contain more muscle fibers. Laryngeal muscle fibers are exclusively fast-twitch in males but are both fast- and slow-twitch in females. The laryngeal electromyogram, a measure of neuromuscular synaptic strength, shows greater potentiation in males than in females. Male-specific physiological features are shared with X. laevis, as well as with a species of the sister clade, Silurana tropicalis, and thus are likely ancestral. In X. borealis, certain aspects of laryngeal morphology and physiology are sexually monomorphic rather than dimorphic. In both sexes, laryngeal muscle fibers are of mixed-twitch type, which limits the production of muscle contractions at rapid intervals. Muscle activity potentiation and discrete tension transients resemble female rather than male X. boumbaensis. The de-masculinization of these laryngeal features suggests an alteration in sensitivity to the gonadal hormones that are known to control the sexual differentiation of the larynx in other Xenopus and Silurana species. PMID:25788725

  2. Contracture of Slow Striated Muscle during Calcium Deprivation

    Science.gov (United States)

    Irwin, Richard L.; Hein, Manfred M.

    1963-01-01

    When deprived of calcium the slow striated muscle fibers of the frog develop reversible contractures in either hypertonic or isotonic solutions. While calcium deprivation continues because of a flowing calcium-free solution the muscles relax slowly and completely. Restoration of calcium during contracture relaxes the muscle promptly to initial tension. When relaxed during calcium lack the return of calcium does not change tension and the muscle stays relaxed. When contractures are induced by solutions containing small amounts of calcium relaxation does not occur or requires several hours. The rate of tension development depends upon the rate at which calcium moves outward since the contractures develop slower in low concentrations of calcium and are absent or greatly slowed in a stagnant calcium-free solution. Withdrawal of calcium prevents the contractile responses to ACh, KCl, or electrical stimulation through the nerve. Muscles return to their original excitability after calcium is restored. Origin of the contractures is unrelated to nerve activity since they are maximal during transmission failure from calcium lack, occur in denervated muscles, and are not blocked by high concentrations of d-tubocurarine, procaine, or atropine. The experiments also indicate that the contractures do not originate from repetitive activity of muscle membranes. The findings are most simply explained by relating the outward movement of calcium as a link for initiating contraction in slow type striated muscle. PMID:14065284

  3. Baltikinin: A New Myotropic Tryptophyllin-3 Peptide Isolated from the Skin Secretion of the Purple-Sided Leaf Frog, Phyllomedusa baltea

    Directory of Open Access Journals (Sweden)

    Daning Shi

    2016-07-01

    Full Text Available Here we report the identification of a novel tryptophyllin-3 peptide with arterial smooth muscle relaxation activity from the skin secretion of the purple-sided leaf frog, Phyllomedusa baltea. This new peptide was named baltikinin and had the following primary structure, pGluDKPFGPPPIYPV, as determined by tandem mass spectrometry (MS/MS fragmentation sequencing and from cloned skin precursor-encoding cDNA. A synthetic replicate of baltikinin was found to have a similar potency to bradykinin in relaxing arterial smooth muscle (half maximal effective concentration (EC50 is 7.2 nM. These data illustrate how amphibian skin secretions can continue to provide novel potent peptides that act through functional targets in mammalian tissues.

  4. Evaluation of the use of Leptodactylus ocellatus (Anura: Leptodactylidae) frog tissues as bioindicator of metal contamination in Contas River, Northeastern Brazil.

    Science.gov (United States)

    Correia, Lívia O; Siqueira Júnior, Sérgio; Carneiro, Paulo L S; Bezerra, Marcos A

    2014-12-01

    This paper presents a study on the viability of the use of tissues of the Leptodactylus ocellatus species (Anura Leptodactylidae) as a bioindicator of metal pollution. The study is based on the determination and correlation of the concentrations of manganese, chromium, zinc, nickel, copper and iron in sediments and tissues (skin, muscles and viscera) of the frog Leptodactylus ocellatus collected in the middle region of the Contas River in Bahia, Brazil. The highest levels of the metals studied were found in the viscera of this animal. In this tissue, a higher correlation of the concentration of these metals with those found in sediments was also observed. The concentrations of elements found in the skin and muscles of these amphibians have revealed no correlation with the sediment where they were collected. According to the results obtained, the viscera of the L. ocellatus species presents itself as a good bioindicator of contamination by the metals studied.

  5. Embryogenesis and laboratory maintenance of the foam-nesting túngara frogs, genus Engystomops (= Physalaemus).

    Science.gov (United States)

    Romero-Carvajal, Andrés; Sáenz-Ponce, Natalia; Venegas-Ferrín, Michael; Almeida-Reinoso, Diego; Lee, Chanjae; Bond, Jennifer; Ryan, Michael J; Wallingford, John B; Del Pino, Eugenia M

    2009-06-01

    The vast majority of embryological research on amphibians focuses on just a single genus of frogs, Xenopus. To attain a more comprehensive understanding of amphibian development, experimentation on non-model frogs will be essential. Here, we report on the early development, rearing, and embryological analysis of túngara frogs (genus Engystomops, also called Physalaemus). The frogs Engystomops pustulosus, Engystomops coloradorum, and Engystomops randi construct floating foam-nests with small eggs. We define a table of 23 stages for the developmental period in the foam-nest. Embryos were immunostained against Lim1, neural, and somite-specific proteins and the expression pattern of RetinoBlastoma Binding Protein 6 (RBBP6) was analyzed by in situ hybridization. Due to their brief life-cycle, frogs belonging to the genus Engystomops are attractive for comparative and genetic studies of development. Developmental Dynamics 238:1444-1454, 2009. (c) 2009 Wiley-Liss, Inc.

  6. Frankixalus, a New Rhacophorid Genus of Tree Hole Breeding Frogs with Oophagous Tadpoles.

    Directory of Open Access Journals (Sweden)

    S D Biju

    Full Text Available Despite renewed interest in the biogeography and evolutionary history of Old World tree frogs (Rhacophoridae, this family still includes enigmatic frogs with ambiguous phylogenetic placement. During fieldwork in four northeastern states of India, we discovered several populations of tree hole breeding frogs with oophagous tadpoles. We used molecular data, consisting of two nuclear and three mitochondrial gene fragments for all known rhacophorid genera, to investigate the phylogenetic position of these new frogs. Our analyses identify a previously overlooked, yet distinct evolutionary lineage of frogs that warrants recognition as a new genus and is here described as Frankixalus gen. nov. This genus, which contains the enigmatic 'Polypedates' jerdonii described by Günther in 1876, forms the sister group of a clade containing Kurixalus, Pseudophilautus, Raorchestes, Mercurana and Beddomixalus. The distinctiveness of this evolutionary lineage is also corroborated by the external morphology of adults and tadpoles, adult osteology, breeding ecology, and life history features.

  7. Frankixalus, a New Rhacophorid Genus of Tree Hole Breeding Frogs with Oophagous Tadpoles

    Science.gov (United States)

    Biju, S. D.; Mahony, Stephen; Kamei, Rachunliu G.; Thomas, Ashish; Shouche, Yogesh; Raxworthy, Christopher J.; Meegaskumbura, Madhava; Bocxlaer, Ines Van

    2016-01-01

    Despite renewed interest in the biogeography and evolutionary history of Old World tree frogs (Rhacophoridae), this family still includes enigmatic frogs with ambiguous phylogenetic placement. During fieldwork in four northeastern states of India, we discovered several populations of tree hole breeding frogs with oophagous tadpoles. We used molecular data, consisting of two nuclear and three mitochondrial gene fragments for all known rhacophorid genera, to investigate the phylogenetic position of these new frogs. Our analyses identify a previously overlooked, yet distinct evolutionary lineage of frogs that warrants recognition as a new genus and is here described as Frankixalus gen. nov. This genus, which contains the enigmatic ‘Polypedates’ jerdonii described by Günther in 1876, forms the sister group of a clade containing Kurixalus, Pseudophilautus, Raorchestes, Mercurana and Beddomixalus. The distinctiveness of this evolutionary lineage is also corroborated by the external morphology of adults and tadpoles, adult osteology, breeding ecology, and life history features. PMID:26790105

  8. Isolation of Brucella inopinata-Like Bacteria from White's and Denny's Tree Frogs.

    Science.gov (United States)

    Kimura, Masanobu; Une, Yumi; Suzuki, Michio; Park, Eun-Sil; Imaoka, Koichi; Morikawa, Shigeru

    2017-05-01

    Brucella inopinata strain BO1 and B. sp. strain BO2 isolated from human patients, respectively, are genetically different from classical Brucella species. We isolated bacteria of the genus Brucella from two species of wild-caught tropical frogs kept in the facilities in Japan: White's tree frog, which inhabits Oceania, and Denny's tree frog, which inhabits Southeast Asia. Phylogenetic analyses based on 16S rRNA and recA gene sequences and multilocus sequence analysis showed that two isolates of Brucella spp. showed significant similarity to BO1, BO2, and the isolates from other wild-caught frogs. These results suggest that a variety of frog species are susceptible to a novel clade of Brucella bacteria, including B. inopinata.

  9. Parasites of the mink frog (rana septentrionalis) from minnesota, U.S.A.

    Science.gov (United States)

    Schotthoefer, A.M.; Bolek, M.G.; Cole, R.A.; Beasley, V.R.

    2009-01-01

    Twenty-two mink frogs, Rana septentrionalis, collected from two locations in Minnesota, United States, were examined for helminth and protozoan blood parasites in July 1999. A total of 16 parasite taxa were recovered including 5 larval digenean trematodes, 7 adult digenean trematodes, 3 nematodes, and I Trypanosorna species. Infracommunities were dominated by the digeneans in terms of richness and abundance. In particular, echinostomatid metacercariae in the kidneys of frogs were the most common parasites found, infecting 100% of the frogs and consisting of about 90% of all helminth individuals recovered. Gorgodera amplicava, Gorgoderina multilohata, Haernaroloechus pan'iplexus, Haernatoloechus breviplexus, Cosnwcercoides dukae, and Oswaldocruzia pipiens represent new host records. The survey presented here represents the second known helminth survey of mink frogs conducted in North America. A summary of metazoan parasites reported from mink frogs is included.

  10. Abundance of green tree frogs and insects in artificial canopy gaps in a bottomland hardwood forest.

    Energy Technology Data Exchange (ETDEWEB)

    Horn, Scott; Hanula, James L.; Ulyshen, Michael D.; Kilgo, John C.

    2005-01-01

    Horn, Scott, James L. Hanula, Michael D. Ulyshen, and John C. Kilgo. 2005. Abundance of green tree frogs and insects in artificial canopy gaps in a bottomland hardwood forest. Am. Midl. Nat. 153:321-326. Abstract: We found more green tree frogs (Hyla cinerea) in canopy gaps than in closed canopy forest. Of the 331 green tree frogs observed, 88% were in canopy gaps. Likewise, higher numbers and biomasses of insects were captured in the open gap habitat. Flies were the most commonly collected insect group accounting for 54% of the total capture. These data suggest that one reason green tree frogs were more abundant in canopy gaps was the increased availability of prey and that small canopy gaps provide early successional habitats that are beneficial to green tree frog populations.

  11. Inventory of frog species in the South Carolina Sandhills with a focus on the pine barrens treefrog and the gopher frog

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Tabular data consists of site specific locations of sampling points on Carolina Sandhills NWR for determination of frog species and more specifically sites with Pine...

  12. Inventory of frog species in the South Carolina Sandhills with a focus on the pine barrens treefrog and the gopher frog

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Proposal is to conduct an inventory of frogs and toads at the Carolina Sandhills NWR and adjoining lands. Special emphasis is to locate the pine barrens treefrog and...

  13. Dynamics of testis-ova in a wild population of Japanese pond frogs, Rana nigromaculata.

    Science.gov (United States)

    Kobayashi, Tohru; Kumakura, Masahiko; Yoshie, Sumio; Sugishima, Tomomi; Horie, Yoshifumi

    2015-02-01

    Although many studies have reported the occurrence of testis-ova in wild frog populations, the origin and trigger of testis-ova differentiation/development remain unclear. A high frequency of testis-ova has been previously reported for wild populations of the Japanese pond frog, Rana nigromaculata (cf. Iwasawa and Asai, '59). In the present study, we aimed to clarify the dynamics of testis-ova in this frog species, including the origin and artificial induction of testis-ova. Testis-ova were observed in both mature frogs and puberty-stage frogs (i.e., 0- and 1-year-old frogs). However, the early stages of testis-ova (~pachytene stage) were mostly observed in puberty-stage male frogs at the onset of spermatogenesis. The early stages of testis-ova were observed in the cysts of early secondary spermatogonia and the single cysts of the primary spermatogonium. This finding indicates that testis-ova differentiation occurs during spermatogonial proliferation and that it is correlated with the initiation of spermatogenesis. We also examined whether estrogen exposure induced testis-ova differentiation and how it is correlated with the progression of spermatogenesis. When 1-year-old frogs were exposed to estradiol-17β during spring (i.e., when spermatogenesis was initiated), testis-ova differentiation was induced in a dose-dependent manner. However, this phenomenon did not occur in 1-year-old frogs during summer, (i.e., when the transition from spermatogonia to spermatocytes mainly occurs). These results present the first evidence that testis-ova of the Japanese pond frog are derived from primary and early secondary spermatogonia, and that estrogen exposure induces testis-ova differentiation accompanied by the initiation of spermatogenesis.

  14. Functional evolution of jumping in frogs: Interspecific differences in take-off and landing.

    Science.gov (United States)

    Reilly, Stephen M; Montuelle, Stephane J; Schmidt, André; Krause, Cornelia; Naylor, Emily; Essner, Richard L

    2016-03-01

    Ancestral frogs underwent anatomical shifts including elongation of the hindlimbs and pelvis and reduction of the tail and vertebral column that heralded the transition to jumping as a primary mode of locomotion. Jumping has been hypothesized to have evolved in a step-wise fashion with basal frogs taking-off with synchronous hindlimb extension and crash-landing on their bodies, and then their limbs move forward. Subsequently, frogs began to recycle the forelimbs forward earlier in the jump to control landing. Frogs with forelimb landing radiated into many forms, locomotor modes, habitats, and niches with controlled landing thought to improve escape behavior. While the biology of take-off behavior has seen considerable study, interspecific comparisons of take-off and landing behavior are limited. In order to understand the evolution of jumping and controlled landing in frogs, data are needed on the movements of the limbs and body across an array of taxa. Here, we present the first description and comparison of kinematics of the hindlimbs, forelimbs and body during take-off and landing in relation to ground reaction forces in four frog species spanning the frog phylogeny. The goal of this study is to understand what interspecific differences reveal about the evolution of take-off and controlled landing in frogs. We provide the first comparative description of the entire process of jumping in frogs. Statistical comparisons identify both homologous behaviors and significant differences among species that are used to map patterns of trait evolution and generate hypotheses regarding the functional evolution of take-off and landing in frogs.

  15. Behavioral Responses of Northern Leopard Frogs (Rana pipiens to Roads and Traffic: Implications for Population Persistence

    Directory of Open Access Journals (Sweden)

    Julie Bouchard

    2009-12-01

    Full Text Available A key goal in road ecology is to determine which species are most vulnerable to the negative effects of roads on population persistence. Theory suggests that species that avoid roads are less likely to be negatively affected by roads than those that do not avoid roads. The goal of this study was to take a step toward testing this prediction by evaluating the behavioral response to roads and traffic of a species whose populations are known to be negatively affected by roads and traffic, the northern leopard frog (Rana pipiens. We studied the movement patterns of northern leopard frogs during their spring migration from overwintering sites in a river to various breeding ponds that were disconnected from the river by roads. We performed short-distance translocations of migrating frogs, followed them visually, and documented their movement coordinates following each hop, both near the roads and in non-roaded areas. We found that frogs took longer to move near roads with more traffic and that their movement was quickest in areas without roads nearby. Frogs tended to deviate more from a straight-line course when they were released near roads than compared with control areas, but this response was independent of traffic volume. All frogs released near roads attempted to cross the road. On very low traffic roads (10.86 mean vehicles per hour, 94% of frogs crossed the road successfully, whereas at higher traffic roads (58.29 mean vehicles per hour 72% were successful. Our results suggest that frog's inability to avoid going onto roads and their slow movement combine to make them particularly vulnerable to road mortality, which likely explains the strong negative effects of roads on frog population abundance. Conservation efforts should focus on preventing frogs from accessing the road surface through the use of drift fencing and culverts.

  16. Elastic properties of relaxed, activated, and rigor muscle fibers measured with microsecond resolution.

    OpenAIRE

    Jung, D. W.; Blangé, T; van der Graaf, H.; Treijtel, B W

    1988-01-01

    Tension responses due to small and rapid length changes (completed within 40 microseconds) were obtained from skinned single-fiber segments (4- to 7-mm length) of the iliofibularis muscle of the frog incubated in relaxing, rigor, and activating solution. The fibers were skinned by freeze-drying. The first 500 microseconds of the responses for all three conditions could be described with a linear model, in which the fiber is regarded as a rod composed of infinitesimally small identical segment...

  17. Which frog's legs do froggies eat? The use of DNA barcoding for identification of deep frozen frog legs (Dicroglossidae, Amphibia commercialized in France

    Directory of Open Access Journals (Sweden)

    Annemarie Ohler

    2017-02-01

    Full Text Available Several millions frogs captured in the wild in Indonesia are sold for food yearly in French supermarkets, as deep frozen frog legs. They are commercialized as Rana macrodon, but up to 15 look-alike species might also be concerned by this trade. From December 2012 to May 2013, we bought 209 specimens of deep frozen frog legs, and identified them through a barcoding approach based on the 16S gene. Our results show that 206 out of the 209 specimens belong to Fejervarya cancrivora, two to Limnonectes macrodon and one to F. moodiei. Thus only 0.96 % of the frogs were correctly identified. Unless misclassification was intentional, it seems that Indonesian frog leg exporters are not able to discriminate between the species. The quasi absence of L. macrodon in our samples might be an indication of its rarity, confirming that its natural populations are declining rapidly, in agreement with its “vulnerable” status according to the IUCN Red List. Our results show that the genetic and morphological diversity of the frogs in trade is much higher than the genetic and morphological diversity measured so far by scientific studies. These results underline the need for large scale studies to assess the status of wild populations.

  18. 论莫言小说《蛙》中的“蛙”意象%The Frog Image in the Novel Frog by Mo Yan

    Institute of Scientific and Technical Information of China (English)

    蒋卉

    2012-01-01

    从远古神话到到当代小说,从考古、民俗到文学想象,“蛙”意象的产生与发展经历了一个漫长而富有变化的过程。文章结合文学人类学的理论对莫言长篇小说《蛙》中的“蛙”意象进行深度分析,追溯到“蛙”原型中的“蛙女神”,将其与小说中突出的人物“姑姑”进行对比,揭示这一原型意象的运用对小说文化蕴涵的提升作用。%The image of frog has a long history since its creation and differs quite well in different texts like ancient mythology,contemporary novels,archeology,folklore and literary i- maginations. This paper analyzes the image of frog from the perspective of literary anthropolo- gy in the novel Frog by Mo Yan. A comparative, study of the protagonist,the aunt of the nar- rator in the novel,and the frog goddess,the prototype frog, will be conducted,which indicates that the archetypal image of frog helps to enrich cultural connotations of the novel.

  19. Surveys for presence of Oregon spotted frog (Rana pretiosa): background information and field methods

    Science.gov (United States)

    Pearl, Christopher A.; Clayton, David; Turner, Lauri

    2010-01-01

    The Oregon spotted frog (Rana pretiosa) is the most aquatic of the native frogs in the Pacific Northwest. The common name derives from the pattern of black, ragged-edged spots set against a brown or red ground color on the dorsum of adult frogs. Oregon spotted frogs are generally associated with wetland complexes that have several aquatic habitat types and sizeable coverage of emergent vegetation. Like other ranid frogs native to the Northwest, Oregon spotted frogs breed in spring, larvae transform in summer of their breeding year, and adults tend to be relatively short lived (3-5 yrs). Each life stage (egg, tadpole, juvenile and adult) has characteristics that present challenges for detection. Breeding can be explosive and completed within 1-2 weeks. Egg masses are laid in aggregations, often in a few locations in large areas of potential habitat. Egg masses can develop, hatch, and disintegrate in <2 weeks during warm weather. Tadpoles can be difficult to identify, have low survival, and spend most of their 3-4 months hidden in vegetation or flocculant substrates. Juveniles and adults are often difficult to capture and can spend summers away from breeding areas. Moreover, a substantial portion of extant populations are of limited size (<100 breeding adults), and field densities of all life stages are often low. An understanding of the biology of the species and use of multiple visits are thus important for assessing presence of Oregon spotted frogs. This report is meant to be a resource for USDA Region 6 Forest Service (FS) and OR/WA Bureau of Land Management (BLM) personnel tasked with surveying for the presence of Oregon spotted frogs. Our objective was to summarize information to improve the efficiency of field surveys and increase chances of detection if frogs are present. We include overviews of historical and extant ranges of Oregon spotted frog. We briefly summarize what is known of Oregon spotted frog habitat associations and review aspects of behavior and

  20. Accessory pathway for sound transfer in a neotropical frog.

    OpenAIRE

    1988-01-01

    A portion of the lateral body wall overlying the lung cavity of the arboreal frog, Eleutherodactylus coqui, vibrates in response to free-field sound. Peak displacement amplitude of the body wall in response to a natural call note presented at 73 decibels sound pressure level is 1.70 X 10(-9) m, roughly 8 decibels less than that of the ipsilateral eardrum, as measured by laser Doppler vibrometry. We show that the vibration magnitude varies predictably across the body profile and is posture and...

  1. Taxonomy Icon Data: Western clawed frog [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available Western clawed frog Xenopus tropicalis Chordata/Vertebrata/Amphibia Xenopus_tropicalis_L.png Xenopus..._tropicalis_NL.png Xenopus_tropicalis_S.png Xenopus_tropicalis_NS.png http://biosciencedbc....jp/taxonomy_icon/icon.cgi?i=Xenopus+tropicalis&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Xenopus+...tropicalis&t=NL http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Xenopus+tropical...is&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Xenopus+tropicalis&t=NS http://togodb.biosciencedbc.jp/togodb/view/taxonomy_icon_comment_en?species_id=137 ...

  2. Plasma membrane electron transport in frog blood vessels

    Indian Academy of Sciences (India)

    Rashmi P Rao; K Nalini; J Prakasa Rao

    2009-12-01

    In an attempt to see if frog blood vessels possess a plasma membrane electron transport system, the postcaval vein and aorta isolated from Rana tigrina were tested for their ability to reduce ferricyanide, methylene blue, and 2,6-dichloroindophenol. While the dyes remained unchanged, ferricyanide was reduced to ferrocyanide. This reduction was resistant to inhibition by cyanide and azide. Heptane extraction or formalin fixation of the tissues markedly reduced the capability to reduce ferricyanide. Denuded aortas retained only 30% of the activity of intact tissue. Our results indicate that the amphibian postcaval vein and aorta exhibit plasma membrane electron transport

  3. Periodic Solutions of a Model of Mitosis in Frog Eggs

    Institute of Scientific and Technical Information of China (English)

    Bei-ye Feng; Zuo-huan Zheng

    2002-01-01

    In this paper,we discuss a simplified model of mitosis in frog eggs proposed by M.T. Borisuk and J.J.Tyson in [1]. By using rigorous qualitative analysis, we prove the existence of the periodic solutions on a large scale and present the space region of the periodic solutions and the parameter region coresponding to the periodic solution. We also present the space region and the parameter region where there are no periodic solutions. The results are in accordance with the numerical results in [1] up to the qualitative property.

  4. Tactical reproductive parasitism via larval cannibalism in Peruvian poison frogs

    Science.gov (United States)

    Brown, Jason L.; Morales, Victor; Summers, Kyle

    2008-01-01

    We report an unusual example of reproductive parasitism in amphibians. Dendrobates variabilis, an Amazonian poison frog, oviposits at the surface of the water in small pools in plants and deposits tadpoles within the pools. Tadpoles are highly cannibalistic and consume young tadpoles if they are accessible. Deposition of embryos and tadpoles in the same pool is common. Genetic analyses indicate that tadpoles are frequently unrelated to embryos in the same pool. A pool choice experiment in the field demonstrated that males carrying tadpoles prefer to place them in pools with embryos, facilitating reproductive parasitism via cannibalism. PMID:19042178

  5. Taxonomy Icon Data: Japanese tree frog [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available Japanese tree frog Hyla japonica Chordata/Vertebrata/Amphibia Hyla_japonica_L.png Hyla_jap...onica_NL.png Hyla_japonica_S.png Hyla_japonica_NS.png http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Hyla+jap...onica&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Hyla+japonica&t=NL http://biosciencedbc....jp/taxonomy_icon/icon.cgi?i=Hyla+japonica&t=S http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Hyla+jap

  6. Muscle pain

    African Journals Online (AJOL)

    Causes of muscle pain include stress, physical activity, infections, hyper or .... Acupuncture. It is a traditional Chinese-based therapeutic method which ..... and Spinal Mechanisms of Pain and Dry Needling Mediated Analgesia: A Clinical.

  7. Evolutionary and natural history of the turtle frog, Myobatrachus gouldii, a bizarre myobatrachid frog in the southwestern Australian biodiversity hotspot.

    Science.gov (United States)

    Vertucci, Samantha; Pepper, Mitzy; Edwards, Danielle L; Roberts, J Dale; Mitchell, Nicola; Keogh, J Scott

    2017-01-01

    Southwest Australia (SWA) is a global biodiversity hotspot and a centre of diversity and endemism for the Australo-Papuan myobatrachid frogs. Myobatrachus gouldii (the turtle frog) has a highly derived morphology associated with its forward burrowing behaviour, largely subterranean habit, and unusual mode of reproduction. Its sister genera Metacrinia and Arenophryne have restricted distributions in Western Australia with significant phylogeographic structure, leading to the recent description of a new species in the latter. In contrast, Myobatrachus is distributed widely throughout SWA over multiple climatic zones, but little is known of its population structure, geographic variation in morphology, or reproduction. We generated molecular and morphological data to test for genetic and morphological variation, and to assess whether substrate specialisation in this species may have led to phylogeographic structuring similar to that of other plant and animal taxa in SWA. We assembled sequence data for one mitochondrial and four nuclear DNA loci (3628 base pairs) for 42 turtle frogs sampled throughout their range. Likelihood phylogenetic analyses revealed shallow phylogeographic structure in the mtDNA locus (up to 3.3% genetic distance) and little variation in three of the four nDNA loci. The mtDNA haplotype network suggests five geographically allopatric groups, with no shared haplotypes between regions. These geographic patterns are congruent with several other SWA species, with genetic groups restricted to major hydrological divisions, the Swan Coastal Plain, and the Darling Scarp. The geographically structured genetic groups showed no evidence of significant morphological differentiation (242 individuals), and there was little sexual size dimorphism, but subtle differences in reproductive traits suggest more opportunistic breeding in lower rainfall zones. Call data were compared to sister genera Metacrinia and Arenophryne and found to be highly conservative across

  8. Fatty acid composition of muscle tissue measured in amphibians living in radiologically contaminated and non-contaminated environments.

    Science.gov (United States)

    Audette-Stuart, M; Ferreri, C; Festarini, A; Carr, J

    2012-09-01

    Fatty acid composition was identified as a potential biological indicator of the effects of environmental exposure to radiological contaminants. This end point was measured in muscle tissues of Mink frogs ( Rana septentrionalis ) obtained from a radiologically contaminated pond and from a non-contaminated pond. It was also measured after the frogs obtained from both ponds were exposed to a 4 Gy (60)Co γ radiation dose delivered in vivo at a dose rate of approximately 8 Gy/min. Statistically significant differences for the increase of a couple of polyunsaturated omega-3 fatty acid residues and the decrease of a polyunsaturated omega-6 fatty acid residue were observed between radiologically contaminated and non-contaminated frogs, indicating a partial remodeling of muscle lipids in response to a chronic low-dose tritium exposure. The effects of an acute high-dose exposure to (60)Co γ radiation, either for the radiologically contaminated or non-contaminated frogs indicated fast post-irradiation fatty acid changes with an increase of polyunsaturated and decrease of saturated fatty acid contents. Fatty acid composition was found to be a sensitive marker that may be useful to study and monitor biota health in environments that are radiologically contaminated, as well as for understanding the differences between low chronic and high acute stress responses.

  9. Chasing maximal performance: a cautionary tale from the celebrated jumping frogs of Calaveras County.

    Science.gov (United States)

    Astley, H C; Abbott, E M; Azizi, E; Marsh, R L; Roberts, T J

    2013-11-01

    Maximal performance is an essential metric for understanding many aspects of an organism's biology, but it can be difficult to determine because a measured maximum may reflect only a peak level of effort, not a physiological limit. We used a unique opportunity provided by a frog jumping contest to evaluate the validity of existing laboratory estimates of maximum jumping performance in bullfrogs (Rana catesbeiana). We recorded video of 3124 bullfrog jumps over the course of the 4-day contest at the Calaveras County Jumping Frog Jubilee, and determined jump distance from these images and a calibration of the jump arena. Frogs were divided into two groups: 'rental' frogs collected by fair organizers and jumped by the general public, and frogs collected and jumped by experienced, 'professional' teams. A total of 58% of recorded jumps surpassed the maximum jump distance in the literature (1.295 m), and the longest jump was 2.2 m. Compared with rental frogs, professionally jumped frogs jumped farther, and the distribution of jump distances for this group was skewed towards long jumps. Calculated muscular work, historical records and the skewed distribution of jump distances all suggest that the longest jumps represent the true performance limit for this species. Using resampling, we estimated the probability of observing a given jump distance for various sample sizes, showing that large sample sizes are required to detect rare maximal jumps. These results show the importance of sample size, animal motivation and physiological conditions for accurate maximal performance estimates.

  10. Prevalence of malformed frogs in Kaoping and Tungkang river basins of southern Taiwan.

    Science.gov (United States)

    Huang, Da-Ji; Chiu, Yuh-Wen; Chen, Chien-Min; Huang, Kai-Hsiang; Wang, Shu-Yin

    2010-05-01

    In this study we found many amphibians with bizarre appearances, known as malformations in Pingtung County southern Taiwan. For this investigation we collected frogs inhabiting the Kaoping and Tungkang river watersheds between February 2006 and June 2007. Among the total number of 10,909 normal frogs (i.e., anurans) collected during the investigation period, the Indian rice frogs (Rana limnocharis) account for the greatest number next is the Chinese bullfrog (Rana rugulosa). Of all the 244 captured malformed frogs, the Indian rice frog account for the greatest proportion. These malformed frogs have their main distribution in upstream areas of these two rivers. Our result indicates that the appearance rate of malformed frogs is 1.8% in the upstream reaches of the Kaoping River and 2.6%, and 0.8%, respectively in the upstream and midstream reaches of the Tungkang river. The most-commonly-found malformation is the lack of palms, followed by the lack of appendages, exostosis, and a malformed appendicular. It is, therefore, reasonable to speculate that the causes for the malformation may be related to the increased organic pollutants and agricultural chemicals used in the upstream reaches of these two rivers.

  11. Landing in basal frogs: evidence of saltational patterns in the evolution of anuran locomotion

    Science.gov (United States)

    Essner, Richard L.; Suffian, Daniel J.; Bishop, Phillip J.; Reilly, Stephen M.

    2010-10-01

    All frogs are assumed to jump in a similar manner by rapidly extending hindlimbs during the propulsive phase and rotating the limbs forward during flight in order to land forelimbs first. However, studies of jumping behavior are lacking in the most primitive living frogs of the family Leiopelmatidae. These semi-aquatic or terrestrial anurans retain a suite of plesiomorphic morphological features and are unique in using an asynchronous (trot-like) rather than synchronous “frog-kick” swimming gait of other frogs. We compared jumping behavior in leiopelmatids to more derived frogs and found that leiopelmatids maintain extended hindlimbs throughout flight and landing phases and do not land on adducted forelimbs. These “belly-flop” landings limit the ability for repeated jumps and are consistent with a riparian origin of jumping in frogs. The unique behavior of leiopelmatids shows that frogs evolved jumping before they perfected landing. Moreover, an inability to rapidly cycle the limbs may provide a functional explanation for the absence of synchronous swimming in leiopelmatids.

  12. Poison frogs rely on experience to find the way home in the rainforest.

    Science.gov (United States)

    Pašukonis, Andrius; Warrington, Ian; Ringler, Max; Hödl, Walter

    2014-11-01

    Among vertebrates, comparable spatial learning abilities have been found in birds, mammals, turtles and fishes, but virtually nothing is known about such abilities in amphibians. Overall, amphibians are the most sedentary vertebrates, but poison frogs (Dendrobatidae) routinely shuttle tadpoles from terrestrial territories to dispersed aquatic deposition sites. We hypothesize that dendrobatid frogs rely on learning for flexible navigation. We tested the role of experience with the local cues for poison frog way-finding by (i) experimentally displacing territorial males of Allobates femoralis over several hundred metres, (ii) using a harmonic direction finder with miniature transponders to track these small frogs, and (iii) using a natural river barrier to separate the translocated frogs from any familiar landmarks. We found that homeward orientation was disrupted by the translocation to the unfamiliar area but frogs translocated over similar distances in their local area showed significant homeward orientation and returned to their territories via a direct path. We suggest that poison frogs rely on spatial learning for way-finding in their local area.

  13. Pathological Study of Blood Parasites in Rice Field Frogs, Hoplobatrachus rugulosus (Wiegmann, 1834

    Directory of Open Access Journals (Sweden)

    Achariya Sailasuta

    2011-01-01

    Full Text Available One hundred and forty adult rice field frogs, Hoplobatrachus rugulosus (Wiegmann, 1834, were collected in Srakaew province, Thailand. For blood parasite examination, thin blood smears were made and routinely stained with Giemsa. The results showed that 70% of the frogs (98/140 were infected with 5 species of blood parasites, including a Trypanosoma rotatorium-like organism, Trypanosoma chattoni, Hepatozoon sp. a, Hepatozoon sp. b, and Lankesterella minima. Pathological examination of the liver, lung, spleen, and kidney of the frogs that were apparently infected with one of these blood parasites were collected and processed by routine histology and subsequently stained with haematoxylin and eosin. Histopathological findings associated with the Trypanosoma rotatorium-like organism and Trypanosoma chattoni-infected frogs showed no pathological lesions. Hepatozoon sp. a and Hepatozoon sp. b-infected frogs developed inflammatory lesions predominantly in the liver, demonstrating granuloma-like lesions with Hepatozoon sp. meronts at the centre. Tissue sections of Lankesterella minima-infected frogs also showed lesions. Liver and spleen showed inflammatory lesions with an accumulation of melanomacrophage centres (MMCs surrounding the meronts and merozoites. It is suggested that Hepatozoon sp. a, Hepatozoon sp. b, and Lankesterella minima-infections are capable of producing inflammatory lesions in the visceral organs of rice field frogs, and the severity of lesions is tentatively related to levels of parasitemia.

  14. Embryo Development of Tree Frog Polypedates leucomystax at Campus of State University of Malang

    Directory of Open Access Journals (Sweden)

    Pearlindah

    2012-12-01

    Full Text Available Tree frogs live in natural places which are unpolluted. Regarding their role as an ecological indicator, the decrease of frogs population in a particular habitat indicates the danger of environment quality decrease. Moreover, this condition can harm the frogs themselves. All kinds of frogs breed in aqueous environment such as ponds, marshes, and farming fields. One of the tree frogs, Polypedates leucomystax, which belongs to Familia Rachophoridae, is widely spread in Indonesia. This frog has yellowish brown skin with black spots or six lines extending from head to the posterior tip of body. A breeding couple of the frog produces foam nests on the water or plants around water body, where they will nest their fertilized eggs. This species produces over a hundred embryos in one spawning season. These embryos require appropriate conditions to develop normally in the nature. Frog embryo development may becomes a reference to understand how the frog population survives. This study focused on P. leucomystax with regards to its decrease in number due to the drying up of the environment and a lot lost of trees in Campus of State University of Malang. The development of P. leucomystax embryos in the reproduction foam was observed until it reached a tadpole stage. The result showed that the embryos developed in the foam until they hatched then they move out of the foam into the water under which they would continue their development. Considering that water body is a critical requirement for the development of P. leucomystax embryos, it is our responsibility to make any efforts to conserve not only the trees but also any type of water bodies including ponds, marshes, and farming fields as well.

  15. The genetic structure of a relict population of wood frogs

    Science.gov (United States)

    Scherer, Rick; Muths, Erin; Noon, Barry; Oyler-McCance, Sara

    2012-01-01

    Habitat fragmentation and the associated reduction in connectivity between habitat patches are commonly cited causes of genetic differentiation and reduced genetic variation in animal populations. We used eight microsatellite markers to investigate genetic structure and levels of genetic diversity in a relict population of wood frogs (Lithobates sylvatica) in Rocky Mountain National Park, Colorado, where recent disturbances have altered hydrologic processes and fragmented amphibian habitat. We also estimated migration rates among subpopulations, tested for a pattern of isolation-by-distance, and looked for evidence of a recent population bottleneck. The results from the clustering algorithm in Program STRUCTURE indicated the population is partitioned into two genetic clusters (subpopulations), and this result was further supported by factorial component analysis. In addition, an estimate of FST (FST = 0.0675, P value \\0.0001) supported the genetic differentiation of the two clusters. Estimates of migration rates among the two subpopulations were low, as were estimates of genetic variability. Conservation of the population of wood frogs may be improved by increasing the spatial distribution of the population and improving gene flow between the subpopulations. Construction or restoration of wetlands in the landscape between the clusters has the potential to address each of these objectives.

  16. Evolution of advertisement calls in African clawed frogs

    Science.gov (United States)

    Tobias, Martha L.; Evans, Ben J.; Kelley, Darcy B.

    2014-01-01

    Summary For most frogs, advertisement calls are essential for reproductive success, conveying information on species identity, male quality, sexual state and location. While the evolutionary divergence of call characters has been examined in a number of species, the relative impacts of genetic drift or natural and sexual selection remain unclear. Insights into the evolutionary trajectory of vocal signals can be gained by examining how advertisement calls vary in a phylogenetic context. Evolution by genetic drift would be supported if more closely related species express more similar songs. Conversely, a poor correlation between evolutionary history and song expression would suggest evolution shaped by natural or sexual selection. Here, we measure seven song characters in 20 described and two undescribed species of African clawed frogs (genera Xenopus and Silurana) and four populations of X. laevis. We identify three call types — click, burst and trill — that can be distinguished by click number, call rate and intensity modulation. A fourth type is biphasic, consisting of two of the above. Call types vary in complexity from the simplest, a click, to the most complex, a biphasic call. Maximum parsimony analysis of variation in call type suggests that the ancestral type was of intermediate complexity. Each call type evolved independently more than once and call type is typically not shared by closely related species. These results indicate that call type is homoplasious and has low phylogenetic signal. We conclude that the evolution of call type is not due to genetic drift, but is under selective pressure. PMID:24723737

  17. Possible postsynaptic action of aminoglycosides in the frog rectus abdominis.

    Directory of Open Access Journals (Sweden)

    Karataş Y

    2000-04-01

    Full Text Available The present study was undertaken to investigate the postsynaptic effects of aminoglycosides on contractions evoked by acetylcholine (ACh, KCl, electrical field stimulation (EFS and Na(+- and Ca(2+-free Ringer solution with 0.2 mM Na2 EDTA (NaFCaFR in the isolated frog rectus abdominis. Neomycin inhibited contraction elicited by ACh, NaFCaFR, and EFS at the higher frequencies (8 and 10 Hz but not those elicited by KCl and EFS at the lower frequencies (2, 3 and 5 Hz. D-tubocurarine inhibited ACh-induced contractions in a concentration-dependent manner. In addition, drug reduced EFS-evoked contractions to a limited extent. Lower concentrations (10(-5, 5 x 10(-5, 10(-4, 2 x 10(-4 and 3 x 10(-4 M but not higher concentrations (4 x 10(-4 and 5 x 10(-4 M of methoxyverapamil exhibited a concentration-dependent inhibitory action on NaFCaFR-induced contractions. Similar inhibitions of the same type of contraction were displayed by aminoglycosides (neomycin, streptomycin, netilmycin, gentamycin and amikacin. These results suggest that in addition to their antagonistic action on nicotinic receptors in the frog rectus abdominis, aminoglycosides may exert stabilizing effects on some functional components contributing to contractions at the membrane.

  18. Octylphenol induced gene expression in testes of Frog, Rana chensinensis.

    Science.gov (United States)

    Li, Xinyi; Liu, Jia; Zhang, Yuhui

    2016-06-01

    Octylphenol (OP) is an endocrine-disrupting chemical (EDC), which can disrupt the reproductive system. To understand the effect of OP, a subtractive cDNA library was constructed using suppression subtractive hybridization (SSH) to identify alterations of gene transcription in the testes of the frog Rana chensinensis after OP exposure. Two hundred positive clones were selected and 134 sequences of gene fragments were produced from the subtractive library randomly. These genes were identified to be involved in metabolic process, cellular process, biological regulation, stimulus, immune system and female pregnancy process. In order to verify the efficiency of the subtractive cDNA library, PSG9 and PAPP-A were analyzed further as two representatives of differentially expressed transcription genes using semi-quantitative RT-PCR. Our result was the first successful construction of the subtractive cDNA library in frog testes after OP treatment. Based on this cDNA library, OP was shown to affect multiple physiological processes including inducing immune response, disrupting the steroid hormone synthesis and influencing spermatogenesis in the testis by up-regulation of specific genes.

  19. Evolution of advertisement calls in African clawed frogs.

    Science.gov (United States)

    Tobias, Martha L; Evans, Ben J; Kelley, Darcy B

    2011-01-01

    For most frogs, advertisement calls are essential for reproductive success, conveying information on species identity, male quality, sexual state and location. While the evolutionary divergence of call characters has been examined in a number of species, the relative impacts of genetic drift or natural and sexual selection remain unclear. Insights into the evolutionary trajectory of vocal signals can be gained by examining how advertisement calls vary in a phylogenetic context. Evolution by genetic drift would be supported if more closely related species express more similar songs. Conversely, a poor correlation between evolutionary history and song expression would suggest evolution shaped by natural or sexual selection. Here, we measure seven song characters in 20 described and two undescribed species of African clawed frogs (genera Xenopus and Silurana) and four populations of X. laevis. We identify three call types - click, burst and trill - that can be distinguished by click number, call rate and intensity modulation. A fourth type is biphasic, consisting of two of the above. Call types vary in complexity from the simplest, a click, to the most complex, a biphasic call. Maximum parsimony analysis of variation in call type suggests that the ancestral type was of intermediate complexity. Each call type evolved independently more than once and call type is typically not shared by closely related species. These results indicate that call type is homoplasious and has low phylogenetic signal. We conclude that the evolution of call type is not due to genetic drift, but is under selective pressure.

  20. [Meiotic chromosomes of the tree frog Smilisca baudinii (Anura: Hylidae)].

    Science.gov (United States)

    Hernández-Guzmán, Javier; Arias-Rodriguez, Lenin; Indy, Jeane Rimber

    2011-03-01

    The Mexican tree frog Smilisca baudinii, is a very common frog in Central America. In spite their importance to keep the ecological equilibrium of the rainforest, its biology and genetics are poorly known. In order to contribute with its biological knowledge, we described the typical meiotic karyotype based in standard cytogenetic protocols to specimens collected in Tabasco, Mexico. The study was centered in the analysis of 131 chromosome spreads at meiotic stage from two adults of the species (one female and one male). The metaphase analysis allowed the establishment of the modal haploid number of 1n = 12 bivalent chromosomes. The chromosomic formulae from the haploid bivalent karyotype was integrated by 12 biarmed chromosomes characterized by twelve pairs of metacentric-submetacentric (msm) chromosomes. The meiotic counting gives the idea that diploid chromosome number is integrated by a complement of 2n = 24 biarmed chromosomes. The presence of sex chromosomes from female and male meiotic spreads was not observed. Current results suggest that S. baudinii chromosome structure is well shared among Hylidae family and "B" chromosomes are particular structures that have very important evolutionary consequences in species diversification.

  1. Localization and characterization of adrenergic receptors on frog skin melanophores.

    Science.gov (United States)

    Longshore, M A; Horowitz, J M

    1981-07-01

    The functional location of adrenergic binding sites was studied in frog skin melanophores by injecting norepinephrine (NE) outside and inside a melanophore. In 49 groups of cells (75% of the fields tested) iontophoretic injection of NE outside the cell caused melanosome aggregation in the target cell and/or in the field. In six cells in which a resting membrane potential was measured before and after intracellular injection (10-90 nA), NE elicited no change in melanosome configuration. Once the receptors were localized, the effect of temperature on these receptors was determined by measuring the reflectance of skins (an indication of melanosome aggregation or dispersion) in two populations of frogs treated with NE, Rana pipiens pipiens (with dominant alpha-receptors) and Rana berlandieri forreri (with dominant beta-receptors). NE (0.1 mM) caused melanosome aggregation in the former and dispersion in the latter tested at 12, 22, and 40 degrees C. The iontophoretic and reflectance results suggest that the binding site of the adrenergic receptor is located on the outer surface of the plasma membrane of melanophores and that alpha- and beta-receptors evoke aggregation and dispersion, respectively, within the temperature range of these experiments.

  2. Remodeling of the metabolome during early frog development.

    Directory of Open Access Journals (Sweden)

    Livia Vastag

    Full Text Available A rapid series of synchronous cell divisions initiates embryogenesis in many animal species, including the frog Xenopus laevis. After many of these cleavage cycles, the nuclear to cytoplasmic ratio increases sufficiently to somehow cause cell cycles to elongate and become asynchronous at the mid-blastula transition (MBT. We have discovered that an unanticipated remodeling of core metabolic pathways occurs during the cleavage cycles and the MBT in X. laevis, as evidenced by widespread changes in metabolite abundance. While many of the changes in metabolite abundance were consistently observed, it was also evident that different female frogs laid eggs with different levels of at least some metabolites. Metabolite tracing with heavy isotopes demonstrated that alanine is consumed to generate energy for the early embryo. dATP pools were found to decline during the MBT and we have confirmed that maternal pools of dNTPs are functionally exhausted at the onset of the MBT. Our results support an alternative hypothesis that the cell cycle lengthening at the MBT is triggered not by a limiting maternal protein, as is usually proposed, but by a decline in dNTP pools brought about by the exponentially increasing demands of DNA synthesis.

  3. Post-stimulation block of frog sciatic nerve by high-frequency (kHz) biphasic stimulation.

    Science.gov (United States)

    Yang, Guangning; Xiao, Zhiying; Wang, Jicheng; Shen, Bing; Roppolo, James R; de Groat, William C; Tai, Changfeng

    2017-04-01

    This study determined if high-frequency biphasic stimulation can induce nerve conduction block that persists after the stimulation is terminated, i.e., post-stimulation block. The frog sciatic nerve-muscle preparation was used in the study. Muscle contraction force induced by low-frequency (0.5 Hz) nerve stimulation was recorded to indicate the occurrence and recovery of nerve block induced by the high-frequency (5 or 10 kHz) biphasic stimulation. Nerve block was observed during high-frequency stimulation and after termination of the stimulation. The recovery from post-stimulation block occurred in two distinct phases. During the first phase, the complete block induced during high-frequency stimulation was maintained. The average maximal duration for the first phase was 107 ± 50 s. During the second phase, the block gradually or abruptly reversed. The duration of both first and second phases was dependent on stimulation intensity and duration but not frequency. Stimulation of higher intensity (1.4-2 times block threshold) and longer duration (5 min) produced the longest period (249 ± 58 s) for a complete recovery. Post-stimulation block can be induced by high-frequency biphasic stimulation, which is important for future investigations of the blocking mechanisms and for optimizing the stimulation parameters or protocols in clinical applications.

  4. Bioaccumulation and effects of metals on oxidative stress and neurotoxicity parameters in the frogs from the Pelophylax esculentus complex.

    Science.gov (United States)

    Prokić, Marko D; Borković-Mitić, Slavica S; Krizmanić, Imre I; Mutić, Jelena J; Trifković, Jelena Đ; Gavrić, Jelena P; Despotović, Svetlana G; Gavrilović, Branka R; Radovanović, Tijana B; Pavlović, Slađan Z; Saičić, Zorica S

    2016-10-01

    Metals are involved in the formation of reactive oxygen species and can induce oxidative stress. The aim of this study was to assess the effects of several metals on oxidative stress in the skin and muscle of the Pelophylax esculentus "complex" frogs (parental species Pelophylax ridibundus, Pelophylax lessonae, and their hybrid Pelophylax esculentus) that inhabit the wetland Obedska Bara in Serbia, and the potential use of these species as bioindicator organisms in biomonitoring studies. The biomarkers of oxidative stress (SOD, CAT, GSH-Px, GR, GST activities and GSH, SH concentrations) and cholinesterase activity were investigated. The concentrations of nine metals (Fe, Cu, Zn, As, Cd, Cr, Hg, Ni, and Pb) were measured in the water and tissues. Correlations were established between metals and biomarkers in the tissues. The results of metal accumulation distinguished the skin of P. lessonae and muscle of P. ridibundus from other P. esculentus complex species. The oxidative stress biomarkers observed in P. ridibundus and P. esculentus had greater similarity than in P. lessonae. The P. lessonae displayed the highest number of correlations between biomarkers and metals. The results of tissue responses revealed that skin was more susceptible to metal-induced oxidative stress, with only exception of As. In the light of these findings, we can suggest the use of P. esculentus complex species as a biomonitoring species in studies of metal accumulation and metal-induced oxidative stress, but with special emphasis on P. lessonae.

  5. Effects of host species and life stage on the helminth communities of sympatric northern leopard frogs (Lithobates pipiens) and wood frogs (Lithobates sylvaticus) in the Sheyenne National Grasslands, North Dakota.

    Science.gov (United States)

    Gustafson, Kyle D; Newman, Robert A; Tkach, Vasyl V

    2013-08-01

    We studied helminth communities in sympatric populations of leopard frogs (Lithobates pipiens) and wood frogs (Lithobates sylvaticus) and assessed the effects of host species and life stage on helminth community composition and helminth species richness. We examined 328 amphibians including 218 northern leopard frogs and 110 wood frogs collected between April and August of 2009 and 2010 in the Sheyenne National Grasslands of southeastern North Dakota. Echinostomatid metacercariae were the most common helminths found, with the highest prevalence in metamorphic wood frogs. Host species significantly influenced helminth community composition, and host life stage significantly influenced the component community composition of leopard frogs. In these sympatric populations, leopard frogs were common hosts for adult trematodes whereas wood frogs exhibited a higher prevalence of nematodes with direct life cycles. Metamorphic frogs were commonly infected with echinostomatid metacercariae and other larval trematodes whereas juvenile and adult frogs were most-frequently infected with directly transmitted nematodes and trophically transmitted trematodes. Accordingly, helminth species richness increased with the developmental life stage of the host.

  6. The hyal and ventral branchial muscles in caecilian and salamander larvae: homologies and evolution.

    Science.gov (United States)

    Kleinteich, Thomas; Haas, Alexander

    2011-05-01

    Amphibians (Lissamphibia) are characterized by a bi-phasic life-cycle that comprises an aquatic larval stage and metamorphosis to the adult. The ancestral aquatic feeding behavior of amphibian larvae is suction feeding. The negative pressure that is needed for ingestion of prey is created by depression of the hyobranchial apparatus as a result of hyobranchial muscle action. Understanding the homologies of hyobranchial muscles in amphibian larvae is a crucial step in understanding the evolution of this important character complex. However, the literature mostly focuses on the adult musculature and terms used for hyal and ventral branchial muscles in different amphibians often do not reflect homologies across lissamphibian orders. Here we describe the hyal and ventral branchial musculature in larvae of caecilians (Gymnophiona) and salamanders (Caudata), including juveniles of two permanently aquatic salamander species. Based on previous alternative terminology schemes, we propose a terminology for the hyal and ventral branchial muscles that reflects the homologies of muscles and that is suited for studies on hyobranchial muscle evolution in amphibians. We present a discussion of the hyal and ventral branchial muscles in larvae of the most recent common ancestor of amphibians (i.e. the ground plan of Lissamphibia). Based on our terminology, the hyal and ventral branchial musculature of caecilians and salamanders comprises the following muscles: m. depressor mandibulae, m. depressor mandibulae posterior, m. hyomandibularis, m. branchiohyoideus externus, m. interhyoideus, m. interhyoideus posterior, m. subarcualis rectus I, m. subarcualis obliquus II, m. subarcualis obliquus III, m. subarcualis rectus II-IV, and m. transversus ventralis IV. Except for the m. branchiohyoideus externus, all muscles considered herein can be assigned to the ground plan of the Lissamphibia with certainty. The m. branchiohyoideus externus is either apomorphic for the Batrachia (frogs

  7. Passive stiffness of hindlimb muscles in anurans with distinct locomotor specializations.

    Science.gov (United States)

    Danos, Nicole; Azizi, Emanuel

    2015-08-01

    Anurans (frogs and toads) have been shown to have relatively compliant skeletal muscles. Using a meta-analysis of published data we have found that muscle stiffness is negatively correlated with joint range of motion when examined across mammalian, anuran and bird species. Given this trend across a broad phylogenetic sample, we examined whether the relationship held true within anurans. We identified four species that differ in preferred locomotor mode and hence joint range of motion (Lithobates catesbeianus, Rhinella marina, Xenopus laevis and Kassina senegalensis) and hypothesized that smaller in vivo angles (more flexed) at the knee and ankle joint would be associated with more compliant extensor muscles. We measured passive muscle tension during cyclical stretching (20%) around L0 (sarcomere lengths of 2.2 μm) in fiber bundles extracted from cruralis and plantaris muscles. We found no relationship between muscle stiffness and range of motion for either muscle-joint complex. There were no differences in the passive properties of the cruralis muscle among the four species, but the plantaris muscles of the Xenopus and Kassina were significantly stiffer than those of the other two species. Our results suggest that in anurans the stiffness of muscle fibers is a relatively minor contributor to stiffness at the level of joints and that variation in other anatomical properties including muscle-tendon architecture and joint mechanics as well as active control likely contribute more significantly to range of motion during locomotion. Copyright © 2015 Elsevier GmbH. All rights reserved.

  8. Biomimetic agent based modelling using male Frog calling behaviour as a case study

    DEFF Research Database (Denmark)

    Jørgensen, Søren V.; Demazeau, Yves; Christensen-Dalsgaard, Jakob;

    2014-01-01

    A new agent-based modelling tool has been developed to allow the modelling of populations of individuals whose interactions are characterised by tightly timed dynamics. The tool was developed to model male frog calling dynamics, to facilitate research into what local rules may be employed...... Frog, E. coqui, is implemented as a case study for the presentation and discussion of the tool, and results from this model are presented. RANA, in its present stage of development, is shown to be able to handle the problem of modelling calling frogs, and several fruitful extensions are proposed...

  9. Effect of various lysosomes and endotoxin on vascular permeability in frogs and mice.

    Science.gov (United States)

    Csákó, G; Reichel, A; Csernyánszky, H; Reichel, U

    1975-01-01

    Blood-lymph permeability increasing effects of frog liver lysosomes, Escherichia coli 0111 endotoxin, bradykinin and serotonin were demonstrated in frogs with a method developed by the authors. These actions were expressed in a faster dye saturation in the lymph as compared to that of the controls. 2. The method is based on the determinations of concentration of Evans blue transported as protein-bound dye into the lymph. 3. Frog liver and polymorphonuclear leukocyte lysosomes had a capillary permeability increasing action tested by local skin response when injecting Evans blue intravenously in mice. 4. All these phenomena are similar to events described earlier in mammalian systems.

  10. Oxidative phosphorylation efficiency, proton conductance and reactive oxygen species production of liver mitochondria correlates with body mass in frogs.

    Science.gov (United States)

    Roussel, Damien; Salin, Karine; Dumet, Adeline; Romestaing, Caroline; Rey, Benjamin; Voituron, Yann

    2015-10-01

    Body size is a central biological parameter affecting most biological processes (especially energetics) and the mitochondrion is a key organelle controlling metabolism and is also the cell's main source of chemical energy. However, the link between body size and mitochondrial function is still unclear, especially in ectotherms. In this study, we investigated several parameters of mitochondrial bioenergetics in the liver of three closely related species of frog (the common frog Rana temporaria, the marsh frog Pelophylax ridibundus and the bull frog Lithobates catesbeiana). These particular species were chosen because of their differences in adult body mass. We found that mitochondrial coupling efficiency was markedly increased with animal size, which led to a higher ATP production (+70%) in the larger frogs (L. catesbeiana) compared with the smaller frogs (R. temporaria). This was essentially driven by a strong negative dependence of mitochondrial proton conductance on body mass. Liver mitochondria from the larger frogs (L. catesbeiana) displayed 50% of the proton conductance of mitochondria from the smaller frogs (R. temporaria). Contrary to our prediction, the low mitochondrial proton conductance measured in L. catesbeiana was not associated with higher reactive oxygen species production. Instead, liver mitochondria from the larger individuals produced significantly lower levels of radical oxygen species than those from the smaller frogs. Collectively, the data show that key bioenergetics parameters of mitochondria (proton leak, ATP production efficiency and radical oxygen species production) are correlated with body mass in frogs. This research expands our understanding of the relationship between mitochondrial function and the evolution of allometric scaling in ectotherms.

  11. Annual cycles of urinary reproductive steroid concentrations in wild and captive endangered Fijian ground frogs (Platymantis vitiana).

    Science.gov (United States)

    Narayan, Edward J; Molinia, Frank C; Christi, Ketan S; Morley, Craig G; Cockrem, John F

    2010-03-01

    Annual cycles of reproductive steroid metabolites were measured in urine collected from free-living and captive tropical endangered Fijian ground frogs (Platymantis vitiana) a terrestrial breeding. Free-living frogs were sampled on Viwa Island, Fiji and captive frogs were maintained in an outdoor enclosure in Suva, Fiji. Urinary estrone, progesterone and testosterone metabolite concentrations increased in male and female frogs after hCG challenges, with clear peaks in steroid concentrations 2 or 3 days after the challenges. There were annual cycles of testosterone metabolites in wild and captive males, and of estrone and progesterone metabolites in wild and captive females. Peaks of steroid concentrations in the wet season corresponded with periods of mating and egg laying in females in December and January. Steroid concentrations declined in January and February when maximum egg sizes in females were also declining. Body weights of wild male and vitellogenic female frogs showed annual cycles. Body weights of non-vitellogenic female frogs varied significantly between months, although there was no clear pattern of annual changes. Body weights of the 3 captive male frogs and 4 captive female frogs were similar to those of the wild frogs. Estrone metabolites were 80% successful in identifying non-vitellogenic females from males. The results suggest that the Fijian ground frog is a seasonal breeder with an annual gonadal cycle, and this species is likely to be photoperiodic. Urinary steroid measurements can provide useful information on reproductive cycles in endangered amphibians.

  12. Description of the tadpoles of two endemic frogs: the Phu Luang cascade frog Odorrana aureola (Anura: Ranidae) and the Isan big-headed frog Limnonectes isanensis (Anura: Dicroglossidae) from northeastern Thailand.

    Science.gov (United States)

    Ampai, Natee; Rujirawan, Attapol; Arkajag, Jirachai; Mcleod, David S; Aowphol, Anchalee

    2015-07-07

    We describe the external morphology of the tadpoles of two frogs endemic to Thailand: the Phu Luang cascade frog    (Odorrana aureola) and the Isan big-headed frog (Limnonectes isanensis) from the type localities in the Phu Luang Wildlife Sanctuary, Loei Province, northeastern Thailand. Morphological and genetic characters (16S rRNA) were used to identify specimen and match tadpoles to the adults. Detailed descriptions of external morphology and coloration in life are provided for both species. We provide a brief discussion of the ecology of these tadpoles and a comparison to previously published data from tadpoles of closely related taxa. Additionally, we provide evidence for the utility of larval morphology in resolving the taxonomic puzzles presented by cryptic species complexes.

  13. Effects of predatory fish on survival and behavior of larval gopher frogs (Rana capito) and Southern Leopard Frogs (Rana sphenocephala)

    Science.gov (United States)

    Gregoire, D.R.; Gunzburger, M.S.

    2008-01-01

    Southern Leopard Frogs, Rana sphenocephala, are habitat generalists occurring in virtually all freshwater habitats within their geographic range, whereas Gopher Frogs, Rana capito, typically breed in ponds that do not normally contain fish. To evaluate the potential for predation by fish to influence the distribution of these species, we conducted a randomized factorial experiment. We examined the survival rate and behavior of tadpoles when exposed to Warmouth Sunfish, Lepomis gulosus, Banded Sunfish, Enneacanthus obesus, and Eastern Mosquitofish, Gambusia holbrooki. We also conducted a choice experiment to examine the survival rate of the two species of tadpoles when a predator is given a choice of both species simultaneously. Lepomis gulosus consumed the most tadpoles and ate significantly more tadpoles of R. capito than R. sphenocephala. Gambusia holbrooki injured the most tadpoles, especially R. capito. Enneacanthus obesus did not have an effect on behavior or survival of either anuran species. Tadpoles of both anurans increased hiding when in the presence of L. gulosus and G. holbrooki, but a greater proportion of R. capito hid than did R. sphenocephala. Our results suggest that R. capito are more vulnerable to predation by fish than are R. sphenocephala. The introduction of fish may play a role in population declines of certain anurans breeding in normally fish-free wetlands, and even small fish, such as mosquitofish, may have significant negative effects on the tadpoles of R. capito. Copyright 2008 Society for the Study or Amphibians and Reptiles.

  14. Modulation of forelimb and hindlimb muscle activity during quadrupedal tied-belt and split-belt locomotion in intact cats.

    Science.gov (United States)

    Frigon, A; Thibaudier, Y; Hurteau, M-F

    2015-04-02

    The modulation of the neural output to forelimb and hindlimb muscles when the left and right sides step at different speeds from one another in quadrupeds was assessed by obtaining electromyography (EMG) in seven intact adult cats during split-belt locomotion. To determine if changes in EMG during split-belt locomotion were modulated according to the speed of the belt the limb was stepping on, values were compared to those obtained during tied-belt locomotion (equal left-right speeds) at matched speeds. Cats were chronically implanted for EMG, which was obtained from six muscles: biceps brachii, triceps brachii, flexor carpi ulnaris, sartorius, vastus lateralis and medial gastrocnemius. During tied-belt locomotion, cats stepped from 0.4 to 1.0m/s in 0.1m/s increments whereas during split-belt locomotion, cats stepped with left-right speed differences of 0.1 to 0.4m/s in 0.1m/s increments. During tied-belt locomotion, EMG burst durations and mean EMG amplitudes of all muscles respectively decreased and increased with increasing speed. During split-belt locomotion, there was a clear differential modulation of the EMG patterns between flexors and extensors and between the slow and fast sides. Changes in the EMG pattern of some muscles could be explained by the speed of the belt the limb was stepping on, while in other muscles there were clear dissociations from tied-belt values at matched speeds. Therefore, results show that EMG patterns during split-belt locomotion are modulated to meet task requirements partly via signals related to the stepping speed of the homonymous limb and from the other limbs.

  15. Instruction Manual and Frog Survey Protocols for Region 1 National Wildlife Refuges, East-side Zone

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This manual is intended to assist biologists wishing to conduct surveys for frogs and toads. The document includes detailed information on how to conduct surveys,...

  16. Western spotted frog (Rana pretiosa) distribution in the Bonneville Basin of western Utah: Research in progress

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report provides information on the western spotted frog (Rana pretiosa) which occurs in Tule Valley, Utah. The following topics are discussed; general...

  17. A New Hybrid Shuffled Frog Leaping Algorithm to Solve Non-convex Economic Load Dispatch Problem

    Directory of Open Access Journals (Sweden)

    Ehsan Bijami

    2011-11-01

    Full Text Available This paper presents a New Hybrid Shuffled Frog Leaping (NHSFL algorithm applied to solve Economic Load Dispatch (ELD problem. Practical ELD has non-convex cost function and various equality and inequality constraints that convert the ELD problem as a nonlinear, non-convex and non-smooth optimization problem. In this paper, a new frog leaping rule is proposed to improve the local exploration and the performance of the conventional SFL algorithm. Also a genetic mutation operator is used for the creation of new frogs instead of random frog creation that improves the convergence. To show the efficiency of the proposed approach, the non-convex ELD problem is solved using conventional SFL and an improved SFL method proposed by other researchers. Then the results of SFL methods are compared to the results obtained by the proposed NHSFL algorithm. Simulation studies show that the results obtained by NHSFL are more effective and better compared with these algorithms.

  18. Recovery plan for the California Red-legged frog (Rana aurora draytonii)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The objective of this plan is to reduce threats and improve the population status of the California red-legged frog sufficiently to warrant delisting. Actions...

  19. Okefenokee and Banks Lake National Wildlife Refuge 2009 Frog Abnormality Survey Summary

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Summary of frog observations for abnormal conditions at select sites on both Okefenokee and Banks Lake NWRs. During the 2009 summer, STEP students Zach Carter along...

  20. The Inconsistency Between The Notorious Jumping Frog of Calaveras County and The Man That Corrupted Hadleyburg

    Institute of Scientific and Technical Information of China (English)

    TAN Wen-hua

    2015-01-01

    This paper compares Mark Twain’s The Notorious Jumping Frog of Calaveras County and The Man That Corrupted Had⁃leyburg, in terms of their stylistic and semantic inconsistency, specifically, their narrative technique and moral vision.

  1. Signal perception in frogs and bats and the evolution of mating signals.

    Science.gov (United States)

    Akre, Karin L; Farris, Hamilton E; Lea, Amanda M; Page, Rachel A; Ryan, Michael J

    2011-08-05

    Psychophysics measures the relationship between a stimulus's physical magnitude and its perceived magnitude. Because decisions are based on perception of stimuli, this relationship is critical to understanding decision-making. We tested whether psychophysical laws explain how female túngara frogs (Physalaemus pustulosus) and frog-eating bats (Trachops cirrhosus) compare male frog calls, and how this imposes selection on call evolution. Although both frogs and bats prefer more elaborate calls, they are less selective as call elaboration increases, because preference is based on stimulus ratios. Thus, as call elaboration increases, both relative attractiveness and relative predation risk decrease because of how receivers perceive and compare stimuli. Our data show that female cognition can limit the evolution of sexual signal elaboration.

  2. Adaptive Grouping Cloud Model Shuffled Frog Leaping Algorithm for Solving Continuous Optimization Problems

    Directory of Open Access Journals (Sweden)

    Haorui Liu

    2016-01-01

    Full Text Available The shuffled frog leaping algorithm (SFLA easily falls into local optimum when it solves multioptimum function optimization problem, which impacts the accuracy and convergence speed. Therefore this paper presents grouped SFLA for solving continuous optimization problems combined with the excellent characteristics of cloud model transformation between qualitative and quantitative research. The algorithm divides the definition domain into several groups and gives each group a set of frogs. Frogs of each region search in their memeplex, and in the search process the algorithm uses the “elite strategy” to update the location information of existing elite frogs through cloud model algorithm. This method narrows the searching space and it can effectively improve the situation of a local optimum; thus convergence speed and accuracy can be significantly improved. The results of computer simulation confirm this conclusion.

  3. Report on Oregon Spotted Frog Egg Mass Surveys 2013-2015

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Oregon spotted frogs (Rana pretiosa) were once common across wetlands throughout western Washington and Oregon and were found in northern California and southern...

  4. PHENOBARBITAL AFFECTS THYROID HISTOLOGY AND LARVAL DEVELOPMENT IN THE AFRICAN CLAWED FROG XENOPUS LAEVIS

    Science.gov (United States)

    The abstract highlights our recent study to explore endocrine disrupting effects of phenobarbital in the African clawed frog, Xenopus laevis. In mammals, this chemical is known to induce the biotransforming enzyme UDP-glucuronosyltransferase (UDPGT) resulting in increased thyroid...

  5. Squaw Creek National Wildlife Refuge 2001 Frog and Toad Breeding Survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The first breeding frog and toad survey on Squaw Creek NWR (SCNWR) was conducted this past Spring. This survey was undertaken to assist the Missouri Department of...

  6. Oregon Spotted Frog Monitoring in the Oregon Cascades 2012-2016

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset contains information from visual encounter surveys conducted between 2012 and 2016 by USGS as part of an ongoing Oregon spotted frog (Rana pretiosa)...

  7. Hexokinase and not glycogen synthase controls the flux through the glycogen synthesis pathway in frog oocytes

    National Research Council Canada - National Science Library

    Preller, Ana; Wilson, Christian A.M; Quiroga-Roger, Diego; Ureta, Tito

    2013-01-01

    .... Acute microinjection experiments in frog oocytes were specifically designed to change the endogenous activities of the enzymes, either by directly injecting increasing amounts of a given enzyme (HK, PGM and UGPase...

  8. Adaptive Grouping Cloud Model Shuffled Frog Leaping Algorithm for Solving Continuous Optimization Problems.

    Science.gov (United States)

    Liu, Haorui; Yi, Fengyan; Yang, Heli

    2016-01-01

    The shuffled frog leaping algorithm (SFLA) easily falls into local optimum when it solves multioptimum function optimization problem, which impacts the accuracy and convergence speed. Therefore this paper presents grouped SFLA for solving continuous optimization problems combined with the excellent characteristics of cloud model transformation between qualitative and quantitative research. The algorithm divides the definition domain into several groups and gives each group a set of frogs. Frogs of each region search in their memeplex, and in the search process the algorithm uses the "elite strategy" to update the location information of existing elite frogs through cloud model algorithm. This method narrows the searching space and it can effectively improve the situation of a local optimum; thus convergence speed and accuracy can be significantly improved. The results of computer simulation confirm this conclusion.

  9. The Developmental Effects Of A Municipal Wastewater Effluent On The Northern Leopard Frog, Rana pipiens

    Science.gov (United States)

    Wastewater effluents are complex mixtures containing a variety of anthropogenic compounds, many of which are known endocrine disruptors. In order to characterize the development and behavorial effects of such a complex mixture, northern leopard frogs, Rana pipiens, were e...

  10. Hargreaves does not evaluate nociception following a surgical laparotomy in Xenopus leavis frogs.

    Science.gov (United States)

    Vachon, P

    2014-10-01

    The present study was performed to determine the effectiveness of the Hargreaves test for the evaluation of nociception in frogs, more precisely to determine if cutaneous thresholds to a radiant heat stimulus would increase with analgesics following an abdominal laparotomy performed under general anaesthesia. Non breeding female Xenopus leavis frogs (3 groups (non-anaesthetized, anaesthetized with tricaine methanesulfonate (MS222), with or without an abdominal laparotomy) were used to evaluate the effectiveness of the Hargreaves test. Cutaneous thresholds were evaluated at baseline and following anaesthetic recovery (over 8 h) at six different body locations. Increased reaction times were observed in the gular area only at 1 h post-recovery following a MS222 bath immersion in frogs with (p leavis frogs.

  11. Exploratory evaluation of nutrient enrichment and frog response at Conboy Lake National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — We sampled nutrient and water quality parameters and surveyed Oregon spotted frogs (Rana pretiosa) life stages (eggs, larvae and recently metamorphosed juveniles) to...

  12. A Novel Vasoactive Proline-Rich Oligopeptide from the Skin Secretion of the Frog Brachycephalus ephippium.

    Directory of Open Access Journals (Sweden)

    Daniel Dias Rufino Arcanjo

    Full Text Available Proline-rich oligopeptides (PROs are a large family which comprises the bradykinin-potentiating peptides (BPPs. They inhibit the activity of the angiotensin I-converting enzyme (ACE and have a typical pyroglutamyl (Pyr/proline-rich structure at the N- and C-terminus, respectively. Furthermore, PROs decrease blood pressure in animals. In the present study, the isolation and biological characterization of a novel vasoactive BPP isolated from the skin secretion of the frog Brachycephalus ephippium is described. This new PRO, termed BPP-Brachy, has the primary structure WPPPKVSP and the amidated form termed BPP-BrachyNH2 inhibits efficiently ACE in rat serum. In silico molecular modeling and docking studies suggest that BPP-BrachyNH2 is capable of forming a hydrogen bond network as well as multiple van der Waals interactions with the rat ACE, which blocks the access of the substrate to the C-domain active site. Moreover, in rat thoracic aorta BPP-BrachyNH2 induces potent endothelium-dependent vasodilatation with similar magnitude as captopril. In DAF-FM DA-loaded aortic cross sections examined by confocal microscopy, BPP-BrachyNH2 was found to increase the release of nitric oxide (NO. Moreover, BPP-BrachyNH2 was devoid of toxicity in endothelial and smooth muscle cell cultures. In conclusion, the peptide BPP-BrachyNH2 has a novel sequence being the first BPP isolated from the skin secretion of the Brachycephalidae family. This opens for exploring amphibians as a source of new biomolecules. The BPP-BrachyNH2 is devoid of cytotoxicity and elicits endothelium-dependent vasodilatation mediated by NO. These findings open for the possibility of potential application of these peptides in the treatment of endothelial dysfunction and cardiovascular diseases.

  13. Museum material reveals a frog parasite emergence after the invasion of the cane toad in Australia

    Directory of Open Access Journals (Sweden)

    Phalen David N

    2010-06-01

    Full Text Available Abstract Background A parasite morphologically indistinguishable from Myxidium immersum (Myxozoa: Myxosporea found in gallbladders of the invasive cane toad (Bufo marinus was identified in Australian frogs. Because no written record exists for such a parasite in Australian endemic frogs in 19th and early 20th century, it was assumed that the cane toad introduced this parasite. While we cannot go back in time ourselves, we investigated whether material at the museum of natural history could be used to retrieve parasites, and whether they were infected at the time of their collection (specifically prior to and after the cane toad translocation to Australia in 1935. Results Using the herpetological collection at the Australian Museum we showed that no myxospores were found in any animals (n = 115 prior to the cane toad invasion (1879-1935. The green and golden bell frog (Litoria aurea, the Peron's tree frog (Litoria peronii, the green tree frog (Litoria caerulea and the striped marsh frog (Limnodynastes peronii were all negative for the presence of the parasite using microscopy of the gallbladder content and its histology. These results were sufficient to conclude that the population was free from this disease (at the expected minimum prevalence of 5% at 99.7% confidence level using the 115 voucher specimens in the Australian Museum. Similarly, museum specimens (n = 29 of the green and golden bell frog from New Caledonia, where it was introduced in 19th century, did not show the presence of myxospores. The earliest specimen positive for myxospores in a gallbladder was a green tree frog from 1966. Myxospores were found in eight (7.1%, n = 112 frogs in the post cane toad introduction period. Conclusion Australian wildlife is increasingly under threat, and amphibian decline is one of the most dramatic examples. The museum material proved essential to directly support the evidence of parasite emergence in Australian native frogs. This parasite can be

  14. Distribution and postbreeding environmental relationships of Northern leopard frogs (Rana [Lithobates] pipiens) in Washington

    Science.gov (United States)

    Germaine, S.S.; Hays, D.W.

    2009-01-01

    Northern leopard frogs (Rana [Lithobates] pipiens) are considered sensitive, threatened, or endangered in all western states and western Canadian provinces. Historically present in eastern Washington in 6 major river drainages, leopard frogs are now only known to occur at 2 localized areas in the Crab Creek drainage in Grant County. During the summers of 2002-2005, we surveyed both areas to document extent of leopard frog distributions and to describe habitat and vertebrate community characteristics associated with leopard frog site occupancy. At Gloyd Seeps, 2 juvenile leopard frogs were observed in a total of 8.2 person-days of searching along a 5-km stream reach. At Potholes Reservoir, we surveyed 243 wetland sites in 7 management units known to have been occupied by leopard frogs during the 1980s. We confirmed leopard frog presence at only 87 sites (36%) in 4 management units. Site occupancy models for individual ponds indicated that, compared to unoccupied sites, occupied sites had slightly greater pond depths, less tall emergent vegetation, more herbaceous vegetative cover, and fewer neighboring ponds containing nonnative predatory fish. Models developed at the 1-km2 scale indicated that occupied areas had greater average midsummer pond depths, fewer ponds occupied by bullfrogs (Rana [Lithobates] catesbeiana) and carp (Cyprinus carpio), and more herbaceous vegetation surrounding ponds. The Gloyd Seeps population now appears defunct, and the Potholes Reservoir population is in sharp decline. Unless management actions are taken to reduce nonnative fish and bullfrogs and to enhance wetland vegetation, leopard frogs may soon be extirpated from both sites and possibly, therefore, from Washington.

  15. Density dependent growth in adult brown frogs Rana arvalis and Rana temporaria - A field experiment

    Science.gov (United States)

    Loman, Jon; Lardner, Björn

    2009-11-01

    In species with complex life cycles, density regulation can operate on any of the stages. In frogs there are almost no studies of density effects on the performance of adult frogs in the terrestrial habitat. We therefore studied the effect of summer density on the growth rate of adult frogs during four years. Four 30 by 30 m plots in a moist meadow were used. In early summer, when settled after post-breeding migration, frogs ( Rana arvalis and Rana temporaria that have a very similar ecology and potentially compete) were enclosed by erecting a fence around the plots. Frogs were captured, measured, marked and partly relocated to create two high density and two low density plots. In early autumn the frogs were again captured and their individual summer growth determined. Growth effects were evaluated in relation to two density measures: density by design (high/low manipulation), and actual (numerical) density. R. arvalis in plots with low density by design grew faster than those in high density plots. No such effect was found for R. temporaria. For none of the species was growth related to actual summer density, determined by the Lincoln index and including the density manipulation. The result suggests that R. arvalis initially settled according to an ideal free distribution and that density had a regulatory effect (mediated through growth). The fact that there were no density effects on R. temporaria (and a significant difference in its response to that of R. arvalis) suggests it is a superior competitor to R. arvalis during the terrestrial phase. There were no density effects on frog condition index, suggesting that the growth rate modifications may actually be an adaptive trait of R. arvalis. The study demonstrates that density regulation may be dependent on resources in frogs' summer habitat.

  16. Reproduction and hybrid load in all-hybrid populations of Rana esculenta water frogs in Denmark

    DEFF Research Database (Denmark)

    Christiansen, Ditte Guldager; Fog, Kåre; Pedersen, Bo Vest;

    2005-01-01

    All-hybrid populations of the water frog, Rana esculenta, are exceptional in consisting of independently and to some extent sexually reproducing interspecific hybrids. In most of its range R. esculenta reproduces hemiclonally with one of the parental species, R. lessonae or R. ridibunda, but viable...... gametogenesis and mating between frogs with incompatible gametes induce a significant hybrid load in all-hybrid populations of R. esculenta, and we discuss compensating advantages and potential evolutionary trajectories to reduce this hybrid load....

  17. Landscape associations of frog and toad species in Iowa and Wisconsin, U.S.A

    Science.gov (United States)

    Knutson, M.G.; Sauer, J.R.; Olsen, D.A.; Mossman, M.J.; Hemesath, L.M.; Lannoo, M.J.; Kaiser, Hinrich; Casper, Gary S.; Bernstein, Neil P.

    2000-01-01

    Landscape habitat associations of frogs and toads in Iowa and Wisconsin were tested to determine whether they support or refute previous general habitat classifications. We examined which Midwestern species shared similar habitats to see if these associations were consistent across large geographic areas (states). Rana sylvatica (wood frog), Hyla versicolor (eastern gray treefrog), Pseudacris crucifer (spring peeper), and Acris crepitans (cricket frog) were identified as forest species, P. triseriata (chorus frog), H. chrysoscelis (Cope's gray treefrog), R. pipiens (leopard frog), and Bufo americanus (American toad) as grassland species, and R. catesbeiana (bullfrog), R. clamitans (green frog), R. palustris (pickerel frog), and R. septentrionalis (mink frog) as lake or stream species. The best candidates to serve as bioindicators of habitat quality were the forest species R. sylvatica, H. versicolor, and P. crucifer, the grassland species R. pipiens and P. triseriata, and a cold water wetland species, R. palustris. Declines of P. crucifer, R. pipiens, and R. palustris populations in one or both states may reflect changes in habitat quality. Habitat and community associations of some species differed between states, indicating that these relationships may change across the range of a species. Acris crepitans may have shifted its habitat affinities from open habitats, recorded historically, to the more forested habitat associations we recorded. We suggest contaminants deserve more investigation regarding the abrupt and widespread declines of this species. Interspersion of different habitat types was positively associated with several species. A larger number of wetland patches may increase breeding opportunities and increase the probability of at least one site being suitable. We noted consistently negative associations between anuran species and urban development. Given the current trend of urban growth and increasing density of the human population, declines of

  18. Asplenium bird’s nest ferns in rainforest canopies are climate-contingent refuges for frogs

    OpenAIRE

    Brett R Scheffers; Ben L. Phillips; Shoo, Luke P

    2014-01-01

    Epiphytes are important for canopy dwelling organisms because they provide a cool and moist microhabitat in the relatively hot and dry canopy. Here we examine whether epiphytic Asplenium ferns act as important habitats for arboreal frogs. We conducted extensive fern and habitat surveys for frogs in the Philippines, and complimented these surveys with roaming day and night canopy surveys to identify the full extent of habitat use across the vertical strata. We artificially dried ferns of vario...

  19. Sexual differences in prevalence of a new species of trypanosome infecting túngara frogs

    Directory of Open Access Journals (Sweden)

    Ximena E. Bernal

    2016-04-01

    Full Text Available Trypanosomes are a diverse group of protozoan parasites of vertebrates transmitted by a variety of hematophagous invertebrate vectors. Anuran trypanosomes and their vectors have received relatively little attention even though these parasites have been reported from frog and toad species worldwide. Blood samples collected from túngara frogs (Engystomops pustulosus, a Neotropical anuran species heavily preyed upon by eavesdropping frog-biting midges (Corethrella spp., were examined for trypanosomes. Our results revealed sexual differences in trypanosome prevalence with female frogs being rarely infected (<1%. This finding suggests this protozoan parasite may be transmitted by frog-biting midges that find their host using the mating calls produced by male frogs. Following previous anuran trypanosome studies, we examined 18S ribosomal RNA gene to characterize and establish the phylogenetic relationship of the trypanosome species found in túngara frogs. A new species of giant trypanosome, Trypanosoma tungarae n. sp., is described in this study. Overall the morphometric data revealed that the trypomastigotes of T. tungarae n. sp. are similar to other giant trypanosomes such as Trypanosoma rotatorium and Trypanosoma ranarum. Despite its slender and long cell shape, however, 18S rRNA gene sequences revealed that T. tungarae n. sp. is sister to the rounded-bodied giant trypanosome, Trypanosoma chattoni. Therefore, morphological convergence explains similar morphology among members of two non-closely related groups of trypanosomes infecting frogs. The results from this study underscore the value of coupling morphological identification with molecular characterization of anuran trypanosomes.

  20. Pecular Features of Hematopoiesis in the Liver of Mature and Immature Green Frogs (Pelophylax Esculentus Complex

    Directory of Open Access Journals (Sweden)

    Akulenko N. M.

    2016-12-01

    Full Text Available The article describes characteristic features of the hematopoiesis in mature and immature green frogs (Pelophylax esculentus complex. Quantitative differences in liver myelograms were insignificant. However, in a sample of mature animals numerous significant correlations between the number of pigment inclusions in the liver and indicators of erythropoiesis and myelopoiesis were observed. Those correlations were absent in the immature frogs. We concluded that aft er the frogs’ breeding a lack of plastic resources, in particular, hemosiderin remains up to the hibernation.

  1. Pathological Study of Blood Parasites in Rice Field Frogs, Hoplobatrachus rugulosus (Wiegmann, 1834)

    OpenAIRE

    Achariya Sailasuta; Jetjun Satetasit; Malinee Chutmongkonkul

    2011-01-01

    One hundred and forty adult rice field frogs, Hoplobatrachus rugulosus (Wiegmann, 1834), were collected in Srakaew province, Thailand. For blood parasite examination, thin blood smears were made and routinely stained with Giemsa. The results showed that 70% of the frogs (98/140) were infected with 5 species of blood parasites, including a Trypanosoma rotatorium-like organism, Trypanosoma chattoni, Hepatozoon sp. a, Hepatozoon sp. b, and Lankesterella minima. Pathological examination of the li...

  2. Cutaneous transport of Ca2+ in the frog Rana pipiens: significance and specificity.

    Science.gov (United States)

    Stiffler, D F; Eskandari, S; Dejbakhsh, S

    1997-04-01

    Rana pipiens were divided into four groups: controls; hypocalcemic frogs, depleted of salts by acclimation to deionized water; hypercalcemic frogs, calcium-loaded by the introduction of 40 mumol calcium gluconate; and frogs exposed to the potential competing ions Mg2+, Sr2+, and Ba2+. All groups displayed calcium influx that was proportional to external [Ca2+]; however, the group acclimated to deionized water also displayed hypocalcemia (P 0.3 mM) external [Ca2+]. Ca2+ efflux was depressed in hypocalcemic frogs, and thus net Ca2+ flux shifted from net loss in control frogs to net uptake in hypocalcemic frogs. Hypocalcemia also resulted in increased skin Ca2+ deposits which may be related to a decreased Ca2+ (and other ions) permeability as a consequence of the acclimation to deionized water. Another group of frogs was Ca(2+)-loaded by injecting calcium gluconate: Sodium gluconate controls did not significantly alter Ca2+ fluxes. The frogs that received calcium gluconate treatments became hypercalcemic (P < 0.01) and did not display significant changes in calcium fluxes, nor did they show significant changes in skin calcium deposits. We conclude that hypocalcemia leads to regulatory responses that stimulate active Ca2+ transport in Rana pipiens skin and possibly inhibits cutaneous and renal efflux. We also conclude that hypercalcemia does not alter calcium fluxes across skin. The ions from Group IIA of the Periodic Table of Elements had little effect on Ca2+ fluxes at concentrations ranging from 0.5-4.0 mM; neither Sr2+ or Ba2+ affected Ca2+ influx. The only divalent ion tested that influenced Ca2+ was Mg2+, which significantly inhibited Ca2+ influx but only at 4.0 mM or eight times the external [Ca2+]. We conclude, therefore, that the Ca2+ transport mechanism is fairly specific for Ca2+ within Group IIA.

  3. Transformation of frog embryos with a rabbit beta-globin gene.

    OpenAIRE

    Rusconi, S; Schaffner, W

    1981-01-01

    In order to study the fate and possible expression of foreign DNA during embryogenesis of the frog Xenopus laevis, we have injected a rabbit beta-globin gene into fertilized Xenopus eggs. Frog embryo DNA was extracted at various stages of development, fractionated by agarose gel electrophoresis, transferred to nitrocellulose filters, and hybridized to labeled beta-globin recombinant plasmid DNA. It was found that the injected DNA replicated extrachromosomally, reaching, at gastrula stage, a l...

  4. Small frogs get their worms first: the role of nonodonate arthropods in the recruitment of Haematoloechus coloradensis and Haematoloechus complexus in newly metamorphosed northern leopard frogs, Rana pipiens, and woodhouse's toads, Bufo woodhousii.

    Science.gov (United States)

    Bolek, Matthew G; Janovy, John

    2007-04-01

    Studies on the life cycles and epizootiology of North American frog lung flukes indicate that most species utilize odonates as second intermediate hosts; adult frogs become infected by ingesting odonate intermediate hosts. Newly metamorphosed frogs are rarely infected with these parasites, predominantly because they are gape-limited predators that cannot feed on large intermediate hosts such as dragonflies. We examined the role of the frog diet and potential intermediate hosts in the recruitment of the frog lung fluke, Haematoloechus coloradensis, to metamorphosed northern leopard frogs (Rana pipiens), Woodhouse's toads (Bufo woodhousii), and bullfrogs (Rana catesbeiana) from western Nebraska. Because of the uncertain validity of H. coloradensis as a distinct species from Haematoloechus complexus, morphological characters of both species were reevaluated and the life cycles of both species were completed in the laboratory. The morphological data on H. coloradensis and H. coimplexus indicate that they differ in their oral sucker to pharynx ratio, uterine loop distribution, and placement of vitelline follicles. However, in terms of their life cycles, both species are quite similar in their use of physid snails as first intermediate hosts, a wide range of nonodonate and odonate arthropods as second intermediate hosts, and leopard frogs and toads as definitive hosts. These results indicate that H. coloradensis and H. complexus are generalists at the second intermediate host level and might be able to infect newly metamorphosed leopard frogs and toads by using small nonodonate arthropods more commonly than other frog lung fluke species. Comparisons of population structure of adult flukes in newly metamorphosed leopard frogs indicate that the generalist nature of H. coloradensis metacercariae enables it to colonize young of the year leopard frogs more commonly than other Haematoloechus spp. that only use odonates as second intermediate hosts. In this respect, the

  5. Muscle strain (image)

    Science.gov (United States)

    A muscle strain is the stretching or tearing of muscle fibers. A muscle strain can be caused by sports, exercise, a ... something that is too heavy. Symptoms of a muscle strain include pain, tightness, swelling, tenderness, and the ...

  6. Evaluating group housing strategies for the ex-situ conservation of harlequin frogs (Atelopus spp. using behavioral and physiological indicators.

    Directory of Open Access Journals (Sweden)

    Shawna J Cikanek

    Full Text Available We have established ex situ assurance colonies of two endangered Panamanian harlequin frogs, Atelopus certus and Atelopus glyphus, but observed that males fought with each other when housed as a group. Housing frogs individually eliminated this problem, but created space constraints. To evaluate the potential stress effects from aggressive interactions when grouping frogs, we housed male frogs in replicated groups of one, two, and eight. We measured aggressive behavioral interactions and fecal glucocorticoid metabolite (GC concentrations as indicators of stress in each tank. In both small and large groups, frogs initially interacted aggressively, but aggressive interactions and fecal GCs declined significantly after the first 2 weeks of being housed together, reaching the lowest levels by week 4. We conclude that aggressive interactions in same-sex groups of captive Atelopus may initially cause stress, but the frogs become habituated within a few weeks and they can safely be housed in same-sex groups for longer periods of time.

  7. Checklist and Simple Identification Key for Frogs and Toads from District IV of The MADA Scheme, Kedah, Malaysia.

    Science.gov (United States)

    Jaafar, Ibrahim; Chai, Teoh Chia; Sah, Shahrul Anuar Mohd; Akil, Mohd Abdul Muin Md

    2009-12-01

    A survey was conducted to catalogue the diversity of anurans in District IV of the Muda Agriculture Development Authority Scheme (MADA) in Kedah Darul Aman, Malaysia, from July 1996 to January 1997. Eight species of anurans from three families were present in the study area. Of these, the Common Grass Frog (Fejevarya limnocharis) was the most abundant, followed by Mangrove Frog (Fejevarya cancrivora), Long-legged Frog (Hylarana macrodactyla), and Common Toad (Duttaphrynus melanostictus). Puddle Frog (Occidozyga lima), Taiwanese Giant Frog (Hoplobatrachus rugulosus), and Banded Bullfrog (Kaluola pulchra) were rare during the sampling period, and only one Paddy Frog (Hylarana erythraea) was captured. A simple identification key for the anurans of this area is included for use by scientists and laymen alike.

  8. Spirometra mansoni sparganum infection in frogs from Qingyuan city markets%清远市市售蛙类曼氏裂头蚴感染情况调查

    Institute of Scientific and Technical Information of China (English)

    林燕锋; 杨普贤; 徐国洪; 陈文青

    2014-01-01

    目的 了解清远市市售蛙类曼氏裂头蚴的感染状况.方法 从市场购买人工养殖的虎纹蛙和野生泽蛙,逐只解剖查找曼氏裂头蚴.结果 检查100只人工饲养的虎纹蛙,均为阴性;检查107只野生泽蛙,曼氏裂头蚴感染率为41.12%(44/107),平均感染度为6.55条/只;不同大小泽蛙曼氏裂头蚴感染率差异有统计学意义(x2=7.40,P<0.01);曼氏裂头蚴可在蛙体内任何部位的肌肉寄生,其中以大腿部肌肉寄生最为常见,占62.85%(181/288).结论 清远市市售人工养殖的虎纹蛙未发现曼氏裂头蚴,野生蛙类体内曼氏裂头蚴感染率较高,野生蛙类为重点防范对象,开展健康教育,预防曼氏裂头蚴病的工作十分必要.%Objective To investigate the infection condition Spirometra marsoni Sparganum in frogs from Qingyuan city markets.Methods Rana tigrina and wild Rana limnocharis were bought from markets in Qingyuan city,and were dissected for finding Sparganum mansoni.Results 100 Rana tigrina were dissected; the infection rate was zero.107 wild R.limnocharis were dissected,with an infection rate of 41.12% (44/107),and with an average infection of 6.55 Sparganum per frog.There were significant differences on the infection rates of Sparganum in different sizes of R.imnocharis (x2=7.40,P<O.01);Sparganum mansoni can lodge in any muscle of frogs,and the thigh muscle was the most common parasitic location,accounted for 62.85% (181/288).Conclusion There was no Sparganum mansoni in Rana tigrina from Qingyuan city markets.The infection rate of sparganum of Spirometra mansoni in wild frogs was high,so the wild frogs were the main precautionary subjects.It is necessary to carry out health education for preventing sparganosis mansoni.

  9. Origin of invasive Florida frogs traced to Cuba

    Science.gov (United States)

    Heinicke, Matthew P.; Diaz, Luis M.; Hedges, S. Blair

    2011-01-01

    Two of the earliest examples of successful invasive amphibians are the greenhouse frog (Eleutherodactylus planirostris) and the Cuban treefrog (Osteopilus septentrionalis) in Florida. Although both are generally assumed to be recent introductions, they are widespread on Caribbean islands and also have been proposed as natural colonizers. We obtained nucleotide sequence data for both species and their closest relatives in their native and introduced ranges. Phylogenetic analyses trace the origin of E. planirostris to a small area in western Cuba, while O. septentrionalis is derived from at least two Cuban sources, one probably a remote peninsula in western Cuba. The tropical-to-temperate invasion began with colonization of the Florida Keys followed by human-mediated dispersal within peninsular Florida. The subtropical Keys may have served as an adaptive stepping stone for the successful invasion of the North American continent. PMID:21270024

  10. Genome evolution in the allotetraploid frog Xenopus laevis

    Science.gov (United States)

    Session, Adam M.; Uno, Yoshinobu; Kwon, Taejoon; Chapman, Jarrod A.; Toyoda, Atsushi; Takahashi, Shuji; Fukui, Akimasa; Hikosaka, Akira; Suzuki, Atsushi; Kondo, Mariko; van Heeringen, Simon J.; Quigley, Ian; Heinz, Sven; Ogino, Hajime; Ochi, Haruki; Hellsten, Uffe; Lyons, Jessica B; Simakov, Oleg; Putnam, Nicholas; Stites, Jonathan; Kuroki, Yoko; Tanaka, Toshiaki; Michiue, Tatsuo; Watanabe, Minoru; Bogdanovic, Ozren; Lister, Ryan; Georgiou, Georgios; Paranjpe, Sarita S.; van Kruijsbergen, Ila; Shu, Shengquiang; Carlson, Joseph; Kinoshita, Tsutomu; Ohta, Yuko; Mawaribuchi, Shuuji; Jenkins, Jerry; Grimwood, Jane; Schmutz, Jeremy; Mitros, Therese; Mozaffari, Sahar; Suzuki, Yutaka; Haramoto, Yoshikazu; Yamamoto, Takamasa S.; Takagi, Chiyo; Heald, Rebecca; Miller, Kelly; Haudenschild, Christian; Kitzman, Jacob; Nakayama, Takuya; Izutsu, Yumi; Robert, Jacques; Fortriede, Joshua; Burns, Kevin; Lotay, Vaneet; Karimi, Kamran; Yasuoka, Yuuri; Dichmann, Darwin S.; Flajnik, Martin F.; Houston, Douglas W; Shendure, Jay; DuPasquier, Louis; Vize, Peter D.; Zorn, Aaron M.; Ito, Michihiko; Marcotte, Ed; Wallingford, John B.; Ito, Yuzuru; Asashima, Makoto; Ueno, Naoto; Matsuda, Yoichi; Veenstra, Gert Jan C.; Fujiyama, Asao

    2017-01-01

    To explore the origins and consequences of tetraploidy in the African clawed frog, we sequenced the Xenopus laevis genome and compared it to the related diploid X. tropicalis genome. We demonstrate the allotetraploid origin of X. laevis by partitioning its genome into two homeologous subgenomes, marked by distinct families of “fossil” transposable elements. Based on the activity of these elements and the age of hundreds of unitary pseudogenes, we estimate that the two diploid progenitor species diverged ~34 million years ago (Mya) and combined to form an allotetraploid ~17–18 Mya. 56% of all genes are retained in two homeologous copies. Protein function, gene expression, and the amount of flanking conserved sequence all correlate with retention rates. The subgenomes have evolved asymmetrically, with one chromosome set more often preserving the ancestral state and the other experiencing more gene loss, deletion, rearrangement, and reduced gene expression. PMID:27762356

  11. Predator-prey relationships among larval dragonflies, salamanders, and frogs.

    Science.gov (United States)

    Caldwell, J P; Thorp, J H; Jervey, T O

    1980-09-01

    Tadpoles of the barking tree frog, Hyla gratiosa, are abundant in spring and summer in some ponds and Carolina bays on the Savannah River Plant near Aiken, South Carolina. To determine how these tadpoles survive in the presence of predaceous salamander larvae, Ambystoma talpoideum, and larvae of an aeshnid dragonfly, Anax junius, we determined fields densities and sizes of the predators and the prey and conducted predation experiments in the laboratory. Tadpoles rapidly grow to a size not captured by Ambystoma, although Anax larvae can capture slightly larger tadpoles. Differing habitat preferences among the tadpoles and the two predator species probably aid in reducing predation pressure. Preliminary work indicates that the tadpoles may have an immobility response to an attack by a predator. In addition, the smallest, most vulnerable tadpoles have a distinctive color pattern which may function to disrupt the body outline and make them indiscernable to predators.

  12. Genome evolution in the allotetraploid frog Xenopus laevis.

    Science.gov (United States)

    Session, Adam M; Uno, Yoshinobu; Kwon, Taejoon; Chapman, Jarrod A; Toyoda, Atsushi; Takahashi, Shuji; Fukui, Akimasa; Hikosaka, Akira; Suzuki, Atsushi; Kondo, Mariko; van Heeringen, Simon J; Quigley, Ian; Heinz, Sven; Ogino, Hajime; Ochi, Haruki; Hellsten, Uffe; Lyons, Jessica B; Simakov, Oleg; Putnam, Nicholas; Stites, Jonathan; Kuroki, Yoko; Tanaka, Toshiaki; Michiue, Tatsuo; Watanabe, Minoru; Bogdanovic, Ozren; Lister, Ryan; Georgiou, Georgios; Paranjpe, Sarita S; van Kruijsbergen, Ila; Shu, Shengquiang; Carlson, Joseph; Kinoshita, Tsutomu; Ohta, Yuko; Mawaribuchi, Shuuji; Jenkins, Jerry; Grimwood, Jane; Schmutz, Jeremy; Mitros, Therese; Mozaffari, Sahar V; Suzuki, Yutaka; Haramoto, Yoshikazu; Yamamoto, Takamasa S; Takagi, Chiyo; Heald, Rebecca; Miller, Kelly; Haudenschild, Christian; Kitzman, Jacob; Nakayama, Takuya; Izutsu, Yumi; Robert, Jacques; Fortriede, Joshua; Burns, Kevin; Lotay, Vaneet; Karimi, Kamran; Yasuoka, Yuuri; Dichmann, Darwin S; Flajnik, Martin F; Houston, Douglas W; Shendure, Jay; DuPasquier, Louis; Vize, Peter D; Zorn, Aaron M; Ito, Michihiko; Marcotte, Edward M; Wallingford, John B; Ito, Yuzuru; Asashima, Makoto; Ueno, Naoto; Matsuda, Yoichi; Veenstra, Gert Jan C; Fujiyama, Asao; Harland, Richard M; Taira, Masanori; Rokhsar, Daniel S

    2016-10-20

    To explore the origins and consequences of tetraploidy in the African clawed frog, we sequenced the Xenopus laevis genome and compared it to the related diploid X. tropicalis genome. We characterize the allotetraploid origin of X. laevis by partitioning its genome into two homoeologous subgenomes, marked by distinct families of 'fossil' transposable elements. On the basis of the activity of these elements and the age of hundreds of unitary pseudogenes, we estimate that the two diploid progenitor species diverged around 34 million years ago (Ma) and combined to form an allotetraploid around 17-18 Ma. More than 56% of all genes were retained in two homoeologous copies. Protein function, gene expression, and the amount of conserved flanking sequence all correlate with retention rates. The subgenomes have evolved asymmetrically, with one chromosome set more often preserving the ancestral state and the other experiencing more gene loss, deletion, rearrangement, and reduced gene expression.

  13. California red-legged frog (Rana draytonii) movement and habitat use: Implications for conservation

    Science.gov (United States)

    Fellers, G.M.; Kleeman, P.M.

    2007-01-01

    Nonbreeding habitats are critically important for Rana draytonii, especially for individuals that breed in temporary bodies of water. We radiotracked 123 frogs to evaluate seasonal habitat use. Individual frogs were continuously tracked for up to 16 months. Some individuals remained at breeding ponds all year, but 66% of female and 25% of male frogs moved to nonbreeding areas, even when the breeding site retained water. Frogs at our main study site moved 150 m (median), roughly the distance to the nearest suitable nonbreeding area. The greatest straight-line distance traveled was 1.4 km, although the presumed distance traveled was 2.8 km. Females were more likely than males to move from permanent ponds (38% of females, 16% of males), but among dispersing frogs, males and females did not differ in distance moved. Some frogs left breeding sites shortly after oviposition (median = 12 days for females, 42.5 days for males), but many individuals remained until the site was nearly dry. Fog provided moisture for dispersal or migration throughout the summer. Our data demonstrate that maintaining populations of pond-breeding amphibians requires that all essential habitat components be protected; these include (1) breeding habitat, (2) nonbreeding habitat, and (3) migration corridors. In addition, a buffer is needed around all three areas to ensure that outside activities do not degrade any of the three habitat components. Copyright 2007 Society for the Study of Amphibians and Reptiles.

  14. Impact of Dams on Riparian Frog Communities in the Southern Western Ghats, India

    Directory of Open Access Journals (Sweden)

    Rohit Naniwadekar

    2014-08-01

    Full Text Available The Western Ghats is a global biodiversity hotspot and home to diverse and unique assemblages of amphibians. Several rivers originate from these mountains and hydropower is being tapped from them. The impacts of hydrological regulation of riparian ecosystems to wildlife and its habitat are poorly documented, and in particular the fate of frog populations is unknown. We examined the effects of dams on riparian frog communities in the Thamirabarani catchment in southern Western Ghats. We used nocturnal visual encounter surveys constrained for time, to document the species richness of frogs below and above the dam, and also at control sites in the same catchment. While we did not find differences in species richness below and above the dams, the frog community composition was significantly altered as a likely consequence of altered flow regime. The frog species compositions in control sites were similar to above-dam sites. Below-dam sites had a distinctly different species composition. Select endemic frog species appeared to be adversely impacted due to the dams. Below-dam sites had a greater proportion of generalist and widely distributed species. Dams in the Western Ghats appeared to adversely impact population of endemic species, particularly those belonging to the genus Nyctibatrachus that shows specialization for intact streams.

  15. The island rule in the Brazilian frog Phyllodytes luteolus (Anura: Hylidae: incipient gigantism?

    Directory of Open Access Journals (Sweden)

    Marcio Mageski

    2015-10-01

    Full Text Available ABSTRACT The island rule suggests that, when mainland animals are isolated on islands, large animals tend to become smaller, while small animals tend to become larger. A small frog in eastern Brazil, Phyllodytes luteolus (Wied-Neuwied, 1824, is widely distributed in association with bromeliads. At the end of the last glaciation, parts of the mainland became islands due to rising sea levels, thereby isolating frog populations on these islands. If the island rule holds, we predicted that frogs on islands would tend to be larger than frogs on the mainland. We compared sizes (weight and length of 30 randomly selected male frogs from the mainland with 30 from an island in the state of Espírito Santo, Brazil. We also sampled population density on the island and mainland because concurrent with changing sizes, depending on the causal relationship, density may also change. As predicted, island frogs tended to be larger (both in snout-vent length and weight and were much more abundant. While not specifically addressed in this study, the absence of predators and interspecific competitors may explain both of these trends.

  16. Acute Toxicity of a Heavy Metal Cadmium to an Anuran, the Indian Skipper Frog Rana cyanophlyctis

    Directory of Open Access Journals (Sweden)

    Ajai Kumar Srivastav

    2016-08-01

    Full Text Available Background: There has been increasing awareness throughout the world regarding the remarkable decrease in amphibian population. For such amphibian population decline several causes have been given. Cadmium, a heavy metal is released both from natural sources (leaching of cadmium rich soils and anthropogenic activities to the aquatic and terrestrial environments. This study evaluated the toxicity of heavy metal cadmium to Indian skipper frog Rana cyanophlyctis. Methods: For the determination of LC50 values for cadmium, four-day static renewal acute toxicity test was used. Five replicates each containing ten frogs were subjected to each concentration of cadmium chloride (15, 20, 25, 30, 35, 40, 45 and 50 mg/L. At different exposure periods (24, 48, 72 and 96 h, the mortality of the frog was subjected to Probit analysis with the POLO-PC software (LeOra Software to calculate the LC50 and 95% confidence level. Results: The LC50 values of cadmium chloride for the frog R. cyanophlyctis at 24, 48, 72, and 96 h are 32.586, 29.994, 27.219 and 23.048 mg/L, respectively. The results have been discussed with the toxicity reported for other aquatic vertebrate --fish. Conclusion: Cadmium caused mortality to the frog and this could be one of the reasons for population decline of frogs which inhabit water contaminated with heavy metals.

  17. Electroencephalographic and physiologic changes after tricaine methanesulfonate immersion of African clawed frogs (Xenopus laevis).

    Science.gov (United States)

    Lalonde-Robert, Vanessa; Desgent, Sébastien; Duss, Sandra; Vachon, Pascal

    2012-01-01

    The objective of this study was to determine electroencephalographic and complementary physiologic changes in Xenopus leavis frogs after bath immersion in MS222. We also evaluated the addition of sodium pentobarbital injected intracoelomi- cally 2 h after MS222 immersion to achieve euthanasia. Frogs (n = 9) weighing 105.5 ± 8.4 g (mean ± 1 SD) were immersed in MS222 at either 1 or 3 g/L until anesthesia was achieved; a conductive stainless steel screw then was implanted in the skull on top of the outer pial surface of the brain. Frogs were immersed again in MS222 at the same concentration as previously, and electroencephalograms, heart rate, oxygen saturation, and respiratory movements were recorded. Amplitude and mean frequency of the electroencephalographic signal were evaluated at 15-min intervals until a flat-line signal was achieved. At 2 h after induction, frogs were injected intracoelomically with sodium pentobarbital (0.5 mL; 240 mg/mL) to accelerate euthanasia. Immersion of frogs in 1 or 3 g/L of MS222 depressed cerebral activity within 30 min without a significant effect on cardiac function. Intracoelomic injection of sodium pentobarbital at 2 h after MS222 administration rapidly (3.2 ± 1.7 min) induced cardiac arrest. In conclusion, immersion in MS222 can be used for the collection of organs from X. laevis frogs, but the addition of pentobarbital is required to achieve euthanasia.

  18. Diffraction Ellipsometry Studies on Insect Flight Muscle

    Science.gov (United States)

    Shen, Sui

    Characterization of the orientation and distribution of myosin cross-bridge at rigor, relax, low ionic strength (36 mM) and activation (pCa 4.3) conditions are of great interest since these states have been proposed to be transient steps in the cyclical interaction of myosin heads with actin during contraction. Measurements sensitive to the cross-bridge orientation in chemically skinned single muscle fibers of the insect, Lethocerus collossicus have been performed under various physiological conditions using laser diffraction ellipsometry. Determination of both the total birefringence, Deltan, and the differential field ratio, rm DFR (defined as {E_parallel -E_|over E_parallel-E _|}),is necessary for complete characterization of the optical polarization state. For rigor insect fiber, the birefringence value was close to the value we obtained from chemically skinned frog muscle fibers. However, the differential field ratio, DFR, was a negative value for insect fiber, while we always measured a positive value from frog muscle fibers. Polarization states of light diffracted from fibers exhibited a dependence on configurations of structural proteins at different conditions: fluid index matching using o-toluidine, alpha -chymotrypsin cleavage, KCl myosin extraction, rigor state, relaxed state, exogenous S-1 binding on rigor fiber, low ionic strength state, activation state at resting or stretched length. Results of our data analysis suggested that: (1) the negative DFR value of the insect flight muscle was contributed by alpha-actinin arranged perpendicular to the fiber axis in the Z-line, (2) in rigor fiber, 70% of myosin heads are doubly bound (45^circ and 90^ circ) while the rest of 30% are in single head binding configuration (90^circ), (3) myosin heads are randomly oriented in relaxed fiber, (4) mean axial angle is about 62^ circ for exogenous myosin heads binding on rigor fiber, (5) at low ionic strength, 25% of the total myosin heads are weakly attached to actin

  19. Characteristics of acute groin injuries in the hip flexor muscles - a detailed MRI study in athletes.

    Science.gov (United States)

    Serner, A; Weir, A; Tol, J L; Thorborg, K; Roemer, F; Guermazi, A; Yamashiro, E; Hölmich, P

    2017-06-26

    Hip flexor injuries account for one-third of acute groin injuries; however, little is known about specific injury characteristics. The aims of this study were to describe acute hip flexor injuries using magnetic resonance imaging (MRI) in athletes with acute groin pain and to compare specific muscle injuries with reported injury situations. Male athletes with acute groin pain were prospectively and consecutively included during three sports seasons. MRI was performed within 7 days of injury using a standardized protocol and a reliable assessment approach. All athletes with an MRI confirmed acute hip flexor muscle injury were included. A total of 156 athletes presented with acute groin pain of which 33 athletes were included, median age 26 years (range 18-35). There were 16 rectus femoris, 12 iliacus, 7 psoas major, 4 sartorius, and 1 tensor fascia latae injury. Rectus femoris injuries primarily occurred during kicking (10) and sprinting (4), whereas iliacus injuries most frequently occurred during change of direction (5). In 10 (63%) rectus femoris injuries, tendinous injury was observed. The iliacus and psoas major injuries were mainly observed at the musculotendinous junction (MTJ), and two included tendinous injury. We have illustrated specific injury locations within these muscles, which may be relevant for the clinical diagnosis and prognosis of these injuries. Most proximal rectus femoris injuries included tendinous injury. In contrast, distinct acute iliacus and psoas injuries predominantly occurred at the MTJ. Only the iliacus or psoas major were injured during change of direction, whereas rectus femoris injuries occurred primarily during kicking and sprinting. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Hypertrophy of the tensor fascia lata muscle as a complication of total hip arthroplasty.

    Science.gov (United States)

    Rodríguez-Roiz, Juan Miguel; Bori, Guillem; Tomas, Xavier; Fernández-Valencia, Jenaro A; García-Díez, Ana Isabel; Pomés, Jaume; Garcia, Sebastián

    2017-02-01

    Hypertrophy of the tensor fascia lata muscle (HTFLM) is a rare complication after total hip arthroplasty (THA) and is a potential source of pain, palpable mass, or both. We retrospectively analyzed 1285 primary THAs and 482 THA revisions (THAR) performed at our center from 2008 to 2014. Among these, five patients had HTFLM (average age 68.8 years). The type of surgery and symptoms were evaluated, as were imaging studies (CT or MRI) of both hips (10 hips), and functional outcomes with the Merle d'Aubigné score. The suspected diagnosis was established at an average of 30.2 months after surgery. Four cases occurred after THA and one case after THAR. A modified Hardinge approach was used in four cases and a Röttinger approach in one case. Two cases had pain and palpable mass in the trochanteric region and three cases only pain. The asymmetric HTFLM of the THA side against the nonsurgical side was confirmed by measuring the cross section of the tensor fascia lata muscle on imaging. The sartorius muscle was measured for reference in each case. The Merle d'Aubigne scale had a mean value of 16.6 (range 13-18) at 38 months after the procedure. HTFLM after THA is a benign condition that could be mistaken for a tumor when presenting as a palpable mass. We propose that it should be considered in the differential diagnosis of pain in the lateral aspect of hips that have previously undergone THA.

  1. Apical Na+ permeability of frog skin during serosal Cl- replacement.

    Science.gov (United States)

    Leibowich, S; DeLong, J; Civan, M M

    1988-05-01

    Gluconate substitution for serosal Cl- reduces the transepithelial short-circuit current (Isc) and depolarizes short-circuited frog skins. These effects could result either from inhibition of basolateral K+ conductance, or from two actions to inhibit both apical Na+ permeability (PapNa) and basolateral pump activity. We have addressed this question by studying whole-and split-thickness frog skins. Intracellular Na+ concentration (CcNa) and PapNa have been monitored by measuring the current-voltage relationship for apical Na+ entry. This analysis was conducted by applying trains of voltage pulses, with pulse durations of 16 to 32 msec. Estimates of PapNa and CcNa were not detectably dependent on pulse duration over the range 16 to 80 msec. Serosal Cl- replacement uniformly depolarized short-circuited tissues. The depolarization was associated with inhibition of Isc across each split skin, but only occasionally across the whole-thickness preparations. This difference may reflect the better ionic exchange between the bulk medium and the extracellular fluid in contact with the basolateral membranes, following removal of the underlying dermis in the split-skin preparations. PapNa was either unchanged or increased, and CcNa either unchanged or reduced after the anionic replacement. These data are incompatible with the concept that serosal Cl- replacement inhibits PapNa and Na,K-pump activity. Gluconate substitution likely reduces cell volume, triggering inhibition of the basolateral K+ channels, consistent with the data and conclusions of S.A. Lewis, A.G. Butt, M.J. Bowler, J.P. Leader and A.D.C. Macknight (J. Membrane Biol. 83:119-137, 1985) for toad bladder. The resulting depolarization reduces the electrical force favoring apical Na+ entry. The volume-conductance coupling serves to conserve volume by reducing K+ solute loss. Its molecular basis remains to be identified.

  2. Clinical signs, pathology and dose-dependent survival of adult wood frogs, Rana sylvatica, inoculated orally with frog virus 3 Ranavirus sp., Iridoviridae.

    Science.gov (United States)

    Forzn, Mara J; Jones, Kathleen M; Vanderstichel, Raphal V; Wood, John; Kibenge, Frederick S B; Kuiken, Thijs; Wirth, Wytamma; Ariel, Ellen; Daoust, Pierre-Yves

    2015-05-01

    Amphibian populations suffer massive mortalities from infection with frog virus 3 FV3, genus Ranavirus, family Iridoviridae, a pathogen also involved in mortalities of fish and reptiles. Experimental oral infection with FV3 in captive-raised adult wood frogs, Rana sylvatica Lithobates sylvaticus, was performed as the first step in establishing a native North American animal model of ranaviral disease to study pathogenesis and host response. Oral dosing was successful LD50 was 10(2.93 2.423.44) p.f.u. for frogs averaging 35mm in length. Onset of clinical signs occurred 614days post-infection p.i. median 11 days p.i. and time to death was 1014 days p.i. median 12 days p.i.. Each tenfold increase in virus dose increased the odds of dying by 23-fold and accelerated onset of clinical signs and death by approximately 15. Ranavirus DNA was demonstrated in skin and liver of all frogs that died or were euthanized because of severe clinical signs. Shedding of virus occurred in faeces 710 days p.i. 34.5days before death and skin sheds 10 days p.i. 01.5days before death of some frogs dead from infection. Most common lesions were dermal erosion and haemorrhages haematopoietic necrosis in bone marrow, kidney, spleen and liver and necrosis in renal glomeruli, tongue, gastrointestinal tract and urinary bladder mucosa. Presence of ranavirus in lesions was confirmed by immunohistochemistry. Intracytoplasmic inclusion bodies probably viral were present in the bone marrow and the epithelia of the oral cavity, gastrointestinal tract, renal tubules and urinary bladder. Our work describes a ranaviruswood frog model and provides estimates that can be incorporated into ranavirus disease ecology models.

  3. Developmental Toxicity of Drinking Water Disinfection By-Products to Embryos of the African Clawed Frog (Xenopus laevis)

    Science.gov (United States)

    2005-06-10

    developmental toxicity tests with embryos of the South African clawed frog Xenopus laevis used to evaluate four individual DWDB; bromodichloromethane...SUBJECT TERMS Developmental toxicity; FETAX; water disinfection by-products; frogs ; Xenopus laevis; embryo malformations; embryo mortality...Disinfection By-Products to Embryos of the African Clawed Frog (Xenopus laevis) L. M. Brennan,1 M. W. Toussaint,1 D. M. Kumsher,1 W. E. Dennis,’ A. B

  4. To the problem of cross-bridge tension in steady muscle shortening and lengthening

    CERN Document Server

    Kokshenev, Valery B

    2009-01-01

    Despite the great success of the Huxley sliding filament model proposed half a century ago for actin-myosin linkages (cross-bridges), it fails to explain the force-velocity behavior of stretching skeletal muscles. Huxley's two-state kinetic equation for cross-bridge proportions is therefore reconsidered and a new solution to the problem of steady muscle eccentric and concentric contractions is reported. When the second law of statistical thermodynamics is applied to cross-bridge proportions, the weakly bound states appear to be correlated to the strongly bound states via structural and kinetic intrinsic muscle characteristics. The explicit force-velocity curve fits the empirical tension-velocity data on frog muscle shortening using only one adjustable parameter, while the Huxley model employed four parameters.

  5. Range extension of the critically endambersngered true poison-dart frog, Phyllobates terribilis (Anura: Dendrobatidae), in western Colombia

    National Research Council Canada - National Science Library

    Roberto Márquez; Germán Corredor; Carlos Galvis; Daniel Góez; Adolfo Amézquita

    2012-01-01

    The poison-dart frog Phyllobates terribilis is currently classified as endangered or critically endangered due to its extremely restricted geographic distribution and intensive smuggling by pet traffickers...

  6. Frog species richness, composition and beta-diversity in coastal Brazilian restinga habitats.

    Science.gov (United States)

    Rocha, C F D; Hatano, F H; Vrcibradic, D; Van Sluys, M

    2008-02-01

    We studied the species richness and composition of frogs in 10 restinga habitats (sand dune environments dominated by herbaceous and shrubby vegetation) along approximately 1500 km of coastal areas of three Brazilian States: Rio de Janeiro (Grumari, Maricá, Massambaba, Jurubatiba and Grussaí), Espírito Santo (Praia das Neves and Setiba) and Bahia (Prado and Trancoso). We estimated beta-diversity and similarity among areas and related these parameters to geographic distance between areas. All areas were surveyed with a similar sampling procedure. We found 28 frog species belonging to the families Hylidae, Microhylidae, Leptodactylidae and Bufonidae. Frogs in restingas were in general nocturnal with no strictly diurnal species. The richest restinga was Praia das Neves (13 species), followed by Grussaí and Trancoso (eight species in each). The commonest species in the restingas was Scinax alter (found in eight restingas), followed by Aparasphenodon brunoi (seven areas). Our data shows that richness and composition of frog communities vary consistently along the eastern Brazilian coast and, in part, the rate of species turnover is affected by the distance among areas. Geographic distance explained approximately 12% of species turnover in restingas and about 9.5% of similarity among frog assemblages. Although geographic distance somewhat affects frog assemblages, other factors (e.g. historical factors, disturbances) seem to be also involved in explaining present frog assemblage composition in each area and species turnover among areas. The frog fauna along restinga habitats was significantly nested (matrix community temperature = 26.13 degrees; p = 0.007). Our data also showed that the most hospitable restinga was Praia das Neves and indicated that this area should be protected as a conservation unit. Frog assemblage of each area seems to partially represent a nested subset of the original assemblage, although we should not ignore the importance of historical

  7. Frog species richness, composition and beta-diversity in coastal Brazilian restinga habitats

    Directory of Open Access Journals (Sweden)

    CFD. Rocha

    Full Text Available We studied the species richness and composition of frogs in 10 restinga habitats (sand dune environments dominated by herbaceous and shrubby vegetation along approximately 1500 km of coastal areas of three Brazilian States: Rio de Janeiro (Grumari, Maricá, Massambaba, Jurubatiba and Grussaí, Espírito Santo (Praia das Neves and Setiba and Bahia (Prado and Trancoso. We estimated beta-diversity and similarity among areas and related these parameters to geographic distance between areas. All areas were surveyed with a similar sampling procedure. We found 28 frog species belonging to the families Hylidae, Microhylidae, Leptodactylidae and Bufonidae. Frogs in restingas were in general nocturnal with no strictly diurnal species. The richest restinga was Praia das Neves (13 species, followed by Grussaí and Trancoso (eight species in each. The commonest species in the restingas was Scinax alter (found in eight restingas, followed by Aparasphenodon brunoi (seven areas. Our data shows that richness and composition of frog communities vary consistently along the eastern Brazilian coast and, in part, the rate of species turnover is affected by the distance among areas. Geographic distance explained approximately 12% of species turnover in restingas and about 9.5% of similarity among frog assemblages. Although geographic distance somewhat affects frog assemblages, other factors (e.g. historical factors, disturbances seem to be also involved in explaining present frog assemblage composition in each area and species turnover among areas. The frog fauna along restinga habitats was significantly nested (matrix community temperature = 26.13°; p = 0.007. Our data also showed that the most hospitable restinga was Praia das Neves and indicated that this area should be protected as a conservation unit. Frog assemblage of each area seems to partially represent a nested subset of the original assemblage, although we should not ignore the importance of historical

  8. Interindividual differences in leg muscle mass and pyruvate kinase activity correlate with interindividual differences in jumping performance of Hyla multilineata.

    Science.gov (United States)

    James, Rob S; Wilson, Robbie S; de Carvalho, José E; Kohlsdorf, Tiana; Gomes, Fernando R; Navas, Carlos A

    2005-01-01

    Frog jumping is an excellent model system for examining the structural basis of interindividual variation in burst locomotor performance. Some possible factors that affect jump performance, such as total body size, hindlimb length, muscle mass, and muscle mechanical and biochemical properties, were analysed at the interindividual (intraspecies) level in the tree frog Hyla multilineata. The aim of this study was to determine which of these physiological and anatomical variables both vary between individuals and are correlated with interindividual variation in jump performance. The model produced via stepwise linear regression analysis of absolute data suggested that 62% of the interindividual variation in maximum jump distance could be explained by a combination of interindividual variation in absolute plantaris muscle mass, total hindlimb muscle mass (excluding plantaris muscle), and pyruvate kinase activity. When body length effects were removed, multiple regression indicated that the same independent variables explained 43% of the residual interindividual variation in jump distance. This suggests that individuals with relatively large jumping muscles and high pyruvate kinase activity for their body size achieved comparatively large maximal jump distances for their body size.

  9. Each to their own: skeletal muscles of different function use different biochemical strategies during aestivation at high temperature.

    Science.gov (United States)

    Young, Karen M; Cramp, Rebecca L; Franklin, Craig E

    2013-03-15

    Preservation of muscle morphology depends on a continuing regulatory balance between molecules that protect and molecules that damage muscle structural integrity. Excessive disruption of the biochemical balance that favours reactive oxygen species (ROS) in disused muscles may lead to oxidative stress, which in turn is associated with increased atrophic or apoptotic signalling and/or oxidative damage to the muscle and thus muscle disuse atrophy. Increases in the rate of oxygen consumption likely increase the overall generation of ROS in vivo. Temperature-induced increases in oxygen consumption rate occur in some muscles of ectotherms undergoing prolonged muscular disuse during aestivation. In the green-striped burrowing frog, Cyclorana alboguttata, both large jumping and small non-jumping muscles undergo atrophy seemingly commensurate with their rate of oxygen consumption during aestivation. However, because the extent of atrophy in these muscles is not enhanced at higher temperatures, despite a temperature-sensitive rate of oxygen consumption in the jumping muscle, we proposed that muscles are protected by biochemical means that, when mobilised at higher temperatures, inhibit atrophy. We proposed that the biochemical response to temperature would be muscle-specific. We examined the effect of temperature on the antioxidant and heat shock protein systems and determined the extent of oxidative damage to lipids and proteins in two functionally different skeletal muscles, the gastrocnemius (jumping muscle) and the iliofibularis (non-jumping muscle), by aestivating frogs at 24 and 30°C for 6 months. We assayed small molecule antioxidant capacity, mitochondrial and cytosolic superoxide dismutase activities and Hsp70 concentrations to show that protective mechanisms in disused muscles are differentially regulated with respect to both temperature and aestivation. High aestivation temperature results in an antioxidant response in the metabolically temperature

  10. Pre-swing deficits in forward propulsion, swing initiation and power generation by individual muscles during hemiparetic walking.

    Science.gov (United States)

    Peterson, Carrie L; Hall, Allison L; Kautz, Steven A; Neptune, Richard R

    2010-08-26

    Clinical studies of hemiparetic walking have shown pre-swing abnormalities in the paretic leg suggesting that paretic muscle contributions to important biomechanical walking subtasks are different than those of non-disabled individuals. Three-dimensional forward dynamics simulations of two representative hemiparetic subjects with different levels of walking function classified by self-selected walking speed (i.e., limited community=0.4-0.8 m/s and community walkers = or > 0.8m/s) and a speed-matched control were generated to quantify individual muscle contributions to forward propulsion, swing initiation and power generation during the pre-swing phase (i.e., double support phase proceeding toe-off). Simulation analyses identified decreased paretic soleus and gastrocnemius contributions to forward propulsion and power generation as the primary impairment in the limited community walker compared to the control subject. The non-paretic leg did not compensate for decreased forward propulsion by paretic muscles during pre-swing in the limited community walker. Paretic muscles had the net effect to absorb energy from the paretic leg during pre-swing in the community walker suggesting that deficits in swing initiation are a primary impairment. Specifically, the paretic gastrocnemius and hip flexors (i.e., iliacus, psoas and sartorius) contributed less to swing initiation and the paretic soleus and gluteus medius absorbed more power from the paretic leg in the community walker compared to the control subject. Rehabilitation strategies aimed at diminishing these deficits have much potential to improve walking function in these hemiparetic subjects and those with similar deficits.

  11. Biodiversity of frog haemoparasites from sub-tropical northern KwaZulu-Natal, South Africa.

    Science.gov (United States)

    Netherlands, Edward C; Cook, Courtney A; Kruger, Donnavan J D; du Preez, Louis H; Smit, Nico J

    2015-04-01

    Since South Africa boasts a high biodiversity of frog species, a multispecies haemoparasite survey was conducted by screening the blood from 29 species and 436 individual frogs. Frogs were collected at three localities in sub-tropical KwaZulu-Natal, a hotspot for frog diversity. Twenty per cent of the frogs were infected with at least one of five groups of parasites recorded. Intraerythrocytic parasites comprising Hepatozoon, Dactylosoma, and viral or bacterial organisms, as well as extracellular parasites including trypanosomes and microfilarid nematodes were found. A significant difference (P < 0.01) in the prevalence of parasitaemia was found across species, those semi-aquatic species demonstrating the highest, followed by semi-terrestrial frog species. None of those species described as purely terrestrial and aquatic were infected. Hepatozoon and Trypanosoma species accounted for most of the infections, the former demonstrating significant differences in intensity of infection across species, families and habitat types (P = 0.028; P = 0.006; P = 0.007 respectively). Per locality, the first, the formally protected Ndumo Game Reserve, had the highest biodiversity of haemoparasite infections, with all five groups of parasites recorded. The other two sites, that is the area bordering the reserve and the Kwa Nyamazane Conservancy, had a lower diversity with no parasite infections recorded and only Hepatozoon species recorded respectively. Such findings could be ascribed to the anthropogenic impact on the latter two sites, the first by the rural village activities, and the second by the bordering commercial sugar cane agriculture. Future studies should include both morphological and molecular descriptions of the above parasites, as well as the identification of potential vectors, possibly clarifying the effects human activities may have on frog haemoparasite life cycles and as such their biodiversity.

  12. Biodiversity of frog haemoparasites from sub-tropical northern KwaZulu-Natal, South Africa

    Directory of Open Access Journals (Sweden)

    Edward C. Netherlands

    2015-04-01

    Full Text Available Since South Africa boasts a high biodiversity of frog species, a multispecies haemoparasite survey was conducted by screening the blood from 29 species and 436 individual frogs. Frogs were collected at three localities in sub-tropical KwaZulu-Natal, a hotspot for frog diversity. Twenty per cent of the frogs were infected with at least one of five groups of parasites recorded. Intraerythrocytic parasites comprising Hepatozoon, Dactylosoma, and viral or bacterial organisms, as well as extracellular parasites including trypanosomes and microfilarid nematodes were found. A significant difference (P < 0.01 in the prevalence of parasitaemia was found across species, those semi-aquatic species demonstrating the highest, followed by semi-terrestrial frog species. None of those species described as purely terrestrial and aquatic were infected. Hepatozoon and Trypanosoma species accounted for most of the infections, the former demonstrating significant differences in intensity of infection across species, families and habitat types (P = 0.028; P = 0.006; P = 0.007 respectively. Per locality, the first, the formally protected Ndumo Game Reserve, had the highest biodiversity of haemoparasite infections, with all five groups of parasites recorded. The other two sites, that is the area bordering the reserve and the Kwa Nyamazane Conservancy, had a lower diversity with no parasite infections recorded and only Hepatozoon species recorded respectively. Such findings could be ascribed to the anthropogenic impact on the latter two sites, the first by the rural village activities, and the second by the bordering commercial sugar cane agriculture. Future studies should include both morphological and molecular descriptions of the above parasites, as well as the identification of potential vectors, possibly clarifying the effects human activities may have on frog haemoparasite life cycles and as such their biodiversity.

  13. Defects in host immune function in tree frogs with chronic chytridiomycosis.

    Directory of Open Access Journals (Sweden)

    Sam Young

    Full Text Available The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd has caused mass mortality leading to population declines and extinctions in many frog species worldwide. The lack of host resistance may be due to fungal immunosuppressive effects that have been observed when Bd is incubated with cultured lymphocytes, but whether in vivo host immunosuppression occurs is unknown. We used a broad range of hematologic and protein electrophoresis biomarkers, along with various functional tests, to assess immune competence in common green (Litoria caerulea and white-lipped (L. infrafrenata tree frogs experimentally infected with Bd. Compared with uninfected frogs, Bd infection in L. caerulea caused a reduction in immunoglobulin and splenic lymphocyte responses to antigenic stimulation with sheep red blood cells, along with decreased white blood cell and serum protein concentrations, indicating possible impaired immune response capability of Bd-infected frogs. This is the first in vivo study suggesting that infection with Bd causes multiple defects in systemic host immune function, and this may contribute to disease development in susceptible host species. Although L. infrafrenata failed to maintain Bd infection after exposure, white blood cell and serum globulin concentrations were lower in recovered frogs compared with unexposed frogs, but antigen-specific serum and splenic antibody, and splenic cellular, responses were similar in both recovered and unexposed frogs. This may indicate potential systemic costs associated with infection clearance and/or redirection of host resources towards more effective mechanisms to overcome infection. No clear mechanism for resistance was identified in L. infrafrenata, suggesting that localized and/or innate immune defense mechanisms may be important factors involved in disease resistance in this species.

  14. Cytological maps of lampbrush chromosomes of European water frogs (Pelophylax esculentus complex) from the Eastern Ukraine.

    Science.gov (United States)

    Dedukh, Dmitry; Mazepa, Glib; Shabanov, Dmitry; Rosanov, Juriy; Litvinchuk, Spartak; Borkin, Leo; Saifitdinova, Alsu; Krasikova, Alla

    2013-04-16

    Hybridogenesis (hemiclonal inheritance) is a kind of clonal reproduction in which hybrids between parental species are reproduced by crossing with one of the parental species. European water frogs (Pelophylax esculentus complex) represent an appropriate model for studying interspecies hybridization, processes of hemiclonal inheritance and polyploidization. P. esculentus complex consists of two parental species, P. ridibundus (the lake frog) and P. lessonae (the pool frog), and their hybridogenetic hybrid - P. esculentus (the edible frog). Parental and hybrid frogs can reproduce syntopically and form hemiclonal population systems. For studying mechanisms underlying the maintenance of water frog population systems it is required to characterize the karyotypes transmitted in gametes of parental and different hybrid animals of both sexes. In order to obtain an instrument for characterization of oocyte karyotypes in hybrid female frogs, we constructed cytological maps of lampbrush chromosomes from oocytes of both parental species originating in Eastern Ukraine. We further identified certain molecular components of chromosomal marker structures and mapped coilin-rich spheres and granules, chromosome associated nucleoli and special loops accumulating splicing factors. We recorded the dissimilarities between P. ridibundus and P. lessonae lampbrush chromosomes in the length of orthologous chromosomes, number and location of marker structures and interstitial (TTAGGG)n-repeat sites as well as activity of nucleolus organizer. Satellite repeat RrS1 was mapped in centromere regions of lampbrush chromosomes of the both species. Additionally, we discovered transcripts of RrS1 repeat in oocytes of P. ridibundus and P. lessonae. Moreover, G-rich transcripts of telomere repeat were revealed in association with terminal regions of P. ridibundus and P. lessonae lampbrush chromosomes. The constructed cytological maps of lampbrush chromosomes of P. ridibundus and P. lessonae provide

  15. An Analysis of Predator Selection to Affect Aposematic Coloration in a Poison Frog Species.

    Directory of Open Access Journals (Sweden)

    Corinna E Dreher

    Full Text Available Natural selection is widely noted to drive divergence of phenotypic traits. Predation pressure can facilitate morphological divergence, for example the evolution of both cryptic and conspicuous coloration in animals. In this context Dendrobatid frogs have been used to study evolutionary forces inducing diversity in protective coloration. The polytypic strawberry poison frog (Oophaga pumilio shows strong divergence in aposematic coloration among populations. To investigate whether predation pressure is important for color divergence among populations of O. pumilio we selected four mainland populations and two island populations from Costa Rica and Panama. Spectrometric measurements of body coloration were used to calculate color and brightness contrasts of frogs as an indicator of conspicuousness for the visual systems of several potential predators (avian, crab and snake and a conspecific observer. Additionally, we conducted experiments using clay model frogs of different coloration to investigate whether the local coloration of frogs is better protected than non-local color morphs, and if predator communities vary among populations. Overall predation risk differed strongly among populations and interestingly was higher on the two island populations. Imprints on clay models indicated that birds are the main predators while attacks of other predators were rare. Furthermore, clay models of local coloration were equally likely to be attacked as those of non-local coloration. Overall conspicuousness (and brightness contrast of local frogs was positively correlated with attack rates by birds across populations. Together with results from earlier studies we conclude that conspicuousness honestly indicates toxicity to avian predators. The different coloration patterns among populations of strawberry poison frogs in combination with behavior and toxicity might integrate into equally efficient anti-predator strategies depending on local predation and

  16. An Analysis of Predator Selection to Affect Aposematic Coloration in a Poison Frog Species.

    Science.gov (United States)

    Dreher, Corinna E; Cummings, Molly E; Pröhl, Heike

    2015-01-01

    Natural selection is widely noted to drive divergence of phenotypic traits. Predation pressure can facilitate morphological divergence, for example the evolution of both cryptic and conspicuous coloration in animals. In this context Dendrobatid frogs have been used to study evolutionary forces inducing diversity in protective coloration. The polytypic strawberry poison frog (Oophaga pumilio) shows strong divergence in aposematic coloration among populations. To investigate whether predation pressure is important for color divergence among populations of O. pumilio we selected four mainland populations and two island populations from Costa Rica and Panama. Spectrometric measurements of body coloration were used to calculate color and brightness contrasts of frogs as an indicator of conspicuousness for the visual systems of several potential predators (avian, crab and snake) and a conspecific observer. Additionally, we conducted experiments using clay model frogs of different coloration to investigate whether the local coloration of frogs is better protected than non-local color morphs, and if predator communities vary among populations. Overall predation risk differed strongly among populations and interestingly was higher on the two island populations. Imprints on clay models indicated that birds are the main predators while attacks of other predators were rare. Furthermore, clay models of local coloration were equally likely to be attacked as those of non-local coloration. Overall conspicuousness (and brightness contrast) of local frogs was positively correlated with attack rates by birds across populations. Together with results from earlier studies we conclude that conspicuousness honestly indicates toxicity to avian predators. The different coloration patterns among populations of strawberry poison frogs in combination with behavior and toxicity might integrate into equally efficient anti-predator strategies depending on local predation and other ecological

  17. Enzymatic regulation of glycogenolysis in a subarctic population of the wood frog: implications for extreme freeze tolerance.

    Directory of Open Access Journals (Sweden)

    M Clara F do Amaral

    Full Text Available The wood frog, Rana sylvatica, from Interior Alaska survives freezing at -16°C, a temperature 10-13°C below that tolerated by its southern conspecifics. We investigated the hepatic freezing response in this northern phenotype to determine if its profound freeze tolerance is associated with an enhanced glucosic cryoprotectant system. Alaskan frogs had a larger liver glycogen reserve that was mobilized faster during early freezing as compared to conspecifics from a cool-temperate region (southern Ohio, USA. In Alaskan frogs the rapid glucose production in the first hours of freezing was associated with a 7-fold increase in glycogen phosphorylase activity above unfrozen frog levels, and the activity of this enzyme was higher than that of frozen Ohioan frogs. Freezing of Ohioan frogs induced a more modest (4-fold increase in glycogen phosphorylase activity above unfrozen frog values. Relative to the Ohioan frogs, Alaskan frogs maintained a higher total protein kinase A activity throughout an experimental freezing/thawing time course, and this may have potentiated glycogenolysis during early freezing. We found populational variation in the activity and protein level of protein kinase A which suggested that the Alaskan population had a more efficient form of this enzyme. Alaskan frogs modulated their glycogenolytic response by decreasing the activity of glycogen phosphorylase after cryoprotectant mobilization was well under way, thereby conserving their hepatic glycogen reserve. Ohioan frogs, however, sustained high glycogen phosphorylase activity until early thawing and consumed nearly all their liver glycogen. These unique hepatic responses of Alaskan R. sylvatica likely contribute to this phenotype's exceptional freeze tolerance, which is necessary for their survival in a subarctic climate.

  18. Enzymatic regulation of glycogenolysis in a subarctic population of the wood frog: implications for extreme freeze tolerance.

    Science.gov (United States)

    do Amaral, M Clara F; Lee, Richard E; Costanzo, Jon P

    2013-01-01

    The wood frog, Rana sylvatica, from Interior Alaska survives freezing at -16°C, a temperature 10-13°C below that tolerated by its southern conspecifics. We investigated the hepatic freezing response in this northern phenotype to determine if its profound freeze tolerance is associated with an enhanced glucosic cryoprotectant system. Alaskan frogs had a larger liver glycogen reserve that was mobilized faster during early freezing as compared to conspecifics from a cool-temperate region (southern Ohio, USA). In Alaskan frogs the rapid glucose production in the first hours of freezing was associated with a 7-fold increase in glycogen phosphorylase activity above unfrozen frog levels, and the activity of this enzyme was higher than that of frozen Ohioan frogs. Freezing of Ohioan frogs induced a more modest (4-fold) increase in glycogen phosphorylase activity above unfrozen frog values. Relative to the Ohioan frogs, Alaskan frogs maintained a higher total protein kinase A activity throughout an experimental freezing/thawing time course, and this may have potentiated glycogenolysis during early freezing. We found populational variation in the activity and protein level of protein kinase A which suggested that the Alaskan population had a more efficient form of this enzyme. Alaskan frogs modulated their glycogenolytic response by decreasing the activity of glycogen phosphorylase after cryoprotectant mobilization was well under way, thereby conserving their hepatic glycogen reserve. Ohioan frogs, however, sustained high glycogen phosphorylase activity until early thawing and consumed nearly all their liver glycogen. These unique hepatic responses of Alaskan R. sylvatica likely contribute to this phenotype's exceptional freeze tolerance, which is necessary for their survival in a subarctic climate.

  19. Rangewide phylogeography of the western U.S. endemic frog Rana boylii (Ranidae): Implications for the conservation of frogs and rivers

    Science.gov (United States)

    A.J. Lind; H.B. Shaffer; P.Q. Spinks; G.M. Fellers

    2011-01-01

    Genetic data are increasingly being used in conservation planning for declining species. We sampled both the ecological and distributional limits of the foothill yellow-legged frog, Rana boylii to characterize mitochondrial DNA (mtDNA) variation in this declining, riverine amphibian. We evaluated 1525 base pairs (bp) of cytochrome b...

  20. Identification of a Novel Vasodilatory Octapeptide from the Skin Secretion of the African Hyperoliid Frog, Kassina senegalensis

    Directory of Open Access Journals (Sweden)

    Qiang Du

    2017-07-01

    Full Text Available The defensive skin secretions of amphibians continue to be an excellent source of novel biologically-active peptides. Here we report the identification and pharmacological activity of a novel C-terminally amided myotropic octapeptide from the skin secretion of the African hyperoliid frog, Kassina senegalensis. The 8-amino acid peptide has the following primary structure: WMSLGWSL-amide and has a molecular mass of 978 Da. The primary structure and organisation of the biosynthetic precursor of WL-8 amide was successfully deduced from cloned skin secretion-derived cDNA. The open-reading frame encoded a single copy of WL-8, located at the C-terminus. Synthetic WL-8 amide was found to cause relaxation of rat tail artery smooth muscle with an EC50 of 25.98 nM. This peptide is unique in terms of its primary structure and is unlike any other peptide previously isolated from an amphibian source which has been archived in the NCBI database. WL-8 amide thus represents the prototype of a novel family of myotropic peptide from amphibian defensive skin secretions.