Science.gov

Sample records for los hombres rana

  1. PHYLOGEOGRAPHY OF RANA YAVAPAIENSIS AND RANA ONCA: PRELIMINARY FINDINGS WITH CONSERVATION IMPLICATIONS

    EPA Science Inventory

    The closely related aridland frogs Rana onca (Relict Leopard Frog) and Rana yavapaiensis (Lowland Leopard Frog) have both experienced dramatic population declines. Rana onca currently occurs naturally at only 6 disjunct sites in southern Nevada. Rana yavapaiensis is present acros...

  2. RANA CATESBEIANA (AMERICAN BULLFROG) DIET

    EPA Science Inventory

    RANA CATESBELANA (American Bullfrog). DIET. Data were obtained opportunistically
    from 28 adult (M = 14; F = 14) bullftogs collected in April 2001 from the Meadow Valley Wash
    located between the cities of Carp and Elgin, Lincoln County, Nevada, USA (N37'17':WI14'30'). Alth...

  3. Aceptabilidad del diagnóstico rápido casero para HIV entre hombres gay y otros hombres que tienen sexo con hombres (G&HSH) de la Ciudad de Buenos Aires.

    PubMed

    Balán, Iván C; Carballo-Diéguez, Alex; Marone, Rubén O; Pando, María A; Barreda, Victoria; Avila, María M

    2011-03-01

    El uso del diagnóstico rápido para HIV en Argentina, así como otros países de Latinoamérica, ha sido limitado hasta el momento. Este trabajo reporta los resultados provenientes de un estudio cualitativo realizado entre hombres gays y otros hombres que tienen sexo con hombres (G&HSH) de la Ciudad de Buenos Aires, Argentina. El objetivo principal del mismo fue conocer las ventajas y desventajas que los hombres G&HSH perciben en relación al diagnóstico rápido casero para HIV. Se realizaron ocho grupos focales con 73 participantes en los cuales se discutió acerca de las ventajas y desventajas del uso de los diagnósticos rápidos. Las respuestas fueron codificadas utilizando un programa para análisis de datos cualitativos (NVivo) y analizadas temáticamente. Los participantes describieron numerosas ventajas sobre el uso del diagnóstico rápido casero, aunque algunos reportaron importantes preocupaciones dentro de las cuales se destaca la posibilidad de impulsos suicidas si alguien recibe un resultado positivo estando solo. En términos generales se observó una gran aceptabilidad para el uso del diagnóstico rápido si el mismo es realizado por personal de salud en lugares acondicionados para este fin.

  4. Aceptabilidad del diagnóstico rápido casero para HIV entre hombres gay y otros hombres que tienen sexo con hombres (G&HSH) de la Ciudad de Buenos Aires

    PubMed Central

    Balán, Iván C.; Carballo-Diéguez, Alex; Marone, Rubén O.; Pando, María A.; Barreda, Victoria; Ávila, María M.

    2011-01-01

    Resumen El uso del diagnóstico rápido para HIV en Argentina, así como otros países de Latinoamérica, ha sido limitado hasta el momento. Este trabajo reporta los resultados provenientes de un estudio cualitativo realizado entre hombres gays y otros hombres que tienen sexo con hombres (G&HSH) de la Ciudad de Buenos Aires, Argentina. El objetivo principal del mismo fue conocer las ventajas y desventajas que los hombres G&HSH perciben en relación al diagnóstico rápido casero para HIV. Se realizaron ocho grupos focales con 73 participantes en los cuales se discutió acerca de las ventajas y desventajas del uso de los diagnósticos rápidos. Las respuestas fueron codificadas utilizando un programa para análisis de datos cualitativos (NVivo) y analizadas temáticamente. Los participantes describieron numerosas ventajas sobre el uso del diagnóstico rápido casero, aunque algunos reportaron importantes preocupaciones dentro de las cuales se destaca la posibilidad de impulsos suicidas si alguien recibe un resultado positivo estando solo. En términos generales se observó una gran aceptabilidad para el uso del diagnóstico rápido si el mismo es realizado por personal de salud en lugares acondicionados para este fin. PMID:25284951

  5. Aceptabilidad del diagnóstico rápido casero para HIV entre hombres gay y otros hombres que tienen sexo con hombres (G&HSH) de la Ciudad de Buenos Aires.

    PubMed

    Balán, Iván C; Carballo-Diéguez, Alex; Marone, Rubén O; Pando, María A; Barreda, Victoria; Avila, María M

    2011-03-01

    El uso del diagnóstico rápido para HIV en Argentina, así como otros países de Latinoamérica, ha sido limitado hasta el momento. Este trabajo reporta los resultados provenientes de un estudio cualitativo realizado entre hombres gays y otros hombres que tienen sexo con hombres (G&HSH) de la Ciudad de Buenos Aires, Argentina. El objetivo principal del mismo fue conocer las ventajas y desventajas que los hombres G&HSH perciben en relación al diagnóstico rápido casero para HIV. Se realizaron ocho grupos focales con 73 participantes en los cuales se discutió acerca de las ventajas y desventajas del uso de los diagnósticos rápidos. Las respuestas fueron codificadas utilizando un programa para análisis de datos cualitativos (NVivo) y analizadas temáticamente. Los participantes describieron numerosas ventajas sobre el uso del diagnóstico rápido casero, aunque algunos reportaron importantes preocupaciones dentro de las cuales se destaca la posibilidad de impulsos suicidas si alguien recibe un resultado positivo estando solo. En términos generales se observó una gran aceptabilidad para el uso del diagnóstico rápido si el mismo es realizado por personal de salud en lugares acondicionados para este fin. PMID:25284951

  6. Complete mitochondrial genomes of two brown frogs, Rana dybowskii and Rana cf. chensinensis (Anura: Ranidae).

    PubMed

    Li, Jiao; Lei, Guangchun; Fu, Cuizhang

    2016-01-01

    We first determined complete mitochondrial genomes of Rana dybowskii and Rana cf. chensinensis (Anura: Ranidae). The mitogenomic lengths of R. dybowskii and R. cf. chensinensis were 18,864 and 18,808 bp, respectively. The two mitogenomes have similar gene compositions including 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and a control region. Rana dybowskii and R. cf. chensinensis mitogenomes displayed same gene order arrangements and similar base compositions with an A + T bias. Mitogenomic data of the two species contributed to provide molecular marker for their conservative genetics and clarified their phylogenetic position under mitogenome-based phylogeny of the genus Rana.

  7. Pesticide distributions and population declines of California alpine frogs, Rana muscosa and Rana sierrae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Atmospherically deposited pesticides from the intensively cultivated Central Valley of California have been implicated as a cause for population declines of several amphibian species, with the strongest evidence for the frogs, Rana muscosa and Rana sierrae at high elevation in the Sierra Nevada moun...

  8. Pesticide Distributions and Population Declines of California Alpine Frogs, Rana Muscosa and Rana Sierrae

    EPA Science Inventory

    Atmospherically deposited pesticides from the intensively cultivated Central Valley of California have been implicated as a cause for population declines of several amphibian species, with the strongest evidence for the frogs Rana muscosa and Rana sierrae at high elevation in th...

  9. Peptides with antimicrobial activity from four different families isolated from the skins of the North American frogs Rana luteiventris, Rana berlandieri and Rana pipiens.

    PubMed

    Goraya, J; Wang, Y; Li, Z; O'Flaherty, M; Knoop, F C; Platz, J E; Conlon, J M

    2000-02-01

    The skins of frogs of the genus Rana synthesize a complex array of antimicrobial peptides that may be grouped into eight families on the basis of structural similarity. A total of 24 peptides with differential growth-inhibitory activity towards the Gram-positive bacterium Staphylococcus aureus, the Gram-negative bacterium Escherichia coli and the yeast Candida albicans were isolated from extracts of the skins of three closely related North American frogs, Rana luteiventris (spotted frog), Rana berlandieri (Rio Grande leopard frog) and Rana pipiens (Northern leopard frog). Structural characterization of the antimicrobial peptides demonstrated that they belonged to four of the known families: the brevinin-1 family, first identified in skin of the Asian frog Rana porosa brevipoda; the esculentin-2 family, first identified in the European frog Rana esculenta; the ranatuerin-2 family, first identified in the North American bullfrog Rana catesbeiana; and the temporin family, first identified in the European frog Rana temporaria. Peptides belonging to the brevinin-2, ranalexin, esculentin-1 and ranatuerin-1 families were not identified in the extracts. Despite the close phylogenetic relationship between the various species of Ranid frogs, the distribution and amino-acid sequences of the antimicrobial peptides produced by each species are highly variable and species-specific, suggesting that they may be valuable in taxonomic classification and molecular phylogenetic analysis.

  10. Aumento de la supervivencia en hombres con cáncer de próstata metastásico que reciben quimioterapia

    Cancer.gov

    Los hombres con cáncer de próstata metastásico sensible a las hormonas que recibieron el fármaco quimioterapéutico docetaxel al inicio de la terapia hormonal convencional vivieron más tiempo que los pacientes que recibieron solo terapia hormonal, de acuer

  11. 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.

    PubMed

    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.

  12. Estrategia innovadora enfocada en parejas del mismo sexo para disminuir la infección del VIH en hombres Latinos

    PubMed Central

    Martinez, Omar; Wu, Elwin; Sandfort, Theo; Shultz, Andrew Z.; Capote, Jonathan; Chávez, Silvia; Moya, Eva; Dodge, Brian; Morales, Gabriel; Porras, Antonio; Ovejero, Hugo

    2014-01-01

    Resumen El VIH es un problema de salud importante dentro de la comunidad latina de los Estados Unidos. Gracias a los esfuerzos de prevención, los niveles de contagio entre los latinos se han mantenido estables por más de una década. Sin embargo, esta población sigue siendo afectada a niveles muy altos, en particular entre hombres que tienen sexo con hombres (HSH), de origen latino y que hablan principalmente el idioma español. Existen varios factores que contribuyen a la transmisión del VIH entre esta población, como son: el uso de drogas; la violencia dentro de la pareja; la presencia de infecciones de transmisión sexual; relaciones sexuales sin protección, dentro y fuera de la pareja; el evadir la búsqueda de recursos (prueba y tratamiento adecuado) por temor a ser discriminado o por su estatus migratorio; la escasez de recursos económicos o estado de pobreza y los patrones relacionados a la migración. En particular, Investigaciones Epidemiológicas de Comportamientos han determinado: cómo algunas dinámicas en parejas están directamente asociadas a los comportamientos sexuales de riesgos. En consecuencia, es necesaria mayor investigación para identificar esas dinámicas, y a su vez, realizar intervenciones dirigidas a la reducción de conductas de riesgo enfocadas en parejas de hombres del mismo sexo. En este escrito, se describe la importancia del uso de las relaciones de pareja como estrategia en la reducción de la trasmisión del VIH/SIDA en HSH de origen latino y que hablan principalmente el idioma español en los Estados Unidos. PMID:25580466

  13. Molecular phenotyping of maternally mediated parallel adaptive divergence within Rana arvalis and Rana temporaria.

    PubMed

    Shu, Longfei; Laurila, Anssi; Suter, Marc J-F; Räsänen, Katja

    2016-09-01

    When similar selection acts on the same traits in multiple species or populations, parallel evolution can result in similar phenotypic changes, yet the underlying molecular architecture of parallel phenotypic divergence can be variable. Maternal effects can influence evolution at ecological timescales and facilitate local adaptation, but their contribution to parallel adaptive divergence is unclear. In this study, we (i) tested for variation in embryonic acid tolerance in a common garden experiment and (ii) used molecular phenotyping of egg coats to investigate the molecular basis of maternally mediated parallel adaptive divergence in two amphibian species (Rana arvalis and Rana temporaria). Our results on three R. arvalis and two R. temporaria populations show that adaptive divergence in embryonic acid tolerance is mediated via maternally derived egg coats in both species. We find extensive polymorphism in egg jelly coat glycoproteins within both species and that acid-tolerant clutches have more negatively charged egg jelly - indicating that the glycosylation status of the jelly coat proteins is under divergent selection in acidified environments, likely due to its impact on jelly water balance. Overall, these data provide evidence for parallel mechanisms of adaptive divergence in two species. Our study highlights the importance of studying intraspecific molecular variation in egg coats and, specifically, their glycoproteins, to increase understanding of underlying forces maintaining variation in jelly coats. PMID:27482650

  14. Development of beaks of Rana pipiens larvae.

    PubMed

    Kaung, H C

    1975-08-01

    Rana pipiens larval beaks of consist of column cells, sheath cells and basal cells which supply cells to column and sheath. Each column consists of disk-like precone cells, cone cells and keratinized cone cells; they are cells in different stages of the process of keratinization. Breaks first appear externally at embryonic stage 24. Epidermal cells align at the tip of the jaw at stage 21. They increase in number and change in shape. Keratinization starts at stage 23. By stage 24, the apical column cells are keratinized and the histological organization is set for the whole larval period. During the larval period, the numbers of column cells increase until stages VIII or IV, stay relatively constant during mid-larval stages, and decrease at late larval stages. The beak is completely shed at stage XX. The widening of the beaks goes on during the entire larval period. Along the cutting edge of the jaw the tooth spikes increase in number and in individual width as the animal grows older and larger. Thyroid hormone causes a premature reduction of the column cell number and a precocious beak loss. The loss of break at metamorphic climax is thyroid dependent event.

  15. Calcium channel inactivation in frog (Rana pipiens and Rana moctezuma) skeletal muscle fibres.

    PubMed Central

    Cota, G; Nicola Siri, L; Stefani, E

    1984-01-01

    The decay of the Ca2+ current (ICa) during a maintained depolarization was studied in intact twitch skeletal muscle fibres of Rana pipiens and Rana moctezuma with the three-micro-electrode voltage-clamp technique. ICa was recorded at 23 degrees C, after blocking K+ currents, in TEA methanesulphonate saline with 10 mM-Ca2+ made hypertonic by adding 350 mM-sucrose. In two-pulse experiments, ICa during the test pulse was reduced to about 80% (R. pipiens) or 50% (R. moctezuma) of the control value, without any detectable inward ICa during 7 s conditioning pre-pulses. The experimental points of the steady-state inactivation curve (h infinity) were fitted to h infinity = (1 + exp [Em - Vh)/kh]-1, where Em is the membrane potential and with Vh = -33 +/- 3 mV and kh = 6 +/- 1 mV for R. pipiens, and Vh = -44 +/- 3 mV and kh = 9.5 +/- 1.0 mV for R. moctezuma. The rate constant of decay for inactivated currents (range -8 to -47 mA cm-3) and for control currents (range -23 to -62 mA cm-3), was independent of ICa amplitude. The average rate constant of decay at 0 mV was 1.18 +/- 0.02 s-1 (66). These results indicate that in intact fibres under hypertonic solution ICa decay can be explained by a voltage-dependent inactivation process and not by depletion of tubular Ca2+. The absence of depletion could be due to a large fractional tubular volume or to the presence of a Ca2+ pump in the tubular system. PMID:6090655

  16. Pesticide distributions and population declines of California, USA, alpine frogs, Rana muscosa and Rana sierrae.

    PubMed

    Bradford, David F; Knapp, Roland A; Sparling, Donald W; Nash, Maliha S; Stanley, Kerri A; Tallent-Halsell, Nita G; McConnell, Laura L; Simonich, Staci M

    2011-03-01

    Atmospherically deposited pesticides from the intensively cultivated Central Valley of California, USA, have been implicated as a cause for population declines of several amphibian species, with the strongest evidence for the frogs Rana muscosa and Rana sierrae at high elevation in the Sierra Nevada mountains. Previous studies on these species have relied on correlations between frog population status and either a metric for amount of upwind pesticide use or limited measurements of pesticide concentrations in the field. The present study tested the hypothesis that pesticide concentrations are negatively correlated with frog population status (i.e., fraction of suitable water bodies occupied within 2 km of a site) by measuring pesticide concentrations in multiple media twice at 28 sites at high elevation in the southern Sierra Nevada. Media represented were air, sediment, and Pseudacris sierra tadpoles. Total cholinesterase (ChE), which has been used as an indicator for organophosphorus and carbamate pesticide exposure, was also measured in P. sierra tadpoles. Results do not support the pesticide-site occupancy hypothesis. Among 46 pesticide compounds analyzed, nine were detected with ≥ 30% frequency, representing both historically and currently used pesticides. In stepwise regressions with a chemical metric and linear distance from the Central Valley as predictor variables, no negative association was found between frog population status and the concentration of any pesticide or tadpole ChE activity level. By contrast, frog population status showed a strong positive relationship with linear distance from the Valley, a pattern that is consistent with a general west-to-east spread across central California of the amphibian disease chytridiomycosis observed by other researchers.

  17. Density dependent growth in adult brown frogs Rana arvalis and Rana temporaria - A field experiment

    NASA Astrophysics Data System (ADS)

    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.

  18. IMPLICATIONS OF THE DISCOVERY OF RANA YAVAPAIENSIS IN THE WESTERN GRAND CANYON TO THE CONSERVATION STRATEGY FOR RANA ONCA

    EPA Science Inventory

    The minimum historical range of the relict leopard frog, Rana onca, comprises the drainages of the Virgin and Colorado rivers from the vicinity ofHurricane, Utah, to Black Canyon below Lake Mead, in Nevada and Arizona. Extant populations are known near only the Black Canyon and O...

  19. Effect of neurohypophysial hormones on fluid movement across isolated bladder of Rana cancrivora, Rana temporaria and Bufo melanostictus

    PubMed Central

    Dicker, S. E.; Elliott, Annie B.

    1970-01-01

    1. The rate of fluid movement across the wall of isolated amphibian urinary bladder was estimated using hemi-bladders of the tropical euryhaline Rana cancrivora, the temperate R. temporaria and the tropical Bufo melanostictus. 2. The rate of water outflow across the bladder walls was: Rana cancrivora, 4·8 μl./cm2.hr; R. temporaria, 7·2 μl./cm2.hr; Bufo melanostictus, 3·7 μl./cm2.hr. 3. When neurohypophysial peptides were added to the serosal solution the rates of water outflow were increased; dose—response curves were prepared relating the augmented rate of fluid movement to the concentration in the bathing fluid of vasopressin, oxytocin or vasotocin. 4. The potencies of the peptides in respect of bladders of each species were: Vasopressin, B. melanostictus:Rana temporaria:R. cancrivora, 500:20:1. Oxytocin, R. temporaria:B. melanostictus:Rana cancrivora, 100:5:1. 5. The ratio of sensitivity of the bladder of each species to the presence of the different peptides was: R. cancrivora, vasotocin:oxytocin:vasopressin, 1000:5:1. R. temporaria, oxytocin:vasopressin, 15:1. Bufo melanostictus, oxytocin:vasopressin, 1:30. 6. The effect of extract of the pituitary gland of Rana cancrivora was examined on R. cancrivora bladder. It had a dose—response curve similar to the dose—response curve of vasotocin. 7. The vasotocin content of the pituitary gland of R. cancrivora was estimated (a) from the dose—response curves using R. cancrivora bladder, (b) by a three-point assay using R. cancrivora bladder and (c) by its effect on water uptake across the skin of Bufo melanostictus. One pituitary gland of Rana cancrivora was found to contain about 0·1 μg vasotocin. 8. The urinary bladder of R. cancrivora was less responsive to neurohypophysial peptides than the bladder of R. temporaria or Bufo melanostictus. 9. The hormonal content of the pituitary gland of Rana cancrivora was smaller than that found in other amphibians. PMID:5500771

  20. EVIDENCE OF PHYLOGENETICALLY DISTINCT LEOPARD FROGS (RANA ONCA) FROM THE BORDER REGION OF NEVADA, UTAH, AND ARIZONA

    EPA Science Inventory

    Remnant populations of leopard frogs within the Virgin River drainage and adjacent portions of the Colorado River (Black Canyon) in northwestern Arizona and southern Nevada either represent the reportedly extinct taxon Rana onca or northern, disjunct Rana yavapaiensis. To determi...

  1. Mitotic activity in dorsal epidermis of Rana pipiens.

    NASA Technical Reports Server (NTRS)

    Garcia-Arce, H.; Mizell, S.

    1972-01-01

    Study of statistically significant rhythms of mitotic division in dorsal epidermis of frogs, Rana pipiens, exposed to a 12:12 light:dark environment for 14 days. The results include the findings that (1) male animals have a primary period of 22 hr in summer and 18 hr in winter, (2) female animals have an 18 hr period, and (3) parapinealectomy and blinding abolish the rhythm.

  2. ASYMMETRICAL EFFECTS OF INTRODUCED BULLFROGS (RANA CATESBEIANA) ON NATIVE RANID FROGS IN OREGON

    EPA Science Inventory

    Introduced American Bullfrogs (Rana catesbeiana) have become widely established in the Pacific Northwest over the last century and are throught to be an important predator of native amphibians throughout the western United States. The Northern Red-Legged Frog (Rana aurora aurora...

  3. Efferent system in the retina of the frog, Rana catesbiana.

    PubMed

    Tasaki, K; Tsukahara, Y; Watanabe, M

    1978-12-01

    Single units were recorded through glass microelectrodes placed on the optic disk or on the retina of the opened eye of the frog (Rana catesbiana). Units were classified as A-, B-, and C-fibers according to conduction velocities. By the method of collision between naturally elicited and electrically elicited impulses, many of the B-fibers and some A- and C-fibers, which showed unusual behavior to photic stimulation, were found to be efferent fibers. Retinal effects of the efferent nerves were studied by repetitive stimulation and cooling of the optic nerve. The effects were found to be both inhibitory and excitatory. PMID:314669

  4. Distribution and localization of galectin purified from Rana catesbeiana oocytes.

    PubMed

    Uchiyama, H; Komazaki, S; Oyama, M; Matsui, T; Ozeki, Y

    1997-12-01

    Galectins are a family of lectins that recognize beta-D-galactosides independently of calcium ions, and are widely distributed in animals. To characterize a galectin previously purified from oocytes of Rana catesbeiana (American bullfrog), we studied its distribution and localization in several tissues from this frog. Hemagglutination assay and western blotting showed that this lectin is present in many tissues including the liver, skin, kidney, skeletal muscle, and sciatic nerve, but is particularly concentrated in the ovary. Light microscopic immunohistochemistry showed that this lectin is localized in such places as cell-cell junctions, basement membranes, extracellular matrix, or secretory substances in several organs, indicating that this galectin is mainly distributed extracellularly. However, in the ovary, light microscopy showed that this lectin is present in or associated with the yolk platelet. Electron microscopy further revealed that it is localized in the periphery of the yolk platelet (the yolk plasm), but not in the cortical granule. These results indicate that Rana oocytes contain abundant galectin in their yolk platelets in contrast to Xenopus laevis oocytes, which have been found not to contain galectins but other classes of lectins in their yolk platelets and cortical granules.

  5. Range-wide phylogeographic analysis of the spotted frog complex (Rana luteiventris and Rana pretiosa) in northwestern North America

    USGS Publications Warehouse

    Funk, W.C.; Pearl, C.A.; Draheim, H.M.; Adams, M.J.; Mullins, T.D.; Haig, S.M.

    2008-01-01

    The dynamic geological and climatic history of northwestern North America has made it a focal region for phylogeography. We conducted a range-wide phylogeographic analysis of the spotted frog complex (Rana luteiventris and Rana pretiosa) across its range in northwestern North America to understand its evolutionary history and the distribution of clades to inform conservation of R. pretiosa and Great Basin R. luteiventris, candidates for listing under the US Endangered Species Act. Mitochondrial DNA sequence data from a segment of the cytochrome b gene were obtained from 308 R. luteiventris and R. pretiosa from 96 sites. Phylogenetic analysis revealed one main R. pretiosa clade and three main R. luteiventris clades, two of which overlapped in southeastern Oregon. The three R. luteiventris clades were separated from each other by high levels of sequence divergence (average of 4.75-4.97%). Two divergent clades were also uncovered within the Great Basin. Low genetic variation in R. pretiosa and the southeastern Oregon clade of R. luteiventris suggests concern about their vulnerability to extinction. ?? 2008 Elsevier Inc.

  6. Effects of predatory fish on survival and behavior of larval gopher frogs (Rana capito) and Southern Leopard Frogs (Rana sphenocephala)

    USGS Publications Warehouse

    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.

  7. Effects of polychlorinated biphenyl 126 on green frog (Rana clamitans) and leopard frog (Rana pipiens) hatching success, development, and metamorphosis

    SciTech Connect

    Rosenshield, M.L.; Jofre, M.B.; Karasov, W.H.

    1999-11-01

    Although increasing evidence links plana chlorinated hydrocarbons, such as polychlorinated biphenyls (PCBs), to decreases in survival and reproduction of fish, mammals, and birds near Green Bay, Wisconsin, and the Great Lakes, USA, relatively little is known of their bioaccumulation or of their possible effects in amphibians. The authors exposed embryos and larvae of two ranid species commonly occurring in the Green Bay ecosystem, the green frog (Rana clamitans) and the leopard frog (Rana pipiens), to PCB 126, a model coplanar PCB compound. Nominal concentrations ranged from 0.005 to 50 {micro}g/L, and exposure lasted through metamorphosis. Tissue concentrations of PCB 126 in tadpoles that did not metamorphose by the end of the experiment ranged from 1.2 to 9,600 ng/g wet mass. No significant mortality of embryos occurred before hatching; however, survival of larvae was significantly reduced at the highest concentration for both species. Few deformities were observed, but the incidence of edema was significantly higher in tadpoles exposed to 50 {micro}g/L. Swimming speed and growth of tadpoles was also significantly reduced in this treatment. The percent of tadpoles that reached metamorphosis was significantly lower in green frogs at the highest concentration, and no leopard frogs survived past day 47 of the experiment in this treatment. At high concentrations, PCB 126 affected both ranid species; however, sublethal effects were not apparent for the parameters the authors measured at concentrations that occur in water in the Green Bay ecosystem.

  8. Humoral immune responses in Rana catesbiana frogs and tadpoles.

    PubMed

    Pross, S H; Rowlands, D T

    1976-07-01

    Rana catesbiana adult frogs and tadpoles were immunized with the bacteriophage F2, 0X-174, and T4 and the haptens 2,4 dinitrophenyl (DNP) and fluorescein (FTC). The haptens were conjugated with bovine serum albumin (BSA), bovine gamma globulin (BGG), or horsehoe crab hemocyanin (Hycn). Sera were obtained from immunized animals at invervals up to six months after immunization. The antibody activities were measured by bacteriophage neutralization techniques. Sucrose density gradients were used to separate the antibody classes. Both adults and tadpoles responded to each of the antigens tested. High molecular weight antibodies were predominant in both groups of animals. Low molecular weight antibody activity was not found in adults until nine weeks post immunization but, thereafter, this fraction increased throughout the immune response. Low molecular weight antibodies could also be identified in serum of tadpoles, but only under certain conditions. PMID:59790

  9. Extraction and antioxidant activity of polysaccharides from Rana chensinensis skin.

    PubMed

    Wang, Zhanyong; Zhao, Yuanyuan; Su, Tingting

    2015-01-22

    The extraction process of polysaccharides from Rana chensinensis skin was optimized by using a Box-Behnken design. The optimum extraction conditions were as follows: extraction time, 4.96h; extraction temperature, 100°C; ratio of water to raw material, 60; and extraction frequency, 1. Under these conditions, the experimental polysaccharide yield was 2.03±0.14%, which agreed with the predicted yield. The purified polysaccharide RCSP II was successfully obtained by diethylaminoethanol-Sepharose and Sepharose CL-6B column chromatography. In vitro experiments showed that RCSP II exhibited a strong scavenging activity against superoxide anion and 1,1-diphenyl-2-picrylhydrazyl radicals but a weak scavenging activity against hydroxyl radicals. RCSP II also showed a strong reducing capacity. Thus, this polysaccharide can be used as a natural antioxidant in functional foods or medicines.

  10. Induction of photolyase activity in wood frog (Rana sylvatica) embryos.

    PubMed

    Smith, M A; Kapron, C M; Berrill, M

    2000-10-01

    Rising ultraviolet-B (UVB, 280-320 nm) radiation has been proposed as a factor which may explain nonnormal amphibian population declines. Accordingly research has been directed toward estimating the photolyase activity of several amphibian species in order to predict a species' resilience to UV damage. Unfortunately, in spite of published research which demonstrated that the activity of one of the principal photorepair enzymes, photolyase, can be induced, these estimates did not address the potential for in vivo induction by environmental factors present in situ. We show here that wood frog (Rana sylvatica) embryos exposed to periods of ambient solar radiation (1) displayed significantly different photolyase activities from embryos exposed to equivalent periods of dark; and (2) were positively correlated with the UVB fluence received in vivo. Such results suggest that previous conclusions regarding the relationship between photorepair and population decline must be reevaluated. Estimating amphibian photorepair is a complicated process, and caution must be exercised when interpreting such data. PMID:11045732

  11. Nephrotoxic effects of lead nitrate in Rana ridibunda.

    PubMed

    Loumbourdis, N S

    2003-09-01

    The impact of lead (Pb) on kidney histopathology of the frog Rana ridibunda was investigated. Female frogs were exposed for 4, 10 and 30 days to 14 ppm lead (as lead nitrate). All the lead concentrations and many histological changes were time dependent. Light microscopy of kidney revealed morphological changes mainly in the proximal convoluted tubule (PCT) cells. The most severe changes such as vacuolation, Perl's stained material, infiltration, brush border destruction and proximal tubule damage were detected in the animals exposed for 10 and 30 days. Karyomegaly was highest at 10-days exposure, probably as a result of intense stress caused by the lead. Some PCT in the 30-days-exposed animals were von Kossa's method positive, suggesting the presence of calcium. The possibility is discussed that some of these changes, such as karyomegaly and intranuclear inclusions, might be preneoplastic if lead was supplied at high concentrations and for long time.

  12. Phylogenetic relationships of leopard frogs (Rana pipiens complex) from an isolated coastal mountain range in southern Sonora, Mexico.

    PubMed

    Pfeiler, E; Markow, T A

    2008-10-01

    Mitochondrial DNA sequence data from the control region and 12S rRNA in leopard frogs from the Sierra El Aguaje of southern Sonora, Mexico, together with GenBank sequences, were used to infer taxonomic identity and provide phylogenetic hypotheses for relationships with other members of the Rana pipiens complex. We show that frogs from the Sierra El Aguaje belong to the Rana berlandieri subgroup, or Scurrilirana clade, of the R. pipiens group, and are most closely related to Rana magnaocularis from Nayarit, Mexico. We also provide further evidence that Rana magnaocularis and R. yavapaiensis are close relatives.

  13. The HoMBReS and HoMBReS Por un Cambio Interventions to Reduce HIV Disparities Among Immigrant Hispanic/Latino Men.

    PubMed

    Rhodes, Scott D; Leichliter, Jami S; Sun, Christina J; Bloom, Fred R

    2016-02-12

    Hispanics/Latinos in the United States are affected disproportionately by human immunodeficiency virus (HIV) infection, acquired immunodeficiency syndrome (AIDS), and other sexually transmitted diseases (STDs); however, few effective evidence-based prevention interventions for this population exist. This report describes the Hombres Manteniendo Bienestar y Relaciones Saludables (Men Maintaining Wellbeing and Healthy Relationships) (HoMBReS) intervention, which was developed by a community-based, participatory research partnership in North Carolina and initially implemented during 2005-2009. HoMBReS is an example of an effective intervention that uses lay health advisors (known as Navegantes [navigators]) in the context of existing social networks (i.e., recreational soccer teams) to promote consistent condom use and HIV and STD testing among Hispanic/Latino men. In 2012, HoMBReS was classified as a best-evidence community-level HIV prevention intervention (CDC. Compendium of evidence-based behavioral interventions and best practices for HIV prevention. Atlanta, GA: US Department of Health and Human Services, CDC; 2015). The intervention has been implemented elsewhere, enhanced, and further evaluated in longitudinal intervention and implementation studies. HoMBReS has been adapted for other populations, including men who have sex with men and transgender persons. Additional evaluation has found that Navegantes continue in their roles as health advisors, opinion leaders, and community advocates after study support ends. Hispanic/Latino men's social networks can be leveraged to promote sexual health within the community by decreasing HIV risk behaviors among Hispanics/Latinos in the United States.

  14. The HoMBReS and HoMBReS Por un Cambio Interventions to Reduce HIV Disparities Among Immigrant Hispanic/Latino Men.

    PubMed

    Rhodes, Scott D; Leichliter, Jami S; Sun, Christina J; Bloom, Fred R

    2016-02-12

    Hispanics/Latinos in the United States are affected disproportionately by human immunodeficiency virus (HIV) infection, acquired immunodeficiency syndrome (AIDS), and other sexually transmitted diseases (STDs); however, few effective evidence-based prevention interventions for this population exist. This report describes the Hombres Manteniendo Bienestar y Relaciones Saludables (Men Maintaining Wellbeing and Healthy Relationships) (HoMBReS) intervention, which was developed by a community-based, participatory research partnership in North Carolina and initially implemented during 2005-2009. HoMBReS is an example of an effective intervention that uses lay health advisors (known as Navegantes [navigators]) in the context of existing social networks (i.e., recreational soccer teams) to promote consistent condom use and HIV and STD testing among Hispanic/Latino men. In 2012, HoMBReS was classified as a best-evidence community-level HIV prevention intervention (CDC. Compendium of evidence-based behavioral interventions and best practices for HIV prevention. Atlanta, GA: US Department of Health and Human Services, CDC; 2015). The intervention has been implemented elsewhere, enhanced, and further evaluated in longitudinal intervention and implementation studies. HoMBReS has been adapted for other populations, including men who have sex with men and transgender persons. Additional evaluation has found that Navegantes continue in their roles as health advisors, opinion leaders, and community advocates after study support ends. Hispanic/Latino men's social networks can be leveraged to promote sexual health within the community by decreasing HIV risk behaviors among Hispanics/Latinos in the United States. PMID:26916740

  15. Presentación del estudio "Links" de hombres que tienes sexo con hombres en Buenos Aires, Argentina.

    PubMed

    Carballo-Diéguez, Alex; Avila, María M; Balán, Iván C; Marone, Rubén; Pando, María A; Barreda, Victoria

    2011-03-01

    Estudios previos en Buenos Aires reportaron altas prevalencias de HIV entre HSH, con valores que oscilan entre 9 y 14% durante casi 10 años de continuo testeo. El objetivo principal de este estudio fue la evaluación de factores relacionados al comportamiento de alto riesgo para transmisión del HIV entre HSH entre los que se incluyen el conocimiento y factores emocionales, socioculturales y ambientales. Por otro lado se realizó la estimación de prevalencia e incidencia de HIV utilizando RDS (Respondent Driven Sampling), así como la presencia de otras infecciones de transmisión sexual. Por último se evaluaron los hábitos de testeo para HIV indagando que factores facilitan o impiden su realización. El estudio constó de dos fases, en primer lugar una fase cualitativa y posteriormente una fase cuantitativa con una duración total de 4 años y medio. Durante la fase cualitativa se realizaron 44 entrevistas individuales en profundidad, 8 grupos focales y 10 observaciones etnográficas (hoteles, baños públicos ("teteras"), cines pornográficos, fiestas privadas, dark rooms y discotecas). Durante la fase cuantitativa del estudio se realizó el reclutamiento de 500 participantes que provinieron de la Ciudad Autónoma de Buenos Aires, así como del Gran Buenos Aires. El reclutamiento se comenzó con 16 participantes llamados semillas. Se realizó el diagnóstico de infección por HIV, hepatitis B y C (HBV y HCV), Treponema pallidum, Virus Papiloma Humano (HPV) y Chlamidias. La colaboración establecida entre los grupos de trabajo enfocados en áreas diversas posibilitó el abordaje conjunto de nuevas estrategias de investigación antes no exploradas en nuestro país. Los resultados más relevantes de esta investigación serán progresivamente publicados en sucesivos números de Actualizaciones en SIDA.

  16. Presentación del estudio “Links” de hombres que tienes sexo con hombres en Buenos Aires, Argentina

    PubMed Central

    Carballo-Diéguez, Alex; Ávila, María M; Balán, Iván C.; Marone, Rubén; Pando, María A.; Barreda, Victoria

    2011-01-01

    Resumen Estudios previos en Buenos Aires reportaron altas prevalencias de HIV entre HSH, con valores que oscilan entre 9 y 14% durante casi 10 años de continuo testeo. El objetivo principal de este estudio fue la evaluación de factores relacionados al comportamiento de alto riesgo para transmisión del HIV entre HSH entre los que se incluyen el conocimiento y factores emocionales, socioculturales y ambientales. Por otro lado se realizó la estimación de prevalencia e incidencia de HIV utilizando RDS (Respondent Driven Sampling), así como la presencia de otras infecciones de transmisión sexual. Por último se evaluaron los hábitos de testeo para HIV indagando que factores facilitan o impiden su realización. El estudio constó de dos fases, en primer lugar una fase cualitativa y posteriormente una fase cuantitativa con una duración total de 4 años y medio. Durante la fase cualitativa se realizaron 44 entrevistas individuales en profundidad, 8 grupos focales y 10 observaciones etnográficas (hoteles, baños públicos (“teteras”), cines pornográficos, fiestas privadas, dark rooms y discotecas). Durante la fase cuantitativa del estudio se realizó el reclutamiento de 500 participantes que provinieron de la Ciudad Autónoma de Buenos Aires, así como del Gran Buenos Aires. El reclutamiento se comenzó con 16 participantes llamados semillas. Se realizó el diagnóstico de infección por HIV, hepatitis B y C (HBV y HCV), Treponema pallidum, Virus Papiloma Humano (HPV) y Chlamidias. La colaboración establecida entre los grupos de trabajo enfocados en áreas diversas posibilitó el abordaje conjunto de nuevas estrategias de investigación antes no exploradas en nuestro país. Los resultados más relevantes de esta investigación serán progresivamente publicados en sucesivos números de Actualizaciones en SIDA. PMID:25264397

  17. Presentación del estudio "Links" de hombres que tienes sexo con hombres en Buenos Aires, Argentina.

    PubMed

    Carballo-Diéguez, Alex; Avila, María M; Balán, Iván C; Marone, Rubén; Pando, María A; Barreda, Victoria

    2011-03-01

    Estudios previos en Buenos Aires reportaron altas prevalencias de HIV entre HSH, con valores que oscilan entre 9 y 14% durante casi 10 años de continuo testeo. El objetivo principal de este estudio fue la evaluación de factores relacionados al comportamiento de alto riesgo para transmisión del HIV entre HSH entre los que se incluyen el conocimiento y factores emocionales, socioculturales y ambientales. Por otro lado se realizó la estimación de prevalencia e incidencia de HIV utilizando RDS (Respondent Driven Sampling), así como la presencia de otras infecciones de transmisión sexual. Por último se evaluaron los hábitos de testeo para HIV indagando que factores facilitan o impiden su realización. El estudio constó de dos fases, en primer lugar una fase cualitativa y posteriormente una fase cuantitativa con una duración total de 4 años y medio. Durante la fase cualitativa se realizaron 44 entrevistas individuales en profundidad, 8 grupos focales y 10 observaciones etnográficas (hoteles, baños públicos ("teteras"), cines pornográficos, fiestas privadas, dark rooms y discotecas). Durante la fase cuantitativa del estudio se realizó el reclutamiento de 500 participantes que provinieron de la Ciudad Autónoma de Buenos Aires, así como del Gran Buenos Aires. El reclutamiento se comenzó con 16 participantes llamados semillas. Se realizó el diagnóstico de infección por HIV, hepatitis B y C (HBV y HCV), Treponema pallidum, Virus Papiloma Humano (HPV) y Chlamidias. La colaboración establecida entre los grupos de trabajo enfocados en áreas diversas posibilitó el abordaje conjunto de nuevas estrategias de investigación antes no exploradas en nuestro país. Los resultados más relevantes de esta investigación serán progresivamente publicados en sucesivos números de Actualizaciones en SIDA. PMID:25264397

  18. Antimicrobial peptide defenses of the Tarahumara frog, Rana tarahumarae.

    PubMed

    Rollins-Smith, Louise A; Reinert, Laura K; Miera, Verma; Conlon, J Michael

    2002-09-20

    Populations of the Tarahumara frog Rana tarahumarae have decreased markedly in recent years in the northern part of their range. Infection by the chytrid fungus Batrachochytrium dendrobatidis has been implicated in these declines. To determine whether antimicrobial peptides in the skin provide protection against this pathogen, norepinephrine-stimulated skin secretions were tested for their ability to inhibit growth of B. dendrobatidis in vitro. After concentration, crude mixtures of skin peptides inhibited the growth of the chytrid in a concentration-dependent manner. Proteomic analysis led to the identification and characterization of three peptides belonging to the brevinin-1 family of antimicrobial peptides and three belonging to the ranatuerin-2 family. The two most abundant peptides, ranatuerin-2TRa (GIMDSIKGAAKEIAGHLLDNLKCKITGC) and brevinin-1TRa (FLPVIAGIAANVLPKLFCKLTKRC), were active against B. dendrobatidis (MIC of 50 microM for ranatuerin-2TRa and 12.5 microM for brevinin-1TRa against zoospores). These data clearly show that antimicrobial peptides in the skin secretions of the Tarahumara frog are active against B. dendrobatidis and should provide some protection against infection. Therefore, the observed susceptibility of these frogs to this pathogen in the wild may be due to the effects of additional environmental factors that impair this innate defense mechanism, leading to the observed population declines.

  19. Erythrocyte differentiation during the metamorphic hemoglobin switch of Rana catesbeiana.

    PubMed Central

    Dorn, A R; Broyles, R H

    1982-01-01

    Anurans (frogs and toads) switch from tadpole to adult hemoglobin synthesis during metamorphosis. A number of workers have attempted to determine whether tadpole and adult Hb types are expressed in the same or different erythroid cells during the switch. If the different Hb types are found in different cells during the transition, the switch in globin gene expression occurs at an early stage of cellular differentiation. Previous studies, in which immunocytochemical techniques were used to approach this question, are in conflict in regard to the metamorphic Hb switch of the North American bullfrog Rana catesbeiana. We have purified newly differentiating erythroid cells from the blood of metamorphosing tadpoles by using Percoll gradients. These new cells have an immature morphology, are very active in the synthesis of adult Hb, and contain no detectable tadpole Hb. The tadpole cells have no detectable adult Hb, are synthetically inactive, increase in density during the switch, and are then cleared from the circulation. Thus, only adult Hb expression is detected in newly differentiating erythroid cells during metamorphosis. Images PMID:6182567

  20. Liver lesions produced by aflatoxins in Rana catesbeiana (bullfrog).

    PubMed

    Grassi, Tony Fernando; Pires, Paulo Wagner; Barbisan, Luis Fernando; Pai-Silva, Maeli Dal; Said, Roueda Abou; de Camargo, João Lauro Viana

    2007-09-01

    This study describes alterations induced in Rana catesbeiana (bullfrog) liver after extended dietary exposure to aflatoxins (AFs). Bullfrogs of both sexes were fed for 120 days a commercial chow blended with a rice bran-based mixture of AFs containing 667.0, 11.65, 141.74, and 3.53 mg/kg of AFs B1, B2, G1, and G2, respectively. Animals were sacrificed on study days 45, 90, and 120. Severe and progressive liver lesions with structural collapse, increased hepatocyte and biliary duct cell proliferation, appearance of basophilic hepatocytes, and diffuse scarring, were observed at all time points. There were no quantitative alterations in the liver melanomacrophage centers of the AFs-exposed animals. Increased amounts of lipid hydroperoxides, indicative of ongoing oxidative stress, were more evident in the Addutor magnum muscle than in the AFs-damaged livers. No tumors were found in the R. catesbeiana livers after 120 days of exposure to relatively high doses of AFs. PMID:16996133

  1. Erythrocyte differentiation during the metamorphic hemoglobin switch of Rana catesbeiana.

    PubMed

    Dorn, A R; Broyles, R H

    1982-09-01

    Anurans (frogs and toads) switch from tadpole to adult hemoglobin synthesis during metamorphosis. A number of workers have attempted to determine whether tadpole and adult Hb types are expressed in the same or different erythroid cells during the switch. If the different Hb types are found in different cells during the transition, the switch in globin gene expression occurs at an early stage of cellular differentiation. Previous studies, in which immunocytochemical techniques were used to approach this question, are in conflict in regard to the metamorphic Hb switch of the North American bullfrog Rana catesbeiana. We have purified newly differentiating erythroid cells from the blood of metamorphosing tadpoles by using Percoll gradients. These new cells have an immature morphology, are very active in the synthesis of adult Hb, and contain no detectable tadpole Hb. The tadpole cells have no detectable adult Hb, are synthetically inactive, increase in density during the switch, and are then cleared from the circulation. Thus, only adult Hb expression is detected in newly differentiating erythroid cells during metamorphosis.

  2. Individual voice recognition in a territorial frog (Rana catesbeiana).

    PubMed

    Bee, Mark A; Gerhardt, H Carl

    2002-07-22

    Some territorial animals display low levels of aggression towards a familiar territorial neighbour in its usual territory, but exhibit high levels of aggression towards neighbours in novel locations and unfamiliar individuals. Here, we report results from a field playback study that investigated whether territorial males of the North American bullfrog (Rana catesbeiana) could discriminate between the acoustic signals of simulated neighbours and strangers in the absence of contextual cues associated with a specific location. Following repeated exposures to synthetic bullfrog calls from a particular location, subjects responded significantly less aggressively to a familiar call, compared with an unfamiliar one, when both calls were broadcast from familiar and novel locations, indicating that bullfrogs could recognize a neighbour's calls independently of the contextual cues provided by the direction of the neighbour's territory. Subjects responded equally aggressively to unfamiliar calls broadcast from either a familiar or a novel location, which indicates that they could perceive unfamiliar calls as those of a stranger, regardless of where the stranger was encountered. Together, these two results provide evidence that a frog possesses a capacity for individual voice recognition.

  3. Liver lesions produced by aflatoxins in Rana catesbeiana (bullfrog).

    PubMed

    Grassi, Tony Fernando; Pires, Paulo Wagner; Barbisan, Luis Fernando; Pai-Silva, Maeli Dal; Said, Roueda Abou; de Camargo, João Lauro Viana

    2007-09-01

    This study describes alterations induced in Rana catesbeiana (bullfrog) liver after extended dietary exposure to aflatoxins (AFs). Bullfrogs of both sexes were fed for 120 days a commercial chow blended with a rice bran-based mixture of AFs containing 667.0, 11.65, 141.74, and 3.53 mg/kg of AFs B1, B2, G1, and G2, respectively. Animals were sacrificed on study days 45, 90, and 120. Severe and progressive liver lesions with structural collapse, increased hepatocyte and biliary duct cell proliferation, appearance of basophilic hepatocytes, and diffuse scarring, were observed at all time points. There were no quantitative alterations in the liver melanomacrophage centers of the AFs-exposed animals. Increased amounts of lipid hydroperoxides, indicative of ongoing oxidative stress, were more evident in the Addutor magnum muscle than in the AFs-damaged livers. No tumors were found in the R. catesbeiana livers after 120 days of exposure to relatively high doses of AFs.

  4. Heavy Metal Accumulation in Leaves of Hydrocharis Morsus-Ranae L. and Biomonitoring Applications

    NASA Astrophysics Data System (ADS)

    Polechońska, Ludmiła; Dambiec, Małgorzata

    2014-06-01

    In present study the concentrations of Hg, Mn, Zn, Fe and Cu in water, bottom sediments and leaves of Hydrocharis morsus-ranae from 11 oxbow lakes of the Odra River were determined by atomic absorption spectrometry. Trace metal concentration in water and bottom sediments were below the geochemical background, indicating no anthropogenic impact in the studied area. On average, the concentrations of metals in leaves of H. morsus ranae exceeded natural thresholds. A high bioaccumulation factors for metals were recorded. The significant positive correlations found between the content Zn, Fe and Hg of in water and in the H. morsus ranae indicate the potential use of the species in the biomonitoring of environmental contamination with these metals.

  5. Ontogenetic changes in the epiphyseal cartilage of Rana (Pelophylax) caralitana (Anura: Ranidae).

    PubMed

    Erismis, Ugur Cengiz; Chinsamy, Anusuya

    2010-11-01

    We document histological changes through ontogeny in the epiphyseal cartilage of the third phalanx of Rana caralitana from Turkey and provide an assessment of the maturation of the epiphysis from newly metamorphosed froglets to 10-year-old individuals. The epiphysis of R. caralitana is compared to other Rana taxa previously studied, and we report on novel histological data pertaining to later stages of epiphyseal growth in this taxon. In addition, we document the development of endochondral ossification in late stages of ontogeny in R. caralitana. Our results suggest a correlation between the long lifespan of R. caralitana and the developmental changes and maturation of the epiphyseal cartilage in this taxon. This study also provides a quantitative assessment of the different regions of the epiphyseal cartilage in the epiphysis of Rana through ontogeny, and has therefore permitted quantifiable deductions about the relative maturation and differentiation of the chondrocytes of the epiphysis through time.

  6. Unmasking Rana okinavana Boettger, 1895 from the Ryukyus, Japan (Amphibia: Anura: Ranidae).

    PubMed

    Matsui, Masafumi

    2007-02-01

    Examination of the lectotype and a paralectotype of Rana okinavana Boettger, 1895 revealed that the species is not a brown frog of the subgenus Rana, occurring in the middle group of the Ryukyu Archipelago, but is identical with a frog of the subgenus Nidirana from the southern group of the Archipelago and Taiwan, now called R. psaltes Kuramoto, 1985. The type locality of R. okinavana given in the original description, Okinawa of the middle Ryukyus, is highly doubtful and should be somewhere in the Yaeyama Islands of the southern Ryukyus. The name R. psaltes is relegated to a subjective junior synonym of R. okinavana Boettger, 1895, while the brown frog of the subgenus Rana from the northern Ryukyus requires a replacement name.

  7. Effects of hypoxia on embryonic development in two Ambystoma and two Rana species.

    PubMed

    Mills, N E; Barnhart, M C

    1999-01-01

    Oxygen available to amphibian embryos fluctuates widely and is often very low. We investigated the effects of oxygen partial pressure (1. 3-16.9 kPa) on embryonic development and hatching of two salamander (Ambystoma) and two frog (Rana) species. In Ambystoma, chronic hypoxia resulted in slowed development, delayed hatching, and embryos that were less developed at the time of hatching. Although hypoxia was not lethal to embryos, temporary developmental abnormalities were observed in Ambystoma at oxygen partial pressures of 3.8 kPa and below. Posthatching survival decreased below 3.3 kPa. In Rana, hypoxia did not affect developmental rate, presumably because hatching occurs at a very early stage of development relative to Ambystoma. However, Rana embryos hatched sooner in hypoxia than in normoxia, resulting in less developed embryos at the time of hatching. The results suggest that embryonic hypoxia may negatively affect survival and fitness in these species. PMID:10068621

  8. Complete mitochondrial genome of a brown frog, Rana kunyuensis (Anura: Ranidae).

    PubMed

    Li, Jiao; Yin, Wei; Xia, Rong; Lei, Guangchun; Fu, Cuizhang

    2016-01-01

    The first complete mitochondrial genome (mitogenome) of Rana sensu stricto (sensu Frost, 2013) was determined using Rana kunyuensis as a representative species. The mitogenome was 22,255 bp in length, including 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes and duplicated control regions. The mitogenome of R. kunyuensis showed novel gene order arrangement with a translocation of tRNA(Leu)((CUN)) and ND5 in comparison with published anuran mitogenomes to date. This mitogenome should contribute to understand the evolution of anuran mitochondrial gene order arrangements.

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

    USGS Publications Warehouse

    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. Metabolic effects of dehydration on an aquatic frog, Rana pipiens.

    PubMed

    Churchill, T A; Storey, K B

    1995-01-01

    Cellular responses to dehydration were analyzed in six organs of leopard frogs Rana pipiens. Frogs at 5 degrees C endured the loss of up to 50% of their total body water content but water contents of individual organs were strongly defended. Skeletal muscle water content was strongly affected by dehydration, dropping from 80.7% of wet mass in controls to 67.2% in frogs that had lost 50% of their total body water. However, water contents of internal organs dropped by only 3-8% of their wet masses. Water contents of all organs except skeletal muscle were fully restored by 24h of rehydration in water at 5 degrees C. Dehydration had no consistent effect on the protein content of five organs but in a sixth, the kidney, protein levels were elevated (by 60-72%) at the higher levels of dehydration and during rehydration. Dehydration led to a rapid increase in glucose concentration in the liver; compared with control values of 13 +/- 2 nmol mg-1 protein, levels were doubled by 12.2% dehydration and continued to increase to a maximum of 307 +/- 44 nmol mg-1 protein (20 mumol g-1 wet mass) in 50% dehydrated frogs. Glucose accumulation was supported by a decrease in liver glycogen content and a parallel rise in glucose 6-phosphate levels, but not in the levels of other glycolytic intermediates, confirming that glycogenolytic flux was being directed into glucose synthesis. Blood glucose levels also increased as a function of increasing dehydration, reaching values 13.8 times higher than controls, but only the kidney and brain showed a significant accumulation of glucose over the course of dehydration.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7891032

  11. Effects of lead-contaminated sediment on Rana sphenocephala tadpoles

    USGS Publications Warehouse

    Sparling, D.W.; Krest, S.K.; Ortiz-Santaliestra, M.

    2006-01-01

    We exposed larval southern leopard frogs (Rana sphenocephala) to lead-contaminated sediments to determine the lethal and sublethal effects of this metal. Tadpoles were laboratory-raised from early free-swimming stage through metamorphosis at lead concentrations of 45, 75, 180, 540, 2360, 3940, 5520, and 7580 mg/kg dry weight in sediment. Corresponding pore water lead concentrations were 123, 227, 589, 1833, 8121, 13,579, 19,038, and 24,427 ug/L. Tadpoles exposed to lead concentrations in sediment of 3940 mg/kg or higher died within 2 to 5 days of exposure. At lower concentrations, mortality through metamorphosis ranged from 3.5% at 45 mg/kg lead to 37% at 2360 mg/kg lead in sediment. The LC50 value for lead in sediment was 3728 mg/kg (95% CI=1315 to 72,847 mg/kg), which corresponded to 12,539 ug/L lead in pore water (95% CI= 4000 to 35,200 ug/L). Early growth and development were depressed at 2,360 mg/kg lead in sediment (8100 ug/L in pore water) but differences were not evident by the time of metamorphosis. The most obvious effect of lead was its pronounced influence on skeletal development. Whereas tadpoles at 45 mg/kg lead in sediment did not display permanent abnormalities, skeletal malformations increased in frequency and severity at all higher lead concentrations. By 2360 mg/kg, 100% of surviving metamorphs displayed severe spinal problems, reduced femur and humerus lengths, deformed digits, and other bone malformations. Lead concentrations in tissues correlated positively with sediment and pore water concentrations.

  12. Photoinduced toxicity of fluoranthene to northern leopard frogs (Rana pipiens)

    SciTech Connect

    Monson, P.D.; Call, D.J.; Cox, D.A.; Liber, K.; Ankley, G.T.

    1999-02-01

    Rana pipiens larvae were exposed for 48 h in a flow-through system to clean water or five concentrations of the phototoxic polycyclic aromatic hydrocarbon (PAH) fluoranthene. Following this uptake period, the larvae were divided into four groups: one for immediate tissue residue analysis, a second for residue analysis following 48 h of depuration in clean water, and two for a 48-h exposure in clean water to ultraviolet (UV) light at two different levels. At the highest treatment, mean intensity was 8.12 {+-} 0.19 {times} 10{sup 2} {micro}W/cm{sup 2}, whereas at a lower treatment the UVA intensity was 4.45 {+-} 0.05 {times} 10{sup 2} {micro}W/cm{sup 2}. Larval frogs bioaccumulated fluoranthene in direct proportion to the water exposure concentrations, with initial whole-body PAH concentrations of 1.48, 3.53, 4.85, 11.3, and 18.7 {micro}g/g at the five treatment levels. No mortality of the animals occurred during the 48-h uptake phase. When the frogs were placed in clean water, the fluoranthene was rapidly depurated, with up to 80% lost in 48 h. Exposure to UV light following fluoranthene exposure significantly enhanced toxicity of the PAH. Median time to death decreased as the product of UVA light intensity and fluoranthene body residue increased. For larval R. Pipiens, sufficient tissue residues of fluoranthene were bioaccumulated within 48 h, at water exposure concentrations in the range of 2 to 10 {micro}g/L, to be lethal when combined with a UVA exposure simulating a fraction of summertime, midday sunlight in northern latitudes.

  13. Skin peptides protect juvenile leopard frogs (Rana pipiens) against chytridiomycosis.

    PubMed

    Pask, James D; Cary, Tawnya L; Rollins-Smith, Louise A

    2013-08-01

    One issue of great concern for the scientific community is the continuing loss of diverse amphibian species on a global scale. Amphibian populations around the world are experiencing serious losses due to the chytrid fungus, Batrachochytrium dendrobatidis. This pathogen colonizes the skin, leading to the disruption of ionic balance and eventual cardiac arrest. In many species, antimicrobial peptides secreted into the mucus are thought to contribute to protection against colonization by skin pathogens. Although it is generally thought that antimicrobial peptides are an important component of innate immune defenses against B. dendrobatidis, much of the current evidence relies on correlations between effective antimicrobial peptide defenses and species survival. There have been few studies to directly demonstrate that antimicrobial peptides play a role. Using the northern leopard frog, Rana pipiens, we show here that injection of noradrenaline (norepinephrine) brings about a long-term depletion of skin peptides (initial concentrations do not recover until after day 56). When peptide stores recovered, the renewed peptides were similar in composition to the initial peptides as determined by MALDI-TOF mass spectrometry and in activity against B. dendrobatidis as determined by growth inhibition assays. Newly metamorphosed froglets depleted of their peptide stores and exposed to B. dendrobatidis died more rapidly than B. dendrobatidis-exposed froglets with their peptides intact. Thus, antimicrobial peptides in the skin mucus appear to provide some resistance to B. dendrobatidis infections, and it is important for biologists to recognize that this defense is especially important for newly metamorphosed frogs in which the adaptive immune system is still immature. PMID:23580715

  14. Behavioural consistency and life history of Rana dalmatina tadpoles.

    PubMed

    Urszán, Tamás János; Török, János; Hettyey, Attila; Garamszegi, László Zsolt; Herczeg, Gábor

    2015-05-01

    The focus of evolutionary behavioural ecologists has recently turned towards understanding the causes and consequences of behavioural consistency, manifesting either as animal personality (consistency in a single behaviour) or behavioural syndrome (consistency across more behaviours). Behavioural type (mean individual behaviour) has been linked to life-history strategies, leading to the emergence of the integrated pace-of-life syndrome (POLS) theory. Using Rana dalmatina tadpoles as models, we tested if behavioural consistency and POLS could be detected during the early ontogenesis of this amphibian. We targeted two ontogenetic stages and measured activity, exploration and risk-taking in a common garden experiment, assessing both individual behavioural type and intra-individual behavioural variation. We observed that activity was consistent in all tadpoles, exploration only became consistent with advancing age and risk-taking only became consistent in tadpoles that had been tested, and thus disturbed, earlier. Only previously tested tadpoles showed trends indicative of behavioural syndromes. We found an activity-age at metamorphosis POLS in the previously untested tadpoles irrespective of age. Relative growth rate correlated positively with the intra-individual variation of activity of the previously untested older tadpoles. In previously tested older tadpoles, intra-individual variation of exploration correlated negatively and intra-individual variation of risk-taking correlated positively with relative growth rate. We provide evidence for behavioural consistency and POLS in predator- and conspecific-naive tadpoles. Intra-individual behavioural variation was also correlated to life history, suggesting its relevance for the POLS theory. The strong effect of moderate disturbance related to standard behavioural testing on later behaviour draws attention to the pitfalls embedded in repeated testing.

  15. Atrazine increases the sodium absorption in frog (Rana esculenta) skin.

    PubMed

    Cassano, Giuseppe; Bellantuono, Vito; Ardizzone, Concetta; Lippe, Claudio

    2006-02-01

    The presence of atrazine in agricultural sites has been linked to the decline in amphibian populations. The efforts of the scientific community generally are directed toward investigating the long-term effect of atrazine on complex functions (reproduction or respiration), but in the present study, we investigated the short-term effect on the short-circuit current (I(sc)), a quantitative measure of the ion transport operated by frog (Rana esculenta) skin. Treatment with 5 microM atrazine (1.08 mg/L) does not affect the transepithelial outfluxes of [14C]mannitol or [14C]urea; therefore, atrazine does not damage the barrier properties of frog skin. Atrazine causes a dose-dependent increase in the short-circuit current, with a minimum of 4.64 +/- 0.76 microA/cm2 (11.05% +/- 1.22%) and a maximum of 12.7 +/- 0.7 microA/cm2 (35% +/- 2.4%) measured at 10 nM and 5 microM, respectively. An increase in Isc also is caused by 5 microM ametryne, prometryn, simazine, terbuthylazine, or terbutryn (other atrazine derivatives). In particular, atrazine increases the transepithelial 22Na+ influx without affecting the outflux. Finally, stimulation of Isc by atrazine is suppressed by SQ 22536, H89, U73122, 2-aminoethoxydiphenyl borate, and W7 (blockers of adenylate cyclase, protein kinase A, phospholipase C, intracellular Ca2+ increase, and calmodulin, respectively), whereas indomethacin and calphostin C (inhibitors of cyclooxygenase and protein kinase C, respectively) have no effect.

  16. EVIDENCE FOR PHYLOGENETICALLY DISTINCT LEOPARD FROGS (RANA ONCA) FROM THE BORDER REGION OF NEVADA, UTAH, ARIZONA

    EPA Science Inventory


    Remnant populations of leopard frogs exist within the Virgin River drainage and adjacent portions of the Colorado River (Black Canyon) in northwestern Arizona and southern Nevada. These populations either represent the reportedly extinct taxa Rana onca or northern, disjunct R...

  17. PHOTOINDUCED TOXICITY OF FLUORANTHENE TO LARVAE OF THE LEOPARD FROG (RANA PIPENS)

    EPA Science Inventory

    Rana pipiens larvae (96-118 hr old) were exposed to in a flow-through diluter system to five concentrations of fluoranthene for 48 hr. Following the uptake period the exposed larvae were divided into three groups: one for tissue residue analysis, a second for residue analysis fo...

  18. POPULATION STATUS AND DISTRIBUTION OF A DECIMATED AMPHIBIAN, THE RELICT LEOPARD FROG (RANA ONCA)

    EPA Science Inventory

    The relict leopard frog (Rana onca) was once thought to be extinct, but has recently been shown to comprise a valid taxon with extant populations. We delineate the minimum historical range of the species, and report results of surveys at 12 historical and 54 other localities to d...

  19. The Developmental Effects Of A Municipal Wastewater Effluent On The Northern Leopard Frog, Rana pipiens

    EPA Science Inventory

    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...

  20. Emerging Pathogen in Wild Amphibians and Frogs (Rana catesbeiana) Farmed for International Trade

    PubMed Central

    Mazzoni, Rolando; Daszak, Peter; Apolo, Ada; Perdomo, Eugenio; Speranza, Gustavo

    2003-01-01

    Chytridiomycosis is an emerging disease responsible for global decline and extinction of amphibians. We report the causative agent, Batrachochytrium dendrobatidis, in North American bullfrogs (Rana catesbeiana) farmed for the international restaurant trade. Our findings suggest that international trade may play a key role in the global dissemination of this and other emerging infectious diseases in wildlife. PMID:12967500

  1. Serum chemistry and hematology values for anesthetized American bullfrogs (Rana catesbeiana).

    PubMed

    Cathers, T; Lewbart, G A; Correa, M; Stevens, J B

    1997-06-01

    Samples taken from seven male and seven female adult American bullfrogs (Rana catesbeiana) were evaluated by complete blood count and serum chemistry to establish baseline data on commercially available frogs destined for laboratory use. Differences between sexes were analyzed and females had higher plasma protein, calcium, and sodium levels.

  2. AMBIENT SOLAR UV RADIATION CAUSES MORTALITY IN LARVAE OF THREE SPECIES OF RANA

    EPA Science Inventory

    Recent reports concerning the lethal effects of solar ultraviolet-B (UV-B) radiation on amphibians suggest that this stressor has the potential to impact some amphibian populations. In this study embryos and larvae of three anuran species, Rana pipiens, R. clamitans, and R. septe...

  3. Antipredator defenses along a latitudinal gradient in Rana temporaria.

    PubMed

    Laurila, Anssi; Lindgren, Beatrice; Laugen, Ane T

    2008-05-01

    Antipredator defenses are expected to decrease toward higher latitudes because predation rates are predicted to decrease with latitude. However, latitudinal variation in predator avoidance and defense mechanisms has seldom been studied. We studied tadpole antipredator defenses in seven Rana temporaria populations collected along a 1500-km latitudinal gradient across Sweden, along which previous studies have found increasing tadpole growth and development rates. In a laboratory common garden experiment, we measured behavioral and morphological defenses by raising tadpoles in the presence and absence of a predator (Aeshna dragonfly larva) in two temperature treatments. We also estimated tadpole survival in the presence of free-ranging predators and compared predator densities between R. temporaria breeding ponds situated at low and high latitudes. Activity and foraging were generally positively correlated with latitude in the common garden experiment. While all populations responded to predator presence by decreasing activity and foraging, high-latitude populations maintained higher activity levels in the presence of the predator. All populations exhibited defensive morphology in body and tail shape. However, whereas tail depth tended to increase with latitude in the presence of predator, it did not change with latitude in the absence of the predator. Predator presence generally increased larval period and decreased growth rate. In the southern populations, predator presence tended to have a negative effect on metamorphic size, whereas in the northern populations predators had little or a positive effect on size. Latitude of origin had a strong effect on survival in the presence of a free-ranging predator, with high-latitude tadpoles experiencing higher mortality than those from the low latitudes. In the wild, predator densities were significantly lower in high-latitude than in mid-latitude breeding ponds. Although the higher activity level in the northern

  4. Spatial Heterogeneity of Rana boylii Habitat: Quantification and Ecological Meaningfulness

    NASA Astrophysics Data System (ADS)

    Yarnell, S. M.

    2005-05-01

    Analysis of the heterogeneity of stream habitat and how biological communities respond to that complexity are fundamental components of ecosystem analysis that are often inadequately addressed in watershed assessments and restoration practices. Many aquatic species, such as the Foothill Yellow-legged Frog (Rana boylii), known to associate with certain physical habitats at various times throughout their lifecycle may require some degree of habitat complexity at a larger reach scale for a population to persist. Recent research in the field of landscape ecology has expanded the use of spatial heterogeneity indices to other fields of ecology as an objective method to quantify variability in habitat. Provided that indices are used in an appropriate context and are shown to be ecologically meaningful, they provide a potentially useful tool for quantifying the variability in riverine habitat for aquatic species such as R. boylii. This study evaluated whether stream reaches with a high heterogeneity of geomorphic features, as measured by several key spatial heterogeneity indices, correlated with a greater relative abundance of R. boylii. R. boylii habitat associations were quantified throughout a single season to obtain further insight into the local hydraulic and geomorphic conditions preferred by each lifestage. The two best predictors of habitat associations by lifestage were velocity and substrate size, two key characteristics of geomorphic units such as riffles and pools. The heterogeneity of geomorphic units was then quantified and measured at the reach scale using a variety of spatial indices. Indices of spatial composition, such as Shannon's Diversity Index, were found to correlate well with frog abundance, while indices of spatial configuration, such as Contagion, were not significant. These findings indicate R. boylii may select stream reaches with increased geomorphic complexity that potentially provide habitats suitable to each lifestage with multiple functions

  5. Spatiotemporal Diversification of the True Frogs (Genus Rana): A Historical Framework for a Widely Studied Group of Model Organisms.

    PubMed

    Yuan, Zhi-Yong; Zhou, Wei-Wei; Chen, Xin; Poyarkov, Nikolay A; Chen, Hong-Man; Jang-Liaw, Nian-Hong; Chou, Wen-Hao; Matzke, Nicholas J; Iizuka, Koji; Min, Mi-Sook; Kuzmin, Sergius L; Zhang, Ya-Ping; Cannatella, David C; Hillis, David M; Che, Jing

    2016-09-01

    True frogs of the genus Rana are widely used as model organisms in studies of development, genetics, physiology, ecology, behavior, and evolution. Comparative studies among the more than 100 species of Rana rely on an understanding of the evolutionary history and patterns of diversification of the group. We estimate a well-resolved, time-calibrated phylogeny from sequences of six nuclear and three mitochondrial loci sampled from most species of Rana, and use that phylogeny to clarify the group's diversification and global biogeography. Our analyses consistently support an "Out of Asia" pattern with two independent dispersals of Rana from East Asia to North America via Beringian land bridges. The more species-rich lineage of New World Rana appears to have experienced a rapid radiation following its colonization of the New World, especially with its expansion into montane and tropical areas of Mexico, Central America, and South America. In contrast, Old World Rana exhibit different trajectories of diversification; diversification in the Old World began very slowly and later underwent a distinct increase in speciation rate around 29-18 Ma. Net diversification is associated with environmental changes and especially intensive tectonic movements along the Asian margin from the Oligocene to early Miocene. Our phylogeny further suggests that previous classifications were misled by morphological homoplasy and plesiomorphic color patterns, as well as a reliance primarily on mitochondrial genes. We provide a phylogenetic taxonomy based on analyses of multiple nuclear and mitochondrial gene loci. [Amphibians; biogeography; diversification rate; Holarctic; transcontinental dispersal. PMID:27288482

  6. Spatiotemporal Diversification of the True Frogs (Genus Rana): A Historical Framework for a Widely Studied Group of Model Organisms.

    PubMed

    Yuan, Zhi-Yong; Zhou, Wei-Wei; Chen, Xin; Poyarkov, Nikolay A; Chen, Hong-Man; Jang-Liaw, Nian-Hong; Chou, Wen-Hao; Matzke, Nicholas J; Iizuka, Koji; Min, Mi-Sook; Kuzmin, Sergius L; Zhang, Ya-Ping; Cannatella, David C; Hillis, David M; Che, Jing

    2016-09-01

    True frogs of the genus Rana are widely used as model organisms in studies of development, genetics, physiology, ecology, behavior, and evolution. Comparative studies among the more than 100 species of Rana rely on an understanding of the evolutionary history and patterns of diversification of the group. We estimate a well-resolved, time-calibrated phylogeny from sequences of six nuclear and three mitochondrial loci sampled from most species of Rana, and use that phylogeny to clarify the group's diversification and global biogeography. Our analyses consistently support an "Out of Asia" pattern with two independent dispersals of Rana from East Asia to North America via Beringian land bridges. The more species-rich lineage of New World Rana appears to have experienced a rapid radiation following its colonization of the New World, especially with its expansion into montane and tropical areas of Mexico, Central America, and South America. In contrast, Old World Rana exhibit different trajectories of diversification; diversification in the Old World began very slowly and later underwent a distinct increase in speciation rate around 29-18 Ma. Net diversification is associated with environmental changes and especially intensive tectonic movements along the Asian margin from the Oligocene to early Miocene. Our phylogeny further suggests that previous classifications were misled by morphological homoplasy and plesiomorphic color patterns, as well as a reliance primarily on mitochondrial genes. We provide a phylogenetic taxonomy based on analyses of multiple nuclear and mitochondrial gene loci. [Amphibians; biogeography; diversification rate; Holarctic; transcontinental dispersal.

  7. Ranatuerins: antimicrobial peptides isolated from the skin of the American bullfrog, Rana catesbeiana.

    PubMed

    Goraya, J; Knoop, F C; Conlon, J M

    1998-09-29

    Nine peptides, termed ranatuerins 1-9, with antimicrobial activity towards Staphylococcus aureus, were isolated from an extract of the skin of the adult American bullfrog, Rana catesbeiana. In common with other cytolytic peptides from Ranid frogs, (e.g. ranalexin, gaegurins, brevinins), ranatuerins 1 and 4 contain an intramolecular disulfide bridge forming a heptapeptide ring whereas in ranatuerins 2 and 3 the disulfide bridge forms a hexapeptide ring. The structurally related ranatuerins 5-9 comprise 12 - 14 amino acids and show sequence similarity towards the hemolytic peptides A1 and B9 previously isolated from the skin of Rana esculenta. Of the peptides purified, ranatuerin 1 (SMLSVLKNLGKVGLG FVACKINKQC) showed the broadest spectrum of antimicrobial action with inhibitory activity against S. aureus, Escherichia coli and Candida albicans.

  8. Asymmetrical Effects of Introduced Bullfrogs (Rana catesbeiana) on Native Ranid Frogs in Oregon

    USGS Publications Warehouse

    Pearl, C.A.; Adams, M.J.; Bury, R.B.; McCreary, B.

    2004-01-01

    Introduced American Bullfrogs (Rana catesbeiana) have become widely established in the Pacific Northwest over the last century and are thought to be an important predator of native amphibians throughout the western United States. The Northern Red-Legged Frog (Rana aurora aurora) and Oregon Spotted Frog (Rana pretiosa) historically coexisted in portions of the Pacific Northwest now invaded by R. catesbeiana, but R. pretiosa has declined more severely than R. a. aurora. We investigated whether microhabitat and behavioral differences that facilitate sympatric coexistence of the natives predict which species is more susceptible to predation by introduced R. catesbeiana. Our laboratory experiments demonstrate that R. catesbeiana adults prefer aquatic microhabitats, that R. pretiosa juveniles are more aquatic than R. a. aurora, and that adult R. catesbeiana consume more R. pretiosa than R. a. aurora juveniles. Mean and maximum jump distances of R. pretiosa were shorter than equally sized R. a. aurora, and the difference between these two species increased with larger frog sizes. Our examination of field survey data indicates that R. pretiosa coexist with R. catesbeiana less frequently than R. a. aurora. We conclude that R. catesbeiana is a greater threat to survival of R. pretiosa than to R. a. aurora and suggest that microhabitat use and escape abilities of native ranid frogs may be linked to this asymmetrical effect. Analysis of behavioral and microhabitat differences among related native species may be a useful tool in predicting the effects of introduced predators on amphibians and can assist in developing conservation priorities for these species.

  9. Asymmetrical effects of introduced Rana catesbeiana on native ranid frogs in Oregon, USA

    USGS Publications Warehouse

    Pearl, Christopher A.; Adams, Michael J.; Bury, R. Bruce; McCreary, B.

    2004-01-01

    Introduced American Bullfrogs (Rana catesbeiana) have become widely established in the Pacific Northwest over the last century and are thought to be an important predator of native amphibians throughout the western United States. The Northern Red-Legged Frog (Rana aurora aurora) and Oregon Spotted Frog (Rana pretiosa) historically coexisted in portions of the Pacific Northwest now invaded by R. catesbeiana, but R. pretiosa has declined more severely than R. a. aurora. We investigated whether microhabitat and behavioral differences that facilitate sympatric coexistence of the natives predict which species is more susceptible to predation by introduced R. catesbeiana. Our laboratory experiments demonstrate that R. catesbeiana adults prefer aquatic microhabitats, that R. pretiosa juveniles are more aquatic than R. a. aurora, and that adult R. catesbeiana consume more R. pretiosa than R. a. aurora juveniles. Mean and maximum jump distances of R. pretiosa were shorter than equally sized R. a. aurora, and the difference between these two species increased with larger frog sizes. Our examination of field survey data indicates that R. pretiosa coexist with R. catesbeiana less frequently than R. a. aurora. We conclude that R. catesbeiana is a greater threat to survival of R. pretiosa than to R. a. aurora and suggest that microhabitat use and escape abilities of native ranid frogs may be linked to this asymmetrical effect. Analysis of behavioral and microhabitat differences among related native species may be a useful tool in predicting the effects of introduced predators on amphibians and can assist in developing conservation priorities for these species.

  10. Etnografía acelerada para transformar normas sociales sobre género y sexualidad en hombres puertorriqueños heterosexuales1,2

    PubMed Central

    Ortiz-Torres, Blanca; Rivera-Ortiz, Rafael J.; Mendoza, Sigrid

    2014-01-01

    Resumen La construcción de roles de género dominantes contribuyen al riesgo de contraer VIH, y por tal razón se ha urgido a que se integren las normas sociales relativas al género en las intervenciones preventivas del VIH. Este estudio pretende adaptar y desarrollar una intervención que facilite la transformación de normas sociales del género y de prácticas sexuales en hombres puertorriqueños. La intervención propone transformar normas sociales relacionadas al género y sexualidad en barras comunitarias utilizando el modelo de líderes de opinión. Luego de ser elegidos/as, los/as líderes de opinión diseminan mensajes integrando la importancia de relaciones equitativas entre parejas para la prevención del VIH. La primera fase de esta intervención es discutida en este artículo, la cual incluye un proceso de etnografía acelerada para identificar los escenarios comunitarios en los que podemos desarrollar esta intervención y permitirnos entender la cultura de las barras comunitarias. A partir de las observaciones etnográficas, pudimos: desarrollar un protocolo de seguridad para realizar las observaciones, desarrollar un perfil de la cultura de las barras, elegir las barras a participar en las dos condiciones del estudio y adaptar los instrumentos de la intervención para que respondieran a la particularidad de los/as participantes. PMID:25530828

  11. Evidence from the primary structures of dermal antimicrobial peptides that Rana tagoi okiensis and Rana tagoi tagoi (Ranidae) are not conspecific subspecies.

    PubMed

    Conlon, J Michael; Coquet, Laurent; Jouenne, Thierry; Leprince, Jérôme; Vaudry, Hubert; Iwamuro, Shawichi

    2010-01-01

    Morphological evidence and data from comparisons of nucleotide sequences of mitochondrial genes demonstrate considerable intraspecies variation among populations of the Japanese brown frog Rana tagoi Okada 1928 (Tago's brown frog). Five peptides with antimicrobial activity were isolated from an extract of the skins of specimens of Rana tagoi okiensis collected on the Oki Islands, Japan. Determination of their primary structures demonstrated that two peptides belong to the ranatuerin-2 family, two peptides to the temporin family, and one peptide to the brevinin-1 family. Ranatuerin-2 peptides were not previously identified in the skin of specimens of R. t. tagoi collected in Chiba Prefecture, Japan and the structures of the temporin peptides from R. t. okiensis (temporin-TOa: FLPILGKLLSGFL.NH(2) and temporin-TOb: FLPILGKLLSGLL.NH(2)) are different from temporin-TGa (FLPILGKLLSGIL.NH(2)) isolated from R. t. tagoi. Similarly, the acyclic C-terminally alpha-amidated brevinin-1 peptide from R. t. okiensis (Brevinin-1TOa, GIGSILGVIAKGLPTLISWIKNR.NH(2)) shows three amino acid substitutions (Gly(1)-->Ala, Val(8)-->Ala, Ile(9)-->Leu) compared to the ortholog from R. t. tagoi. In addition, bradykinin, identical to the mammalian peptide, is present in high concentration in the skin of R. t. okiensis but not R. t. tagoi. The data provide evidence to support the proposal that R. t. tagoi and R. t. okiensis should be regarded as separate species (R. tagoi and R. okiensis) rather than conspecific subspecies. PMID:19799928

  12. The effects of solar UV-B radiation on embryonic mortality and development in three boreal anurans (Rana temporaria, Rana arvalis and Bufo bufo).

    PubMed

    Häkkinen, J; Pasanen, S; Kukkonen, J V

    2001-07-01

    Many species of amphibians have experienced population and range reductions. It has been hypothesized that sensitivity to UV-B may contribute to the population declines of some amphibian species. We performed field experiments to measure the effects of solar UV-B on the hatching success of three Finnish anuran species, the common frog (Rana temporaria), moor frog (Rana arvalis) and common toad (Bufo bufo). Further, the effects of natural UV-B radiation on survival of the tadpoles of the same three species of anurans were tested. A significant percentage of R. temporaria and B. bufo embryos survived when exposed to and protected from solar UV-B and hatching success was not affected by solar radiation. Elimination of solar UV-B significantly increased the hatching success of R. arvalis, but embryonic mortality was high in both treatments. The data indicates that under natural conditions, solar UV-B radiation influences embryo survival in R. arvalis, but has no effect on R. temporaria and B. bufo. Solar UV-B radiation had no effect on R. temporaria and R. arvalis tadpoles, but elimination of UV-B significantly increased survival of B. bufo tadpoles. It seems that ambient UV-radiation levels have no effect on R. temporaria but may affect R. arvalis and B. bufo at different developmental stages. PMID:11459149

  13. Arterial supply of the choriocapillaris of anuran amphibians (Rana temporaria, Rana esculenta). Scanning electron-microscopic (SEM) study of microcorrosion casts.

    PubMed

    Miodoński, A J; Bär, T

    1987-07-01

    The pattern of the vascular supply to the choroid of the frog eye was studied in toto with the use of the injection-replication-SEM technique. The choroid of anuran amphibians is composed mainly of the choriocapillaris. In both species studied (Rana temporaria, Rana esculenta), an independent arterial supply to the choriocapillaris supplemented that from the ciliary arteries. This additional vascular route arises from the optic artery, a separate branch of the arteria infundibularis superficialis. The optic artery, accompanied by its vein within the vascular sheath of the optic nerve, joins the rich arterial capillary network of the choriocapillaris and supplies the posterior pole of the ocular bulb. The superficial capillary network displays a dense collar around the entrance of the optic nerve into the eye and is composed of a circular meshwork of small capillaries, several layers deep. More peripherally, however, it becomes a single layered. This capillary network, as a whole, establishes numerous connections with the adjacent choriocapillaris at the posterior pole of the ocular bulb. In anuran amphibians the complex arrangement of both arterial systems supporting the choriocapillaris may be regarded as a more complete equivalent of the short posterior ciliary arteries of mammals.

  14. Body size affects the predatory interactions between introduced American Bullfrogs (Rana catesbeiana) and native anurans in China: An experimental study

    USGS Publications Warehouse

    Wang, Y.; Guo, Z.; Pearl, C.A.; Li, Y.

    2007-01-01

    Introduced American Bullfrogs (Rana catesbeiana) have established breeding populations in several provinces in China since their introduction in 1959. Although Bullfrogs are viewed as a potentially important predator of Chinese native anurans, their impacts in the field are difficult to quantify. We used two experiments to examine factors likely to mediate Bullfrog predation on native anurans. First, we examined effects of Bullfrog size and sex on daily consumption of a common Chinese native (Rana limnocharis). Second, we examined whether Bullfrogs consumed similar proportions of four Chinese natives: Black-Spotted Pond Frog (Rana nigromaculata), Green Pond Frog (Rana plancyi plancyi), Rice Frog (R. limnocharis), and Zhoushan Toad (Bufo bufo gargarizans). We found that larger Rana catesbeiana consumed more R. limnocharis per day than did smaller R. catesbeiana, and that daily consumption of R. limnocharis was positively related to R. catesbeiana body size. When provided with adults of four anurans that differed significantly in body size, R. catesbeiana consumed more individuals of the smallest species (R. limnocharis). However, when provided with similarly sized juveniles of the same four species, R. catesbeiana did not consume any species more than expected by chance. Our results suggest that body size plays an important role in the predatory interactions between R. catesbeiana and Chinese native anurans and that, other things being equal, smaller species and individuals are at greater risk of predation by R. catesbeiana. Copyright 2007 Society for the Study of Amphibians and Reptiles.

  15. Informe a la nación indica que los índices de muertes por cáncer siguen bajando

    Cancer.gov

    Los índices de mortalidad por todos los cánceres combinados para hombres, mujeres y niños siguieron bajando en Estados Unidos entre 2004 y 2008, según el Informe Anual a la Nación sobre el Estado del Cáncer de 1975 a 2008. El índice general de diagnóstico

  16. Complete mitochondrial genome of the Seoul frog Rana chosenica (Amphibia, Ranidae): comparison of R. chosenica and R. plancyi.

    PubMed

    Ryu, Shi Hyun; Hwang, Ui Wook

    2011-06-01

    Here, we have sequenced the complete mitochondrial genome of the Seoul frog Rana chosenica (Amphibia, Ranidae), which is known as a Korean endemic species. It is listed as a vulnerable species by IUCN Red List and also an endangered species in South Korea. The complete mitochondrial genome of R. chosenica consists of 18,357 bp. Its gene arrangement pattern was identical with those of other Rana frogs. We compared the mitochondrial genome of R. chosenica with that of the Peking frog Rana plancyi that has been known closely related to R. chosenica. Nucleotide sequence similarity between the two whole mitochondrial genomes was 95.7%, and the relatively low similarity seems to indicate that the two species are distinctly separated on the species level. The information of mitochondrial genome comparison of the two species was discussed in detail.

  17. [The correlation of the ecological niches of the common (Rana temporaria L.) and of the moor (Rana arvalis Nilss.) frogs (Anura, Amphibia)].

    PubMed

    Severtsov, A S; Liapkov, S M; Surova, G S

    1998-01-01

    During 25 years ecology and population dynamic of two brown frog species (Rana temporaria and R. arvalis) were studied in Moscow region, Solovki island and South Ural. We compared life cycles characteristics, namely biotope preferences, diet, migration, enemies, hibernation places using own and available literature data. Then we analyse how these parameters are changed among the species area and ecological niches were compared. We found that these two species do not compete in any stage of life cycle. Ecological niches are very closed and differences are determined generally by abiotic factors. So, R. temporaria prefers more wet biotope and more sensitive to acidity (low pH value). Differences in spawning time do not associate with interference in spawning places. We conclude that interspecific competition did not take place neither in the past nor in present and the reason of differences in ecological niches are determined by separate ways of evolutionary development of these species.

  18. Potential endocrine disruption of sexual development in free ranging male northern leopard frogs (Rana pipiens) and green frogs (Rana clamitans) from areas of intensive row crop agriculture.

    PubMed

    McDaniel, Tana V; Martin, Pamela A; Struger, John; Sherry, Jim; Marvin, Chris H; McMaster, Mark E; Clarence, Stacey; Tetreault, Gerald

    2008-07-30

    Intensive row crop agriculture (IRCA) for corn and soybean production is predominant in eastern and central North America. IRCA relies heavily on pesticide and nutrient inputs to maximize production under conventional systems. In 2003-2005, we assessed the occurrence of a suite of potential endocrine effects in amphibians inhabiting farm ponds and agricultural drains in IRCA areas of southwestern Ontario. Effects were compared to amphibians from two agricultural reference sites as well as four non-agricultural reference sites. Pesticide and nutrient concentrations were also determined in water samples from those sites. Atrazine and metolachlor were detected in most samples, exceeding 1 microg L(-1) at some sites. Blood samples were taken from northern leopard frogs (Rana pipiens) and green frogs (Rana clamitans) for analysis of circulating sex steroids and vitellogenin-like protein (Vtg-lp), a biomarker of exposure to environmental estrogens. Gonads were histologically examined for evidence of abnormalities. Some evidence of exposure to endocrine disrupting compounds was apparent from the data. The occurrence of testicular ovarian follicles (TOFS) in male R. pipiens was significantly higher (42%; p<0.05) at agricultural sites, particularly those in Chatham county compared to frogs from reference sites (7%). There was no difference in circulating sex steroid levels between frogs from agricultural and reference sites and sex steroid levels did not correlate with pesticide concentrations in the environment. No differences were detected in the gonadosomatic indices or stage of spermatogenesis between frogs from agricultural and non-agricultural regions (p>0.05). Plasma Vtg-lp was detected in only one male R. pipiens from an agricultural site. Neither gonad size, gonad maturity nor sex steroid levels differed between normal males and those with testicular oocytes. Although the proportion of testicular oocytes did not correlate directly with atrazine concentrations, it

  19. Food supply modifies the trade-off between past and future reproduction in a sexual parasite-host system (Rana esculenta, Rana lessonae).

    PubMed

    Waelti, Marc Olivier; Reyer, Heinz-Ulrich

    2007-06-01

    Life history theory is concerned with the costs of survival, growth and reproduction under different ecological conditions and the allocation of resources to meet these costs. Typical approaches used to address these topics include manipulation of food resources, followed by measures of subsequent reproductive traits, and measures of the relationship between current and future reproductive investment. Rarely, however, do studies test for the interaction of past investment, present resource availability and future investment simultaneously. Here, we investigate this interaction in females of a sexual parasite-host system consisting of the hybridogenetic frog Rana esculenta (E) and one of its parental species Rana lessonae (L). We kept females from each of two groups (with or without previous reproduction) under two food treatments (low or high) and regularly recorded their growth as well as their body condition and hormone titres as measures of future reproductive condition. After keeping them in hibernation until the following spring, we exposed the females to males, recorded whether they spawned or not and related this response to their condition in the previous autumn. Past reproduction negatively affected growth during summer and condition during autumn which, in turn, reduced the following year's reproductive output. These costs of previous reproduction were less pronounced under the high than under the low food treatment and lower in R. lessonae than in R. esculenta. Increasing food supply improved reproductive condition more in L than in E females. These species differences in reproductive costs and food requirements provide a mechanistic explanation for why E females skip annual reproduction almost twice as often as L females. Since R. esculenta is a sexual parasite that depends on R. lessonae for successful reproduction, these species-specific life history patterns not only affect individual fitness but also the spatial structure and temporal dynamics of

  20. Catecholamine innervation of the forebrain in the bull frog, Rana catesbiana.

    PubMed

    Tohyama, M; Yamamoto, K; Satoh, K; Sakumoto, T; Shimizu, N

    1977-01-01

    The innervation of forebrain catecholamine (CA) were experimentally investigated with use of sensitive fluorescence method of glyoxylic acid formaldehyde in the brain of the bull frog, Rana catesbiana. The CA of the olfactory bulb is supplied by CA neurons situated in olfactory bulb. And CA neurons in the hypothalamus contribute the main source for the forebrain CA except olfactory bulb. The hypothalamic CA neurons also give rise to long descending axons to innervate the brain stem. Judging from their anatomical aspects it seems that the structure homologous to mammalian nigro-neostriatal dopamine or mesolimbic dopamine system is not present in amphibian brain. PMID:303652

  1. Effects of nitrate and ammonium on larvae of Rana temporaria from the Pyrenees.

    PubMed

    Oromí, Neus; Sanuy, Delfí; Vilches, Marcel

    2009-05-01

    In order to investigate the effects of nitrate and ammonium on the amphibians in a pasture zone of the Catalonian Pyrenees, larvae of Rana temporaria from several ponds were exposed to different concentrations of nitrate (0-500 mg/L) and ammonium (0-1.2 mg/L). High concentrations of nitrate in the water caused mortality and reduced larval size of R. temporaria, whereas no effects on larvae were observed in ammonium conditions. The results suggest that, if the levels of nitrate reach about 100 mg/L, the possibility of survival of R. temporaria larvae may be reduced.

  2. Studying common-pool resources over time: A longitudinal case study of the Buen Hombre fishery in the Dominican Republic.

    PubMed

    Wilson, Margaret; Pavlowich, Tyler; Cox, Michael

    2016-03-01

    Like many small-scale fishing communities around the world, the community of Buen Hombre in the Dominican Republic is dealing with a set of challenges to reconcile its fishing activities with the ecology on which it depends. Also like many such communities, this case has been examined at a particular period in time by a group of social scientists, but not over substantial lengths of time in order to examine the longitudinal validity of the conclusions made during this period. In this paper we combine data from previous anthropological work with our own primary social and ecological data to conduct a longitudinal case study of the Buen Hombre fishery. Our over-time comparison focuses on a suite of mostly social and institutional variables to explain what we find to be a continued degradation of the fishery, and we conclude the analysis by presenting a causal-loop diagram, summarizing our inferences regarding the complex interactions among these variables. We find that a mix of factors, notably changes in gear and fishing sites used, the number of fishermen and their livelihood diversity, as well as an increased connectivity between Buen Hombre and its external environment, have contributed to the decline of the condition of Buen Hombre coral reef fishery. We conclude with a discussion of what may lie ahead for this particular case and others like it.

  3. Rana catesbeiana virus Z (RCV-Z): a novel pathogenic ranavirus.

    PubMed

    Majji, Sai; LaPatra, Scott; Long, Scott M; Sample, Robert; Bryan, Locke; Sinning, Allan; Chinchar, V Gregory

    2006-11-21

    A virus, designated Rana catesbeiana virus Z (RCV-Z), was isolated from the visceral tissue of moribund tadpoles of the North American bullfrog Rana catesbeiana. SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis) analysis of viral proteins and sequence analysis of the amino terminal end of the major capsid protein showed that RCV-Z was similar to frog virus 3 (FV3) and other ranaviruses isolated from anurans and fish. However, analysis of restriction fragment profiles following digestion of viral genomic DNA with XbaI and BamHI indicated that RCV-Z was markedly different from FV3. Moreover, in contrast to FV3, RCV-Z contained a full-length copy of the viral homolog of eukaryotic initiation factor 2 alpha (eIF-2alpha). Experimental infection of bullfrog tadpoles with FV3 and RCV-Z demonstrated that RCV-Z was much more pathogenic than FV3, and that prior infection with FV3 protected them from subsequent RCV-Z induced mortality. Collectively, these results suggest that RCV-Z may represent a novel species of ranavirus capable of infecting frogs and that possession of a viral eIF-2alpha homolog (vIF-2alpha) correlates with enhanced virulence. PMID:17240747

  4. Sublethal effects of chronic exposure to an organochlorine compound on northern leopard frog (Rana pipiens) tadpoles.

    PubMed

    Glennemeler, K A; Denver, R J

    2001-01-01

    Global contamination with organochlorine compounds (OCs) has posed developmental and reproductive problems in wildlife worldwide. However, little is known about the impact of OCs or other pollutants on amphibians, despite mounting concerns about amphibian population declines and developmental deformities in the wild. Wildlife populations may be affected critically by sublethal impacts of anthropogenic disturbances, yet little research has focused on such effects in amphibians. In the current study, northern leopard frog (Rana pipiens) tadpoles were chronically exposed to a polychlorinated biphenyl (PCB) congener, 77-TCB, and effects on behavior, morphology, competitive performance, and corticosterone content were determined. R. pipiens activity levels and feeding rates were decreased by 77-TCB exposure, but morphology of mouthparts and body proportions were unaffected. 77-TCB enhanced growth and altered competitive interactions between R. pipiens and wood frog (Rana sylvatica) tadpoles. R. pipiens tadpoles exposed to 77-TCB showed decreased whole-body corticosterone content compared to controls both before and after injection with adrenocorticotropic hormone (ACTH). All of the factors examined in the current study play critical roles in tadpole development, growth, survivorship, and eventual reproductive success, suggesting negative population-level consequences for amphibians in PCB-contaminated habitats.

  5. Contribution of eye retraction to swallowing performance in the northern leopard frog, Rana pipiens.

    PubMed

    Levine, Robert P; Monroy, Jenna A; Brainerd, Elizabeth L

    2004-03-01

    Most anurans retract and close their eyes repeatedly during swallowing. Eye retraction may aid swallowing by helping to push food back toward the esophagus, but this hypothesis has never been tested. We used behavioral observations, cineradiography, electromyography and nerve transection experiments to evaluate the contribution of eye retraction to swallowing in the northern leopard frog, Rana pipiens. Behavioral observations of frogs feeding on 1.5 cm long crickets reveal a high degree of variability in eye retraction and swallowing. Eye retraction can occur bilaterally or unilaterally, and both swallowing movements and eye retraction can occur separately as well as together. During swallowing, cineradiography shows that the eyes and associated musculature retract well into the oropharynx and appear to make contact with the prey item. This contact appears to help push the prey toward the esophagus, and it may also serve to anchor the prey for tongue-based transport. Electromyographic recordings confirm strong activity in the retractor bulbi muscles during eye retraction. After bilateral denervation of the retractor bulbi, frogs maintain the ability to swallow but show a 74% increase in the number of swallows required per cricket (from a mean of 2.3 swallows to a mean of 4.0 swallows per cricket). Our results indicate that, in Rana pipiens feeding on medium-sized crickets, eye retraction is an accessory swallowing mechanism that assists the primary tongue-based swallowing mechanism.

  6. Annual morphological cycles of testis and thumb pad of the male frog (Rana ridibunda).

    PubMed

    Kaptan, Engin; Murathanoğlu, Osman

    2008-09-01

    In this study, Rana ridibunda was used as samples because of their wide use in Turkey. Male frogs were collected in the East Marmara region each month throughout 1 year. Frogs from every monthly collection were used to analyze structural components of the thumb pads and testes. Spermatogenetic activity of Rana ridibunda living in the East Marmara region was determined to be "potentially continuous" type. Generally, the increase in the number and the size of nuclei of Leydig cells was inversely proportional to the fluctuation of spermatogenetic activity. The lumen of the seminiferous tubules in testes contained, in addition to the spermatogenic cells, a Periodic-acid Schiff-positive granular material. The amount of this material varied throughout the year, and that finding suggested a function related to spermiation. The components of thumb pads exhibited structural changes with respect to the activities of Leydig cells. During the periods where the Leydig cells were active, mucus glands (also called breeding glands) of thumb pads were also developed. On the other hand, we observed mixed glands with unknown function, which as first reported by us, and were poison glands in the thumb pads. The results suggest structural changes in the thumb pads are linked to changes in the testes. PMID:18509874

  7. Rana catesbeiana virus Z (RCV-Z): a novel pathogenic ranavirus.

    PubMed

    Majji, Sai; LaPatra, Scott; Long, Scott M; Sample, Robert; Bryan, Locke; Sinning, Allan; Chinchar, V Gregory

    2006-11-21

    A virus, designated Rana catesbeiana virus Z (RCV-Z), was isolated from the visceral tissue of moribund tadpoles of the North American bullfrog Rana catesbeiana. SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis) analysis of viral proteins and sequence analysis of the amino terminal end of the major capsid protein showed that RCV-Z was similar to frog virus 3 (FV3) and other ranaviruses isolated from anurans and fish. However, analysis of restriction fragment profiles following digestion of viral genomic DNA with XbaI and BamHI indicated that RCV-Z was markedly different from FV3. Moreover, in contrast to FV3, RCV-Z contained a full-length copy of the viral homolog of eukaryotic initiation factor 2 alpha (eIF-2alpha). Experimental infection of bullfrog tadpoles with FV3 and RCV-Z demonstrated that RCV-Z was much more pathogenic than FV3, and that prior infection with FV3 protected them from subsequent RCV-Z induced mortality. Collectively, these results suggest that RCV-Z may represent a novel species of ranavirus capable of infecting frogs and that possession of a viral eIF-2alpha homolog (vIF-2alpha) correlates with enhanced virulence.

  8. Cellular and serum immune response to dinitrophenol in adult Rana pipiens.

    PubMed

    Zettergren, L D; Boldt, B W; Schmid, L S

    1988-01-01

    A rabbit anti-Rana anti-DNP antiserum was used in order to estimate changes in frequency of bone marrow (BM) cells containing cytoplasmic anti-DNP antibodies (cId+) for eight weeks following a single injection. We found that (i) cId+ cells increased from 0.2 to 4.3 percent of total mononuclear cells (MNC's) during the first 8 weeks, (ii) BM granulocytes increased in frequency up to week 2, then gradually decreased to week 8, and (iii) serum anti-DNP antibody levels, evaluated by ELISA, increased to week 8. Our observations (i) support those which suggest that Rana BM resembles mammaliam BM as a source of antibody-producing cells, (ii) indicate that specific immune responses in BM may result in a 20-fold increase in the frequency of antigen-related plasma cells among total MNC's, and (iii) suggest that BM B cell clonal expansion, maturation and secretion may result in an increase in specific antibody levels in serum.

  9. Ovarian opioids and the reproductive cycle of the frog Rana esculenta.

    PubMed

    Facchinetti, F; Genazzani, A R; Pestarino, M; Vallarino, M; Pierantoni, R; Fasano, S; D'Antonio, M; Carnevali, O; Mosconi, G; Polzonetti-Magni, A

    1992-01-01

    In mammals, proopiomelanocortin-related peptides are involved in reproductive processes both at the hypothalamo-pituitary and ovarian levels. Using immunocytochemical, biochemical and physiological "in vitro" studies, we provide here evidence for a diffuse POMC-related opioid system in the frog Rana esculenta. Ovarian beta-endorphin (beta-EP) is expressed in thecal cells and changes during the reproductive cycle in an inverse relationship with follicular development. Seasonal changes in the ovary are different to those in the brain or in the pituitary. The ratio of acetylated vs native beta-EP in the ovary also changes over the reproductive period, affecting the biological activity of the peptide. During both the reproductive spring period and the summer post-reproductive phase pMol amounts of beta-EP stimulate follicular androgen secretion in vitro, in a naloxone-reversible way. In either period, an inhibition of estradiol, possibly mediated via other factors, is the result of opioid action. In conclusion, these data demonstrate for the first time the widespread presence of beta-EP-related peptides in the frog Rana esculenta. Both immunocytochemical and biochemical evidence, as well as in vitro responses, support a physiological role for beta-EP in ovarian seasonality during the reproductive cycle of this amphibian.

  10. Pond and landscape determinants of Rana dalmatina population sizes in a Romanian rural landscape

    NASA Astrophysics Data System (ADS)

    Hartel, Tibor; Nemes, Szilárd; Cogălniceanu, Dan; Öllerer, Kinga; Moga, Cosmin Ioan; Lesbarrères, David; Demeter, László

    2009-01-01

    Amphibians are good indicators of human impact, declining steadily worldwide. We explored the relationships between the ponds and nearby landscape parameters and population size of the Agile Frog ( Rana dalmatina), estimated from the number of egg masses, in a cultural landscape within the central section of Târnava Mare Basin, Romania. Forty-three permanent ponds were surveyed in a 2600 km 2 area. The average number of egg masses per pond was 211.13 (SD = 426.41). The egg mass number was significantly and positively related to the emergent aquatic macrophyte cover (its effect peaks at around 50%) and the green connecting corridors between the ponds and forests, and negatively related to the extent of nearby urban areas. The proximity of the forest (positive effect) and the presence of high traffic roads (negative effect) were highly correlated with green corridors and further eliminated from the model due to multicollinearity. Both these variables had significant effects when incorporated in univariate models and multivariate models without green corridors. Since a large part of our study area was currently declared as Natura 2000 site, there is an increased need for management proposals and conservation applications for biodiversity, including amphibians. Rana dalmatina is an important species for monitoring because it is common in the studied area and is suited for short surveys.

  11. Highly complex mitochondrial DNA genealogy in an endemic Japanese subterranean breeding brown frog Rana tagoi (Amphibia, Anura, Ranidae).

    PubMed

    Eto, Koshiro; Matsui, Masafumi; Sugahara, Takahiro; Tanaka-Ueno, Tomoko

    2012-10-01

    The endemic Japanese frog Rana tagoi is unique among Holarctic brown frogs in that it breeds in small subterranean streams. Using mitochondrial 16S ribosomal RNA and NADH dehydrogenase subunit 1 genes, we investigated genealogical relationships among geographic samples of this species together with its relative R. sakuraii, which is also a unique stream breeder. These two species together form a monophyletic group, within which both are reciprocally paraphyletic. Rana tagoi is divided into two major clades (Clade A and B) that are composed of 14 genetic groups. Rana sakuraii is included in Clade A and split into two genetic groups, one of which forms a clade (Subclade A-2) with sympatric R. tagoi. This species-level paraphyly appears to be caused by incomplete taxonomy, in addition to introgressive hybridization and/or incomplete lineage sorting. Rana tagoi strongly differs from other Japanese anurans in its geographic pattern of genetic differentiation, most probably in relation to its unique reproductive habits. Taxonomically, R. tagoi surely includes many cryptic species.

  12. Preliminary evidence that American bullfrogs (Rana catesbeiana) are suitable hosts for Escherichia coli O157:H7.

    PubMed

    Gray, Matthew J; Rajeev, Sreekumari; Miller, Debra L; Schmutzer, A Chandler; Burton, Elizabeth C; Rogers, Emily D; Hickling, Graham J

    2007-06-01

    We orally inoculated Rana catesbeiana tadpoles (n=23) and metamorphs (n=24) to test their suitability as hosts for Escherichia coli O157:H7. Tadpoles were housed in flowthrough aquaria and did not become infected. Metamorphs were housed in stagnant aquaria, and 54% tested positive through 14 days postinoculation, suggesting that they are suitable hosts for E. coli O157:H7.

  13. The yellow mutation in the frog Rana rugosa: pigment organelle deformities in the three types of chromatophore.

    PubMed

    Ichikawa, Y; Ohtani, H; Miura, I

    2001-08-01

    Crossing experiments revealed that a single recessive gene mutation (yellow) gives rise to the yellow phenotype of Rana rugosa in Japan. Ultrastructural observation of dermal chromatophores showed that the pigment organelles; melanosomes, pterinosomes, and reflecting platelets, all had structural deformities. This suggests that the yellow gene acts at the level of a primordial pigment organelle common to the three types of chromatophore.

  14. Informe trata el descenso del cáncer y los tumores cerebrales

    Cancer.gov

    Los índices de mortalidad en los Estados Unidos de todos los cánceres en hombres y mujeres siguieron bajando entre 2003 y 2007, que es el período más reciente del que se disponen datos, según el último Informe Anual a la Nación sobre el Estado del Cáncer. El informe encuentra también que el índice general combinado de nuevos diagnósticos de cáncer en hombres y mujeres decreció un promedio un poco menos de 1% por año en el mismo período.

  15. Sequence and chronology of the Cuerpo de Hombre paleoglacier (Iberian Central System) during the last glacial cycle

    NASA Astrophysics Data System (ADS)

    Carrasco, Rosa M.; Pedraza, Javier; Domínguez-Villar, David; Willenbring, Jane K.; Villa, Javier

    2015-12-01

    The Cuerpo de Hombre paleoglacier occupies the upper sector of the Cuerpo de Hombre river basin, located on the northwest slope of the Sierra de Béjar Mountains (Iberian Central System). At the stage of the maximum ice extent during the last glacial cycle, this paleoglacier was one of the longest tongues emerging from the Sierra de Béjar plateau glacier. The study of the morphostratigraphic succession and the geometric and genetic relations between the geomorphological indicators of this paleoglacier has revealed its evolutionary sequence during the last glacial cycle. The comparison between this sequence and the one previously established by a regional evolutionary pattern shows that although they both coincide in general terms, some stages/substages of this pattern must be corrected or more clearly defined. The absolute chronology of the different stages was obtained using terrestrial cosmogenic nuclides (10Be). The maximum ice extent of Cuerpo de Hombre paleoglacier has been dated to ˜25.0 ka (MIS2 and concurrent with the LGM). This chronology coincides with date obtained for other paleoglaciers in the Iberian Central System, but is slightly more modern than the regional chronology estimated as most likely for the maximum ice extent in these areas. Subsequent to reaching the maximum extent, the glacier had a retreat (minimum age ˜20.6 ka), followed by another stage of expansion or readvance, after which it stabilised until the start of the deglaciation stage (˜17.8 ka). In all previous work, the deglaciation stages in the Iberian Central System have been described as one continuous recession process. However, in the Cuerpo de Hombre paleoglacier, all the data point to stabilisations of considerable magnitude, and particularly to another stage of readvance of the glacier. Based on its chronology (minimum age ˜11.1 ka) and its evolutionary significance, this new readvance has been correlated with the Older Dryas stadial. Finally, the evolutionary context

  16. Hombre Seguro (Safe Men): a sexual risk reduction intervention for male clients of female sex workers

    PubMed Central

    2014-01-01

    Background Male clients of female sex workers (FSWs) are at risk of HIV and other sexually transmitted infections (STIs). We conducted a two-arm randomized controlled trial to test the efficacy of a sexual risk reduction intervention for male clients of FSWs in Tijuana, Mexico. Methods/Design Male clients of FSWs who were at least 18, were HIV-negative at baseline, and reported recent unprotected sex with FSWs were randomized to the Hombre Seguro sexual risk reduction intervention, or a time-attention didactic control condition. Each condition lasted approximately one hour. Participants underwent interviewer-administered surveys and testing for HIV and other STIs at baseline, and at 4, 8, and 12 month follow-ups. Combined HIV/STI incidence and unprotected vaginal and anal sex acts with FSWs were the primary outcomes. Discussion A total of 400 participants were randomized to one of the two conditions. Analyses indicated that randomization was successful; there were no significant differences between the participants in the two conditions at baseline. Average follow-up was 84% across both conditions. This is the first study to test the efficacy of a sexual risk reduction intervention for male clients of FSWs using the rigor of a randomized controlled trial. Trial registration NCT01280838, Date of registration: January 19, 2011. PMID:24885949

  17. Los plaguicidas y la contaminacion del medio ambiente Venezolano

    USGS Publications Warehouse

    Stickel, L.F.; Stickel, W.H.

    1972-01-01

    RESUMEN DE RECOMENDACIONES Recomendaciones para el Programa de Investigacion: 1. Establecer un sistema de muestreo biologico para detectar los niveles tendencias de los productos quimicos toxicos en un peque?o numero de si tios representativos. 2. Mantener continua vigilancia de la contaminacion ambiental, mediante la seleccion acertadamente dirigida de las zonas afectadas y de las fuentes de contaminacion. 3. Realizar estudios acerca de las poblaciones de animales silvestres, y del exito de los procesos reproductivos de las especies o grupos clayes de animales que se consideran mas gravemente afectados. 4. Preparar recomendaciones para una accion gubernamental de proteccion al hombre, a la fauna silvestre y al medio ambiente. Recomendaciones para la Accion Administrativa: 1. Establecer limites a la tolerancia de los residuos de plaguicidas en los alimentos. Constituye una medida clave para disminuir la contaminacion ambiental. 2. Establecer normas de calidad del agua para las corrientes, represas, la gos y otros cuerpos. Es la segunda medida clave para reducir la contaminacion del ambiente 3. Exigir un tratamiento adecuado de los efluentes industriales, especialmente antes de que se construyan las nuevas plantas. 4. Exigir a los agricultores que en el uso de plaguicidas sigan los consejos tecnicos autorizados y negar a los vendedores el derecho a recomendar productos por su cuenta. 5. Tomar medidas para recoger y eliminar los recipientes y sobrantes de los plaguicidas.

  18. Predation by Oregon spotted frogs (Rana pretiosa) on Western toads (Bufo boreas) in Oregon, USA

    USGS Publications Warehouse

    Pearl, Christopher A.; Hayes, M.P.

    2002-01-01

    Toads of the genus Bufo co-occur with true frogs (family Ranidae) throughout their North American ranges. Yet, Bufo are rarely reported as prey for ranid frogs, perhaps due to dermal toxins that afford them protection from some predators. We report field observations from four different localities demonstrating that Oregon spotted frogs (Rana pretiosa) readily consume juvenile western toads (Bufo boreas) at breeding sites in Oregon. Unpalatability thought to deter predators of selected taxa and feeding mode may not protect juvenile stages of western toads from adult Oregon spotted frogs. Activity of juvenile western toads can elicit ambush behavior by Oregon spotted frog adults. Our review of published literature suggests that regular consumption of toadlets sets Oregon spotted frogs apart from most North American ranid frogs. Importance of the trophic context of juvenile western toads as a seasonally important resource to Oregon spotted frogs needs critical investigation.

  19. Optical and tomographic imaging of a middle ear malformation in the bullfrog (Rana catesbeiana).

    PubMed

    Horowitz, Seth S; Simmons, Andrea Megela; Ketten, Darlene R

    2005-08-01

    Using a combination of in vivo computerized tomography and histological staining, a middle ear anomaly in two wild-caught American bullfrogs (Rana catesbeiana) is characterized. In these animals, the tympanic membrane, extrastapes, and pars media (shaft) of the stapes are absent on one side of the head, with the other side exhibiting normal morphology. The pars interna (footplate) of the stapes and the operculum are present in their normal positions at the entrance of the otic capsule on both the affected and unaffected sides. The pattern of deformity suggests a partial failure of development of tympanic pathway tissues, but with a preservation of the opercularis pathway. While a definitive proximate cause of the condition could not be determined, the anomalies show similarities to developmental defects in mammalian middle ear formation. PMID:16158670

  20. Peptidomics and genomics analysis of novel antimicrobial peptides from the frog, Rana nigrovittata.

    PubMed

    Ma, Yufang; Liu, Cunbao; Liu, Xiuhong; Wu, Jing; Yang, Hailong; Wang, Yipeng; Li, Jianxu; Yu, Haining; Lai, Ren

    2010-01-01

    Much attention has been paid on amphibian peptides for their wide-ranging pharmacological properties, clinical potential, and gene-encoded origin. More than 300 antimicrobial peptides (AMPs) from amphibians have been studied. Peptidomics and genomics analysis combined with functional test including microorganism killing, histamine-releasing, and mast cell degranulation was used to investigate antimicrobial peptide diversity. Thirty-four novel AMPs from skin secretions of Rana nigrovittata were identified in current work, and they belong to 9 families, including 6 novel families. Other three families are classified into rugosin, gaegurin, and temporin family of amphibian AMP, respectively. These AMPs share highly conserved preproregions including signal peptides and spacer acidic peptides, while greatly diversified on mature peptides structures. In this work, peptidomics combined with genomics analysis was confirmed to be an effective way to identify amphibian AMPs, especially novel families. Some AMPs reported here will provide leading molecules for designing novel antimicrobial agents. PMID:19778602

  1. Parasites of the mink frog (rana septentrionalis) from minnesota, U.S.A.

    USGS Publications Warehouse

    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.

  2. Breeding phenology in Rana temporaria. Local variation is due to pond temperature and population size.

    PubMed

    Loman, Jon

    2016-09-01

    Frog breeding phenology in temperate zones is usually compared to progress of spring temperatures at a regional scale. However, local populations may differ substantially in phenology. To understand this, local climate and other aspects must be studied. In this study, breeding phenology of the common frog, Rana temporaria, in a set of ponds in southern Sweden is analyzed. There was within year a variation of up to 3 weeks in start of breeding among local populations. Water temperature was measured in the ponds, and breeding tended to be earlier in warmer ponds (surprise!). Breeding was also earlier in ponds with a large breeding congregation. Alternative reasons for these patterns are suggested and discussed. There was a large residual variation. The common frog has a wide range of acceptable wintering sites, and I hypothesize that the particular choice by a local population may explain part of this residual variation. PMID:27648237

  3. Genotoxicity of some sulfur dyes on tadpoles (Rana hexadactyla) measured using the comet assay.

    PubMed

    Rajaguru, P; Kalpana, R; Hema, A; Suba, S; Baskarasethupathi, B; Kumar, P A; Kalaiselvi, K

    2001-01-01

    This report presents the results of a genotoxicity study to evaluate the DNA damage caused by four sulfur dyes used in the textile and tannery industries. Alkaline single-cell gel electrophoresis assay (SCGE) was performed on erythrocytes from Rana hexadactyla tadpoles following whole-body exposure to increasing concentrations of the dyes. The dyes, along with their active ingredients, were Sandopel Basic Black BHLN, Negrosine, Dermapel Black FNI, and Turquoise Blue. The dye-treated tadpoles showed significant DNA damage, measured as mean DNA length:width ratio, when compared with unexposed control animals. Among the four tested dyes Sandopel Basic Black BHLN appears to be highly genotoxic, Dermapel Black FNI was least genotoxic, and Negrosine and Turquoise Blue were moderately toxic to R. hexadactyla tadpoles. The tadpoles showed a significant reduction in DNA damage when placed in dechlorinated tap water after exposure for a 24-hr period to the dye solutions.

  4. Changes in activity of the organon vasculosum laminae terminalis in the annual cycle in Rana temporaria.

    PubMed

    Krawczyk, S; Dziubek, K; Lach, H

    1978-01-01

    In 70 sexually mature male and femal Rana temporaria frogs captured in natural habitat, mean nuclear volumes for the cells of the pars ependymalis and pars parenchymalis of the organon vasculosum laminae terminalis (OVLT) were determined in seven characteristic stages in life. The mean nuclear volume for the cells of the pars ependymalis and pars parenchymalis of the OVLT showed distinct annual fluctuation. Maximum nuclear volume of the cells in both investigated parts of the OVLT were observed during the breeding period (Ist decade of April), and minimum volume of the nuclei of the pars ependymalis at the beginning of hibernation (IIIrd decade of October), and in the pars parenchymalis near the end of active life (Ist decade of September).

  5. Effects of exposure to ultraviolet light on the development of Rana pipiens, the northern leopard frog

    SciTech Connect

    Williams, J.J.; Wofford, H.W.

    1996-10-01

    The increase in ultraviolet light intensity levels due to ozone depletion recently has been linked to the decline in amphibian population. In this experiment, eggs and larvae of Rana pipiens were subjected to differing amounts of ultraviolet radiation to determine the effects of ultraviolet light on the development of amphibian tadpoles. The total length, length of body without tail, and maximum width of each specimen was recorded for a month of the tadpoles` development, including several measurements after the ultraviolet exposures were concluded. It was found that ultraviolet exposure significantly reduced the size of the organisms in comparison with the control group in all three measured areas. Ultraviolet radiation altered the health and appearance of the exposed organisms and was lethal at large amounts. This experiment showed that ultraviolet radiation could cause many problems in developing amphibians. By slowing their development and physically weakening predation, thus contributing to a decline in overall population levels.

  6. Pathophysiology in mountain yellow-legged frogs (Rana muscosa) during a chytridiomycosis outbreak.

    PubMed

    Voyles, Jamie; Vredenburg, Vance T; Tunstall, Tate S; Parker, John M; Briggs, Cheryl J; Rosenblum, Erica Bree

    2012-01-01

    The disease chytridiomycosis is responsible for declines and extirpations of amphibians worldwide. Chytridiomycosis is caused by a fungal pathogen (Batrachochytrium dendrobatidis) that infects amphibian skin. Although we have a basic understanding of the pathophysiology from laboratory experiments, many mechanistic details remain unresolved and it is unknown if disease development is similar in wild amphibian populations. To gain a better understanding of chytridiomycosis pathophysiology in wild amphibian populations, we collected blood biochemistry measurements during an outbreak in mountain yellow-legged frogs (Rana muscosa) in the Sierra Nevada Mountains of California. We found that pathogen load is associated with disruptions in fluid and electrolyte balance, yet is not associated with fluctuations acid-base balance. These findings enhance our knowledge of the pathophysiology of this disease and indicate that disease development is consistent across multiple species and in both laboratory and natural conditions. We recommend integrating an understanding of chytridiomycosis pathophysiology with mitigation practices to improve amphibian conservation.

  7. Optical and tomographic imaging of a middle ear malformation in the bullfrog (Rana catesbeiana).

    PubMed

    Horowitz, Seth S; Simmons, Andrea Megela; Ketten, Darlene R

    2005-08-01

    Using a combination of in vivo computerized tomography and histological staining, a middle ear anomaly in two wild-caught American bullfrogs (Rana catesbeiana) is characterized. In these animals, the tympanic membrane, extrastapes, and pars media (shaft) of the stapes are absent on one side of the head, with the other side exhibiting normal morphology. The pars interna (footplate) of the stapes and the operculum are present in their normal positions at the entrance of the otic capsule on both the affected and unaffected sides. The pattern of deformity suggests a partial failure of development of tympanic pathway tissues, but with a preservation of the opercularis pathway. While a definitive proximate cause of the condition could not be determined, the anomalies show similarities to developmental defects in mammalian middle ear formation.

  8. Optical and tomographic imaging of a middle ear malformation in the bullfrog (Rana catesbeiana)

    NASA Astrophysics Data System (ADS)

    Horowitz, Seth S.; Simmons, Andrea Megela; Ketten, Darlene R.

    2005-08-01

    Using a combination of in vivo computerized tomography and histological staining, a middle ear anomaly in two wild-caught American bullfrogs (Rana catesbeiana) is characterized. In these animals, the tympanic membrane, extrastapes, and pars media (shaft) of the stapes are absent on one side of the head, with the other side exhibiting normal morphology. The pars interna (footplate) of the stapes and the operculum are present in their normal positions at the entrance of the otic capsule on both the affected and unaffected sides. The pattern of deformity suggests a partial failure of development of tympanic pathway tissues, but with a preservation of the opercularis pathway. While a definitive proximate cause of the condition could not be determined, the anomalies show similarities to developmental defects in mammalian middle ear formation.

  9. Comparative toxicity of chlorpyrifos, diazinon, malathion and their oxon derivatives to larval Rana boylii.

    PubMed

    Sparling, D W; Fellers, G

    2007-06-01

    Organophosphorus pesticides (OPs) are ubiquitous in the environment and are highly toxic to amphibians. They deactivate cholinesterase, resulting in neurological dysfunction. Most chemicals in this group require oxidative desulfuration to achieve their greatest cholinesterase-inhibiting potencies. Oxon derivatives are formed within liver cells but also by bacterial decay of parental pesticides. This study examines the toxicity of chlorpyrifos, malathion and diazinon and their oxons on the foothill yellow-legged frog (Rana boylii). R. boylii is exposed to agricultural pesticides in the California Central Valley. Median lethal concentrations of the parental forms during a 96 h exposure were 3.00 mg/L (24h) for chlorpyrifos, 2.14 mg/L for malathion and 7.49 mg/L for diazinon. Corresponding oxons were 10 to 100 times more toxic than their parental forms. We conclude that environmental concentrations of these pesticides can be harmful to R. boylii populations.

  10. Morphological variations among output neurons of the olfactory bulb in the frog (Rana ridibunda).

    PubMed

    Jiang, T; Holley, A

    1992-06-01

    Morphological properties of putative output cells have been studied in detail in the olfactory bulb of frogs (Rana ridibunda). Intracellular injection of Lucifer Yellow was used to reconstruct individual neurons. Ten different anatomical features related to cell shape and position were studied quantitatively. The results show that output cells, generally considered to be a homogeneous group in the olfactory bulb of amphibians, are, in fact, quite different in their morphology. Using multidimensional analysis to examine differences among the output neurons, we found that they might be divided into at least two groups. In one group, the cell somata were located near the glomerular layer and the dendrites lay at large angles with respect to each other. In the other group, the cell somata were farther from the glomerular layer and their dendrites lay at smaller angles. From their morphology, these two cell groups appear to be homologous, respectively, to the superficial/middle tufted cells and deep tufted/mitral cells of mammals.

  11. Atrazine is an immune disruptor in adult northern leopard frogs (Rana pipiens).

    PubMed

    Brodkin, Marc A; Madhoun, Hareth; Rameswaran, Muthuramanan; Vatnick, Itzick

    2007-01-01

    Atrazine, the most widely used herbicide in the United States, has been shown in several studies to be an endocrine disruptor in adult frogs. Results from this study indicate that atrazine also functions as an immune disruptor in frogs. Exposure to atrazine (21 ppb for 8 d) affects the innate immune response of adult Rana pipiens in similar ways to acid exposure (pH 5.5), as we have previously shown. Atrazine exposure suppressed the thioglycollate-stimulated recruitment of white blood cells to the peritoneal cavity to background (Ringer exposed) levels and also decreased the phagocytic activity of these cells. Unlike acid exposure, atrazine exposure did not cause mortality. Our results, from a dose-response study, indicate that atrazine acts as an immune disruptor at the same effective doses that it disrupts the endocrine system.

  12. De novo Assembly and Analysis of the Northern Leopard Frog Rana pipiens Transcriptome

    PubMed Central

    Christenson, Matthew K.; Trease, Andrew J.; Potluri, Lakshmi-Prasad; Jezewski, Andrew J.; Davis, Vincent M.; Knight, Lindsey A.; Kolok, Alan S.; Davis, Paul H.

    2014-01-01

    The northern leopard frog Rana (Lithobates) pipiens is an important animal model, being used extensively in cancer, neurology, physiology, and biomechanical studies. R. pipiens is a native North American frog whose range extends from northern Canada to southwest United States, but over the past few decades its populations have declined significantly and is now considered uncommon in large portions of the United States and Canada. To aid in the study and conservation of R. pipiens, this paper describes the first R. pipiens transcriptome. The R. pipiens transcriptome was annotated using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Eukaryotic Orthologous Groups (KOG). Differential expression analysis revealed universal and tissue specific genes, and endocrine-related genes were identified. Transcriptome assemblies and other sequence data are available for download. PMID:25371763

  13. Columbia spotted frog (Rana luteiventris) in southeastern Oregon: A survey of historical localities, 2009

    USGS Publications Warehouse

    Pearl, Chistopher A.; Galvan, Stephanie K.; Adams, Michael J.; McCreary, Brome

    2010-01-01

    The Columbia spotted frog (Rana luteiventris) occupies a large range in western North America and is comprised of at least three genetic units. Concern exists regarding the status of the Great Basin populations in Oregon, Idaho, and Nevada. We surveyed target and nearby alternate sites on public lands in southeastern Oregon where there was evidence that Columbia spotted frogs were historically present. We found the species at 59.5 percent (25 of 42) of target or nearby alternate sites. They were in 15 of 23 permanent streams and 8 of 13 intermittent streams. Our surveys do not provide evidence of widespread population losses in our sites. Interpretation of status of Columbia spotted frogs in this study is limited by a lack of precision in some of the historical locations and by our inability to determine if locations where only adults were indicated in the historical record once had breeding populations. Our results support the need for continued investigation of these populations.

  14. Characteristics of Columbia spotted frog (Rana luteiventris) oviposition sites in northeastern Oregon, USA

    USGS Publications Warehouse

    Pearl, C.A.; Adams, M.J.; Wente, W.H.

    2007-01-01

    Several western ranid frogs possess a unique strategy of breeding communally over a short temporal window and reusing oviposition sites between years. However, little is published on the characteristics of oviposition sites selected by these explosive breeders. The Columbia spotted frog (Rana luteiventris) is native to northwestern North America and is of conservation concern in the southern portions of its range. As part of a study examining relationships between livestock grazing and R. luteiventris habitat, we assessed characteristics of the species' oviposition sites in 25 fishless ponds in northeastern Oregon. Oviposition sites were generally in shallow water (<25 cm) close to shore and tended to be in the northeastern portion of ponds. Oviposition sites were found more frequently over heavily vegetated substrates and in areas of less substrate slope and shade than random points in littoral zones. We did not quantify temperature differences within ponds, but the patterns we documented are consistent with preferential use of warmer microhabitats for oviposition.

  15. Description of a new brown frog from Tsushima Island, Japan (Anura: Ranidae: Rana).

    PubMed

    Matsui, Masafumi

    2014-09-01

    Because all available evidence from allozymes, mtDNA sequences, and artificial hybridization suggests presence of high genetic differentiation between populations of East Asian brown frogs currently assigned to Rana dybowskii Günther, 1876, I compared morphological characters between specimens from Tsushima Island of Japan and Maritime territory of Russia. The population from Tsushima is slightly, but significantly different from R. dybowskii from Russia, including the holotype. I therefore consider the Tsushima population to be specifically distinct, and describe it as a new species R. uenoi. The new species also occurs in the Korean Peninsula and adjacent islands, but the distributional relationships with R. dybowskii are unclear, as detailed distribution in northern Korea is lacking.

  16. Pathophysiology in Mountain Yellow-Legged Frogs (Rana muscosa) during a Chytridiomycosis Outbreak

    PubMed Central

    Voyles, Jamie; Vredenburg, Vance T.; Tunstall, Tate S.; Parker, John M.; Briggs, Cheryl J.; Rosenblum, Erica Bree

    2012-01-01

    The disease chytridiomycosis is responsible for declines and extirpations of amphibians worldwide. Chytridiomycosis is caused by a fungal pathogen (Batrachochytrium dendrobatidis) that infects amphibian skin. Although we have a basic understanding of the pathophysiology from laboratory experiments, many mechanistic details remain unresolved and it is unknown if disease development is similar in wild amphibian populations. To gain a better understanding of chytridiomycosis pathophysiology in wild amphibian populations, we collected blood biochemistry measurements during an outbreak in mountain yellow-legged frogs (Rana muscosa) in the Sierra Nevada Mountains of California. We found that pathogen load is associated with disruptions in fluid and electrolyte balance, yet is not associated with fluctuations acid-base balance. These findings enhance our knowledge of the pathophysiology of this disease and indicate that disease development is consistent across multiple species and in both laboratory and natural conditions. We recommend integrating an understanding of chytridiomycosis pathophysiology with mitigation practices to improve amphibian conservation. PMID:22558145

  17. Comparative toxicity of chlorpyrifos, diazinon, malathion and their oxon derivatives to larval Rana boylii

    USGS Publications Warehouse

    Sparling, D.W.; Fellers, G.

    2007-01-01

    Organophosphorus pesticides (OPs) are ubiquitous in the environment and are highly toxic to amphibians. They deactivate cholinesterase, resulting in neurological dysfunction. Most chemicals in this group require oxidative desulfuration to achieve their greatest cholinesterase-inhibiting potencies. Oxon derivatives are formed within liver cells but also by bacterial decay of parental pesticides. This study examines the toxicity of chlorpyrifos, malathion and diazinon and their oxons on the foothill yellow-legged frog (Rana boylii). R. boylii is exposed to agricultural pesticides in the California Central Valley. Median lethal concentrations of the parental forms during a 96 h exposure were 3.00 mg/L (24 h) for chlorpyrifos, 2.14 mg/L for malathion and 7.49 mg/L for diazinon. Corresponding oxons were 10 to 100 times more toxic than their parental forms. We conclude that environmental concentrations of these pesticides can be harmful to R. boylii populations. ?? 2006 Elsevier Ltd. All rights reserved.

  18. Pseudacris triseriata (western chorus frog) and Rana sylvatica (wood frog) chytridiomycosis

    USGS Publications Warehouse

    Rittman, S.E.; Muths, E.; Green, D.E.

    2003-01-01

    The chytrid fungus Batrachochytrium dendrobatidis is a known pathogen of anuran amphibians, and has been correlated with amphibian die-offs worldwide (Daszak et. al. 1999. Emerging Infectious Diseases 5:735-748). In Colorado, B. dendrobatidis has infected Boreal toads (Bufo boreas) (Muths et. al., in review) and has been identified on museum specimens of northern leopard frogs (Rana pipiens) (Carey et. al. 1999. Develop. Comp. Immunol. 23:459-472). We report the first verified case of chytrid fungus in chorus frogs (Pseudacris triseriata) and wood frogs (Rana sylvatica) in the United States. We collected seven P. triseriata, and two adult and two juvenile R. sylvatica in the Kawuneeche Valley in Rocky Mountain National Park (RMNP) during June 2001. These animals were submitted to the National Wildlife Health Center (NWHC) as part of an amphibian health evaluation in RMNP. Chorus frogs were shipped in one container. Wood frog adults and juveniles were shipped in two separate containers. Histological examinations of all chorus frogs and 3 of 4 wood frogs were positive for chytrid fungus infection. The fourth (adult) wood frog was too decomposed for meaningful histology. Histological findings consisted of multifocally mild to diffusely severe infections of the epidermis of the ventrum and hindlimb digital skin. Chytrid thalli were confined to the thickened epidermis (hyperkeratosis), were spherical to oval, and occasional thalli contained characteristic discharge pores or zoospores (Green and Kagarise Sherman 1999. J. Herpetol 35:92-103; Fellers et al. 2001. Copeia 2001:945-953). We cannot confirm that all specimens carried the fungus at collection, because infection may have spread from one individual to all other individuals in each container during transport. Further sampling of amphibians in Kawuneeche Valley is warranted to determine the rate of infection and mortality in these populations.

  19. Distribution and postbreeding environmental relationships of Northern leopard frogs (Rana [Lithobates] pipiens) in Washington

    USGS Publications Warehouse

    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.

  20. Comparative microhabitat characteristics at oviposition sites of the California red-legged frog (Rana draytonii)

    USGS Publications Warehouse

    Alvarez, Jeff A.; Cook, David G.; Yee, Julie L.; van Hattem, Michael G.; Fong, Darren R.; Fisher, Robert N.

    2013-01-01

    We studied the microhabitat characteristics of 747 egg masses of the federally-threatened Rana draytonii (California red-legged frog) at eight sites in California. our study showed that a broad range of aquatic habitats are utilized by ovipositing R. draytonii, including sites with perennial and ephemeral water sources, natural and constructed wetlands, lentic and lotic hydrology, and sites surrounded by protected lands and nested within modified urban areas. We recorded 45 different egg mass attachment types, although the use of only a few types was common at each site. These attachment types ranged from branches and roots of riparian trees, emergent and submergent wetland vegetation, flooded upland grassland/ruderal vegetation, and debris. eggs were deposited in relatively shallow water (mean 39.7 cm) when compared to maximum site depths. We found that most frogs in artificial pond, natural creek, and artificial channel habitats deposited egg masses within one meter of the shore, while egg masses in a seasonal marsh averaged 27.3 m from the shore due to extensive emergent vegetation. Rana draytonii appeared to delay breeding in lotic habitats and in more inland sites compared to lentic habitats and coastal sites. eggs occurred as early as mid-december at a coastal artificial pond and as late as mid-April in an inland natural creek. We speculate that this delay in breeding may represent a method of avoiding high-flow events and/or freezing temperatures. Understanding the factors related to the reproductive needs of this species can contribute to creating, managing, or preserving appropriate habitat, and promoting species recovery.

  1. Molecular phylogenetics of western North American frogs of the Rana boylii species group.

    PubMed

    Macey, J R; Strasburg, J L; Brisson, J A; Vredenburg, V T; Jennings, M; Larson, A

    2001-04-01

    Phylogenetic relationships among frogs of the genus Rana from western North America are investigated using 2013 aligned bases of mitochondrial DNA sequence from the genes encoding ND1 (subunit one of NADH dehydrogenase), tRNA(Ile), tRNA(Gln), tRNA(Met), ND2, tRNA(Trp), tRNA(Ala), tRNA(Asn), tRNA(Cys), tRNA(Tyr), and COI (subunit I of cytochrome c oxidase), plus the origin for light-strand replication (O(L)) between the tRNA(Asn) and tRNA(Cys) genes. The aligned sequences contain 401 phylogenetically informative characters. A well-resolved phylogenetic hypothesis in which the Rana boylii species group (R. aurora, R. boylii, R. cascadae, R. muscosa, and R. pretiosa) is monophyletic is obtained. Molecular sequence divergence suggests that the R. boylii species group is approximately 8 million years old. The traditional hypothesis showing monophyly of the yellow-legged frogs (R. boylii and R. muscosa) is statistically rejected in favor of a hypothesis in which R. aurora, R. cascadae, and R. muscosa form a clade. Reanalyses of published nuclear ribosomal DNA restriction-site data and allozymic data support a monophyletic R. boylii group, but do not effectively resolve relationships among species within this group. Eight populations of R. muscosa form two major clades separated by a biogeographic break in the Sierra Nevada of California. This biogeographic break is broadly concordant with breaks found in four other amphibian and reptilian taxa. The two major clades within R. muscosa are estimated to have diverged approximately 2.2 million years before present. Each of these major clades contains two subgroups showing approximately 1.5 million years divergence, implicating climatic effects of Pleistocene glaciation in vicariance. The four distinct subgroups of R. muscosa separated by at least 1.4 million years of evolutionary divergence are suggested as potential units for conservation.

  2. Falcaustra lowei n. sp. and other helminths from the Tarahumara frog, Rana tarahumarae (Anura: Ranidae), from Sonora, Mexico.

    PubMed

    Bursey, C R; Goldberg, S R

    2001-04-01

    Seventy-four specimens of Falcaustra lowei n. sp. were recovered from the intestines of 9 of 42 (21%) Tarahumara frogs. Rana tarahumarae, from Sonora, Mexico. F. lowei is the 14th Nearctic species to be described and belongs to that group of species possessing a pseudosucker, namely F. catesbeianae, F. chabaudi, F. chelydrae, F. mexicana, and F. wardi. The new species can be readily differentiated from these by the arrangement of caudal papillae and length of spicules. Priority description of F. affinis is established and F. concinnae is removed from synonymy with F. affinis. In addition to F. lowei, 3 species of Digenea, Glypthelmins quieta, Haematoloechus breviplexus, Langeronia macrocirra; 1 species of Eucestoda, Ophiotaenia magna; 7 species of Nematoda, F. inglisi, Foleyellides striatus, Oswaldocruzia pipiens, Rhabdias ranae, Subulascaris falcaustriformis, Physaloptera sp. (larvae): and 1 species of Acanthocephala, an unidentified oligacanthorhynchid cystacanth, were found.

  3. Developmental effects of ambient UV-B light and landfill leachate in Rana blairi and Hyla chrysoscelis.

    PubMed

    Bruner, M A; Shipman, P A; Rao, M; Bantle, J A

    2002-09-01

    This study assessed the effects of ambient UV light on the development of two native species of anurans, Rana blairi and Hyla chrysoscelis, during their normal breeding season in Oklahoma. Additionally, the effects of ambient UV light and water contaminated with landfill leachate in Rana blairi were examined. Embryos were collected from the field and distributed equally among replicates of four filter treatments of ambient UV light in experimental tubs filled with either FETAX solution or landfill leachate diluted to 25, 10, and 5% concentrations. Three endpoints (mortality, teratogenesis, and growth) were compared between filter treatments. By itself, UV-B caused no significant effects. Leachate at 10 and 25% concentrations caused 100% mortality across all filter treatments. There was a significant interaction between filter treatment and water toxicity at leachate concentrations of 5% for both malformation and growth. Increased UV-B exposure decreased the malformation rate and increased growth in the leachate treatments. PMID:12481861

  4. Preliminary evidence that American bullfrogs (Rana catesbeiana) are suitable hosts for Escherichia coli O157:H7.

    PubMed

    Gray, Matthew J; Rajeev, Sreekumari; Miller, Debra L; Schmutzer, A Chandler; Burton, Elizabeth C; Rogers, Emily D; Hickling, Graham J

    2007-06-01

    We orally inoculated Rana catesbeiana tadpoles (n=23) and metamorphs (n=24) to test their suitability as hosts for Escherichia coli O157:H7. Tadpoles were housed in flowthrough aquaria and did not become infected. Metamorphs were housed in stagnant aquaria, and 54% tested positive through 14 days postinoculation, suggesting that they are suitable hosts for E. coli O157:H7. PMID:17449685

  5. Exposure of leopard frogs to a pesticide mixture affects life history characteristics of the lungworm Rhabdias ranae.

    PubMed

    Gendron, A D; Marcogliese, D J; Barbeau, S; Christin, M-S; Brousseau, P; Ruby, S; Cyr, D; Fournier, M

    2003-05-01

    We tested the hypothesis that exposure of leopard frogs ( Rana pipiens) to agricultural pesticides can affect the infection dynamics of a common parasite of ranid frogs, the lungworm Rhabdias ranae. After a 21-day exposure to sublethal concentrations of a pesticide mixture composed of atrazine, metribuzin, aldicarb, endosulfan, lindane and dieldrin, or to control solutions (water, dimethyl sulfoxide), parasite-free juvenile frogs were challenged with 30 infective larvae of R. ranae. Approximately 75% of the larvae penetrated the skin and survived in both exposed and control animals, suggesting that pesticides did not influence host recognition or penetration components of the transmission process. Rather, we found that the migration of R. ranae was significantly accelerated in hosts exposed to the highest concentrations of pesticides, leading to the establishment of twice as many adult worms in the lungs of frogs 21 days post-infection. Pesticide treatment did not influence the growth of lungworms but our results indicate that they matured and reproduced earlier in pesticide-exposed frogs compared to control animals. Such alterations in life history characteristics that enhance parasite transmission may lead to an increase in virulence. Supporting evidence shows that certain components of the frog immune response were significantly suppressed after exposure to the pesticide mixture. This suggests that the immune system of anurans exerts a control over lungworm migration and maturation and that agricultural contaminants can interfere with these control mechanisms. Our results also contribute to the ongoing debate regarding the role that anthropogenic factors could play in the perplexing disease-related die-offs of amphibians observed in several parts of the world.

  6. Bioaccumulation of macro- and trace elements by European frogbit (Hydrocharis morsus-ranae L.) in relation to environmental pollution.

    PubMed

    Polechońska, Ludmiła; Samecka-Cymerman, Aleksandra

    2016-02-01

    The aim of present study was to investigate the level of trace metals and macroelements in Hydrocharis morsus-ranae collected from regions differing in the degree and type of pollution. Concentrations of 17 macro- and microelements were determined in roots and shoots of European frogbit as well as in water and bottom sediments from 30 study sites. Plants differed in concentrations of elements and bioaccumulation capacity depending on the characteristics of dominant anthropogenic activities in the vicinity of the sampling site. Shoots of H. morsus-ranae growing in the vicinity of organic chemistry plants and automotive industry contained particularly high levels of Cd, Co, and S. Plants from area close to heat and power plant, former ferrochrome industry and new highway, were distinguished by the highest concentrations of Cr, Cu, and Pb. European frogbit from both these regions contained more Fe, Hg, Mn, Ni, and Zn than plants from agricultural and recreational areas. The concentrations of alkali metals and Co, Fe, and N in H. morsus-ranae were elevated in relation to the natural content in macrophytes irrespectively to their content in the environment. Based on the values of Bioaccumulation and Translocation Factors, European frogbit is an accumulator for Co, Cr, Cu, Fe, K, Mn, Ni, Pb, and Zn and a good candidate for phytoremediation of water polluted with Co, Cu, Hg, K, Mn, and Ni. The amount of Co and Mn removed from water and accumulated in the plant biomass during the vegetation season was considerably high.

  7. Ambient solar UV radiation causes mortality in larvae of three species of Rana under controlled exposure conditions.

    PubMed

    Tietge, J E; Diamond, S A; Ankley, G T; DeFoe, D L; Holcombe, G W; Jensen, K M; Degitz, S J; Elonen, G E; Hammer, E

    2001-08-01

    Recent reports concerning the lethal effects of solar ultraviolet-B (UV-B) (290-320 nm) radiation on amphibians suggest that this stressor has the potential to impact some amphibian populations. In this study embryos and larvae of three anuran species, Rana pipiens, Rana clamitans and Rana septentrionalis, were exposed to full-spectrum solar radiation and solar radiation filtered to attenuate UV-B radiation or UV-B and ultraviolet-A (UV-A) (290-380 nm) radiation to determine the effects of each wavelength range on embryo and larval survival. Ambient levels of solar radiation were found to be lethal to all three species under exposure conditions that eliminated shade and refuge. Lethality was ameliorated by filtration of UV-B radiation alone, demonstrating that ambient UV-B radiation is sufficient to cause mortality. Although several studies have qualitatively demonstrated the lethality of UV-B to early life stage amphibians this study demonstrates that the larval life stages of the three species tested are more sensitive than the embryonic stages. This suggests that previous reports that have not included the larval life stage may underestimate the risk posed to some anuran populations by increasing UV-B exposure. Furthermore, this study reports quantitative UV-B dosimetry data, collected in conjunction with the exposures, which can be used to begin the assessment of the impact of environmental changes which increase UV-B exposure of these anurans. PMID:11547564

  8. Mountain Yellow-legged Frogs (Rana muscosa) did not Produce Detectable Antibodies in Immunization Experiments with Batrachochytrium dendrobatidis.

    PubMed

    Poorten, Thomas J; Stice-Kishiyama, Mary J; Briggs, Cheryl J; Rosenblum, Erica Bree

    2016-01-01

    Chytridiomycosis is a devastating infectious disease of amphibians caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd). A growing number of studies have examined the role of amphibian adaptive immunity in response to this pathogen, with varying degrees of immune activation reported. Here we present immunologic data for the mountain yellow-legged frog, Rana muscosa, and the Sierra Nevada yellow-legged frog, Rana sierrae, which are two endangered and ecologically important species experiencing Bd-inflicted declines. Previous studies on these species that examined transcriptional response during Bd infection, and the effective of immunization, provided little evidence of immune activation to Bd. However, the studies did not directly assay immune effectors in the frog hosts. We performed experiments to examine antibody production, which is a hallmark of systemic adaptive immune activation. We used controlled laboratory experiments and enzyme-linked immunosorbent assays to examine the antibody response to Bd immunization and live Bd exposure. Rana muscosa and R. sierrae individuals did not produce detectable antibodies with the capacity to bind to denatured Bd antigens under our experimental conditions. While we cannot rule out antibody response to Bd in these species, our results suggest weak, poor, or inefficient production of antibodies to denatured Bd antigens. Our findings are consistent with susceptibility to chytridiomycosis in these species and suggest additional work is needed to characterize the potential for adaptive immunity.

  9. Diet of introduced bullfrogs (Rana catesbeiana): Predation on and diet overlap with native frogs on Daishan Island, China

    USGS Publications Warehouse

    Wu, Zhengjun; Li, Y.; Wang, Y.; Adams, Michael J.

    2005-01-01

    We examined diet of introduced Bullfrogs (Rana catesbeiana) and three native frog species (Rana limnocharis, Rana nigromaculata, and Bufo bufo gargarizans) co-occurring at a group of ponds on Daishan Island, east of China, to gain insight into the nature of potential interactions between Bullfrogs and native frog species. For postmetamorphic Bullfrogs, aquatic prey items dominated volumetrically. Prey size, diet volume and volumetric percentage of native frogs in diet increased with Bullfrog body size. The number and volumetric percentage of native frogs in the diet were not different for female and male Bullfrogs, and both were higher for adults than for juveniles. Diet overlap between males and juveniles was higher than that between males and females and between females and juveniles. Diet overlap with each native frog species of male Bullfrogs was lower than that of female Bullfrogs and juvenile Bullfrogs. We did not exam effects of Bullfrogs on native frogs but our results suggest that the primary threat posed by juvenile Bullfrogs to native frogs on Daishan Island is competition for food, whereas the primary threat posed by male Bullfrogs is direct predation. Female Bullfrogs may threaten native frogs by both competition and predation. These differences among Bullfrog groups may be attributed to differences in body size and microhabitat use.

  10. The expression of prostaglandin-E2 and its receptor in the oviduct of Chinese brown frog (Rana dybowskii).

    PubMed

    Hu, Ruiqi; Xi, Liqin; Cao, Qing; Yang, Rui; Liu, Yuning; Sheng, Xia; Han, Yingying; Yuan, Zhengrong; Guo, Yan; Weng, Qiang; Xu, Meiyu

    2016-07-01

    The Chinese brown frog (Rana dybowskii) has one special physiological phenomenon, which is that its oviduct expands prior to hibernation rather than in the breeding period. In this study, we investigated the immunolocalization and expression levels of prostaglandin-E2 (PGE2), cyclooxygenase (COX)-1 and COX-2, as well as one of its receptor subtypes 4 (EP4) in the oviduct of Rana dybowskii during the pre-hibernation and breeding period. PGE2, COX-1, COX-2 and EP4 have been observed in glandular and epithelial cells in the breeding period, whereas only in the epithelial cells during the pre-hibernation. Consistently, the protein levels of COX-2 and EP4 were higher in the pre-hibernation as compared to the breeding period, but the diversity of COX-1 was not obvious. In addition, oviductal PGE2 concentration was also significantly higher in the pre-hibernation. These results suggested that prostaglandin-E2 may play an important autocrine or paracrine role in oviductal cell proliferation and differentiation of Rana dybowskii during pre-hibernation. PMID:27246901

  11. Effects of agricultural pesticides on the immune system of Rana pipiens and on its resistance to parasitic infection.

    PubMed

    Christin, Marie-Soleil; Gendron, Andrée D; Brousseau, Pauline; Ménard, Lucie; Marcogliese, David J; Cyr, Daniel; Ruby, Sylvia; Fournier, Michel

    2003-05-01

    In the past 30 years, many amphibian species have suffered population declines throughout the world. Mass mortality have been frequently reported, and in several instances, infectious diseases appear to be the cause of death. The role that contaminants could play in these die-offs through immunotoxic effects has been poorly investigated. In this study, juvenile leopard frogs (Rana pipiens) were exposed for 21 d to a mixture of six pesticides (atrazine, metribuzin, aldicarb, endosulfane, lindane, and dieldrin) and subsequently challenged with a parasitic nematode, Rhabdias ranae. Exposure to the mixture at environmentally realistic concentrations significantly reduced lymphocyte proliferation. Three weeks after the end of the exposure, lymphocyte proliferation had recovered and was stimulated in frogs challenged with parasites with the exception of those previously exposed to the highest concentration. No pesticide effects on phagocytosis and splenocyte numbers were detectable at the end of the exposure period, but these two parameters were diminished 21 d after the infection challenge in frogs previously exposed to the highest levels of pesticides. In these animals, the prevalence of lung infection by R. ranae also tended to be higher. These results suggest that agricultural pesticides can alter the immune response of frogs and affect their ability to deal with parasitic infection.

  12. Patterns of Cranial Development in Larval Rana macrocnemis: Chondrocranial Size and Shape Relationship With Pelophylax bedriagae (Anura: Ranidae).

    PubMed

    Yildirim, Elıf; Kaya, Uğur

    2016-06-01

    Notwithstanding the abundance of amphibians, there are few descriptions about ranid cranial development. Herein, larval chondrocranial development of Uludağ frog, Rana macrocnemis (Boulenger, 1885), is described on cleared and double-stained specimens. Descriptions are related with the ontogeny of the chondrocranium and osteogenesis of the cranial skeleton. The larval chondrocranial development of R. macrocnemis is compared to those of Rana and Pelophylax larvae (Pelophylax bedriagae, Rana pipiens, R. palustris, R. sphenocephala, R. catesbeiana, R. clamitans and R. sylvatica). In R. macrocnemis, the first bones to ossify are the parasphenoid and exoccipital (Stage 33), followed by the frontoparietal and prootic (stages 35 and 40, respectively). The major reconstruction of the chondrocranium begins at Stage 41. The ossification sequence of R. macrocnemis is distinguished from other ranids. Adult cranial osteology of R. macrocnemis is compared to that of P. bedriagae. Osteologically, R. macrocnemis is different from P. bedriagae by the shape and size of the vomer and number of teeth. Additionally, geometric morphometric methods are used to analyze chondrocranial size and shape changes of ranid larva of R. macrocnemis and P. bedriagae. Anat Rec, 299:711-721, 2016. © 2016 Wiley Periodicals, Inc.

  13. Bioaccumulation of macro- and trace elements by European frogbit (Hydrocharis morsus-ranae L.) in relation to environmental pollution.

    PubMed

    Polechońska, Ludmiła; Samecka-Cymerman, Aleksandra

    2016-02-01

    The aim of present study was to investigate the level of trace metals and macroelements in Hydrocharis morsus-ranae collected from regions differing in the degree and type of pollution. Concentrations of 17 macro- and microelements were determined in roots and shoots of European frogbit as well as in water and bottom sediments from 30 study sites. Plants differed in concentrations of elements and bioaccumulation capacity depending on the characteristics of dominant anthropogenic activities in the vicinity of the sampling site. Shoots of H. morsus-ranae growing in the vicinity of organic chemistry plants and automotive industry contained particularly high levels of Cd, Co, and S. Plants from area close to heat and power plant, former ferrochrome industry and new highway, were distinguished by the highest concentrations of Cr, Cu, and Pb. European frogbit from both these regions contained more Fe, Hg, Mn, Ni, and Zn than plants from agricultural and recreational areas. The concentrations of alkali metals and Co, Fe, and N in H. morsus-ranae were elevated in relation to the natural content in macrophytes irrespectively to their content in the environment. Based on the values of Bioaccumulation and Translocation Factors, European frogbit is an accumulator for Co, Cr, Cu, Fe, K, Mn, Ni, Pb, and Zn and a good candidate for phytoremediation of water polluted with Co, Cu, Hg, K, Mn, and Ni. The amount of Co and Mn removed from water and accumulated in the plant biomass during the vegetation season was considerably high. PMID:26490926

  14. Characterization of circannual patterns of metabolic recovery from activity in Rana catesbeiana at 15 degrees C.

    PubMed

    Petersen, A M; Gleeson, T T

    2007-05-01

    We characterized carbohydrate metabolism following activity in the American bullfrog, Rana catesbeiana, and compared whole body metabolic profiles between two seasons. Forty-eight adult male Rana catesbeiana were chronically cannulated and injected with [U-(14)C]L-lactic acid sodium salt in either summer (June) or winter (January) after acclimation for 2 weeks at 15 degrees C with a 12 h:12 h L:D photoperiod. Following injection with [(14)C]lactate, frogs were either allowed to rest for 240 min (REST), hopped for 2 min on a treadmill and immediately sacrificed (PE), or hopped for 2 min on a treadmill and allowed to recover for 240 min (REC 4). Exercise caused a significant increase in blood lactate level from 2.7+/-0.1 mmol l(-1) at rest to 17.0+/-2.1 mmol l(-1) immediately following exercise. This increase persisted throughout the recovery period, with average blood lactate level only reduced to 13.7+/-1.1 mmol l(-1) after 240 min of recovery, despite complete recovery of intramuscular lactate levels. Lactate levels were not significantly different between seasons in any treatment (REST, PE, REC4), in either gastrocnemius muscle or blood. The vast majority of [(14)C]lactate was recovered in the muscle, in both winter (86.3%) and summer (87.5%). Season had no effect on total amount of (14)C label recovered. [(14)C]Lactate was measured in the forms of lactate, glucose and glycogen, in the liver and the muscle sampled. The most robust difference found in seasonal metabolism was that both the liver and the gastrocnemius contained significantly higher levels of intracellular free glucose under all treatments in winter. These data suggest that, overall, bullfrogs accumulate and slowly clear lactate in a manner quite similar to findings in fish, other amphibians and lizards. Additionally, our findings indicate that lactate metabolism is not highly influenced by season alone, but that intracellular glucose levels may be sensitive to annual patterns. PMID:17488942

  15. Characterization of circannual patterns of metabolic recovery from activity in Rana catesbeiana at 15 degrees C.

    PubMed

    Petersen, A M; Gleeson, T T

    2007-05-01

    We characterized carbohydrate metabolism following activity in the American bullfrog, Rana catesbeiana, and compared whole body metabolic profiles between two seasons. Forty-eight adult male Rana catesbeiana were chronically cannulated and injected with [U-(14)C]L-lactic acid sodium salt in either summer (June) or winter (January) after acclimation for 2 weeks at 15 degrees C with a 12 h:12 h L:D photoperiod. Following injection with [(14)C]lactate, frogs were either allowed to rest for 240 min (REST), hopped for 2 min on a treadmill and immediately sacrificed (PE), or hopped for 2 min on a treadmill and allowed to recover for 240 min (REC 4). Exercise caused a significant increase in blood lactate level from 2.7+/-0.1 mmol l(-1) at rest to 17.0+/-2.1 mmol l(-1) immediately following exercise. This increase persisted throughout the recovery period, with average blood lactate level only reduced to 13.7+/-1.1 mmol l(-1) after 240 min of recovery, despite complete recovery of intramuscular lactate levels. Lactate levels were not significantly different between seasons in any treatment (REST, PE, REC4), in either gastrocnemius muscle or blood. The vast majority of [(14)C]lactate was recovered in the muscle, in both winter (86.3%) and summer (87.5%). Season had no effect on total amount of (14)C label recovered. [(14)C]Lactate was measured in the forms of lactate, glucose and glycogen, in the liver and the muscle sampled. The most robust difference found in seasonal metabolism was that both the liver and the gastrocnemius contained significantly higher levels of intracellular free glucose under all treatments in winter. These data suggest that, overall, bullfrogs accumulate and slowly clear lactate in a manner quite similar to findings in fish, other amphibians and lizards. Additionally, our findings indicate that lactate metabolism is not highly influenced by season alone, but that intracellular glucose levels may be sensitive to annual patterns.

  16. Cloning, Characterization, and Expression Analysis of MyD88 in Rana dybowskii.

    PubMed

    Niu, Shudong; Shi, Xuecan; Zhang, Jingyu; Chai, Longhui; Xiao, Xianghong

    2016-05-01

    The myeloid differentiation factor 88 (MyD88) is the most common adaptor protein in toll-like receptor (TLR) signaling pathways and plays an important role in the innate immune system. In this report, we conducted rapid amplification of complementary DNA (cDNA) ends (RACE), multiple sequence alignment, conserved domain search, phylogenetic tree construction, and quantitative real-time PCR to obtain and analyze the full-length cDNA sequence, the amino acid sequential structures, and the expression patterns of Rana dybowskii (Rd) MyD88. The full-length cDNA of RdMyD88 is 1472 bp, with an open reading frame of 855 bp, encoding a protein of 285 amino acid residues. The RdMyD88 amino acid sequence contains a death domain (DD) and a Toll/interleukin-1 receptor (TIR) domain. RdMyD88 was calculated as a hydrophilic protein with predicted molecular mass and pI of 32.79 kDa and 6.00, respectively. Eighteen possible phosphorylation sites including eight serine residues, six tyrosine residues, and four threonine residues are predicted. Analysis of multiple sequence alignment and phylogenetic tree revealed that the predicted RdMyD88 protein is closest to its Xenopus counterparts. The PCR result showed that RdMyD88 is expressed in various tissues of R. dybowskii. Quantitative real-time PCR (qPCR) was used to examine the expression of RdMyD88 in the heart, liver, and kidney. After Rana grylio virus (RGV) exposure, the expression of RdMyD88 in the heart, liver, and kidney were significantly upregulated and reached peak levels at 48, 48, and 72 h post-infection (hpi), respectively. Meanwhile, in response to Aeromonas hydrophila (AH) infection, clear upregulation of RdMyD88 was observed in the heart, liver, and kidney and reached its peak at 48, 6, and 12 hpi, respectively. The highest levels of induction were found in the kidney after both RGV and AH infections. These findings indicate that RdMyD88 has a conserved structure and is probably an important component of the innate

  17. Identification and characterization of a novel envelope protein in Rana grylio virus.

    PubMed

    Zhao, Zhe; Ke, Fei; Huang, You-Hua; Zhao, Jiu-Gang; Gui, Jian-Fang; Zhang, Qi-Ya

    2008-08-01

    Viral envelope proteins have been proposed to play significant roles in virus infection and assembly. In this study, an envelope protein gene, 53R, was cloned and characterized from Rana grylio virus (RGV), a member of the family Iridoviridae. Database searches found its homologues in all sequenced iridoviruses, and sequence alignment revealed several conserved structural features shared by virus capsid or envelope proteins: a myristoylation site, two predicted transmembrane domains and two invariant cysteine residues. Subsequently, RT-PCR and Western blot detection revealed that the transcripts encoding RGV 53R and the protein itself appeared late during infection of fathead minnow cells and that their appearance was blocked by viral DNA replication inhibitor, indicating that RGV 53R is a late expression gene. Moreover, immunofluorescence localization found an association of 53R with virus factories in RGV-infected cells, and this association was further confirmed by expressing a 53R-GFP fusion protein in pEGFP-N3/53R-transfected cells. Furthermore, detergent extraction and Western blot detection confirmed that RGV 53R was associated with virion membrane. Therefore, the current data suggest that RGV 53R is a novel viral envelope protein and that it may play an important role in virus assembly. This is thought to be the first report on a viral envelope protein that is conserved in all sequenced iridoviruses.

  18. [Morpho-functional changes in small intestine epithelium of frog Rana temporaria during hibernation].

    PubMed

    Seliverstova, E V; Prutskova, N P

    2012-01-01

    Structure and function of small intestinal epithelium were studied in overwintering frogs Rana temporaria at various stages of hibernation. In the process of testing of absorption of arginine vasotocin (AVT) in experiments in vitro it is established that at the period of hibernation there is preserved the capability of the epithelium for absorption of this nonapeptide without hydrolysis. However, as compared with October-December, in January-February and later, a decrease of the AVT absorption takes place, which is the most pronounced in March-April. Changes in epithelial structures appear by the middle of winter and are progressing by spring. In April-May, as compared with the beginning of hibernation, the height of enterocytes, the length of microvilli, and the number of microvilli decrease by 33 %, 40 %, and 57 %, respectively. The absence of features of destruction indicates an adaptive character of the observed changes. Dynamics of the studied parameters indicates morphological plasticity of the small intestine epithelium of R. temporaria at the period of hibernation.

  19. Is body size of the water frog Rana esculenta complex responding to climate change?

    PubMed

    Tryjanowski, Piotr; Sparks, Tim; Rybacki, Mariusz; Berger, Leszek

    2006-03-01

    Recent studies on climate responses in ectothermic (cold-blooded) vertebrates have been few in number and focussed on phenology rather than morphology. According to Bergmann's rule, endothermic (warm-blooded) vertebrates from cooler climates tend to be larger than congeners from warmer regions. Although amphibians are ectothermic vertebrates, weather and climatic conditions may also impact on their morphology, and thereby affect their survival rates and population dynamics. In this paper, we show, in a unique long-term study during the period 1963-2003 in an agricultural landscape in western Poland, that the body length of two water frog parental species (males of both Rana ridibunda and R. lessonae) increased significantly. However, their hybridogenetic hybrid R. esculenta did not show similar changes. A significant relationship with a large-scale climatic factor, the winter North Atlantic Oscillation index, was found positive for R. ridibunda males and R. lessonae females, and negative for R. esculenta females. Our findings, the first for amphibians, are consistent with other studies reporting that recent climate change has affected the morphology of animals. However, we also show that changes in amphibian phenotype linked to climate may vary independently between (even very similar) species.

  20. Widespread occurrence of the chytrid fungus batrachochytrium dendrobatidis on oregon spotted frogs (rana pretiosa)

    USGS Publications Warehouse

    Pearl, C.A.; Bowerman, J.; Adams, M.J.; Chelgren, N.D.

    2009-01-01

    The pathogen Batrachochytrium dendrobatidis (Bd) has been associated with amphibian declines in multiple continents, including western North America. We investigated Bd prevalence in Oregon spotted frog (Rana pretiosa), a species that has declined across its range in the Pacific Northwest. Polymerase chain reaction analysis of skin swabs indicated that Bd was prevalent within populations (420 of 617 juvenile and adults) and widespread among populations (36 of 36 sites) where we sampled R. pretiosa in Oregon and Washington. We rarely detected Bd in R. pretiosa larvae (2 of 72). Prevalence of Bd in postmetamorphic R. pretiosa was inversely related to frog size. We found support for an interactive effect of elevation and sampling date on Bd: prevalence of Bd generally increased with date, but this effect was more pronounced at lower elevations. We also found evidence that the body condition of juvenile R. pretiosa with Bd decreased after their first winter. Our data indicate that some Oregon spotted frog populations are currently persisting with relatively high Bd prevalence, but the risk posed by Bd is unknown. ?? 2010 International Association for Ecology and Health.

  1. Evolution of the functional properties of pyruvate kinase isozymes: pyruvate kinase L from Rana pipiens.

    PubMed

    Fournier, P; Guderley, H

    1986-01-01

    The regulatory properties of type L pyruvate kinase from Rana pipiens are intermediate between those of the mammalian K and L isozymes. As with mammalian type L, the levels of the frog isozyme are affected by the animal's nutritional state. The mammalian and amphibian isozymes show similar sensitivities to fructose 1,6-bisphosphate activation and amino acid inhibition. By contrast, the frog L isozyme shares several properties of the K class: i.e. irreversible inactivation by oxidized glutathione and lack of response to a cyclic AMP stimulated phosphorylation. Furthermore, as for some mammalian K isozymes, frog type L shows a high PEP affinity and a low cooperativity of PEP binding. Insofar as the properties of this present day enzyme reflect those of its counterpart in the amphibian ancestor of higher vertebrates, our results suggest that at its first expression, the type L resembled the type K. Many important regulatory properties of the L isozyme, especially the sensitivity to phosphorylation, were acquired more recently perhaps in association with an increased importance of constant blood glucose. PMID:3489743

  2. Receptor-Mediated Endocytosis of Lysozyme in Renal Proximal Tubules of the Frog Rana Temporaria

    PubMed Central

    Seliverstova, E.V.

    2015-01-01

    The mechanism of protein reabsorption in the kidney of lower vertebrates remains insufficiently investigated in spite of raising interest to the amphibian and fish kidneys as a useful model for physiological and pathophysiological examinations. In the present study, we examined the renal tubular uptake and the internalization rote of lysozyme after its intravenous injection in the wintering frog Rana temporaria using immunohisto- and immunocytochemistry and specific markers for some endocytic compartments. The distinct expression of megalin and cubilin in the proximal tubule cells of lysozyme-injected frogs was revealed whereas kidney tissue of control animals showed no positive immunoreactivity. Lysozyme was detected in the apical endocytic compartment of the tubular cells and colocalized with clathrin 10 min after injection. After 20 min, lysozyme was located in the subapical compartment negative to clathrin (endo-somes), and intracellular trafficking of lysozyme was coincided with the distribution of megalin and cubilin. However, internalized protein was retained in the endosomes and did not reach lysosomes within 30 min after treatment that may indicate the inhibition of intra-cellular trafficking in hibernating frogs. For the first time, we provided the evidence that lysozyme is filtered through the glomeruli and absorbed by receptor-mediated clathrin-dependent endocytosis in the frog proximal tubule cells. Thus, the protein uptake in the amphibian mesonephros is mediated by megalin and cubilin that confirms a critical role of endocytic receptors in the renal reabsorption of proteins in amphibians as in mammals. PMID:26150156

  3. Interactions between the subunits of transducin and cyclic GMP phosphodiesterase in Rana catesbiana rod photoreceptors.

    PubMed

    Yamazaki, A; Hayashi, F; Tatsumi, M; Bitensky, M W; George, J S

    1990-07-15

    In bullfrog (Rana catesbiana) rods the activity of cyclic GMP (cGMP) phosphodiesterase was stimulated 10 times by washing disc membranes with an isotonic, GTP-containing buffer. This stimulation was maintained following hydrolysis of GTP and after removal of guanine nucleotides. At least 60-70% of the inhibitory gamma subunit of cGMP phosphodiesterase (P gamma) was physically released from membranes by these washing procedures. When cGMP phosphodiesterase was activated by a hydrolysis-resistant GTP analogue, P gamma was found in the supernatant complexed with the transducin alpha subunit (T alpha) using three chromatography systems. When GTP was used to activate cGMP phosphodiesterase, P gamma was also found in the supernatant complexed with GDP.T alpha. This complex was also isolated using the same three chromatography systems, indicating that P gamma remained tightly bound to T alpha even after bound GTP was hydrolyzed. Interaction with the beta,gamma subunits of transducin, which remained associated with disc membranes, was required for the release of P gamma from the GDP.T alpha complex, which resulted in the deactivation of active cGMP phosphodiesterase. We conclude that during activation of cGMP phosphodiesterase, P gamma is complexed with T alpha (both GTP and GDP forms) in the supernatant and that, following GTP hydrolysis, beta,gamma subunits of transducin are necessary for the release of P gamma from the complex and the resulting inactivation of cGMP phosphodiesterase in frog photoreceptors. PMID:2164007

  4. Infestation of Wild-caught American Bullfrogs (Rana catesbeiana) by Multiple Species of Metazoan Parasites

    PubMed Central

    Lemke, Laura B; Dronen, Norman; Fox, James G; Nambiar, Prashant R

    2008-01-01

    The American bullfrog (Rana catesbeiana) is an aquatic, carnivorous member of the family Ranidae that is used extensively in physiology education programs and in various physiology, toxicology, sensorineural, and genetics research. Eleven bullfrogs purchased from a vendor distributing wild-caught frogs for use in a physiology research protocol were emaciated but otherwise showed no apparent clinical signs of illness. Necropsies performed on selected emaciated frogs indicated heavy infestation with multiple species of endoparasites. Identified helminths included Gorgodera amplicava, Haematolechus breviplexus, Clinostomum spp, Contracaecum spp, Cosmocercoides dukae, and Eustrongyloides spp. Grossly, parasitized bullfrogs showed encysted trematode larvae within skeletal muscle, nematode impaction of the intestinal tract, and lack of coelemic fat stores. Histopathologic lesions were restricted primarily to the gastrointestinal tract and consisted of parasitic granulomas associated with Contracaecum spp. The parasitic lesions may have been associated with the poor body condition of the bullfrogs. Food crickets maintained in-house were negative for parasite larvae or ova. Heavy parasitism of wild-caught bullfrogs may confound research protocols and markedly impair animal health. We encourage researchers to purchase laboratory-bred and -reared bullfrogs and to routinely monitor the parasite status of colony frogs. PMID:18459712

  5. Plasma pharmacokinetics of selamectin after a single topical administration in the American bullfrog (Rana catesbeiana).

    PubMed

    D'Agostino, Jennifer J; West, Gary; Boothe, Dawn M; Jayanna, Prashanth K; Snider, Timothy; Hoover, John P

    2007-03-01

    Parasitism is common in wild and captive amphibians; however, pharmacologic data are lacking for anthelmintic drugs. This study was developed to determine the plasma pharmacokinetics of selamectin after topical administration in bullfrogs. Thirty-two adult American bullfrogs (Rana catesbeiana) were randomly assigned into eight groups of four with each group representing a different collection time point. Seven groups received selamectin (6 mg/ kg) topically and the remaining group served as the untreated control group. One group of frogs was euthanized and blood samples immediately collected on days 0 (control), 1, 5, 10, 15, 20, 25, and 30. Plasma was analyzed for selamectin using high performance liquid chromatography with fluorescence detection. Individual samples were analyzed, then data were reported as the mean of the four frogs at each time point. A histologic evaluation of the lung, liver, kidney, and skin tissues was performed and none of the frogs showed histologic evidence of toxicity due to selamectin administration. The mean peak plasma concentration was 162.5 +/- 42.3 ng/ml, area under the curve was 2,856 ng day/ml, mean residence time was 12.2 days, and disappearance half-life was 1.87 days. Based on the plasma pharmacokinetics, bullfrogs appear to absorb selamectin very efficiently, concentrations reach high levels in the plasma, and there were no apparent histologic effects from single dose administration. PMID:17469275

  6. Glycan-binding profile and cell adhesion activity of American bullfrog (Rana catesbeiana) oocyte galectin-1.

    PubMed

    Kawsar, Sarkar M A; Matsumoto, Ryo; Fujii, Yuki; Yasumitsu, Hidetaro; Uchiyama, Hideho; Hosono, Masahiro; Nitta, Kazuo; Hamako, Jiharu; Matsui, Taei; Kojima, Noriaki; Ozeki, Yasuhiro

    2009-01-01

    The glycan-binding profile of a beta-galactoside-binding 15 kDa lectin (Galectin-1) purified from the oocytes of the American bullfrog, Rana catesbeiana, was studied using 61 pyridyl-aminated oligosaccharides by frontal affinity chromatography. Human blood type-A-hexasaccharide (GalNAcalpha1-3(Fucalpha1-2)Galbeta;1-4GlcNAcbeta1-4Galbeta1-4Glc) was found to exhibit the strongest ligand binding to the galectin while Forssman antigen (GalNAcalpha1-3GalNAcbeta1-3Galalpha1-4Galbeta1-4Glc) and type-A-tetrasaccharide (GalNAcalpha1-3(Fucalpha1-2)Galbeta1-4GlcNAcbeta1-4Glc) were also extensively recognized. The kinetics of affinity of galectin-1 to type-A oligosaccharide was analysed by surface plasmon resonance using neoglycoprotein with type-A oligosaccharides. R. catesbeiana oocyte galectin adhered to human rhabdomyosarcoma cells dose dependently and the activity was specifically cancelled by the neoglycoprotein. It was concluded that galectin-1 from R. catesbeiana oocytes possesses different and rare glycan-binding properties from typical members in galectin family. PMID:19519529

  7. Infestation of wild-caught American bullfrogs (Rana catesbeiana) by multiple species of metazoan parasites.

    PubMed

    Lemke, Laura B; Dronen, Norman; Fox, James G; Nambiar, Prashant R

    2008-05-01

    The American bullfrog (Rana catesbeiana) is an aquatic, carnivorous member of the family Ranidae that is used extensively in physiology education programs and in various physiology, toxicology, sensorineural, and genetics research. Eleven bullfrogs purchased from a vendor distributing wild-caught frogs for use in a physiology research protocol were emaciated but otherwise showed no apparent clinical signs of illness. Necropsies performed on selected emaciated frogs indicated heavy infestation with multiple species of endoparasites. Identified helminths included Gorgodera amplicava, Haematolechus breviplexus, Clinostomum spp, Contracaecum spp, Cosmocercoides dukae, and Eustrongyloides spp. Grossly, parasitized bullfrogs showed encysted trematode larvae within skeletal muscle, nematode impaction of the intestinal tract, and lack of coelemic fat stores. Histopathologic lesions were restricted primarily to the gastrointestinal tract and consisted of parasitic granulomas associated with Contracaecum spp. The parasitic lesions may have been associated with the poor body condition of the bullfrogs. Food crickets maintained in-house were negative for parasite larvae or ova. Heavy parasitism of wild-caught bullfrogs may confound research protocols and markedly impair animal health. We encourage researchers to purchase laboratory-bred and -reared bullfrogs and to routinely monitor the parasite status of colony frogs. PMID:18459712

  8. Efficacy of potential chemical control compounds for removing invasive American bullfrogs (Rana catesbeiana).

    PubMed

    Witmer, Gary W; Snow, Nathan P; Moulton, Rachael S

    2015-01-01

    Invasive American bullfrogs [Rana catesbeiana (Lithobates catesbeianus)] are outcompeting and predating on native biota and contributing to reductions in biodiversity worldwide. Current methods for controlling American bullfrogs are incapable of stopping their expansion, thus more cost-effective and broadly applicable methods are needed. Although chemical control compounds have been identified as effective for removing other invasive amphibians, none have been tested for American bullfrogs. Our objective was to expand on previous research and test the efficacy of 10 potential chemical control compounds for removing invasive American bullfrogs. After a dermal spray-application of 4 ml, we found 3 compounds (i.e., chloroxylenol, rotenone with permethrin, and caffeine) at 5-10 % concentrations in water were 100 % lethal for adult American bullfrogs. Chloroxylenol and rotenone with permethrin were fast acting with time-to-death <2 h. This research presents a first-step toward incorporating chemical control as part of integrated pest management strategy for controlling invasive American bullfrogs. Follow-up studies on delivery systems and reducing non-target hazards should ensue with these compounds to confirm their effectiveness and safety for removing invasive American bullfrogs. PMID:26389022

  9. Growth of the pectoral girdle of the Leopard frog, Rana pipiens (Anura: Ranidae).

    PubMed

    Shearman, Rebecca M

    2005-04-01

    This article describes the growth of the anuran pectoral girdle of Rana pipiens and compares skeletal development of the shoulder to that of long bones. The pectoral girdle chondrifies as two halves, each adjacent to a developing humerus. In each, the scapula and coracoid form as single foci of condensed chondrocytes that fuse, creating a cartilaginous glenoid bridge articulating with the humerus. Based on histological sections, both the dermal clavicle and cleithrum begin to ossify at approximately the same time as the periosteum forms around the endochondral bones. The dermal and endochondral bones of the girdle form immobile joints with neighboring girdle elements; however, the cellular organization and growth pattern of the scapula and coracoid closely resemble those of a long bone. Similar to a long bone epiphysis, distal margins of both endochondral elements have zones of hyaline, stratified, and hypertrophic cartilages. As a result, fused elements of the girdle can grow without altering the glenoid articulation with the humerus. Comparisons of anuran long bone and pectoral girdle growth suggest that different bones can have similar histology and development regardless of adult morphology.

  10. Comparison of nitrate tolerance between different populations of the common frog, Rana temporaria.

    PubMed

    Johansson, M; Räsänen, K; Merilä, J

    2001-09-01

    Euthrophication-associated changes in the physical and biological environment of lakes and ponds are potentially a source of major stress for many aquatic organisms. In Scandinavia, the nitrate concentrations in lakes and ponds decrease towards north due to a naturally lower productivity of the habitats, but also due to lower supplementation of anthropogenic nitrogen. A chronic experiment using ecologically relevant concentrations of sodium nitrate (0-5000 micro gl(-1)) was used to test whether common frog (Rana temporaria L.) larvae from northern parts of Scandinavia are less well adapted to cope with high nitrate concentrations than those from the southern parts. Slight, but significant differences in nitrate tolerance, as measured in terms of growth rate and size at metamorphosis, between the two regions were found. High concentrations of nitrate reduced the growth rates and metamorphic size in north, but not in south. However, there was no clear-cut impact of high nitrate concentrations on developmental rate or on mortality until metamorphosis. The general lack of large effects of nitrate treatment on the response variables suggests that nitrates per se do not pose any significant threat to the development of R. temporaria tadpoles under a natural range of concentrations. This was confirmed in an acute test where results suggest that ammonia and nitrite, compounds seldom found in high concentrations in Fennoscandian lakes, are possibly responsible for the larger negative effects of "nitrate" observed in previous studies of amphibians.

  11. Characterization of antimicrobial peptides isolated from the skin of the Chinese frog, Rana dybowskii.

    PubMed

    Jin, Li-Li; Li, Qiang; Song, Shu-Sen; Feng, Kai; Zhang, Dian-Bao; Wang, Qiu-Yu; Chen, Yu-Hua

    2009-10-01

    The skins of amphibians secrete small antimicrobial peptides that fight infection and are being explored as potential alternatives to conventional antibiotics. In this study we combined mass spectrometry with cDNA sequencing to examine antimicrobial peptides in skin secretions from the Chinese frog Rana dybowskii. Thirteen peptides having precursor sequences that resemble known antimicrobial peptides from this genus were identified, ten of which were members of previously described peptide families based on their primary structures; i.e., brevinin-1, Japonicin-1, brevinin-2 and temporin. The other three peptides from R. dybowskii, which were named dybowskin-1CDYa, dybowskin-2 CDYa and dybowskin-2CDYb, had different amino acid compositions and little sequence similarity to known antimicrobial peptides. The carboxyl terminus of dybowskin-1CDY lacked amidation and is therefore clearly distinct from temporin peptides, whereas dybowskin-2CDYa and dybowskin-2CDYb consisted of 18 amino acids and were rich in Arg residues. Chemically synthesized peptides corresponding to mature dybowskin-1CDYa and dybowskin-2CDYa had strong antimicrobial activity and caused little hemolysis of human erythrocytes, suggesting they may serve as interesting templates for the development of novel antibiotics. PMID:19539775

  12. Interactions between chensinin-1, a natural antimicrobial peptide derived from Rana chensinensis, and lipopolysaccharide.

    PubMed

    Dong, Weibing; Sun, Yue; Shang, Dejing

    2015-12-01

    Lipopolysaccharide (LPS) plays a critical role in the pathogenesis of sepsis caused by gram-negative bacterial infections. Therefore, LPS-neutralizing molecules would have important clinical applications. Chensinin-1, a novel antimicrobial peptide with atypical structural features, was found in the skin secretions of the Chinese brown frog Rana chensinensis. To understand the role of LPS in the bacterial susceptibility to chensinin-1 and to investigate its anti-endotoxin effects, the interactions of chensinin-1 with LPS were investigated in this study using circular dichroism, in situ IR, isothermal titration calorimetry, and zeta potential. This study is the first to use in situ IR spectroscopy to evaluate the secondary structural changes of this peptide. The capacity of chensinin-1 to block the LPS-dependent cytokine secretion of macrophages was also investigated. Our results show that chensinin-1 can form α-helical structures in LPS suspensions. LPS can affect the antimicrobial activity of chensinin-1, and chensinin-1 was able to mitigate the effects of LPS. These data may facilitate the development of antimicrobial peptides with potent antimicrobial and anti-endotoxin activities. PMID:26340228

  13. Is body size of the water frog Rana esculenta complex responding to climate change?

    NASA Astrophysics Data System (ADS)

    Tryjanowski, Piotr; Sparks, Tim; Rybacki, Mariusz; Berger, Leszek

    2006-03-01

    Recent studies on climate responses in ectothermic (cold-blooded) vertebrates have been few in number and focussed on phenology rather than morphology. According to Bergmann’s rule, endothermic (warm-blooded) vertebrates from cooler climates tend to be larger than congeners from warmer regions. Although amphibians are ectothermic vertebrates, weather and climatic conditions may also impact on their morphology, and thereby affect their survival rates and population dynamics. In this paper, we show, in a unique long-term study during the period 1963-2003 in an agricultural landscape in western Poland, that the body length of two water frog parental species (males of both Rana ridibunda and R. lessonae) increased significantly. However, their hybridogenetic hybrid R. esculenta did not show similar changes. A significant relationship with a large-scale climatic factor, the winter North Atlantic Oscillation index, was found positive for R. ridibunda males and R. lessonae females, and negative for R. esculenta females. Our findings, the first for amphibians, are consistent with other studies reporting that recent climate change has affected the morphology of animals. However, we also show that changes in amphibian phenotype linked to climate may vary independently between (even very similar) species.

  14. Yolk granules are the major compartment for bullfrog (Rana catesbeiana) oocyte-specific ribonuclease.

    PubMed

    Liao, Y D; Wang, J J

    1994-05-15

    Rana catesbeiana ribonuclease (RC-RNase) is a pyrimidine guanine sequence-specific ribonuclease found only in R. catesbeiana (bullfrog) oocytes, not in other organs. An immunohistochemical assay showed that RC-RNase was present in the regular yolk granules, but not in forming yolk granules, yolk platelets, pigment granules, mitochondria clouds or the nucleus. The RC-RNase was restricted to the lateral amorphous area of the yolk granules, and was absent from the central area that has a vitellogenin crystal lattice. The RC-RNase was extracted from yolk granules by 0.5 M NaCl and purified by dialysis and affinity chromatography. Most of the RC-RNase (94%) was found in the yolk granules, the rest RC-RNase (6%) was found in the cytosol in the form of free RNase and latent RNase. The RC-RNase extracted from yolk granules was further analyzed by immunoprecipitation and RNase activity assay on an SDS/polyacrylamide gel. Our results suggest that the RC-RNase activity is regulated by both compartmentation and inhibitor binding.

  15. Growth and development of larval green frogs (Rana clamitans) exposed to multiple doses of an insecticide

    USGS Publications Warehouse

    Boone, M.D.; Bridges, C.M.; Rothermel, B.B.

    2001-01-01

    Our objective was to determine how green frogs (Rana clamitans) are affected by multiple exposures to a sublethal level of the carbamate insecticide, carbaryl, in outdoor ponds. Tadpoles were added to 1,000-1 ponds at a low or high density which were exposed to carbaryl 0, 1, 2, or 3 times. Length of the larval period, mass, developmental stage, tadpole survival, and proportion metamorphosed were used to determine treatment effects. The frequency of dosing affected the proportion of green frogs that reached metamorphosis and the developmental stage of tadpoles. Generally, exposure to carbaryl increased rates of metamorphosis and development. The effect of the frequency of carbaryl exposure on development varied with the density treatment; the majority of metamorphs and the most developed tadpoles came from high-density ponds exposed to carbaryl 3 times. This interaction suggests that exposure to carbaryl later in the larval period stimulated metamorphosis, directly or indirectly, under high-density conditions. Our study indicates that exposure to a contaminant can lead to early initiation of metamorphosis and that natural biotic factors can mediate the effects of a contaminant in the environment.

  16. Effects of carbaryl on green frog (Rana clamitans) tadpoles: Timing of exposure versus multiple exposures

    USGS Publications Warehouse

    Boone, M.D.; Bridges, C.M.

    2003-01-01

    The majority of studies on pesticide impacts have evaluated the effects of single exposures. However, multiple exposures to a pesticide may be more prevalent. The objective of our study was to determine how multiple exposures versus single exposure at different times during development affected survival to metamorphosis, tadpole survival, tadpole mass, and tadpole developmental stage of green frog (Rana clamitans) tadpoles reared at low and high density in outdoor cattle tank ponds. Tadpoles were exposed to carbaryl zero, one, two, or three times at 14-d intervals. We applied single doses of carbaryl at one of three times, specifically during early, mid, or late development. Overall, we found that multiple exposures had a greater impact than single exposures during development. More individuals reached metamorphosis in ponds exposed to multiple doses of carbaryl compared with controls, indicating that the presence of carbaryl stimulated metamorphosis. The presence of carbaryl in the aquatic environment also resulted in more developed tadpoles compared with controls. Tadpoles in control ponds did not reach metamorphosis and were less developed than individuals exposed to carbaryl; this effect indicates that, under ideal conditions, green frogs could overwinter in ponds so that greater size could be attained before metamorphosis in the following spring or summer. Our study demonstrated the importance of including realistic application procedures when evaluating the effects of a pesticide and that multiple exposures to a short-lived pesticide are more likely to affect an amphibian population.

  17. Hepatotoxic and nephrotoxic effects of cadmium in the frog Rana ridibunda.

    PubMed

    Loumbourdis, Nikolaos S

    2005-08-01

    Histological and histochemical alterations in the liver and kidneys of the frog Rana ridibunda, which was exposed to 200 ppm aqueous solutions of cadmium for 4, 10 and 30 days, respectively were investigated. In both the liver and kidneys, essential changes appeared after 10 days' exposure, the maximum changes being apparent after 30 days of exposure. In the liver, what was very characteristic was an increase in the area occupied by Kupffer cells, with the area in the animals exposed to cadmium for 30 days being the largest observed. What was also apparent was karyomegaly, polyploidy and infiltration. In addition with regard the kidneys, Hyaline Globules (HG) and apoptotic bodies occurred at a higher rate. At 30 days' exposure, most of the above changes were enhanced. In comparison with 10 days' exposure, fibrosis around the blood vessels and between hepatocytes, as well as Proliferating Cell Nuclear Antigen (PCNA) reactivity and apoptotic bodies increased lightly in the liver. In the kidneys, the most pronounced changes were the increase in numbers of apoptotic bodies, PCNA reactivity and hyaline globules. It was concluded that the variability in positive reactions for various proteins in the hyaline globules may be an indication that these (and possibly other) proteins are synthesized by tumor cells, but, most probably, that they may represent liver damage, progressive nephropathy, or progressive glomerulonephropathy.

  18. The melanogenic system of the liver pigmented macrophages of Rana esculenta L.--tyrosinase activity.

    PubMed

    Gallone, A; Sagliano, A; Guida, G; Ito, S; Wakamatsu, K; Capozzi, V; Perna, G; Zanna, P; Cicero, R

    2007-10-01

    The enzyme system responsible for Amphibian Kupffer Cell (KC) melanogenesis has not been entirely elucidated. This research demonstrates that the KC melanosomes of Rana esculenta L. possess a tyrosine-hydroxylase (TH) activity, showing that a tyrosinase is the enzyme involved in the melanogenesis. The TH reaction depends on catalytic Dopa as a cofactor and is not affected by catalase or H2O2, showing that it is catalysed by the tyrosinase and not by the peroxidase present in the melanosomes. The TH reaction is activated by Cu2+ ions but not by other tyrosinase activators such as limited proteolysis, protein ageing, and Sodium Dodecyl Sulphate (SDS). SDS inhibited the KC TH activity even below the critical micelle concentration. All these results suggest that the KC-tyrosinase differs in structure from other known tyrosinases. Using anti-KC-tyrosinase antobodies, we observed that the sites of the tyrosinase location within the cell are the same as those described in the melanocytes. In the immunoblots, the anti-KC-tyrosinase antibodies also recognised two protein bands, at the higher molecular weight ranges, in the protein electrophoretic pattern. Moreover, the tyrosinase activity was limited to the highest molecular weight band of about 260 kDa, suggesting that the enzyme activity could depend on a molecular aggregate. The melanin produced in the liver was found to be a 5,6-dihydroxyindole-rich eumelanin similar to the Sepia melanin. PMID:17616933

  19. Directionality of the pressure-difference receiver ears in the northern leopard frog, Rana pipiens pipiens.

    PubMed

    Ho, Calvin C K; Narins, Peter M

    2006-04-01

    We studied the directional response of the coupled-eardrum system in the northern leopard frog, Rana pipiens pipiens. Eardrum behavior closely approximates a linear time-invariant system, with a highly correlated input-output relationship between the eardrum pressure difference and the eardrum velocity. Variations in the eardrum transfer function at frequencies below 800 Hz indicate the existence of an extratympanic sound transmission pathway which can interfere with eardrum motions. The eardrum velocity was shown to shift in phase as a function of sound incident angle, which was a direct result of the phase-shift of the eardrum pressure difference. We used two laser-Doppler vibrometers to measure the interaural vibration time difference (IVTD) and the interaural vibration amplitude difference (IVAD) between the motions of the two eardrums. The coupled-eardrum system enhanced the IVTD and IVAD by a factor of 3 and 3 dB, respectively, when compared to an isolated-eardrum system of the same size. Our findings are consistent with the time-delay sensitivity of other coupled-eardrum systems such as those found in crickets and flies.

  20. Infestation of wild-caught American bullfrogs (Rana catesbeiana) by multiple species of metazoan parasites.

    PubMed

    Lemke, Laura B; Dronen, Norman; Fox, James G; Nambiar, Prashant R

    2008-05-01

    The American bullfrog (Rana catesbeiana) is an aquatic, carnivorous member of the family Ranidae that is used extensively in physiology education programs and in various physiology, toxicology, sensorineural, and genetics research. Eleven bullfrogs purchased from a vendor distributing wild-caught frogs for use in a physiology research protocol were emaciated but otherwise showed no apparent clinical signs of illness. Necropsies performed on selected emaciated frogs indicated heavy infestation with multiple species of endoparasites. Identified helminths included Gorgodera amplicava, Haematolechus breviplexus, Clinostomum spp, Contracaecum spp, Cosmocercoides dukae, and Eustrongyloides spp. Grossly, parasitized bullfrogs showed encysted trematode larvae within skeletal muscle, nematode impaction of the intestinal tract, and lack of coelemic fat stores. Histopathologic lesions were restricted primarily to the gastrointestinal tract and consisted of parasitic granulomas associated with Contracaecum spp. The parasitic lesions may have been associated with the poor body condition of the bullfrogs. Food crickets maintained in-house were negative for parasite larvae or ova. Heavy parasitism of wild-caught bullfrogs may confound research protocols and markedly impair animal health. We encourage researchers to purchase laboratory-bred and -reared bullfrogs and to routinely monitor the parasite status of colony frogs.

  1. Population estimates for the Toiyabe population of the Columbia spotted frog (Rana luteiventris), 2004–10

    USGS Publications Warehouse

    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.

  2. Cytonuclear discordance and historical demography of two brown frogs, Rana tagoi and R. sakuraii (Amphibia: Ranidae).

    PubMed

    Eto, Koshiro; Matsui, Masafumi

    2014-10-01

    Prior studies of mitochondrial genomic variation reveal that the Japanese brown frog Rana tagoi comprises a complex of cryptic species lineages, and that R. sakuraii arose from within this complex. Neither species forms a monophyletic group on the mitochondrial haplotype tree, precluding a simple explanation for the evolutionary origins of R. sakuraii. We present a more complete sampling of mitochondrial haplotypic variation (from the ND1 and 16S genes) plus DNA sequence variation for five nuclear loci (from the genes encoding NCX1, NFIA, POMC, SLC8A3, and TYR) to resolve the evolutionary histories of these species. We test hypotheses of population assignment (STRUCTURE) and isolation-with-migration (IM) using the more slowly evolving nuclear markers. These demographic analyses of nuclear genetic variation confirm species-level distinctness and integrity of R. sakuraii despite its apparent polyphyly on the mitochondrial haplotype tree. Divergence-time estimates from both the mitochondrial haplotypes and nuclear genomic markers suggest that R. sakuraii originated approximately one million years ago, and that incomplete sorting of mitochondrial haplotype lineages best explains non-monophyly of R. sakuraii mitochondrial haplotypes. Cytonuclear discordance elsewhere in R. tagoi reveals a case of mitochondrial introgression between two species lineages on Honshu. The earliest phylogenetic divergence within this species group occurred approximately four million years ago, followed by cladogenetic events in the Pliocene and early Pleistocene yielding 10-13 extant species lineages, including R. sakuraii as one of the youngest.

  3. Non-specific immune response of bullfrog Rana catesbeiana to intraperitoneal injection of bacterium Aeromonas hydrophila

    NASA Astrophysics Data System (ADS)

    Zhang, Junjie; Zou, Wenzheng; Yan, Qingpi

    2008-08-01

    Non-specific immune response of bullfrog Rana catesbeiana to pathogenic Aeromonas hydrophila was studied to 60 individuals in two groups. Each bullfrog in bacterium-injected group was injected intraperitoneally (i.p.) with 0.2 ml bacterial suspension at a density of 5.2 × 106 CFU/ml, while each one in control group injected i.p. with 0.2 ml sterile saline solution (0.85%, w/v). Three bullfrogs in both groups were sampled at 0, 1, 3, 7, 11, 15 and 20 days post-injection (dpi) for the evaluation of non-specific immune parameters. It was observed that intraperitoneal injection of A. hydrophila significantly increased the number of leucocytes and that of NBT-positive cells in peripheral blood. Significant increases in serum bactericidal activity and serum acid phosphatase activity were also observed in the bacterium-injected frogs when compared with those in the control group. However, a significant reduction was detected in vitro in phagocytosis activity of peripheral blood phagocytes. No significant difference in changes in the number of peripheral erythrocytes, serum superoxide dismutase (SOD) activity, and lysozyme activity was detected between the two groups. It is suggested that bullfrogs may produce a series of non-specific immune reactions in response to the A. hydrophila infection.

  4. Cadmium-induced oxidative stress and apoptosis in the testes of frog Rana limnocharis.

    PubMed

    Zhang, Hangjun; Cai, Chenchen; Shi, Cailei; Cao, Hui; Han, Ziliu; Jia, Xiuying

    2012-10-15

    This study explored the genetic damage induced by cadmium exposure in the testes of Rana limnocharis. Healthy adult frogs were exposed to 2.5, 5, 7.5, or 10 mg/L of cadmium solution for 14 days. The results showed that exposure to these concentrations increased the levels of reactive oxygen species and malondialdehyde content in the testes, clearly indicating a dose-effect relationship. Moreover, the same dosages of Cd(2+) solution increased glutathione (reduced) content, with the values being significantly different from those observed in the control group (P<0.01). The comet assay results demonstrated that the DNA damage rate, tail length, and tail moment of samples obtained from frogs exposed to 2.5-7.5 mg/L of cadmium solution significantly increased compared with those of samples obtained from the control group (P<0.01). These findings suggest that cadmium can induce free radical generation, followed by lipid peroxidation and DNA damage. Ultrastructural observation revealed vacuoles in the spermatogenic cells, cell dispersion, incomplete cell structures, and deformed nucleoli. Moreover, cadmium exposure induced significant down-regulation of Bcl-2 expression and up-regulation of Bax and caspase-3 expressions. Taken together, these data indicate that cadmium can induce testicular cell apoptosis in R. limnocharis. Exploring the effects of cadmium on the mechanism of reproductive toxicity in amphibians will help provide a scientific basis accounting for the global population decline in amphibian species. PMID:22728207

  5. Distribution and innervation of putative arterial chemoreceptors in the bullfrog (Rana catesbeiana).

    PubMed

    Reyes, Catalina; Fong, Angelina Y; Brink, Dee L; Milsom, William K

    2014-11-01

    Peripheral arterial chemoreceptors have been located previously in the carotid labyrinth, the aortic arch, and the pulmocutaneous artery of frogs. In the present study we used cholera toxin B neuronal tract tracing and immunohistochemical markers for cholinergic cells (vesicular acetylcholine transporter [VAChT]), tyrosine hydroxylase (TH), and serotonin (5HT) to identify putative O2-sensing cells in Rana catesbeiana. We found potential O2-sensing cells in all three vascular areas innervated by branches of the vagus nerve, whereas only cells in the carotid labyrinth were innervated by the glossopharyngeal nerve. Cells containing either 5HT or TH were found in all three sites, whereas cells containing both neurotransmitters were found only in the carotid labyrinth. Cell bodies containing VAChT were not found at any site. The morphology and innervation of putative O2-sensing cells were similar to those of glomus cells found in other vertebrates. The presence of 5HT- and TH-immunoreactive cells in the aorta, pulmocutaneous artery, and carotid labyrinth appears to reflect a phylogenetic transition between the major neurotransmitter seen in the putative O2-sensing cells of fish (5HT) and those found in the glomus cells of mammals (acetylcholine, adenosine, and catecholamines). PMID:24954002

  6. Isolation of ice-nucleating active bacteria from the freeze-tolerant frog, Rana sylvatica.

    PubMed

    Lee, M R; Lee, R E; Strong-Gunderson, J M; Minges, S R

    1995-08-01

    Ice-nucleating active (INA) bacteria were isolated from the gut of field-collected freeze-tolerant wood frogs (Rana sylvatica) collected in winter. Thirteen strains of Pseudomonas fluorescens, four strains of Pseudomonas putida, and two strains of Enterobacter agglomerans had ice-nucleating activity. Each of the INA pseudomonad strains was psychrophilic. P. putida strains were differentiated from P. fluorescens strains by gelatinase, lecithinase, and lipase production. The maximum nucleation temperatures (Tmax) of aqueous suspensions (10(9) bacteria/ml) of the four INA P. putida strains ranged from -1.6 to -3.0 degrees C, which places this INA species among the most potent known biological nucleators. Ingestion of INA P. putida isolated from R. sylvatica by another freeze-tolerant frog. Pseudacris crucifer, decreased the capacity of this frog to supercool and remain unfrozen at -2 degrees C. This is the first report of INA bacteria isolated from a vertebrate, and suggests that, as part of the gut flora in some posthibernation freeze-tolerant wood frogs, these bacteria may play a role in enhancing winter survival by promoting ice nucleation at high subzero temperatures (ca. -2 degrees C). PMID:7656570

  7. Large intestine bacterial flora of nonhibernating and hibernating leopard frogs (Rana pipiens).

    PubMed Central

    Gossling, J; Loesche, W J; Nace, G W

    1982-01-01

    The bacteria in the large intestines of 10 northern leopard frogs (Rana pipiens) were enumerated and partially characterized. Four nonhibernating frogs were collected in the summer, four hibernating frogs were collected in the winter, and two frogs just emerged from hibernation were collected in the spring. All frogs had about 10(10) bacteria per g (wet weight) of intestinal contents and about 10(9) bacteria per g (wet weight) of mucosal scraping, although the counts from the winter frogs were slightly less than those from the other two groups of frogs. Another group of 14 summer frogs, after treatment to induce hibernation, showed a drop in bacterial counts accompanied by a change in the composition of the flora. In most frogs, Bacteroides was the dominant organism. Other bacteria repeatedly isolated at high dilutions were strict anaerobes, including butyrigenic and acetogenic helically coiled bacteria; fusobacteria; and acetogenic, small, gram-positive bacilli. These data indicate that the intestinal flora of frogs is similar to that of mammals and birds and that this flora can be maintained at temperatures close to freezing. PMID:6982025

  8. Plasma pharmacokinetics of selamectin after a single topical administration in the American bullfrog (Rana catesbeiana).

    PubMed

    D'Agostino, Jennifer J; West, Gary; Boothe, Dawn M; Jayanna, Prashanth K; Snider, Timothy; Hoover, John P

    2007-03-01

    Parasitism is common in wild and captive amphibians; however, pharmacologic data are lacking for anthelmintic drugs. This study was developed to determine the plasma pharmacokinetics of selamectin after topical administration in bullfrogs. Thirty-two adult American bullfrogs (Rana catesbeiana) were randomly assigned into eight groups of four with each group representing a different collection time point. Seven groups received selamectin (6 mg/ kg) topically and the remaining group served as the untreated control group. One group of frogs was euthanized and blood samples immediately collected on days 0 (control), 1, 5, 10, 15, 20, 25, and 30. Plasma was analyzed for selamectin using high performance liquid chromatography with fluorescence detection. Individual samples were analyzed, then data were reported as the mean of the four frogs at each time point. A histologic evaluation of the lung, liver, kidney, and skin tissues was performed and none of the frogs showed histologic evidence of toxicity due to selamectin administration. The mean peak plasma concentration was 162.5 +/- 42.3 ng/ml, area under the curve was 2,856 ng day/ml, mean residence time was 12.2 days, and disappearance half-life was 1.87 days. Based on the plasma pharmacokinetics, bullfrogs appear to absorb selamectin very efficiently, concentrations reach high levels in the plasma, and there were no apparent histologic effects from single dose administration.

  9. Adrenergic receptors and the regulation of vascular resistance in bullfrog tadpoles (Rana catesbeiana).

    PubMed

    Kimmel, P B

    1992-01-01

    Vascular adrenergic sensitivity to exogenous catecholamines was examined in tadpoles of the American bullfrog (Rana catesbeiana), ranging from stage III to XIV. Central arterial blood pressure was measured in decerebrate bullfrog tadpoles to determine a reasonable initial infusion pressure. Solutions of epinephrine and phenylephrine were infused into the vasculature of pithed tadpoles, and the resulting changes in vascular resistance (Rv) were used to construct log dose-response relationships. Epinephrine infusion produced a dose-dependent increase in Rv (EC50 = 5.3 x 10(-7) M), which could be reversed by sodium nitroprusside (a smooth muscle relaxant) and blocked by phenoxybenzamine (an alpha-adrenergic antagonist). Larval Rv also increased with infusion of the alpha-agonist phenylephrine (EC50 = 7.4 x 10(-8) M). Infusion of 10(-6) M isoproterenol (a beta-agonist) largely reversed the phenylephrine-induced increase in Rv. These results indicate that the capacity exists for both alpha-mediated vasoconstriction and beta-mediated vasodilation early in bullfrog ontogeny. Neither initial Rv nor the responses to infused epinephrine or phenylephrine were significantly correlated to development over the range of larval stages used in this study.

  10. Mechanical leverage in the middle ear of the American bullfrog, Rana catesbeiana.

    PubMed

    Werner, Yehudah L

    2003-01-01

    Textbooks lump the middle ears of 'submammalian Tetrapoda' as being 'one-ossicle ears'. Conventionally the anuran middle ear is depicted with a shaft-like skeletal unit connecting the tympanic membrane to the inner ear. This shaft comprises mediad a long bony columella and laterad a short cartilaginous extracolumella. But dissection of Rana catesbeiana ears showed: the extracolumella, as long as the columella, is proximally expanded in the vertical plane, forming dorsal and ventral heads. The medio-dorsal head is movably jointed to the columella, between these two there is an obtuse angle ventrad; the extracolumellar medio-ventral head is anchored by a ligament to the middle-ear cavity ceiling. When the tympanic membrane moves outwards, pulling the extracolumella, the medio-dorsal head of the extracolumella must be forced inwards, rotating on the ventral anchorage, pushing the columella towards the inner ear. The ossicular chain thus includes a mechanical lever, possessing the magnitude of the ratio length:width of the extracolumella; this is additional to the lever known from the columellar footplate, which rotates on its firm ventral attachment. These levers are confirmed physiologically, by the difference between the inner-ear sensitivity (shown by isopotential audiograms of microphonic potentials) when stimulated by a vibrator first at the tympanic membrane, then at the proximal stump of the amputated columella. Perusal of the primary literature showed that this morphology is widespread among anuran ears.

  11. Molecular chaperone function of the Rana catesbeiana small heat shock protein, hsp30.

    PubMed

    Kaldis, Angelo; Atkinson, Burr G; Heikkila, John J

    2004-10-01

    Eukaryotic small heat shock proteins (shps) act as molecular chaperones by binding to denaturing proteins, preventing their heat-induced aggregation and maintaining their solubility until they can be refolded back to their normal state by other chaperones. In this study we report on the functional characterization of a developmentally regulated shsp, hsp30, from the American bullfrog, Rana catesbeiana. An expression vector containing the open reading frame of the hsp30 gene was expressed in Escherichia coli. Purified recombinant hsp30 was recovered as multimeric complexes and was composed of a mixture of alpha-helical and beta-sheet-like structures as determined by circular dichroism analysis. Hsp30 displayed chaperone activity since it inhibited heat-induced aggregation of citrate synthase. Furthermore hsp30 maintained heat-treated luciferase in a folding competent state. For example, heat denatured luciferase when microinjected into Xenopus oocytes did not regain enzyme activity whereas luciferase heat denatured with hsp30 regained 100% enzyme activity. Finally, hsp30 protected the DNA restriction endonuclease, PstI, from heat inactivation. PstI incubated alone at 42 degrees C lost its enzymatic function after 1 h whereas PstI supplemented with hsp30 accurately digested plasmid DNA after 4 h at the elevated temperature. These results clearly indicate a molecular chaperone role for R. catesbeiana hsp30.

  12. Respiratory pattern formation in the isolated bullfrog (Rana catesbeiana) brainstem-spinal cord.

    PubMed

    Reid, S G; Milsom, W K

    1998-12-01

    This study characterizes various patterns of motor output obtained from cranial nerves V, VII, X, and XII of in vitro, saline-perfused, brainstem-spinal cord preparations of the American bullfrog (Rana catesbeiana). Motor output indicative of fictive breathing was present in all preparations. In 17 of 26 preparations, fictive breaths were either evenly spaced or randomly distributed, while in the remaining nine preparations fictive breaths occurred in episodes separated by relatively long periods of quiescence. With the exception of fictive breath duration in the non-episodic preparations and the instantaneous frequency of fictive breaths within episodes, all variables associated with fictive breathing were insensitive to changes in perfusion saline pH. In addition to fictive breathing, a large number of other forms of motor output were observed arising from these nerves. While the data suggest that the in vitro preparation is capable of producing a wide repertoire of motor patterns, similar to those seen in vivo, it was difficult, with the current protocol, to reliably produce any single pattern in spite of carefully regulated conditions.

  13. Efficacy of potential chemical control compounds for removing invasive American bullfrogs (Rana catesbeiana).

    PubMed

    Witmer, Gary W; Snow, Nathan P; Moulton, Rachael S

    2015-01-01

    Invasive American bullfrogs [Rana catesbeiana (Lithobates catesbeianus)] are outcompeting and predating on native biota and contributing to reductions in biodiversity worldwide. Current methods for controlling American bullfrogs are incapable of stopping their expansion, thus more cost-effective and broadly applicable methods are needed. Although chemical control compounds have been identified as effective for removing other invasive amphibians, none have been tested for American bullfrogs. Our objective was to expand on previous research and test the efficacy of 10 potential chemical control compounds for removing invasive American bullfrogs. After a dermal spray-application of 4 ml, we found 3 compounds (i.e., chloroxylenol, rotenone with permethrin, and caffeine) at 5-10 % concentrations in water were 100 % lethal for adult American bullfrogs. Chloroxylenol and rotenone with permethrin were fast acting with time-to-death <2 h. This research presents a first-step toward incorporating chemical control as part of integrated pest management strategy for controlling invasive American bullfrogs. Follow-up studies on delivery systems and reducing non-target hazards should ensue with these compounds to confirm their effectiveness and safety for removing invasive American bullfrogs.

  14. Glycan-binding profile and cell adhesion activity of American bullfrog (Rana catesbeiana) oocyte galectin-1.

    PubMed

    Kawsar, Sarkar M A; Matsumoto, Ryo; Fujii, Yuki; Yasumitsu, Hidetaro; Uchiyama, Hideho; Hosono, Masahiro; Nitta, Kazuo; Hamako, Jiharu; Matsui, Taei; Kojima, Noriaki; Ozeki, Yasuhiro

    2009-01-01

    The glycan-binding profile of a beta-galactoside-binding 15 kDa lectin (Galectin-1) purified from the oocytes of the American bullfrog, Rana catesbeiana, was studied using 61 pyridyl-aminated oligosaccharides by frontal affinity chromatography. Human blood type-A-hexasaccharide (GalNAcalpha1-3(Fucalpha1-2)Galbeta;1-4GlcNAcbeta1-4Galbeta1-4Glc) was found to exhibit the strongest ligand binding to the galectin while Forssman antigen (GalNAcalpha1-3GalNAcbeta1-3Galalpha1-4Galbeta1-4Glc) and type-A-tetrasaccharide (GalNAcalpha1-3(Fucalpha1-2)Galbeta1-4GlcNAcbeta1-4Glc) were also extensively recognized. The kinetics of affinity of galectin-1 to type-A oligosaccharide was analysed by surface plasmon resonance using neoglycoprotein with type-A oligosaccharides. R. catesbeiana oocyte galectin adhered to human rhabdomyosarcoma cells dose dependently and the activity was specifically cancelled by the neoglycoprotein. It was concluded that galectin-1 from R. catesbeiana oocytes possesses different and rare glycan-binding properties from typical members in galectin family.

  15. Immunochemical and immunohistochemical studies of cadmium associated proteins in Rana tadpoles.

    PubMed

    Zettergren, L D; Conrad, C A; Petering, D H; Weber, D N; Goodrich, M S

    1991-12-01

    Previous observations suggested that Rana tadpoles treated with aqueous cadmium (Cd) accumulate Cd in their liver and mesonephros. In order to study the response to Cd in these tissues we (a) exposed tadpoles in mid-limb bud stages to sublethal quantities of Cd, (b) isolated Cd-associated protein (CAP) from a liver cytosol fraction, (c) prepared a heterologous rabbit antiserum against glutaraldehyde-treated CAP (G-CAP), (d) used the rabbit anti-G-CAP antiserum in order to assess the tissue distribution of CAP in Cd-treated and untreated tadpoles, and (e) assessed species cross-reactivities of our anti-G-CAP with CAPs and metallothioneins (MTs) isolated from Cd-treated vertebrate liver cytosol fractions. We found that (a) CAP was present in higher quantities in liver cytosol obtained from Cd-treated tadpoles compared to liver cytosol obtained from untreated control tadpoles, (b) indirect immunofluorescent analysis revealed that CAP was localized in liver hepatocytes and kidney tubule epithelial cells in Cd-treated tadpoles, and (c) the anti-G-CAP crossreacted with rodent and fish CAP. These observations suggest that the developing liver and mesonephros are involved in responses to toxic metals and that our anti G-CAP antiserum may be used to gauge exposure to environmental Cd.

  16. Distribution and innervation of putative arterial chemoreceptors in the bullfrog (Rana catesbeiana).

    PubMed

    Reyes, Catalina; Fong, Angelina Y; Brink, Dee L; Milsom, William K

    2014-11-01

    Peripheral arterial chemoreceptors have been located previously in the carotid labyrinth, the aortic arch, and the pulmocutaneous artery of frogs. In the present study we used cholera toxin B neuronal tract tracing and immunohistochemical markers for cholinergic cells (vesicular acetylcholine transporter [VAChT]), tyrosine hydroxylase (TH), and serotonin (5HT) to identify putative O2-sensing cells in Rana catesbeiana. We found potential O2-sensing cells in all three vascular areas innervated by branches of the vagus nerve, whereas only cells in the carotid labyrinth were innervated by the glossopharyngeal nerve. Cells containing either 5HT or TH were found in all three sites, whereas cells containing both neurotransmitters were found only in the carotid labyrinth. Cell bodies containing VAChT were not found at any site. The morphology and innervation of putative O2-sensing cells were similar to those of glomus cells found in other vertebrates. The presence of 5HT- and TH-immunoreactive cells in the aorta, pulmocutaneous artery, and carotid labyrinth appears to reflect a phylogenetic transition between the major neurotransmitter seen in the putative O2-sensing cells of fish (5HT) and those found in the glomus cells of mammals (acetylcholine, adenosine, and catecholamines).

  17. Differentiations of 5-HT and GAS cells in the digestive canals of Rana chensinensis tadpoles

    PubMed Central

    LI, Xin-Yi; LI, Qian; ZHANG, Yu-Hui

    2014-01-01

    In the current study, 5-nydroxytryptamine (5-HT) and gastrin (GAS) cells in the digestive canals of Rana chensinensis tadpoles at different developmental stages were investigated by immunohistochemistry. Results showed that the 5-HT cells were only detected in the duodenum before metamorphosis began, and were extensively distributed in the stomach, duodenum, small intestine, and rectum thereafter, with the highest counts found in the duodenum and rectum when metamorphosis was completed. The GAS cells were only distributed in the stomach and duodenum, and only rarely detected in the duodenum before metamorphosis began, but increased in the stomach during metamorphosis and showed zonal distribution in the gastric mucosa when metamorphosis was completed. Metamorphosis is a critical period for amphibians, during which structural and functional physiological adaptations are required to transition from aquatic to terrestrial environments. During metamorphosis, the differentiations of 5-HT cells in the gastrointestinal canals of tadpoles could facilitate mucus secretion regulation, improve digestive canal lubrication, and help watershortage food digestion in terrestrial environments. Conversely, GAS cell differentiations during metamorphosis might contribute to the digestive and absorptive function transition from herbivore to omnivore. PMID:25017753

  18. Characterization and antioxidant activity in vitro and in vivo of polysaccharide purified from Rana chensinensis skin.

    PubMed

    Wang, Zhanyong; Zhao, Yuanyuan; Su, Tingting; Zhang, Jing; Wang, Fei

    2015-08-01

    Preliminary characterization and antioxidant activity in vitro and in vivo investigation of the polysaccharide fraction named as RCSP II, which was extracted from Rana chensinensis skin, were performed. Results indicated that RCSP II comprised glucose, galactose, and mannose in a molar ratio of 87.82:2.77:1.54 with a molecular weight of 12.8 kDa. Antioxidant activity assay in vitro showed that RCSP II exhibited 75.2% scavenging activity against 2,2'-azino-bis(3-ethylbenz-thiazoline-6-sulfonic acid) radicals at the concentration of 2500 mg/L and 85.1% against chelated ferrous ion at 4000 mg/L. Antioxidant activity assay in vivo further showed that RCSP II increased the activities of antioxidant enzymes, decreased the levels of malondialodehyde, and enhanced total antioxidant capabilities in livers and sera of d-galactose induced mice. These results suggested that RCSP II could have potential antioxidant applications as medicine or functional food.

  19. California red-legged frog (Rana draytonii) movement and habitat use: Implications for conservation

    USGS Publications Warehouse

    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.

  20. Rana computatrix to human language: towards a computational neuroethology of language evolution.

    PubMed

    Arbib, Michael A

    2003-10-15

    Walter's Machina speculatrix inspired the name Rana computatrix for a family of models of visuomotor coordination in the frog, which contributed to the development of computational neuroethology. We offer here an 'evolutionary' perspective on models in the same tradition for rat, monkey and human. For rat, we show how the frog-like taxon affordance model provides a basis for the spatial navigation mechanisms that involve the hippocampus and other brain regions. For monkey, we recall two models of neural mechanisms for visuomotor coordination. The first, for saccades, shows how interactions between the parietal and frontal cortex augment superior colliculus seen as the homologue of frog tectum. The second, for grasping, continues the theme of parieto-frontal interactions, linking parietal affordances to motor schemas in premotor cortex. It further emphasizes the mirror system for grasping, in which neurons are active both when the monkey executes a specific grasp and when it observes a similar grasp executed by others. The model of human-brain mechanisms is based on the mirror-system hypothesis of the evolution of the language-ready brain, which sees the human Broca's area as an evolved extension of the mirror system for grasping. PMID:14599323

  1. Acid stress mediated adaptive divergence in ion channel function during embryogenesis in Rana arvalis

    PubMed Central

    Shu, Longfei; Laurila, Anssi; Räsänen, Katja

    2015-01-01

    Ion channels and pumps are responsible for ion flux in cells, and are key mechanisms mediating cellular function. Many environmental stressors, such as salinity and acidification, are known to severely disrupt ionic balance of organisms thereby challenging fitness of natural populations. Although ion channels can have several vital functions during early life-stages (e.g. embryogenesis), it is currently not known i) how developing embryos maintain proper intracellular conditions when exposed to environmental stress and ii) to what extent environmental stress can drive intra-specific divergence in ion channels. Here we studied the moor frog, Rana arvalis, from three divergent populations to investigate the role of different ion channels and pumps for embryonic survival under acid stress (pH 4 vs 7.5) and whether populations adapted to contrasting acidities differ in the relative role of different ion channel/pumps. We found that ion channels that mediate Ca2+ influx are essential for embryonic survival under acidic pH, and, intriguingly, that populations differ in calcium channel function. Our results suggest that adaptive divergence in embryonic acid stress tolerance of amphibians may in part be mediated by Ca2+ balance. We suggest that ion flux may mediate adaptive divergence of natural populations at early life-stages in the face of environmental stress. PMID:26381453

  2. Antimicrobial peptide defenses of the mountain yellow-legged frog (Rana muscosa).

    PubMed

    Rollins-Smith, Louise A; Woodhams, Douglas C; Reinert, Laura K; Vredenburg, Vance T; Briggs, Cheryl J; Nielsen, Per F; Conlon, J Michael

    2006-01-01

    The mountain yellow-legged frog (Rana muscosa) inhabits high elevation lakes in California that are largely undisturbed by human activities. In spite of this habitation in remote sites, populations continue to decline. Although predation by non-native fish is one cause for declines, some isolated populations in fishless lakes are suffering new declines. One possible cause of the current wave of declines is the introduction of the pathogenic chytrid fungus (Batrachochytrium dendrobatidis) which invades the adult skin to cause chytridiomycosis. In many amphibian species, the skin is protected by antimicrobial peptides secreted into the mucous. Here we show that R. muscosa produces three previously unknown antimicrobial peptides belonging to the ranatuerin-2 and temporin-1 families of antimicrobial peptides. These three peptides, along with bradykinin, are the most abundant peptides in the skin secretions detected by mass spectrometry. Natural mixtures of peptides and individual purified peptides strongly inhibit chytrid growth. The concentration of total peptides recovered from the skin of frogs following a mild norepinephrine induction is sufficient to inhibit chytrid growth in vitro. A comparison of the species susceptibility to chytridiomycosis and the antichytrid activity of peptides between R. muscosa and R. pipiens suggest that although R. muscosa produces more total skin peptides, it appears to be more vulnerable to B. dendrobatidis in nature. Possible differences in the antimicrobial peptide repertoires and life history traits of the two species that may account for differences in susceptibility are discussed.

  3. [Reabsorption of yellow fluorescent protein in the Rana temporaria kidney by receptor-mediated endocytosis].

    PubMed

    Seliverstova, E V; Prutskova, N P

    2014-01-01

    The absorption of yellow fluorescent protein (YFP) and the expression of the endocytic receptors, megalin and cubilin, were investigated in the renal proximal tubules (PT) in frogs Rana temporaria after parenteral YFP injections. The methods of confocal microscopy and immunohistochemistry were used. The dynamics of YFP absorption was analyzed 2 h after injection. The logarithmic time dependence of the accumulation of YFP-containing endocytic vesicles in PT cells and the completion of absorption process 90-120 min after injection were shown. Unlike substantial megalin and cubilin expression 15-30 min after YFP introduction, immunolabeled endocytic receptors were not detected in PT cells after 2 h. The re-injection of YFP led to the appearance of apical endocytic vesicles containing megalin or cubilin colocalized with YFP. At the same time, the decrease of YFP uptake associated with reduction in the number of receptor-containing vesicles was demonstrated, suggesting a failure of megalin and cubilin expression. The decrease of absorption capacity of PT cells after YFP re-injection was similar to that found previously under conditions of the competitive absorption of green fluorescent protein (GFP) and YFP injected in different sequences. The data are the further demonstration of the proposed mechanism limiting the tubular protein absorption in the frog kidney and suggest the involvement of megalin and cubilin in uptake and vesicular transport of YFP.

  4. Lethal and sublethal effects of chronic cadmium exposure on northern leopard frog (Rana pipiens) tadpoles.

    PubMed

    Gross, Jackson A; Chen, Te-Hao; Karasov, William H

    2007-06-01

    Data on the chronic effects of cadmium on amphibians are lacking in spite of widespread anthropogenic contamination of terrestrial and aquatic systems. We exposed embryos and tadpoles of northern leopard frogs (Rana pipiens) to Cd (control, 0.25, 5.0, and 20.0 microg/L as CdCl2, nominal concentrations) in a static renewal system from embryonic stages to complete tail resorption. Survival of embryos (Gosner stage [GS] 17-25) was greater than 97% in all treatments. Tadpole survival was negatively correlated with dose and was significantly reduced in the 5.0 and 20.0 microg/L treatments compared with controls. Tadpole survival was greater than 80% through GS 42, forelimb emergence, for all other treatments. Tadpoles exposed to 0.25 and 5.0 microg/L exhibited increased growth by week 11; tadpoles exposed to 5.0 microg/L were significantly younger at forelimb emergence. Whole-tadpole body burdens of Cd were positively correlated with increasing Cd treatments. Cadmium was shown to alter growth and development in a native amphibian species at ecologically relevant concentrations. The existing chronic water quality criterion for Cd appears to be protective of amphibians. However, additional studies with other chemicals are needed to further explore the potential for adverse effects of contaminants on the complex life cycle of amphibians.

  5. Multiple sublethal chemicals negatively affect tadpoles of the green frog, Rana clamitans

    USGS Publications Warehouse

    Boone, Michelle D.; Bridges, Christine M.; Fairchild, James F.; Little, Edward E.

    2005-01-01

    Many habitats may be exposed to multiple chemical contaminants, particularly in agricultural areas where fertilizer and pesticide use are common; however, the singular and interactive effects of contaminants are not well understood. The objective of our study was to examine how realistic, sublethal environmental levels of ammonium nitrate fertilizer (0, 10, 20 mg/L and ammonium chloride control) and the common insecticide carbaryl (0 or 2.5 mg/L) individually and interactively affect the development, size, and survival of green frog (Rana clamitans) tadpoles. We reared tadpoles for 95 d in outdoor 1,000-L polyethylene ponds. We found that the combination of carbaryl and nitrate had a negative effect on development and mass of tadpoles compared to the positive effect that either contaminant had alone. Presence of carbaryl was generally associated with short-term increases in algal resources, including ponds exposed to both carbaryl and nitrate. However, with exposure to nitrate and carbaryl, tadpole mass and development were not positively affected as with one chemical stressor alone. The combination of these sublethal contaminants may reduce the ability of amphibians to benefit from food-rich environments or have metabolic costs. Our study demonstrates the importance of considering multiple stressors when evaluating population-level responses.

  6. Effects of atrazine on metamorphosis, growth, and gonadal development in the green frog (Rana clamitans).

    PubMed

    Coady, Katherine; Murphy, Margaret; Villeneuve, Daniel; Hecker, Markus; Jones, Paul; Carr, James; Solomon, Keith; Smith, Ernest; Van Der Kraak, Glen; Kendall, Ronald; Giesy, John

    2004-06-25

    Embryos of the green frog (Rana clamitans) were collected from the field and exposed to 1 of 6 water-borne treatments for 273 d (mid July 2001 to mid April 2002). The treatments were 0, 10, or 25 microg/L atrazine, 0.005% ethanol (EtOH), or 0.1 mg/L estradiol or dihydrotestosterone carried in 0.005% EtOH. Treatments were applied in a static renewal system with a 50% test solution replacement approximately every 3 d. Following the exposure period, tadpoles were reared in freshwater until metamorphosis or until study termination (at d 506). Time to initiate and complete metamorphosis, stage-specific mortality, length and weight at metamorphosis, and gross morphology and histology of the gonads were examined. At environmentally relevant concentrations, atrazine did not consistently affect growth or metamorphosis. Compared to controls, the length of the larval period was greater in tadpoles exposed to 10 microg/L atrazine. However, the length of the larval period was not markedly different between tadpoles in the control and 25 microg/L atrazine treatments. Neither gross gonadal morphology nor histopathology of the gonads in postmetamorphic frogs was significantly altered in response to atrazine exposure. This study provides evidence that environmentally relevant concentrations of atrazine do not adversely affect the growth or reproductive development of R. clamitans.

  7. Effects of agricultural pesticides on the immune system of Xenopus laevis and Rana pipiens.

    PubMed

    Christin, M S; Ménard, L; Gendron, A D; Ruby, S; Cyr, D; Marcogliese, D J; Rollins-Smith, L; Fournier, M

    2004-03-30

    Over the last 30 years, there have been mass declines in diverse geographic locations among amphibian populations. Multiple causes have been suggested to explain this decline. Among these, environmental pollution is gaining attention. Indeed, some chemicals of environmental concern are known to alter the immune system. Given that amphibians are frequently exposed to agricultural pesticides, it is possible that these pollutants alter their immune system and render them more susceptible to different pathogens. In this study, we exposed two frog species, Xenopus laevis and Rana pipiens, for a short period of time to a mixture of pesticides (atrazine, metribuzine, endosulfan, lindane, aldicarb and dieldrin) representative in terms of composition and concentrations to what it is found in the environment of the southwest region of the province of Quebec. The pesticides were known to be present in surface water of many tributaries of the St. Lawrence River (Quebec, Canada). Our results demonstrate that the mixture of pesticides could alter the cellularity and phagocytic activity of X. laevis and the lymphocyte proliferation of R. pipiens. Taken together, these results indicate that agricultural pesticides can alter some aspects of the immune response in frogs and could contribute to their global decline by rendering them more susceptible to certain infections.

  8. Lead concentrations in bullfrog Rana catesbeiana and green frog R. clamitans tadpoles inhabiting highway drainages

    USGS Publications Warehouse

    Birdsall, C.W.; Grue, C.E.; Anderson, A.

    1986-01-01

    Lead concentrations were determined in sediment and tadpoles of bullfrogs Rana catesbeiana and green frogs R. clamitans from drainages along highways with different daily average traffic volumes (range, 4272 to I08,800 vehicles day-I) and from ponds >0.4 km from the nearest highway. Lead concentrations (mg kg--I dry weight) in sediment (7-8 to 940) were usually greater (4-5 times) than those in the tadpoles (bullfrog, 0,07 to 270; green frog, 0,90 to 240 mg kg-I). Lead concentrations in sediment (r =0.63) and in both species of tadpoles (bullfrog, r = 0.69; green frog, r = 0.57) were positively correlated with average daily traffic volume. Lead concentrations in both species of tadpoles (bullfrog, r = (). 76: green frog, r = 0.75) were also positively correlated with lead concentrations in sediment. At sites where both bullfrog and green frog tadpoles were collected. lead concentrations in the two species were closely related (r = 0.84). Lead concentrations in tadpoles living near highways may contribute to the elevated lead levels reported in wildlife that are potential tadpole predators. Dietary lead concentrations similar to those in our tadpoles have been associated with physiological and reproductive effects in some species of birds and mammals. However, additional data are needed to determine the hazards to predators of lead concentrations in tadpoles.

  9. New Trends on Antineoplastic Therapy Research: Bullfrog (Rana catesbeiana Shaw) Oil Nanostructured Systems.

    PubMed

    Amaral-Machado, Lucas; Xavier-Júnior, Francisco H; Rutckeviski, Renata; Morais, Andreza R V; Alencar, Éverton N; Dantas, Teresa R F; Cruz, Ana K M; Genre, Julieta; da Silva-Junior, Arnóbio A; Pedrosa, Matheus F F; Rocha, Hugo A O; Egito, Eryvaldo S T

    2016-01-01

    Bullfrog oil is a natural product extracted from the Rana catesbeiana Shaw adipose tissue and used in folk medicine for the treatment of several diseases. The aim of this study was to evaluate the extraction process of bullfrog oil, to develop a suitable topical nanoemulsion and to evaluate its efficacy against melanoma cells. The oil samples were obtained by hot and organic solvent extraction processes and were characterized by titration techniques and gas chromatography mass spectrometry (GC-MS). The required hydrophile-lipophile balance and the pseudo-ternary phase diagram (PTPD) were assessed to determine the emulsification ability of the bullfrog oil. The anti-tumoral activity of the samples was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay for normal fibroblast (3T3) and melanoma (B16F10) cell lines. Both extraction methods produced yielded around 60% and the oil was mainly composed of unsaturated compounds (around 60%). The bullfrog oil nanoemulsion obtained from PTPD presented a droplet size of about 390 nm and polydispersity = 0.05 and a zeta potential of about -25 mV. Both the bullfrog oil itself and its topical nanoemulsion did not show cytotoxicity in 3T3 linage. However, these systems showed growth inhibition in B16F10 cells. Finally, the bullfrog oil presented itself as a candidate for the development of pharmaceutical products free from cytotoxicity and effective for antineoplastic therapy. PMID:27144557

  10. Characterization of gene expression endpoints during postembryonic development of the northern green frog (Rana clamitans melanota).

    PubMed

    Hammond, S Austin; Veldhoen, Nik; Kobylarz, Marek; Webber, Nicholas R; Jordan, Jameson; Rehaume, Vicki; Boone, Michelle D; Helbing, Caren C

    2013-05-01

    Postembryonic development of a larval tadpole into a juvenile frog involves the coordinated action of thyroid hormone (TH) across a diversity of tissues. Changes in the frog transcriptome represent a highly sensitive endpoint in the detection of developmental progression, and for the identification of environmental chemical contaminants that possess endocrine disruptive properties. Unfortunately, in contrast with their vital role as sentinels of environmental change, few gene expression tools currently exist for the majority of native North American frog species. We have isolated seven expressed gene sequences from the Northern green frog (Rana clamitans melanota) that encode proteins associated with TH-mediated postembryonic development and global stress response, and established a quantitative real-time polymerase chain reaction (qPCR) assay. We also obtained three additional species-specific gene sequences that functioned in the normalization of the expression data. Alterations in mRNA abundance profiles were identified in up to eight tissues during R. clamitans postembryonic development, and following exogenous administration of TH to premetamorphic tadpoles. Our results characterize tissue distribution and sensitivity to TH of select mRNA of a common North American frog species and support the potential use of this qPCR assay in identification of the presence of chemical agents in aquatic environments that modulate TH action. PMID:23647014

  11. Rana computatrix to human language: towards a computational neuroethology of language evolution.

    PubMed

    Arbib, Michael A

    2003-10-15

    Walter's Machina speculatrix inspired the name Rana computatrix for a family of models of visuomotor coordination in the frog, which contributed to the development of computational neuroethology. We offer here an 'evolutionary' perspective on models in the same tradition for rat, monkey and human. For rat, we show how the frog-like taxon affordance model provides a basis for the spatial navigation mechanisms that involve the hippocampus and other brain regions. For monkey, we recall two models of neural mechanisms for visuomotor coordination. The first, for saccades, shows how interactions between the parietal and frontal cortex augment superior colliculus seen as the homologue of frog tectum. The second, for grasping, continues the theme of parieto-frontal interactions, linking parietal affordances to motor schemas in premotor cortex. It further emphasizes the mirror system for grasping, in which neurons are active both when the monkey executes a specific grasp and when it observes a similar grasp executed by others. The model of human-brain mechanisms is based on the mirror-system hypothesis of the evolution of the language-ready brain, which sees the human Broca's area as an evolved extension of the mirror system for grasping.

  12. Plasma membrane mediated action of progesterone in amphibian (Rana dybowskii) oocyte maturation.

    PubMed

    Bandyopadhyay, A; Bandyopadhyay, J; Choi, H H; Choi, H S; Kwon, H B

    1998-03-01

    The mechanism of progesterone action within the ovarian follicle was investigated in Rana dybowskii, by using immobilized progesterone. Fluorescein isothiocyanate-labeled progesterone 3-O-carboxymethyloxime-BSA (P-BSA) was localized on the outside surface of the denuded oocyte, which indicated that P-BSA did not cross the barrier of cell surface. Progesterone-BSA induced germinal vesicle breakdown (GVBD) of denuded oocytes in a dose-dependent manner but failed to induce GVBD of follicle wall-enclosed oocytes. The time course of P-BSA-induced GVBD in denuded oocytes was similar to that observed with progesterone. Furthermore, both P-BSA and progesterone induced oocyte maturation in the presence of RU486, a well-known nuclear progesterone receptor antagonist. Treatment of denuded oocytes with P-BSA resulted in a threefold increase in inositol triphosphate (IP3) and a fourfold increase in diacylglycerol levels within 10 min. Additionally protein kinase C (PKC) activity was markedly increased by 30 min of incubation following exposure to P-BSA. Such changes were not observed in denuded oocytes exposed to beta-estradiol-6-O-carboxymethyloxime-BSA, which failed to induce GVBD. These results suggest that progesterone acts initially at the oocyte surface where it triggers generation of membrane-mediated second messengers during oocyte maturation in amphibians.

  13. Proximate causes of adaptive growth rates: growth efficiency variation among latitudinal populations of Rana temporaria.

    PubMed

    Lindgren, B; Laurila, A

    2005-07-01

    In ectothermic organisms, declining season length and lower temperature towards higher latitudes often select for latitudinal variation in growth and development. However, the energetic mechanisms underlying this adaptive variation are largely unknown. We investigated growth, food intake and growth efficiency of Rana temporaria tadpoles from eight populations along a 1500 km latitudinal gradient across Sweden. To gain an insight into the mechanisms of adaptation at organ level, we also examined variation in tadpole gut length. The tadpoles were raised at two temperatures (16 and 20 degrees C) in a laboratory common garden experiment. We found increased growth rate towards higher latitudes, regardless of temperature treatment. This increase in growth was not because of a higher food intake rate, but populations from higher latitudes had higher growth efficiency, i.e. they were more efficient at converting ingested food into body mass. Low temperature reduced growth efficiency most strongly in southern populations. Relative gut length increased with latitude, and tadpoles at low temperature tended to have longer guts. However, variation in gut length was not the sole adaptive explanation for increased growth efficiency as latitude and body length still explained significant amounts of variation in growth efficiency. Hence, additional energetic adaptations are probably involved in growth efficiency variation along the latitudinal gradient.

  14. Spontaneous otoacoustic emissions in the European edible frog (Rana esculenta): spectral details and temperature dependence.

    PubMed

    van Dijk, P; Wit, H P; Segenhout, J M

    1989-11-01

    Spontaneous otoacoustic emissions were recorded in 41 ears of 29 European edible frogs (Rana esculenta). Emission frequencies ranged from 450 to 1350 Hz. The distribution of frequencies shows two distinct populations: one above and one below 1 kHz. With one exception, a maximum number of two emissions were recorded per ear, each in a different population. An amplitude distribution of a frog emission was sampled, from which it was concluded that the emission is generated by an active oscillator. The spectral width of an emission ranged from 1 to 200 Hz (average 38 Hz). There was negative correlation between sound pressure level of an emission and spectral width. In 4 frogs the dependence of emission power and frequency on temperature was investigated. An emission could be 'switched on and off' within a few degrees centigrade. At temperatures below the switching interval no emission was recorded; for higher temperatures emission power showed no dependence on temperature. Frequency increased with temperature (Q10 = 1.1 to 1.3). This yields a mismatch with temperature dependence of best frequencies of auditory fibers. The consequences of this mismatch are discussed. PMID:2691473

  15. The emerging amphibian pathogen Batrachochytrium dendrobatidis globally infects introduced populations of the North American bullfrog, Rana catesbeiana.

    PubMed

    Garner, Trenton W J; Perkins, Matthew W; Govindarajulu, Purnima; Seglie, Daniele; Walker, Susan; Cunningham, Andrew A; Fisher, Matthew C

    2006-09-22

    Batrachochytrium dendrobatidis is the chytridiomycete fungus which has been implicated in global amphibian declines and numerous species extinctions. Here, we show that introduced North American bullfrogs (Rana catesbeiana) consistently carry this emerging pathogenic fungus. We detected infections by this fungus on introduced bullfrogs from seven of eight countries using both PCR and microscopic techniques. Only native bullfrogs from eastern Canada and introduced bullfrogs from Japan showed no sign of infection. The bullfrog is the most commonly farmed amphibian, and escapes and subsequent establishment of feral populations regularly occur. These factors taken together with our study suggest that the global threat of B. dendrobatidis disease transmission posed by bullfrogs is significant. PMID:17148429

  16. Toxicity of 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin in larval and adult forms of Rana catesbeiana.

    PubMed

    Beatty, P W; Holscher, M A; Neal, R A

    1976-11-01

    Varying doses of TCDD ranging from 25 to 1000 mug/kg were administered to the larval and adult forms of the American bullfrog, Rana catesbeiana. Doses of TCDD as high as 1 mg/kg failed to have any significant effect upon survival or completion of metamorphosis in tadpole and doses of up to 500 mug/kg had no effect on survival of adult frogs. Histopathological examination of various tissues from the metamorphosed tadpoles and adult frogs failed to show any abnormalities.

  17. The emerging amphibian pathogen Batrachochytrium dendrobatidis globally infects introduced populations of the North American bullfrog, Rana catesbeiana.

    PubMed

    Garner, Trenton W J; Perkins, Matthew W; Govindarajulu, Purnima; Seglie, Daniele; Walker, Susan; Cunningham, Andrew A; Fisher, Matthew C

    2006-09-22

    Batrachochytrium dendrobatidis is the chytridiomycete fungus which has been implicated in global amphibian declines and numerous species extinctions. Here, we show that introduced North American bullfrogs (Rana catesbeiana) consistently carry this emerging pathogenic fungus. We detected infections by this fungus on introduced bullfrogs from seven of eight countries using both PCR and microscopic techniques. Only native bullfrogs from eastern Canada and introduced bullfrogs from Japan showed no sign of infection. The bullfrog is the most commonly farmed amphibian, and escapes and subsequent establishment of feral populations regularly occur. These factors taken together with our study suggest that the global threat of B. dendrobatidis disease transmission posed by bullfrogs is significant.

  18. Alteration of mitochondrial efficiency affects oxidative balance, development and growth in frog (Rana temporaria) tadpoles.

    PubMed

    Salin, Karine; Luquet, Emilien; Rey, Benjamin; Roussel, Damien; Voituron, Yann

    2012-03-01

    Mitochondria are known to play a central role in life history processes, being the main source of reactive oxygen species (ROS), which promote oxidative constraint. Surprisingly, although the main role of the mitochondria is to produce ATP, the plasticity of mitochondrial ATP generation has received little attention in life history studies. Yet, mitochondrial energy transduction represents the physiological link between environmental resources and energy allocated to animal performance. Studying both facets of mitochondrial functioning (ATP and ROS production) would allow better understanding of the proximate mechanisms underlying life history. We have experimentally modulated the mitochondrial capacity to generate ROS and ATP during larval development of Rana temporaria tadpoles, via chronic exposure (34 days) to a mitochondrial uncoupler (2,4-dinitrophenol, dNP). The aim was to better understand the impact of mitochondrial uncoupling on both responses in terms of oxidative balance, energy input (oxygen and feeding consumption) and energy output (growth and development of the tadpole). Exposure to 2,4-dNP reduced mitochondrial ROS generation, total antioxidant defences and oxidative damage in treated tadpoles compared with controls. Despite the beneficial effect of dNP on oxidative status, development and growth rates of treated tadpoles were lower than those in the control group. Treatment of tadpoles with 2,4-dNP promoted a mild mitochondrial uncoupling and enhanced metabolic rate. These tadpoles did not increase their food consumption, and thus failed to compensate for the energy loss elicited by the decrease in the efficiency of ATP production. These data suggest that the cost of ATP production, rather than the oxidative balance, is the parameter that constrains growth/development of tadpoles, highlighting the central role of energy transduction in larval performance. PMID:22323209

  19. Independent degeneration of W and Y sex chromosomes in frog Rana rugosa.

    PubMed

    Miura, Ikuo; Ohtani, Hiromi; Ogata, Mitsuaki

    2012-01-01

    The frog Rana rugosa uniquely possesses two different sex-determining systems of XX/XY and ZZ/ZW, separately in the geographic populations. The sex chromosomes of both types share the same origin at chromosome 7, and the structural differences between X and Y or Z and W were evolved through two inversions. In order to ascertain the mechanisms of degeneration of W and Y chromosomes, we gynogenetically produced homozygous diploids WW and YY and examined their viability. Tadpoles from geographic group N (W(N)W(N)) containing three populations died of edema at an early developmental stage within 10 days after hatching, while tadpoles from the geographic group K (W(K)W(K)) that contained two populations died of underdeveloped growth at a much later stage, 40-50 days after fertilization. On the contrary, W(N)W(K) and W(K)W(N) hybrid embryos were viable, successfully passed the two lethal stages, and survived till the attainment of adulthood. The observed survival implies that the lethal genes of the W chromosomes are not shared by the two groups and thus demonstrates their independent degeneration histories between the local groups. In sharp contrast, a sex-linked gene of androgen receptor gene (AR) from the W chromosome was down-regulated in expression in both the groups, suggesting that inactivation of the W-AR allele preceded divergence of the two groups and appearance of the lethal genes. Besides, the YY embryos died of cardiac edema immediately after hatching. The symptom of lethality and the stage of developmental arrest differed from those for either of WW lethal embryos. We therefore conclude that the W and Y chromosomes involve no evolutionary common scenario for degeneration.

  20. Chronic, dietary polybrominated diphenyl ether exposure affects survival, growth, and development of Rana pipiens tadpoles.

    PubMed

    Cary Coyle, Tawnya L; Karasov, William H

    2010-01-01

    Levels of polybrominated diphenyl ethers (PBDEs) in the environment have been increasing rapidly over the past two decades; however, the toxicology of these compounds to aquatic organisms is poorly understood. Because amphibians play a role in both aquatic and terrestrial food webs, and are currently undergoing worldwide population declines, it is of interest to determine how PBDEs may affect amphibian health. This is the first study that reports chronic, dietary effects of environmentally relevant levels (7-277 ng/g wet food) of PBDEs in amphibians throughout larval development. Beginning at the free-swimming stage (Gosner Stage [GS] 25), Rana pipiens tadpoles were orally exposed to a technical pentabromodiphenyl ether mixture (DE-71) through metamorphic climax (GS 42). On exposure day 43, a subset of tadpoles was removed for body residue analysis. Sum PBDEs in whole-body tissue correlated linearly to dietary concentrations with BDE-99 represented as the highest contributing congener in both diet and tissue. Survival among all treatments compared to the control was decreased by DE-71 exposure. Further, growth and development were delayed in all but the highest treatment, perhaps indicating greater PBDE tolerance among those individuals that survived the highest treatment. Time to metamorphic climax was delayed, on average, 22 to 36 d in DE-71-treated tadpoles compared to control tadpoles. Additionally, size at metamorphosis was smaller in the highest treatment, suggesting that individuals that survived and metamorphosed similarly to the controls did so with a trade-off in size. At environmentally relevant levels, PBDEs induced mortality as well as sublethal effects on developing tadpoles through dietary exposure.

  1. D-Asp: a new player in reproductive endocrinology of the amphibian Rana esculenta.

    PubMed

    Raucci, Franca; Di Fiore, Maria Maddalena

    2011-11-01

    We investigated the involvement of D-Aspartic acid (D-Asp) on ovarian and testicular morphology of the green frog, Rana esculenta, and its effect on the testosterone production. The study has been performed throughout the reproductive cycle. In both ovary and testis a substantial amount of D-Asp is endogenously present and its concentration varies as function of reproduction. In the frog, D-Asp content is differently correlated with gonadal and plasmatic levels of testosterone, depending on the sex. In fact, the amount of the D-Asp is inversely linked with that of the testosterone in the ovary, while this correlation directly matched in the testis. In vivo short-term experiments, consisting of a single intra-peritoneal injection of D-Asp (2.0 μmol/g body weight), demonstrated that the enantiomer is significantly accumulated by both the ovary and testis, reaching after 3 h the highest uptake and thereafter decreasing to baseline values within 24 h. Furthermore, D-Asp influences the synthesis and/or the release of testosterone, causing a decrease of its level in the female, and an increase in the male, respectively. In vivo long-term experiments, D-Asp, chronically administered to the frogs of both sexes, enhances the maturation of both gonads, determining in the oocytes an higher accumulation of carbohydrate yolk plates in the ooplasm, and stimulating the spermatogenesis in the testis. Taken altogether, our results show that D-Asp operates differently in female and male frog gonads, indicating that it has different targets in the reproductive machinery depending on the sex.

  2. Reactivity of metallothioneins of frog Rana ridibunda treated by copper and zinc ions.

    PubMed

    Falfushynska, H I; Romanchuk, L D; Stoliar, O B

    2010-01-01

    The metal-buffering and stress proteins metallothioneins (MTs) of frog are characterised by unusually high content of copper as for vertebrate animals and instability that was shown in our previous studies. They easily lost copper and especially zinc under unfavourable conditions. The aim of this study was to examine the reactivity of SH groups in the MTs from the liver of frog Rana ridibunda after the effect of Cu2+ (0.01 mg/l) and Zn2+ (0.1 mg/l) ions on the organism during 14 days. The alpha- and beta-domains of MTs with molecular weights of about 4 kDa were separated by the size-exclusion chromatography on Sephadex G-50. Unlike higher vertebrates, frogs demonstrated higher reactivity of alpha-domain than beta-domain with the Ellman's reagent (DTNB). The signs of partial oxidations in beta-domain included the creation of by-products with molecular weight about 12 kDa, low reactivity of SH-groups, and typical of -S-S-bonds peculiarities of UV-spectra. The effect of both metal ions on frog provoked the elevation of SH-groups reactivity in a-domain with the appearance of by-product with molecular weight of 16 kDa and its reduction in beta-domain. The incubation of MTs of control animals with 0.5 and 5.0 mM of H2O2 did not affect its chromatographic characteristics. In the frogs loaded by Cu2+ and Zn2+ the effect of 5.0 mM H2O2 on MTs provoked the release of 4 kDa product. So the alpha-domain is responsible for the increased release of metals from injured MTs in frogs, whereas extremely high oxidizability of beta-domain makes its participation in the exchange of metals elusive and provokes the aggregation of MTs. PMID:21323122

  3. Plasticity of auditory medullary-midbrain connectivity across metamorphic development in the bullfrog, Rana catesbeiana.

    PubMed

    Horowitz, Seth S; Chapman, Judith A; Simmons, Andrea Megela

    2007-01-01

    On the basis of patterns of anterograde, retrograde, and bi-directional transport of tracers from both the superior olivary nucleus (SON) and the torus semicircularis (TS), we report anatomical changes in brainstem connectivity across metamorphic development in the bullfrog, Rana catesbeiana. In early and late stages of larval development (Gosner stages 25-37), anterograde or bi-directional tracers injected into the SON produce terminal/fiber label in the contralateral SON and in the ipsilateral TS. Between stages 38-41 (deaf period), only sparse or no terminal/fiber label is visible in these target nuclei. During metamorphic climax (stages 42-46), terminal/fiber label reappears in both the contralateral SON and in the ipsilateral TS, and now also in the contralateral TS. Injections of retrograde tracers into the SON fail to label cell bodies in the ipsilateral TS in deaf period animals, mirroring the previously-reported failure of retrograde transport from the TS to the ipsilateral SON during this developmental time. Bilateral cell body label emerges in the dorsal medullary nucleus and the lateral vestibular nucleus bilaterally as a result of SON transport during the late larval period, while cell body label in the contralateral TS emerges during climax. At all larval stages, injections into the SON produce anterograde and retrograde label in the medial vestibular nucleus bilaterally. These data show anatomical stability in some pathways and plasticity in others during larval development, with the most dramatic changes occurring during the deaf period and metamorphic climax. Animals in metamorphic climax show patterns of connectivity similar to that of froglets and adults, indicating the maturation during climax of central anatomical substrates for hearing in air.

  4. A pyrimidine-guanine sequence-specific ribonuclease from Rana catesbeiana (bullfrog) oocytes.

    PubMed Central

    Liao, Y D

    1992-01-01

    A pyrimidine-guanine sequence-specific ribonuclease (RC-RNase) was purified from Rana catesbeiana (bullfrog) oocytes by sequential phosphocellulose, Sephadex G75, heparin Sepharose CL 6B and CM-Sepharose CL 6B column chromatography. The purified enzyme with molecular weight of 13,000 daltons gave a single band on SDS-polyacrylamide gel. One CNBr-cleaved fragment has a sequence of NVLSTTRFQLNT/TRTSITPR, which is identical to residues 59-79 of a sialic acid binding lectin from R. catesbeiana eggs, and is 71% homologous to residues 60-80 of an RNase from R. catesbeaina liver. The RC-RNase preferentially cleaved RNA at pyrimidine residues with a 3' flanking guanine under various conditions. The sequence specificity of RC-RNase was further confirmed with dinucleotide as substrates, which were analyzed by thin layer chromatography after enzyme digestion. The values of kcat/km for pCpG, pUpG and pUpU were 2.66 x 10(7) M-1s-1, 2.50 x 10(7) M-1s-1 and 2.44 x 10(6) M-1s-1 respectively, however, those for other phosphorylated dinucleotides were less than 2% of pCpG and pUpG. As compared to single strand RNA, double strand RNA was relatively resistant to RC-RNase. Besides poly (A) and poly (G), most of synthetic homo- and heteropolynucleotides were also susceptible to RC-RNase. The RC-RNase was stable in the acidic (pH 2) and alkaline (pH 12) condition, but could be inactivated by heating to 80 degrees C for 15 min. No divalent cation was required for its activity. Furthermore, the enzyme activity could be enhanced by 2 M urea, and inhibited to 50% by 0.12 M NaCl or 0.02% SDS. Images PMID:1373237

  5. An anti-A-like lectin of Rana catesbiana eggs showing unusual reactivity.

    PubMed

    Sakakibara, F; Takayanagi, G; Kawauchi, H; Watanabe, K; Hakomori, S

    1976-09-24

    A lectin was isolated from Rana catesbiana eggs that agglutinated blood group A-erythrocytes but did not agglutinate blood group B- or 0-erythrocytes. The lectin was purified by Sephadex G-75 gel filtration and by acrylamide gel electrophoresis at pH 4.3 and was proved to be homogeneous on electrophoresis, and the molecular weight was determined as 210 000. The specificity of A-like activity seems to direct towards three monosaccharide units: GalNAcalpha1 leads to 3(or 4)-Galbeta1 leads to 4(or 3)GlcNAcbeta1 leads to R based on inhibition of A-like hemagglutination by various monosaccharides, oligosaccharides and glycolipids, and based on precipitin reaction with various glycolipids and glycoproteins with known structures. Uniquely, A-like agglutination was inhibited not only by alpha-N-acetylgalactosamine analogs but also by N-acetyllactosamine analogs. The lectin showed therefore, two correlated specificities: one directed towards alpha-N-acetylgalactosamine residue at the terminal, and the other towards the subterminal Galbeta1 leads to 4betaGlcNAc (N-acetyllactosaminyl) residue. The reactivity due to the N-acetyllactosamine structure which is also found in erythrocyte ganglioside and in H-active chain might be blocked by sialyl or alpha-L-fucosyl substitution at the terminal, as the reactivity appeared after elimination of these sugar residues. In the A structure the reactivity due to N-acetyllactosaminyl residue seems not to be blocked by the presence of alpha-N-acetylgalactosamine at the terminal as A-agglutination was strongly inhibited by N-acetyllactosamine and its analogs. Although the lectin showed a single band on electrophoresis under different conditions, there is a possibility that the lectin may be a mixture of two proteins with different specificities as mentioned above. PMID:1085640

  6. Impacts of weathered tire debris on the development of Rana sylvatica larvae.

    PubMed

    Camponelli, Kimberly M; Casey, Ryan E; Snodgrass, Joel W; Lev, Steven M; Landa, Edward R

    2009-02-01

    Highway runoff has the potential to negatively impact receiving systems including stormwater retention ponds where highway particulate matter can accumulate following runoff events. Tire wear particles, which contain about 1% Zn by mass, make up approximately one-third of the vehicle derived particulates in highway runoff and therefore may serve as a stressor to organisms utilizing retention ponds as habitat. In this study, we focused on the potential contribution of tire debris to Zn accumulation by Rana sylvatica larvae and possible lethal or sublethal impacts resulting from exposure to weathered tire debris during development. Eggs and larvae were exposed to aged sediments (containing either ZnCl2 or tire particulate matter, both providing nominal concentrations of 1000 mg Zn kg(-1)) through metamorphosis. Water column Zn was elevated in both the ZnCl2 and tire treatments relative to the control treatment, indicating that aging allowed Zn leaching from tire debris to occur. Tissue Zn was also elevated for the ZnCl2 and tire treatments indicating that Zn in the treatments was available for uptake by the amphibians. Exposure to both ZnCl2 and tire treatments increased the time for larvae to complete metamorphosis in comparison with controls. We also observed that the longer the organisms took to complete metamorphosis, the smaller their mass at metamorphosis. Our results indicate that Zn leached from aged tire debris is bioavailable to developing R. sylvatica larvae and that exposure to tire debris amended sediments can result in measurable physiological outcomes to wood frogs that may influence population dynamics. PMID:18995883

  7. Impacts of weathered tire debris on the development of Rana sylvatica larvae

    USGS Publications Warehouse

    Camponelli, K.M.; Casey, R.E.; Snodgrass, J.W.; Lev, S.M.; Landa, E.R.

    2009-01-01

    Highway runoff has the potential to negatively impact receiving systems including stormwater retention ponds where highway particulate matter can accumulate following runoff events. Tire wear particles, which contain about 1% Zn by mass, make up approximately one-third of the vehicle derived particulates in highway runoff and therefore may serve as a stressor to organisms utilizing retention ponds as habitat. In this study, we focused on the potential contribution of tire debris to Zn accumulation by Rana sylvatica larvae and possible lethal or sublethal impacts resulting from exposure to weathered tire debris during development. Eggs and larvae were exposed to aged sediments (containing either ZnCl2 or tire particulate matter, both providing nominal concentrations of 1000 mg Zn kg-1) through metamorphosis. Water column Zn was elevated in both the ZnCl2 and tire treatments relative to the control treatment, indicating that aging allowed Zn leaching from tire debris to occur. Tissue Zn was also elevated for the ZnCl2 and tire treatments indicating that Zn in the treatments was available for uptake by the amphibians. Exposure to both ZnCl2 and tire treatments increased the time for larvae to complete metamorphosis in comparison with controls. We also observed that the longer the organisms took to complete metamorphosis, the smaller their mass at metamorphosis. Our results indicate that Zn leached from aged tire debris is bioavailable to developing R. sylvatica larvae and that exposure to tire debris amended sediments can result in measurable physiological outcomes to wood frogs that may influence population dynamics. ?? 2008 Elsevier Ltd.

  8. Gonadal differentiation in frogs, Rana japonica and R. brevipoda, raised from UV irradiated eggs

    SciTech Connect

    Shirane, T.

    1982-10-10

    The gonadal differentiation of anurans, Rana japonica and R. brevipoda, was examined in animals raised from eggs which had been irradiated at the vegetal hemisphere with UV (9300 erg/mm2) at the 2-cell stage. In R. japonica about 70% of the larvae at stage I from the pressed and UV-irradiated eggs were germ cell free, but at a stage immediately after metamorphosis all animals had at least some germ cells, although their gonads often were extremely small and poorly differentiated. When male animals matured sexually, many of them had abnormal gonads. However, all of them were shown by artificial means to be capable of fertilization. In the nonpressed and irradiated group, no larvae were germ cell free and the animals immediately after metamorphosis showed nearly normal gonadal differentiation except for the presence of a few degenerate oocytes in the ovaries. The results in R. brevipoda were basically similar to those in R. japonica. In both species, sex ratios were determined at two stages, the first immediately after metamorphosis and the other when the animals matured, as based on gonad morphology and histology and on external sexually dimorphic characters as well. Sex ratios at these two stages in frogs from the pressed and irradiated eggs differed markedly in R. brevipoda. The ratio was normal at metamorphosis but high M/F ratios occurred when animals became mature. That sex reversal took place in this species as well as in R. japonica (in which sex-ratio deviation was not statistically significant) was supported by the sex ratios of the progenies of these supernumerary males.

  9. Variation in UV sensitivity among common frog Rana temporaria populations along an altitudinal gradient.

    PubMed

    Marquis, Olivier; Miaud, Claude

    2008-01-01

    Solar ultraviolet-B (UV-B) radiation can be harmful for developing amphibians. As the UV-B dose increases with altitude, it has been suggested that high-altitude populations may have an increased tolerance to high levels of UV-B radiation as compared to lowland populations. We tested this hypothesis with the common frog (Rana temporaria) by comparing populations from nine altitudes (from 333 to 2450m above sea level). Eggs collected in the field were used for laboratory experiments, i.e., exposed to high levels of artificial UV-B radiation. Eggs were reared at 14+/-2 degrees C and exposed to UV treatments until hatching. Embryonic developmental rates increased strongly and linearly with increasing altitude, suggesting a genetic capacity for faster development in highland than lowland eggs. Body length at hatching varied significantly with UV-B treatments, being lower when eggs developed under direct UV-B exposure. Body length at hatching also increased as the altitude of populations increased, but UV-B exposure times were shorter as altitude of population increased. However, the body length difference between exposed and non-exposed individuals in each population decreased as altitude of populations increased, suggesting a costly effect of UV exposure on growth. Type of UV exposure did not influence the mean rates of embryonic mortality and deformity, but both mortality and deformity rates increased as the altitude of populations increased (while UV-B exposure duration decreased). The effect of UV-B on body length at hatching, mortality, and deformities suggests that the sensitivity to UV-B varied among populations along the altitudinal gradient. These results are discussed in evolutionary terms, specifically the potential of R. temporaria high-altitude populations to develop local genetic adaptation to high levels of UV-B. PMID:18495447

  10. Toxic effects of endrin and toxaphene on the southern leopard frog Rana sphenocephala

    USGS Publications Warehouse

    Hall, R.J.; Swineford, D.

    1980-01-01

    Eggs, larvae and sub-adults of the southern leopard frog Rana sphenocephala were exposed to endrin and toxaphene. Exposure was in water by a continuous-flow technique, following standards that have been used successfully in the study of fish and invertebrates. R. sphenocephala is more sensitive to both pesticides than are higher vertebrates but is slightly less sensitive than fish. Eggs seem to be resistant to the effects of both pesticides and are probably poor indicators of environmental hazard. The toxic level of endrin is about equal in larvae and transformed frogs (LC50, 0?005-0?015 ppm). Toxaphene is less toxic to sub-adults (LC50, 0?37-0?790 ppm) than to larvae (LC50, 0?032-0?054 ppm). Delayed mortality, behavioural aberrations and effects on growth have been seen in toxaphene-dosed larvae observed over 30-day periods. Behavioural effects are more severe than those reported in other groups of animals. Effects on growth resulting from a 96-h exposure begin in the 0?013-0?018 ppm range. The maximum accumulation of residues observed for each chemical represented bioconcentration factors of about 100. Endrin residues are apparently lost more readily than toxaphene residues; relative depuration rates correlate well with the time course of toxic action in each chemical. Although less sensitive to these pesticides than fish, amphibians may not be protected in their natural habitats. Future studies of the effects of toxicants on amphibians should employ larvae if only one stage can be tested, should expose subjects for at least 96 h and should continue observations for a total of at least 30 days.

  11. Oxidative stress induced in PCB 126-exposed northern leopard frogs, Rana pipiens

    USGS Publications Warehouse

    Huang, Y.-W.; Hoffman, D.J.; Karasov, W.H.

    2007-01-01

    Northern leopard frogs Rana pipiens exposed to PCB 126 (3,3',4,4',5-pentachlorobiphenyl) were examined for hepatic oxidative stress. In a dose-response study, northern leopard frogs were injected intraperitoneally with either PCB 126 in corn oil (0.2, 0.7, 2.3, or 7.8 mg/kg body weight) or corn oil alone. In a time-course study, frogs received 7.8 mg/kg or corn oil alone, and were examined at 1, 2, 3, and 4 wk after dosing. Hepatic concentrations of reduced glutathione (GSH), thiobarbituric acid-reactive substances (TBARS), and total sulfhydryls (total SH), as well as activities of glutathione peroxidase (GSH-P), GSSG reductase (GSSG-R), glucose-6-phosphate dehydrogenase (G-6-PDH), and glutathione S-transferase (GSH-S-T) were measured. In the dose-response experiment, few effects were apparent 1 wk after dosing. In the time-course experiment, significant changes were observed in the 7.8-mg/kg group at 2 wk or more posttreatment. Hepatic concentrations of GSH and TBARS were higher than in corresponding controls at wk 3 and 4; the activities of GSSG-R and GSH-S-T were higher than in controls at wk 2 and 4; and the activity of G-6-PDH was increased at wk 2 and 4. These data collectively indicate that altered glutathione metabolism and oxidative stress occurred and were indicative of both toxicity and induction of protective mechanisms in frogs exposed to PCB. A similar delay in response was reported in fish and may relate to lower metabolic rate and physiological reactions in ectothermic vertebrates

  12. Radically different phylogeographies and patterns of genetic variation in two European brown frogs, genus Rana.

    PubMed

    Vences, Miguel; Hauswaldt, J Susanne; Steinfartz, Sebastian; Rupp, Oliver; Goesmann, Alexander; Künzel, Sven; Orozco-terWengel, Pablo; Vieites, David R; Nieto-Roman, Sandra; Haas, Sabrina; Laugsch, Clara; Gehara, Marcelo; Bruchmann, Sebastian; Pabijan, Maciej; Ludewig, Ann-Kathrin; Rudert, Dirk; Angelini, Claudio; Borkin, Leo J; Crochet, Pierre-André; Crottini, Angelica; Dubois, Alain; Ficetola, Gentile Francesco; Galán, Pedro; Geniez, Philippe; Hachtel, Monika; Jovanovic, Olga; Litvinchuk, Spartak N; Lymberakis, Petros; Ohler, Annemarie; Smirnov, Nazar A

    2013-09-01

    We reconstruct range-wide phylogeographies of two widespread and largely co-occurring Western Palearctic frogs, Rana temporaria and R. dalmatina. Based on tissue or saliva samples of over 1000 individuals, we compare a variety of genetic marker systems, including mitochondrial DNA, single-copy protein-coding nuclear genes, microsatellite loci, and single nucleotide polymorphisms (SNPs) of transcriptomes of both species. The two focal species differ radically in their phylogeographic structure, with R. temporaria being strongly variable among and within populations, and R. dalmatina homogeneous across Europe with a single strongly differentiated population in southern Italy. These differences were observed across the various markers studied, including microsatellites and SNP density, but especially in protein-coding nuclear genes where R. dalmatina had extremely low heterozygosity values across its range, including potential refugial areas. On the contrary, R. temporaria had comparably high range-wide values, including many areas of probable postglacial colonization. A phylogeny of R. temporaria based on various concatenated mtDNA genes revealed that two haplotype clades endemic to Iberia form a paraphyletic group at the base of the cladogram, and all other haplotypes form a monophyletic group, in agreement with an Iberian origin of the species. Demographic analysis suggests that R. temporaria and R. dalmatina have genealogies of roughly the same time to coalescence (TMRCA ~3.5 mya for both species), but R. temporaria might have been characterized by larger ancestral and current effective population sizes than R. dalmatina. The high genetic variation in R. temporaria can therefore be explained by its early range expansion out of Iberia, with subsequent cycles of differentiation in cryptic glacial refugial areas followed by admixture, while the range expansion of R. dalmatina into central Europe is a probably more recent event.

  13. Effects of ryanodine on calcium sparks in cut twitch fibres of Rana temporaria

    PubMed Central

    Hui, Chiu Shuen; Bidasee, Keshore R; Besch, Henry R

    2001-01-01

    Localized calcium release events (calcium sparks) were studied in voltage-clamped cut twitch fibres of Rana temporaria. A histogram of thousands of spontaneous sparks displayed a monotonically decreasing amplitude distribution from the low to the high limit of > 7 ΔF/F0 units. Several effects of low micromolar concentrations of ryanodine (0.4–2 μm) on spontaneous sparks, reproducing the agent's effects on single ryanodine receptor channel current in bilayers, were observed collectively for the first time in live fibres, namely (a) increases in spark frequency followed by (b) conversions of sparks into steady glows lasting tens of seconds, (c) occasional interruptions of the glows by brief gaps of darkness, and (d) abolition of sparks at the locations of the glows. The glow could reflect the incessant Ca2+ flux through a single (or a few) calcium release channel locked in the semi-open state, which was allowed to make occasional transitions to the closed state but not to the fully open state. Higher concentrations of ryanodine (≥ 20 μm) suppressed the spontaneous sparks effectively and permanently, presumably by deactivating the ryanodine receptors. Depolarization-evoked sparks elicited with small pulses had higher frequencies and larger amplitudes than spontaneous sparks and were abolished by both concentrations of ryanodine. With 1–2 μm ryanodine, however, a uniform non-sparking calcium release persisted during the pulse, with the globally averaged increase in fluorescence intensity being about half that of the control. A possible origin of this non-sparking release may be related to the structural coupling between the voltage sensors and the ryanodine receptors that can exist only in live fibres but not in the bilayer preparation. PMID:11454954

  14. Effects of wetland vs. landscape variables on parasite communities of Rana pipiens: links to anthropogenic factors

    USGS Publications Warehouse

    Schotthoefer, Anna M.; Rohr, Jason R.; Cole, Rebecca A.; Koehler, Anson V.; Johnson, Catherine M.; Johnson, Lucinda B.; Beasley, Val R.

    2011-01-01

    The emergence of several diseases affecting amphibian populations worldwide has prompted investigations into determinants of the occurrence and abundance of parasites in frogs. To understand the spatial scales and identify specific environmental factors that determine risks of parasitism in frogs, helminth communities in metamorphic frogs of the northern leopard frog (Rana pipiens) were examined in relation to wetland and landscape factors at local (1 km) and regional (10 km) spatial extents in an agricultural region of Minnesota (USA) using regression analyses, ordination, and variance partitioning techniques. Greater amounts of forested and woody wetland habitats, shorter distances between woody wetlands, and smaller-sized open water patches in surrounding landscapes were the most consistently positive correlates with the abundances, richness, and diversity of helminths found in the frogs. Wetland and local landscape variables were suggested as most important for larval trematode abundances, whereas local and regional landscape variables appeared most important for adult helminths. As previously reported, the sum concentration of atrazine and its metabolite desethylatrazine, was the strongest predictor of larval trematode communities. In this report, we highlight the additional influences of landscape factors. In particular, our data suggest that anthropogenic activities that have resulted in the loss of the availability and connectivity of suitable habitats in the surrounding landscapes of wetlands are associated with declines in helminth richness and abundance, but that alteration of wetland water quality through eutrophication or pesticide contamination may facilitate the transmission of certain parasite taxa when they are present at wetlands. Although additional research is needed to quantify the negative effects of parasitism on frog populations, efforts to reduce inputs of agrochemicals into wetlands to limit larval trematode infections may be warranted

  15. Dynamics of testis-ova in a wild population of Japanese pond frogs, Rana nigromaculata.

    PubMed

    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.

  16. Molecular cloning and characterization of oocyte-specific Pat1a in Rana rugosa frogs.

    PubMed

    Nakamura, Yoriko; Iwasaki, Takehiro; Umei, Yosuke; Saotome, Kazuhiro; Nakajima, Yukiko; Kitahara, Shoichi; Uno, Yoshinobu; Matsuda, Yoichi; Oike, Akira; Kodama, Maho; Nakamura, Masahisa

    2015-10-01

    The Pat1 gene is expressed in the immature oocytes of Xenopus, and is reportedly involved in regulating the translation of maternal mRNAs required for oocyte-maturation. However, it is still unknown when Pat1a first appears in the differentiating ovary of amphibians. To address this issue, we isolated the full-length Pat1a cDNA from the frog Rana rugosa and examined its expression in the differentiating ovary of this frog. Among eight different tissues examined, the Pat1a mRNA was detectable in only the ovary. When frozen sections from the ovaries of tadpoles at various stages of development were immunostained for Vasa-a germ cell-specific protein-and Pat1a, Vasa-immunopositive signals were observed in all of the germ cells, whereas Pat1a signals were confined to the growing oocytes (50-200 μm in diameter), and absent from small germ cells (<50 μm in diameter). Forty days after testosterone injection into tadpoles to induce female-to-male sex-reversal, Pat1a-immunoreactive oocytes had disappeared completely from the sex-reversed gonad, but Vasa-positive small germ cells persisted. Thus, Pat1a would be a good marker for identifying the sexual status of the sex-reversing gonad in amphibians. In addition, fluorescence in situ hybridization analysis showed Pat1a to have an autosomal locus, suggesting that Pat1a transcription is probably regulated by a tissue-specific transcription factor in R. rugosa.

  17. Evaluation of metomidate hydrochloride as an anesthetic in leopard frogs (Rana pipiens).

    PubMed

    Doss, Grayson A; Nevarez, Javier G; Fowlkes, Natalie; da Cunha, Anderson F

    2014-03-01

    Metomidate hydrochloride is an imidazole-based, nonbarbiturate hypnotic drug primarily used as an immersion sedation and anesthetic agent in freshwater and marine finfish. To the authors' knowledge, there is no documentation in the literature of its use in amphibians. In this study, 7 male and 4 female leopard frogs (Rana pipiens) were induced with metomidate hydrochloride via immersion bath at a concentration of 30 mg/L for 60 min. The pH of the induction solution ranged from 7.63 to 7.75. Each frog was then removed from the induction solution, rinsed, and recovered in 26.6 degrees C amphibian Ringer's solution. After 210 min in the Ringer's solution, the frogs were transferred to moist paper towels for recovery. Heart rate, gular and abdominal respiration rates, righting reflex, superficial and deep pain withdrawal reflexes, corneal and palpebral reflexes, and escape response were monitored and recorded at defined intervals during both induction and recovery. The average time to loss of righting reflex and escape response was 17.36 min and 17.82 min, respectively. Metomidate produced clinical sedation in all frogs (n = 11). Surgical anesthesia was achieved in only 27% (3/11), with an anesthetic duration that ranged from 9 to 20 min. Recovery times were extremely prolonged and varied, with a range from 313 min to longer than 600 min. The findings of this study indicate that metomidate hydrochloride is unsuitable as a sole anesthetic agent in leopard frogs, and further research is needed to evaluate its suitability in other amphibians. PMID:24712162

  18. Cardiovascular responses to catecholamines at 12 degrees C in the American bullfrog (Rana catesbeiana).

    PubMed

    Herman, C A; Robleto, D O; Mata, P L; Heller, R S

    1986-10-01

    The effects of epinephrine, norepinephrine, phenylephrine, and isoproterenol on blood pressure and heart rate were studied in cannulated American bullfrogs, Rana catesbeiana. The bullfrogs were chronically cannulated with a T cannula in the right sciatic artery. In warm-acclimated (22 degrees C) bullfrogs, preinjection mean systemic arterial pressure (SAP) prior to experimental treatment was 13.1 +/- 0.7 mm Hg. Preinjection heart rate was 34.8 +/- 1.8 beats per minute. These parameters were lower in cold-acclimated (12 degrees C) bullfrogs. Cold-acclimated animals had mean SAP values of 8.2 +/- 0.3 mm Hg, and heart rate was 11.1 +/- 1.1 beats per minute. Epinephrine, norepinephrine, and phenylephrine increased blood pressure to an equivalent degree in warm- and cold-acclimated animals. Dose-related decreases in heart rate in response to these catecholamines were observed in warm- but not in cold-acclimated bullfrogs. Warm-acclimated animals were more responsive to isoproterenol from 0.03 micrograms/kg body weight (bw) to 10 micrograms/kg bw than were cold-acclimated animals. The response to isoproterenol was effectively blocked by propranolol (5 mg/kg bw) in both warm- and cold-acclimated animals. Propranolol alone decreased mean SAP in both warm- and cold-acclimated animals, suggesting blockade of endogenous sympathetic activity. Beta receptor response thus appears diminished, but not absent at 12 degrees C. However, the alpha receptors responsible for elevation of blood pressure equally responsive at 12 degrees and 22 degrees C.

  19. Characterization of leukotriene C4 binding sites in the brain of the American bullfrog, Rana catesbeiana.

    PubMed

    Herman, C A; Charlton, G A; Chiono, M

    1992-04-15

    In this study, specific binding sites for [3H]-LTC4 on membrane preparations from American bullfrog (Rana catesbeiana) brain were characterized. Binding assays were done in the presence of serine (5mM) borate (10 mM) for 30 min at 23 degrees C. Under these conditions, no metabolism of LTC4 to LTD4 occurred. Specific binding of [3H]-LTC4 reached steady state within 10 min, remained constant for 60 min, and was reversible with the addition of 1,000-fold excess unlabelled LTC4. Scatchard analysis of the binding data indicated a single class of binding sites with an estimated Kd of 89.83 nM and Bmax of 43.79 pmol/mg protein. Competition binding studies demonstrated that LTD4 and LTE4 were ineffective in displacing [3H]-LTC4 from its binding site. The Ki for LTC4 was 51 nM. S-decylglutathione, glutathione and hematin had Ki values of 44, 312,602, and 25,576 nM, respectively. The mammalian cysteinyl leukotriene antagonist L-660,711 inhibited specific binding of [3H]-LTC4, with a Ki of 87,149 nM. Guanosine-5'-0-3-thiotriphosphate (GTP gamma S) did not affect specific binding of [3H]-LTC4 indicating that, like mammalian LTC4 receptors, a Gi protein is not involved in the transduction mechanism. The LTC4 binding site in bullfrog brain demonstrates both similarities and differences from its mammalian counterpart.

  20. Catecholamine effects on blood pressure and heart rate in the American bullfrog, Rana catesbeiana.

    PubMed

    Herman, C A; Sandoval, E J

    1983-10-01

    The effects of catecholamines and adrenergic blocking agents were studied in vivo on the blood pressure and heart rate of the unanaesthetized American bullfrog, Rana catesbeiana. Bullfrogs were chronically cannulated with a T cannula in the right sciatic artery. The mean systemic arterial blood pressure prior to the infusion of catecholamines was 18.5 +/- 1.5 mm Hg. Mean preinfusion heart rate was 30.9 +/- 2.0 beats/min. Epinephrine elicited the largest increase in blood pressure, with an accompanying decrease in heart rate. Norepinephrine and phenylephrine were less effective. Isoproterenol was the only catecholamine tested which elevated heart rate in a dose-dependent manner. It had no effect on blood pressure. The beta adrenergic antagonist, propranolol, blocked the increase in heart rate elicited by isoproterenol but had no effect on the blood pressure increases elicited by the other catecholamines. The alpha adrenergic antagonist, phentolamine, partially blocked the blood pressure increase by epinephrine, norepinephrine, and phenylephrine as well as the elevation of heart rate by isoproterenol. Atropine alone elevated heart rate 19 +/- 3 beats/min, and prevented slowing of the heart due to epinephrine, norepinephrine, and phenylephrine. Stimulatory effects of epinephrine on heart rate were observed only after atropine had been administered. Beta adrenergic receptors, therefore, appear to function in heart rate regulation; however, the predominant effect of catecholamines is reflex slowing of the heart due to stimulation of the vagus nerve. In contrast, the alpha receptor, stimulated by epinephrine, appears to be the main adrenergic receptor controlling blood pressure changes.

  1. Dmrt1 polymorphism covaries with sex-determination patterns in Rana temporaria.

    PubMed

    Ma, Wen-Juan; Rodrigues, Nicolas; Sermier, Roberto; Brelsford, Alan; Perrin, Nicolas

    2016-08-01

    Patterns of sex-chromosome differentiation and gonadal development have been shown to vary among populations of Rana temporaria along a latitudinal transect in Sweden. Frogs from the northern-boreal population of Ammarnäs displayed well-differentiated X and Y haplotypes, early gonadal differentiation, and a perfect match between phenotypic and genotypic sex. In contrast, no differentiated Y haplotypes could be detected in the southern population of Tvedöra, where juveniles furthermore showed delayed gonadal differentiation. Here, we show that Dmrt1, a gene that plays a key role in sex determination and sexual development across all metazoans, displays significant sex differentiation in Tvedöra, with a Y-specific haplotype distinct from Ammarnäs. The differential segment is not only much shorter in Tvedöra than in Ammarnäs, it is also less differentiated and associates with both delayed gonadal differentiation and imperfect match between phenotypic and genotypic sex. Whereas Tvedöra juveniles with a local Y haplotype tend to ultimately develop as males, those without it may nevertheless become functional XX males, but with strongly female-biased progeny. Our findings suggest that the variance in patterns of sex determination documented in common frogs might result from a genetic polymorphism within a small genomic region that contains Dmrt1. They also substantiate the view that recurrent convergences of sex determination toward a limited set of chromosome pairs may result from the co-option of small genomic regions that harbor key genes from the sex-determination pathway. PMID:27551369

  2. Effects of six chemical deicers on larval wood frogs (Rana sylvatica).

    PubMed

    Harless, Meagan L; Huckins, Casey J; Grant, Jacqualine B; Pypker, Thomas G

    2011-07-01

    Widespread and intensive application of road deicers, primarily road salt (NaCl), in North America threatens water quality and the health of freshwater ecosystems. Intensive use of NaCl can be harmful to sensitive members of freshwater ecosystems such as amphibians. Detection of negative effects of NaCl application has prompted the search for alternative chemical deicers with lower environmental impacts. We conducted a series of 96-h acute toxicity tests to determine the negative sensitivity of larval wood frogs (Rana [Lithobates] sylvatica) to six deicing chemicals: urea (CH(4) N(2) O), sodium chloride (NaCl), magnesium chloride (MgCl(2) ), potassium acetate (CH(3) COOK), calcium chloride (CaCl(2) ), and calcium magnesium acetate (C(8) H(12) CaMgO(8) ). Acetates are sometimes touted as environmentally friendly alternatives to NaCl but have not been examined in enough detail to warrant this designation. When exposed to a range of environmentally realistic concentrations of these chemicals, larvae were least sensitive (i.e., had the lowest mortality rate) to CH(4) N(2) O, NaCl, and MgCl(2) and most sensitive to acetates (C(8) H(12) CaMgO(8) , CH(3) COOK) and CaCl(2) . Our observed median lethal concentration estimates (LC50(96-h) ) for NaCl were over two times higher than values presented in previous studies, which suggests variability in tolerance among R. sylvatica populations. The deicers varied greatly in their toxicity, and further research is warranted to examine the differential effects of this suite of deicers on other species.

  3. [Effects of cadmium on metamorphism and gonad differentiation in Rana chensinensis].

    PubMed

    Huang, Min-Yi; Wang, Hong-Yuan; Zhang, Yu-Hui

    2010-06-01

    200 tadpoles of Rana chensinensis at stage 26 - 27 were exposed to 0.05, 0.1, 0.2 or 0.4 mg/L Cd2+ in tap water respectively until they're fully metamorphic after which the heteromorphic young frogs in different treatments were anatomized, females and males were identified through gonad observation, and the female ratio was calculated. Localization of estrogen receptors (ER) in liver cells was investigated in different treatments using immunocytochemistry. The results showed that Cd2+ might induce limb abnormality, however, there was little correlation between abnormality rate and cadmium concentration in lower Cd2+ levels except for a higher limb abnormality ratio in the 0.4 mg/L group. On the other hand, Cd2+ could affect gonad differentiation. Compared to the control group, the proportion of female population increased in the 0.05 mg/L group and decreased in the 0.1, 0.2 and 0.4 mg/L ones. The sex rate in the 0.2 mg/L group is significantly different from that in the control group. Hermaphrodite gonads appeared in the two treatments with 0.2 mg/L and 0.4 mg/L of Cd2+. Additionally, ER expression was positive in both cytoplasm and nucleolus of liver cells in Cd2+ treated groups. But, there was no linear relationship between ER expressions levels and the concentration of Cd2+. These results suggested that cadmium can influence tadpole metamorphosis and gonad development by affecting the secretion of sex hormone.

  4. Effects of wetland vs. landscape variables on parasite communities of Rana pipiens: links to anthropogenic factors.

    PubMed

    Schotthoefer, Anna M; Rohr, Jason R; Cole, Rebecca A; Koehler, Anson V; Johnson, Catherine M; Johnson, Lucinda B; Beasley, Val R

    2011-06-01

    The emergence of several diseases affecting amphibian populations worldwide has prompted investigations into determinants of the occurrence and abundance of parasites in frogs. To understand the spatial scales and identify specific environmental factors that determine risks of parasitism in frogs, helminth communities in metamorphic frogs of the northern leopard frog (Rana pipiens) were examined in relation to wetland and landscape factors at local (1 km) and regional (10 km) spatial extents in an agricultural region of Minnesota (USA) using regression analyses, ordination, and variance partitioning techniques. Greater amounts of forested and woody wetland habitats, shorter distances between woody wetlands, and smaller-sized open water patches in surrounding landscapes were the most consistently positive correlates with the abundances, richness, and diversity of helminths found in the frogs. Wetland and local landscape variables were suggested as most important for larval trematode abundances, whereas local and regional landscape variables appeared most important for adult helminths. As previously reported, the sum concentration of atrazine and its metabolite desethylatrazine, was the strongest predictor of larval trematode communities. In this report, we highlight the additional influences of landscape factors. In particular, our data suggest that anthropogenic activities that have resulted in the loss of the availability and connectivity of suitable habitats in the surrounding landscapes of wetlands are associated with declines in helminth richness and abundance, but that alteration of wetland water quality through eutrophication or pesticide contamination may facilitate the transmission of certain parasite taxa when they are present at wetlands. Although additional research is needed to quantify the negative effects of parasitism on frog populations, efforts to reduce inputs of agrochemicals into wetlands to limit larval trematode infections may be warranted

  5. [Effects of cadmium on metamorphism and gonad differentiation in Rana chensinensis].

    PubMed

    Huang, Min-Yi; Wang, Hong-Yuan; Zhang, Yu-Hui

    2010-06-01

    200 tadpoles of Rana chensinensis at stage 26 - 27 were exposed to 0.05, 0.1, 0.2 or 0.4 mg/L Cd2+ in tap water respectively until they're fully metamorphic after which the heteromorphic young frogs in different treatments were anatomized, females and males were identified through gonad observation, and the female ratio was calculated. Localization of estrogen receptors (ER) in liver cells was investigated in different treatments using immunocytochemistry. The results showed that Cd2+ might induce limb abnormality, however, there was little correlation between abnormality rate and cadmium concentration in lower Cd2+ levels except for a higher limb abnormality ratio in the 0.4 mg/L group. On the other hand, Cd2+ could affect gonad differentiation. Compared to the control group, the proportion of female population increased in the 0.05 mg/L group and decreased in the 0.1, 0.2 and 0.4 mg/L ones. The sex rate in the 0.2 mg/L group is significantly different from that in the control group. Hermaphrodite gonads appeared in the two treatments with 0.2 mg/L and 0.4 mg/L of Cd2+. Additionally, ER expression was positive in both cytoplasm and nucleolus of liver cells in Cd2+ treated groups. But, there was no linear relationship between ER expressions levels and the concentration of Cd2+. These results suggested that cadmium can influence tadpole metamorphosis and gonad development by affecting the secretion of sex hormone. PMID:20672415

  6. Motor planning modulates sensory-motor control of collision avoidance behavior in the bullfrog, Rana catesbeiana

    PubMed Central

    Nakagawa, Hideki; Nishida, Yuuya

    2012-01-01

    Summary In this study, we examined the collision avoidance behavior of the frog, Rana catesbeiana to an approaching object in the upper visual field. The angular velocity of the frog's escape turn showed a significant positive correlation with the turn angle (r2 = 0.5741, P<0.05). A similar mechanism of velocity control has been known in head movements of the owl and in human saccades. By analogy, this suggests that the frog planned its escape velocity in advance of executing the turn, to make the duration of the escape behavior relatively constant. For escape turns less than 60°, the positive correlation was very strong (r2 = 0.7097, P<0.05). Thus, the frog controlled the angular velocity of small escape turns very accurately and completed the behavior within a constant time. On the other hand, for escape turns greater than 60°, the same correlation was not significant (r2 = 0.065, P>0.05). Thus, the frog was not able to control the velocity of the large escape turns accurately and did not complete the behavior within a constant time. In the latter case, there was a small but significant positive correlation between the threshold angular size and the angular velocity (r2 = 0.1459, P<0.05). This suggests that the threshold is controlled to compensate for the insufficient escape velocity achieved during large turn angles, and could explain a significant negative correlation between the turn angle and the threshold angular size (r2 = 0.1145, P<0.05). Thus, it is likely that the threshold angular size is also controlled by the turn angle and is modulated by motor planning. PMID:23213389

  7. Conditions controlling the onset of breeding migration of the Japanese mountain stream frog, Rana sakuraii

    NASA Astrophysics Data System (ADS)

    Miwa, Tokio

    2007-07-01

    I studied the conditions controlling the timing of breeding migration of the Japanese mountain stream frog Rana sakuraii, an explosive breeder, over 9 years (1992, 1993 and 1999-2005). I analysed two factors: the daily cumulative temperature (DCT) during hibernation and the triggering temperature on the day of migration onset. Frogs hibernated in shallow running water in streams in December. A total of 53,155 breeding migrating adults were captured by traps. Every year, breeding migration was induced by a rise in daily maximum water temperature to about 5°C. However, its date was limited to 1 February at the earliest, and the onset needed a DCT (from 20 January, using 3°C as the threshold for daily effective temperature) of at least about 15°C. Earlier (e.g. in mid- or late January), even if the maximum temperature rose to 5-8°C, migration did not begin. Moreover, even in early February, if the maximum temperature rose to 5°C, if it had been too cold in January and the DCT was low, migration would not begin until mid- or late February. Thus, the earliest date of readiness for migration varied from 1 February to mid-February, depending on the winter DCT. Logistic regression analyses showed that both factors, the DCT and the daily temperature, were significant. I propose that in temperate-zone amphibian explosive breeders, both the passing of an essential number of days and an essential DCT during hibernation are prerequisites for the onset of breeding migration before the daily temperature rises to the threshold.

  8. Heavy metals in bullfrog (Rana catesbeiana) tadpoles: Effects of depuration before analysis

    SciTech Connect

    Burger, J.; Snodgrass, J. |

    1998-11-01

    Although tadpoles may well be excellent organisms to use as bioindicators of heavy metal contamination, the relationship of deposition in the body compared to the tail, and the effect of sediments or other debris in the digestive tract on heavy metal concentrations is unknown. The authors examined the effect of experimental depuration of bullfrog (Rana catesbeiana) tadpoles on heavy metal and selenium concentrations in intact tadpoles, as well as their bodies and tails. They defined depuration in this experiment as allowing defecation as an elimination process for intestinal contents. The authors maintained wild-caught tadpoles in clean water for 0, 24, 48, and 72 h to determine the effects of clearing on heavy metal concentrations. They also examined the concentrations of heavy metals in the whole body and digestive tract separately. The authors test the null hypotheses that no differences occur in metals as a function of time in uncontaminated water, and that no differences occur in metal concentrations in the body compared to the tail and to the digestive tract. They rejected these hypotheses based on regression models. Variance in concentrations of chromium (77%) and lead (70%) were explained by part and clearing time; for manganese (80%), mercury (64%), selenium (28%), and cadmium (25%) the variation was explained only by body part; for arsenic (53%), the variation was explained by part, clearing time, and weight of the various parts. For those metals in which clearing time explained part of the variation, metal concentrations in both the body and tail decreased after 24 and 48 h, but increased slightly thereafter. Clearing, however, did not greatly decrease metal concentrations in either the body or tail. These data suggest that for some metals (mercury, manganese, cadmium, selenium), clearing has no effect, and for others the effect is slight. For fresh tadpoles, however, the digestive tract contained significantly higher concentrations of all metals than

  9. Metabolism of C26 bile alcohols in the bullfrog, Rana catesbeiana

    SciTech Connect

    Noma, Y.; Kihira, K.; Kuramoto, T.; Hoshita, T.

    1988-03-01

    Metabolism of C26 bile alcohols in the bullfrog, Rana catesbeiana, was studied. (24-14C)-24-Dehydro-26-deoxy-5 beta-ranol (3 alpha,7 alpha,12 alpha-trihydroxy-27-nor-5 beta-cholestan-24-one) was chemically synthesized from (24-14C)cholic acid and incubated with bullfrog liver homogenate fortified with NADPH. 24-Dehydro-26-deoxy-5 beta-ranol was shown to be converted into both 26-deoxy-5 beta-ranol and 24-epi-26-deoxy-5 beta-ranol ((24S)- and (24R)-27-nor-5 beta-cholestane-3 alpha,7 alpha,12 alpha,24-tetrols) in addition to 5 beta-ranol ((24R)-27-nor-5 beta-cholestane-3 alpha,7 alpha,12 alpha,24,26-pentol), which is the major bile alcohol of the bullfrog. (24-3H)-26-Deoxy-5 beta-ranol and (24-3H)-24-epi-26-deoxy-5 beta-ranol were prepared from 24-dehydro-26-deoxy-5 beta-ranol by reduction with sodium (3H) borohydride and administered respectively to two each of four bullfrogs by intraperitoneal injection. After 24 h, labeled 5 beta-ranol was isolated from the bile of the bullfrogs that received (24-3H)-26-deoxy-5 beta-ranol. In contrast little if any radioactivity could be detected in 5 beta-ranol or its 24-epimer after administration of (24-3H)-24-epi-26-deoxy-5 beta-ranol.

  10. Shading as a Control Method for Invasive European Frogbit (Hydrocharis morsus-ranae L.)

    PubMed Central

    Zhu, Bin; Ellis, Michael S.; Fancher, Kelly L.; Rudstam, Lars G.

    2014-01-01

    Invasive European frogbit (Hydrocharis morsus-ranae L.) has negative environmental and economic impacts in North American water bodies. It is therefore important to develop effective management tools to control this invasive species. This study investigated shading as a control method for European frogbit in both greenhouse and lake mesocosm experiments. A series of shade treatments (0%, 50%, 60%, 70%, 80%, and 100%) were tested in the greenhouse for three weeks. Results showed that the 100% shade was most effective at controlling European frogbit, and other shade treatments greater than 50% were less effective, reducing frogbit biomass up to 38.2%. There were no differences found in temperature between treatments, but dissolved oxygen decreased as shading increased. A lake mesocosm experiment utilizing 0% shade, 70% shade, and 100% shade treatments was performed in a sheltered inlet of Oneida Lake in New York State for over one month. Resulting European frogbit biomass was significantly (25 times) less in areas treated with the 70% shade and nearly zero with the 100% shade. Shading did not affect temperature but improved DO conditions. Results on the shading effects on submerged macrophytes were not conclusive: no significant differences in changes in species richness and abundance between the three groups at the end of studied period suggested no shading effects; significant differences between the beginning and end communities in the 70% shade and the 100% shade but not in the control group indicated significant impacts of shading. This study is the first one to investigate shading as a control method for European frogbit and it is concluded that a moderately high density shade can effective remove European frogbit likely with minor impacts on the environment. More experiments with larger scales and longer time periods are recommended for further investigation. PMID:24886916

  11. Dmrt1 polymorphism covaries with sex-determination patterns in Rana temporaria.

    PubMed

    Ma, Wen-Juan; Rodrigues, Nicolas; Sermier, Roberto; Brelsford, Alan; Perrin, Nicolas

    2016-08-01

    Patterns of sex-chromosome differentiation and gonadal development have been shown to vary among populations of Rana temporaria along a latitudinal transect in Sweden. Frogs from the northern-boreal population of Ammarnäs displayed well-differentiated X and Y haplotypes, early gonadal differentiation, and a perfect match between phenotypic and genotypic sex. In contrast, no differentiated Y haplotypes could be detected in the southern population of Tvedöra, where juveniles furthermore showed delayed gonadal differentiation. Here, we show that Dmrt1, a gene that plays a key role in sex determination and sexual development across all metazoans, displays significant sex differentiation in Tvedöra, with a Y-specific haplotype distinct from Ammarnäs. The differential segment is not only much shorter in Tvedöra than in Ammarnäs, it is also less differentiated and associates with both delayed gonadal differentiation and imperfect match between phenotypic and genotypic sex. Whereas Tvedöra juveniles with a local Y haplotype tend to ultimately develop as males, those without it may nevertheless become functional XX males, but with strongly female-biased progeny. Our findings suggest that the variance in patterns of sex determination documented in common frogs might result from a genetic polymorphism within a small genomic region that contains Dmrt1. They also substantiate the view that recurrent convergences of sex determination toward a limited set of chromosome pairs may result from the co-option of small genomic regions that harbor key genes from the sex-determination pathway.

  12. Cadmium pollution and amphibians--Studies in tadpoles of Rana limnocharis.

    PubMed

    Patar, Arabinda; Giri, Anirudha; Boro, Freeman; Bhuyan, Krishna; Singha, Utsab; Giri, Sarbani

    2016-02-01

    Cadmium is released into the environment in increasing amounts from different natural and anthropogenic activities contaminating the aquatic habitats. Amphibian tadpoles develop in water and hence are likely to be adversely affected by cadmium present in the aquatic environment. We have studied the toxic and genotoxic effects of CdCl2 on the tadpoles of Rana limnocharis. CdCl2 in the concentration range between 0.1 and 0.4 mg/L induced significant mortality in R. limnocharis tadpoles in a dose and time dependent manner. The 10-day LC50 which has more ecological relevance was far less than the 24-h LC50. Tadpoles exposed to CdCl2 metamorphosed at an early age possibly as a survival strategy to move out of the stressful environment. The body weight of the CdCl2 exposed animals at metamorphosis was lower compared to the control individuals which may affect survival and reproductive fitness in adult life. Besides, the average body length of the metamorphosed individuals in the CdCl2 exposed group was higher than the control group. CdCl2 was found to be genotoxic in micronucleus test and comet assay. The ambient concentration of Cd could reach up to 60 μg/L or more. Exposure to 18.5 μg/L of CdCl2 (1% of 24-h LC50) induced significant increase in DNA strand breaks as compared to the control. The present findings demonstrate that presence of cadmium in the aquatic environment can significantly alter the life history traits and cause DNA damage in amphibians and hence, could contribute towards their population decline.

  13. Oral chytridiomycosis in the mountain yellow-legged frog (Rana muscosa)

    USGS Publications Warehouse

    Fellers, G.M.; Green, D.E.; Longcore, J.E.

    2001-01-01

    The chytrid fungus Batrachochytrium dendrobatidis was originally reported in wild frog populations in Panama and Australia, and from captive frogs in the U.S. National Zoological Park (Washington, DC). This recently described fungus affects the keratinized epidermis of amphibians and has been implicated as a causative factor in the declines of frog populations. We report here the presence of B. dendrobatidis in larval and recently metamorphosed mountain yellow-legged frogs (Rana muscosa) in or near the Sierra Nevada Mountains of California, an area where declines have been documented in all five species of native anurans. Forty-one percent (158 of 387) of larval R. muscosa examined in the field with a hand lens and 18% (14 of 79) of preserved larvae had abnormalities of the oral disc. Twenty-eight larvae were collected from 10 sites where tadpoles had been observed with missing or abnormally keratinized mouthparts, and 24 of these were examined for infection. Sixty-seven percent (16 of 24) of these tadpoles were infected with B. dendrobatidis. Batrachochytrium dendrobatidis was cultured from both tadpoles and recent metamorphs from one of these sites. Tadpoles with mouthpart abnormalities or confirmed chytrid fungus infections were collected at 23 sites spanning a distance of > 440 km and an elevational range from 1658a??3550 m. Life-history traits of R. muscosa may make this species particularly susceptible to infection by Batrachochytrium. We recommend that biologists examine tadpoles for oral disc abnormalities as a preliminary indication of chytridiomycosis. Further, we believe that biologists should take precautions to prevent spreading this and other amphibian diseases from one site to another.

  14. Oral chytridiomycosis in the mountain yellow-legged frog (Rana muscosa)

    USGS Publications Warehouse

    Fellers, G.M.; Green, E.D.; Longcore, J.E.

    2001-01-01

    The chytrid fungus Batrachochytrium dendrobatidis was originally reported in wild frog populations in Panama and Australia, and from captive frogs in the U.S. National Zoological Park (Washington, DC). This recently described fungus affects the keratinized epidermis of amphibians and has been implicated as a causative factor in the declines of frog populations. We report here the presence of B. dendrobatidis in larval and recently metamorphosed mountain yellow-legged frogs (Rana muscosa) in or near the Sierra Nevada Mountains of California, an area where declines have been documented in all five species of native anurans. Forty-one percent (158 of 387) of larval R. muscosa examined in the field with a hand lens and 18% (14 of 79) of preserved larvae had abnormalities of the oral disc. Twenty-eight larvae were collected from 10 sites where tadpoles had been observed with missing or abnormally keratinized mouthparts, and 24 of these were examined for infection. Sixty-seven percent (16 of 24) of these tadpoles were infected with B. dendrobatidis. Batrachochytrium dendrobatidis was cultured from both tadpoles and recent metamorphs from one of these sites. Tadpoles with mouthpart abnormalities or confirmed chytrid fungus infections were collected at 23 sites spanning a distance of > 440 km and an elevational range from 1658-3550 m. Life-history traits of R. muscosa may make this species particularly susceptible to infection by Batrachochytrium. We recommend that biologists examine tadpoles for oral disc abnormalities as a preliminary indication of chytridiomycosis. Further, we believe that biologists should take precautions to prevent spreading this and other amphibian diseases from one site to another.

  15. Ovine thyroid stimulating hormone (TSH) heterologously stimulates production of thyroid hormones from Chinese soft-shell turtle (Pelodiscus sinensis) and bullfrog (Rana catesbeiana and Rana rugulosa) thyroids in vitro.

    PubMed

    Huang, Wei-Tung; Chien, Jung-Tsun; Weng, Ching-Feng; Jeng, Yung-Yue; Lu, Li-Chia; Yu, John Yuh-Lin

    2009-06-01

    Thyroid hormones are important for regulating a variety of developmental processes in vertebrates, including growth, differentiation, metamorphosis, and oxidative metabolism. In particular, this study focused on the in vitro production of thyroxine (T(4)) and triiodothyronine (T(3)) from thyroids in American bullfrogs (Rana catesbeiana), Chinese bullfrogs (Rana rugulosa Wiegmann), and Chinese soft-shell turtles (Pelodiscus sinensis) treated with ovine thyroid stimulating hormone (TSH) at different culture intervals (2, 4, 8, and 12 h) and dosages (1, 10, 50 or 100 ng). The levels of T(4) and T(3) in the tested animals were elevated upon stimulation in a time- and dose-dependent manner, indicating de novo synthesis of T(4) and T(3). Significantly higher hormone levels were observed in the Chinese bullfrog compared to the other two species, for both the time-course and dose-response experiments. Although the bullfrog secreted significantly higher levels of T(4) and T(3), a higher T(4)-conversion capacity was found in the Chinese soft-shell turtle. The highest ratios of T(3) to T(4) were observed in the American bullfrog and Chinese soft-shell turtle for the time-course and dose-response experiments, respectively. These findings suggest that the Chinese soft-shell turtle and bullfrog thyroids can accept ovine TSH for T(4)- and T(3)-formation in a time- and dose-dependent manner, supporting the hypothesis that the binding interactions between TSHs and thyroidal receptors are conserved in vertebrates.

  16. The tactile-stimulated startle response of tadpoles: acceleration performance and its relationship to the anatomy of wood frog (Rana sylvatica), bullfrog (Rana catesbeiana), and American toad (Bufo americanus) tadpoles.

    PubMed

    Eidietis, Laura

    2006-04-01

    I described the tactile-stimulated startle response (TSR) of wood frog (Rana sylvatica), bullfrog (Rana catesbeiana), and American toad (Bufo americanus) tadpoles. One purpose was to rank species in terms of maximum acceleration performance. Also, I tested whether anatomical indicators of performance potential were predictive of realized performance. TSRs were elicited in a laboratory setting, filmed at 250 Hz, and digitally analyzed. TSRs began with two, initial body curls during which tadpoles showed a broad spectrum of movement patterns. TSR performance was quantified by maximum linear acceleration and maximum rotational acceleration of the head/body, both of which tended to occur immediately upon initiation of motion (< 0.012 sec into the response). Bullfrog tadpoles had higher maximum acceleration than the other species, but other interspecific differences were not significant. The species' rank order for the anatomical indicator of linear acceleration potential was bullfrog > wood frog > American toad. The species' rank order for the anatomical indicator of rotational acceleration potential was bullfrog > wood frog = American toad. Thus, the anatomical indicators roughly predicted the rank order of interspecific average performance. However, the anatomical indicators did not correlate with individual tadpole performance. Variability in behavioral patterns may obscure the connection between anatomy and performance. This is seen in the current lack of intraspecific correlation between a morphological indicator of acceleration capacity and acceleration performance. PMID:16493644

  17. Ovine thyroid stimulating hormone (TSH) heterologously stimulates production of thyroid hormones from Chinese soft-shell turtle (Pelodiscus sinensis) and bullfrog (Rana catesbeiana and Rana rugulosa) thyroids in vitro.

    PubMed

    Huang, Wei-Tung; Chien, Jung-Tsun; Weng, Ching-Feng; Jeng, Yung-Yue; Lu, Li-Chia; Yu, John Yuh-Lin

    2009-06-01

    Thyroid hormones are important for regulating a variety of developmental processes in vertebrates, including growth, differentiation, metamorphosis, and oxidative metabolism. In particular, this study focused on the in vitro production of thyroxine (T(4)) and triiodothyronine (T(3)) from thyroids in American bullfrogs (Rana catesbeiana), Chinese bullfrogs (Rana rugulosa Wiegmann), and Chinese soft-shell turtles (Pelodiscus sinensis) treated with ovine thyroid stimulating hormone (TSH) at different culture intervals (2, 4, 8, and 12 h) and dosages (1, 10, 50 or 100 ng). The levels of T(4) and T(3) in the tested animals were elevated upon stimulation in a time- and dose-dependent manner, indicating de novo synthesis of T(4) and T(3). Significantly higher hormone levels were observed in the Chinese bullfrog compared to the other two species, for both the time-course and dose-response experiments. Although the bullfrog secreted significantly higher levels of T(4) and T(3), a higher T(4)-conversion capacity was found in the Chinese soft-shell turtle. The highest ratios of T(3) to T(4) were observed in the American bullfrog and Chinese soft-shell turtle for the time-course and dose-response experiments, respectively. These findings suggest that the Chinese soft-shell turtle and bullfrog thyroids can accept ovine TSH for T(4)- and T(3)-formation in a time- and dose-dependent manner, supporting the hypothesis that the binding interactions between TSHs and thyroidal receptors are conserved in vertebrates. PMID:19535032

  18. The tactile-stimulated startle response of tadpoles: acceleration performance and its relationship to the anatomy of wood frog (Rana sylvatica), bullfrog (Rana catesbeiana), and American toad (Bufo americanus) tadpoles.

    PubMed

    Eidietis, Laura

    2006-04-01

    I described the tactile-stimulated startle response (TSR) of wood frog (Rana sylvatica), bullfrog (Rana catesbeiana), and American toad (Bufo americanus) tadpoles. One purpose was to rank species in terms of maximum acceleration performance. Also, I tested whether anatomical indicators of performance potential were predictive of realized performance. TSRs were elicited in a laboratory setting, filmed at 250 Hz, and digitally analyzed. TSRs began with two, initial body curls during which tadpoles showed a broad spectrum of movement patterns. TSR performance was quantified by maximum linear acceleration and maximum rotational acceleration of the head/body, both of which tended to occur immediately upon initiation of motion (< 0.012 sec into the response). Bullfrog tadpoles had higher maximum acceleration than the other species, but other interspecific differences were not significant. The species' rank order for the anatomical indicator of linear acceleration potential was bullfrog > wood frog > American toad. The species' rank order for the anatomical indicator of rotational acceleration potential was bullfrog > wood frog = American toad. Thus, the anatomical indicators roughly predicted the rank order of interspecific average performance. However, the anatomical indicators did not correlate with individual tadpole performance. Variability in behavioral patterns may obscure the connection between anatomy and performance. This is seen in the current lack of intraspecific correlation between a morphological indicator of acceleration capacity and acceleration performance.

  19. Evidence that the genes encoding the melittin-related peptides in the skins of the Japanese frogs Rana sakuraii and Rana tagoi are not orthologous to bee venom melittin genes: developmental- and tissue-dependent gene expression.

    PubMed

    Suzuki, Hiroe; Conlon, J Michael; Iwamuro, Shawichi

    2007-10-01

    The antimicrobial melittin-related peptides (MRPs) isolated from skin extracts of the Japanese frogs, Rana sakuraii and Rana tagoi, show amino acid sequence similarity with melittin from the venom of honeybees but the evolutionary relationship between the amphibian and insect peptides is unknown. cDNA clones encoding the MRP precursor (preproMRP) were obtained from R. sakuraii and R. tagoi skin total RNA. The nucleotide and deduced amino acid sequences of the clones indicated that the preproMRPs are organized like typical amphibian antimicrobial peptide precursors, with a highly conserved signal peptide, a more variable intervening sequence, and a hypervariable mature peptide region. This organization is markedly different from that of prepromelittin, in which the melittin sequence is flanked by multiple Xaa-Pro and Xaa-Ala dipeptides. The data indicate, therefore, that the genes encoding frog skin MRPs are not orthologous to the genes encoding melittins from bee venom. In adult R. sakuraii specimens, preproMRP gene transcripts were detected in total RNA from skeletal muscle as well as skin but not from heart, stomach, small intestine, or liver. In R. tagoi, preproMRP mRNA was not detected in skin prior to the onset of metamorphosis, but its level increased markedly during metamorphosis reaching a maximum at the stages of metamorphic climax. PMID:17826868

  20. Mass mortality associated with a frog virus 3-like Ranavirus infection in farmed tadpoles Rana catesbeiana from Brazil

    PubMed Central

    Mazzoni, Rolando; de Mesquita, Albenones José; Fleury, Luiz Fernando F.; de Brito, Wilia Marta Elsner Diederichsen; Nunes, Iolanda A.; Robert, Jacques; Morales, Heidi; Coelho, Alexandre Siqueira Guedes; Barthasson, Denise Leão; Galli, Leonardo; Catroxo, Marcia H. B.

    2010-01-01

    Ranviruses (Iridoviridae) are increasingly associated with mortality events in amphibians, fish, and reptiles. They have been recently associated with mass mortality events in Brazilian farmed tadpoles of the American bullfrog Rana catesbeiana Shaw. 1802. The objectives of the present study were to further characterize the virus isolated from sick R. catesbeiana tadpoles and confirm the etiology in these outbreaks. Sick tadpoles were collected in 3 farms located in Goiás State, Brazil, from 2003 to 2005 and processed for virus isolation and characterization, microbiology, histopathology, and parasitology. The phylogenetic relationships of Rana catesbeiana ranavirus (RCV-BR) with other genus members was investigated by PCR with primers specific for the major capsid protein gene (MCP) and the RNA polymerase DNA-dependent gene (Pol II). Sequence analysis and multiple alignments for MCP products showed >99% amino acid identity with other ranaviruses, while Pol II products showed 100% identity. Further diagnostics of the pathology including histology and transmission electron microscopy confirmed the viral etiology of these mass deaths. As for as we know, this is the first report of a ranaviral infection affecting aquatic organisms in Brazil. Additionally, our results suggest that American bullfrogs may have served as a vector of transmission of this virus, which highlights the potential threat of amphibian translocation in the world distribution of pathogens. PMID:20066953

  1. Mass mortality associated with a frog virus 3-like Ranavirus infection in farmed tadpoles Rana catesbeiana from Brazil.

    PubMed

    Mazzoni, Rolando; de Mesquita, Albenones José; Fleury, Luiz Fernando F; de Brito, Wilia Marta Elsner Diederichsen; Nunes, Iolanda A; Robert, Jacques; Morales, Heidi; Coelho, Alexandre Siqueira Guedes; Barthasson, Denise Leão; Galli, Leonardo; Catroxo, Marcia H B

    2009-11-01

    Ranaviruses (Iridoviridae) are increasingly associated with mortality events in amphibians, fish, and reptiles. They have been recently associated with mass mortality events in Brazilian farmed tadpoles of the American bullfrog Rana catesbeiana Shaw, 1802. The objectives of the present study were to further characterize the virus isolated from sick R. catesbeiana tadpoles and confirm the etiology in these outbreaks. Sick tadpoles were collected in 3 farms located in Goiás State, Brazil, from 2003 to 2005 and processed for virus isolation and characterization, microbiology, histopathology, and parasitology. The phylogenetic relationships of Rana catesbeiana ranavirus (RCV-BR) with other genus members was investigated by PCR with primers specific for the major capsid protein gene (MCP) and the RNA polymerase DNA-dependent gene (Pol II). Sequence analysis and multiple alignments for MCP products showed >99% amino acid identity with other ranaviruses, while Pol II products showed 100% identity. Further diagnostics of the pathology including histology and transmission electron microscopy confirmed the viral etiology of these mass deaths. As far as we know, this is the first report of a ranaviral infection affecting aquatic organisms in Brazil. Additionally, our results suggest that American bullfrogs may have served as a vector of transmission of this virus, which highlights the potential threat of amphibian translocation in the world distribution of pathogens. PMID:20066953

  2. Host defense peptides in skin secretions of the Oregon spotted frog Rana pretiosa: implications for species resistance to chytridiomycosis.

    PubMed

    Conlon, J Michael; Mechkarska, Milena; Ahmed, Eman; Coquet, Laurent; Jouenne, Thierry; Leprince, Jérôme; Vaudry, Hubert; Hayes, Marc P; Padgett-Flohr, Gretchen

    2011-06-01

    Population declines due to chytridiomycosis among frogs belonging to the Amerana (Rana boylii) species group from western North America have been particularly severe. Norepinephrine-stimulated skin secretions from the Oregon spotted frog Rana pretiosa Baird and Girard, 1853 were collected from individuals that had been previously infected with the causative agent Batrachochytrium dendrobatidis but had proved resistant to developing chytridiomycosis. These secretions contained a more diverse array of antimicrobial peptides than found in other species from the Amerana group and 14 peptides were isolated in pure form. Determination of their primary structures identified the peptides as esculentin-2PRa and -2PRb; ranatuerin-2PRa, -2PRb, -2PRc, -2PRd, and -2PRe; brevinin-1PRa, -1PRb, -1PRc, and -1PRd; and temporin-PRa, -PRb, and -PRc. The strongly cationic ranatuerin-2PRd and the esculentin-2 peptides, which have not been identified in the secretions of other Amerana species except for the closely related R. luteiventris, showed the highest growth inhibitory potency against microorganisms. The strongly hydrophobic brevinin-1PRd was the most cytotoxic to erythrocytes. Although no clear correlation exists between production of dermal antimicrobial peptides by a species and its resistance to fatal chytridiomycosis, the diversity of these peptides in R. pretiosa may be pivotal in defending the species against environmental pathogens such as B. dendrobatidis. PMID:21295070

  3. Expression of P450arom and Estrogen Receptor Alpha in the Oviduct of Chinese Brown Frog (Rana dybowskii) during Prehibernation

    PubMed Central

    Weng, Ji; Liu, Yuning; Xu, Ying; Hu, Ruiqi; Zhang, Haolin; Sheng, Xia; Watanabe, Gen; Taya, Kazuyoshi; Weng, Qiang; Xu, Meiyu

    2015-01-01

    One specific physiological phenomenon of Chinese brown frog (Rana dybowskii) is that its oviduct expands prior to hibernation instead of expanding during the breeding period. In this study, we investigated the expression of P450arom and estrogen receptors α and β (ERα and ERβ) in the oviduct of Rana dybowskii during the breeding period and prehibernation. The results of the present study showed that there were significant differences in both oviductal weight and size with values markedly higher in prehibernation than in the breeding period. P450arom was observed in stromal tissue in both the breeding period and prehibernation. ERα was expressed in stromal tissue and epithelial cells in both periods, whereas ERβ could not be detected. The mean protein and mRNA levels of P450arom and ERα were significantly higher in prehibernation as compared to the breeding period. Besides, oviductal content of 17β-estradiol was also higher in prehibernation than in the breeding period. These results suggested that estrogen may play autocrine/paracrine roles mediated by ERα in regulating the oviductal hypertrophy during prehibernation. PMID:25802518

  4. Mass mortality associated with a frog virus 3-like Ranavirus infection in farmed tadpoles Rana catesbeiana from Brazil.

    PubMed

    Mazzoni, Rolando; de Mesquita, Albenones José; Fleury, Luiz Fernando F; de Brito, Wilia Marta Elsner Diederichsen; Nunes, Iolanda A; Robert, Jacques; Morales, Heidi; Coelho, Alexandre Siqueira Guedes; Barthasson, Denise Leão; Galli, Leonardo; Catroxo, Marcia H B

    2009-11-01

    Ranaviruses (Iridoviridae) are increasingly associated with mortality events in amphibians, fish, and reptiles. They have been recently associated with mass mortality events in Brazilian farmed tadpoles of the American bullfrog Rana catesbeiana Shaw, 1802. The objectives of the present study were to further characterize the virus isolated from sick R. catesbeiana tadpoles and confirm the etiology in these outbreaks. Sick tadpoles were collected in 3 farms located in Goiás State, Brazil, from 2003 to 2005 and processed for virus isolation and characterization, microbiology, histopathology, and parasitology. The phylogenetic relationships of Rana catesbeiana ranavirus (RCV-BR) with other genus members was investigated by PCR with primers specific for the major capsid protein gene (MCP) and the RNA polymerase DNA-dependent gene (Pol II). Sequence analysis and multiple alignments for MCP products showed >99% amino acid identity with other ranaviruses, while Pol II products showed 100% identity. Further diagnostics of the pathology including histology and transmission electron microscopy confirmed the viral etiology of these mass deaths. As far as we know, this is the first report of a ranaviral infection affecting aquatic organisms in Brazil. Additionally, our results suggest that American bullfrogs may have served as a vector of transmission of this virus, which highlights the potential threat of amphibian translocation in the world distribution of pathogens.

  5. [The underwater EOG of the frog Rana temporaria to stimulation of the olfactory receptors with solutions of fragrances and amino acids].

    PubMed

    Kruzhalov, N B

    1991-01-01

    Studies have been made on the effectiveness of 16 amino acids and 9 odorants in olfactory perception of the frog Rana temporaria. It was shown that the effectiveness of amino acids is close to that of odorants. Basic amino acids and cysteine were more effective than other amino acids. Sensitivity of the olfactory receptors to amino acids in frogs is lower than in fishes.

  6. STATUS OF THE RELICT LEOPARD FROG (RANA ONCA): OUR LIMITED UNDERSTANDING OF THE DISTRIBUTION, SIZE, AND DYNAMICS OF EXTANT AND RECENTLY EXTINCT POPULATIONS

    EPA Science Inventory

    The relict leopard frog (Rana onca) was once thought to be extinct, but has recently been shown to comprise a valid taxon with extant populations. Here, we discuss research from several studies, conducted between 1991 and 200 1, that represent the basis for our understanding of t...

  7. Estudio muestra reducción de mortalidad en hombres con cáncer de próstata de grado intermedio

    Cancer.gov

    Terapia hormonal por corto tiempo administrada en combinación con radioterapia a hombres con cáncer de próstata en estadio inicial aumentó sus posibilidades de vivir más en comparación con tratamiento de radioterapia sola, según un estudio clínico patroci

  8. ADAPTATION AND IMPLEMENTATION OF HoMBReS: A COMMUNITY-LEVEL, EVIDENCE-BASED HIV BEHAVIORAL INTERVENTION FOR HETEROSEXUAL LATINO MEN IN THE MIDWESTERN UNITED STATES

    PubMed Central

    Martinez, Omar; Roth, Alexis M.; Kelle, Guadalupe; Downs, Mario; Rhodes, Scott D.

    2014-01-01

    Over the past decade, the midwestern United States has witnessed a dramatic increase in its Latino population. The lack of culturally and linguistically congruent resources coupled with high incidence and prevalence rates of HIV among Latinos living in the Midwest merits attention. HoMBReS: Hombres Manteniendo Bienestar y Relaciones Saludables (Men Maintaining Wellbeing and Healthy Relationships) is a community-level social network intervention designed for Latino men. We describe the adaptation and implementation of HoMBReS for Latino men living in Indianapolis, Indiana, the second largest city in the Midwest. Five Navegantes (lay health educators) were trained; they provided a total of 34 educational charlas (small group didactic sessions). A total of 270 Latino men attended the charlas and were offered no-cost screening for HIV and sexually transmitted infections (STI). Three participants tested HIV positive and 15 screened positive for STI. The charlas coupled with the testing initiative, served as a successful method to increase sexual health knowledge among Latino men and to link newly-diagnosed HIV/STI-positive individuals to treatment and care. The adaptation and implementation of HoMBReS respond to the CDC and NIH call to increase HIV testing and service provision among vulnerable populations. PMID:24450279

  9. The effects of purine compounds on the isolated aorta of the frog Rana temporaria.

    PubMed Central

    Knight, G. E.; Burnstock, G.

    1996-01-01

    1. In the isolated aorta of the frog, Rana temporaria, adenosine concentration-dependently, endothelium-independently relaxed adrenaline pre-constricted vessels. None of the adenosine analogues including D-5'-(N-ethylcarboxamide) adenosine (NECA), R- and S-N6-(2-phenylisopropyl) adenosine (R-and S-PIA) and 2-chloroadenosine (2-CA), or the more selective A1, A2 and A3 agonists cyclopentyladenosine (CPA), CGS 21680 and N6-(3-iodobenzyl) adenosine-5'-N-methylcarboxamide (IB-MECA) respectively, had any effect. 2. The non-selective adenosine antagonist, 8-p-sulphophenyl-theophylline (8-pSPT; 30 microM) failed to inhibit adenosine relaxations, as did NG-nitro-L-arginine methyl ester (L-NAME; 0.1 mM) and indomethacin (30 microM). 3. Adenosine 5'-triphosphate (ATP), alpha, beta-methylene ATP (alpha, beta-MeATP), beta, gamma-methylene ATP (beta, gamma-MeATP), 2-methylthio ATP (2-MeSATP) and uridine 5'-triphosphate (UTP) all concentration-dependently contracted the frog aorta. ATP and alpha, beta-MeATP were equipotent and more potent than UTP and beta, gamma-MeATP; 2-MeSATP had little activity. 4. The P2-purinoceptor antagonist, suramin (0.1 mM) inhibited contractions to alpha, beta-MeATP but not to ATP. Pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPADS; 30 microM) also inhibited contractions to alpha, beta-MeATP but not to ATP. Contractions to ATP were, however, inhibited by indomethacin (30 microM). 5. In conclusion, in the frog aorta there appears to be a novel subclass of P1-purinoceptor mediating vasodilatation, although like the A3 subclass it is not blocked by methylxanthines; a P2-purinoceptor mediates vasconstriction which resembles a P2x subtype, based on the agonist potency of alpha, beta-MeATP being more potent than 2-MeSATP (UTP has moderate activity) and PPADS is an effective antagonist. There is no evidence for the presence of a P2y-purinoceptor, mediating vasodilatation, in this preparation. PMID:8851504

  10. Experimental Repatriation of Mountain Yellow-legged Frogs (Rana muscosa) in the Sierra Nevada of California

    USGS Publications Warehouse

    Fellers, Gary M.; Bradford, David F.; Pratt, David; Wood, Leslie

    2008-01-01

    In the late 1970s, Rana muscosa (mountain yellow-legged frog) was common in the Tableland area of Sequoia National Park, California where it was possible to find hundreds of tadpoles and adults around many of the ponds and lakes. Surveys in 1993-1995 demonstrated that R. muscosa was absent from more than half of all suitable habitat within the park, including the Tableland area. At that same time, R. muscosa was still common at Sixty Lake Basin, Kings Canyon National Park, 30 km to the northeast. To evaluate the potential causes for the extirpation, we repatriated R. muscosa eggs, tadpoles, subadults, and adult frogs from Sixty Lake Basin to four sites in the Tableland area in 1994 and 1995. We subsequently surveyed each release site and the surrounding area 2 - 3 times per week in 1994-1995, and intermittently in 1996-1997, to monitor the survival of all life history stages, and to detect dispersal of adults and subadults. We also monitored predation, water quality, weather, and water temperature. Our techniques for capturing, holding, transporting, and releasing R. muscosa were refined during the study, and during 1995 resulted in high initial survival rates of all life history stages. Adult frogs were anaesthetized, weighed, measured, tagged, and held in plastic boxes with wet paper towels. Tadpoles were collected and held in fiberglass screen cages set in the water at the edge of a pond. This resulted in relatively natural conditions with less crowding and good water circulation. Frogs, tadpoles, and eggs were placed in Ziploc bags for transport to the Tableland by helicopter. Short-term survival of tadpoles, subadults, and adults was high at all four release sites, tadpoles reached metamorphosis, and adult frogs were still present. However, we detected no evidence of reproduction at three sites (e.g., no new eggs or small tadpoles) and nearly all life history stages disappeared within 12 months. At the fourth site, there was limited reproduction, but it was

  11. Surveys for presence of Oregon spotted frog (Rana pretiosa): background information and field methods

    USGS Publications Warehouse

    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

  12. Respiratory activity in the facial nucleus in an in vitro brainstem of tadpole, Rana catesbeiana.

    PubMed Central

    Liao G-S; Kubin, L; Galante, R J; Fishman, A P; Pack, A I

    1996-01-01

    1. In studies of the central neural control of breathing, little advantage has been taken of comparative approaches. We have developed an in vitro brainstem preparation using larval Rana catesbeiana which generates two rhythmic neural activities characteristic of lung and gill ventilation. Based on the pattern of the facial (VII) nerve activity both lung and gill rhythm-related respiratory cycles were divided into three distinct phases. The purpose of this study was to characterize and classify membrane potential trajectories of respiratory motoneurons in the VII nucleus at intermediate stages (XII-XVII) of development. 2. Seventy-five respiratory-modulated neurons were recorded intracellularly within the facial motor nucleus region. Their resting membrane potential was between -40 and -80 mV. Sixty of them were identified as VII motoneurons and fifteen were non-antidromically activated. Membrane potentials of fifty-six of the seventy-five neurons were modulated with both lung (5-27 mV) and gill rhythms (3-15 mV) and the remaining nineteen neurons had only a modulation with lung rhythmicity (6-23 mV). No cells with gill modulation alone were observed. 3. All of the cells modulated with lung rhythmicity had only phase-bound depolarizing or hyperpolarizing membrane potential swings which could be categorized into four distinct patterns. In contrast, of the fifty-six cells modulated with gill rhythmicity, thirty-two were phasically depolarized during distinct phases of the gill cycle (four patterns were distinguished), whereas the remaining twenty-four were phase spanning with two distinct patterns. The magnitudes of lung and gill modulations were proportionally related to each other in the cells modulated with both rhythms. 4. In all sixteen neurons studied, a reduction or a reversal of phasic inhibitory inputs during a portion of the lung or gill respiratory cycle was observed following a negative current or chloride ion (Cl-) injection. The phasic membrane

  13. Evaluation of the effects of titanium dioxide nanoparticles on cultured Rana catesbeiana tailfin tissue.

    PubMed

    Hammond, S Austin; Carew, Amanda C; Helbing, Caren C

    2013-01-01

    Nanoparticles (NPs), materials that have one dimension less than 100 nm, are used in manufacturing, health, and food products, and consumer products including cosmetics, clothing, and household appliances. Their utility to industry is derived from their high surface-area-to-volume ratios and physico-chemical properties distinct from their bulk counterparts, but the near-certainty that NPs will be released into the environment raises the possibility that they could present health risks to humans and wildlife. The thyroid hormones (THs), thyroxine, and 3,3',5-triiodothyronine (T3), are involved in development and metabolism in vertebrates including humans and frogs. Many of the processes of anuran metamorphosis are analogous to human post-embryonic development and disruption of TH action can have drastic effects. These shared features make the metamorphosis of anurans an excellent model for screening for endocrine disrupting chemicals (EDCs). We used the cultured tailfin (C-fin) assay to examine the exposure effects of 0.1-10 nM (~8-800 ng/L) of three types of ~20 nm TiO2 NPs (P25, M212, M262) and micron-sized TiO2 (μ TiO2) ±10 nM T3. The actual Ti levels were 40.9-64.7% of the nominal value. Real-time quantitative polymerase chain reaction (QPCR) was used to measure the relative amounts of mRNA transcripts encoding TH-responsive THs receptors (thra and thrb) and Rana larval keratin type I (rlk1), as well as the cellular stress-responsive heat shock protein 30 kDa (hsp30), superoxide dismutase (sod), and catalase (cat). The levels of the TH-responsive transcripts were largely unaffected by any form of TiO2. Some significant effects on stress-related transcripts were observed upon exposure to micron-sized TiO2, P25, and M212 while no effect was observed with M262 exposure. Therefore, the risk of adversely affecting amphibian tissue by disrupting TH-signaling or inducing cellular stress is low for these compounds relative to other previously-tested NPs. PMID:24312126

  14. Evaluation of the effects of titanium dioxide nanoparticles on cultured Rana catesbeiana tailfin tissue

    PubMed Central

    Hammond, S. Austin; Carew, Amanda C.; Helbing, Caren C.

    2013-01-01

    Nanoparticles (NPs), materials that have one dimension less than 100 nm, are used in manufacturing, health, and food products, and consumer products including cosmetics, clothing, and household appliances. Their utility to industry is derived from their high surface-area-to-volume ratios and physico-chemical properties distinct from their bulk counterparts, but the near-certainty that NPs will be released into the environment raises the possibility that they could present health risks to humans and wildlife. The thyroid hormones (THs), thyroxine, and 3,3′,5-triiodothyronine (T3), are involved in development and metabolism in vertebrates including humans and frogs. Many of the processes of anuran metamorphosis are analogous to human post-embryonic development and disruption of TH action can have drastic effects. These shared features make the metamorphosis of anurans an excellent model for screening for endocrine disrupting chemicals (EDCs). We used the cultured tailfin (C-fin) assay to examine the exposure effects of 0.1–10 nM (~8–800 ng/L) of three types of ~20 nm TiO2 NPs (P25, M212, M262) and micron-sized TiO2 (μ TiO2) ±10 nM T3. The actual Ti levels were 40.9–64.7% of the nominal value. Real-time quantitative polymerase chain reaction (QPCR) was used to measure the relative amounts of mRNA transcripts encoding TH-responsive THs receptors (thra and thrb) and Rana larval keratin type I (rlk1), as well as the cellular stress-responsive heat shock protein 30 kDa (hsp30), superoxide dismutase (sod), and catalase (cat). The levels of the TH-responsive transcripts were largely unaffected by any form of TiO2. Some significant effects on stress-related transcripts were observed upon exposure to micron-sized TiO2, P25, and M212 while no effect was observed with M262 exposure. Therefore, the risk of adversely affecting amphibian tissue by disrupting TH-signaling or inducing cellular stress is low for these compounds relative to other previously-tested NPs. PMID

  15. Behavioural and physiological adaptations to low-temperature environments in the common frog, Rana temporaria

    PubMed Central

    2014-01-01

    Background Extreme environments can impose strong ecological and evolutionary pressures at a local level. Ectotherms are particularly sensitive to low-temperature environments, which can result in a reduced activity period, slowed physiological processes and increased exposure to sub-zero temperatures. The aim of this study was to assess the behavioural and physiological responses that facilitate survival in low-temperature environments. In particular, we asked: 1) do high-altitude common frog (Rana temporaria) adults extend the time available for larval growth by breeding at lower temperatures than low-altitude individuals?; and 2) do tadpoles sampled from high-altitude sites differ physiologically from those from low-altitude sites, in terms of routine metabolic rate (RMR) and freeze tolerance? Breeding date was assessed as the first day of spawn observation and local temperature recorded for five, paired high- and low-altitude R. temporaria breeding sites in Scotland. Spawn was collected and tadpoles raised in a common laboratory environment, where RMR was measured as oxygen consumed using a closed respiratory tube system. Freeze tolerance was measured as survival following slow cooling to the point when all container water had frozen. Results We found that breeding did not occur below 5°C at any site and there was no significant relationship between breeding temperature and altitude, leading to a delay in spawning of five days for every 100 m increase in altitude. The relationship between altitude and RMR varied by mountain but was lower for individuals sampled from high- than low-altitude sites within the three mountains with the highest high-altitude sites (≥900 m). In contrast, individuals sampled from low-altitudes survived freezing significantly better than those from high-altitudes, across all mountains. Conclusions Our results suggest that adults at high-altitude do not show behavioural adaptations in terms of breeding at lower temperatures. However

  16. Respiratory activity in the facial nucleus in an in vitro brainstem of tadpole, Rana catesbeiana.

    PubMed

    Liao G-S; Kubin, L; Galante, R J; Fishman, A P; Pack, A I

    1996-04-15

    1. In studies of the central neural control of breathing, little advantage has been taken of comparative approaches. We have developed an in vitro brainstem preparation using larval Rana catesbeiana which generates two rhythmic neural activities characteristic of lung and gill ventilation. Based on the pattern of the facial (VII) nerve activity both lung and gill rhythm-related respiratory cycles were divided into three distinct phases. The purpose of this study was to characterize and classify membrane potential trajectories of respiratory motoneurons in the VII nucleus at intermediate stages (XII-XVII) of development. 2. Seventy-five respiratory-modulated neurons were recorded intracellularly within the facial motor nucleus region. Their resting membrane potential was between -40 and -80 mV. Sixty of them were identified as VII motoneurons and fifteen were non-antidromically activated. Membrane potentials of fifty-six of the seventy-five neurons were modulated with both lung (5-27 mV) and gill rhythms (3-15 mV) and the remaining nineteen neurons had only a modulation with lung rhythmicity (6-23 mV). No cells with gill modulation alone were observed. 3. All of the cells modulated with lung rhythmicity had only phase-bound depolarizing or hyperpolarizing membrane potential swings which could be categorized into four distinct patterns. In contrast, of the fifty-six cells modulated with gill rhythmicity, thirty-two were phasically depolarized during distinct phases of the gill cycle (four patterns were distinguished), whereas the remaining twenty-four were phase spanning with two distinct patterns. The magnitudes of lung and gill modulations were proportionally related to each other in the cells modulated with both rhythms. 4. In all sixteen neurons studied, a reduction or a reversal of phasic inhibitory inputs during a portion of the lung or gill respiratory cycle was observed following a negative current or chloride ion (Cl-) injection. The phasic membrane

  17. Use of femur bone density to segregate wild from farmed Dybowski's frog (Rana dybowskii).

    PubMed

    Yang, Shu Hui; Huang, Xiao Ming; Xia, Rui; Xu, Yan Chun; Dahmer, Thomas D

    2011-04-15

    Wildlife has been utilized by humans throughout history and demand continues to grow today. Farming of wildlife can supplement the supply of wild-harvested wildlife products and, in theory, can reduce pressure on free-ranging populations. However, poached wildlife products frequently enter legal markets where they are fraudulently sold as farmed wildlife products. To effectively close this illegal trade in wild-captured wildlife, there is a need to discriminate wild products from farmed products. Because of the strong market demand for wild-captured frog meat and the resulting strong downward pressure on wild populations, we undertook research to develop a method to discriminate wild from farmed Dybowski's frog (Rana dybowskii) based on femur bone density. We measured femur bone density (D(f)) as the ratio of bone mass to bone volume. D(f) of wild frogs revealed a slightly increasing linear trend with increasing age (R(2)=0.214 in males and R(2)=0.111 in females, p=0.000). Wild males and wild females of age classes from 2 to ≥ 5 years had similar D(f) values. In contrast, 2-year-old farmed frogs showed significantly higher D(f) values (p=0.000) among males (mean D(f)=0.623 ± 0.011 g/ml, n=32) than females (mean D(f)=0.558 ± 0.011 g/ml, n=27). For both sexes, D(f) of wild frogs was significantly higher than that of farmed frogs (p=0.000). Among males, 87.5% (28 of 32 individuals) of farmed frogs were correctly identified as farmed frogs and 86.3% (69 of 80 individuals) of wild frogs were correctly identified as wild frogs. These results suggest that femur bone density is one reliable tool for discriminating between wild and farmed Dybowski's frog. This study also highlights a novel strategy with explicit forensic potential to discriminate wild from captive bred wildlife species.

  18. Kawachin na ri kitzij-kipixab' Qanan Qatat--Florezcan las palabras de los hombres de maiz (The Blossoming of Our Ancestors' Words). [CD-ROM].

    ERIC Educational Resources Information Center

    Academy for Educational Development, Washington, DC.

    This CD-ROM is part of an interactive and dynamic multimedia package of information and games for learning K'iche' and Ixil. This CD-ROM contains selected radio programs for preschool students, scripted from the four storybooks created by Project "Enlace Quiche." It includes stories in K'iche', Ixil, and Spanish. (VWL)

  19. Frog lysozyme. I. Its identification, occurrence as isozymes, and quantitative distribution in tissues of the leopard frog, Rana pipiens.

    PubMed

    Ostrovsky, D S; Snyder, J A; Iwata, T; Izaka, K I; Maglott, D S; Nace, G W

    1976-02-01

    In the course of examining the etiology of the Lucké renal adenocarcinoma of the frog, Rana pipiens, it was found that organs of the normal adult contain bacteriolytic enzymes. These enzymes all satisfied the six criteria for the identification of lysozymes and at least eight forms were separable by polyacrylamide gel electrophoresis. Their qualitative and quantitative distribution was organ-specific. All eight isozymes were found in normal kidney, while liver and spleen contained seven forms; skin, six; ovarian egg, five; and serum, two. In quantitative assays using a radial diffusion test, spleen had the greatest lysozyme concentration, followed in descending order by kidney, liver, skin, and ovary. Serum contained very low amounts. In terms of enzyme activity per animal, ovary was the highest ranking organ. As such a large number of lysozyme isozymes has not been reported in any other organism, their origins and functions are considered in the context of their presence in an ectotherm.

  20. The precarious persistence of the endangered Sierra Madre yellow-legged frog Rana muscosa in southern California, USA

    USGS Publications Warehouse

    Backlin, Adam R.; Hitchcock, Cynthia J.; Gallegos, Elizabeth A.; Yee, Julie L.; Fisher, Robert N.

    2015-01-01

    We conducted surveys for the Endangered Sierra Madre yellow-legged frog Rana muscosa throughout southern California to evaluate the current distribution and status of the species. Surveys were conducted during 2000–2009 at 150 unique streams and lakes within the San Gabriel, San Bernardino, San Jacinto, and Palomar mountains of southern California. Only nine small, geographically isolated populations were detected across the four mountain ranges, and all tested positive for the amphibian chytrid fungus Batrachochytrium dendrobatidis. Our data show that when R. muscosa is known to be present it is easily detectable (89%) in a single visit during the frog's active season. We estimate that only 166 adult frogs remained in the wild in 2009. Our research indicates that R. muscosa populations in southern California are threatened by natural and stochastic events and may become extirpated in the near future unless there is some intervention to save them.

  1. Mycobacterium marinum causes both long-term subclinical infection and acute disease in the leopard frog (Rana pipiens).

    PubMed Central

    Ramakrishnan, L; Valdivia, R H; McKerrow, J H; Falkow, S

    1997-01-01

    Mycobacterium marinum grows at an optimal temperature of 33 degrees C, far lower than that for M. tuberculosis. Consequently, M. marinum infection of mammals is restricted largely to the cooler surfaces of the body, such as the extremities, but it causes a systemic infection in a large number of poikilothermic animals. Here, we describe a laboratory animal model for M. marinum disease in the leopard frog (Rana pipiens), a natural host species. M. marinum causes a chronic granulomatous, nonlethal disease in immunocompetent frogs. Immunosuppression of the frogs with hydrocortisone results in an acute, fulminant, lethal disease. This animal model, in which a spectrum of tuberculosis-like disease can be produced, will be useful for the dissection of the genetic basis of mycobacterial pathogenesis. PMID:9009340

  2. Prevalence of the pathogenic chytrid fungus, Batrachochytrium dendrobatidis, in an endangered population of northern leopard frogs, Rana pipiens

    PubMed Central

    2010-01-01

    Background Emerging infectious diseases threaten naïve host populations with extinction. Chytridiomycosis, an emerging infectious disease of amphibians, is caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd) and has been linked to global declines in amphibians. Results We monitored the prevalence of Bd for four years in the Northern leopard frog, Rana pipiens, which is critically imperiled in British Columbia (BC), Canada. The prevalence of Bd initially increased and then remained constant over the last three years of the study. Young of the year emerging from breeding ponds in summer were rarely infected with Bd. Some individuals cleared their Bd infections and the return rate between infected and uninfected individuals was not significantly different. Conclusions The BC population of R. pipiens appears to have evolved a level of resistance that allows it to co-exist with Bd. However, this small population of R. pipiens remains vulnerable to extinction. PMID:20202208

  3. Endogenous peroxidase activity in brush cell-like cells in the large intestine of the bullfrog tadpole, Rana catesbeiana.

    PubMed

    Sugimoto, K; Ichikawa, Y; Nakamura, I

    1983-01-01

    A special cell type was identified in the mucosal epithelium of the large intestine of the tadpole of the bullfrog, Rana catesbeiana. It is a slender, columnar cell, with a dark, basally situated nucleus. By electron microscopy the cell displays prominent bundles of filaments emerging from each microvillus and extending deep into the cytoplasm without ending in the terminal web. It has longer and more crowded microvilli than the absorptive cell. The specialized cell is also characterized by the presence of many apical vesicles and numerous subapical dense bodies. These cytological features suggest that it may be a brush cell (Rhodin and Dalhamn 1956). These cells displayed endogenous peroxidase activity in smooth and rough endoplasmic reticulum, in the well-developed Golgi apparatus and in apical vesicles. Furthermore, peroxidase reaction product was frequently observed on their luminal surface membrane. These findings suggest that the brush cell in the large intestine of the bullfrog tadpole may be a secretory cell.

  4. Development of antimicrobial peptide defenses of southern leopard frogs, Rana sphenocephala, against the pathogenic chytrid fungus, Batrachochytrium dendrobatidis.

    PubMed

    Holden, Whitney M; Reinert, Laura K; Hanlon, Shane M; Parris, Matthew J; Rollins-Smith, Louise A

    2015-01-01

    Amphibian species face the growing threat of extinction due to the emerging fungal pathogen Batrachochytrium dendrobatidis, which causes the disease chytridiomycosis. Antimicrobial peptides (AMPs) produced in granular glands of the skin are an important defense against this pathogen. Little is known about the ontogeny of AMP production or the impact of AMPs on potentially beneficial symbiotic skin bacteria. We show here that Rana (Lithobates) sphenocephala produces a mixture of four AMPs with activity against B. dendrobatidis, and we report the minimum inhibitory concentration (MIC) of synthesized replicates of these four AMPs tested against B. dendrobatidis. Using mass spectrometry and protein quantification assays, we observed that R. sphenocephala does not secrete a mature suite of AMPs until approximately 12 weeks post-metamorphosis, and geographically disparate populations produce a different suite of peptides. Use of norepinephrine to induce maximal secretion significantly reduced levels of culturable skin bacteria.

  5. Size-sex variation in survival rates and abundance of pig frogs, Rana grylio, in northern Florida wetlands

    USGS Publications Warehouse

    Wood, K.V.; Nichols, J.D.; Percival, H.F.; Hines, J.E.

    1998-01-01

    During 1991-1993, we conducted capture-recapture studies on pig frogs, Rana grylio, in seven study locations in northcentral Florida. Resulting data were used to test hypotheses about variation in survival probability over different size-sex classes of pig frogs. We developed multistate capture-recapture models for the resulting data and used them to estimate survival rates and frog abundance. Tests provided strong evidence of survival differences among size-sex classes, with adult females showing the highest survival probabilities. Adult males and juvenile frogs had lower survival rates that were similar to each other. Adult females were more abundant than adult males in most locations at most sampling occasions. We recommended probabilistic capture-recapture models in general, and multistate models in particular, for robust estimation of demographic parameters in amphibian populations.

  6. Atrazine-induced hermaphroditism at 0.1 ppb in American leopard frogs (Rana pipiens): laboratory and field evidence.

    PubMed Central

    Hayes, Tyrone; Haston, Kelly; Tsui, Mable; Hoang, Anhthu; Haeffele, Cathryn; Vonk, Aaron

    2003-01-01

    Atrazine is the most commonly used herbicide in the United States and probably the world. Atrazine contamination is widespread and can be present in excess of 1.0 ppb even in precipitation and in areas where it is not used. In the current study, we showed that atrazine exposure (> or = to 0.1 ppb) resulted in retarded gonadal development (gonadal dysgenesis) and testicular oogenesis (hermaphroditism) in leopard frogs (Rana pipiens). Slower developing males even experienced oocyte growth (vitellogenesis). Furthermore, we observed gonadal dysgenesis and hermaphroditism in animals collected from atrazine-contaminated sites across the United States. These coordinated laboratory and field studies revealed the potential biological impact of atrazine contamination in the environment. Combined with reported similar effects in Xenopus laevis, the current data raise concern about the effects of atrazine on amphibians in general and the potential role of atrazine and other endocrine-disrupting pesticides in amphibian declines. PMID:12676617

  7. Atrazine-induced hermaphroditism at 0.1 ppb in American leopard frogs (Rana pipiens): laboratory and field evidence.

    PubMed

    Hayes, Tyrone; Haston, Kelly; Tsui, Mable; Hoang, Anhthu; Haeffele, Cathryn; Vonk, Aaron

    2003-04-01

    Atrazine is the most commonly used herbicide in the United States and probably the world. Atrazine contamination is widespread and can be present in excess of 1.0 ppb even in precipitation and in areas where it is not used. In the current study, we showed that atrazine exposure (> or = to 0.1 ppb) resulted in retarded gonadal development (gonadal dysgenesis) and testicular oogenesis (hermaphroditism) in leopard frogs (Rana pipiens). Slower developing males even experienced oocyte growth (vitellogenesis). Furthermore, we observed gonadal dysgenesis and hermaphroditism in animals collected from atrazine-contaminated sites across the United States. These coordinated laboratory and field studies revealed the potential biological impact of atrazine contamination in the environment. Combined with reported similar effects in Xenopus laevis, the current data raise concern about the effects of atrazine on amphibians in general and the potential role of atrazine and other endocrine-disrupting pesticides in amphibian declines.

  8. The quantitative genetic basis of adaptive divergence in the moor frog (Rana arvalis) and its implications for gene flow.

    PubMed

    Hangartner, S; Laurila, A; Räsänen, K

    2012-08-01

    Knowledge on the relative contribution of direct genetic, maternal and environmental effects to adaptive divergence is important for understanding the drivers of biological diversification. The moor frog (Rana arvalis) shows adaptive divergence in embryonic and larval fitness traits along an acidification gradient in south-western Sweden. To understand the quantitative genetic basis of this divergence, we performed reciprocal crosses between three divergent population pairs and reared embryos and larvae at acid and neutral pH in the laboratory. Divergence in embryonic acid tolerance (survival) was mainly determined by maternal effects, whereas the relative contributions of maternal, additive and nonadditive genetic effects in larval life-history traits differed between traits, population pairs and rearing environments. These results emphasize the need to investigate the quantitative genetic basis of adaptive divergence in multiple populations and traits, as well as different environments. We discuss the implications of our findings for maintenance of local adaptation in the context of migrant and hybrid fitness.

  9. Short-term occupancy and abundance dynamics of the Oregon spotted frog (Rana pretiosa) across its core range

    USGS Publications Warehouse

    Adams, Michael J.; Pearl, Christopher A.; Mccreary, Brome; Galvan, Stephanie

    2014-01-01

    The Oregon spotted frog (Rana pretiosa) occupies only a fraction of its original range and is listed as Threatened under the Endangered Species Act. We surveyed 93 sites in a rotating frame design (2010–13) in the Klamath and Deschutes Basins, Oregon, which encompass most of the species’ core extant range. Oregon spotted frogs are declining in abundance and probability of site occupancy. We did not find an association between the probability that Oregon spotted frogs disappear from a site (local extinction) and any of the variables hypothesized to affect Oregon spotted frog occupancy. This 4-year study provides baseline data, but the 4-year period was too short to draw firm conclusions. Further study is essential to understand how habitat changes and management practices relate to the status and trends of this species.

  10. Endogenous peroxidase activity in brush cell-like cells in the large intestine of the bullfrog tadpole, Rana catesbeiana.

    PubMed

    Sugimoto, K; Ichikawa, Y; Nakamura, I

    1983-01-01

    A special cell type was identified in the mucosal epithelium of the large intestine of the tadpole of the bullfrog, Rana catesbeiana. It is a slender, columnar cell, with a dark, basally situated nucleus. By electron microscopy the cell displays prominent bundles of filaments emerging from each microvillus and extending deep into the cytoplasm without ending in the terminal web. It has longer and more crowded microvilli than the absorptive cell. The specialized cell is also characterized by the presence of many apical vesicles and numerous subapical dense bodies. These cytological features suggest that it may be a brush cell (Rhodin and Dalhamn 1956). These cells displayed endogenous peroxidase activity in smooth and rough endoplasmic reticulum, in the well-developed Golgi apparatus and in apical vesicles. Furthermore, peroxidase reaction product was frequently observed on their luminal surface membrane. These findings suggest that the brush cell in the large intestine of the bullfrog tadpole may be a secretory cell. PMID:6601990

  11. Susceptibility of the European common frog Rana temporaria to a panel of ranavirus isolates from fish and amphibian hosts.

    PubMed

    Bayley, Amanda E; Hill, Barry J; Feist, Stephen W

    2013-04-11

    Ranaviruses are an emerging group of viruses and have been implicated in an increase of epidemics in susceptible species. They have a wide host range, infecting fish, amphibians and reptiles, with some isolates able to infect multiple species from different animal classes. Whilst some information exists on the pathogenicity of ranaviruses to novel hosts, there is none on the pathogenicity of fish ranaviruses to amphibians; this information is needed to develop measures to prevent the further spread of ranaviral disease in the aquatic environment. We undertook bath infection trials to assess the susceptibility of the European common frog Rana temporaria to 9 ranavirus isolates comprising doctor fish virus (DFV), European sheatfish virus (ESV), epizootic haematopoietic necrosis virus (EHNV), guppy virus 6 (GV6), pike-perch iridovirus (PPIV) and short-finned eel ranavirus (SERV) from fish hosts, and Bohle iridovirus (BIV), frog virus 3 (FV3) and Rana esculenta virus 282/I02 (REV) from amphibians. Animals were challenged as tadpoles at 15 and 20°C and as recent metamorphs at room temperature (20 ± 1°C) to investigate the effect of temperature and amphibian developmental stage on virus pathogenicity. Tadpoles were susceptible to FV3, PPIV and REV, but refractory to the other ranaviruses. Post-metamorphs were susceptible to FV3 and REV but refractory to BIV (the other ranaviruses were not tested). Significant mortality occurred in post-metamorphs and in tadpoles challenged at 20°C but was low in tadpoles challenged at 15°C. This study presents the first evidence of mortality in an amphibian species after challenge with ranavirus originally isolated from fish.

  12. Low detection of ranavirus DNA in wild postmetamorphic green frogs, Rana (Lithobates) clamitans, despite previous or concurrent tadpole mortality.

    PubMed

    Forzán, María J; Wood, John

    2013-10-01

    Ranavirus (Iridoviridae) infection is a significant cause of mortality in amphibians. Detection of infected individuals, particularly carriers, is necessary to prevent and control outbreaks. Recently, the use of toe clips to detect ranavirus infection through PCR was proposed as an alternative to the more frequently used lethal liver sampling in green frogs (Rana [Lithobates] clamitans). We attempted reevaluate the use of toe clips, evaluate the potential use of blood onto filter paper and hepatic fine needle aspirates (FNAs) as further alternatives, and explore the adequacy of using green frogs as a target-sampling species when searching for ranavirus infection in the wild. Samples were obtained from 190 postmetamorphic (≥1-yr-old) green frogs from five ponds on Prince Edward Island (PEI), Canada. Three of the ponds had contemporary or recent tadpole mortalities due to Frog Virus 3 (FV3) ranavirus. PCR testing for ranavirus DNA was performed on 190 toe clips, 188 blood samples, 72 hepatic FNAs, and 72 liver tissue samples. Only two frogs were ranavirus-positive: liver and toe clip were positive in one, liver only was positive in the other; all blood and FNAs, including those from the two positive frogs, were negative. Results did not yield a definitive answer on the efficacy of testing each type of sample, but resemble what is found in salamanders infected with Ambystoma tigrinum (rana)virus. Findings indicate a low prevalence of FV3 in postmetamorphic green frogs on PEI (≤2.78%) and suggest that green frogs are poor reservoirs (carriers) for the virus.

  13. Marketing HIV prevention for heterosexually identified Latino men who have sex with men and women: the Hombres Sanos campaign.

    PubMed

    Fernández Cerdeño, Araceli; Martínez-Donate, Ana P; Zellner, Jennifer A; Sañudo, Fernando; Carrillo, Héctor; Engelberg, Moshe; Sipan, Carol; Hovell, Melbourne

    2012-01-01

    This article describes the development process of Hombres Sanos, a social marketing campaign to promote HIV testing and condom use for heterosexually identified Latino men who have sex with men and women. The steps included qualitative formative research and a social marketing analytic framework to understand our target audience better, identify incentives and barriers to risk reduction, guide product development, define an optimal promotional campaign, and inform the selection of campaign platforms. A better grasp of the authors' target beneficiaries' needs and values led to an innovative dual strategy for audience segmentation and targeting. The campaign had consumer-centered, culturally sensitive, and theory-driven communication materials. The authors found communication materials and events to be appealing and effective. The campaign was well received among the wider community, and evaluation showed promising results among Latino men in general and among heterosexually identified Latino men who have sex with men and women in particular. The authors provide a step-by-step overview of the project's formative research, including research methods and findings, and how these were translated into a social marketing campaign. In addition, the authors discuss the challenges encountered in this process and the potential of social marketing to reduce HIV risk among Latinos.

  14. Oregon Spotted Frog (Rana pretiosa) movement and demography at Dilman Meadow: implications for future monitoring

    USGS Publications Warehouse

    Chelgren, Nathan D.; Pearl, Christopher A.; Bowerman, Jay; Adams, Michael J.

    2007-01-01

    Introduction The Oregon spotted frog (Rana pretiosa) is a highly aquatic frog that has been extirpated from a large portion of its historic range in the Pacific Northwest, and remaining populations are reduced and isolated (Hayes 1997, Pearl and Hayes 2005). Loss and alteration of marsh habitat, predation and competition from exotic fish and bullfrogs, and degraded water quality from agriculture and livestock grazing are implicated in their decline (Hayes 1997, Pearl and Hayes 2005). In 2001, an interagency team translocated a population of frogs from a site that was to be eliminated by the renovation of the dam impounding Wickiup Reservoir, to newly created ponds at Dilman Meadow (121i?? 39' 52" W, 43i?? 41' 58" N), 2.5 km from the original site in central Oregon, USA. We monitored Oregon spotted frog demography and movements at Dilman Meadow for > 4 yr to assess the efficacy of these mitigation efforts, determine metrics for long-term monitoring, and inform future management at the site. More broadly, many aspects of Oregon spotted frog life history are poorly known, so understanding demography and movement patterns is likely to be useful in its conservation. Although wildlife translocations have been attempted extensively as conservation means, few such projects have been sufficiently monitored for demographic rates to understand the causes for the translocation's success or failure (Dodd and Seigel 1991). Our objective here is to document demographic and movement patterns in the population of Oregon spotted frog at Dilman Meadow so that this information will be available to guide management decisions. To better evaluate amphibian population responses to management actions it is important to consider the contribution of each life history stage and both genders to the balance of reproduction and mortality. Population growth or contraction occurs as a complicated function of the probability of breeding, fecundity, and survival during multiple life history stages

  15. Icosiella turgeocauda n. sp. (Nematoda: Onchocercidae) and Seuratascaris numidica (Nematoda: Ascarididae), parasites of the frog, Rana cancrivora (Anura: Ranidae), from Luzon, Republic of the Philippines.

    PubMed

    Bursey, Charles R; Telford, Sam R; Goldberg, Stephen R

    2003-04-01

    Icosiella turgeocauda n. sp. from the intestinal mesenteries of Rana cancrivora collected at Luzon, Republic of the Philippines, is described and illustrated. Icosiella turgeocauda n. sp. represents the ninth species to be assigned to the genus and is easily differentiated from all the previously described species by the position of the vulva and the presence of bilateral umbos on the caudal end of the male. Seuratascaris numidica also was found. The Philippines represents a new location record for S. numidica.

  16. Hind limb malformations in free-living northern leopard frogs (Rana pipiens) from Maine, Minnesota, and Vermont suggest multiple etiologies

    USGS Publications Warehouse

    Meteyer, C.U.; Loeffler, I.K.; Fallon, J.F.; Converse, K.A.; Green, E.; Helgen, J.C.; Kersten, S.; Levey, R.; Eaton-Poole, L.; Burkhart, J.G.

    2000-01-01

    Background Reports of malformed frogs have increased throughout the North American continent in recent years. Most of the observed malformations have involved the hind limbs. The goal of this study was to accurately characterize the hind limb malformations in wild frogs as an important step toward understanding the possible etiologies. Methods During 1997 and 1998, 182 recently metamorphosed northern leopard frogs (Rana pipiens) were collected from Minnesota, Vermont, and Maine. Malformed hind limbs were present in 157 (86%) of these frogs, which underwent necropsy and radiographic evaluation at the National Wildlife Health Center. These malformations are described in detail and classified into four major categories: (1) no limb (amelia); (2) multiple limbs or limb elements (polymelia, polydactyly, polyphalangy); (3) reduced limb segments or elements (phocomelia, ectromelia, ectrodactyly, and brachydactyly; and (4) distally complete but malformed limb (bone rotations, bridging, skin webbing, and micromelia). Results Amelia and reduced segments and/or elements were the most common finding. Frogs with bilateral hind limb malformations were not common, and in only eight of these 22 frogs were the malformations symmetrical. Malformations of a given type tended to occur in frogs collected from the same site, but the types of malformations varied widely among all three states, and between study sites within Minnesota. Conclusions Clustering of malformation type suggests that developmental events may produce a variety of phenotypes depending on the timing, sequence, and severity of the environmental insult. Hind limb malformations in free-living frogs transcend current mechanistic explanations of tetrapod limb development.

  17. Combined effects of malathion and nitrate on early growth, abnormalities, and mortality of wood frog (Rana sylvatica) tadpoles.

    PubMed

    Krishnamurthy, S V; Smith, G R

    2011-08-01

    Use of pesticides and other agro-chemicals adversely influence amphibians either directly by killing them or by inducing sublethal, chronic effects. Many studies have investigated the effect of mixtures of pesticides or fertilizers. We studied the combined effects of nitrate and malathion ([(dimethoxy phosphino thioyl] butanediotae) on the early growth, expression of abnormalities, and mortality of Wood Frog (Rana sylvatica) tadpoles in a laboratory experiment. Tadpoles were treated with factorial combinations of 0, 8, and 16 mg NO(3)-N l(-1) and 0, 250, 500, and 1,000 μg malathion l(-1) for a period of 14 days. Feeding behaviour, total length, mean tadpole mass, frequencies of abnormalities, and survivorship in each treatment were recorded. Malathion showed a significant negative influence on all parameters and strongly influenced the frequencies of morphological anomalies. In contrast, nitrate alone did not produce any significant effects on behavior, total length, tadpole mass, or the frequency of abnormalities during the experiment. Malathion and nitrate had an interactive effect on tadpole length and mass, but did not affect any other parameters. Our results suggest that exposure to malathion, even at relatively low concentrations can have serious negative consequences for Wood Frog tadpoles. In addition, our results also indicate that there was little synergistic interaction between malathion and nitrate exposure under laboratory conditions. PMID:21533775

  18. Species boundaries, phylogeography and conservation genetics of the red-legged frog (Rana aurora/draytonii) complex.

    PubMed

    Shaffer, H Bradley; Fellers, G M; Voss, S Randal; Oliver, J C; Pauly, Gregory B

    2004-09-01

    The red-legged frog, Rana aurora, has been recognized as both a single, polytypic species and as two distinct species since its original description 150 years ago. It is currently recognized as one species with two geographically contiguous subspecies, aurora and draytonii; the latter is protected under the US Endangered Species Act. We present the results of a survey of 50 populations of red-legged frogs from across their range plus four outgroup species for variation in a phylogenetically informative, approximately 400 base pairs (bp) fragment of the mitochondrial cytochrome b gene. Our mtDNA analysis points to several major results. (1) In accord with several other lines of independent evidence, aurora and draytonii are each diagnosably distinct, evolutionary lineages; the mtDNA data indicate that they do not constitute a monophyletic group, but rather that aurora and R. cascadae from the Pacific northwest are sister taxa; (2) the range of the draytonii mtDNA clade extends about 100 km further north in coastal California than was previously suspected, and corresponds closely with the range limits or phylogeographical breaks of several codistributed taxa; (3) a narrow zone of overlap exists in southern Mendocino County between aurora and draytonii haplotypes, rather than a broad intergradation zone; and (4) the critically endangered population of draytonii in Riverside County, CA forms a distinct clade with frogs from Baja California, Mexico. The currently available evidence favours recognition of aurora and draytonii as separate species with a narrow zone of overlap in northern California. PMID:15315679

  19. Mechanics of the inner ear of the bullfrog (Rana catesbeiana): the contact membranes and the periotic canal.

    PubMed

    Purgue, A P; Narins, P M

    2000-05-01

    The frog inner ear consists of a complex of fluid-filled membranous sacs and canals containing eight distinct clusters of sensory hair cells. In this study we attempt to delineate the potential pathways for acoustic energy flow toward two of these clusters located within the amphibian papilla and the basilar papilla. Detailed morphological measurements of the periotic canal based on internal casts of the inner ear in the bullfrog (Rana catesbeiana) revealed that it is divided into a wide, tapered section and a narrower section comprised of two branches one short and blind projecting into the endolymphatic space and another longer, terminating in the round window. Additionally, we used laser Doppler velocimetry to record the velocity responses of the contact membranes of the amphibian papilla and basilar papilla. We found that the acoustic energy flow through these two structures is frequency dependent such that the amphibian papilla contact membrane displays a peak velocity amplitude at frequencies less than 500 Hz, whereas the basilar papilla contact membrane velocity response exhibits a maximum above 1,100 Hz. Our data advocate a mechanical substrate underlying the frequency segregation in the auditory nerve fibers innervating the amphibian papilla and the basilar papilla.

  20. Biospectroscopy reveals the effect of varying water quality on tadpole tissues of the common frog (Rana temporaria).

    PubMed

    Strong, Rebecca J; Halsall, Crispin J; Ferenčík, Martin; Jones, Kevin C; Shore, Richard F; Martin, Francis L

    2016-06-01

    Amphibians are undergoing large population declines in many regions around the world. As environmental pollution from both agricultural and urban sources has been implicated in such declines, there is a need for a biomonitoring approach to study potential impacts on this vulnerable class of organism. This study assessed the use of infrared (IR) spectroscopy as a tool to detect changes in several tissues (liver, muscle, kidney, heart and skin) of late-stage common frog (Rana temporaria) tadpoles collected from ponds with differing water quality. Small differences in spectral signatures were revealed between a rural agricultural pond and an urban pond receiving wastewater and landfill run-off; these were limited to the liver and heart, although large differences in body size were apparent, surprisingly with tadpoles from the urban site larger than those from the rural site. Large differences in liver spectra were found between tadpoles from the pesticide and nutrient impacted pond compared to the rural agricultural pond, particularly in regions associated with lipids. Liver mass and hepatosomatic indices were found to be significantly increased in tadpoles from the site impacted by pesticides and trace organic chemicals, suggestive of exposure to environmental contamination. Significant alterations were also found in muscle tissue between tadpoles from these two ponds in regions associated with glycogen, potentially indicative of a stress response. This study highlights the use of IR spectroscopy, a low-cost, rapid and reagent-free technique in the biomonitoring of a class of organisms susceptible to environmental degradation. PMID:26925755

  1. Pre-hibernation energy reserves in a temperate anuran, Rana chensinensis, along a relatively fine elevational gradient

    USGS Publications Warehouse

    Lu, X.; Li, B.; Li, Y.; Ma, X.; Fellers, G.M.

    2008-01-01

    Temperate anurans have energy substrates in the liver, fat bodies, carcass and gonads; these stores provide support for metabolism and egg production during hibernation, and for breeding activities in spring. This paper compares the energy budget shortly before hibernation among Rana chensinensis populations at elevations of 1400, 1700 and 2000 m along a river in northern China. The larger frogs, regardless of elevation, had relatively heavy storage organs and the masses of nearly all these organs were positively correlated with each other. After controlling for the effect of body size, we found no significant difference in energetic organ mass among different age classes for each of the three populations. There were sexual differences in energy strategy. Males in all populations accumulated greater reserves in liver, fat bodies and carcass than did females. In contrast, females put more energy into their ovaries and oviducts. Frogs from higher elevations tended to have heavier organs than those from lower elevations; however, the pattern did not vary systematically along fine environmental gradients. Mid-elevation R. chensinensis built up significantly more reserves than low-elevation individuals, but were similar to their highland conspecifics. Males from higher elevations tended to have heavier liver and fat bodies; females were similar in liver and ovary mass across all elevations, but formed heavier fat bodies, oviducts and somatic tissue at higher elevation sites.

  2. Calcium paradox induces apoptosis in the isolated perfused Rana ridibunda heart: involvement of p38-MAPK and calpain.

    PubMed

    Aggeli, Ioanna-Katerina; Zacharias, Triantafyllos; Papapavlou, Georgia; Gaitanaki, Catherine; Beis, Isidoros

    2013-12-01

    "Calcium paradox" as a term describes the deleterious effects conferred to a heart perfused with a calcium-free solution followed by repletion, including loss of mechanical activity and sarcomere disruption. Given that the signaling mechanisms triggered by calcium paradox remain elusive, in the present study, we tried to investigate them in the isolated perfused heart from Rana ridibunda. Calcium paradox was found to markedly activate members of the MAPKs (p43-ERK, JNKs, p38-MAPK). In addition to lactate dehydrogenase (LDH) release in the perfusate (indicative of necrosis), we also confirmed the occurrence of apoptosis by using the TUNEL assay and identifying poly(ADP-ribose) polymerase (PARP) fragmentation and upregulated Bax expression. Furthermore, using MDL28170 (a selective calpain inhibitor), a role for this protease was revealed. In addition, various divalent cations were shown to exert a protective effect against the calcium paradox. Interestingly, SB203580, a p38-MAPK inhibitor, alleviated calcium-paradox-conferred apoptosis. This result indicates that p38-MAPK plays a pro-apoptotic role, contributing to the resulting myocardial dysfunction and cell death. To our knowledge, this is the first time that the calcium paradox has been shown to induce apoptosis in amphibians, with p38-MAPK and calpain playing significant roles.

  3. Phylogenetic origins of antibody structure. II. Immunoglobulins in the primary immune response of the bullfrog, Rana catesbiana.

    PubMed

    Marchalonis, J; Edelman, G M

    1966-11-01

    The anuran amphibian, Rana catesbiana, has been found to possess at least two kinds of immunoglobulins corresponding to gammaG- and gammaM-classes. These classes have the same chain structures as those of their counterparts in higher animal species. Light chains of both immunoglobulins had molecular weights of 20,000. Heavy chains of the gammaM-class had molecular weights of 72,100; those of the gammaG-class had molecular weights of 53,600. The carbohydrate content of the gammaG-immunoglobulin was 2.1%, and that of the gammaM-protein was 10.8%. The amino acid compositions of the immunoglobulins were generally similar to those of mammalian immunoglobulins. After a single injection of phage antigen (f2), the order of appearance of phage-neutralizing activity in the frog immunoglobulin classes was (a) gammaM-antibodies, and (b) gammaG-antibodies. The results of this and previous studies suggest that the gammaG-immunoglobulins emerged at some point in evolution between the elasmobranchs and the anuran amphibians. PMID:4162734

  4. Impact of wastewater treatment configuration and seasonal conditions on thyroid hormone disruption and stress effects in Rana catesbeiana tailfin.

    PubMed

    Wojnarowicz, Pola; Ogunlaja, Olumuyiwa O; Xia, Chen; Parker, Wayne J; Helbing, Caren C

    2013-12-01

    Improved endocrine disrupting compound (EDC) removal is desirable in municipal wastewater treatment plants (MWWTPs) although increased removal does not always translate into reduced biological activity. Suitable methods for determining reduction in biological activity of effluents are needed. In order to determine which MWWTPs are the most effective at removing EDC activities, we operated three configurations of pilot sized biological reactors (conventional activated sludge, CAS; nitrifying activated sludge, NAS; and biological nutrient removal, BNR) receiving the same influent under simulated winter and summer conditions. As frogs are model organisms for the study of thyroid hormone (TH) action, we used the North American species Rana catesbeiana in a cultured tadpole tailfin (C-fin) assay to compare the effluents. TH-responsive (thyroid hormone receptors alpha (thra) and beta (thrb)) and stress-responsive (superoxide dismutase, catalase, and heat shock protein 30) mRNA transcript levels were examined. Effluents infrequently perturbed stress-responsive transcript abundance but thra/thrb levels were significantly altered. In winter conditions, CAS caused frequent TH perturbations while BNR caused none. In summer conditions, however, BNR caused substantial TH perturbations while CAS caused few. Our findings contrast other studies of seasonal variations of EDC removal and accentuate the importance of utilizing appropriate biological readouts for assessing EDC activities. PMID:24180706

  5. Characterization of the Skin Microbiota in Italian Stream Frogs (Rana italica) Infected and Uninfected by a Cutaneous Parasitic Disease.

    PubMed

    Federici, Ermanno; Rossi, Roberta; Fidati, Laura; Paracucchi, Romina; Scargetta, Silvia; Montalbani, Elena; Franzetti, Andrea; La Porta, Gianandrea; Fagotti, Anna; Simonceli, Francesca; Cenci, Giovanni; Di Rosa, Ines

    2015-01-01

    In human and wildlife populations, the natural microbiota plays an important role in health maintenance and the prevention of emerging infectious diseases. In amphibians, infectious diseases have been closely associated with population decline and extinction worldwide. Skin symbiont communities have been suggested as one of the factors driving the different susceptibilities of amphibians to diseases. The activity of the skin microbiota of amphibians against fungal pathogens, such as Batrachochytrium dendrobatidis, has been examined extensively, whereas its protective role towards the cutaneous infectious diseases caused by Amphibiocystidium parasites has not yet been elucidated in detail. In the present study, we investigated, for the first time, the cutaneous microbiota of the Italian stream frog (Rana italica) and characterized the microbial assemblages of frogs uninfected and infected by Amphibiocystidium using the Illumina next-generation sequencing of 16S rRNA gene fragments. A total of 629 different OTUs belonging to 16 different phyla were detected. Bacterial populations shared by all individuals represented only one fifth of all OTUs and were dominated by a small number of OTUs. Statistical analyses based on Bray-Curtis distances showed that uninfected and infected specimens had distinct cutaneous bacterial community structures. Phylotypes belonging to the genera Janthinobacterium, Pseudomonas, and Flavobacterium were more abundant, and sometimes almost exclusively present, in uninfected than in infected specimens. These bacterial populations, known to exhibit antifungal activity in amphibians, may also play a role in protection against cutaneous infectious diseases caused by Amphibiocystidium parasites. PMID:26370166

  6. Heavy metals alter the survival, growth, metamorphosis, and antipredatory behavior of Columbia spotted frog (Rana luteiventris) tadpoles.

    PubMed

    Lefcort, H; Meguire, R A; Wilson, L H; Ettinger, W F

    1998-10-01

    Amphibian populations appear to be declining around the world. Although there is no single cause, one factor may be pollution from heavy metals. As a result of mining in the Silver Valley of Idaho, heavy metals have been released into habitats containing many species of sensitive organisms, including spotted frogs (Rana luteiventris). While the gross extent of pollution has been well documented, the more subtle behavioral effects of heavy metals such as lead, zinc, and cadmium are less well studied. We tested the effects of heavy metals on the short-term survival (LC50) of spotted frog tadpoles. Compared to single metals, metals presented together were toxic at lower doses. We also raised the tadpoles in outdoor mini-ecosystems containing either a single heavy metal or soil from an EPA Superfund site in the Silver Valley known to be composed of numerous heavy metals. Exposure to Silver Valley soil resulted in delayed metamorphosis. We tested the ability of metal-exposed tadpoles to detect and respond to chemical cues emanating from predacious rainbow trout. We found that high levels of Silver Valley soil, medium levels of zinc, and medium and high levels of lead resulted in a decreased fright response. Low levels of cadmium, zinc, and lead did not cause a significant effect, but low levels of soil did result in a decreased fright response. Heavy metals may alter interactions between tadpoles and their predators. PMID:9732476

  7. Accumulation and pharmacokinetics of estrogenic chemicals in the pre- and post-hatch embryos of the frog Rana rugosa.

    PubMed

    Takase, Minoru; Shinto, Hideaki; Takao, Yuji; Iguchi, Taisen

    2012-01-01

    Amphibian eggs spawned in water are exposed immediately to various chemicals present in their water. The present study aimed to investigate the accumulation and pharmacokinetics of 17α-ethynylestradiol (EE(2)), bisphenol A (BPA), and nonylphenol (NP), as well as 17β-estradiol (E(2)), in the pre-hatch and post-hatch embryos of the frog Rana rugosa. Fertilized eggs were exposed to chemicals at a final concentration of 500 nM in breeding water for two days, then the embryos with jelly coats were reared in fresh-breeding water without supplementation of the xenoestrogens for six more days. All exogenous chemicals were concentrated in the embryo body at two days after fertilization, whereas their concentrations in the jelly coat were the same as those in the breeding water. The bioconcentration factors for E(2), EE(2), BPA, and NP were 217.9, 170.2, 382.3, and 289.1, respectively, suggesting that the estrogenic chemicals were concentrated in the embryo body through the jelly coat.

  8. Surface ultrastructure of the cornea and adjacent epidermis during metamorphosis of Rana pipiens: a scanning electron microscopic study

    SciTech Connect

    Kaltenbach, J.C.; Harding, C.V.; Susan, S.

    1980-01-01

    The external surface of the cornea and adjacent epidermis of larvae in representative developmental stages and of adult frogs, Rana pipiens, was studied by scanning electron microscopy. Surface cells are polygonal, usually hexagonal, in outline and covered with microprojections. During larval development prior to metamorphic stages, neither eyelids nor Harderian glands have developed; microprojections on the corneal surface are high and branched, and cell boundaries are elevated. On the anterior portion of the cornea and on the epidermis near the eye, the surface pattern is less dense, and ciliated cells are present. During metamorphic stages, corneal cell boundaries become less prominent and the pattern of microprojections more variable and markedly different from that of larvae of earlier stages. Corneal cells have a spongy appearance, are covered by a coating material, or are characterized as light or dark based on their brightness and surface texture. As eyelids develop in metamorphic stages XX-XXI, the numbers of ciliated cells increase dramatically, both on the corneal surface and on the edges of the developing lids. In later metamorphic stages XXII to XXV, lids and Harderian glands become well-developed, and cilia are no longer observed. The adjacent epidermal surface becomes devoid of cilia but perforated by openings of cutaneous glands. Its spongy appearance is similar to that of both the cornea and neighboring epidermis of the mature frog. Changes in corneal surface features are probably metamorphic events associated with development of lids and Harderian glands and a shift from an aqueous to an air environment.

  9. Long-term effects of pesticide exposure at various life stages of the southern leopard frog (Rana sphenocephala)

    USGS Publications Warehouse

    Bridges, C.M.

    2000-01-01

    Amphibian larvae are commonly exposed to low levels of pesticides during their development. Chronic studies generally examine the effects of long-term exposure, but they often disregard the importance of the individual life stage at which tadpoles are exposed. I determined the point during development at which carbaryl effects are manifested by exposing southern leopard frog tadpoles (Rana sphenocephala) to the pesticide carbaryl at five different times during development. Metamorphs exposed throughout the tadpole stage and throughout development (egg, embryo, tadpole) experienced significant mortality at all chemical levels. Although the length of the larval period was the same for all experimental groups, metamorphs exposed during the egg stage were smaller than their corresponding controls, independent of whether they were exposed at any other stage. Nearly 18% of individuals exposed to carbaryl during development exhibited some type of developmental deformity (including both visceral and limb malformities), compared to a single deformed (< 1%) control tadpole, demonstrating that a chemical hypothesis for amphibian deformities remains viable. Because exposure to nonpersistent chemicals may last for only a short period of time, it is important to examine the long-term effects that short-term exposure has on larval amphibians and the existence of any sensitive life stage. Any delay in metamorphosis or decrease in size at metamorphosis can impact demographic processes of the population, potentially leading to declines or local extinction.

  10. Thermal acclimation of metabolic rate may be seasonally dependent in the subtropical anuran Latouche's frog (Rana latouchii, Boulenger).

    PubMed

    Chang, Yuan-Mou; Lucy Hou, Ping-Chun

    2005-01-01

    We tested the hypothesis that the lack of metabolic thermal acclimation ability in tropical and subtropical amphibians is dependent on season and investigated the effects of body size, sex, time of day, and season on metabolic rates in Rana latouchii. The males were acclimated at 15 degrees, 20 degrees, and 25 degrees C, and their oxygen consumption was measured at 15 degrees, 20 degrees, 25 degrees, and 30 degrees C in all four seasons, with the exception that we did not measure oxygen consumption at 30 degrees C in winter frogs. We also acclimated the males at 30 degrees C in summer for investigating diel variation of metabolic rate. The females were acclimated at 20 degrees and 25 degrees C, and their oxygen consumption was measured at 15 degrees , 20 degrees , 25 degrees , and 30 degrees C in summer. Our results showed that metabolic rates of R. latouchii differed by time of day, season, and acclimation temperature but did not differ by sex if the results were adjusted for differences in body mass. Summer males exhibited a 26%-48% increase in metabolic rates from the lowest values in the seasons. There was a trend of increased oxygen consumption in cold-acclimated males, but it was significant only at 15 degrees and 25 degrees C in summer, autumn, and winter. These results support the hypothesis that thermal acclimation of metabolism is seasonally dependent, which has not been reported in other tropical and subtropical amphibians.

  11. Genetic variation in insecticide tolerance in a population of southern leopard frogs (Rana sphenocephala): Implications for amphibian conservation

    USGS Publications Warehouse

    Bridges, C.M.; Semlitsch, R.D.

    2001-01-01

    Currently, conservation efforts are devoted to determining the extent and the causes of the decline of many amphibian species worldwide. Human impacts frequently degrade amphibian habitat and have been implicated in many declines. Because genetic variance is critical in determining the persistence of a species in a changing environment, we examined the amount of genetic variability present in a single population for tolerance to an environmental stressor. We examined the amount of genetic variability among full- and half-sib families in a single population of southern leopard frogs (Rana sphenocephala) with respect to their tolerance to lethal concentrations of the agricultural chemical, carbaryl. Analysis of time-to-death data indicated significant differences among full-sib families and suggests a large amount of variability present in the responses to this environmental stressor. Significant differences in responses among half-sib families indicated that there is additive genetic variance. These data suggest that this population may have the ability to adapt to environmental stressors. It is possible that declines of amphibian populations in the western United States may be attributed to low genetic variability resulting from limited migration among populations and small population sizes.

  12. Evolutionary dynamics of a rapidly receding southern range boundary in the threatened California red-legged frog (Rana draytonii)

    USGS Publications Warehouse

    Richmond, Jonathan Q.; Barr, Kelly R.; Backlin, Adam R.; Vandergast, Amy G.; Fisher, Robert N.

    2013-01-01

    Populations forming the edge of a species range are often imperiled by isolation and low genetic diversity, with proximity to human population centers being a major determinant of edge stability in modern landscapes. Since the 1960s, the California red-legged frog (Rana draytonii) has undergone extensive declines in heavily urbanized southern California, where the range edge has rapidly contracted northward while shifting its cardinal orientation to an east-west trending axis. We studied the genetic structure and diversity of these frontline populations, tested for signatures of contemporary disturbance, specifically fire, and attempted to disentangle these signals from demographic events extending deeper into the past. Consistent with the genetic expectations of the ‘abundant-center’ model, we found that diversity, admixture, and opportunity for random mating increases in populations sampled successively further away from the range boundary. Demographic simulations indicate that bottlenecks in peripheral isolates are associated with processes extending tens to a few hundred generations in the past, despite the demographic collapse of some due to recent fire-flood events. While the effects of recent disturbance have left little genetic imprint on these populations, they likely contribute to an extinction debt that will lead to continued range contraction unless management intervenes to stall or reverse the process.

  13. Multifarious selection through environmental change: acidity and predator-mediated adaptive divergence in the moor frog (Rana arvalis).

    PubMed

    Egea-Serrano, Andrés; Hangartner, Sandra; Laurila, Anssi; Räsänen, Katja

    2014-04-01

    Environmental change can simultaneously cause abiotic stress and alter biological communities, yet adaptation of natural populations to co-changing environmental factors is poorly understood. We studied adaptation to acid and predator stress in six moor frog (Rana arvalis) populations along an acidification gradient, where abundance of invertebrate predators increases with increasing acidity of R. arvalis breeding ponds. First, we quantified divergence among the populations in anti-predator traits (behaviour and morphology) at different rearing conditions in the laboratory (factorial combinations of acid or neutral pH and the presence or the absence of a caged predator). Second, we evaluated relative fitness (survival) of the populations by exposing tadpoles from the different rearing conditions to predation by free-ranging dragonfly larvae. We found that morphological defences (relative tail depth) as well as survival of tadpoles under predation increased with increasing pond acidity (under most experimental conditions). Tail depth and larval size mediated survival differences among populations, but the contribution of trait divergence to survival was strongly dependent on prior rearing conditions. Our results indicate that R. arvalis populations are adapted to the elevated predator pressure in acidified ponds and emphasize the importance of multifarious selection via both direct (here: pH) and indirect (here: predators) environmental changes. PMID:24552840

  14. Odorous and non-fatal skin secretion of adult wrinkled frog (Rana rugosa) is effective in avoiding predation by snakes.

    PubMed

    Yoshimura, Yuri; Kasuya, Eiiti

    2013-01-01

    The roles played by nonfatal secretions of adult anurans in the avoidance of predation remain unknown. The adult Wrinkled frog (Rana rugosa) has warty skin with the odorous mucus secretion that is not fatal to the snake Elaphe quadrivirgata. We fed R. rugosa or Fejervarya limnocharis, which resembles R. rugosa in appearance and has mucus secretion, to snakes and compared the snakes' responses to the frogs. Compared to F. limnocharis, R. rugosa was less frequently bitten or swallowed by snakes. The snakes that bit R. rugosa spat out the frogs and showed mouth opening (gaping) behavior, while the snakes that bit F. limnocharis did not show gaping behavior. We also compared the responses of the snakes to R. rugosa and F. limnocharis secretions. We coated palatable R. japonica with secretions from R. rugosa or F. limnocharis. The frogs coated by R. rugosa secretion were less frequently bitten or swallowed than those coated by F. limnocharis secretion. We concluded that compared to different frog species of similar sizes, the adult R. rugosa was less frequently preyed upon by, and that its skin secretion was effective in avoiding predation by snakes.

  15. Electrospun poly(l-lactide)/zein nanofiber mats loaded with Rana chensinensis skin peptides for wound dressing.

    PubMed

    Zhang, Mei; Li, Xueqi; Li, Siming; Liu, Yongjia; Hao, Linlin

    2016-09-01

    Electrospun nanofiber mats can display impressive performance as an ideal wound dressing. In this study, poly(l-lactide)(PLLA)/zein nanofiber mats loaded with Rana chensinensis skin peptides (RCSPs) were successfully produced by two different electrospinning techniques, blend and coaxial, with the goal of developing a wound dressing material. The nanofiber mats were investigated by environmental scanning electron microscope (ESEM), transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR), differential scanning calorimeter (DSC), water contact angle, mechanical tests and cell viability. The resulting nanofiber mats exhibited smooth surfaces, tiny diameters and different cross-sectional shapes from pure PLLA and zein nanofibers. The FTIR result showed that PLLA, zein and RCSPs were well dispersed, without chemical interactions. Compared with coaxial nanofiber mats, blending zein-RCSPs with PLLA enhanced hydrophilicity but decreased mechanical properties. Adding RCSPs into the electrospun nanofibers significantly improved the mechanical properties of the mats. Cell viability studies with human foreskin fibroblasts demonstrated that cell growth on PLLA/zein-RCSPs nanofiber mats was significantly higher than that on PLLA/zein nanofiber mats. The results indicate that nanofiber mats containing RCSPs are potential candidates for wound dressing. PMID:27432415

  16. The effects of four arthropod diets on the body and organ weights of the leopard frog, Rana pipiens, during vitellogenesis.

    PubMed

    Lehman, G C

    1978-12-01

    Wild-caught adult Rana pipiens females were captured in midsummer and fed diets of crickets, flies sowbugs or wax moth larvae during a three-month period of active vitellogenesis. The cricket diet supported the most extensive body weight gain during this time and promoted a prolonged period of weight increase in an additional long-term study. Synchronous growth of the oocytes occurred in all four groups, but the ovaries and oviducts of cricket-fed animals were significantly larger than those of frogs on the other three diets. The significantly higher liver weights of frogs fed wax moth larvae may have reflected an augmentation of hepatic energy stores. Fat body weights were also highest in this group of animals. Frogs fed crickets and wax moth larvae possessed larger fat bodies than did the midsummer control animals killed immediately after their arrival in the laboratory. In contrast, frogs fed flies and sowbugs had smaller fat bodies than did the initial controls, suggesting that animals on these diets had utilized fat body lipid during vitellogenesis. Gastrocnemius and final body weights were lowest in frogs fed wax moth larvae. These findings may have reflected the nutritional content of the diet or the reduction in appetite frequently noted in these animals during observations of feeding behavior.

  17. Sodium arsenite induced changes in survival, growth, metamorphosis and genotoxicity in the Indian cricket frog (Rana limnocharis).

    PubMed

    Singha, Utsab; Pandey, Neelam; Boro, Freeman; Giri, Sarbani; Giri, Anirudha; Biswas, Somava

    2014-10-01

    Arsenic contamination of the environment is a matter of great concern. Understanding the effects of arsenic on aquatic life will act as biological early warning system to assess how arsenic could shape the biodiversity in the affected areas. Rapid decline in amphibian population in recent decades is a cause of major concern. Over the years, amphibians have been recognized as excellent bio-indicators of environmental related stress. In the present study, we examined the toxic and genotoxic effects of sodium arsenite in the tadpoles of the Indian cricket frog (Rana limnocharis). Sodium arsenite at different concentrations (0, 50, 100, 200 and 400 μg L(-1)) neither induced lethality nor significantly altered body weight at metamorphosis. However, it accelerated the rate of metamorphosis at higher concentrations, reduced body size (snout-vent length) and induced developmental deformities such as loss of limbs. Besides, at concentration ranges between 100 and 400 μg L(-1), sodium arsenite induced statistically significant genotoxicity at 24, 48, 72 and 96 h of the exposure in a concentration-dependent manner. However, it did not show time effects as the highest frequency was found between 48 and 72 h which remained steady subsequently. The genotoxicity was confirmed by comet assay in the whole blood cells. These findings suggest that arsenic at environmentally relevant concentrations has significant sub-lethal effects on R.limnocharis, which may have long-term fitness consequence to the species and may have similar implications in other aquatic life too.

  18. Growth and developmental effects of coal combustion residues on Southern Leopard Frog (Rana sphenocephala) tadpoles exposed throughout metamorphosis

    SciTech Connect

    Peterson, J.D.; Peterson, V.A.; Mendonca, M.T.

    2008-09-15

    The effects of aquatic deposition of coal combustion residues (CCRs) on amphibian life histories have been the focus of many recent studies. In summer 2005, we raised larval Southern Leopard Frogs, Rana sphenocephala, on either sand or CCR substrate (approximately 1 cm deep within plastic bins) and documented effects of sediment type on oral disc condition, as well as time to, mass at, and total body length at key developmental stages, including metamorphosis (Gosner stages (GS) 37, 42, and 46). We found no significant difference in mortality between the two treatments and mortality was relatively low (eight of 48 in the control group and four of 48 in the CCR group). Ninety percent of exposed tadpoles displayed oral disc abnormalities, while no control individuals displayed abnormalities. Tadpoles raised on CCR-contaminated sediment had decreased developmental rates and weighed significantly less at all developmental stages, on average, when compared to controls. The CCR treatment group was also significantly shorter In length than controls at the completion of metamorphosis (GS 46). Collectively, these findings are the most severe sub-lethal effects noted for any amphibian exposed to CCRs to date. More research is needed to understand how these long term effects may contribute to the dynamics of local amphibian populations.

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

    PubMed

    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.

  20. Characterization of the Skin Microbiota in Italian Stream Frogs (Rana italica) Infected and Uninfected by a Cutaneous Parasitic Disease.

    PubMed

    Federici, Ermanno; Rossi, Roberta; Fidati, Laura; Paracucchi, Romina; Scargetta, Silvia; Montalbani, Elena; Franzetti, Andrea; La Porta, Gianandrea; Fagotti, Anna; Simonceli, Francesca; Cenci, Giovanni; Di Rosa, Ines

    2015-01-01

    In human and wildlife populations, the natural microbiota plays an important role in health maintenance and the prevention of emerging infectious diseases. In amphibians, infectious diseases have been closely associated with population decline and extinction worldwide. Skin symbiont communities have been suggested as one of the factors driving the different susceptibilities of amphibians to diseases. The activity of the skin microbiota of amphibians against fungal pathogens, such as Batrachochytrium dendrobatidis, has been examined extensively, whereas its protective role towards the cutaneous infectious diseases caused by Amphibiocystidium parasites has not yet been elucidated in detail. In the present study, we investigated, for the first time, the cutaneous microbiota of the Italian stream frog (Rana italica) and characterized the microbial assemblages of frogs uninfected and infected by Amphibiocystidium using the Illumina next-generation sequencing of 16S rRNA gene fragments. A total of 629 different OTUs belonging to 16 different phyla were detected. Bacterial populations shared by all individuals represented only one fifth of all OTUs and were dominated by a small number of OTUs. Statistical analyses based on Bray-Curtis distances showed that uninfected and infected specimens had distinct cutaneous bacterial community structures. Phylotypes belonging to the genera Janthinobacterium, Pseudomonas, and Flavobacterium were more abundant, and sometimes almost exclusively present, in uninfected than in infected specimens. These bacterial populations, known to exhibit antifungal activity in amphibians, may also play a role in protection against cutaneous infectious diseases caused by Amphibiocystidium parasites.

  1. Endocrine-disrupting effects and reproductive toxicity of low dose MCLR on male frogs (Rana nigromaculata) in vivo.

    PubMed

    Jia, Xiuying; Cai, Chenchen; Wang, Jia; Gao, Nana; Zhang, Hangjun

    2014-10-01

    Toxic cyanobacterial blooms are potential global threats to aquatic ecosystems and human health. The World Health Organization has set a provisional guideline limit of 1 μg/L microcystin-LR (MCLR) in freshwater. However, MCLR concentrations in several water bodies have exceeded this level. Despite this recommended human safety standard, MCLR-induced endocrine-disrupting effects and reproductive toxicity on male frog (Rana nigromaculata) were demonstrated in this study. Results showed that sperm motility and sperm count were significantly and negatively correlated with exposure time and concentration. By contrast, abnormal sperm rate was positively correlated with both parameters. Ultrastructural observation results revealed abnormal sperm morphologies, vacuoles in spermatogenic cells, cell dispersion, incomplete cell structures, and deformed nucleoli. These results indicated that MCLR could induce toxic effects on the reproductive system of frogs, significantly decrease testosterone content, and rapidly increase estradiol content. Prolonged exposure and increased concentration enhanced the relative expression levels of P450 aromatase and steroidogenic factor 1; thus, endocrine function in frogs was disrupted. This study is the first to demonstrate in vivo MCLR toxicity in the reproductive system of male R. nigromaculata. This study provided a scientific basis of the global decline in amphibian populations.

  2. Dietary exposure to low pesticide doses causes long-term immunosuppression in the leopard frog (Rana pipiens).

    PubMed

    Albert, Anathea; Drouillard, Ken; Haffner, G Douglas; Dixon, Brian

    2007-06-01

    This study examines the relationship between dietary exposure of pesticides, DDT, and dieldrin and immunosuppression in the northern leopard frog (Rana pipiens). Immune function was measured before, during, and after a 10-week exposure period with the use of both adaptive and innate immunity responses. Exposure to low doses (75 ng/g body wt DDT or 2.1 ng/g dieldrin total dose over the 10 weeks) resulted in significant suppressive effects on antibody production and secondary delayed-type hypersensitivity (DTH). The high doses (750 ng/g DDT and 21 ng/g dieldrin), however, did not affect antibody production, DTH, or oxidative burst in a predictable dose-response manner. The differences in magnitude and direction of the effects of the two dosing regimes were likely due to differences in chemical exposure on the basis of feeding and effectiveness of chemical uptake. The low dose results demonstrated that moderate concentrations of pesticides, frequently observed in the environment, are able to weaken the immune response of R. pipiens.

  3. Tissue distribution, elimination and metabolism of [3H]-leukotriene C4 in the American bullfrog, Rana catesbeiana.

    PubMed

    Pfeifer, C A; Furilla, R A; Gronert, K; Goss, D D; Romig, K E; Herman, C A

    1993-03-01

    Tissue distribution, elimination, and metabolism of [3H]-leukotriene C4 were studied at 2.5 hours after injection in the conscious and anesthetized American bullfrog, Rana catesbeiana. Conscious frogs were injected via the dorsal lymph sac or the sciatic vein. Anesthetized frogs were injected via the abdominal vein. The organs containing the greatest percent of injected radioactivity at 2.5 hours after injection were liver, small intestine and kidney. Route of injection and anesthesia appears to alter distribution and elimination of leukotrienes. [3H]-leukotrienes were eliminated into bladder water and bile. In addition, 7.8 +/- 2.2 and 5.2 +/- 2.5 percent of the injected radioactivity was found in the pan water bathing the ventral surface of the venously and dorsally injected conscious frogs, respectively, suggesting transfer of radioactivity across the skin. At 2.5 hours, polar metabolites represented 50% of the radioactivity found in liver, bile, and bladder water. These polar metabolites were determined to be 18-carboxy-19,20-dinor-leukotriene E4, 20-carboxy-leukotriene E4, and 20-hydroxy-leukotriene E4. Of the non-oxidized leukotrienes, bile contained mainly LTD4 while bladder water contained primarily LTE4. N-acetyl LTE4 was not detected in any samples. The tissue distribution, elimination and metabolism of leukotrienes in the bullfrog was similar to mammalian studies and suggests evolutionary conservation of leukotriene processing.

  4. Purification and characterization of a non-vitellogenin, estrogen-induced plasma protein from the American bullfrog Rana catesbeiana.

    PubMed

    Mitchell, R O; Dean, W L; Hess, P P; Feldhoff, R C

    1985-07-01

    A non-vitellogenin, estrogen-induced protein has been detected for the first time in the plasma of male Rana catesbeiana. A greater than 90% purification of this plasma protein was achieved by salt fractionation with Mg(II) followed by ion-exchange chromatography on DEAE- and CM-cellulose. Immunoelectrophoretic analysis with various antisera showed no immunological cross-reactivity between this protein and vitellogenin. The molecular mass of the purified protein was determined to be 116 000 daltons by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis and 105 000 daltons by analytical ultracentrifugation. Sedimentation studies indicate the protein is a nonaggregating spherical monomer with a sedimentation coefficient of 7.5 S. Amino acid analysis demonstrated a composition different from that of vitellogenin and lipovitellin A. Limited proteolysis with trypsin, chymotrypsin, and Bacillus subtilis protease revealed no common peptides on SDS-polyacrylamide gels. Phosphate analysis indicated that, on a molar basis, the non-vitellogen, estrogen-induced protein had less than or equal to 3% of the phosphate found in vitellogenin. Further studies of the structure, function, and metabolism of this protein may reveal information relating to the hormonal control of vitellogenesis.

  5. Temporal effects of infused corticosterone and aldosterone on plasma glucose levels in the American bullfrog (Rana catesbeiana).

    PubMed

    Broughton, R E; deRoos, R

    1984-02-01

    The effects of a single infusion of corticosterone or aldosterone on plasma glucose levels were compared in the American bullfrog (Rana catesbeiana). The corticoids were administered, and serial blood samples were collected, via a cannula placed in the common iliac artery. Plasma glucose was estimated by the glucose oxidase method. Plasma glucose levels were essentially unchanged from the time-zero levels at 3 hr after the infusion of 1.0 mg/100 g body wt of corticosterone. The levels subsequently increased to maxima that were approximately 45% greater than the time-zero levels at 9 through 24 hr and then declined to approximately the initial levels by 48 hr after treatment. Infusion of 0.24 mg/100 g body wt of aldosterone did not significantly alter plasma glucose levels. The results suggest that elevated circulating corticosterone is not involved in the primary hyperglycemic response to a stress, but may function synergistically and sequentially with elevated circulating catecholamines in subsequent compensatory adjustments.

  6. Attenuated cardiovascular effects of prostaglandin I2 and prostaglandin F2 alpha in cold acclimated American bullfrogs, Rana catesbeiana.

    PubMed

    Herman, C A; Robleto, D O; Mata, P L; Lujan, M D

    1986-05-01

    American bullfrogs, Rana catesbeiana respond to prostaglandins with changes in heart rate and blood pressure. These studies compare responses of warm (22 degrees C) and cold acclimated (5 degrees C) bullfrogs to prostaglandins. Gas chromatographic analysis determined equivalent fatty acid profiles in total lipids of heart and artery tissue from warm and cold acclimated animals. Arachidonic acid was the fatty acid precursor found in greatest abundance in both groups. For cardiovascular experiments, bullfrogs were cannulated by using a T-cannula implanted in the right sciatic artery. In warm acclimated bullfrogs, preinfusion systemic arterial pressure (SAP) was 14.7 +/- 0.5 mm Hg, and heart rate was 33.0 +/- 1.7 beats/min. Cold acclimated bullfrogs had SAP values of 8.0 +/- 0.8 mm Hg, and heart rate was 6.9 +/- 0.3 beats/min. Arachidonic and eicosapentaenoic acid infusions (2,000 micrograms/kg body weight [bw]) were hypertensive in cold acclimated and hypotensive in warm acclimated animals. These effects were blocked by indomethacin (4 mg/kg bw). In both warm and cold acclimated bullfrogs, prostaglandin F2 alpha (3-100 micrograms/kg bw) was hypertensive, while prostaglandin I2 (0.03-3 micrograms/kg bw) was hypotensive, with both prostaglandins stimulating a greater absolute response in warm acclimated animals. In addition, both prostaglandins increased heart rate in warm but not in cold acclimated bullfrogs. The results suggest diminished cardiovascular sensitivity to prostaglandins at low environmental temperatures.

  7. Impact of wastewater treatment configuration and seasonal conditions on thyroid hormone disruption and stress effects in Rana catesbeiana tailfin.

    PubMed

    Wojnarowicz, Pola; Ogunlaja, Olumuyiwa O; Xia, Chen; Parker, Wayne J; Helbing, Caren C

    2013-12-01

    Improved endocrine disrupting compound (EDC) removal is desirable in municipal wastewater treatment plants (MWWTPs) although increased removal does not always translate into reduced biological activity. Suitable methods for determining reduction in biological activity of effluents are needed. In order to determine which MWWTPs are the most effective at removing EDC activities, we operated three configurations of pilot sized biological reactors (conventional activated sludge, CAS; nitrifying activated sludge, NAS; and biological nutrient removal, BNR) receiving the same influent under simulated winter and summer conditions. As frogs are model organisms for the study of thyroid hormone (TH) action, we used the North American species Rana catesbeiana in a cultured tadpole tailfin (C-fin) assay to compare the effluents. TH-responsive (thyroid hormone receptors alpha (thra) and beta (thrb)) and stress-responsive (superoxide dismutase, catalase, and heat shock protein 30) mRNA transcript levels were examined. Effluents infrequently perturbed stress-responsive transcript abundance but thra/thrb levels were significantly altered. In winter conditions, CAS caused frequent TH perturbations while BNR caused none. In summer conditions, however, BNR caused substantial TH perturbations while CAS caused few. Our findings contrast other studies of seasonal variations of EDC removal and accentuate the importance of utilizing appropriate biological readouts for assessing EDC activities.

  8. Ranalexin. A novel antimicrobial peptide from bullfrog (Rana catesbeiana) skin, structurally related to the bacterial antibiotic, polymyxin.

    PubMed

    Clark, D P; Durell, S; Maloy, W L; Zasloff, M

    1994-04-01

    Antimicrobial peptides comprise a diverse class of molecules used in host defense by plants, insects, and animals. In this study we have isolated a novel antimicrobial peptide from the skin of the bullfrog, Rana catesbeiana. This 20 amino acid peptide, which we have termed Ranalexin, has the amino acid sequence: NH2-Phe-Leu-Gly-Gly-Leu-Ile-Lys-Ile-Val-Pro-Ala-Met-Ile-Cys-Ala-Val-Thr- Lys-Lys - Cys-COOH, and it contains a single intramolecular disulfide bond which forms a heptapeptide ring within the molecule. Structurally, Ranalexin resembles the bacterial antibiotic, polymyxin, which contains a similar heptapeptide ring. We have also cloned the cDNA for Ranalexin from a metamorphic R. catesbeiana tadpole cDNA library. Based on the cDNA sequence, it appears that Ranalexin is initially synthesized as a propeptide with a putative signal sequence and an acidic amino acid-rich region at its amino-terminal end. Interestingly, the putative signal sequence of the Ranalexin cDNA is strikingly similar to the signal sequence of opioid peptide precursors isolated from the skin of the South American frogs Phyllomedusa sauvagei and Phyllomedusa bicolor. Northern blot analysis and in situ hybridization experiments demonstrated that Ranalexin mRNA is first expressed in R. catesbeiana skin at metamorphosis and continues to be expressed into adulthood.

  9. Ontogeny of B cells expressing IgM in embryonic and larval tissues of the American grass frog, Rana pipiens.

    PubMed

    Zettergren, L D

    2000-06-01

    Affinity-purified, fluorochrome-tagged F(ab')(2) antibody fragments specific for heavy (mu) chains of Rana pipiens IgM were prepared from hyperimmune rabbit sera. By using two-color immunofluorescent procedures we observed that (1) the first cells expressing IgM, termed pre-B cells, lack detectable quantities of membrane or surface IgM but contain detectable quantities of cytoplasmic IgM (smu(-)/cmu(+)), (2) sIgM(+) B cells were the second type of IgM containing cell to appear in development, and (3) plasma cells, which contain copious quantities of cIgM, were the final phenotype to appear in the development of B cells expressing IgM. These cells were first observed in the pronephros of the developing urogenital system. Shortly after their appearance in the pronephros, cells in B lineages were observed in the liver. These observations (1) are consistent with recent studies of B lymphopoiesis in the aorta-gonad-mesonephros (AGM) region in endothermic vertebrates, including mice, (2) suggest that there are fundamental ontogenetic and phylogenetic similarities between cells and tissues of developing vertebrate immune systems, and (3) evoke questions concerning the possible function(s) of lymphocytes in developing anurans up to metamorphosis and beyond.

  10. Conservation genetics of evolutionary lineages of the endangered mountain yellow-legged frog, Rana muscosa (Amphibia: Ranidae), in southern California

    USGS Publications Warehouse

    Schoville, Sean D.; Tustall, Tate S.; Vredenburg, Vance T.; Backlin, Adam R.; Gallegos, Elizabeth; Wood, Dustin A.; Fisher, Robert N.

    2011-01-01

    Severe population declines led to the listing of southern California Rana muscosa (Ranidae) as endangered in 2002. Nine small populations inhabit watersheds in three isolated mountain ranges, the San Gabriel, San Bernardino and San Jacinto. One population from the Dark Canyon tributary in the San Jacinto Mountains has been used to establish a captive breeding population at the San Diego Zoo Institute for Conservation Research. Because these populations may still be declining, it is critical to gather information on how genetic variation is structured in these populations and what historical inter-population connectivity existed between populations. Additionally, it is not clear whether these populations are rapidly losing genetic diversity due to population bottlenecks. Using mitochondrial and microsatellite data, we examine patterns of genetic variation in southern California and one of the last remaining populations of R. muscosa in the southern Sierra Nevada. We find low levels of genetic variation within each population and evidence of genetic bottlenecks. Additionally, substantial population structure is evident, suggesting a high degree of historical isolation within and between mountain ranges. Based on estimates from a multi-population isolation with migration analysis, these populations diversified during glacial episodes of the Pleistocene, with little gene flow during population divergence. Our data demonstrate that unique evolutionary lineages of R. muscosa occupy each mountain range in southern California and should be managed separately. The captive breeding program at Dark Canyon is promising, although mitigating the loss of neutral genetic diversity relative to the natural population might require additional breeding frogs.

  11. Status of the California Red-legged Frog (Rana draytonii) in the State of Baja California, México

    USGS Publications Warehouse

    Peralta-Garcia, Anny; Hellingsworth, Bradford D.; Richmond, Jonathan Q.; Valdez-Villavicencio, Jorge H.; Ruiz-Campos, Gorgonio; Fisher, Robert N.; Cruz-Hernandez, Pedro; Galina-Tessaro, Patricia

    2016-01-01

    The California Red-legged Frog (Rana draytonii) is a threatened species in the United States that has undergone population declines, especially in southern California. Due to the lack of information on the status of Mexican populations, we surveyed for the presence of R. draytonii in Baja California and assessed possible threats to population persistence. Our study area extended from the U.S.-Mexican border to the southern end of the distribution of the species in the Sierra San Pedro Mártir. We found R. draytonii at six of 15 historical sites, none at five proxy sites (i.e., alternative sites chosen because the historical record lacked precise locality data), and four at 24 additional sites. The 10 occupied sites are within three watersheds in the Sierra San Pedro Mártir (two sites at Arroyo San Rafael, two sites at Arroyo San Telmo, and six sites at Arroyo Santo Domingo). We did not detect R. draytonii at 60% of historical sites, including the highest elevation site at La Encantada and multiple low-elevation coastal drainages, suggesting the species has declined in Baja California. The threats we noted most frequently were presence of exotic aquatic animal species, water diversion, and cattle grazing. Management of remaining populations and local education is needed to prevent further declines.

  12. Growth, size and age at maturity of the agile frog (Rana dalmatina) in an Iberian Peninsula population.

    PubMed

    Sarasola-Puente, Vanessa; Gosá, Alberto; Oromí, Neus; Madeira, María José; Lizana, Miguel

    2011-06-01

    The mean age of a population of agile frogs (Rana dalmatina) from the Iberian Peninsula was estimated using mark and recapture and skeletochronology. Life-history parameters, including growth rate, body length, age and size at maturity, sexual dimorphism and longevity, were studied. The regression between age and snout-vent length (SVL) was highly significant in both sexes. Males reached sexual maturity at two years of age, although sometimes they can reach it at only one year of age. The average SVL at maturity was 51.75 mm (standard error (SE)=0.71; n=45). Females reached sexual maturity at two years of age with an average SVL of 62.14 mm (SE=2.20; n=14). A subset of the female population reached sexual maturity at three years of age. Growth was rapid until sexual maturity was reached. There was an overlap of SVL between different age classes. Growth was continuous, fulfilling the conditions of Von Bertalanffy's model. The growth coefficient (K) was 0.840 in males and 0.625 in females. The maximum SVL was greater in females (73.00 mm) than in males (59.50mm). Sexual dimorphism was significantly biased towards females in all age classes. The maximum longevity observed was 6 years in females and 8 years in males. Management strategies for agile frogs should take into account factors such as these life-history characteristics.

  13. Effect of temperature on host response to Batrachochytrium dendrobatidis infection in the mountain yellow-legged frog (Rana muscosa).

    PubMed

    Andre, Sara E; Parker, John; Briggs, Cheryl J

    2008-07-01

    The pathogenic chytrid fungus Batrachochytrium dendrobatidis, which causes the disease chytridiomycosis, has been implicated in declines of amphibian populations throughout the world, including declines and extinctions of local populations of mountain yellow-legged frogs, Rana muscosa, in the California Sierra Nevada. Previous studies have shown B. dendrobatidis achieves its maximum growth rate in culture in the temperature range of 17-25 C, and exposure to very high temperatures can clear frogs of B. dendrobatidis infection. Here we present the results of a laboratory experiment in which experimentally infected R. muscosa tadpoles were followed through metamorphosis at temperatures of 17 and 22 C. All infected animals developed clinical disease within a similar time frame. However, frogs housed at 22 C exhibited a significantly lower mortality than those housed at 17 C. Within 35 days after metamorphosis, 50% of the frogs housed at 22 C died, while 95% of the frogs housed at 17 C died. Clinical signs subsided in the surviving frogs at 22 C, despite persistent infection. Because both temperatures are within the optimal thermal range for growth of B. dendrobatidis, we propose that the difference in outcome indicates the effect of temperature on the host's resistance to chytridiomycosis, rather than an effect on the fungus alone.

  14. Pesticides in mountain yellow-legged frogs (Rana muscosa) from the Sierra Nevada Mountains of California, USA.

    PubMed

    Fellers, Gary M; McConnell, Laura L; Pratt, David; Datta, Seema

    2004-09-01

    In 1997, pesticide concentrations were measured in mountain yellow-legged frogs (Rana muscosa) from two areas in the Sierra Nevada Mountains of California, USA. One area (Sixty Lakes Basin, Kings Canyon National Park) had large, apparently healthy populations of frogs. A second area (Tablelands, Sequoia National Park) once had large populations, but the species had been extirpated from this area by the early 1980s. The Tablelands is exposed directly to prevailing winds from agricultural regions to the west. When an experimental reintroduction of R. muscosa in 1994 to 1995 was deemed unsuccessful in 1997, the last 20 (reintroduced) frogs that could be found were collected from the Tablelands, and pesticide concentrations in both frog tissue and the water were measured at both the Tablelands and at reference sites at Sixty Lakes. In frog tissues, dichlorodiphenyldichloroethylene (DDE) concentration was one to two orders of magnitude higher than the other organochlorines (46+/-20 ng/g wet wt at Tablelands and 17+/-8 Sixty Lakes). Both gamma-chlordane and trans-nonachlor were found in significantly greater concentrations in Tablelands frog tissues compared with Sixty Lakes. Organophosphate insecticides, chlorpyrifos, and diazinon were observed primarily in surface water with higher concentrations at the Tablelands sites. No contaminants were significantly higher in our Sixty Lakes samples.

  15. Absorption capacity of renal proximal tubular cells studied by combined injections of YFP and GFP in Rana temporaria L.

    PubMed

    Prutskova, N P; Seliverstova, E V

    2013-09-01

    The capacity for protein reabsorption in the renal proximal tubule (PT) was studied in Rana temporaria frogs by separate, simultaneous and sequential introduction of yellow fluorescent protein (YFP) and green fluorescent protein (GFP). The uptake patterns of YFP and GFP in PT epithelial cells were investigated 15-120min after their bolus intravenous and intraperitoneal injection. As shown by confocal microscopy, the tubular uptake of YFP and GFP was time- and dose-dependent. These proteins are absorbed in similar way and can be accumulated in the same endocytic vesicles after their combined injections. When GFP was injected 30 and 90min before YFP, and vice versa, the number of vesicles with pre-injected protein increased and the percentage of vesicles with colocalized GFP and YFP reduced. At the same time, the uptake rate of a protein injected later progressively and significantly decreased. Subcellular localization of endocytic receptors, megalin and cubilin, in renal PT cells after intravenous YFP introduction were revealed by immunofluorescent microscopy. Colocalization of internalized YFP with megalin or cubilin in the endocytic vesicles was demonstrated. The data suggest the possibility of protein uptake by receptor-mediated endocytosis and the existence of a mechanism limiting the protein absorption rate in wintering frogs.

  16. Long-term effects of pesticide exposure at various life stages of the southern leopard frog (Rana sphenocephala).

    PubMed

    Bridges, C M

    2000-07-01

    Amphibian larvae are commonly exposed to low levels of pesticides during their development. Chronic studies generally examine the effects of long-term exposure, but they often disregard the importance of the individual life stage at which tadpoles are exposed. I determined the point during development at which carbaryl effects are manifested by exposing southern leopard frog tadpoles (Rana sphenocephala) to the pesticide carbaryl at five different times during development. Metamorphs exposed throughout the tadpole stage and throughout development (egg, embryo, tadpole) experienced significant mortality at all chemical levels. Although the length of the larval period was the same for all experimental groups, metamorphs exposed during the egg stage were smaller than their corresponding controls, independent of whether they were exposed at any other stage. Nearly 18% of individuals exposed to carbaryl during development exhibited some type of developmental deformity (including both visceral and limb malformities), compared to a single deformed (< 1%) control tadpole, demonstrating that a chemical hypothesis for amphibian deformities remains viable. Because exposure to nonpersistent chemicals may last for only a short period of time, it is important to examine the long-term effects that short-term exposure has on larval amphibians and the existence of any sensitive life stage. Any delay in metamorphosis or decrease in size at metamorphosis can impact demographic processes of the population, potentially leading to declines or local extinction.

  17. Partial life-cycle toxicity and bioconcentration modeling of perfluorooctanesulfonate in the northern leopard frog (Rana pipiens).

    PubMed

    Ankley, Gerald T; Kuehl, Douglas W; Kahl, Michael D; Jensen, Kathleen M; Butterworth, Brian C; Nichols, John W

    2004-11-01

    A number of recent monitoring studies have demonstrated elevated concentrations of perfluorooctanesulfonate (PFOS) in humans and wildlife throughout the world. Although no longer manufactured in the United States, the global distribution and relative persistence of PFOS indicates a need to understand its potential ecological effects. Presently, little is known concerning toxicity of PFOS in chronic exposures with aquatic species. Therefore, we evaluated the effects of PFOS on survival and development of the northern leopard frog (Rana pipiens) from early embryogenesis through complete metamorphosis. Exposures were conducted via water at measured PFOS concentrations ranging from 0.03 to 10 mg/L. Animals exposed to 10 mg/L began dying within approximately two weeks of test initiation. Survival was not affected by PFOS at lower concentrations; however, time to metamorphosis was delayed and growth reduced in the 3-mg/L treatment group. Tadpoles readily accumulated PFOS directly from water. Using a one-compartment bioaccumulation model, growth was shown to have a modest impact on steady-state PFOS concentrations. Variability in observed growth rates and the possible contribution of a size-dependent decrease in PFOS elimination rate contributed uncertainty to modeling efforts. Nevertheless, fitted uptake and elimination rate constants were comparable to those determined in earlier studies with juvenile rainbow trout. Overall, our studies suggest that R. pipiens is not exceptionally sensitive to PFOS in terms of either direct toxicity or bioconcentration potential of the chemical.

  18. Genotoxicity of select herbicides in Rana catesbeiana tadpoles using the alkaline single-cell gel DNA electrophoresis (comet) assay.

    PubMed

    Clements, C; Ralph, S; Petras, M

    1997-01-01

    Pesticides are broadly used for pest control in agriculture despite possible negative impacts they may pose to the environment. Thus, we examined the DNA damage caused by five herbicides commonly used in southern Ontario (Canada). Erythrocytes from Rana catesbeiana (bullfrog) tadpoles were evaluated for DNA damage following exposure to selected herbicides, using the alkaline single-cell gel DNA electrophoresis (SCG) or "comet" assay [Singh et al. (1988): Exp Cell Res 175:184-191; Ralph et al. (1996): Eviron Mol Mutagen 28:112-120]. This approach involves detection, under alkaline conditions, of DNA fragments that upon electrophoresis migrate from the nuclear care, resulting in a comet formation. The herbicides tested, along with their active ingredients, were AAtrex Nine-O (atrazine), Dual-960E (metalochlor), Roundup (glyphosate), Sencor-500F (metribuzin), and Amsol (2,4-D amine). Tadpoles were exposed in the laboratory for a 24-hr period to several concentrations of the herbicides dissolved in dechlorinated water. Methyl methanesulphonate was used as a positive control. The herbicides AAtrex Nine-O-, Dual-960E-, Roundup-, and Sencor-500F-treated tadpoles showed significant DNA damage when compared with unexposed control animals, whereas, Amsol-treated tadpoles did not. Unlike the other responding herbicides, Sencor-500F did not show a relationship between dosage and DNA damage. In summary, the results indicate that at least some of the herbicides currently used in southern Ontario are capable of inducing DNA damage in tadpoles.

  19. Effects of testosterone on contractile properties of sexually dimorphic forelimb muscles in male bullfrogs (Rana catesbeiana, Shaw 1802)

    PubMed Central

    Kampe, Aaron R.; Peters, Susan E.

    2013-01-01

    Summary This study examined the effects of testosterone (T) on the contractile properties of two sexually dimorphic forelimb muscles and one non-dimorphic muscle in male bullfrogs (Rana catesbeiana, Shaw 1802). The dimorphic muscles in castrated males with testosterone replacement (T+) achieved higher forces and lower fatigability than did castrated males without replaced testosterone (T0 males), but the magnitude of the differences was low and many of the pair-wise comparisons of each muscle property were not statistically significant. However, when taken as a whole, the means of seven contractile properties varied in the directions expected of masculine values in T+ animals in the sexually dimorphic muscles. Moreover, these data, compared with previous data on male and female bullfrogs, show that values for T+ males are similar to normal males and are significantly different from females. The T0 males tended to be intermediate in character between T+ males and females, generally retaining masculine values. This suggests that the exposure of young males to T in their first breeding season produces a masculinizing effect on the sexually dimorphic muscles that is not reversed between breeding seasons when T levels are low. The relatively minor differences in contractile properties between T+ and T0 males may indicate that as circulating T levels rise during breeding season in normal males, contractile properties can be enhanced rapidly to maximal functional levels for breeding success. PMID:24143280

  20. Removal of nonnative fish results in population expansion of a declining amphibian (mountain yellow-legged frog, Rana muscosa).

    PubMed

    Knapp, Roland A; Boiano, Daniel M; Vredenburg, Vance T

    2007-02-01

    The mountain yellow-legged frog (Rana muscosa) was once a common inhabitant of the Sierra Nevada (California, USA), but has declined precipitously during the past century due in part to the introduction of nonnative fish into naturally fishless habitats. The objectives of the current study were to describe (1) the effect of fish removal from three lakes (located in two watersheds) on the small, remnant R. muscosa populations inhabiting those lakes, and (2) the initial development of metapopulation structure in each watershed as R. muscosa from expanding populations in fish-removal lakes dispersed to adjacent habitats. At all three fish-removal lakes, R. muscosa population densities increased significantly following the removal of predatory fish. The magnitude of these increases was significantly greater than that observed over the same time period in R. muscosa populations inhabiting control lakes that remained in their natural fishless condition. Following these population increases, R. muscosa dispersed to adjacent suitable (but unoccupied) sites, moving between 200 and 900 m along streams or across dry land. Together, these results suggest that large-scale removal of introduced fish could result in at least partial reversal of the decline of R. muscosa. Continued monitoring of R. muscosa at the fish-removal sites will be necessary to determine whether the positive effects of fish eradication are sustained over the long-term, especially in light of the increasingly important role played by an emerging infectious disease (chytridiomycosis, caused by Batrachochytrium dendrobatidis) in influencing R. muscosa populations. PMID:17396156

  1. Multifarious selection through environmental change: acidity and predator-mediated adaptive divergence in the moor frog (Rana arvalis).

    PubMed

    Egea-Serrano, Andrés; Hangartner, Sandra; Laurila, Anssi; Räsänen, Katja

    2014-04-01

    Environmental change can simultaneously cause abiotic stress and alter biological communities, yet adaptation of natural populations to co-changing environmental factors is poorly understood. We studied adaptation to acid and predator stress in six moor frog (Rana arvalis) populations along an acidification gradient, where abundance of invertebrate predators increases with increasing acidity of R. arvalis breeding ponds. First, we quantified divergence among the populations in anti-predator traits (behaviour and morphology) at different rearing conditions in the laboratory (factorial combinations of acid or neutral pH and the presence or the absence of a caged predator). Second, we evaluated relative fitness (survival) of the populations by exposing tadpoles from the different rearing conditions to predation by free-ranging dragonfly larvae. We found that morphological defences (relative tail depth) as well as survival of tadpoles under predation increased with increasing pond acidity (under most experimental conditions). Tail depth and larval size mediated survival differences among populations, but the contribution of trait divergence to survival was strongly dependent on prior rearing conditions. Our results indicate that R. arvalis populations are adapted to the elevated predator pressure in acidified ponds and emphasize the importance of multifarious selection via both direct (here: pH) and indirect (here: predators) environmental changes.

  2. Biospectroscopy reveals the effect of varying water quality on tadpole tissues of the common frog (Rana temporaria).

    PubMed

    Strong, Rebecca J; Halsall, Crispin J; Ferenčík, Martin; Jones, Kevin C; Shore, Richard F; Martin, Francis L

    2016-06-01

    Amphibians are undergoing large population declines in many regions around the world. As environmental pollution from both agricultural and urban sources has been implicated in such declines, there is a need for a biomonitoring approach to study potential impacts on this vulnerable class of organism. This study assessed the use of infrared (IR) spectroscopy as a tool to detect changes in several tissues (liver, muscle, kidney, heart and skin) of late-stage common frog (Rana temporaria) tadpoles collected from ponds with differing water quality. Small differences in spectral signatures were revealed between a rural agricultural pond and an urban pond receiving wastewater and landfill run-off; these were limited to the liver and heart, although large differences in body size were apparent, surprisingly with tadpoles from the urban site larger than those from the rural site. Large differences in liver spectra were found between tadpoles from the pesticide and nutrient impacted pond compared to the rural agricultural pond, particularly in regions associated with lipids. Liver mass and hepatosomatic indices were found to be significantly increased in tadpoles from the site impacted by pesticides and trace organic chemicals, suggestive of exposure to environmental contamination. Significant alterations were also found in muscle tissue between tadpoles from these two ponds in regions associated with glycogen, potentially indicative of a stress response. This study highlights the use of IR spectroscopy, a low-cost, rapid and reagent-free technique in the biomonitoring of a class of organisms susceptible to environmental degradation.

  3. The quality and fertility of sperm collected from European common frog (Rana temporaria) carcasses refrigerated for up to 7 days.

    PubMed

    Shishova, Natalia V; Uteshev, Viktor K; Sirota, Nikolai P; Kuznetsova, Elena A; Kaurova, Svetlana A; Browne, Robert K; Gakhova, Edith N

    2013-01-01

    There is a catastrophic decrease in the biodiversity of amphibians coupled with the loss of genetic variation. The perpetuation of amphibian biodiversity demands a multifaceted approach, including the use of reproduction technologies (RTs), to enable efficient reproduction in captivity and to prevent the loss of genetic variation. Reproduction technologies for the storage of amphibian sperm for days to weeks, when refrigerated at 4°C, or for millennia when cryopreserved have recently undergone rapid development. Sperm from amphibians may be obtained through excision and maceration of testes; however, this is sometimes not possible with rare or endangered species. Alternate methods of obtaining sperm are through hormonal induction, or as spermatozoa from the carcasses of recently dead amphibians. The use of sperm from carcasses of recently dead amphibians is particularly valuable when sampled from genetically important founders in conservation breeding programs, or where catastrophic mortality is occurring in natural population. Sperm harvested over a period of 7 days from the testes of European common frog (Rana temporaria) carcasses stored in a refrigerator were assessed for percentage and progressive motility, cell membrane integrity, nuclear DNA fragmentation, and fertilizing ability. In addition, the survival of resulting embryos to hatch was recorded. Results indicated that some sperm of R. temporaria remain motile and fertile when harvested from frog carcasses refrigerated up to 7 days post-mortem, and resulting embryos can develop to hatch. PMID:23609917

  4. Demography and movement in a relocated population of Oregon Spotted Frogs (Rana pretiosa): Influence of season and gender

    USGS Publications Warehouse

    Chelgren, N.D.; Pearl, C.A.; Adams, M.J.; Bowerman, J.

    2008-01-01

    We used five years of recapture data and Bayesian estimation to assess seasonal survival, movement, and growth of Oregon Spotted Frogs (Rana pretiosa) relocated into created ponds at Dilman Meadow in Oregon, USA. We evaluate hypotheses specific to the relocation and elucidate aspects of R. pretiosa life history that are poorly known. The odds of survival of relocated individuals during the first year following relocation were 0.36 times the survival odds of relocated and non-relocated frogs after one year since the relocation. Survival rate was higher for large frogs. After accounting for frog size, we found little variation in survival between ponds at Dilman Meadow. Survival was lowest for males during the breeding/post-breeding redistribution period, suggesting a high cost of breeding for males. The highest survival rates occurred during winter for both genders, and one small spring was used heavily during winter but was used rarely during the rest of the year. Individual growth was higher in ponds that were not used for breeding, and increased with increasing pond age. Our study supports other evidence that R. pretiosa use different habitats seasonally and are specific in their overwintering habitat requirements. Because frogs were concentrated during winter, predator-free overwintering springs are likely to be of particular value for R. pretiosa populations. ?? 2008 by the American Society of Ichthyologists and Herpetologists.

  5. Pesticides in mountain yellow-legged frogs (Rana muscosa) from the Sierra Nevada Mountains of California, USA

    USGS Publications Warehouse

    Fellers, G.M.; McConnell, L.L.; Pratt, D.; Datta, S.

    2004-01-01

    In 1997, pesticide concentrations were measured in mountain yellow-legged frogs (Rana muscosa) from two areas in the Sierra Nevada Mountains of California, USA. One area (Sixty Lakes Basin, Kings Canyon National Park) had large, apparently healthy populations of frogs. A second area (Tablelands, Sequoia National Park) once had large populations, but the species had been extirpated from this area by the early 1980s. The Tablelands is exposed directly to prevailing winds from agricultural regions to the west. When an experimental reintroduction of R. muscosa in 1994 to 1995 was deemed unsuccessful in 1997, the last 20 (reintroduced) frogs that could be found were collected from the Tablelands, and pesticide concentrations in both frog tissue and the water were measured at both the Tablelands and at reference sites at Sixty Lakes. In frog tissues, dichlorodiphenyldichloroethylene (DDE) concentration was one to two orders of magnitude higher than the other organochlorines (46 ?? 20 ng/g wet wt at Tablelands and 17 ?? 8 Sixty Lakes). Both ??-chlordane and trans-nonachlor were found in significantly greater concentrations in Tablelands frog tissues compared with Sixty Lakes. Organophosphate insecticides, chlorpyrifos, and diazinon were observed primarily in surface water with higher concentrations at the Tablelands sites. No contaminants were significantly higher in our Sixty Lakes samples.

  6. Characterization of the Skin Microbiota in Italian Stream Frogs (Rana italica) Infected and Uninfected by a Cutaneous Parasitic Disease

    PubMed Central

    Federici, Ermanno; Rossi, Roberta; Fidati, Laura; Paracucchi, Romina; Scargetta, Silvia; Montalbani, Elena; Franzetti, Andrea; La Porta, Gianandrea; Fagotti, Anna; Simonceli, Francesca; Cenci, Giovanni; Di Rosa, Ines

    2015-01-01

    In human and wildlife populations, the natural microbiota plays an important role in health maintenance and the prevention of emerging infectious diseases. In amphibians, infectious diseases have been closely associated with population decline and extinction worldwide. Skin symbiont communities have been suggested as one of the factors driving the different susceptibilities of amphibians to diseases. The activity of the skin microbiota of amphibians against fungal pathogens, such as Batrachochytrium dendrobatidis, has been examined extensively, whereas its protective role towards the cutaneous infectious diseases caused by Amphibiocystidium parasites has not yet been elucidated in detail. In the present study, we investigated, for the first time, the cutaneous microbiota of the Italian stream frog (Rana italica) and characterized the microbial assemblages of frogs uninfected and infected by Amphibiocystidium using the Illumina next-generation sequencing of 16S rRNA gene fragments. A total of 629 different OTUs belonging to 16 different phyla were detected. Bacterial populations shared by all individuals represented only one fifth of all OTUs and were dominated by a small number of OTUs. Statistical analyses based on Bray-Curtis distances showed that uninfected and infected specimens had distinct cutaneous bacterial community structures. Phylotypes belonging to the genera Janthinobacterium, Pseudomonas, and Flavobacterium were more abundant, and sometimes almost exclusively present, in uninfected than in infected specimens. These bacterial populations, known to exhibit antifungal activity in amphibians, may also play a role in protection against cutaneous infectious diseases caused by Amphibiocystidium parasites. PMID:26370166

  7. Odorous and Non-Fatal Skin Secretion of Adult Wrinkled Frog (Rana rugosa) Is Effective in Avoiding Predation by Snakes

    PubMed Central

    Yoshimura, Yuri; Kasuya, Eiiti

    2013-01-01

    The roles played by nonfatal secretions of adult anurans in the avoidance of predation remain unknown. The adult Wrinkled frog (Rana rugosa) has warty skin with the odorous mucus secretion that is not fatal to the snake Elaphe quadrivirgata. We fed R. rugosa or Fejervarya limnocharis, which resembles R. rugosa in appearance and has mucus secretion, to snakes and compared the snakes’ responses to the frogs. Compared to F. limnocharis, R. rugosa was less frequently bitten or swallowed by snakes. The snakes that bit R. rugosa spat out the frogs and showed mouth opening (gaping) behavior, while the snakes that bit F. limnocharis did not show gaping behavior. We also compared the responses of the snakes to R. rugosa and F. limnocharis secretions. We coated palatable R. japonica with secretions from R. rugosa or F. limnocharis. The frogs coated by R. rugosa secretion were less frequently bitten or swallowed than those coated by F. limnocharis secretion. We concluded that compared to different frog species of similar sizes, the adult R. rugosa was less frequently preyed upon by, and that its skin secretion was effective in avoiding predation by snakes. PMID:24278410

  8. Comparative anatomy of the locus coeruleus. II. Organization and projection of the catecholamine containing neurons in the upper rhombencephalon of the frog, Rana catesbiana.

    PubMed

    Tohyama, M; Maeda, T; Shimizu, N

    1976-01-01

    The organization and projection of the catecholamine (CA) containing neurons in the upper rhombencephalon were experimentally investigated with histofluorescence method in the brain of the bullfrog, Rana catesbiana. A small number of catecholamine containing neurons are located in the upper rhombencephalon. These neurons do not send ascending fibers to contribute CA projection to the forebrain, but give rise to relatively short axons to innervate the cerebellum and neighbouring reticular formation. Judging from their anatomical aspects, it seems that the structure homologous to the mammalian locus coeruleus is not present in the amphibian brain. PMID:1085783

  9. Water molds of the genera Saprolegnia and Leptolegnia are pathogenic to the North American frogs Rana catesbeiana and Pseudacris crucifer, respectively.

    PubMed

    Ruthig, Gregory R

    2009-04-27

    Water molds are commonly associated with amphibian mortality. Since water molds often act as saprophytes, it is important to test their effects on amphibians to determine whether they can also act as pathogens. In controlled experiments, the eggs of 2 amphibian species, the American bullfrog Rana catesbeiana and the spring peeper Pseudacris crucifer, suffered higher mortality when they were exposed to zoospores of water molds of the genera Saprolegnia and Leptolegnia, respectively. Water molds are important pathogens in many amphibian systems, yet their ecological impact on amphibians remains mostly unknown. PMID:19565694

  10. Changes in nuclear volume of Purkinje cells in the cerebellum of the water frog (Rana Esculenta L.) in the annual cycle.

    PubMed

    Dziubek, K; Lach, H; Krawczyk, S

    1980-01-01

    In sexually mature female and male Rana esculenta L. frogs directly from natural habitat, in six characteristic periods of their life cycle, nuclear volume in Purkinje cells of the cerebellum was determined. Nuclear volume in Purkinje cells changed distinctly in the course of the year. Nuclear volume was greatest in females in the breeding period (3rd decade of May), and in males in the middle of the period of active life (2nd decade of July). Nuclear volume was the smallest at the beginning of hibernation (3rd decade of October).

  11. Mechanistic basis of adaptive maternal effects: egg jelly water balance mediates embryonic adaptation to acidity in Rana arvalis.

    PubMed

    Shu, Longfei; Suter, Marc J-F; Laurila, Anssi; Räsänen, Katja

    2015-11-01

    Environmental stress, such as acidification, can challenge persistence of natural populations and act as a powerful evolutionary force at ecological time scales. The ecological and evolutionary responses of natural populations to environmental stress at early life-stages are often mediated via maternal effects. During early life-stages, maternal effects commonly arise from egg coats (the extracellular structures surrounding the embryo), but the role of egg coats has rarely been studied in the context of adaptation to environmental stress. Previous studies on the moor frog Rana arvalis found that the egg coat mediated adaptive divergence along an acidification gradient in embryonic acid stress tolerance. However, the exact mechanisms underlying these adaptive maternal effects remain unknown. Here, we investigated the role of water balance and charge state (zeta potential) of egg jelly coats in embryonic adaptation to acid stress in three populations of R. arvalis. We found that acidic pH causes severe water loss in the egg jelly coat, but that jelly coats from an acid-adapted population retained more water than jelly coats from populations not adapted to acidity. Moreover, embryonic acid tolerance (survival at pH 4.0) correlated with both water loss and charge state of the jelly, indicating that negatively charged glycans influence jelly water balance and contribute to embryonic adaptation to acidity. These results indicate that egg coats can harbor extensive intra-specific variation, probably facilitated in part via strong selection on water balance and glycosylation status of egg jelly coats. These findings shed light on the molecular mechanisms of environmental stress tolerance and adaptive maternal effects.

  12. Identification and localization of gastrointestinal hormones in the skin of the bullfrog Rana catesbeiana during periods of activity and hibernation.

    PubMed

    Wang, Huan; Zhou, Naizhen; Zhang, Rui; Wu, Yuanyuan; Zhang, Ruidong; Zhang, Shengzhou

    2014-10-01

    Amphibian skin and its secretions contain a wide variety of biogenic amines and biologically active peptides, some of which are either identical or highly homologous to gastrointestinal hormones (GHs) of higher vertebrates. This study investigated the distribution density and immunoreactive (IR) intensity of 5-hydroxytryptamine (5-HT), gastrin (GAS), somatostatin (SS), pancreatic polypeptide (PP), neuropeptide Y (NPY) and glucagon (GLU) IR cells in the skin of the bullfrog Rana catesbeiana during periods of activity and hibernation. The results indicated that the six types of GHs were all present in the bullfrog skin and were most predominant in the epidermis and mucous glands. In dorsal skin, the density of the GHs-IR cells in mucous glands was higher than that in epidermis except for GAS-IR cells. In ventral skin, the density of 5-HT, PP and NPY-IR cells in mucous glands was also higher than that in the epidermis. During hibernation, the density of the six types of GHs-IR cells and the IR intensity of GAS, SS, NPY and GLU-IR cells in the epidermis of dorsal skin increased significantly. The IR intensity of SS, PP and NPY-IR cells in granular glands of ventral skin also increased significantly during hibernation. These results suggested that multiple types of GHs-IR cells present in the skin of R. catesbeiana, may play important roles in the regulation of the physiological functions of skin. Also, adaptive changes in the density and IR intensity of GHs-IR cells occurred during hibernation.

  13. Chilled frogs are hot: hibernation and reproduction of the Endangered mountain yellow-legged frog Rana muscosa

    USGS Publications Warehouse

    Santana, Frank E.; Swaisgood, Ronald R.; Lemm, Jeffrey M.; Fisher, Robert N.; Clark, Rulon W.

    2015-01-01

    In the face of the sixth great extinction crisis, it is imperative to establish effective breeding protocols for amphibian conservation breeding programs. Captive efforts should not proceed by trial and error, nor should they jump prematurely to assisted reproduction techniques, which can be invasive, difficult, costly, and, at times, counterproductive. Instead, conservation practitioners should first look to nature for guidance, and replicate key conditions found in nature in the captive environment, according to the ecological and behavioral requirements of the species. We tested the effect of a natural hibernation regime on reproductive behaviors and body condition in the Endangered mountain yellow-legged frog Rana muscosa. Hibernation had a clear positive effect on reproductive behavior, manifesting in vocal advertisement signaling, female receptivity, amplexus, and oviposition. These behaviors are critical components of courtship that lead to successful reproduction. Our main finding was that captive R. muscosa require a hibernation period for successful reproduction, as only hibernated females produced eggs and only hibernated males successfully fertilized eggs. Although hibernation also resulted in a reduced body condition, the reduction appeared to be minimal with no associated mortality. The importance of hibernation for reproduction is not surprising, since it is a major component of the conditions that R. muscosa experiences in the wild. Other amphibian conservation breeding programs can also benefit from a scientific approach that tests the effect of natural ecological conditions on reproduction. This will ensure that captive colonies maximize their role in providing genetic reservoirs for assurance and reintroduction efforts.

  14. Chemopreventive Effect of Cinnamon Extract on Carbon Tetrachloride-Induced Physiological Changes in the Frog, Rana ridibunda

    NASA Astrophysics Data System (ADS)

    Al-Attar, Atef M.

    The present study examined the preventive influences of an aqueous extract of cinnamon on carbon tetrachloride-induced some physiological alterations in the frog, Rana ridibunda. The experimental animals were divided into five batches. The first batch was untreated and served as control. The other batches were treated for 6 weeks with carbon tetrachloride, cinnamon extract plus carbon tetrachloride, cinnamon and corn oil, respectively. Haematological, biochemical and hepatosomatic index indices were chosen as physiological indicators. These parameters were evaluated at 2, 4 and 6 weeks. In comparison with control and cinnamon plus CCl4 batches, significant decreases of red blood cell count, haemoglobin concentration, haematocrit, mean corpuscular haemoglobin concentration and increases of glutamic pyruvic acid transaminase values were noted in CCl4-exposed batch at all experimental periods. Also, glutamic oxaloacetic acid transaminase and hepatosomatic index levels were significantly elevated, while mean corpuscular haemoglobin values were decreased at second and last periods. Mean cell volume values were only increased at the first period. In comparison with control batch, significant decreases of red blood cell count, haemoglobin concentration, haematocrit, and increases of glutamic oxaloacetic acid transaminase, glutamic pyruvic acid transaminase and hepatosomatic index values were observed in frogs treated with cinnamon plus CCl4 at 2 and 6 weeks. Mean cell volume and mean corpuscular haemoglobin values were statistically elevated at second period. Mean corpuscular haemoglobin concentration values were declined at last period. Moreover, the percentage changes of these parameters in cinnamon plus CCl4 batch tended to be lower than CCl4 treated the experimental animals. In addition, it is conceivable therefore, that the cinnamon aqueous extract exhibits a protective influence against carbon tetrachloride-induced some physiological changes, probably mediated

  15. Parathyroid hormone-related protein in tissues of the emerging frog (Rana temporaria): immunohistochemistry and in situ hybridisation

    PubMed Central

    DANKS, J. A.; McHALE, J. C.; MARTIN, T. J.; INGLETON, P. M.

    1997-01-01

    Using antiserum to human parathyroid hormone-related protein (1–16) [PTHrP(1–16)] we have examined tissues of the common frog (Rana temporaria) for the presence of immunoreactive PTHrP (irPTHrP) at the stage of emergence from water to land. irPTHrP was detected in dorsal and ventral stratum granulosum of the skin, in the developing ovary, striated muscle and the choroid plexus epithelium of the brain as well as in the olfactory gland epithelium and olfactory lobe neurons of the brain. In the pituitary and hypothalamus irPTHrP protein could be demonstrated in the median eminence, infundibular stem and principally in the neural lobe and pars distalis of the pituitary with weak reaction in the pars intermedia. In situ hybridisation of the same tissues with an oligonucleotide probe to chicken PTHrP 55–65 clearly showed the presence of mRNA for PTHrP-like molecule in all the tissues containing irPTHrP. There was a major inconsistency in the pituitary in that the highest level of gene expression, assessed by in situ hybridisation, was found in the pars intermedia with only very low expression in the pars distalis and neural lobe and undetectable levels in the infundibular stem and median eminence. These observations suggest that tissues of the frog synthesise a PTHrP-like molecule but that in the pituitary the pars intermedia cells may export the protein to cells in other regions of the pituitary and hypothalamus. PMID:9061446

  16. Function of the sexually dimorphic ear of the American bullfrog, Rana catesbeiana: brief review and new insight.

    PubMed

    Werner, Y L; Pylka, J; Schneider, H; Seifan, M; Walkowiak, W; Werner-Reiss, U

    2009-07-01

    The dimorphic ear of the bullfrog, Rana catesbeiana, has long been enigmatic. The male's tympanic membrane (TM) area approximates twice the area of the female's; however, similar size differences in the area of the columellar footplate were not observed between the sexes. Hence, the male's hearing is expected to be more sensitive than the female's but this is not the case. Asking what offsets the advantage of the large TM, we applied a series of experiments to the auditory system. Male and female audiograms based on stimulation with airborne sound and on both multi-unit responses from the brain and alternating cochlear potentials ('microphonics') showed equal sensitivity and a small difference in frequency response; at low frequencies the male was more sensitive than the female. Amputating the columella and stimulating the stump with mechanical vibration showed that for an equal microphonic response, the male's footplate vibrated with lower amplitude than the female's footplate. Mechanically stimulating the TM of the intact ear replicated this result, excluding the involvement of the mechanical lever. The TM of the male weighs five times the TM of the female, and artificial loading of the TM of either sex greatly reduced the ear's sensitivity. Hence, the male's excessive area ratio (TM to columellar footplate) is offset by the heavier cartilage cushion on the male's TM, damping the TM's response to sound. This is corroborated by experimentally artificially loading the TM. The product of area ratio and footplate vibration amplitude would result in similar stimulation of the inner ear in the two sexes. PMID:19561210

  17. De novo Transcriptome Assemblies of Rana (Lithobates) catesbeiana and Xenopus laevis Tadpole Livers for Comparative Genomics without Reference Genomes.

    PubMed

    Birol, Inanc; Behsaz, Bahar; Hammond, S Austin; Kucuk, Erdi; Veldhoen, Nik; Helbing, Caren C

    2015-01-01

    In this work we studied the liver transcriptomes of two frog species, the American bullfrog (Rana (Lithobates) catesbeiana) and the African clawed frog (Xenopus laevis). We used high throughput RNA sequencing (RNA-seq) data to assemble and annotate these transcriptomes, and compared how their baseline expression profiles change when tadpoles of the two species are exposed to thyroid hormone. We generated more than 1.5 billion RNA-seq reads in total for the two species under two conditions as treatment/control pairs. We de novo assembled these reads using Trans-ABySS to reconstruct reference transcriptomes, obtaining over 350,000 and 130,000 putative transcripts for R. catesbeiana and X. laevis, respectively. Using available genomics resources for X. laevis, we annotated over 97% of our X. laevis transcriptome contigs, demonstrating the utility and efficacy of our methodology. Leveraging this validated analysis pipeline, we also annotated the assembled R. catesbeiana transcriptome. We used the expression profiles of the annotated genes of the two species to examine the similarities and differences between the tadpole liver transcriptomes. We also compared the gene ontology terms of expressed genes to measure how the animals react to a challenge by thyroid hormone. Our study reports three main conclusions. First, de novo assembly of RNA-seq data is a powerful method for annotating and establishing transcriptomes of non-model organisms. Second, the liver transcriptomes of the two frog species, R. catesbeiana and X. laevis, show many common features, and the distribution of their gene ontology profiles are statistically indistinguishable. Third, although they broadly respond the same way to the presence of thyroid hormone in their environment, their receptor/signal transduction pathways display marked differences. PMID:26121473

  18. Effects of intramuscular meloxicam administration on prostaglandin E2 synthesis in the North American bullfrog (Rana catesbeiana).

    PubMed

    Minter, Larry J; Clarke, Elsburgh O; Gjeltema, Jenessa L; Archibald, Kate E; Posner, Lysa P; Lewbart, Gregory A

    2011-12-01

    Meloxicam is a commonly used nonsteroidal anti-inflammatory drug (NSAID) in veterinary medicine, but its use in amphibians has not been reported in the literature. NSAIDs are known to act by providing anti-inflammatory and analgesic actions by inhibiting the synthesis of prostaglandin E2 (PGE2). The objective of this study was to evaluate whether the intramuscular administration of meloxicam would decrease the circulating serum PGE2 levels in the North American bullfrog (Rana catesbeiana) following tissue trauma induced by a punch biopsy. Eighteen adult North American bullfrogs were randomly assigned to two treatment groups: meloxicam (0.1 mg/kg i.m.) and control (0.9% saline i.m.). Blood was obtained via cardiocentesis immediately prior to administration of the two treatment regimes and serum was frozen. A 4-mm punch biopsy was taken from the right triceps femoris muscle to induce an inflammatory response. Twenty-four hours later, a second blood sample was collected and serum was harvested and frozen. Serum PGE2 concentrations were measured using a commercial PGE2 enzyme assay (EIA) kit. Twenty-four hours following the biopsy, the mean circulating PGE2 levels of animals treated with meloxicam was 57.79 +/- 12.35 pg/ml, which did not differ significantly from animals that were treated with saline (85.63 +/- 17.55 pg/ml, P > or = 0.05). The calculated means of the absolute change between the circulating baseline PGE2 levels and the postinjury circulating PGE2 levels were significantly lower in animals treated with meloxicam (13.11 +/- 17.31 pg/ml) than in control animals treated with saline (46.14 +/- 38.02 pg/ml) (P < or = 0.05). These results suggest that the systemic administration of meloxicam at a dosage of 0.1 mg/kg once daily suppresses circulating serum PGE2 levels postinjury in the North American bullfrog. PMID:22204063

  19. De novo Transcriptome Assemblies of Rana (Lithobates) catesbeiana and Xenopus laevis Tadpole Livers for Comparative Genomics without Reference Genomes

    PubMed Central

    Birol, Inanc; Behsaz, Bahar; Hammond, S. Austin; Kucuk, Erdi; Veldhoen, Nik; Helbing, Caren C.

    2015-01-01

    In this work we studied the liver transcriptomes of two frog species, the American bullfrog (Rana (Lithobates) catesbeiana) and the African clawed frog (Xenopus laevis). We used high throughput RNA sequencing (RNA-seq) data to assemble and annotate these transcriptomes, and compared how their baseline expression profiles change when tadpoles of the two species are exposed to thyroid hormone. We generated more than 1.5 billion RNA-seq reads in total for the two species under two conditions as treatment/control pairs. We de novo assembled these reads using Trans-ABySS to reconstruct reference transcriptomes, obtaining over 350,000 and 130,000 putative transcripts for R. catesbeiana and X. laevis, respectively. Using available genomics resources for X. laevis, we annotated over 97% of our X. laevis transcriptome contigs, demonstrating the utility and efficacy of our methodology. Leveraging this validated analysis pipeline, we also annotated the assembled R. catesbeiana transcriptome. We used the expression profiles of the annotated genes of the two species to examine the similarities and differences between the tadpole liver transcriptomes. We also compared the gene ontology terms of expressed genes to measure how the animals react to a challenge by thyroid hormone. Our study reports three main conclusions. First, de novo assembly of RNA-seq data is a powerful method for annotating and establishing transcriptomes of non-model organisms. Second, the liver transcriptomes of the two frog species, R. catesbeiana and X. laevis, show many common features, and the distribution of their gene ontology profiles are statistically indistinguishable. Third, although they broadly respond the same way to the presence of thyroid hormone in their environment, their receptor/signal transduction pathways display marked differences. PMID:26121473

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

    PubMed Central

    Gerber, Victoria E.M.; Wijenayake, Sanoji

    2016-01-01

    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. PMID:27042393

  1. Temporal occurrence and community structure of helminth parasites in southern leopard frogs, Rana sphenocephala, from north central Oklahoma.

    PubMed

    Vhora, M Suhail; Bolek, Matthew G

    2015-03-01

    Currently, little information is available about the temporal recruitment of helminth communities in amphibian hosts. We examined the helminth community structure and temporal recruitment of helminth parasites in southern leopard frogs, Rana sphenocephala. Specifically, we were interested in how host life history such as habitat, age and/or size, diet, sex, and temporal variation in abiotic factors (precipitation and temperature) were important in determining monthly infection patterns of helminth populations and communities in southern leopard frogs. From May to September 2011, 74 southern leopard frogs were collected from Teal Ridge in Stillwater Payne County, OK, USA. Sixty-nine (93 %) of 74 frogs were infected with 1 or more helminth species. During our collecting period, the average monthly temperature was lowest in May and highest in July, and monthly precipitation was highest in May and lowest during the first week of September. The component community consisted of 11 species of helminth, including 1 larval and 1 adult cestode, 2 larval and 3 adult trematodes, and 1 juvenile and 3 adult nematodes. Of the 1790 helminths recovered, 51 % (911) were nematodes, 47 % (842) were cestodes, and 2 % (37) were trematodes. There were significant differences in the total abundance and mean species richness of helminths acquired by skin contact or through frog diet in monthly component communities of southern leopard frogs. A positive correlation existed for percentage of all helminths acquired by skin contact and monthly precipitation (r = 0.94, P < 0.01). Conversely, a negative correlation existed for monthly precipitation and percentage of helminths acquired by diet (r = -0.94, P < 0.01). Our results indicate that abiotic conditions such as precipitation have a major influence on the avenues for and constraints on the transmission of helminths with life cycles associated with water/moisture or terrestrial intermediate/paratenic hosts and are important in structuring

  2. Exposure to heptachlor: evaluation of the effects on the larval and adult epidermis of Rana kl. esculenta.

    PubMed

    Fenoglio, Carla; Grosso, Amelia; Boncompagni, Eleonora; Gandini, Carlo; Milanesi, Gloria; Barni, Sergio

    2009-01-31

    Widely used in the past against termites and soil insects, the chlorinated insecticide heptachlor (H) is a toxic contaminant which represents a risk for both terrestrial and aquatic organisms. Like many organochlorine pesticides, heptachlor and heptachlor epoxide (HE), with oxidation products synthesized by many plant and animal species, degrade slowly since many of the derived compounds are persistent. This increases the status of heptachlor as a hazardous pollutant. In the present experimental study we exposed specimens of Rana kl. esculenta, from the tadpole stage through to their complete metamorphosis, to three different concentrations of heptachlor (4, 40 and 400 ppb). Mortality and HE bioaccumulation were evaluated on all the experimental groups. Since amphibian integument directly interacts with the environmental constituents (water, air and soil), we investigated the toxic effects on the ventral epidermis of both tadpole and adult samples by employing such histo-cytopathological biomarkers as ultrastructural morphology, certain enzyme activities (acid and alkaline phosphatases, AcPase, and AlkPase; succinic dehydrogenase, SDH; alpha-naphtyl butyrate esterase, ANBE; nitric oxide synthase/NADPH diaphorase, NOS/NADPHd). Also, the levels of reactive oxygen species (ROS) in the different conditions were evaluated. The results obtained were of ecological relevance, in particular as regards the effects of this environmental toxicant on the samples of tadpole epidermis. Severe morphological alterations were observed in the larval epidermal cells (apical and skein cells), whereas the cell epidermis (keratinocytes and mitochondria-rich cells) of the adult survivors showed changes in enzyme activities, particularly those involved in the protective response to xenobiotic injury. In general, morpho-histochemical studies, analysis of HE bioaccumulation and mortality showed a relation to the H doses employed.

  3. Species boundaries, phylogeography, and conservation genetics of the red-legged frog (Rana aurora/draytonii) complex

    USGS Publications Warehouse

    Shaffer, H. Bradley; Fellers, Gary M.; Voss, S. Randal; Oliver, J. C.; Pauly, Gregory B.

    2004-01-01

    The red-legged frog, Rana aurora, has been recognized as both a single, polytypic species and as two distinct species since its original description 150 years ago. It is currently recognized as one species with two geographically contiguous subspecies, aurora and draytonii; the latter is protected under the US Endangered Species Act. We present the results of a survey of 50 populations of red-legged frogs from across their range plus four outgroup species for variation in a phylogenetically informative, ∼400 base pairs (bp) fragment of the mitochondrial cytochromeb gene. Our mtDNA analysis points to several major results. (1) In accord with several other lines of independent evidence, aurora and draytonii are each diagnosably distinct, evolutionary lineages; the mtDNA data indicate that they do not constitute a monophyletic group, but rather that aurora and R. cascadae from the Pacific northwest are sister taxa; (2) the range of thedraytonii mtDNA clade extends about 100 km further north in coastal California than was previously suspected, and corresponds closely with the range limits or phylogeographical breaks of several codistributed taxa; (3) a narrow zone of overlap exists in southern Mendocino County between aurora and draytonii haplotypes, rather than a broad intergradation zone; and (4) the critically endangered population of draytonii in Riverside County, CA forms a distinct clade with frogs from Baja California, Mexico. The currently available evidence favours recognition of auroraand draytonii as separate species with a narrow zone of overlap in northern California.

  4. Cardiovascular effects of prostaglandin I2 and prostaglandin F2 alpha in the unanesthetized bullfrog, Rana catesbeiana.

    PubMed

    Robleto, D O; Herman, C A

    1988-04-01

    The cardiovascular effects of prostaglandin (PG)I2 and PGF2 alpha were compared in the unanesthetized American bullfrog (Rana catesbeiana). Control mean arterial pressure (MAP) and heart rate (HR) were 25.7 +/- 1.1 mm Hg and 35.1 +/- 1.1 beats/min, respectively. Intravenous injections of PGI2 decreased MAP and increased HR in a dose-dependent fashion over the range of concentrations tested (0.03, 0.3, 3, and 10 micrograms/kg-body weight [bw]. Neither atropine (1 mg/kg-bw) nor verapamil (1 mg/kg-bw) treatment altered the MAP or HR responses to PGI2 (3 micrograms/kg-bw). However, propranolol (5 mg/kg-bw) significantly blunted the hypotensive effects without affecting the increase in HR. Prostaglandin F2 alpha (tested at 0.3, 3, 30, and 100 micrograms/kg-bw) increased both MAP and HR. Mean arterial pressure increased with concentrations greater than 0.3 microgram/kg-bw and reached peak effects at 30 micrograms/kg-bw. Prostaglandin F2 alpha increased HR at doses greater than 0.3 microgram/kg-bw. Neither the pressor nor positive chronotropic effects of PGF2 alpha (30 micrograms/kg-bw) were affected by atropine or propranolol. However, verapamil significantly attenuated the pressor effects without affecting the increase in HR. These results demonstrate that both prostaglandins have qualitatively similar effects on HR, but opposite effects on MAP. Prostaglandin I2 is a hypotensive prostaglandin, while PGF2 alpha is hypertensive. The pressor effects of PGF2 alpha are partially dependent on calcium influx. The positive chronotropic effects of both prostaglandins are independent of the autonomic nervous system, suggesting a different mechanism of action.

  5. Catecholamine effects on blood pressure and heart rate in warm- and cold-acclimated American bullfrogs (Rana catesbeiana).

    PubMed

    Herman, C A; Mata, P L

    1985-09-01

    The effects of epinephrine (E), norepinephrine (NE), phenylephrine (PHE), and isoproterenol (ISO) were studied in vivo on the blood pressure and heart rate of the conscious American bullfrog, Rana catesbeiana. Bullfrogs were chronically cannulated with a T cannula in the right sciatic artery. In warm-acclimated (22 degrees, W-A) bullfrogs, baseline mean systemic arterial blood pressure (SAP) prior to catecholamine infusion was 16.8 +/- 1.1 mm Hg and mean preinfusion heart rate (HR) was 36.4 +/- 2.1 beats per min. In contrast, cold-acclimated bullfrogs (5 degrees, C-A) had baseline SAP values of 7.4 +/- 0.7 mm Hg and HR values of 6.9 +/- 0.3 beats per min. W-A bullfrogs infused with ISO (0.03 to 30 micrograms/kg body wt) demonstrated a dose-related increase in HR, while the HR of C-A bullfrogs did not respond to any tested dose of ISO. ISO administered to W-A bullfrogs exposed to 5 degrees for 60 min produced no significant HR increase. When the animals were returned to 22 degrees, the HR response to ISO was restored. ISO did not affect SAP in either group. E, NE, and PHE increased SAP in both W-A and C-A bullfrogs, with E the most effective. All three catecholamines affected the SAP of C-A animals less than the W-A group. In W-A bullfrogs, E, NE, and PHE decreased HR, while no effect on HR was observed in the C-A group.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Sexually dimorphic expression of steroidogenic factor 1 (SF-1) in developing gonads of the American bullfrog, Rana catesbeiana.

    PubMed

    Mayer, Loretta P; Overstreet, Stefanie L; Dyer, Cheryl A; Propper, Catherine R

    2002-06-01

    Genetic sex determination leads to gonadal differentiation and ultimately the differences between the sexes in steroid hormone secretion. Gonadal steroidogenesis is critical for the development of a sexually dimorphic phenotype and adult reproductive function. Control of gonadal development and steroidogenesis is under the regulation, at least in part, of steroidogenic factor-1 (SF-1). We have begun to characterize SF-1 expression in an amphibian to determine the role of this protein in development and reproduction. We have detected a putative SF-1 protein from several tissues in the American bullfrog, Rana catesbeiana, that co-migrates with mouse SF-1 on a Western blot. Our results show that bullfrog SF-1 protein is expressed in steroidogenic and other reproductive tissues in a manner similar to that reported for other species, with high expression in the brain, pituitary, gonad, liver, and interrenal, but little or no expression in non-reproductive tissues such as skin and intestine. Using a quantitative Western blot analysis system, we documented changes in SF-1 protein in the gonads of developing tadpoles. Our results indicate that there is sexually dimorphic expression of SF-1 protein that becomes evident at the time of sexual differentiation of the gonads. In males, the expression of SF-1 decreases following testicular formation and in females the expression increases with the formation of ovaries. This is the first study to investigate changes in SF-1 during development at the protein level. The expression is similar to that reported for changes in SF-1 mRNA expression in chickens and alligators, however, opposite to that seen in mammals and turtles. These results indicate that SF-1 may play a pivotal role in development of the reproductive system in amphibians as it does in other vertebrate groups.

  7. Pharmacological and biochemical properties of saxiphilin, a soluble saxitoxin-binding protein from the bullfrog (Rana catesbeiana).

    PubMed

    Mahar, J; Lukács, G L; Li, Y; Hall, S; Moczydlowski, E

    1991-01-01

    Supernatant fractions of various tissues and plasma from the North American bullfrog, Rana catesbeiana, specifically bind saxitoxin with high affinity. Binding of [3H]saxitoxin to bullfrog plasma follows single-site behavior with an equilibrium dissociation constant of Kd = 0.16 +/- 0.03 nM at 0 degrees C and a maximum binding capacity of 380 +/- 60 pmole/ml plasma. High-affinity binding of [3H]saxitoxin is chemically specific since it is unaffected by tetrodotoxin and a variety of cationic peptides, amino acids and drugs. The structure-activity dependence of binding to this site was investigated with eight different natural and synthetic derivatives of saxitoxin. Substitution of the carbamoyl side chain or the C-12 beta-hydroxyl group of saxitoxin with a hydrogen atom had little effect on binding affinity, but addition of a hydroxyl group at the N-1 position decreased the binding affinity from 430- to 710-fold in three different molecular pairs. High performance size exclusion chromatography of supernatant from bullfrog skeletal muscle showed that the [3H]saxitoxin-binding component migrates with an apparent molecular weight of Mr = 74,000 +/- 8000 or a Stokes radius of 35 +/- 2A. The [3H]saxitoxin-binding protein in skeletal muscle extract or plasma is retained on a cation-exchange column at pH 6.0, suggesting that the protein contains a region of exposed basic residues. Column isoelectric focusing of a sample from plasma indicated that the protein has a basic isoelectric point near pH = 10.7.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Function of the sexually dimorphic ear of the American bullfrog, Rana catesbeiana: brief review and new insight.

    PubMed

    Werner, Y L; Pylka, J; Schneider, H; Seifan, M; Walkowiak, W; Werner-Reiss, U

    2009-07-01

    The dimorphic ear of the bullfrog, Rana catesbeiana, has long been enigmatic. The male's tympanic membrane (TM) area approximates twice the area of the female's; however, similar size differences in the area of the columellar footplate were not observed between the sexes. Hence, the male's hearing is expected to be more sensitive than the female's but this is not the case. Asking what offsets the advantage of the large TM, we applied a series of experiments to the auditory system. Male and female audiograms based on stimulation with airborne sound and on both multi-unit responses from the brain and alternating cochlear potentials ('microphonics') showed equal sensitivity and a small difference in frequency response; at low frequencies the male was more sensitive than the female. Amputating the columella and stimulating the stump with mechanical vibration showed that for an equal microphonic response, the male's footplate vibrated with lower amplitude than the female's footplate. Mechanically stimulating the TM of the intact ear replicated this result, excluding the involvement of the mechanical lever. The TM of the male weighs five times the TM of the female, and artificial loading of the TM of either sex greatly reduced the ear's sensitivity. Hence, the male's excessive area ratio (TM to columellar footplate) is offset by the heavier cartilage cushion on the male's TM, damping the TM's response to sound. This is corroborated by experimentally artificially loading the TM. The product of area ratio and footplate vibration amplitude would result in similar stimulation of the inner ear in the two sexes.

  9. Elevation of plasma glucose, alanine, and urea levels by mammalian ACTH in the American bullfrog (Rana catesbeiana).

    PubMed

    Rosenthal, E J; deRoos, R

    1985-08-01

    The effects of a single infusion of mammalian ACTH on plasma glucose, alanine, urea, and lactate were determined in the American bullfrog (Rana catesbeiana). The ACTH (10 U/250 g body wt) was administered, and serial blood samples were collected via a nonocclusive cannula chronically placed in the right truncus arteriosus. Plasma metabolite levels were estimated by standard enzymatic techniques. The plasma metabolites declined following the surgery to levels that were relatively stable by postoperative Day 2. The levels did not vary significantly for the remainder of the 3- or 4-day pretreatment period and in the control bullfrogs during the 48-hr experiments. Plasma glucose levels were essentially unchanged from the time-zero levels at 6 hr following ACTH infusion. Plasma glucose levels subsequently increased to levels that were approximately 24% greater than the control levels by 24 hr and then declined to near control levels by 48 hr. Plasma alanine increased to levels that were approximately 60% greater than the control levels by 12 hr after ACTH treatment and returned to essentially the time-zero levels by 24 hr. Plasma urea rose to levels that were approximately 110% greater than the control levels by 45 min after ACTH infusion, but urea returned to essentially the time-zero levels by 1.5 through 3 hr. Plasma urea increased again to levels that were approximately 90% greater than the control levels by 6 hr and returned to essentially the initial levels by 24 hr. Plasma lactate levels were not significantly influenced by ACTH treatment. The results suggest that a function of the bullfrog hypothalamic-pituitary-adrenocortical axis is to regulate gluconeogenesis from alanine, and probably other glucogenic amino acids.

  10. The American bullfrog (Rana catesbeiana) exhibits differential cardiovascular responses to LTC4 after short- and long-term cold exposure.

    PubMed

    Sun, J; Herman, C A

    1995-02-01

    Mean arterial pressure (MAP) and heart rate (HR) responses to leukotriene (LT)C4 have been studied in warm (W-A) and cold-acclimated (C-A) America bullfrogs, Rana catesbeiana, but nothing is known about how the length of cold treatment affects the response to LTC4 or how responses are affected by return to room temperature following cold exposure. In this study, two groups of frogs were placed at 5 degrees either for 30 days (C-A) or for 1 day (W-C) and LTC4 dose-response curves obtained at 5 degrees. After the frogs were removed from cold, the baseline MAP and HR were monitored for 120 min, and dose-response curves were repeated at 2, 24, and 48 hr. The LTC4 dose-response curves were also obtained during the three experimental days on frogs which had never been placed at cold temperature (W-A). C-A frogs showed greater MAP response than W-C frogs at 5 degrees, and also showed the greatest MAP response of the three groups 48 hr after the animals were removed from cold temperature. These data suggest that up regulation of LTC4 receptors may have occurred in C-A frogs. Cold exposure alone eliminated reflex HR response to LTC4 in both C-A and W-C groups. Longer duration of action was also observed in these groups. The results demonstrate that short-term cold exposure can affect the response to LTC4 in frogs, but that physiological adjustments occur in frogs undergoing long-term exposure.

  11. Effects of intramuscular meloxicam administration on prostaglandin E2 synthesis in the North American bullfrog (Rana catesbeiana).

    PubMed

    Minter, Larry J; Clarke, Elsburgh O; Gjeltema, Jenessa L; Archibald, Kate E; Posner, Lysa P; Lewbart, Gregory A

    2011-12-01

    Meloxicam is a commonly used nonsteroidal anti-inflammatory drug (NSAID) in veterinary medicine, but its use in amphibians has not been reported in the literature. NSAIDs are known to act by providing anti-inflammatory and analgesic actions by inhibiting the synthesis of prostaglandin E2 (PGE2). The objective of this study was to evaluate whether the intramuscular administration of meloxicam would decrease the circulating serum PGE2 levels in the North American bullfrog (Rana catesbeiana) following tissue trauma induced by a punch biopsy. Eighteen adult North American bullfrogs were randomly assigned to two treatment groups: meloxicam (0.1 mg/kg i.m.) and control (0.9% saline i.m.). Blood was obtained via cardiocentesis immediately prior to administration of the two treatment regimes and serum was frozen. A 4-mm punch biopsy was taken from the right triceps femoris muscle to induce an inflammatory response. Twenty-four hours later, a second blood sample was collected and serum was harvested and frozen. Serum PGE2 concentrations were measured using a commercial PGE2 enzyme assay (EIA) kit. Twenty-four hours following the biopsy, the mean circulating PGE2 levels of animals treated with meloxicam was 57.79 +/- 12.35 pg/ml, which did not differ significantly from animals that were treated with saline (85.63 +/- 17.55 pg/ml, P > or = 0.05). The calculated means of the absolute change between the circulating baseline PGE2 levels and the postinjury circulating PGE2 levels were significantly lower in animals treated with meloxicam (13.11 +/- 17.31 pg/ml) than in control animals treated with saline (46.14 +/- 38.02 pg/ml) (P < or = 0.05). These results suggest that the systemic administration of meloxicam at a dosage of 0.1 mg/kg once daily suppresses circulating serum PGE2 levels postinjury in the North American bullfrog.

  12. Cardiac inotropic effects of leukotriene C4 and prostaglandin I2 in the unanesthetized American bullfrog, Rana catesbeiana.

    PubMed

    Robleto, D O; Reitmeyer, S T; Herman, C A

    1988-03-01

    The cardiovascular effects of leukotriene (LT) C4 and prostaglandin (PG) I2 were compared in the unanesthetized American bullfrog, Rana catesbeiana. Bullfrogs were instrumented to measure mean arterial pressure, peak ventricular pressure, its derivative (VP + dP/dt), and heart rate. Two hours after recovery from anesthesia, intravenous injections of LTC4 or PGI2 were tested over a dose range from 0.003 to 3 micrograms/kg body weight (bw). Both eicosanoids decreased mean arterial pressure, systolic ventricular pressure, and its derivative (VP + dP/dt). The effects of LTC4 and PGI2 on all parameters were similar at doses below 3 micrograms/kg bw. However, at 3 micrograms/kg bw, LTC4 had more potent negative inotropic effects than PGI2. Both compounds increased heart rate at 0.3 microgram/kg bw, but at 3 micrograms/kg bw PGI2 caused greater increases than LTC4. The hypotensive and negative inotropic effects of LTC4 were blunted in animals pretreated with indomethacin (4 mg/kg bw) to prevent endogenous prostaglandin and thromboxane synthesis, whereas the cardiovascular effects of PGI2 were unaffected by the blockade. The data show that both eicosanoids have similar qualitative effects on blood pressure and cardiac performance. However, the effects of LTC4 may be partially mediated by release of endogenous cyclooxygenase products, possibly PGI2. These results suggest that the bullfrog, an animal with no coronary arteries, is a useful model for comparative studies of cardiac actions of eicosanoids which are independent of effects mediated by changes in coronary vascular resistance.

  13. De novo Transcriptome Assemblies of Rana (Lithobates) catesbeiana and Xenopus laevis Tadpole Livers for Comparative Genomics without Reference Genomes.

    PubMed

    Birol, Inanc; Behsaz, Bahar; Hammond, S Austin; Kucuk, Erdi; Veldhoen, Nik; Helbing, Caren C

    2015-01-01

    In this work we studied the liver transcriptomes of two frog species, the American bullfrog (Rana (Lithobates) catesbeiana) and the African clawed frog (Xenopus laevis). We used high throughput RNA sequencing (RNA-seq) data to assemble and annotate these transcriptomes, and compared how their baseline expression profiles change when tadpoles of the two species are exposed to thyroid hormone. We generated more than 1.5 billion RNA-seq reads in total for the two species under two conditions as treatment/control pairs. We de novo assembled these reads using Trans-ABySS to reconstruct reference transcriptomes, obtaining over 350,000 and 130,000 putative transcripts for R. catesbeiana and X. laevis, respectively. Using available genomics resources for X. laevis, we annotated over 97% of our X. laevis transcriptome contigs, demonstrating the utility and efficacy of our methodology. Leveraging this validated analysis pipeline, we also annotated the assembled R. catesbeiana transcriptome. We used the expression profiles of the annotated genes of the two species to examine the similarities and differences between the tadpole liver transcriptomes. We also compared the gene ontology terms of expressed genes to measure how the animals react to a challenge by thyroid hormone. Our study reports three main conclusions. First, de novo assembly of RNA-seq data is a powerful method for annotating and establishing transcriptomes of non-model organisms. Second, the liver transcriptomes of the two frog species, R. catesbeiana and X. laevis, show many common features, and the distribution of their gene ontology profiles are statistically indistinguishable. Third, although they broadly respond the same way to the presence of thyroid hormone in their environment, their receptor/signal transduction pathways display marked differences.

  14. Regulation of cell cycle components during exposure to anoxia or dehydration stress in the wood frog, Rana sylvatica.

    PubMed

    Roufayel, Rabih; Biggar, Kyle K; Storey, Kenneth B

    2011-10-01

    The wood frog (Rana sylvatica) exhibits a well-developed natural anoxia and dehydration tolerance. The degree of stress tolerance depends on numerous biochemical adaptations, including stress-induced hypometabolism that helps to preserve long-term viability by reducing ATP demand. We hypothesized that the mechanisms involved in cell cycle control could act to aid in the establishment of the hypometabolic state required for stress survival. Selected proteins involved in the proliferation of cells were evaluated using immunoblotting in liver and skeletal muscle of wood frogs comparing controls with animals subjected to either 24-hr anoxia exposure under a nitrogen gas atmosphere or dehydration to 40% of total body water lost (all at 5°C). Levels of cyclins (type A, B, D, and E) decreased significantly under both stresses in liver and skeletal muscle. Similar reductions were seen for Cyclin-dependant kinases (Cdk) types 2, 4, and 6 in both liver and skeletal muscle; however, an increase in the relative amount of phosphorylated inactive p-Cdk (Thr14/Tyr15) was observed in liver under both stresses. Levels of positive regulators of Cdk activity (Cdc25 type A and C) were significantly reduced in both tissues under both stresses, whereas negative regulators of Cdk activity (p16(INK4a) and p27(KIP1) ) increased significantly in liver under both anoxia and dehydration stress (but not in muscle). This study provides the first report of differential regulation of cell cycle components in an anoxia and dehydration tolerant vertebrate, the wood frog, suggesting that cell cycle suppression is an active part of stress resistance and life extension in hypometabolic states.

  15. Toxicity of cadmium, endosulfan, and atrazine in adrenal steroidogenic cells of two amphibian species, Xenopus laevis and Rana catesbeiana.

    PubMed

    Goulet, Benoît N; Hontela, Alice

    2003-09-01

    The effects of cadmium, endosulfan, and atrazine on corticosterone secretion and viability of adrenal cells of African clawed frog (Xenopus laevis) and bullfrog (Rana catesbeiana) were assessed in vitro using a new bioassay. The bioassay relies on stimulation with adrenocorticotropic hormone (ACTH), the endogenous secretagogue for corticosterone secretion, and with dibutyryl cyclic adenosine monophosphate (dbcAMP), an analogue of cAMP, to pinpoint the site of action of the xenobiotics within the steroidogenic cell. To compare the test toxicants according to their endocrine-disrupting potential, the lethal concentration needed to kill 50% of the cells:effective concentration of 50% (LC50:EC50) ratio was calculated, with LC50 as the concentration that kills 50% of the steroidogenic cells and the EC50 as the concentration that impairs corticosterone secretion by 50%. The higher the ratio, the higher the potential for endocrine disruption. Atrazine had no affect on cell viability and on corticosterone secretion in X. laevis, but its endocrine-disrupting potential was high in R. catesbeiana. The LC50:EC50 ratio for cadmium and endosulfan in X. laevis was 26.07 and 1.23, respectively, and for atrazine, cadmium, and endosulfan in R. catesbeiana it was 909, 41, and 3, respectively. The dbcAMP did not restore corticosterone secretion in the cells exposed to the test toxicants in both species. Our study suggests that the secretory capacity of adrenal cells of amphibians can be impaired by environmental chemicals, especially atrazine in the bullfrog, and that these adrenotoxicants disrupt the enzymatic pathways leading to corticosterone secretion downstream from the step-generating cAMP.

  16. Antimicrobial properties of two purified skin peptides from the Mink Frog (Rana septentrionalis) against bacteria isolated from the natural habitat

    PubMed Central

    Ashcroft, Jonathan W.; Zalinger, Zachary B.; Bevier, Catherine R.; Fekete, Frank A.

    2015-01-01

    This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Numerous peptides exhibiting antimicrobial properties have been isolated from the skins of many amphibian species. These peptides offer an innate chemical defense system against various microbial agents that exist in the amphibian's environment. Amphibian skin peptides are typically tested for antimicrobial activity against microbial strains that are pathogenic to humans, but not on potential pathogenic or opportunistic bacteria that exist in the organism's habitat. Two peptides, a brevinin-2 related peptide and temporin-1SPb previously isolated from secretions of the Mink Frog, Rana septentrionalis, were tested for antimicrobial activity on bacterial isolates endemic to the frog's habitat. Ten isolates were identified, using 16S rRNA sequencing techniques, in the genera Pseudomonas, Serratia, Bacillus, Aeromonas, Burkholderia, Microbacterium, and Delftia. Bacterial isolates were tested with peptides at concentrations ranging from 0.8 μM to 1000 μM to determine the minimum inhibitory concentration (MIC) to inhibit growth. Growth of four of the isolates was inhibited by temporin-1SPb at the concentrations used, but all of the isolates were inhibited by the brevinin-2 related within the range of peptide concentrations used. This demonstrates the efficacy of both peptides as a component of the frog's innate chemical defense system. PMID:17499556

  17. Effect of mercuric chloride on fertilization and larval development in the River Frog, Rana heckscheri (Wright) (Anura: Ranidae)

    SciTech Connect

    Punzo, F. )

    1993-10-01

    Previous investigations have indicated that heavy metals such as copper, cadmium, lead and mercury can act as systemic toxicants in many species of wildlife. Although numerous studies have emphasized the effects of metals and pesticides on metabolism, growth, survivorship, neural processes and reproduction in a number of taxa, little information is available on the effects of sublethal concentrations of metals on the reproductive physiology of amphibians. Industrial processes and mining activities can release substantial concentrations of heavy metals such as mercury into aquatic habitats. Since most amphibians have obligate aquatic larval stages, they are exposed to pollutants discharged into the aquatic environment. Amphibians can act as accumulators of heavy metals and their larval stages are useful indicators of pollution levels in the field. What little data are available, indicate that metals can significantly reduce viability in amphibians through their actions on metabolism, development and gametogenesis. The recent concerns over worldwide declines in amphibian populations and the susceptibility of amphibian populations to environmental toxicants, led me to assess the effect of mercuric chloride, one of the most common and persistent toxicants in aquatic environments, on fertilization and larval development in the river frog, Rana heckscheri (Wright). Although there is some information on fish, very little data are available on the effects of mercury on fertilization in amphibians generally, and no published data exist for R. heckscheri. This species is a conspicuous component of the aquatic fauna of parts of the southeastern United States where mercury levels have increased significantly over the last two decades. 22 refs., 2 tabs.

  18. Mechanistic basis of adaptive maternal effects: egg jelly water balance mediates embryonic adaptation to acidity in Rana arvalis.

    PubMed

    Shu, Longfei; Suter, Marc J-F; Laurila, Anssi; Räsänen, Katja

    2015-11-01

    Environmental stress, such as acidification, can challenge persistence of natural populations and act as a powerful evolutionary force at ecological time scales. The ecological and evolutionary responses of natural populations to environmental stress at early life-stages are often mediated via maternal effects. During early life-stages, maternal effects commonly arise from egg coats (the extracellular structures surrounding the embryo), but the role of egg coats has rarely been studied in the context of adaptation to environmental stress. Previous studies on the moor frog Rana arvalis found that the egg coat mediated adaptive divergence along an acidification gradient in embryonic acid stress tolerance. However, the exact mechanisms underlying these adaptive maternal effects remain unknown. Here, we investigated the role of water balance and charge state (zeta potential) of egg jelly coats in embryonic adaptation to acid stress in three populations of R. arvalis. We found that acidic pH causes severe water loss in the egg jelly coat, but that jelly coats from an acid-adapted population retained more water than jelly coats from populations not adapted to acidity. Moreover, embryonic acid tolerance (survival at pH 4.0) correlated with both water loss and charge state of the jelly, indicating that negatively charged glycans influence jelly water balance and contribute to embryonic adaptation to acidity. These results indicate that egg coats can harbor extensive intra-specific variation, probably facilitated in part via strong selection on water balance and glycosylation status of egg jelly coats. These findings shed light on the molecular mechanisms of environmental stress tolerance and adaptive maternal effects. PMID:25983113

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

    PubMed

    Gerber, Victoria E M; Wijenayake, Sanoji; Storey, Kenneth B

    2016-01-01

    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. PMID:27042393

  20. Hepatic metallothioneins in molecular responses to cobalt, zinc, and their nanoscale polymeric composites in frog Rana ridibunda.

    PubMed

    Falfushynska, Halina; Gnatyshyna, Lesya; Fedoruk, Olga; Mitina, Natalia; Zaichenko, Alexander; Stoliar, Oksana; Stoika, Rostyslav

    2015-01-01

    Despite numerous studies suggesting a dramatic decline of amphibians, the biochemical mechanisms of adaptation in these animals to polluted environment are poorly studied. The aim of this study was to elucidate the ability to release cobalt (Co) and zinc (Zn) from their nanoscale complexes (NCs) derived from the polymeric substance of N-vinylpyrrolidone (PS) in the liver of amphibian (Rana ridibunda). Frog males were subjected to 14days exposure to waterborne Co(2+) (50μg/L), Zn(2+) (100μg/L), as well as corresponding concentrations of Co-NC, Zn-NC or PS. Main attention was paid to MT's interrelations with indices of stress and toxicity. Only Co(2+) and Zn(2+) caused elevation of the correspondent metal in MTs. Co(2+) caused down-regulation of cathepsin D activity, while Zn(2+), Zn-NC and the PS up-regulated this activity. Zn(2+) provoked 1.6 times increase of metal-bounded form of the MT (MT-Me), while all other exposures caused the elevation of the ratio of MT total protein concentration (MT-SH) and concentrations of the MT-Me and/or immunoreactive (MTi) form (up to ~10 times) accompanied by a decrease in the levels of oxyradicals. The increased DNA fragmentation and down-regulation of caspase-3 activity in relation to the redox state of glutathione and/or lactate/pyruvate were shown at all exposures. These data indicate the vulnerability of the redox state of cellular thiols and inability to release Co and Zn from NCs in frog's liver.

  1. A family of brevinin-2 peptides with potent activity against Pseudomonas aeruginosa from the skin of the Hokkaido frog, Rana pirica.

    PubMed

    Conlon, J Michael; Sonnevend, Agnes; Patel, Mahrendra; Al-Dhaheri, Khawla; Nielsen, Per F; Kolodziejek, Jolanta; Nowotny, Norbert; Iwamuro, Shawichi; Pál, Tibor

    2004-05-15

    Nine peptides displaying varying degrees of antimicrobial activity were extracted from the skin of the Hokkaido frog, Rana pirica. Five structurally related peptides were identified as members of the brevinin-2 family. These peptides were active against reference strains of Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Enterobacter cloacae, Klebsiella pneumoniae) and Gram-positive (Staphlococcus aureus) bacteria but displayed relatively low hemolytic activity. The most abundant peptide, brevinin-2PRa (680 nmol/g weight of dry skin) showed high potency [minimal inhibitory concentration (MIC) values between 6 and 12 microM] against a range of clinical isolates of P. aeruginosa. In addition, activity was unaffected by NaCl concentrations up to 200 mM. Cladistic analysis based on the primary structures of brevinin-2 peptides supports a close phylogenetic relationship between R. pirica and Japanese mountain brown frog Rana ornativentris. One peptide of the ranatuerin-2 family and one strongly hemolytic peptide of the brevinin-1 family were also isolated from the extract along with two members of the temporin family, temporin-1PRa (ILPILGNLLNGLL.NH(2)) and temporin-1PRb (ILPILGNLLNSLL.NH(2)) that atypically lacked basic amino acid residues and showed only very weak antimicrobial and hemolytic activity.

  2. Influence of Ribeiroia ondatrae (Trematoda: Digenea) infection on limb development and survival of northern leopard frogs (Rana pipiens): effects of host stage and parasite-exposure level

    USGS Publications Warehouse

    Schotthoefer, Anna M.; Koehler, Anson V.; Meteyer, Carol U.; Cole, Rebecca A.

    2003-01-01

    Recent evidence suggests that infection by larvae of the trematode Ribeiroia ondatrae accounts for a significant proportion of limb malformations currently observed in amphibian populations of North America. However, the effects of R. ondatrae infection on northern leopard frogs (Rana pipiens), one of the species most frequently reported with malformations, have not been adequately explored. Moreover, the risk factors associated with R. ondatrae-induced malformations have not been clearly identified. We examined the effects of timing of infection on tadpole survival and limb development. Rana pipiens tadpoles were individually exposed to R. ondatrae cercariae at the pre-limb-bud (Gosner stages 24 and 25), limb-bud (Gosner stages 27 and 28), or paddle (Gosner stages 31–33) stages of development and monitored through metamorphosis. The effects of infection were stage-specific. Infections acquired at the pre-limb-bud stage resulted in a high mortality rate (47.5–97.5%), whereas tadpoles infected at the limb-bud stage displayed a high malformation rate (16% overall), and the magnitude of effects increased with the level of exposure to cercariae. In contrast, infections acquired at the paddle stage had no effect on limb development or tadpole survival, which suggests that the timing of R. ondatrae infection in relation to the stage structure of tadpole populations in the wild is an important determinant of the degree to which populations are affected by R. ondatrae.

  3. Genetic relationships among Korean brown frog species (Anura, Ranidae), with special reference to evolutionary divergences between two allied species Rana dybowskii and R. huanrenensis.

    PubMed

    Kim, Jong-Bum; Min, Mi-Sook; Yang, Suh-Yung; Matsui, Masafumi

    2002-03-01

    Allozyme analysis for 41 populations of brown frog species, Rana dybowskii, R. huanrenensis, and R. amurensis from Korea and three reference species (Chinese R. chensinensis and Japanese R. dybowskii and R. tsushimensis), were performed to clarify taxonomic status of Korean brown frogs. The level of average genetic differentiation (Nei's D) among local populations of each species in Korea was very low (D<0.01 2) and Korean and Japanese R. dybowskii also showed conspecific level of differentiation (D=0.070). Whereas, much larger, discrete genetic differences were detected in the interspecific comparisons (D>0.370). In the genetic relationships among five species examined, the 24 chromosome brown frogs (R. dybowskii, R. huanrenensis, and R. chensinensis) did not form a monophyletic group. Rana dybowskii with the chromosome number of 2n=24 was grouped together with R. amurensis with the chromosome number of 2n=26. The hypothesis of reversal change from 24 to 26 in Korean R. amurensis seems to better explain the phylogenetic relationships of east Asian brown frogs than the assumption of parallel reduction in chromosome number from 2n=26 to 24 in R. dybowskii and in the common ancestor of R. huanrenensis and R. chensinensis. The genetic, morphological, and reproductive divergences between Korean R. dybowskii and R. huanrenensis were compared.

  4. Discordance between mitochondrial DNA genealogy and nuclear DNA genetic structure in the two morphotypes of Rana tagoi tagoi (Amphibia: Anura: Ranidae) in the Kinki Region, Japan.

    PubMed

    Eto, Koshiro; Matsui, Masafumi; Sugahara, Takahiro

    2013-07-01

    Two morphotypes, with a large and small body size, of a brown frog Rana t. tagoi occur sympatrically in the Kinki region, central Honshu of Japan. Previous mitochondrial (mt) DNA genealogical study recognized two main lineages (A and B) and several sublineages in R. tagoi, where the small type was placed in the group A-1b, and the large type in groups A-1a and B-2a. Using haplotype network and structure analysis of three nuclear genes, we examined the discrepancy between morphology and mitochondrial genealogy. The results showed that the small type is reproductively isolated from its co-occurring large type (A-1a or B-2a), and that unlimited gene flow occurred between parapatrically occurring two mtDNA lineages of large types (A-1a and B-2a). Discordant genetic relationships between mtDNA and nuclear DNA results may be caused by the past mitochondrial introgression, and possibly, the incomplete lineage sorting. These results also suggest a heterospecific relationship between the large (A-1a and B-2a) and small types (A-1b). The large type is identified as Rana t. tagoi as it is genetically very close to the topotypes of the nominal subspecies, while the small type remains unnamed.

  5. Terrestrial activity and conservation of adult California red-legged frogs Rana aurora draytonii in coastal forests and grasslands

    USGS Publications Warehouse

    Bulger, J.B.; Scott, N.J.; Seymour, R.B.

    2003-01-01

    The federally threatened California red-legged frog Rana aurora draytonii occupies both aquatic and terrestrial habitats in its adult life stage. The terrestrial activities of this species are not well known and require documentation to assist in the development of appropriate levels of protection under the US Endangered Species Act. We studied the terrestrial activities of radio-tagged red-legged frogs (n = 8-26) inhabiting a coastal watershed in Santa Cruz County, California, during 1997-1998. In particular, we investigated (1) the use of terrestrial habitats by non-migrating adults in relation to season, breeding chronology, and precipitation, and (2) adult migration behavior, including seasonal timing, duration, distances traveled, and the use of corridors. Non-migrating red-legged frogs occupied terrestrial habitats briefly (median = 4-6 days) following infrequent summer rains, but resided nearly continuously on land (median = 20-30 days) from the onset of the winter wet-season until breeding activities commenced 1-2 months later. All of the non-migrating frogs remained within 130 m of their aquatic site of residence (median <25 m). Intervals spent on land were again brief during mid/late winter (median = 1-4 days), despite frequent and copious rainfall. Adult migration to and from breeding sites occurred from late October through mid-May (wet season). We monitored 25 migration events between aquatic sites that were 200-2800 m apart. Short distance movements ( <300 m) were completed in 1-3 days, longer movements required up to 2 months. Most migrating frogs moved overland in approximately straight lines to target sites without apparent regard to vegetation type or topography. Riparian corridors were neither essential nor preferred as migration routes. Frogs traveling overland occurred in upland habitats as far as 500 m from water. Approximately 11-22% of the adult population was estimated to migrate to and from breeding sites annually, whereas the bulk of the

  6. Molecular cloning and characterization of an L-epinephrine transporter from sympathetic ganglia of the bullfrog, Rana catesbiana.

    PubMed

    Apparsundaram, S; Moore, K R; Malone, M D; Hartzell, H C; Blakely, R D

    1997-04-15

    Chemical signaling by dopamine (DA) and L-norepinephrine (L-NE) at synapses is terminated by uptake via specialized presynaptic transport proteins encoded by the DA transporter (DAT) and L-NE transporter (NET) genes, respectively. In some vertebrate neurons, particularly the sympathetic neurons of amphibians, L-NE is converted to L-epinephrine (L-Epi, adrenaline) and released as the primary neurotransmitter. Although evidence exists for a molecularly distinct L-Epi transporter (ET) in the vertebrate brain and peripheral nervous system, a transporter specialized for extracellular L-Epi clearance has yet to be identified. To pursue this issue, we cloned transporter cDNAs from bullfrog (Rana catesbiana) paravertebral sympathetic ganglia and characterized functional properties via heterologous expression in non-neuronal cells. A cDNA of 2514 bp (fET) was identified for which the cognate 3.1 kb mRNA is highly enriched in frog sympathetic ganglia. Sequence analysis of the fET cDNA reveals an open reading frame coding for a protein of 630 amino acids. Inferred fET protein sequence bears 75, 66, and 48% amino acid identity with human NET, DAT, and the 5-hydroxytryptamine transporter (SERT), respectively. Transfection of fET confers Na+- and Cl--dependent catecholamine uptake in HeLa cells. Uptake of [3H]-L-NE by fET is inhibited by catecholamines in a stereospecific manner. L-Epi and DA inhibit fET-mediated [3H]-L-NE uptake more potently than they inhibit [3H]-L-NE uptake by human NET (hNET), whereas L-NE exhibits equivalent potency between the two carriers. Moreover, fET exhibits a greater maximal velocity (Vmax) for the terminal products of catecholamine biosynthesis (L-Epi > L-NE > DA), unlike hNET, in which a Vmax rank order of L-NE > DA > L-Epi is observed. fET-mediated transport of catecholamines is sensitive to cocaine and tricyclic antidepressants, with antagonist potencies significantly correlated with hNET inhibitor sensitivity. Amino acid conservation and

  7. Octylphenol and UV-B radiation alter larval development and hypothalamic gene expression in the leopard frog (Rana pipiens).

    PubMed Central

    Crump, Douglas; Lean, David; Trudeau, Vance L

    2002-01-01

    We assessed octylphenol (OP), an estrogenic endocrine-disrupting chemical, and UV-B radiation, a known stressor in amphibian development, for their effects on hypothalamic gene expression and premetamorphic development in the leopard frog Rana pipiens. Newly hatched tadpoles were exposed for 10 days to OP alone at two different dose levels; to subambient UV-B radiation alone; and to two combinations of OP and UV-B. Control animals were exposed to ethanol vehicle (0.01%) exposure, a subset of tadpoles from each treatment group was raised to metamorphosis to assess differences in body weight and time required for hindlimb emergence. Tadpoles from one of the OP/UV-B combination groups had greater body weight and earlier hindlimb emergence (p < 0.05), but neither OP nor UV-B alone produced significant changes in body weight or hindlimb emergence, indicating a potential mechanism of interaction between OP and UV-B. We hypothesized that the developing hypothalamus might be a potential environmental sensor for neurotoxicologic studies because of its role in the endocrine control of metamorphosis. We used a differential display strategy to identify candidate genes differentially expressed in the hypothalamic region of the exposed tadpoles. Homology cloning was performed to obtain R. pipiens glutamate decarboxylases--GAD65 and GAD67, enzymes involved in the synthesis of the neurotransmitter gamma-aminobutyric acid (GABA). cDNA expression profiles revealed that OP and UV-B affected the levels of several candidate transcripts in tadpole (i.e., Nck, Ash, and phospholipase C gamma-binding protein 4 and brain angiogenesis inhibitor-3) and metamorph (i.e., GAD67, cytochrome C oxidase, and brain angiogenesis inhibitor-2 and -3) brains. This study represents a novel approach in toxicology that combines physiologic and molecular end points and indicates that levels of OP commonly found in the environment and subambient levels of UV-B alter the expression of important hypothalamic

  8. Octylphenol and UV-B radiation alter larval development and hypothalamic gene expression in the leopard frog (Rana pipiens).

    PubMed

    Crump, Douglas; Lean, David; Trudeau, Vance L

    2002-03-01

    We assessed octylphenol (OP), an estrogenic endocrine-disrupting chemical, and UV-B radiation, a known stressor in amphibian development, for their effects on hypothalamic gene expression and premetamorphic development in the leopard frog Rana pipiens. Newly hatched tadpoles were exposed for 10 days to OP alone at two different dose levels; to subambient UV-B radiation alone; and to two combinations of OP and UV-B. Control animals were exposed to ethanol vehicle (0.01%) exposure, a subset of tadpoles from each treatment group was raised to metamorphosis to assess differences in body weight and time required for hindlimb emergence. Tadpoles from one of the OP/UV-B combination groups had greater body weight and earlier hindlimb emergence (p < 0.05), but neither OP nor UV-B alone produced significant changes in body weight or hindlimb emergence, indicating a potential mechanism of interaction between OP and UV-B. We hypothesized that the developing hypothalamus might be a potential environmental sensor for neurotoxicologic studies because of its role in the endocrine control of metamorphosis. We used a differential display strategy to identify candidate genes differentially expressed in the hypothalamic region of the exposed tadpoles. Homology cloning was performed to obtain R. pipiens glutamate decarboxylases--GAD65 and GAD67, enzymes involved in the synthesis of the neurotransmitter gamma-aminobutyric acid (GABA). cDNA expression profiles revealed that OP and UV-B affected the levels of several candidate transcripts in tadpole (i.e., Nck, Ash, and phospholipase C gamma-binding protein 4 and brain angiogenesis inhibitor-3) and metamorph (i.e., GAD67, cytochrome C oxidase, and brain angiogenesis inhibitor-2 and -3) brains. This study represents a novel approach in toxicology that combines physiologic and molecular end points and indicates that levels of OP commonly found in the environment and subambient levels of UV-B alter the expression of important hypothalamic

  9. Protein kinase C in the wood frog, Rana sylvatica: reassessing the tissue-specific regulation of PKC isozymes during freezing

    PubMed Central

    Storey, Kenneth B.

    2014-01-01

    The wood frog, Rana sylvatica, survives whole-body freezing and thawing each winter. The extensive adaptations required at the biochemical level are facilitated by alterations to signaling pathways, including the insulin/Akt and AMPK pathways. Past studies investigating changing tissue-specific patterns of the second messenger IP3 in adapted frogs have suggested important roles for protein kinase C (PKC) in response to stress. In addition to their dependence on second messengers, phosphorylation of three PKC sites by upstream kinases (most notably PDK1) is needed for full PKC activation, according to widely-accepted models. The present study uses phospho-specific immunoblotting to investigate phosphorylation states of PKC—as they relate to distinct tissues, PKC isozymes, and phosphorylation sites—in control and frozen frogs. In contrast to past studies where second messengers of PKC increased during the freezing process, phosphorylation of PKC tended to generally decline in most tissues of frozen frogs. All PKC isozymes and specific phosphorylation sites detected by immunoblotting decreased in phosphorylation levels in hind leg skeletal muscle and hearts of frozen frogs. Most PKC isozymes and specific phosphorylation sites detected in livers and kidneys also declined; the only exceptions were the levels of isozymes/phosphorylation sites detected by the phospho-PKCα/βII (Thr638/641) antibody, which remained unchanged from control to frozen frogs. Changes in brains of frozen frogs were unique; no decreases were observed in the phosphorylation levels of any of the PKC isozymes and/or specific phosphorylation sites detected by immunoblotting. Rather, increases were observed for the levels of isozymes/phosphorylation sites detected by the phospho-PKCα/βII (Thr638/641), phospho-PKCδ (Thr505), and phospho-PKCθ (Thr538) antibodies; all other isozymes/phosphorylation sites detected in brain remained unchanged from control to frozen frogs. The results of this study

  10. Regulation of the respiratory central pattern generator by chloride-dependent inhibition during development in the bullfrog (Rana catesbeiana).

    PubMed

    Broch, Lise; Morales, Rey D; Sandoval, Anthony V; Hedrick, Michael S

    2002-04-01

    Isolated brainstem preparations from larval (tadpole) and adult Rana catesbeiana were used to examine inhibitory mechanisms for developmental regulation of the respiratory central pattern generator (CPG). Preparations were superfused at 20-22 degrees C with Cl(-)-free artificial cerebrospinal fluid (aCSF) or with aCSF containing agonists/antagonists of gamma-aminobutyric acid (GABA) or glycine receptors. Respiratory motor output from the CPG, measured as neural activity from cranial nerve roots, was associated with fictive gill ventilation and lung ventilation in tadpoles and with fictive lung ventilation in adults. In tadpoles, fictive lung burst frequency was 0.8+/-0.2 min(-1) and did not change significantly with Cl(-)-free aCSF superfusion; however, lung burst amplitude increased by nearly 400 % (P<0.01). Fictive gill ventilation averaged 41.6+/-3.3 min(-1) and was reversibly abolished by Cl(-)-free aCSF. Superfusion with Cl(-)-free aCSF abolished lung bursts in two of seven adult preparations, and overall lung burst frequency decreased from 3.1+/-0.7 to 0.4+/-0.03 min(-1) (P<0.01), but burst amplitude was unchanged. Low concentrations of GABA (0.5 mmol l(-1)) produced a significant increase in lung burst frequency followed by almost complete inhibition at 5.0 mmol l(-1), accompanied by the abolition of gill ventilation at 2.5-5.0 mmol l(-1). By contrast, fictive lung ventilation in adults was inhibited in a dose-dependent manner by glycine and GABA, and inhibition occurred at approximately 10-fold lower concentrations compared with tadpoles. The glycine receptor antagonist strychnine (2.5-25.0 micromol l(-1)) and the GABA(A) receptor antagonist bicuculline (1-10 micromol l(-1)) inhibited fictive gill ventilation and increased fictive lung ventilation in tadpoles. However, bicuculline and strychnine inhibited fictive lung ventilation in adults. These results suggest that lung ventilation in the tadpole brainstem may be driven by a pacemaker-like mechanism since

  11. Temperature and pH/CO(2) modulate respiratory activity in the isolated brainstem of the bullfrog (Rana catesbeiana).

    PubMed

    Morales, Rey D; Hedrick, Michael S

    2002-06-01

    The effects of temperature and pH/CO(2) were examined in isolated brainstem preparations from adult North American bullfrogs (Rana catesbeiana). These experiments were undertaken to determine the effects of temperature on fictive breathing, central pH/CO(2) chemoreception, and to examine potential alphastat regulation of respiration in vitro. Adult bullfrog brainstem preparations were isolated, superfused with an artificial cerebrospinal fluid (aCSF) and respiratory-related neural activity was recorded from cranial nerves V, X and XII. In Series I experiments (N=8), brainstem preparations were superfused with aCSF equilibrated with 2% CO(2) at temperatures ranging from 10 to 30 degrees C. Neural activity was present in all preparations in the temperature range of 15-25 degrees C, but was absent in most preparations when aCSF was at 10 or 30 degrees C. The absence of fictive breathing at high (30 degrees C) temperatures was transient since fictive breathing could be restored upon returning the preparation to 20 degrees C. In Series II experiments (N=10), preparations were superfused with aCSF equilibrated with 0%, 2% and 5% CO(2) at temperatures of 15, 20 and 25 degrees C. Fictive breathing frequency (f(R)) was significantly dependent upon aCSF pH at all three temperatures, with slopes ranging from -0.82 min(-1) pH unit(-1) (15 degrees C) to -3.3 min(-1) pH unit(-1) (20 degrees C). There was a significant difference in these slopes (P<0.02), indicating that central chemoreceptor sensitivity increased over this temperature range. Fictive breathing frequency was significantly dependent upon the calculated alpha-imidazole (alpha(Im)) ionization (P<0.05), consistent with the alphastat hypothesis for the effects of temperature on the regulation of ventilation. However, most of the variation in f(R) was not explained by alpha(Im) (R(2)=0.05), suggesting that other factors account for the regulation of fictive breathing in this preparation. The results indicate that the in

  12. Nitric oxide as a modulator of central respiratory rhythm in the isolated brainstem of the bullfrog (Rana catesbeiana).

    PubMed

    Hedrick, M S; Morales, R D

    1999-11-01

    Nitric oxide (NO) is a unique interneuronal neurotransmitter and/or neuromodulator that is involved in a variety of physiological functions within the central nervous system (CNS). In neural tissue, NO is generated from an oxygen-dependent, constitutive NO synthase (NOS) by glutamatergic stimulation of N-methyl-D-aspartate (NMDA) receptors. Recent studies indicate that NO has excitatory effects on breathing within the CNS and mediates a central component of the hypoxic ventilatory reflex in mammals. Because NMDA receptors are important in central respiratory rhythmogenesis, we hypothesized that NO would have significant effects on the central pattern generator (CPG) for breathing in the brainstem. To test this hypothesis, the effects of NO on respiratory-related neural activity were investigated using an in vitro brainstem preparation from North American bullfrogs (Rana catesbeiana). Extracellular recordings of respiratory-related burst activity were made from cranial nerves V, X and XII before and during superfusion of the brainstem with NO-generating compounds, or inhibitors of NO synthesis. Addition of the NO donor, sodium nitroprusside (SNP; 0.1-1.0 mM), or the amino acid precursor for NO synthesis, L-arginine (L-Arg; 0.01-1.0 mM), caused significant increases in respiratory-related burst frequency. Inhibition of NOS with N omega-nitro-L-arginine (L-NA; 5-10 mM), a non-selective NOS inhibitor, caused a significant reduction in burst frequency or reversibly abolished neural activity. Brainstem perfusion with the specific neuronal NOS (nNOS) inhibitor, 7-nitro indazole (7-NI), produced significant, dose-dependent reversible reductions in burst frequency at concentrations of 0.1, 0.5 and 1.0 mM. These results suggest that production of NO, probably via nNOS, provides an excitatory input to the respiratory CPG in the amphibian brainstem. Our results suggest that NO may be a necessary inter- or intracellular messenger for neurotransmission and/or neuromodulation of

  13. Expression of the myosin heavy chain genes in the tail muscle of thyroid hormone-induced metamorphosing Rana catesbeiana tadpoles.

    PubMed

    Hu, H; Merrifield, P; Atkinson, B G

    1999-01-01

    In tadpoles of the North American bullfrog, Rana catesbeiana, spontaneous and thyroid hormone (T3)-induced metamorphosis is characterized by regression of the tail, which is preceded by a decrease in total protein synthesis in tail tissues. We have demonstrated that thyroid hormone treatment of a tadpole does not affect the synthesis of all proteins equally in the tadpole tail muscle. For example, the synthesis of myosin heavy chains (MHCs) is depressed within 1 day and decreases to 45% of control values after 5 days of T3 treatment, whereas the decreased synthesis of soluble muscle proteins is transient and returns to above control levels by day 5. To determine whether the hormone-induced decrease in MHC synthesis is the result of changes in the transcription of translation of MHC mRNAs, we isolated cDNAs complementary to five different MHC mRNAs from a tail muscle cDNA library and used them to examine the levels of each MHC mRNA in the tail muscle of T3-treated tadpoles. mRNAs that recognize the cDNAs for these five different MHCs are all expressed in the tadpole tail and limb muscles, as well as in the adult leg muscles. MHC mRNAs unique to tadpole tail were not detected. Interestingly, the relative amounts of mRNA for four of the five MHCs increase in tail muscle after T3 treatment of the tadpole, suggesting that repression of MHC gene expression at the protein level does not result from a decrease in the amount of MHC mRNAs. Rather, these results support the contention that the decreased synthesis of MHCs in the tail muscle of T3-treated tadpoles is caused by this hormone, either directly or indirectly, depressing the translation of the MHC mRNAs in this tissue. These results, coupled with the observation that the synthesis of soluble muscle proteins is depressed only in a transient fashion, suggest that T3 may be initiating the expression of a gene(s) that encodes a protein(s) responsible for inhibiting the translation of the MHCs and, perhaps, other

  14. Effects of chronic aluminum and copper exposure on growth and development of wood frog (Rana sylvatica) larvae.

    PubMed

    Peles, John D

    2013-09-15

    Wood frogs (Rana sylvatica) were exposed to aluminum (Al; 10, 100, 500, 1000, or 2000 μgL(-1)) or copper (Cu; 1, 10, 50, 100, 200 μgL(-1)) at a pH of 4.70 from the beginning of the larval period through the completion of metamorphosis (range=43-102 days). Observations on mortality, malformation, time to reach specific developmental stages, body mass at these stages, and metamorphic success were made throughout the larval developmental period. Only one case of malformation was observed and mortality was ≤ 10% at all concentrations except the highest Cu concentration where the rate was 33%. All larvae that survived the experiment successfully completed metamorphosis, but significant effects on growth and development occurred for both metals and these were most prominent for Cu. At the highest Al concentration (2000 μgL(-1)), body mass of larvae was significantly lower (reduced by 17% compared to the control) at 20 days post hatching (DPH) and the time to reach the hind-limb (HL), front-limb (FL), and tail resorption (TR) stages was significantly increased (9-10 days longer than the control). Body mass of larvae exposed to the three highest concentrations of Cu (50, 100, 200 μgL(-1)) was reduced by 30-34% at 20 DPH. Exposure to these concentrations also resulted in increased time to reach the HL, FL, and TR stages with larvae in the highest concentration taking 21-29 days longer to reach these stages. Larvae exposed to 10 μgL(-1) Cu also took longer to reach the FL and TR stages of development, and exposure to all Cu concentrations increased tail resorption time by more than two days compared to the control. Although the only observed effects of Al were for a concentration that is probably not ecologically relevant, results demonstrate that environmentally-realistic levels of Cu may have significant biological effects that could influence individual fitness and population-level processes.

  15. Water uptake by the crab-eating frog Rana cancrivora, as affected by osmotic gradients and by neurohypophysial hormones.

    PubMed

    Dicker, S E; Elliott, A B

    1970-03-01

    1. The rate of water uptake across the skin was investigated in live Rana cancrivora, an euryhaline frog which has been reported to tolerate sea water. When they were exposed to distilled water at 29 degrees C, the rate of water uptake was 8.4 +/- 0.4 mul./cm(2).hr; when bathed in solutions ranging from 30 to 570 m-osmole/l., irrespective of whether the solute was sucrose, urea or NaCl, the rate of fluid uptake during the first day was inversely related to the osmolarity of the solution. No appreciable fluid movement was observed when the bathing solution had an osmolar concentration of 270 m-osmole/l.2. The rate of fluid uptake was not affected by injections of vasopressin, oxytocin or of extracts of amphibian or rat pituitary glands, irrespective of whether R. cancrivora were bathed in distilled water or in solutions of NaCl or sucrose.3. In Bufo melanostictus, in contrast with R. cancrivora, injections of neurohypophysial extracts produced a marked increase of the rate of fluid uptake.4. In the laboratory, R. cancrivora could be acclimatized stepwise to tolerate NaCl solutions up to 700 m-osmole/l. for 7 days.5. After 24 hr exposure either to distilled water or to NaCl solutions from 100 to 670 m-osmole/l., the osmolar concentration of the plasma of R. cancrivora was always higher than that of the bathing fluid. In R. pipiens or R. temporaria plasma osmolar concentration was higher than that of the bathing fluid only when the latter did not exceed 300 m-osmole/l.6. Under all conditions investigated, the osmolar concentration of the urine of R. cancrivora was always lower than that of the plasma.7. The amounts of pressor and oxytocic activities of pituitary glands of R. cancrivora kept in distilled water or in NaCl solutions up to 300 m-osmole/l. were 8.9 +/- 0.8 and 1.8 +/- 0.3 m-u./gland, irrespective of sex or body weight within the range 30-50 g. After 3 days exposure to hypertonic NaCl solutions, the amounts of pressor and oxytocic activities were 14.7 +/- 1

  16. [The formation of new characteristics in life cycle of the marsh frog (Rana ridibunda) in thermal pond conditions].

    PubMed

    Fominykh, A S; Liapkov, S M

    2011-01-01

    Using mark and recapture approach, the long-term population dynamics in the marsh frog (Rana ridibunda) was studied. Group-marking of metamorphs was conducted in a small thermal pond serving as a sedimentation basin for discharged waters from Nizhny Tagil metallurgic works. Depending on the time of metamorphosis, three groups of individuals could be singled out, namely: early ones (group I), middle ones (group II), and late ones that overwinter as tadpoles and complete metamorphosis in May of the next year (group III). Upon metamorphosis completion, individuals of group I were found to be significantly larger than those of group II, and individuals of both these groups to be significantly smaller than those of group III. After first wintering, immature individuals from group I were significantly larger than either individuals from group II or metamorphs from group III, though a growth rate of the latter was significantly higher than in groups I and II. These discrepancies were observed both between immature and adult individuals. Over the period from metamorphosis completion to the first wintering ending, survivorship in group I was significantly higher and did not differ between groups II and III. In adult frogs, maximum survivorship was registered in group III and minimum one in group II; the detected differences recurred in each age class till the fourth wintering. However, in age classes that overwintered 4 and 5 times, maximum survivorship was observed in group II, which can be treated as a compensation for rather low survivorship of this group at younger ages. All the events of tadpoles of this species overwintering (except in other thermal water bodies) that are described in literature, correspond to rare deviations from normal ontogenesis. Therefore, the revealed formation of a numerous group of overwintering tadpoles in successive generations should be considered as a new adaptation which sense is a decrease of competition between tadpole groups when using

  17. Nitric oxide changes its role as a modulator of respiratory motor activity during development in the bullfrog (Rana catesbeiana).

    PubMed

    Hedrick, Michael S; Chen, Anna K; Jessop, Kristy L

    2005-10-01

    Nitric oxide (NO) is a unique chemical messenger that has been shown to play a role in the modulation of breathing in amphibians and other vertebrates. In the post-metamorphic tadpole and adult amphibian brainstem, NO, acting via the neuronal isoform of nitric oxide synthase (nNOS), is excitatory to the generation of lung burst activity. In this study, we examine the modulation of breathing by NO during development of the amphibian brainstem. Isolated brainstem preparations from pre-metamorphic and late-stage post-metamorphic tadpoles (Rana catesbeiana) were used to determine the role of NO in modulating central respiratory neural activity. Respiratory neural activity was monitored with suction electrodes recording extracellular activity of cranial nerve rootlets that innervate respiratory musculature. Brainstems were superfused with an artificial cerebrospinal fluid (aCSF) at 20-22 degrees C containing l-nitroarginine (l-NA; 1-10 mM), a non-selective NOS inhibitor. In pre-metamorphic tadpoles, l-NA increased fictive gill ventilation frequency and amplitude, and increased lung burst frequency. By contrast, l-NA applied to the post-metamorphic tadpole brainstem had little effect on fictive buccal activity, but significantly decreased lung burst frequency and the frequency of lung burst episodes. These data indicate that early in development, NO provides a tonic inhibitory input to gill and lung burst activity, but as development progresses, NO provides an excitatory input to lung ventilation. This changing role for NO coincides with the shift in importance in the different respiratory modes during development in amphibians; that is, pre-metamorphic tadpoles rely predominantly on gill ventilation whereas post-metamorphic tadpoles have lost the gills and are obligate air-breathers primarily using lungs for gas exchange. We hypothesize that NO provides a tonic input to the respiratory CPG during development and this changing role reflects the modulatory influence of NO

  18. Study of agglutination of mouse mammary carcinoma (FM3A) cell induced by egg agglutinin of Rana catesbiana. II. Phytohemagglutinin P and protamine.

    PubMed

    Takeda, S; Kubota, K; Endo, Y; Matsuzawa, T

    1981-01-01

    When mouse mammary carcinoma (FM3A) cells were treated with egg agglutinin of Rana catesbiana for 15 min at 25 degrees C, percent total particle number of both cell aggregates and single cells was in direct proportion to the cell electrophoretic mobility. Phytohemagglutinin P mediated agglutination proceeded with biphasic kinetics: the higher the concentration of phytohemagglutinin P the shorter was the lag period between the first and second stages of agglutination. In protamine-mediated agglutination, the percent total particle number was reduced at low concentrations, while the electrophoretic mobility reduced only at high concentrations. Agglutinating and cytotoxic activities of these three reagents were in an intimate relation: the higher the agglutinating activity, the greater was their cytotoxic activity. PMID:6969671

  19. Bullfrog tadpole (Rana catesbeiana) and red swamp crayfish (Procambarus clarkii) predation on early life stages of endangered razorback sucker (Xyrauchen texanus)

    USGS Publications Warehouse

    Mueller, G.A.; Carpenter, J.; Thornbrugh, D.

    2006-01-01

    Bullfrog tadpoles (Rana catesbeiana) and red swamp crayfish (Procambarus clarkii) are widespread introduced taxa that are problematic throughout the western United States. Their impact on native amphibians and crustaceans is well documented, but less is known regarding their influence on native fishes. Predator-prey tank tests showed both species consumed eggs and larvae of the endangered razorback sucker (Xyrauchen texanus) in a laboratory setting. Tadpoles consumed 2.2 razorback sucker eggs/d and 1.4 razorback sucker larvae/d, while crayfish ate 6.0 eggs/d and 3.5 larvae/d. Relatively high densities of bullfrog tadpoles and crayfish in razorback sucker spawning areas suggest that these nonnative taxa might pose a threat to the recruitment success of this and other imperiled native fish.

  20. Genetic structure of a Japanese brown frog (Rana japonica) population implies severe restriction of gene flow caused by recent urbanization in a satoyama landscape.

    PubMed

    Kobayashi, Soh; Abe, Seiya; Matsuki, Rikyu

    2013-12-01

    Rapid urbanization is one of the major pressures on amphibian species. Elucidating changes in genetic structure will be useful in evaluating the effects of urbanization on amphibian populations. Our study focused on Rana japonica, which is common in complex agricultural landscapes known as satoyama, which are also under intense development pressure. We conducted landscape genetic analyses based on mitochondrial DNA haplotype frequencies of 13 breeding sites in a rapidly urbanizing area of Japan. We found several breeding sites had significantly higher F(st) values, and we also identified the barriers to gene flow between these sites. Observation of past aerial photographs revealed that these barriers coincided with the construction of man-made structures in the last few decades, suggesting that urbanization has restricted gene flow in R. japonica. Our results show that landscape genetic approaches are useful in conservation planning where rapid habitat degradation has taken place.

  1. Calcium oxalate nephrolithiasis and tubular necrosis in recent metamorphs of Rana sylvatica (Lithobates sylvaticus) fed spinach during the premetamorphic (tadpole) stage.

    PubMed

    Forzán, M J; Ferguson, L V; Smith, T G

    2015-03-01

    Amphibians in the family Ranidae (true frogs) seem highly susceptible to oxalosis, particularly when fed a diet high in oxalic acid during the premetamorphic (tadpole) stage. The authors describe the mortality of 150 captive-raised wood frogs (Rana sylvatica or Lithobates sylvaticus) from oxalate nephrolithiasis and renal tubular necrosis caused by consumption of boiled spinach during tadpole development. Renal lesions were due to intraluminal transparent crystals which were birefringent under polarized light and were identified morphologically and histochemically as composed of calcium oxalate. Evidence of early fibrosis or squamous metaplasia, and a presentation at least 2 weeks after spinach consumption had ended, suggested a subacute course. Tadpole-feeding protocols should avoid plants with high oxalate content (eg, spinach and rhubarb leaves), and any episode of high mortality in captive amphibians along with nephrolithiasis should prompt an evaluation of the feed sources for material with high oxalate content.

  2. A de novo Assembly of the Common Frog (Rana temporaria) Transcriptome and Comparison of Transcription Following Exposure to Ranavirus and Batrachochytrium dendrobatidis.

    PubMed

    Price, Stephen J; Garner, Trenton W J; Balloux, Francois; Ruis, Chris; Paszkiewicz, Konrad H; Moore, Karen; Griffiths, Amber G F

    2015-01-01

    Amphibians are experiencing global declines and extinctions, with infectious diseases representing a major factor. In this study we examined the transcriptional response of metamorphic hosts (common frog, Rana temporaria) to the two most important amphibian pathogens: Batrachochytrium dendrobatidis (Bd) and Ranavirus. We found strong up-regulation of a gene involved in the adaptive immune response (AP4S1) at four days post-exposure to both pathogens. We detected a significant transcriptional response to Bd, covering the immune response (innate and adaptive immunity, complement activation, and general inflammatory responses), but relatively little transcriptional response to Ranavirus. This may reflect the higher mortality rates found in wild common frogs infected with Ranavirus as opposed to Bd. These data provide a valuable genomic resource for the amphibians, contribute insight into gene expression changes after pathogen exposure, and suggest potential candidate genes for future host-pathogen research.

  3. A de novo Assembly of the Common Frog (Rana temporaria) Transcriptome and Comparison of Transcription Following Exposure to Ranavirus and Batrachochytrium dendrobatidis

    PubMed Central

    Price, Stephen J.; Garner, Trenton W. J.; Balloux, Francois; Ruis, Chris; Paszkiewicz, Konrad H.; Moore, Karen; Griffiths, Amber G. F.

    2015-01-01

    Amphibians are experiencing global declines and extinctions, with infectious diseases representing a major factor. In this study we examined the transcriptional response of metamorphic hosts (common frog, Rana temporaria) to the two most important amphibian pathogens: Batrachochytrium dendrobatidis (Bd) and Ranavirus. We found strong up-regulation of a gene involved in the adaptive immune response (AP4S1) at four days post-exposure to both pathogens. We detected a significant transcriptional response to Bd, covering the immune response (innate and adaptive immunity, complement activation, and general inflammatory responses), but relatively little transcriptional response to Ranavirus. This may reflect the higher mortality rates found in wild common frogs infected with Ranavirus as opposed to Bd. These data provide a valuable genomic resource for the amphibians, contribute insight into gene expression changes after pathogen exposure, and suggest potential candidate genes for future host-pathogen research. PMID:26111016

  4. Diverse families of antimicrobial peptides isolated from skin secretions of three species of East Asian frogs, Babina daunchina, Babina adenopleura, and Rana omeimontis (Ranidae).

    PubMed

    Hu, Yuhong; Xu, Shiqi; Hu, Yonghong; Guo, Chao; Meng, Hao; Li, Jing; Liu, Jingze; Wang, Hui

    2014-07-01

    Twenty-two novel cDNAs encoding 22 peptide precursors for 19 mature peptides including antimicrobial peptides (AMPs) were identified from East Asian frog species Babina daunchina, Babina adenopleura, and Rana omeimontis skin-derived cDNA libraries. Two atypical members of the brevinin-1 family AMPs, named brevinin-1AN1 (FLTGVLKLASKIPSVLCAVLKTC) and brevinin-1DN1(FLKGVINLASKIPSMLCAVLKTC), were purified from the skin secretions of B. adenopleura and B. daunchina, respectively. A member of the ranatuerin-2 family AMP named ranatuerin-2DN1 (GLFDSITQGLKDTAVKLLDKIKCKLSACPPA) was also purified from the skin secretion of B. daunchina. One AMP named japonicin-2OM1 (FIVPSIFLLKKAFCIALKKNC) was purified from the skin secretion of R. omeimontis. The antimicrobial tests showed that brevinin-1DN1, brevinin-1DN2, brevinin-1AN1, and japonicin-2OM1 possess higher antimicrobial activity against Gram-positive bacteria than Gram-negative bacteria.

  5. Incidence and impact of axial malformations in larval bullfrogs (Rana catesbeiana) developing in sites polluted by a coal-burning power plant

    SciTech Connect

    Hopkins, W.A.; Congdon, J.; Ray, J.K.

    2000-04-01

    Amphibian malformations have recently received much attention from the scientific community, but few studies have provided evidence linking environmental pollution to larval amphibian malformations in the field. The authors document an increased incidence of axial malformations in bullfrog larvae (Rana catesbeiana) inhabiting two sites contaminated with coal combustion wastes. In the polluted sites, 18 and 37% of larvae exhibited lateral curvatures of the spine, whereas zero and 4% of larvae from two reference sites had similar malformations. Larvae from the most heavily polluted site had significantly higher tissue concentrations of potentially toxic trace elements, including As, Cd, Se, Cu, Cr, and V, compared with conspecifics from the reference sites. In addition, malformed larvae from the cost contaminated site had decreased swimming speeds compared with those of normal larvae from the same site. The authors hypothesize that the complex mixture of contaminants produced by coal combustion is responsible for the high incidence of malformations and associated effects on swimming performance.

  6. Response of the Italian agile frog (Rana latastei) to a Ranavirus, frog virus 3: a model for viral emergence in naïve populations.

    PubMed

    Pearman, Peter B; Garner, Trenton W J; Straub, Monika; Greber, Urs F

    2004-10-01

    Ranavirus (family Iridoviridae) is a genus of pathogens of poikilotherms, and some ranaviruses may play a role in widespread mortality of amphibians. Ecology of viral transmission in amphibians is poorly known but can be addressed through experimentation in the laboratory. In this study, we use the Ranavirus frog virus 3 (FV3) as an experimental model for pathogen emergence in naive populations of tadpoles. We simulated emerging disease by exposing tadpoles of the Italian agile frog (Rana latastei), to the North American Ranavirus FV3. We demonstrated that mortality occurred due to viral exposure, exposure of tadpoles to decreasing concentrations of FV3 in the laboratory produced dose-dependent survival rates, and cannibalism of virus-carrying carcasses increased mortality due to FV3. These experiments suggest the potential for ecological mechanisms to affect the level of exposure of tadpoles to Ranavirus and to impact transmission of viral pathogens in aquatic systems.

  7. [Analysis of helminthofauna of common spaedfoot Pelobates fuscus (Laurenti, 1768) and moor frog Rana arvalis Nilsson, 1842 (Amphibia: Anura) at their joint habitation].

    PubMed

    Ruchin, A B; Chikhliaev, I V; Lukiianov, S V

    2009-01-01

    The helminths fauna of common spaedfoot Pelobates fuscus (Laurenti, 1768) and moor frog Rana arvalis Nilsson, 1842 has been studied at their joint habitation. The stuff was collected in 1998-2002, 2004-2006 years in several regions (republic Mordovia, Samara and Saratov areas). The processing of a stuff is conducted by a method of full helmintologic dissecting. The fauna of helminths considerably differs. For common spaedfoot only 13 species of helminths was detected which also parasitized moor frog (for moor frog 23 species) are detected. The index Jaccar demonstrated mean resemblance structure of helminths and varied from 0.25 till 0.69, and the index Morisite--from 44.58 of % till 74.51 of %. The communities of parasites of common spaedfoot was characterized by low values of an index of Shannon, but the high indexes of an index Simpson, whereas for moor frog tracked the return tendence.

  8. Stockpile Stewardship: Los Alamos

    SciTech Connect

    McMillan, Charlie; Morgan, Nathanial; Goorley, Tom; Merrill, Frank; Funk, Dave; Korzekwa, Deniece; Laintz, Ken

    2012-01-26

    "Heritage of Science" is a short video that highlights the Stockpile Stewardship program at Los Alamos National Laboratory. Stockpile Stewardship was conceived in the early 1990s as a national science-based program that could assure the safety, security, and effectiveness of the U.S. nuclear deterrent without the need for full-scale underground nuclear testing. This video was produced by Los Alamos National Laboratory for screening at the Lab's Bradbury Science Museum in Los Alamos, NM and is narrated by science correspondent Miles O'Brien.

  9. Stockpile Stewardship: Los Alamos

    ScienceCinema

    McMillan, Charlie; Morgan, Nathanial; Goorley, Tom; Merrill, Frank; Funk, Dave; Korzekwa, Deniece; Laintz, Ken

    2016-07-12

    "Heritage of Science" is a short video that highlights the Stockpile Stewardship program at Los Alamos National Laboratory. Stockpile Stewardship was conceived in the early 1990s as a national science-based program that could assure the safety, security, and effectiveness of the U.S. nuclear deterrent without the need for full-scale underground nuclear testing. This video was produced by Los Alamos National Laboratory for screening at the Lab's Bradbury Science Museum in Los Alamos, NM and is narrated by science correspondent Miles O'Brien.

  10. Plasma sex steroid and thyroid hormones profile in male water frogs of the Rana esculenta complex from agricultural and pristine areas.

    PubMed

    Mosconi, G; Di Rosa, I; Bucci, S; Morosi, L; Franzoni, M F; Polzonetti-Magni, A M; Pascolini, R

    2005-07-01

    Some chemical compounds used in intensive agriculture have been found to induce estrogenic effects; therefore a histological analysis of the testes and an evaluation of plasma levels of sex steroid, thyroid hormones, and vitellogenin were carried out in adult male water frogs of two coexisting taxa (Rana lessonae and the hemiclonal hybrid Rana esculenta) sampled in agricultural and pristine areas. Differences in seasonal profiles of hormones were found in water frogs living in the agricultural area where the presence of endocrine disrupting compounds was suspected on the basis of a previous study. In R. esculenta, sampled in the pristine area, high androgen levels were found in May; the opposite trend was found for R. esculenta sampled in agricultural areas in which the highest androgen levels were found in September, significantly lower compared with those found in R. esculenta sampled in the pristine area. Low androgen levels were also recorded in R. lessonae males sampled both in pristine and agricultural areas, while the highest levels were found in September. Regarding the trend of estradiol-17beta, an increase of this hormone was found in July both in esculenta and lessonae sampled in the agricultural area, and in the same month an estradiol-17beta peak, even though lower, was also found both in esculenta and lessonae males captured in the pristine area; detectable vitellogenin was found neither in males captured in the agricultural area, nor in those sampled in the pristine one. Moreover, while no significant changes of thyroid hormones were found either in the esculenta or lessonae males sampled in the pristine area, increased T3 and T4 titers were found in July in both esculenta and lessonae captured in the agricultural area. Morphological differences of the testes in males of parental species captured in the agricultural area were also observed. These findings indicate alterations in endocrine and reproductive function in frogs in the agricultural area

  11. Toxicity of the conventional energetics TNT and RDX relative to new insensitive munitions constituents DNAN and NTO in Rana pipiens tadpoles.

    PubMed

    Stanley, Jacob K; Lotufo, Guilherme R; Biedenbach, James M; Chappell, Pornsawan; Gust, Kurt A

    2015-04-01

    An initiative within the US military is targeting the replacement of traditional munitions constituents with insensitive munitions to reduce risk of accidental detonation. The purpose of the present study was to comparatively assess toxicity of the traditional munitions constituents 2,4,6-trinitrotoluene (TNT) and 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) with the new insensitive munitions constituents 2,4-dinitroanisole (DNAN) and 3-nitro-1,2,4-triazol-5-one (NTO). The following exposure durations were performed with Rana pipiens (leopard frog) tadpoles: TNT and DNAN, 96 h and 28 d; RDX, 10 d and 28 d; NTO, 28 d. The 96-h 50% lethal concentration (LC50) values and 95% confidence intervals for TNT and DNAN were 4.4 mg/L (4.2 mg/L, 4. 7 mg/L) and 24.3 mg/L (21.3 mg/L, 27.6 mg/L), respectively. No significant impacts on survival were observed in the 10-d exposure to RDX up to 25.3 mg/L. Effects on tadpole swimming distance were observed with a lowest-observed-effect concentration (LOEC) of 5.9 mg/L RDX. In the 28-d exposures, the LOECs for survival for TNT, DNAN, and NTO were 0.003 mg/L, 2.4 mg/L, and 5.0 mg/L, respectively. No significant mortality was observed in the RDX chronic 28-d exposure up to the highest treatment level tested of 28.0 mg/L. Neither tadpole developmental stage nor growth was significantly affected in any of the 28-d exposures. Rana pipiens were very sensitive to chronic TNT exposure, with an LOEC 3 orders of magnitude lower than those for insensitive munitions constituents DNAN and NTO.

  12. Influence of Nitrate and Nitrite on Thyroid Hormone Responsive and Stress-Associated Gene Expression in Cultured Rana catesbeiana Tadpole Tail Fin Tissue

    PubMed Central

    Hinther, Ashley; Edwards, Thea M.; Guillette, Louis J.; Helbing, Caren C.

    2012-01-01

    Nitrate and nitrite are common aqueous pollutants that are known to disrupt the thyroid axis. In amphibians, thyroid hormone (TH)-dependent metamorphosis is affected, although whether the effect is acceleration or deceleration of this developmental process varies from study to study. One mechanism of action of these nitrogenous compounds is through alteration of TH synthesis. However, direct target tissue effects on TH signaling are hypothesized. The present study uses the recently developed cultured tail fin biopsy (C-fin) assay to study possible direct tissue effects of nitrate and nitrite. Tail biopsies obtained from premetamorphic Rana catesbeiana tadpoles were exposed to 5 and 50 mg/L nitrate (NO3–N) and 0.5 and 5 mg/L nitrite (NO2–N) in the absence and presence of 10 nM T3. Thyroid hormone receptor β (TRβ) and Rana larval keratin type I (RLKI), both of which are TH-responsive gene transcripts, were measured using quantitative real time polymerase chain reaction. To assess cellular stress which could affect TH signaling and metamorphosis, heat shock protein 30, and catalase (CAT) transcript levels were also measured. We found that nitrate and nitrite did not significantly change the level of any of the four transcripts tested. However, nitrate exposure significantly increased the heteroscedasticity in response of TRβ and RLKI transcripts to T3. Alteration in population variation in such a way could contribute to the previously observed alterations of metamorphosis in frog tadpoles, but may not represent a major mechanism of action. PMID:22493607

  13. Los Alamos offers Fellowships

    NASA Astrophysics Data System (ADS)

    Los Alamos National Laboratory in New Mexico is calling for applications for postdoctoral appointments and research fellowships. The positions are available in geoscience as well as other scientific disciplines.The laboratory, which is operated by the University of California for the Department of Energy, awards J. Robert Oppenheimer Research Fellowships to scientists that either have or will soon complete doctoral degrees. The appointments are for two years, are renewable for a third year, and carry a stipend of $51,865 per year. Potential applicants should send a resume or employment application and a statement of research goals to Carol M. Rich, Div. 89, Human Resources Development Division, MS P290, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 by mid-November.

  14. The Los Alamos primer

    SciTech Connect

    Serber, R.

    1992-01-01

    This book contains the 1943 lecture notes of Robert Serber. Serber was a protege of J. Robert Oppenheimer and member of the team that built the first atomic bomb - reveal what the Los Alamos scientists knew, and did not know, about the terrifying weapon they were building.

  15. Los Angeles, CA.

    NASA Technical Reports Server (NTRS)

    1982-01-01

    A general view of the greater Los Angeles region of California (34,0N, 118.5W) showing the coastline, Vandenberg AFB, the south end of the Central Valley and the dry lake beds at Edwards AFB, landing site of the space shuttle.

  16. Genetic basis of phenotypic plasticity for predator-induced morphological defenses in anuran tadpole, Rana pirica, using cDNA subtraction and microarray analysis.

    PubMed

    Mori, Tsukasa; Hiraka, Ikuei; Kurata, Youichi; Kawachi, Hiroko; Kishida, Osamu; Nishimura, Kinya

    2005-05-20

    Anuran tadpoles (Rana pirica) are induced to develop a higher tail and a bulgy body as predator-specific morphological responses when they are exposed to predatory larval salamanders. Subtractive hybridization was performed using induced tadpole body skin and normal tadpoles' body skin. A total of 196 clones showed higher expression, and 104 clones showed lower expression, when they formed bulgy bodies. In the subtraction, carboxypeptidase B, trypsinogen, elastase I, fibrinogen, elastase II, triacyl-glycerol lipase, and alpha1-antitrypsin genes showed lower expression. In contrast, RT-like protein, bullous pemphigoid antigen, phosphoserine aminotransferase, uromodulin, tetranectin, chaperonin-like protein, zinc finger protein, osteonectin, aldehyde dehydrogenase, Sec 23A protein, and ribosomal protein showed higher gene expression. Microarray analysis was also performed using this subtracted cDNA (nine replicates). Results of the microarray data essentially corresponded with those of the subtraction data, and the degree of the suppressed genes was much stronger than that of the expressed genes. Carboxypeptidase B showed the strongest suppression, and its inhibition range was from 1/100 to 3/100 compared with that of control body skin. Strong suppression was also observed with trypsinogen, elastase I, fibrinogen, and elastase II as well. These results can be interpreted as increases of fibrinolysis by strong depression of both carboxypeptidase B and other genes simultaneously, resulting in the retention of blood vessels and facilitating the circulation of blood. Expression was observed in phosphoserine aminotransferase, aldehyde dehydrogenase, RT-related protein, chaperonin-like protein, tetranectin, bullous pemphigoid antigen, uromodulin, and Sec 23A protein. They were significantly (p<0.05) increased and were at least 1.5 times greater compared with the control. From the appearance, it seems that the bulgy shaped body is highly connecting to the bullous pemphigoid

  17. Variations in the expressed antimicrobial peptide repertoire of northern leopard frog (Rana pipiens) populations suggest intraspecies differences in resistance to pathogens

    PubMed Central

    Tennessen, Jacob A.; Woodhams, Douglas C.; Chaurand, Pierre; Reinert, Laura K.; Billheimer, Dean; Shyr, Yu; Caprioli, Richard M.; Blouin, Michael S.; Rollins-Smith, Louise A.

    2010-01-01

    The northern leopard frog (Rana pipiens or Lithobates pipiens) is historically found in most of the provinces of Canada and the northern and southwest states of the United States. In the last 50 years, populations have suffered significant losses, especially in the western regions of the species range. Using a peptidomics approach, we show that the pattern of expressed antimicrobial skin peptides of frogs from three geographically separated populations are distinct, and we report the presence of four peptides (brevinin-1Pg, brevinin-1Pl, ranatuerin-2Pb, and ranatuerin-2Pc) that have not previously been found in skin secretions. The differences in expressed peptides reflect differences in the distribution of alleles for the newly described Brevinin1.1 locus in the three populations. When enriched peptide mixtures were tested for their ability to inhibit growth of the pathogenic amphibian chytrid (Batrachochytrium dendrobatidis), peptides from Minnesota or Vermont frogs were more effective that peptides from Michigan frogs. Four of the purified peptides were tested for their ability to inhibit growth of two bacterial pathogens (Aeromonas hydrophila and Staphylococcus epidermidis) and B. dendrobatidis. Three of the four were effective inhibitors of B. dendrobatidis and S. epidermidis, but none inhibited A. hydrophila. We interpret these differences in expression and activity of antimicrobial peptides as evidence to suggest that each population may have been selected to express a suite of peptides that reflects current and past encounters with skin microbes. PMID:19622371

  18. Observations of Interspecific amplexus between western North American ranid frogs and the introduced American bullfrog (Rana catesbeiana) and an hypothesis concerning breeding interference

    USGS Publications Warehouse

    Pearl, Christopher A.; Hayes, M.P.; Haycock, Russ; Engler, Joseph D.; Bowerman, Jay

    2005-01-01

    Introduced American bullfrogs (Rana catesbeiana) come in contact with native amphibians on four continents and are well established in lowlands of western North America. To date, research on the effects of introduced bullfrogs on native frogs has focused on competition and predation, and is based largely on larval interactions. We present observations of interspecific amplexus between bullfrogs and two native ranid frogs (R. aurora and R. pretiosa) from six sites across the Pacific Northwest that imply that this interaction is more widespread than currently recognized. Our observations indicate that R. catesbeiana juveniles and subadults in this region are of appropriate size to elicit marked amplectic responses from males of both native species. Our literature review suggests that greater opportunity may exist for pairings between R. catesbeiana and native R. aurora or R. pretiosa than among syntopic native ranids in western North America. We hypothesize that interspecific amplexus with introduced R. catesbeiana could result in reproductive interference with negative demographic consequences in native ranid populations that have been reduced or altered by other stressors.

  19. Immunoreactivities of IL-1β and IL-1R in oviduct of Chinese brown frog (Rana dybowskii) during pre-hibernation and the breeding period.

    PubMed

    Hu, Ruiqi; Liu, Yuning; Deng, Yu; Ma, Sihui; Sheng, Xia; Weng, Qiang; Xu, Meiyu

    2016-03-01

    The Chinese brown frog (Rana dybowskii) has one special physiological phenomenon, which is that its oviduct goes through expansion prior to hibernation instead of during the breeding period. In this study, we investigated the localization and expression level of interleukin-1 (IL-1β) and its functional membrane receptor type I (IL1R1) proteins in the oviduct of R. dybowskii during pre-hibernation and the breeding period. There were significant differences in both oviductal weight and pipe diameter, with values markedly higher in pre-hibernation than in the breeding period. Histologically, epithelium cells, glandular cells and tubule lumen were identified in the oviduct during pre-hibernation and the breeding period, while sizes of both cell types are larger in the pre-hibernation than those of the breeding period. IL-1β was immunolocalized in the cytoplasm of epithelial and glandular cells in both periods, whereas IL-1R1 was observed in the membrane of epithelial and glandular cells in the breeding period, whereas only in epithelial cells during pre-hibernation. Consistently, the protein levels of IL-1β and IL-1R1 were higher in pre-hibernation as compared to the breeding period. These results suggested that IL-1β may play an important autocrine or paracrine role in oviductal cell proliferation and differentiation of R. dybowskii.

  20. European phylogeography of the common frog (Rana temporaria): routes of postglacial colonization into the British Isles, and evidence for an Irish glacial refugium.

    PubMed

    Teacher, A G F; Garner, T W J; Nichols, R A

    2009-05-01

    We use phylogenetic techniques to investigate the postglacial re-population of Europe by the common frog and, in particular, the colonization of Ireland. Three main hypotheses have been proposed for the re-establishment of the Irish fauna after the last ice age: arrival across a late-glacial land bridge from Britain; expansion from a glacial refuge in the south of Ireland and, for some species, re-introduction by humans from Iberia. We examined the phylogeographic structure of 52 populations of the common frog (Rana temporaria) throughout Europe using 476-bp mitochondrial cytochrome b gene sequences. Our data replicate earlier studies in showing substantial sequence divergence (3%) between Eastern and Western European common frog haplotypes. However, we uncover a new evidence that these haplotypes co-exist in Spain, Switzerland and France, and infer an expansion of the eastern clade along the Mediterranean coastal corridor. All the British samples fall within the Western European clade, but the Irish data imply a different history. Genetically distinct haplotypes occur in populations from the south-west of Ireland. This local genetic differentiation may be a consequence of a local glacial refuge, possibly combined with natural colonization or introduction from Western Europe. PMID:19156165

  1. Characterization of the composition of the aqueous humor and the vitreous body of the eye of the frog Rana temporaria L.

    PubMed

    Panova, Ina G; Sharova, Natalia P; Dmitrieva, Svetlana B; Levin, Peter P; Tatikolov, Alexander S

    2008-12-01

    This study aimed to analyze the aqueous humor (AH) and the vitreous body (VB) of the eye of the adult frog Rana temporaria L. as a representative species of amphibians, which lead a semi-terrestrial life. The presence of collagen, albumin, uric acid and electron donors was shown in both media; however, there are slight differences in their concentrations. To determine collagen, a spectral-fluorescent probe, cyanine dye, was used. The presence of collagen in AH of the frog was found at the first time. The total content of electron donors (ascorbic and uric acids, tryptophan, and tyrosine) in VB and HA was roughly estimated at approximately 1.5x10(-4) mol/L. Both VB and AH absorb light in similar UV regions. The total protein and albumin contents in AH were found to be somewhat higher than those in VB. The uric acid content was at an equally low level in both intraocular media. It is supposed that the similarity of VB and AH compositions shown in this work is due to some exchange between VB and AH contents in the course of accommodation. The role of intraocular fluids in physiological functions of the eye and in protecting the retina against UV light is discussed. PMID:18793742

  2. Expression of steroidogenic acute regulatory protein (StAR) in male American bullfrog (Rana catesbeiana) and preliminary evaluation of the response to TNT.

    PubMed

    Paden, Norka E; Carr, James A; Kendall, Ronald J; Wages, Mike; Smith, Ernest E

    2010-06-01

    We examined the expression of steroidogenic acute regulatory (StAR) protein mRNA in the American bullfrog (Rana catesbeiana). Primers and probes were designed to obtain a partial sequence of bullfrog StAR cDNA consisting of 349 base pairs. Quantitative PCR analysis of StAR mRNA equivalents was performed in tissues of juvenile and adult bullfrogs. In this study 18S mRNA was used as an internal standard. There were no differences in the expression of 18S RNA among tissues or between age groups. In juvenile males, the rank order for the constitutive levels of StAR was testes>skin>brain>kidneys. In adult males, StAR mRNA equivalent was greatest in testes, followed by kidneys, brain, and skin. In addition, stimulation and induction of testicular StAR by human chorionic gonadotropin significantly increased expression of StAR at 2, 4, and 6h after injection. Preliminary evaluation of 2, 4, 6-trinitrotoluene (TNT) revealed that acute exposure is associated with reduction of StAR mRNA expression. The information provided in this study will be useful for future research on StAR gene expression in amphibian reproductive biology and the development of reproductive biomarkers. PMID:20416921

  3. Comparison of diet, reproductive biology, and growth of the pig frog (Rana grylio) from harvested and protected areas of the Florida Everglades

    USGS Publications Warehouse

    Ugarte, C.A.; Rice, K.G.; Donnelly, M.A.

    2007-01-01

    Distinct differences in body size exist among three Rana grylio populations in areas of the Florida Everglades that differ in frog harvest pressure and hydroperiod. Frogs from two populations are harvested regularly throughout the year, while those in the third are protected from harvest. We compared seasonal and sex differences in diet, reproduction, and growth across these populations to examine life-history patterns. By volume, crayfish and anurans were the most abundant prey items for all adults across sites. Frogs from drier sites consumed more crayfish than frogs from the wettest site. Anurans were abundant in the diet during the wet season, while crayfish and fish were abundant during the dry season. More frogs with empty stomachs were captured during the wet season than the dry season. Feeding, growth, and fat deposition were greatest during the dry season across all sites. Although females were found in all reproductive stages throughout the year, the highest percentage of females had mature ova during the late dry season and spent ovaries during the early wet season. Individual patterns of growth were similar across all sites and matched historical growth data from the 1950s. Differences in body size among sites were most likely attributable to differential mortality (i.e., harvest pressure, predation) rather than to differences in food access or growth. ?? 2007 by the American Society of Ichthyologists and Herpetologists.

  4. Induction of cytochrome P450-associated monooxygenases in northern leopard frogs, Rana pipiens, by 3,3',4,4',5-pentachlorobiphenyl

    USGS Publications Warehouse

    Huang, Y.-W.; Melancon, M.J.; Jung, R.E.; Karasov, W.H.

    1998-01-01

    Northern leopard frogs (Rana pipiens) were injected intraperitoneally either with a solution of polychlorinated biphenyl (PCB) 126 in corn oil at a concentration of 0.2, 0.7, 2.3 and 7.8 mg/kg body weight or with corn oil alone. Appropriate assay conditions with hepatic microsomes were determined for four cytochrome P450-associated monooxygenases: ethoxyresorufin-O-dealkylase (EROD), methoxy-ROD (MROD), benzyloxy-ROD (BROD) and pentoxy-ROD (PROD). One week after PCB administration, the specific activities of EROD, MROD, BROD and PROD were not elevated at doses ? 0.7 mg/kg (p > 0.05), but were significantly increased at doses ? 2.3 mg/kg compared to the control groups (p < 0.05). The increased activity of these four enzymes ranged from 3to 6.4fold relative to control levels. The increased activities were maintained for at least four weeks. Due to a lack of induction at low doses of PCB 126, which were still relatively high compared to currentlyknown environmental concentrations, we suspect that EROD, MROD, BROD, and PROD activities are not sensitive biomarkers for coplanar PCB exposure in leopard frogs.

  5. An integrative study of the temperature dependence of whole animal and muscle performance during jumping and swimming in the frog Rana temporaria.

    PubMed

    Navas, C A; James, R S; Wakeling, J M; Kemp, K M; Johnston, I A

    1999-12-01

    The aims of this study were: (1) to analyze individual variation in frog locomotor performance, (2) to compare the thermal sensitivity of jumping and swimming, and (3) to contrast whole animal versus muscle fiber performance at different temperatures. The jumping and swimming performance of Rana temporaria was analyzed at 5, 10, 15 and 20 degrees C. Muscle fiber bundles were isolated from lateral gastrocnemius and subjected to the length and activation patterns thought to occur in vivo. As temperature increased, locomotor performance in R. temporaria improved with a Q10 of 1.2 for both jump take-off velocity and mean swimming velocity. The slope of the relationship between performance and temperature (TE) was similar for both locomotor parameters and was described by the equation z-scores of locomotor performance = 0.127 x TE - 1.585. Although some frogs performed better than others relative performance was affected by locomotor type and temperature. Locomotor performance improved with temperature as the power required during take-off and the mean muscle power output increased with Q10 values of 1.7 and 1.6 respectively. The mean muscle power output during take-off was only 34% of the calculated requirements for the whole animal, suggesting the involvement of elastic strain energy storage mechanisms.

  6. Analysis of skin and secretions of Dybowski's frogs (Rana dybowskii) exposed to Staphylococcus aureus or Escherichia coli identifies immune response proteins.

    PubMed

    Xiao, Xiang-Hong; Miao, Hui-Min; Xu, Yi-Gang; Zhang, Jing-Yu; Chai, Long-Hui; Xu, Jia-Jia

    2014-04-01

    The aim of the present study was to investigate responses in Dybowski's frogs (Rana dybowskii) exposed to bacteria, using proteomic and transcriptomic approaches. Staphylococcus aureus and Escherichia coli were used as representative Gram-positive and Gram-negative bacteria, respectively, in an infectious challenge model. Frog skin and skin secretions were collected and protein expression in infected frogs compared to control frogs by two-dimensional gel electrophoresis, silver staining, and image analysis. Proteins that demonstrated differential expression were analysed by mass spectrometry and identified by searching protein databases. More than 180 protein spots demonstrated differential expression in E. coli- or S. aureus-challenged groups and, of these, more than 55 spots were up- or down-regulated at least sixfold, post-infection. Proteins with a potential function in the immune response were identified, such as stathmin 1a, annexin A1, superoxide dismutase A, C-type lectin, lysozyme, antimicrobial peptides, cofilin-1-B, mannose receptor, histone H4, prohormone convertase 1, carbonyl reductase 1 and some components of the Toll-like receptor (TLR) signalling pathway. These molecules are potential candidates for further investigation of immune mechanisms in R. dybowskii; in particular, TLR-mediated responses, which might be activated in frogs exposed to pathogenic bacteria as part of innate immune defence, but which might also impact on adaptive immunity to infection.

  7. Characterization of the Rana grylio virus 3{beta}-hydroxysteroid dehydrogenase and its novel role in suppressing virus-induced cytopathic effect

    SciTech Connect

    Sun Wei; Huang Youhua; Zhao Zhe; Gui Jianfang; Zhang Qiya . E-mail: zhangqy@ihb.ac.cn

    2006-12-08

    The 3{beta}-hydroxysteroid dehydrogenase (3{beta}-HSD) isoenzymes play a key role in cellular steroid hormone synthesis. Here, a 3{beta}-HSD gene homolog was cloned from Rana grylio virus (RGV), a member of family Iridoviridae. RGV 3{beta}-HSD gene has 1068 bp, encoding a 355 aa predicted protein. Transcription analyses showed that RGV 3{beta}-HSD gene was transcribed immediate-early during infection from an initiation site 19 nucleotides upstream of the translation start site. Confocal microscopy revealed that the 3{beta}-HSD-EGFP fusion protein was exclusively colocalized with the mitochondria marker (pDsRed2-Mito) in EPC cells. Upon morphological observation and MTT assay, it was revealed that overexpression of RGV 3{beta}-HSD in EPC cells could apparently suppress RGV-induced cytopathic effect (CPE). The present studies indicate that the RGV immediate-early 3{beta}-HSD gene encodes a mitochondria-localized protein, which has a novel role in suppressing virus-induced CPE. All these suggest that RGV 3{beta}-HSD might be a protein involved in host-virus interaction.

  8. Rangewide phylogeography and landscape genetics of the Western U.S. endemic frog Rana boylii (Ranidae): Implications for the conservation of frogs and rivers

    USGS Publications Warehouse

    Lind, A.J.; Spinks, P.Q.; Fellers, G.M.; Shaffer, H.B.

    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 and ND2 fragments for 77 individuals from 34 localities using phylogenetic and population genetic analyses. We constructed gene trees using maximum likelihood and Bayesian inference, and quantified genetic variance (using AMOVA and partial Mantel tests) within and among hydrologic regions and river basins. Several moderately supported, geographically-cohesive mtDNA clades were recovered for R. boylii. While genetic variation was low among populations in the largest, most inclusive clade, samples from localities at the edges of the geographic range demonstrated substantial genetic divergence from each other and from more central populations. Hydrologic regions and river basins, which represent likely dispersal corridors for R. boylii, accounted for significant levels of genetic variation. These results suggest that both rivers and larger hydrologic and geographic regions should be used in conservation planning for R. boylii. ?? 2010 US Government.

  9. Induction of cytochrome P450-associated monooxygenases in northern leopard frogs, Rana pipiens, by 3,3{prime},4,4{prime},5-pentachlorobiphenyl

    SciTech Connect

    Huang, Y.; Jung, R.E.; Karasov, W.H.; Melancon, M.J.

    1998-08-01

    In the past decade, biochemical and physiological characteristics such as hepatic detoxifying system. DNA adducts, thyroid malfunction, and acetylcholinesterase inhibition have been used extensively as biomarkers for contaminant exposure. Northern leopard frogs (Rana pipiens) were injected intraperitoneally either with a solution of polychlorinated biphenyl (PCB) 126 m corn oil at a concentration of 0.2, 0.7, 2.3, or 7.8 mg/kg body weight or with corn oil alone. Appropriate assay conditions with hepatic microsomes were determined for four cytochrome P450-associated monooxygenases: ethoxyresorufin-O-dealkylase (EROD), methoxy-ROD (MROD), benzyloxy-ROD (BROD), and pentoxy-ROD (PROD). One week after PCB administration, the specific activities of EROD, MROD, BROD, and PROD were not elevated at doses {le}0.7 mg/kg (p > 0.05) but were significantly increased at doses {ge}2.3 mg/kg compared to the control groups (p < 0.05). The increased activities of these four enzymes were 3 to 6.4 times those in the control groups. The increased activities were maintained for at least 4 weeks. Because of a lack of induction at low doses of PCB 126, which were still relatively high compared to currently known environmental concentration, the authors suspect that EROD, MROD, BROD, and PROD activities are not sensitive biomarkers for coplanar PCB exposure in leopard frogs.

  10. Immunocytochemical localization of a non-vitellogenin, estrogen-induced plasma protein in the hepatocyte of the American bullfrog, Rana catesbeiana.

    PubMed

    Herbener, G H; Bendayan, M; Feldhoff, R C

    1985-11-01

    Recently, a non-vitellogenin, estrogen-induced frog plasma protein of unknown function and site of synthesis, which has been given the temporary name, protein-RcX, was isolated and partially characterized by Mitchell et al. In the present study, the protein A-gold immunocytochemical technique was applied to investigate its site of secretion; this was found to be the hepatocyte of the estradiol-17 beta-treated adult, male American bullfrog, Rana catesbeiana. Specific immunolabeling for protein-RcX was present over those intracellular compartments involved in protein secretion, i.e., the rough endoplasmic reticulum, Golgi apparatus and secretory granules, in addition, lysosomes were also labeled. No specific labeling for this protein was observed on hepatocytes of normal, non-estrogen treated, adult, male bullfrogs. Further, the labeling was abolished when plasma containing protein-RcX was added to the antibody prior to incubation but remained when purified vitellogenin was added. These observations support the hypothesis that protein-RcX is a non-vitellogenin, estrogen-induced plasma protein which is synthesized and secreted in parallel with vitellogenin by the hepatocyte of the estrogen-treated frog.

  11. Localization and changes in distribution of brain alpha 2- and beta-adrenoceptors in response to acclimation state in the American bullfrog (Rana catesbeiana).

    PubMed

    Bachman, G L; Uhlén, S; Herman, C A

    1998-05-01

    Alpha (alpha)- and beta (beta)-adrenoceptors regulate physiological processes in vertebrates. This study determined the location of alpha 2- and beta-adrenoceptors in the brain of the American bullfrog, Rana catesbeiana, using autoradiography. As the density of receptors may be affected by environmental temperature, a comparative numerical analysis of adrenoceptors in the areas of localization with respect to warm and cold acclimation was also carried out. Areas of greatest concentration of alpha 2-adrenoceptors were the accessory olfactory bulb, medial pallium, and olfactory bulb. Adrenoceptor numbers were significantly decreased in the accessory olfactory bulb and medial pallium in cold-acclimated animals. beta-adrenoceptors were localized in the thalamus, cerebellum, medial pallium, and amygdala/ striatum. Cold acclimation decreased adrenoceptor density in medial pallium and torus semicircularis and increased adrenoceptor density in the thalamus and hypothalamic preoptic areas. Among the alpha 2- and beta-adrenoceptors, only four regions of overlap existed, the medial pallium, hypothalamic preoptic area, optic tract, and isthmic tegmentum. Otherwise, where there were alpha 2-adrenoceptors, there were few or no beta-adrenoceptors. No alpha 2- or beta-adrenoceptors were found in the pituitary and optic chiasm. The distribution of adrenoceptors in particular areas of the brain may have functional significance with respect to physiological changes which occur in response to hibernation.

  12. 3,3',5-Triiodothyronine-induced differences in water-insoluble protein synthesis in primary epidermal cell cultures from the hind limb of premetamorphic Rana catesbeiana tadpoles.

    PubMed

    Ketola-Pirie, C A; Atkinson, B G

    1988-02-01

    Epidermal cells from the hind limb of premetamorphic tadpoles of the American bullfrog Rana catesbeiana (stages IX-XI) were maintained in primary culture for 120 hr. Cultures, maintained for 36 hr in medium supplemented with L-triiodothyronine (T3; 3 x 10(-10) mol T3/ml medium), synthesize water-insoluble proteins with Mrs of 59, 50, 48, and 43. The 59 and 48 kDa proteins synthesized by T3-supplemented cultures are not detectably synthesized by 36-hr-old cell cultures without added T3, but they are synthesized by both hormone-supplemented and unsupplemented cultures after 120 hr. These two proteins have Mrs and pIs which correspond with keratins detected in stratifying mammalian epidermis and are immunoprecipitated by antibodies prepared against human keratins. These observations indicate that T3 induces epidermal cell cultures from the hind limb of premetamorphic tadpoles to precociously synthesize water-insoluble proteins which (1) have Mrs and pIs similar to keratins from differentiating amphibian epidermal tissue and (2) are biochemically and immunologically similar to keratins associated with the differentiation of mammalian epidermal tissue.

  13. Expression of steroidogenic acute regulatory protein (StAR) in male American bullfrog (Rana catesbeiana) and preliminary evaluation of the response to TNT.

    PubMed

    Paden, Norka E; Carr, James A; Kendall, Ronald J; Wages, Mike; Smith, Ernest E

    2010-06-01

    We examined the expression of steroidogenic acute regulatory (StAR) protein mRNA in the American bullfrog (Rana catesbeiana). Primers and probes were designed to obtain a partial sequence of bullfrog StAR cDNA consisting of 349 base pairs. Quantitative PCR analysis of StAR mRNA equivalents was performed in tissues of juvenile and adult bullfrogs. In this study 18S mRNA was used as an internal standard. There were no differences in the expression of 18S RNA among tissues or between age groups. In juvenile males, the rank order for the constitutive levels of StAR was testes>skin>brain>kidneys. In adult males, StAR mRNA equivalent was greatest in testes, followed by kidneys, brain, and skin. In addition, stimulation and induction of testicular StAR by human chorionic gonadotropin significantly increased expression of StAR at 2, 4, and 6h after injection. Preliminary evaluation of 2, 4, 6-trinitrotoluene (TNT) revealed that acute exposure is associated with reduction of StAR mRNA expression. The information provided in this study will be useful for future research on StAR gene expression in amphibian reproductive biology and the development of reproductive biomarkers.

  14. Assessment of heavy metals and metalloids in tissues of two frog species: Rana tigrina and Euphlyctis cyanophlyctis from industrial city Sialkot, Pakistan.

    PubMed

    Qureshi, Irfan Zia; Kashif, Zeshan; Hashmi, Muhammad Zaffar; Su, Xiaomei; Malik, Riffat Naseem; Ullah, Kalim; Hu, Jinxing; Dawood, Muhammad

    2015-09-01

    In the present study, we investigated the concentrations of Ni, Fe, Pb, Cu, Co, Zn, Cd, Mn, and Cr in selected body tissues (liver, stomach, kidney, heart, lungs, and skeletal muscles) of two frog species: Rana tigrina and Euphlyctis cyanophlyctis captured from industrial wastewater of Sialkot city known worldwide for its tanning industry. The both frog species had darker appearance, distinctively different wet body weight, and snout-vent length. The results revealed that the heavy metal concentrations were high in the samples collected from industrial sites as compared to non-industrial sites. The different tissues of R. tigrina and E. cyanophlyctis exhibited little significant differences from two sites. The concentrations of heavy metals were more in tissues of R. tigrina as compared to E. cyanophlyctis. Mean concentration of Cd, Fe, Ni, Mn, Cu, and Cr was comparatively greater in R. tigrina, whereas Pb and Co were higher in E. cyanophlyctis. The concentration of Cu and Cd in the liver and kidney were relatively more in both species as compared to other organs. Further, the results indicated that frogs collected from industrial sites showed decreased body length and weight, and greater metal accumulation. The results will help the authorities for the conservation of these frog species which are under the influence of heavy metal contamination.

  15. Bioaccumulation kinetics of the conventional energetics TNT and RDX relative to insensitive munitions constituents DNAN and NTO in Rana pipiens tadpoles.

    PubMed

    Lotufo, Guilherme R; Biedenbach, James M; Sims, Jerre G; Chappell, Pornsawan; Stanley, Jacob K; Gust, Kurt A

    2015-04-01

    The manufacturing of explosives and their loading, assembling, and packing into munitions for use in testing on training sites or battlefields has resulted in contamination of terrestrial and aquatic sites that may pose risk to populations of sensitive species. The bioaccumulative potential of the conventional explosives 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and of the insensitive munitions (i.e., less shock sensitive) compound 2,4-dinitroanisole (DNAN) were assessed using the Northern leopard frog, Rana pipiens. Trinitrotoluene entering the organism was readily biotransformed to aminodinitrotoluenes, whereas no transformation products were measured for RDX or DNAN. Uptake clearance rates were relatively slow and similar among compounds (1.32-2.19 L kg(-1) h(-1) ). Upon transfer to uncontaminated water, elimination rate was very fast, resulting in the prediction of fast time to approach steady state (5 h or less) and short elimination half-lives (1.2 h or less). A preliminary bioconcentration factor of 0.25 L kg(-1) was determined for the insensitive munitions compound 3-nitro-1,2,4-trizole-5-one (NTO) indicating negligible bioaccumulative potential. Because of the rapid elimination rate for explosives, tadpoles inhabiting contaminated areas are expected to experience harmful effects only if under constant exposure conditions given that body burdens can rapidly depurate preventing tissue concentrations from persisting at levels that may cause detrimental biological effects.

  16. Liver microsomes from the yellow rat snake (Elaphe obsoleta) and American bullfrog (Rana catesbeiana) oxidize polyunsaturated fatty acids by NADPH-dependent hydroxylation and epoxidation.

    PubMed

    Herman, C A; Oliw, E H

    1998-01-01

    Polyunsaturated fatty acids (PUFAs) can be oxygenated by mammalian hepatic P450s to a series of metabolites. The most prominent of these are formed by omega- and (omega-1)-hydroxylation, epoxidation of the double bonds or bisallylic hydroxylation. The object of the present investigation was to determine whether similar oxygenations are catalyzed by liver microsomes of the yellow rat snake (Elaphe obsoleta) and the American bullfrog (Rana catesbeiana). Liver microsomes were incubated with [1-14C]-labeled arachidonic (AA), eicosapentaenoic (EPA), and linoleic acids (LA) in the presence or absence of 1 mM NADPH, and the major metabolites were analyzed by reverse-phase and straight-phase high performance liquid chromatography and capillary gas chromatography-mass spectroscopy. No metabolites were produced in the absence of NADPH. Profiles of metabolites were different depending on the organism and the acclimation state. In all incubations, EPA was the most effective substrate utilized and LA the least effective. The major products from EPA were 19-HEPE, 13-HEPE, and 20-HEPE from cold-acclimated (5 degrees C), warm-acclimated (22 degrees C) frogs, and snakes (22 degrees C), respectively. In contrast, 20-HETE production from AA was greater than 19-HETE in all three. Cold-acclimated frog liver microsomes produced significantly more of all metabolites when compared with microsomes from warm-acclimated frogs. We conclude that amphibian and snake liver can catalyze epoxidation and hydroxylation of PUFAs and that products are species-specific and acclimation-state dependent.

  17. An X-linked body color gene of the frog Rana rugosa and its application to the molecular analysis of gonadal sex differentiation.

    PubMed

    Miura, I; Kitamoto, H; Koizumi, Y; Ogata, M; Sasaki, K

    2011-01-01

    We identified a sex-linked, recessive body color gene, presently designated w (whitish-yellow), in the frog Rana rugosa from the Iwakuni population in Western Japan. This is the first time a sex-linked body color gene was found in amphibians so far. In this population of R. rugosa, males are the heterogametic sex, but the sex chromosomes are still homomorphic. When heterozygous males (Ww), which were produced by crossing a whitish-yellow female (ww) found in the field and a wild-type male (WW) of the same population, were backcrossed to the homozygous whitish-yellow female (ww), the resultant male offspring were all wild-type, whereas the females were all whitish-yellow. This result definitely indicates that w is recessive and X-linked, and its wild-type allele W is located on the Y chromosome. Using this strain (X(w)X(w) female and X(w)Y(W) male), we found that expression of Dmrt1 and Rspo1, which are involved in testicular and ovarian differentiation in vertebrates, was higher in males and females, respectively, prior to the onset of the sexually dimorphic expression of Cyp17 and Cyp19, which are involved in biosynthesis of sex steroids and are critical markers of gonadal sex differentiation.

  18. Quantifying the disease transmission function: effects of density on Batrachochytrium dendrobatidis transmission in the mountain yellow-legged frog Rana muscosa.

    PubMed

    Rachowicz, Lara J; Briggs, Cheryl J

    2007-07-01

    1. Chytridiomycosis is an emerging infectious disease of amphibians, caused by the fungal pathogen Batrachochytrium dendrobatidis, which has been implicated recently in population declines and possible extinctions throughout the world. 2. The transmission rate of this pathogen was quantified in the mountain yellow-legged frog Rana muscosa through laboratory and field experiments, and a maximum likelihood approach was used to determine the form of the transmission function that was best supported by the experimental data. 3. The proportion of R. muscosa tadpole hosts that became infected increased with the number of previously infected R. muscosa tadpoles to which they were exposed, as would be expected in an infectious disease. 4. The laboratory experiment revealed some support for a transmission function in which the transmission rate levels off as the density of infected individuals increases. However, there was not enough power to distinguish between a frequency-dependent form and several other asymptotic forms of the transmission function. 5. The impacts of crowding and temperature on transmission were also investigated; however, neither of these factors significantly affected the transmission rate.

  19. Isolation of peptides of the brevinin-1 family with potent candidacidal activity from the skin secretions of the frog Rana boylii.

    PubMed

    Conlon, J M; Sonnevend, A; Patel, M; Davidson, C; Nielsen, P F; Pál, T; Rollins-Smith, L A

    2003-11-01

    The emergence of strains of the human pathogen Candida albicans with resistance to commonly used antibiotics has necessitated a search for new types of antifungal agents. Six peptides with antimicrobial activity were isolated from norepinephrine-stimulated skin secretions from the foothill yellow-legged frog Rana boylii. Brevinin-1BYa (FLPILASLAA10KFGPKLF CLV20TKKC) was particularly potent against C. albicans [minimal inhibitory concentration (MIC) = 3 microm] and also active against Escherichia coli (MIC = 17 microm) and Staphylococcus aureus (MIC = 2 microm), but its therapeutic potential for systemic use is limited by its strong hemolytic activity (HC50 = 4 microm). The single amino acid substitution (Phe12 --> Leu) in brevinin-1BYb resulted in a fourfold lower potency against C. albicans and the additional amino acid substitutions (Lys11 --> Thr, Phe17 --> Leu and Val20 --> Ile) in brevinin-1BYc resulted in a ninefold decrease in activity. Two members of the ranatuerin-2 family and one member of the temporin family were also isolated from the secretions but showed relatively low potency against the three microorganisms tested.

  20. Density-dependent growth and metamorphosis in the larval bronze frog Rana temporalis is influenced by genetic relatedness of the cohort.

    PubMed

    Girish, S; Saidapur, S K

    2003-06-01

    Effects of density and kinship on growth and metamorphosis in tadpoles of Rana temporalis were studied in a 2 4 factorial experiment. Fifteen egg masses were collected from streams in the Western Ghat region of south India. The tadpoles were raised as siblings or in groups of non-siblings at increasing density levels, viz. 15, 30, 60 and 120/5 l water. With an increase in density level from 15 to 120 tadpoles/5 l water, duration of the larval stage increased and fewer individuals metamorphosed irrespective of whether they belonged to sibling or non-sibling groups by day 100 when the experiments were terminated. The size of individuals at metamorphosis declined significantly with increase in the density of rearing. However, at higher densities (60 and 120 tadpoles/5 l water) sibling group tadpoles performed better compared to mixed groups and took significantly less time to metamorphose. Also, more individuals of sibling groups metamorphosed compared to non-sibling groups at a given density. Mixed rearing retarded growth rates, prolonged larval duration resulting in a wider spectrum of size classes, and lowered the number of individuals recruited to terrestrial life. The study shows that interference competition occurred more strongly in cohorts of mixed relatedness than in sibling groups.

  1. Adaptive divergence in moor frog (Rana arvalis) populations along an acidification gradient: inferences from Q(st) -F(st) correlations.

    PubMed

    Hangartner, Sandra; Laurila, Anssi; Räsänen, Katja

    2012-03-01

    Microevolutionary responses to spatial variation in the environment seem ubiquitous, but the relative role of selection and neutral processes in driving phenotypic diversification remain often unknown. The moor frog (Rana arvalis) shows strong phenotypic divergence along an acidification gradient in Sweden. We here used correlations among population pairwise estimates of quantitative trait (P(ST) or Q(ST) from common garden estimates of embryonic acid tolerance and larval life-history traits) and neutral genetic divergence (F(ST) from neutral microsatellite markers), as well as environmental differences (pond pH, predator density, and latitude), to test whether this phenotypic divergence is more likely due to divergent selection or neutral processes. We found that trait divergence was more strongly correlated with environmental differences than the neutral marker divergence, suggesting that divergent natural selection has driven phenotypic divergence along the acidification gradient. Moreover, pairwise P(ST) s of embryonic acid tolerance and Q(ST) s of metamorphic size were strongly correlated with breeding pond pH, whereas pairwise Q(ST) s of larval period and growth rate were more strongly correlated with geographic distance/latitude and predator density, respectively. We suggest that incorporating measurements of environmental variation into Q(ST) -F(ST) studies can improve our inferential power about the agents of natural selection in natural populations.

  2. River islands, refugia and genetic structuring in the endemic brown frog Rana kukunoris (Anura, Ranidae) of the Qinghai-Tibetan Plateau.

    PubMed

    Zhou, Weiwei; Yan, Fang; Fu, Jinzhong; Wu, Shifang; Murphy, Robert W; Che, Jing; Zhang, Yaping

    2013-01-01

    Frequently, Pleistocene climatic cycling has been found to be the diver of genetic structuring in populations, even in areas that did not have continental ice sheets, such as on the Qinghai-Tibetan Plateau (QTP). Typically, species distributed on the plateau have been hypothesized to re-treat to south-eastern refugia, especially during the Last Glacial Maximum (LGM). We evaluated sequence variation in the mitochondrial DNA gene Cytb and the nuclear DNA gene RAG-1 in Rana kukunoris, a species endemic to the QTP. Two major lineages, N and S, were identified, and lineage N was further subdivided into N1 and N2. The geographical distribution and genealogical divergences supported the hypothesis of multiple refugia. However, major lineages and sublineages diverged prior to the LGM. Demographical expansion was detected only in lineage S and sublineage N2. Sublineage N1 might have survived several glacial cycles in situ and did not expand after the LGM because of the absence of suitable habitat; it survived in river islands. Genetic analysis and environment modelling suggested that the north-eastern edge of QTP contained a major refugium for R. kukunoris. From here, lineage S dispersed southwards after the LGM. Two microrefugia in northern Qilian Mountains greatly contributed to current level of intraspecific genetic diversity. These results were found to have important implications for the habitat conservation in Northwest China.

  3. Exposure to coal combustion residues during metamorphosis elevates corticosterone content and adversely affects oral morphology, growth, and development in Rana sphenocephala

    SciTech Connect

    Peterson, J.D.; Peterson, V.A.; Mendonca, M.T.

    2009-01-15

    Coal combustion residues (CCRs) are documented to negatively impact oral morphology, growth, and development in larval amphibians. It is currently unclear what physiological mechanisms may mediate these effects. Corticosterone, a glucocorticoid hormone, is a likely mediator because when administered exogenously it, like CCRs, also negatively influences oral morphology, growth, and development in larval amphibians. In an attempt to identify if corticosterone mediates these effects, we raised larval Southern Leopard Frogs, Rana sphenocephala, on either sand or CCR substrate and documented effects of sediment type on whole body corticosterone, oral morphology, and time to and mass at key metamorphic stages. Coal combustion residue treated tadpoles contained significantly more corticosterone than controls throughout metamorphosis. However, significantly more oral abnormalities occurred early in metamorphosis when differences in corticosterone levels between treatments were minimal. Overall, CCR-treated tadpoles took significantly more time to transition between key stages and gained less mass between stages than controls, but these differences between treatments decreased during later stages when corticosterone differences between treatments were greatest. Our results suggest endogenous increase in corticosterone content and its influence on oral morphology, growth and development is more complex than previously thought.

  4. Relationships between seasonal thermal variations and cell proliferation in heterothermic vertebrates, as revealed by PCNA expression in the brain of adult Rana bergeri (Günther, 1986).

    PubMed

    Margotta, Vito

    2012-01-01

    The cyclic variations of temperature with seasons, which are accompanied by variations in photoperiod, can activate proliferation in stem cells which survive in various organs and tissues of adult vertebrates, both poikilo- (aquatic and terrestrial) and homeothermic (male songbirds and Mammals). In the brain of these organisms such stem cells are mainly placed in the ependymal and/or sub-ependymal layers. To assess the influence of environmental temperature on the proliferative activity of those cells, an immunocytochemical investigation has been carried out on the brain of normal adult Rana bergeri, taken from the wild in late autumn and immediately submitted to observation. The results were compared with those of previous investigations on the same animal species, caught in their habitat in late autumn as in this study, but housed in standard laboratory environment for several days before beginning the experiments. I have now observed a widespread reduction in proliferation. This finding discordance is reasonably imputable to the former stay of the specimens in a thermostable environment during the previous investigations and appears in agreement with what is known from the literature for comparable experimental conditions, suggesting that a stay for days in a thermally stable, warm environment can counteract the anti-proliferative effect of exposition to the late autumn climate.

  5. Assessment of heavy metals and metalloids in tissues of two frog species: Rana tigrina and Euphlyctis cyanophlyctis from industrial city Sialkot, Pakistan.

    PubMed

    Qureshi, Irfan Zia; Kashif, Zeshan; Hashmi, Muhammad Zaffar; Su, Xiaomei; Malik, Riffat Naseem; Ullah, Kalim; Hu, Jinxing; Dawood, Muhammad

    2015-09-01

    In the present study, we investigated the concentrations of Ni, Fe, Pb, Cu, Co, Zn, Cd, Mn, and Cr in selected body tissues (liver, stomach, kidney, heart, lungs, and skeletal muscles) of two frog species: Rana tigrina and Euphlyctis cyanophlyctis captured from industrial wastewater of Sialkot city known worldwide for its tanning industry. The both frog species had darker appearance, distinctively different wet body weight, and snout-vent length. The results revealed that the heavy metal concentrations were high in the samples collected from industrial sites as compared to non-industrial sites. The different tissues of R. tigrina and E. cyanophlyctis exhibited little significant differences from two sites. The concentrations of heavy metals were more in tissues of R. tigrina as compared to E. cyanophlyctis. Mean concentration of Cd, Fe, Ni, Mn, Cu, and Cr was comparatively greater in R. tigrina, whereas Pb and Co were higher in E. cyanophlyctis. The concentration of Cu and Cd in the liver and kidney were relatively more in both species as compared to other organs. Further, the results indicated that frogs collected from industrial sites showed decreased body length and weight, and greater metal accumulation. The results will help the authorities for the conservation of these frog species which are under the influence of heavy metal contamination. PMID:25966879

  6. The absence of the long 3'-non-translated region in mRNA coding for eye lens alpha A2-crystallin of the frog (Rana temporaria).

    PubMed

    Tomarev, S I; Zinovieva, R D; Dolgilevich, S M; Krayev, A S; Skryabin, K G; Gause, G G

    1983-10-01

    The nucleotide sequence of a cloned cDNA (clone pRt(1)297; GENE (1982) 17, 131) coding for a 18 kDa polypeptide of the frog eye lens has been determined. The sequence, 791 nucleotide in length has only one long open reading frame (447 nucleotides). The derived amino acid sequence in this frame has greater than 90% homology with the region 25-173 of alpha A2-crystallin amino acid sequence from a related frog species Rana pipiens. The 5'-terminal part of mRNA corresponding to the first 24 amino acids of alpha A2-crystallin has been lost in cloning and substituted by an artefactual sequence. The 3'-terminal part appears to be intact as follows from the presence of the universal poly(A) addition site and poly(A) tract. The 3'-nontranslated region present in frog alpha A2-crystallin mRNA (130 nucleotides) is about 4-times shorter than in mammalian alpha A2-crystallin mRNA. Intact alpha A2-crystallin mRNA with a size of about 700 nucleotides as determined by Northern blot hybridization is about twice smaller than corresponding mammalian mRNAs.

  7. Ameliorative effects of sodium chloride on acute copper toxicity among Cope's gray tree frog (Hyla chrysoscelis) and green frog (Rana clamitans) embryos.

    PubMed

    Brown, Maria G; Dobbs, Emily K; Snodgrass, Joel W; Ownby, David R

    2012-04-01

    Urban stormwater runoff is composed of a mixture of components, including polycyclic aromatic hydrocarbons, metals, deicing agents, and many others. The fate of these chemicals is often in stormwater detention ponds that are used by amphibians for breeding. Among aquatic organisms, the toxic mechanism for many metals involves interference with active Na(+) and Cl(-) uptake. Addition of cations has been shown to reduce the toxicity of metals among some aquatic organisms through competitive inhibition, but no studies have investigated the interaction between NaCl and Cu among amphibian embryos and larvae. To determine the degree to which NaCl may ameliorate the toxicity of Cu to amphibian embryos and larvae, the authors exposed Hyla chrysoscelis (Cope's gray treefrogs) and Rana (Lithobates) clamitans (green frogs) to seven levels of Cu and NaCl in fully factorial experiments. When exposure was in artificial hard water, Cu was highly toxic to both species (96-h median lethal concentration [LC50] of 44.7 µg/L and 162.6 µg/L for H. chrysoscelis and R. clamitans, respectively). However, approximately 500 mg/L of NaCl eliminated Cu toxicity over the range of Cu concentrations used in the experiments (maximum 150 µg Cu/L for H. chrysoscelis and 325 µg Cu/L for R. clamitans). The current results suggest that NaCl is likely responsible for the toxic effects of NaCl and metal mixtures that might be typical of runoff from road surfaces in northern latitudes.

  8. Los Angeles, CA, USA

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This rare cloud and smog free view of Los Angeles, CA (34.0N, 118.5W) is a result of strong Santa Ana winds blowing from the east. Both cultural and natural features are well displayed and all of the major streets, highways and freeways can be traced in their entirety throughout the city as well as the major business and commercial sections. On the eastern edge of the scene, the San Andreas fault cuts across from southeast to northwest.

  9. The crab-eating frog, Rana cancrivora, up-regulates hepatic carbamoyl phosphate synthetase I activity and tissue osmolyte levels in response to increased salinity.

    PubMed

    Wright, Patricia; Anderson, Paul; Weng, Lei; Frick, Natasha; Wong, Wei Peng; Ip, Yuen Kwong

    2004-07-01

    The crab-eating frog Rana cancrivora is one of only a handful of amphibians worldwide that tolerate saline waters. They typically inhabit brackish water of mangrove forests of Southeast Asia, but live happily in freshwater and can be acclimated to 75% seawater (25 ppt) or higher. We report here that after transfer of juvenile R. cancrivora from freshwater (1 ppt) to brackish water (10 -->20 or 20 -->25 ppt; 4-8 d) there was a significant increase in the specific activity of the key hepatic ornithine urea cycle enzyme (OUC), carbamoyl phosphate synthetase I (CPSase I). At 20 ppt, plasma, liver and muscle urea levels increased by 22-, 21-, and 11-fold, respectively. As well, muscle total amino acid levels were significantly elevated by 6-fold, with the largest changes occurring in glycine and beta-alanine levels. In liver, taurine levels were 5-fold higher in frogs acclimated to 20 ppt. There were no significant changes in urea or ammonia excretion rates to the environment. As well, the rate of urea influx (J(in) (urea)) and efflux (J(out) (urea)) across the ventral pelvic skin did not differ between frogs acclimated to 1 versus 20 ppt. Taken together, these findings suggest that acclimation to saline water involves the up-regulation of hepatic urea synthesis, which in turn contributes to the dramatic rise in tissue urea levels. The lack of change in urea excretion rates, despite the large increase in tissue-to-water gradients further indicates that mechanisms must be in place to prevent excessive loss of urea in saline waters, but these mechanisms do not include cutaneous urea uptake. Also, amino acid accumulation may contribute to an overall rise in the osmolarity of the muscle tissue, but relative to urea, the contribution is small. PMID:15229866

  10. Steroid-induced changes in the morphology of GnRH neurons in the male leopard frog, Rana pipiens: correlation with plasma gonadotropin and gonadal size.

    PubMed

    Tsai, Pei-San; Jones, Jeremy T

    2005-04-01

    Previously, we reported that hypothalamic explants isolated from male leopard frogs (Rana pipiens) implanted with 17beta-estradiol (E2), but not 5alpha-dihydrotestosterone (DHT), released significantly higher levels of gonadotropin-releasing hormone (GnRH) in response to a veratridine challenge. In this study, we measured changes in GnRH soma size, circulating luteinizing hormone (LH), and gonadosomatic index (GSI) in response to these two steroid hormones to further assess the impact of these hormones on the hypothalamic-pituitary-gonadal axis. Sexually mature male R. pipiens were implanted with silastic capsules containing cholesterol (Ch; control), E2, or DHT for 20 days. GnRH immunocytochemistry (ICC) revealed that both E2 and DHT significantly enlarged GnRH soma size without affecting the total number of GnRH neurons in the forebrain. The effects of E2 and DHT were specific, since neither hormone altered the soma size of tyrosine hydroxylase neurons in the dorsomedial posterior tuberculum. Circulating LH levels were significantly reduced in animals treated with both steroid hormones, with E2 exerting the most potent inhibitory effect. A significant inverse correlation was observed between the GSI and GnRH soma size in Ch controls, suggesting animals with larger GnRH neurons tended to have smaller gonads. Overall, our results showed that both steroid hormones induced the accumulation of GnRH and ultimately the swelling of the GnRH soma. Further, larger GnRH neurons were associated with smaller gonads and lower circulating levels of LH, suggesting a link between enlarged GnRH neurons and an overall decrease in the reproductive activity of R. pipiens.

  11. Effects of dibutyl phthalate as an environmental endocrine disruptor on gonadal sex differentiation of genetic males of the frog Rana rugosa.

    PubMed Central

    Ohtani, H; Miura, I; Ichikawa, Y

    2000-01-01

    To examine the effects of dibutyl phthalate (DBP) on gonadal sex differentiation, genetically male tadpoles of Rana rugosa were exposed to dilute solutions of DBP at concentrations of 0.1, 1, or 10 microM during days 19-23 after fertilization, which is the critical period of gonadal sex differentiation in R. rugosa. Tadpoles were necropsied on day 40. The genetically male tadpoles were produced from crossings between males (ZZ) of one local population, in which females are the heterogametic sex, and females (XX) of another local population, in which males are the heterogametic sex. As positive control groups, tadpoles were exposed to dilute solutions of 17beta-estradiol (E(2)) at concentrations of 0. 01, 0.1, or 1 microM during the same period. The internal structure of the gonads was histologically examined in a total of 30 control tadpoles, 86 E(2)-treated tadpoles, and 90 DBP-treated tadpoles. The gonads of the control tadpoles all showed the typical structure of testes. In contrast, 0.01, 0.1, and 1 microM E(2) treatments caused the undifferentiated gonads of 18, 63, and 100% of the tadpoles, respectively, to develop into gonads of complete or partial ovarian structure. After 0.1, 1, and 10 microM DBP treatment, 0, 7, and 17% of tadpoles, respectively, were similarly affected. These findings suggest that DBP was about 1,000-fold less potent than E(2). Nevertheless, DBP is an environmentally dangerous hormone that disrupts the pathways of testicular differentiation in genetically male animals. PMID:11133400

  12. Identification of organ-autonomous constituents of the molecular memory conferred by thyroid hormone exposure in cold temperature-arrested metamorphosing Rana (Lithobates) catesbeiana tadpoles.

    PubMed

    Austin Hammond, S; Jackman, Kevin W; Partovi, Shireen H; Veldhoen, Nik; Helbing, Caren C

    2016-03-01

    Environmental temperature modulates thyroid hormone (TH)-dependent metamorphosis in some amphibian species. The North American bullfrog--Rana (Lithobates) catesbeiana - tadpole is naturally adapted to a wide range of temperatures over multiple seasons. Cold temperatures delay while warmer temperatures accelerate metamorphosis. Exogenous TH exposure of premetamorphic tadpoles results in a rapid precocious induction of metamorphosis at warm temperatures (20-25 °C). The same exposure at cold temperatures (4-5 °C) does not elicit an overt metamorphic response. However, a molecular memory of TH exposure is established such that cold, TH-exposed tadpoles returned to permissive warm temperatures will rapidly execute TH-induced genetic programs. Previous mRNA profiling has identified TH-regulated transcription factors encoded by thra, thrb, thibz, klf9, and cebp1 as components of the molecular memory after one week post-exposure. However, a further hierarchy may exist within the initiation phase since many gene transcripts demonstrated tissue-specific patterns. Whether the molecular memory is organ autonomous or requires additional modulating factors is unknown. Herein we examine tail fin and back skin and determine that thibz is the only transcript that is TH-responsive after 2 days post-exposure at low temperature in both tissues in the intact animal. In back skin, cebp1 is also TH-responsive under these conditions. Serum-free tail fin organ culture (C-Fin) reveals that the thibz response is organ autonomous whereas cultured back skin (C-Skin) results suggest that thibz and cebp1 require an additional factor for induction from elsewhere within the intact animal. Subsequent investigations are now possible to identify endogenous factors that modulate the molecular memory in intact animals. PMID:26795672

  13. Comparison of thyroid hormone-dependent gene responses in vivo and in organ culture of the American bullfrog (Rana (Lithobates) catesbeiana) lung.

    PubMed

    Veldhoen, Nik; Stevenson, Mitchel R; Helbing, Caren C

    2015-12-01

    Postembryonic frog development requires a thyroid hormone (TH)-dependent metamorphic transition from an aquatic larva to a terrestrial frog. Such change in environment involves lung maturation in preparation for breathing air. However, little is known regarding the underlying molecular events and the role of THs in this process. Using quantitative real-time polymerase chain reaction, we evaluated Rana (Lithobates) catesbeiana lung mRNA transcripts representing key elements of TH and oxidative stress signaling pathways during natural and TH-induced precocious metamorphosis. TH induction was evaluated in two ways: 1) in vivo through interperitoneal injection of 10pmol/g body weight of 3,3', 5-triiodothyronine (T3) into premetamorphic tadpoles and analysis after 48h, and 2) in serum-free organ culture in the presence of 10nM T3 after 48h. Abundance of transcripts encoding the transcriptional regulators TH receptors α and β, TH-induced bZip protein, and CCAAT/enhancer binding protein 1 was increased during postembryonic development and following administration of exogenous THs to premetamorphic tadpoles in vivo and culture. In contrast, mRNA representing Krüppel-like factor 9 and cold-inducible RNA binding protein revealed differential effects between natural and precocious metamorphosis. Elevated levels of catalase and Cu/Zn superoxide dismutase mRNA were observed at the end of metamorphosis with transcript levels displaying minimal TH-dependency. No change in stress-responsive heat shock protein 30 mRNA abundance was noted. The results support a role for TH-dependent reprogramming of the lung transcriptome during frog development and reveal a requirement for increased antioxidant capacity following anuran metamorphosis. PMID:26462067

  14. Effects of acute exposure to the non-steroidal anti-inflammatory drug ibuprofen on the developing North American Bullfrog (Rana catesbeiana) tadpole.

    PubMed

    Veldhoen, Nik; Skirrow, Rachel C; Brown, Lorraine L Y; van Aggelen, Graham; Helbing, Caren C

    2014-09-01

    A variety of pharmaceutical chemicals can represent constituents of municipal effluent outflows that are dispersed into aquatic receiving environments worldwide. Increasingly, there is concern as to the potential of such bioactive substances to interact with wildlife species at sensitive life stages and affect their biology. Using a combination of DNA microarray, quantitative real-time polymerase chain reaction, and quantitative nuclease protection assays, we assessed the ability of sub-lethal and environmentally relevant concentrations of ibuprofen (IBF), a non-steroidal anti-inflammatory agent and prevalent environmental contaminant, to function as a disruptor of endocrine-mediated post-embryonic development of the frog. While the LC50 of IBF for pre-metamorphic Rana catesbeiana tadpoles is 41.5 mg/L (95% confidence interval: 32.3-53.5 mg/L), exposure to concentrations in the ppb range elicited molecular responses both in vivo and in organ culture. A nominal concentration of 15 μg/L IBF (actual = 13.7 μg/L) altered the abundance of 26 mRNA transcripts within the liver of exposed pre-metamorphic R. catesbeiana tadpoles within 6 d. IBF-treated animals demonstrated subsequent disruption of thyroid hormone-mediated reprogramming in the liver transcriptome affecting constituents of several metabolic, developmental, and signaling pathways. Cultured tadpole tail fin treated with IBF for 48 h also demonstrated altered mRNA levels at drug concentrations as low as 1.5 μg/L. These observations raise the possibility that IBF may alter the post-embryonic development of anuran species in freshwater environs, where IBF is a persistent or seasonal pollutant. PMID:25111458

  15. Combined effects of UV-B, nitrate, and low pH reduce the survival and activity level of larval cascades frogs (Rana cascadae).

    PubMed

    Hatch, A C; Blaustein, A R

    2000-11-01

    We investigated interactions between low pH, high nitrate level, and ultraviolet-B (UV-B) light on the survival and activity level of larval Cascades frogs (Rana cascadae). We used a fully factorial experimental design, with pH levels of 5 and 7; initial "pulse" nitrate exposure levels of 0, 5, and 20 mg/L; and UV-B present or absent. After a 3-week laboratory exposure, we measured survival and activity level of the larvae. The experiment was repeated two times, in two separate years. Similar effects on survival and activity level were observed in both experiments. R. cascadae survival was not significantly reduced in treatments with individual factors alone (i.e., UV-B control, pH 5 control, or high nitrate level without pH or UV-B). However, in experiments from both years, survival and activity levels of larval R. cascadae were significantly reduced in the treatment with low pH, high nitrate, and UV-B together. In both years, analysis of variance (ANOVA) indicated that pH and nitrate had the greatest effect on survival and that UV-B and nitrate had the greatest effect on activity level. Additional effects were observed in the 1998 experiment on both survival and activity level. In 1998, UV radiation and the interaction term between pH and nitrate (pH x nitrate) had a significant effect on survival. Also in the 1998 experiment, activity level was significantly reduced in treatments at neutral pH with UV, at initial nitrate doses of 5 and 20 mg/L and at neutral pH without UV at an initial nitrate dose of 20 mg/L. We suggest that the adverse effects were due to the multiple stressors acting together. PMID:11031310

  16. Vitellogenin of the northern leopard frog (Rana pipiens): development of an ELISA assay and evaluation of induction after immersion in xenobiotic estrogens.

    PubMed

    Selcer, Kyle W; Verbanic, Jodi D

    2014-10-01

    An immunoassay for leopard frog (Rana pipiens) vitellogenin was developed for studying endocrine disruption. Male frogs were injected with estradiol-17β to stimulate vitellogenin for purification. SDS-PAGE revealed high amounts of a 170-180 kDa protein, which was confirmed to be vitellogenin by Western blotting. Vitellogenin was purified by DEAE chromatography and used to generate a polyclonal antibody. A competitive ELISA was developed for leopard frog vitellogenin with a detection limit of 6.0 ng mL(-1) and a working range of 20-1000 ng mL(-1). The intra-assay coefficient of variation averaged 5.47% for control sera and 9.71% for estrogen-treated sera. The inter-assay coefficient of variation averaged 8.21% for control sera and 9.93% for estrogen-treated sera. Recovery of purified vitellogenin averaged 95.2%. Vitellogenin was measured in male frogs immersed in the estrogenic compound diethylstilbestrol (DES) for various times and doses. Serum vitellogenin was detected within five days after immersion in 1.0 mg L(-1) DES and levels continued to increase through 20 d. In a 20-day dose-response experiment, serum vitellogenin was detected in frogs immersed in 0.01 mg L(-1) DES and vitellogenin concentration increased with dose. Immersion of frogs in one of several xenobiotic estrogens (nonylphenol, octylphenol, bisphenol-A) for 20 d did not increase vitellogenin for any treatment, suggesting that this frog may be less sensitive than fish to endocrine disruptors. Vitellogenin induction in R.pipiens may be a useful amphibian model system for field studies of endocrine disruption, due to its broad geographic range. PMID:25048926

  17. Artificial Warming Facilitates Growth but Not Survival of Plateau Frog (Rana kukunoris) Tadpoles in Presence of Gape-Limited Predatory Beetles

    PubMed Central

    Zhao, Jiyan; Yang, Yangheshan; Xi, Xinqiang; Zhang, Changbing; Sun, Shucun

    2014-01-01

    Background Global warming has been frequently demonstrated to increase growth rate in larval amphibians that have considerable phenotypic plasticity; this may lead to an increase in larval survival because large larvae are less likely to be captured by gape-limited predators. This study is to test whether warming could improve tadpole growth and thereby enhance the tadpole survival in plateau frog Rana kukunoris. Methodology We conducted an experiment involving growing tadpoles under two contrasting temperatures, i.e. ambient temperature vs. warming by 3.8°C, with and without their major predators – the gape-limited predaceous diving beetles Agabus sp. in eastern Tibetan Plateau, in a factorial arrangement. We recorded the survival and measured body fresh weight and morphological characteristics of the tadpoles. Principal Findings Warming significantly increased body fresh weight in the presence of predators after three weeks of treatments. However, the predators imposed significant and similar effects on the survival of tadpoles under both ambient and elevated temperatures, with the effects mostly occurring in the first three weeks of the experiment. Changes in the body form, i.e. the greater whole length at a given fresh weight and the longer tail at a given body length, could have acted as mechanisms of defense and escape for the tadpoles. Conclusions/Significance Warming did not increase tadpole survival with or without presence of predators. Moreover, an increased growth rate (due to warming in the presence of predators) was not a major factor contributing to the tadpole survival. We postulate that even if warming increases the tadpole growth rate in the plateau frog, it does not necessarily improve their survival in the presence of gape-limited predators. PMID:24905846

  18. Clinical signs, pathology and dose-dependent survival of adult wood frogs, Rana sylvatica, inoculated orally with frog virus 3 Ranavirus sp., Iridoviridae.

    PubMed

    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.

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

    PubMed

    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 < 0.05). Additionally, the blood-brain barrier was found to work efficiently to suppress these compounds entering brain tissues in this species (liver/brain concentration ratio > 1, p < 0.05), and the molecular weight was a key factor impacting the extent of the blood-brain barrier. Compared to levels in the muscle and brain tissue, a preferential enrichment of syn-DP was observed in the liver tissue, suggesting the occurrence of stereo-selective bioaccumulation in the wild frog.

  20. Population declines lead to replicate patterns of internal range structure at the tips of the distribution of the California red-legged frog (Rana draytonii)

    USGS Publications Warehouse

    Richmond, Jonathan Q.; Backlin, Adam R.; Tatarian, Patricia J.; Solvesky, Ben G.; Fisher, Robert N.

    2014-01-01

    Demographic declines and increased isolation of peripheral populations of the threatened California red-legged frog (Rana draytonii) have led to the formation of internal range boundaries at opposite ends of the species’ distribution. While the population genetics of the southern internal boundary has been studied in some detail, similar information is lacking for the northern part of the range. In this study, we used microsatellite and mtDNA data to examine the genetic structuring and diversity of some of the last remaining R. draytonii populations in the northern Sierra Nevada, which collectively form the northern external range boundary. We compared these data to coastal populations in the San Francisco Bay Area, where the species is notably more abundant and still exists throughout much of its historic range. We show that ‘external’ Sierra Nevada populations have lower genetic diversity and are more differentiated from one another than their ‘internal’ Bay Area counterparts. This same pattern was mirrored across the distribution in California, where Sierra Nevada and Bay Area populations had lower allelic variability compared to those previously studied in coastal southern California. This genetic signature of northward range expansion was mirrored in the phylogeography of mtDNA haplotypes; northern Sierra Nevada haplotypes showed greater similarity to haplotypes from the south Coast Ranges than to the more geographically proximate populations in the Bay Area. These data cast new light on the geographic origins of Sierra Nevada R. draytonii populations and highlight the importance of distinguishing the genetic effects of contemporary demographic declines from underlying signatures of historic range expansion when addressing the most immediate threats to population persistence. Because there is no evidence of contemporary gene flow between any of the Sierra Nevada R. draytonii populations, we suggest that management activities should focus on

  1. Effects of acute exposure to the non-steroidal anti-inflammatory drug ibuprofen on the developing North American Bullfrog (Rana catesbeiana) tadpole.

    PubMed

    Veldhoen, Nik; Skirrow, Rachel C; Brown, Lorraine L Y; van Aggelen, Graham; Helbing, Caren C

    2014-09-01

    A variety of pharmaceutical chemicals can represent constituents of municipal effluent outflows that are dispersed into aquatic receiving environments worldwide. Increasingly, there is concern as to the potential of such bioactive substances to interact with wildlife species at sensitive life stages and affect their biology. Using a combination of DNA microarray, quantitative real-time polymerase chain reaction, and quantitative nuclease protection assays, we assessed the ability of sub-lethal and environmentally relevant concentrations of ibuprofen (IBF), a non-steroidal anti-inflammatory agent and prevalent environmental contaminant, to function as a disruptor of endocrine-mediated post-embryonic development of the frog. While the LC50 of IBF for pre-metamorphic Rana catesbeiana tadpoles is 41.5 mg/L (95% confidence interval: 32.3-53.5 mg/L), exposure to concentrations in the ppb range elicited molecular responses both in vivo and in organ culture. A nominal concentration of 15 μg/L IBF (actual = 13.7 μg/L) altered the abundance of 26 mRNA transcripts within the liver of exposed pre-metamorphic R. catesbeiana tadpoles within 6 d. IBF-treated animals demonstrated subsequent disruption of thyroid hormone-mediated reprogramming in the liver transcriptome affecting constituents of several metabolic, developmental, and signaling pathways. Cultured tadpole tail fin treated with IBF for 48 h also demonstrated altered mRNA levels at drug concentrations as low as 1.5 μg/L. These observations raise the possibility that IBF may alter the post-embryonic development of anuran species in freshwater environs, where IBF is a persistent or seasonal pollutant.

  2. Identification of organ-autonomous constituents of the molecular memory conferred by thyroid hormone exposure in cold temperature-arrested metamorphosing Rana (Lithobates) catesbeiana tadpoles.

    PubMed

    Austin Hammond, S; Jackman, Kevin W; Partovi, Shireen H; Veldhoen, Nik; Helbing, Caren C

    2016-03-01

    Environmental temperature modulates thyroid hormone (TH)-dependent metamorphosis in some amphibian species. The North American bullfrog--Rana (Lithobates) catesbeiana - tadpole is naturally adapted to a wide range of temperatures over multiple seasons. Cold temperatures delay while warmer temperatures accelerate metamorphosis. Exogenous TH exposure of premetamorphic tadpoles results in a rapid precocious induction of metamorphosis at warm temperatures (20-25 °C). The same exposure at cold temperatures (4-5 °C) does not elicit an overt metamorphic response. However, a molecular memory of TH exposure is established such that cold, TH-exposed tadpoles returned to permissive warm temperatures will rapidly execute TH-induced genetic programs. Previous mRNA profiling has identified TH-regulated transcription factors encoded by thra, thrb, thibz, klf9, and cebp1 as components of the molecular memory after one week post-exposure. However, a further hierarchy may exist within the initiation phase since many gene transcripts demonstrated tissue-specific patterns. Whether the molecular memory is organ autonomous or requires additional modulating factors is unknown. Herein we examine tail fin and back skin and determine that thibz is the only transcript that is TH-responsive after 2 days post-exposure at low temperature in both tissues in the intact animal. In back skin, cebp1 is also TH-responsive under these conditions. Serum-free tail fin organ culture (C-Fin) reveals that the thibz response is organ autonomous whereas cultured back skin (C-Skin) results suggest that thibz and cebp1 require an additional factor for induction from elsewhere within the intact animal. Subsequent investigations are now possible to identify endogenous factors that modulate the molecular memory in intact animals.

  3. Comparative effects of epinephrine, norepinephrine, and a gentle handling stress on plasma lactate, glucose, and hematocrit levels in the American bullfrog (Rana catesbeiana).

    PubMed

    MbangKollo, D; deRoos, R

    1983-02-01

    The effects of a single infusion of epinephrine or norepinephrine and of a 2-min handling stress on plasma lactate, glucose, and hematocrit levels were compared in the American bullfrog (Rana catesbeiana). The catecholamines were administered, and serial blood samples were collected, via a cannula placed in the truncus arteriosus. Plasma lactate was estimated by the lactate dehydrogenase method and glucose by the glucose oxidase method. Dose-dependent increases occurred in plasma lactate, glucose, and hematocrit levels after the infusion of 50 and 500 micrograms/kg body weight of epinephrine. Norepinephrine infusion resulted in dose-dependent increases in hematocrit levels, but plasma lactate and glucose levels were not increased significantly by 50 micrograms/kg body weight of norepinephrine. The infusion of 500 micrograms/kg body weight of norepinephrine caused a lactacidemia that was similar to that which occurred with the same dose of epinephrine, but the hyperglycemia was less. The plasma lactate increases after handling were similar to those that occurred after treatment with 500 micrograms/kg body weight of the catecholamines; however, the hematocrit elevations were less and the glucose levels were not increased significantly. In addition, the plasma lactate and hematocrit responses to handling were more rapid than those that occurred after the catecholamines. The results suggest that immediate physiological adjustments to a sudden threat are mediated in the bullfrog by direct nervous stimulation of the relevant organs. Catecholamines and corticoids secreted by the adrenal glands probably function synergistically and sequentially when a stress is more severe and/or more prolonged than the brief, gentle handling employed in this study.

  4. Comparison of thyroid hormone-dependent gene responses in vivo and in organ culture of the American bullfrog (Rana (Lithobates) catesbeiana) lung.

    PubMed

    Veldhoen, Nik; Stevenson, Mitchel R; Helbing, Caren C

    2015-12-01

    Postembryonic frog development requires a thyroid hormone (TH)-dependent metamorphic transition from an aquatic larva to a terrestrial frog. Such change in environment involves lung maturation in preparation for breathing air. However, little is known regarding the underlying molecular events and the role of THs in this process. Using quantitative real-time polymerase chain reaction, we evaluated Rana (Lithobates) catesbeiana lung mRNA transcripts representing key elements of TH and oxidative stress signaling pathways during natural and TH-induced precocious metamorphosis. TH induction was evaluated in two ways: 1) in vivo through interperitoneal injection of 10pmol/g body weight of 3,3', 5-triiodothyronine (T3) into premetamorphic tadpoles and analysis after 48h, and 2) in serum-free organ culture in the presence of 10nM T3 after 48h. Abundance of transcripts encoding the transcriptional regulators TH receptors α and β, TH-induced bZip protein, and CCAAT/enhancer binding protein 1 was increased during postembryonic development and following administration of exogenous THs to premetamorphic tadpoles in vivo and culture. In contrast, mRNA representing Krüppel-like factor 9 and cold-inducible RNA binding protein revealed differential effects between natural and precocious metamorphosis. Elevated levels of catalase and Cu/Zn superoxide dismutase mRNA were observed at the end of metamorphosis with transcript levels displaying minimal TH-dependency. No change in stress-responsive heat shock protein 30 mRNA abundance was noted. The results support a role for TH-dependent reprogramming of the lung transcriptome during frog development and reveal a requirement for increased antioxidant capacity following anuran metamorphosis.

  5. Plasma retinoid profile in bullfrogs, Rana catesbeiana, in relation to agricultural intensity of sub-watersheds in the Yamaska River drainage basin, Québec, Canada.

    PubMed

    Bérubé, Virginie E; Boily, Monique H; DeBlois, Chistian; Dassylva, Nathalie; Spear, Philip A

    2005-01-26

    Amphibian populations are decreasing globally and the causes are presently unclear. Retinoids have been extensively studied in other vertebrate classes where they are associated with pleiotropic effects such as susceptibility to disease (including cancer and parasitic infections), deformities and reproduction. To investigate the hypothesis that retinoid homeostasis is influenced by agricultural activities, blood samples were collected from adult bullfrogs, Rana catesbeiana, at each of six sub-watersheds chosen to represent a gradient of agricultural intensity within the Yamaska River drainage basin. Samples of surface water were collected at each of the study sites approximately 1 month after spraying and analyzed for 53 pesticides. Male body weight was significantly different (p<0.001) between study sites with the smallest bullfrogs captured from the Rivière à la Barbue sub-watershed associated with high agricultural intensity. A significant linear regression (p<0.001; R2=0.176) was obtained between plasma retinol and body weight. Plasma retinol concentrations were significantly different between study sites (p<0.001) being lowest at both Rivière Noire and Rivière à la Barbue. More than 60% of the land area in these sub-watersheds is under intensive corn-soya cultivation and surface water contained the highest concentrations of the herbicides atrazine, deethyl-atrazine, simazine, metolachlor, dimethenamide, chlopyralide, dicamba and bentazone. Plasma 13-cis-4-oxo-retinoic acid was significantly different (p<0.001) between sub-watersheds, however this effect was apparently unrelated to agricultural intensity. Plasma retinol was negatively correlated (p=0.026; r=-0.237) with plasma 13-cis-4-oxo-retinoic acid. These results suggest that retinoid homeostasis in bullfrogs may be influenced by agricultural practices.

  6. Don't get the blues: conspicuous nuptial colouration of male moor frogs (Rana arvalis) supports visual mate recognition during scramble competition in large breeding aggregations.

    PubMed

    Sztatecsny, Marc; Preininger, Doris; Freudmann, Anita; Loretto, Matthias-Claudio; Maier, Franziska; Hödl, Walter

    2012-12-01

    Conspicuous male colouration is expected to have evolved primarily through selection by female choice. In what way conspicuous colours could be advantageous to males scrambling for mates remains largely unknown. The moor frog (Rana arvalis) belongs to the so-called explosive breeders in which spawning period is short; intrasexual competition is strong, and males actively search and scramble for females. During breeding, male body colouration changes from a dull brown (similar to females) to a conspicuous blue, and we wanted to test if male blueness influences mating success or facilitates male mate recognition. To do so, we first measured the colour of mated and non-mated males using a spectrophotometer. In an experiment, we then analysed interactions of actual male moor frogs in natural spawning aggregations with a brown (resembling a female or a non-breeding male) and a blue model frog. Mated and non-mated males did not differ in colouration, suggesting that female choice based on colour traits was unlikely. In our behavioural experiment, male moor frogs spent significantly more time in contact and in amplexus with the brown model than with the blue model. Our results suggest that the nuptial colouration in moor frogs can act as a new type of visual signal in anurans evolved to promote instantaneous mate recognition allowing males to quickly move between rivals while scrambling for females. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00265-012-1412-6) contains supplementary material, which is available to authorized users.

  7. Effects of Evans Blue and amiloride on anti-diuretic hormone (ADH)-induced sodium transport across frog (Rana hexadactyla) skin.

    PubMed

    Jared, Silviya Rajakumari; Rao, Jonakuty Prakasa

    2013-05-01

    The epithelial sodium channel (ENaC) has four subunits, namely α (alpha), β (beta), γ (gamma) and δ (delta). The functional ENaC is formed by the combination of either αβγ or δβγ subunits. The aim of the present study is to determine the combination of ENaC subunits predominant on the apical side of the frog skin, and the effect of ADH on sodium transport though these two ENaCs subunit combinations. The ventral abdominal skin of the frog, Rana hexadactyla was mounted in an Ussing-type chamber. The voltage-clamp method was performed to measure the ionic transport across the frog skin with normal Ringer solution (NR) on both sides. Evans blue (300 µM) and amiloride (100 µM) were added to the NR on the apical side and ADH (40 nM) was added on the serosal side. Statistical significance was analyzed by Student's paired t-test and repeated-measures ANOVA, P < 0.05 was considered significant. This study suggests that the ENaC of the frog skin consist of both αβγ and δβγ subunit combinations on the apical side. Though both types of subunit combination are present, the αβγ type was found to be more common than δβγ. ADH increases the sodium transport across the frog skin. The effect of ADH on sodium transport is achieved through the combination of δ-subunits, not through the combination of a-subunits in the skin of Pana hexadactyla.

  8. Colonization of frog Rana temporaria L. urinary bladder by Gram-negative bacteria leads to decreased effect of arginine-vasotocin on water reabsorption from the urinary bladder.

    PubMed

    Fock, Ekaterina; Lavrova, Elena; Parnova, Rimma

    2013-11-01

    In frogs and toads the urinary bladder is very important for the maintenance of water balance due to its ability to store water which can be reabsorbed under the action of arginine-vasotocin (AVT). The usage of isolated bladders as a model for studying the osmotic water permeability (OWP) regulation has a disadvantage which relates to high variability of AVT effect among individuals, some showing insensitivity to the hormone. We hypothesized that the response of the bladder to AVT could depend on the colonization of the mucosal epithelium by Gram-negative bacteria. To test this, paired hemibladders of the frog Rana temporaria were used for measurement of OWP and for analysis of Gram-negative bacteria in the bladder tissue or isolated epithelial cells. Among the 206 frogs studied, 41% were infected by different Enterobacteriaceae, with prevalence of Hafnia alvei and Escherichia coli. In infected bladders the basal level of OWP was unchanged, whereas OWP stimulated by AVT was reduced (non-infected: 2.53 ± 0.13, n = 59, infected: 1.21 ± 0.17 µL min(-1)  cm(-2), n = 38, for the 15 min of AVT action, P < 0.001). In the sample, 100% of hemibladders that responded to AVT very weakly (OWP <0.5 µL min(-1)  cm(-2)) had a bacterial infection. Overnight treatment of hemibladders with mucosal lipopolysaccharide E. coli decreased OWP induced by AVT, forskolin, or IBMX lowering basal and stimulated level of cAMP. The data obtained indicate that the frog bladder epithelium could be colonized by Gram-negative bacteria, probably of cloacal origin, leading to reduction of sensitivity to AVT and to impairment of the urinary bladder to provide osmoregulation. PMID:23836531

  9. Effects of maturation and acidosis on the chaos-like complexity of the neural respiratory output in the isolated brainstem of the tadpole, Rana esculenta

    PubMed Central

    Samara, Ziyad; Fiamma, Marie-Noëlle; Bautin, Nathalie; Ranohavimparany, Anja; Le Coz, Patrick; Golmard, Jean-Louis; Darré, Pierre; Zelter, Marc; Poon, Chi-Sang; Similowski, Thomas

    2011-01-01

    Human ventilation at rest exhibits mathematical chaos-like complexity that can be described as long-term unpredictability mediated (in whole or in part) by some low-dimensional nonlinear deterministic process. Although various physiological and pathological situations can affect respiratory complexity, the underlying mechanisms remain incompletely elucidated. If such chaos-like complexity is an intrinsic property of central respiratory generators, it should appear or increase when these structures mature or are stimulated. To test this hypothesis, we employed the isolated tadpole brainstem model [Rana (Pelophylax) esculenta] and recorded the neural respiratory output (buccal and lung rhythms) of pre- (n = 8) and postmetamorphic tadpoles (n = 8), at physiologic (7.8) and acidic pH (7.4). We analyzed the root mean square of the cranial nerve V or VII neurograms. Development and acidosis had no effect on buccal period. Lung frequency increased with development (P < 0.0001). It also increased with acidosis, but in postmetamorphic tadpoles only (P < 0.05). The noise-titration technique evidenced low-dimensional nonlinearities in all the postmetamorphic brainstems, at both pH. Chaos-like complexity, assessed through the noise limit, increased from pH 7.8 to pH 7.4 (P < 0.01). In contrast, linear models best fitted the ventilatory rhythm in all but one of the premetamorphic preparations at pH 7.8 (P < 0.005 vs. postmetamorphic) and in four at pH 7.4 (not significant vs. postmetamorphic). Therefore, in a lower vertebrate model, the brainstem respiratory central rhythm generator accounts for ventilatory chaos-like complexity, especially in the postmetamorphic stage and at low pH. According to the ventilatory generators homology theory, this may also be the case in mammals. PMID:21325645

  10. Molecular cloning and expression of prohormone convertases PC1 and PC2 in the pituitary gland of the bullfrog, Rana catesbeiana.

    PubMed

    Yaoi, Yuichi; Suzuki, Masakazu; Tomura, Hideaki; Kikuyama, Sakae; Tanaka, Shigeyasu

    2003-09-01

    We cloned cDNAs encoding PC1 and PC2 from a cDNA library constructed for the anterior pituitary gland of the bullfrog (Rana catesbeiana) and sequenced them. The bullfrog PC1 cDNA consisted of 2972 base pairs (bp) with an open reading frame of 2208 bp and encoded a protein of 736 amino acids, including a putative signal peptide of 26 amino acids. The protein showed a high homology to R. ridibunda PC1 (95.1%) and mammalian PC1 (72.6%). The bullfrog PC2 cDNA consisted of 2242 bp with an open reading frame of 1914 bp and encoded a protein of 638 amino acids, including a putative signal peptide of 23 amino acids. This protein showed a high homology to R. ridibunda PC2 (95.5%) and mammalian PC2 (84.8%). The catalytic triad of serine proteinases of the subtilisin family was found at Asp-168, His-209, and Ser-383 in the PC1 protein and at Asp-167, His-208, and Ser-384 in the PC2 protein. In situ hybridization staining revealed that PC2 mRNA was detected in corticotrope cells of the tadpoles, but not in those of the adults. In the adult, only PC1 mRNA was detected in the pars distalis but both PC1 and PC2 mRNAs were detected in the pars intermedia. The data also showed that PC1 mRNA was expressed in gonadotrope cells. PMID:14578575

  11. Los Alamos National Laboratory

    SciTech Connect

    Dogliani, Harold O

    2011-01-19

    The purpose of the briefing is to describe general laboratory technical capabilities to be used for various groups such as military cadets or university faculty/students and post docs to recruit into a variety of Los Alamos programs. Discussed are: (1) development and application of high leverage science to enable effeictive, predictable and reliability outcomes; (2) deter, detect, characterize, reverse and prevent the proliferation of weapons of mass destruction and their use by adversaries and terrorists; (3) modeling and simulation to define complex processes, predict outcomes, and develop effective prevention, response, and remediation strategies; (4) energetic materials and hydrodynamic testing to develop materials for precise delivery of focused energy; (5) materials cience focused on fundamental understanding of materials behaviors, their quantum-molecular properties, and their dynamic responses, and (6) bio-science to rapidly detect and characterize pathogens, to develop vaccines and prophylactic remedies, and to develop attribution forensics.

  12. Los biocombustibles y el futuro

    NASA Video Gallery

    ¿Cómo podremos utilizar los biocombustibles en el futuro? La ingeniera aeroespacial de la NASA, Diana Centeno Gómez nos explica el futuro de los biocombustibles y cómo un día podrías trabajar con d...

  13. NARSTO EPA SS LOS ANGELES APS DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS LOS ANGELES APS DATA Project Title:  NARSTO Discipline:  ... Platform:  Ground Station Instrument:  APS - Aerodynamic Particle Sizer Location:  Los Angeles, ... Data Guide Documents:  Los Angeles APS Guide Los Angeles Project Plan  (PDF) Los Angeles ...

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

    PubMed

    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.

  15. Plasma levels of glucose, ketone bodies, lactate, and alanine in the vascular supply to and from the brain of the adult American bullfrog (Rana catesbeiana).

    PubMed

    Gibbs, S R; deRoos, R M

    1991-04-01

    Serial, paired blood samples were collected via cannulae chronically placed in the common carotid artery (A) to and the internal jugular vein (V) from the brain of the fasted adult American bullfrog (Rana catesbeiana). Plasma glucose, beta-hydroxybutyrate, acetoacetate, lactate, and alanine levels were measured by standard enzymatic procedures. Cannula failure ended sampling after 1-2 days in most animals. The common carotid artery plasma metabolite levels were greatest at the time of surgery and subsequently declined to relatively stable levels. The summarized data indicated glucose uptake and alanine release by the brain, but no significant beta-hydroxybutyrate or lactate A-V percentage changes. Initially, acetoacetate levels also were measured, but were discontinued in favor of continued beta-hydroxybutyrate determinations when no significant A-V percentage changes occurred. Separate analysis of the metabolite levels during the surgery and recovery period (less than or equal to 24 hr) and the "normal" under the experimental conditions period (greater than 24 hr) revealed that summarizing the data masked important A-V percentage changes during the two different physiological conditions. Glucose was the only metabolite extracted by the brain during the less than or equal to 24 hr period of elevated and subsequently declining metabolite levels. In contrast, glucose uptake did not occur during the greater than 24 hr period of stable levels, but there was lactate release. If the bullfrog brain stores substantial glycogen as do the other ectothermic vertebrates studied, glucose uptake when plasma levels are elevated, for example after feeding, may serve both to fuel the brain and to replenish endogenous glycogen reserves that may be mobilized to provide glucose for the brain after plasma glucose levels return to normal. Assuming that mammalian and bullfrog metabolic pathways are the same, the release of lactate and alanine by the brain, possibly to remove excess

  16. Helminth community structure of sympatric eastern American toad, Bufo americanus americanus, northern leopard frog, Rana pipiens, and blue-spotted salamander, Ambystoma laterale, from southeastern Wisconsin.

    PubMed

    Bolek, Matthew G; Coggins, James R

    2003-08-01

    One-hundred twelve amphibians, including 51 blue-spotted salamanders, Ambystoma laterale, 30 eastern American toads, Bufo americanus americanus, and 31 northern leopard frogs, Rana pipiens, were collected during April-October 1996 from Waukesha County, Wisconsin and examined for helminth parasites. The helminth compound community of this amphibian assemblage consisted of at least 10 species: 9 in American toads, 8 in leopard frogs, and 3 in blue-spotted salamanders. American toads shared 7 species with leopard frogs, and 2 species occurred in all 3 host species. Although there was a high degree of helminth species overlap among these sympatric amphibians, statistically significant differences were found among host species and percent of indirect or direct-life cycle parasites of amphibian species individual component communities (chi2 = 1,015, P < 0.001). American toads had a higher relative abundance of nematodes, 59%, than larval cestodes, 31%, and larval and adult trematodes, 10%, whereas leopard frogs had a higher relative abundance of larval cestodes, 71.3%, and larval and adult trematodes, 25.3%, than nematodes 3.4%. This is related to ecological differences in habitat and dietary preferences between these 2 anuran species. Helminth communities of blue-spotted salamanders were depauperate and were dominated by larval trematodes, 94%, and few nematodes, 6%. Low helminth species richness in this host species is related to this salamander's relatively small host body size, smaller gape size, lower vagility, and more fossorial habitat preference than the other 2 anuran species. Adult leopard frogs and toads had significantly higher mean helminth species richness than metamorphs, but there was no significant difference in mean helminth species richness among adult and metamorph blue-spotted salamanders. Considering adult helminths, the low species richness and low vagility of caudatans as compared with anurans suggest that local factors may be more important in

  17. Rhabdias esculentarum n. sp. (Nematoda: Rhabdiasidae) from green frogs of the Rana esculenta species complex in Italy: molecular evidence, morphological description and genetic differentiation from its congeners in frogs and toads.

    PubMed

    Cipriani, Paolo; Mattiucci, Simonetta; Paoletti, Michela; Santoro, Mario; Nascetti, Giuseppe

    2012-06-01

    A new taxon, Rhabdias esculentarum n. sp., is described based on DNA sequence analysis at multiple loci (i.e. mtDNA cox-1, 12S rRNA, ITS-1 and partial ITS-2 regions of the nuclear rDNA) and morphometric analysis carried out on specimens collected from the green frogs of the Rana esculenta species complex in Italy (i.e. R. lessonae Camerano and R. esculenta Linnaeus, identified genetically by diagnostic allozyme loci). Rhabdias esculentarum n. sp. was differentiated genetically, at both mitochondrial and nuclear levels, from Rh. bufonis (Schrank, 1788) (sensu Hartwich, 1972) and Rh. sphaerocephala Goodey, 1924 recovered from the toad Bufo bufo Linnaeus collected sympatrically with the specimens of Rana lessonae and R. esculenta examined in the present study. Moreover, the new taxon proved to be different from the other species of Rhabdias from anurans, which had previously been sequenced using the same genes and deposited in GeneBank. Phylogenetic analyses (MP and ML) inferred from mitochondrial (mtDNA cox-1 and 12S ribosomal RNA) and nuclear (ITS-1 and ITS-2 of the rDNA regions) sequences datasets were congruent in depicting Rh. esculentarum n. sp. as forming a highly supported clade distinct from the sympatric species Rh. bufonis, as well as from Rh. sphaerocephala, characterised on the basis of the same loci. Morphometric analysis and the differential diagnosis of genetically characterised specimens of the new species have revealed differences in several features in comparison with the type-species, Rh. bufonis. Material of the latter species included voucher specimens from Germany deposited by Hartwich (1972) and other specimens collected from B. bufo in Italy. Among the diagnostic characters, the particular cup-shaped buccal capsule characterising Rh. esculentarum is clearly different from the tear-shaped buccal capsule observed in material of R. bufonis obtained from Berlin Museum and collected in the same geographical area as the green frogs under study. Rh

  18. ASC platforms at Los Alamos.

    SciTech Connect

    Shaw, S. R.

    2004-01-01

    This talk describes the history, current state, and future plans for ASC computational and data storage service at Los Alamos. The of the systems and services described is limited to those installed in and managed by Group CCN-7.

  19. Los Alamos National Laboratory Overview

    SciTech Connect

    Neu, Mary

    2010-06-02

    Mary Neu, Associate Director for Chemistry, Life and Earth Sciences at Los Alamos National Laboratory, delivers opening remarks at the "Sequencing, Finishing, Analysis in the Future" meeting in Santa Fe, NM

  20. Triazines facilitate neurotransmitter release of synaptic terminals located in hearts of frog (Rana ridibunda) and honeybee (Apis mellifera) and in the ventral nerve cord of a beetle (Tenebrio molitor).

    PubMed

    Papaefthimiou, Chrisovalantis; Zafeiridou, Georgia; Topoglidi, Aglaia; Chaleplis, George; Zografou, Stella; Theophilidis, George

    2003-07-01

    Three triazine herbicides, atrazine, simazine and metribuzine, and some of their major metabolites (cyanuric acid and 6-azauracil) were investigated for their action on synaptic terminals using three different isolated tissue preparations from the atria of the frog, Rana ridibunda, the heart of the honeybee, Apis mellifera macedonica, and the ventral nerve cord of the beetle, Tenebrio molitor. The results indicate that triazines facilitate the release of neurotransmitters from nerve terminals, as already reported for the mammalian central nervous system. The no observed effect concentration, the maximum concentration of the herbicide diluted in the saline that has no effect on the physiological properties of the isolated tissue, was estimated for each individual preparation. According to their relative potency, the three triazines tested can be ranked as follows: atrazine (cyanuric acid), simazine>metribuzine (6-azauracil). The action of these compounds on the cholinergic (amphibians, insects), adrenergic (amphibian) and octopaminergic (insects) synaptic terminals is discussed.

  1. 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.

    PubMed

    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

  2. Mayo de Los Capomos, Sinaloa (Mayo of Los Capomos, Sinaloa).

    ERIC Educational Resources Information Center

    Freeze, Ray A.

    This document is one of 17 volumes on indigenous Mexican languages and is the result of a project undertaken by the Archivo de Lenguas Indigenas de Mexico. This volume contains information on Mayo, an indigenous language of Mexico spoken in Los Capomos, in the state of Sinaloa. The objective of collecting such a representative sampling of the…

  3. Los NIH anuncian el lanzamiento de los estudios ALCHEMIST

    Cancer.gov

    Los Estudios sobre la Secuenciación e Identificación de Marcadores para el Mejoramiento de la Terapia Adjuvante para el Cáncer de Pulmón, ALCHEMIST, identificarán a pacientes con cáncer de pulmón en estadio inicial cuyos tumores tienen cambios genéticos.

  4. Palace Revolt in Los Angeles?

    ERIC Educational Resources Information Center

    Fuller, Bruce

    2010-01-01

    Antonio Villaraigosa, the mayor of Los Angeles, comes alive when recalling his start in local politics--as a labor organizer agitating for reform inside decrepit and overcrowded schools. In his quest to turn around the schools, the mayor has united working-class Latino parents, civil rights leaders, and big-money Democrats to challenge union…

  5. Los Angeles and Its Mistress Machine

    ERIC Educational Resources Information Center

    Marx, Wesley

    1973-01-01

    Los Angeles city has acute air pollution problems because of lack of an adequate mass transit system and the type of local industries. Air pollution in Los Angeles has affected agricultural production, vegetation, and public health in nearby areas. (PS)

  6. Los Alamos Critical Assemblies Facility

    SciTech Connect

    Malenfant, R.E.

    1981-06-01

    The Critical Assemblies Facility of the Los Alamos National Laboratory has been in existence for thirty-five years. In that period, many thousands of measurements have been made on assemblies of /sup 235/U, /sup 233/U, and /sup 239/Pu in various configurations, including the nitrate, sulfate, fluoride, carbide, and oxide chemical compositions and the solid, liquid, and gaseous states. The present complex of eleven operating machines is described, and typical applications are presented.

  7. John Ash, AIA, Photographer August 1997. VIEW OF LOS ANGELES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    John Ash, AIA, Photographer August 1997. VIEW OF LOS ANGELES CITY HALL TENTH FLOOR SOUTH WING CAFETERIA FOOD LINE, FACING NORTH - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  8. Monica Griesbach, Photographer August 1997. VIEW OF LOS ANGELES CITY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Monica Griesbach, Photographer August 1997. VIEW OF LOS ANGELES CITY HALL TWENTY-FOURTH FLOOR EXISTING CONDITIONS SHOWING STRUCTURE AND BRACING, FACING NORTHWEST - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  9. John Ash, AIA, Photographer August 1997. VIEW OF LOS ANGELES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    John Ash, AIA, Photographer August 1997. VIEW OF LOS ANGELES CITY HALL TWENTY-SIXTH FLOOR EXISTING CONDITIONS SHOWING STRUCTURE AND BRACING, FACING SOUTHEAST - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  10. John Ash, AIA, Photographer August 1997. VIEW OF LOS ANGELES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    John Ash, AIA, Photographer August 1997. VIEW OF LOS ANGELES CITY HALL TWENTY-SIXTH FLOOR EXISTING CONDITIONS SHOWING STRUCTURE AND BRACING, FACING NORTHWEST - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  11. Monica Griesbach, Photographer August 1997. VIEW OF LOS ANGELES CITY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Monica Griesbach, Photographer August 1997. VIEW OF LOS ANGELES CITY HALL TWENTY-FOURTH FLOOR EXISTING CONDITIONS SHOWING STRUCTURE AND BRACING, FACING SOUTH - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  12. John Ash, AIA, Photographer August 1997. VIEW OF LOS ANGELES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    John Ash, AIA, Photographer August 1997. VIEW OF LOS ANGELES CITY HALL TWENTY-SIXTH FLOOR EXISTING CONDITIONS SHOWING STRUCTURE AND BRACING, FACING NORTHEAST - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  13. Monica Griesbach, Photographer August 1997. VIEW OF LOS ANGELES CITY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Monica Griesbach, Photographer August 1997. VIEW OF LOS ANGELES CITY HALL TWENTY-FOURTH FLOOR EXISTING CONDITIONS SHOWING STRUCTURE AND BRACING, FACING EAST. - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  14. John Ash, AIA, Photographer August 1997. VIEW OF LOS ANGELES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    John Ash, AIA, Photographer August 1997. VIEW OF LOS ANGELES CITY HALL TWENTY-SIXTH FLOOR EXISTING CONDITIONS SHOWING STRUCTURE AND BRACING, FACING SOUTHWEST - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  15. John Ash, AIA, Photographer August 1997. DETAIL OF LOS ANGELES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    John Ash, AIA, Photographer August 1997. DETAIL OF LOS ANGELES CITY HALL TENTH FLOOR NORTH OFFICE WING SHOWING RADIATOR AND WINDOW, FACING EAST - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  16. John Ash, ALA., Photographer August 1997. VIEW OF LOS ANGELES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    John Ash, ALA., Photographer August 1997. VIEW OF LOS ANGELES CITY HALL NINTH FLOOR NORTH OFFICE WING SHOWING PARTITIONS, WINDOWS AND RADIATOR, FACING SOUTHWEST - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  17. John Ash, AIA, Photographer August 1997. VIEW OF LOS ANGELES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    John Ash, AIA, Photographer August 1997. VIEW OF LOS ANGELES CITY HALL NINTH FLOOR NORTH OFFICE WING SHOWING PARTITIONS, WINDOWS AND RADIATOR, FACING EAST - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  18. Monica Griesbach, Photographer August 1997. VIEW OF LOS ANGELES CITY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Monica Griesbach, Photographer August 1997. VIEW OF LOS ANGELES CITY HALL FIFTH FLOOR BREAK ROOM OFF OF ORIGINAL ART COMMISSION ROOMS, FACING NORTHEAST - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  19. Monica Griesbach, Photographer August 1997. VIEW OF LOS ANGELES CITY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Monica Griesbach, Photographer August 1997. VIEW OF LOS ANGELES CITY HALL FIFTH FLOOR BREAK ROOM OFF OF ORIGINAL ART COMMISSION ROOMS, FACING SOUTHEAST - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  20. Monica Griesbach, Photographer August 1997. VIEW OF LOS ANGELES CITY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Monica Griesbach, Photographer August 1997. VIEW OF LOS ANGELES CITY HALL FIRST FLOOR DOORS TO THE CITY CLERK AND TAX & PERMIT DIVISION OFFICES, FACING NORTH. - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  1. Monica Griesbach, Photographer August 1997. DETAIL OF LOS ANGELES CITY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Monica Griesbach, Photographer August 1997. DETAIL OF LOS ANGELES CITY HALL THIRD FLOOR SHOWING ROTUNDA COLUMN CAPITALS AND LIGHT FIXTURES, FACING SOUTHEAST. - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  2. Bruce D. Judd, FAIA, Photographer August 1997. DETAIL OF LOS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Bruce D. Judd, FAIA, Photographer August 1997. DETAIL OF LOS ANGELES CITY HALL NORTH ENTRANCE SHOWING DOORS AND LIGHT FIXTURES, FACING SOUTH. - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  3. John Ash, AIA, Photographer August 1997. DETAIL OF LOS ANGELES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    John Ash, AIA, Photographer August 1997. DETAIL OF LOS ANGELES CITY HALL TENTH FLOOR SOUTH WING CAFETERIA LIGHT FIXTURE, FACING SOUTHWEST - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  4. Monica Griesbach, Photographer August 1997. DETAIL OF LOS ANGELES CITY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Monica Griesbach, Photographer August 1997. DETAIL OF LOS ANGELES CITY HALL THIRD FLOOR SHOWING ROTUNDA COLUMN CAPITALS AND LIGHT FIXTURES, FACING SOUTHEAST - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  5. Monica Griesbach, Photographer August 1997. DETAIL OF LOS ANGELES CITY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Monica Griesbach, Photographer August 1997. DETAIL OF LOS ANGELES CITY HALL THIRD FLOOR SHOWING ROTUNDA STANDING LIGHT FIXTURE, FACING NORTHEAST. - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  6. Monica Griesbach, Photographer August 1997. DETAIL OF LOS ANGELES CITY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Monica Griesbach, Photographer August 1997. DETAIL OF LOS ANGELES CITY HALL SOUTH ENTRY SHOWING DOORS AND LIGHT FIXTURES, FACING NORTH. - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  7. Monica Griesbach, Photographer August 1997. DETAIL OF LOS ANGELES CITY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Monica Griesbach, Photographer August 1997. DETAIL OF LOS ANGELES CITY HALL EAST ENTRANCE PORCH SHOWING VAULTS AND LIGHT FIXTURE, FACING UP. - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  8. Monica Griesbach, Photographer August 1997. DETAIL OF LOS ANGELES CITY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Monica Griesbach, Photographer August 1997. DETAIL OF LOS ANGELES CITY HALL WEST ENTRANCE COURTYARD SHOWING BRONZE DOORS, LIGHT FIXTURES AND GRILLS, FACING EAST. - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  9. John Ash, AIA, Photographer August 1997. DETAIL OF LOS ANGELES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    John Ash, AIA, Photographer August 1997. DETAIL OF LOS ANGELES CITY HALL THIRD FLOOR CITY COUNCIL CHAMBERS SHOWING COLUMN, ARCADE AND SPECTATOR SEATING, FACING SOUTHWEST. - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  10. John Ash, AIA, Photographer August 1997. DETAIL OF LOS ANGELES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    John Ash, AIA, Photographer August 1997. DETAIL OF LOS ANGELES CITY HALL THIRD FLOOR CITY COUNCIL CHAMBERS SHOWING PODIUM AND SEATING, FACING SOUTH. - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  11. John Ash, AIA, Photographer August 1997. DETAIL OF LOS ANGELES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    John Ash, AIA, Photographer August 1997. DETAIL OF LOS ANGELES CITY HALL THIRD FLOOR CITY COUNCIL CHAMBERS SHOWING COLUMN, ARCADE AND SPECTATOR SEATING, FACING SOUTHWEST - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  12. John Ash, AIA, Photographer August 1997. DETAIL OF LOS ANGELES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    John Ash, AIA, Photographer August 1997. DETAIL OF LOS ANGELES CITY HALL SEVENTH FLOOR CORRIDOR NEAR ELEVATOR LOBBY SHOWING FIRE HOSE CABINET, FACING EAST - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  13. Monica Griesbach, Photographer August 1997. DETAIL OF LOS ANGELES CITY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Monica Griesbach, Photographer August 1997. DETAIL OF LOS ANGELES CITY HALL FOURTEENTH FLOOR FIRE HOSE NEAR NORTHEAST STAIR, FACING EAST - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  14. John Ash, AIA, Photographer August 1997. VIEW OF LOS ANGELES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    John Ash, AIA, Photographer August 1997. VIEW OF LOS ANGELES CITY HALL FIFTH FLOOR NORTH OFFICE AREA, FACING NORTHEAST - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  15. John Ash, AIA, Photographer August 1997. DETAIL OF LOS ANGELES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    John Ash, AIA, Photographer August 1997. DETAIL OF LOS ANGELES CITY HALL SEVENTH FLOOR SOUTH OFFICE AREA SHOWING RADIATOR AND WINDOWS, FACING EAST - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  16. Monica Griesbach, Photographer August 1997. VIEW OF LOS ANGELES CITY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Monica Griesbach, Photographer August 1997. VIEW OF LOS ANGELES CITY HALL FIFTH FLOOR WEST OFFICE AREA THAT WAS ORIGINAL ART COMMISSION ROOMS, FACING NORTHEAST - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  17. Monica Griesbach, Photographer August 1997. VIEW OF LOS ANGELES CITY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Monica Griesbach, Photographer August 1997. VIEW OF LOS ANGELES CITY HALL FIFTH FLOOR NORTH OFFICE AREA, FACING NORTH - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  18. Monica Griesbach, Photographer August 1997. DETAIL OF LOS ANGELES CITY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Monica Griesbach, Photographer August 1997. DETAIL OF LOS ANGELES CITY HALL NINETEENTH FLOOR MAIN OFFICE AREA SHOWING BEAM AND COLUMN CONNECTION NEAR NORTHWEST CORNER, FACING NORTHWEST - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  19. Monica Griesbach, Photographer August 1997. DETAIL OF LOS ANGELES CITY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Monica Griesbach, Photographer August 1997. DETAIL OF LOS ANGELES CITY HALL NINETEENTH FLOOR MAIN OFFICE AREA SHOWING DEMOLITION OF SOUTH WALL, FACING SOUTH - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  20. Monica Griesbach, Photographer August 1997. DETAIL OF LOS ANGELES CITY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Monica Griesbach, Photographer August 1997. DETAIL OF LOS ANGELES CITY HALL NINETEENTH FLOOR MAIN OFFICE AREA SHOWING BEAM AND COLUMN CONNECTION NEAR SOUTHEAST CORNER, FACING SOUTHEAST - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA