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. PMID:25284951

  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. 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...

  6. 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...

  7. The identity of Rana lutea Molina, 1782 (Amphibia, Anura).

    PubMed

    Ferraro, Daiana P; Lavilla, Esteban O

    2013-01-01

    Rana lutea is one of the two anuran species described in 1782 by the Chilean born priest and naturalist Juan Ignacio Molina, and its nomenclatural history is confusing. After a detailed revision of the pertinent literature, we demonstrate that Bufo thaul Schneider, 1799, is a junior objective synonym of Rana lutea Molina, 1782, but based on the usage of both nomina, we revert the precedence and consider Rana lutea Molina, 1782 as a nomen oblitum whereas Bufo thaul Schneider, 1799 is a nomen protectum. Thus, the authorship of the species currently known as Pleurodema thaul (Lesson, 1826) changes to Pleurodema thaul (Schneider, 1799). PMID:24614468

  8. 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

  9. Reproductive interference between Rana dalmatina and Rana temporaria affects reproductive success in natural populations.

    PubMed

    Hettyey, Attila; Vági, Balázs; Kovács, Tibor; Ujszegi, János; Katona, Patrik; Szederkényi, Márk; Pearman, Peter B; Griggio, Matteo; Hoi, Herbert

    2014-10-01

    Experimental evidence suggests that reproductive interference between heterospecifics can seriously affect individual fitness; support from field studies for such an effect has, however, remained scarce. We studied reproductive interference in 25 natural breeding ponds in an area where two ranid frogs, Rana dalmatina and Rana temporaria, co-occur. The breeding seasons of the two species usually overlap and males of both species are often found in amplexus with heterospecific females, even though matings between heterospecifics produce no viable offspring. We estimated species abundance ratios based on the number of clutches laid and evaluated fertilization success. In ponds with low spatial complexity and a species abundance ratio biased towards R. temporaria, the average fertilization success of R. dalmatina eggs decreased, while this relationship was not detectable in spatially more complex ponds. Fertilization success of R. temporaria did not decrease with increasing relative numbers of heterospecifics. This asymmetry in fitness effects of reproductive interference may be attributed to R. temporaria males being more competitive in scramble competition for females than R. dalmatina males. Our study is among the first to demonstrate that in natural breeding populations of vertebrates interference among heterospecifics has the potential to substantially lower reproductive success at the population level, which may in turn affect population dynamics. PMID:25138258

  10. 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.

  11. 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

  12. 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...

  13. 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.

  14. Optical Spectra of Melanin Films Extracted from Rana esculenta L.

    NASA Astrophysics Data System (ADS)

    Perna, G.; Gallone, A.; Capozzi, V.; Biagi, P. F.; Fratello, A.; Guida, G.; Zanna, P.; Argenzio, E.; Cicero, R.

    2005-01-01

    The melanin pigment extracted from the liver of Rana esculenta L. has been deposited as thin film on quartz substrate. The Raman spectra, as well as optical absorption and photoluminescence measurements have been investigated. The results show that the melanin can be described as a network of clusters having different size. The larger size clusters determine the absorption edge of the film and the smaller size ones are mainly involved in the radiative emission process.

  15. 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...

  16. 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.

  17. 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.

  18. 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.

  19. 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. PMID:25439863

  20. [Origin of the differences of superficial potentials in Rana esculenta].

    PubMed

    Fontas, B; Mambrini, J

    1977-07-18

    The spatial distributions of superficial D.C. potentials on the skin of Rana esculenta have been compared to those of the intensity of short-circuit current (S.C.C.) expressing the transcutaneous active transport of sodium ions. It has been observed that the sites of maximum D.C. potentials coincide with the localisations of maximum S.C.C. values. Moreover, superficial D.C. potentials and S.C.C. are similarly modified by the depression of metabolic activity due to lowered temperature or poisoning by dinitrophenol (DNP). It is thus proposed that the spatial distribution of the transcutaneous active transport system for sodium ions is the origin of the electric generator of superficial D.C. potentials. PMID:409557

  1. 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

  2. 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. PMID:18625327

  3. Octylphenol induced gene expression in testes of Frog, Rana chensinensis.

    PubMed

    Li, Xinyi; Liu, Jia; Zhang, Yuhui

    2016-06-01

    Octylphenol (OP) is an endocrine-disrupting chemical (EDC), which can disrupt the reproductive system. To understand the effect of OP, a subtractive cDNA library was constructed using suppression subtractive hybridization (SSH) to identify alterations of gene transcription in the testes of the frog Rana chensinensis after OP exposure. Two hundred positive clones were selected and 134 sequences of gene fragments were produced from the subtractive library randomly. These genes were identified to be involved in metabolic process, cellular process, biological regulation, stimulus, immune system and female pregnancy process. In order to verify the efficiency of the subtractive cDNA library, PSG9 and PAPP-A were analyzed further as two representatives of differentially expressed transcription genes using semi-quantitative RT-PCR. Our result was the first successful construction of the subtractive cDNA library in frog testes after OP treatment. Based on this cDNA library, OP was shown to affect multiple physiological processes including inducing immune response, disrupting the steroid hormone synthesis and influencing spermatogenesis in the testis by up-regulation of specific genes. PMID:26896894

  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. 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.

  6. 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?|

  7. 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.

  8. Immunostimulatory Activity of Protein Hydrolysate from Oviductus Ranae on Macrophage In Vitro

    PubMed Central

    Huang, Di; Yang, Lubing; Wang, Chenlu; Ma, Sihui; Cui, Li; Huang, Shiyang; Sheng, Xia; Weng, Qiang; Xu, Meiyu

    2014-01-01

    Oviductus Ranae is the dry oviduct of Rana chensinensis, which is also called R. chensinensis oil. Oviductus Ranae is a valuable Chinese crude drug and is recorded in the Pharmacopoeia of the People's Republic of China. The aim of this study was to investigate the immunostimulatory activity of protein hydrolysate of Oviductus Ranae (ORPH) and to assess its possible mechanism. Immunomodulatory activity of ORPH was examined in murine macrophage RAW 264.7 cells. The effect of ORPH on the phagocytic activity of macrophages was determined by the neutral red uptake assay. After treatment with ORPH, NO production levels in the culture supernatant were investigated by Griess assay. The mRNA and protein expressions of inducible nitric oxide synthase (iNOS) were detected by RT-PCR and Western blotting. The production of TNF-α, IL-1β, and IL-6 after treatment with ORPH was measured using ELISA assay. In addition, NF-κB levels were also investigated by Western blot. The results showed that ORPH enhanced the phagocytosis of macrophage, increased productions of TNF-α, IL-1β, IL-6, and NO in RAW 264.7 cells, and upregulated the mRNA and protein expression of iNOS. Besides, NF-κB, levels in RAW 264.7 cells were elevated after ORPH treatment. These findings suggested that ORPH might stimulate macrophage activities by activating the NF-κB pathway. PMID:25610475

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  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. 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

  16. 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

  17. 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

  18. 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

  19. Investigation of the anti-glioma activity of Oviductus ranae protein hydrolysate.

    PubMed

    Sui, Xin; Li, Xiao-Hua; Duan, Ming-Hua; Jia, Ai-Ling; Wang, Ye; Liu, Da; Li, Yi-Ping; Qiu, Zhi-Dong

    2016-07-01

    Oviductus Ranae is the dry oviducts of Rana temporaria chensinensis, and it has been reported to have a range of biological activities. This study aimed to investigate the effects of Oviductus Ranae protein hydrolysate (ORPH) on human glioma C6 cell proliferation and apoptosis in vitro and in vivo. Following in vitro treatment, cell viability and colony formation assays showed that ORPH inhibited C6 cell proliferation. In addition, the results of western blotting also demonstrated that ORPH effectively regulated the expression of the apoptosis related proteins, cleaved caspase-3, Bax and Bcl-2, DNA staining and flow cytometry analysis demonstrated that ORPH significantly promoted apoptosis in this cell line, a finding that was confirmed in vivo using terminal deoxynucleotidyl transferase dUTP nick end labeling. Further investigation demonstrated that ORPH increased apoptosis by modulating the release of inflammatory cytokines and the phosphoinositide 3-kinase (PI3K)/AKT signaling pathway; this was demonstrated using a PI3K/AKT inhibitor (NVP-BEZ235). In summary, the present study suggested that ORPH promoted apoptosis and inhibited glioma cell proliferation by influencing the PI3K/AKT signaling pathway. PMID:27261592

  20. 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.

  1. 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.

  2. 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.

  3. [NAG-infection in grass frogs (Rana temporaria) subjected to hypothermia].

    PubMed

    Avtsyn, A P; Shakhlamov, V A; Trager, R S; Timashkevich, T B; Poliakova, G P

    1976-12-01

    Rana temporaria kept under hypothermic conditions approaching anabiosis were inoculated with NAG-vibrios and examined clinically, bacteriologically, histologically, and electron microscopically. Oral inoculation of hypothermic frogs with NAG-vibrios resulted in 18 to 24 hours in the development of acute NAG-infection resembling the cholera-like syndrome, and characterized by general intoxication and local enteropathogenic effects. NAG-vibrios persisted in the frog gastrointestinal tract for a long time after the cessation of the acute period of the disease. PMID:1088086

  4. Temperature-dependent elaboration of collagenase by the renal adenocarcinoma of the leopard frog, Rana pipiens.

    PubMed

    Ogilvie, D J; McKinnell, R G; Tarin, D

    1984-08-01

    Naturally occurring renal adenocarcinoma in North American leopard frogs, Rana pipiens, metastasize frequently (77%) when these ectothermic animals are kept in a warm environment but not when they are kept cold. We have found that explants of these tumors secrete collagenase, an enzyme capable of dissolving connective tissue fibers and found previously to be closely correlated with metastatic colony-forming capability of murine mammary tumors, and that the amount released sequentially rises and falls as the ambient temperature is shifted between metastasis-permissive and -inhibitory levels. In contrast, normal frog renal tissue has low collagenase output, unaffected by temperature changes. PMID:6331646

  5. A physiological measure of shifting connections in the Rana pipiens retinotectal system.

    PubMed

    Fraser, S E; Hunt, R K

    1986-06-01

    The retinotectal connections of developing Rana tadpoles and froglets have been studied using light-pipe techniques to directly assay the pattern of the projection from the retina to the tectum. The projection site of the retina surrounding the optic nerve head was determined at two different stages of development (late larval and metamorphic frog) on the same animal. Small electrolytic marker lesions were used to mark the tectal sites to which the optic nerve head projected at these two times. Comparison of the positions of the two lesions gives a direct measure of the shift in the projection during the interlesion time interval of one week. The results indicate a shift in the projection of 275 micron week-1 in late larval life. Previous work in Xenopus using the light-pipe techniques indicated a qualitatively similar shift during equivalent stages of development, but significantly smaller in magnitude. In the present study, topographic postsynaptic units could be recorded at all stages investigated, indicating functional synapses between the optic nerve fibres and the tectum. Thus, these studies offer evidence of a significant shift in the functional connection pattern of the amphibian retinotectal map during development, in agreement with the recent anatomical data from other laboratories on the Rana and goldfish visual system. PMID:3489803

  6. Humane anesthesia and pain management in amphibian limb surgery of Rana pipiens.

    PubMed

    Koustubhan, Punita; Kaplan, David L; Levin, Michael

    2013-02-01

    Adult Rana pipiens frogs are used as a model to investigate mechanisms of vertebrate organ regeneration, anti-tumor ribonucleases, zoological impacts of various pollutants, oncogenesis, neuroplasticity, and neurogenesis. In regenerative biology, the adult Rana pipiens frog is an important alternative to other frog models, such as Xenopus laevis, because it offers the opportunity to study and attempt to augment limb regeneration in an animal that spends significant time out of water and bears weight on its limbs. To elucidate regenerative processes, it is necessary to amputate the limb to study the processes associated with wound healing, blastema formation, and morphogenesis. Being able to revive the animal successfully with little or no side effects is paramount to these studies. Anesthesia and the effect it has on the frogs can vary based on the methods and post-operative care exercised during surgery. However, useful information is not readily available regarding current anesthesia methods or effective and humane analgesia use in amphibians. Amphibian patients are very sensitive to drug dosages, changes in temperature, humidity and water quality; here, special attention is given to these factors. This protocol establishes a humane anesthesia technique while maintaining physiological homeostasis during procedures in amphibians as well as a post-operative care plan addressing the clinical benefits of using analgesics in pain management. Suggestions for infection prevention are covered with a sample treatment plan to ensure that all of the animals have a positive outcome and all of the surgeries have reproducible results. PMID:23378649

  7. 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.

  8. 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

  9. Chloride conductance in amphibian skin: regulatory control in the skin of Rana pipiens.

    PubMed

    Rozman, A; Katz, U; Nagel, W

    2008-09-01

    Chloride conductance across the isolated skin of Rana pipiens shows a voltage-activated component (G(Cl)(V)) which requires the presence of mucosal Cl. G(Cl)(V) is normally low or dormant. It is stimulated by elevated intracellular cAMP, irrespective whether originating from application of ss-adrenergic agonists (isoproterenol), stimulators of the adenylyl-cyclase (forskolin), inhibitors of the phosphodiesterases (isobutyl-methyl-xanthine) or membrane-permeable cAMP analogues (CPT-cAMP). Baseline G(Cl) under inactivating conditions increases also with cAMP dose-dependently. The data indicate that cAMP is a central regulator of the passive, conductive chloride transport across amphibian skin. PMID:18599332

  10. 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.

  11. 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. PMID:22558145

  12. Classification and distribution of large intestinal bacteria in nonhibernating and hibernating leopard frogs (Rana pipiens).

    PubMed Central

    Banas, J A; Loesche, W J; Nace, G W

    1988-01-01

    The large intestinal flora of the leopard frog, Rana pipiens, was examined to determine whether differences existed between the nonhibernating and hibernating states of the animal and to determine the relative concentrations and proportions of potential frog pathogens. Hibernators had a logarithmic decrease of bacteria per milligram of intestine averaging one, and significantly greater proportions of facultative bacteria and psychrophiles relative to nonhibernators. The predominant anaerobic bacteria were gram-positive Clostridium species and gram-negative Bacteroides and Fusobacterium species. The predominant facultative bacteria were enterobacteria in nonhibernators but Pseudomonas species in hibernators. Many species of Pseudomonas are pathogenic for frogs, and thus the intestinal flora in hibernators may be a potential source of infectious disease. PMID:3263838

  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. 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.

  15. 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.

  16. 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.

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

    PubMed Central

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

    2010-01-01

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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Seismic activity, inferred crustal stresses and seismotectonics in the Rana region, Northern Norway

    NASA Astrophysics Data System (ADS)

    Hicks, Erik C.; Bungum, Hilmar; Lindholm, Conrad D.

    2000-10-01

    The seismotectonic significance of the Rana region is known both from the fact that this was the location of the largest known earthquake in Fennoscandia in recent times, the MS 5.8-6.2 earthquake of August 31, 1819, and from its relatively high, constant seismic activity also in the 20th century. In order to study this region in more detail, a local seismic network has been in operation there since July 1997, as part of the NEONOR (Neotectonics in Norway) project. The network was primarily designed to detect possible activity on the Båsmoen fault which runs ˜50 km subparallel to the Rana fjord, and which shows signs of likely post glacial activity. The results have revealed a quite complex spatio-temporal distribution of seismic activity, and has also shown no activity on the Båsmoen fault itself. During the first 18 months of operation (July 1997-January 1999), the network has detected 373 locatable seismic events, of which 267 were local earthquakes. Most of these earthquakes occurred in five groups in the western parts of the network. All five groups had similar NNW-ESW trends in epicenter locations, and all have shallow foci (2-12 km), similar to what has also been found earlier for other concentrated earthquake zones in Northern Norway, and the magnitude range is between ML 0.1 and 2.8. Earthquake focal mechanism solutions within the network reveal a predominance for normal faulting with the tensional stress axis perpendicular do the coastline (implying an unusual coast-parallel orientation of the principal horizontal compressive stress). The earthquakes occur in a region of maximum post-glacial uplift gradients, which supports deglaciation flexure as a viable explanation for these earthquakes. A certain influence from more local factors, however, tied in general to crustal in homogeneities, cannot be ruled out.

  3. Aeromonas hydrophila subsp. ranae subsp. nov., isolated from septicaemic farmed frogs in Thailand.

    PubMed

    Huys, Geert; Pearson, Marianne; Kämpfer, Peter; Denys, Rik; Cnockaert, Margo; Inglis, Valerie; Swings, Jean

    2003-05-01

    A group of seven sucrose-negative Aeromonas strains (referred to as group Au) isolated from the internal organs of septicaemic farmed frogs (Rana rugulosa) in Thailand was subjected to a polyphasic taxonomic study including fluorescent amplified fragment length polymorphism (FAFLP) and ERIC-PCR fingerprinting, 16S rDNA sequencing, microplate DNA-DNA hybridizations and extensive phenotypic characterization. Comparison of FAFLP and ERIC-PCR fingerprints indicated that the group Au isolates belonged to the species Aeromonas hydrophila DNA hybridization group (HG) 1 in which they represent a genotypic subgroup closely affiliated to A. hydrophila subsp. hydrophila and subsp. dhakensis. One representative of the Au group exhibited > or = 99.0% 16S rDNA sequence similarity with the type strains of the two A. hydrophila subspecies. DNA-DNA hybridization with type and reference strains of all known Aeromonas taxa revealed that the Au group represented a homogeneous taxon that exhibited the highest relatedness with members of the two A. hydrophila subspecies, ranging from 75 to 93%. Phenotypic characterization on the basis of 152 features further revealed that the Au group isolates differed from A. hydrophila subsp. hydrophila or subsp. dhakensis in a total of 13 biochemical properties. Of these, assimilation of L-glycine and isobutyrate as sole carbon source, acid production from salicin and D-sucrose, and aesculin hydrolysis were of diagnostic value. From the results of this study, it can be concluded that the Aeromonas frog isolates of the Au group represent a new subspecies of A. hydrophila, for which the name Aeromonas hydrophila subsp. ranae subsp. nov. is proposed. Its type strain is Au-1D12(T) (=LMG 19707(T) = CCUG 46211(T)). PMID:12807217

  4. 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.

  5. 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

  6. Juvenile Green Frog (Rana clamitans) Predatory Ability not Affected by Exposure to Carbaryl at Different Times During Larval Development

    PubMed Central

    Davis, Melanie J.; Kleinhenz, Peter; Boone, Michelle D.

    2011-01-01

    Larval exposure to pesticides can occur at different times during development, and can negatively impact amphibian fitness. We examined the effects of larval green frog (Rana clamitans) exposure to carbaryl at 2, 4, 8, or 16 weeks of development on juvenile predatory ability. We did not find evidence that predatory ability was affected by exposure to carbaryl, which suggests that carbaryl does not have latent effects on the predatory performance of green frogs in subsequent life stages. PMID:21462236

  7. 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. PMID:26540180

  8. 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. PMID:26950267

  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. 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

  11. 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

  12. 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. PMID:26216142

  13. 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

  14. Effective population sizes and temporal stability of genetic structure in Rana pipiens, the northern leopard frog.

    PubMed

    Hoffman, Eric A; Schueler, Frederick W; Blouin, Michael S

    2004-11-01

    Although studies of population genetic structure are very common, whether genetic structure is stable over time has been assessed for very few taxa. The question of stability over time is particularly interesting for frogs because it is not clear to what extent frogs exist in dynamic metapopulations with frequent extinction and recolonization, or in stable patches at equilibrium between drift and gene flow. In this study we collected tissue samples from the same five populations of leopard frogs, Rana pipiens, over a 22-30 year time interval (11-15 generations). Genetic structure among the populations was very stable, suggesting that these populations were not undergoing frequent extinction and colonization. We also estimated the effective size of each population from the change in allele frequencies over time. There exist few estimates of effective size for frog populations, but the data available suggest that ranid frogs may have much larger ratios of effective size (Ne) to census size (Nc) than toads (bufonidae). Our results indicate that R. pipiens populations have effective sizes on the order of hundreds to at most a few thousand frogs, and Ne/Nc ratios in the range of 0.1-1.0. These estimates of Ne/Nc are consistent with those estimated for other Rana species. Finally, we compared the results of three temporal methods for estimating Ne. Moment and pseudolikelihood methods that assume a closed population gave the most similar point estimates, although the moment estimates were consistently two to four times larger. Wang and Whitlock's new method that jointly estimates Ne and the rate of immigration into a population (m) gave much smaller estimates of Ne and implausibly large estimates of m. This method requires knowing allele frequencies in the source of immigrants, but was thought to be insensitive to inexact estimates. In our case the method may have failed because we did not know the true source of immigrants for each population. The method may be more

  15. [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. PMID:25782287

  16. 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.

  17. Volume regulation mechanisms in Rana castebeiana cardiac tissue under hyperosmotic stress.

    PubMed

    Cruz, Laura N; Souza, Marta M

    2008-01-01

    Volume changes of cardiac tissue under hyperosmotic stress in Rana catesbeiana were characterized by the identification of the osmolytes involved and the possible regulatory processes activated by both abrupt and gradual changes in media osmolality (from 220 to 280mosmol/kg H(2)O). Slices of R. catesbeiana cardiac tissue were subjected to hyperosmotic shock, and total tissue Na(+), K(+), Cl(-) and ninhydrin-positive substances were measured. Volume changes were also induced in the presence of transport inhibitors to identify osmolyte pathways. The results show a maximum volume loss to 90.86+/-0.73% of the original volume (measured as 9% decrease in wet weight) during abrupt hyperosmotic shock. However, during a gradual osmotic challenge the volume was never significantly different from that of the control. During both types of hyperosmotic shock, we observed an increase in Na(+) but no significant change in Cl(-) contents. Additionally, we found no change in ninhydrin-positive substances during any osmotic challenge. Pharmacological analyses suggest the involvement of the Na(+)/H(+) exchanger, and perhaps the HCO(3)(-)/Cl(-) exchanger. There is indirect evidence for decrease in Na(+)/K(+)-ATPase activity. The Na(+) fluxes seem to result from Mg(2+) signaling, as saline rich in Mg(2+) enhances the regulatory volume increase, followed by a higher intracellular Na(+) content. The volume maintenance mechanisms activated during the gradual osmotic change are similar to that activated by abrupt osmotic shock. PMID:18457937

  18. Metamorphic changes in localization of sugars in skin of the leopard frog, Rana pipiens.

    PubMed

    Faszewski, Ellen E; Tyrell, Annemarie; Guin, Sujata; Kaltenbach, Jane C

    2008-08-01

    A lectin histochemical study was carried out to determine the distribution of specific sugars in glycoconjugates within an important osmoregulatory organ, amphibian skin. Paraffin sections were made of Rana pipiens skin from dorsal and ventral regions of aquatic larvae in representative developmental stages as well as from several body regions of semiaquatic adult frogs. Sections were incubated with horseradish peroxidase (HRP)-conjugated lectins, which bind to specific terminal sugar residues of glycoconjugates. Such sites were visualized by DAB-H2O2. The following HRP-lectins were used: UEA-1 for alpha-L-fucose, SBA for N-acetyl-D-galactosamine, WGA for N-acetyl-beta-D-glucosamine, PNA for beta-galactose, and Con A for alpha-mannose. We found that lectin binding patterns in larvae change during metamorphic climax as the skin undergoes extensive histological remodeling; this results in adult skin with staining patterns that are specific for each lectin and are similar in all body regions. Such findings in R. pipiens provide additional insight into the localization of molecules involved in osmoregulation in amphibian skin. PMID:18512706

  19. Receptor-mediated endocytosis of lysozyme in renal proximal tubules of the frog Rana temporaria.

    PubMed

    Seliverstova, E V; Prutskova, N P

    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 (endosomes), 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 intracellular 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

  20. 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.

  1. 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

  2. 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

  3. 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

  4. Characterization and steroidal regulation of gonadotropin beta subunits in the male leopard frog, Rana pipiens.

    PubMed

    Zhang, Lihong; Kessler, Ann E; Tsai, Pei-San

    2007-01-01

    In ranid frogs, the secretion of gonadotropins (GtHs), luteinizing hormone (LH), and follicle-stimulating hormone (FSH), is potently regulated by gonadal steroids. To better understand the gonadal regulation of GtHs at the molecular level, we elucidated the full-length cDNA sequences of LH and FSH beta subunits from the leopard frog, Rana pipiens. The cDNAs for LHbeta and FSHbeta were 1084 and 667 bp in size excluding the poly (A) tail, and encoded proteins of 138 and 127 amino acids, respectively. Using reverse-transcription polymerase chain reaction (RT-PCR), the messages for LHbeta and FSHbeta were found in the pituitary, but not in the brain, heart, kidney, or the liver. Semi-quantitative RT-PCR revealed a significant elevation of FSHbeta, but not LHbeta, in mature male R. pipiens 21 days after gonadectomy (GDX). 17beta-estradiol implant for 21 days in GDX male frogs significantly suppressed the levels of both LHbeta and FSHbeta transcripts, whereas 5alpha-dihydrotestosterone implant suppressed only the latter. Together, these results laid the groundwork for investigating gonadal regulation of GtHbeta subunits in a ranid frog. Importantly, these data also revealed differential feedback effects of an androgen and an estrogen upon GtHbeta expression. PMID:16920113

  5. 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.

  6. Does testis weight decline towards the Subarctic? A case study on the common frog, Rana temporaria

    NASA Astrophysics Data System (ADS)

    Hettyey, Attila; Laurila, Anssi; Herczeg, Gábor; Jönsson, K. Ingemar; Kovács, Tibor; Merilä, Juha

    2005-04-01

    Interpopulation comparisons of variation in resource availability and in allocation patterns along altitudinal and latitudinal gradients allow insights into the mechanisms shaping the life history of animals. Patterns of between-population differences in female life history traits have been studied intensively across a wide range of taxa, but similar investigations in males have remained scarce. To study if testis weight—a measure of reproductive investment—varies on a geographical scale in anurans, we focussed on the variation in relative testis weight (RelTW) and asymmetry in 22 populations of the common frog Rana temporaria along a 1,600-km latitudinal transect across the Scandinavian peninsula. We found that RelTW decreased towards the north. Body mass and body length both had independent positive effects on testes mass. We found evidence for directional asymmetry (DA) in testis weight with the right testis being larger than the left. The level of DA in testis weight was not related to latitude, but both body mass and testes mass had independent positive effects on asymmetry. We discuss the northwards decrease in RelTW in terms of a decreased reproductive investment as a possible consequence of harsher environmental conditions, and perhaps also, weaker sexual selection in the north than in the south.

  7. 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

  8. Directionality of phase locking in auditory nerve fibers of the leopard frog Rana pipiens pipiens.

    PubMed

    Schmitz, B; White, T D; Narins, P M

    1992-06-01

    A dorsal approach to the eighth nerve and free-field stimulation were used to investigate the effect of sound direction and intensity on phase locking in auditory nerve fibers of the leopard frog Rana pipiens pipiens. Tuning curves of 75 auditory neurons were analyzed (Fig. 2). Amphibian papillar neurons, but not basilar papillar neurons, exhibit significant phase locking to short tone bursts at the characteristic frequency (CF), the degree of phase locking (vector strength) decreasing with the neuron's CF (Figs. 3, 4 and 10E). Vector strength increases with sound pressure level to saturate about 20 dB above threshold, while the preferred firing phase is only slightly affected (Figs. 5 and 6). In contrast, sound direction hardly affects vector strength (Figs. 7, 8, 9A and 10A and C), but has a strong influence on the preferred firing phase (Figs. 7, 8, 9B and C, 10B and D): With respect to anterior tone presentation there are phase lags for ipsilateral and phase leads for posterior and contralateral presentation. Phase differences between both ears show a sinusoidal or cardioid/ovoidal directional characteristic; maximum differences are found with antero-lateral tone presentation (Fig. 11). The directionality of phase locking decreases with the neuron's CF (Fig. 10F) and only slightly changes with sound pressure level (Fig. 12). Thus, phase locking of amphibian papilla neurons can potentially provide intensity-independent information for sound localization. PMID:1507157

  9. Stable Isotope Stratigraphy of a Late Last Interglacial Speleothem from Rana, Northern Norway

    NASA Astrophysics Data System (ADS)

    Linge, Henriette; Lauritzen, Stein-Erik; Lundberg, Joyce

    2001-09-01

    A stalagmite from Rana, northern Norway, dated by the TIMS uranium-series technique, yields records of stable oxygen and carbon isotopes covering the period from late marine oxygen isotope substages (MIS) 5e to 5a, that is, 123,350 to 73,300 yr ago. Rapid growth (∼46 μm/yr) between 123,350 and 119,500 yr ago reflects climatic conditions favorable for speleothem growth. This period is characterized by century- to millennial-scale oscillations in both stable isotope records, where both the absolute values and the isotope ranges are similar to Holocene and older samples from the region. From 119,500 to 107,700 yr ago, speleothem growth was slow (∼0.7 μm/yr), and between 107,700 and 73,300 yr ago growth is barely noticeable (0.07 μm/yr). During the period of slow growth the stable isotope records show an overall enrichment trend. The transition between rapid and slow growth rate occurring sometime between 119,500 and 107,700 yr ago is believed to reflect the termination of interglacial climate in this region. The absence of detritus and corrosion features in the slowly deposited calcite suggests that the valley outside the cave remained sufficiently ice free for speleothem growth to occur until at least 73,300 yr ago.

  10. 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.

  11. First isolation and identification of Elizabethkingia meningoseptica from cultured tiger frog, Rana tigerina rugulosa.

    PubMed

    Xie, Zhen-Yu; Zhou, Yong-Can; Wang, Shi-Feng; Mei, Bing; Xu, Xian-Dong; Wen, Wan-Yao; Feng, Yong-Qin

    2009-07-01

    Elizabethkingia meningoseptica has been recognised as an occasional but serious opportunistic bacterial pathogen to human beings. Recently, it was frequently isolated from tiger frog, Rana tigerina rugulosa, with cataract disease, which is the most common disease of unknown aetiology of frogs in Hainan, China. The purpose of this study was to identify and characterise the bacterial strains isolated from the recent outbreaks of cataract disease in farmed tiger frog in Hainan, China, and to evaluate their pathogenicity to the frog and their sensitivity to 20 chemotherapeutic agents. The 16S rRNA gene sequences of strains W0701 (1478bp), W0702 (1477bp) and W0703 (1478bp) showed 98.6-98.7% similarity with the sequence of E. meningoseptica type strain (ATCC 13253) and 99.9-100% similarity with that of E. meningoseptica NTU 870424-IL. Six strains (W0701-W0706) were selected to represent 24 isolates retrieved from six moribund frogs. The morphological, physiological and biochemical characteristics of the six representative isolates were consistent with those of E. meningoseptica strains. The organisms were only susceptible to vancomycin and moderately susceptible to cefoperazone among the 20 investigated chemotherapeutic agents. Virulence test with strain W0702 was conducted and pathogenicity (by intramuscular injection) was demonstrated in the tiger frog. In conclusion, 24 isolates obtained from frogs with cataract disease were the E. meningoseptica strains highly pathogenic to tiger frog, and this is the first report of E. meningoseptica as a pathogen for tiger frog. PMID:19327918

  12. 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

  13. Development of tectal connectivity across metamorphosis in the bullfrog (Rana catesbeiana).

    PubMed

    Horowitz, Seth S; Simmons, Andrea Megela

    2010-01-01

    In the bullfrog (Rana catesbeiana), the process of metamorphosis culminates in the appearance of new visual and visuomotor behaviors reflective of the emergence of binocular vision and visually-guided prey capture behaviors as the animal transitions to life on land. Using several different neuroanatomical tracers, we examined the substrates that may underlie these behavioral changes by tracing the afferent and efferent connectivity of the midbrain optic tectum across metamorphic development. Intratectal, tectotoral, tectotegmental, tectobulbar, and tecto-thalamic tracts exhibit similar trajectories of neurobiotin fiber label across the developmental span from early larval tadpoles to adults. Developmental variability was apparent primarily in intensity and distribution of cell and puncta label in target nuclei. Combined injections of cholera toxin subunit β and Phaseolus vulgaris leucoagglutinin consistently label cell bodies, puncta, or fiber segments bilaterally in midbrain targets including the pretectal gray, laminar nucleus of the torus semicircularis, and the nucleus of the medial longitudinal fasciculus. Developmentally stable label was observed bilaterally in medullary targets including the medial vestibular nucleus, lateral vestibular nucleus, and reticular gray, and in forebrain targets including the posterior and ventromedial nuclei of the thalamus. The nucleus isthmi, cerebellum, lateral line nuclei, medial septum, ventral striatum, and medial pallium show more developmentally variable patterns of connectivity. Our results suggest that even during larval development, the optic tectum contains substrates for integration of visual with auditory, vestibular, and somatosensory cues, as well as for guidance of motivated behaviors. PMID:21266803

  14. 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

  15. 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

  16. 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.

  17. Population structure of Columbia spotted frogs (Rana luteiventris) is strongly affected by the landscape

    USGS Publications Warehouse

    Funk, W.C.; Blouin, M.S.; Corn, P.S.; Maxell, B.A.; Pilliod, D.S.; Amish, S.; Allendorf, F.W.

    2005-01-01

    Landscape features such as mountains, rivers, and ecological gradients may strongly affect patterns of dispersal and gene flow among populations and thereby shape population dynamics and evolutionary trajectories. The landscape may have a particularly strong effect on patterns of dispersal and gene flow in amphibians because amphibians are thought to have poor dispersal abilities. We examined genetic variation at six microsatellite loci in Columbia spotted frogs (Rana luteiventris) from 28 breeding ponds in western Montana and Idaho, USA, in order to investigate the effects of landscape structure on patterns of gene flow. We were particularly interested in addressing three questions: (i) do ridges act as barriers to gene flow? (ii) is gene flow restricted between low and high elevation ponds? (iii) does a pond equal a 'randomly mating population' (a deme)? We found that mountain ridges and elevational differences were associated with increased genetic differentiation among sites, suggesting that gene flow is restricted by ridges and elevation in this species. We also found that populations of Columbia spotted frogs generally include more than a single pond except for very isolated ponds. There was also evidence for surprisingly high levels of gene flow among low elevation sites separated by large distances. Moreover, genetic variation within populations was strongly negatively correlated with elevation, suggesting effective population sizes are much smaller at high elevation than at low elevation. Our results show that landscape features have a profound effect on patterns of genetic variation in Columbia spotted frogs.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Effects of fluoride on development and growth of Rana chensinensis embryos and larvae.

    PubMed

    Chai, Lihong; Dong, Suiming; Zhao, Hongfeng; Deng, Hongzhang; Wang, Hongyuan

    2016-04-01

    The present study examined the adverse effects of fluoride exposure on embryos and larvae of Rana chensinensis. Survival, morphological abnormalities, growth and development, time to metamorphosis and size at metamorphic climax of R. chensinensis were examined. Our results showed that embryos malformation occurred in all fluoride treatments. Morphological abnormalities of embryos are characterized by axial flexures, the extrusion of fin axis, edema, and ruffled dorsal and ventral fin. Additionally, 4.1mg F(-)/L and above could significantly inhibit embryos growth and development. On day 15, total length and weight of tadpole were significantly lower in 19.6 and 42.4 mg F(-)/L treatments compared to control. However, significant reductions in total length and weight were observed only at 42.4 mg F(-)/L on day 30. Moreover, significant metamorphic delay and decrease in the size at metamorphic climax were found in larvae exposed to 42.4 mg F(-)/L. Taken together, embryos of R. chensinensis are more vulnerable to fluoride exposure than their tadpoles. Our results suggested that the presence of high concentrations fluoride might increase mortality risk and a reduction in juvenile recruitment in the field by increasing embryos malformation, delaying metamorphosis and decreasing size at metamorphosis. PMID:26745004

  3. 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

  4. 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

  5. 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.

  6. 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

  7. Effects of 4-tert-Octylphenol on the incubation of eggs in Japanese brown frogs (Rana japonica).

    PubMed

    Kawaguchi, Hiroaki; Umekita, Yoshihisa; Souda, Masakazu; Yoshida, Hiroki

    2008-01-01

    4-tert-Octylphenol (OP), is an endocrine disruptor or surfactant widely used in herbicides. Its effects (0, 1 and 10 mg/l) on the incubation of eggs were examined using wild Japanese brown frogs (Rana japonica). In 10 mg/l OP, all the eggs were corrupted and no eggs developed. In 1 mg/l OP, 9.8% eggs developed and systemic edema, malformations such as crooked vertebrae and atrophy of the systemic muscles were observed in all the surviving tadpoles. These results suggested that OP use in paddy fields may affect the survival rate of wild frogs and induce malformation. PMID:18396791

  8. 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.

  9. 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.

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. 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

  15. 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

  16. 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.

  17. Adaptive divergence of the moor frog (Rana arvalis) along an acidification gradient

    PubMed Central

    2011-01-01

    Background Environmental stress can result in strong ecological and evolutionary effects on natural populations, but to what extent it drives adaptive divergence of natural populations is little explored. We used common garden experiments to study adaptive divergence in embryonic and larval fitness traits (embryonic survival, larval growth, and age and size at metamorphosis) in eight moor frog, Rana arvalis, populations inhabiting an acidification gradient (breeding pond pH 4.0 to 7.5) in southwestern Sweden. Embryos were raised until hatching at three (pH 4.0, 4.3 and 7.5) and larvae until metamorphosis at two (pH 4.3 and 7.5) pH treatments. To get insight into the putative selective agents along this environmental gradient, we measured relevant abiotic and biotic environmental variables from each breeding pond, and used linear models to test for phenotype-environment correlations. Results We found that acid origin populations had higher embryonic and larval acid tolerance (survival and larval period were less negatively affected by low pH), higher larval growth but slower larval development rates, and metamorphosed at a larger size. The phenotype-environment correlations revealed that divergence in embryonic acid tolerance and metamorphic size correlated most strongly with breeding pond pH, whereas divergence in larval period and larval growth correlated most strongly with latitude and predator density, respectively. Conclusion Our results suggest that R. arvalis has diverged in response to pH mediated selection along this acidification gradient. However, as latitude and pH were closely spatially correlated in this study, further studies are needed to disentangle the specific agents of natural selection along acidification gradients. Our study highlights the need to consider the multiple interacting selective forces that drive adaptive divergence of natural populations along environmental stress gradients. PMID:22182445

  18. 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

  19. 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. PMID:21472773

  20. 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

  1. Variation of total mercury concentrations in pig frogs (Rana grylio) across the Florida Everglades, USA.

    PubMed

    Ugarte, Cristina A; Rice, Kenneth G; Donnelly, Maureen A

    2005-06-01

    The Pig Frog (Rana grylio) is an aquatic frog that is an abundant component of the Everglades ecosystem. South Floridians recreationally and commercially hunt pig frogs in marshes throughout Water Conservation Areas (WCA) and Big Cypress National Preserve (BCNP) in South Florida. Most of these areas are under fish consumption advisories because of high levels of methylmercury present in game fish tissues. It is important to understand how mercury is distributed throughout Pig Frog populations because their consumption from certain areas may present a risk to human health. We sampled 88 pig frogs along a north-south transect through the Florida Everglades. There were substantial differences in total mercury (THg) concentrations from leg muscle tissue among sites. Total mercury in frog leg tissue was highest from areas protected from harvest in Everglades National Park (ENP), with a maximum concentration of 2051 ng/g wet mass. The THg levels in R. grylio leg tissue from most harvested areas are below Federal advisory limits. However, many pig frogs collected near Frog City, and one from WCA 3B and 3AN, harvested sites, had THg levels above the USEPA 0.3 mg/kg Fish Tissue Residue Criterion. Spatial patterns in the mercury found among pig frogs were similar to those of other wildlife species from the Everglades. We found frogs to have high THg levels in areas where alligators and mosquito fish also have high THg. THg in ENP frogs had an exponential relationship to SVL, we found no other relationship in frogs from other sites. Our data suggests that pig frogs should not be harvested or consumed from sites that exceed federal limits. PMID:15919527

  2. 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.

  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. PMID:20672415

  4. 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

  5. Cathelicidins from the Bullfrog Rana catesbeiana Provides Novel Template for Peptide Antibiotic Design

    PubMed Central

    Xie, Zeping; Wei, Lin; Yu, Haining; Wang, Yipeng

    2014-01-01

    Cathelicidins, a class of gene-encoded effector molecules of vertebrate innate immunity, provide a first line of defense against microbial invasions. Although cathelicidins from mammals, birds, reptiles and fishes have been extensively studied, little is known about cathelicidins from amphibians. Here we report the identification and characterization of two cathelicidins (cathelicidin-RC1 and cathelicidin-RC2) from the bullfrog Rana catesbeiana. The cDNA sequences (677 and 700 bp, respectively) encoding the two peptides were successfully cloned from the constructed lung cDNA library of R. catesbeiana. And the deduced mature peptides are composed of 28 and 33 residues, respectively. Structural analysis indicated that cathelicidin-RC1 mainly assumes an amphipathic alpha-helical conformation, while cathelicidin-RC2 could not form stable amphipathic structure. Antimicrobial and bacterial killing kinetic analysis indicated that the synthetic cathelicidin-RC1 possesses potent, broad-spectrum and rapid antimicrobial potency, while cathelicidin-RC2 exhibited very weak antimicrobial activity. Besides, the antimicrobial activity of cathelicidin-RC1 is salt-independent and highly stable. Scanning electron microscopy (SEM) analysis indicated that cathelicidin-RC1 kills microorganisms through the disruption of microbial membrane. Moreover, cathelicidin-RC1 exhibited low cytotoxic activity against mammalian normal or tumor cell lines, and low hemolytic activity against human erythrocytes. The potent, broad-spectrum and rapid antimicrobial activity combined with the salt-independence, high stability, low cytotoxic and hemolytic activities make cathelicidin-RC1 an ideal template for the development of novel peptide antibiotics. PMID:24675879

  6. Influence of temperature on thyroid hormone signaling and endocrine disruptor action in Rana (Lithobates) catesbeiana tadpoles.

    PubMed

    Hammond, S Austin; Veldhoen, Nik; Helbing, Caren C

    2015-08-01

    Thyroid hormones (THs) are essential for normal growth, development, and metabolic control in vertebrates. Their absolute requirement during amphibian metamorphosis provides a powerful means to detect and assess the impact of environmental contaminants on TH signaling in the field and laboratory. As poikilotherms, frogs can experience considerable temperature fluctuations. Previous work demonstrated that low temperature prevents precocious TH-dependent induction of metamorphosis. However, a shift to a permissive higher temperature allows resumption of the induced metamorphic program regardless of whether or not TH remains. We investigated the impact of temperature on the TH-induced gene expression programs of premetamorphic Rana (Lithobates) catesbeiana tadpoles following a single injection of 10pmol/g body wet weight 3,3',5-triiodothyronine (T3). Abundance profiles of several T3-responsive mRNAs in liver, brain, lung, back skin, and tail fin were characterized under permissive (24°C), nonpermissive (5°C), or temperature shift (5-24°C) conditions. While responsiveness to T3 was retained to varying degrees at nonpermissive temperature, T3 modulation of thibz occurred in all tissues at 5°C suggesting an important role for this transcription factor in initiation of T3-dependent gene expression programs. Low temperature immersion of tadpoles in water containing 10nM T3 and the nonsteroidal anti-inflammatory drug, ibuprofen, or the antimicrobial agent, triclosan, perturbed some aspects of the gene expression programs of tail fin and back skin that was only evident upon temperature shift. Such temporal uncoupling of chemical exposure and resultant biological effects in developing frogs necessitates a careful evaluation of environmental temperature influence in environmental monitoring programs. PMID:25583582

  7. 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.

  8. 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.

  9. 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

  10. 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

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

    PubMed

    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

  12. 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...

  13. 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

  14. 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

  15. Electrogenic active proton pump in Rana esculenta skin and its role in sodium ion transport.

    PubMed Central

    Ehrenfeld, J; Garcia-Romeu, F; Harvey, B J

    1985-01-01

    Kinetic and electrophysiological studies were carried out in the in vitro Rana esculenta skin, bathed in dilute sodium solution, to characterize the proton pump and coupling between sodium absorption (JNa+n) and proton excretion (JH+n). JNa+n and JH+n were both dependent on transepithelial potential (psi ms); hyperpolarizing the skin decreased JNa+n and increased JH+n; depolarization produced the opposite effects. Amiloride (5 X 10(-5) M) at a clamped psi ms of +50 mV inhibited JNa+n without affecting JH+n. Variations of psi ms or pH had identical effects on JH+n. Ethoxzolamide inhibited JH+n and simultaneously increased psi ms by 15-30 mV. These changes were accompanied by depolarization of the apical membrane potential psi mc from -47 to -25 mV and an increase in apical membrane resistance of 30%; no significant effects on basolateral membrane potential (psi cs) and resistance (Rb) nor on shunt resistance (Rj) were observed. The proton pump appears to be localized at the apical membrane. The proton pump was also inhibited by deoxygenation, oligomycin, dicyclohexylcarbodiimide and vanadate (100, 78, 83 and 100% inhibition respectively). The variations of JH+n and of the measured electrical currents were significantly correlated. These findings are supportive evidence of a primary active proton pump, electrogenic and strictly linked to aerobic metabolism. The current-voltage (I-V) relation of the proton pump was obtained as the difference in the I-V curves of the apical membrane extracted before and after proton-pump inhibition by ethoxzolamide during amiloride block of sodium transport. The proton-pump current (IP) was best described by a saturable exponential function of psi mc. Maximal pump current (ImaxP) was calculated to be 200 nequiv h-1 cm-2 at a psi mc of +50 mV and the pump reversal potential ERP was -130 mV. The effect of ethoxzolamide to depolarize psi mc was dependent on the relation between psi mc and ERP. Maximal induced depolarization occurred at a

  16. 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. PMID:20933347

  17. 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

  18. Hombres Sanos: Evaluation of a Social Marketing Campaign for Heterosexually Identified Latino Men Who Have Sex With Men and Women

    PubMed Central

    Zellner, Jennifer A.; Sañudo, Fernando; Fernandez-Cerdeño, Araceli; Hovell, Melbourne F.; Sipan, Carol L.; Engelberg, Moshe; Carrillo, Hector

    2010-01-01

    Objectives. We evaluated the effectiveness of Hombres Sanos [Healthy Men] a social marketing campaign to increase condom use and HIV testing among heterosexually identified Latino men, especially among heterosexually identified Latino men who have sex with men and women (MSMW). Methods. Hombres Sanos was implemented in northern San Diego County, California, from June 2006 through December 2006. Every other month we conducted cross-sectional surveys with independent samples of heterosexually identified Latino men before (n = 626), during (n = 752), and after (n = 385) the campaign. Respondents were randomly selected from 12 targeted community venues to complete an anonymous, self-administered survey on sexual practices and testing for HIV and other sexually transmitted infections. About 5.6% of respondents (n = 98) were heterosexually identified Latino MSMW. Results. The intervention was associated with reduced rates of recent unprotected sex with both females and males among heterosexually identified Latino MSMW. The campaign was also associated with increases in perception of HIV risk, knowledge of testing locations, and condom carrying among heterosexual Latinos. Conclusions. Social marketing represents a promising approach for abating HIV transmission among heterosexually identified Latinos, particularly for heterosexually identified Latino MSMW. Given the scarcity of evidence-based HIV prevention interventions for these populations, this prevention strategy warrants further investigation. PMID:21068423

  19. 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.

  20. 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. PMID:25218643

  1. Influence of sex and breeding condition on microhabitat selection and diet in the pig frog Rana grylio

    SciTech Connect

    Lamb, T.

    1984-04-01

    A 14-month study was conducted on the pig frog (Rana grylio) in SW Georgia. This species has a prolonged breeding season as males call from late March to September. Mature spermatozoa were present in the testes year-round, though seasonal testicular changes were detectable with spermatogenesis reaching a peak in June. Females contained mature ova from April through July and development of the following year's ova began in August. Stomachs of 122 postlarval specimens contained mainly anthropods. Coleoptera, Decopoda (Procambarus) and Odonata accounted for the majority of individual prey items, constituting 24.3, l9.8 and 11.9%, respectively. Intersexual dietary differences were apparent among adult frogs during the breeding season; variation in diet was strongly influenced by behavioral and habitat differences at this time.

  2. Developmental and thyroid hormone-induced expression of preprotemporin genes in the skin of Japanese mountain brown frog Rana ornativentris.

    PubMed

    Ohnuma, Aya; Conlon, J Michael; Iwamuro, Shawichi

    2009-04-01

    Temporins are a group of small, highly hydrophobic, antimicrobial peptides widely distributed in the skin of frogs from the Ranidae family. In order to examine the mechanisms of regulation of temporin gene expression, we measured expression levels of preprotemporin mRNA in the skin of the Japanese mountain brown frog Rana ornativentris, using a semiquantitative RT-PCR system. Preprotemporin mRNAs were not detected in skin prior to the onset of metamorphosis but their levels increased markedly during metamorphosis, reaching a maximum at the stages of metamorphic climax, suggesting a correlation with thyroid hormone concentrations. Consequently, we examined direct effects of triiodothyronine (T(3)) on in vivo preprotemporin gene expression. Treatment of adult animals with 2 x 10(-9) mol/L T(3) for 48 h raised the preprotemporin mRNA levels in skin by 1.5-fold compared with untreated controls. PMID:19456397

  3. 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.

  4. Changes in the micro-structure of the vestibular apparatus of tadpoles (Rana temporaria) developed in simulated weightlessness

    NASA Astrophysics Data System (ADS)

    Neubert, J.; Briegleb, W.

    The vestibular apparatus of tadpoles (Rana temporaria) exposed to simulated weightlessness was examined by electron microscopy. Extended exposure to simulated weightlessness is followed by significant alterations in the sensory epithelia and also in the otolith membrane. Large vacuoles, filled with necrobiotic mitochondria and fragments of endoplasmic reticulum, were concentrated in the region where an otolith membrane covers the hair cells but were mostly absent in zones of the epithelia with undifferentiated cells. The number of otoconia in the otolith membrane was diminished. The results were compared with data from space flight experiments and some concordance was noted. The possible connection between some unusual behavior of the tadpoles after weightlessness simulation and the structural alterations in the gravitational sensors was discussed.

  5. 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

  6. 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. PMID:24502715

  7. 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

  8. Evidence of a progesterone receptor in the liver of the green frog Rana esculenta and its down-regulation by 17 beta estradiol and progesterone.

    PubMed

    Paolucci, M; Guerriero, G; Ciarcia, G

    1999-12-01

    Progesterone is a versatile hormone showing an ample variety of effects. One of the numerous functions attributed to progesterone is the modulation of vitellogenesis in oviparous vertebrates. As a prerequisite for the possible involvement of progesterone in vitellogenesis modulation, we investigated the presence of a progesterone receptor (PR) in the liver of the female green frog Rana esculenta. 3H-Progesterone (3H-P) binding activity was found in both cytosol and nuclear extract of the liver of Rana esculenta. The progesterone-binding moiety showed the typical characteristics of a true receptor, such as high affinity, low capacity, and specificity for progesterone. It also bound to DNA-cellulose and was eluted with a linear salt gradient at a concentration of 0.05 M of NaCl. The progesterone-binding moiety was down regulated by steroid hormones, in that ovariectomy resulted in a significant increase, in both cytosol and nuclear extract, of 3H-P binding activity with respect to intact females. On the contrary, 3H-P binding activity was almost undetectable after estradiol and/or progesterone treatment. The progesterone binding moiety of Rana esculenta was analyzed by Western blotting with the aid of a monoclonal antibody raised against the subunits A and B of the chicken PR. An immunoreactive band of about 67 kDa was observed in the liver of both intact and treated females. The 67 kDa band showed an increased intensity in ovariectomized animals, while it was faint following treatment with estradiol and/or progesterone. This is the first report on the presence of a progesterone receptor (PR) in the liver of an amphibian. PR of Rana esculenta is down regulated by estradiol and/or progesterone and shows peculiar immunological and biochemical characteristics, which make it rather different from the PR of other vertebrates. PMID:10589507

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Effect of physiological stress on expression of glucose transporter 2 in liver of the wood frog, Rana sylvatica.

    PubMed

    Rosendale, Andrew J; Lee, Richard E; Costanzo, Jon P

    2014-12-01

    Glucose transporters (GLUTs) have been implicated in the survival of various physiological stresses in mammals; however, little is known about the role of these proteins in stress tolerance in lower vertebrates. The wood frog (Rana sylvatica), which survives multiple winter-related stresses by copiously mobilizing hepatic glycogen stores, is an interesting subject for the study of glucose transport in amphibians. We examined the effects of several physiological stresses on GLUT2 protein and mRNA levels in the liver of R. sylvatica. Using immunoblotting techniques to measure relative GLUT2 abundance, we found that GLUT2 numbers increased in response to organismal freezing, hypoxia exposure, and glucose loading; whereas, experimental dehydration and urea loading did not affect GLUT2 abundance. GLUT2 mRNA levels, assessed using quantitative real-time polymerase chain reaction, changed in accordance with protein abundance for most stresses, indicating that transcriptional regulation of GLUT2 occurs in response to stress. Overall, hepatic GLUT2 seems to be important in stress survival in R. sylvatica and is regulated to meet the physiological need to accumulate glucose. PMID:25384572

  16. Transcript expression of the freeze responsive gene fr10 in Rana sylvatica during freezing, anoxia, dehydration, and development.

    PubMed

    Sullivan, K J; Biggar, K K; Storey, K B

    2015-01-01

    Freeze tolerance is a critical winter survival strategy for the wood frog, Rana sylvatica. In response to freezing, a number of genes are upregulated to facilitate the survival response. This includes fr10, a novel freeze-responsive gene first identified in R. sylvatica. This study analyzes the transcriptional expression of fr10 in seven tissues in response to freezing, anoxia, and dehydration stress, and throughout the Gosner stages of tadpole development. Transcription of fr10 increased overall in response to 24 h of freezing, with significant increases in expression detected in testes, heart, brain, and lung when compared to control tissues. When exposed to anoxia; heart, lung, and kidney tissues experienced a significant increase, while the transcription of fr10 in response to 40% dehydration was found to significantly increase in both heart and brain tissues. An analysis of the transcription of fr10 throughout the development of the wood frog showed a relatively constant expression; with slightly lower transcription levels observed in two of the seven Gosner stages. Based on these results, it is predicted that fr10 has multiple roles depending on the needs and stresses experienced by the wood frog. It has conclusively been shown to act as a cryoprotectant, with possible additional roles in anoxia, dehydration, and development. In the future, it is hoped that further knowledge of the mechanism of action of FR10 will allow for increased stress tolerance in human cells and tissues. PMID:25280399

  17. Balantidium honghuensis n. sp. (Ciliophora: Trichostomatidae) from the rectum of Rana nigromaculata and R. limnocharis from Honghu Lake, China.

    PubMed

    Li, Ming; Li, Weidong; Zhang, Lei; Wang, Chong

    2013-08-01

    A new trichostome ciliate, Balantidium honghuensis n. sp., was isolated from the recta of Rana nigromaculata and R. limnocharis during parasite surveys in Honghu Lake, Hubei Province, central China in summer of 2010 and 2011. Its detailed morphometric characters based on LM and SEM studies were described herein. The organism is oval in shape and thickly ciliated. The vestibulum is "V" shaped and occupies about 1/3 to 2/5 of the body length. The vestibular and nearby regions possess strong peripheral fibers which form a marked axial fiber about the cytopharynx. More than 10 contractile vacuoles are distributed along the periphery of the latter body. Comparisions were made between this new species and B. sinensis Nie, 1935. They were discriminated from each other in terms of general body forms, body size, and vestibulum shapes. Besides, special attention was paid to its high-speed daughter swarmers which we believed to be the infective stage of B. honghuensis. Possible infection routes of anura amphibian balantidia were discussed. PMID:24039285

  18. Characterization of [3H]-diprenorphine binding in Rana pipiens: observations of filter binding enhanced by naltrexone.

    PubMed

    Newman, L C; Wallace, D R; Stevens, C W

    1999-02-01

    Initial studies were undertaken to examine the properties of [3H]-diprenorphine binding to Rana pipiens whole brain tissue using naltrexone for the definition of nonspecific binding. Saturation analysis demonstrated the binding of [3H]-diprenorphine to be saturable with a K(D) value of 0.65 nM and a Bmax value of 287.7 fmol/mg protein. Unlabeled diprenorphine dose-dependently displaced [3H]-diprenorphine from a single noninteractive site in competition studies which yielded a Ki of 0.22 nM. However, control studies in the absence of tissue revealed significant binding of [3H]-diprenorphine to the filter alone. Interestingly, [3H]-diprenorphine in the presence of unlabeled naltrexone as well as with unlabeled naloxone showed significantly greater binding to the filter than did [3H]-diprenorphine alone. Given this observation of increased nonspecific binding, an artificially low Bmax value would be expected. It is our hypothesis that the unlabeled nonspecific drug forms a complex with [3H]-diprenorphine preventing it from being effectively washed through the filter or the unlabeled drug itself is blocking the flow of [3H]-diprenorphine through the filter. The latter is unlikely however as other binding studies done in our lab using the radioligand [3H]-naloxone with unlabeled naltrexone do not show significant binding to the filter. PMID:10507757

  19. 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

  20. Local adaptation with high gene flow: temperature parameters drive adaptation to altitude in the common frog (Rana temporaria)

    PubMed Central

    Muir, A P; Biek, R; Thomas, R; Mable, B K

    2014-01-01

    Both environmental and genetic influences can result in phenotypic variation. Quantifying the relative contributions of local adaptation and phenotypic plasticity to phenotypes is key to understanding the effect of environmental variation on populations. Identifying the selective pressures that drive divergence is an important, but often lacking, next step. High gene flow between high- and low-altitude common frog (Rana temporaria) breeding sites has previously been demonstrated in Scotland. The aim of this study was to assess whether local adaptation occurs in the face of high gene flow and to identify potential environmental selection pressures that drive adaptation. Phenotypic variation in larval traits was quantified in R. temporaria from paired high- and low-altitude sites using three common temperature treatments. Local adaptation was assessed using QST–FST analyses, and quantitative phenotypic divergence was related to environmental parameters using Mantel tests. Although evidence of local adaptation was found for all traits measured, only variation in larval period and growth rate was consistent with adaptation to altitude. Moreover, this was only evident in the three mountains with the highest high-altitude sites. This variation was correlated with mean summer and winter temperatures, suggesting that temperature parameters are potentially strong selective pressures maintaining local adaptation, despite high gene flow. PMID:24330274

  1. 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

  2. The involvement of the endothelium in the relaxation of the leopard frog (Rana pipiens) aorta in response to acetylcholine.

    PubMed Central

    Knight, G. E.; Burnstock, G.

    1996-01-01

    1. The vasodilator response to acetylcholine (ACh) was investigated in the aortic arches of the leopard frog (Rana pipiens). 2. With adrenaline pre-constricted preparations, both ACh and sodium nitroprusside (SNP) caused concentration-dependent relaxations. Damage to the endothelial layer abolished relaxations to ACh, or reduced them greatly, but had no effect on vasodilatation to SNP. 3. NG-Nitro-L-arginine methyl ester (L-NAME; 1-100 microM) concentration-dependently inhibited relaxations in response to ACh, but had no effect on the ability of SNP to induce vasodilatation. 4. L-Arginine (L-Arg; 100-200 times the concentration of L-NAME) failed to reverse the inhibitory effect of L-NAME (1-100 microM) apart from one isolated instance. 5. In summary, this study has shown endothelium-dependent vasodilatation to ACh in an amphibian blood vessel that appears to be mediated via nitric oxide (NO). The response to ACh differs from many mammalian preparations in that the inhibitory effect of L-NAME could not be overcome by L-Arg, in addition to L-NAME itself having no direct effect upon the tone of the vessel. PMID:8832080

  3. 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.

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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

  12. 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

  13. 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

  14. Radiation-induced micronuclei in peripheral erythrocytes of Rana catesbeiana: an aquatic animal model for in vivo genotoxicity studies

    SciTech Connect

    Krauter, P.W.; Anderson, S.L.; Harrison, F.L.

    1987-01-01

    An in vivo micronucleus assay for peripheral erythrocytes of Rana catesbeiana tadpoles was developed and evaluated. The assay was used to determine the spontaneous frequency of micronuclei in circulating erythrocytes in tadpoles from two different populations, to define the time from administering the clastogen to the maximum micronucleus frequency in peripheral erythrocytes, and to determine the response to radiation. The spontaneous frequency of micronuclei in circulating erythrocytes of early-stage tadpoles was low, but higher than that of late-stage tadpoles. The time from the exposure of early-stage tadpoles to radiation (2.1 Gy) to the maximum micronucleus frequency was about 2 wk. The increase in frequency of micronuclei in peripheral erythrocytes of late-stage tadpoles receiving doses ranging from 0.5 to 3.0 Gy was linear with dose; a 3-fold increase was obtained with a dose of 3.0 Gy. The spontaneous frequency of micronuclei in erythrocytes and the increase in frequency induced by radiation appeared to differ in tadpoles from different populations. Quantification of micronuclei in the peripheral erythrocytes of R castesbeiana tadpoles provides a promising whole-animal system for studies of genotoxicity in aquatic environments.

  15. Radiation-induced micronuclei in peripheral erythrocytes of Rana catesbeiana: an aquatic animal model for in vivo genotoxicity studies

    SciTech Connect

    Krauter, P.W.; Anderson, S.L.; Harrison, F.L.

    1987-01-01

    An in vivo micronucleus assay for peripheral erythrocytes of Rana catesbeiana tadpoles was developed and evaluated. The assay was used to determine the spontaneous frequency of micronuclei in circulating erythrocytes in tadpoles from two different populations, to define the time from administering the clastogen to the maximum micronucleus frequency in peripheral erythrocytes, and to determine the response to radiation. The spontaneous frequency of micronuclei in circulating erythrocytes of early-stage tadpoles was low (3.6 +/- 2.8 micronuclei per 1,000 erythrocytes, MN o/oo), but higher than that of late-stage tadpoles (1.7 +/- 0.7 MN o/oo). The time from the exposure of early-stage tadpoles to radiation (2.1 Gy) to the maximum micronucleus frequency was about 2 wk. The increase in frequency of micronuclei in peripheral erythrocytes of late-stage tadpoles receiving doses ranging from 0.5 to 3.0 Gy was linear with dose; a 3-fold increase was obtained with a dose of 3.0 Gy. The spontaneous frequency of micronuclei in erythrocytes and the increase in frequency induced by radiation appeared to differ in tadpoles from different populations. Quantification of micronuclei in the peripheral erythrocytes of R catesbeiana tadpoles provides a promising whole-animal system for studies of genotoxicity in aquatic environments.

  16. 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.

  17. 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

  18. 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.

  19. 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)

  20. 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. PMID:22500921

  1. 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

  2. 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

  3. 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. PMID:25440532

  4. 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

  5. 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.

  6. The influence of water quality on the embryonic survivorship of the Oregon spotted frog (Rana pretiosa) in British Columbia, Canada.

    PubMed

    McKibbin, René; Dushenko, William T; vanAggelen, Graham; Bishop, Christine A

    2008-05-20

    In Canada, the Oregon spotted frog (Rana pretiosa) is a critically endangered species with only three known populations and an estimated breeding population of less than 400 located in isolated sites in the extreme south-west corner of British Columbia. Floating Nitex cages were used to assess embryonic survivorship in two populations of Oregon spotted frogs from 2002-2005. One population, near Aldergrove, BC experienced declines in population size while the other population, at Maria Slough, increased during the period 1997-2001. During embryo development, we measured trace metals, nutrients and physical parameters in the water at each site. These were used to test the hypothesis that water quality parameters were correlated with embryonic survivorship. During the study period in the declining population at Aldergrove R. pretiosa bred at two distinct sub sites (A and B) located 500 m apart within the wetland. Mean embryonic survivorship varied from 9% to 36% at sub site A and from 78% to 88% at sub site B whereas in the population in Maria Slough, the mean embryonic survivorship varied from 77% to 84%. Sulphate was the only water chemistry variable that differed significantly between the two study sites and was the highest at Maria Slough. A weak significant positive correlation was found between chloride and embryonic survivorship and conductivity and embryonic survivorship. A multiple regression model found conductivity was the only significant variable. We concluded that natural water chemistry conditions of low chloride and consequently low conductivity may be contributing to low embryonic survivorship in the population of R. pretiosa at MD Aldergrove, BC. PMID:18336868

  7. 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

  8. Stress-induced activation of the AMP-activated protein kinase in the freeze-tolerant frog Rana sylvatica.

    PubMed

    Rider, Mark H; Hussain, Nusrat; Horman, Sandrine; Dilworth, Stephen M; Storey, Kenneth B

    2006-12-01

    Survival in the frozen state depends on biochemical adaptations that deal with multiple stresses on cells including long-term ischaemia and tissue dehydration. We investigated whether the AMP-activated protein kinase (AMPK) could play a regulatory role in the metabolic re-sculpting that occurs during freezing. AMPK activity and the phosphorylation state of translation factors were measured in liver and skeletal muscle of wood frogs (Rana sylvatica) subjected to anoxia, dehydration, freezing, and thawing after freezing. AMPK activity was increased 2-fold in livers of frozen frogs compared with the controls whereas in skeletal muscle, AMPK activity increased 2.5-, 4.5- and 3-fold in dehydrated, frozen and frozen/thawed animals, respectively. Immunoblotting with phospho-specific antibodies revealed an increase in the phosphorylation state of eukaryotic elongation factor-2 at the inactivating Thr56 site in livers from frozen frogs and in skeletal muscles of anoxic frogs. No change in phosphorylation state of eukaryotic initiation factor-2alpha at the inactivating Ser51 site was seen in the tissues under any of the stress conditions. Surprisingly, ribosomal protein S6 phosphorylation was increased 2-fold in livers from frozen frogs and 10-fold in skeletal muscle from frozen/thawed animals. However, no change in translation capacity was detected in cell-free translation assays with skeletal muscle extracts under any of the experimental conditions. The changes in phosphorylation state of translation factors are discussed in relation to the control of protein synthesis and stress-induced AMPK activation. PMID:16973146

  9. 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

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. Alteration of the hypothalamic-pituitary-gonadal axis in estrogen- and androgen-treated adult male leopard frog, Rana pipiens

    PubMed Central

    Tsai, Pei-San; Kessler, Ann E; Jones, Jeremy T; Wahr, Kathleen B

    2005-01-01

    Background Gonadal steroids, in particular 5 alpha-dihydrotestosterone (DHT) and 17 beta-estradiol (E2), have been shown to feed back on the hypothalamic-pituitary-gonadal (HPG) axis of the ranid frog. However, questions still remain on how DHT and E2 impact two of the less-studied components of the ranid HPG axis, the hypothalamus and the gonad, and if the feedback effects are consistently negative. Thus, the goal of the study was to examine the effects of DHT and E2 upon the HPG axis of the gonadally-intact, sexually mature male leopard frogs, Rana pipiens. Methods R. pipiens were implanted with silastic capsules containing either cholesterol (Ch, a control), DHT, or E2 for 10 or 30 days. At each time point, steroid-induced changes in hypothalamic GnRH and pituitary LH concentrations, circulating luteinizing hormone (LH), and testicular histology were examined. Results Frogs implanted with DHT or E2 for 10 days did not show significant alterations in the HPG axis. In contrast, frogs implanted with hormones for 30 days had significantly lower circulating LH (for both DHT and E2), decreased pituitary LH concentration (for E2 only), and disrupted spermatogenesis (for both DHT and E2). The disruption of spermatogenesis was qualitatively similar between DHT and E2, although the effects of E2 were consistently more potent. In both DHT and E2-treated animals, a marked loss of all pre-meiotic germ cells was observed, although the loss of secondary spermatogonia appeared to be the primary cause of disrupted spermatogenesis. Unexpectedly, the presence of post-meiotic germ cells was either unaffected or enhanced by DHT or E2 treatment. Conclusions Overall, these results showed that both DHT and E2 inhibited circulating LH and disrupted spermatogenesis progressively in a time-dependent manner, with the longer duration of treatment producing the more pronounced effects. Further, the feedback effects exerted by both steroid hormones upon the HPG axis were largely negative

  15. 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., Jr.; 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

  16. 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

  17. 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.

  18. 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.

  19. 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. PMID:15650083

  20. 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. PMID:25586961

  1. Synergistic inhibition of the lethal fungal pathogen Batrachochytrium dendrobatidis: the combined effect of symbiotic bacterial metabolites and antimicrobial peptides of the frog Rana muscosa.

    PubMed

    Myers, Jillian M; Ramsey, Jeremy P; Blackman, Alison L; Nichols, A Elizabeth; Minbiole, Kevin P C; Harris, Reid N

    2012-08-01

    A powerful mechanism for protection against disease in animals is synergy between metabolites present in the natural microbiota of the host and antimicrobial peptides (AMPs) produced by the host. We studied this method of protection in amphibians in regard to the lethal disease chytridiomycosis, which is caused by Batrachochytrium dendrobatidis (Bd). In this study, we show that the AMPs of Rana muscosa, as well as the metabolite 2,4-diacetylphloroglucinol (2,4-DAPG) from Pseudomonas fluorescens, a bacterial species normally found on the skin of R. muscosa, were inhibitory to the growth of Bd in vitro. When both AMPs and 2,4-DAPG were used in growth inhibition assays, they worked synergistically to inhibit the growth of Bd. This synergy resulted in reduced minimum concentrations necessary for inhibition by either 2,4-DAPG or AMPs. This inhibitory concentration of AMPs did not inhibit the growth of a P. fluorescens strain that produced 2,4-DAPG in vitro, although its growth was inhibited at higher peptide concentrations. These data suggest that the AMPs secreted onto frog skin and the metabolites secreted by the resident beneficial bacteria may work synergistically to enhance protection against Bd infection on amphibian skin. These results may aid conservation efforts to augment amphibian skins' resistance to chytridiomycosis by introducing anti-Bd bacterial species that work synergistically with amphibian AMPs. PMID:22914957

  2. 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

  3. 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. PMID:25524181

  4. Seasonal variation and response to osmotic challenge in urea transporter expression in the dehydration- and freeze-tolerant wood frog, Rana sylvatica.

    PubMed

    Rosendale, Andrew J; Costanzo, Jon P; Lee, Richard E

    2012-08-01

    Urea accumulation is a universal response to osmotic challenge in anuran amphibians, and facilitative urea transporters (UTs) seem to play an important role in this process by acting in the osmoregulatory organs to mediate urea retention. Although UTs have been implicated in urea reabsorption in anurans, little is known about the physiological regulation of UT protein abundance. We examined seasonal variation in and effects of osmotic challenge on UT protein and mRNA levels in kidney and urinary bladder of the wood frog (Rana sylvatica), a terrestrial species that tolerates both dehydration and tissue freezing. Using immunoblotting techniques to measure relative UT abundance, we found that UT numbers varied seasonally, with a low abundance prevailing in the fall and winter, and higher levels occurring in the spring. Experimental dehydration of frogs increased UT protein abundance in the urinary bladder, whereas experimental urea loading decreased the abundance of UTs in kidney and bladder. Experimental freezing, whether or not followed by thawing, had no effect on UT numbers. UT mRNA levels, assessed using quantitative real-time polymerase chain reaction, did not change seasonally nor in response to any of our experimental treatments. These findings suggest that regulation of UTs depends on the nature and severity of the osmotic stress and apparently occurs posttranscriptionally in response to multiple physiological factors. Additionally, UTs seem to be regulated to meet the physiological need to accumulate urea, with UT numbers increasing to facilitate urea reabsorption and decreasing to prevent retention of excess urea. PMID:22639427

  5. Hepatocyte responses to in vitro freezing and β-adrenergic stimulation: Insights into the extreme freeze tolerance of subarctic Rana sylvatica.

    PubMed

    do Amaral, M Clara F; Lee, Richard E; Costanzo, Jon P

    2015-02-01

    The wood frog, Rana sylvatica LeConte 1825, is a freeze-tolerant amphibian widely distributed in North America. Subarctic populations of this species can survive experimental freezing to temperatures below -16 °C, whereas temperate populations tolerate freezing only at temperatures above -6 °C. We investigated whether hepatocytes isolated from frogs indigenous to Interior Alaska (subarctic) or southern Ohio (temperate) had distinct characteristics that could contribute to this variation in freeze tolerance capacity. Following in vitro freezing, cell damage, as assessed from lactate dehydrogenase leakage, was similar between samples from Alaskan and Ohioan frogs. Preincubation of cells in media containing glucose or urea, the two primary cryoprotectants used by R. sylvatica, markedly reduced freezing damage to hepatocytes; however, results suggested that cells of the northern phenotype were comparatively more amenable to cryoprotection by urea. Stimulation of isolated hepatocytes with β-adrenergic agonists, which simulates the freezing-induced cryoprotectant mobilization response, gave rates of glucose production from endogenous glycogen reserves that were similar between the populations. Our findings suggest that extreme freeze tolerance in subarctic R. sylvatica does not require an enhanced ability of the liver to resist freezing stress or rapidly mobilize cryoprotectant. PMID:25581737

  6. 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. PMID:26746863

  7. 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.

  8. 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.

  9. 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.

  10. Identification of a proglucagon cDNA from Rana tigrina rugulosa that encodes two GLP-1s and that is alternatively spliced in a tissue-specific manner.

    PubMed

    Yeung, C M; Chow, B K

    2001-11-01

    Glucagon plays a pivotal role in the regulation of metabolism. A glucagon receptor has been previously characterized in the frog, Rana tigrina rugulosa, and the frog and human glucagon receptors have been shown to possess similar binding affinities toward human glucagon. To study the structural evolution of glucagon peptide and its receptor in vertebrates, in the current study, a proglucagon cDNA from the same frog species was cloned. Interestingly, in contrast to the mammalian proglucagons that contain only one GLP-1 peptide, the frog proglucagon cDNA encodes two GLP-1 peptides (GLP-1A and GLP-1B) in addition to a glucagon peptide and a glucagon-like peptide 2 (GLP-2). By reverse transcriptase-PCR (RT-PCR) analysis, the proglucagon gene expression was widely detected in the brain, colon, small intestine, liver, lung, and pancreas, suggesting that the proglucagon-derived peptides have diverse functions in frogs. Moreover, tissue-specific alternative mRNA splicing was observed in the brain, colon, and pancreas. In these tissues, proglucagon transcripts with a 135 bp in frame deletion encoding GLP-1A were found. This splicing event in R. tigrina rugulosa is novel because it deletes a GLP-1 encoding sequence instead of the GLP-2 observed in other vertebrates. These findings should enhance understanding of the proglucagon evolution, structure, and expression in vertebrates. PMID:11703080

  11. Functional studies of a glucagon receptor isolated from frog Rana tigrina rugulosa: implications on the molecular evolution of glucagon receptors in vertebrates.

    PubMed

    Ngan, E S; Chow, L S; Tse, D L; Du, X; Wei, Y; Mojsov, S; Chow, B K

    1999-09-01

    In this report, the first amphibian glucagon receptor (GluR) cDNA was characterized from the liver of the frog Rana tigrina rugulosa. Functional expression of the frog GluR in CHO and COS-7 cells showed a high specificity of the receptor towards human glucagon with an EC(50) value of 0.8+/-0.5 nM. The binding of radioiodinated human glucagon to GluR was displaced in a dose-dependent manner only with human glucagon and its antagonist (des-His(1)-[Nle(9)-Ala(11)-Ala(16)]) with IC(50) values of 12.0+/-3. 0 and 7.8+/-1.0 nM, respectively. The frog GluR did not display any affinity towards fish and human GLP-1s, and towards glucagon peptides derived from two species of teleost fishes (goldfish, zebrafish). These fish glucagons contain substitutions in several key residues that were previously shown to be critical for the binding of human glucagon to its receptor. By RT-PCR, mRNA transcripts of frog GluR were located in the liver, brain, small intestine and colon. These results demonstrate a conservation of the functional characteristics of the GluRs in frog and mammalian species and provide a framework for a better understanding of the molecular evolution of the GluR and its physiological function in vertebrates. PMID:10471837

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. Los Alamos National Laboratory.

    ERIC Educational Resources Information Center

    Hammel, Edward F., Jr.

    1982-01-01

    Current and post World War II scientific research at the Los Alamos National Laboratory (New Mexico) is discussed. The operation of the laboratory, the Los Alamos consultant program, and continuation education, and continuing education activities at the laboratory are also discussed. (JN)

  17. 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

  18. 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

  19. 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

  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. 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. PMID:25593158

  2. 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

  3. 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.

  4. Stockpile Stewardship: Los Alamos

    ScienceCinema

    McMillan, Charlie; Morgan, Nathanial; Goorley, Tom; Merrill, Frank; Funk, Dave; Korzekwa, Deniece; Laintz, Ken

    2014-08-12

    "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.

  5. Interaction between autumnal temperature-photoperiod and experimentally induced transient cold shock influences proliferative activity in the brain of an adult terrestrial heterothermic vertebrate, Rana bergeri (Günther, 1986).

    PubMed

    Margotta, Vito

    2015-01-01

    It has been shown previously that in adult Rana esculenta, caught in nature, cold-shocked and brain-injured, encephalic cell proliferation is increased when capture and experiment occurred in spring and depressed when they occurred in autumn. Upon exclusive thermal stress cell proliferation appeared weak in spring and intense in autumn. The present study has investigated cold-shocked, but otherwise uninjured Rana bergeri to assess the impact of autumnal environment on encephalic cell proliferation. Lowering temperature--natural or experimental--seemed to exert a mild stimulation on the proliferative activity only in the forebrain. These results complete those previously obtained in spring and appear in substantial agreement with past reports about antithetical interactions between natural (season climate-photoperiod) and experimental (cold stimulus) environmental factors. However, the present results do not seem sufficient to explain the regenerative events described by past authors. A possible explanation of this discrepancy might be that if the spread between the autumnal environmental conditions and the entity of the cold shock is small the latter would be less effective. Alternatively, cold shock may need to be accompanied by further stimuli, such as surgical trauma (partial resection of brain tissue), to achieve extended stimulation and in the absence of those stimuli it would promote cell proliferation only in the forebrain, which is the region best provided with stand-by putative stem cells. PMID:27086419

  6. 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.

  7. 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.

  8. 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.

  9. 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...

  10. Interaction between spring temperature-photoperiod and experimentally induced transient cold shock influencing proliferative activity in the brain of an adult terrestrial heterothermic vertebrate, Rana bergeri (Günther, 1986).

    PubMed

    Chimenti, Claudio; Margotta, Vito

    2015-01-01

    The seasonal thermal cycle and correlated variations in photoperiod exert antithetical influences on the proliferation of the reserve brain stem cells, which are mostly ependymal and subependymal, of adult earth-dwelling heterothermic vertebrates upon deprivation of an encephalic area. Also, an induced sudden, transient thermal stress preceding surgical cerebral maiming increases or depresses the proliferation of these stand-by cells, depending on the season. In particular, the concomitance of spring temperature and photoperiod with a cold stimulus increases proliferation. To re-evaluate these findings, normal adults of Rana bergeri were exposed to a cold shock in spring time. The outlined patterns, as revealed by immunocytochemical detection of a proliferation-linked antigen, showed that those conditions affect only the forebrain, where immunoreactivity was identifiable in quiescent cells mostly located in peculiar telencephalic ependymal sites, known as zonae germinativae dorsales and ventrales, while the regions lying behind had no substantial proliferative response. These results may be due to the absence of further proliferative stimuli (surgical stress, cerebral ablation), so that only the stand-by cells in the encephalic areas more rich in such cells are activated to proliferate. The findings are in line with the subordinate position of Anurans as compared with Urodeles, which are the most gifted with spontaneous and experimentally induced reparative and regenerative capacity among vertebrates. PMID:27086439

  11. 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

  12. 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.

  13. 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…

  14. 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…

  15. RFQ development at Los Alamos

    SciTech Connect

    Wangler, T.P.; Crandall, K.R.; Stokes, R.H.

    1982-01-01

    The basic principles of the radio-frequency quadrupole (RFQ) linac are reviewed and a summary of past and present Los Alamos work is presented. Some beam-dynamics effects, important for RFQ design, are discussed. A design example is shown for xenon and a brief discussion of low-frequency RFQ structures is given.

  16. 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)

  17. Men and Families = Hombres y Familias, 1995.

    ERIC Educational Resources Information Center

    Men and Families Newsletter, 1995

    1995-01-01

    This newsletter, published in both English and Spanish versions, focuses on men and their roles in families. It stems from a 3-day workshop held at the National Autonomous University of Mexico (UNAM) in Mexico City. The 24 participating researchers and practitioners discussed ways to support men in fathering roles in order to enhance the…

  18. RFQ development at Los Alamos

    SciTech Connect

    Armstrong, D.D.; Cornelius, W.D.; Purser, F.O.; Jameson, R.A.; Wangler, T.P.

    1984-01-01

    We report recent progress on the two radio-frequency quadrupole (RFQ) structures being developed at Los Alamos. First, we report on the second 425-MHz RFQ for H/sup -/ acceleration, which is being built in a research effort to understand and further develop the RFQ. Second, we discuss progress on the 80-MHz cw RFQ for deuterons, which is being built for the Fusion Materials Irradiation Test (FMIT) facility.

  19. Bruce D. Judd, FAIA, Photographer August 1997. VIEW OF LOS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Bruce D. Judd, FAIA, Photographer August 1997. VIEW OF LOS ANGELES CITY HALL ELEVENTH FLOOR ELEVATOR LOBBY, FACING NORTH - 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 WEST ENTRANCE COURTYARD NORTHWEST CORNER SHOWING DAMAGED STONE, FACING NORTHWEST. - 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 FOURTEENTH FLOOR SOUTH OFFICE WING SHOWING TYPICAL DOOR HARDWARE, FACING SOUTH - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  2. 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 NINTH FLOOR NORTH CORRIDOR STAIR NUMBER NINE DOOR HARDWARE, FACING WEST. - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  3. 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

  4. Bruce D. Judd, FAIA, Photographer August 1997. VIEW OF LOS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Bruce D. Judd, FAIA, Photographer August 1997. VIEW OF LOS ANGELES CITY HALL SIXTH FLOOR ZONING ADMINISTRATORS OFFICE SHOWING WOOD AND GLASS PARTITIONS, FACING SOUTHEAST - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  5. 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

  6. 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

  7. 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

  8. 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 WEST ELEVATION FROM PARKING LOT ACROSS SPRING STREET, FACING EAST. - 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 TENTH FLOOR SOUTH WING CAFETERIA FOOD LINE, FACING NORTH - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA

  10. 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 FOURTEENTH FLOOR Y-CORRIDOR, FACING NORTHWEST - Los Angeles City Hall, 200 North Spring Street, Los Angeles, Los Angeles County, CA