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Sample records for leopard frog rana

  1. 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...

  2. 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...

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

    PubMed

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

    2013-08-01

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

  4. 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.

  5. 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.

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  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. 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.

  13. Clinal patterns in genetic variation for northern leopard frog (Rana pipiens): Conservation status and population histories

    USGS Publications Warehouse

    Stockwell, Craig A.; Fisher, Justin D.L.; McLean, Kyle I.

    2016-01-01

    The security of the northern leopard frog (Rana pipiens) varies spatially with populations east and west of North Dakota considered as secure and at risk, respectively. We used genetic markers to characterize the conservation status of northern leopard frog populations across North Dakota. We used multiple regression analyses and model selection to evaluate correlations of expected heterozygosity (HE) with the direct and additive effects of: i) geographic location,ii) wetland density and iii) average annual precipitation. There was lower genetic diversity in the western portion of the state due to lower levels of diversity for populations southwest of the Missouri River. This may reflect a refugial/colonization signature for the only non-glaciated area of North Dakota. Genetic diversity was also positively associated with wetland densities which is consistent with the reliance of this species on a mosaic of wetlands. Our findings suggest that populations in the southwestern part of North Dakota are of higher conservation concern, a finding consistent with the higher risk noted for northern leopard frog populations in most states west of North Dakota. Our findings also pose the hypothesis that climate change induced changes in wetland densities will reduce genetic diversity of northern leopard frog populations.

  14. 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.

  15. 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.

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

    PubMed

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

    1988-09-01

    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.

  17. Accelerated hatching of southern leopard frog (Rana sphenocephala) eggs in response to the presence of a crayfish Procambarus nigrocinctus predator

    Treesearch

    Daniel Saenz; James B. Johnson; Cory K. Adams; Gage H. Dayton

    2003-01-01

    Phenotypic plasticity, such as morphological and behavioral changes in response to predators, is common in larval anurans. Less is known about inducible defenses in the embryonic stages of development. We investigated the predation risk imposed by crayfish (Procambarus nigrocinctus) on southern leopard frog (Rana sphenocephala)...

  18. Haematoloechus sp. infection in wild-caught northern leopard frogs (Rana pipiens).

    PubMed

    Hsu, Charlie; Carter, D Bart; Williams, Donna; Besch-Williford, Cynthia

    2004-11-01

    Three male, wild-caught northern leopard frogs (Rana pipiens) died over a 1-week period with no previous history of clinical illness or disease. Noteworthy necropsy findings in one of the three frogs included depleted fat bodies in the coelomic cavity, indicating a poor nutritional condition, and a heavy parasite burden in the lungs. The location of infection and morphologic characteristics of the parasite were consistent with infection by the common lung fluke, Haematoloechus sp. In contrast to the heavy fluke load, only minor microscopic changes were observed in the lungs. Lesions included mild hypertrophy of the bronchiolar epithelium, with few submucosal inflammatory cells consisting predominantly of lymphocytes. Subsequent review of the literature revealed little about the pathologic effects of these parasites except that small numbers are thought to cause the host little harm. Our findings suggest that even with a large number of parasites, there is minimal pathologic impact in the lungs. We conclude that heavy lung-fluke infection should not be diagnosed as the sole or major etiology of death or illness in leopard frogs.

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

    PubMed

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

    2014-03-01

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

  20. 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

  1. Patterns of infection by lungworms, Rhabdias ranae and Haematoloechus spp., in northern leopard frogs: a relationship between sex and parasitism.

    PubMed

    Dare, Oluwayemisi K; Forbes, Mark R

    2009-04-01

    We examined a population of northern leopard frogs to determine whether sex biases in investment in immunity, previously reported for this host species under controlled exposures to lung nematodes, is predictive of patterns of parasitism in nature. We examined Rhabdias ranae and Haematoloechus spp. infections in 74 breeding adult, 28 non-breeding adult, and 53 juvenile frogs. Contrary to our predictions, R. ranae prevalence and mean abundance were higher in breeding female frogs (prevalence: 39.4%, abundance: 3.05 +/- 0.85) than on breeding males (prevalence: 26.0%, abundance: 1.17 +/- 0.52), although no sex bias was observed among non-breeding adults or juvenile frogs. Female frogs also carried larger R. ranae worms, on average, than did males (females: 6407.38 microm +/- 153.80; males: 5198 microm +/- 131.09), regardless of age or breeding condition. We observed no sex-linked patterns of parasitism by Haematoloechus spp. worms in either adult or juvenile frogs. Alternative hypotheses, such as differences among sexes in the selection of thermal clines for hibernation, may explain the observed female bias in parasitism by nematode lungworms in nature and, thus, need to be considered.

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

    PubMed

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

    2008-07-30

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

  3. 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.

  4. 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

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

    PubMed

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

    2003-05-01

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

  6. 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.

  7. The influence of predator threat on the timing of a life-history switch point: predator-induced hatching in the southern leopard frog (Rana sphenocephala)

    Treesearch

    James B. Johnson; Daniel Saenz; Cory K. Adams; Richard N. Conner

    2003-01-01

    Abstract: We tested the hypotheses that potential egg predators, crayfish Procambarus nigrocinctus and dytiscid Cybister sp. larvae, would accelerate the timing of hatching and that a larval predator, dragonfly naiad Anax junius, would delay hatching in the southern leopard frog (Rana...

  8. 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...

  9. 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...

  10. Extinction of montane populations of the northern leopard frog (Rana pippins) in Colorado

    USGS Publications Warehouse

    Corn, Paul Stephen; Fogleman, James C.

    1984-01-01

    Between 1973 and 1982 nine populations of the northern leopard frog in the Red Feather Lakes region of Larimer County, Colorado, failed in reproduce. These failures all resulted in extinction of the populations. One area formerly supporting a population was recolonized in 1980, but no frogs were observed at any of the nine sites in 1981 or 1982. Six of the populations went extinct because the breeding ponds dried up. The remaining populations were small enough to be susceptible to random events, but the nature of these events is unknown.

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

    PubMed

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

    2003-04-01

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

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

    PubMed Central

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

    2003-01-01

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

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

    PubMed Central

    2010-01-01

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

  14. Small frogs get their worms first: the role of nonodonate arthropods in the recruitment of Haematoloechus coloradensis and Haematoloechus complexus in newly metamorphosed northern leopard frogs, Rana pipiens, and woodhouse's toads, Bufo woodhousii.

    PubMed

    Bolek, Matthew G; Janovy, John

    2007-04-01

    Studies on the life cycles and epizootiology of North American frog lung flukes indicate that most species utilize odonates as second intermediate hosts; adult frogs become infected by ingesting odonate intermediate hosts. Newly metamorphosed frogs are rarely infected with these parasites, predominantly because they are gape-limited predators that cannot feed on large intermediate hosts such as dragonflies. We examined the role of the frog diet and potential intermediate hosts in the recruitment of the frog lung fluke, Haematoloechus coloradensis, to metamorphosed northern leopard frogs (Rana pipiens), Woodhouse's toads (Bufo woodhousii), and bullfrogs (Rana catesbeiana) from western Nebraska. Because of the uncertain validity of H. coloradensis as a distinct species from Haematoloechus complexus, morphological characters of both species were reevaluated and the life cycles of both species were completed in the laboratory. The morphological data on H. coloradensis and H. coimplexus indicate that they differ in their oral sucker to pharynx ratio, uterine loop distribution, and placement of vitelline follicles. However, in terms of their life cycles, both species are quite similar in their use of physid snails as first intermediate hosts, a wide range of nonodonate and odonate arthropods as second intermediate hosts, and leopard frogs and toads as definitive hosts. These results indicate that H. coloradensis and H. complexus are generalists at the second intermediate host level and might be able to infect newly metamorphosed leopard frogs and toads by using small nonodonate arthropods more commonly than other frog lung fluke species. Comparisons of population structure of adult flukes in newly metamorphosed leopard frogs indicate that the generalist nature of H. coloradensis metacercariae enables it to colonize young of the year leopard frogs more commonly than other Haematoloechus spp. that only use odonates as second intermediate hosts. In this respect, the

  15. Vitellogenic cycles in laboratory-maintained females of the leopard frog, Rana pipiens.

    PubMed

    Smalley, K N; Nace, G W

    1983-05-01

    As a part of studies on the reproduction of laboratory maintained frogs, wild-caught Rana pipiens were ovulated and maintained at 22-27 degrees C for up to 18 months. Vitellogenic oocytes were periodically staged and counted, and a "maturity index" was calculated to assess the progress of the vitellogenic cycle. The initial cycle was similar to that of wild frogs except that the first oocytes to reach stage 5 (mature eggs) usually began to degenerate before later starting oocytes became mature. In addition, a second cycle began before the first was completed. After more than 1 year at room temperature, abnormal cycles were common. Ovaries of such animals contained very few mature eggs. Many of their oocytes were in early stages of vitellogenesis or, if pigmented, had begun to degenerate. These deficiencies were partially corrected in females placed in 4 degrees C for 4-6 weeks. The average number of mature eggs increased 15-fold and ovary weights more than doubled. Oviduct weights almost doubled. Although the rates of cooling, photoperiod, and nutritional status could be important influences, the results imply that cold treatment alone increases estrogen secretion. We suggest that low estrogen secretion may account for the reproductive deficiencies seen in R. pipiens cultured at room temperature.

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

    EPA Science Inventory

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

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

    EPA Science Inventory

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

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

    SciTech Connect

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

    2008-09-15

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

  19. 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.

  20. 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.

  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. 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...

  3. Cryptic invasion of Northern Leopard Frogs (Rana pipiens) across phylogeographic boundaries and a dilemma for conservation of a declining amphibian

    USGS Publications Warehouse

    O'Donnell, Ryan P.; Drost, Charles A.; Mock, Karen E.

    2017-01-01

    Anthropogenic introduction of species is a major contributor to loss of biodiversity. Translocations within the range of a species are less frequently recognized, but have the potential for negative effects as well. Genetic mixing may lead to loss of local adaptations or further decline through outbreeding depression. These cryptic invasions may be quite difficult to recognize, but genetic tools can be used to recognize and monitor such intraspecific introductions. Conversely, translocations within species can be an important conservation tool to reduce inbreeding depression and replace lost genetic diversity. Thus, cryptic invasions can be either an aid or a hindrance to conservation efforts. We tested for the presence of non-native genotypes and assessed the extent and nature of introgression in populations of Northern Leopard Frog (Rana pipiens) in the southwestern US, where populations have declined to a few remnant populations. The most abundant and diverse complex of populations in the region contained a mitochondrial haplotype that was not native to the western US, probably resulting from the introduction of released pets, laboratory animals, or release during fish stocking. These non-native haplotypes were well integrated into a large complex of ponds and lakes, contributing to high genetic diversity in this area. Logistically, the geographic extent of non-native genetic influence within this population precludes eliminating or controlling the non-native component of this population. We recommend assessing the progress and fate of the introgression over time—along with population fitness parameters—to determine whether this introduction is beneficial or detrimental to population persistence. Meanwhile, translocations from nearby locations with similar environmental conditions have the best prospects for avoiding problems with outbreeding depression in other declining populations and will also most effectively preserve regional genetic diversity.

  4. 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...

  5. Possible mechanisms responsible for the reduced intestinal flora in hibernating leopard frogs (Rana pipiens).

    PubMed Central

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

    1988-01-01

    Mechanisms and factors that normally control the large intestinal flora were investigated to determine whether changes in these parameters could account for the decreased bacterial concentration and facultative nature of the flora found in hibernating frogs. It appeared that low temperatures and limited nutrients were the main factors responsible for the decrease in the bacterial concentration and may also have been responsible for the increase in the proportions of facultative organisms, since no change in the redox potential was seen. The hibernating frogs were extremely sluggish in the removal of India ink particles from the circulatory system by the Kupffer cells of the liver compared with nonhibernating frogs. They were unable to mount an antibody response to bovine serum albumin, but their serum did exhibit killing of Pseudomonas paucimobilis, suggesting opsonization by preformed antibody and complement. The role of these host factors in protecting the hibernating frog against this indigenous flora is discussed. PMID:3263839

  6. 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

  7. 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.

  8. Leopard frog and wood frog reproduction in Colorado and Wyoming

    USGS Publications Warehouse

    Corn, Paul Stephen; Livo, Lauren J.

    1989-01-01

    Between 1978 and 1988, we recorded reproductive information from populations of ranid frogs in Colorado and Wyoming. Egg masses from five plains and montane populations of northern leopard frogs (Rana pipiens) contained 645-6272 eggs (x̄ = 3045, N = 68 egg masses). In two montane populations of wood frogs (Rana sylvatica) numbers of eggs per egg mass varied from 711-1248 (x̄ = 876, N = 15) and probably were equal to total clutch size. Mean hatching success was 90% in egg masses from one R. sylvatica population and ranged from 70% to 99% in R. pipiens egg masses. Rana pipiens egg masses from one location were assigned to three overlapping size distributions, which we believe reflects the underlying age structure of female frogs.

  9. Induction of cytochrome P450-associated monooxygenases in northern leopard frogs, Rana pipiens, by 3,3{prime},4,4{prime},5-pentachlorobiphenyl

    SciTech Connect

    Huang, Y.; Jung, R.E.; Karasov, W.H.; Melancon, M.J.

    1998-08-01

    In the past decade, biochemical and physiological characteristics such as hepatic detoxifying system. DNA adducts, thyroid malfunction, and acetylcholinesterase inhibition have been used extensively as biomarkers for contaminant exposure. Northern leopard frogs (Rana pipiens) were injected intraperitoneally either with a solution of polychlorinated biphenyl (PCB) 126 m corn oil at a concentration of 0.2, 0.7, 2.3, or 7.8 mg/kg body weight or with corn oil alone. Appropriate assay conditions with hepatic microsomes were determined for four cytochrome P450-associated monooxygenases: ethoxyresorufin-O-dealkylase (EROD), methoxy-ROD (MROD), benzyloxy-ROD (BROD), and pentoxy-ROD (PROD). One week after PCB administration, the specific activities of EROD, MROD, BROD, and PROD were not elevated at doses {le}0.7 mg/kg (p > 0.05) but were significantly increased at doses {ge}2.3 mg/kg compared to the control groups (p < 0.05). The increased activities of these four enzymes were 3 to 6.4 times those in the control groups. The increased activities were maintained for at least 4 weeks. Because of a lack of induction at low doses of PCB 126, which were still relatively high compared to currently known environmental concentration, the authors suspect that EROD, MROD, BROD, and PROD activities are not sensitive biomarkers for coplanar PCB exposure in leopard frogs.

  10. 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.

  11. Variations in the expressed antimicrobial peptide repertoire of northern leopard frog (Rana pipiens) populations suggest intraspecies differences in resistance to pathogens.

    PubMed

    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

    2009-12-01

    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.

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

    PubMed

    Lehman, G C

    1978-12-01

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

  13. 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.

  14. Impacts of agriculture on the parasite communities of northern leopard frogs (Rana pipiens) in southern Quebec, Canada.

    PubMed

    King, K C; McLaughlin, J D; Gendron, A D; Pauli, B D; Giroux, I; Rondeau, B; Boily, M; Juneau, P; Marcogliese, D J

    2007-12-01

    Given that numerous amphibians are suffering population declines, it is becoming increasingly important to examine the relationship between disease and environmental disturbance. Indeed, while many studies relate anthropogenic activity to changes in the parasitism of snails and fishes, little is known of the impact on the parasites of amphibians, particularly from agriculture. For 2 years, the parasite communities of metamorphic northern leopard frogs from 7 agricultural wetlands were compared with those from 2 reference wetlands to study differences in parasite community diversity and abundance of various species under pristine conditions and 3 categories of disturbance: only agricultural landscape, only pesticides, and agricultural landscape with pesticides. Agricultural (and urban) area was negatively related to species richness, and associated with the near absence of adult parasites and species that infect birds or mammals. We suggest that agriculture and urbanization may hinder parasite transmission to frogs by limiting access of other vertebrate hosts of their parasites to wetlands. The only parasite found at all localities was an unidentified echinostome infecting the kidneys. This parasite dominated communities in localities surrounded by the most agricultural land, suggesting generalist parasites may persist in disrupted habitats. Community composition was associated with dissolved organic carbon and conductivity, but few links were found with pesticides. Pollution effects may be masked by a strong impact of land use on parasite transmission.

  15. Phylogeography of Declining Relict and Lowland Leopard Frogs in the Desert Southwest of North America

    EPA Science Inventory

    We investigated the phylogeography of the closely related relict leopard frog (Rana onca) and lowland leopard frog (R. yavapaiensis) – two declining anurans from the warm-desert regions of southwestern North America. We used sequence data from two mitochondrial DNA genes to asses...

  16. Phylogeography of Declining Relict and Lowland Leopard Frogs in the Desert Southwest of North America

    EPA Science Inventory

    We investigated the phylogeography of the closely related relict leopard frog (Rana onca) and lowland leopard frog (R. yavapaiensis) – two declining anurans from the warm-desert regions of southwestern North America. We used sequence data from two mitochondrial DNA genes to asses...

  17. Estrogenic exposure affects metamorphosis and alters sex ratios in the northern leopard frog (Rana pipiens): identifying critically vulnerable periods of development.

    PubMed

    Hogan, Natacha S; Duarte, Paula; Wade, Michael G; Lean, David R S; Trudeau, Vance L

    2008-05-01

    During the transformation from larval tadpole to juvenile frog, there are critical periods of metamorphic development and sex differentiation that may be particularly sensitive to endocrine disruption. The aim of the present study was to identify sensitive developmental periods for estrogenic endocrine disruption in the northern leopard frog (Rana pipiens) using short, targeted exposures to the synthetic estrogen, ethinylestradiol (EE2). Post-hatch tadpoles (Gosner stage 27) were exposed over five distinct periods of metamorphosis: early (stage 27-30), mid (stage 30-36), early and mid (stage 27-36), late (stage 36-42), and the entire metamorphic period (chronic; stage 27-42). For each period, animals were sampled immediately following the EE2 exposure and at metamorphic climax (stage 42). The effects of EE2 on metamorphic development and sex differentiation were assessed through measures of length, weight, developmental stage, days to metamorphosis, sex ratios and incidence of gonadal intersex. Our results show that tadpoles exposed to EE2 during mid-metamorphosis were developmentally delayed immediately following exposure and took 2 weeks longer to reach metamorphic climax. In the unexposed groups, there was low proportion (0.15) of intersex tadpoles at stage 30 and gonads appeared to be morphologically distinct (male and female) in all individuals by stage 36. Tadpoles exposed early in development displayed a strong female-biased sex ratio compared to the controls. Moreover, these effects were also seen at metamorphic climax, approximately 2-3 months after the exposure period, demonstrating that transient early life-stage exposure to estrogen can induce effects on the reproductive organs that persist into the beginning of adult life-stages.

  18. Assessment of the risk of solar ultraviolet radiation to amphibians. I. Dose-dependent induction of hindlimb malformations in the northern leopard frog (Rana pipiens).

    PubMed

    Ankley, Gerald T; Diamond, Stephen A; Tietge, Joseph E; Holcombe, Gary W; Jensen, Kathleen M; Defoe, David L; Peterson, Ryan

    2002-07-01

    A number of environmental stressors have been hypothesized as responsible for recent increases in limb malformations in several species of North American amphibians. The purpose of this study was to generate dose-response data suitable for assessing the potential role of solar ultraviolet (UV) radiation in causing limb malformations in a species in which this phenomenon seemingly is particularly prevalent, the northern leopard frog (Rana pipiens). Frogs were exposed from early embryonic stages through complete metamorphosis to varying natural sunlight regimes, including unaltered (100%) sunlight, sunlight subjected to neutral density filtration to achieve relative intensities of 85%, 75%, 65%, 50%, and 25% of unaltered sunlight, and sunlight filtered with glass or acrylamide to attenuate, respectively, the UVB (290-320 nm) and UVB plus UVA (290-380 nm) portions of the spectrum. The experiments were conducted in a controlled setting, with continual monitoring of UVB, UVA, and visible light to support a robust exposure assessment. Full sunlight caused approximately 50% mortality of the frogs during early larval development; no significant treatment-related mortality occurred under any of the other exposure regimes, including 100% sunlight with glass or acrylamide filtration. There was a dose-dependent (p < 0.0001) induction of hindlimb malformations in the frogs, with the percentage of affected animals ranging from about 97% under unaltered sunlight to 0% in the 25% neutral density treatment. Malformations were comprised mostly of missing or truncated digits, and generally were bilateral as well as symmetrical. Filtration of sunlight with either glass or acrylamide both significantly reduced the incidence of malformed limbs. The estimated sunlight dose resulting in a 50% limb malformation rate (ED50) was 63.5%. The limb ED50 values based on measured sunlight intensities corresponded to average daily doses of 4.5 and 100 Wh x m(-2) for UVB and UVA, respectively

  19. Chiricahua leopard frog status in the Galiuro Mountains, Arizona, with a monitoring framework for the species' entire range

    Treesearch

    Lawrence L. C. Jones; Michael J. Sredl

    2005-01-01

    The Chiricahua leopard frog (Rana chiricahuensis) was historically widespread in suitable habitat throughout its range. Reports of recent population declines led to inventories of Chiricahua leopard frog localities. Surveys reported here establish a new baseline of occurrence in the Galiuros: only two of 21 historical localities were found to be...

  20. The Classroom Animal: The Leopard Frog.

    ERIC Educational Resources Information Center

    Science and Children, 1985

    1985-01-01

    Describes the natural history of the leopard frog and factors which make it appropriate for short-term study in the classroom. Information on the frog's habits, life cycle, housing, care, and health is included. (DH)

  1. 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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Semi-automated identification of leopard frogs

    USGS Publications Warehouse

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

    2014-01-01

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

  3. Leopard frog PCB levels and evaluation of EROD as a biomarker in Green Bay ecosystem

    SciTech Connect

    Huang, Y.W.; Karasov, W.H.; Patnode, K.P.

    1995-12-31

    The induction of mixed function oxidases has been shown to be a promising biomarker in many taxa of wildlife, though not yet tested for amphibians. The three hypotheses tested in this study were (1) activities of hepatic EROD of leopard frog (Rana pipiens) are induced following exposure to planar chlorinated PCBs, (2) tissue PCB residue levels of leopard frogs are positively correlated with their wetland sediment PCB levels, and (3) EROD activities are positively correlated with tissue PCB concentrations and sediment PCB. In the laboratory, EROD was increased 2--3 times seven days after i.p. injection with PCB 126 at doses {ge} 2.3 ppm (wet mass basis). Leopard frogs from seven sites along the Lower Fox River and Green Bay in 1994--1995 were assayed for hepatic EROD activities and total PCB levels in carcasses. Tissue PCB levels ranged from 3 to 152 ppb (including coplanar congeners) and were highest from sites with higher sediment PCB. EROD activity in frogs collected in August--September was not significantly correlated with frog body mass and was similar among sites with one exception. There was no significant correlation between EROD activity and tissue PCB concentration. This result was consistent with the fact that the frogs collected from the Green Bay ecosystem had relatively low PCB levels compared with what was required for induction in the laboratory. The authors conclude that EROD activity is not a sensitive biomarker of PCB exposure in leopard frogs in this ecosystem.

  4. A new species of leopard frog (Anura: Ranidae) from the urban northeastern US.

    PubMed

    Newman, Catherine E; Feinberg, Jeremy A; Rissler, Leslie J; Burger, Joanna; Shaffer, H Bradley

    2012-05-01

    Past confusion about leopard frog (genus Rana) species composition in the Tri-State area of the US that includes New York (NY), New Jersey (NJ), and Connecticut (CT) has hindered conservation and management efforts, especially where populations are declining or imperiled. We use nuclear and mitochondrial genetic data to clarify the identification and distribution of leopard frog species in this region. We focus on four problematic frog populations of uncertain species affiliation in northern NJ, southeastern mainland NY, and Staten Island to test the following hypotheses: (1) they are conspecific with Rana sphenocephala or R. pipiens, (2) they are hybrids between R. sphenocephala and R. pipiens, or (3) they represent one or more previously undescribed cryptic taxa. Bayesian phylogenetic and cluster analyses revealed that the four unknown populations collectively form a novel genetic lineage, which represents a previously undescribed cryptic leopard frog species, Rana sp. nov. Statistical support for R. sp. nov. was strong in both the Bayesian (pp=1.0) and maximum-likelihood (bootstrap=99) phylogenetic analyses as well as the Structure cluster analyses. While our data support recognition of R. sp. nov. as a novel species, we recommend further study including fine-scaled sampling and ecological, behavioral, call, and morphological analyses before it is formally described. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. A new species of leopard frog (Anura: Ranidae) from the urban northeastern US

    PubMed Central

    Newman, Catherine E.; Feinberg, Jeremy A.; Rissler, Leslie J.; Burger, Joanna; Shaffer, H. Bradley

    2014-01-01

    Past confusion about leopard frog (genus Rana) species composition in the Tri-State area of the US that includes New York (NY), New Jersey (NJ), and Connecticut (CT) has hindered conservation and management efforts, especially where populations are declining or imperiled. We use nuclear and mitochondrial genetic data to clarify the identification and distribution of leopard frog species in this region. We focus on four problematic frog populations of uncertain species affiliation in northern NJ, southeastern mainland NY, and Staten Island to test the following hypotheses: (1) they are conspecific with Rana sphenocephala or R. pipiens, (2) they are hybrids between R. sphenocephala and R. pipiens, or (3) they represent one or more previously undescribed cryptic taxa. Bayesian phylogenetic and cluster analyses revealed that the four unknown populations collectively form a novel genetic lineage, which represents a previously undescribed cryptic leopard frog species, Rana sp. nov. Statistical support for R. sp. nov. was strong in both the Bayesian (pp = 1.0) and maximum-likelihood (bootstrap = 99) phylogenetic analyses as well as the Structure cluster analyses. While our data support recognition of R. sp. nov. as a novel species, we recommend further study including fine-scaled sampling and ecological, behavioral, call, and morphological analyses before it is formally described. PMID:22321689

  6. 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.

  7. 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

  8. A new species of Rhabdias from lungs of the wood frog, Rana sylvatica, in North America: the last sibling of Rhabdias ranae?

    PubMed

    Tkach, Vasyl V; Kuzmin, Yuriy; Pulis, Eric E

    2006-06-01

    Rhabdias bakeri n. sp. is described from specimens found in lungs of the wood frog, Rana sylvatica, from North Dakota. The new species has previously been mistakenly identified as Rhabdias ranae Walton, 1929, a common parasite of the leopard frog, Rana pipiens. The new species differs from R. ranae and Rhabdias joaquinensis Ingles, 1935 by the shape and size of pseudolabia, shape and size of buccal capsule, and wider esophageal bulb. Molecular analysis based on the partial sequences of nuclear 18S rDNA gene, complete sequences of internal transcribed spacer region, and partial sequences of 28S gene demonstrates clear differences between Rhabdias from Ra. sylvatica and Ra. pipiens, and supports the status of R. bakeri as a new species.

  9. Naloxone blocks the analgesic action of levorphanol but not of dextrorphan in the leopard frog.

    PubMed

    Stevens, C W; Pezalla, P D

    1984-05-28

    Intraspinal injection of levorphanol (3 micrograms) at the lumbar area of the leopard frog, Rana pipiens, induced analgesia which was completely blocked by co-injection of naloxone (3 micrograms), whereas dextrorphan (3 micrograms) induced analgesia which was unaffected by naloxone. Subcutaneous levorphanol (20 or 80 mg/kg) induced a dose-dependent analgesia which was blocked by concurrent naloxone (2 mg/kg), while only the higher dose of dextrorphan (80 mg/kg) induced analgesia which was unaffected by concurrent naloxone at 8 or 80 mg/kg. These data are the first to indicate naloxone-insensitive, dextrorphan-induced analgesia.

  10. 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...

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

    USDA-ARS?s Scientific Manuscript database

    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...

  12. 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...

  13. Phylogeography of declining relict and lowland leopard frogs in the desert Southwest of North America

    USGS Publications Warehouse

    Olah-Hemmings, V.; Jaeger, J.R.; Sredl, M.J.; Schlaepfer, Martin A.; Jennings, R.D.; Drost, C.A.; Bradford, D.F.; Riddle, B.R.

    2010-01-01

    We investigated the phylogeography of the closely related relict leopard frog Rana onca (=Lithobates onca) and lowland leopard frog Rana yavapaiensis (=Lithobates yavapaiensis) – two declining anurans from the warm-desert regions of south-western North America. We used sequence data from mitochondrial DNA (mtDNA) to assess 276 individuals representing 30 sites from across current distributions. Our analysis supports a previously determined phylogenetic break between these taxa, and we found no admixing of R. onca and R. yavapaiensis haplotypes within our extensive sampling of sites. Our phylogeographic assessment, however, further divided R. yavapaiensis into two distinct mtDNA lineages, one representing populations across Arizona and northern Mexico and the other a newly discovered population within the western Grand Canyon, Arizona. Estimates of sequence evolution indicate a possible Early Pleistocene divergence of R. onca and R. yavapaiensis, followed by a Middle Pleistocene separation of the western Grand Canyon population of R. yavapaiensis from the main R. yavapaiensis clade. Phylogeographic and demographic analyses indicate population or range expansion for R. yavapaiensis within its core distribution that appears to predate the latest glacial maximum. Species distribution models under current and latest glacial climatic conditions suggest that R. onca and R. yavapaiensis may not have greatly shifted ranges.

  14. The disappearing northern leopard frog (Lithobates pipiens): conservation genetics and implications for remnant populations in western Nevada

    PubMed Central

    Rogers, Serena D; Peacock, Mary M

    2012-01-01

    Global amphibian declines suggest a major shift in the amount and quality of habitat for these sensitive taxa. Many species that were once widespread are now experiencing declines either in part of or across their historic range. The northern leopard frog (Rana [Lithobates] pipiens] has undergone significant declines particularly in the western United States and Canada. Leopard frog population losses in Nevada are largely due to habitat fragmentation and the introduction of nonnative fish, amphibian, and plant species. Only two populations remain in the Truckee and Carson River watersheds of western Nevada which represents the western boundary of this species range. We used sequence data for an 812 base pair fragment of the mitochondrial NADH dehydrogenase 1 (ND1) gene to support a native origin for western Nevada populations. All frogs had a single haplotype (W07) from the distinct western North America ND1 haplotype clade. Data from seven polymorphic microsatellite loci show that Truckee and Carson River populations are highly differentiated from each other and from leopard frogs collected from eastern Nevada sites. Lack of gene flow among and distinct color morphs among the western Nevada populations likely predates the current geographical isolation. Comparisons with other peripheral L. pipiens populations show western Nevada populations have similar levels of gene diversity despite their contemporary isolation (HE 0.411, 0.482). Restoration of leopard frog populations in these watersheds will be challenging given well-entrenched nonnative bullfrog populations and major changes to the riparian zone over the past century. Declines of once common amphibian species has become a major conservation concern. Contemporary isolation of populations on a species range periphery such as the leopard frog populations in the Truckee and Carson rivers further exacerbate extirpation risk as these populations are likely to have fewer genetic resources to adaptively respond to

  15. Field evidence for linking Altosid applications with increased amphibian deformities in southern leopard frogs [abstract

    USGS Publications Warehouse

    Sparling, D.W.

    1998-01-01

    During the summer of 1997 we repeatedly sprayed Altosid, a formulation of 4% methoprene used for mosquito control, on six constructed macrocosms. Six additional macrocosms were sprayed with Abate4E, containing the organophosphate pesticide temephos, and six were sprayed with water (controls). The wetlands were created on an impermeable foundation for research purposes and averaged 215 m2 in area and 0.5 m deep. Application rates and frequency of Abate4E and Altosid followed label directions and mimicked procedures for mosquito control in National Wildlife Refuges. In early September juvenile frogs and metamorphing tadpoles were collected with dip nets from each pond and examined for deformities. In all, 91 juveniles and metamorph southern leopard frogs (Rana utricularia) were collected from Altosid sprayed wetlands with 14 (15%) demonstrating deformities. Seventyseven juveniles and metamorphs were collected from control wetlands with three (4%) showing deformities. Only six juveniles and metamorphs were collected from Abate4E wetlands and none showed deformities. Deformities included missing or deformed hind limbs (9 of 10 involving only the right hind limb), missing eyes, and abnormal color. The differences in rate of deformities was dependent on treatment (X2=6.44, p< 0.02). The number of leopard frogs caught per unit effort (tadpoles and juveniles) differed among treatments (p=0.032) with Abate4E wetlands producing fewer individuals per capture effort than either Altosid or control wetlands.

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

    PubMed

    Düşen, Serdar

    2007-01-01

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

  17. Population status and population genetics of northern leopard frogs in Arizona

    USGS Publications Warehouse

    Theimer, Tad C.; Drost, Charles A.; O'Donnell, Ryan P.; Mock, Karen E.

    2011-01-01

    Increasing isolation of populations by habitat fragmentation threatens the persistence of many species, both from stochastic loss of small isolated populations, and from inbreeding effects in populations that have become genetically isolated. In the southwestern United States, amphibian habitat is naturally patchy in occurrence because of the prevailing aridity of the region. Streams, rivers, and other wetlands are important both as habitat and as corridors that connect populations. However, populations of some species have become more fragmented and isolated by habitat degradation and loss. Northern leopard frogs (Rana pipiens) have experienced serious declines in the Southwest. We conducted an extensive survey across the known range of northern leopard frogs in Arizona to determine the current distribution and abundance of the species. From a range that once spanned much of the northern and central part of the State, northern leopard frogs have been reduced to three or four widely separated populations, near Lyman Lake in east-central Arizona, in the Stoneman Lake area south of Flagstaff, along Truxton Wash near Peach Springs, and a population of uncertain extent on Navajo Nation lands. The Lyman Lake and Truxton Wash populations are small and extremely isolated. The Stoneman Lake population, however, is an extensive metapopulation spread across several stream drainages, including numerous ponds, wetlands, and artificial tanks. This is the only population in Arizona that is increasing in extent and numbers, but there is concern about the apparent introduction of nonnative genetic stock from eastern North America into this area. We analyzed genetic diversity within and genetic divergence among populations of northern leopard frogs, across both extant and recently extirpated populations in Arizona. We also analyzed mitochondrial DNA to place these populations into a larger phylogenetic framework and to determine whether any populations contained genetic material

  18. Batrachochytrium dendrobatidis and the Decline and Survival of the Relict Leopard Frog.

    PubMed

    Jaeger, Jef R; Waddle, Anthony W; Rivera, Rebeca; Harrison, D Tyler; Ellison, Silas; Forrest, Matthew J; Vredenburg, Vance T; van Breukelen, Frank

    2017-06-01

    Epizootic disease caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd) is a major driver of amphibian declines, yet many amphibians declined before the pathogen was described. The Relict Leopard Frog, Rana onca (=Lithobates onca), was nearly extinct, with the exception of populations within a few geothermal springs. Growth of Bd, however, is limited by high water temperature, and geothermal springs may have provided refuge during outbreaks of chytridiomycosis. We conducted field surveys and laboratory experiments to assess the susceptibility of R. onca to Bd. In the field, we found Bd at one of the two areas where remnant populations of R. onca still occur, but not in the other. In the laboratory, we infected juvenile frogs from these two areas with two hypervirulent Bd isolates associated with declines in other ranid species. In our experiments, these Bd isolates did not affect survivorship of R. onca and most infections (64%) were cleared by the end of the experiments. We propose that R. onca either has inherent resistance to Bd or has recently evolved such resistance. These results may be important for conservation efforts aimed at establishing new populations of R. onca across a landscape where Bd exists. Resistance, however, varies among life stages, and we also did not assess Bd from the local environment. We caution that the resistance we observed for young frogs under laboratory conditions may not translate to the situation for R. onca in the wild.

  19. 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.

  20. Metal levels in southern leopard frogs from the Savannah River Site: location and body compartment effects.

    PubMed

    Burger, J; Snodgrass, J

    2001-06-01

    Tadpoles have been proposed as useful bioindicators of environmental contamination; yet, recently it has been shown that metal levels vary in different body compartments of tadpoles. Metals levels are higher in the digestive tract of bullfrog (Rana catesbeiana) tadpoles, which is usually not removed during such analysis. In this paper we examine the heavy metal levels in southern leopard frog (R. utricularia) tadpoles from several wetlands at the Savannah River Site and test the null hypotheses that (1) there are no differences in metal levels in different body compartments of the tadpoles, including the digestive tract; (2) there are no differences in heavy metal levels among different wetlands; and (3) there are no differences in the ratio of metals in the tail/body and in the digestive tract/body as a function of metal or developmental stage as indicated by body weight. Variations in heavy metal levels were explained by wetland and body compartment for all metals and by tadpole weight for selenium and manganese. In all cases, levels of metals were higher in the digestive tract than in the body or tail of tadpoles. Metal levels were highest in a wetland that had been remediated and lowest in a wetland that was never a pasture or remediated (i.e., was truly undisturbed). Although tadpoles are sometimes eaten by fish and other aquatic predators, leopard frogs usually avoid laying their eggs in ponds with such predators. However, avian predators will eat them. These data suggest that tadpoles can be used as bioindicators of differences in metal levels among wetlands and as indicators of potential exposure for higher-trophic-level organisms, but that to assess effects on the tadpoles themselves, digestive tracts should be removed before analysis.

  1. 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?|

  2. Helminths of two native frog species (Rana chiricahuensis, Rana yavapaiensis) and one introduced frog species (Rana catesbeiana) (Ranidae) from Arizona.

    PubMed

    Goldberg, S R; Bursey, C R; Cheam, H

    1998-02-01

    The gastrointestinal tracts, lungs, urinary bladders, and body cavities of Rana catesbeiana (n = 25), Rana chiricahuensis (n = 25), and Rana yavapaiensis (N = 37) from Arizona were examined for helminths. Helminths representing 9 species of trematodes: Cephalogonimus brevicirrus, Glypthelmins quieta, Gorgoderina attenuata, Haematoloechus complexus, Haematoloechus langiplexus, Megalodiscus temperatus, Alaria sp., Clinostomum sp., and an unidentified strigeid; and 4 species of nematodes: Falcaustra catesbeianae, Rhabdias ranae, Physaloptera sp., and an unidentified ascarid were found. The helminth fauna of introduced R. catesbeiana differed markedly from that of native ranids. Helminths of R. chiricahuensis and R. yavapaiensis represent new host records. Arizona is a new locality record for C. brevicirrus, G. attenuata, H. complexus, H. longiplexus, M. temperatus, and R. ranae.

  3. Enterobacteriaceae and Aeromonas hydrophila in Minnesota frogs and tadpoles (Rana pipiens).

    PubMed Central

    Hird, D W; Diesch, S L; McKinnell, R G; Gorham, E; Martin, F B; Meadows, C A; Gasiorowski, M

    1983-01-01

    In 222 Rana pipiens frogs and 34 tadpoles captured in and near Minnesota, Aeromonas hydrophila and 29 species of Enterobacteriaceae, including yersinia enterocolitica and Salmonella arizonae, were isolated from intestines. The prevalence of members of the family Enterobacteriaceae was lowest in frogs captured in early spring and highest in frogs captured in late summer. PMID:6607034

  4. Effects of the Chytrid fungus on the Tarahumara frog (Rana tarahumarae) in Arizona and Sonora, Mexico

    Treesearch

    Stephen F. Hale; Philip C. Rosen; James L. Jarchow; Gregory A. Bradley

    2005-01-01

    We conducted histological analyses on museum specimens collected 1975-1999 from 10 sites in Arizona and Sonora to test for the pathogenic chytrid fungus (Batrachochytrium dendrobatidis) in ranid frogs, focusing on the Tarahumara frog (Rana tarahumarae). During 1981-2000, frogs displaying disease signs were found in the field, and...

  5. Topological analysis of the brain stem of the frogs Rana esculenta and Rana catesbeiana.

    PubMed

    Opdam, R; Kemali, M; Nieuwenhuys, R

    1976-02-01

    The ventricular sulcal pattern and the cytoarchitectonic organization of the brain stem of the frogs Rana esculenta and Rana catesbeiana have been studied in transversely cut, Nissl stained serial sections. Four longitudinal sulci, the sulcus medianus inferior, the sulcus intermedius ventralis, the sulcus limitans and the sulcus medianus superior could be distinguished in both species. A fifth longitudinal groove, the sulcus intermedius dorsalis, was found only in Rana esculenta. With the aid of the usual cytoarchitectonic criteria 25 cell masses have been delineated in Rana esculenta and 27 in Rana catesbeiana. These cell masses can be distributed over the following categories (numbers added in brackets for Rana catesbeiana, if different from those in Rana esculenta): primary efferent or motor, 8; primary afferent or sensory, 4(6); "relay" centers, 7. Contrary to statements in the literature the reticular formation can be divided into six separate cell groups. The majority of the nuclei form part of the central gray, which constitutes a rather wide zone in anurans; three reticular nuclei lie partly within the stratum griseum and partly within the stratum album; six nuclei are entirely embedded in the stratum album. The morphological pattern of the cell masses and their relationship to the ventricular sulci were studied with the aid of a graphical reconstruction procedure termed topological analysis (cf. Nieuwenhuys, '74 and figs. 15, 16). This analysis yielded the following results: The sulcus limitans extends throughout the rhombencephalon, dividing this brain part into a basal plate and an alar plate. The cell masses in the basal plate fit into two longitudinal zones, a medial area ventralis and a lateral area intermedioventralis. The area ventralis contains three somatic motor nuclei (IV, VI and XII) and the rhombencephalic medial reticular zone. The latter may be primarily considered as a somatic motor coordinating center. The area intermedioventralis contains

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

    PubMed

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

    1993-10-01

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

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

    EPA Science Inventory

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

  8. Interdigitating cells in the thymus of the frog, Rana temporaria.

    PubMed

    Bigaj, J; Płytycz, B

    1987-01-01

    Interdigitating cells (IDC) of the thymic medulla of the frog, Rana temporaria, collected in the summer, were examined by electron microscopy. The most characteristic cytological features of IDC are voluminous electron-lucent cytoplasm and widespread interdigitations and invaginations of the cell membrane. IDC possess an excentrically located nucleus with pronounced nucleoli and a thin rim of a dense chromatine as well as a perinuclear area with characteristic tubulo-vesicular complex. In our material Birbeck granules were absent. Some IDC contain phagocytized material. A few transitional forms between monocytes and IDC were observed. On the basis of these observations it is highly probable that the amphibian IDC belong to the mononuclear phagocyte system.

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

    PubMed

    De Perez, G; Hindelang, C

    1985-01-01

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

  10. Primary structures of skin antimicrobial peptides indicate a close, but not conspecific, phylogenetic relationship between the leopard frogs Lithobates onca and Lithobates yavapaiensis (Ranidae).

    PubMed

    Conlon, J Michael; Coquet, Laurent; Leprince, Jérôme; Jouenne, Thierry; Vaudry, Hubert; King, Jay D

    2010-04-01

    The phylogenetic relationship between the relict leopard frog Lithobates (Rana) onca (Cope, 1875) and the lowland leopard frog Lithobates (Rana) yavapaiensis (Platz and Frost, 1984) is unclear. Chromatographic analysis of norepinephrine-stimulated skin secretions from L. onca led to the identification of six peptides with antimicrobial activity. Determination of their primary structures indicated that four of the peptides were identical to brevinin-1Ya, brevinin-1Yb, brevinin-1Yc and ranatuerin-2Ya previously isolated from skin secretions of L. yavapaiensis. However, a peptide belonging to the temporin family (temporin-ONa: FLPTFGKILSGLF.NH(2)) and an atypical member of the ranatuerin-2 family containing a C-terminal cyclic heptapeptide domain (ranatuerin-2ONa: GLMDTVKNAAKNLAGQMLDKLKCKITGSC) were isolated from the L. onca secretions but were not present in the L. yavapaiensis secretions. Ranatuerin-2ONa inhibited the growth of Escherichia coli (MIC=50muM) and Candida albicans (MIC=100muM ) and showed hemolytic activity (LC(50)=90muM) but was inactive against Staphylococcus aureus. The data indicate a close phylogenetic relationship between L. onca and L. yavapaiensis but suggest that they are not conspecific species.

  11. Oregon spotted frog (Rana pretiosa) monitoring at Jack Creek 2015-2016

    USGS Publications Warehouse

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

    2017-01-01

    This dataset contains information from mark-recapture and egg mass surveys conducted 2015-2016 by USGS as part of an ongoing Oregon spotted frog (Rana pretiosa) monitoring effort at Jack Creek, Klamath County, Oregon. Data consist of spotted frog counts aggregated by date, location, life stage, and sex, as well as data on environmental conditions at the time each survey.

  12. Fat body of the frog Rana esculenta: an ultrastructural study.

    PubMed

    Zancanaro, C; Merigo, F; Digito, M; Pelosi, G

    1996-03-01

    In the frog, the fat body is the largest body lipid deposit and is associated with the gonad. The aim of the present work was to investigate the fine structure of the fat body at different periods of the annual cycle and during prolonged starvation. Results indicate that fat body cells of Rana esculenta caught in autumn and after winter hibernation resemble mammalian adipocytes of white adipose tissue and contain markers of adipose tissue, such as S-100 protein and lipoproteinlipase. However, unlike mammalian adipocytes, fat body adipocytes consistently show small lipid droplets associated with their single, large lipid deposits, a lack of a definite external lamina, and the presence of cellular prolongations and spicula at their surfaces. Transmission and scanning electron microscopy in association with lanthanum tracer experiments suggest that in fat body adipocytes a vesicular-tubular system connects the cytoplasm and the interstitial space. In June (i.e., during the reproductive period), fat body adipocytes appear to have lost much of their lipid deposit and adjacent adipocytes show interdigitation of their plasma membranes and prominent Golgi complexes. In starved frogs, fat body cells can be almost devoid of lipid and in regression to a near-mesenchymal state. Nevertheless, these fat bodies still contain lipoproteinlipase activity (approximately 45% of that found in lipid-filled ones), indicating persistent adipose differentiation of the cells therein. Results presented here show that the R. esculenta fat body is an adipose organ undergoing reversible extreme changes in adipocyte fat content, which are associated with definite ultrastructural features. The fat body represents a suitable model for studying adipose tissue under different and extreme physiological conditions.

  13. 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.

  14. Effect of mono-ortho and di-ortho substituted polychlorinated biphenyl (PCB) congeners on leopard frog survival and sexual development.

    PubMed

    Jofré, Mariana Beatriz; Karasov, William H

    2008-02-01

    We tested the effect of mono-ortho and di-ortho PCB congeners on northern leopard frog (Rana pipiens) hatching success, survival and sexual development. Embryos and tadpoles were exposed to two levels (0.5 and 50 microg/l) of two PCBs. PCBs 101 and 70 were selected because they were present in amphibians collected in the Fox River-Green Bay ecosystem and they have the theoretical structural requirements to be able to bind to the estrogen receptor and mediate estrogenic responses. The exposure of leopard frog embryos and tadpoles to PCB 70 and 101 did not significantly affect hatchability, survival, deformities or growth. There were significant departures from the expected 50:50 sex ratio in tadpoles/froglets exposed to PCB 101 and PCB 70. In all the cases of significant departure, the bias was towards higher number of females. Decrease in the proportion of male gonads and increase in the proportion of intersex gonads were observed with increasing PCB tissue concentrations. The effects of PCB congeners on sexual differentiation occur at concentrations higher than observed in frogs in the Fox River/Green Bay ecosystem.

  15. Seasonal cycles in testicular activity in the frog, Rana perezi.

    PubMed

    Delgado, M J; Gutiérrez, P; Alonso-Bedate, M

    1989-01-01

    Studies of seasonal testicular cycle based on spermatogenetic activity and direct measurement of plasma testosterone were made in male frog Rana perezi obtained from its natural biotope in the Iberian Peninsula. Testosterone plasma level was determined by radioimmunoassay and exhibited notable differences according to season: plasma testosterone was lowest (less than 0.5 ng/ml) in summer and then increased progressively to reach a peak in spring (3-4 ng/ml), coincident with mating. After spermiation, when an increase in temperature and photoperiod in the natural habitat occurs, levels decline. Fat bodies also show a pronounced seasonal cycle with total regression following breeding and maximal development in winter. However, testicular weight was independent of seasons, and no significant change was observed throughout the year. Histological evidence indicates that although cell nests of different types are present every month of the year, the most important spermatogenetic activity is initiated in summer. The possible relationship between spermatogenetic activity and testosterone production and the importance of environmental factors as synchronizers of seasonal reproduction are discussed.

  16. Pathogenesis of Frog Virus 3 ( Ranavirus, Iridoviridae) Infection in Wood Frogs ( Rana sylvatica).

    PubMed

    Forzán, M J; Jones, K M; Ariel, E; Whittington, R J; Wood, J; Markham, R J Frederick; Daoust, P-Y

    2017-01-01

    Wood frogs ( Rana sylvatica) are highly susceptible to infection with Frog virus 3 (FV3, Ranavirus, Iridoviridae), a cause of mass mortality in wild populations. To elucidate the pathogenesis of FV3 infection in wood frogs, 40 wild-caught adults were acclimated to captivity, inoculated orally with a fatal dose of 10(4.43) pfu/frog, and euthanized at 0.25, 0.5, 1, 2, 4, 9, and 14 days postinfection (dpi). Mild lesions occurred sporadically in the skin (petechiae) and bone marrow (necrosis) during the first 2 dpi. Severe lesions occurred 1 to 2 weeks postinfection and consisted of necrosis of medullary and extramedullary hematopoietic tissue, lymphoid tissue in spleen and throughout the body, and epithelium of skin, mucosae, and renal tubules. Viral DNA was first detected (polymerase chain reaction) in liver at 4 dpi; by dpi 9 and 14, all viscera tested (liver, kidney, and spleen), skin, and feces were positive. Immunohistochemistry (IHC) first detected viral antigen in small areas devoid of histologic lesions in the oral mucosa, lung, and colon at 4 dpi; by 9 and 14 dpi, IHC labeling of viral antigen associated with necrosis was found in multiple tissues. Based on IHC staining intensity and lesion severity, the skin, oral, and gastrointestinal epithelium and renal tubular epithelium were important sites of viral replication and shedding, suggesting that direct contact (skin) and fecal-oral contamination are effective routes of transmission and that skin tissue, oral, and cloacal swabs may be appropriate antemortem diagnostic samples in late stages of disease (>1 week postinfection) but poor samples to detect infection in clinically healthy frogs.

  17. Reproductive and lipid cycles in the male frog Rana ridibunda in northern Greece.

    PubMed

    Loumbourdis, N S; Kyriakopoulou-Sklavounou, P

    1991-01-01

    1. Reproductive and lipid cycles in the male frog Rana ridibunda were studied. 2. The spermatogenesis of Rana ridibunda is of the potentially continuous type. 3. During prehibernating season (September-November) a part of lipid is mobilized from fat bodies to other body sites or is transformed to other metabolites. 4. During wintering this frog consumes mainly glycogen. 5. In February the lipid is accumulated in the fat bodies and the liver mass shows a second peak, probably as a result of glycogen accumulation. 6. The greatest decrease of metabolites was observed during the breeding season and this is the result of the intensive activities related to the reproduction and maintenance.

  18. Reproductive strategies of leopard toad and mascarene frog from Giza, Egypt.

    PubMed

    Akef, Mamdouh S A

    2014-01-01

    I examined the reproductive strategies of leopard toad and mascarene frog by studying their annual vitellogenic cycle, monthly changes of masses of ovary, liver and fat bodies as well as egg size and number in two study areas, Abo Roash and El Mansuriya, and in the years 2001, 2005, and 2008-2009, particularly during the final two years of that period. Based on the presence of the mature ova, I found that vitellogenic cycle is continuous in toad, but discontinuous in frog. Further, leopard body reserves allocated more energy to vitellogenesis than did mascarene frog. Hence, fecundity in toad was higher than that in frog, as associated with higher egg number and size. During oviposition, female mascarene retained a small portion of a clutch, whereas toad shed all egg mass at once. Over the study period, both body and reproductive conditions reacted positively in toad, but negatively in frog. Warm temperature and long photoperiod elucidated ovarian development under high relative humidity in frog. In contrast, in toad, low relative humidity may be an environmental cue for the increase in ovarian mass. Thus, higher sexual activities occurred in spring for toad (dry environment), but in moist summer for frog. Ovarian mass and egg number were temperature-dependent in frog, but independent in toad. Relative humidity correlated significantly and negatively to egg size in both populations. It also related inversely to egg number in toad, but not in frog. Hence, eggs of the frog are controlled by both temperature and humidity in summer season. Rainfall had no effect on sexual parameters in both species.

  19. Responses of foothill yellow-legged frog (Rana boylii) larvae to an introduced predator

    Treesearch

    David J. Paoletti; Deanna H. Olson; Andrew R. Blaustein

    2011-01-01

    The consequences of species introductions into non-native habitats are a major cause for concern in the U.S. Of particular interest are the effects of predation by introduced fishes on native amphibian communities. We sought to determine whether Foothill Yellow-legged Frog (Rana boylii) larvae could recognize non-native Small mouth Bass (...

  20. Indirect effects of introduced trout on Cascades frogs (Rana cascadae) via shared aquatic prey

    Treesearch

    Maxwell B. Joseph; Jonah Piovia-Scott; Sharon P. Lawler; Karen L. Pope

    2010-01-01

    1. The introduction of trout to montane lakes has negatively affected amphibian populations across the western United States. In northern California’s Klamath–Siskiyou Mountains, introduced trout have diminished the distribution and abundance of a native ranid frog, Rana (=Lithobates)

  1. Foothill yellow-legged frog (Rana boylii) oviposition site choice at multiple spatial scales

    Treesearch

    Amy J. Lind; Hartwell H. Welsh; Clara A. Wheeler

    2016-01-01

    Studies of resource selection at multiple scales are critical to understanding ecological and evolutionary attributes of a species. We analyzed relative abundance, habitat use, and oviposition site selection of Foothill Yellow-Legged Frogs (Rana boylii) at 11 localities across two geographic regions in California (northern Coast Range and Sierra...

  2. Site fidelity of the declining amphibian Rana sierrae (Sierra Nevada yellow-legged frog)

    Treesearch

    Kathleen Matthews; Haiganoush Preisler

    2010-01-01

    From 1997 to 2006, we used mark–recapture models to estimate the site fidelity of 1250 Sierra Nevada yellow-legged frogs (Rana sierrae) in Kings Canyon National Park, California, USA, during their three main activity periods of overwintering, breeding, and feeding. To quantify site fidelity, the tendency to return to and reuse previously occupied...

  3. Mating strategy and breeding patterns of the foothill yellow-legged frog (Rana boylii)

    Treesearch

    Clara A. Wheeler; Hartwell H. Welsh Jr.

    2008-01-01

    The Foothill Yellow-legged Frog (Rana boylii) has declined across much of its native range in California. Improper stream management may lower egg mass survival and reduce the availability of suitable breeding habitats. We collected data during six breeding-seasons (2002-2007) along an unregulated stream in northwestern California. We monitored...

  4. Efficient induction of spawning of Northern leopard frogs (Lithobates pipiens) during and outside the natural breeding season

    PubMed Central

    2013-01-01

    Background Amphibian declines are now recognized globally. It is also well known that many anurans do not reproduce easily in captivity, especially when held over long periods, or if they require hibernation before breeding. A simple method to induce spawning and subsequent development of large numbers of healthy tadpoles is therefore required to meet research and conservation goals. Methods The method is based on simultaneous injection of both female and male leopard frogs, Lithobates pipiens (formerly called Rana pipiens) with a cocktail of a gonadotropin-releasing hormone agonist (GnRH-A) and a dopamine antagonist. We call this the AMPHIPLEX method, which is derived from the combination of the words amphibian and amplexus. Following injection, the animals are thereby induced, and perform amplexus and natural fertilization under captive conditions. Results We tested combinations of a GnRH agonist with 2 different dopamine antagonists in L. pipiens in the breeding season. The combination of des-Gly10, D-Ala6, Pro-NHEt9-GnRH (0.4 micrograms/g body weight; GnRH-A) with metoclopramide hydrochloride (10 micrograms/g body weight; MET) or domperidone (DOM) were equally effective, producing 89% and 88% successful spawning, respectively. This yielded more than 44,000 eggs for the 16/18 females that ovulated in the GnRH-A+MET group, and more than 39,000 eggs for the 15/17 females that ovulated in the GnRH-A+DOM group. We further tested the GnRH-A+MET in frogs collected in the wild in late autumn and hibernated for a short period under laboratory conditions, and report a low spawning success (43%). However, GnRH-A priming 24 hours prior to injections of the GnRH-A+MET cocktail in animals hibernated for 5–6 weeks produced out-of-season spawning (89%) and fertilization (85%) comparable to those we observed for in-season spawning. Assessment of age and weight at metamorphosis indicated that L. pipiens tadpoles resulting from out-of-season spawning grew normally and

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

    PubMed

    Li, Jiao; Lei, Guangchun; Fu, Cuizhang

    2016-01-01

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

  6. A reference system for animal biometrics: application to the northern leopard frog

    USGS Publications Warehouse

    Petrovska-Delacretaz, D.; Edwards, A.; Chiasson, J.; Chollet, G.; Pilliod, D.S.

    2014-01-01

    Reference systems and public databases are available for human biometrics, but to our knowledge nothing is available for animal biometrics. This is surprising because animals are not required to give their agreement to be in a database. This paper proposes a reference system and database for the northern leopard frog (Lithobates pipiens). Both are available for reproducible experiments. Results of both open set and closed set experiments are given.

  7. Context-Dependent Effects of Ranaviral Infection on Northern Leopard Frog Life History Traits

    PubMed Central

    Echaubard, Pierre; Little, Kevin; Pauli, Bruce; Lesbarrères, David

    2010-01-01

    Pathogens have important effects on host life-history traits, but the magnitude of these effects is often strongly context-dependent. The outcome of an interaction between a host and an infectious agent is often associated with the level of stress experienced by the host. Ranavirus causes disease and mortality in amphibian populations in various locations around the world, but most known cases of ranaviral infection have occurred in North America and the United Kingdom. While Ranavirus virulence has been investigated, the outcome of Ranavirus infection has seldom been related to the host environment. In a factorial experiment, we exposed Northern leopard frog (Lithobates pipiens, formerly Rana pipiens) tadpoles to different concentrations of Ranavirus and investigated the effect of host density on certain life-history traits, namely survival, growth rate, developmental stage and number of days from virus exposure to death. Our results suggest a prominent role of density in driving the direction of the interaction between L. pipiens tadpoles and Ranavirus. We showed that increasing animal holding density is detrimental for host fitness as mortality rate is higher, day of death earlier, development longer and growth rate significantly lower in high-density tanks. We observed a linear increase of detrimental effects when Ranavirus doses increased in low-density conditions, with control tadpoles having a significantly higher overall relative fitness. However, this pattern was no longer observed in high-density conditions, where the effects of increasing Ranavirus dose were limited. Infected and control animals fitness were consequently similar. We speculate that the host may eventually diverts the energy required for a metabolic/immune response triggered by the infection (i.e., direct costs of the infection) to better cope with the increase in environmental “stress” associated with high density (i.e., indirect benefits of the infection). Our results illustrate how

  8. The influence of temperature and spatial distribution on the susceptibility of southern leopard frog eggs to disease.

    PubMed

    Ruthig, Gregory R

    2008-07-01

    Since host defenses to infectious disease are often costly, one would expect hosts to use their defenses only when the threat of infection is high. Southern leopard frogs (Rana sphenocephala) at Ellenton Bay in South Carolina (USA) have an extended breeding season and their eggs are exposed to a wide range of temperatures depending on the time of year when they are laid. Adults aggregate their egg masses in cold temperatures, but separate them in warm temperatures. The spatial aggregation of egg masses may insulate eggs from cold temperatures, but may also affect the transmission of pathogens between the eggs. I examined the effects of temperature, pathogens, and spatial distribution on the survival of R. sphenocephala in the egg stage. Field observations found that temperature had little effect on the number of infected eggs within egg masses, but that egg masses in colder water were more likely to be aggregated together. In a controlled laboratory experiment, the presence of aquatic oomycetes led to higher mortality in cold temperatures than they did at warmer temperatures. Infectious disease may be a selective force that favors R. sphenocephala adults that aggregate their offspring when the threat of disease is high. Host aggregation can reduce the risk of infection when pathogens have a slow generation time that hinders them from responding to an abundance of hosts.

  9. 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.

  10. CARCINOMA IN THE LEOPARD FROG: ITS PROBABLE CAUSATION BY A VIRUS

    PubMed Central

    Lucké, Balduin

    1938-01-01

    An epithelial tumor with acidophilic intranuclear inclusions frequently occurs in the kidneys of leopard frogs. This tumor usually has the appearance of an infiltrating and destructive adenocarcinoma, which, when large, not uncommonly metastasizes; less often it is more orderly and adenomatous. When inoculated as living fragments or cell suspensions into the lymph sacs, the cranial cavity, or the abdomen, no significant local growth results and the implanted material is resorbed. However, in approximately 20 per cent of the frogs surviving inoculation for more than 6 months, tumors develop in the kidney, which are like the "spontaneous" neoplasms. The incidence far exceeds that in the controls. Desiccated and glycerinated tumor injected into the abdomen gives the same result as inoculation with living tumor; in somewhat over 20 per cent of animals surviving more than 6 months kidney tumors occur. In alien species of frogs, no such tumors are produced by inoculation either with living or with desiccated tumor. These experiments indicate the probability that the kidney tumor of the leopard frog is caused by an inclusion-forming, organ-specific virus. PMID:19870798

  11. 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.

  12. 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.

  13. 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.

  14. 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...

  15. 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...

  16. 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.

  17. Oregon spotted frog (Rana pretiosa) monitoring in the Oregon Cascades 2012-2016

    USGS Publications Warehouse

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

    2017-01-01

    This dataset contains information from visual encounter surveys conducted between 2012 and 2016 by USGS as part of an ongoing Oregon spotted frog (Rana pretiosa) monitoring effort in the Oregon Cascade Mountain Range. We surveyed 91 sites using a rotating frame design in the Klamath and Deschutes Basins, Oregon, which encompass most of the species' core extant range. Data consist of spotted frog counts aggregated by date, location, and life stage, as well as data on environmental conditions at the time of each survey.

  18. Cutaneous transport of Ca2+ in the frog Rana pipiens: significance and specificity.

    PubMed

    Stiffler, D F; Eskandari, S; Dejbakhsh, S

    1997-04-01

    Rana pipiens were divided into four groups: controls; hypocalcemic frogs, depleted of salts by acclimation to deionized water; hypercalcemic frogs, calcium-loaded by the introduction of 40 mumol calcium gluconate; and frogs exposed to the potential competing ions Mg2+, Sr2+, and Ba2+. All groups displayed calcium influx that was proportional to external [Ca2+]; however, the group acclimated to deionized water also displayed hypocalcemia (P < 0.025) and enhanced Ca2+ influx at higher (> 0.3 mM) external [Ca2+]. Ca2+ efflux was depressed in hypocalcemic frogs, and thus net Ca2+ flux shifted from net loss in control frogs to net uptake in hypocalcemic frogs. Hypocalcemia also resulted in increased skin Ca2+ deposits which may be related to a decreased Ca2+ (and other ions) permeability as a consequence of the acclimation to deionized water. Another group of frogs was Ca(2+)-loaded by injecting calcium gluconate: Sodium gluconate controls did not significantly alter Ca2+ fluxes. The frogs that received calcium gluconate treatments became hypercalcemic (P < 0.01) and did not display significant changes in calcium fluxes, nor did they show significant changes in skin calcium deposits. We conclude that hypocalcemia leads to regulatory responses that stimulate active Ca2+ transport in Rana pipiens skin and possibly inhibits cutaneous and renal efflux. We also conclude that hypercalcemia does not alter calcium fluxes across skin. The ions from Group IIA of the Periodic Table of Elements had little effect on Ca2+ fluxes at concentrations ranging from 0.5-4.0 mM; neither Sr2+ or Ba2+ affected Ca2+ influx. The only divalent ion tested that influenced Ca2+ was Mg2+, which significantly inhibited Ca2+ influx but only at 4.0 mM or eight times the external [Ca2+]. We conclude, therefore, that the Ca2+ transport mechanism is fairly specific for Ca2+ within Group IIA.

  19. Survival estimates for reintroduced populations of the Chiricahua Leopard Frog (Lithobates chiricahuensis)

    USGS Publications Warehouse

    Howell, Paige E; Hossack, Blake R.; Muths, Erin L.; Sigafus, Brent H.; Chandler, Richard B.

    2016-01-01

    Global amphibian declines have been attributed to a number of factors including disease, invasive species, habitat degradation, and climate change. Reintroduction is one management action that is commonly used with the goal of recovering imperiled species. The success of reintroductions varies widely, and evaluating their efficacy requires estimates of population viability metrics, such as underlying vital rates and trends in abundance. Although rarely quantified, assessing vital rates for recovering populations provides a more mechanistic understanding of population growth than numerical trends in population occupancy or abundance. We used three years of capture-mark-recapture data from three breeding ponds and a Cormack-Jolly-Seber model to estimate annual apparent survival for reintroduced populations of the federally threatened Chiricahua Leopard Frog (Lithobates chiricahuensis) at the Buenos Aires National Wildlife Refuge (BANWR), in the Altar Valley, Arizona, USA. To place our results in context, we also compiled published survival estimates for other ranids. Average apparent survival of Chiricahua Leopard Frogs at BANWR was 0.27 (95% CI [0.07, 0.74]) and average individual capture probability was 0.02 (95% CI [0, 0.05]). Our apparent survival estimate for Chiricahua Leopard Frogs is lower than for most other ranids and is not consistent with recent research that showed metapopulation viability in the Altar Valley is high. We suggest that low apparent survival may be indicative of high emigration rates. We recommend that future research should estimate emigration rates so that actual, rather than apparent, survival can be quantified to improve population viability assessments of threatened species following reintroduction efforts.

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

    PubMed

    Kobayashi, Tohru; Kumakura, Masahiko; Yoshie, Sumio; Sugishima, Tomomi; Horie, Yoshifumi

    2015-02-01

    Although many studies have reported the occurrence of testis-ova in wild frog populations, the origin and trigger of testis-ova differentiation/development remain unclear. A high frequency of testis-ova has been previously reported for wild populations of the Japanese pond frog, Rana nigromaculata (cf. Iwasawa and Asai, '59). In the present study, we aimed to clarify the dynamics of testis-ova in this frog species, including the origin and artificial induction of testis-ova. Testis-ova were observed in both mature frogs and puberty-stage frogs (i.e., 0- and 1-year-old frogs). However, the early stages of testis-ova (~pachytene stage) were mostly observed in puberty-stage male frogs at the onset of spermatogenesis. The early stages of testis-ova were observed in the cysts of early secondary spermatogonia and the single cysts of the primary spermatogonium. This finding indicates that testis-ova differentiation occurs during spermatogonial proliferation and that it is correlated with the initiation of spermatogenesis. We also examined whether estrogen exposure induced testis-ova differentiation and how it is correlated with the progression of spermatogenesis. When 1-year-old frogs were exposed to estradiol-17β during spring (i.e., when spermatogenesis was initiated), testis-ova differentiation was induced in a dose-dependent manner. However, this phenomenon did not occur in 1-year-old frogs during summer, (i.e., when the transition from spermatogonia to spermatocytes mainly occurs). These results present the first evidence that testis-ova of the Japanese pond frog are derived from primary and early secondary spermatogonia, and that estrogen exposure induces testis-ova differentiation accompanied by the initiation of spermatogenesis.

  1. 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.

  2. 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.

  3. Complex spatial dynamics maintain northern leopard frog (Lithobates pipiens) genetic diversity in a temporally varying landscape

    USGS Publications Warehouse

    Mushet, David M.; Euliss, Ned H.; Chen, Yongjiu; Stockwell, Craig A.

    2013-01-01

    In contrast to most local amphibian populations, northeastern populations of the Northern Leopard Frog (Lithobates pipiens) have displayed uncharacteristically high levels of genetic diversity that have been attributed to large, stable populations. However, this widely distributed species also occurs in areas known for great climatic fluctuations that should be reflected in corresponding fluctuations in population sizes and reduced genetic diversity. To test our hypothesis that Northern Leopard Frog genetic diversity would be reduced in areas subjected to significant climate variability, we examined the genetic diversity of L. pipiens collected from 12 sites within the Prairie Pothole Region of North Dakota. Despite the region's fluctuating climate that includes periods of recurring drought and deluge, we found unexpectedly high levels of genetic diversity approaching that of northeastern populations. Further, genetic structure at a landscape scale was strikingly homogeneous; genetic differentiation estimates (Dest) averaged 0.10 (SD = 0.036) across the six microsatellite loci we studied, and two Bayesian assignment tests (STRUCTURE and BAPS) failed to reveal the development of significant population structure across the 68 km breadth of our study area. These results suggest that L. pipiens in the Prairie Pothole Region consists of a large, panmictic population capable of maintaining high genetic diversity in the face of marked climate variability.

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

    USGS Publications Warehouse

    Halstead, Brian J.; Kleeman, Patrick M.

    2017-01-01

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

  5. 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.

  6. Effects of exposure to cold on metabolic characteristics in gastrocnemius muscle of frog (Rana pipiens).

    PubMed Central

    Ohira, M; Ohira, Y

    1988-01-01

    1. Responses of enzymic characteristics of gastrocnemius muscle were studied when frogs (Rana pipiens) were exposed to cold environment (4 degrees C). 2. The content of adenosine triphosphate (ATP) decreased significantly after cold exposure. This decrease was greater in starved than in fed frogs. 3. Although the glycogen content did not change, lactate levels were lower in cold-exposed than room-temperature (control) frogs. No change was observed in glycogen and lactate between fed and unfed frogs kept at 4 degrees C for 2 months. Lactate dehydrogenase activity tended to increase during chronic cold exposure, but not significantly. 4. The activities of citrate synthase, cytochrome oxidase, and beta-hydroxyacyl CoA dehydrogenase were higher in gastrocnemius of chronically cold-exposed frogs than in room-temperature controls. This increase was statistically significant only in the muscles of starved frogs; these muscles had the greatest decrease in ATP. 5. It was suggested that chronic cold exposure decreases skeletal muscle ATP content but may not affect glycolysis. The data also suggested that the decrease in ATP content stimulates mitochondrial biogenesis which increases enzyme activities. PMID:3261790

  7. 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.

  8. Endohelminth fauna of the marsh frog Rana ridibunda from Lake Hazar, Turkey.

    PubMed

    Saglam, Naim; Arikan, Hatice

    2006-10-27

    In this study, 236 marsh frogs Rana ridibunda collected from Lake Hazar (Elazig, Turkey) at 15 d intervals between March 2001 and February 2002 were examined for endohelminths; of these, 148 (62.71%) frogs were found to be infected with helminths. In total, 9 helminth species (3 trematodes, 5 nematodes and 1 acanthocephalan) were identified. We observed Gorgoderina vitelliloba (prevalence 2.97%) in the urinary bladder, Haematoloechus variegatus (4.66%) and Rhabdias bufonis (8.90%) in the lung, Pleurogenoides medians (1.69%), Oswaldocruzia filiformis (3.81 %) and Acanthocephalus ranae (26.27 %) in the small intestine, Neoxysomatium brevicaudatum (16.95%) and Cosmocercoides sp. (3.39%) in the large intestine, and Eustrongylides excisus (14.41%) in the body cavity and on,the stomach. No helminth was found in the spleen, kidney, gall bladder, liver, heart or muscle. Of the 9 helminth species identified, Acanthocephalus ranae (26.27 %) had the highest prevalence and abundance and Oswaldocruzia filiformis (8.33+/-4.09) had the highest mean intensity.

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

    USGS Publications Warehouse

    Pearl, Christopher A.; Clayton, David; Turner, Lauri

    2010-01-01

    The Oregon spotted frog (Rana pretiosa) is the most aquatic of the native frogs in the Pacific Northwest. The common name derives from the pattern of black, ragged-edged spots set against a brown or red ground color on the dorsum of adult frogs. Oregon spotted frogs are generally associated with wetland complexes that have several aquatic habitat types and sizeable coverage of emergent vegetation. Like other ranid frogs native to the Northwest, Oregon spotted frogs breed in spring, larvae transform in summer of their breeding year, and adults tend to be relatively short lived (3-5 yrs). Each life stage (egg, tadpole, juvenile and adult) has characteristics that present challenges for detection. Breeding can be explosive and completed within 1-2 weeks. Egg masses are laid in aggregations, often in a few locations in large areas of potential habitat. Egg masses can develop, hatch, and disintegrate in <2 weeks during warm weather. Tadpoles can be difficult to identify, have low survival, and spend most of their 3-4 months hidden in vegetation or flocculant substrates. Juveniles and adults are often difficult to capture and can spend summers away from breeding areas. Moreover, a substantial portion of extant populations are of limited size (<100 breeding adults), and field densities of all life stages are often low. An understanding of the biology of the species and use of multiple visits are thus important for assessing presence of Oregon spotted frogs. This report is meant to be a resource for USDA Region 6 Forest Service (FS) and OR/WA Bureau of Land Management (BLM) personnel tasked with surveying for the presence of Oregon spotted frogs. Our objective was to summarize information to improve the efficiency of field surveys and increase chances of detection if frogs are present. We include overviews of historical and extant ranges of Oregon spotted frog. We briefly summarize what is known of Oregon spotted frog habitat associations and review aspects of behavior and

  10. Expression of leptin receptor in the oviduct of Chinese brown frog (Rana dybowskii).

    PubMed

    Xi, Liqin; Liu, Yuning; Tang, Zeqi; Sheng, Xia; Zhang, Haolin; Weng, Qiang; Xu, Meiyu

    2017-06-01

    The oviduct of Chinese brown frog (Rana dybowskii) expands specifically during prehibernation instead of in the breeding period. In this study, we investigated the expression of leptin receptor (Ob-Rb) in Rana dybowskii oviduct during the breeding period and prehibernation. Histologically, the oviduct of Rana dybowskii consists of glandular cells, tubule lumen, and epithelial cells. The oviductal weight and pipe diameter also revealed significant differences, which were higher in prehibernation than that of the breeding period. Ob-Rb was observed in stromal cells of oviductal tissue in both the breeding period and prehibernation. The mean protein and mRNA levels of the Ob-Rb were significantly higher in prehibernation as compared with the breeding period. In addition, oviductal content of leptin was also higher in prehibernation than that of the breeding period. These results suggested that oviduct of Rana dybowskii might be a target organ of leptin, and leptin may play an autocrine/paracrine role mediated by Ob-Rb in regulating the oviductal hypertrophy during prehibernation. Copyright © 2017 the American Physiological Society.

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

    PubMed

    Ryu, Shi Hyun; Hwang, Ui Wook

    2011-06-01

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

  12. Peptide defenses of the Cascades frog Rana cascadae: implications for the evolutionary history of frogs of the Amerana species group.

    PubMed

    Conlon, J Michael; Al-Dhaheri, Ahmed; Al-Mutawa, Eissa; Al-Kharrge, Rokaya; Ahmed, Eman; Kolodziejek, Jolanta; Nowotny, Norbert; Nielsen, Per F; Davidson, Carlos

    2007-06-01

    The Cascades frog Rana cascadae belongs to the Amerana (or Rana boylii) group that includes six additional species from western North America (R. aurora, R. boylii, R. draytonii, R. luteiventris, R. muscosa, and R. pretiosa). R. cascadae is particularly susceptible to pathogenic microorganisms in the environment and populations have declined precipitously in parts of its range so that the protection afforded by dermal antimicrobial peptides may be crucial to survival of the species. Peptidomic analysis of norepinephrine-stimulated skin secretions led to the identification of six peptides with differential cytolytic activities that were present in high abundance. Structural characterization showed that they belonged to the ranatuerin-2 (one peptide), brevinin-1 (one peptide), and temporin (four peptides) families. Ranatuerin-2CSa (GILSSFKGVAKGVAKDLAGKLLETLKCKITGC) and brevinin-1CSa (FLPILAGLAAKIVPKLFCLATKKC) showed broad spectrum antibacterial activity (MICfrogs is currently in a considerable state of flux. The ranatuerin-2 gene is expressed in all members of the Amerana group studied to-date and cladistic analysis based upon a comparison of the amino acid sequences of this peptide indicates that R. cascadae, R. muscosa and R. aurora form a clade that is distinct from one containing R. draytonii, R. boylii, and R. luteiventris. This conclusion is consistent with previous analyses based upon comparisons of the nucleotide sequences of mitochondrial genes.

  13. Diversity and phylogeography of Northeast Asian brown frogs allied to Rana dybowskii (Anura, Ranidae).

    PubMed

    Yang, Bao-Tian; Zhou, Yu; Min, Mi-Sook; Matsui, Masafumi; Dong, Bing-Jun; Li, Pi-Peng; Fong, Jonathan J

    2017-07-01

    We investigated the species diversity and phylogeography of the Northeast Asian brown frogs allied to Rana dybowskii (the R. dybowskii species complex: R. dybowskii, R. pirica, and R. uenoi) using four mitochondrial and three nuclear loci. Phylogenetic analyses confirmed the existence of three distinct species in this complex; using extensive molecular data, we confirm the validity of Rana uenoi recognized as a distinct species, and infer R. dybowskii and R. pirica to be sister species. Also, we included populations from previously unsampled regions in Northeast China, and identified them to be R. dybowskii. While many species in Northeast Asia diverged due to Pleistocene glaciation, divergence-dating analyses inferred older, Miocene speciation in the R. dybowskii species complex. Ancestral area reconstruction identified the orogenic movement of the Changbai Mountain Range and the opening of the Sea of Japan/East Sea being major events influencing allopatric speciation. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Glucose concentration regulates freeze tolerance in the wood frog Rana sylvatica.

    PubMed

    Costanzo, J P; Lee, R E; Lortz, P H

    1993-08-01

    In spring, the lowest temperature during freezing that can be survived by wood frogs (Rana sylvatica) from southern Ohio is approximately -3 degrees C. We investigated whether the thermal limit of freeze tolerance in these frogs is regulated by tissue levels of glucose, a putative cryoprotectant that is distributed to tissues during freezing. Frogs receiving exogenous glucose injections prior to freezing showed dose-dependent increases in glucose within the heart, liver, skeletal muscle and blood. Tissue glucose concentrations were further elevated during freezing by the production of endogenous glucose. Most glucose-loaded frogs survived freezing to -5 degrees C, whereas all control (saline-injected) frogs succumbed. Further, we investigated some mechanisms by which glucose might function as a cryoprotectant in R. sylvatica. Organ dehydration, a normal, beneficial response that reduces freezing injury to tissues, occurred independently of tissue glucose concentrations. However, elevated glucose levels reduced both body ice content and in vivo erythrocyte injury. These results not only provided conclusive evidence for glucose's cryoprotective role in R. sylvatica, but also revealed that tissue glucose level is a critical determinant of freeze tolerance capacity in this species.

  15. 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.

  16. Eight new tetranucleotide microsatellite loci for the agile frog (Rana dalmatina).

    PubMed

    Hauswaldt, J S; Fuessel, J; Guenther, J; Steinfartz, S

    2008-11-01

    We describe eight new polymorphic tetranucleotide microsatellite loci isolated from the agile frog (Rana dalmatina). In 25 individuals from the Nature Reserve Lüneburger Heide (Lower Saxony, Germany), the number of alleles per locus ranged from four to nine and average observed heterozygosities from 69.1% to 80.7%. No evidence for linkage disequilibrium was found and none of the loci showed significant deviation from Hardy-Weinberg expectations. These microsatellite DNA markers are suitable tools for addressing population genetics issues in this endangered species.

  17. [Role of the hypothalamus in the regulation of primary sleep in the frog Rana temporaria].

    PubMed

    Shilling, N V

    1980-01-01

    It has been demonstrated that in the frog Rana temporaria the anterior hypothalamus is involved into regulation of the depth of two forms of rest--one with plastic, the other with decreased muscle tone. Resting state with catatonic muscle activity is associated with activation of the posterior hypothalamus. Participation of the anterior hypothalamus in regulation of the resting state with the decreased tone of skeletal muscles may be taken as one of the indications that this form of rest plays the role of sleep in amphibians, being transformed during evolution of vertebrates into the sleep of poikilotherms.

  18. 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.

  19. Pathological and microbiological findings from incidents of unusual mortality of the common frog (Rana temporaria).

    PubMed

    Cunningham, A A; Langton, T E; Bennett, P M; Lewin, J F; Drury, S E; Gough, R E; Macgregor, S K

    1996-11-29

    In 1992 we began an investigation into incidents of unusual and mass mortalities of the common frog (Rana temporaria) in Britain which were being reported unsolicited to us in increasing numbers by members of the public. Investigations conducted at ten sites of unusual mortality resulted in two main disease syndromes being found: one characterized by skin ulceration and one characterized by systemic haemorrhages. However, frogs also were found with lesions common to both of these syndromes and microscopic skin lesions common to both syndromes were seen. The bacterium Aeromonas hydrophila, which has been described previously as causing similar lesions, was isolated significantly more frequently from haemorrhagic frogs than from those with skin ulceration only. However, as many of the latter were euthanased, this may have been due to differences in post mortem bacterial invasion. An iridovirus-like particle has been identified on electron microscopical examination of skin lesions from frogs with each syndrome and iridovirus-like inclusions have been detected in the livers of frogs with systemic haemorrhages. Also, an adenovirus-like particle has been cultured from one haemorrhagic frog. A poxvirus-like particle described previously from diseased frogs has now been found also in control animals and has been identified as a melanosome. Both the prevalence of the iridovirus-like particle and its association with lesions indicate that it may be implicated in the aetiology of the disease syndromes observed. Specifically, we hypothesize that primary iridovirus infection, with or without secondary infection with opportunistic pathogens such as A. hydrophila, may cause natural outbreaks of 'red-leg', a disease considered previously to be due to bacterial infection only.

  20. 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.

  1. Neurodistribution of Androgen Receptor Immunoreactivity in the Male Frog, Rana esculenta

    PubMed Central

    Guerriero, G.; Prins, G. S.; Birch, L.; Ciarcia, G.

    2010-01-01

    Sexual behavior in vertebrates depends on the cyclic release of steroids and their binding to the brain receptors. Previously, we demonstrated the presence of specific binding of 3H-testosterone and staining with PG-21 in the brain of the adult male frog, Rana esculenta. Here, we report our further receptor characterization using an anti–androgen receptor antiserum, PG-21, and the androgen site of action in frog brain. Nuclei, which contained cells labeled for the androgen receptor (AR), were mainly identified in the olfactory bulbs, preoptic-septal region, infundibulum, amygdala, thalamus, tectum, torus semicircularis, and medulla. The neuroanatomical AR staining appears similar to that in other lower vertebrates. PMID:15891054

  2. Expression of frequenin at the frog (Rana) neuromuscular junction, muscle spindle and nerve.

    PubMed

    Werle, M J; Roder, J; Jeromin, A

    2000-04-21

    Frequenin is a calcium binding protein previously implicated in the regulation of neurotransmission in Drosophila and Xenopus. We have used the frog (Rana pipiens) to study the localization and regulation of expression of frequenin-like molecules in the vertebrate peripheral nervous system. Affinity purified antibodies to frequenin recognize molecules in the neuromuscular junction, axons in the peripheral nerve, and neuronal processes in muscle spindles. Western blots of endplate regions, peripheral nerve, and brain, resulted in the labelling of a single 24 kDa band, which is the expected size for frequenin. These results suggest that frequenin expression is high in the frog peripheral nervous system, and may reflect a function for frequenin in synaptic transmission in vertebrates.

  3. [Role of acetylcholine in the Ca2+-dependent regulation of functional activity of myocardium of frog Rana temporaria].

    PubMed

    Shemarova, I V; Kuznetsov, S V; Demina, I N; Nesterov, V P

    2008-01-01

    To study role of ACh in the Ca2+-dependent regulation of rhythm and strength of cardiac contractions in frog Rana temporaria, the ACh chrono- and inotropic effects have been studied in parallel experiments on the background of blockers of potential-controlled Ca2+-channels, ryanodine and muscarine receptors. The obtained results indicate participation of acetylcholine in the Ca2+-dependent regulation of rhythm and strength of frog cardiac contractions.

  4. Rangewide phylogeography of the western U.S. endemic frog Rana boylii (Ranidae): Implications for the conservation of frogs and rivers

    Treesearch

    A.J. Lind; H.B. Shaffer; P.Q. Spinks; G.M. Fellers

    2011-01-01

    Genetic data are increasingly being used in conservation planning for declining species. We sampled both the ecological and distributional limits of the foothill yellow-legged frog, Rana boylii to characterize mitochondrial DNA (mtDNA) variation in this declining, riverine amphibian. We evaluated 1525 base pairs (bp) of cytochrome b...

  5. Post-Wildfire Sedimentation in Saguaro National Park, Rincon Mountain District, and Effects on Lowland Leopard Frog Habitat

    USGS Publications Warehouse

    Parker, John T.C.

    2006-01-01

    The Rincon Mountain District of Saguaro National Park occupies about 272 square kilometers of mountains, canyons, and alluvial fans in southeastern Arizona just east of Tucson. The park contains some of the last remaining habitat in the Tucson Basin of the lowland leopard frog that lives in the bedrock pools called tinajas in canyons at elevations between 850 and 1,800 meters. Those tinajas that contain water year-round are critical winter habitat for tadpoles, and the breeding success of the leopard frogs depends on these features. In recent years, many tinajas that previously had provided habitat for the leopard frogs have been buried beneath large volumes of coarse sandy gravel that resulted from severe, stand-replacing wildfires in the watersheds above them. The U. S. Geological Survey in cooperation with the National Park Service, conducted a study in 2004-06 to determine critical sediment-source areas, and the mechanisms of sediment delivery from hillslopes to stream channels to areas of leopard frog habitat and to estimate the increase in rates of sedimentation resulting from wildfires. Spatial data of watershed characteristics, as well as historical data, including photographs, monitoring surveys, precipitation and stream discharge records, were used in conjunction with field observations conducted between spring 2004 and fall 2005. The Helens II fire in 2003, the fifth largest wildfire to burn in the Rincon Mountains since 1989, offered an opportunity to observe mechanisms of sediment erosion, transport, and deposition in the immediate post-fire environment. Reduction of the forest canopy, understory vegetation, and organic litter on the ground surface in severe burn areas caused increased surface runoff in the Joaquin Canyon watershed that led to intensified erosion of hillslopes. An initial flush of fine material, mostly ash, was transported to lower channel reaches with the first significant precipitation event following the fire. Subsequently, the main

  6. The pathogen of frogs Amphibiocystidium ranae is a member of the order dermocystida in the class mesomycetozoea.

    PubMed

    Pereira, Cristiane N; Di Rosa, Ines; Fagotti, Anna; Simoncelli, Francesca; Pascolini, Rita; Mendoza, Leonel

    2005-01-01

    The pathogen of frogs Amphibiocystidium ranae was recently described as a new genus. Due to its spherical shape, containing hundred of endospores, it was thought to be closely related to the pathogens of fish, mammals, and birds known as Dermocystidium spp., Rhinosporidium seeberi, and Sphaerothecum destruens in the Mesomycetozoea, but further studies were not conducted to confirm this relationship. To investigate its phylogenetic affinities, total genomic DNA was extracted from samples collected from infected frogs containing multiple cysts (sporangia) and endospores. The universal primers NS1 and NS8, used to amplify the 18S small-subunit rRNA by PCR, yielded approximately 1,770-bp amplicons. Sequencing and basic local alignment search tool analyses indicated that the 18S small-subunit rRNA of A. ranae from both Rana esculenta and Rana lessonae was closely related to all of the above organisms. Our phylogenetic analysis placed this pathogen of frogs as the sister group to the genus Dermocystidium and closely related to Rhinosporidium. These data strongly supported the placement of the genus Amphibiocystidium within the mesomycetozoeans, which is in agreement with the phenotypic features that A. ranae shares with the other members of this class. Interestingly, during this study Dermocystidium percae did not group within the Dermocystidium spp. from fish; rather, it was found to be the sister group to Sphaerothecum destruens. This finding suggests that D. percae could well be a member of the genus Sphaerothecum or perhaps represents a new genus.

  7. Status of RNAs, localized in Xenopus laevis oocytes, in the frogs Rana pipiens and Eleutherodactylus coqui.

    PubMed

    Nath, Kimberly; Boorech, Jamie L; Beckham, Yvonne M; Burns, Mary M; Elinson, Richard P

    2005-01-15

    Early development in the frog model, Xenopus laevis, is governed by RNAs, localized to the vegetal cortex of the oocyte. These RNAs include Xdazl RNA, which is involved in primordial germ cell formation, and VegT RNA, which specifies the mesoderm and endoderm. In order to determine whether orthologues of these RNAs are localized and have similar functions in other frogs, we cloned RpDazl and RpVegT from Rana pipiens, a frog that is phylogenetically distant from X. laevis. RNAs from both genes are localized to the vegetal cortex of the R. pipiens oocyte, indicating that the vegetal localization is likely the basal state. The animal location of EcVegT RNA in Eleutherodactylus coqui that we found previously (Beckham et al., 2003) is then a derived state, probably due to the great increase in egg size required for direct development of this species. To answer the question of function, we injected RpVegT or EcVegT RNAs into X. laevis embryos, and assayed animal caps for gene expression. Both of these RNAs induced the expression of endodermal, mesodermal, and organizer genes, showing that the function of RpVegT and EcVegT as meso-endodermal determinants is conserved in frogs. The RNA localizations and the function of VegT orthologues in germ layer specification may be synapomorphies for anuran amphibians.

  8. Effects of host species and life stage on the helminth communities of sympatric northern leopard frogs (Lithobates pipiens) and wood frogs (Lithobates sylvaticus) in the Sheyenne National Grasslands, North Dakota.

    PubMed

    Gustafson, Kyle D; Newman, Robert A; Tkach, Vasyl V

    2013-08-01

    We studied helminth communities in sympatric populations of leopard frogs (Lithobates pipiens) and wood frogs (Lithobates sylvaticus) and assessed the effects of host species and life stage on helminth community composition and helminth species richness. We examined 328 amphibians including 218 northern leopard frogs and 110 wood frogs collected between April and August of 2009 and 2010 in the Sheyenne National Grasslands of southeastern North Dakota. Echinostomatid metacercariae were the most common helminths found, with the highest prevalence in metamorphic wood frogs. Host species significantly influenced helminth community composition, and host life stage significantly influenced the component community composition of leopard frogs. In these sympatric populations, leopard frogs were common hosts for adult trematodes whereas wood frogs exhibited a higher prevalence of nematodes with direct life cycles. Metamorphic frogs were commonly infected with echinostomatid metacercariae and other larval trematodes whereas juvenile and adult frogs were most-frequently infected with directly transmitted nematodes and trophically transmitted trematodes. Accordingly, helminth species richness increased with the developmental life stage of the host.

  9. Habitat use and home range of the endangered gold-spotted pond frog (Rana chosenica).

    PubMed

    Ra, Nam-Yong; Sung, Ha-Cheol; Cheong, Seokwan; Lee, Jung-Hyun; Eom, Junho; Park, Daesik

    2008-09-01

    Because of their complex life styles, amphibians and reptiles living in wetlands require both aquatic and terrestrial buffer zones in their protected conservation areas. Due to steep declines in wild populations, the gold-spotted pond frog (Rana chosenica) is listed as vulnerable by the IUCN. However, lack of data about its movements and use of habitat prevents effective conservation planning. To determine the habitat use and home range of this species, we radio-tracked 44 adult frogs for 37 days between 10 July and 4 Nov. 2007 to observe three different populations in the breeding season, non-breeding season, and late fall. The gold-spotted pond frog was very sedentary; its daily average movement was 9.8 m. Frogs stayed close to breeding ponds (within 6.6 m), and did not leave damp areas surrounding these ponds, except for dormancy migration to terrestrial sites such as dried crop fields. The average distance of dormancy migration of seven frogs from the edge of their breeding ponds was 32.0 m. The average size of an individual's home range was 713.8 m(2) (0.07 ha). The year-round population home range, which accounts for the home ranges of a population of frogs, was determined for two populations to be 8,765.0 m(2) (0.88 ha) and 3,700.9 m(2) (0.37 ha). Our results showed that to conserve this endangered species, appropriately sized wetlands and extended terrestrial buffer areas surrounding the wetlands (at least 1.33 ha, diameter 130 m) should be protected.

  10. Water velocity tolerance in tadpoles of the foothill yellow-legged frog (Rana boylii): Swimming performance, growth, and survival

    Treesearch

    S. Kupferberg; A. Lind; V. Thill; S. Yarnell

    2011-01-01

    We explored the effects of large magnitude flow fluctuations in rivers with dams, commonly referred to as pulsed flows, on tadpoles of the lotic-breeding Foothill Yellow-legged Frog, Rana boylii. We quantified the velocity conditions in habitats occupied by tadpoles and then conducted experiments to assess the tolerance to values at the upper limit...

  11. Postbreeding movements of the dark gopher frog, Rana sevosa goin and netting: Implications for conservation and management

    Treesearch

    Stephen C. Richter; Jeanne E. Young; Richard A. Seigal; Glen N. Johnson

    2001-01-01

    Conservation plans for amphibians often focus on activities at the breeding site, but for species that use temstrial habitats for much of the year, an understanding of nonbreeding habitat use is also essential. We used radio telemetry to study the postbreeding movements of individuals of the only known population of dark gopher frogs, Rana sevosa,...

  12. Experimental exposure of adult San Marcos salamanders and larval leopard frogs to the cercariae of Centrocestus formosanus.

    PubMed

    Huston, D C; Cantu, V; Huffman, D G

    2014-04-01

    The gill parasite Centrocestus formosanus (Trematoda: Heterophyidae) is an exotic parasite of concern in Texas because it has been shown to infect multiple threatened and endangered fish species. The purpose of this study was to determine if C. formosanus could present a threat to larval anurans, as well as threatened neotenic salamanders endemic to the spring-fed systems of Texas. We exposed adults of the San Marcos salamander Eurycea nana (Caudata: Plethodontidae) and tadpoles of the Rio Grande leopard frog Lithobates berlandieri (Anura: Ranidae) to the cercariae of C. formosanus . The San Marcos salamander showed no signs of metacercarial infection, suggesting that E. nana may be refractory to C. formosanus cercariae. Centrocestus formosanus readily infects the gills of leopard frog tadpoles, but the metacercariae apparently died prior to reaching maturity in our tadpoles.

  13. Modeling habitat connectivity to inform reintroductions: a case study with the Chiricahua Leopard Frog

    USGS Publications Warehouse

    Jarchow, Christopher J; Hossack, Blake R.; Sigafus, Brent H.; Schwalbe, Cecil R.; Muths, Erin L.

    2016-01-01

    Managing species with intensive tools such as reintroduction may focus on single sites or entire landscapes. For vagile species, long-term persistence will require colonization and establishment in neighboring habitats. Therefore, both suitable colonization sites and suitable dispersal corridors between sites are required. Assessment of landscapes for both requirements can contribute to ranking and selection of reintroduction areas, thereby improving management success. Following eradication of invasive American Bullfrogs (Lithobates catesbeianus) from most of Buenos Aires National Wildlife Refuge (BANWR; Arizona, United States), larval Chiricahua Leopard Frogs (Lithobates chiricahuensis) from a private pond were reintroduced into three stock ponds. Populations became established at all three reintroduction sites followed by colonization of neighboring ponds in subsequent years. Our aim was to better understand colonization patterns by the federally threatened L. chiricahuensis which could help inform other reintroduction efforts. We assessed the influence of four landscape features on colonization. Using surveys from 2007 and information about the landscape, we developed a habitat connectivity model, based on electrical circuit theory, that identified potential dispersal corridors after explicitly accounting for imperfect detection of frogs. Landscape features provided little insight into why some sites were colonized and others were not, results that are likely because of the uniformity of the BANWR landscape. While corridor modeling may be effective in more-complex landscapes, our results suggest focusing on local habitat will be more useful at BANWR. We also illustrate that existing data, even when limited in spatial or temporal resolution, can provide information useful in formulating management actions.

  14. Cryptic Diversity in Metropolis: Confirmation of a New Leopard Frog Species (Anura: Ranidae) from New York City and Surrounding Atlantic Coast Regions

    PubMed Central

    Feinberg, Jeremy A.; Newman, Catherine E.; Watkins-Colwell, Gregory J.; Schlesinger, Matthew D.; Zarate, Brian; Curry, Brian R.; Shaffer, H. Bradley; Burger, Joanna

    2014-01-01

    We describe a new cryptic species of leopard frog from the New York City metropolitan area and surrounding coastal regions. This species is morphologically similar to two largely parapatric eastern congeners, Rana sphenocephala and R. pipiens. We primarily use bioacoustic and molecular data to characterize the new species, but also examine other lines of evidence. This discovery is unexpected in one of the largest and most densely populated urban parts of the world. It also demonstrates that new vertebrate species can still be found periodically even in well-studied locales rarely associated with undocumented biodiversity. The new species typically occurs in expansive open-canopied wetlands interspersed with upland patches, but centuries of loss and impact to these habitats give some cause for conservation concern. Other concerns include regional extirpations, fragmented extant populations, and a restricted overall geographic distribution. We assign a type locality within New York City and report a narrow and largely coastal lowland distribution from central Connecticut to northern New Jersey (based on genetic data) and south to North Carolina (based on call data). PMID:25354068

  15. Cryptic diversity in metropolis: confirmation of a new leopard frog species (Anura: Ranidae) from New York City and surrounding Atlantic coast regions.

    PubMed

    Feinberg, Jeremy A; Newman, Catherine E; Watkins-Colwell, Gregory J; Schlesinger, Matthew D; Zarate, Brian; Curry, Brian R; Shaffer, H Bradley; Burger, Joanna

    2014-01-01

    We describe a new cryptic species of leopard frog from the New York City metropolitan area and surrounding coastal regions. This species is morphologically similar to two largely parapatric eastern congeners, Rana sphenocephala and R. pipiens. We primarily use bioacoustic and molecular data to characterize the new species, but also examine other lines of evidence. This discovery is unexpected in one of the largest and most densely populated urban parts of the world. It also demonstrates that new vertebrate species can still be found periodically even in well-studied locales rarely associated with undocumented biodiversity. The new species typically occurs in expansive open-canopied wetlands interspersed with upland patches, but centuries of loss and impact to these habitats give some cause for conservation concern. Other concerns include regional extirpations, fragmented extant populations, and a restricted overall geographic distribution. We assign a type locality within New York City and report a narrow and largely coastal lowland distribution from central Connecticut to northern New Jersey (based on genetic data) and south to North Carolina (based on call data).

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

    PubMed

    Wahl, Manfred

    1969-07-01

    1. At a pond near Tübingen, West-Germany, the calling period of the green frog, Rana esculenta, lasts for a period ranging from the middle to the end of April, to the beginning to the end of July. The calling period is parted because of two changes in the behavior of calling and the changing number of the calling groups in: pre spawning period, spawning period and post spawning period. 2. Male frogs form calling groups. The males of each group cry in a rhythmic chorus. 3. The calling activity is influenced by 3 external factors, weather, water temperature and temperature of the air. The dependance of calling activity by these factors is not linear. During a period of good weather the calling activity increases daily. During a period of bad weather there is a daily decrease. The highest calling activity is on sunny days with a water temperature of between 17.5 and 22°C plus or minus 1 degree. From this level the activity falls with decreasing or increasing water temperature asymptotic to zero. The lower limit of calling activity ranges from 10 to 12°C, the upper one by 36.5 plus or minus 0.5°C. With the growing increase of air temperature the number of calls per time period falls asymptotic to zero. 4. The male green frog emits 6 calls; one mating call, two territorial calls, two release calls and one distress call. The calls consist of impulses, which, in the case of the mating call, are arranged to characteristic impulse-groups. The female green frog also emits calls, but no mating calls. 5. The parameters of mating and territorial calls are influenced by the water temperature. With increasing water temperature the duration of calls decreases linear, on the other hand the sequence of impulses and the repetition rate of impulse-groups show a positive linear regression. Also the size of the frog influences the calling parameters. With the increase of body length the duration of mating calls and territorial calls decreases and the sequence of impulses increases

  17. Enzymatic regulation of seasonal glycogen cycling in the freeze-tolerant wood frog, Rana sylvatica.

    PubMed

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

    2016-12-01

    Liver glycogen is an important energy store in vertebrates, and in the freeze-tolerant wood frog, Rana sylvatica, this carbohydrate also serves as a major source of the cryoprotectant glucose. We investigated how variation in the levels of the catalytic subunit of protein kinase A (PKAc), glycogen phosphorylase (GP), and glycogen synthase (GS) relates to seasonal glycogen cycling in a temperate (Ohioan) and subarctic (Alaskan) populations of this species. In spring, Ohioan frogs had reduced potential for glycogen synthesis, as evidenced by low GS activity and high PKAc protein levels. In addition, glycogen levels in spring were the lowest of four seasonal samples, as energy input was likely directed towards metabolism and somatic growth during this period. Near-maximal glycogen levels were reached by mid-summer, and remained unchanged in fall and winter, suggesting that glycogenesis was curtailed during this period. Ohioan frogs had a high potential for glycogenolysis and glycogenesis in winter, as evidenced by large glycogen reserves, high levels of GP and GS proteins, and high GS activity, which likely allows for rapid mobilization of cryoprotectant during freezing and replenishing of glycogen reserves during thawing. Alaskan frogs also achieved a near-maximal liver glycogen concentration by summer and displayed high glycogenic and glycogenolytic potential in winter, but, unlike Ohioan frogs, started replenishing their energy reserves early in spring. We conclude that variation in levels of both glycogenolytic and glycogenic enzymes likely happens in response to seasonal changes in energetic strategies and demands, with winter survival being a key component to understanding the regulation of glycogen cycling in this species.

  18. Regulation of 5'-adenosine monophosphate deaminase in the freeze tolerant wood frog, Rana sylvatica

    PubMed Central

    Dieni, Christopher A; Storey, Kenneth B

    2008-01-01

    Background The wood frog, Rana sylvatica, is one of a few vertebrate species that have developed natural freeze tolerance, surviving days or weeks with 65–70% of its total body water frozen in extracellular ice masses. Frozen frogs exhibit no vital signs and their organs must endure multiple stresses, particularly long term anoxia and ischemia. Maintenance of cellular energy supply is critical to viability in the frozen state and in skeletal muscle, AMP deaminase (AMPD) plays a key role in stabilizing cellular energetics. The present study investigated AMPD control in wood frog muscle. Results Wood frog AMPD was subject to multiple regulatory controls: binding to subcellular structures, protein phosphorylation, and effects of allosteric effectors, cryoprotectants and temperature. The percentage of bound AMPD activity increased from 20 to 35% with the transition to the frozen state. Bound AMPD showed altered kinetic parameters compared with the free enzyme (S0.5 AMP was reduced, Hill coefficient fell to ~1.0) and the transition to the frozen state led to a 3-fold increase in S0.5 AMP of the bound enzyme. AMPD was a target of protein phosphorylation. Bound AMPD from control frogs proved to be a low phosphate form with a low S0.5 AMP and was phosphorylated in incubations that stimulated PKA, PKC, CaMK, or AMPK. Bound AMPD from frozen frogs was a high phosphate form with a high S0.5 AMP that was reduced under incubation conditions that stimulated protein phosphatases. Frog muscle AMPD was activated by Mg·ATP and Mg·ADP and inhibited by Mg·GTP, KCl, NaCl and NH4Cl. The enzyme product, IMP, uniquely inhibited only the bound (phosphorylated) enzyme from muscle of frozen frogs. Activators and inhibitors differentially affected the free versus bound enzyme. S0.5 AMP of bound AMPD was also differentially affected by high versus low assay temperature (25 vs 5°C) and by the presence/absence of the natural cryoprotectant (250 mM glucose) that accumulates during freezing

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

    DTIC Science & Technology

    2008-10-01

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

  20. 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.

  1. Disentangling genetic vs. environmental causes of sex determination in the common frog, Rana temporaria.

    PubMed

    Matsuba, Chikako; Miura, Ikuo; Merilä, Juha

    2008-01-08

    Understanding of sex ratio dynamics in a given species requires understanding its sex determination system, as well as access for reliable tools for sex identification at different life stages. As in the case of many other amphibians, the common frogs (Rana temporaria) do not have well differentiated sex chromosomes, and an identification of individuals' genetic sex may be complicated by sex reversals. Here, we report results of studies shedding light on the sex determination system and sex ratio variation in this species. A microsatellite locus RtSB03 was found to be sex-linked in four geographically disparate populations, suggesting male heterogamy in common frogs. However, in three other populations examined, no or little evidence for sex-linkage was detected suggesting either ongoing/recent recombination events, and/or frequent sex-reversals. Comparison of inheritance patterns of alleles in RtSB03 and phenotypic sex within sibships revealed a mixed evidence for sex-linkage: all individuals with male phenotype carried a male specific allele in one population, whereas results were more mixed in another population. These results make sense only if we assume that the RtSB03 locus is linked to male sex determination factor in some, but not in all common frog populations, and if phenotypic sex-reversals - for which there is earlier evidence from this species - are frequently occurring.

  2. Polychlorinated biphenyls, sex steroid hormones and liver retinoids in adult male European common frogs Rana temporaria.

    PubMed

    Mikkelsen, Mattis; Jenssen, Bjørn Munro

    2006-05-01

    Declines in amphibian populations and species biodiversity during the last decades has called for an assessment of possible threats to these animals. Polychlorinated biphenyls (PCBs) are known endocrine disrupting contaminants and are found in high levels in some populations of wild living amphibians. To evaluate the endocrine disrupting potential of PCBs in adult frogs, Aroclor 1,254 were subcutaneously injected into male European common frogs Rana temporaria. The injected doses ranged from 0.01 to 100 mg/kg body mass, resulting in liver concentrations between 74 and 133,619 microg/kg ww. After 14 days, serum testosterone (T), estradiol (E) and hepatic retinol (R) and retinylpalmitate (RP) were easured. No dose dependent effects were found on levels of hormones or retinoids. However, a significantly higher within-group variation in the E-T ratio in the exposed groups may indicate that the sex-hormone homeostasis of male R. temporaria is affected by PCBs shortly after arousal from hibernation, but that the effects are subtle and that several different mechanisms are involved. The lack of direct effect on T, E, R and RP may be due to the timing of exposure (shortly after arousal from hibernation), or due to a relatively short exposure time to Aroclor 1,254. Based on the results, we propose that future research should focus on effects of PCBs in relation to the different physiological phases frogs experience throughout the year (hibernation, reproduction etc.).

  3. A Threshold Dosage of Testosterone for Female-to-Male Sex Reversal in Rana rugosa Frogs.

    PubMed

    Oike, Akira; Kodama, Maho; Nakamura, Yoriko; Nakamura, Masahisa

    2016-10-01

    Androgens play a critical role in testicular differentiation in many species of vertebrates. While female-to-male sex reversal can be induced by testosterone (T) in some species of amphibians, the mechanism still remains largely unknown even at the histological level. In this study, we determined a threshold dosage of T to induce female-to-male sex reversal in the Japanese frog Rana (R.) rugosa. Tadpoles were allowed to metamorphose into frogs with T present in the rearing water. At 0.2 ng/mL T, female frogs formed tissue comprising a mixture of ovary and testis, the so-called ovotestis, the size of which was significantly smaller than the wild-type ovary. Histological changes occurring in the oocytes of T-treated ovaries induced oocyte degeneration in the masculinizing ovaries leading to their final disappearance. In parallel, many germ cells emerged in the cortex of the ovotestis and, later, in the medulla as well. RT-PCR analysis revealed upregulated expression of CYP17 and Dmrt1 but not 17βHSD in the ovotestis, and downregulation of Pat1a expression. Furthermore, immunohistology revealed CYP17-positive signals in the cortex of the masculinizing ovary, spreading throughout the whole area as the testis developed. These results indicate that oocytes are sensitive to T in the ovary of R. rugosa and that male-type germ cells expand in the masculinizing gonad (testis) contemporaneous with oocyte disappearance.

  4. Recent Emergence of a Chytrid Fungal Pathogen in California Cascades Frogs (Rana cascadae).

    PubMed

    De León, Marina E; Vredenburg, Vance T; Piovia-Scott, Jonah

    2016-12-12

    The pathogenic fungus Batrachochytrium dendrobatidis (Bd) has been associated with global amphibian declines, but it is often difficult to discern the relative importance of Bd as a causal agent in declines that have already occurred. Retrospective analyses of museum specimens have allowed researchers to associate the timing of Bd arrival with the timing of past amphibian declines. Cascades frogs (Rana cascadae) have experienced dramatic declines in northern California, but it is not clear whether the onset of these declines corresponds to the arrival of Bd. We used quantitative real-time PCR assays of samples collected from museum specimens to determine historical Bd prevalence in the northern California range of Cascades frogs. We detected Bd in 13 of 364 (3.5%) Cascades frog specimens collected between 1907 and 2003, with the first positive result from 1978. A Bayesian analysis suggested that Bd arrived in the region between 1973 and 1978, which corresponds well with the first observations of declines in the 1980s.

  5. Disentangling genetic vs. environmental causes of sex determination in the common frog, Rana temporaria

    PubMed Central

    Matsuba, Chikako; Miura, Ikuo; Merilä, Juha

    2008-01-01

    Background Understanding of sex ratio dynamics in a given species requires understanding its sex determination system, as well as access for reliable tools for sex identification at different life stages. As in the case of many other amphibians, the common frogs (Rana temporaria) do not have well differentiated sex chromosomes, and an identification of individuals' genetic sex may be complicated by sex reversals. Here, we report results of studies shedding light on the sex determination system and sex ratio variation in this species. Results A microsatellite locus RtSB03 was found to be sex-linked in four geographically disparate populations, suggesting male heterogamy in common frogs. However, in three other populations examined, no or little evidence for sex-linkage was detected suggesting either ongoing/recent recombination events, and/or frequent sex-reversals. Comparison of inheritance patterns of alleles in RtSB03 and phenotypic sex within sibships revealed a mixed evidence for sex-linkage: all individuals with male phenotype carried a male specific allele in one population, whereas results were more mixed in another population. Conclusion These results make sense only if we assume that the RtSB03 locus is linked to male sex determination factor in some, but not in all common frog populations, and if phenotypic sex-reversals – for which there is earlier evidence from this species – are frequently occurring. PMID:18182101

  6. 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.

  7. Antimicrobial peptides with atypical structural features from the skin of the Japanese brown frog Rana japonica.

    PubMed

    Isaacson, Todd; Soto, AnaMaria; Iwamuro, Shawichi; Knoop, Floyd C; Conlon, J Michael

    2002-03-01

    Japonicin-1 (FFPIGVFCKIFKTC) and japonicin-2 (FGLPMLSILPKALCILLKRKC), two peptides with differential growth-inhibitory activity against the Gram-negative bacterium, Escherichia coli and the Gram-positive bacterium Staphylococcus aureus, were isolated from an extract of the skin of the Japanese brown frog Rana japonica. Both peptides show little amino acid sequence similarity to previously characterized antimicrobial peptides isolated from the skins of Ranid frogs. Circular dichroism studies, however, demonstrate that japonicin-2 adopts an alpha-helical conformation in 50% trifluoroethanol in common with many other cationic antimicrobial peptides synthesized in amphibian skin. Peptides belonging to the brevinin-1, brevinin-2, and tigerinin families, previously identified in the skins of Asian Ranid frogs, were not detected but a temporin-related peptide (ILPLVGNLLNDLL.NH(2); temporin-1Ja), that atypically bears no net positive charge, was isolated from the extract. The minimum inhibitory concentrations (MICs) of the peptides against E. coli were japonicin-1, 30 microM; japonicin-2, 12 microM; and temporin-1Ja > 100 microM. The MICs against S. aureus were japonicin-1, > 100 microM; japonicin-2, 20 microM; and temporin-1Ja, > 100 microM.

  8. Variations of intestinal calcium absorption in adult frogs (Rana esculenta). Effect of lysine.

    PubMed

    el Maraghi-Ater, H; Hourdry, J; Mesnard, J; Dupuis, Y

    1987-01-01

    Intestinal calcium absorption was investigated in an adult frog (Rana esculenta) by injecting a CaCl2 solution containing 45Ca into the lumen. The 45Ca absorption coefficient in the proximal loop was higher than in the distal loop, only when the CaCl2 solution was left for 4 h. This coefficient increased both in the proximal and distal loops when a 4-h treatment was substituted for a 1-h treatment. The coefficient increased in the whole intestine during the first 2 h of treatment (1 h: 21%; 2 h: 55%) and remained stable afterwards in our experimental conditions. The intestinal calcium absorption increase occurred early in the presence of L-lysine (100 mM), since the coefficient already reached its maximum value (52%) after a 1-h treatment.

  9. The isolated and perfused working heart of the frog, Rana esculenta: an improved preparation.

    PubMed

    Acierno, R; Gattuso, A; Cerra, M C; Pellegrino, D; Agnisola, C; Tota, B

    1994-05-01

    1. An in vitro preparation of the intact heart of the frog Rana esculenta was set up. 2. The isolated heart, perfused at constant pressure, was spontaneously beating and able to generate physiological values of output pressure, cardiac output, ventricle work and power. It showed the typical phenomenon of the "hypodynamic state" after a relatively constant time from the onset of the perfusion. 3. Perfusion with air-saturated saline and 99.5% oxygen-saturated saline did not show significant differences in the recorded parameters. 4. This experimental model represents a useful tool for physiological and pharmacological studies, especially when the direct analysis of the effects of hormones, mediators or drugs requires an intact heart preparation.

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

    PubMed

    Matsui, Masafumi

    2014-09-01

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

  11. 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

    From 2001 to 2005, we studied the demography and seasonal movement of Oregon spotted frogs (Rana pretiosa) translocated into created ponds in Dilman Meadow in central Oregon. Our objectives were to inform future monitoring and management at the site, and to elucidate poorly known aspects of the species’ population ecology. Movement rates revealed complementary use of sites seasonally, with one small spring being preferred during winter that was rarely used during the rest of the year. Growth rates were significantly higher in ponds that were not used for breeding, and larger size resulted in significantly higher survival. When variation in survival by size was accounted for there was little variation among ponds in survival. Seasonal estimates of survival were lowest for males during the breeding/post-breeding redistribution period, suggesting a high cost of breeding for males. Overwintering survival for both genders was relatively high. Our study supports others in suggesting Oregon spotted frogs are specific in their overwintering habitat requirements, and that predator-free springs may be of particular value. We suggest that any future monitoring include measures of the rate of pond succession. Demographic monitoring should include metrics of both frog reproduction and survival: counts of egg masses at all ponds during spring, and capture-recapture study of survival in mid and late summer when capture rates are highest. Additional study of early life stages would be particularly useful to broaden our understanding of the species’ ecology. Specifically, adding intensive capture and marking effort after larval transformation in fall would enable a full understanding of the annual life cycle. Complete study of the annual life cycle is needed to isolate the life stages and mechanisms through which Oregon spotted frogs are affected by stressors such as nonnative predators. Dilman Meadow, which lacks many hypothesized stressors, is an important reference for

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Tissue-specific transcriptome characterization for developing tadpoles of the northern leopard frog (Lithobates pipiens).

    PubMed

    Row, Jeffrey R; Donaldson, Michael E; Longhi, Jessica N; Saville, Barry J; Murray, Dennis L

    2016-12-01

    A potential cause of amphibian population declines are the impacts of environmental degradation on tadpole development. We conducted RNA sequencing on developing northern leopard frog tadpoles and through de novo transcriptome assembly we annotated a large number of open reading frames comparable in number and extent to genes identified in Xenopus. Using our transcriptome, we found transcript level changes between early (Gosner 26-31) and late (Gosner 36-41) stage tadpoles were the greatest in the tail, which is reabsorbed throughout development. There was an up-regulation of immunity genes in both the head and tail of the late tadpoles and a down-regulation of genes associated with the energy pathways of the mitochondria and the production of myosin. Overall, transcript level changes across development were consistent with studies on Xenopus and our findings highlight the broader utility of using RNA-seq to identify genes differentially expressed throughout development and in response to environmental pressures. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Unlikely Remedy: Fungicide Clears Infection from Pathogenic Fungus in Larval Southern Leopard Frogs (Lithobates sphenocephalus)

    PubMed Central

    Hanlon, Shane M.; Kerby, Jacob L.; Parris, Matthew J.

    2012-01-01

    Amphibians are often exposed to a wide variety of perturbations. Two of these, pesticides and pathogens, are linked to declines in both amphibian health and population viability. Many studies have examined the separate effects of such perturbations; however, few have examined the effects of simultaneous exposure of both to amphibians. In this study, we exposed larval southern leopard frog tadpoles (Lithobates sphenocephalus) to the chytrid fungus Batrachochytrium dendrobatidis and the fungicide thiophanate-methyl (TM) at 0.6 mg/L under laboratory conditions. The experiment was continued until all larvae completed metamorphosis or died. Overall, TM facilitated increases in tadpole mass and length. Additionally, individuals exposed to both TM and Bd were heavier and larger, compared to all other treatments. TM also cleared Bd in infected larvae. We conclude that TM affects larval anurans to facilitate growth and development while clearing Bd infection. Our findings highlight the need for more research into multiple perturbations, specifically pesticides and disease, to further promote amphibian heath. PMID:22912890

  18. Unlikely remedy: fungicide clears infection from pathogenic fungus in larval southern leopard frogs (Lithobates sphenocephalus).

    PubMed

    Hanlon, Shane M; Kerby, Jacob L; Parris, Matthew J

    2012-01-01

    Amphibians are often exposed to a wide variety of perturbations. Two of these, pesticides and pathogens, are linked to declines in both amphibian health and population viability. Many studies have examined the separate effects of such perturbations; however, few have examined the effects of simultaneous exposure of both to amphibians. In this study, we exposed larval southern leopard frog tadpoles (Lithobates sphenocephalus) to the chytrid fungus Batrachochytrium dendrobatidis and the fungicide thiophanate-methyl (TM) at 0.6 mg/L under laboratory conditions. The experiment was continued until all larvae completed metamorphosis or died. Overall, TM facilitated increases in tadpole mass and length. Additionally, individuals exposed to both TM and Bd were heavier and larger, compared to all other treatments. TM also cleared Bd in infected larvae. We conclude that TM affects larval anurans to facilitate growth and development while clearing Bd infection. Our findings highlight the need for more research into multiple perturbations, specifically pesticides and disease, to further promote amphibian heath.

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

    USGS Publications Warehouse

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

    2014-01-01

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

  20. 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.

  1. Effect of sex steroids on gonadal differentiation and sex reversal in the frog, Rana curtipes.

    PubMed

    Saidapur, S K; Gramapurohit, N P; Shanbhag, B A

    2001-10-01

    The bicolored frog, Rana curtipes, is endemic to Western Ghats of Southern India, having a prolonged larval life. In this species, gonadal differentiation is of the semidifferentiated type. The gonads initially differentiate into ovaries in all the individuals at Gosner stage 25. Later, in genetic males, the oocytes degenerate and testicular differentiation occurs at stages 30-31. Exposure of R. curtipes tadpoles to 50 microg/L of testosterone (T) or estradiol-17beta (E(2)) during stages 24-26 or 29-32 did not affect gonadal sex differentiation and proportion of males and females at metamorphosis. In all the groups, the sex ratio was almost 1:1 as in the controls. Likewise, exposure of tadpoles to low concentration of steroids (12.5 microg/L T or E(2)) throughout larval development was ineffective in altering the sex ratio or the gonadal sex differentiation. On the other hand, exposure to higher concentrations of steroids (25 and 50 microg/L) throughout the larval development (stages 25-45) significantly skewed the sex ratio toward the male or female direction, depending upon the sex steroid used. Thus, exposure to T or E(2) throughout the larval period could produce 93% males or 79% females, respectively, indicating the ability of these steroids to cause sex reversal. This study shows a possible absence of a "critical stage" that is sensitive to sex steroids for gonadal sex reversal in this frog. Copyright 2001 Academic Press.

  2. 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.

  3. 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.

  4. An immunohistochemical study of the pancreatic endocrine cells of the Korean golden frog, Rana plancyi chosenica

    PubMed Central

    Lee, H.S.; Chang, J.H.; Ku, S.K.

    2012-01-01

    The regional distribution and quantitative frequency of pancreatic endocrine cells were demonstrated in the Korean golden frog (Rana plancyi chosenica Okada), which is known as a Korean endemic species, for the first time by immunohistochemical methods using specific mammalian antisera to insulin, glucagon, somatostatin and human pancreatic polypeptide (PP). In the pancreas of the Korean golden frog, all four endocrine cell types were demonstrated. Insulin- and glucagon-positive cells were located in the pancreas as single cells or islet-like clusters, respectively. Somatostatin-containing cells were also dispersed in the pancreas as single cells or clusters but in the case of clusters, they are exclusively situated in the marginal regions of insulin- or glucagon-positive cell clusters. PP-containing cells were also distributed as single cells or clusters. Clusters consisted of PP-positive cells are distributed as a core type and a marginally distributed type. Overall, there were 40.84±3.81% insulin-, 26.02±1.71% glucagon-, 7.63±2.09% somatostatin- and 25.51±3.26% PP-IR cells. PMID:22472893

  5. Ranid Herpesvirus 3 and Proliferative Dermatitis in Free-Ranging Wild Common Frogs (Rana Temporaria).

    PubMed

    Origgi, F C; Schmidt, B R; Lohmann, P; Otten, P; Akdesir, E; Gaschen, V; Aguilar-Bultet, L; Wahli, T; Sattler, U; Stoffel, M H

    2017-07-01

    Amphibian pathogens are of current interest as contributors to the global decline of amphibians. However, compared with chytrid fungi and ranaviruses, herpesviruses have received relatively little attention. Two ranid herpesviruses have been described: namely, Ranid herpesvirus 1 (RHV1) and Ranid herpesvirus 2 (RHV2). This article describes the discovery and partial characterization of a novel virus tentatively named Ranid herpesvirus 3 (RHV3), a candidate member of the genus Batrachovirus in the family Alloherpesviridae. RHV3 infection in wild common frogs (Rana temporaria) was associated with severe multifocal epidermal hyperplasia, dermal edema, a minor inflammatory response, and variable mucous gland degeneration. Intranuclear inclusions were numerous in the affected epidermis together with unique extracellular aggregates of herpesvirus-like particles. The RHV3-associated skin disease has features similar to those of a condition recognized in European frogs for the last 20 years and whose cause has remained elusive. The genome of RHV3 shares most of the features of the Alloherpesviruses. The characterization of this presumptive pathogen may be of value for amphibian conservation and for a better understanding of the biology of Alloherpesviruses.

  6. Physiological evidence for β3-adrenoceptor in frog (Rana esculenta) heart.

    PubMed

    Mazza, Rosa; Angelone, Tommaso; Pasqua, Teresa; Gattuso, Alfonsina

    2010-11-01

    β3-Adrenergic receptors (ARs) have been recently identified in mammalian hearts where, unlike β1- and β2-ARs, induce cardio-suppressive effects. The aim of this study was to describe β3-AR role in the frog (Rana esculenta) heart and to examine its signal transduction pathway. The presence of β3-AR, by using Western blotting analysis, has been also identified. BRL(37344), a selective β3-AR agonist, induced a dose-dependent negative inotropic effect at concentrations from 10(-12) to 10(-6)M. This effect was not modified by nadolol (β1/β2-AR antagonist) and by phentolamine (α-AR antagonist), but it was suppressed by the β3-AR-specific antagonist SR(59230) and by exposure to the Gi/o proteins inhibitor Pertussis Toxin. In addition, the involvement of EE-NOS-cGMP-PKG/PDE2 pathway in the negative inotropism of BRL(37344) has been assessed. BRL(37344) treatment induced eNOS and Akt phosphorylation as well as an increase of cGMP levels. β3-ARs activation induce a non-competitive antagonism against ISO stimulation which disappeared in presence of PKG and PDE2 inhibition. Taken together our findings provide, for the first time in the frog, a role for β3-ARs in the cardiac performance modulation which involves Gi/o protein and occurs via an EE-NO-cGMP-PKG/PDE2 cascade.

  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.

  8. Movement ecology and seasonal distribution of mountain yellow-legged frogs, Rana muscosa, in a high-elevation Sierra Nevada basin.

    Treesearch

    K.L. Pope; K.R. Matthews

    2001-01-01

    Movement ecology and seasonal distribution of mountain yellow-legged frogs (Rana muscosa) in Dusy Basin (3470 m), Kings Canyon National Park, California, were characterized using passive integrated transponder (PIT) surveys and visual encounter surveys. We individually PIT-tagged 500 frogs during the summers of 1997 and 1998 and monitored these individuals during seven...

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

    PubMed

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

    2012-10-01

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

  10. [Resident and circulating mast cells in propulsative organs of the frog Rana temporaria].

    PubMed

    Krylova, M I

    2009-01-01

    Mast cells (MCs) of the "blood" and lymph hearts of the adult frog Rana temporaria were investigated at histochemical and ultrastructural levels. Two populations of MCs were revealed in these propulsative organs: population of resident MCs and population of circulating MCs. It has been shown that the resident cardiac MCs have an oval or elongated form and are located between atrial or ventricular myocytes and under endocardial endothelium. The resident cardiac MCs are situated in connective tissue of epicardium, too. Avascular myocardium of the frog ventricle consists of a spongy network of muscle trabeculae. We revealed circulating MCs in intertrabecular spaces and clefts of the spongy myocardium and in the blood of the main central cavity. Circulating MCs are round in shape and contain a large central nucleus enriched with condensed chromatin. They resemble the lymphocytes, but show cytoplasm filled with granules. These granules ultrastructure is much like that of the granules of the cardiac resident MCs. In the lymph heart, oval and somewhat elongated resident MCs are located in the interstitial space among cross-striated muscle fibers and among smooth muscle cells of tubular (afferent and efferent) valves. Sometimes lymphocyte-like circulating MCs are revealed in the cavity of lymph heart. Circulating MCs are also present in the lymphatics located adjacent to the lymph hearts. In certain parts of the lymphatic walls MCs are in close adhesion to the mesothelial cells lining the lymphatic cavity. Our histochemical investigation revealed that both the resident and circulating MCs of the propulsative organs give a strongly positive reaction with alcian blue, but weakly red with safranin and weakly metachromatic with toluidine blue. The presence of population of circulating MCs in the frog suggests that there are differences in biology of MCs between lower and higher vertebrates.

  11. 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

  12. Mass spectrometric study of peptides secreted by the skin glands of the brown frog Rana arvalis from the Moscow region.

    PubMed

    Samgina, T Yu; Artemenko, K A; Gorshkov, V A; Ogourtsov, S V; Zubarev, R A; Lebedev, A T

    2009-05-01

    A high-performance liquid chromatography nano-electrospray ionization Fourier transform mass spectrometry (HPLC/nanoESI-FTMS) approach involving recording of collision-activated dissociation (CAD) and electron-capture dissociation (ECD) spectra of an intact sample and two its modifications after performic oxidation and reduction followed by carboxamidomethylation helps to establish peptide profiles in the crude secretion of frog species at mid-throughput level, including de novo sequencing. The proposed derivatization procedures allow increasing of the general sequence coverage in the backbone, providing complementary information and, what is more important, reveal the amino acid sequence in the cystine ring ('rana box'). Thus purely mass spectrometric efficient sequencing becomes possible for longer than usual proteolytic peptides. Seventeen peptides belonging to four known families were identified in the secretion of the European brown frog Rana arvalis inhabiting the Moscow region in Russia. Ranatuerins, considered previously a unique feature of the North American species, as well as a new melittin-related peptide, are worth special mention. The developed approach was previously successfully used for the identification of peptides in the skin secretion of the Caucasian green frog Rana ridibunda. Copyright (c) 2009 John Wiley & Sons, Ltd.

  13. 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.

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

    PubMed

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

    2012-04-01

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

  15. First-generation linkage map for the common frog Rana temporaria reveals sex-linkage group

    PubMed Central

    Cano, J M; Li, M-H; Laurila, A; Vilkki, J; Merilä, J

    2011-01-01

    The common frog (Rana temporaria) has become a model species in the fields of ecology and evolutionary biology. However, lack of genomic resources has been limiting utility of this species for detailed evolutionary genetic studies. Using a set of 107 informative microsatellite markers genotyped in a large full-sib family (800 F1 offspring), we created the first linkage map for this species. This partial map—distributed over 15 linkage groups—has a total length of 1698.8 cM. In line with the fact that males are the heterogametic sex in this species and a reduction of recombination is expected, we observed a lower recombination rate in the males (map length: 1371.5 cM) as compared with females (2089.8 cM). Furthermore, three loci previously documented to be sex-linked (that is, carrying male-specific alleles) in adults from the wild mapped to the same linkage group. The linkage map described in this study is one of the densest ones available for amphibians. The discovery of a sex linkage group in Rana temporaria, as well as other regions with strongly reduced male recombination rates, should help to uncover the genetic underpinnings of the sex-determination system in this species. As the number of linkage groups found (n=15) is quite close to the actual number of chromosomes (n=13), the map should provide a useful resource for further evolutionary, ecological and conservation genetic work in this and other closely related species. PMID:21587305

  16. Effect of temperature on electrical resonance in leopard frog saccular hair cells.

    PubMed

    Smotherman, M S; Narins, P M

    1998-01-01

    Leopard frog saccular hair cells exhibit an electrical resonance in response to a depolarizing stimulus that has been proposed to contribute to the tuning properties of the frog sacculus by acting as an electrical band-pass filter. With the whole cell patch-clamp technique, we have investigated the effect of temperature on electrical resonances in isolated saccular hair cells, and we have described the effects of temperature on the currents and channel kinetics underlying electrical resonance. A hair cell's onset resonant frequency in response to a constant depolarizing current pulse increases linearly with temperature at a rate of 11 Hz/1 degrees C, exhibiting a mean Q10 of 1.7 between 15 and 35 degrees C. However, offset resonant frequencies continue to double every 10 degrees C, exhibiting a mean Q10 of 2.1. If steady-state voltage during the stimulus is held constant, all oscillatory frequencies increase with a mean Q10 of 2.1. The average level of steady-state depolarization during a +150-pA depolarizing current pulse decreases with increasing temperature (-6 mV from 15 to 25 degrees C). This temperature-dependent reduction of the steady-state membrane potential causes a shift in the voltage-dependent channel kinetics to slower rates, thus reducing the apparent Q10 for onset resonant frequencies. The peak outward tail current and net steady-state outward current, which is the sum of a voltage-dependent inward calcium current (ICa) and an outward calcium-dependent potassium current (IK(Ca)), increase with temperature, exhibiting a mean Q10 of 1.7 between 15 and 25 degrees C. The activation rate (T1/2) of the outward current exhibits a mean Q10 of 2.3 between 15 and 25 degrees C, while the deactivation rate (taurel) exhibits a mean Q10 of 2.9 over the same temperature range. These results support previous models of the molecular determination of resonant frequency, which have proposed that a combination of IK(Ca) channel kinetics and the overall magnitude of the

  17. Interactive effects of competition and predator cues on immune responses of leopard frogs at metamorphosis.

    PubMed

    Groner, Maya L; Rollins-Smith, Louise A; Reinert, Laura K; Hempel, John; Bier, Mark E; Relyea, Rick A

    2014-02-01

    Recent hypotheses suggest that immunosuppression, resulting from altered environmental conditions, may contribute to the increased incidence of amphibian disease around the world. Antimicrobial peptides (AMPs) in amphibian skin are an important innate immune defense against fungal, viral and bacterial pathogens. Their release is tightly coupled with release of the stress hormone noradrenaline (norepinephrine). During metamorphosis, AMPs may constitute the primary immune response in the skin of some species because acquired immune functions are temporarily suppressed in order to prevent autoimmunity against new adult antigens. Suppression of AMPs during this transitional stage may impact disease rates. We exposed leopard frog tadpoles (Lithobates pipiens) to a factorial combination of competitor and caged-predator environments and measured their development, growth and production of hydrophobic skin peptides after metamorphosis. In the absence of predator cues, or if the exposure to predator cues was late in ontogeny, competition caused more than a 250% increase in mass-standardized hydrophobic skin peptides. Predator cues caused a decrease in mass-standardized hydrophobic skin peptides when the exposure was late in ontogeny under low competition, but otherwise had no effect. Liquid chromatography tandem mass spectrometry of the skin peptides showed that they include six AMPs in the brevinin and temporin families and at least three of these peptides are previously uncharacterized. Both of these peptide families have previously been shown to inhibit harmful microbes including Batrachochytrium dendrobatidis, the fungal pathogen associated with global amphibian declines. Our study shows that amphibians may be able to adjust their skin peptide defenses in response to stressors that are experienced early in ontogeny and that these effects extend through an important life-history transition.

  18. 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

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

    PubMed

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

    2016-11-01

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

  1. Distribution of somatostatin-like immunoreactivity in the brain of the frog, Rana esculenta, during development.

    PubMed

    Vallarino, M; Mathieu, M; D'Aniello, B; Rastogi, R K

    1998-03-12

    The anatomical distribution of somatostatin-like immunoreactivity in the central nervous system of the frog, Rana esculenta, during development and in juvenile specimens was investigated by indirect immunofluorescence. Soon after hatching, at stages II-III, somatostatin-like immunoreactive structures were found in the preoptic-median eminence complex. In stage VI tadpoles, new groups of immunopositive perikarya and nerve fibers appeared in the diencephalon, within the ventral infundibular nucleus and in the ventral area of the thalamus, as well as in the medial pallium. In stages XII-XIV of development, immunopositive perikarya were also present in the dorsal infundibular nucleus of the hypothalamus and ventrolateral area of the thalamus. A small group of somatostatin-like immunoreactive neurons appeared in the posteroventral nucleus of the rhombencephalon. However, these neurons were not seen in later stages of development. Tadpoles in stages XVIII, XXI-XXII and in juveniles were characterized by a wider distribution of immunoreactive cell bodies and fibers in the pallium. New groups of immunoreactive neurons were found in the dorsal and lateral pallium. The presence of positive perikarya in the lateral pallium is a transient expression found only in these stages. The organization of the somatostatinergic system was most complex during the metamorphic climax, with the appearance of positive cell bodies in the posterocentralis area of the thalamus, and in juvenile animals with the presence of perikarya in the ventral part of the medial pallium and within the central grey rhombencephali. In contrast to the adult frog, somatostatin neurons were not observed in the mesencephalon of tadpoles and juveniles.

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

    PubMed

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

    2015-10-01

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

  3. Metabolic depression induced by urea in organs of the wood frog, Rana sylvatica: effects of season and temperature.

    PubMed

    Muir, Timothy J; Costanzo, Jon P; Lee, Richard E

    2008-03-01

    It has long been suspected that urea accumulation plays a key role in the induction or maintenance of metabolic suppression during extended dormancy in animals from diverse taxa. However, little evidence supporting that hypothesis in living systems exists. We measured aerobic metabolism of isolated organs from the wood frog (Rana sylvatica) in the presence or absence of elevated urea at various temperatures using frogs acclimatized to different seasons. The depressive effect of urea on metabolism was not consistent across organs, seasons, or temperatures. None of the organs from summer frogs, which were tested at 20 degrees C, or from winter frogs tested at 4 degrees C were affected by urea treatment. However, liver, stomach, and heart from spring frogs tested at 4 degrees C had significantly lower metabolic rates when treated with urea as compared with control samples. Additionally, when organs from winter frogs were tested at 10 degrees C, metabolism was significantly decreased in urea-treated liver and stomach by approximately 15% and in urea-treated skeletal muscle by approximately 50%. Our results suggest that the presence of urea depresses the metabolism of living organs, and thereby reduces energy expenditure, but its effect varies with temperature and seasonal acclimatization. The impact of our findings may be wide ranging owing to the number of diverse organisms that accumulate urea during dormancy.

  4. 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.

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

    PubMed

    Seliverstova, E V; Prutskova, N P

    2012-01-01

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

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

    PubMed

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

    1995-10-01

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

  8. Metamorphic changes in the stomach of the frog Rana temporaria tadpoles.

    PubMed

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

    1995-02-01

    The histological transformation of amphibian stomach during metamorphosis was studied in the frog Rana temporaria. The earliest metamorphic changes occur shortly before regression of the cloacal piece of tail and appearance of forelegs. Autolysis of primary, larval epithelial cells and activity of phagocytes lead to regression of the apical mucosa, which is shed into the gastric lumen. Histogenesis takes place from the very beginning of metamorphosis in the basal region of the mucosa; undifferentiated, regenerative cells, arranged in small compact cords and surrounded by a thick basement membrane, give rise to secondary lining epithelium and glands. Lining epithelial cells differentiate into a typical mucosecretory epithelium. Oxyntic cells present in larval glands are substituted by both ion- and protein-secreting oxyntic-peptic cells. During metamorphosis, connective and muscular tissues markedly increase, a submucosa, not present in larval tadpoles, gradually develops. A muscularis mucosae is also formed and the muscular propria becomes thicker. At late metamorphosis, folded structures involving both mucosa and submucosa develop, increasing the luminal surface as in adults. Removal of the larval gastric mucosa and its replacement by a new, adult-type definitive one, together with development of peripheral connective and muscular tissues, account for metamorphosis of tadpole stomach.

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

    PubMed

    Eto, Koshiro; Matsui, Masafumi

    2014-10-01

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

  10. 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.

  11. Batrachochytrium dendrobatidis infection dynamics in the Columbia spotted frog Rana luteiventris in north Idaho, USA.

    PubMed

    Russell, Danelle M; Goldberg, Caren S; Waits, Lisette P; Rosenblum, Erica Bree

    2010-11-01

    The pathogenic chytrid fungus Batrachochytrium dendrobatidis (Bd) is contributing to amphibian declines worldwide. Temperature plays an important role in both pathogen growth and host immune function, but little is known about seasonal dynamics of Bd infection in north temperate regions. Our objective was to increase understanding of Bd disease ecology by investigating patterns of Bd infection of Columbia spotted frogs Rana luteiventris across seasons, age classes, and sexes in north Idaho, USA. We collected skin swabs from 223 R. luteiventris in spring, summer, and fall 2009 at 7 ponds in the Palouse region and quantified Bd zoospores for each sample using quantitative PCR. Across seasons, Bd prevalence of adults was higher in summer than in spring or fall, suggesting that individuals may be clearing low-level infections over the summer. Among age classes, all but one late stage tadpole (Gosner stage 43-45) tested negative for Bd. Conversely, 100% of metamorphs tested positive for Bd and had the highest Bd loads of all age classes, suggesting they may be the most vulnerable age class. Adult R. luteiventris had high infection prevalence (> 60%) in all seasons, indicating that Bd infection is maintained within populations and that adults likely serve as disease reservoirs across seasons. Among adults, we also found weak evidence for females having higher infection prevalence than males. Further laboratory and field studies are needed to determine whether there are individual and population impacts from Bd on R. luteiventris and other amphibians in north Idaho.

  12. Characteristics of the myogenic behaviour of arteries of the common European frog (Rana temporaria).

    PubMed

    Comerford, L; Bolger, N M; Bund, S J

    2008-03-01

    Mammalian small arteries exhibit pressure-dependent myogenic behaviour characterised by an active constriction in response to an increased transmural pressure or an active dilatation in response to a decreased transmural pressure. This study aimed to determine whether pressure-dependent myogenic responses are a functional feature of amphibian arteries. Mesenteric and skeletal muscle arteries from the common European frog (Rana temporaria) were cannulated at either end with two fine glass micropipettes in the chamber of an arteriograph. Arterial pressure-diameter relationships (5-40 mmHg) were determined in the presence and absence of Ca2+. All arteries dilated passively with increasing pressure in the absence of Ca2+. In the presence of Ca2+ proximal mesenteric branches and tibial artery branches dilated with increasing transmural pressure but tone (p < 0.05) was evident in both arteries. A clear myogenic response to a step increase or decrease in pressure was observed in small distal arteries (6 of 13 mesenteric and 7 of 10 sciatic branches) resulting in significantly (p < 0.05) narrower diameters in Ca2+ in the range 10-40 mmHg in mesenteric and 20-40 mmHg in sciatic arteries, respectively. The results demonstrate that arteries of an amphibian can generate spontaneous pressure-dependent tone. This is the first study to demonstrate myogenic contractile behaviour in arteries of nonmammalian origin.

  13. Determination of biogeographical range: an application of molecular phylogeography to the European pool frog Rana lessonae.

    PubMed Central

    Zeisset, I.; Beebee, T. J.

    2001-01-01

    Understanding how species are constrained within their biogeographical ranges is a central problem in evolutionary ecology. Essential prerequisites for addressing this question include accurate determinations of range borders and of the genetic structures of component populations. Human translocation of organisms to sites outside their natural range is one factor that increasingly complicates this issue. In areas not far beyond presumed natural range margins it can be particularly difficult to determine whether a species is native or has been introduced. The pool frog (Rana lessonae) in Britain is a specific example of this dilemma . We used variation at six polymorphic microsatellite loci for investigating the phylogeography of R. lessonae and establishing the affinities of specimens from British populations. The existence and distribution of a distinct northern clade of this species in Norway, Sweden and England infer that it is probably a long-standing native of Britain, which should therefore be included within its natural range. This conclusion was further supported by posterior probability estimates using Bayesian clustering. The phylogeographical analysis revealed unexpected patterns of genetic differentiation across the range of R. lessonae that highlighted the importance of historical colonization events in range structuring. PMID:11370966

  14. Asymmetric competition in larval amphibian communities: conservation implications for the northern crawfish frog, Rana areolata circulosa.

    PubMed

    Parris, Matthew J; Semlitsch, Raymond D

    1998-08-01

    Asymmetric competition in larval amphibians can influence population dynamics and community structure. This density-dependent regulatory mechanism may be of particular importance for rare or endangered species such as the northern crawfish frog, Rana areolata circulosa. Interspecific competition of R. areolata with two congenerics, R. blairi and R. sphenocephala, was examined in artificial ponds. Analysis of covariance (differential mortality covariate) indicated that interspecific competition increased larval period length and decreased metamorphic body mass of R. areolata. The number of metamorphs produced was lower for R. blairi ponds when reared with R. areolata at high density. Body mass at metamorphosis was larger for R. sphenocephala when reared with R. areolata, suggesting that R. areolata facilitates larval growth in R. sphenocephala. These results indicate that the larval performance of R. areolata was reduced in the presence of interspecific competitors. Although many conservation efforts emphasize the preservation of critical habitat or particular rare species, interactive effects of biotic components in the focal community may also be important demographic regulators.

  15. Two novel antimicrobial peptides from skin secretions of the frog, Rana nigrovittata.

    PubMed

    Liu, Xiuhong; Liu, Rui; Wei, Lin; Yang, Hailong; Zhang, Keyun; Liu, Jingze; Lai, Ren

    2011-01-01

    Two novel antimicrobial peptides with similarity to brevinin-2 family are purified and characterized from the skin secretions of the frog, Rana nigrovittata. Their amino acid sequences were determined as GAFGNFLKGVAKKAGLKILSIAQCKLSGTC (brevinin-2-RN1) and GAFGNFLKGVAKKAGLKILSIAQCKLFGTC (brevinin-2-RN2), respectively, by Edman degradation. Different from brevinin-2, which is composed of 33 amino acid residues (aa), both brevinin-2-RN1 and -RN2 contain 30 aa. Five cDNA sequences (Genbank accession numbers, EU136465-9) encoding precursors of brevinin-2-RN1 and -RN2 were screened from the skin cDNA library of R. nigrovittata. These precursors are composed of 72 aa including a predicted signal peptide, an acidic spacer peptide, and a mature brevinin-2-RN. Both brevinin-2-RN1 and -RN2 showed strong antimicrobial activities against gram-positive and gram-negative bacteria and fungi. The current work identified and characterized two novel antimicrobial peptides with unique primary structure. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.

  16. Mobile phone mast effects on common frog (Rana temporaria) tadpoles: the city turned into a laboratory.

    PubMed

    Balmori, Alfonso

    2010-06-01

    An experiment has been made exposing eggs and tadpoles of the common frog (Rana temporaria) to electromagnetic radiation from several mobile (cell) phone antennae located at a distance of 140 meters. The experiment lasted two months, from the egg phase until an advanced phase of tadpole prior to metamorphosis. Measurements of electric field intensity (radiofrequencies and microwaves) in V/m obtained with three different devices were 1.8 to 3.5 V/m. In the exposed group (n = 70), low coordination of movements, an asynchronous growth, resulting in both big and small tadpoles, and a high mortality (90%) was observed. Regarding the control group (n = 70) under the same conditions but inside a Faraday cage, the coordination of movements was normal, the development was synchronous, and a mortality of 4.2% was obtained. These results indicate that radiation emitted by phone masts in a real situation may affect the development and may cause an increase in mortality of exposed tadpoles. This research may have huge implications for the natural world, which is now exposed to high microwave radiation levels from a multitude of phone masts.

  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. Response to pinealectomy and blinding in vitellogenic female frogs (Rana perezi) subjected to high temperature in autumn.

    PubMed

    Alonso-Gómez, A L; Tejera, M; Alonso-Bedate, M; Delgado, M J

    1990-01-01

    The present experiments were carried out to investigate the effects of pinealectomy and bilateral enucleation on the ovarian activity in Rana perezi frogs maintained in 12-h light--12-h dark photoperiod and 20 +/- 1 degrees C during the vitellogenetic growth in late autumn. These environmental conditions, mainly temperature, induce a gonadal and metabolic response similar to that observed in the natural habitat in summer: a marked ovarian follicular regression, a depletion of the energetic resources from fat bodies and liver, and a minimum in oestradiol circulating levels. This response is partially blocked by pinealectomy and blinding. Protein phosphorus, as an index of vitellogenic proteins, and total ovary lipid content were significantly higher in pinealectomized and blinded frogs with respect to sham-operated animals. Likewise, oestradiol concentrations showed a significant increase during the dark phase of the daily photocycle in pinealectomized and blinded animals. From our results, we can suggest that the arrest of vitellogenesis, the depletion of energetic resources, and the regulation of oestradiol levels induced by the high temperature in Rana perezi frogs can be influenced, at least in part, by the pineal complex and lateral eyes.

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

    PubMed

    Bursey, C R; Goldberg, S R

    2001-04-01

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

  20. 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.

  1. Ontogenic delays in effects of nitrite exposure on tiger salamanders (Ambystoma tigrinum tigrinum) and wood frogs (Rana sylvatica).

    PubMed

    Griffis-Kyle, Kerry L

    2005-06-01

    Under certain conditions, nitrite can be present in freshwater systems in quantities that are toxic to the fauna. I exposed wood frog (Rana sylvatica) and eastern tiger salamander (Ambystoma tigrinum tigrinum) embryos and young tadpoles and larvae to elevated concentrations of nitrite in chronic toxicity tests: 0, 0.3, 0.6, 1.2, 2.1, 4.6, and 6.1 mg/L NO2-N, exposing individuals as both embryos and larvae. Nitrite caused significant declines in wood frog hatching success (3.4 mg/L NO2-N, wood frog), and lower concentrations caused significant mortality during the early larval stages (4.6 mg/L NO2-N, salamander; 0.5 mg/L NO2-N, wood frog). Later tests exposing individuals to nitrite only after hatching showed that both wood frog and tiger salamander vulnerability to nitrite declined shortly after hatching. Hence, examining a single life-history stage, especially later in development, may miss critical toxic effects on organisms, causing the researcher potentially to underestimate seriously the ecological consequences of nitrite exposure.

  2. Odorous and Non-Fatal Skin Secretion of Adult Wrinkled Frog (Rana rugosa) Is Effective in Avoiding Predation by Snakes

    PubMed Central

    Yoshimura, Yuri; Kasuya, Eiiti

    2013-01-01

    The roles played by nonfatal secretions of adult anurans in the avoidance of predation remain unknown. The adult Wrinkled frog (Rana rugosa) has warty skin with the odorous mucus secretion that is not fatal to the snake Elaphe quadrivirgata. We fed R. rugosa or Fejervarya limnocharis, which resembles R. rugosa in appearance and has mucus secretion, to snakes and compared the snakes’ responses to the frogs. Compared to F. limnocharis, R. rugosa was less frequently bitten or swallowed by snakes. The snakes that bit R. rugosa spat out the frogs and showed mouth opening (gaping) behavior, while the snakes that bit F. limnocharis did not show gaping behavior. We also compared the responses of the snakes to R. rugosa and F. limnocharis secretions. We coated palatable R. japonica with secretions from R. rugosa or F. limnocharis. The frogs coated by R. rugosa secretion were less frequently bitten or swallowed than those coated by F. limnocharis secretion. We concluded that compared to different frog species of similar sizes, the adult R. rugosa was less frequently preyed upon by, and that its skin secretion was effective in avoiding predation by snakes. PMID:24278410

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

    PubMed

    Yoshimura, Yuri; Kasuya, Eiiti

    2013-01-01

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

  4. Expression of genes encoding antimicrobial and bradykinin-related peptides in skin of the stream brown frog Rana sakuraii.

    PubMed

    Suzuki, Hiroe; Iwamuro, Shawichi; Ohnuma, Aya; Coquet, Laurent; Leprince, Jérôme; Jouenne, Thierry; Vaudry, Hubert; Taylor, Christopher K; Abel, Peter W; Conlon, J Michael

    2007-03-01

    Peptidomic analysis of an extract of the skin of the stream brown frog Rana sakuraii Matsui and Matsui, 1990 led to the isolation of a C-terminally alpha-amidated peptide (VR-23; VIGSILGALASGLPTLISWIKNR x NH2) with broad-spectrum antimicrobial activity that shows structural similarity to the bee venom peptide, melittin together with two peptides belonging to the temporin family (temporin-1SKa; FLPVILPVIGKLLNGIL x NH2 and temporin-1SKb; FLPVILPVIGKLLSGIL x NH2), and peptides whose primary structures identified them as belonging to the brevinin-2 (2 peptides) and ranatuerin-2 (1 peptide) families. Using a forward primer that was designed from a conserved region of the 5'-untranslated regions of Rana temporaria preprotemporins in a 3'-RACE procedure, a cDNA clone encoding preprotemporin-1SKa was prepared from R. sakuraii skin total RNA. Further preprotemporin cDNAs encoding temporin-1SKc (AVDLAKIANIAN KVLSSL F x NH2) and temporin-1SKd (FLPMLAKLLSGFL x NH2) were obtained by RT-PCR. Unexpectedly, the 3'-RACE procedure using the same primer led to amplification of a cDNA encoding a preprobradykinin whose signal peptide region was identical to that of preprotemporin-1SKa except for the substitution Ser18-->Asn. R. sakuraii bradykinin ([Arg0,Leu1,Thr6,Trp8] BK) was 28-fold less potent than mammalian BK in effecting B2 receptor-mediated relaxation of mouse trachea and the des[Arg0] derivative was only a weak partial agonist. The evolutionary history of the Japanese brown frogs is incompletely understood but a comparison of the primary structures of the R. sakuraii dermal peptides with those of Tago's brown frog Rana tagoi provides evidence for a close phylogenetic relationship between these species.

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

    PubMed

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

    1998-01-01

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

  6. Cell cycle regulation in the freeze tolerant wood frog, Rana sylvatica.

    PubMed

    Zhang, Jing; Storey, Kenneth B

    2012-05-01

    The wood frog (Rana sylvatica) is one of only a few vertebrate species that can survive extensive freezing of its body fluids during the winter. The mechanisms of natural freeze tolerance include metabolic rate depression to conserve energy and the implementation of cryoprotective strategies, especially the synthesis of huge amounts of glucose as a cryoprotectant. Liver is the main source of glucose production/export (and other cryoprotective actions) and plays a central role in freezing survival of the whole animal. Freezing is a multi-component stress that includes anoxia/ischemia due to the cessation of blood flow and dehydration of cells caused by ice accumulation in extracellular spaces. To help endure these stresses, cells need to suppress and reprioritize ATP-expensive cell functions. One of these is cell growth and proliferation, and we hypothesized that cell cycle arrest would be key to freezing survival. The present study examines the responses by key cell cycle components to freezing, anoxia and dehydration stresses in wood frog liver. Immunoblotting was used to investigate protein expression of Cdc 2, Cdks (2, 4, 6), and cyclins (A, B1, D1, E) as well as the phosphorylation states of Cdks (Thr14/Tyr15), the phosphatases Cdc25a (Ser76) and Cdc25c (Ser216) and the CIP/KIP Cdk inhibitors p21 (Thr145) and p27 (Thr187). Responses to 24 h freezing, 24 h anoxia and 40% dehydration as well as recovery from these stresses were analyzed. The results showed very similar responses by cell cycle components to anoxia or dehydration and were consistent with cell cycle suppression under stress and reversal during recovery. Freezing showed elements of cell cycle suppression, including reduced protein levels of Cdks and cyclins A and B1, but also showed unique responses by cyclin D1, Cdc25 phosphatases and p21/p27. These may be linked with alternative actions by these proteins that contribute to cryoprotection; e.g., an alternative action of cyclin D1 as a transcription

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

    PubMed

    Miura, Ikuo; Ohtani, Hiromi; Ogata, Mitsuaki

    2012-01-01

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

  8. 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

  9. Ranavirus in wood frogs (Rana sylvatica): potential sources of transmission within and between ponds.

    PubMed

    Harp, Elizabeth M; Petranka, James W

    2006-04-01

    Members of the genus Ranavirus (family Iridoviridae) can cause catastrophic mortality of pond-breeding amphibians and are associated with an emerging infectious disease that may be contributing to amphibian declines. We conducted three experiments to examine factors that may affect transmission both within and between local breeding populations of the wood frog (Rana sylvatica). In a laboratory study, when exposed to moribund tadpoles collected during a local ranaviral die-off, uninfected tadpoles died as soon as 4 days after exposure. The onset of death was accelerated when tadpoles were allowed to scavenge on carcasses of infected tadpoles. In a mesocosm experiment that was conducted in outdoor wading pools, die-offs of tadpoles began approximately 19 days after infected tadpoles were added to pools containing uninfected tadpoles. Mass die-offs with greater than 98% mortality occurred in all pools, regardless of the initial tadpole density. In a second mesocosm experiment, the addition of water and bottom sediments that were collected from a pond during a ranaviral die-off did not result in lower tadpole survival or growth relative to controls. Only a small percentage of tadpoles appeared to be sick, and most tadpoles survived until the first individuals began metamorphosing within a pool. However, tests for ranavirus using polymerase chain reaction were positive for most pools that received contaminated sediment, suggesting that some infections were sublethal. Our results indicate that transmission within ponds is enhanced by scavenging and that spread between local ponds could occur via the transport of contaminated sediment by animals or humans.

  10. Sex reversal and primary sex ratios in the common frog (Rana temporaria).

    PubMed

    Alho, Jussi S; Matsuba, Chikako; Merilä, Juha

    2010-05-01

    Sex reversal has been suggested to have profound implications for the evolution of sex chromosomes and population dynamics in ectotherms. Occasional sex reversal of genetic males has been hypothesized to prevent the evolutionary decay of nonrecombining Y chromosomes caused by the accumulation of deleterious mutations. At the same time, sex reversals can have a negative effect on population growth rate. Here, we studied phenotypic and genotypic sex in the common frog (Rana temporaria) in a subarctic environment, where strongly female-biased sex ratios have raised the possibility of frequent sex reversals. We developed two novel sex-linked microsatellite markers for the species and used them with a third, existing marker and a Bayesian modelling approach to study the occurrence of sex reversal and to determine primary sex ratios in egg clutches. Our results show that a significant proportion (0.09, 95% credible interval: 0.04-0.18) of adults that were genetically female expressed the male phenotype, but there was no evidence of sex reversal of genetic males that is required for counteracting the degeneration of Y chromosome. The primary sex ratios were mostly equal, but three clutches consisted only of genetic females and three others had a significant female bias. Reproduction of the sex-reversed genetic females appears to create all-female clutches potentially skewing the population level adult sex-ratio consistent with field observations. However, based on a simulation model, such a bias is expected to be small and transient and thus does not fully explain the observed female-bias in the field.

  11. Sensory transduction in dorsal cutaneous mechanoreceptors of the frog, Rana pipiens.

    PubMed

    Watts, R E; French, A S

    1985-11-01

    Sensory transduction was studied in dorsal skin mechanoreceptors of the frog, Rana pipiens. The skin was clamped and stretched before being stimulated with the tip of a glass rod mounted on a servo-controlled loudspeaker. Afferent activity was recorded extracellularly from a dorsal cutaneous nerve. Three groups of sensory units could be identified by the size of their recorded action potentials and their response to mechanical stimuli. Action potential amplitudes for the three groups were: less than 50 microV (group I), 50-250 microV (group II) and greater than 300 microV (group III). Group II were selected for further study because of their amplitude and their resistance to fatigue. Three types of mechanical stimuli were used to examine the dynamic properties of group II receptors, steps, sinusoids, and band-limited random displacement. In each case the responses could be well fitted by a power-law model with a fractional exponent of time or frequency. Random stimulation of a large number of group II receptors showed considerable variability in their sensitivity and in their dynamic behavior, as measured by the fractional exponent of frequency. However, the distributions of these two parameters were both unimodal and strongly clustered around the modes, suggesting that the recordings were from a single class of receptors. Varying the temperature of the receptors had little effect on their sensitivity or dynamic properties. This is in contrast to findings on other mechanoreceptors. Doubling the potassium concentration in the bathing solution affected the dynamic properties of the receptors within 5 min but several distinct patterns of change in dynamic behavior were seen.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Female choice for males with greater fertilization success in the Swedish Moor frog, Rana arvalis.

    PubMed

    Sherman, Craig D H; Sagvik, Jörgen; Olsson, Mats

    2010-10-26

    Studies of mate choice in anuran amphibians have shown female preference for a wide range of male traits despite females gaining no direct resources from males (i.e. non-resource based mating system). Nevertheless, theoretical and empirical studies have shown that females may still gain indirect genetic benefits from choosing males of higher genetic quality and thereby increase their reproductive success. We investigated two components of sexual selection in the Moor frog (Rana arvalis), pre-copulatory female choice between two males of different size ('large' vs. 'small'), and their fertilization success in sperm competition and in isolation. Females' showed no significant preference for male size (13 small and six large male preferences) but associated preferentially with the male that subsequently was the most successful at fertilizing her eggs in isolation. Siring success of males in competitive fertilizations was unrelated to genetic similarity with the female and we detected no effect of sperm viability on fertilization success. There was, however, a strong positive association between a male's innate fertilization ability with a female and his siring success in sperm competition. We also detected a strong negative effect of a male's thumb length on his competitive siring success. Our results show that females show no preference for male size but are still able to choose males which have greater fertilization success. Genetic similarity and differences in the proportion of viable sperm within a males ejaculate do not appear to affect siring success. These results could be explained through pre- and/or postcopulatory choice for genetic benefits and suggest that females are able to perceive the genetic quality of males, possibly basing their choice on multiple phenotypic male traits.

  13. 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.

  14. Trait Performance Correlations across Life Stages under Environmental Stress Conditions in the Common Frog, Rana temporaria

    PubMed Central

    Johansson, Frank; Lederer, Baptiste; Lind, Martin I.

    2010-01-01

    If an organism's juvenile and adult life stages inhabit different environments, certain traits may need to be independently adapted to each environment. In many organisms, a move to a different environment during ontogeny is accompanied by metamorphosis. In such organisms phenotypic induction early in ontogeny can affect later phenotypes. In laboratory experiments we first investigated correlations between body morphology and the locomotor performance traits expressed in different life stages of the common frog, Rana temporaria: swimming speed and acceleration in tadpoles; and jump-distance in froglets. We then tested for correlations between these performances across life stages. We also subjected tadpoles to unchanging or decreasing water levels to explore whether decreasing water levels might induce any carry-over effects. Body morphology and performance were correlated in tadpoles; morphology and performance were correlated in froglets: hence body shape and morphology affect performance within each life stage. However, performance was decoupled across life stages, as there was no correlation between performance in tadpoles and performance in froglets. While size did not influence tadpole performance, it was correlated with performance of the metamorphosed froglets. Experiencing decreasing water levels accelerated development time, which resulted in smaller tadpoles and froglets, i.e., a carry-over effect. Interestingly, decreasing water levels positively affected the performance of tadpoles, but negatively affected froglet performance. Our results suggest that performance does not necessarily have to be correlated between life stages. However, froglet performance is size dependent and carried over from the tadpole stage, suggesting that some important size-dependent characters cannot be decoupled via metamorphosis. PMID:20657779

  15. 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.

  16. Female Choice for Males with Greater Fertilization Success in the Swedish Moor Frog, Rana arvalis

    PubMed Central

    Sherman, Craig D. H.; Sagvik, Jörgen; Olsson, Mats

    2010-01-01

    Background Studies of mate choice in anuran amphibians have shown female preference for a wide range of male traits despite females gaining no direct resources from males (i.e. non-resource based mating system). Nevertheless, theoretical and empirical studies have shown that females may still gain indirect genetic benefits from choosing males of higher genetic quality and thereby increase their reproductive success. Methodology/Principal Findings We investigated two components of sexual selection in the Moor frog (Rana arvalis), pre-copulatory female choice between two males of different size (‘large’ vs. ‘small’), and their fertilization success in sperm competition and in isolation. Females' showed no significant preference for male size (13 small and six large male preferences) but associated preferentially with the male that subsequently was the most successful at fertilizing her eggs in isolation. Siring success of males in competitive fertilizations was unrelated to genetic similarity with the female and we detected no effect of sperm viability on fertilization success. There was, however, a strong positive association between a male's innate fertilization ability with a female and his siring success in sperm competition. We also detected a strong negative effect of a male's thumb length on his competitive siring success. Conclusions/Significance Our results show that females show no preference for male size but are still able to choose males which have greater fertilization success. Genetic similarity and differences in the proportion of viable sperm within a males ejaculate do not appear to affect siring success. These results could be explained through pre- and/or postcopulatory choice for genetic benefits and suggest that females are able to perceive the genetic quality of males, possibly basing their choice on multiple phenotypic male traits. PMID:21049015

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

    PubMed

    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.

  18. Identification and characterisation of a novel antimicrobial polypeptide from the skin secretion of a Chinese frog (Rana chensinensis).

    PubMed

    Jin, Li L; Song, Shu S; Li, Qiang; Chen, Yu H; Wang, Qiu Y; Hou, Sheng T

    2009-06-01

    Amphibians secrete small antimicrobial polypeptides from their skin that have been explored as alternatives to conventional antibiotics. In this study, mass spectrometry was used to identify and characterise protein secretions from the skin of a Chinese frog, Rana chensinensis. The skin of this kind of frog has been used in traditional Chinese medicine for centuries as a remedy against inflammation. A novel antimicrobial peptide was identified and the characteristics of this peptide were analysed using far-ultraviolet circular dichroism. When dissolved in aqueous solution, the peptide displayed a high level of random coil structure, in contrast to a more ordered alpha-helical structure when dissolved in 50% trifluoroethanol. Functional studies showed that this peptide has potent antimicrobial activity both against Gram-positive and Gram-negative bacteria and has extremely low haemolytic activity to human red blood cells. Taken together, these studies suggest that this novel peptide can be further developed as an antimicrobial agent.

  19. Population genetic patterns suggest a behavioural change in wild common frogs (Rana temporaria) following disease outbreaks (Ranavirus).

    PubMed

    Teacher, Amber G F; Garner, Trenton W J; Nichols, Richard A

    2009-08-01

    We use 14 microsatellite loci to investigate the impact of a viral disease (Ranavirus) on the population genetic structure of wild common frogs (Rana temporaria). Populations with a history of Ranavirus mortalities (and 83% declines in the number of frogs) were compared with populations with no history of infection. Infected ponds showed significantly elevated F(IS) (homozygote excess), significantly reduced relatedness, and no detectable effect on allelic richness. We hypothesize that the elevated F(IS) and reduced relatedness are consequences of assortative mating, and that allelic richness is maintained by immigration from nearby populations. Simulations indicate that the elevated F(IS) cannot be explained by population size reductions, but can indeed be explained by assortative mating (even if a mate choice locus is unlinked to the genetic markers). While the majority of studies consider demographic outcomes following disease outbreaks, our results indicate that emerging infectious diseases could also result in behavioural changes.

  20. The function of fat bodies in relation to the hypothalamo-hypophyseal-gonadal axis in the frog, Rana esculenta.

    PubMed

    Chieffi, G; Rastogi, R K; Iela, L; Milone, M

    1975-08-18

    In this study the authors have tried to furnish experimental support for the importance of fat bodies in the normal functioning of the hypothalamo-hypophyseal-gonadal system of the male frog, Rana esculenta. These experiments have shown a hypothalamo-hypophyseal control of the mobilization of fat body contents, directly involved in the control of testicular activity. Furthermore it is proposed that the fat body contents are released into the testis through direct vascular contacts between the two organs. We suggest that the A1 cells (lactotrophs) and/or B2 cells (FSH-gonadotrops) of the pars distalis gonadotropins are incapable of stimulating the testis in the absence of fat bodies. In the light of these results a scheme has been put forward showing the position of fat bodies in the hypothalamo-hypophyseal-gonadal axis of the frog.

  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. Origin of centrifugal fibers to the labyrinth in the frog (Rana esculenta). A study with the fluorescent retrograde neuronal tracer 'Fast blue'.

    PubMed

    Strutz, J; Spatz, W B; Schmidt, C L; Stürmer, C

    1981-06-29

    After injecting a solution of a fluorescent retrograde neuronal tracer (Fast blue, Diamidino compound 253/50) into the perilymphatic space of the frog labyrinth (Rana esculenta), labeled cells were found in the ventral and dorsal nuclei of the VIIIth nerve and in the nucleus reticularis medius. We consider these labeled cells to be the origin of the efferent innervation of the frog labyrinth. No evidence was found for the existence of a direct cerebello-labyrinthine connection.

  3. 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.

  4. Landscape resistance to frog movements

    USGS Publications Warehouse

    Mazerolle, M.J.; Desrochers, A.

    2005-01-01

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

  5. The response of Rana muscosa, the mountain yellow-legged frog, to short distance translocations.

    Treesearch

    K. R. Matthews

    2003-01-01

    ABSTRACT.—To determine the response of Mountain Yellow-Legged Frogs to short distance translocations, I placed transmitters on 20 adult frogs and moved them short distances from 144–630 m and monitored their responses for up to 30 days. Of the 20 translocated frogs, seven frogs returned to their original capture site, four frogs moved in the direction of their capture...

  6. Environmental stress responsive expression of the gene li16 in Rana sylvatica, the freeze tolerant wood frog.

    PubMed

    Sullivan, Katrina J; Storey, Kenneth B

    2012-06-01

    Wood frogs (Rana sylvatica) can endure weeks of subzero temperature exposure during the winter with up to 65% of their body water frozen as extracellular ice. Associated with freezing survival is elevated expression of a number of genes/proteins including the unidentified gene, li16, first described in liver. The current study undertakes a broad analysis of li16 expression in response to freezing in 12 tissues of wood frogs as well as expression responses to anoxia and dehydration. Transcript levels of li16 increased significantly after 24h freezing (at -2.5 °C) demonstrating increases of approximately 3-fold in testes, greater than 2-fold in heart, ventral skin and lung, and over 1.5-fold in brain, liver and hind leg muscle as compared to unfrozen controls at 5 °C. Increased li16 transcript levels in brain, muscle and heart were mirrored by elevated Li16 protein in frozen frogs. Significant upregulation of li16 in response to both anoxia and dehydration (both components of freezing) was demonstrated in brain, kidney and heart. Overall, the results indicate that Li16 protein has a significant role to play in cell/organ responses to freezing in wood frogs and that its up-regulation may be linked with oxygen restriction that is a common element in the three stress conditions examined.

  7. Cocaine- and amphetamine-regulated transcript (CART) peptide as an in vivo regulator of cardiac function in Rana ridibunda frog.

    PubMed

    Ivanova, Iliyana V; Schubert, Rudolf; Duridanova, Dessislava B; Bolton, Thomas B; Lubomirov, Lubomir T; Gagov, Hristo S

    2007-11-01

    The aim of this study was to investigate the effect of CART peptide on cardiac performance and on the physiological signalling pathways involved using Rana ridibunda frog heart preparations in vivo. The CART peptide, when injected into the venous sinus, significantly and reproducibly increased the force of frog heart contractions by up to 33.0 +/- 6.4% during the first 15 min after its application but did not influence the chronotropic activity of the frog heart. The positive inotropic effect was entirely blocked by prazosin, pertussis toxin, R(p)-adenosine 3',5'-cyclic monophosphorothioate, autosauvagine 30 or metyrapone, as well as by extirpation of the pituitary gland, functional elimination of the inter-renal glands and long-lasting starvation, and was not observed on isolated heart preparations. Propranolol and double pithing were without significant effect on this phenomenon. It was concluded that: (i) CART peptide, administered to frogs in vivo, increases the force of heart contractions; (ii) this effect of the peptide is exerted via activation of the hypothalamic-pituitary-inter-renal gland axis through a corticoliberin-sensitive mechanism; (iii) CART augments the pumping function of the heart via a corticosteroid-dependent potentiation of myocardial alpha(1)-adrenoreceptors signalling; and (iv) prolonged food deprivation abolishes the positive inotropic effect of CART, suggesting the participation of endogenous CART in the physiological adaptation of the circulatory system to limitations of energy consumption.

  8. Host-defense peptides isolated from the skin secretions of the Northern red-legged frog Rana aurora aurora.

    PubMed

    Conlon, J Michael; Sonnevend, Agnes; Davidson, Carlos; Demandt, Anni; Jouenne, Thierry

    2005-01-01

    Antimicrobial peptides in the skin secretions of anurans constitute a component of the innate immunity that protects the organism against invading pathogens. Four peptides with antimicrobial activity were isolated in high yield from norepinephrine-stimulated skin secretions of the Northern red-legged frog Rana aurora aurora and their primary structures determined. Ranatuerin-2AUa (GILSSFKGVAKGVAKNLAGKLLDELKCKITGC) showed potent growth-inhibitory activity against a range of Gram-positive and Gram-negative bacteria (minimum inhibitory concentrations < 20 microM) but low hemolytic activity against human erythrocytes (50% hemolysis at 290 microM). Brevinin-1AUa (FLPILAGLAAKLVPKVFCSITKKC) and brevinin-1AUb (FLPILAGLAANILPKVFCSITKKC) also showed potent antimicrobial activity but were strongly hemolytic (HC50 < 10 microM). Temporin-1AUa (FLPIIGQLLSGLL.NH2) atypically lacked a basic amino acid residue and showed very weak antimicrobial and hemolytic activity. Its biological function remains to be established. The primary structures of the antimicrobial peptides are consistent with a close phylogenetic relationship between R. aurora, Rana boylii and Rana luteiventris. Copyright 2004 Elsevier Ltd.

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

    PubMed

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

    2011-06-01

    Population declines due to chytridiomycosis among frogs belonging to the Amerana (Rana boylii) species group from western North America have been particularly severe. Norepinephrine-stimulated skin secretions from the Oregon spotted frog Rana pretiosa Baird and Girard, 1853 were collected from individuals that had been previously infected with the causative agent Batrachochytrium dendrobatidis but had proved resistant to developing chytridiomycosis. These secretions contained a more diverse array of antimicrobial peptides than found in other species from the Amerana group and 14 peptides were isolated in pure form. Determination of their primary structures identified the peptides as esculentin-2PRa and -2PRb; ranatuerin-2PRa, -2PRb, -2PRc, -2PRd, and -2PRe; brevinin-1PRa, -1PRb, -1PRc, and -1PRd; and temporin-PRa, -PRb, and -PRc. The strongly cationic ranatuerin-2PRd and the esculentin-2 peptides, which have not been identified in the secretions of other Amerana species except for the closely related R. luteiventris, showed the highest growth inhibitory potency against microorganisms. The strongly hydrophobic brevinin-1PRd was the most cytotoxic to erythrocytes. Although no clear correlation exists between production of dermal antimicrobial peptides by a species and its resistance to fatal chytridiomycosis, the diversity of these peptides in R. pretiosa may be pivotal in defending the species against environmental pathogens such as B. dendrobatidis. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Membrane adaptation in phospholipids and cholesterol in the widely distributed, freeze-tolerant wood frog, Rana sylvatica.

    PubMed

    Reynolds, Alice M; Lee, Richard E; Costanzo, Jon P

    2014-04-01

    Maintaining proper membrane phase and fluidity is important for preserving membrane structure and function, and by altering membrane lipid composition many organisms can adapt to changing environmental conditions. We compared the phospholipid and cholesterol composition of liver and brain plasma membranes in the freeze-tolerant wood frog, Rana sylvatica, from southern Ohio and Interior Alaska during summer, fall, and winter. We also compared membranes from winter-acclimatized frogs from Ohio that were either acclimated to 0, 4, or 10 °C, or frozen to -2.5 °C and sampled before or after thawing. Lipids were extracted from isolated membranes, separated by one-dimensional thin-layer chromatography, and analyzed via densitometry. Liver membranes underwent seasonal changes in phospholipid composition and lipid ratios, including a winter increase in phosphatidylethanolamine, which serves to increase fluidity. However, whereas Ohioan frogs decreased phosphatidylcholine and increased sphingomyelin, Alaskan frogs only decreased phosphatidylserine, indicating that these phenotypes use different adaptive strategies to meet the functional needs of their membranes. Liver membranes showed no seasonal variation in cholesterol abundance, though membranes from Alaskan frogs contained relatively less cholesterol, consistent with the need for greater fluidity in a colder environment. No lipid changed seasonally in brain membranes in either population. In the thermal acclimation experiment, cold exposure induced an increase in phosphatidylethanolamine in liver membranes and a decrease in cholesterol in brain membranes. No changes occurred during freezing and thawing in membranes from either organ. Wood frogs use tissue-specific membrane adaptation of phospholipids and cholesterol to respond to changing environmental factors, particularly temperature, though not with freezing.

  11. Turning population trend monitoring into active conservation: Can we save the Cascades Frog (Rana cascadae) in the Lassen region of California?

    Treesearch

    Gary M. Fellers; Karen L. Pope; Jonathan E. Stead; Michelle S. Koo; Hartwell H. Welsh

    2007-01-01

    Monitoring the distribution, population size, and trends of declining species is necessary to evaluate their vulnerability to extinction. It is the responsibility of scientists to alert management professionals of the need for preemptive action if a species approaches imminent, regional extirpation. This is the case with Rana cascadae (Cascades Frog...

  12. Interaction of an Introduced Predator with Future Effects of Climate Change in the Recruitment Dynamics of the Imperiled Sierra Nevada Yellow-legged Frog (Rana sierrae)

    Treesearch

    I Lacan; Kathleen R. Matthews; K.V. Feldman

    2008-01-01

    Between-year variation in snowpack (from 20 to 200% of average) and summer rainfall cause large fluctuations in volume of small lakes in the higher elevation (> 3000 m) Sierra Nevada, which are important habitat for the imperiled Sierra Nevada Yellow-legged Frog, Rana sierrae. Climate change (global warming) is predicted to increase these...

  13. 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

  14. Terrestrial activity and conservation of adult California red-legged frogs Rana aurora draytonii in coastal forests and grasslands

    USGS Publications Warehouse

    Bulger, J.B.; Scott, N.J.; Seymour, R.B.

    2003-01-01

    The federally threatened California red-legged frog Rana aurora draytonii occupies both aquatic and terrestrial habitats in its adult life stage. The terrestrial activities of this species are not well known and require documentation to assist in the development of appropriate levels of protection under the US Endangered Species Act. We studied the terrestrial activities of radio-tagged red-legged frogs (n = 8-26) inhabiting a coastal watershed in Santa Cruz County, California, during 1997-1998. In particular, we investigated (1) the use of terrestrial habitats by non-migrating adults in relation to season, breeding chronology, and precipitation, and (2) adult migration behavior, including seasonal timing, duration, distances traveled, and the use of corridors. Non-migrating red-legged frogs occupied terrestrial habitats briefly (median = 4-6 days) following infrequent summer rains, but resided nearly continuously on land (median = 20-30 days) from the onset of the winter wet-season until breeding activities commenced 1-2 months later. All of the non-migrating frogs remained within 130 m of their aquatic site of residence (median <25 m). Intervals spent on land were again brief during mid/late winter (median = 1-4 days), despite frequent and copious rainfall. Adult migration to and from breeding sites occurred from late October through mid-May (wet season). We monitored 25 migration events between aquatic sites that were 200-2800 m apart. Short distance movements ( <300 m) were completed in 1-3 days, longer movements required up to 2 months. Most migrating frogs moved overland in approximately straight lines to target sites without apparent regard to vegetation type or topography. Riparian corridors were neither essential nor preferred as migration routes. Frogs traveling overland occurred in upland habitats as far as 500 m from water. Approximately 11-22% of the adult population was estimated to migrate to and from breeding sites annually, whereas the bulk of the

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

    PubMed

    Muir, Anna P; Biek, Roman; Mable, Barbara K

    2014-05-23

    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. 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. Our results suggest that adults at high-altitude do not show behavioural adaptations in terms of breeding at lower temperatures. However, tadpoles appear to have the

  16. 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

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

    PubMed

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

    2014-10-01

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

  18. Changes in formaldehyde-induced fluorescence of the hypothalamus and pars intermedia in the frog, Rana temporaria, following background adaptation.

    PubMed

    Prasada Rao, P D

    1982-01-01

    Adaptation of the frog, Rana temporaria, to a white background for 12 hr has resulted in an intense formaldehyde-induced fluorescence (FIF) in the neurons of the preoptic recess organ (PRO), paraventricular organ (PVO), nucleus infundibularis dorsalis (NID) and their basal processes permitting visualization of the PRO- and PVO-hypophysial tracts that extend into the median eminence (ME) and pars intermedia (PI); the FIF is reduced in all the structures by 3 days. In frogs adapted to a black background, for 12 hr and 3 days, there was a general reduction in the FIF of the PRO neurons and PRO-hypophysial tract. By 12 hr black background adaptation, the PVO/NID neurons and only their adjacent basal processes show FIF which was sharply reduced by 3 days, making the PVO-hypophysial tract undetectable. In the PI fibers the fluorescence was more intense in black-adapted frogs than in white-adapted ones at both the intervals studied. The simultaneous changes in the FIF of the hypothalamic nuclei, tracts and PI suggest that the PRO and PVO/NID neurons participate in PI control through release of neurotransmitter(s) at the axonal ends.

  19. Effect of exposure to continuous light and melatonin on ovarian follicular kinetics in the skipper frog, Rana cyanophlyctis.

    PubMed

    Udaykumar, K; Joshi, B N

    1997-01-01

    Ovarian follicular kinetics and gravimetric changes in the ovary and oviducts were studied in the skipper frog, Rana cyanophlyctis, following exposure to continuous light and melatonin treatment during the breeding season. Daily late-afternoon injections of melatonin (15 micrograms subcutaneous) for 30 days decreased the gonadosomatic index (GSI), whereas continuously available melatonin from subcutaneous implants did not influence the GSI compared to those of controls. Exposure to continuous light for 30 days stimulated the GSI, and melatonin given as daily injections prevented the continuous-light induced increase in GSI. Oviductal weights decreased only in the melatonin-injected groups. Data on follicular kinetics revealed a decrease in first-growth-phase (FGP) oocytes and an increase in medium-sized second-growth-phase (MSGP) and large-sized second-growth-phase (LSGP) oocytes following continuous-light exposure. Melatonin administered to continuous-light-exposed frogs did not change the FGP oocyte number; however, it reduced both the MSGP and LSGP oocytes. Melatonin administration to frogs held in a light and dark cycle increased FGP oocytes and decreased MSGP and LSGP oocytes. Atretic follicles increased in all melatonin-treated groups. The results suggest that continuous light stimulates and melatonin inhibits reproductive function in this species.

  20. A telemetric study of the movement patterns and habitat use of Rana muscosa, the mountain yellow-legged frog, in a high-elevation basin in Kings Canyon National Park, California

    Treesearch

    K.R. Matthews; K.L. Pope

    1999-01-01

    ABSTRACTS.–In a high-elevation (3470 m) lake basin (upper Dusy Basin) in Kings Canyon National Park, California, we used radio transmitters on 24 mountain yellow-legged frogs (Rana muscosa) to gather basic information on their movement patterns. Rana muscosa have declined throughout their range in the Sierra Nevada and restoration plans require information on their...

  1. Acid-shock, aluminium, and presence of Sphagnum aurantiacum: effect on embryological development in the common frog, Rana temporaria and the moor frog, Rana arvalis

    SciTech Connect

    Olsson, M.; Hogstrand, C.; Dahlberg, A.; Berglind, S.A.

    1987-07-01

    During the last two decades, several effects of acidification have been shown, e.g., enhanced leaching of metals from sediments and soil. Furthermore, an increased growth of Sphagnum aurantiacum frequently occurs in acidified waters. The aim of the present study is to investigate some effects of acidification on the embryological development on two Anurans. The toxicity of aluminium is thought to vary with pH. The highest toxicity of aluminium in the hydroxyl form have been found at pH 5. In the present study a laboratory experiment was performed to investigate the toxicity of Al to frog embryos in water with pH 5.0. In acidified waters Sphagnum and especially S. aurantiacum, is competitive and quickly become established. It has been indicated that frog spawn deposited on Sphagnum show an unusually high mortality and questions have been raised if Sphagnum reinforces the detrimental effects of acidification on Anuran reproduction.

  2. Juvenile frogs compensate for small metamorph size with terrestrial growth: Overcoming the effects of larval density and insecticide exposure

    USGS Publications Warehouse

    Boone, M.D.

    2005-01-01

    I reared four species of anurans (Rana sphenocephala [Southern Leopard Frog], Rana blairi [Plains Leopard Frog], Rana clamitans [Green Frog], and Bufo woodhousii [Woodhouse's Toad]) for seven to 12 months in small, outdoor terrestrial enclosures (1 x 2 m) to examine the consequences of larval competition (via density) and contaminant exposure (via the insecticide carbaryl). I added six Rana clamitans, eight Rana sphenocephala, eight Rana blairi, and 10 Bufo woodhousii to terrestrial enclosures shortly after metamorphosis and recaptured them during the following spring. All anurans from low-density ponds were significantly larger than those from high-density ponds, but these size differences did not significantly affect survival to or size at spring emergence. However, R. sphenocephala, R. blairi, and R. clamitans that survived to spring had been larger at metamorphosis on average than those that did not survive; in contrast, B. woodhousii that survived the winter were smaller at metamorphosis on average than those that did not survive. Carbaryl exposure affected mass at metamorphosis of R. clamitans and B. woodhousii that were added to enclosures, but this difference disappeared or did not increase by spring emergence. Overall, exposure to carbaryl during the larval period did not have any apparent effects on survival or growth during the terrestrial phase. In my study, anurans were able to offset small size at metamorphosis with terrestrial growth, although there was a trend of reduced overwinter survival for ranid species that metamorphosed at a smaller size. Copyright 2005 Society for the Study of Amphibians and Reptiles.

  3. Hindlimb muscle fiber types in two frogs (Rana catesbeiana and Litoria caerulea) with different locomotor behaviors: histochemical and enzymatic comparison.

    PubMed

    Crockett, Christy J; Peters, Susan E

    2008-03-01

    To test how differences in locomotor behaviors may be reflected in muscle fiber-type diversity within anurans, a comparison of hindlimb muscles between the powerful terrestrial hopper, Rana catesbeiana, and the tree frog, Litoria caerulea, was done. One postural muscle (tibialis posticus, TP) and one primary hopping muscle (plantaris longus, PL), were characterized to identify muscle fiber types using standard histochemical methods. In addition, spectophotometric analysis of activity levels of the oxidative enzyme citrate synthase (CS) and the glycolytic enzyme lactate dehydrogenase (LDH) were done in each muscle. In spite of presumed differences in behavior between the species, we found no significant differences in the proportions of the identified fiber types when the muscles were compared across species. In addition, there were no significant differences in the proportions of the different fiber types between the postural versus phasic muscles within species. Within Rana, the postural muscle (TP) had greater oxidative capacity (as measured by CS activity) than did the phasic muscle (PL). Both muscles had equivalent LDH activities. Within Litoria, PL and TP did not differ in either LDH or CS activities. Both PL and TP of Litoria had less LDH activity and greater CS activity than their homologs in Rana. Thus, in spite of the uniform populations of fiber types between muscles and species, the metabolic diversity based on enzyme activity is consistent with behavioral differences between the species. These results suggest that the range of functional diversity within fiber types may be very broad in anurans, and histochemical fiber typing alone is not a clear indicator of their metabolic or functional properties.

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

    PubMed Central

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

    2015-01-01

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

  5. Purification, molecular cloning, and antimicrobial activity of peptides from the skin secretion of the black-spotted frog, Rana nigromaculata.

    PubMed

    Li, Ang; Zhang, Yong; Wang, Che; Wu, Geng; Wang, Zhenchun

    2013-10-01

    Antimicrobial peptides from a wide range of amphibian species, especially frogs of the genus Rana, have been characterised and are potential therapeutic agents. Here we describe the isolation, purification, and structural and biological characterisation of three novel antimicrobial peptides from the skin secretions of the black spotted frog, Rana nigromaculata, from Northeastern China. The peptides were identified as belonging to two known families: the temporin, which was first identified in R. nigromaculata from China, and the brevinin-2. Temporin-1RNa and temporin-1RNb both containing three positive charges and have a high potency against microorganisms (MIC: 3.13-8.3 μM against Gram-positive bacteria, 12.5-25.0 μM against Gram-negative bacteria, and 6.25-12.5 μM against Candida albicans) and a high haemolytic activity against human erythrocytes (HC50: 100-150 μM). Brevinin-2RNa contains a single intra-disulphide bridge at the C-terminus that is active towards the tested Gram-positive bacteria but is not active against E. coli and P. aeruginosa. The cDNAs encoding three novel peptide precursors were also subsequently cloned from an R. nigromaculata skin cDNA library and sequenced. The precursors contain 58-72 amino acid residues, which include a conserved signal peptide, acidic propeptide, and the mature temporin-1RNa, temporin-1RNb and brevinin-2RNa. The CD spectra of temporin-1RNa and temporin-1RNb in water, 30 mM SDS and 50 % trifluoroethanol (TFE) indicated that both peptides adopted an aperiodic structure in water and an organised structure with an α-helical conformation in TFE and SDS solution. The conformational transition induced by TFE or SDS reflects the potential ability of temporin-1RNa and temporin-1RNb to interact with anionic membranes.

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

    PubMed

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

    2016-01-01

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

  7. [Analysis of helminthofauna of common spaedfoot Pelobates fuscus (Laurenti, 1768) and moor frog Rana arvalis Nilsson, 1842 (Amphibia: Anura) at their joint habitation].

    PubMed

    Ruchin, A B; Chikhliaev, I V; Lukiianov, S V

    2009-01-01

    The helminths fauna of common spaedfoot Pelobates fuscus (Laurenti, 1768) and moor frog Rana arvalis Nilsson, 1842 has been studied at their joint habitation. The stuff was collected in 1998-2002, 2004-2006 years in several regions (republic Mordovia, Samara and Saratov areas). The processing of a stuff is conducted by a method of full helmintologic dissecting. The fauna of helminths considerably differs. For common spaedfoot only 13 species of helminths was detected which also parasitized moor frog (for moor frog 23 species) are detected. The index Jaccar demonstrated mean resemblance structure of helminths and varied from 0.25 till 0.69, and the index Morisite--from 44.58 of % till 74.51 of %. The communities of parasites of common spaedfoot was characterized by low values of an index of Shannon, but the high indexes of an index Simpson, whereas for moor frog tracked the return tendence.

  8. Exposure of northern leopard frogs in the Green Bay ecosystem to polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans is measured by direct chemistry but not hepatic ethoxyresorufin-O-deethylase activity

    SciTech Connect

    Huang, Y.W.; Karasov, W.H.; Patnode, K.A.; Jefcoate, C.R.

    1999-10-01

    The authors measured concentrations of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs) in northern leopard frogs collected from the Green Bay ecosystem and explored the catalytic activity of hepatic cytochrome P450-associated monooxygenase (P450 enzyme) as a biomarker for exposure to aryl hydrocarbon receptor (AhR) agonists. The two hypotheses tested were PCH concentrations in northern leopard frogs would be positively correlated with sediment polychlorinated hydrocarbon (PCH) levels in wetland habitats along a contamination gradient and hepatic ethoxyresorufin-O-deethylase (EROD) activity of northern leopard frogs, which is presumably mediated by aryl hydrocarbon receptor (AhR), would be positively correlated with PCH concentrations in frog carcasses from different collection sites. In 1994 and 1995, frogs from seven sites along the lower Fox River and Green Bay, USA, were assayed for hepatic EROD activities and whole carcass concentrations of PCBs, PCDDs, and PCDFs. Tissue total PCB concentrations ranging from 3 to 154 ng/g were significantly correlated with sediment PCB levels. Only one PCDD and two PCDFs at concentrations of 6 to 8 pg/g were found in the frogs collected with frog body weight and was similar among sites except for Peter's Marsh. No significant correlation was found between EROD activity and carcass PCB concentration. This result was consistent with the fact that the frogs collected from the Green Bay ecosystem had relatively low PCB concentrations compared with what was required for induction in the laboratory.

  9. Subtle effects of environmental stress observed in the early life stages of the Common frog, Rana temporaria

    PubMed Central

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

    2017-01-01

    Worldwide amphibian populations are declining due to habitat loss, disease and pollution. Vulnerability to environmental contaminants such as pesticides will be dependent on the species, the sensitivity of the ontogenic life stage and hence the timing of exposure and the exposure pathway. Herein we investigated the biochemical tissue ‘fingerprint’ in spawn and early-stage tadpoles of the Common frog, Rana temporaria, using attenuated total reflection-Fourier-transform infrared (ATR-FTIR) spectroscopy with the objective of observing differences in the biochemical constituents of the respective amphibian tissues due to varying water quality in urban and agricultural ponds. Our results demonstrate that levels of stress (marked by biochemical constituents such as glycogen that are involved in compensatory metabolic mechanisms) can be observed in tadpoles present in the pond most impacted by pollution (nutrients and pesticides), but large annual variability masked any inter-site differences in the frog spawn. ATR-FTIR spectroscopy is capable of detecting differences in tadpoles that are present in selected ponds with different levels of environmental perturbation and thus serves as a rapid and cost effective tool in assessing stress-related effects of pollution in a vulnerable class of organism. PMID:28317844

  10. Growth, size and age at maturity of the agile frog (Rana dalmatina) in an Iberian Peninsula population.

    PubMed

    Sarasola-Puente, Vanessa; Gosá, Alberto; Oromí, Neus; Madeira, María José; Lizana, Miguel

    2011-06-01

    The mean age of a population of agile frogs (Rana dalmatina) from the Iberian Peninsula was estimated using mark and recapture and skeletochronology. Life-history parameters, including growth rate, body length, age and size at maturity, sexual dimorphism and longevity, were studied. The regression between age and snout-vent length (SVL) was highly significant in both sexes. Males reached sexual maturity at two years of age, although sometimes they can reach it at only one year of age. The average SVL at maturity was 51.75 mm (standard error (SE)=0.71; n=45). Females reached sexual maturity at two years of age with an average SVL of 62.14 mm (SE=2.20; n=14). A subset of the female population reached sexual maturity at three years of age. Growth was rapid until sexual maturity was reached. There was an overlap of SVL between different age classes. Growth was continuous, fulfilling the conditions of Von Bertalanffy's model. The growth coefficient (K) was 0.840 in males and 0.625 in females. The maximum SVL was greater in females (73.00 mm) than in males (59.50mm). Sexual dimorphism was significantly biased towards females in all age classes. The maximum longevity observed was 6 years in females and 8 years in males. Management strategies for agile frogs should take into account factors such as these life-history characteristics.

  11. 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.

  12. Different responses of biochemical markers in frogs (Rana ridibunda) from urban and rural wetlands to the effect of carbamate fungicide.

    PubMed

    Falfushinska, Halina I; Romanchuk, Liliya D; Stolyar, Oksana B

    2008-09-01

    Laboratory studies were conducted to determine the effects of carbamate fungicide TATTU (mixture of propamocarb and mancozeb, 0.091 mg L(-1)) on biochemical markers of exposure in Rana ridibunda from clean (reference) and polluted sites. The untreated animals from the polluted site had lower Cu,Zn- and Mn-superoxide dismutase (SOD) and acetylcholinesterase activity, the levels of lipid peroxidation products (TBARS) and protein carbonyls in the liver and vitellogenin-like proteins (Vtg-LP) in the serum, but higher levels of glutathione in the liver in comparison with untreated frogs from the reference site. Catalase activity, superoxide anion and metallothionein levels were the same in both groups. The animals from two sites demonstrate different response on the effect of TATTU during 14 days. In the frogs from polluted site the oxidative damage (the decrease of Mn-SOD activity, lipids and protein oxidative destruction), neurotoxicity (depletion of acetylcholinesterase activity), and endocrine disruption (increase of Vtg-LP level) were revealed. On the other hand, the part of the indices in the animals from the reference site was unchanged after the treatment and the level of metallothionein was elevated demonstrating the satisfactory ability for the adaptation to unfavourable conditions.

  13. 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

  14. Disease associated with integumentary and cloacal parasites in tadpoles of northern red-legged frog Rana aurora aurora.

    PubMed

    Nieto, Nathan C; Camann, Michael A; Foley, Janet E; Reiss, John O

    2007-10-31

    A total of 6830 northern red-legged frog Rana aurora aurora tadpoles were examined under a dissecting microscope for oral disc, integumentary, and cloacal abnormalities in 13 ponds in and near Redwood National Park in northern California. Of these, 163 tadpoles were collected for histopathological investigation, including 115 randomly collected individuals, 38 collected with oral disc abnormalities, and 10 collected due to severe morbidity of unknown etiology. The tadpoles were infected with 8 parasites, including Batrachochytrium dendrobatidis (the amphibian chytrid), trematodes, leeches, and protozoa. Chytridiomycosis was detected at an overall prevalence of 6.4%, but prevalence was higher in tadpoles with oral disc lesions than in those with normal oral discs (43.5% versus 6.1%). Interestingly, infection was associated with some environmental and co-infection risk factors. Individual tadpoles possessed 0 to 5 species of parasites in varying intensities. Apiosoma sp. was the most prevalent (66%) and widespread. Tadpoles infected with B. dendrobatidis had a lower diversity of oral parasites than those uninfected. During the field portion of the study, a large number (approximately 500) of moribund and dead tadpoles was seen occurring at multiple locations within and surrounding Redwood National Park. Ten animals were collected for histological examination and a diverse protozoal infection was discovered, including some known pathogens of fish. This study is the first reporting parasitism and disease in natural populations of northern red-legged frogs.

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

    PubMed

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

    2010-09-02

    Chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), has resulted in the decline or extinction of approximately 200 frog species worldwide. It has been reported throughout much of North America, but its presence on Prince Edward Island (PEI), on the eastern coast of Canada, was unknown. To determine the presence and prevalence of Bd on PEI, skin swabs were collected from 115 frogs from 18 separate sites across the province during the summer of 2009. The swabs were tested through single round end-point PCR for the presence of Bd DNA. Thirty-one frogs were positive, including 25/93 (27%) green frogs Lithobates (Rana) clamitans, 5/20 (25%) northern leopard frogs L. (R.) pipiens, and 1/2 (50%) wood frogs L. sylvaticus (formerly R. sylvatica); 12 of the 18 (67%) sites had at least 1 positive frog. The overall prevalence of Bd infection was estimated at 26.9% (7.2-46.7%, 95% CI). Prevalence amongst green frogs and leopard frogs was similar, but green frogs had a stronger PCR signal when compared to leopard frogs, regardless of age (p < 0.001) and body length (p = 0.476). Amongst green frogs, juveniles were more frequently positive than adults (p = 0.001). Green frogs may be the most reliable species to sample when looking for Bd in eastern North America. The 1 wood frog positive for Bd was found dead from chytridiomycosis; none of the other frogs that were positive for Bd by PCR showed any obvious signs of illness. Further monitoring will be required to determine what effect Bd infection has on amphibian population health on PEI.

  16. Characterisation of acid-soluble and pepsin-solubilised collagen from frog (Rana nigromaculata) skin.

    PubMed

    Zhang, Junjie; Duan, Rui

    2017-08-01

    As the first vertebrates connecting water and land, frogs must have evolved certain specialisations. To find the difference among the collagens from amphibian, fish and mammal animals, acid-soluble collagen (ASC) and pepsin-solubilised collagen (PSC) from frog skin were isolated and characterised. The yield of PSC (19.59%, dry weight) was higher than that of ASC (1.83%, dry weight). The hydroxyproline-to-protein ratio of frog skin was 8.37%, which was higher than that of carp skin ASC (7.83%) but significantly lower than that of calf skin collagen (10.16%), which was in accordance with the living environment of frog. The denaturation temperature of frog skin collagens was approximately 31.5°C. The SDS-PAGE electrophoresis revealed that ASC and PSC were type I collagens. Fourier transform infrared spectroscopy proved that the ASC and PSC retained their helical structures. The results indicated the properties of frog skin collagen were close to those of skin collagen from freshwater fish. The frog skin collagens can potentially be used in biomaterial and other fields. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Molecular cloning of novel antimicrobial peptide genes from the skin of the Chinese brown frog, Rana chensinensis.

    PubMed

    Zhao, Jie; Sun, Yan; Li, Zhi; Su, Qi

    2011-02-01

    One species of the Chinese brown frog, Rana chensinensis, is widely distributed in north-central China. In this study, a cDNA library was constructed to clone the antimicrobial peptides' genes from the skin of R. chensinensis. Twenty-three prepropeptide cDNA sequences encoding twelve novel mature antimicrobial peptides were isolated and characterized. Six peptides belonged to three known families previously identified from other Ranid frogs: temporin (4 peptides), brevinin-2 (1 peptide), and palustrin-2 (1 peptide). The other six peptides showed little similarity to known antimicrobial peptides. According to the amino acid sequences, with or without α-helix structure, and either hydrophilic or hydrophobic, these were organized into four new families: chensinin-1 (3 peptides), chensinin-2 (1 peptide), chensinin-3 (1 peptide), and chensinin-4 (1 peptide). Five peptides from different families were chemically synthesized, and their antimicrobial, cytolytic, and hemolytic activities were evaluated. Of these, brevinin-2CE showed strongest antimicrobial activities against both the Gram-positive and Gram-negative bacteria with a slight hemolysis. Temporin-1CEe and palustrin-2CE also displayed a slight hemolysis, but they had different activities to prokaryotic cells. Temporin-1CEe showed higher antimicrobial activity against Gram-positive bacteria than Gram-negative bacteria, whereas it was contrary to palustrin-2CE. Chensinin-1 CEb and chensinin-3CE only had moderate antimicrobial activity against microorganisms. In addition, the brevinin-2 peptides from different brown frogs were analyzed to reveal the taxonomy and phylogenetic relationships of R. chensinensis.

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

    USGS Publications Warehouse

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

    2004-01-01

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

  19. Behavioral effects of morphine, levorphanol, dextrorphan and naloxone in the frog Rana pipiens.

    PubMed

    Pezalla, P D; Stevens, C W

    1984-08-01

    Systemic morphine induces explosive motor behavior and generalized muscular rigidity in frogs. Naloxone does not reverse either of these effects of morphine but at high doses causes muscular flaccidity and unresponsiveness to stimulation. Intraspinal morphine induces rigidity, but not explosive motor behavior, and this action is blocked by naloxone. Behavioral effects are seen rarely after intraspinal levorphanol (rigidity) and never after intraspinal dextrorphan or naloxone. In contrast to systemic morphine and naloxone, systemic levorphanol and dextrorphan are lethal to frogs at high doses.

  20. Helminth parasites of the leopard frog Lithobates sp. Colima (Amphibia: Ranidae) from Colima, Mexico.

    PubMed

    Cabrera-Guzmán, Elisa; Garrido-Olvera, Lorena; León-Règagnon, Virginia

    2010-08-01

    The helminth fauna inhabiting Lithobates sp. Colima from Ticuizitán, Colima, Mexico, comprises 10 species: 4 digeneans ( Clinostomum sp., Glypthelmins quieta , Haematoloechus sp., and Langeronia macrocirra ), 5 nematodes ( Aplectana itzocanensis , Cosmocerca podicipinus , Foleyellides striatus , Oswaldocruzia subauricularis , and Rhabdias sp.), and 1 cestode (Cyclophyllidea). Glypthelmins quieta , L. macrocirra , and A. itzocanensis represent new host records. These observations, added to previous records from Acapulco, Guerrero, Mexico, indicate that the helminth fauna of Lithobates sp. from Colima comprises 25 taxa. Frogs are being parasitized by 3 infection routes: ingestion of intermediate host, skin penetration by larval forms, and transmission by vectors. Species of Aplectana , Cosmocerca , Foleyellides , and Oswaldocruzia occurred in high prevalence in Colima, similar to a previous study on the same frog species from Guerrero. In Colima, Glypthelmins , Haematoloechus , and Rhabdias also occurred in high prevalence. Haematoloechus species reached the highest mean intensity in both localities. The semiaquatic habits of this species of frog and the availability of particular feeding resources appear to determine the helminth composition and infection levels; however, co-speciation events also play an important role structuring these helminth communities.

  1. A study of ovarian follicular kinetics, oviduct, fat body, and liver mass cycles in laboratory-maintained Rana cyanophlyctis in comparison with wild-caught frogs.

    PubMed

    Pancharatna, K; Saidapur, S K

    1992-11-01

    Ovarian follicular dynamics and fluctuations in fat body, oviducal, and liver masses were studied in captive Rana cyanophlyctis in comparison with wild-caught frogs, sampled at monthly intervals over a period of 12 months. In both the captive and wild-caught frogs first growth phase (FGP) and second growth phase (SGP) or vitellogenic oocytes were produced throughout the period examined; however, changes in ovarian and oviducal weights were less marked in the former group. In the captive frogs SGP oocyte production was reduced by 50%, and, maximum ovarian weight and SGP oocyte number were attained 2-3 months earlier than in wild-caught controls. The FGP oocyte pool in laboratory-maintained frogs, however, was comparable with that of the corresponding wild-caught frogs. Captivity caused a threefold increase in atresia and reduced the number of oocytes reaching SGP. The depletion of fat stores in fat bodies during the later phases of captivity suggests that the deposition of lipids into oocytes (for SGP) was given priority over storage in the fat bodies. The low oviducal weights of captive frogs was correlated with a reduced number of SGP oocytes, which are the source of estrogen. On the other hand, liver weight remained high, indicating adequate hepatic vitellogenin synthesis. Possible reduction in its output was not detected, possibly due to the reduced number of follicles reaching SGP. The findings indicate that stress of captivity decreases gonadotrophins and estrogen levels. Oviducal growth is reduced in captive frogs.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Purification and characterization of antimicrobial peptides from the skin secretions of the carpenter frog Rana virgatipes (Ranidae, Aquarana).

    PubMed

    Conlon, J Michael; Abraham, Bency; Sonnevend, Agnes; Jouenne, Thierry; Cosette, Pascal; Leprince, Jerome; Vaudry, Hubert; Bevier, Catherine R

    2005-11-01

    The members of the Aquarana (or Rana catesbeiana species group) form a well-supported monophyletic clade but phylogenetic relationships between species within the group are incompletely understood. Peptides that differentially inhibited the growth of bacteria were purified from electrically stimulated skin secretions of the carpenter frog Rana virgatipes. Structural characterization identified members of the ranatuerin-2 (3 peptides) and temporin (3-peptides) families, previously found in the skins of R. catesbeiana, R. clamitans, R. grylio and R. septentrionalis. Ranalexin, a peptide previously found only in the Aquarana, was isolated together with a variant (FFGLHNLVPSMLCVVRKKC) that lacks the propensity to adopt an alpha-helical conformation and so was devoid of antimicrobial activity. Two C-terminally alpha-amidated peptides belonging to the brevinin-2 family were isolated from the skin secretions that, like an ortholog from R. septentrionalis, lacked the C-terminal cyclic heptapeptide domain associated with members of this family. Ranatuerin-1, previously isolated from R. catesbeiana, R. clamitans and R. grylio but absent from R. septentrionalis, was also not identified in R. virgatipes. Synthetic replicates of temporin-1Va (FLSSIGKILGNLL.NH2), temporin-IVb (FLSIIAKVLGSLF.NH2) and temporin-1Vc (FLPLVTMLLGKLF.NH2) potently inhibited growth of Gram-positive bacteria (including methicillin-resistant Staphylococcus aureus). Temporin-1Va was also active against Gram-negative bacteria and the opportunistic yeast pathogen Candida albicans and had relatively weak hemolytic activity (LD50=120 microM) and may therefore represent a candidate for drug development. Our data support the placement of R. virgatipes in the Aquarana and indicate a closer phylogenetic relationship of R. virgatipes with R. septentrionalis than with R. catesbeiana, R. clamitans and R. grylio.

  3. [Characteristics of the phase-dependent vagus effects in the heart of the frog Rana temporaria and of the cod Gadus morhua].

    PubMed

    Kopylova, G N; Sokolova, N A; Samonina, G E; Krupnova, E P

    1987-01-01

    In experiments on the heart of the cod Gadus morhua and frog Rana temporaria in situ, studies have been made of changes in the heart rate induced by stimulation of the vagal nerve by single brief bursts delivered at various intervals after P wave of the ECG. Certain differences were found in changes of the heart rate between these animals. In the cod, maximum chronotropic effect was equal to 65% of the duration of initial cardiac cycle, the latency of this effect being equal to 290 ms; in the frog, corresponding figures were 12-13% and approximately 940 ms. The duration of negative chronotropic effect in the heart of the cod was equal to 700 ms, that of the frog--to 2.700 ms. Functional role of these differences is discussed in relation to the problem of the development of parasympathetic regulation of the heart rate in phylogenesis of vertebrates.

  4. Rangewide phylogeography and landscape genetics of the Western U.S. endemic frog Rana boylii (Ranidae): Implications for the conservation of frogs and rivers

    USGS Publications Warehouse

    Lind, A.J.; Spinks, P.Q.; Fellers, G.M.; Shaffer, H.B.

    2011-01-01

    Genetic data are increasingly being used in conservation planning for declining species. We sampled both the ecological and distributional limits of the foothill yellow-legged frog, Rana boylii to characterize mitochondrial DNA (mtDNA) variation in this declining, riverine amphibian. We evaluated 1525 base pairs (bp) of cytochrome b and ND2 fragments for 77 individuals from 34 localities using phylogenetic and population genetic analyses. We constructed gene trees using maximum likelihood and Bayesian inference, and quantified genetic variance (using AMOVA and partial Mantel tests) within and among hydrologic regions and river basins. Several moderately supported, geographically-cohesive mtDNA clades were recovered for R. boylii. While genetic variation was low among populations in the largest, most inclusive clade, samples from localities at the edges of the geographic range demonstrated substantial genetic divergence from each other and from more central populations. Hydrologic regions and river basins, which represent likely dispersal corridors for R. boylii, accounted for significant levels of genetic variation. These results suggest that both rivers and larger hydrologic and geographic regions should be used in conservation planning for R. boylii. ?? 2010 US Government.

  5. Ameliorative effects of sodium chloride on acute copper toxicity among Cope's gray tree frog (Hyla chrysoscelis) and green frog (Rana clamitans) embryos.

    PubMed

    Brown, Maria G; Dobbs, Emily K; Snodgrass, Joel W; Ownby, David R

    2012-04-01

    Urban stormwater runoff is composed of a mixture of components, including polycyclic aromatic hydrocarbons, metals, deicing agents, and many others. The fate of these chemicals is often in stormwater detention ponds that are used by amphibians for breeding. Among aquatic organisms, the toxic mechanism for many metals involves interference with active Na(+) and Cl(-) uptake. Addition of cations has been shown to reduce the toxicity of metals among some aquatic organisms through competitive inhibition, but no studies have investigated the interaction between NaCl and Cu among amphibian embryos and larvae. To determine the degree to which NaCl may ameliorate the toxicity of Cu to amphibian embryos and larvae, the authors exposed Hyla chrysoscelis (Cope's gray treefrogs) and Rana (Lithobates) clamitans (green frogs) to seven levels of Cu and NaCl in fully factorial experiments. When exposure was in artificial hard water, Cu was highly toxic to both species (96-h median lethal concentration [LC50] of 44.7 µg/L and 162.6 µg/L for H. chrysoscelis and R. clamitans, respectively). However, approximately 500 mg/L of NaCl eliminated Cu toxicity over the range of Cu concentrations used in the experiments (maximum 150 µg Cu/L for H. chrysoscelis and 325 µg Cu/L for R. clamitans). The current results suggest that NaCl is likely responsible for the toxic effects of NaCl and metal mixtures that might be typical of runoff from road surfaces in northern latitudes.

  6. Cytotoxic peptides with insulin-releasing activities from skin secretions of the Italian stream frog Rana italica (Ranidae).

    PubMed

    Conlon, J Michael; Musale, Vishal; Attoub, Samir; Mangoni, Maria Luisa; Leprince, Jérôme; Coquet, Laurent; Jouenne, Thierry; Abdel-Wahab, Yasser H A; Flatt, Peter R; Rinaldi, Andrea C

    2017-10-01

    Peptidomic analysis of norepinephrine-stimulated skin secretions from Italian stream frog Rana italica led to the purification and characterization of two host-defense peptides differing by a single amino acid residue belonging to the brevinin-1 family (brevinin-1ITa and -1ITb), a peptide belonging to the temporin family (temporin-ITa) and a component identified as prokineticin Bv8. The secretions contained relatively high concentrations of the methionine-sulphoxide forms of brevinin-1ITa and -1ITb suggesting that these peptides may have a role as antioxidants in the skin of this montane frog. Brevinin-1ITa (IVPFLLGMVPKLVCLITKKC) displayed potent cytotoxicity against non-small cell lung adenocarcinoma A549 cells (LC50  = 18 μM), breast adenocarcinoma MDA-MB-231 cells (LC50  = 8 μM) and colorectal adenocarcinoma HT-29 cells (LC50  = 18 μM), but the peptide was also strongly hemolytic against mouse erythrocytes (LC50  = 7 μM). Temporin-ITa (VFLGAIAQALTSLLGKL.NH2 ) was between three and fivefold less potent against these cells. Brevinin-1ITa inhibited growth of both Gram-positive Staphylococcus epidermidis and Gram-negative Escherichia coli as well as a strain of the opportunist yeast pathogen Candida parapsilosis, whereas temporin-ITa was active only against S. epidermidis and C. parapsilosis. Both peptides stimulated the release of insulin from BRIN-BD11 clonal β-cells at concentrations ≥1 nM, but brevinin-1ITa was cytotoxic to the cells at concentrations ≥3 μM. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.

  7. Cold acclimation-induced up-regulation of the ribosomal protein L7 gene in the freeze tolerant wood frog, Rana sylvatica.

    PubMed

    Wu, Shaobo; De Croos, J N Amritha; Storey, Kenneth B

    2008-11-15

    Natural freezing survival by the wood frog, Rana sylvatica, involves multiple organ-specific changes in gene expression. The present study used differential display PCR to find cold-responsive genes in wood frog skin. A cDNA was retrieved from skin that was in higher amounts in cold- versus warm-acclimated frogs. The cDNA was used to probe a wood frog liver cDNA library and retrieve a long sequence that, after the further application of 5'RACE, was shown to encode the full sequence of the ribosomal large subunit protein 7 (RPL7) (GenBank accession number AF175983). Wood frog RPL7 contained 246 amino acids and shared 90% identity with Xenopus laevis RPL7, 82-83% with chicken and zebrafish homologues, and 79% with mammalian RPL7. Multiple binding domains found in human RPL7 showed differing degrees of conservation in the frog protein. Transcript levels of rpl7 were elevated up to 4-fold in skin of cold-acclimated frogs as compared with warm-acclimated animals. Organ-specific responses by rpl7 transcripts also occurred when frogs were given survivable freezing exposures. Transcripts rose by 1.8-3.3 fold in brain and skeletal muscle during freezing but were unaffected in central organs such as liver and heart. Up-regulation of rpl7 also occurred in brain of anoxia-exposed frogs and RPL7 protein levels increased strongly in heart under both freezing and dehydration stresses. Cold- and freezing-responsive up-regulation of the rpl7 gene and RPL7 protein in selected organs suggests that targeted changes in selected ribosomal proteins may be an integral part of natural freeze tolerance.

  8. Spatio-temporal dynamics of pond use and recruitment in Florida gopher frogs (Rana capito aesopus)

    Treesearch

    Cathryn H. Greenberg

    2001-01-01

    This study examines spatio-temporal dynamics of Florida gopher frog (Rang capito aesopus) breeding and juvenile recruitment. Ponds were situated within a hardwood-invaded or a savanna-like longleaf pine-wiregrass upland matrix. Movement (N = 1444) was monitored using intermittent drift fences with pitfall and funnel traps at eight...

  9. Multiple invasions of the Ryukyu Archipelago by Oriental frogs of the subgenus Odorrana with phylogenetic reassessment of the related subgenera of the genus Rana.

    PubMed

    Matsui, Masafumi; Shimada, Tomohiko; Ota, Hidetoshi; Tanaka-Ueno, Tomoko

    2005-12-01

    The genus Rana, notably diversified in Oriental regions from China to Southeast Asia, includes a group of cascade frogs assigned to subgenera Odorrana and Eburana. Among them, R. ishikawae and the R. narina complex represent the northernmost members occurring from Taiwan to the Ryukyu Archipelago of Japan. Relationships of these frogs with the continental members, as well as the history of their invasions to islands, have been unclear. The taxonomic status of Odorrana and related genera varies among authors and no phylogenetic reassessment has been done. Using partial sequences of mitochondrial 12S and 16S rRNA genes, we estimated phylogenetic relationships among 17 species of the section Hylarana including Odorrana and Eburana, and related species from the Ryukyus, Taiwan, China, Thailand, Malaysia, and Indonesia. We estimate that (1) Odorrana is monophyletic and encompasses species of Eburana and R. hosii, which is now placed in Chalcorana, (2) the ancestor of R. ishikawae separated from other Rana in the middle to late Miocene prior to its entry to the Ryukyu Archipelago, (3) the ancestor of the R. narina complex later diversified in continental Asia, and invaded the Ryukyu Archipelago through Taiwan, (4) the R. narina complex attained its current distribution within the Ryukyus through niche segregations, and (5) vicariance of R. hosii between Malay Peninsula and Borneo occurred much later than the divergence events in the R. narina complex. Current subgeneric classification of Rana, at least of Southeast Asian members, requires full reassessment in the light of phylogenetic relationships.

  10. Relationship between epithelial and connective tissues in the stomach of the frog Rana temporaria during metamorphosis: an ultrastructural study.

    PubMed

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

    1998-08-01

    In the course of metamorphosis of the stomach of Rana temporaria tadpoles there is a marked increase in the amount of active mesenchymal fibroblasts and extracellular matrix underlying the regenerating gastric epithelium. At the onset of metamorphosis, a thick PAS-positive basement membrane is developed around the epithelial component of the mucosa, formed by the apical, degenerating larval epithelium and the basal, regenerative epithelial cords. Under the electron microscope, a folded basement membrane is usually revealed under the apical degenerating epithelium while a compact basement membrane (up to 1-2 microns thick), forming both patches and more extensive areas, is frequently seen around the regenerative glandular cords. Cytoplasmic processes, extending from both the epithelial and mesenchymal fibroblastic cells, cross the basement membrane and make physical contact between the two cellular types. At mid-metamorphosis areas of thick PAS-positive basement membrane are still observed around the differentiating glandular outlines, before disappearing completely at late metamorphosis. The probable involvement of intertissue interactions between epithelium and connective elements in the morphogenesis, proliferation and differentiation of secondary, definitive frog stomach is discussed. Early contacts between epithelium and phagocytes, probably related to the invasion of epithelium by the phagocytic cells, have also been observed.

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

    PubMed

    Ishii, Yoshiki; Tsuchiya, Teizo

    2010-07-01

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

  12. Use of a light-dependent magnetic compass for y-axis orientation in European common frog (Rana temporaria) tadpoles.

    PubMed

    Diego-Rasilla, Francisco J; Luengo, Rosa M; Phillips, John B

    2013-07-01

    We provide evidence for the use of a magnetic compass for y-axis orientation (i.e., orientation along the shore-deep water axis) by tadpoles of the European common frog (Rana temporaria). Furthermore, our study provides evidence for a wavelength-dependent effect of light on magnetic compass orientation in amphibians. Tadpoles trained and then tested under full-spectrum light displayed magnetic compass orientation that coincided with the trained shore-deep water axes of their training tanks. Conversely, tadpoles trained under long-wavelength (≥500 nm) light and tested under full-spectrum light, and tadpoles trained under full-spectrum light and tested under long-wavelength (≥500 nm) light, exhibited a 90° shift in magnetic compass orientation relative to the trained y-axis direction. Our results are consistent with earlier studies showing that the observed 90° shift in the direction of magnetic compass orientation under long-wavelength (≥500 nm) light is due to a direct effect of light on the underlying magnetoreception mechanism. These findings also show that wavelength-dependent effects of light do not compromise the function of the magnetic compass under a wide range of natural lighting conditions, presumably due to a large asymmetry in the relatively sensitivity of antagonistic short- and long-wavelength inputs to the light-dependent magnetic compass.

  13. Identification and characterization of a novel freezing inducible gene, li16, in the wood frog Rana sylvatica.

    PubMed

    McNally, J Dayre; Wu, Shao-Bo; Sturgeon, Christopher M; Storey, Kenneth B

    2002-06-01

    The wood frog Rana sylvatica survives for weeks during winter hibernation with up to 65% body water frozen as ice. Natural freeze tolerance includes both seasonal and freeze-induced molecular adaptations that control ice formation, deal with long-term ischemia, regulate cell volume changes, and protect macromolecules. This report identifies and characterizes a novel freeze-inducible gene, li16, that codes for a protein of 115 amino acids. Northern blot analysis showed that li16 transcript levels rose quickly during freezing to reach levels 3.7-fold higher than control values after 24 h; immunoblotting showed a parallel 2.4-fold rise in Li16 protein. Regulatory influences on gene expression were assessed. Nuclear runoff assays confirmed that freezing initiated an increase in the rate of li16 transcription, and analysis of signal transduction pathways via in vitro incubation of liver slices implicated a cGMP-mediated pathway in li16 expression. Gene and protein expression in liver was also strongly stimulated by anoxia exposure, whereas the gene was less responsive to dehydration stress. The strong response of li16 to both freezing and anoxia, and the rapid down-regulation of the gene when oxygen was reintroduced, suggest that the Li16 protein may play a role in ischemia resistance during freezing.

  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. Removal of nonnative fish results in population expansion of a declining amphibian (mountain yellow-legged frog, Rana muscosa)

    PubMed Central

    KNAPP, Roland A.; BOIANO, Daniel M.; VREDENBURG, Vance T.

    2007-01-01

    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

  16. 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.

  17. Molecular cloning and functional characterization of novel antimicrobial peptides from the skin of brown frog, Rana zhenhaiensis.

    PubMed

    Xu, Baohua; Che, Helong; Kang, Lumei; Zheng, Shuangyan; Mu, Songniu; Wan, Fusheng

    2012-09-01

    Rana zhenhaiensis, a species of brown frog, is widely distributed in central and south China. In the present study, a total of 14 cDNA sequences encoding eight novel antimicrobial peptides (AMPs) were cloned from the synthesized cDNAs of R. zhenhaiensis skin. The eight novel AMPs belong to four families: brevinin-1 (four peptides), brevinin-2 (one peptide), ranatuerin-2 (one peptide) and chensinin-1 (two peptides), five AMPs from the four families (brevinin-1ZHa, brevinin-1ZHb, brevinin-2ZHa, ranatuerin-2ZHa and chensinin-1ZHa) were chemically synthesized, their antimicrobial and hemolytic activities were examined. The results indicated that the five AMPs possess different antimicrobial and hemolytic activities. Of these, brevinin-2ZHa exhibited the strongest and most broad-spectrum antimicrobial activity. Furthermore, scanning electron microscopy (SEM) experiment was carried out to investigate the potential antimicrobial mechanism of chensinin-1ZHa. The result indicated that chensinin-1ZHa may exert its function through disruption of the bacterial membrane.

  18. 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

  19. 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.

  20. Alterations of biochemical parameters in malformed Indian rice frogs, Rana limnocharis from Southern Taiwan.

    PubMed

    Chiu, Yuh-Wen; Wang, Shu-Yin; Wu, Jui-Pin; Huang, Da-Ji

    2011-11-01

    The purpose of this study is to investigate the factors that cause malformed frogs in upstream Kaoping river (KP site) and Tungkang river (T site) of Southern Taiwan. In this experiment, the activities of monooxygenase (MO), glutathione-S-transferase (GST), acetylcholinesterase (AchE) as well as the concentration of vitellogenin (Vg) in the liver were measured. Results show that activities of MO, GST and AchE, and Vg levels in normal frogs (male/female) were 0.09 +/- 0.02/0.09+/-0.01 deltaA min(-1) mg(-1) protein, 0.12 +/- 0.04/0.13 +/- 0.04 deltaA min(-1) mg(-1) protein, 6.13 +/- 2.69/6.01 +/- 2.09 U mg(-1) protein and 0.87 +/- 0.42/2.18 +/- 0.50 microg mg(-1) protein, respectively. Activities of MO, GST and AchE, and Vg levels in malformed frogs (male/female) were 0.15 +/- 0.04/0.21 +/- 0.07 deltaA min(-1) mg(-1) protein, 0.27 +/- 0.08/0.30 +/- 0.12 deltaA min(-1) mg(-1) protein, 4.59 +/- 2.71/5.19 +/- 3.74 U mg(-1) protein and 1.46 +/- 0.61/3.15 +/- 0.88 microg mg(-1) protein, respectively in KP site, and were 0.16 +/- 0.69/0.1 +/- 80.07 deltaA min(-1) mg(-1) protein, 0.21 +/- 0.07/0.24 +/- 0.08 deltaA min(-1) mg(-1) protein, 5.13 +/- 4.58/3.94 +/- 1.33 U mg(-1) protein and 2.23 +/- 1.47/4.11 +/- 1.63 microg mg(-1) protein, respectively in T site. These results indicate that male and female malformed frogs in both rivers upstream are found with higher activities. No significant difference in AchE activity was found between normal and malformed frogs in this investigation. It is therefore reasonable to speculate that the organic chemicals released from agricultural activities are presumable the main factors that lead to the malformation of frogs.

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

    PubMed

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

    2010-01-01

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

  2. Hemodynamic consequences of delayed ventriculoconal conduction in the frog Rana catesbeiana.

    PubMed

    Liberthson, R R; Szidon, J P; Bharati, S; Lev, M; Fishman, A P

    1975-10-01

    We investigated the function of the conus arteriosus in the bullfrog Rana catesbeiana using a combination of anatomical and physiological techniques. Although there is a normal delay in ventriculoconal conduction and we could induce a spectrum of ventriculoconal conduction disturbances by manipulating the region of the ventriculoconal junction, we found no histological evidence of specialized conducting myocardial tissue in this region. The performance of the conus arteriosus was explored during various disturbances of ventriculoconal conduction and also during hemodynamic disturbances produced by hemorrhage and afterloading. The conus was found to contribute little to forward flow under ordinary circumstances, but its contribution increased greatly during bleeding or partial occlusion of the truncus. In contrast to the conclusion of others, no evidence could be adduced to support the idea that the conus serves as a depulsating chamber. Disparities in previous reports concerning the operation of the conus as a booster pump are attributed to special experimental circumstances.

  3. Fat body involvement in vitellogenin fate in the green frog, Rana esculenta.

    PubMed

    Varriale, B; Di Matteo, L; Minucci, S; Pierantoni, R; Chieffi, G

    1988-01-01

    1. Since, in Rana esculenta, fat bodies contain vitellogenin, the present study was performed in order to determine whether or not fat bodies are involved in the fate of vitellogenin. 2. The experiment of November shows that fat body excision provokes plasma vitellogenin increase even in animals treated with estradion-17 beta + pituitary crude homogenate (as compared with relative control). The same picture has been shown in the April experiment. 3. The result on protein-bound phosphate in ovaries from the April experiment has shown that fat body extirpation causes a decrease of protein-bound phosphate in the ovary. 4. This results indicates that fat bodies play an important role in sequestrating circulating vitellogenin by the ovary.

  4. Lividins: novel antimicrobial peptide homologs from the skin secretion of the Chinese Large Odorous frog, Rana (Odorrana) livida. Identification by "shotgun" cDNA cloning and sequence analysis.

    PubMed

    Zhou, Mei; Chen, Tianbao; Walker, Brian; Shaw, Chris

    2006-09-01

    Odorous frogs of the sub-genus Odorrana are of oriental distribution, and are so called due to the foul smell of their defensive skin secretions released from specialized skin glands following stress or predator attack. Here we report the application of a "shotgun" skin secretion cDNA library cloning technique which can rapidly expedite identification of secretion bioactive peptides. From a library constructed from the skin secretion of the Large Chinese Odorous frog, Rana (Odorrana) livida, we have identified four novel peptides whose primary structures were deduced initially from cloned precursors. Subsequently, mature peptides were located in and structurally characterized from reverse phase HPLC fractions of skin secretion. Named lividins 1-4, these were found to be structural homologs of known antimicrobial peptide families from Rana frogs. Rapid identification of novel peptides can thus be rapidly achieved using this non-invasive, non-destructive technology and the extensive similarities revealed between antimicrobial peptide precursor organization and nucleic acid sequences would lend support to the hypothesis that they have a common ancestral origin.

  5. Effects of herbicides and the chytrid fungus Batrachochytrium dendrobatidis on the health of post-metamorphic northern leopard frogs (Lithobates pipiens).

    PubMed

    Paetow, Linda J; Daniel McLaughlin, J; Cue, Roger I; Pauli, Bruce D; Marcogliese, David J

    2012-06-01

    Effects of exposure to contaminants such as pesticides along with exposure to pathogens have been listed as two major contributors to the global crisis of declining amphibian populations. These two factors have also been linked in explanations of the causes of these population declines. We conducted a combined exposure experiment to test the hypothesis that exposure to two agricultural herbicides would increase the susceptibility of post-metamorphic northern leopard frogs (Lithobates pipiens) to the amphibian fungal pathogen Batrachochytrium dendrobatidis (Bd). We assessed the independent and interactive effects of these exposures on the health and survival of the frogs. Wild-caught frogs underwent a 21-day exposure to a nominal concentration of either 2.1 μg/L atrazine (Aatrex(®) Liquid 480) or 100 μg a.e./L glyphosate (Roundup(®) Original), followed by Bd, and then were observed until 94 days post-initial exposure to the herbicides. Actual levels of atrazine were between 4.28 ± 0.04 μg/L and 1.70 ± 0.26 μg/L while glyphosate degraded from 100 μg a.e./L to approximately 7 μg a.e./L within 6 days of initial exposure to the herbicides. Compared to controls, the glyphosate formulation reduced the snout-vent length of frogs during the pesticide exposure (at Day 21), and the atrazine formulation reduced gain in mass up to Day 94. No treatment affected survival, splenosomatic or hepatosomatic indices, the densities and sizes of hepatic and splenic melanomacrophage aggregates, the density and size of hepatic granulomas, proportions of circulating leucocytes, the ratio of neutrophils to lymphocytes, or the ratio of leucocytes to erythrocytes. Histological assessment of samples collected at Day 94 revealed no evidence of Bd infection in any Bd-exposed frogs, while real-time PCR detected only one case of light infection in a single atrazine- and Bd-exposed frog. Frogs exposed to Bd shed their skin significantly more frequently than Bd-unexposed frogs, which may

  6. Analysis of skin and secretions of Dybowski's frogs (Rana dybowskii) exposed to Staphylococcus aureus or Escherichia coli identifies immune response proteins.

    PubMed

    Xiao, Xiang-Hong; Miao, Hui-Min; Xu, Yi-Gang; Zhang, Jing-Yu; Chai, Long-Hui; Xu, Jia-Jia

    2014-04-01

    The aim of the present study was to investigate responses in Dybowski's frogs (Rana dybowskii) exposed to bacteria, using proteomic and transcriptomic approaches. Staphylococcus aureus and Escherichia coli were used as representative Gram-positive and Gram-negative bacteria, respectively, in an infectious challenge model. Frog skin and skin secretions were collected and protein expression in infected frogs compared to control frogs by two-dimensional gel electrophoresis, silver staining, and image analysis. Proteins that demonstrated differential expression were analysed by mass spectrometry and identified by searching protein databases. More than 180 protein spots demonstrated differential expression in E. coli- or S. aureus-challenged groups and, of these, more than 55 spots were up- or down-regulated at least sixfold, post-infection. Proteins with a potential function in the immune response were identified, such as stathmin 1a, annexin A1, superoxide dismutase A, C-type lectin, lysozyme, antimicrobial peptides, cofilin-1-B, mannose receptor, histone H4, prohormone convertase 1, carbonyl reductase 1 and some components of the Toll-like receptor (TLR) signalling pathway. These molecules are potential candidates for further investigation of immune mechanisms in R. dybowskii; in particular, TLR-mediated responses, which might be activated in frogs exposed to pathogenic bacteria as part of innate immune defence, but which might also impact on adaptive immunity to infection.

  7. 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.

  8. [Opposite actions of different doses of arginine-vasotocin and 1-deamino-arginine-vasotocin on sodium ion transport in skin of the frog Rana temporaria].

    PubMed

    Bogolepova, A E

    2011-01-01

    Active transport of sodium ions across the isolated abdominal skin of the frog Rana temporaria after application of arginine-vasotocin (AVT) and 1-deamino-arginine-vasotocin (1dAVT) was studied by measurement of the short-circuit current (SCC). The maximal increase in the SCC values (26 and 19 microA/cm2) was observed after addition of 10 nM AVT or 100 nM 1dAVT, respectively, to the frog skin basal surface. An increase of concentration of AVT to 100 nM and of IdAVT to 1 microM terminated the sodium transport in the frog skin. A preliminary addition of an antagonist of arginine-vasopressin V1a-receptors to the Ringer's solution at the frog skin basal surface led to a rise in the SCC values in response to administration of ineffective doses of AVT or 1dAVT. V2-receptor antagonists did not affect the frog skin reaction to administration of these doses of AVT or IdAVT.

  9. Spatio-temporal Dynamics of Pond Use and Recruitment in Florida Gopher Frogs (Rana Capito aesopus)

    SciTech Connect

    Greenberg, C.H.

    2000-05-16

    We examined spatio-temporal dynamics of the Florida Gopher frog breeding and juvenile recruitment. Ponds were situated in a hardwood or pine-savanna matrix of upland forest. Movement was monitored from 1994-1999. Adult pond use was low but relatively constant. Juvenile recruitment was higher in the upland savanna matrix. Body size was negatively correlated with the number of juveniles exiting the pond in only one year suggesting intraspecific competition is one of many factors. Most immigration occurred in May through August and was unrelated to rainfall.

  10. [Peculiarities of Ca2+ regulation of functional activity of myocardium of frog Rana temporaria].

    PubMed

    Shemarova, I V; Kuznetsov, S V; Demina, I N; Nesterov, V P

    2008-01-01

    To elucidate role of intra- and extracellular Ca2+ in regulation of rhythm and strength of frog heart contractions, there were studied ECC and isometric contraction of myocardium preparations in response to verapamil, adrenaline, and blockers of alpha- and beta-adrenoreceptors. It has been shown that after an intramuscular injection of verapamil (6 mg/kg), bradycardia develops, the heart rate (HR) decreasing by 50-70 %. Further, the cardiac arrest occurred; however, administration to the animals of adrenaline (100 mg/kg) restored the cardiac rhythm for a short while. After an intramuscular injection of adrenaline at doses of 0.1-10 mg/kg, no essential changes were observed in the potential action amplitude and HR; an increase of the administered adrenalin concentration to 100 mg/kg was not accompanied by the cardiac rhythm stimulation, as this takes place in homoiothermal animals and human; on the contrary, an essential HR deceleration was revealed. Phentolamine (5 mg/kg) gradually decelerated HR rhythm by 32-45 %. The potential amplitude changed insignificantly. A subsequent intracardiac injection of adrenaline (100 mg/kg) on the background of block of alpha-adrenoreceptors produced acceleration of the rhythm (by 13-21%) and fall of the electrogram amplitude. These results can indicate that in the frog heart, phentolamine interacts predominanty with alpha-adrenoreceptors. An intracardiac administration of propranolol (1 mg/kg) to frogs promoted inhibition of beta-adrenergic receptors and produced a gradual cardiac rhythm deceleration. In experiments on assessment of verapamil effect on the character of contractions this preparation at a concentration of 150 microM was established to produce a significant dosedependent decrease of the contraction strength. A rise of verapamil concentration in the sample to 200 microM led to a decrease of the amplitude, on average, by 68-70 % and in individual preparations -- by 80-85 %; however, administration into the sample of

  11. Distribution of extracellular matrix macromolecules in the vestibular nuclei and cerebellum of the frog, Rana esculenta.

    PubMed

    Gaál, B; Rácz, É; Juhász, T; Holló, K; Matesz, C

    2014-01-31

    The axons of transected and re-apposed vestibulocochlear nerve of the frog, in contrast to mammalian species, regenerate and establish functional contacts within their original termination areas of the vestibular nuclear complex and the cerebellum. The lack of regenerative capability of the mammalian central nervous system (CNS) is partially attributed to various extracellular matrix (ECM) molecules, such as chondroitin sulfate proteoglycans (CSPG) and tenascin-R (TN-R), which exert inhibition on axon regeneration. In contrast to these molecules, hyaluronan (HA) was reported to be permissive for CNS regeneration. Using histochemical and immunohistochemical methods, we investigated the distribution pattern of these molecules in the medial (MVN), lateral (LVN), superior and descending vestibular nuclei and the cerebellum of the frog and detected regional differences in the organization of the ECM. In the vestibular nuclear complex, pericellular condensation of the ECM, the perineuronal nets (PNNs) were recognizable in the LVN and MVN and were positive only for HA. The neuropil of the vestibular nuclei showed either a diffuse appearance with varying intensity of reactions, or dots and ring-like structures, which may represent the perinodal ECM of the vestibular fibers. In the cerebellum, indistinct PNNs that were only labeled for HA were present in the granular layer. Our findings suggest that the HA-rich, but CSPG and TN-R-free PNNs may be associated with the high degree of plasticity and regenerative potential of the amphibian vestibular system. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

  12. Epidermal laser stimulation of action potentials in the frog sciatic nerve

    NASA Astrophysics Data System (ADS)

    Jindra, Nichole M.; Goddard, Douglas; Imholte, Michelle; Thomas, Robert J.

    2010-01-01

    Measurements of laser-stimulated action potentials in the sciatic nerve of leopard frogs (Rana pipiens) are made using two infrared lasers. The dorsal sides of the frog's hind limbs are exposed to short-pulsed 1540- and 1064-nm wavelengths at three separate spot sizes: 2, 3, and 4 mm. Energy density thresholds are determined for eliciting an action potential at each experimental condition. Results from these exposures show similar evoked potential thresholds for both wavelengths. The 2-mm-diam spot sizes yield action potentials at radiant exposure levels almost double that seen with larger beam sizes.

  13. [The formation of new characteristics in life cycle of the marsh frog (Rana ridibunda) in thermal pond conditions].

    PubMed

    Fominykh, A S; Liapkov, S M

    2011-01-01

    Using mark and recapture approach, the long-term population dynamics in the marsh frog (Rana ridibunda) was studied. Group-marking of metamorphs was conducted in a small thermal pond serving as a sedimentation basin for discharged waters from Nizhny Tagil metallurgic works. Depending on the time of metamorphosis, three groups of individuals could be singled out, namely: early ones (group I), middle ones (group II), and late ones that overwinter as tadpoles and complete metamorphosis in May of the next year (group III). Upon metamorphosis completion, individuals of group I were found to be significantly larger than those of group II, and individuals of both these groups to be significantly smaller than those of group III. After first wintering, immature individuals from group I were significantly larger than either individuals from group II or metamorphs from group III, though a growth rate of the latter was significantly higher than in groups I and II. These discrepancies were observed both between immature and adult individuals. Over the period from metamorphosis completion to the first wintering ending, survivorship in group I was significantly higher and did not differ between groups II and III. In adult frogs, maximum survivorship was registered in group III and minimum one in group II; the detected differences recurred in each age class till the fourth wintering. However, in age classes that overwintered 4 and 5 times, maximum survivorship was observed in group II, which can be treated as a compensation for rather low survivorship of this group at younger ages. All the events of tadpoles of this species overwintering (except in other thermal water bodies) that are described in literature, correspond to rare deviations from normal ontogenesis. Therefore, the revealed formation of a numerous group of overwintering tadpoles in successive generations should be considered as a new adaptation which sense is a decrease of competition between tadpole groups when using

  14. 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.

  15. Discordant patterns of nuclear and mitochondrial introgression in Iberian populations of the European common frog (Rana temporaria).

    PubMed

    Veith, Michael; Baumgart, Andrea; Dubois, Alain; Ohler, Annemarie; Galán, Pedro; Vieites, David R; Nieto-Román, Sandra; Vences, Miguel

    2012-01-01

    Amphibians often show complex histories of intraspecific and interspecific genetic introgression, which might differ in mitochondrial and nuclear genes. In our study of the genetic differentiation of the European common frog, Rana temporaria (159 specimens from 23 populations were analyzed for 24 presumptive allozyme loci; 82 specimens were sequenced for a 540-bp fragment of the mitochondrial 16S rRNA gene), multilocus correspondence analysis (CA) and Bayesian assignment tests of the nuclear data were concordant in identifying 2 population groups corresponding to 1) the Pyrenees in the east and 2) the Galicia and Asturias regions in the west, the latter corresponding to the subspecies R. temporaria parvipalmata. Geographically intermediate populations were genetically intermediate in the allozyme CA and, less clearly in the Bayesian assignment, with mitochondrial haplotypes exclusively belonging to the parvipalmata group. This indicates different degrees of introgression in the mitochondrial and nuclear genomes. Although Pyrenean high-altitude populations are morphologically distinct from low-altitude populations, these 2 groups were not separate clusters in any analysis. This suggests that the morphological differences may be due to fast adaptation to elevational gradients, likely under maintenance of gene flow, and that the underlying genetic changes are not detectable by the analyzed markers. We argue that a parsimonious explanation for the observed pattern along the east-west axis in northern Spain may be competition between invading and resident populations, with no need to invoke selection. However, in order to conclusively rule out selective processes, additional and finer scale data are required to test for asymmetric mating preference/behaviour, sex-biased gene flow, or sex-biased survival of potential hybrids.

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

    PubMed

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

    2014-10-01

    Arsenic contamination of the environment is a matter of great concern. Understanding the effects of arsenic on aquatic life will act as biological early warning system to assess how arsenic could shape the biodiversity in the affected areas. Rapid decline in amphibian population in recent decades is a cause of major concern. Over the years, amphibians have been recognized as excellent bio-indicators of environmental related stress. In the present study, we examined the toxic and genotoxic effects of sodium arsenite in the tadpoles of the Indian cricket frog (Rana limnocharis). Sodium arsenite at different concentrations (0, 50, 100, 200 and 400 μg L(-1)) neither induced lethality nor significantly altered body weight at metamorphosis. However, it accelerated the rate of metamorphosis at higher concentrations, reduced body size (snout-vent length) and induced developmental deformities such as loss of limbs. Besides, at concentration ranges between 100 and 400 μg L(-1), sodium arsenite induced statistically significant genotoxicity at 24, 48, 72 and 96 h of the exposure in a concentration-dependent manner. However, it did not show time effects as the highest frequency was found between 48 and 72 h which remained steady subsequently. The genotoxicity was confirmed by comet assay in the whole blood cells. These findings suggest that arsenic at environmentally relevant concentrations has significant sub-lethal effects on R.limnocharis, which may have long-term fitness consequence to the species and may have similar implications in other aquatic life too. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. 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

  19. A de novo Assembly of the Common Frog (Rana temporaria) Transcriptome and Comparison of Transcription Following Exposure to Ranavirus and Batrachochytrium dendrobatidis.

    PubMed

    Price, Stephen J; Garner, Trenton W J; Balloux, Francois; Ruis, Chris; Paszkiewicz, Konrad H; Moore, Karen; Griffiths, Amber G F

    2015-01-01

    Amphibians are experiencing global declines and extinctions, with infectious diseases representing a major factor. In this study we examined the transcriptional response of metamorphic hosts (common frog, Rana temporaria) to the two most important amphibian pathogens: Batrachochytrium dendrobatidis (Bd) and Ranavirus. We found strong up-regulation of a gene involved in the adaptive immune response (AP4S1) at four days post-exposure to both pathogens. We detected a significant transcriptional response to Bd, covering the immune response (innate and adaptive immunity, complement activation, and general inflammatory responses), but relatively little transcriptional response to Ranavirus. This may reflect the higher mortality rates found in wild common frogs infected with Ranavirus as opposed to Bd. These data provide a valuable genomic resource for the amphibians, contribute insight into gene expression changes after pathogen exposure, and suggest potential candidate genes for future host-pathogen research.

  20. Autonomic regulation of mucociliary transport rate in the oesophagus of the frog, Rana temporaria.

    PubMed Central

    Morley, J; Sanjar, S

    1984-01-01

    Transport of lead particles along the mucosal surface of the frog oesophagus has been measured by direct observation with the aid of video recording. Electrical stimulation of the vagus nerve increased the rate of particle transport. This acceleration was suppressed by atropine or by hexamethonium. Acetylcholine and other parasympathomimetic agents accelerated particle transport rate. Such acceleration was abolished by atropine. Nicotine increased the rate of particle transport and this effect was suppressed by hexamethonium or by atropine. Atropine did not significantly alter basal particle transport rate. Neither basal particle transport rate nor the response to vagal nerve stimulation were affected by eserine. Adrenaline, noradrenaline or isoprenaline did not affect basal particle transport rate. Adrenaline or noradrenaline were without effect on the increased particle transport rate due to electrical stimulation of the vagus. PMID:6332901

  1. PARTIAL LIFE-CYCLE TOXICITY AND BIOCONCENTRATION MODELLING OF PERFLUOROOCTANE SULFONATE (PFOS) IN THE NORTHERN LEOPARD FROG (RANA PIPIENS)

    EPA Science Inventory

    A number of recent monitoring studies have demonstrated elevated concentrations of perfluorooctane sulfonate (PFOS) in humans and wildlife throughout the world. Although no longer manufactured in the U.S., the global distribution and relative persistence of PFOS indicates a need ...

  2. PARTIAL LIFE-CYCLE TOXICITY AND BIOCONCENTRATION MODELLING OF PERFLUOROOCTANE SULFONATE (PFOS) IN THE NORTHERN LEOPARD FROG (RANA PIPIENS)

    EPA Science Inventory

    A number of recent monitoring studies have demonstrated elevated concentrations of perfluorooctane sulfonate (PFOS) in humans and wildlife throughout the world. Although no longer manufactured in the U.S., the global distribution and relative persistence of PFOS indicates a need ...

  3. Within-population polymorphism of sex-determination systems in the common frog (Rana temporaria).

    PubMed

    Rodrigues, N; Betto-Colliard, C; Jourdan-Pineau, H; Perrin, N

    2013-07-01

    In sharp contrast with birds and mammals, the sex chromosomes of ectothermic vertebrates are often undifferentiated, for reasons that remain debated. A linkage map was recently published for Rana temporaria (Linnaeus, 1758) from Fennoscandia (Eastern European lineage), with a proposed sex-determining role for linkage group 2 (LG2). We analysed linkage patterns in lowland and highland populations from Switzerland (Western European lineage), with special focus on LG2. Sibship analyses showed large differences from the Fennoscandian map in terms of recombination rates and loci order, pointing to large-scale inversions or translocations. All linkage groups displayed extreme heterochiasmy (total map length was 12.2 cM in males, versus 869.8 cM in females). Sex determination was polymorphic within populations: a majority of families (with equal sex ratios) showed a strong correlation between offspring phenotypic sex and LG2 paternal haplotypes, whereas other families (some of which with female-biased sex ratios) did not show any correlation. The factors determining sex in the latter could not be identified. This coexistence of several sex-determination systems should induce frequent recombination of X and Y haplotypes, even in the absence of male recombination. Accordingly, we found no sex differences in allelic frequencies on LG2 markers among wild-caught male and female adults, except in one high-altitude population, where nonrecombinant Y haplotypes suggest sex to be entirely determined by LG2. Multifactorial sex determination certainly contributes to the lack of sex-chromosome differentiation in amphibians. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

  4. Induction of ethoxy-resorufin-O-deethylase activity by halogenated aromatic hydrocarbons and polycyclic aromatic hydrocarbons in primary hepatocytes of the green frog (Rana esculenta).

    PubMed

    Rankouhi, Tanja Rouhani; Koomen, Bas; Sanderson, J Thomas; Bosveld, Albertus T C; Seinen, Willem; van den Berg, Martin

    2005-06-01

    In this study, we measured the ethoxy-resorufin-O-deethylase (EROD) activity in primary hepatocytes of the common green frog Rana esculenta as a biomarker for cytochrome P4501A induction. We exposed hepatocytes derived from male and female frogs to several halogenated aromatic hydrocarbons, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 2,3,4,7,8-pentachlorodibenzofuran (PCDF), polychlorinated biphenyls (PCB-126, PCB-118), and polycyclic aromatic hydrocarbons such as benzo[a]pyrene (BaP), chrysene, anthracene, and pyrene. Exposure to PCB-118, anthracene, and pyrene, up to 1 microM, did not induce EROD activity, whereas TCDD and PCDF induced EROD activity maximally. In our primary frog hepatocytes, exposure to chrysene and BaP resulted in median effective concentration values (EC50) in the high nM range (82-1035 nM). Exposure to TCDD, PCDF, and PCB-126 resulted in EC50 values of 0.4 to 8, 0.07 to 0.7, and 3 to 133 nM, respectively, which is in the same range as EC50 values found in primary hepatocytes of birds. Compared to our frog hepatocytes, primary rat hepatocytes seem to be more sensitive to TCDD, chrysene, and BaP.

  5. Assessment of heavy metals and metalloids in tissues of two frog species: Rana tigrina and Euphlyctis cyanophlyctis from industrial city Sialkot, Pakistan.

    PubMed

    Qureshi, Irfan Zia; Kashif, Zeshan; Hashmi, Muhammad Zaffar; Su, Xiaomei; Malik, Riffat Naseem; Ullah, Kalim; Hu, Jinxing; Dawood, Muhammad

    2015-09-01

    In the present study, we investigated the concentrations of Ni, Fe, Pb, Cu, Co, Zn, Cd, Mn, and Cr in selected body tissues (liver, stomach, kidney, heart, lungs, and skeletal muscles) of two frog species: Rana tigrina and Euphlyctis cyanophlyctis captured from industrial wastewater of Sialkot city known worldwide for its tanning industry. The both frog species had darker appearance, distinctively different wet body weight, and snout-vent length. The results revealed that the heavy metal concentrations were high in the samples collected from industrial sites as compared to non-industrial sites. The different tissues of R. tigrina and E. cyanophlyctis exhibited little significant differences from two sites. The concentrations of heavy metals were more in tissues of R. tigrina as compared to E. cyanophlyctis. Mean concentration of Cd, Fe, Ni, Mn, Cu, and Cr was comparatively greater in R. tigrina, whereas Pb and Co were higher in E. cyanophlyctis. The concentration of Cu and Cd in the liver and kidney were relatively more in both species as compared to other organs. Further, the results indicated that frogs collected from industrial sites showed decreased body length and weight, and greater metal accumulation. The results will help the authorities for the conservation of these frog species which are under the influence of heavy metal contamination.

  6. [Peculiarities of functioning of liver mitochondria of river lamprey Lampetra fluviatilis and common frog Rana temporaria at periods of suppression and activation of energy metabolism].

    PubMed

    Emel'ianova, L V; Savina, M V; Beliaeva, E A; Braĭlovskaia, I V

    2007-01-01

    The work dealt with study of mitochondria in reversible metabolic suppression of hepatocytes of the river lamprey Lampetra fluviatilis in the course of prespawning starvation and of liver mitochondria of the common frog Rana temporaria during hibernation and activity. In winter the metabolic depression of lamprey hepatocytes, unlike that of frog hepatocytes, has been found to be due to deactivation of complex I of the electron transport mitochondrial chain, a low rate of NAD-dependent substrate oxidation, a low content of adenine nucleotide content, and a high degree of mitochondrial membrane permeability to H+ and other monovalent ions (KCl-, K+). The mitochondrial membrane permeability decreases in the presence of ethyleneglycoldiamineethyltetraacetic acid (EGTA), cyclosporine A (CsA), adenosine-5'-diphosphate (ADP), and Mg+. These facts indicate the presence in these mitochondria of the Ca2+ -dependent unspecific pore in the low-conductance state. Histological studies showed the lamprey and the frog to have principal differences in use of energy substrates at the period of metabolic depression. Lampreys utilize predominantly lipids, whereas frogs--glycogen. The clearly pronounces activation of lipid consumption is observed at the spring period before spawning and death of lamprey. Possible causes of metabolic depression are discussed as well as similarity and difference in behavior of mitochondria of cyclostomes and amphibians throughout metabolic depression and activity.

  7. Nitrite modulates contractility of teleost (Anguilla anguilla and Chionodraco hamatus, i.e. the Antarctic hemoglobinless icefish) and frog (Rana esculenta) hearts.

    PubMed

    Cerra, M C; Angelone, T; Parisella, M L; Pellegrino, D; Tota, B

    2009-07-01

    Being the largest form of intravascular and tissue storage of nitric oxide (NO) and a signalling molecule itself, the nitrite anion (NO(2)(-)) has emerged as a key player in many biological processes. Since the heart is under an important NO-mediated autocrine-paracrine control, in mammals the cardiac effects of nitrite are under intensive investigation. In contrast, nothing is known in non-mammalian vertebrates. We evaluated nitrite influence on cardiac performance in the perfused beating heart of three different cold-blooded vertebrates, i.e. two teleost fishes, the temperate red-blooded Anguilla anguilla, the Antarctic stenotherm, hemoglobinless Chionodraco hamatus (icefish), and the frog Rana esculenta. We showed that, under basal conditions, in all animals nitrite influences cardiac mechanical performance, inducing negative inotropism in eel and frog, while being a positive inotrope in C. hamatus. In all species, these responses parallel the inotropic effects of authentic NO. We also demonstrated that the nitrite-dependent inotropic effects are i) dependent from NO synthase (NOS) activity in fish; ii) sensitive to NO scavenging in frog; iii) cGMP/PKG-dependent in both eel and frog. Results suggest that nitrite is an integral physiological source of NO and acts as a signalling molecule in lower vertebrate hearts, exerting relevant inotropic actions through different species-specific mechanisms.

  8. The luteotrophic effect of homoplastic pituitary pars distalis homogenate, PMSG, and HCG on the corpora lutea of the hypophysectomized frog, Rana cyanophlyctis (SCHN).

    PubMed

    Pancharatna, M; Saidapur, S K

    1984-03-01

    The effect of homoplastic pituitary pars distalis homogenate (PDH), PMSG, and HCG on the postovulatory follicles/corpora lutea (CL) of the frog Rana cyanophlyctis was studied to elucidate the factors regulating the life span of the luteal cells. Ovulation and spawning was induced in hypophysectomized frogs using PDH. Starting from Day 1 of spawning 1/2 PDH, 50 IU PMSG, or 50 IU HCG was injected daily for 3 days. In the saline-injected control frogs, the granulosa lutein cells regressed markedly on Day 2 with a steady progressive increase in the pycnosis of their nuclei. The sudanophilic lipid droplets of the luteal cells were fine on Day 1 but became coarser and reduced in number on subsequent days. Histochemically, the luteal cell 3 beta-HSDH and G-6-PDH also decreased drastically by Day 2. In PDH-treated frogs the granulosa lutein cells were healthy on all 4 days of the experiment. The nuclear diameter of the luteal cells increased progressively due to PDH. The pycnosis of the luteal cells was limited to 7.6% on Day 4 due to PDH as opposed to 68% seen in the controls. Histochemically, 3 beta-HSDH and G-6-PDH activities remained much higher than in the controls with abundant sudanophilic lipids (both fine and coarse) in the luteal cells of PDH treated frogs even on Day 4. PMSG treatment also maintained the granulosa lutein cells beyond their normal life span but the luteotrophic effect was less than that of PDH. HCG was least effective. The present studies suggest that the structural integrity of CL in the frog can be extended beyond the normal life span by injecting PDH or PMSG.

  9. Effects of short-term exposure to the DDT metabolite p,p'-DDE on bone tissue in male common frog (Rana temporaria).

    PubMed

    Lundberg, Rebecca; Jenssen, Björn Munro; Leiva-Presa, Angels; Rönn, Monika; Hernhag, Carolina; Wejheden, Carolina; Larsson, Sune; Orberg, Jan; Lind, P Monica

    2007-04-01

    Experimental studies as well as studies in free-ranging animals have shown that endocrine-disrupting chemicals (EDCs) impair bone tissue composition and strength. The aim of the present study was to expand our studies on bone tissue in a new group of animals by investigating whether bone tissue in frogs is an additional potential target of EDCs. Adult male European common frogs (Rana temporaria) were divided into 5 groups (n = 20) and injected (sc, single injection) with p,p'-DDE, a total dose of 0.01, 0.1, 1, or 10 mg of p,p'-DDE/kg body weight, respectively. A control group was treated with the vehicle (corn oil). Two weeks after injection the frogs were euthanized and samples taken. The diaphysis of the excised left femur was scanned using peripheral quantitative computed tomography (pQCT) and cortical variables, such as cortical bone mineral density (BMD), cortical cross-sectional area (CSA), and periosteal circumference, were determined. In addition, biomechanical three-point bending of the bones was conducted, with the load being applied to the same point as where the pQCT measurement was performed. The results from the pQCT measurements show that bone tissue in male frogs exposed to p,p'-DDE is negatively affected. A significant decrease in cortical BMD at the diaphysis was observed in frogs exposed to 1 mg p,p'-DDE. However, the biomechanical testing of the bones showed no significant differences between exposed and control group. Although this is the only study performed to date examining the possible relationships between EDCs and negative effects on frog bones, it supports both previous experimental findings in rodents and findings in free-ranging animals.

  10. Ultrastructural study of the semicircular canal cells of the frog Rana esculenta.

    PubMed

    Oudar, O; Ferrary, E; Feldmann, G

    1988-03-01

    The ultrastructure of the nonsensory cells (dark cells, transitional cells, and undifferentiated cells) of the frog semicircular canal was studied by using transmission electron microscopy in an attempt to correlate the structure with the functions of these epithelial cells. All the nonsensory cells were linked by tight junctions and desmosomes; this suggested that there is little paracellular ionic transport from perilymph to endolymph. In the dark cell epithelium, the apical intercellular spaces were dilated; in the basal part, numerous basolateral plasma membrane infoldings, containing mitochondria, delimited electron-lucent spaces. The undifferentiated cells and the transitional cells were devoid of any basal membrane infolding. Surrounding the semicircular canal, very flattened and interdigitated mesothelial cells constituted a thin multilayer tissue which limited the perilymphatic space. The morphological aspect of the dark cells suggests that they may play a role in the secretion and/or in the reabsorption of endolymph, which bathes the apical pole of these cells. The undifferentiated and transitional cells can play a role in the maintenance of the endolymphatic ionic composition because of their apical tight junctions and desmosomes.

  11. Sex-chromosome differentiation and ‘sex races’ in the common frog (Rana temporaria)

    PubMed Central

    Rodrigues, Nicolas; Vuille, Yvan; Loman, Jon; Perrin, Nicolas

    2015-01-01

    Sex-chromosome differentiation was recently shown to vary among common frog populations in Fennoscandia, suggesting a trend of increased differentiation with latitude. By rearing families from two contrasted populations (respectively, from northern and southern Sweden), we show this disparity to stem from differences in sex-determination mechanisms rather than in XY-recombination patterns. Offspring from the northern population display equal sex ratios at metamorphosis, with phenotypic sexes that correlate strongly with paternal LG2 haplotypes (the sex chromosome); accordingly, Y haplotypes are markedly differentiated, with male-specific alleles and depressed diversity testifying to their smaller effective population size. In the southern population, by contrast, a majority of juveniles present ovaries at metamorphosis; only later in development do sex ratios return to equilibrium. Even at these later stages, phenotypic sexes correlate only mildly with paternal LG2 haplotypes; accordingly, there are no recognizable Y haplotypes. These distinct patterns of gonadal development fit the concept of ‘sex races’ proposed in the 1930s, with our two populations assigned to the ‘differentiated’ and ‘semi-differentiated’ races, respectively. Our results support the suggestion that ‘sex races’ differ in the genetic versus epigenetic components of sex determination. Analysing populations from the ‘undifferentiated race’ with high-density genetic maps should help to further test this hypothesis. PMID:25833852

  12. Sex-chromosome differentiation and 'sex races' in the common frog (Rana temporaria).

    PubMed

    Rodrigues, Nicolas; Vuille, Yvan; Loman, Jon; Perrin, Nicolas

    2015-05-07

    Sex-chromosome differentiation was recently shown to vary among common frog populations in Fennoscandia, suggesting a trend of increased differentiation with latitude. By rearing families from two contrasted populations (respectively, from northern and southern Sweden), we show this disparity to stem from differences in sex-determination mechanisms rather than in XY-recombination patterns. Offspring from the northern population display equal sex ratios at metamorphosis, with phenotypic sexes that correlate strongly with paternal LG2 haplotypes (the sex chromosome); accordingly, Y haplotypes are markedly differentiated, with male-specific alleles and depressed diversity testifying to their smaller effective population size. In the southern population, by contrast, a majority of juveniles present ovaries at metamorphosis; only later in development do sex ratios return to equilibrium. Even at these later stages, phenotypic sexes correlate only mildly with paternal LG2 haplotypes; accordingly, there are no recognizable Y haplotypes. These distinct patterns of gonadal development fit the concept of 'sex races' proposed in the 1930s, with our two populations assigned to the 'differentiated' and 'semi-differentiated' races, respectively. Our results support the suggestion that 'sex races' differ in the genetic versus epigenetic components of sex determination. Analysing populations from the 'undifferentiated race' with high-density genetic maps should help to further test this hypothesis. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  13. Natural stressors and ranavirus susceptibility in larval wood frogs (Rana sylvatica).

    PubMed

    Reeve, Brooke C; Crespi, Erica J; Whipps, Christopher M; Brunner, Jesse L

    2013-06-01

    Chronic exposure to stressors has been shown to suppress immune function in vertebrates, making them more susceptible to pathogens. It is less clear, however, whether many natural stressors are immunosuppressive. Moreover, whether stressors make disease more likely or more severe in populations is unclear because animals respond to stressors both behaviorally and physiologically. We tested whether chronic exposure to three natural stressors of wood frog tadpoles-high-densities, predator-cues, and low-food conditions-influence their susceptibility to a lethal ranavirus both individually in laboratory experiments, and collectively in outdoor mesocosms. Prior to virus exposure, we observed elevated corticosterone only in low-food treatments, although other treatments altered rates of growth and development as well as tadpole behavior. None of the treatments, however, increased susceptibility to ranavirus as measured by the proportion of tadpoles that became infected or died, or the time to death compared to controls. In fact, mortality in the mesocosms was actually lower in the high-density treatment even though most individuals became infected, largely because of increased rates of metamorphosis. Overall we find no support for the hypothesis that chronic exposure to common, ecologically relevant challenges necessarily elevates corticosterone levels in a population or leads to more severe ranaviral disease or epidemics. Conditions may, however, conspire to make ranavirus infection more common in metamorphosing amphibians.

  14. Effects of road de-icing salt (NaCl) on larval wood frogs (Rana sylvatica).

    PubMed

    Sanzo, Domenico; Hecnar, Stephen J

    2006-03-01

    Vast networks of roads cover the earth and have numerous environmental effects including pollution. A major component of road runoff in northern countries is salt (mostly NaCl) used as a winter de-icing agent, but few studies of effects of road salts on aquatic organisms exist. Amphibians require aquatic habitats and chemical pollution is implicated as a major factor in global population declines. We exposed wood frog tadpoles to NaCl. Tests revealed 96-h LC50 values of 2,636 and 5,109 mg/l and tadpoles experienced reduced activity, weight, and displayed physical abnormalities. A 90 d chronic experiment revealed significantly lower survivorship, decreased time to metamorphosis, reduced weight and activity, and increased physical abnormalities with increasing salt concentration (0.00, 0.39, 77.50, 1,030.00 mg/l). Road salts had toxic effects on larvae at environmentally realistic concentrations with potentially far-ranging ecological impacts. More studies on the effects of road salts are warranted.

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

    PubMed

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

    2009-07-15

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

  16. Effects of external calcium on potassium contractures in tonic muscle fibers of the frog (Rana pipiens).

    PubMed Central

    Huerta, M; Muñiz, J; Stefani, E

    1986-01-01

    K+ contractures of tonic bundles from cruralis muscle of the frog were studied with different K+ concentrations (10-120 mM). K+ contractures had an initial transient phase followed by a sustained tension. The amplitude of the sustained tension diminished with high K+ concentration (80-120 mM). However, in all cases, tension was maintained for several minutes. External Ca2+ reduction practically abolished the sustained phase of the K+ contractures. The initial phase was also reduced and tension spontaneously relaxed. The curve relating the peak tension with log [K+]o, showed that the threshold was not affected but the peak tension was reduced to about 70% in low-Ca2+ saline (0 Ca2+ + 3 mM-Mg2+) and 50% in Ca2+-free saline (1 mM-EGTA + 3 mM-Mg2+). The dependence of the sustained tension on external Ca2+ was further confirmed by Ca2+ withdrawal and re-establishment and/or by Ni2+ substitution for Ca2+ before or during K+ contractures. These results indicate that external Ca2+ had to be continuously present to maintain the tension during K+ contractures and that Ni2+ was not able to restore the normal temporal course of K+ contracture. The sustained phase was diminished by blocking agents of Ca2+ channels, such as nifedipine (1 microM) and diltiazem (1-10 microM). The present results can be explained by a direct control of the Ca2+ currents on K+ contracture or by specific interactions between external Ca2+ and Ca2+-binding sites in the membrane. PMID:3491902

  17. Amphibian population genetics in agricultural landscapes: does viniculture drive the population structuring of the European common frog (Rana temporaria)?

    PubMed

    Lenhardt, Patrick P; Brühl, Carsten A; Leeb, Christoph; Theissinger, Kathrin

    2017-01-01

    Amphibian populations have been declining globally over the past decades. The intensification of agriculture, habitat loss, fragmentation of populations and toxic substances in the environment are considered as driving factors for this decline. Today, about 50% of the area of Germany is used for agriculture and is inhabited by a diverse variety of 20 amphibian species. Of these, 19 are exhibiting declining populations. Due to the protection status of native amphibian species, it is important to evaluate the effect of land use and associated stressors (such as road mortality and pesticide toxicity) on the genetic population structure of amphibians in agricultural landscapes. We investigated the effects of viniculture on the genetic differentiation of European common frog (Rana temporaria) populations in Southern Palatinate (Germany). We analyzed microsatellite data of ten loci from ten breeding pond populations located within viniculture landscape and in the adjacent forest block and compared these results with a previously developed landscape permeability model. We tested for significant correlation of genetic population differentiation and landscape elements, including land use as well as roads and their associated traffic intensity, to explain the genetic structure in the study area. Genetic differentiation among forest populations was significantly lower (median pairwise FST = 0.0041 at 5.39 km to 0.0159 at 9.40 km distance) than between viniculture populations (median pairwise FST = 0.0215 at 2.34 km to 0.0987 at 2.39 km distance). Our analyses rejected isolation by distance based on roads and associated traffic intensity as the sole explanation of the genetic differentiation and suggest that the viniculture landscape has to be considered as a limiting barrier for R. temporaria migration, partially confirming the isolation of breeding ponds predicted by the landscape permeability model. Therefore, arable land may act as a sink habitat, inhibiting genetic

  18. Experimental and model analyses of the effects of competition on individual size variation in wood frog (Rana sylvatica) tadpoles.

    PubMed

    Peacor, Scott D; Pfister, Catherine A

    2006-07-01

    1. Size variation is a ubiquitous feature of animal populations and is predicted to strongly influence species abundance and dynamics; however, the factors that determine size variation are not well understood. 2. In a mesocosm experiment, we found that the relationship between mean and variation in wood frog (Rana sylvatica) tadpole size is qualitatively different at different levels of competition created by manipulating resource supply rates or tadpole density. At low competition, relative size variation (as measured by the coefficient of variation) decreased as a function of mean size, while at high competition, relative size variation increased. Therefore, increased competition magnified differences in individual performance as measured by growth rate. 3. A model was developed to estimate the contribution of size-dependent factors (i.e. based on size alone) and size-independent factors (i.e. resulting from persistent inherent phenotypic differences other than size that affect growth) on the empirical patterns. 4. Model analysis of the low competition treatment indicated that size-dependent factors alone can describe the relationship between mean size and size variation. To fit the data, the size scaling exponent that describes the dependence of growth rate on size was determined. The estimated value, 0-83, is in the range of that derived from physiological studies. 5. At high competition, the model analysis indicated that individual differences in foraging ability, either size-based or due to inherent phenotypic differences (size-independent factors), were much more pronounced than at low competition. The model was used to quantify the changes in size-dependent or size-independent factors that underlie the effect of competition on size-variation. In contrast to results at low competition, parameters derived from physiological studies could not be used to describe the observed relationships. 6. Our experimental and model results elucidate the role of size

  19. Waterborne amitrole affects the predator-prey relationship between common frog tadpoles (Rana temporaria) and larval spotted salamander (Salamandra salamandra).

    PubMed

    Mandrillon, Anne-Lise; Saglio, Philippe

    2007-08-01

    Within their aquatic habitats, larval amphibians are often subjected to multiple natural and anthropic stressors. Among these, predation and waterborne pollution represent two types of stressing factor that frequently co-occur. In this connection, the present laboratory study was designed to investigate the effects of amitrole, a commonly used triazole herbicide, on the predator-prey relationship between common frog tadpoles (Rana temporaria) and larval spotted salamander (Salamandra salamandra). Tadpoles were exposed for 3 days to 0, 0.01, 0.1, 1, and 10 mg/L amitrole, either in the absence or in the presence of larval salamanders. Tadpole behavior (refuge use, movements) was monitored every day, and the predation efficiency was assessed at the end of the experiment by counting the number of surviving tadpoles. In the absence of the predator, amitrole-exposed tadpoles (at 0.01, 0.1, and 1 mg/L) increased their refuge use and decreased their rate of movements. In the presence of the predator, amitrole contamination did not affect tadpole behavior, except on the first day, where tadpoles exposed to 10 mg/L were found to be significantly more active than unexposed control tadpoles. Throughout the experiment, control tadpoles were the only group to show significant reductions of activity and visibility in response to the predator's presence. In contrast, tadpoles exposed to 0.01 and 0.1 mg/L amitrole increased their refuge use in response to the predator, whereas their rate of movements remained unaffected. Furthermore, exposures of tadpoles to the two highest amitrole concentrations (1 and 10 mg/L) resulted in the loss of both behavioral responses to the predator's presence. Interestingly, the lack of antipredator behavior in amitrole-exposed tadpoles did not enhance their vulnerability to predation by the larval salamander. Moreover, tadpoles exposed to the two highest herbicide concentrations showed a better survival than unexposed controls, indicating that

  20. Effects of chronic aluminum and copper exposure on growth and development of wood frog (Rana sylvatica) larvae.

    PubMed

    Peles, John D

    2013-09-15

    Wood frogs (Rana sylvatica) were exposed to aluminum (Al; 10, 100, 500, 1000, or 2000 μgL(-1)) or copper (Cu; 1, 10, 50, 100, 200 μgL(-1)) at a pH of 4.70 from the beginning of the larval period through the completion of metamorphosis (range=43-102 days). Observations on mortality, malformation, time to reach specific developmental stages, body mass at these stages, and metamorphic success were made throughout the larval developmental period. Only one case of malformation was observed and mortality was ≤ 10% at all concentrations except the highest Cu concentration where the rate was 33%. All larvae that survived the experiment successfully completed metamorphosis, but significant effects on growth and development occurred for both metals and these were most prominent for Cu. At the highest Al concentration (2000 μgL(-1)), body mass of larvae was significantly lower (reduced by 17% compared to the control) at 20 days post hatching (DPH) and the time to reach the hind-limb (HL), front-limb (FL), and tail resorption (TR) stages was significantly increased (9-10 days longer than the control). Body mass of larvae exposed to the three highest concentrations of Cu (50, 100, 200 μgL(-1)) was reduced by 30-34% at 20 DPH. Exposure to these concentrations also resulted in increased time to reach the HL, FL, and TR stages with larvae in the highest concentration taking 21-29 days longer to reach these stages. Larvae exposed to 10 μgL(-1) Cu also took longer to reach the FL and TR stages of development, and exposure to all Cu concentrations increased tail resorption time by more than two days compared to the control. Although the only observed effects of Al were for a concentration that is probably not ecologically relevant, results demonstrate that environmentally-realistic levels of Cu may have significant biological effects that could influence individual fitness and population-level processes. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Don't get the blues: conspicuous nuptial colouration of male moor frogs (Rana arvalis) supports visual mate recognition during scramble competition in large breeding aggregations.

    PubMed

    Sztatecsny, Marc; Preininger, Doris; Freudmann, Anita; Loretto, Matthias-Claudio; Maier, Franziska; Hödl, Walter

    2012-12-01

    Conspicuous male colouration is expected to have evolved primarily through selection by female choice. In what way conspicuous colours could be advantageous to males scrambling for mates remains largely unknown. The moor frog (Rana arvalis) belongs to the so-called explosive breeders in which spawning period is short; intrasexual competition is strong, and males actively search and scramble for females. During breeding, male body colouration changes from a dull brown (similar to females) to a conspicuous blue, and we wanted to test if male blueness influences mating success or facilitates male mate recognition. To do so, we first measured the colour of mated and non-mated males using a spectrophotometer. In an experiment, we then analysed interactions of actual male moor frogs in natural spawning aggregations with a brown (resembling a female or a non-breeding male) and a blue model frog. Mated and non-mated males did not differ in colouration, suggesting that female choice based on colour traits was unlikely. In our behavioural experiment, male moor frogs spent significantly more time in contact and in amplexus with the brown model than with the blue model. Our results suggest that the nuptial colouration in moor frogs can act as a new type of visual signal in anurans evolved to promote instantaneous mate recognition allowing males to quickly move between rivals while scrambling for females. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00265-012-1412-6) contains supplementary material, which is available to authorized users.

  2. Effects of Evans Blue and amiloride on anti-diuretic hormone (ADH)-induced sodium transport across frog (Rana hexadactyla) skin.

    PubMed

    Jared, Silviya Rajakumari; Rao, Jonakuty Prakasa

    2013-05-01

    The epithelial sodium channel (ENaC) has four subunits, namely α (alpha), β (beta), γ (gamma) and δ (delta). The functional ENaC is formed by the combination of either αβγ or δβγ subunits. The aim of the present study is to determine the combination of ENaC subunits predominant on the apical side of the frog skin, and the effect of ADH on sodium transport though these two ENaCs subunit combinations. The ventral abdominal skin of the frog, Rana hexadactyla was mounted in an Ussing-type chamber. The voltage-clamp method was performed to measure the ionic transport across the frog skin with normal Ringer solution (NR) on both sides. Evans blue (300 µM) and amiloride (100 µM) were added to the NR on the apical side and ADH (40 nM) was added on the serosal side. Statistical significance was analyzed by Student's paired t-test and repeated-measures ANOVA, P < 0.05 was considered significant. This study suggests that the ENaC of the frog skin consist of both αβγ and δβγ subunit combinations on the apical side. Though both types of subunit combination are present, the αβγ type was found to be more common than δβγ. ADH increases the sodium transport across the frog skin. The effect of ADH on sodium transport is achieved through the combination of δ-subunits, not through the combination of a-subunits in the skin of Pana hexadactyla.

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

    PubMed

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

    2003-05-01

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

  4. Interrelationship between food availability, fat body, and ovarian cycles in the frog, Rana tigrina, with a discussion on the role of fat body in anuran reproduction.

    PubMed

    Girish, S; Saidapur, S K

    2000-04-01

    Long-term experiments were conducted to study the progression of vitellogenic cycles in Rana tigrina (an annual breeder) having different foraging backgrounds and held under conditions of weekly or daily food supply and in presence or absence of abdominal fat bodies. They were autopsied in June to assess fecundity. In nature an adult R. tigrina produces on an average 4,000 eggs/100 g body mass (b.m.) And spawns in June-July following monsoon rains. Weekly feeding from July to next breeding season, June resulted in a significant decrease in both fecundity (1700 eggs/100 g body b.m.) And mean size of eggs, compared to well-fed or wild-caught frogs. The abdominal fat bodies were barely seen in frogs fed weekly throughout, whereas in frogs fed weekly from July-December but daily from January onwards, the fat bodies became noticeable (1% of b.m.) And number and mean size of eggs increased significantly over those fed weekly throughout. Frogs captured in January possessed enlarged fat bodies (5% of b.m.), depicting a good foraging history. Maintenance of these frogs on a weekly feeding regimen led to an exhaustion of fat stores. They produced less number of eggs (2, 000/100 g b.m.) As compared to wild frogs but of normal size, whereas daily feeding slowed down a depletion of fat body mass and also significantly increased fecundity (3,000/100 g b.m.) Over the weekly fed individuals. Sham operation or fat body ablation in October or February had no significant effect on total fecundity per se (3,000-3,500 eggs/100 g b.m.) Compared to that of wild-caught frogs. However, eggs were significantly smaller due to fat body ablation despite daily feeding. The study shows that food abundance/fat bodies influence egg size and number in R. tigrina and that a direct or indirect functional relationship exists between fat body and ovarian cycles that are characteristically inverse to each other. J. Exp. Zool. 286:487-493, 2000.

  5. Diverse families of antimicrobial peptides isolated from skin secretions of three species of East Asian frogs, Babina daunchina, Babina adenopleura, and Rana omeimontis (Ranidae).

    PubMed

    Hu, Yuhong; Xu, Shiqi; Hu, Yonghong; Guo, Chao; Meng, Hao; Li, Jing; Liu, Jingze; Wang, Hui

    2014-07-01

    Twenty-two novel cDNAs encoding 22 peptide precursors for 19 mature peptides including antimicrobial peptides (AMPs) were identified from East Asian frog species Babina daunchina, Babina adenopleura, and Rana omeimontis skin-derived cDNA libraries. Two atypical members of the brevinin-1 family AMPs, named brevinin-1AN1 (FLTGVLKLASKIPSVLCAVLKTC) and brevinin-1DN1(FLKGVINLASKIPSMLCAVLKTC), were purified from the skin secretions of B. adenopleura and B. daunchina, respectively. A member of the ranatuerin-2 family AMP named ranatuerin-2DN1 (GLFDSITQGLKDTAVKLLDKIKCKLSACPPA) was also purified from the skin secretion of B. daunchina. One AMP named japonicin-2OM1 (FIVPSIFLLKKAFCIALKKNC) was purified from the skin secretion of R. omeimontis. The antimicrobial tests showed that brevinin-1DN1, brevinin-1DN2, brevinin-1AN1, and japonicin-2OM1 possess higher antimicrobial activity against Gram-positive bacteria than Gram-negative bacteria.

  6. Bioremediation of tetrachloroethylene-contaminated groundwater in a model aquifer: effects on green frogs (Rana clamitans) and Xenopus laevis as potential wetland receptors.

    PubMed

    McDaniel, Tana V; Ross, Nathalie; Martin, Pamela A; Steer, Helena; Abbey, Ann-Marie Irwin; Lesage, Suzanne

    2007-04-01

    Recent regulations require that the ecological effects of microorganisms introduced into the environment, such as for groundwater bioremediation, be assessed prior to their utilization. A native anuran (Rana clamitans) and a model anuran (Xenopus laevis) were used as potential wetland receptors of tetrachloroethylene (PCE)-contaminated groundwater, undergoing three bioremediation treatments: natural attenuation (NA), biostimulation (ST), and bioaugmentation (AU). Eggs of both species were exposed acutely (96 h) to remediated effluents. Xenopus tadpoles were chronically exposed to the effluents for 100 days and were screened for the presence of bacterial pathogens. There was no impact on the survivorship of the frogs exposed either acutely or chronically to the NA, ST, or AU effluents; nor was there any evidence of bacterial infection found, with the exception of control individuals. The results of these exposures suggest that bioremediation with KB-1trade mark culture poses a minimal threat to anuran development and survivorship.

  7. Evidence for Directional Selection at a Novel Major Histocompatibility Class I Marker in Wild Common Frogs (Rana temporaria) Exposed to a Viral Pathogen (Ranavirus)

    PubMed Central

    Teacher, Amber G. F.; Garner, Trenton W. J.; Nichols, Richard A.

    2009-01-01

    Whilst the Major Histocompatibility Complex (MHC) is well characterized in the anuran Xenopus, this region has not previously been studied in another popular model species, the common frog (Rana temporaria). Nor, to date, have there been any studies of MHC in wild amphibian host-pathogen systems. We characterise an MHC class I locus in the common frog, and present primers to amplify both the whole region, and specifically the antigen binding region. As no more than two expressed haplotypes were found in over 400 clones from 66 individuals, it is likely that there is a single class I locus in this species. This finding is consistent with the single class I locus in Xenopus, but contrasts with the multiple loci identified in axolotls, providing evidence that the diversification of MHC class I into multiple loci likely occurred after the Caudata/Anura divergence (approximately 350 million years ago) but before the Ranidae/Pipidae divergence (approximately 230 mya). We use this locus to compare wild populations of common frogs that have been infected with a viral pathogen (Ranavirus) with those that have no history of infection. We demonstrate that certain MHC supertypes are associated with infection status (even after accounting for shared ancestry), and that the diseased populations have more similar supertype frequencies (lower FST) than the uninfected. These patterns were not seen in a suite of putatively neutral microsatellite loci. We interpret this pattern at the MHC locus to indicate that the disease has imposed selection for particular haplotypes, and hence that common frogs may be adapting to the presence of Ranavirus, which currently kills tens of thousands of amphibians in the UK each year. PMID:19240796

  8. Evaluation of the skin peptide defenses of the Oregon spotted frog Rana pretiosa against infection by the chytrid fungus Batrachochytrium dendrobatidis.

    PubMed

    Conlon, J Michael; Reinert, Laura K; Mechkarska, Milena; Prajeep, Manju; Meetani, Mohammed A; Coquet, Laurent; Jouenne, Thierry; Hayes, Marc P; Padgett-Flohr, Gretchen; Rollins-Smith, Louise A

    2013-06-01

    Population declines due to amphibian chytridiomycosis among selected species of ranid frogs from western North America have been severe, but there is evidence that the Oregon spotted frog, Rana pretiosa Baird and Girard, 1853, displays resistance to the disease. Norepinephrine-stimulated skin secretions were collected from a non-declining population of R. pretiosa that had been exposed to the causative agent Batrachochytrium dendrobatidis. Peptidomic analysis led to identification and isolation, in pure form, of a total of 18 host-defense peptides that were characterized structurally. Brevinin-1PRa, -1PRb, -1PRc, and -1PRd, esculentin-2PRa and -PRb, ranatuerin-2PRa, -2PRb, -2PRc, and -2PRe, temporin-PRb and -PRc were identified in an earlier study of skin secretions of frogs from a different population of R. pretiosa known to be declining. Ranatuerin-2PRf, -2PRg, -2PRh, temporin-PRd, -PRe, and -PRf were not identified in skin secretions from frogs from the declining population, whereas temporin-PRa and ranatuerin-2PRd, present in skin secretions from the declining population, were not detected in the current study. All purified peptides inhibited the growth of B. dendrobatidis zoospores. Peptides of the brevinin-1 and esculentin-2 families displayed the highest potency (minimum inhibitory concentration = 6.25-12.5 μM). The study provides support for the hypothesis that the multiplicity and diversity of the antimicrobial peptide repertoire in R. pretiosa and the high growth-inhibitory potency of certain peptides against B. dendrobatidis are important in conferring a measure of resistance to fatal chytridiomycosis.

  9. Cytochemical and immunocytochemical characterization of blood cells and immunohistochemical analysis of spleen cells from 2 species of frog, Rana (Aquarana) catesbeiana and Xenopus laevis.

    PubMed

    Bricker, Nelson K; Raskin, Rose E; Densmore, Christine L

    2012-09-01

    Mechanisms of amphibian diseases are not characterized as well as those in domestic mammalian species. Antemortem laboratory testing is limited in frogs, presenting a diagnostic challenge to zoos, laboratories, and exotic veterinarians. This study aimed to characterize blood cells and splenic cells from 2 anuran species based on characteristics identified by Wright staining, cytochemical staining, and immunochemical analysis and on histologic examination of spleens. Blood specimens and spleens were obtained from 2 species of frog, the American bullfrog (Rana [Aquarana] catesbeiana) and the African clawed frog (Xenopus laevis). Blood smears were evaluated after Wright staining and cytochemical staining for α-naphthyl butyrate esterase (NBE), chloroacetate esterase (CAE), myeloperoxidase (PER), Sudan black B (SBB), and leukocyte alkaline phosphatase (LAP) reactions and for immunoreactivity for antibodies against CD3ε, CD79a, and BLA.36 antigens. Histologic sections of spleen were evaluated after staining with H&E and for immunoreactivity for CD3ε, CD79a, and BLA.36 antigens. In bullfrogs, neutrophils, eosinophils, and monocytes were positive for some or all of the following: NBE, CAE, PER, and SBB; lymphocytes occasionally were positive for CAE. In clawed frogs, neutrophils, basophils, and monocytes were positive for some or all of the following: NBE, CAE, PER, and SBB; eosinophils occasionally were positive for CAE and PER, and lymphocytes were negative for all cytochemical stains. LAP was not a useful marker for any leukocyte type. In both species, peripheral blood lymphocytes were strongly immunoreactive for CD3ε, CD79a, and BLA.36. In splenic tissue, histologic patterns varied and there was diffuse immunoreactivity for CD79a and BLA.36 with focal reactivity for CD3ε, but with different distribution patterns in each species. Cytochemical and immunochemical analysis of cells may be helpful in identification and characterization of amphibian blood cells and

  10. Effects of D-aspartate treatment on D-aspartate oxidase, superoxide dismutase, and caspase 3 activities in frog (Rana esculenta) tissues.

    PubMed

    Burrone, Lavinia; Di Giovanni, Marcello; Di Fiore, M Maddalena; Baccari, Gabriella Chieffi; Santillo, Alessandra

    2010-06-01

    Although D-aspartate (D-Asp) has been recognized to have a physiological role within different organs, high concentrations could elicit detrimental effects on those same organs. In this study, we examined the D-aspartate oxidase (D-AspO) activity and the expression of superoxide dismutase 1 (SOD1) and caspase 3 in different tissues of the frog Rana esculenta after chronic D-Asp treatment. Our in vivo experiments, consisting of intraperitoneal (ip) injections of D-Asp (2.0 micromol/g b.w.) in frogs for ten consecutive days, revealed that all examined tissues can take up and accumulate D-Asp. Further, in D-Asp treated frogs, i) the D-AspO activity significantly increased in all tissues (kidney, heart, testis, liver, and brain), ii) the SOD1 expression (antioxidant enzyme) significantly increased in the kidney, and iii) the caspase 3 level (indicative of apoptosis) increased in both brain and heart. Particularly, after the D-Asp treatment we found in both brain and heart (which showed the lowest SOD1 levels) a significant increase of the caspase 3 expression and, vice versa, in the kidney (which showed the highest SOD1 expression) a significant decrease of the caspase 3 expression. Therefore, we speculate that, in frog tissue, D-AspO plays an essential role in modulating the D-Asp concentration. In addition, exaggerated D-Asp concentrations activated SOD1 as cytoprotective mechanism in the kidney, whereas, in the brain and in the heart, where the antioxidant action of SOD1 is limited, caspase 3 was activated.

  11. 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. © 2013 Wiley Periodicals, Inc.

  12. [Effect of aminotriazole on the activity of catalase and glucose-6-phosphate dehydrogenase in tissues of two frog species--Rana ridibunda and Rana esculenta].

    PubMed

    Lushchak, O V; Bahniukova, T V; Lushchak, V I

    2003-01-01

    Changes of the activity of catalase and glucose-6-phosphate dehydrogenase (G6PDH) during 48 hrs after intraperitoneal injection of 1.0, 0.5 and 0.1 mg aminotriazole per gram of body weight of two frog species as well as catalase inhibition by aminotriazole in vitro were investigated. Both aminotriazole concentration and species affiliation affected the catalase inhibition. The sensitivity of catalase from different tissues was decreased in the order: liver--kidney--lung--muscle--brain. The constant of half inhibition of lung catalase was significantly lower than that of liver and kidney catalase. The activity of G6PDH of AMT-treated frogs R. esculenta was higher comparing to control group. Possible ways of compensation of antioxidant defense under catalase inhibition are discussed.

  13. An integrative study of the temperature dependence of whole animal and muscle performance during jumping and swimming in the frog Rana temporaria.

    PubMed

    Navas, C A; James, R S; Wakeling, J M; Kemp, K M; Johnston, I A

    1999-12-01

    The aims of this study were: (1) to analyze individual variation in frog locomotor performance, (2) to compare the thermal sensitivity of jumping and swimming, and (3) to contrast whole animal versus muscle fiber performance at different temperatures. The jumping and swimming performance of Rana temporaria was analyzed at 5, 10, 15 and 20 degrees C. Muscle fiber bundles were isolated from lateral gastrocnemius and subjected to the length and activation patterns thought to occur in vivo. As temperature increased, locomotor performance in R. temporaria improved with a Q10 of 1.2 for both jump take-off velocity and mean swimming velocity. The slope of the relationship between performance and temperature (TE) was similar for both locomotor parameters and was described by the equation z-scores of locomotor performance = 0.127 x TE - 1.585. Although some frogs performed better than others relative performance was affected by locomotor type and temperature. Locomotor performance improved with temperature as the power required during take-off and the mean muscle power output increased with Q10 values of 1.7 and 1.6 respectively. The mean muscle power output during take-off was only 34% of the calculated requirements for the whole animal, suggesting the involvement of elastic strain energy storage mechanisms.

  14. Immunocytochemical and ultrastructural characterization of endocrine cells in the larval stomach of the frog Rana temporaria tadpoles: a comparison with adult specimens.

    PubMed

    Villaro, A C; Rovira, J; Bodegas, M E; Burrell, M A; García-Ros, D; Sesma, P

    2001-10-01

    According to immunostaining and ultrastructural patterns, Rana temporaria tadpole stomach displays a well-differentiated endocrine population comprising, at least, six cellular types: ECL, EC [serotonin], D [somatostatin] - all three of them abundant -, P [bombesin] - less numerous -, CCK-8 [cholecystokinin/gastrin] and A [glucagon/glicentin] - both very scarce. Larval endocrine cells are mainly located in the surface epithelium and show open or closed morphologies. Cellular diversity is similar in tadpoles and frogs, with the exception of immunoreactivity for gastrin-17, found in adults in numerous cells. Larval cells display mature ultrastructural traits, although with smaller secretory granules. The different distribution of endocrine cells, which in adults are preferentially located in the glands, probably refers to different functional requirements. However, the rich vascular plexus present in larval mucosa may be an efficient transport medium of surface hormones to-gastric targets. The enhancement in adults of endocrine population and correlative increase in hormonal secretion indicates a more active functional role, probably related to the shift from herbivorous to carnivorous habits. In summary, the tadpole gastric endocrine population, although not as numerous as that of adult frogs, displays histological traits that indicate a relevant (immunoreactive and ultrastructural properties, cellular diversity) and specific (surface location, relative abundance of open-type cells) role of local regulatory factors in amphibian larval gastric function.

  15. Antitumor effects and cell selectivity of temporin-1CEa, an antimicrobial peptide from the skin secretions of the Chinese brown frog (Rana chensinensis).

    PubMed

    Wang, Che; Li, Hui-Bing; Li, Song; Tian, Li-Li; Shang, De-Jing

    2012-02-01

    Many antimicrobial peptides from amphibian exhibit additional anticancer properties due to a similar mechanism of action at both bacterial and cancer cells. We have previously reported the cDNA sequence of the antimicrobial peptide temporin-1CEa precursor cloned from the Chinese brown frog Rana chensinensis. In this study, we purified, synthesized and structurally characterized temporin-1CEa from the skin secretions of R. chensinensis. The cytotoxicity and cell selectivity of temporin-1CEa were further examined on twelve human carcinoma cell lines and on normal human umbilical vein smooth muscle cells (HUVSMCs). Our results indicated that temporin-1CEa has the amino acid sequence of FVDLKKIANIINSIF-NH(2), and exhibits 50-56% identity with temporin family peptides from other frog species. The CD spectra for temporin-1CEa adopted a well-defined α-helical structure in 50% TFE/water solution. The results of MTT assay showed that temporin-1CEa exhibits cytotoxicity to all tested cancer cell lines in a concentration-dependent manner, being MCF-7 cells the most sensitive. Moreover, temporin-1CEa had lower hemolytic effect to human erythrocytes and had no significant cytotoxicity to normal HUVSMCs at concentrations showed potent antitumor activity. In summary, temporin-1CEa, an amphiphilic α-helical cationic peptide, may represent a novel anticancer agent for breast cancer therapy, considering its cancer cell selectivity and relatively lower cytotoxicity to normal cells. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  16. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2001-03-01

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

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

    PubMed

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

    2014-03-01

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

  19. Morphological and ultrastructural characteristics of Myxobolus ridibundae n. sp. (Myxosporea: Bivalvulida) infecting the testicular tissue of the marsh frog Rana ridibunda (Amphibia: Ranidae) in Egypt.

    PubMed

    Abdel-Ghaffar, Fathy; Abdel-Gaber, Rewaida; Maher, Sherein; El Deeb, Nashwa; Kamel, Reem; Al Quraishy, Saleh; Mehlhorn, Heinz

    2017-01-01

    Myxozoans are one of the most economically important groups of protozoan parasites causing many serious diseases of their hosts. In the present study, a total of 60 live adult male specimens of the marsh frog Rana ridibunda have been randomly captured during the period of January-December 2015 in different areas at Kafr El-Sheikh Governorate, Egypt and were examined for infection by myxosporidian parasites. A total of 48 (80.0 %) out of 60 frog specimens were found to be infected with Myxobolus species. Parasitic infection was restricted to the testicular tissue of the examined frogs. Macroscopic cysts (plasmodia) which heavily infested different parts of the testes were recovered. Morphological and ultrastructural characteristics of these myxosporidian species were carried out using light and transmission electron microscopy. Plasmodia measured 0.16-0.53 (0.34 ± 0.01) mm in diameter. Mature spores appeared oval in frontal view, measuring 8.9-11.5 (9.6 ± 0.1) μm in length and 7.5-9.1 (8.4 ± 0.1) μm in width containing 5-6 turns of polar filaments. Morphometric characterization revealed that the very small size of the present Myxobolus species was the most distinctive feature that separates them from all previously described Myxobolus species. Ultrastructural analysis showed that the plasmodia are surrounded by a plasma membrane with numerous pinocytotic protrusions extending toward the host cell. The generative cells and the different developmental stages are arranged at the periphery of the plasmodia, while immature and mature spores are centrally located. Sporogenesis, capsulogenesis, valvogenesis, and spore maturation of the present parasite are also described. The present species is described as Myxobolus ridibundae and represents a new species.

  20. LEOPARD syndrome

    MedlinePlus

    LEOPARD syndrome is a very rare inherited disorder in which there are problems with the skin, face, ... LEOPARD syndrome is inherited as an autosomal dominant trait. This means the person only needs the abnormal ...

  1. Characterization of kappa 1 and kappa 2 opioid binding sites in frog (Rana esculenta) brain membrane preparation

    SciTech Connect

    Benyhe, S.; Varga, E.; Hepp, J.; Magyar, A.; Borsodi, A.; Wollemann, M.

    1990-09-01

    The distribution and properties of frog brain kappa-opioid receptor subtypes differ not only from those of the guinea pig brain, but also from that of the rat brain. In guinea pig cerebellum the kappa 1 is the dominant receptor subtype, frog brain contains mainly the kappa 2 subtype, and the distribution of the rat brain subtypes is intermediate between the two others. In competition experiments it has been established that ethylketocyclazocine and N-cyclopropylmethyl-norazidomorphine, which are nonselective kappa-ligands, have relatively high affinities to frog brain membranes. The kappa 2 ligands (Met5)enkephalin-Arg6-Phe7 and etorphine also show high affinities to the frog brain. Kappa 1 binding sites measured in the presence of 5 microM/D-Ala2-Leu5/enkephalin represent 25-30% of (3H)ethylketocyclazocine binding in frog brain membranes. The kappa 2 subtype in frog brain resembles more to the mu subtype than the delta subtype of opioid receptors, but it differs from the mu subtype in displaying low affinity toward beta-endorphin and /D-Ala2-(Me)Phe4-Gly5-ol/enkephalin (DAGO). From our data it is evident that the opioid receptor subtypes are already present in the amphibian brain but the differences among them are less pronounced than in mammalian brain.

  2. Sequencing and analysis of the internal transcribed spacers (ITSs) and coding regions in the EcoR I fragment of the ribosomal DNA of the Japanese pond frog Rana nigromaculata.

    PubMed

    Sumida, Masayuki; Kato, Yoji; Kurabayashi, Atsushi

    2004-04-01

    The rDNA of eukaryotic organisms is transcribed as the 40S-45S rRNA precursor, and this precursor contains the following segments: 5' - ETS - 18S rRNA - ITS 1 - 5.8S rRNA - ITS 2 - 28S rRNA - 3'. In amphibians, the nucleotide sequences of the rRNA precursor have been completely determined in only two species of Xenopus. In the other amphibian species investigated so far, only the short nucleotide sequences of some rDNA fragments have been reported. We obtained a genomic clone containing the rDNA precursor from the Japanese pond frog Rana nigromaculata and analyzed its nucleotide sequence. The cloned genomic fragment was 4,806 bp long and included the 3'-terminus of 18S rRNA, ITS 1, 5.8S rRNA, ITS 2, and a long portion of 28S rRNA. A comparison of nucleotide sequences among Rana, the two species of Xenopus, and human revealed the following: (1) The 3'-terminus of 18S rRNA and the complete 5.8S rRNA were highly conserved among these four taxa. (2) The regions corresponding to the stem and loop of the secondary structure in 28S rRNA were conserved between Xenopus and Rana, but the rate of substitutions in the loop was higher than that in the stem. Many of the human loop regions had large insertions not seen in amphibians. (3) Two ITS regions had highly diverged sequences that made it difficult to compare the sequences not only between human and frogs, but also between Xenopus and Rana. (4) The short tracts in the ITS regions were strictly conserved between the two Xenopus species, and there was a corresponding sequence for Rana. Our data on the nucleotide sequence of the rRNA precursor from the Japanese pond frog Rana nigromaculata were used to examine the potential usefulness of the rRNA genes and ITS regions for evolutionary studies on frogs, because the rRNA precursor contains both highly conserved regions and rapidly evolving regions.

  3. Regeneration of lumbar dorsal root axons into the spinal cord of adult frogs (Rana pipiens), an HRP study.

    PubMed

    Liuzzi, F J; Lasek, R J

    1985-02-22

    Lumbar dorsal roots of adult frogs were crushed or cut and reanastomosed. Following survival times of up to 75 days, the regenerating dorsal roots were recut and anterogradely injury-filled with horseradish peroxidase. This revealed that in the adult frog, regenerating axons re-enter the spinal cord. Comparison of the distribution of these axons with that of normal dorsal root axons showed that there is a partial restoration of the segmental distribution in the gray matter. However, the long ascending sensory tract of the dorsal funiculus was not restored. The dorsal funiculus was markedly gliotic and had relatively few labelled, regenerated axons. The labelled axons that were seen in the dorsal funiculus either extended longitudinally for a distance just beneath the pia, apparently in association with the glia limitans, or traversed the region to enter the dorsal gray matter. Most of the large and small diameter axons that entered the gray matter did so by passing through the region of the dorsolateral fasciculus. Within the gray matter, small diameter, regenerated axons arborized in the region of the dorsal terminal field, a region that has been shown in the normal frog to receive cutaneous afferents only. Many large diameter axons, presumably muscle afferents, arborized in the ventral terminal field, a region shown in the normal frog to receive muscle afferents exclusively. However, many of these large diameter axons had arborizations that extended to both terminal fields, thus suggesting that some abberant connections are made during dorsal root regeneration in the adult frog.

  4. Big mountains but small barriers: Population genetic structure of the Chinese wood frog (Rana chensinensis) in the Tsinling and Daba Mountain region of northern China

    PubMed Central

    Zhan, Aibin; Li, Cheng; Fu, Jinzhong

    2009-01-01

    Background Amphibians in general are poor dispersers and highly philopatric, and landscape features often have important impacts on their population genetic structure and dispersal patterns. Numerous studies have suggested that genetic differentiation among amphibian populations are particularly pronounced for populations separated by mountain ridges. The Tsinling Mountain range of northern China is a major mountain chain that forms the boundary between the Oriental and Palearctic zoogeographic realms. We studied the population structure of the Chinese wood frog (Rana chensinensis) to test whether the Tsinling Mountains and the nearby Daba Mountains impose major barriers to gene flow. Results Using 13 polymorphic microsatellite DNA loci, 523 individuals from 12 breeding sites with geographical distances ranging from 2.6 to 422.8 kilometers were examined. Substantial genetic diversity was detected at all sites with an average of 25.5 alleles per locus and an expected heterozygosity ranging from 0.504 to 0.855, and two peripheral populations revealed significantly lower genetic diversity than the central populations. In addition, the genetic differentiation among the central populations was statistically significant, with pairwise FST values ranging from 0.0175 to 0.1625 with an average of 0.0878. Furthermore, hierarchical AMOVA analysis attributed most genetic variation to the within-population component, and the between-population variation can largely be explained by isolation-by-distance. None of the putative barriers detected from genetic data coincided with the location of the Tsinling Mountains. Conclusion The Tsinling and Daba Mountains revealed no significant impact on the population genetic structure of R. chensinensis. High population connectivity and extensive juvenile dispersal may account for the significant, but moderate differentiation between populations. Chinese wood frogs are able to use streams as breeding sites at high elevations, which may

  5. Big mountains but small barriers: population genetic structure of the Chinese wood frog (Rana chensinensis) in the Tsinling and Daba Mountain region of northern China.

    PubMed

    Zhan, Aibin; Li, Cheng; Fu, Jinzhong

    2009-04-09

    Amphibians in general are poor dispersers and highly philopatric, and landscape features often have important impacts on their population genetic structure and dispersal patterns. Numerous studies have suggested that genetic differentiation among amphibian populations are particularly pronounced for populations separated by mountain ridges. The Tsinling Mountain range of northern China is a major mountain chain that forms the boundary between the Oriental and Palearctic zoogeographic realms. We studied the population structure of the Chinese wood frog (Rana chensinensis) to test whether the Tsinling Mountains and the nearby Daba Mountains impose major barriers to gene flow. Using 13 polymorphic microsatellite DNA loci, 523 individuals from 12 breeding sites with geographical distances ranging from 2.6 to 422.8 kilometers were examined. Substantial genetic diversity was detected at all sites with an average of 25.5 alleles per locus and an expected heterozygosity ranging from 0.504 to 0.855, and two peripheral populations revealed significantly lower genetic diversity than the central populations. In addition, the genetic differentiation among the central populations was statistically significant, with pairwise FST values ranging from 0.0175 to 0.1625 with an average of 0.0878. Furthermore, hierarchical AMOVA analysis attributed most genetic variation to the within-population component, and the between-population variation can largely be explained by isolation-by-distance. None of the putative barriers detected from genetic data coincided with the location of the Tsinling Mountains. The Tsinling and Daba Mountains revealed no significant impact on the population genetic structure of R. chensinensis. High population connectivity and extensive juvenile dispersal may account for the significant, but moderate differentiation between populations. Chinese wood frogs are able to use streams as breeding sites at high elevations, which may significantly contribute to the

  6. Adenylate cyclase and carbonic anhydrase in the semicircular canal epithelium of the frog Rana esculenta. An ultrastructural cytochemical localization.

    PubMed

    Oudar, O; Ferrary, E; Feldmann, G

    1990-12-01

    Because the secretion of endolymph has been localized in the ampullar part of the frog semicircular canal, we attempted to determine by cytochemical methods the ultrastructural localization of two enzymes that are assumed to play a role in endolymph secretion: carbonic anhydrase and adenylate cyclase. Functionally, the epithelium of the frog semicircular canal can be schematically divided into three areas: sensory (crista ampullaris), secretory (dark cells), and non-sensory and nonsecretory (transitional and undifferentiated cells) areas. Carbonic anhydrase activity was widely distributed in dark cells. Dark cell labeling disappeared in the presence of acetazolamide. The other cells of the canal did not show any carbonic anhydrase labeling except for the supporting cells of the sensory cells. Adenylate cyclase activity was found on the basolateral and apical membranes of dark cells, and on the apical membrane of sensory cells; weak labeling was also observed in the other epithelial cells. In the apical membrane of the dark cells, adenylate cyclase labeling was dependent on the presence of vasotocin, the frog antidiuretic hormone. The dark cells of the frog semicircular canal thus possess the enzyme equipment needed for the secretion of endolymph and its possible hormonal regulation.

  7. 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

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

    PubMed

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

    2009-11-09

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

  9. 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.

  10. The complex array of bradykinin-related peptides (BRPs) in the peptidome of pickerel frog (Rana palustris) skin secretion is the product of transcriptional economy.

    PubMed

    McCrudden, Cian Michael; Zhou, Mei; Chen, Tianbao; O'Rourke, Martin; Walker, Brian; Hirst, David; Shaw, Chris

    2007-06-01

    Previous peptidomic analyses of the defensive skin secretion from the North American pickerel frog, Rana palustris, have established the presence of canonical bradykinin and multiple bradykinin-related peptides (BRPs). As a consequence of the multiplicity of peptides identified and their diverse primary structures, it was speculated that they must represent the products of expression of multiple genes. Here, we present unequivocal evidence that the majority of BRPs (11/13) identified in skin secretion by the peptidomic approach can be generated by differential site-specific protease cleavage from a single common precursor of 321 amino acid residues, named skin kininogen 1, whose primary structure was deduced from cloned skin secretion-derived cDNA. The organization of skin kininogen 1 consists of a hydrophobic signal peptide followed by eight non-identical domains each encoding a single copy of either canonical bradykinin or a BRP. Two additional splice variants, encoding precursors of 233 (skin kininogen 2) or 189 amino acid residues (skin kininogen 3), were also cloned and were found to lack BRP-encoding domains 5 and 6 or 4, 5 and 6, respectively. Thus, generation of peptidome diversity in amphibian defensive skin secretions can be achieved in part by differential protease cleavage of relatively large and multiple-encoding domain precursors reflecting a high degree of transcriptional economy.

  11. 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.

  12. Population and life-stage-specific effects of two herbicide formulations on the aquatic development of European common frogs (Rana temporaria).

    PubMed

    Wagner, Norman; Veith, Michael; Lötters, Stefan; Viertel, Bruno

    2017-01-01

    Environmental contamination is suggested to contribute to amphibian population declines. However, the effects of a contaminant on a particular amphibian species can differ among populations. The authors investigated the toxic effects of 2 herbicide formulations on different populations and on representative developmental stages of the European common frog (Rana temporaria). Larvae from forest populations were more sensitive to a commonly used glyphosate-based herbicide compared with individuals from agrarian land. Median lethal concentrations correlated with measured glyphosate levels in the breeding ponds, which may be a sign of evolved tolerances. The reverse result was observed for a less commonly used cycloxydim-based herbicide. Effects of the glyphosate-based herbicide were stronger for earlier larval stages compared with later larval stages. Hence, applications in early spring (when early larvae are present in breeding ponds) pose greater risk concerning acute toxic effects on R. temporaria. With regard to late larval stages, short exposure (96 h) of prometamorphic larvae prolonged time to metamorphosis, but only at the highest test concentration that did not significantly induce mortality. This could be due to impairment of the thyroid axis. Notably, nearly all test concentrations of the 2 herbicides provoked growth retardation. Further research on how evolved or induced tolerances are acquired, actual contamination levels of amphibian habitats, and potential endocrine effects of glyphosate-based herbicides is necessary. Environ Toxicol Chem 2017;36:190-200. © 2016 SETAC. © 2016 SETAC.

  13. Coexistence of alpha1 and beta adrenergic receptors in the liver of the frog Rana esculenta, the toad Bufo bufo, the lizard Podarcis sicula campestris, and the turtle Pseudemys picta elegans.

    PubMed

    Fabbri, E; Barbin, L; Capuzzo, A

    1997-09-01

    In mammals and birds the characteristics of alpha1 adrenergic receptors and their biological role in liver metabolism have been clearly described, although the predominance of receptor subtypes varies with species. In contrast, the actual presence of hepatic alpha1 adrenergic receptors in fish, amphibians, and reptiles has been questioned. Only recently has their existence been demonstrated in some fish species and also in the wood frog Rana sylvatica. The present study assessed the presence of alpha1 adrenergic binding sites on hepatic membranes of frogs, toads, lizards, and turtles using the specific alpha1 adrenergic receptor antagonist [3H]prazosin; for comparison, the binding of the specific beta adrenergic receptor antagonist [3H]CGP-12177A was evaluated in the same preparations. alpha1 Adrenergic receptors are indeed present in the liver of the ectotherms examined. Specific binding is saturable, reversible, and linear as a function of tissue concentration. The binding data indicated the presence of two classes of binding sites displaying high and low affinities with Kds in the nanomolar and micromolar ranges, respectively. The present study provides the first evidence for the presence of alpha1 adrenergic receptors in the liver of toad, lizard, and turtle while confirming their existence in another species of frog, Rana esculenta.

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

    PubMed Central

    Al-attar, Rasha; Zhang, Yichi

    2017-01-01

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

  15. Inbreeding and road effect zone in a Ranidae: the case of Agile frog, Rana dalmatina Bonaparte, 1840.

    PubMed

    Lesbarrères, David; Pagano, Alain; Lodé, Thierry

    2003-08-01

    Inbreeding has often been invoked in the extinction of local populations. In eleven western France populations of Agile frog studied, observed heterozygosity was significantly lower than expected in all cases, giving new evidence of such a depression in small populations. It especially occurred in ponds located near an highway rather than in undisturbed populations (FIS = 0.544 and 0.315, respectively). Thus, our results argue for a "road effect zone". Discussing about road distance and conservation policies, we propose that roads are directly involved in inbreeding and in local extinction. Thus, road construction ought to consider conservation management.

  16. Connections of the torus semicircularis and oliva superior in the frog, Rana esculenta: a Phaseolus vulgaris leucoagglutinin labeling study.

    PubMed

    Matesz, C; Kulik, A

    1996-01-01

    The afferent and efferent connections of the frog principal nucleus (TP) of torus semicircularis (TOS) and superior olive (SO) were examined by employing the anterograde and retrograde transport patterns of Phaseolus vulgaris leucoagglutinin (PHA-L). After injecting the tracer into these nuclei it was found that the TP projected to the ipsilateral posterior and central thalamic nuclei, all subdivisions of the bilateral TDS and the ipsilateral nucleus isthmi (NI). In the rhombencephalon the projection was restricted mainly to the contralateral SO and the cochlear nucleus (CN). Retrogradely labeled cells were found in most of the areas that contained anterogradely labeled terminals. The termination areas of the SO fibers were similar to the projections of fibers of TP origin in the diencephalic and in the mesencephalic auditory centers. A strong projection was followed into the contralateral SO; the CNs received fibers at both sides. Caudally to the SO the reticular formation, the spinal nucleus of the trigeminal nerve, the solitary nucleus and the dorsal column nuclei were supplied by the fibers of the SO origin. Retrogradely labeled cells were found in the TOS, tegmental nuclei, solitary nucleus, dorsal column nuclei and in the spinal nucleus of the trigeminal nerve. Our results indicate that the frog auditory pathway is more complex at the level of the secondary and tertiary fiber projections than has been previously recognized.

  17. Distribution of adrenomedullin and proadrenomedullin N-terminal 20 peptide immunoreactivity in the pituitary gland of the frog Rana perezi.

    PubMed

    Collantes, M; Bodegas, M E; Sesma, M P; Villaro, A C

    2003-08-01

    Adrenomedullin (AM) and proadrenomedullin N-terminal 20 peptide (PAMP) are two multifunctional peptides processed from a common precursor which have been described in numerous mammalian organs, including the pituitary gland. Previous studies have found AM immunoreactivity in neurohypophysis nerve fibers of amphibian pituitary. In the present study, immunocytochemical and Western blot analysis in the pituitary gland of the amphibian Rana perezi demonstrated in the adenohypophysis both AM and PAMP. AM-like immunoreactivity was found in a moderate number of endocrine cells of the pars distalis. In the neurohypophysis, AM was observed not only in nerve fibers of pars nervosa and axonal projections innervating the pars intermedia, but also in the outer zone of the median eminence. PAMP staining was observed in numerous endocrine cells scattered all over the pars distalis and in some cells of the pars tuberalis, but not in the neurohypophysis. In order to compare the quantity of AM and PAMP immunoreactivity between pars distalis of female and male specimens, an image analysis study was done. Significant differences for AM immunoreactivity (p<0.001) between sexes was found, the males showing higher immunostained area percentage. Differences of PAMP immunoreactivity were not significant (p=0.599). Western blot analysis detected bands presumably corresponding to precursor and/or intermediate species in the propeptide processing.

  18. 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

  19. Cloning and expression of genes enocoding antimicrobial peptides and bradykinin from the skin and brain of Oki Tago's brown frog, Rana tagoi okiensis.

    PubMed

    Tazato, Shoro; Conlon, J Michael; Iwamuro, Shawichi

    2010-08-01

    Previous studies led to the isolation from skin extracts of Oki Tago's brown frog, Rana tagoi okiensis of five antimicrobial peptides belonging to the brevinin-1 (brevinin-1TOa), temporin (temporin-TOa and -TOb), and ranatuerin-2 (ranatuerin-2TOa and -2TOb) families, and bradykinin (BK) identical to mammalian BK. Using the reverse-transcription polymerase chain reaction (RT-PCR), we have now cloned from skin total RNA preparations cDNAs encoding biosynthetic precursors of brevinin-1TOa and brevinin-1TOb (containing the substitution Gly(1)-->Val), temporin-TOa and -TOb, and ranatuerin-2TOa and -2TOb. In addition, three cDNA clones encoding preprobradykinins were obtained that contained either one, two, or three tandem repeats of the sequence of BK followed by the sequence of [Thr(6)]-BK. In tissue expression analyses, preprobrevinin-1, preprotemporin, and preproranatuerin-2 gene transcripts were detected at higher levels in brain compared with peripheral tissues (heart, small intestine, kidney, liver lung, skeletal muscle, stomach, and testis). RT-PCR of brain RNA resulted in the amplification of cDNAs encoding ranatuerin-2TOc and ranatuerin-2TOd that contained the amino acid substitutions Lys(6)-->Arg and Ala(14)-->Thr, respectively compared with ranatuerin-2TOb. cDNAs encoding preprobrevinin-1TOa and preprotemporin-TOa were amplified from brain RNA as well as a second preprotemporin cDNA that contained a 10-nucleotide insertion that introduced a frame shift resulting in a premature stop codon. A cDNA encoding a novel peptide, DK25 (DVNDLKNLCAKTHNLLPMCAMFGKK) was amplified from brain RNA but neither DK25 nor its putative post-translationally modified form, DF22-amide (DVNDLKNLCAKTHNLLPMCAMF.NH(2)) displayed antimicrobial or hemolytic activities. Copyright 2010 Elsevier Inc. All rights reserved.

  20. Alteration of the sex determining system resulting from structural change of the sex chromosomes in the frog Rana rugosa.

    PubMed

    Ohtani, H; Miura, I; Hanada, H; Ichikawa, Y

    2000-02-15

    Rana rugosa in Japan is divided into four geographical races on the basis of the karyotype of the sex chromosomes: one in which heteromorphic sex chromosomes occur in the female sex (ZW/ZZ-system), another in which they are present in males (XX/XY-system), and the remaining two in which no heteromorphism is seen in either sex. The last two inherit the XX/XY sex determining system. Y and Z chromosomes in the former two are of the same karyotype as the no. 7 chromosomes seen in one of the latter two, whereas X and W are caused by two inversions that occurred in the original Xs (no. 7). In this study, we first attempted to detect the structural difference between the resulting X and W by examining their chiasma formation. The chiasma distribution between X and W was closely similar to that between two Xs, suggesting that the W and X are identical in structure. Regarding the change from XX/XY- to ZW/ZZ-system, the simplest explanation is that the putative female-determining gene(s) on the W grew functionally stronger by inversions. Next, we examined the sex of triploids having two Xs and one Z. The data showed that the triploids with two original Xs and a Z were all male, whereas most of those with two resulting Xs and a Z developed into females as expected. We speculated that the female-determining gene(s) on the resulting X grew mildly stronger functionally by position effect, whereas those on the W grew much stronger for some other reason (e.g., duplication). J. Exp. Zool. 286:313-319, 2000. Copyright 2000 Wiley-Liss, Inc.

  1. The genetic contribution to sex determination and number of sex chromosomes vary among populations of common frogs (Rana temporaria).

    PubMed

    Rodrigues, N; Vuille, Y; Brelsford, A; Merilä, J; Perrin, N

    2016-07-01

    The patterns of sex determination and sex differentiation have been shown to differ among geographic populations of common frogs. Notably, the association between phenotypic sex and linkage group 2 (LG2) has been found to be perfect in a northern Swedish population, but weak and variable among families in a southern one. By analyzing these populations with markers from other linkage groups, we bring two new insights: (1) the variance in phenotypic sex not accounted for by LG2 in the southern population could not be assigned to genetic factors on other linkage groups, suggesting an epigenetic component to sex determination; (2) a second linkage group (LG7) was found to co-segregate with sex and LG2 in the northern population. Given the very short timeframe since post-glacial colonization (in the order of 1000 generations) and its seemingly localized distribution, this neo-sex chromosome system might be the youngest one described so far. It does not result from a fusion, but more likely from a reciprocal translocation between the original Y chromosome (LG2) and an autosome (LG7), causing their co-segregation during male meiosis. By generating a strict linkage between several important genes from the sex-determination cascade (Dmrt1, Amh and Amhr2), this neo-sex chromosome possibly contributes to the 'differentiated sex race' syndrome (strictly genetic sex determination and early gonadal development) that characterizes this northern population.

  2. Superimposed maps of the monocular visual fields in the caudolateral optic tectum in the frog, Rana pipiens.

    PubMed

    Winkowski, Daniel E; Gruberg, Edward R

    2005-01-01

    The superficial layers of the frog optic tectum receive a projection from the contralateral eye that forms a point-to-point map of the visual field. The monocular part of the visual field of the contralateral eye is represented in the caudolateral region of the tectum while the binocular part of the visual field is represented in the rostromedial tectum. Within the representation of the binocular field (rostromedial tectum), the maps of visual space from each eye are aligned. The tectal representation of the binocular visual field of the ipsilateral eye is mediated through a crossed projection from the midbrain nucleus isthmi. This isthmotectal projection also terminates in the caudolateral region of the optic tectum, yet there has been no indication that it forms a functional connection. By extracellular recording in intermediate layer 7 of the caudolateral tectum, we have discovered electrical activity driven by visual stimulation in the monocular visual field of the ipsilateral eye. The units driven from the ipsilateral eye burst upon initial presentation of the stimulus. At individual layer 7 recording sites in the caudolateral tectum, the multiunit receptive field evoked from the ipsilateral eye is located at the mirror image spatial location to the multiunit receptive field driven by the contralateral eye. Thus, as revealed electrophysiologically, there are superimposed topographic maps of the monocular visual fields in the caudolateral tectum. The ipsilateral eye monocular visual field representation can be abolished by electrolytic ablation of contralateral nucleus isthmi.

  3. Long-term in vivo modulation of synaptic efficacy at the neuromuscular junction of Rana pipiens frogs

    PubMed Central

    Bélair, Eve-Lyne; Vallée, Joanne; Robitaille, Richard

    2005-01-01

    Prolonged changes in motor neurone activity can result in long-term changes in synaptic transmission. We investigated whether mechanisms commonly thought to be involved in determining synaptic efficacy of vertebrate motor neurones are involved in these long-term changes. The nerve supplying the cutaneus pectoris muscle was chronically stimulated via skin surface electrodes in freely moving frogs for 5–7 days. Chronic stimulation induced a 50% reduction in evoked endplate potential (EPP) amplitude at stimulated neuromuscular junctions (NMJs). These changes appear to be presynaptic since miniature EPP (mEPP) amplitude was unchanged while mEPP frequency was decreased by 46% and paired-pulse facilitation was increased by 26%. High frequency facilitation (40 Hz, 2 s) was also increased by 89%. Moreover, stimulated NMJs presented a 92% decrease in synaptic depression (40 Hz, 2 s). An increase in mitochondrial metabolism was observed as indicated by a more pronounced labelling of active mitochondria (Mitotracker) in stimulated nerve terminals, which could account for their greater resistance to synaptic depression. NMJ length visualized by α-bungarotoxin staining of nAChRs was not affected. Presynaptic calcium signals measured with Calcium Green-1 were larger in stimulated NMJs at low frequency (0.2 Hz) and not different from control NMJs at higher frequency (40 Hz, 2 s and 30 s). These results suggest that some mechanisms downstream of calcium entry are responsible for the determination of synaptic output, such as a down-regulation of some calcium-binding proteins, which could explain the observed results. The possibility of a change in frequenin expression, a calcium-binding protein that is more prominently expressed in phasic synapses, was, however, refuted by our results. PMID:16166159

  4. [Influence of oxidative processes in mitochondria on contractility of the frog Rana temporaria heart muscle. Effects of cadmium].

    PubMed

    Shemarova, I V; Korotkov, S M; Nesterov, V P

    2011-01-01

    The inotropic Cd2+ action on frog heart is studied with taking into account its toxic effects upon mitochondria. Cd2+ at concentrations of 1, 10, and 20 microM is established to decrease dosedependently (21.3, 50.3, and 72.0%, respectively) the muscle contraction amplitude; this is explained by its competitive action on the potential-controlled Ca2(+)-channels of the L-type (Ca 1.2). In parallel experiments on isolated rat heart mitochondria (RHM) it was shown that Cd2+ at concentrations of 15 and 25 microM produces swelling of non-energized and energized mitochondria in isotonic (with KNO2 and NH4NO3) and hypoosmotic (with 25 mM CH3COOK) media. Study of oxidative processes in RHM by polarographic method has shown 20 microM Cd2+ to disturb activity of respiratory mitochondrial chain. The rate of endogenous respiration of isolated mitochondria in the medium with Cd2+ in the presence of malate and succinate was approximately 5 times lower than in control. In experimental preparations, addition into the medium of DNP-uncoupler of oxidation and phosphorylation did not cause an increase of the oxygen consumption rate. Thus, the obtained data indicate that a decrease in the cardiac muscle contractility caused by Cd2+ is due not only to its direct blocking action on Ca2(+)-channels, but also is mediated by toxic effect on rat heart mitochondria, which was manifested as an increase in ion permeability of the inner mitochondrial membrane (IMM), acceleration of the energy-dependent K+ transport into the matrix of mitochondria, and inhibition of their respiratory chain.

  5. Prevalence of skeletal and eye malformations in frogs from north-central United States: estimations based on collections from randomly selected sites

    USGS Publications Warehouse

    Schoff, P.K.; Johnson, C.M.; Schotthoefer, A.M.; Murphy, J.E.; Lieske, C.; Cole, R.A.; Johnson, L.B.; Beasley, V.R.

    2003-01-01

    Skeletal malformation rates for several frog species were determined in a set of randomly selected wetlands in the north-central USA over three consecutive years. In 1998, 62 sites yielded 389 metamorphic frogs, nine (2.3%) of which had skeletal or eye malformations. A subset of the original sites was surveyed in the following 2 yr. In 1999, 1,085 metamorphic frogs were collected from 36 sites and 17 (1.6%) had skeletal or eye malformations, while in 2000, examination of 1,131 metamorphs yielded 16 (1.4%) with skeletal or eye malformations. Hindlimb malformations predominated in all three years, but other abnormalities, involving forelimb, eye, and pelvis were also found. Northern leopard frogs (Rana pipiens) constituted the majority of collected metamorphs as well as most of the malformed specimens. However, malformations were also noted in mink frogs (R. septentrionalis), wood frogs (R. sylvatica), and gray tree frogs (Hyla spp.). The malformed specimens were found in clustered sites in all three years but the cluster locations were not the same in any year. The malformation rates reported here are higher than the 0.3% rate determined for metamorphic frogs collected from similar sites in Minnesota in the 1960s, and thus, appear to represent an elevation of an earlier baseline malformation rate.

  6. Effects of cell volume changes on membrane ionic permeabilities and sodium transport in frog skin (Rana ridibunda).

    PubMed Central

    Costa, P M; Fernandes, P L; Ferreira, H G; Ferreira, K T; Giraldez, F

    1987-01-01

    1. Membrane potential and conductances and short-circuit current were continuously measured with microelectrodes and conventional electrophysiological techniques in a stripped preparation of frog skin epithelium. The effects of the removal of chloride or sodium ions and the concentration or dilution of the serosal (inner) bathing solution were studied. 2. Chloride- or sodium-free solutions produced a cell depolarization of about 30 mV in parallel with a fall in the short-circuit current. Mucosal and serosal membrane conductances both decreased and the sodium permeability of the mucosal barrier was calculated to fall to about one-half its value in standard Ringer solution. The observed decrease in the short-circuit current is probably related to the combined effect of the decrease in sodium permeability and the decrease in the driving force across the mucosal membrane. 3. The removal of chloride or sodium ions reduced the depolarization caused by serosal perfusion with high-potassium solutions (50 mM-KCl). The ratio of the change in cell membrane potential under short-circuit conditions to the change in the potassium equilibrium potential (delta Ec(s.c.)/delta EK), was 0.59 in standard Ringer solution and 0.26 and 0.24 after the removal of chloride or sodium respectively. The depolarizing effect of barium-containing solutions (2 mM-BaCl2) was also markedly reduced in chloride- or sodium-free solutions, suggesting a decrease of the potassium selectivity of the serosal membrane in these conditions. 4. Increasing the osmolality of the serosal bathing solution produced similar effects, i.e. cell depolarization, fall in the short-circuit current and membrane conductances and reduction of the depolarizing effect of high-potassium and barium solutions. On the contrary, dilution of the serosal bath produced the opposite effects, consistent with an increase in the serosal permeability to potassium. 5. The effects of chloride- or sodium-free solutions were reversed by the

  7. ASSESSMENT OF THE RISK OF SOLAR ULTRAVIOLET RADIATION TO AMPHIBIANS. 1) DOSE-DEPENDENT INDUCTION OF HINDLIMB MALFORMATIONS IN THE NORTHERN LEOPARD FROG (RANA PIPIENS)

    EPA Science Inventory

    A number of environmental stressors have been hypothesized as responsible for seeming increases in limb malformations in several species of North American amphibians. The purpose of this study was to generate dose-response data suitable for assessing the potential role of solar u...

  8. ASSESSMENT OF THE RISK OF SOLAR ULTRAVIOLET RADIATION TO AMPHIBIANS. 1) DOSE-DEPENDENT INDUCTION OF HINDLIMB MALFORMATIONS IN THE NORTHERN LEOPARD FROG (RANA PIPIENS)

    EPA Science Inventory

    A number of environmental stressors have been hypothesized as responsible for seeming increases in limb malformations in several species of North American amphibians. The purpose of this study was to generate dose-response data suitable for assessing the potential role of solar u...

  9. Conservation in the Teaching Laboratory--Substitution of Xenopus for Rana.

    ERIC Educational Resources Information Center

    Bernhart, David M; And Others

    1991-01-01

    Reports on experimental comparisons between the leopard frog, currently captured for laboratory use, and the African clawed frog, raised specifically for research. Except for the increased longevity of isolated nerve axons in the clawed frog, no other significant differences were established. Recommends laboratory use of clawed frogs as…

  10. Conservation in the Teaching Laboratory--Substitution of Xenopus for Rana.

    ERIC Educational Resources Information Center

    Bernhart, David M; And Others

    1991-01-01

    Reports on experimental comparisons between the leopard frog, currently captured for laboratory use, and the African clawed frog, raised specifically for research. Except for the increased longevity of isolated nerve axons in the clawed frog, no other significant differences were established. Recommends laboratory use of clawed frogs as…

  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. Potential for Loss of Breeding Habitat for Imperiled Mountain Yellow-legged Frog ( Rana muscosa) in High Sierra Nevada Mountain Water Bodies due to Reduced Snowpack: Interaction of Climate Change and an Introduced Predator

    NASA Astrophysics Data System (ADS)

    Lacan, I.; Matthews, K. R.

    2005-12-01

    Year to year variation in snowpack (20-200% average) and summer rain create large fluctuations in the volume of water in ponds and small lakes of the higher elevation (> 3000 m) Sierra Nevada. These water bodies are critical habitat for the imperiled mountain yellow-legged frog, Rana muscosa, which has decreased in abundance by 90% during the past century, due in part to the loss of suitable habitat and introduction of a fish predator (trout, Oncorhynchus spp.). Climate change is predicted to reduce the amount of snowpack, potentially impacting amphibian habitats throughout the Sierra Nevada by further reducing the lake and pond water levels and resulting in drying of small lakes during the summer. Mountain yellow-legged frogs are closely tied to water during all life stages, and are unique in having a three- to four-year tadpole phase. Thus, tadpole survival and future recruitment of adult frogs requires adequate water in lakes and ponds throughout the year, but larger lakes are populated with fish that prey on frogs and tadpoles. Thus, most successful frog breeding occurs in warm, shallow, fishless ponds that undergo wide fluctuations in volume. These water bodies would be most susceptible to the potential climate change effects of reduced snowpack, possibly resulting in lower tadpole survival. This study explores the link between the changes in water availability -- including complete pond drying -- and the abundance and recruitment of mountain yellow-legged frog in Dusy Basin, Kings Canyon National Park, California, USA. We propose using the low-snowpack years (1999, 2002, 2004) as comparative case studies to predict future effects of climate change on aquatic habitat availability and amphibian abundance and survival. To quantify the year to year variation and changes in water volume available to amphibians, we initiated GPS lake mapping in 2002 to quantify water volumes, water surface area, and shoreline length. We tracked these changes by repeated mapping of

  13. Isolation and characterization of viruses from the kidneys of Rana pipiens with renal adenocarcinoma before and after passage in the red eft (Triturus viridescens).

    PubMed

    Clark, H F; Brennan, J C; Zeigel, R F; Karzon, D T

    1968-06-01

    Viruses were isolated from kidneys of normal and renal tumor-bearing Vermont Rana pipiens after subinoculation into red eft newts (Triturus viridescens). Organs of efts inoculated with viable cell suspensions from four of seven tumor-bearing kidneys yielded virus (LT-1, -2, -3, -4) when inoculated into TH-1 (Terrapene heart) cell culture. One tumor-bearing kidney also yielded virus (L-4) by direct inoculation into TH-1 cells. An additional isolate (L-5) was obtained from 1 of 52 normal Vermont frog kidneys inoculated directly into TH-1 cells. LT-1 was propagated with cytopathic effect (CPE) in each of 38 cell types tested, of fish, amphibian, reptilian, avian, and mammalian origin, at 23 or 30 C. LT-1 through LT-4, L-4 and L-5, and FV-1 through FV-3 each induced similar CPE in all cells tested. LT-2, however, induced CPE that progressed at a slower rate than that caused by the other isolates and produced smaller plaques (<0.8 mm) under starch gel overlay. Each of the viruses replicated to high titer in embryonated eggs incubated at 30 C. The viruses also grew in efts and adult newts, but not in bullfrog (Rana catesbeiana) tadpoles or adult leopard frogs. Tumor induction in adult leopard frogs inoculated with LT-1 was not demonstrated. Electron microscopic observations of LT-1 and LT-2 viruses revealed cytoplasmic particles, hexagonal in cross section, approximately 120 to 140 mmu in diameter, containing a dense nucleoid. LT-1 and LT-2 viruses were indistinguishable from FV-1 and Tipula iridescent virus. LT-1 was presumed to be a deoxyribonucleic acid virus on the basis of 5-bromodeoxyuridine inhibition. The isolates were ether-sensitive. On the basis of biological, physicochemical, and antigenic similarities, LT-1 through LT-4, L-4, L-5, FV-1 through FV-3, and isolates recently recovered from the bullfrog and the newt may represent strains of the same amphibian cytoplasmic virus.

  14. Landscape associations of frog and toad species in Iowa and Wisconsin, U.S.A

    USGS Publications Warehouse

    Knutson, M.G.; Sauer, J.R.; Olsen, D.A.; Mossman, M.J.; Hemesath, L.M.; Lannoo, M.J.; Kaiser, Hinrich; Casper, Gary S.; Bernstein, Neil P.

    2000-01-01

    Landscape habitat associations of frogs and toads in Iowa and Wisconsin were tested to determine whether they support or refute previous general habitat classifications. We examined which Midwestern species shared similar habitats to see if these associations were consistent across large geographic areas (states). Rana sylvatica (wood frog), Hyla versicolor (eastern gray treefrog), Pseudacris crucifer (spring peeper), and Acris crepitans (cricket frog) were identified as forest species, P. triseriata (chorus frog), H. chrysoscelis (Cope's gray treefrog), R. pipiens (leopard frog), and Bufo americanus (American toad) as grassland species, and R. catesbeiana (bullfrog), R. clamitans (green frog), R. palustris (pickerel frog), and R. septentrionalis (mink frog) as lake or stream species. The best candidates to serve as bioindicators of habitat quality were the forest species R. sylvatica, H. versicolor, and P. crucifer, the grassland species R. pipiens and P. triseriata, and a cold water wetland species, R. palustris. Declines of P. crucifer, R. pipiens, and R. palustris populations in one or both states may reflect changes in habitat quality. Habitat and community associations of some species differed between states, indicating that these relationships may change across the range of a species. Acris crepitans may have shifted its habitat affinities from open habitats, recorded historically, to the more forested habitat associations we recorded. We suggest contaminants deserve more investigation regarding the abrupt and widespread declines of this species. Interspersion of different habitat types was positively associated with several species. A larger number of wetland patches may increase breeding opportunities and increase the probability of at least one site being suitable. We noted consistently negative associations between anuran species and urban development. Given the current trend of urban growth and increasing density of the human population, declines of

  15. What's the Difference between Frogs and Toads?

    ERIC Educational Resources Information Center

    Brown, Herrick

    2004-01-01

    The difference between frogs and toads can be determined scientifically but is based in the historic use of the terms frog and toad. These are Old English words for the common frog, "Rana temporaria," and the common toad, "Bufo bufo," both inhabitants of the British Isles. In the process of describing a new anuran species,…

  16. What's the Difference between Frogs and Toads?

    ERIC Educational Resources Information Center

    Brown, Herrick

    2004-01-01

    The difference between frogs and toads can be determined scientifically but is based in the historic use of the terms frog and toad. These are Old English words for the common frog, "Rana temporaria," and the common toad, "Bufo bufo," both inhabitants of the British Isles. In the process of describing a new anuran species,…

  17. Balancing Selection at a Frog Antimicrobial Peptide Locus: Fluctuating Immune Effector Alleles?

    PubMed Central

    Blouin, Michael S.

    2008-01-01

    Balancing selection is common on many defense genes, but it has rarely been reported for immune effector proteins such as antimicrobial peptides (AMPs). We describe genetic diversity at a brevinin-1 AMP locus in three species of leopard frogs (Rana pipiens, Rana blairi, and Rana palustris). Several highly divergent allelic lineages are segregating at this locus. That this unusual pattern results from balancing selection is demonstrated by multiple lines of evidence, including a ratio of nonsynonymous/synonymous polymorphism significantly higher than 1, the ZnS test, incongruence between the number of segregating sites and haplotype diversity, and significant Tajima's D values. Our data are more consistent with a model of fluctuating selection in which alleles change frequencies over time than with a model of stable balancing selection such as overdominance. Evidence for fluctuating selection includes skewed allele frequencies, low levels of synonymous variation, nonneutral values of Tajima's D within allelic lineages, an inverse relationship between the frequency of an allelic lineage and its degree of polymorphism, and divergent allele frequencies among populations. AMP loci could be important sites of adaptive genetic diversity, with consequences for host–pathogen coevolution and the ability of species to resist disease epidemics. PMID:18799711

  18. LTQ Orbitrap Velos in routine de novo sequencing of non-tryptic skin peptides from the frog Rana latastei with traditional and reliable manual spectra interpretation.

    PubMed

    Samgina, Tatiana Yu; Tolpina, Miriam D; Trebse, Polonca; Torkar, Gregor; Artemenko, Konstantin A; Bergquist, Jonas; Lebedev, Albert T

    2016-01-30

    Mass spectrometry has shown itself to be the most efficient tool for the sequencing of peptides. However, de novo sequencing of novel natural peptides is significantly more challenging in comparison with the same procedure applied for the tryptic peptides. To reach the goal in this case it is essential to select the most efficient methods of triggering fragmentation and combine all the possible complementary techniques. Collision-induced dissociation (CID), high-energy collision dissociation (HCD), and electron-transfer dissociation (ETD) tandem mass spectra recorded with a LTQ Orbitrap Velos instrument were used for the elucidation of the sequence of the natural non-tryptic peptides from the skin secretion of Rana latastei. Manual interpretation of the spectra was applied. The combined approach using CID, HCD, and ETD tandem mass spectra of the multiprotonated peptides in various charge states, as well as of their proteolytic fragments, allowed the sequences of seven novel peptides from the skin secretion of Rana latastei to be established. Manual mass spectrometry sequencing of natural non-tryptic peptides from the skin secretion of Rana latastei provided the opportunity to work successfully with these species and demonstrated once again its advantage over automatic approaches.

  19. The current voltage relationship of the delayed outward current in the heart of the frog (Rana esculenta) and the tortoise (Testudo germani).

    PubMed

    de Hemptinne, A

    1978-11-30

    Steady state and non steady state I-V relationships of the resting membrane and delayed rectifying membrane were analysed by applying trapezoid voltage clamp pulses on atrial fibres isolated from the frog and the tortoise. The fibres were disposed in a perfusion chamber for double sucrose gap. In both types of preparation, a component of delayed rectification current was identified which was activated following a comparable time course. The amplitude of the delayed rectification current, when expressed either as normalized to the calculated membrane capacity or to the initial background current, is significantly larger in the frog than in the tortoise. Full activation of the delayed rectifying system can be demonstrated in the tortoise, while in the frog this process is presumably complicated by simultaneous accumulation of K ions in the extracellular region. The difference in magnitude of the delayed outward current has no influence on the duration of action potential which is recorded over the sucrose gap.

  20. Cascades frog conservation assessment

    Treesearch

    Karen Pope; Catherine Brown; Marc Hayes; Gregory Green; Diane Macfarlane

    2014-01-01

    The Cascades frog (Rana cascadae) is a montane, lentic-breeding amphibian that has become rare in the southern Cascade Range and remains relatively widespread in the Klamath Mountains of northern California. In the southern Cascades, remaining populations occur primarily in meadow habitats where the fungal disease, chytridiomycosis, and habitat...

  1. An immunocytochemical and ultrastructural study of the larval anterior intestine of the frog Rana temporaria, with especial reference to endocrine cells.

    PubMed

    Bodegas, M E; Villaro, A C; Burrell, M A; Rovira, J; Valverde, E; Ortiz De Zárate, A; Sesma, P

    1997-10-01

    Endocrine cells of the larval intestine of Rana temporaria tadpoles have been identified by argyrophilic, immunocytochemical and electron-microscopical techniques. Scarce endocrine cells have been found in both the short non-absorptive zone immediately following the stomach, and in the rest of the anterior intestine. Endocrine cells are frequently seen to extend a cytoplasmic process towards the lumen. Immunoreactivity for serotonin, somatostatin, bombesin and cholecystokinin-8 has been detected. According to the ultrastructural traits of the endocrine granules, three larval intestinal endocrine populations have been differentiated.

  2. Water molds of the genera Saprolegnia and Leptolegnia are pathogenic to the North American frogs Rana catesbeiana and Pseudacris crucifer, respectively.

    PubMed

    Ruthig, Gregory R

    2009-04-27

    Water molds are commonly associated with amphibian mortality. Since water molds often act as saprophytes, it is important to test their effects on amphibians to determine whether they can also act as pathogens. In controlled experiments, the eggs of 2 amphibian species, the American bullfrog Rana catesbeiana and the spring peeper Pseudacris crucifer, suffered higher mortality when they were exposed to zoospores of water molds of the genera Saprolegnia and Leptolegnia, respectively. Water molds are important pathogens in many amphibian systems, yet their ecological impact on amphibians remains mostly unknown.

  3. Glucose and free amino acids in the blood of lampreys (Lampetra fluviatilis L.) and frogs (Rana temporaria L.) under prolonged starvation.

    PubMed

    Emelyanova, Larisa V; Koroleva, Elena M; Savina, Margarita V

    2004-08-01

    The content variation dynamics of glucose and free amino acids in blood plasma was followed for lampreys and frogs from autumn till spring, when the exogenous feeding is switched off. In October, the glucose level is rather high (8-10 mM) in blood plasma of both lampreys and frogs. It falls by 50% during winter and falls to a critically low level (1-2 mM) during spring. The lamprey plasma amino acid levels increase by 74% from November to April and thus reach the lower limit known for mammals. The amount of free amino acids in frog plasma decreases by 40% by spring in comparison with the values in autumn. More intensive proteolysis in lamprey tissues compared with that in frog tissues has been confirmed by quantitatively determining leucine, isoleucine, and valine in the blood of these animals. Besides these three amino acids, alanine, glycine, lysine, threonine and, in certain periods, tyrosine have been found to be quantitatively significant in the plasma of both animals.

  4. Number of mast cells in the harderian gland of the green frog, Rana esculenta: the annual cycle and its relation to environmental and hormonal factors.

    PubMed Central

    Chieffi Baccari, G; Minucci, S; Marmorino, C; Vitiello Izzo, I

    1991-01-01

    The Harderian gland of the green frog contains mast cells. Their number shows annual variations, being more numerous in the winter months. The increase of mast cell number (MCN) is matched by a marked degranulation. No sex differences are found throughout the year. Manipulations of the photoperiod and temperature, either in winter or in summer, suggest that only the latter is responsible for the annual variations. Exposure to higher temperatures causes a decrease in the MCN in the winter frogs, while exposure of the summer frogs to low temperatures provokes the opposite effect. The pituitary gland also influences MCN. Hypophysectomy causes a decrease of MCN, with a return to normal following replacement therapy with homologous pars distalis homogenate. Among pituitary hormones, only ACTH mimics the effect of pars distalis homogenate. However, a possible link seems to exist between environmental (temperature) and hormonal (pituitary) factors, since hypophysectomy prevents the increase of MCN in the summer frogs exposed to low temperatures. Images Fig. 2 PMID:1817144

  5. [Histochemical determination of RNA and protein in the brain during primary sleep in the frog Rana temporaria and during intermediate sleep in the turtle Emys orbicularis].

    PubMed

    Karmanova, I G; Popova, D I; Khomutetskaia, O E; Dëmin, N N; Rubinskaia, N L

    1984-01-01

    It has been shown that resting forms of the primary sleep in the frog and intermediate sleep in the tortoise (P-1, P-2 and P-3) differ from each other with respect to neurochemical characteristics. Cytospectrophotometric studies reveal the increase in the content (per one cell) and concentration of total protein and RNA in cells of the preoptic nuclei of the frog only during one of the resting forms of the primary sleep (P-3), which represents functional homologue of the intermediate sleep of reptiles and sleep of homoiothermic animals. These anabolic changes were not observed during two other resting forms of the primary sleep, this finding being consistent with divergent development of resting forms of the primary sleep in evolution of vertebrates.

  6. The contribution of ventricular apicobasal and transmural repolarization patterns to the development of the T wave body surface potentials in frogs (Rana temporaria) and pike (Esox lucius).

    PubMed

    Vaykshnorayte, Marina A; Azarov, Jan E; Tsvetkova, Alena S; Vityazev, Vladimir A; Ovechkin, Alexey O; Shmakov, Dmitry N

    2011-05-01

    The study aimed at the simultaneous determination of the transmural and apicobasal differences in the repolarization timing and the comparison of the contributions of these two repolarization gradients to the development of the body surface T wave potentials in animals with the single heart ventricle (fishes and amphibians). Unipolar potentials were measured on the body surface, epicardium and in the intramural (subepicardial, Epi; midmyocardial; and subendocardial, Endo) ventricular layers of 9 pike and 8 frogs. Activation times, repolarization times and activation-recovery intervals were determined. A transmural gradient in repolarization durations in frogs (Endo>Epi, P<0.024) corresponds to the gradient in repolarization times. No significant transmural difference in repolarization duration is observed in pike that produces a repolarization sequence from Endo to Epi (Endofrogs.

  7. Relationship between estradiol-17 beta seasonal profile and annual vitellogenin content of liver, fat body, plasma, and ovary in the frog (Rana esculenta).

    PubMed

    Varriale, B; Pierantoni, R; Di Matteo, L; Minucci, S; Milone, M; Chieffi, G

    1988-03-01

    The seasonal plasma estradiol-17 beta (E2-17 beta) profile and annual vitellogenin content of liver, fat body, plasma, and ovary were investigated in Rana esculenta. Concomitant with the increase in E2-17 beta, vitellogenin peaked in liver, plasma, and ovary during autumn and winter, while it remained at a relatively high concentration in fat body during spring. In vitro experiments showed that E2-17 beta (10(-9) M) is ineffective in inducing vitellogenin production in fat body, but is effective in inducing vitellogenin production in liver. As fat bodies do not produce the vitellogenin they contain, we suggest that fat bodies are involved in the transfer of vitellogenin to the ovary.

  8. Immunofluorescence studies on gonadotropin releasing hormone (GRH) in the fore-brain and the neurohypophysis of the green frog, Rana esculenta L.

    PubMed

    Goos, H J; Ligtenberg, P J; van Oordt, P G

    1976-05-13

    Using antibodies against mammalian LH-RH, the double antibody-immunofluorecence technique has been applied to serial cross sections of the brains of adult Rana esculenta. Immunoreactive material was found in perikarya of an unpaired nucleus in front of the preoptic recess. The axons of these perikarya also contain fluorescing material. They form a single bundle which passes under the preoptic recess, than splits into two tracts, one on either side of the optic chiasm. The two tracts reunite just before entering the median eminence. The axons end near the capillaries in the outer zone of the median eminence. The possibility of two separate centres for the stimulation of gonadotropic activity in the brains of anurans is discussed.

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

    EPA Science Inventory

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

  10. Premitotic DNA synthesis in the brain of the adult frog (Rana esculenta L. ): An autoradiographic sup 3 H-thymidine study

    SciTech Connect

    Bernocchi, G.; Scherini, E.; Giacometti, S.; Mares, V. )

    1990-12-01

    Replicative synthesis of DNA in the brain of the adult frog was studied by light microscope autoradiography. Animals collected during the active period (May-June) and in hibernation (January) were used. In active frogs, 3H-thymidine labelling occurred mainly in the ependymal cells which line the ventricles. The mean labelling index (LI%) was higher in the ependyma of the lateral and fourth ventricles than in the ependyma of the lateral diencephalon and tectal parts of the mesencephalon. In the recessus infundibularis and preopticus the number of labelled cells (LCs) was several times greater than in the lateral parts of the third ventricle. LCs were seen subependymally only occasionally. The incidence of LCs in the parenchyma of the brain was much lower in most regions than in the ventricular ependyma; LCs were mainly small and, from their nuclear morphology, they were glial cells. The LI% reached the highest value in the septum hippocampi and in the nucleus entopeduncularis. In these locations, LCs were larger and closer in size to the nerve cells of these regions. From comparison with data obtained earlier in the brain of mammals, it is evident that the distribution of proliferating cells in the olfactory and limbic system is phylogenetically conservative. The occurrence of pyknotic cells in the same areas which contain LCs, suggests that cell division reflects in part the process of cell renewal observed in mammals. However, proliferating cells could also be linked to the continuous growth observed in non-mammalian vertebrates. In hibernating frogs, LCs and pyknoses were not seen or were found occasionally, which further indicates the functional significance of both processes.

  11. Morphological correlates of aquatic and terrestrial locomotion in a semi-aquatic frog, Rana esculenta: no evidence for a design conflict

    PubMed Central

    Nauwelaerts, Sandra; Ramsay, Jason; Aerts, Peter

    2007-01-01

    Semi-aquatic frogs are faced with an unusual locomotory challenge. They have to swim and jump using the same apparatus, i.e. the hind limbs. Optimization of two tasks that require mutually incompatible morphologies or physiologies cannot occur simultaneously. In such cases, natural selection will result in some compromise, i.e. an intermediate phenotype that can perform both tasks reasonably well, but its performance will never match that of a specialized phenotype. We found no direct evidence for a trade-off between jumping and swimming performance nor for a coupled optimization. This could be due to the importance of overall quality, as suggested by the fact that some frogs possess greater overall muscularity than others, irrespective of their body size. Another explanation could be that some morphological characteristics have a positive effect on both locomotor modes and others show a trade-off effect. The net effect of these characteristics could result in an overall absence of correlation between the two locomotor performances. Size has a great influence on the morphological data and on jumping performance, but not if performance is expressed as velocity. The body shape of an anuran is conservative and scales mostly isometrically. PMID:17331179

  12. [Effect of the level of lighting on 14C-GABA efflux from the isolated retina of the frog Rana ridibunda].

    PubMed

    Arutiunian, Zh E; Gevorgian, G A; Petrosian, A M

    1981-01-01

    Studies have been made of the effect of changes in illumination levels on 14C + GABA efflux in the isolated retina of the frog R. ridibunda. When the retina loaded with 14C-GABA is stimulated by darkness, the efflux of radioactivity immediately increases. After reaching a peak, the efflux of 14C-GABA slightly decreases attaining steady level which is higher than the level of spontaneous efflux observed during weak (approximately 0.05 lux) illumination. This high level is preserved as long as the retina remains in darkness. During illumination of the retina (transition from darkness to 60 lux), two types of response are observed. In some cases, insignificant increase of GABA efflux from the retina is followed by its rapid decrease up to the level which is observed during weak illumination. In other cases, immediately after illumination the decrease in GABA efflux takes place (in 6 experiments out of 10). In accordance with the data of Voaden [6], it is suggested that 14C + GABA is liberated from horizontal and amacrine cells. The data obtained in the present investigation are discussed in terms of Trifonov [14] and Byzov [15] hypothesis. These data confirm the idea that GABA acts as a retinal neurotransmitter in the frog.

  13. River islands, refugia and genetic structuring in the endemic brown frog Rana kukunoris (Anura, Ranidae) of the Qinghai-Tibetan Plateau.

    PubMed

    Zhou, Weiwei; Yan, Fang; Fu, Jinzhong; Wu, Shifang; Murphy, Robert W; Che, Jing; Zhang, Yaping

    2013-01-01

    Frequently, Pleistocene climatic cycling has been found to be the diver of genetic structuring in populations, even in areas that did not have continental ice sheets, such as on the Qinghai-Tibetan Plateau (QTP). Typically, species distributed on the plateau have been hypothesized to re-treat to south-eastern refugia, especially during the Last Glacial Maximum (LGM). We evaluated sequence variation in the mitochondrial DNA gene Cytb and the nuclear DNA gene RAG-1 in Rana kukunoris, a species endemic to the QTP. Two major lineages, N and S, were identified, and lineage N was further subdivided into N1 and N2. The geographical distribution and genealogical divergences supported the hypothesis of multiple refugia. However, major lineages and sublineages diverged prior to the LGM. Demographical expansion was detected only in lineage S and sublineage N2. Sublineage N1 might have survived several glacial cycles in situ and did not expand after the LGM because of the absence of suitable habitat; it survived in river islands. Genetic analysis and environment modelling suggested that the north-eastern edge of QTP contained a major refugium for R. kukunoris. From here, lineage S dispersed southwards after the LGM. Two microrefugia in northern Qilian Mountains greatly contributed to current level of intraspecific genetic diversity. These results were found to have important implications for the habitat conservation in Northwest China. © 2012 Blackwell Publishing Ltd.

  14. Density-dependent growth and metamorphosis in the larval bronze frog Rana temporalis is influenced by genetic relatedness of the cohort.

    PubMed

    Girish, S; Saidapur, S K

    2003-06-01

    Effects of density and kinship on growth and metamorphosis in tadpoles of Rana temporalis were studied in a 2 4 factorial experiment. Fifteen egg masses were collected from streams in the Western Ghat region of south India. The tadpoles were raised as siblings or in groups of non-siblings at increasing density levels, viz. 15, 30, 60 and 120/5 l water. With an increase in density level from 15 to 120 tadpoles/5 l water, duration of the larval stage increased and fewer individuals metamorphosed irrespective of whether they belonged to sibling or non-sibling groups by day 100 when the experiments were terminated. The size of individuals at metamorphosis declined significantly with increase in the density of rearing. However, at higher densities (60 and 120 tadpoles/5 l water) sibling group tadpoles performed better compared to mixed groups and took significantly less time to metamorphose. Also, more individuals of sibling groups metamorphosed compared to non-sibling groups at a given density. Mixed rearing retarded growth rates, prolonged larval duration resulting in a wider spectrum of size classes, and lowered the number of individuals recruited to terrestrial life. The study shows that interference competition occurred more strongly in cohorts of mixed relatedness than in sibling groups.

  15. [Cadmium distribution in tissues and Na,K-ATPase activity of the skin of the frog Rana temporaria in different routes of cadmium uptake by the body].

    PubMed

    Vasil'eva, V F; Gusev, G P; Krestinskaia, T V; Burovina, I V; Ukhanov, K Iu

    1987-01-01

    Accumulation, distribution of Cd in tissues and its toxic effect depend of the mode of uptake of Cd by the organism. Subcutaneous injections of Cd (0.12-0.24 mg/100 g per day) for 10 days resulted in a significant accumulation of Cd in the liver and kidney. No death cases were observed. Addition of CdCl2 to the aquatic environment (more than 0.002%) caused acute toxic effect on frogs. Within 10 days, significant amounts of Cd were found in the skin, especially in its outside layers, small amounts were found in the kidney and liver. High external concentrations of CdCl2 (0.005%) inhibited the activity of Na,K-ATPase in the skin epithelium. It is suggested that adaptive detoxication of cadmium in the liver and kidney operating in mammals, is ineffective in amphibians provided cadmium uptake occurs via the skin.

  16. 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.

  17. Effects of dibutyl phthalate as an environmental endocrine disruptor on gonadal sex differentiation of genetic males of the frog Rana rugosa.

    PubMed Central

    Ohtani, H; Miura, I; Ichikawa, Y

    2000-01-01

    To examine the effects of dibutyl phthalate (DBP) on gonadal sex differentiation, genetically male tadpoles of Rana rugosa were exposed to dilute solutions of DBP at concentrations of 0.1, 1, or 10 microM during days 19-23 after fertilization, which is the critical period of gonadal sex differentiation in R. rugosa. Tadpoles were necropsied on day 40. The genetically male tadpoles were produced from crossings between males (ZZ) of one local population, in which females are the heterogametic sex, and females (XX) of another local population, in which males are the heterogametic sex. As positive control groups, tadpoles were exposed to dilute solutions of 17beta-estradiol (E(2)) at concentrations of 0. 01, 0.1, or 1 microM during the same period. The internal structure of the gonads was histologically examined in a total of 30 control tadpoles, 86 E(2)-treated tadpoles, and 90 DBP-treated tadpoles. The gonads of the control tadpoles all showed the typical structure of testes. In contrast, 0.01, 0.1, and 1 microM E(2) treatments caused the undifferentiated gonads of 18, 63, and 100% of the tadpoles, respectively, to develop into gonads of complete or partial ovarian structure. After 0.1, 1, and 10 microM DBP treatment, 0, 7, and 17% of tadpoles, respectively, were similarly affected. These findings suggest that DBP was about 1,000-fold less potent than E(2). Nevertheless, DBP is an environmentally dangerous hormone that disrupts the pathways of testicular differentiation in genetically male animals. PMID:11133400

  18. Toward understanding the genetic basis of adaptation to high-elevation life in poikilothermic species: A comparative transcriptomic analysis of two ranid frogs, Rana chensinensis and R. kukunoris

    PubMed Central

    2012-01-01

    Background Understanding how organisms adapt to high-elevation environments at a genome scale provides novel insights into the process of adaptive evolution. Previous studies have mainly focused on endothermic organisms, while poikilothermic species may have evolved different mechanisms to cope with high-elevation environments. In this context, we sequenced transcriptomes of a pair of closely related anuran species, Rana chensinensis and R. kukunoris, which inhabit respective low- and high-elevation habitats. By comparing the two transcriptomes, we identified candidate genes that may be involved in high-elevation adaption in poikilothermic species. Results Over 66 million sequence reads from each transcriptome were generated. A total of 41,858 and 39,293 transcripts for each species were obtained by de novo assembly. By comparing the orthologous transcripts, we identified 125 protein-coding genes that have likely experienced strong positive selection (Ka/Ks>1). In addition, 335 genes that may bear a signature of positive selection (1≥Ka/Ks>0.5) were also recognized. By considering their functions, fourteen candidate genes were determined to be likely involved in high-elevation adaptation, including two CYP genes, USP-1, and several others. Conclusions We identified a set of candidate genes that may have promoted adaptation of R. kukunoris to its high-elevation environment. These include several genes that have previously been associated with oxygen binding, response to UV radiation, and repair of free radical injury. Detailed molecular, physiological, and phenotypic studies are required to better understand the roles of these genes in improving the performance of R. kukunoris in a high-elevation environment. We have evidence for both convergent and divergent evolution between endothermic and poikilothemic species, but additional research across a wide range of organisms will be necessary to comprehend the complexity of high-elevation adaptation. PMID:23116153

  19. Spatial distribution of yolk platelets and fat droplets in oocytes and cleaving embryos of the common frog (Rana temporaria) and toad (Bufo bufo).

    PubMed

    Romek, M

    1998-01-01

    Animal-vegetal gradients of fat droplets and yolk platelets have been quantitatively determined in mature oocytes and in cleaving embryos in two anuran species Rana temporaria and Bufo bufo using stereological methods. Volume densities Vv which describe properly the amount of nutrients in embryos have been used during the measurements. The embryos till the stage of late blastula are spherical: the spherical form is not distorted even by blastocoel forming eccentrically, in the animal hemisphere. Increased diameters during cleavage, which have been observed in the two species, can be ascribed to growth of the blastocoel and increased number of blastomeres while the quantity of the cytoplasm does not increase. The volume densities of yolk platelets and fat droplets per unit of cytoplasm volume remains constant throughout the cleavage. Volume densities change along the animal-vegetal axis in accordance with the course of the 3rd polynomial depending on the distance of the area under study from the vegetative pole f: y-->Vv, f = ay3 + by2 + cy + d. Parameters of fitting functions a, b, c and d change considerably during development of the embryo, which proves reorganisation of the cytoplasm during cleavage: the most significant changes occur from fertilisation to the four-cell stage and during growth of the blastocoel from morula to late blastula stage. Distortion of the axial symmetry of yolk platelet distribution in embryos occurring after fertilisation is not extensive in the two studied species. The mathematical model of spatial distribution of yolk platelets and fat droplets in oocytes and cleaving embryos in the studied anuran species was proposed using the above data.

  20. Role for corticoids in mediating the response of Rana pipiens tadpoles to intraspecific competition.

    PubMed

    Glennemeier, Karen Ann; Denver, Robert John

    2002-01-01

    Competition is known to decrease growth and development rate in tadpoles, but the physiological basis for this phenomenon is poorly understood. We hypothesized that competition results in increased production of stress hormones and that these hormones are responsible for the suppression of growth and development. To test this hypothesis, we measured whole-body corticosterone content in premetamorphic Leopard frog (Rana pipiens) tadpoles raised at two different population densities and three different food levels. Whole body corticosterone content was elevated in tadpoles subjected to either limited food (at low density) or high density. Within the low and intermediate food treatments, high density reduced tadpole growth and slowed development. Limited food slowed growth and development at all densities. Blocking corticoid synthesis by treating tadpoles with metyrapone (MTP) reversed the growth suppression caused by high density (tested in the intermediate food level treatment) but did not alter the effect of density on development rate. MTP treatment did not alter the depressive effect of limited resources on growth or development. Our results suggest that elevated corticoid biosynthesis mediates the negative effect of increased population density (i.e., increased intraspecific competition) on tadpole growth. Copyright 2002 Wiley-Liss, Inc.

  1. Experimental alteration of the relationship between the external calcium concentration and the contractile force generated by auricular trabeculae isolated from the heart of the frog, Rana pipiens.

    PubMed

    Chapman, R A

    1971-10-01

    1. The contractile strength generated by isolated frog auricular trabeculae has been determined by perfusion with high-K Ringer over a range of [Ca](o).2. Experiments are described in which the cubic relationship between the contracture tension and [Ca](o) has been changed to a square or a linear relationship.3. These results have been interpreted by proposing that three Ca compounds, whose concentrations are proportional to [Ca](o), act co-operatively at some stage of the process leading to the generation of tension.4. The change in contractile strength, determined by regular electrically evoked twitches, has been investigated at different temperatures and the results have been explained by assuming that the concentrations of the three hypothetical activating compounds vary at different rates when [Ca](o) is altered.5. The staircase response is supposed to develop as the consequence of an increase in the concentrations of the two activating Ca compounds with the slowest time constants.6. The possible physical representations of the hypothetical activating compounds are discussed.

  2. Seasonal changes in the cytomorphology of hypophyseal ACTH cells in relation to the reproduction cycle of the female of the frog Rana tigerina (Daud.).

    PubMed

    Pramoda, S; Saidapur, S K

    1991-01-01

    The hypophyseal ACTH (basophil type 3 or B3), cells of R. tigerina display seasonal changes in cytomorphology (nuclear, cytoplasm and cell area), staining intensity and cytoplasmic granulation. The cytoplasmic granules are fine and stain blackish purple with McConaill's lead haematoxylin, with Herlant's AB and the PAS and OG techniques they stain brownish red. The tinctorial response of their cytoplasm is PAS- and OG-positive and AB-negative. The B3 cells are low columnar or cuboidal in form and are smaller than the gonadotrophs (B2 cells). Towards the rostral border of the pars distalis they are larger and are associated with blood vessels, whereas in the caudal region they are smaller. Seasonal changes in the granulation and degranulation of the ACTH cells are also more prominent in the rostral region of the pars distalis than in the caudal region. During April, May and June a marked increase occurs in ACTH cell size and the number of cytoplasmic secretory granules, concurrently with events like vitellogenesis, lipid depletion from the fat bodies and breeding activity. During the post-breeding regression phase (and especially from August to November), the B3 cells decrease markedly in size and become devoid of secretory granules; their recovery begins slowly from December onwards. The findings suggest that the secretory activity of the ACTH cells in the frog undergoes seasonal changes which possibly influence vitellogenesis, lipolysis of the fat bodies and breeding activity.

  3. [T-channels and Na+,Ca2+-exchangers as components of the Ca2+-system of the myocardial activity regulation of the frog Rana temporaria].

    PubMed

    Shemarova, I V; Kuznetsov, S V; Demina, I N; Nesterov, V P

    2009-01-01

    Earlier we have shown that regulation of rhythm and strength of the frog heart contractions, mediated by transmitters of the autonomic nervous system, is of the Ca2+-character. In the present work, we studied chrono- and inotropic effect of verapamil--an inhibitor of Ca2+-channels of the L-type, of nickel chloride--an inhibitor of Ca2+-channels of the T-type, and of Na+,Ca2+-exchangers as well as of adrenaline and acetylcholine (ACh) after nickel chloride. It has been found that the intracardially administered NiCl2 at a dose of 0.01 microg/kg produced a sharp fall of amplitude of action potential (AP) and an almost twofold deceleration of heart rate (HR). The intracardiac administration of NiCl2 (0.01 microg/kg) on the background of action of verapamil (6 mg/kg, i/m) led as soon as after 3 min to even more prominent HR deceleration and to further fall of the AP amplitude by more than 50% as compared with norm. The intracardiac administration of adrenaline (0.5 mg/kg) partly restored the cardiac activity. However, preservation of the myocardium electrical activity in such animals was brief and its duration did not exceed several minutes. Administration of Ni2+ on the background of acetylcholine (3.6 mg/kg) led to almost complete cessation of cardiac activity. As soon as after 3 min after injection of this agent the HR decreased to 2 contractions/min. On EG, the 10-fold fall of the AP amplitude was recorded. The elucidate role of extra- and intracellular Ca2+ in regulation of heart contractions, isometric contraction of myocardium preparations was studied in response to action of NiCl2 (10-200 microM), verapamil (70 microM), adrenaline (5 microM), and acetylcholine (0.2 microM) after NiCl2. It is found that Ni2+ caused a dose-dependent increase of the muscle contraction amplitude. Minimal change of the contraction amplitude (on average, by 14.9% as compared with control) was recorded at a Ni2+ concentration of 100 microM. An increase of Ni2+ in the sample to 200

  4. Patch Clamp on the Luminal Membrane of Exocrine Gland Acini from Frog Skin (Rana esculenta) Reveals the Presence of Cystic Fibrosis Transmembrane Conductance Regulator–like Cl− Channels Activated by Cyclic AMP

    PubMed Central

    Sørensen, Jakob Balslev; Larsen, Erik Hviid

    1998-01-01

    Chloride channels in the luminal membrane of exocrine gland acini from frog skin (Rana esculenta) constituted a single homogeneous population. In cell-attached patches, channels activated upon exposure to isoproterenol, forskolin, or dibutyryl-cAMP and isobutyl-1-methyl-xanthine rectified in the outward direction with a conductance of 10.0 ± 0.4 pS for outgoing currents. Channels in stimulated cells reversed at 0 mV applied potential, whereas channels in unstimulated cells reversed at depolarized potentials (28.1 ± 6.7 mV), indicating that Cl− was above electrochemical equilibrium in unstimulated, but not in stimulated, cells. In excised inside-out patches with 25 mM Cl− on the inside, activity of small (8-pS) linear Cl−-selective channels was dependent upon bath ATP (1.5 mM) and increased upon exposure to cAMP-dependent protein kinase. The channels displayed a single substate, located just below 2/3 of the full channel amplitude. Halide selectivity was identified as PBr > PI > PCl from the Goldman equation; however, the conductance sequence when either halide was permeating the channel was GCl > GBr >> GI. In inside-out patches, the channels were blocked reversibly by 5-nitro-2-(3-phenylpropylamino)benzoic acid, glibenclamide, and diphenylamine-2-carboxylic acid, whereas 4,4-diisothiocyanatostilbene-2,2-disulfonic acid blocked channel activity completely and irreversibly. Single-channel kinetics revealed one open state (mean lifetime = 158 ± 72 ms) and two closed states (lifetimes: 12 ± 4 and 224 ± 31 ms, respectively). Power density spectra had a double-Lorentzian form with corner frequencies 0.85 ± 0.11 and 27.9 ± 2.9 Hz, respectively. These channels are considered homologous to the cystic fibrosis transmembrane conductance regulator Cl− channel, which has been localized to the submucosal skin glands in Xenopus by immunohistochemistry (Engelhardt, J.F., S.S. Smith, E. Allen, J.R. Yankaskas, D.C. Dawson, and J.M. Wilson. 1994. Am. J. Physiol. 267

  5. Physiological responses of freeze-tolerant and -intolerant frogs: clues to evolution of anuran freeze tolerance.

    PubMed

    Costanzo, J P; Lee, R E; Lortz, P H

    1993-10-01

    Freeze tolerance in the wood frog, Rana sylvatica, is promoted by multiple, integrated physiological responses to ice forming within body tissues. By analyzing the freezing responses of the sympatric, but freeze intolerant, leopard frog (R. pipiens), we sought clues to the evolution of anuran freeze tolerance. Physiological responses critical to R. sylvatica's freeze tolerance, such as the synthesis and distribution of the cryoprotectant glucose, protective dehydration of organs, and deferred cardiac failure, were present, but comparatively less pronounced, in R. pipiens. Both species were innately tolerant of hyperglycemia. Glucose supplements did not enhance the freezing viability of R. pipiens, although in vitro tests of cryoprotectant efficacy revealed that glucose and glycerol provided comparable protection to erythrocytes of both species. We conclude that the evolution of freeze tolerance in R. sylvatica is not only promoted by its desiccation tolerance and the fortuitous biophysical consequences of freezing (e.g., exothermic induction of cardioacceleration and moderation of cooling rate) but also involves a progressive enhancement of fundamental physiological stress responses.

  6. Smokes and Obscurants: A Guidebook of Environmental Assessment. Volume 2. A Sample Environmental Assessment

    DTIC Science & Technology

    1987-09-04

    gairdneri) have been observed in the areas below 3000 feet. Large numbers of tiger salamanders (Ambystoma tigrinium) and leopard frogs (Rana pipens...gairdneri Rainbow Trout Common Pimepholes promelas Fathead Minnow Common Abystoma tigridium Tiger Salamander Common Rana pipens Leopard Frog Comimon... leopard frogs (Rana pipens) and tiger salamanders (Ambystomo tigrinium) have been found in Grand Island Creek; they are also common species in the area. c

  7. 75 FR 8733 - Least Chub and Columbia Spotted Frog Candidate Conservation Agreement With Assurances; Receipt of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-25

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

  8. Foothill yellow-legged frog conservation assessment in California

    Treesearch

    Marc P. Hayes; Clara A. Wheeler; Amy J. Lind; Gregory A. Green; Diane C. Macfarlane

    2016-01-01

    The foothill yellow-legged frog (Rana boylii) is a stream-breeding amphibian that has experienced significant population declines over a large portion of its historical range. This frog is nearing extirpation in much of the Sierra Nevada region where existing populations are sparse. Water development and diversions are likely to be the primary...

  9. Modeling potential river management conflicts between frogs and salmonids

    Treesearch

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

    2016-01-01

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

  10. 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. (R825867)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  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. (R825867)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  12. Effects of water temperature on breeding phenology, growth and timing of metamorphosis of foothill yellow-legged frogs (Rana boylii) on the mainstem and selected tributaries of California's Trinity River - 2004-2009.

    Treesearch

    Clara Wheeler; James Bettaso; Donald Ashton; Hartwell Welsh

    2013-01-01

    The cold temperatures maintained in the Trinity River are beneficial to fish but may be problematic for foothill yellow-legged frogs. We examined the timing of breeding, reproductive output, and growth and development of tadpoles for populations of foothill yellow-legged frogs on the mainstem and six tributaries of the Trinity River. On the colder mainstem, onset of...

  13. 50 CFR 17.43 - Special rules-amphibians.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... State law will also be a violation of the Act. (b) Chiricahua leopard frog (Rana chiricahuensis). (1... of § 17.31 will apply to the Chiricahua leopard frog. (2) What activities are allowed on private, State, or Tribal land? Incidental take of the Chiricahua leopard frog will not be considered a violation...

  14. 50 CFR 17.43 - Special rules-amphibians.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... State law will also be a violation of the Act. (b) Chiricahua leopard frog (Rana chiricahuensis). (1... of § 17.31 will apply to the Chiricahua leopard frog. (2) What activities are allowed on private, State, or Tribal land? Incidental take of the Chiricahua leopard frog will not be considered a violation...

  15. LEOPARD on a personal computer

    SciTech Connect

    Lancaster, D.B.

    1988-01-01

    The LEOPARD code is very widely used to produce four- or two-group cross sections for water reactors. Although it is heavily used it had not been downloaded to the PC. This paper has been written to announce the completion of downloading LEOPARD. LEOPARD can now be run on anything from the early PC to the most advanced 80386 machines. The only requirements are 512 Kbytes of memory (LEOPARD actually only needs 235, but with buffers, 256 Kbytes may not be enough) and two disk rives (preferably, one is a hard drive). The run times for various machines and configurations are summarized. The accuracy of the PC-LEOPARD results are documented.

  16. A fatal leopard attack.

    PubMed

    Hejna, Petr

    2010-05-01

    A rare case of a big cat fatal attack is presented. A male leopard that had escaped from its unlocked cage attacked a 26-year-old male zoo worker. The man sustained penetrating injuries to the neck with consequent external bleeding. The man died while being transported to the hospital as a result of the injuries sustained. The wounds discovered on the victim's body corresponded with the known methods of leopard attacks and with findings on the carcasses of animals killed by leopards in the wild. The conclusion of the medicolegal investigation was that the underlying cause of death was a bite wound to the neck which lacerated the left internal jugular vein, the two main branches of the left external carotid artery, and the cervical spine. The cause of death was massive external bleeding. Special attention is paid to the general pattern of injuries sustained from big cat attacks.

  17. The weak link: do muscle properties determine locomotor performance in frogs?

    PubMed Central

    Roberts, Thomas J.; Abbott, Emily M.; Azizi, Emanuel

    2011-01-01

    Muscles power movement, yet the conceptual link between muscle performance and locomotor performance is poorly developed. Frog jumping provides an ideal system to probe the relationship between muscle capacity and locomotor performance, because a jump is a single discrete event and mechanical power output is a critical determinant of jump distance. We tested the hypothesis that interspecific variation in jump performance could be explained by variability in available muscle power. We used force plate ergometry to measure power produced during jumping in Cuban tree frogs (Osteopilus septentrionalis), leopard frogs (Rana pipiens) and cane toads (Bufo marinus). We also measured peak isotonic power output in isolated plantaris muscles for each species. As expected, jump performance varied widely. Osteopilus septentrionalis developed peak power outputs of 1047.0 ± 119.7 W kg−1 hindlimb muscle mass, about five times that of B. marinus (198.5 ± 54.5 W kg−1). Values for R. pipiens were intermediate (543.9 ± 96.2 W kg−1). These differences in jump power were not matched by differences in available muscle power, which were 312.7 ± 28.9, 321.8 ± 48.5 and 262.8 ± 23.2 W kg−1 muscle mass for O. septentrionalis, R. pipiens and B. marinus, respectively. The lack of correlation between available muscle power and jump power suggests that non-muscular mechanisms (e.g. elastic energy storage) can obscure the link between muscle mechanical performance and locomotor performance. PMID:21502120

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

    PubMed

    Matsui, Masafumi

    2007-02-01

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

  19. Return of the Tarahumara frog to Arizona

    Treesearch

    James C. Rorabaugh; Stephen F. Hale; Michael J. Sredl; Craig Ivanyi

    2005-01-01

    The last wild Tarahumara frog (Rana tarahumarae) in Arizona was found dead in Big Casa Blanca Canyon, Santa Rita Mountains, in May 1983. However, the species is still well represented in the majority of its range in the northern Sierra Madre Occidental and adjacent Sky Islands of Sonora and Chihuahua. Plans to re-establish R. tarahumarae...

  20. 76 FR 55413 - Proposed Safe Harbor Agreement for California Red-legged Frog, California Tiger Salamander, Smith...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-07

    ... Fish and Wildlife Service Proposed Safe Harbor Agreement for California Red-legged Frog, California... federally threatened California red-legged frog (Rana draytonii) and California tiger salamander (Ambystoma... Applicant to develop the proposed Agreement for the conservation of the California red-legged frog...

  1. 76 FR 45602 - Proposed Safe Harbor Agreement for California Red-Legged Frog, at Swallow Creek Ranch, San Luis...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-29

    ... Fish and Wildlife Service Proposed Safe Harbor Agreement for California Red-Legged Frog, at Swallow... the Federally threatened California red-legged frog (Rana draytonii), under the Endangered Species Act... California red-legged frog on the property subject to the Agreement (Enrolled Property), which is owned and...

  2. 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. © 2015 SETAC.

  3. 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.

  4. 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.

  5. 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.

  6. 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. © 2014 SETAC.

  7. Only skin deep: shared genetic response to the deadly chytrid fungus in susceptible frog species.

    PubMed

    Rosenblum, Erica Bree; Poorten, Thomas J; Settles, Matthew; Murdoch, Gordon K

    2012-07-01

    Amphibian populations around the world are threatened by an emerging infectious pathogen, the chytrid fungus Batrachochytrium dendrobatidis (Bd). How can a fungal skin infection kill such a broad range of amphibian hosts? And do different host species have a similar response to Bd infection? Here, we use a genomics approach to understand the genetic response of multiple susceptible frog species to Bd infection. We characterize the transcriptomes of two closely related endangered frog species (Rana muscosa and Rana sierrae) and analyse whole genome expression profiles from frogs in controlled Bd infection experiments. We integrate the Rana results with a comparable data set from a more distantly related susceptible species (Silurana tropicalis). We demonstrate that Bd-infected frogs show massive disruption of skin function and show no evidence of a robust immune response. The genetic response to infection is shared across the focal susceptible species, suggesting a common effect of Bd on susceptible frogs.

  8. Myofiber turnover is used to retrofit frog jaw muscles during metamorphosis.

    PubMed

    Alley, K E

    1989-01-01

    Metamorphic reorganization of the head in anuran amphibians entails abrupt restructuring of the jaw complex as larval feeding structures are transformed into their adult configurations. In this morphometric study, light microscopy wa used to analyze the larval maturation and metamorphic transfiguration of the adductor jaw muscles in the leopard frog (Rana pipiens). Larval jaw muscles, first established during embryogenesis, continue to grow by fiber addition until prometamorphosis, stage XII. Thereafter, fiber number remains stable but additional muscle growth continues by hypertrophy of the individual fibers until metamorphic climax. During metamorphic stages XIX-XXIII, a complete involution of all larval myofibers occurs. Simultaneously, within the same muscle beds, a second wave of myogenesis produces myoblasts which are the precursors of adult jaw myofibers. New muscle fibers continue to be added to these muscles well after the completion of metamorphosis; however, the total duration of the postmetamorphic myogenic period has not been defined. These observations provide clear evidence that the entir population of primary myofibers used in larval oral activity disappears from the adductor muscle beds and is replaced by a second wave of myogenesis commencing during climax. These findings indicate that the adductor jaw muscles are prepared for adult feeding by a complicated cellular process that retrofits existing muscle beds with a completely new complement of myofibers.

  9. Climatic oscillations triggered post-Messinian speciation of Western Palearctic brown frogs (Amphibia, Ranidae).

    PubMed

    Veith, M; Kosuch, J; Vences, M

    2003-02-01

    Oscillating glacial cycles over the past 2.4 million years are proposed to have had a major impact on the diversity of contemporary species communities. We used mitochondrial and nuclear DNA sequence data to infer phylogenetic relationships within Western Palearctic brown frogs and to test the influence of Pliocene and Pleistocene climatic changes on their evolution. We sequenced 1976bp of the mitochondrial genes 16S rRNA and cytochrome b and of the nuclear rhodopsin gene for all current species and subspecies. Based on an established allozyme clock for Western Palearctic water frogs and substitution rate constancy among water frogs and brown frogs, we calibrated a molecular clock for 1425bp of the 16S and rhodopsin genes. We applied this clock to date speciation events among brown frogs. Western Palearctic brown frogs underwent a basal post-Messinian radiation about 4 million years ago (mya) into five major clades: three monotypic lineages (Rana dalmatina, Rana latastei, Rana graeca), an Anatolian lineage, and a lineage comprising Rana italica, Rana arvalis, and all Iberian taxa. Polytypic lineages radiated further in concordance with the onset of climatic oscillations ca. 3.2, 2.0, and 1.0-0.6 mya, respectively. The dated fossil record corroborates our paleobiogeographic scenario. We conclude that drastic climatic changes followed by successive temperature oscillations "trapped" most brown frog species in their southern European glacial refugia with enough time to speciate. Substantial dispersal was only possible during extensive interglacial periods of a constant subtropical climate.

  10. Comparison of the intracellular membrane potentials in crystalline lenses of various frogs.

    PubMed

    Okajima, Y; Akaike, N

    1984-01-01

    The intracellular membrane potentials were measured in the individual lens fibers of three kinds of frogs (Rana catesbeiana, Rana pipiens japonica, Rana nigromata) by a conventional glass microelectrode technique, in which the electrode was advanced to a depth of 200 micron from the anterior surface into the lens interior. The maximum intracellular membrane potentials obtained in both anterior and posterior sides of all preparations were between -90 and -95 mV. The measured potentials were nearly close to the EK, and the membrane potentials in in vitro experiments correlated well with in vivo measurements. Low membrane potentials reported previously in various frog lenses were discussed in comparison with the present results.

  11. Tyzzer's disease in snow leopards.

    PubMed

    Schmidt, R E; Eisenbrandt, D L; Hubbard, G B

    1984-01-01

    Tyzzer's disease was diagnosed histologically in 2 litters of newborn snow leopard kittens. The gross and histological lesions were similar to those reported in domestic cats and other animals. No signs of illness was noted in either of the snow leopard dams.

  12. Surveys for California red-legged frog and arroyo toad on the Los Padres National Forest

    Treesearch

    Valerie K. Hubbartt; Thomas G. Murphey

    2005-01-01

    Starting in the spring of 1999 through the fall of 2000, USDA Forest Service biologists have conducted surveys throughout the Los Padres National Forest for the federally-listed California red-legged frog (Rana aurora draytonii) and arroyo toad (Bufo californicus). Sites known to have frogs or toads present were monitored for...

  13. Influence of anuran prey on the condition and distribution of Rana muscosa in the Sierra Nevada

    Treesearch

    K.L. Pope; K.R. Matthews

    2002-01-01

    Mountain yellow-legged frogs (Rana muscosa) at high elevations of the Sierra Nevada must obtain enough food during summer to survive 7–9 winter months when their aquatic habitats are frozen and food is presumably unavailable. Adults of R. muscosa prey on a variety of organisms, including aquatic and terrestrial invertebrates and...

  14. A stockpile of ova in the grass frog Rana temporaria is established once for the life span. Do ovaries in amphibians and in mammals follow the same evolutionary strategy?

    PubMed

    Ogielska, Maria; Kotusz, Agnieszka; Augustyńska, Renata; Ihnatowicz, Jerzy; Paśko, Łukasz

    2013-04-01

    Most anuran amphibians produce high numbers of eggs during several consecutive breeding seasons. The question is still open whether oocytes are formed anew as a result of oogonial proliferation after each spawning or the definitive pool of oocytes is established during the juvenile period and is sufficient for the whole reproductive life span of a female. Our quantitative studies show that primary oogonia in adult female frogs can proliferate, but they fail to differentiate further and do not enter meiosis, and thereby there is no supplementation of new generations of oocytes after each spawning. Ovaries of one-year-old grass frogs contain (median) 53,447 diplotene oocytes, in two-years-old frogs this number decreased to 33,583 and eventually reached 25,679 in virgin mature females. More than 50% decrease in the total oocyte number was accompanied by massive degeneration (atresia) of oocytes. The final number of oocytes in a female forms a stock for 11-12 breeding seasons and exceeds the number of eggs produced during the potential reproductive life span of this species. The phylogenetic context of oocyte recruitment modes in the major clades of vertebrates is discussed in respect to their ability to replenish the stock (a renewable stock in ovaries named "open" vs. a non-renewable stock in ovaries named "closed"). Copyright © 2013 Wiley Periodicals, Inc.

  15. Periodontal status in snow leopards.

    PubMed

    Cook, R A; Stoller, N H

    1986-11-01

    Periodontal examinations were performed on ten 1- to 22-year-old snow leopards (6 males and 4 females), using dentistry methods for determining the plaque and gingival indices. All tooth surfaces were probed, and alveolar bone attachment loss was determined. After subgingival plaque removal, plaque specimens were examined for differential bacterial morphotypes. The small number of leopards evaluated precluded definitive statistical analysis. However, the progression from gingival health to gingivitis to periodontitis was similar to that seen in man. Therefore, the use of plaque index, gingival index, alveolar bone attachment loss, and differential bacterial morphotypes can be used to determine the dental health of snow leopards.

  16. An early post-traumatic reaction of lymph-heart striated muscle fibers in adult frog Rana temporaria during the first postoperative week: An electron microscopic and autoradiographic study.

    PubMed

    Krylova, Marina I; Bogolyubov, Dmitry S

    2015-12-01

    According to the current opinion, lymph-heart striated muscle represents a specialized type of skeletal muscles in frogs. Here, we studied muscle fibers in mechanically damaged lymph hearts during the first postoperative week using electron-microscopic autoradiography. We present evidence that both, the satellite cells and pre-existing muscle fibers bordering the site of injury, contribute directly to the lymph-heart muscle regeneration. Several muscle fibers located in the vicinity of the damaged area displayed features of nuclear and sarcoplasmic activation. We also observed ultrastructural changes indicating activation of a few satellite cells, namely decondensation of chromatin, enlargement of nuclei and nucleoli, appearance of free ribosomes and rough endoplasmic reticulum tubules in the cytoplasm. Electron-microscopic autoradiography showed that 4 h after single (3)H-thymidine administration on the seventh day after injury not only the activated satellite cells, but also some nuclei of myofibers bordering the injured zone are labeled. We showed that both, the myonuclei of fibers displaying the signs of degenerative/reparative processes in the sarcoplasm and the myonuclei of the fibers enriched with highly organized myofibrils, can re-enter into the S-phase. Our results indicate that the nuclei of lymph-heart myofibers can reactivate DNA synthesis during regenerative myogenesis, unlike the situation in regenerating frog skeletal muscle where myogenic cells do not synthesize DNA at the onset of myofibrillogenesis.

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

    EPA Science Inventory

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

  18. Pesticides and Population Declines of California Alpine Frogs

    EPA Science Inventory

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

  19. Pesticides and Population Declines of California Alpine Frogs

    EPA Science Inventory

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

  20. Ecology of the Columbia spotted frog in northeastern Oregon.

    Treesearch

    Evelyn L. Bull

    2005-01-01

    The Columbia spotted frog (Rana luteiventris) is one of several amphibians in the Western United States experiencing population declines. The breeding, postbreeding, and overwintering habitat and ecology of this species were investigated in 10 study sites in northeastern Oregon from 1997 through 2004. A variety of habitats with permanent water were...

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

    EPA Science Inventory

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

  2. Freezing tolerance of the European water frogs: the good, the bad, and the ugly.

    PubMed

    Voituron, Yann; Joly, Pierre; Eugène, Michel; Barré, Hervé

    2005-06-01

    Survival and some physiological responses to freezing were investigated in three European water frogs (Rana lessonae, Rana ridibunda, and their hybridogen Rana esculenta). The three species exhibited different survival times during freezing (from 10 h for R. lessonae to 20 h for R. ridibunda). The time courses of percent water frozen were similar; however, because of the huge differences in body mass among species (from 10 g for Rana lessonae to nearly 100 g for Rana ridibunda), the ice mass accumulation rate varied markedly (from 0.75 +/- 0.12 to 1.43 +/- 0.11 g ice/h, respectively) and was lowest in the terrestrial hibernator Rana lessonae. The hybrid Rana esculenta exhibited an intermediate response between the two parental species; furthermore, within-species correlation existed between body mass and ice mass accumulation rates, suggesting the occurrence of subpopulations in this species (0.84 +/- 0.08 g ice/h for small R. esculenta and 1.78 +/- 0.09 g ice/h for large ones). Biochemical analyses showed accumulation of blood glucose and lactate, liver glucose (originating from glycogen), and liver alanine in Rana lessonae and Rana esculenta but not in Rana ridibunda in response to freezing. The variation of freeze tolerance between these three closely related species could bring understanding to the physiological processes involved in the evolution of freeze tolerance in vertebrates.

  3. Acid exposure is an immune disruptor in adult Rana pipiens.

    PubMed

    Vatnick, Itzick; Andrews, Jaime; Colombo, Matthew; Madhoun, Hareth; Rameswaran, Muthuramanan; Brodkin, Marc A

    2006-01-01

    Acidic environments are physiological stressors for amphibians. The objective of the present study was to document the effect of an acidic environment on innate immune system function under controlled experimental conditions in Rana pipiens. We developed an in vivo assay, by injecting a suspension of 1-microm fluorescent beads in fluid thioglycollate, to induce peritonitis. The number of peritoneal exudate leukocytes and their phagocytic activity did not increase with thioglycollate injection when frogs were exposed to pH 5.5 compared to when frogs were exposed to pH 7.0. An environment of pH 5.5 disrupted the inflammatory response of frogs compared to an environment of pH 7.0; at pH 5.5, more nonphagocytic leukocytes and fewer highly phagocytic leukocytes were found compared to those in frogs exposed to pH 7.0. Frogs stimulated by thioglycollate injection and exposed to pH 5.5 had a 50% increase in cells that did not exhibit phagocytosis and a 4- to 10-fold reduction in the number of highly phagocytic cells. This is evidence that acid exposure functions as an immune disruptor in adult R. pipiens under laboratory conditions.

  4. 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.

  5. Effect of melatonin on the spermatogenesis of Rana hexadactyla (Lesson).

    PubMed

    Kasinathan, S; Gregalatchoumi, S

    1988-04-01

    It has been reported that melatonin produces either progonadal or antigonadal effects in mammals, depending on the time and mode of administration. Information on the melatonin-effect on the testis in toads indicated varied changes during the breeding and hibernating seasons. The present study in Rana hexadactyla (Lesson), a continuous breeder revealed that administration of melatonin at a dosage of 50 micrograms/frog/day either in the morning or evening for a week inhibited spermatogenesis; however, when melatonin was administered for a longer period, this inhibitory effect was lost. Moreover, treatment with melatonin both in the morning and evening had no net effect on the testes.

  6. Population size, survival, growth, and movements of Rana sierrae

    USGS Publications Warehouse

    Fellers, Gary M.; Kleeman, Patrick M.; Miller, David A. W.; Halstead, Brian J.; Link, William

    2013-01-01

    Based on 2431 captures of 757 individual frogs over a 9-yr period, we found that the population of R. sierrae in one meadow–stream complex in Yosemite National Park ranged from an estimated 45 to 115 adult frogs. Rana sierrae at our relatively low elevation site (2200 m) grew at a fast rate (K = 0.73–0.78), had high overwintering survival rates (44.6–95%), lived a long time (up to 16 yr), and tended to be fairly sedentary during the summer (100% minimum convex polygon annual home ranges of 139 m2) but had low year-to-year site fidelity. Even though the amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) has been present in the population for at least 13 yr, there was no clear downward trend as might be expected from reports of R. sierrae population declines associated with Bd or from reports of widespread population decline of R. sierrae throughout its range.

  7. 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.

  8. Inhibitory vs. protective effects of N-acetyl-l-cysteine (NAC) on the electromechanical properties of the spontaneously beating atria of the frog (Rana ridibunda): an ex vivo study.

    PubMed

    Papaefthimiou, Chrisovalantis; Antonopoulou, Efthimia; Theophilidis, George

    2009-03-01

    The results of this study have shown that N-acetyl-l-cysteine (NAC), a compound used for protection of tissues or cell cultures against the deleterious effects of various environmental pollutants, has certain unusual effects on the contraction of the spontaneously beating atria of the frog isolated in saline (ex vivo): (1) NAC, 6.0 and 10.0mM, eliminated, in a concentration-dependent manner, the contractile properties of the atria (force and frequency) within minutes, without affecting its electrical properties; (2) the IC(50) of NAC for the force was 5.09+/-1.01 mM (n=6) [4.98-5.19 mM, 95% confidence interval (CI)], significantly lower than the IC(50) for the frequency, 6.15+/-1.01 mM, (6.02-6.29 mM, 95% CI), indicating that working atria cells are more sensitive to NAC than autorhythmic cells. The no-observed-effect concentration (NOEC) was 1-2mM; (3) the pattern of NAC-induced inhibition of electromechanical activity was similar to that of verapamil, an indication that NAC possibly affects L-type voltage-gated calcium channels; (4) NAC at 2mM protected against cadmium-induced inhibition of atria contraction. The IC(50) for cadmium was 17.9+/-1.1 microM (n=6) (16.9-19.0 microM, 95% CI), while in the presence of 2mM NAC, it became 123.3+/-1.0 microM (n=6) (114.8-132.4 microM, 95% CI). The same concentration of NAC failed to exert any protective effects against rotenone (5 microM)-induced inhibition of atria contraction. The protective effects of NAC are probably due to chelation of cadmium, rather than scavenging of oxidants.

  9. Low levels of the herbicide atrazine alter sex ratios and reduce metamorphic success in Rana pipiens tadpoles raised in outdoor mesocosms.

    PubMed

    Langlois, Valérie S; Carew, Amanda C; Pauli, Bruce D; Wade, Michael G; Cooke, Gerard M; Trudeau, Vance L

    2010-04-01

    There are conflicting reports regarding the effects of atrazine (ATZ) on amphibian development. Therefore, further studies are needed to examine the potential mechanisms of action of ATZ in amphibians. Our aim in this study was to determine whether low concentrations of ATZ affect gonadal development and metamorphosis in the Northern leopard frog, Rana pipiens. Tadpoles were exposed in outdoor mesocosms to nominal concentrations of 0.1 and 1.8 microg/L of formulated ATZ from Gosner stage 27 (G27) to metamorphic climax (G42). Exposure to 17alpha-ethinylestradiol (EE2; 1.5 microg/L) provided a positive control for induction of testicular oocytes in males. Endocrine-related gene expression and gonadal histopathology were examined at G42 and in a subset of premetamorphic G34 tadpoles that failed to metamorphose. Gonadal gross morphology revealed that the 1.8-microg/L ATZ treatment produced 20% more females compared with the control. Histologic analysis revealed that 22% of EE2-treated males had testicular oocytes, whereas none were observed in any animals from the control or either ATZ groups. ATZ increased brain estrogen receptor alpha mRNA to 2.5 times that of the control at premetamorphosis and altered liver levels of 5beta-reductase activity at metamorphosis. In contrast, brain aromatase mRNA level and activity did not change. ATZ treatments significantly reduced metamorphic success (number of animals reaching metamorphosis) without affecting body weight, snout-vent length, or age at metamorphosis. Gene expression analysis indicated that ATZ decreased the expression of deiodinase type 3 in the tail at premetamorphosis. Our study indicates that exposure to low concentrations of ATZ in experimental mesocosms alters gonadal differentiation and metamorphosis in developing R. pipiens.

  10. The first see-through frog created by breeding: description, inheritance patterns, and dermal chromatophore structure.

    PubMed

    Sumida, Masayuki; Islam, Mohammed Mafizul; Igawa, Takeshi; Kurabayashi, Atsushi; Furukawa, Yukari; Sano, Naomi; Fujii, Tamotsu; Yoshizaki, Norio

    2016-04-15

    We have succeeded in creating see-through frogs from natural color mutants of the Japanese brown frog Rana japonica, which usually possesses an ochre or brown back; this coloration enables the organs, blood vessels, and eggs to be observed through the skin without performing dissection. We crossed two kinds of recessive color mutant (black-eyed and gray-eyed) frogs through artificial insemination, and F2 offspring produced frogs whose skin is translucent throughout the life cycle. Three kinds of dermal chromatophores--xanthophores, iridophores, and melanophores--are observed in a layered arrangement in the skin of wild-type frogs, but few chromatophores were present in the skin of the see-through frogs. The translucent skin enables observation of organ growth and cancer formation and progression in the animal, which can be monitored over its entire life without the need for dissection. See-through frogs thus provide a useful animal model for environmental, medical, and biological research.

  11. Effects of adenosine perfusion on the metabolism and contractile activity of Rana ridibunda heart.

    PubMed

    Lazou, A; Beis, I

    1987-01-01

    The effects of adenosine were examined on the isolated perfused heart of the frog Rana ridibunda. Adenosine produced negative chronotropic and inotropic effects on frog ventricle in a concentration-dependent manner. The effects of adenosine on cardiac metabolism were also investigated by measuring the tissue content of adenine nucleotides, lactate, pyruvate, adenosine and inorganic phosphate, during adenosine perfusion. Adenosine had no effect on the tissue content of metabolites. No net synthesis of adenine nucleotides was observed during perfusion with increasing concentrations of adenosine. Lactate output from the heart decreased significantly with adenosine perfusion. Correlation of adenosine effects on cardiac muscle with the effects of hypoxia are discussed.

  12. Limb malformations and abnormal sex hormone concentrations in frogs.

    PubMed Central

    Sower, S A; Reed, K L; Babbitt, K J

    2000-01-01

    Declines in amphibian populations, and amphibians with gross malformations, have prompted concern regarding the biological status of many anuran species. A survey of bullfrogs, Rana catesbeiana, and green frogs, Rana clamitans, conducted in central and southern New Hampshire showed malformed frogs at 81% of the sites sampled (13 of 16 sites). Brain gonadotropin-releasing hormone (GnRH) and the synthesis of androgens and estradiol, hormones essential to reproductive processes, were measured from limb-malformed and normal (no limb malformation) frogs. Normal frogs had significantly higher concentrations (nearly 3-fold) of in vitro produced androgens and of brain GnRH than malformed frogs. Because most malformations are thought to occur during development, we propose that environmental factors or endocrine-disrupting chemicals that may cause developmental abnormalities also act during early development to ultimately cause abnormally reduced GnRH and androgen production in adult frogs. The consequences of reduced GnRH and androgens on anuran reproductive behavior and population dynamics are unknown but certainly may be profound and warrant further research. PMID:11102301

  13. Evolutionary avenues for, and constraints on, the transmission of frog lung flukes (Haematoloechus spp.) in dragonfly second intermediate hosts.

    PubMed

    Bolek, Matthew G; Janovy, John

    2007-06-01

    Metacercariae survival patterns and their distribution in second intermediate odonate hosts were examined for 4 species of frog lung flukes. Surveys of aquatic larvae and recently emerged teneral dragonflies and damselflies indicated that prevalence and mean abundance of Haematoloechus spp. metacercariae were significantly lower in teneral dragonflies than larval dragonflies, while there was no significant difference in prevalence or mean abundance of Haematoloechus spp. metacercariae among larval and teneral damselflies. Experimental infections of dragonflies indicated that metacercariae of Haematoloechus coloradensis and Haematoloechus complexus were located in the head, thorax, and branchial basket of dragonflies, whereas metacercariae of Haematoloechus longiplexus and Haematoloechus parviplexus were restricted to the branchial basket of these hosts. Metacercariae of H. coloradensis, H. complexus, and H. longiplexus infected the head, thorax, and abdomen of damselflies, but these insects were resistant to infection with H. parviplexus. Subsequent metamorphosis experiments on experimentally infected dragonflies indicated that most metacercariae of H. longiplexus were lost from the branchial basket during metamorphosis, but most metacercariae of H. coloradensis, H. complexus, and H. parviplexus survived dragonfly metamorphosis. These observations suggest that the observed ecological host specificity of H. longiplexus in semiterrestrial leopard frogs may be due to few metacercariae of H. longiplexus reaching these frogs in a terrestrial environment. Because of the uncertain validity of Haematoloechus varioplexus as a distinct species from its synonym H. parviplexus, their morphological characters were reevaluated. The morphological data on H. varioplexus and H. parviplexus indicate that they differ in their acetabulum length and width, ovary shape, testes length, and egg length and width. Experimental infections of plains leopard frogs, northern leopard frogs, and

  14. Frequency-Selective Response of the Tectorial Membrane in the Frog Basilar Papilla

    NASA Astrophysics Data System (ADS)

    Schoffelen, R. L. M.; Segenhout, J. M.; van Dijk, P.

    2009-02-01

    The frog's basilar papilla is a useful study object for cochlear mechanics, because of it's relatively simple anatomy and functionality. We investigated the displacement amplitudes of the basilar papilla's tectorial membrane in response to stimulation of the oval window at various frequencies within the auditory range of the Northern leopard frog. From our measurement data we find that the tectorial membrane exhibits a frequency selective response. The peak response was found to occur at 1500Hz in correspondence with known data for the response of auditory nerve fibers from the organ. From these data we conclude that mechanical tuning contributes significantly to the frequency selectivity of the frog's basilar papilla

  15. The Effects of Alkali Metal Cations and Common Anions on the Frog Skin Potential

    PubMed Central

    Lindley, Barry D.; Hoshiko, T.

    1964-01-01

    The effects on the potential difference across isolated frog skin (R. catesbeiana, R. pipiens) of changing the ionic composition of the bathing solutions have been examined. Estimates of mean values and precision are presented for the potential changes produced by substituting other alkali metal cations for Na at the outside border and for K at the inside border. In terms of ability to mimic Na at the outside border of bullfrog skin, the selectivity order is Li > Rb, K, Cs; at the outside border of leopard frog skin, Li > Cs, K, Rb. In terms of ability to mimic K at the inside border of bullfrog and leopard frog skin: Rb > Cs > Li > Na. Orders of anion selectivity in terms of sensitivity of the potential for the outside border of bullfrog skin are Br > Cl > NO3 > I > SO4, isethionate and of leopard frog skin are Br, Cl > I, NO3, SO4. An effect of the solution composition (ionic strength?) on the apparent Na-K selectivity of the outside border is described. The results of the investigation have been interpreted and discussed in terms of the application of the constant field equation to the Koefoed-Johnsen-Ussing frog skin model. These observations may be useful in constructing and testing models of biological ionic selectivity. PMID:14127610

  16. Humane Anesthesia and Pain Management in Amphibian Limb Surgery of Rana pipiens

    PubMed Central

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

    2013-01-01

    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 ad