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Sample records for newt notophthalmus viridescens

  1. Tetrodotoxin does not protect red-spotted newts, Notophthalmus viridescens, from intestinal parasites.

    PubMed

    Mebs, Dietrich; Yotsu-Yamashita, Mari; Seitz, Hanns Martin; Arakawa, Osamu

    2012-07-01

    Tetrodotoxin (TTX) and its analogue 6-epiTTX had been detected in the red-spotted newt, Notophthalmus viridescens. Thirty specimens of a population from Pennsylvania, USA were histologically examined for the presence of intestinal parasites. More than 50% were found to be infected with nematodes (Trichocephalidae), trematodes or cestodes (Pseudophyllidae). The mean values of TTX and 6-epiTTX in parasitized and in non-parasitized newts were not significantly different. Using a monoclonal antibody-based immunoenzymatic technique, TTX was localized in the intestinal tissue as well as in the parasites indicating that they accumulate the toxin and suggesting that TTX and 6-epiTTX are not providing protection from parasites to the newts.

  2. Growth and apoptosis during larval forelimb development and adult forelimb regeneration in the newt ( Notophthalmus viridescens).

    PubMed

    Vlaskalin, Tatjana; Wong, Christine J; Tsilfidis, Catherine

    2004-09-01

    Many of the genes involved in the initial development of the limb in higher vertebrates are also expressed during regeneration of the limb in urodeles such as Notophthalmus viridescens. These similarities have led researchers to conclude that the regeneration process is a recapitulation of development, and that patterning of the regenerate mimics pattern formation in development. However, the developing limb and the regenerating limb do not look similar. In developing urodele forelimbs, digits appear sequentially as outgrowths from the limb palette. In regeneration, all the digits appear at once. In this work, we address the issue of whether regeneration and development are similar by examining growth and apoptosis patterns. In contrast to higher vertebrates, forelimb development in the newt, N. viridescens, does not use interdigital apoptosis as the method of digit separation. During adult forelimb regeneration, apoptosis seems to play an important role in wound healing and again during cartilage to bone turnover in the advanced digits and radius/ulna. However, similar to forelimb development, demarcation of the digits in adult forelimb regeneration does not involve interdigital apoptosis. Outgrowth, rather than regression of the interdigital mesenchyme, leads to the individualization of forelimb digits in both newt development and regeneration.

  3. Keystone predators (eastern newts, Notophthalmus viridescens) reduce the impacts of an aquatic invasive species

    USGS Publications Warehouse

    Smith, Kimberly G.

    2006-01-01

    Predation, competition, and their interaction are known to be important factors that influence the structure of ecological communities. In particular, in those cases where a competitive hierarchy exists among prey species, the presence of certain keystone predators can result in enhanced diversity in the prey community. However, little is known regarding the influence of keystone predator presence on invaded prey communities. Given the widespread occurrence of invasive species and substantial concern regarding their ecological impacts, studies on this topic are needed. In this study I used naturalistic replications of an experimental tadpole assemblage to assess the influence of predatory eastern newts, Notophthalmus viridescens, on the outcome of interspecific competition among native and nonindigenous tadpoles. When newts were absent, the presence of the tadpoles of one invasive species, the Cuban treefrog, Osteopilus septentrionalis, resulted in decreased survival and growth rate of the dominant native species, Bufo terrestris, and dominance of the tadpole assemblage by O. septentrionalis. However, the presence of one adult newt generally reduced or eliminated the negative impacts of O. septentrionalis tadpoles, resulting in comparable survival and performance of native species in invaded and noninvaded treatments. Differential mortality among the tadpole species suggests that newts preyed selectively on O. septentrionalis tadpoles, supporting the hypothesis that newts acted as keystone predators in the invaded assemblage. The presence of nonindigenous larval cane toads, Bufo marinus, did not significantly affect native species, and this species was not negatively affected by the presence of newts. Collectively, these results suggest that eastern newts significantly modified the competitive hierarchy of the invaded tadpole assemblage and reduced the impacts of a competitively superior invasive species. If general, these results suggest that the presence of

  4. Toxicity of coal-tar and asphalt sealants to eastern newts, Notophthalmus viridescens.

    PubMed

    Bommarito, Thomas; Sparling, Donald W; Halbrook, Richard S

    2010-09-01

    Between 1970 and 2000 the concentration of total polycyclic aromatic hydrocarbons (TPAH) in several lakes across the country increased whereas those of other persistent organic pollutants (POPs) tended to remain stable or declined. Urbanized watersheds experienced greater rises in TPAH concentration compared to non-urban lakes. Sources for urban PAHs include industrial wastes, vehicular exhausts and oil leaks and sealants from pavement surfaces. Both coal-tar and asphalt sealants are used to protect surfaces but runoff from surfaces coated with coal-tar can have mean concentrations of 3500 mg TPAHs kg(-1), much higher than runoff from asphalt-sealed or cement surfaces. Unaltered parent compounds of PAHs can have many lethal and sublethal toxic effects, but oxidation and UV radiation can alter the toxicity of these compounds, sometimes creating degradates that are many times more toxic than parent compounds. The purposes of this study were to determine if coal-tar sealants can be toxic to adult eastern newts (Notophthalmus viridescens) and to compare the toxicity of coal-tar sealant to that of asphalt sealant. Newts were exposed to sediments containing dried sealants ranging from 0 mg kg(-1) to 1500 mg kg(-1) under simultaneous exposure to UV radiation and visible light to determine concentration/response relationships. No significant mortality occurred with any treatment. Significant effects due to sealants included decreased righting ability and diminished liver enzyme activities. Coal-tar sealant was more effective in inducing these changes than was asphalt sealant.

  5. Chemical Defense of the Eastern Newt (Notophthalmus viridescens): Variation in Efficiency against Different Consumers and in Different Habitats

    PubMed Central

    Marion, Zachary H.; Hay, Mark E.

    2011-01-01

    Amphibian secondary metabolites are well known chemically, but their ecological functions are poorly understood—even for well-studied species. For example, the eastern newt (Notophthalmus viridescens) is a well known secretor of tetrodotoxin (TTX), with this compound hypothesized to facilitate this salamander's coexistence with a variety of aquatic consumers across the eastern United States. However, this assumption of chemical defense is primarily based on observational data with low replication against only a few predator types. Therefore, we tested the hypothesis that N. viridescens is chemically defended against co-occurring fishes, invertebrates, and amphibian generalist predators and that this defense confers high survivorship when newts are transplanted into both fish-containing and fishless habitats. We found that adult eastern newts were unpalatable to predatory fishes (Micropterus salmoides, Lepomis macrochirus) and a crayfish (Procambarus clarkii), but were readily consumed by bullfrogs (Lithobates catesbeianus). The eggs and neonate larvae were also unpalatable to fish (L. macrochirus). Bioassay-guided fractionation confirmed that deterrence is chemical and that ecologically relevant concentrations of TTX would deter feeding. Despite predatory fishes rejecting eastern newts in laboratory assays, field experiments demonstrated that tethered newts suffered high rates of predation in fish-containing ponds. We suggest that this may be due to predation by amphibians (frogs) and reptiles (turtles) that co-occur with fishes rather than from fishes directly. Fishes suppress invertebrate consumers that prey on bullfrog larvae, leading to higher bullfrog densities in fish containing ponds and thus considerable consumption of newts due to bullfrog tolerance of newt chemical defenses. Amphibian chemical defenses, and consumer responses to them, may be more complex and indirect than previously appreciated. PMID:22164212

  6. Variability of tetrodotoxin and of its analogues in the red-spotted newt, Notophthalmus viridescens (Amphibia: Urodela: Salamandridae).

    PubMed

    Yotsu-Yamashita, Mari; Gilhen, John; Russell, Ronald W; Krysko, Kenneth L; Melaun, Christian; Kurz, Alexander; Kauferstein, Silke; Kordis, Dusan; Mebs, Dietrich

    2012-02-01

    Efts and adult specimens (n = 142) of the red-spotted newt Notophthalmus viridescens from various locations in Canada and USA were analyzed for the presence of tetrodotoxin (TTX) and of its analogues 6-epitetrodotoxin and 11-oxotetrodotoxin. Considerable individual variations in toxin levels were found within and among populations from New Hampshire, New York, Pennsylvania, and Virginia ranging from non-detectable to 69 μg TTX per g newt. TTX and its analogues were absent in efts and adults from various locations in the Canadian province Nova Scotia, the northernmost distribution of the newt, and in adults from Florida. Newts kept in captivity for several years and reared on toxin-free diet lost their toxicity. Bayesian and maximum likelihood phylogenetic analysis of specimens from the various populations using three phylogenetic markers (COI, ND2 and 16S RNA) revealed that populations from the northern states of the USA and Canada are genetically homogenous, whereas the newts from Florida exhibited a much higher level of genetic divergence. An exogenous source of TTX in the newts either via the food chain or by synthesis of symbiotic bacteria is suggested to explain the high variability and lack of TTX in certain populations.

  7. The thermal plasticity of locomotor performance has diverged between northern and southern populations of the eastern newt (Notophthalmus viridescens).

    PubMed

    Mineo, Patrick M; Schaeffer, Paul J

    2015-01-01

    Many temperate ectotherms undergo thermal acclimation to remain functional over a wide range of body temperatures, but few studies have investigated whether populations of a single species have evolved differences in the thermal plasticity of locomotor performance. Therefore, we asked whether the thermal plasticity of locomotor performance has diverged between northern and southern populations of eastern newts (Notophthalmus viridescens). We acclimated eastern newts from Florida and Maine to cold (6 °C) or warm (28 °C) conditions for 12 weeks. Following acclimation, we measured the burst speed of newts at 6, 11.5, 17, 22.5, 28, and 33.5 °C. We also measured the activities of creatine kinase (CK) and lactate dehydrogenase (LDH) in skeletal muscle of newts. The newts from Maine were better able to acclimate to low temperature compared to newts from Florida. Regardless of acclimation, the thermal sensitivity of burst speed was higher in the Florida compared to the Maine population. In general, newts from Maine performed better at low temperatures, whereas newts from Florida performed better at high temperatures. The activities of CK and LDH were lower in cold compared to warm-acclimated newts in the Florida population, but acclimation did not affect the activities of these enzymes in the Maine population. The activities of CK and LDH do not explain differences in the thermal plasticity of locomotor performance between populations. Our results demonstrate that the thermal sensitivity and plasticity of locomotor performance differ between northern and southern populations of eastern newts, suggesting that these traits readily adapt to the thermal environment.

  8. Intrinsic electric fields promote epithelization of wounds in the newt, Notophthalmus viridescens.

    PubMed

    Chiang, M C; Cragoe, E J; Vanable, J W

    1991-08-01

    The lateral electric fields (LFs) in the vicinity of small wounds made in hindlimb digit tip skin of Notophthalmus viridescens have been measured and manipulated. Healing of these wounds was assessed by crystal violet staining and by histology. Paired experiments were conducted on the animals: the healing of one digit's wound was compared with healing of the contralateral digit's wound whose LF was changed from that of its contralateral wound. When currents were passed through the animal (into one wound and out of the contralateral wound) so that the LF of one wound was zero while the contralateral wound had an enhanced LF, the wounds with the enhanced LF healed more rapidly than the wounds with the zero LF. When digits on one side were treated with 30 microM benzamil in an artificial pond water so that their wound LFs were reduced to approximately zero, and the contralateral wounds were kept in artificial pond water without benzamil so that they had normal wound LFs, there was significantly less epithelization of the benzamil-treated wounds than of the control wounds. This effect on wound healing was reversed by adding currents that restored the normal wound LFs, but not by adding currents that reversed the wound LFs to the opposite polarity. When currents were added to reverse the wound LFs on one side of the animal, leaving the contralateral wounds free of added currents, the wounds with the reversed LFs healed more poorly than the contralateral wounds with normal LFs. These results are consistent with the hypothesis that the intrinsic LFs in the vicinity of wounds promote epithelization of these wounds.

  9. Retinal ganglion cells in the eastern newt Notophthalmus viridescens: topography, morphology, and diversity.

    PubMed

    Pushchin, Igor I; Karetin, Yuriy A

    2009-10-20

    The topography and morphology of retinal ganglion cells (RGCs) in the eastern newt were studied. Cells were retrogradely labeled with tetramethylrhodamine-conjugated dextran amines or horseradish peroxidase and examined in retinal wholemounts. Their total number was 18,025 +/- 3,602 (mean +/- SEM). The spatial density of RGCs varied from 2,100 cells/mm(2) in the retinal periphery to 4,500 cells/mm(2) in the dorsotemporal retina. No prominent retinal specializations were found. The spatial resolution estimated from the spatial density of RGCs varied from 1.4 cycles per degree in the periphery to 1.95 cycles per degree in the region of the peak RGC density. A sample of 68 cells was camera lucida drawn and subjected to quantitative analysis. A total of 21 parameters related to RGC morphology and stratification in the retina were estimated. Partitionings obtained by using different clustering algorithms combined with automatic variable weighting and dimensionality reduction techniques were compared, and an effective solution was found by using silhouette analysis. A total of seven clusters were identified and associated with potential cell types. Kruskal-Wallis ANOVA-on-Ranks with post hoc Mann-Whitney U tests showed significant pairwise between-cluster differences in one or more of the clustering variables. The average silhouette values of the clusters were reasonably high, ranging from 0.52 to 0.79. Cells assigned to the same cluster displayed similar morphology and stratification in the retina. The advantages and limitations of the methodology adopted are discussed. The present classification is compared with known morphological and physiological RGC classifications in other salamanders.

  10. An acute increase in the stress hormone corticosterone is associated with mating behavior in both male and female red-spotted newts, Notophthalmus viridescens.

    PubMed

    Reedy, Aaron M; Edwards, Alex; Pendlebury, Chloe; Murdaugh, Laura; Avery, Ryan; Seidenberg, Jake; Aspbury, Andrea S; Gabor, Caitlin R

    2014-11-01

    Hormones play key, functional roles in mediating the tradeoff between survival and reproduction. Glucocorticoid hormones can inhibit reproduction and improve chances of survival during periods of stress. However, glucocorticoid hormones are, at times, also associated with successfully engaging in energetically costly courtship and mating behaviors. Corticosterone (CORT), a primary glucocorticoid hormone in amphibians, reptiles and birds, may be important in activating or sustaining energetically costly mating behaviors. We used a non-invasive, water-borne hormone assay to measure CORT release rates of male and female red-spotted newts (Notophthalmus viridescens) collected when either engaged in amplexus or when not engaged in amplexus. Because amplexus is energetically costly for males, we predicted that males would have higher CORT release rates than females. We also predicted that females in amplexus would have elevated CORT release rates because the restraint of amplexus prevents foraging and breathing and may be costly. Here we show that an acute increase in CORT is associated with amplexus behavior in both male and female red-spotted newts. Additionally we demonstrate that males have higher overall CORT release rates both in and out of amplexus than do females. Our results support the hypothesis that glucocorticoid hormones are associated with energetically costly courtship and mating behaviors for both sexes.

  11. Correlation of seasonal acclimatization in metabolic enzyme activity with preferred body temperature in the Eastern red spotted newt (Notophthalmus viridescens viridescens).

    PubMed

    Berner, Nancy J; Bessay, Emmanuel P

    2006-08-01

    Eastern red spotted newts, as aquatic adults, are active year round. They are small and easy to handle, and thus lent themselves to a laboratory study of seasonal changes in preferred body temperature and biochemical acclimatization. We collected newts in summer (n=20), late fall (n=10) and winter (n=5). Ten each of the summer and late fall newts were subjected to an aquatic thermal gradient. Summer newts maintained higher cloacal temperatures than late fall newts (26.8+/-0.5 degrees C and 17.2+/-0.4 degrees C, respectively). In addition, the activity of three muscle metabolic enzymes (cytochrome c oxidase (CCO), citrate synthase (CS) and lactate dehydrogenase (LDH)) was studied in all newts collected. Newts compensated for lower late fall and winter temperatures by increasing the activity of CCO during those seasons over that in summer newts at all assay temperatures (8, 16 and 26 degrees C). The activity of CS was greater in winter over summer newts at 8 and 16 degrees C. No seasonal differences in LDH activity were demonstrated. These data in newts indicate that this amphibian modifies some muscle metabolic enzymes in relation to seasonal changes and can modify its behavioral in a way that correlates with those biochemical changes.

  12. A reference transcriptome and inferred proteome for the salamander Notophthalmus viridescens.

    PubMed

    Abdullayev, Ilgar; Kirkham, Matthew; Björklund, Åsa K; Simon, András; Sandberg, Rickard

    2013-05-01

    Salamanders have a remarkable capacity to regenerate complex tissues, such as limbs and brain, and are therefore an important comparative model system for regenerative medicine. Despite these unique properties among adult vertebrates, the genomic information for amphibians in general, and salamanders in particular, is scarce. Here, we used massive parallel sequencing to reconstruct a de novo reference transcriptome of the red spotted newt (Notophthalmus viridescens) containing 118,893 transcripts with a N50 length of 2016 nts. Comparisons to other vertebrates revealed a newt transcriptome that is comparable in size and characteristics to well-annotated vertebrate transcriptomes. Identification of putative open reading frames (ORFs) enabled us to infer a comprehensive proteome, including the annotation of 19,903 newt proteins. We used the identified domain architectures (DAs) to assign ORFs phylogenetic positions, which also revealed putative salamander specific proteins. The reference transcriptome and inferred proteome of the red spotted newt will facilitate the use of systematic genomic technologies for regeneration studies in salamanders and enable evolutionary analyses of vertebrate regeneration at the molecular level.

  13. Hox C6 expression during development and regeneration of forelimbs in larval Notophthalmus viridescens.

    PubMed

    Khan, P A; Tsilfidis, C; Liversage, R A

    1999-06-01

    A central theme concerning the epimorphic regenerative potential of urodele amphibian appendages is that limb regeneration in the adult parallels larval limb development. Results of previous research have led to the suggestion that homeobox containing genes are "re-expressed" during the epimorphic regeneration of forelimbs of adult Notophthalmus viridescens in patterns which retrace larval limb development. However, to date no literature exists concerning expression patterns of any homeobox containing genes during larval development of this species. The lack of such information has been a hindrance in exploring the similarities as well as differences which exist between limb regeneration in adults and limb development in larvae. Here we report the first such results of the localization of Hox C6 (formerly, NvHBox-1) in developing and regenerating forelimbs of N. viridescens larvae as demonstrated by whole-mount in situ hybridization. Inasmuch as the pattern of Hox C6 expression is similar in developing forelimb buds of larvae and epimorphically regenerating forelimb blastemata of both adults and larvae, our results support the paradigm that epimorphic regeneration in adult newts parallels larval forelimb development. However, in contrast with observations which document the presence of Hox C6 in both intact, as well as regenerating hindlimbs and tails of adult newts, our results reveal no such Hox C6 expression during larval development of hindlimbs or the tail. As such, our findings indicate that critical differences in larval hindlimb and tail development versus adult expression patterns of this gene in these two appendages may be due primarily to differences in gene regulation as opposed to gene function. Thus, the apparent ability of urodeles to regulate genes in such a highly co-ordinated fashion so as to replace lost, differentiated, appendicular structures in adult animals may assist, at least in part, in better elucidating the phenomenon of epimorphic

  14. Modifications of the genital kidney proximal and distal tubules for sperm transport in Notophthalmus viridescens (Amphibia, Urodela, Salamandridae).

    PubMed

    Nicholson, Abbigail E; Siegel, Dustin S

    2014-08-01

    Male salamanders use nephrons from the genital kidney to transport sperm from the testicular lobules to the Wolffian duct. The microstructure of the epithelia of the genital kidney proximal tubule and distal tubule was studied over 1 year in a population of Notophthalmus viridescens from Crawford and Pike counties in central Missouri. Through ultrastructural analysis, we were able to support the hypothesis that the genital kidney nephrons are modified to aid in the transportation of sperm. A lack of folding of the basal plasma membrane, in both the genital kidney proximal and distal tubules when compared to the pelvic kidney proximal and distal tubules, reduces the surface area and thus likely decreases the efficiency of reabsorption in these nephron regions of the genital kidney. Ciliated epithelial cells are also present along the entire length of the genital kidney proximal tubule, but are lacking in the epithelium of the pelvic kidney proximal tubule. The exact function of these cilia remains unknown, but they may aid in mixing of seminal fluids or the transportation of immature sperm through the genital kidney nephrons. Ultrastructural analysis of proximal and distal tubules of the genital kidney revealed no seasonal variation in cellular activity and no mass production of seminal fluids throughout the reproductive cycle. Thus, we failed to support the hypothesis that the cellular activity of the epithelia lining the genital kidney nephrons is correlated to specific events in the reproductive cycle. The cytoplasmic contents and overall structure of the genital and pelvic kidney epithelial cells were similar to recent observations in Ambystoma maculatum, with the absence of abundant dense bodies apically in the epithelial cells lining the genital kidney distal tubule.

  15. Habitat Suitability Index Models: Red-spotted newt

    USGS Publications Warehouse

    Sousa, Patrick J.

    1985-01-01

    A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the red-spotted newt (Notophthalmus viridescens viridescens). The model consolidates habitat use information into a framework appropriate for field application, and is scaled to produce an index between 0.0 (unsuitable habitat) to 1.0 (optimum habitat). HSI models are designed to be used with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service.

  16. Data mining in newt-omics, the repository for omics data from the newt.

    PubMed

    Looso, Mario; Braun, Thomas

    2015-01-01

    Salamanders are an excellent model organism to study regenerative processes due to their unique ability to regenerate lost appendages or organs. Straightforward bioinformatics tools to analyze and take advantage of the growing number of "omics" studies performed in salamanders were lacking so far. To overcome this limitation, we have generated a comprehensive data repository for the red-spotted newt Notophthalmus viridescens, named newt-omics, merging omics style datasets on the transcriptome and proteome level including expression values and annotations. The resource is freely available via a user-friendly Web-based graphical user interface ( http://newt-omics.mpi-bn.mpg.de) that allows access and queries to the database without prior bioinformatical expertise. The repository is updated regularly, incorporating new published datasets from omics technologies.

  17. Parasite age-intensity relationships in red-spotted newts: does immune memory influence salamander disease dynamics?

    PubMed

    Raffel, Thomas R; LeGros, Robert P; Love, Brenda C; Rohr, Jason R; Hudson, Peter J

    2009-01-01

    Acquired immune memory in vertebrates influences transmission and persistence of infections, with consequences for parasite dynamics at both the individual and population levels. The potential impact of acquired immunity is of particular interest for salamanders, whose acquired immune systems are thought to be less effective than those of frogs and other tetrapods. One way to examine the importance of acquired immunity to parasite dynamics at the population level is by examining the relationship between host age and parasite infection intensity. Acquired immunity reduces infection rates in older animals, causing decreased parasite intensity in older age classes and leading to curvilinear age-intensity relationships for persistent parasites and convex age-intensity relationships for transient parasites. We used age-intensity relationships to look for the signature of acquired immunity for 12 parasite taxa of red-spotted newts (Notophthalmus viridescens), using data from a 2-year parasitological survey of six newt populations. We estimated ages from snout-vent length (SVL) based on the relationship between SVL and skeletochronologically-derived ages in a subset of newts. We found evidence of acquired immunity to two parasite taxa, bacterial pathogens and the protist Amphibiocystidium viridescens, whose convex age-intensity relationships could not be easily explained by alternative mechanisms. Our results suggest that the acquired immune response of newts is sufficient to influence the dynamics of at least some parasites.

  18. Disease dynamics of red-spotted newts and their anuran prey in a montane pond community.

    PubMed

    Rothermel, Betsie B; Miller, Debra L; Travis, Emilie R; Gonynor McGuire, Jessica L; Jensen, John B; Yabsley, Michael J

    2016-02-25

    Long-term monitoring of amphibians is needed to clarify population-level effects of ranaviruses (Rv) and the fungal pathogen Batrachochytrium dendrobatidis (Bd). We investigated disease dynamics of co-occurring amphibian species and potential demographic consequences of Rv and Bd infections at a montane site in the Southern Appalachians, Georgia, USA. Our 3-yr study was unique in combining disease surveillance with intensive population monitoring at a site where both pathogens are present. We detected sub-clinical Bd infections in larval and adult red-spotted newts Notophthalmus viridescens viridescens, but found no effect of Bd on body condition of adult newts. Bd infections also occurred in larvae of 5 anuran species that bred in our fishless study pond, and we detected co-infections with Bd and Rv in adult newts and larval green frogs Lithobates clamitans. However, all mortality and clinical signs in adult newts and larval anurans were most consistent with ranaviral disease, including a die-off of larval wood frogs Lithobates sylvaticus in small fish ponds located near our main study pond. During 2 yr of drift fence monitoring, we documented high juvenile production in newts, green frogs and American bullfrogs L. catesbeianus, but saw no evidence of juvenile recruitment in wood frogs. Larvae of this susceptible species may have suffered high mortality in the presence of both Rv and predators. Our findings were generally consistent with results of Rv-exposure experiments and support the purported role of red-spotted newts, green frogs, and American bullfrogs as common reservoirs for Bd and/or Rv in permanent and semi-permanent wetlands.

  19. A de novo assembly of the newt transcriptome combined with proteomic validation identifies new protein families expressed during tissue regeneration

    PubMed Central

    2013-01-01

    Background Notophthalmus viridescens, an urodelian amphibian, represents an excellent model organism to study regenerative processes, but mechanistic insights into molecular processes driving regeneration have been hindered by a paucity and poor annotation of coding nucleotide sequences. The enormous genome size and the lack of a closely related reference genome have so far prevented assembly of the urodelian genome. Results We describe the de novo assembly of the transcriptome of the newt Notophthalmus viridescens and its experimental validation. RNA pools covering embryonic and larval development, different stages of heart, appendage and lens regeneration, as well as a collection of different undamaged tissues were used to generate sequencing datasets on Sanger, Illumina and 454 platforms. Through a sequential de novo assembly strategy, hybrid datasets were converged into one comprehensive transcriptome comprising 120,922 non-redundant transcripts with a N50 of 975. From this, 38,384 putative transcripts were annotated and around 15,000 transcripts were experimentally validated as protein coding by mass spectrometry-based proteomics. Bioinformatical analysis of coding transcripts identified 826 proteins specific for urodeles. Several newly identified proteins establish novel protein families based on the presence of new sequence motifs without counterparts in public databases, while others containing known protein domains extend already existing families and also constitute new ones. Conclusions We demonstrate that our multistep assembly approach allows de novo assembly of the newt transcriptome with an annotation grade comparable to well characterized organisms. Our data provide the groundwork for mechanistic experiments to answer the question whether urodeles utilize proprietary sets of genes for tissue regeneration. PMID:23425577

  20. Is there more than one way to skin a newt? Convergent toxin resistance in snakes is not due to a common genetic mechanism

    PubMed Central

    Feldman, C R; Durso, A M; Hanifin, C T; Pfrender, M E; Ducey, P K; Stokes, A N; Barnett, K E; Brodie III, E D; Brodie Jr, E D

    2016-01-01

    Convergent evolution of tetrodotoxin (TTX) resistance, at both the phenotypic and genetic levels, characterizes coevolutionary arms races between amphibians and their snake predators around the world, and reveals remarkable predictability in the process of adaptation. Here we examine the repeatability of the evolution of TTX resistance in an undescribed predator–prey relationship between TTX-bearing Eastern Newts (Notophthalmus viridescens) and Eastern Hog-nosed Snakes (Heterodon platirhinos). We found that that local newts contain levels of TTX dangerous enough to dissuade most predators, and that Eastern Hog-nosed Snakes within newt range are highly resistant to TTX. In fact, these populations of Eastern Hog-nosed Snakes are so resistant to TTX that the potential for current reciprocal selection might be limited. Unlike all other cases of TTX resistance in vertebrates, H. platirhinos lacks the adaptive amino acid substitutions in the skeletal muscle sodium channel that reduce TTX binding, suggesting that physiological resistance in Eastern Hog-nosed Snakes is conferred by an alternate genetic mechanism. Thus, phenotypic convergence in this case is not due to parallel molecular evolution, indicating that there may be more than one way for this adaptation to arise, even among closely related species. PMID:26374236

  1. Transcriptome Analysis of Newt Lens Regeneration Reveals Distinct Gradients in Gene Expression Patterns

    PubMed Central

    Maki, Nobuyasu; Ivester, Clifford J.; Braun, Thomas; Tsonis, Panagiotis A.

    2013-01-01

    Regeneration of the lens in newts is quite a unique process. The lens is removed in its entirety and regeneration ensues from the pigment epithelial cells of the dorsal iris via transdifferentiation. The same type of cells from the ventral iris are not capable of regenerating a lens. It is, thus, expected that differences between dorsal and ventral iris during the process of regeneration might provide important clues pertaining to the mechanism of regeneration. In this paper, we employed next generation RNA-seq to determine gene expression patterns during lens regeneration in Notophthalmus viridescens. The expression of more than 38,000 transcripts was compared between dorsal and ventral iris. Although very few genes were found to be dorsal- or ventral-specific, certain groups of genes were up-regulated specifically in the dorsal iris. These genes are involved in cell cycle, gene regulation, cytoskeleton and immune response. In addition, the expression of six highly regulated genes, TBX5, FGF10, UNC5B, VAX2, NR2F5, and NTN1, was verified using qRT-PCR. These graded gene expression patterns provide insight into the mechanism of lens regeneration, the markers that are specific to dorsal or ventral iris, and layout a map for future studies in the field. PMID:23613853

  2. Cellular proliferation in the skin of X-rayed newt limbs (with a note on x-ray-induced limb regression)

    SciTech Connect

    Wertz, R.L.

    1982-07-01

    Left hind limbs, including the pelvis, of adult newts (Notophthalmus viridescens) were locally irradiated with a dose of x-rays that inhibited regeneration (2,000 R). This x-ray dose and other doses (700-2,000 R) capable of inhibiting limb regeneration also cause limb regression prior to amputation. Before limb regression occurred, there was a latent period of 3 to 6 weeks. Limb regression was characterized by necrotic wasting and resorption of distal elements. The degree of loss was variable and dependent upon dosage. After this further degenerative changes were not noted. Proliferation of epidermal cells was examined 4 days after irradiation prior to limb regression or after x-ray-induced degeneration of the limbs had ended. Proliferative activity in x-rayed limbs was also compared at various stages of contralateral control limb regeneration. Limbs examined after x-ray-induced limb regression had ended showed levels of (/sup 3/H)-thymidine incorporation into DNA comparable to normal epidermis. In contrast, limbs examined 4 days after irradiation had lower levels of DNA synthesis (P much less than 0.01). Amputation of limbs in both groups caused an increase in DNA synthesis (P much less than 0.01). Histological examination showed that cellular proliferation was associated primarily with the epidermis. These results indicate that epidermal cell proliferation was not resistant to x-rays. However, levels of normal cell division were observed after amputation of after cessation of x-ray-induced limb regression.

  3. The association between male-biased sex ratio and indicators of stress in red-spotted newts.

    PubMed

    Aspbury, Andrea S; Grayson, Kristine L; Fantaye, Selamawit; Nichols, Ian; Myers-Burton, Miranda; Ortiz-Mangual, Xavier; Gabor, Caitlin R

    2017-05-01

    In populations with a male-biased operational sex ratio, coercive mating by males can have fitness consequences for females. One component of reduced fitness for females in populations with a male-biased OSR may be greater activation of the stress response, resulting in higher corticosterone release rates (CORT; a glucocorticoid stress hormone in amphibians). We test the hypothesis that a male-biased sex ratio affects female activity and release rates of CORT and testosterone (T) in male and female red-spotted newts (Notophthalmus viridescens). First, we evaluated if chemical cues from a male-biased sex ratio affect activity and CORT release rates in females. We predicted that females exposed to chemical cues of three males would be less active and have higher CORT release rates than those exposed to chemical cues of one male. Second, we measured CORT release rates of red-spotted newts in field enclosures with either a male-biased or a female-biased sex ratio. We predicted that females in the male-biased treatment would have higher CORT and T release rates than those in a female-biased treatment, owing to higher levels of male harassment. We also predicted that males would have higher CORT and T release rates in male-biased treatments due to higher levels of male-male competition. Females were not less active in response to chemical cues from more males over fewer males, but there was a positive relationship between female activity and CORT when they were exposed to the cues of three males. We also found that females, but not males, in the male-biased sex ratio treatment had higher CORT and T release rates than those in the female-biased treatment. Our results support the hypothesis that a male-biased sex ratio leads to a higher stress response, which may underlie the observed decrease in immune function and body condition in previous work exposing female red-spotted newts to a male-biased sex ratio. This study furthers our understanding of the mechanistic basis

  4. A microarray analysis of gene expression patterns during early phases of newt lens regeneration

    PubMed Central

    Sousounis, Konstantinos; Michel, Christian S.; Bruckskotten, Marc; Maki, Nobuyasu; Borchardt, Thilo; Braun, Thomas; Tsonis, Panagiotis A.

    2013-01-01

    Purpose Notophthalmus viridescens, the red-spotted newt, possesses tremendous regenerative capabilities. Among the tissues and organs newts can regenerate, the lens is regenerated via transdifferentiation of the pigment epithelial cells of the dorsal iris, following complete removal (lentectomy). Under normal conditions, the same cells from the ventral iris are not capable of regenerating. This study aims to further understand the initial signals of lens regeneration. Methods We performed microarray analysis using RNA from a dorsal or ventral iris isolated 1, 3, and 5 days after lentectomy and compared to RNA isolated from an intact iris. This analysis was supported with quantitative real-time polymerase chain reaction (qRT-PCR) of selected genes. Results Microarrays showed 804 spots were differentially regulated 1, 3, and 5 days post-lentectomy in the dorsal and ventral iris. Functional annotation using Gene Ontology revealed interesting terms. Among them, factors related to cell cycle and DNA repair were mostly upregulated, in the microarray, 3 and 5 days post-lentectomy. qRT-PCR for rad1 and vascular endothelial growth factor receptor 1 showed upregulation for the dorsal iris 3 and 5 days post- lentectomy and for the ventral iris 5 days post-lentectomy. Rad1 was also upregulated twofold more in the dorsal iris than in the ventral iris 5 days post-lentectomy (p<0.001). Factors related to redox homeostasis were mostly upregulated in the microarray in all time points and samples. qRT-PCR for glutathione peroxidase 1 also showed upregulation in all time points for the ventral and dorsal iris. For the most part, mitochondrial enzymes were downregulated with the notable exception of cytochrome c–related oxidases that were mostly upregulated at all time points. qRT-PCR for cytochrome c oxidase subunit 2 showed upregulation especially 3 days post-lentectomy for the dorsal and ventral iris (p<0.001). Factors related to extracellular matrix and tissue remodeling showed

  5. Orientation and migration distances of a pond-breeding salamander (Notophthalmus perstriatus, Salamandridae)

    USGS Publications Warehouse

    Johnson, S. A.

    2003-01-01

    Habitat loss and modification have played a significant role in the decline of amphibian populations and species. Loss of wetlands, which are used as breeding sites for many amphibians, has contributed to the decline. The protection of small, isolated wetlands and core areas of associated uplands is one way in which population declines in certain species can be slowed or prevented. Nevertheless, migration distances of individuals of most amphibian species from their breeding sites are unknown. Using drift fences and pitfall traps, I studied migration distance and orientation of striped newts (Notophthalmus perstriatus) at a breeding pond in northern Florida, USA. Newts entered (immigration) and exited (emigration) the pond basin in a nonrandom fashion but no obvious effects of upland habitat were apparent. Patterns of emigration and immigration differed significantly between sexes, life-history stages, and migration events. Individuals tended to exit and enter the pond basin within the same quadrant, sometimes leaving and returning at the same point. Newts moved hundreds of meters into the sandhill uplands surrounding the pond. I found an inverse relationship between the proportion of newts migrating and distance from the pond. Nonetheless, I estimated that at least 16% of individuals breeding at the pond migrated in excess of 500 m from the pond. Thus, a core of protected upland with a radius of approximately 800 m from the pond would be needed to preserve the area used by the vast majority of individuals that breed at the pond. These data underscore the need to study upland habitat requirements for amphibians; findings for one taxon (e.g. ambystomatids) may not be applicable to others (e.g., salamandrids). Without such data, designating terrestrial core habitat to conserve aquatic-breeding amphibians will be difficult or impossible. However, without better protection of small, isolated wetlands, arguments to preserve surrounding uplands are irrelevant.

  6. Classroom Animal: Newts.

    ERIC Educational Resources Information Center

    Kramer, David C.

    1987-01-01

    Describes the habitats and life cycles of newts. Provides tips on collecting and caring for newts, along with suggestions for observational lessons related to the collection, study, and release of these organisms. (TW)

  7. Life history of the striped newt at a north-central Florida breeding pond

    USGS Publications Warehouse

    Johnson, S.A.

    2002-01-01

    I studied the life history of Striped Newts (Notophthalmus perstriatus) at a breeding pond in north-central Florida. Newts were captured in pitfall traps at a drift-fence as they migrated into and out of the pond basin. During the 2-year study, I recorded 10,290 captures (8,127 individuals) of newts at the drift-fence. Newts were active during each month of the study, but there were four peak activity periods, each of which included immigration and emigration events. Immigration events were almost exclusively comprised of adults, whereas emigration events were comprised of adults and recently transformed larvae. I documented 5,296 recently transformed, immature larvae (efts) and 435 recently transformed mature larvae (paedomorphs) during four distinct periods of emigration. Efts matured in the uplands before returning to the pond to breed. In the uplands, male efts (n = 16) grew 0.0183 mm/day on average, whereas average female (n = 24) growth was 0.0167 mm/day. Immigrating adults of both sexes were significantly smaller than emigrating adults. Emigrating efts were smallest, followed by emigrating paedomorphs, immigrating adults, then emigrating adults. The overall adult sex ratio was 1:1.25 (m:f). Sex ratio of emigrating paedomorphs was highly skewed towards females, with one male for every 4.43 females. Newts tended to move during wetter periods, and captures were significantly correlated with rainfall, but rainfall was a poor predictor of the magnitude of newt movements.

  8. Mutagenesis in Newts: Protocol for Iberian Ribbed Newts.

    PubMed

    Hayashi, Toshinori; Takeuchi, Takashi

    2016-01-01

    Newts have the remarkable capability of organ/tissue regeneration, and have been used as a unique experimental model for regenerative biology. The Iberian ribbed newt (Pleurodeles waltl) is suitable as a model animal. We have established methods for artificial insemination and efficient transgenesis using P. waltl newts. In addition to the transgenic technique, development of TALENs enables targeting mutagenesis in the newts. We have reported that TALENs efficiently disrupted targeted genes in newt embryos. In this chapter, we introduce a protocol for TALEN-mediated gene targeting in Iberian ribbed newts.

  9. A Bayesian approach on molecules and behavior: reconsidering phylogenetic and evolutionary patterns of the Salamandridae with emphasis on Triturus newts.

    PubMed

    Steinfartz, Sebastian; Vicario, Saverio; Arntzen, J W; Caccone, Adalgisa

    2007-03-15

    The monophyly of European newts of the genus Triturus within the family Salamandridae has for decades rested on presumably homologous behavioral and morphological characters. Molecular data challenge this hypothesis, but the phylogenetic position of Triturus within the Salamandridae has not yet been convincingly resolved. We addressed this issue and the temporal divergence of Triturus within the Salamandridae with novel Bayesian approaches applied to DNA sequence data from three mitochondrial genes (12S, 16S and cytb). We included 38 salamandrid species comprising all 13 recognized species of Triturus and 16 out of 17 salamandrid genera. A clade comprising all the "Newts" can be separated from the "True Salamanders" and Salamandrina clades. Within the "Newts" well-supported clades are: Tylototriton-Pleurodeles, the "New World Newts" (Notophthalmus-Taricha), and the "Modern Eurasian Newts" (Cynops, Pachytriton, Paramesotriton=together the "Modern Asian Newts", Calotriton, Euproctus, Neurergus and Triturus species). We found that Triturus is a non-monophyletic species assemblage, which includes four groups that are themselves monophyletic: (i) the "Large-Bodied Triturus" (six species), (ii) the "Small-Bodied Triturus" (five species), (iii) T. alpestris and (iv) T. vittatus. We estimated that the last common ancestor of Triturus existed around 64 million years ago (mya) while the root of the Salamandridae dates back to 95 mya. This was estimated using a fossil-based molecular dating approach and an explicit framework to select calibration points that least underestimated their corresponding nodes. Using the molecular phylogeny we mapped the evolution of life history and courtship traits in Triturus and found that several Triturus-specific courtship traits evolved independently.

  10. Astronewt: early development of newt in space

    NASA Astrophysics Data System (ADS)

    Mogami, Y.; Imamizo, M.; Yamashita, M.; Izumi-Kurotani, A.; Wiederhold, M. L.; Koike, H.; Asashima, M.

    AstroNewt experiment explores the effects of earth gravity on the early development of Japanese red-bellied newt, Cynops pyrrhogaster. Since female newts keep spermatophore in cloaca, fertilized eggs could be obtained without mating. Fertilization of newt's egg occurs just prior to spawning, so that gonadotrophic cues applied to females in orbit leads to laying eggs fertilized just in space. A property of newt being kept in hibernation at low temperature may be of great help for the space experiment carried out with much limited resources. A general outline of the AstroNewt project is shown here in addition to some technical advances for the development of the project. Experimental schemes of two space experiments (IML-2 in summer 1994 and unmanned SFU at the beginning of 1995) are also shown.

  11. Acanthagrion viridescens (Odonata: Coenagrionidae): description of the final larval stadium and biological notes.

    PubMed

    Gutiérrez, Yeisson; Freitas, Hemerson L; Oliveira, Eugênio E

    2015-12-09

    The development of the nymphal stages of Acanthagrion viridescens Leonard was examined under laboratory conditions. Based on specimens collected in Minas Gerais state (Brazilian Southeastern Region), we described and illustrated the last-instar nymph and illustrated the egg and other nymphal stages. The nymphs of A. viridescens went through 11 instars, each of them with an average duration of approximately 13 days. The combinations of the following characteristics distinguish the last-instar nymph of A. viridescens from congeners: prementum with 2+1 setae in each side; labial palp with six apical denticles; mandibular formula L 1+2 3 4 5 y a, R 1+2 3 4 5 y- a b; presence of trifid spine in the ventral distal region of the tibia and in the tarsi; format of the male and female gonapophyses; and the distinctive pattern of the tracheae in the caudal gills. This also represents the first record of this species from southeastern Brazil.

  12. Expressing exogenous genes in newts by transgenesis.

    PubMed

    Casco-Robles, Martin Miguel; Yamada, Shouta; Miura, Tomoya; Nakamura, Kenta; Haynes, Tracy; Maki, Nobuyasu; Del Rio-Tsonis, Katia; Tsonis, Panagiotis A; Chiba, Chikafumi

    2011-05-01

    The great regenerative abilities of newts provide the impetus for studies at the molecular level. However, efficient methods for gene regulation have historically been quite limited. Here we describe a protocol for transgenically expressing exogenous genes in the newt Cynops pyrrhogaster. This method is simple: a reaction mixture of I-SceI meganuclease and a plasmid DNA carrying a transgene cassette flanked by the enzyme recognition sites is directly injected into fertilized eggs. The protocol achieves a high efficiency of transgenesis, comparable to protocols used in other animal systems, and it provides a practical number of transgenic newts (∼20% of injected embryos) that survive beyond metamorphosis and that can be applied to regenerative studies. The entire protocol for obtaining transgenic adult newts takes 4-5 months.

  13. Molecular genetic system for regenerative studies using newts.

    PubMed

    Hayashi, Toshinori; Yokotani, Naoki; Tane, Shoji; Matsumoto, Akira; Myouga, Ayumi; Okamoto, Mitsumasa; Takeuchi, Takashi

    2013-02-01

    Urodele newts have the remarkable capability of organ regeneration, and have been used as a unique experimental model for more than a century. However, the mechanisms underlying regulation of the regeneration are not well understood, and gene functions in particular remain largely unknown. To elucidate gene function in regeneration, molecular genetic analyses are very powerful. In particular, it is important to establish transgenic or knockout (mutant) lines, and systematically cross these lines to study the functions of the genes. In fact, such systems have been developed for other vertebrate models. However, there is currently no experimental model system using molecular genetics for newt regenerative research due to difficulties with respect to breeding newts in the laboratory. Here, we show that the Iberian ribbed newt (Pleurodeles waltl) has outstanding properties as a laboratory newt. We developed conditions under which we can obtain a sufficient number and quality of eggs throughout the year, and shortened the period required for sexual maturation from 18 months to 6 months. In addition, P. waltl newts are known for their ability, like other newts, to regenerate various tissues. We revealed that their ability to regenerate various organs is equivalent to that of Japanese common newts. We also developed a method for efficient transgenesis. These studies demonstrate that P. waltl newts are a suitable model animal for analysis of regeneration using molecular genetics. Establishment of this experimental model will enable us to perform comparable studies using these newts and other vertebrate models.

  14. Newt prolactin and its involvement in reproduction.

    PubMed

    Kikuyama, S; Yazawa, T; Abe, S; Yamamoto, K; Iwata, T; Hoshi, K; Hasunuma, I; Mosconi, G; Polzonetti-Magni, A M

    2000-12-01

    The amino acid sequence of newt (Cynops pyrrhogaster) prolactin deduced from the nucleotide sequence of its cDNA showed a relatively high homology with sequences of chicken and sea turtle prolactins as well as with those of anuran prolactins. Cynops prolactin receptor transcripts were detected in various tissues and organs, suggesting that prolactin plays multiple roles in urodeles. Urodele prolactin was purified from the pituitaries of C. pyrrhogaster. Antiserum against this prolactin was used for radioimmunoassay of plasma prolactin and immunoneutralization experiments. Endogenous prolactin was shown to induce migration to water, courtship behavior, and cessation of spermatocytogenesis in the Cynops newt. The hormone was found to be involved in the development of cloacal glands such as the lateral and abdominal glands, growth of the tail and Mauthner neurons, secretion of oviducal jelly, and enhanced synthesis of a female attracting pheromone (sodefrin), and responsiveness of the olfactory epithelium to sodefrin. In most of these cases, prolactin was found to act synergistically or antagonistically with sex steroids. We also discovered that hypersecretion of prolactin in the newts subjected to cold temperature was induced by hypothalamic stimulation rather than release from hypothalamic inhibition.

  15. Paedogenesis in european newts (Triturus: salamandridae): cranial morphology during ontogeny.

    PubMed

    Djorović, A; Kalezić, M L

    2000-02-01

    A cross-sectional analysis using different ontogenetic stages (larvae, juveniles, paedotypic, and metamorphic adults) of the smooth newt, Triturus vulgaris, and the alpine newt, T.alpestris, revealed a broad spectrum of perennibranchiation influences on cranial ontogeny in European newts, more pronounced than previously thought. These influences included marked variation in ossification levels, pronounced morphometric variability of many cranial elements, and considerable skull shape changes in the transition from larvae to the adult stage. In comparison with metamorphosed individuals, paedotypic newts had a higher level of variability in both individual cranial traits and cranial shape changes. Sexual size difference of the skull traits was mostly negligible, especially in comparison to the influence of paedogenesis. The main changes in cranial shape of the European newts occurred during metamorphosis. Cranial morphological organization in the majority of examined paedotypes corresponds to cranial organization at late larval stages prior to metamorphosis or at the onset of metamorphosis.

  16. Fundamental differences in dedifferentiation and stem cell recruitment during skeletal muscle regeneration in two salamander species.

    PubMed

    Sandoval-Guzmán, Tatiana; Wang, Heng; Khattak, Shahryar; Schuez, Maritta; Roensch, Kathleen; Nacu, Eugeniu; Tazaki, Akira; Joven, Alberto; Tanaka, Elly M; Simon, András

    2014-02-06

    Salamanders regenerate appendages via a progenitor pool called the blastema. The cellular mechanisms underlying regeneration of muscle have been much debated but have remained unclear. Here we applied Cre-loxP genetic fate mapping to skeletal muscle during limb regeneration in two salamander species, Notophthalmus viridescens (newt) and Ambystoma mexicanum (axolotl). Remarkably, we found that myofiber dedifferentiation is an integral part of limb regeneration in the newt, but not in axolotl. In the newt, myofiber fragmentation results in proliferating, PAX7(-) mononuclear cells in the blastema that give rise to the skeletal muscle in the new limb. In contrast, myofibers in axolotl do not generate proliferating cells, and do not contribute to newly regenerated muscle; instead, resident PAX7(+) cells provide the regeneration activity. Our results therefore show significant diversity in limb muscle regeneration mechanisms among salamanders and suggest that multiple strategies may be feasible for inducing regeneration in other species, including mammals.

  17. Row erupts over axed chapter from Newt Gingrich book

    NASA Astrophysics Data System (ADS)

    Gwynne, Peter

    2012-02-01

    A chapter written by a respected climate scientist for a book co-edited by Republican presidential candidate Newt Gingrich has been canned because its author asserts that humans are responsible for climate change.

  18. Japanese red-bellied newts in Space--AstroNewt experiment on Space Shuttle IML-2 and Space Flyer Unit.

    PubMed

    Yamashita, M; Izumi-Kurotani, A; Imamizo, M; Koike, H; Okuno, M; Pfeiffer, C J; Komazaki, S; Sasaki, F; Ohira, Y; Kashima, I; Kikuyama, S; Ohnishi, T; Mogami, Y; Asashima, M

    2001-10-01

    Biological effects of gravity was examined in embryonic development of Japanese red bellied newt. Two space newt missions were conducted in 1994 and 1995. The Second International Microgravity Laboratory was flown in 1994 as one of the SpaceLab missions. Space Flyer Unit, a Japanese space platform, was delivered to the earth orbit by the third launch of the H-II rocket and retrieved by Space Shuttle in 1996. Female newts were induced to lay eggs in orbit at these two space missions. Eggs were successfully obtained on both missions, and exposed to space environment from its early developmental stages. Morphology of the embryos was found not deviated from those developed on ground, as long as in the images taken in orbit or the examined specimen retrieved to ground. On the other hand, pathological changes were discovered in several organs of the adult newts that returned alive from their space flight.

  19. [In vitro organotypic cultivation of adult newt and rat retinas].

    PubMed

    Novikova, Iu P; Aleĭnikova, K S; Krasnov, M S; Poplinskaia, V A; Grigorian, E N

    2010-01-01

    Adult rat and newt retinas were studied during long organotypic 3D cultivation. A high proliferation level was discovered in the region of growth by applying DNA synthesis markers and in vitro mitosis registration in newt retina. Aggregates were formed in the retina spheroid cavity because dedifferentiated cells migrated into this region. Small cell populations in nuclear layers also had dividing and migration capacity. Rosette formation has been shown in newt retina. It is a characteristic of fetal retinal development under pathological conditions. The antiG FAP antibody dye demonstrated an increase in the parent M@uller cell population and generation of a small cell pool with short GFAP-extensions de novo. Recoverin expression studies detected its translocation from photoreceptor extensions to the cell bodies. Moreover, protein was presented in some cells inside the spheroid. It has been shown for the first time that cell proliferation occurred in the developing adult rat retinal spheroid in vitro; BrdU-positive cells and multiple mitoses were revealed in this zone. However, the source of proliferation was not in the peripheral retina, and stable macrophages and glial cells located among neurons of the inner nuclear layer had the ability to divide. The antiGFAP antibody showed an increase in GFAP fibers in the rat retina as well as in the newt retina. Recoverin translocated into photoreceptor perikaryons and the outer plexiform layer in cultivated rat retina. Interestingly, some cells with probably de novo expression of recoverin were discovered in rat and newt retinas.

  20. Cryptic crested newt diversity at the Eurasian transition: the mitochondrial DNA phylogeography of Near Eastern Triturus newts.

    PubMed

    Wielstra, B; Themudo, G Espregueira; Güçlü, O; Olgun, K; Poyarkov, N A; Arntzen, J W

    2010-09-01

    Crested newts of the Triturus karelinii group occur in a phylogeographically understudied region: the Near East. Controversy surrounds the systematic position of these newts within the complete crested newt assemblage (the Triturus cristatus superspecies). We explore the situation using mitochondrial sequence data (ND2 and ND4, approximately 1.7kb) and employing different methods of phylogenetic inference (Bayesian inference and Maximum Likelihood using mixed models) and molecular dating (r8s and BEAST). The T. karelinii group is monophyletic and constitutes one of four main lineages in the T. cristatus superspecies. The separation of the T. karelinii group from the remaining crested newts around 9Ma is related to the formation of the Mid-Aegean Trench, which separated the Balkan and Anatolian landmasses. The T. karelinii group comprises three geographically structured clades (eastern, central and western). The genetic divergence shown by these clades is comparable to that among recognized crested newt species. We suggest the uplift of the Armenian Plateau to be responsible for the separation of the eastern clade around 7Ma, and the re-establishment of a marine connection between the Black Sea and the Mediterranean at the end of the Messinian Salinity Crisis to have caused the split between the central and western clade around 5.5Ma. Genetic structuring within the three clades dates to the Quaternary Ice Age (<2.59Ma) and is associated with alternating periods of isolation and reconnection caused by periodic changes in sea level and surface runoff.

  1. Effects of overtraining on extinction in newts (Cynops pyrrhogaster).

    PubMed

    Shibasaki, Masahiro; Ishida, Masato

    2012-11-01

    The overtraining extinction effect (OEE), a phenomenon in which extended training facilitates extinction, has been found in mammals and reptiles. However, fish have never shown OEE. No study has yet investigated OEE in newts, a representative amphibian species. We tested whether newts, Cynops pyrrhogaster, show OEE in a straight-array task. All animals received five trials per day and were given a piece of dried worm during reinforced trials. They showed significant acquisition and extinction effects in reinforced and nonreinforced trials. However, we found no difference in extinction performance between a group with 25-trial acquisition and one with 75-trial acquisition, suggesting that OEE was not found in newts. OEE has generally been explained in terms of frustration-related mechanisms. Our results suggest that emotional reactions to nonreward, such as frustration, may not influence behavior in amphibians.

  2. A developmentally regulated switch from stem cells to dedifferentiation for limb muscle regeneration in newts.

    PubMed

    Tanaka, Hibiki Vincent; Ng, Nathaniel Chuen Yin; Yang Yu, Zhan; Casco-Robles, Martin Miguel; Maruo, Fumiaki; Tsonis, Panagiotis A; Chiba, Chikafumi

    2016-03-30

    The newt, a urodele amphibian, is able to repeatedly regenerate its limbs throughout its lifespan, whereas other amphibians deteriorate or lose their ability to regenerate limbs after metamorphosis. It remains to be determined whether such an exceptional ability of the newt is either attributed to a strategy, which controls regeneration in larvae, or on a novel one invented by the newt after metamorphosis. Here we report that the newt switches the cellular mechanism for limb regeneration from a stem/progenitor-based mechanism (larval mode) to a dedifferentiation-based one (adult mode) as it transits beyond metamorphosis. We demonstrate that larval newts use stem/progenitor cells such as satellite cells for new muscle in a regenerated limb, whereas metamorphosed newts recruit muscle fibre cells in the stump for the same purpose. We conclude that the newt has evolved novel strategies to secure its regenerative ability of the limbs after metamorphosis.

  3. A developmentally regulated switch from stem cells to dedifferentiation for limb muscle regeneration in newts

    PubMed Central

    Tanaka, Hibiki Vincent; Ng, Nathaniel Chuen Yin; Yang Yu, Zhan; Casco-Robles, Martin Miguel; Maruo, Fumiaki; Tsonis, Panagiotis A.; Chiba, Chikafumi

    2016-01-01

    The newt, a urodele amphibian, is able to repeatedly regenerate its limbs throughout its lifespan, whereas other amphibians deteriorate or lose their ability to regenerate limbs after metamorphosis. It remains to be determined whether such an exceptional ability of the newt is either attributed to a strategy, which controls regeneration in larvae, or on a novel one invented by the newt after metamorphosis. Here we report that the newt switches the cellular mechanism for limb regeneration from a stem/progenitor-based mechanism (larval mode) to a dedifferentiation-based one (adult mode) as it transits beyond metamorphosis. We demonstrate that larval newts use stem/progenitor cells such as satellite cells for new muscle in a regenerated limb, whereas metamorphosed newts recruit muscle fibre cells in the stump for the same purpose. We conclude that the newt has evolved novel strategies to secure its regenerative ability of the limbs after metamorphosis. PMID:27026263

  4. Expression of stem cell pluripotency factors during regeneration in newts.

    PubMed

    Maki, Nobuyasu; Suetsugu-Maki, Rinako; Tarui, Hiroshi; Agata, Kiyokazu; Del Rio-Tsonis, Katia; Tsonis, Panagiotis A

    2009-06-01

    In this study, we present data indicating that mammalian stem cell pluripotency-inducing factors are expressed during lens and limb regeneration in newts. The apparent expression even in intact tissues and the ensued regulation during regeneration raises the possibility that these factors might regulate tissue-specific reprogramming and regeneration. Furthermore, these factors should enable us to understand the similarities and differences between animal regeneration in the newt and stem cell strategies in mammals. Developmental Dynamics 238:1613-1616, 2009. (c) 2009 Wiley-Liss, Inc.

  5. Spaceflight Effects on the Hematopoietic Tissue of Ribbed Newts

    NASA Astrophysics Data System (ADS)

    Domaratskaya, E. I.; Almeida, E. A. C.; Butorina, N. N.; Nikonova, T. M.; Grigoryan, E. N.; Poplinskaya, V. A.

    2008-06-01

    The newts Pleurodeles waltl flown on Foton-M2 for 12 days were used for studying the effects of spaceflight on hematopoiesis in lower vertebrates. Prior to the flight, all the animals underwent to removal their lenses and tail tips for regeneration studies. No significant differences in blood cell contents were detected between flight and control animals. Morphological examination of hematopoietic areas of the liver in both groups also showed no significant differences. Experiments with BrdU incorporation revealed labeled cells in the hemopoietic area of the liver as well as in blood. The blood cell composition of newts flown on Foton-M3 was similar to that in intact (nonoperated) newts used in Bion-11 and Foton-M2 experiments. The lack of blood changes in newts during the current experiments distinguishes them from mammals flown in space (rats and mice), which developed significant changes in both blood cell counts, stem and committed cells in the blood-forming tissues.

  6. Blood and clonogenic hemopoietic cells of newts after the space flight

    NASA Astrophysics Data System (ADS)

    Michurina, T. V.; Domaratskaya, E. I.; Nikonova, T. M.; Khrushchov, N. G.

    Ribbed newts were used for studying the effect of space flight on board of the biosatellite (Cosmos-2229) on blood and clonogenic hemopoietic cells. In blood of newts of the flight group, the relative proportion of neutrophils increased, whereas that of lymphocytes and eosinophils decreased. Space flight did not result in loss of the ability of newt blood cells to incorporate H^3-thymidine. Analysis of clonogenic hemopoietic cells was performed using the method of hemopoietic colony formation on cellulose acetate membranes implanted into the peritoneal cavity of irradiated newts. To analyze reconstitution of hemopoiesis after irradiation donor hemopoietic cells from flight or control newts were transplanted into irradiated newts whose hemopoietic organs were investigated. The newt can be considered an adequate model for studying hemopoiesis under the conditions of the space flight. Previous studies on rats subjected to 5- to 19-day space flights revealed a decrease in the number of clonogenic cells in their hemopoietic organs accompanied by specific changes in the precursor cell compartment and in blood /1,2/. Hence, it was interesting to analyze blood and hemopoietic tissue of lower vertebrates after a space flight and to compare the response to it of animals belonging to different taxonomic groups. We analyzed blood and clonogenic hemopoietic cells of ribbed newts, Pleurodeles waltl (age one year, weight 20-28 g) subjected to a 12-day space flight on board of a Cosmos-2229 biosatellite. The same animals were used in studies on limb and lens regeneration. The results were compared with those obtained with control groups of newts: (1) basic control, operated newts sacrificed on the day of biosatellite launching (BC); (2) synchronous control, operated newts kept in the laboratory under simulated space flight conditions (SC); and (3) intact newts (IC).

  7. A discrete stage-structured model of California newt population dynamics during a period of drought.

    PubMed

    Jones, Marjorie T; Milligan, William R; Kats, Lee B; Vandergon, Thomas L; Honeycutt, Rodney L; Fisher, Robert N; Davis, Courtney L; Lucas, Timothy A

    2017-02-07

    We introduce a mathematical model for studying the population dynamics under drought of the California newt (Taricha torosa), a species of special concern in the state of California. Since 2012, California has experienced a record-setting drought, and multiple studies predict drought conditions currently underway will persist and even increase in severity. Recent declines and local extinctions of California newt populations in Santa Monica Mountain streams motivate our study of the impact of drought on newt population sizes. Although newts are terrestrial salamanders, they migrate to streams each spring to breed and lay eggs. Since egg and larval stages occur in water, a precipitation deficit due to drought conditions reduces the space for newt egg-laying and the necessary habitat for larval development. To mathematically forecast newt population dynamics, we develop a nonlinear system of discrete equations that includes demographic parameters such as survival rates for newt life stages and egg production, which depend on habitat availability and rainfall. We estimate these demographic parameters using 15 years of stream survey data collected from Cold Creek in Los Angeles County, California, and our model captures the observed decline of the parameterized Cold Creek newt population. Based upon data analysis, we predict how the number of available newt egg-laying sites varies with annual precipitation. Our model allows us to make predictions about how the length and severity of drought can affect the likelihood of persistence and the time to critical endangerment of a local newt population. We predict that sustained severe drought will critically endanger the newt population but that the newt population can rebound if a drought is sufficiently short.

  8. Ghrelin receptor in Japanese fire belly newt, Cynops pyrrhogaster.

    PubMed

    Kaiya, Hiroyuki; Kangawa, Kenji; Miyazato, Mikiya

    2015-11-01

    We identified cDNA encoding a functional ghrelin receptor (growth hormone secretagogue-receptor 1a (GHS-R1a)) in a urodele amphibian, the Japanese fire belly newt (Cynops pyrrhogaster). Two functional receptor proteins, composed of 378- and 362-amino acids, were deduced from the identified cDNA because two candidate initiation methionine sites were found. The long-chain receptor protein shared 80%, 69%, and 59% identities with the bullfrog GHS-R1a, human GHS-R1a and tilapia GHS-R1a-like receptor, respectively. Phylogenetic analysis suggested that the newt receptor is grouped to the clade of the tetrapod homologs, and very closed to anuran amphibians. In functional analyses, homologous newt ghrelin, heterologous bullfrog and rat ghrelin, and a GHS-R1a agonist, GHRP-6 increased intracellular Ca(2+) concentration in human embryonic kidney (HEK) 293 cells stably expressed newt GHS-R1a. The responsiveness was much greater in the short-chain receptor than in the long-chain receptor. Both receptors preferred to bind Ser(3)-ghrelin including newt and rat ghrelin than Thr(3)-ghrelin with bullfrog ghrelin. GHRP-6 has a similar affinity to bullfrog ghrelin. GHS-R1a mRNA was expressed in the brain, pituitary, intestine, pancreas, testis and fat body with high level, and eyes, heart, stomach, liver, gall bladder, kidney and dorsal skin with low level. In a fasting experiment, gene expression of GHS-R1a in the brain and pituitary increased 4days after fasting, and the increased level decreased to the initial level 2weeks after fasting. These changes are consistent with the change in ghrelin mRNA. In contrast, expression of ghrelin and GHS-R1a mRNA in the stomach decreased on day 4 after fasting, and increased 2weeks after fasting. These results indicate that ghrelin and its receptor system are present and altered by energy states in this newt.

  9. A highly divergent picornavirus in an amphibian, the smooth newt (Lissotriton vulgaris)

    PubMed Central

    Boros, Ákos; Tóth, Zoltán; Gia Phan, Tung; Delwart, Eric; Pankovics, Péter

    2015-01-01

    Genetically highly divergent picornavirus (Newt/2013/HUN, KP770140) was detected using viral metagenomics in faecal samples of free-living smooth newts (Lissotriton vulgaris). Newt picornavirus was identified by reverse transcription-polymerase chain reaction (RT-PCR) in six (25 %) of the 24 samples originating from individuals caught in two out of the six investigated natural ponds in Hungary. The first picornavirus in amphibians expands the host range of members of the Picornaviridae, and opens a new research field in picornavirus evolution in lower vertebrates. Newt picornavirus represents a novel species in a novel genus within the family Picornaviridae, provisionally named genus Ampivirus (amphibian picornavirus). PMID:26018961

  10. Newt limb regeneration studied with synchrotron micro-CT

    NASA Astrophysics Data System (ADS)

    Stock, Stuart R.; Ignatiev, Konstantin I.; Simon, Hans-Georg; De Carlo, Francesco

    2004-10-01

    Newts are the most developed vertebrates which retain the ability as adults to regenerate missing limbs; they are, therefore, of great interest in terms understanding how such regeneration could be triggered in mammals. In this study, synchrotron microCT was used to study bone microstructure in control forelimbs and in forelimbs regenerated for periods from 37 to 85 days. The bone microstructure in newts has been largely neglected, and interesting patterns within the original bone and in the regenerating arm and hand are described. Periosteal bone formation in the regenerating arm and finger bones, delayed ossification of carpal (but not metacarpal) bones and the complex microstructure of the original carpal bones are areas where microCT reveals detail of particular interest.

  11. Atomic force microscope observations of otoconia in the newt

    NASA Technical Reports Server (NTRS)

    Hallworth, R.; Wiederhold, M. L.; Campbell, J. B.; Steyger, P. S.

    1995-01-01

    Calcitic and aragonitic otoconia from the Japanese red-bellied newt, Cynops pyrrhogaster, were examined using an atomic force microscope. The surface structure of both otoconial polymorphs consisted of arrays of elements approximately 50 nm in diameter. Elements were generally round and were separated by shallow depressions of no more than 20 nm. The elements are suggested to be single crystals of calcium carbonate. The relationship of these observations to theories of otoconial genesis is discussed.

  12. [Photoreceptors and visual pigments in three species of newts].

    PubMed

    Koremiak, D A; Govardovskiĭ, V I

    2013-01-01

    Photoreceptor complement and retinal visual pigments in three newt (Caudata, Salamandridae, Pleurodelinae) species (Pleurodeles waltl, Lissotriton (Triturus) vulgaris and Cynops orientalis) were studied by light mucroscopy and microspectrophotometry. Retinas of all three species contain "red" (rhodopsin/porphyropsin) rods, large and small single cones, and double cones. Large single cones and both components of double cones contain red-sensitive (presumably LWS) visual pigment whose absorbance spectrum peaks between 593 and 611 nm. Small single cones are either blue- (SWS2, maximum absorbance between 470 and 489 nm) or UV-sensitive (SWS1, maximum absorbance between 340 and 359 nm). Chromophore composition of visual pigments (A1 vs. A2) was assessed both from template fitting of absorption spectra and by the method of selective bleaching. All pigments contained a mixture of A1 (11-cis retinal) and A2 (11-cis-3,4-dehydroretinal) chromophore in the proportion depending on the species and cell type. In all cases, A2 was dominant. However, in C. orientalis rods the fraction of A1 could reach 45%, while in P. waltl and L. vulgaris cones it did not exceed 5%. Remarkably, the absorbance of the newt blue-sensitive visual pigment was shifted by up to 45 nm toward the longer wavelength, as compared with all other amphibian SWS2-pigments. We found no "green" rods typical of retinas of Anura and some Caudata (ambystomas) in the three newt species studied.

  13. Mechanism of Action of Secreted Newt Anterior Gradient Protein

    PubMed Central

    Grassme, Kathrin S.; Garza-Garcia, Acely; Delgado, Jean-Paul; Godwin, James W.; Kumar, Anoop; Gates, Phillip B.; Brockes, Jeremy P.

    2016-01-01

    Anterior gradient (AG) proteins have a thioredoxin fold and are targeted to the secretory pathway where they may act in the ER, as well as after secretion into the extracellular space. A newt member of the family (nAG) was previously identified as interacting with the GPI-anchored salamander-specific three-finger protein called Prod1. Expression of nAG has been implicated in the nerve dependence of limb regeneration in salamanders, and nAG acted as a growth factor for cultured newt limb blastemal (progenitor) cells, but the mechanism of action was not understood. Here we show that addition of a peptide antibody to Prod1 specifically inhibit the proliferation of blastema cells, suggesting that Prod1 acts as a cell surface receptor for secreted nAG, leading to S phase entry. Mutation of the single cysteine residue in the canonical active site of nAG to alanine or serine leads to protein degradation, but addition of residues at the C terminus stabilises the secreted protein. The mutation of the cysteine residue led to no detectable activity on S phase entry in cultured newt limb blastemal cells. In addition, our phylogenetic analyses have identified a new Caudata AG protein called AG4. A comparison of the AG proteins in a cell culture assay indicates that nAG secretion is significantly higher than AGR2 or AG4, suggesting that this property may vary in different members of the family. PMID:27100463

  14. 'Fixed-axis' magnetic orientation by an amphibian: non-shoreward-directed compass orientation, misdirected homing or positioning a magnetite-based map detector in a consistent alignment relative to the magnetic field?

    PubMed

    Phillips, John B; Borland, S Chris; Freake, Michael J; Brassart, Jacques; Kirschvink, Joseph L

    2002-12-01

    Experiments were carried out to investigate the earlier prediction that prolonged exposure to long-wavelength (>500 nm) light would eliminate homing orientation by male Eastern red-spotted newts Notophthalmus viridescens. As in previous experiments, controls held in outdoor tanks under natural lighting conditions and tested in a visually uniform indoor arena under full-spectrum light were homeward oriented. As predicted, however, newts held under long-wavelength light and tested under either full-spectrum or long-wavelength light (>500 nm) failed to show consistent homeward orientation. The newts also did not orient with respect to the shore directions in the outdoor tanks in which they were held prior to testing. Unexpectedly, however, the newts exhibited bimodal orientation along a more-or-less 'fixed' north-northeast-south-southwest magnetic axis. The orientation exhibited by newts tested under full-spectrum light was indistinguishable from that of newts tested under long-wavelength light, although these two wavelength conditions have previously been shown to differentially affect both shoreward compass orientation and homing orientation. To investigate the possibility that the 'fixed-axis' response of the newts was mediated by a magnetoreception mechanism involving single-domain particles of magnetite, natural remanent magnetism (NRM) was measured from a subset of the newts. The distribution of NRM alignments with respect to the head-body axis of the newts was indistinguishable from random. Furthermore, there was no consistent relationship between the NRM of individual newts and their directional response in the overall sample. However, under full-spectrum, but not long-wavelength, light, the alignment of the NRM when the newts reached the 20 cm radius criterion circle in the indoor testing arena (estimated by adding the NRM alignment measured from each newt to its magnetic bearing) was non-randomly distributed. These findings are consistent with the earlier

  15. Asymmetric female preferences for courtship pheromones in two closely-related newt species, the smooth newt (Lissotriton vulgaris) and the Carpathian newt (L. montandoni) (Salamandridae).

    PubMed

    Osikowski, Artur

    2012-06-01

    The smooth (Lissotriton vulgaris) and Carpathian (L. montandoni) newts are sister species. These are separated by a moderate genetic distance, but exhibit striking morphological differences, especially in male epigamic traits. In the areas where they co-occur, they readily mate with each other and produce viable hybrids. However, a high level of pre-zygotic isolation with an unknown behavioral basis has been reported. The complex courtship of newts consists of at least three types of modality: chemical, visual, and tactile. The relative significance of these in mate choice is unclear, but it is commonly accepted that pheromones are an important communication channel. The goal of this study was to determine whether the females of L. vulgaris and L. montandoni exhibit preferences for conspecific extracts from the pheromone-producing abdominal (dorsal) glands. Females of both species spent more time in proximity to the source of the abdominal gland extracts of their own species when a liver extract was presented as an alternative. In a second trial, females were simultaneously confronted with conspecific and heterospecific abdominal gland extracts. Asymmetric preferences were found. Lissotriton vulgaris females were not selective, whereas L. montandoni females preferred the conspecific abdominal gland extract. This finding is consistent with the results of earlier experiments on mate choice in these species. The results strongly indicate that pheromones play a crucial role in courtship and species recognition in this pair of closely related, hybridizing species.

  16. A robust transcriptional program in newts undergoing multiple events of lens regeneration throughout their lifespan.

    PubMed

    Sousounis, Konstantinos; Qi, Feng; Yadav, Manisha C; Millán, José Luis; Toyama, Fubito; Chiba, Chikafumi; Eguchi, Yukiko; Eguchi, Goro; Tsonis, Panagiotis A

    2015-11-02

    Newts have the ability to repeatedly regenerate their lens even during ageing. However, it is unclear whether this regeneration reflects an undisturbed genetic activity. To answer this question, we compared the transcriptomes of lenses, irises and tails from aged newts that had undergone lens regeneration 19 times with the equivalent tissues from young newts that had never experienced lens regeneration. Our analysis indicates that repeatedly regenerated lenses showed a robust transcriptional program comparable to young never-regenerated lenses. In contrast, the tail, which was never regenerated, showed gene expression signatures of ageing. Our analysis strongly suggests that, with respect to gene expression, the regenerated lenses have not deviated from a robust transcriptional program even after multiple events of regeneration throughout the life of the newt. In addition, our study provides a new paradigm in biology, and establishes the newt as a key model for the study of regeneration in relation to ageing.

  17. Diurnal changes in the synthesis of the neurosteroid 7alpha-hydroxypregnenolone stimulating locomotor activity in newts.

    PubMed

    Koyama, Teppei; Haraguchi, Shogo; Vaudry, Hubert; Tsutsui, Kazuyoshi

    2009-04-01

    We recently identified 7alpha-hydroxypregnenolone as a novel amphibian neurosteroid stimulating locomotor activity in newts. Because male newts show marked diurnal changes in locomotor activity, we hypothesized that 7alpha-hydroxypregnenolone may be a key factor for the induction of diurnal changes in locomotor activity in male newts. In this study, we found diurnal changes in 7alpha-hydroxypregnenolone synthesis in the brain of male newts, which paralleled locomotor activity. Interestingly, the production of 7alpha-hydroxypregnenolone in the male newt brain increased during the dark phase when locomotor activity of males was high.

  18. Seasonal changes in the synthesis of the neurosteroid 7alpha-hydroxypregnenolone stimulating locomotor activity in newts.

    PubMed

    Haraguchi, Shogo; Matsunaga, Masahiro; Koyama, Teppei; Do Rego, Jean-Luc; Tsutsui, Kazuyoshi

    2009-04-01

    We recently found that the newt brain actively produces 7alpha-hydroxypregnenolone, a novel amphibian neurosteroid stimulating locomotor activity. It is well known that locomotor activity of male newts increases during the breeding period. To understand the physiological role of 7alpha-hydroxypregnenolone, we investigated seasonal changes in 7alpha-hydroxypregnenolone synthesis in the brain of male newts. Interestingly, 7alpha-hydroxypregnenolone synthesis in the brain showed marked changes during the annual breeding cycle, with a maximal level in the breeding period when locomotor activity of male newts increases. These results suggest that 7alpha-hydroxypregnenolone induces seasonal locomotor changes in male newts.

  19. Multiple sex pheromone genes are expressed in the abdominal glands of the smooth newt (Lissotriton vulgaris) and Montandon's Newt (L. montandoni) (Salamandridae).

    PubMed

    Artur, Osikowski; Wiesław, Babik; Paweł, Grzmil; Jacek M, Szymura

    2008-06-01

    The smooth newt (Lissotriton "Triturus" vulgaris) and Montandon's newt (L."T." montandoni) are sister species exhibiting pronounced differences in male secondary sexual traits but nevertheless hybridizing and producing fertile hybrids in nature. Since pheromonal communication is an important aspect of the reproductive biology of urodeles, structural differentiation of peptide pheromones and their receptors may contribute to incipient reproductive isolation. The aim of the study was the identification of genes encoding putative courtship pheromone precursors in two newt species and the reconstruction of phylogenetic relationships among them. Our analyses were based on cDNA obtained from the transcripts from the abdominal glands of male newts. We identified five unique cDNA sequences encoding the putative pheromone precursors in L. vulgaris and three additional unique sequences in L. montandoni. The results indicate that in the abdominal glands of Lissotriton newts more than one pheromone-encoding gene is expressed and that these loci form a gene family. Phylogenetic analysis indicates that the divergence of at least some of these genes predates the radiation of European newts.

  20. Hemopoietic tissue in newts flown aboard Foton M3

    NASA Astrophysics Data System (ADS)

    Domaratskaya, Elena I.; Almeida, Eduardo; Butorina, Nina N.; Nikonova, Tatyana M.; Grigoryan, Eleonora N.; Poplinskaya, Valentina A.; Souza, Kenneth; Skidmore, Mike

    The effect of 12-day spaceflight aboard the Foton-M3 biosatellite on the hematopoietic tissue of P. waltl newts was studied. These animals used at the same time in regeneration experiments after lens and tail tip amputation. In flight and synchronous groups there were performed video recording, temperature and radiation monitoring and continuous contact (via skin) with thymidine analog BrdU. We took differential blood counts and assessed histologically the liver in the flight (F), basal (BC) and synchronous (SC)control groups of animals. In the peripheral blood, we identified neutrophils, eosinophils, basophils, lymphocytes, and monocytes. Lymphocytes (L) and neutrophils (N) prevailed, accounting for about 60 and 20% of white blood cells, respectively. The spaceflight had no apparent effect on the differential blood count in the F group: neither the L and N contents nor the maturing to mature N - ratio differed from those in the control groups. No significant differences between F, SC and BC groups were observed with respect to the structure of hematopoietic areas and the liver morphology. As in Foton-M2, BrdU labeled cells revealed in blood as well as in the hemopoietic areas of the liver. However, in previous experiments performed at satellites Bion-10 and Foton-M2 the changes in peripheral blood contents were registered in operated F newts, and we supposed it could be the result of additive effects of spaceflight factors and stimulation of reparative potency and stress due to surgical operation. Possibly, the temperature conditions also may provide some influence on blood cell content of newts that belong to poikilothermic animals. Thus, in present experiment F and SC groups were reared in the same temperature regims, whereas it was nearly 3o C differences between SC and F groups exposed on Foton-M2. At the same time as it was found in experiments on Bion-11 and Foton-M2 spaceflight factors did not affect on differential blood counts of intact non

  1. The application of eDNA for monitoring of the Great Crested Newt in the UK

    PubMed Central

    Rees, Helen C; Bishop, Keith; Middleditch, David J; Patmore, James R M; Maddison, Ben C; Gough, Kevin C

    2014-01-01

    Current ecological surveys for great crested newts are time-consuming and expensive and can only be carried out within a short survey window. Additional survey methods which would facilitate the detection of rare or protected species such as the great crested newt (Triturus cristatus) would be extremely advantageous. Environmental DNA (eDNA) analysis has been utilized for the detection of great crested newts in Denmark. Here, the same methodology has been applied to water samples taken from UK ponds concurrently with conventional field surveying techniques. Our eDNA analysis exhibited an 84% success rate with a kappa coefficient of agreement between field and eDNA surveys of 0.86. One pond determined to be negative for great crested newt by field survey was positive by eDNA analysis, revealing the potential for improved detection rates using this methodology. Analysis of water samples collected in late summer indicates that eDNA analysis could be used to detect great crested newt after the optimal survey window for current field techniques had passed. Consequently, eDNA analysis could augment currently stipulated techniques for great crested newt surveying as a relatively quick and inexpensive tool for collecting great crested newt presence and distribution data within the UK instead of or prior to full field surveys. PMID:25505530

  2. Proteome analysis of the liver in the Chinese fire-bellied newt Cynops orientalis.

    PubMed

    Zang, X Y; Guo, J L; Geng, X F; Li, P F; Sun, J Y; Wang, Q W; Xu, C S

    2016-08-12

    The Chinese fire-bellied newt, Cynops orientalis, belonging to Amphibia, Caudata, Salamandridae is a species endemic to China. The liver, which is an important digestive gland and the largest amphibian organ, has various functions, including detoxification, glycogen storage, protein synthesis, and hormone production. However, the newt liver has rarely been studied at the molecular level. We performed histomorphology and high-throughput proteomic analysis of the Chinese fire-bellied newt liver, using hematoxylin and eosin (H&E) staining and two-dimensional electrophoresis coupled with mass spectrometry. The H&E staining showed that the newt liver nuclei are large and round, are located in the lateral cytoplasm, and contain a large quantity of lipid droplets. Melanins were abundantly present throughout the hepatic parenchyma. The proteome analysis showed a total of 545 proteins detected in the newt liver. Furthermore, a gene ontology analysis suggested that these proteins were associated with metabolism, immune response, cellular homeostasis, etc. Among these, proteins with metabolic functions were found to be the most abundant and highly expressed. This supports the role of the liver as the metabolic center. The proteomic results provide new insights into the aspects of the liver proteomes of the Chinese fire-bellied newt. The identification of a more global liver proteome in the newt may provide a basis for characterizing and comparing the liver proteomes from other amphibian species.

  3. Optimal experimental design for improving the estimation of growth parameters of Lactobacillus viridescens from data under non-isothermal conditions.

    PubMed

    Longhi, Daniel Angelo; Martins, Wiaslan Figueiredo; da Silva, Nathália Buss; Carciofi, Bruno Augusto Mattar; de Aragão, Gláucia Maria Falcão; Laurindo, João Borges

    2017-01-02

    In predictive microbiology, the model parameters have been estimated using the sequential two-step modeling (TSM) approach, in which primary models are fitted to the microbial growth data, and then secondary models are fitted to the primary model parameters to represent their dependence with the environmental variables (e.g., temperature). The Optimal Experimental Design (OED) approach allows reducing the experimental workload and costs, and the improvement of model identifiability because primary and secondary models are fitted simultaneously from non-isothermal data. Lactobacillus viridescens was selected to this study because it is a lactic acid bacterium of great interest to meat products preservation. The objectives of this study were to estimate the growth parameters of L. viridescens in culture medium from TSM and OED approaches and to evaluate both the number of experimental data and the time needed in each approach and the confidence intervals of the model parameters. Experimental data for estimating the model parameters with TSM approach were obtained at six temperatures (total experimental time of 3540h and 196 experimental data of microbial growth). Data for OED approach were obtained from four optimal non-isothermal profiles (total experimental time of 588h and 60 experimental data of microbial growth), two profiles with increasing temperatures (IT) and two with decreasing temperatures (DT). The Baranyi and Roberts primary model and the square root secondary model were used to describe the microbial growth, in which the parameters b and Tmin (±95% confidence interval) were estimated from the experimental data. The parameters obtained from TSM approach were b=0.0290 (±0.0020) [1/(h(0.5)°C)] and Tmin=-1.33 (±1.26) [°C], with R(2)=0.986 and RMSE=0.581, and the parameters obtained with the OED approach were b=0.0316 (±0.0013) [1/(h(0.5)°C)] and Tmin=-0.24 (±0.55) [°C], with R(2)=0.990 and RMSE=0.436. The parameters obtained from OED approach

  4. STS-65 Mission Specialist Thomas with newt in IML-2 module aboard OV-102

    NASA Technical Reports Server (NTRS)

    1994-01-01

    STS-65 Mission Specialist Donald A. Thomas is seen in the spacelab science module at the Rack 1 Workbench making an observation of one of the newts. Smaller organisms, such as the newts, are able to develop from embryos and hatch during the mission as part of an overall program to determine if development occurs normally in the space environment. Temporary home for the newts, the Aquatic Animal Experiment Unit (AAEU) (out of frame) also contained Medaka and goldfish. Thomas joined five other NASA astronauts and a Japanese payload specialist for two weeks of experimenting onboard the Space Shuttle Columbia, Orbiter Vehicle (OV) 102, in Earth orbit.

  5. Amphibian skin may select for rare environmental microbes

    PubMed Central

    Walke, Jenifer B; Becker, Matthew H; Loftus, Stephen C; House, Leanna L; Cormier, Guy; Jensen, Roderick V; Belden, Lisa K

    2014-01-01

    Host-microbe symbioses rely on the successful transmission or acquisition of symbionts in each new generation. Amphibians host a diverse cutaneous microbiota, and many of these symbionts appear to be mutualistic and may limit infection by the chytrid fungus, Batrachochytrium dendrobatidis, which has caused global amphibian population declines and extinctions in recent decades. Using bar-coded 454 pyrosequencing of the 16S rRNA gene, we addressed the question of symbiont transmission by examining variation in amphibian skin microbiota across species and sites and in direct relation to environmental microbes. Although acquisition of environmental microbes occurs in some host-symbiont systems, this has not been extensively examined in free-living vertebrate-microbe symbioses. Juvenile bullfrogs (Rana catesbeiana), adult red-spotted newts (Notophthalmus viridescens), pond water and pond substrate were sampled at a single pond to examine host-specificity and potential environmental transmission of microbiota. To assess population level variation in skin microbiota, adult newts from two additional sites were also sampled. Cohabiting bullfrogs and newts had distinct microbial communities, as did newts across the three sites. The microbial communities of amphibians and the environment were distinct; there was very little overlap in the amphibians' core microbes and the most abundant environmental microbes, and the relative abundances of OTUs that were shared by amphibians and the environment were inversely related. These results suggest that, in a host species-specific manner, amphibian skin may select for microbes that are generally in low abundance in the environment. PMID:24858782

  6. Sex- and context-dependent migration in a pond-breeding amphibian.

    PubMed

    Grayson, Kristine L; Wilbur, Henry M

    2009-02-01

    Partial migration, variation in the percentage of a population that completes a migration, can be influenced by the local environment and condition of an individual. We examined the direct and interacting effects of habitat quality and gender on migration decision by manipulating population density and sex ratio in a factorial field experiment using aquatic enclosures. In partially migrating red-spotted newts (Notophthalmus viridescens), we measured the percentage of newts migrating to the terrestrial habitat vs. overwintering as pond residents. Density significantly influenced migration, with 63% of newts migrating from high-density enclosures compared to 39% from low-density enclosures. Newts also migrated earlier from high-density enclosures, but no significant effects of the sex ratio treatment were found. Females migrated earlier than males, and 64% more females developed the migrant phenotype, suggesting important sex-based trade-offs of migration. No differences were found between migrants and residents in initial body size, counter to our prediction that larger individuals would be more likely to remain pond residents. This study demonstrates experimentally that migration can be a plastic response influenced by both local density and gender.

  7. Amphibian skin may select for rare environmental microbes.

    PubMed

    Walke, Jenifer B; Becker, Matthew H; Loftus, Stephen C; House, Leanna L; Cormier, Guy; Jensen, Roderick V; Belden, Lisa K

    2014-11-01

    Host-microbe symbioses rely on the successful transmission or acquisition of symbionts in each new generation. Amphibians host a diverse cutaneous microbiota, and many of these symbionts appear to be mutualistic and may limit infection by the chytrid fungus, Batrachochytrium dendrobatidis, which has caused global amphibian population declines and extinctions in recent decades. Using bar-coded 454 pyrosequencing of the 16S rRNA gene, we addressed the question of symbiont transmission by examining variation in amphibian skin microbiota across species and sites and in direct relation to environmental microbes. Although acquisition of environmental microbes occurs in some host-symbiont systems, this has not been extensively examined in free-living vertebrate-microbe symbioses. Juvenile bullfrogs (Rana catesbeiana), adult red-spotted newts (Notophthalmus viridescens), pond water and pond substrate were sampled at a single pond to examine host-specificity and potential environmental transmission of microbiota. To assess population level variation in skin microbiota, adult newts from two additional sites were also sampled. Cohabiting bullfrogs and newts had distinct microbial communities, as did newts across the three sites. The microbial communities of amphibians and the environment were distinct; there was very little overlap in the amphibians' core microbes and the most abundant environmental microbes, and the relative abundances of OTUs that were shared by amphibians and the environment were inversely related. These results suggest that, in a host species-specific manner, amphibian skin may select for microbes that are generally in low abundance in the environment.

  8. Triturus newts defy the running-swimming dilemma.

    PubMed

    Gvozdík, Lumir; Van Damme, Raoul

    2006-10-01

    Conflicts between structural requirements for carrying out different ecologically relevant functions may result in a compromise phenotype that maximizes neither function. Identifying and evaluating functional trade-offs may therefore aid in understanding the evolution of organismal performance. We examined the possibility of an evolutionary trade-off between aquatic and terrestrial locomotion in females of European species of the newt genus Triturus. Biomechanical models suggest a conflict between the requirements for aquatic and terrestrial locomotion. For instance, having an elongate, slender body, a large tail, and reduced limbs should benefit undulatory swimming, but at the cost of reduced running capacity. To test the prediction of an evolutionary trade-off between swimming and running capacity, we investigated relationships between size-corrected morphology and maximum locomotor performance in females of ten species of newts. Phylogenetic comparative analyses revealed that an evolutionary trend of body elongation (increasing axilla-groin distance) is associated with a reduction in head width and forelimb length. Body elongation resulted in reduced maximum running speed, but, surprisingly, also led to a reduction in swimming speed. The evolution of longer tails was associated with an increase in maximal swimming speed. We found no evidence for an evolutionary trade-off between aquatic and terrestrial locomotor performance, probably because of the unexpected negative effect of body elongation on swimming speed. We conclude that the idea of a design conflict between aquatic and terrestrial locomotion, mediated through antagonistic effects of body elongation, does not apply to our model system.

  9. Mothers Matter Too: Benefits of Temperature Oviposition Preferences in Newts

    PubMed Central

    Kurdíková, Vendula; Smolinský, Radovan; Gvoždík, Lumír

    2011-01-01

    The maternal manipulation hypothesis states that ectothermic females modify thermal conditions during embryonic development to benefit their offspring (anticipatory maternal effect). However, the recent theory suggests that the ultimate currency of an adaptive maternal effect is female fitness that can be maximized also by decreasing mean fitness of individual offspring. We evaluated benefits of temperature oviposition preferences in Alpine newts (Ichthyosaura [formerly Triturus] alpestris) by comparing the thermal sensitivity of maternal and offspring traits across a range of preferred oviposition temperatures (12, 17, and 22°C) and by manipulating the egg-predation risk during oviposition in a laboratory thermal gradient (12–22°C). All traits showed varying responses to oviposition temperatures. Embryonic developmental rates increased with oviposition temperature, whereas hatchling size and swimming capacity showed the opposite pattern. Maternal oviposition and egg-predation rates were highest at the intermediate temperature. In the thermal gradient, females oviposited at the same temperature despite the presence of caged egg-predators, water beetles (Agabus bipustulatus). We conclude that female newts prefer a particular temperature for egg-deposition to maximize their oviposition performance rather than offspring fitness. The evolution of advanced reproductive modes, such as prolonged egg-retention and viviparity, may require, among others, the transition from selfish temperature preferences for ovipositon to the anticipatory maternal effect. PMID:21887330

  10. Male Courtship Pheromones Induce Cloacal Gaping in Female Newts (Salamandridae)

    PubMed Central

    Janssenswillen, Sunita; Bossuyt, Franky

    2016-01-01

    Pheromones are an important component of sexual communication in courting salamanders, but the number of species in which their use has been demonstrated with behavioral evidence remains limited. Here we developed a behavioral assay for demonstrating courtship pheromone use in the aquatically courting Iberian ribbed newt Pleurodeles waltl. By performing an in-depth study of the courtship behavior, we show that females invariably open their cloaca (cloacal gaping) before engaging in pinwheel behavior, the circling movement that is the prelude to spermatophore uptake. In contrast, cloacal gaping was not observed in failed courtships, where females escaped or displayed thanatosis. Since gaping mainly occurred during male amplexus and cloacal imposition, which is the obvious period of pheromone transfer, we next investigated whether male courtship water (i.e., water holding courtship pheromones) alone was able to induce this reaction in females. These tests showed that courtship water induced cloacal gaping significantly more than water, even in the absence of a male. Cloacal gaping thus provides a simple and robust test for demonstrating courtship pheromone use in the Iberian ribbed newt. Since opening the cloaca is an essential prerequisite for spermatophore pick-up in all internally fertilizing salamanders, we hypothesize that variations on this assay will also be useful in several other species. PMID:26771882

  11. Do female newts modify thermoregulatory behavior to manipulate egg size?

    PubMed

    Toufarová, Eliška; Gvoždík, Lumír

    2016-04-01

    Reproductive females manipulate offspring phenotypes by modifying conditions during embryogenesis. In ectotherms, the environmental control over embryogenesis is often realized by changes in maternal thermoregulation during gravidity. To determine if reproduction influences thermoregulatory behavior in species where females lay eggs shortly after fertilization (strict oviparity), we compared preferred body temperatures (Tp) between reproductive (egg-laying) and non-reproductive female newts, Ichthyosaura alpestris. Next, we exposed reproductive females to temperatures mimicking Tp ranges of reproductive and non-reproductive individuals to find out whether the maternally modified thermal regime influences ovum and jelly coat volume, and early cleavage rates at the time of oviposition. In the thermal gradient, reproductive females maintained their body temperatures within a narrower range than non-reproductive individuals. The exposure of ovipositing females to temperatures preferred during their reproductive and non-reproductive period had a negligible influence on egg size and early cleavage rates. We conclude that the modification of maternal thermoregulatory behavior provides a limited opportunity to manipulate egg traits in newts.

  12. Male Courtship Pheromones Induce Cloacal Gaping in Female Newts (Salamandridae).

    PubMed

    Janssenswillen, Sunita; Bossuyt, Franky

    2016-01-01

    Pheromones are an important component of sexual communication in courting salamanders, but the number of species in which their use has been demonstrated with behavioral evidence remains limited. Here we developed a behavioral assay for demonstrating courtship pheromone use in the aquatically courting Iberian ribbed newt Pleurodeles waltl. By performing an in-depth study of the courtship behavior, we show that females invariably open their cloaca (cloacal gaping) before engaging in pinwheel behavior, the circling movement that is the prelude to spermatophore uptake. In contrast, cloacal gaping was not observed in failed courtships, where females escaped or displayed thanatosis. Since gaping mainly occurred during male amplexus and cloacal imposition, which is the obvious period of pheromone transfer, we next investigated whether male courtship water (i.e., water holding courtship pheromones) alone was able to induce this reaction in females. These tests showed that courtship water induced cloacal gaping significantly more than water, even in the absence of a male. Cloacal gaping thus provides a simple and robust test for demonstrating courtship pheromone use in the Iberian ribbed newt. Since opening the cloaca is an essential prerequisite for spermatophore pick-up in all internally fertilizing salamanders, we hypothesize that variations on this assay will also be useful in several other species.

  13. Mothers matter too: benefits of temperature oviposition preferences in newts.

    PubMed

    Kurdíková, Vendula; Smolinský, Radovan; Gvoždík, Lumír

    2011-01-01

    The maternal manipulation hypothesis states that ectothermic females modify thermal conditions during embryonic development to benefit their offspring (anticipatory maternal effect). However, the recent theory suggests that the ultimate currency of an adaptive maternal effect is female fitness that can be maximized also by decreasing mean fitness of individual offspring. We evaluated benefits of temperature oviposition preferences in Alpine newts (Ichthyosaura [formerly Triturus] alpestris) by comparing the thermal sensitivity of maternal and offspring traits across a range of preferred oviposition temperatures (12, 17, and 22°C) and by manipulating the egg-predation risk during oviposition in a laboratory thermal gradient (12-22°C). All traits showed varying responses to oviposition temperatures. Embryonic developmental rates increased with oviposition temperature, whereas hatchling size and swimming capacity showed the opposite pattern. Maternal oviposition and egg-predation rates were highest at the intermediate temperature. In the thermal gradient, females oviposited at the same temperature despite the presence of caged egg-predators, water beetles (Agabus bipustulatus). We conclude that female newts prefer a particular temperature for egg-deposition to maximize their oviposition performance rather than offspring fitness. The evolution of advanced reproductive modes, such as prolonged egg-retention and viviparity, may require, among others, the transition from selfish temperature preferences for ovipositon to the anticipatory maternal effect.

  14. Microgravity effects on neural retina regeneration in the newt

    NASA Astrophysics Data System (ADS)

    Grigoryan, E. N.; Anton, H. J.; Mitashov, V. I.

    Data on forelimb and eye lens regenerationin in urodeles under spaceflight conditions (SFC) have been obtained in our previous studies. Today, evidence is available that SFC stimulate regeneration in experimental animals rather than inhibit it. The results of control on-ground experiments with simulated microgravity suggest that the stimulatory effect of SFC is due largely to weightlessness. An original experimental model is proposed, which is convenient for comprehensively analyzing neural regeneration under SFC. The initial results described here concern regeneration of neural retina in Pleurodeles waltl newts exposed to microgravity simulated in radial clinostat. After clinorotation for seven days (until postoperation day 16), a positive effect of altered gravity on structural restoration of detached neural retina was confirmed by a number of criteria. Specifically, an increased number of Müllerian glial cells, an increased relative volume of the plexiform layers, reduced cell death, advanced redifferentiation of retinal pigment epithelium, and extended areas of neural retina reattachment were detected in experimental newts. Moreover, cell proliferation in the inner nuclear layer of neural retina increased as compared with control. Thus, low gravity appears to intensify natural cytological and molecular mechanisms of neural retina regeneration in lower vertebrates.

  15. Imorin: a sexual attractiveness pheromone in female red-bellied newts (Cynops pyrrhogaster)

    PubMed Central

    Nakada, Tomoaki; Toyoda, Fumiyo; Matsuda, Kouhei; Nakakura, Takashi; Hasunuma, Itaru; Yamamoto, Kazutoshi; Onoue, Satomi; Yokosuka, Makoto; Kikuyama, Sakae

    2017-01-01

    The male red-bellied newt (Cynops pyrrhogaster) approaches the female’s cloaca prior to performing any courtship behaviour, as if he is using some released substance to gauge whether she is sexually receptive. Therefore, we investigated whether such a female sexual attractiveness pheromone exists. We found that a tripeptide with amino acid sequence Ala-Glu-Phe is secreted by the ciliary cells in the epithelium of the proximal portion of the oviduct of sexually developed newts and confirmed that this is the major active substance in water in which sexually developed female newts have been kept. This substance only attracted sexually developed male newts and acted by stimulating the vomeronasal epithelial cells. This is the first female sexual attractiveness peptide pheromone to be identified in a vertebrate. PMID:28120945

  16. Ranavirus-associated mass mortality in imported red tailed knobby newts (Tylototriton kweichowensis): a case report.

    PubMed

    Pasmans, Frank; Blahak, Silvia; Martel, An; Pantchev, Nikola; Zwart, Peer

    2008-05-01

    A mass die-off of imported red tailed knobby newts (Tylototriton kweichowensis) occurred in 2004 in Belgium and the Netherlands. In addition to massive infection with Rhabdias tokyoensis, Ranavirus was isolated from three dead newts examined virologically and the gene coding for the major capsid protein of the virus was sequenced. The isolate showed 99.8% similarity to the published sequence of frog virus 3. Upon experimental infection of axolotls (Ambystoma mexicanum) with this isolate, no marked pathology was noticed and the virus could not be re-isolated at 9weeks post-inoculation. Apart from the possibility of exposure of a non-sensitive host, the mortality episode in the newts may be related to stress resulting from the importation of the newts in breeding condition. This possibility is supported by the presence of degenerating egg-follicles in the females.

  17. Metacercariae of Clinostomum complanatum (Trematoda: Digenea) in European newts Triturus carnifex and Lissotriton vulgaris (Caudata: Salamandridae).

    PubMed

    Caffara, M; Bruni, G; Paoletti, C; Gustinelli, A; Fioravanti, M L

    2014-09-01

    Adults of Clinostomum spp. are digenetic trematodes found in fish-eating birds, reptiles and occasionally mammals, including humans. Freshwater snails serve as first intermediate hosts and many fish species and amphibians as second intermediate hosts. To date, amphibian hosts of Clinostomum metacercariae include members of urodele and anuran families in North America, but no data are available on infections of European amphibians, including newts. In this study, we characterize infections of Clinostomum complanatum metacercariae in four smooth (Lissotriton vulgaris) and 18 Italian crested newts (Triturus carnifex) from an artificial pond located in a protected area in Tuscany, Italy. Parasites were surgically removed from the infected newts and identified both morphologically and using sequences of a mitochondrial gene, cytochrome c oxidase I, and the ribosomal markers, internal transcribed spacers. This is the first record of C. complanatum in European newts and, more generally, in amphibians in Europe.

  18. Imorin: a sexual attractiveness pheromone in female red-bellied newts (Cynops pyrrhogaster).

    PubMed

    Nakada, Tomoaki; Toyoda, Fumiyo; Matsuda, Kouhei; Nakakura, Takashi; Hasunuma, Itaru; Yamamoto, Kazutoshi; Onoue, Satomi; Yokosuka, Makoto; Kikuyama, Sakae

    2017-01-25

    The male red-bellied newt (Cynops pyrrhogaster) approaches the female's cloaca prior to performing any courtship behaviour, as if he is using some released substance to gauge whether she is sexually receptive. Therefore, we investigated whether such a female sexual attractiveness pheromone exists. We found that a tripeptide with amino acid sequence Ala-Glu-Phe is secreted by the ciliary cells in the epithelium of the proximal portion of the oviduct of sexually developed newts and confirmed that this is the major active substance in water in which sexually developed female newts have been kept. This substance only attracted sexually developed male newts and acted by stimulating the vomeronasal epithelial cells. This is the first female sexual attractiveness peptide pheromone to be identified in a vertebrate.

  19. Floral visitation by the Argentine ant reduces pollinator visitation and seed set in the coast barrel cactus, Ferocactus viridescens.

    PubMed

    LeVan, Katherine E; Hung, Keng-Lou James; McCann, Kyle R; Ludka, John T; Holway, David A

    2014-01-01

    Mounting evidence indicates that trade-offs between plant defense and reproduction arise not only from resource allocation but also from interactions among mutualists. Indirect costs of plant defense by ants, for example, can outweigh benefits if ants deter pollinators. Plants can dissuade ants from occupying flowers, but such arrangements may break down when novel ant partners infiltrate mutualisms. Here, we examine how floral visitation by ants affects pollination services when the invasive Argentine ant (Linepithema humile) replaces a native ant species in a food-for-protection mutualism with the coast barrel cactus (Ferocactus viridescens), which, like certain other barrel cacti, produces extrafloral nectar. We compared the effects of floral visitation by the Argentine ant with those of the most prevalent native ant species (Crematogaster californica). Compared to C. californica, the Argentine ant was present in higher numbers in flowers. Cactus bees (Diadasia spp.), the key pollinators in this system, spent less time in flowers when cacti were occupied by the Argentine ant compared to when cacti were occupied by C. californica. Presumably as a consequence of decreased duration of floral visits by Diadasia, cacti occupied by L. humile set fewer seeds per fruit and produced fewer seeds overall compared to cacti occupied by C. californica. These data illustrate the importance of mutualist identity in cases where plants balance multiple mutualisms. Moreover, as habitats become increasingly infiltrated by introduced species, the loss of native mutualists and their replacement by non-native species may alter the shape of trade-offs between plant defense and reproduction.

  20. Turning the fate of reprogramming cells from retinal disorder to regeneration by Pax6 in newts

    PubMed Central

    Casco-Robles, Martin Miguel; Islam, Md Rafiqul; Inami, Wataru; Tanaka, Hibiki Vincent; Kunahong, Ailidana; Yasumuro, Hirofumi; Hanzawa, Shiori; Casco-Robles, Roman Martin; Toyama, Fubito; Maruo, Fumiaki; Chiba, Chikafumi

    2016-01-01

    The newt, a urodele amphibian, has an outstanding ability– even as an adult –to regenerate a functional retina through reprogramming and proliferation of the retinal pigment epithelium (RPE) cells, even though the neural retina is completely removed from the eye by surgery. It remains unknown how the newt invented such a superior mechanism. Here we show that disability of RPE cells to regenerate the retina brings about a symptom of proliferative vitreoretinopathy (PVR), even in the newt. When Pax6, a transcription factor that is re-expressed in reprogramming RPE cells, is knocked down in transgenic juvenile newts, these cells proliferate but eventually give rise to cell aggregates that uniformly express alpha smooth muscle actin, Vimentin and N-cadherin, the markers of myofibroblasts which are a major component of the sub-/epi-retinal membranes in PVR. Our current study demonstrates that Pax6 is an essential factor that directs the fate of reprogramming RPE cells toward the retinal regeneration. The newt may have evolved the ability of retinal regeneration by modifying a mechanism that underlies the RPE-mediated retinal disorders. PMID:27640672

  1. A robust transcriptional program in newts undergoing multiple events of lens regeneration throughout their lifespan

    PubMed Central

    Sousounis, Konstantinos; Qi, Feng; Yadav, Manisha C; Millán, José Luis; Toyama, Fubito; Chiba, Chikafumi; Eguchi, Goro; Tsonis, Panagiotis A

    2015-01-01

    Newts have the ability to repeatedly regenerate their lens even during ageing. However, it is unclear whether this regeneration reflects an undisturbed genetic activity. To answer this question, we compared the transcriptomes of lenses, irises and tails from aged newts that had undergone lens regeneration 19 times with the equivalent tissues from young newts that had never experienced lens regeneration. Our analysis indicates that repeatedly regenerated lenses showed a robust transcriptional program comparable to young never-regenerated lenses. In contrast, the tail, which was never regenerated, showed gene expression signatures of ageing. Our analysis strongly suggests that, with respect to gene expression, the regenerated lenses have not deviated from a robust transcriptional program even after multiple events of regeneration throughout the life of the newt. In addition, our study provides a new paradigm in biology, and establishes the newt as a key model for the study of regeneration in relation to ageing. DOI: http://dx.doi.org/10.7554/eLife.09594.001 PMID:26523389

  2. Morphing of the phylogeographic lineages of the Balkan alpine newts (Ichthyosaura alpestris, Caudata, Salamandridae): in situ morphological diversification.

    PubMed

    Vukov, Tanja D; Sotiropoulos, Konstantinos; Kalezić, Miloš L; Džukić, Georg

    2011-12-01

    Numerous alpine newt (Ichthyosaura alpestris) populations from the Balkans, representing all the previously established phylogeographic lineages, were studied for variations in various morphological characteristics (body size and shape, skull qualitative traits and number of trunk vertebrae). Here, we present a decoupling of morphological and mtDNA phylogeographic substructuring in the alpine newt on the Balkan Peninsula. In sharp contrast to other European newts (Triturus spp., Lissotriton spp.), the vast majority of morphological variation in the alpine newt is concentrated at the population level indicating an in situ morphological diversification. We found that the rate of morphological change is similar to the rate of mtDNA change. We hypothesize that the alpine newts are characterized by non-adaptive morphological evolution.

  3. Temperature variability and moisture synergistically interact to exacerbate an epizootic disease

    PubMed Central

    Raffel, Thomas R.; Halstead, Neal T.; McMahon, Taegan A.; Davis, Andrew K.; Rohr, Jason R.

    2015-01-01

    Climate change is altering global patterns of precipitation and temperature variability, with implications for parasitic diseases of humans and wildlife. A recent study confirmed predictions that increased temperature variability could exacerbate disease, because of lags in host acclimation following temperature shifts. However, the generality of these host acclimation effects and the potential for them to interact with other factors have yet to be tested. Here, we report similar effects of host thermal acclimation (constant versus shifted temperatures) on chytridiomycosis in red-spotted newts (Notophthalmus viridescens). Batrachochytrium dendrobatidis (Bd) growth on newts was greater following a shift to a new temperature, relative to newts already acclimated to this temperature (15°C versus 25°C). However, these acclimation effects depended on soil moisture (10, 16 and 21% water) and were only observed at the highest moisture level, which induced greatly increased Bd growth and infection-induced mortality. Acclimation effects were also greater following a decrease rather than an increase in temperature. The results are consistent with previous findings that chytridiomycosis is associated with precipitation, lower temperatures and increased temperature variability. This study highlights host acclimation as a potentially general mediator of climate–disease interactions, and the need to account for context-dependencies when testing for acclimation effects on disease. PMID:25567647

  4. Interactions of bullfrog tadpole predators and an insecticide: Predation release and facilitation

    USGS Publications Warehouse

    Boone, M.D.; Semlitsch, R.D.

    2003-01-01

    The effect of a contaminant on a community may not be easily predicted, given that complex changes in food resources and predator-prey dynamics may result. The objectives of our study were to determine the interactive effects of the insecticide carbaryl and predators on body size, development, survival, and activity of tadpoles of the bullfrog (Rana catesbeiana). We conducted the study in cattle tank mesocosm ponds exposed to 0, 3.5, or 7.0 mg/l carbaryl, and no predators or two red-spotted newts (Notophthalmus viridescens), bluegill sunfish (Lepomis macrochirus), or crayfish (Orconectes sp.). Carbaryl negatively affected predator survival by eliminating crayfish from all ponds, and by eliminating bluegill sunfish from ponds exposed to the highest concentration of carbaryl; carbaryl exposure did not effect survival of red-spotted newts. Because crayfish were eliminated by carbaryl, bullfrogs were released from predation and survival was near that of predator controls at low concentrations of carbaryl exposure. High concentrations of carbaryl reduced tadpole survival regardless of whether predators survived carbaryl exposure or not. Presence of crayfish and newts reduced tadpole survival, while bluegill sunfish appeared to facilitate bullfrog tadpole survival. Presence of carbaryl stimulated bullfrog tadpole mass and development. Our study demonstrates that the presence of a contaminant stress can alter community regulation by releasing prey from predators that are vulnerable to contaminants in some exposure scenarios.

  5. The newt reprograms mature RPE cells into a unique multipotent state for retinal regeneration

    PubMed Central

    Islam, Md. Rafiqul; Nakamura, Kenta; Casco-Robles, Martin Miguel; Kunahong, Ailidana; Inami, Wataru; Toyama, Fubito; Maruo, Fumiaki; Chiba, Chikafumi

    2014-01-01

    The reprogramming of retinal pigment epithelium (RPE) cells in the adult newt immediately after retinal injury is an area of active research for the study of retinal disorders and regeneration. We demonstrate here that unlike embryonic/larval retinal regeneration, adult newt RPE cells are not directly reprogrammed into retinal stem/progenitor cells; instead, they are programmed into a unique state of multipotency that is similar to the early optic vesicle (embryo) but preserves certain adult characteristics. These cells then differentiate into two populations from which the prospective-neural retina and -RPE layers are formed with the correct polarity. Furthermore, our findings provide insight into the similarity between these unique multipotent cells in newts and those implicated in retinal disorders, such as proliferative vitreoretinopathy, in humans. These findings provide a foundation for biomedical approaches that aim to induce retinal self-regeneration for the treatment of RPE-mediated retinal disorders. PMID:25116407

  6. Phenotypic flexibility of gape anatomy fine-tunes the aquatic prey-capture system of newts.

    PubMed

    Van Wassenbergh, Sam; Heiss, Egon

    2016-07-07

    A unique example of phenotypic flexibility of the oral apparatus is present in newts (Salamandridae) that seasonally change between an aquatic and a terrestrial habitat. Newts grow flaps of skin between their upper and lower jaws, the labial lobes, to partly close the corners of the mouth when they adopt an aquatic lifestyle during their breeding season. Using hydrodynamic simulations based on μCT-scans and cranial kinematics during prey-capture in the smooth newt (Lissotriton vulgaris), we showed that this phenotypic flexibility is an adaptive solution to improve aquatic feeding performance: both suction distance and suction force increase by approximately 15% due to the labial lobes. As the subsequent freeing of the corners of the mouth by resorption of the labial lobes is assumed beneficial for the terrestrial capture of prey by the tongue, this flexibility of the mouth fine-tunes the process of capturing prey throughout the seasonal switching between water and land.

  7. A comparative analysis of predator-induced plasticity in larval Triturus newts.

    PubMed

    Schmidt, B R; Van Buskirk, J

    2005-03-01

    Species that occupy similar habitats are expected to show convergent phenotypes. If habitats are defined by the presence of predators, then traits that modify vulnerability to predation, including predator-induced phenotypic plasticity, should be similar within habitats. We tested this idea using larvae of six syntopic newt species belonging to the two Triturus clades. Behavioural plasticity induced by odonate predators was strongly dissimilar between the two main clades but similar within them. Morphological plasticity was variable among species, even between one pair of closely related species. A predation experiment tested whether differences between clades could be caused by differences in body size. Size-specific vulnerability differed between newts in the small-bodied and large-bodied clades, indicating that similar predators may affect the two clades differently. The results showed both similarity and dissimilarity in predator-induced phenotypic plasticity in syntopic larval newts although theory suggests that divergence is unlikely in such ecologically similar species.

  8. Aquatic-to-terrestrial habitat shift reduces energy expenditure in newts.

    PubMed

    Kristín, Peter; Gvoždík, Lumír

    2014-04-01

    Many organisms seasonally modify their standard metabolic rates (SMR). However, the diversity of cues triggering the acclimatization response remains little understood. We examined the influence of experimentally induced aquatic-to-terrestrial habitat shift on the thermal sensitivity of SMR in newts. Standard metabolic rates increased with temperature (13-23°C), although consistently lower in terrestrial than aquatic individuals. Motor activity during respirometry trials decreased with temperature at similar rates in both groups. We conclude that in newts, a habitat shift might represent an important modulator of the seasonal acclimatization response in SMR. Lowered SMR suggests the potential to reduce newt maintenance costs and depletion of caloric reserves during the activity-limited period on land.

  9. Phenotypic flexibility of gape anatomy fine-tunes the aquatic prey-capture system of newts

    PubMed Central

    Van Wassenbergh, Sam; Heiss, Egon

    2016-01-01

    A unique example of phenotypic flexibility of the oral apparatus is present in newts (Salamandridae) that seasonally change between an aquatic and a terrestrial habitat. Newts grow flaps of skin between their upper and lower jaws, the labial lobes, to partly close the corners of the mouth when they adopt an aquatic lifestyle during their breeding season. Using hydrodynamic simulations based on μCT-scans and cranial kinematics during prey-capture in the smooth newt (Lissotriton vulgaris), we showed that this phenotypic flexibility is an adaptive solution to improve aquatic feeding performance: both suction distance and suction force increase by approximately 15% due to the labial lobes. As the subsequent freeing of the corners of the mouth by resorption of the labial lobes is assumed beneficial for the terrestrial capture of prey by the tongue, this flexibility of the mouth fine-tunes the process of capturing prey throughout the seasonal switching between water and land. PMID:27383663

  10. Phenotypic flexibility of gape anatomy fine-tunes the aquatic prey-capture system of newts

    NASA Astrophysics Data System (ADS)

    van Wassenbergh, Sam; Heiss, Egon

    2016-07-01

    A unique example of phenotypic flexibility of the oral apparatus is present in newts (Salamandridae) that seasonally change between an aquatic and a terrestrial habitat. Newts grow flaps of skin between their upper and lower jaws, the labial lobes, to partly close the corners of the mouth when they adopt an aquatic lifestyle during their breeding season. Using hydrodynamic simulations based on μCT-scans and cranial kinematics during prey-capture in the smooth newt (Lissotriton vulgaris), we showed that this phenotypic flexibility is an adaptive solution to improve aquatic feeding performance: both suction distance and suction force increase by approximately 15% due to the labial lobes. As the subsequent freeing of the corners of the mouth by resorption of the labial lobes is assumed beneficial for the terrestrial capture of prey by the tongue, this flexibility of the mouth fine-tunes the process of capturing prey throughout the seasonal switching between water and land.

  11. Visualization of newt aragonitic otoconial matrices using transmission electron microscopy

    NASA Technical Reports Server (NTRS)

    Steyger, P. S.; Wiederhold, M. L.

    1995-01-01

    Otoconia are calcified protein matrices within the gravity-sensing organs of the vertebrate vestibular system. These protein matrices are thought to originate from the supporting or hair cells in the macula during development. Previous studies of mammalian calcitic, barrel-shaped otoconia revealed an organized protein matrix consisting of a thin peripheral layer, a well-defined organic core and a flocculent matrix inbetween. No studies have reported the microscopic organization of the aragonitic otoconial matrix, despite its protein characterization. Pote et al. (1993b) used densitometric methods and inferred that prismatic (aragonitic) otoconia have a peripheral protein distribution, compared to that described for the barrel-shaped, calcitic otoconia of birds, mammals, and the amphibian utricle. By using tannic acid as a negative stain, we observed three kinds of organic matrices in preparations of fixed, decalcified saccular otoconia from the adult newt: (1) fusiform shapes with a homogenous electron-dense matrix; (2) singular and multiple strands of matrix; and (3) more significantly, prismatic shapes outlined by a peripheral organic matrix. These prismatic shapes remain following removal of the gelatinous matrix, revealing an internal array of organic matter. We conclude that prismatic otoconia have a largely peripheral otoconial matrix, as inferred by densitometry.

  12. Changes in the numbers of osteoclasts in newts under conditions of microgravity

    NASA Astrophysics Data System (ADS)

    Berezovska, O. P.; Rodionova, N. V.; Grigoryan, E. N.; Mitashov, V. I.

    Intensity of osteoclastic resorption and calcium content were investigated in intact limb bones of the newts flown on board of a biosatellite Cosmos-2229 after amputation of their forelimbs and tail. Using X-ray microanalysis it was shown an increase in calcium content in the bones on 20^th day after operation. Histological study revealed an activation of osteoclastic resorption on endosteal surface of long bones. The newts exposed after surgery on a biosatellite had the same level of bone mineralisation as operated ground control ones, but the increase in number of polynuclear osteoclasts was lower.

  13. Redescription of Pseudolepidapedon balistis Manter, 1940 and a biological variant (Trematoda: Acanthocolpidae) from the Red Sea fishes; Balistoides viridescens and Rhinecanthus assasi.

    PubMed

    Khalifa, Refaat Ma; Hassan, Hemely Abdel-Shafy; Mohamadain, Hoda Saady; Karar, Yasser Farhat Mahmoud

    2015-04-01

    During a survey of Red Sea fish parasites, two trematodes belonging to the genus Pseudolepidapedon Yamaguti, 1938 were encountered: P. balistis Manter, 1940 was found in the small intestine of the fish Balistoides viridescens and was redescribed for the first time from Egypt; adding many detailed morphological and ultrastructural characters. The second trematode was found in the small intestine of the fish Rhinecanthus assasi and found to represent a biological variant of the previous species as it differs from it in its generally smaller dimensions, shape of suckers and pharynx and the testes. SEM details of the first species were described for the first time illustrating the differences in the spination and papillae on different parts of the body; which may be of taxonomic importance in recognizing future different species of the genus.

  14. Experimental evidence for a cost of resistance to the fungal pathogen, Batrachochytrium dendrobatidis, for the palmate newt, Lissotriton helveticus

    PubMed Central

    2013-01-01

    Background Batrachochytrium dendrobatidis (Bd), the causative agent of chytridiomycosis, is decimating amphibians worldwide. Unsurprisingly, the majority of studies have therefore concentrated on documenting morbidity and mortality of susceptible species and projecting population consequences as a consequence of this emerging infectious disease. Currently, there is a paucity of studies investigating the sub-lethal costs of Bd in apparently asymptomatic species, particularly in controlled experimental conditions. Here we report the consequences of a single dose of B. dendrobatidis zoospores on captive adult palmate newts (Lissotriton helveticus) for morphological and behavioural traits that associate with reproductive success. Results A single exposure to ~2000 zoospores induced a subclinical Bd infection. One week after inoculation 84% of newts tested positive for Bd, and of those, 98% had apparently lost the infection by the day 30. However, exposed newts suffered significant mass loss compared with control newts, and those experimental newts removing higher levels of Bd lost most mass. We found no evidence to suggest that three secondary sexual characteristics (areas of dorsal crest and rear foot webbing, and length of tail filament) were reduced between experimental versus control newts; in fact, rear foot webbing was 26% more expansive at the end of the experiment in exposed newts. Finally, compared with unexposed controls, exposure to Bd was associated with a 50% earlier initiation of the non-reproductive terrestrial phase. Conclusions Our results suggest that Bd has measureable, but sub-lethal effects, on adult palmate newts, at least under the laboratory conditions presented. We conclude that the effects reported are most likely to be mediated through the initiation of costly immune responses and/or tissue repair mechanisms. Although we found no evidence of hastened secondary sexual trait regression, through reducing individual body condition and potentially

  15. Flexibility is everything: prey capture throughout the seasonal habitat switches in the smooth newt Lissotriton vulgaris.

    PubMed

    Heiss, Egon; Aerts, Peter; Van Wassenbergh, Sam

    Transitions between aquatic and terrestrial habitats are significant steps in vertebrate evolution. Due to the different biophysical demands on the whole organism in water and air, such transitions require major changes of many physiological functions, including feeding. Accordingly, the capability to modulate the pre-programmed chain of prey-capture movements might be essential to maintain performance in a new environment. Newts are of special interest in this regard as they show a multiphasic lifestyle where adults change seasonally between an aquatic and a terrestrial stage. For instance, the Alpine newt is capable of using tongue prehension to feed on land only when in the terrestrial stage, but still manages to suction feed if immersed whilst in terrestrial stage. During the aquatic stage, terrestrial feeding always involved grasping prey by the jaws. Here, we show that this seasonal shift in feeding behavior is also present in a species with a shorter terrestrial stage, the smooth newt Lissotriton vulgaris. Behavioral variability increases when animals change from aquatic to terrestrial strikes in the aquatic stage, but prey-capture movements seem to be generally well-coordinated across the feeding modes. Only suction feeding in the terrestrial stage was seldom performed and appeared uncoordinated. Our results indicate that newts exhibit a high degree of seasonal flexibility of the prey-capture behavior. The similarity between movement patterns of suction feeding and terrestrial feeding suggests that only relatively subtle neuromotoric adjustments to the ancestral, suction-feeding motor program are required to successfully feed in the new environment.

  16. Development of the gravity-sensing organs in the Japanese red-bellied newt, Cynops pyrrhogaster

    NASA Technical Reports Server (NTRS)

    Wiederhold, Michael L.; Yamashita, Masamichi; Asashima, Makoto

    1992-01-01

    Pre-mated adult female newts and fertilized eggs will be flown on the International Microgravity Laboratory-2 flight, schedule for 1994. One objective of the flight will be to observe the influence of microgravity on the development of the gravity-sensing organs in the inner ear. These organs contain sensory hair cells covered by a layer of dense stones (otoliths). Gravity and linear acceleration exert forces on these masses, leading to excitation of the nerve fibers innervating the hair cells. If the production of the otoliths is regulated to reach an optimal weight, their development would be abnormal in microgravity. Ground-based control experiments are reported describing the developmental sequence in which the otoliths and their associated sensory epithelium appear and increase in size. Three-dimensional reconstruction of serial sections through the otic vesicle of newt embryos at stages 31 through 40 demonstrate the first appearance, relative position and growth of the otoliths. In adult newts, the otoconia in the utricle appear similar to mammalian otoconia, which are composed of calcite. The newt saccular otoconia are at least 99% aragonite, as is found in most aquatic species. Reports of experiments in which fertilized frog eggs were flown on a Russian Cosmos mission conclude that the utricular otolith is increased in volume, whereas the saccular otolith maintains normal size, suggesting that at least the utricular weight might be regulated.

  17. Behavioral rhythms of the Japanese newts, Cynops pyrrhogaster, under a semi-natural condition

    NASA Astrophysics Data System (ADS)

    Nagai, Kiyoko; Oishi, T.

    Locomotor activity rhythms of the Japanese newt, Cynops pyrrhogaster, were recorded under a semi-natural condition using phototransistor systems. The daily activity rhythm showed a seasonal change: the locomotor activity was mainly diurnal (active during the daytime) from spring to early summer; mainly nocturnal (active during the night-time) from summer to autumn; and showed either a diurnal or nocturnal pattern, depending on the ambient temperature, in winter. To analyze the daily activity in detail, we observed the behavior of a group of newts (three males, three females) throughout 24 h. Four types of behavior (respiration, feeding, mating, and resting on the land) were observed. Each behavior had daily rhythms and showed a seasonal change. The behavior on land showed mainly a nocturnal or bimodal pattern (activity rhythms with two peaks) throughout the year and was more frequently observed in summer. Mating behavior also showed a seasonal change: high activity in spring, with peaks in the early morning and evening, but no activity in summer. Except in winter, feeding and respiratory behavior showed no seasonal changes in either activity period or frequency. Coupling between behavior and the clock seems to be weak in the Japanese newt because of indistinct daily rhythms and frequent phase changes of locomotor activity in water. Physical factors such as humidity and temperature seem to affect strongly the daily activity of the newts.

  18. Love is blind: indiscriminate female mating responses to male courtship pheromones in newts (Salamandridae).

    PubMed

    Treer, Dag; Van Bocxlaer, Ines; Matthijs, Severine; Du Four, Dimitri; Janssenswillen, Sunita; Willaert, Bert; Bossuyt, Franky

    2013-01-01

    Internal fertilization without copulation or prolonged physical contact is a rare reproductive mode among vertebrates. In many newts (Salamandridae), the male deposits a spermatophore on the substrate in the water, which the female subsequently takes up with her cloaca. Because such an insemination requires intense coordination of both sexes, male newts have evolved a courtship display, essentially consisting of sending pheromones under water by tail-fanning towards their potential partner. Behavioral experiments until now mostly focused on an attractant function, i.e. showing that olfactory cues are able to bring both sexes together. However, since males start their display only after an initial contact phase, courtship pheromones are expected to have an alternative function. Here we developed a series of intraspecific and interspecific two-female experiments with alpine newt (Ichthyosaura alpestris) and palmate newt (Lissotriton helveticus) females, comparing behavior in male courtship water and control water. We show that male olfactory cues emitted during tail-fanning are pheromones that can induce all typical features of natural female mating behavior. Interestingly, females exposed to male pheromones of their own species show indiscriminate mating responses to conspecific and heterospecific females, indicating that visual cues are subordinate to olfactory cues during courtship.

  19. Economic thermoregulatory response explains mismatch between thermal physiology and behaviour in newts.

    PubMed

    Gvoždík, Lumír; Kristín, Peter

    2017-03-15

    Temperature is an important factor determining distribution and abundance of organisms. Predicting the impact of warming climate on ectotherm populations requires information about species' thermal requirements, i.e. their so-called 'thermal niche'. The characterization of thermal niche remains a complicated task. We compared the applicability of two indirect approaches, based on reaction norm (aerobic scope curve) and optimality (preferred body temperature) concepts, for indirect estimation of thermal niche while using newts, Ichthyosaura alpestris, as a study system. If the two approaches are linked, then digesting newts should keep their body temperatures close to values maximizing aerobic scope for digestion. After feeding, newts maintained their body temperatures within a narrower range than did hungry individuals. The range of preferred body temperatures was well below the temperature maximizing aerobic scope for digestion. Optimal temperatures for factorial aerobic scope fell within the preferred body temperature range of digesting individuals. We conclude that digesting newts prefer body temperatures that are optimal for the maximum aerobic performance but relative to the maintenance costs. What might be termed the 'economic' thermoregulatory response explains the mismatch between thermal physiology and behaviour in this system.

  20. Analysis of the hematopoietic tissue in Pleurodeles waltl newts exposed to 2 g hypergravity

    NASA Astrophysics Data System (ADS)

    Domaratskaya, Elena; Nikonova, Tatyana M.; Grigoryan, Eleonora N.; Dvorochkin, Natalya; Yousuf, Rukhsana; Almeida, Eduardo; Butorina, Nina N.

    2012-07-01

    Gravity is an important factor in creating biologically-relevant mechanical loads, and in spaceflight living organisms encounter both microgravity as well as hypergravity conditions. Here we studied the influence of hypergravity on the hematopoietic tissue of P. waltl newts in parallel with tissue regeneration experiments of the newt lens and tail. At day 9 post-surgery one group of newts was subjected to centrifugation at 2 g (2G, 12 days), while another was kept at 1 g. In addition, a basal control in wet mats, at 1g, (BC, 1G), and an aquarium control, neutrally buoyant, (AC, low G), were also performed. Differential blood counts and histological analysis of the spleen and liver were carried out in experimental and control groups of animals. At day 21 post-surgery in all groups (AC, 1G, and 2G), the number of neutrophils in the blood was significantly lower than in BC indicating a decrease in the inflammation induced by surgery. The 2G group however, showed numbers of neutrophils significantly higher than AC (neutrally buoyant) animals. This result suggests that post-operative inflammation can persist longer at 2 g that under unloaded aquarium conditions. In contrast we did not observe any significant differences in lymphocyte numbers between any experimental and control groups. Histological examination of the liver and spleen also did not show any significant morphological alterations due to hypergravity. These results indicate that 12 day exposure to hypergravity at 2 g, had only partial influence on newt hematopoiesis, possibly extending the duration of surgery-related inflammatory responses. Data obtained with newts in our previous experiments on Foton-M2 and Foton-M3 flights in microgravity also showed only slight effect on blood cells. Furthermore microgravity also did not cause any morphological changes in the hematopoietic and lymphoid tissues, and did not impair the proliferative capacity of newt hematopoietic cells. In sum these results indicate the

  1. Metamorphosis inhibition: an alternative rearing protocol for the newt, Cynops pyrrhogaster.

    PubMed

    Chiba, Chikafumi; Yamada, Shouta; Tanaka, Hibiki; Inae-Chiba, Maiko; Miura, Tomoya; Casco-Robles, Martin Miguel; Yoshikawa, Taro; Inami, Wataru; Mizuno, Aki; Islam, Md Rafiqul; Han, Wenje; Yasumuro, Hirofumi; Matsumoto, Mikiko; Takayanagi, Miyako

    2012-05-01

    The newt is an indispensable model animal, of particular utility for regeneration studies. Recently, a high-throughput transgenic protocol was established for the Japanese common newt, Cynops pyrrhogaster. For studies of regeneration, metamorphosed animals may be favorable; however, for this species, there is no efficient protocol for maintaining juveniles after metamorphosis in the laboratory. In these animals, survival drops drastically after metamorphosis as their foraging behaviour changes to adapt to a terrestrial habitat, making feeding in the laboratory with live or moving foods more difficult. To elevate the efficiency of laboratory rearing of this species, we examined metamorphosis inhibition (Ml) protocols to bypass the period (four months to two years after hatching) in which the animal feeds exclusively on moving foods. We found that approximately 30% of animals survived after 2-year Ml, and that the survivors continuously grew, only with static food while maintaining their larval form and foraging behaviour in 0.02% thiourea (TU) aqueous solution, then metamorphosed when returned to a standard rearing solution even after 2-year-MI. The morphology and foraging behavior (feeding on static foods in water) of these metamorphosed newts resembled that of normally developed adult newts. Furthermore, they were able to fully regenerate amputated limbs, suggesting regenerative capacity is preserved in these animals. Thus, controlling metamorphosis with TU allows newts to be reared with the same static food under aqueous conditions, providing an alternative rearing protocol that offers the advantage of bypassing the critical period and obtaining animals that have grown sufficiently for use in regeneration studies.

  2. Promotion of spermatogonial proliferation by neuregulin 1 in newt (Cynops pyrrhogaster) testis.

    PubMed

    Oral, Ozlem; Uchida, Ichiro; Eto, Ko; Nakayama, Yuki; Nishimura, Osamu; Hirao, Yukako; Ueda, Junko; Tarui, Hiroshi; Agata, Kiyokazu; Abé, Shin-Ichi

    2008-01-01

    We have previously shown that mammalian follicle-stimulating hormone (FSH) promotes the proliferation of spermatogonia and their differentiation into primary spermatocytes in organ culture of newt testis. In the current study, we performed microarray analysis to isolate local factors secreted from somatic cells upon FSH treatment and acting on the germ cells. We identified neuregulin 1 (NRG1) as a novel FSH-upregulated clone homologous to mouse NRG1 known to control cell proliferation, differentiation and survival in various tissues. We further isolated cDNAs encoding two different clones. Amino acid sequences of the two clones were 75% and 94% identical to Xenopus leavis immunoglobulin (Ig)-type and cysteine-rich domain (CRD)-type NRG1, respectively, which had distinct sequences in their N-terminal region but identical in their epidermal growth factor (EGF)-like domain. Semi-quantitative and quantitative PCR analyses indicated that both clones were highly expressed at spermatogonial stage than at spermatocyte stage. In vitro FSH treatment increased newt Ig-NRG1 (nIg-NRG1) mRNA expression markedly in somatic cells, whereas newt CRD-NRG1 (nCRD-NRG1) mRNA was only slightly increased by FSH. To elucidate the function of newt NRG1 (nNRG1) in spermatogenesis, recombinant EGF domain of nNRG1 (nNRG1-EGF) was added to organ and reaggregated cultures with or without somatic cells: it promoted spermatogonial proliferation in all cases. Treatment of the cultures with the antibody against nNRG1-EGF caused remarkable suppression of spermatogonial proliferation activated by FSH. These results indicated that nNRG1 plays a pivotal role in promoting spermatogonial proliferation by both direct effect on spermatogonia and indirect effect via somatic cells in newt testes.

  3. Facilitating permeability of landscapes impacted by roads for protected amphibians: patterns of movement for the great crested newt

    PubMed Central

    Petrovan, Silviu; Ward, Alastair I.; Wheeler, Philip

    2017-01-01

    Amphibian populations are highly vulnerable to road mortality and habitat fragmentation caused by road networks. Wildlife road tunnels are considered the most promising road mitigation measure for amphibians yet generally remain inadequately monitored, resulting in mixed success rates in the short-term and uncertain conservation benefits in the long-term. We monitored a complex multi-tunnel and fence system over five years and investigated the impact of the scheme on movement patterns of two newt species, including the largest known UK population of the great crested newt (Triturus cristatus), a European Protected Species. We used a stage descriptive approach based on capture positions to quantify newt movement patterns. Newt species successfully used the mitigation but the system constituted a bottleneck to movements from the fences to the tunnels. Crossing rates varied widely among years and were skewed towards autumn dispersal rather than spring breeding migration. There was a substantial negative bias against adult male great crested newts using the system. This study indicates that road tunnels could partially mitigate wider connectivity loss and fragmentation at the landscape scale for newt species. However, the observed bottleneck effects and seasonal bias could have population-level effects which must be better understood, especially for small populations, so that improvements can be made. Current requirements for monitoring mitigation schemes post-implementation are probably too short to assess their effectiveness in maintaining connectivity and to adequately understand their population-level impacts. PMID:28265490

  4. A novel RNA-binding protein from Triturus carnifex identified by RNA-ligand screening with the newt hammerhead ribozyme

    PubMed Central

    Denti, Michela A.; Alba, A. Emilio Martínez de; Sägesser, Rudolf; Tsagris, Mina; Tabler, Martin

    2000-01-01

    The newt hammerhead ribozyme is transcribed from Satellite 2 DNA, which consists of tandemly repeated units of 330 bp. However, different transcripts are synthesized in different tissues. In all somatic tissues and in testes, dimeric and multimeric RNA transcripts are generated which, to some extent, self-cleave into monomers at the hammerhead domain. In ovaries, primarily a distinct monomeric unit is formed by transcription, which retains an intact hammerhead self-cleavage site. The ovarian monomeric RNA associates to form a 12S complex with proteins that are poorly characterised so far. In this work we identified NORA, a protein that binds the ovarian form of the newt ribozyme. We show that the newt ribozyme binds to the Escherichia coli-expressed protein, as well as to a protein of identical size that is found exclusively in newt ovaries. Also NORA mRNA was detectable only in ovary, but in neither somatic tissues nor testes. The tissue-specific expression of NORA is analogous to the ovary-specific transcription of the newt ribozyme. Although NORA was identified by its ability to bind to the newt ribozyme in the presence of a vast excess of carrier RNA, it was able to interact with certain other RNA probes. This novel RNA-binding protein does not contain any motif characteristic for RNA-binding proteins or any other known protein domain, but it shares a striking similarity with a rat resiniferatoxin-binding protein. PMID:10666442

  5. Intra-specific variability of hindlimb length in the palmate newt: an indicator of population isolation induced by habitat fragmentation?

    PubMed Central

    Le Chevalier, Hugo; Baillat, Boris; Barthe, Laurent; Pottier, Gilles; Calvez, Olivier; Ribéron, Alexandre

    2016-01-01

    Habitat fragmentation is one of the main drivers of global amphibian decline. Anthropogenic landscape elements can act as barriers, hindering the dispersal that is essential for maintaining gene flow between populations. Dispersal ability can be influenced by locomotor performance, which in turn can depend on morphological traits, such as hindlimb length (HLL) in amphibians. Here, we tested relationships between HLL and environmental variables—road types, forests and agricultural lands—among 35 sub-populations of palmate newts (Lissotriton helveticus) in southwestern France. We expected roads to select for short-legged newts due to a higher mortality of more mobile individuals (long-legged newts) when crossing roads. Accordingly, short-legged newts were found in the vicinity of roads, whereas long-legged newts were found closer to forests and in ponds close geographically to another water body. HLL in newts was hence influenced by habitat types in a heterogeneous landscape, and could therefore be used as an indicator of population isolation in a meta-population system. PMID:27122009

  6. Influence of temperature on female, embryonic and hatchling traits in syntopic newts, Ichthyosaura alpestris and Lissotriton vulgaris.

    PubMed

    Mettouris, Onoufrios; Dalmyras, Dimitrios; Giokas, Sinos

    2017-01-01

    Amphibian populations have been declining globally for the last several decades, and climate change is often regarded as one of the most important factors driving these declines. Amphibians are particularly sensitive to climatic changes due to their physiological, ecological and behavioral characteristics. Here we performed a laboratory experiment to investigate how temperature affects ovipositing females, eggs and hatchlings in two syntopic populations of alpine newts, Ichthyosaura alpestris, and smooth newts, Lissotriton vulgaris. Female newts were assigned to two different oviposition temperatures (11°C and 14°C) for the duration of their oviposition period. Deposited eggs were equally divided and assigned to three different incubation temperatures (11°C, 14°C and 17°C). We hypothesized that oviposition will be affected by temperature, that the combination of different oviposition and incubation temperatures may have an effect on embryonic and hatchling traits (embryonic mortality, days to hatch and hatchling length), and that these effects might differ between the two newt species. Temperature affected the number of deposited eggs in smooth newts, but not in alpine newts. Larval hatching success was not affected by oviposition or incubation temperature. Temperature effects on hatching time and hatchling length differed between the two species. These results suggest that temperature changes may have disparate effects on amphibian reproduction, even in syntopic taxa.

  7. Integrative Phylogeography of Calotriton Newts (Amphibia, Salamandridae), with Special Remarks on the Conservation of the Endangered Montseny Brook Newt (Calotriton arnoldi)

    PubMed Central

    Valbuena-Ureña, Emilio; Amat, Fèlix; Carranza, Salvador

    2013-01-01

    The genus Calotriton includes two species of newts highly adapted to live in cold and fast-flowing mountain springs. The Pyrenean brook newt (Calotriton asper), restricted to the Pyrenean region, and the Montseny brook newt (Calotriton arnoldi), endemic to the Montseny massif and one of the most endangered amphibian species in Europe. In the present manuscript, we use an integrative approach including species distribution modeling (SDM), molecular analyses of mitochondrial and nuclear DNA sequence data and morphology to unravel the historical processes that have contributed to shaping the biogeography and genetic structure of the genus Calotriton, with special emphasis on the conservation of C. arnoldi. The results of the molecular analyses confirm that, despite having originated recently, being ecologically similar and geographically very close, there is no signal of hybridization between C. asper and C. arnoldi. SDM results suggest that tough environmental conditions on mountains tops during glacial periods, together with subsequent warmer periods could have prevented the contact between the two species. Within the critically endangered C. arnoldi, a high genetic structure is revealed despite its extremely small distribution range compared to C. asper. Haplotype networks, AMOVA and SAMOVA analyses suggest that two distinct groups of populations can be clearly differentiated with absence of gene flow. This is in concordance with morphological differentiation and correlates with its geographical distribution, as the two groups are situated on the eastern and western sides of a river valley that acts as a barrier. The genetic and morphological results are highly important for the ongoing conservation program of C. arnoldi and strongly justify the management of this species into at least two independent evolutionary significant units (eastern and western sectors) to guarantee the long-term population viability. PMID:23750201

  8. Integrative phylogeography of Calotriton newts (Amphibia, Salamandridae), with special remarks on the conservation of the endangered Montseny brook newt (Calotriton arnoldi).

    PubMed

    Valbuena-Ureña, Emilio; Amat, Fèlix; Carranza, Salvador

    2013-01-01

    The genus Calotriton includes two species of newts highly adapted to live in cold and fast-flowing mountain springs. The Pyrenean brook newt (Calotriton asper), restricted to the Pyrenean region, and the Montseny brook newt (Calotriton arnoldi), endemic to the Montseny massif and one of the most endangered amphibian species in Europe. In the present manuscript, we use an integrative approach including species distribution modeling (SDM), molecular analyses of mitochondrial and nuclear DNA sequence data and morphology to unravel the historical processes that have contributed to shaping the biogeography and genetic structure of the genus Calotriton, with special emphasis on the conservation of C. arnoldi. The results of the molecular analyses confirm that, despite having originated recently, being ecologically similar and geographically very close, there is no signal of hybridization between C. asper and C. arnoldi. SDM results suggest that tough environmental conditions on mountains tops during glacial periods, together with subsequent warmer periods could have prevented the contact between the two species. Within the critically endangered C. arnoldi, a high genetic structure is revealed despite its extremely small distribution range compared to C. asper. Haplotype networks, AMOVA and SAMOVA analyses suggest that two distinct groups of populations can be clearly differentiated with absence of gene flow. This is in concordance with morphological differentiation and correlates with its geographical distribution, as the two groups are situated on the eastern and western sides of a river valley that acts as a barrier. The genetic and morphological results are highly important for the ongoing conservation program of C. arnoldi and strongly justify the management of this species into at least two independent evolutionary significant units (eastern and western sectors) to guarantee the long-term population viability.

  9. Fidelity to the breeding site in the alpine newt Triturus Alpestris.

    PubMed

    Joly, P; Miaud, C

    1989-06-01

    In a context of several closed breeding sites (archipelago model), the great majority of alpine newts are sedentary, visiting the same site during two successive years. A homing experiment offered the animals a choice between two breeding sites, one from which they came and the other which was inhabited by another population. This experiment demonstrates the fidelity of a great majority of newts for their site of origin. Fidelity was stronger when sites were distant (150 m) than when nearer (25 m). The speed and the probability of return still varied according to both the distance and the nature of the environment of the release point. The performances were better when the animals were released in the wood than when released in the pasture. The mechanisms of orientation and navigation which should explain such results, as well as the genetic consequences of the fidelity, are examined and discussed.

  10. Identification of cDNAs associated with late dedifferentiation in adult newt forelimb regeneration.

    PubMed

    Vascotto, Sandy G; Beug, Shawn; Liversage, Richard A; Tsilfidis, Catherine

    2005-06-01

    Epimorphic limb regeneration in the adult newt involves the dedifferentiation of differentiated cells to yield a pluripotent blastemal cell. These mesenchymal-like cells proliferate and subsequently respond to patterning and differentiation cues to form a new limb. Understanding the dedifferentiation process requires the selective identification of dedifferentiating cells within the heterogeneous population of cells in the regenerate. In this study, representational differences analysis was used to produce an enriched population of dedifferentiation-associated cDNA fragments. Fifty-nine unique cDNA fragments were identified, sequenced, and analyzed using bioinformatics tools and databases. Some of these clones demonstrate significant similarity to known genes in other species. Other clones can be linked by homology to pathways previously implicated in the dedifferentiation process. These data will form the basis for further analyses to elucidate the role of candidate genes in the dedifferentiation process during newt forelimb regeneration.

  11. Tetrodotoxin levels in larval and metamorphosed newts (Taricha granulosa) and palatability to predatory dragonflies.

    PubMed

    Gall, Brian G; Stokes, Amber N; French, Susannah S; Schlepphorst, Elizabeth A; Brodie, Edmund D; Brodie, Edmund D

    2011-06-01

    Some populations of the newt Taricha granulosa possess extremely high concentrations of the neurotoxin tetrodotoxin (TTX). Tetrodotoxin is present in adult newts and their eggs, but has been assumed to be absent from the larval stage. We tested larval and metamorphosed juveniles for the presence of TTX and evaluated the palatability of these developmental stages to predatory dragonfly nymphs. All developmental stages retained substantial quantities of TTX and almost all individuals were unpalatable to dragonfly nymphs. Tetrodotoxin quantity varied greatly among individuals. When adjusted for mass, TTX concentrations declined steadily through metamorphosis. Several juveniles were palatable to dragonflies and these individuals had significantly lower TTX levels than unpalatable juveniles. These results suggest that despite previous assumptions, substantial quantities of TTX, originally deposited in the embryo, are retained by the developing larvae and metamorphosed juveniles and this quantity is enough to make them unpalatable to some potential predators.

  12. Regenerative capacity in newts is not altered by repeated regeneration and ageing.

    PubMed

    Eguchi, Goro; Eguchi, Yukiko; Nakamura, Kenta; Yadav, Manisha C; Millán, José Luis; Tsonis, Panagiotis A

    2011-07-12

    The extent to which adult newts retain regenerative capability remains one of the greatest unanswered questions in the regeneration field. Here we report a long-term lens regeneration project spanning 16 years that was undertaken to address this question. Over that time, the lens was removed 18 times from the same animals, and by the time of the last tissue collection, specimens were at least 30 years old. Regenerated lens tissues number 18 and number 17, from the last and the second to the last extraction, respectively, were analysed structurally and in terms of gene expression. Both exhibited structural properties identical to lenses from younger animals that had never experienced lens regeneration. Expression of mRNAs encoding key lens structural proteins or transcription factors was very similar to that of controls. Thus, contrary to the belief that regeneration becomes less efficient with time or repetition, repeated regeneration, even at old age, does not alter newt regenerative capacity.

  13. Resource partitioning in two heterochronic populations of Greek Alpine newts, Triturus alpestris veluchiensis

    NASA Astrophysics Data System (ADS)

    Denoël, Mathieu; Schabetsberger, Robert

    2003-04-01

    Current ecological models suggest that the maintenance of trophic polymorphisms is favoured by a different resource use in alternative morphs. Facultative paedomorphosis in newts is an example of phenotypic variation as paedomorphs retain morphological larval traits, such as gills and gill slits. The aim of this study was to find out whether heterochronic morphs occupy particular micro-habitats and focus on specific prey items. Resource partitioning was found between morphs. It concerns mainly food selection with paedomorphs preying more on plankton and less on terrestrial invertebrates than metamorphs. Some habitat specializations were also found with metamorphs being more abundant at the water surface than paedomorphs. Diel variation in habitat use of the two different morphs was minimal. Polymorphism allows Alpine newts to exploit the different resources in the lakes in order to minimize intraspecific competition, but the extent of resource partitioning depends on habitat characteristics.

  14. Monoclonal antibodies that recognize transcription unit proteins on newt lampbrush chromosomes

    PubMed Central

    1987-01-01

    We prepared hybridoma cell lines from mice injected with newt germinal vesicle proteins. We tested culture supernates from these cell lines for antibodies that bound to specific morphological structures in lampbrush chromosome preparations (nucleoli, loops, chromomeres, etc.). Four mAbs that recognize antigens on the lateral transcription loops are described here. We suggest that these antigens are proteins associated with nascent RNA transcripts, although they are not among the 30-40-kD "core" heterogeneous nuclear ribonucleoproteins. PMID:3308902

  15. Morphogenetic changes occurring in the regenerating newt tail under changed gravity conditions

    NASA Astrophysics Data System (ADS)

    Radugina, Elena A.; Grigoryan, Eleonora N.; Dvorochkin, Natasha; Almeida, Eduardo

    2012-07-01

    It is widely accepted that gravity greatly affects animal physiology, development, and alters gene expression. Recently it became apparent that it can also affect tissue morphogenesis. In our work, we developed special laboratory conditions that allow us to produce the gravity-dependent alterations in tail regenerates of the newt Pleurodeles waltl. We examined the dynamic morphogenetic changes during 50-day tail regeneration using computer morphometric analysis. Changes that we observed under these conditions were comparable with those found earlier in our spaceflight experiments. The newts kept in aquarium deep water (low g) after 1/3 tail amputation developed normal lanceolate regenerates. In contrast, the animals that stayed on the moist mat (1g) developed tail regenerates curved ventrally, with tips almost touching the mat. The similar results were obtained with a 12-day centrifugation at 2g. The study of the regenerate morphology in low g, 1g, and 2g animal groups allowed us to determine the stage at which the morphological changes in regenerates become apparent, and to detect the main morphological events associated with the development of tail curve, such as bending of ependymal tube and reorientation of the forming cartilage. We describe cellular processes foregoing observed tissue morphogenetic changes, such as cell migration, condensation in cell population, and unequal proliferation in different areas of epidermis and blastema. Cell proliferation in epidermis and blastema of tails regenerated under the conditions of different gravitational load was evaluated by BrdU assay. In 1g newts, cell proliferation increased within the dorso-apical region of the regenerates compared with that in low g group. These results provide us with a valuable insight into the regenerative tissue homostasis that involves cell division, cell death, and migration in the newt regenerating tail. In addition, these findings could provide us with better understanding of the

  16. Can Newts Cope with the Heat? Disparate Thermoregulatory Strategies of Two Sympatric Species in Water

    PubMed Central

    Balogová, Monika; Gvoždík, Lumír

    2015-01-01

    Many ectotherms effectively reduce their exposure to low or high environmental temperatures using behavioral thermoregulation. In terrestrial ectotherms, thermoregulatory strategies range from accurate thermoregulation to thermoconformity according to the costs and limits of thermoregulation, while in aquatic taxa the quantification of behavioral thermoregulation have received limited attention. We examined thermoregulation in two sympatric newt species, Ichthyosaura alpestris and Lissotriton vulgaris, exposed to elevated water temperatures under semi-natural conditions. According to a recent theory, we predicted that species for which elevated water temperatures pose a lower thermal quality habitat, would thermoregulate more effectively than species in thermally benign conditions. In the laboratory thermal gradient, L. vulgaris maintained higher body temperatures than I. alpestris. Semi-natural thermal conditions provided better thermal quality of habitat for L. vulgaris than for I. alpestris. Thermoregulatory indices indicated that I. alpestris actively thermoregulated its body temperature, whereas L. vulgaris remained passive to the thermal heterogeneity of aquatic environment. In the face of elevated water temperatures, sympatric newt species employed disparate thermoregulatory strategies according to the species-specific quality of the thermal habitat. Both strategies reduced newt exposure to suboptimal water temperatures with the same accuracy but with or without the costs of thermoregulation. The quantification of behavioral thermoregulation proves to be an important conceptual and methodological tool for thermal ecology studies not only in terrestrial but also in aquatic ectotherms. PMID:25993482

  17. Quantifying tetrodotoxin levels in the California newt using a non-destructive sampling method.

    PubMed

    Bucciarelli, Gary M; Li, Amy; Zimmer, Richard K; Kats, Lee B; Green, David B

    2014-03-01

    Toxic or noxious substances often serve as a means of chemical defense for numerous taxa. However, such compounds may also facilitate ecological or evolutionary processes. The neurotoxin, tetrodotoxin (TTX), which is found in newts of the genus Taricha, acts as a selection pressure upon predatory garter snakes, is a chemical cue to conspecific larvae, which elicits antipredator behavior, and may also affect macroinvertebrate foraging behavior. To understand selection patterns and how potential variation might affect ecological and evolutionary processes, it is necessary to quantify TTX levels within individuals and populations. To do so has often required that animals be destructively sampled or removed from breeding habitats and brought into the laboratory. Here we demonstrate a non-destructive method of sampling adult Taricha that obviates the need to capture and collect individuals. We also show that embryos from oviposited California newt (Taricha torosa) egg masses can be individually sampled and TTX quantified from embryos. We employed three different extraction techniques to isolate TTX. Using a custom fabricated high performance liquid chromatography (HPLC) system we quantified recovery of TTX. We found that a newly developed micro-extraction technique significantly improved recovery compared to previously used methods. Results also indicate our improvements to the HPLC method have high repeatability and increased sensitivity, with a detection limit of 48 pg (0.15 pmol) TTX. The quantified amounts of TTX in adult newts suggest fine geographic variation in toxin levels between sampling localities isolated by as little as 3 km.

  18. Cloacal anatomy of the male Carpathian newt, Lissotriton montandoni (Amphibia, Salamandridae), in the breeding season.

    PubMed

    Osikowski, Artur; Cierniak-Zuzia, Karolina

    2013-09-01

    This study presents the first light microscopy-based description of the cloacal anatomy of male Carpathian newts (Lissotriton montandoni). This European newt species hybridizes with its sister species, the smooth newt (L. vulgaris), despite a high level of prezygotic isolation. The goal of the study was to ascertain possible anatomical differences in cloacal anatomy, especially pheromone and spermatophore producing glands, which might potentially affect reproductive isolation between L. montandoni and L. vulgaris. The cloaca of L. montandoni males consists of the cloacal tube, cloacal chamber, pseudopenis, and aggregations of cloacal glands. Four main types of cloacal glands were recognized. Pheromone-producing dorsal glands are of two types due to differences in their secretory epithelium: cuboidal and high prismatic. The remaining glands: ventral, pelvic, and Kingsbury's glands, are most likely involved in the synthesis of spermatophore components. Two distinct groups of ventral glands were identified: posterior and anterior ventral glands. In comparison with L. vulgaris, no evident differences were found that could potentially affect courtship pheromone synthesis by dorsal glands or the base and the cap of the spermatophore produced by the remaining cloacal glands.

  19. C5-C10 directly bonded tetrodotoxin analogues: possible biosynthetic precursors of tetrodotoxin from newts.

    PubMed

    Kudo, Yuta; Yamashita, Yoko; Mebs, Dietrich; Cho, Yuko; Konoki, Keiichi; Yasumoto, Takeshi; Yotsu-Yamashita, Mari

    2014-12-22

    The identification of novel tetrodotoxin (TTX, 1) analogues would significantly contribute to the elucidation of its biosynthetic pathway. In this study, the first C5-C10 directly bonded TTX analogues, 4,9-anhydro-10-hemiketal-5-deoxyTTX (2) and 4,9-anhydro-8-epi-10-hemiketal-5,6,11-trideoxyTTX (3), were found in the newt Cynops ensicauda popei by using a screening method involving HILIC-LC-MS/MS focused on the fragment ions of TTX analogues, and their structures were elucidated by spectroscopic methods. Compound 2 was detected in a wide range of newt species, and the 2 and TTX contents of 22 newt specimens were correlated (rs =0.88). Based on these results and its structural features, 2 was predicted to serve as a precursor of TTX that would be directly converted into 4,9-anhydroTTX (4) by Baeyer-Villiger-like oxidation or via 4,9-anhydro-5-deoxyTTX formed by cleavage of the C5-C10 bond. The bicyclic carbon skeletons of 2 and 3 suggested a possible monoterpene origin for TTX.

  20. Sperm transport after insemination in the Alpine newt (Triturus alpestris, Caudata, Salamandridae).

    PubMed

    Osikowski, Artur

    2007-01-01

    The goal of this study was to test if sperm transport to the spermathecae in the Alpine newt (Triturus alpestris) requires active co-operation of the female. Artificial insemination of anaesthetised female newts was conducted using spermatophores collected from courting males and with sperm duct contents collected from sacrificed males. Sperm was present in the spermathecae of 9 out of 10 females inseminated with the spermatophores but in only 1 out of 8 females inseminated with sperm duct contents. The females of both groups laid some eggs after insemination, and a portion of these eggs in group of females inseminated with spermatophores were fertilized. However, the number of eggs produced by the females was much lower than typical egg-production in newts. The presence of sperm in the spermathecae of females inseminated with spermatophores and lack of sperm in the spermathecae of females inseminated with sperm duct contents suggests that sperm transport is either induced by the substances present in spermatophores and/or that sperm from the sperm duct is not fully mobile in comparison with sperm from the spermatophores.

  1. Can newts cope with the heat? Disparate thermoregulatory strategies of two sympatric species in water.

    PubMed

    Balogová, Monika; Gvoždík, Lumír

    2015-01-01

    Many ectotherms effectively reduce their exposure to low or high environmental temperatures using behavioral thermoregulation. In terrestrial ectotherms, thermoregulatory strategies range from accurate thermoregulation to thermoconformity according to the costs and limits of thermoregulation, while in aquatic taxa the quantification of behavioral thermoregulation have received limited attention. We examined thermoregulation in two sympatric newt species, Ichthyosaura alpestris and Lissotriton vulgaris, exposed to elevated water temperatures under semi-natural conditions. According to a recent theory, we predicted that species for which elevated water temperatures pose a lower thermal quality habitat, would thermoregulate more effectively than species in thermally benign conditions. In the laboratory thermal gradient, L. vulgaris maintained higher body temperatures than I. alpestris. Semi-natural thermal conditions provided better thermal quality of habitat for L. vulgaris than for I. alpestris. Thermoregulatory indices indicated that I. alpestris actively thermoregulated its body temperature, whereas L. vulgaris remained passive to the thermal heterogeneity of aquatic environment. In the face of elevated water temperatures, sympatric newt species employed disparate thermoregulatory strategies according to the species-specific quality of the thermal habitat. Both strategies reduced newt exposure to suboptimal water temperatures with the same accuracy but with or without the costs of thermoregulation. The quantification of behavioral thermoregulation proves to be an important conceptual and methodological tool for thermal ecology studies not only in terrestrial but also in aquatic ectotherms.

  2. Arginine: A Potent Prey Attractant to Predatory Newts in Mountain Streams

    NASA Astrophysics Data System (ADS)

    Ferrer, R. P.; Zimmer, R. K.

    2005-05-01

    Chemoreception of aquatic organisms has been well-studied in the laboratory, but rarely in the field. The California newt, Taricha torosa, in natural stream habitats is an excellent animal for exploring behavioral responses to prey odors. Here, we selected 13 amino acids for field bioassays based on their concentrations in prey tissue extracts. Bioassays were calibrated for stimulus dilution by means of fluorescent dye releases and flow-through spectrofluorometry. Moreover, hydrodynamic properties of stream flows were determined using an electromagnetic current meter. Of all amino acids tested, only arginine, alanine and glycine were significantly attractive (relative to stream water controls). These three substances caused free-ranging newts to turn upstream and swim towards the odor sources. Additional experiments showed that arginine was the most effective attractant, evoking plume-tracking behavior at concentrations as low as 10 nM. In subsequent trials, nine arginine analogs were tested, but each compound failed to elicit a significant response. Even subtle changes to arginine, such as the addition of a single carbon to the side chain, destroyed all bioactivity. Within its natural habitat, the California newt thus exhibits keen sensitivity and narrow tuning to the free amino acid, arginine, a chemical signal of its prey.

  3. Female newts (Taricha granulosa) produce tetrodotoxin laden eggs after long term captivity.

    PubMed

    Gall, Brian G; Stokes, Amber N; French, Susannah S; Brodie, Edmund D; Brodie, Edmund D

    2012-11-01

    We investigated the presence of tetrodotoxin (TTX) in the eggs of wild-caught newts (Taricha granulosa) at capture and again after one, two, and three years in captivity. Females initially produced eggs that contained quantities of TTX similar to previous descriptions of eggs from wild-caught adults. After the first year in captivity, the egg toxicity from each female declined, ultimately remaining constant during each of the successive years in captivity. Despite declining, all females continued to produce eggs containing substantial quantities of TTX during captivity. The decline in toxicity can not be attributed to declining egg mass but may be the result of the abbreviated reproductive cycle to which the captive newts were subjected in the lab. Finally, an estimate of the amount of TTX provisioned in the entire clutch from each female is similar to the quantity of TTX regenerated in the skin after electrical stimulation. These results, coupled with other long-term studies on the maintenance and regeneration of TTX in the skin, suggests an endogenous origin of TTX in newts.

  4. Interactions of Amphibians, Fish, and Macroinvertebrates in a Southeastern Wetland

    NASA Astrophysics Data System (ADS)

    Schultheis, R. D.; Batzer, D. P.

    2005-05-01

    In fishless habitats, amphibians often compete with and are predators of macroinvertebrates. Unlike fish, the effects these interactions have on macroinvertebrate communities have been largely unexplored. We conducted an experiment in a semi-permanent oxbow wetland in the Piedmont region of Georgia to explore interactions between amphibians and macroinvertebrates. The predator community was dominated by Ambystoma opacum (Marbled Salamander) and Notophthalmus viridescens (Eastern Newt). Salamanders and newts were excluded from areas of wetland habitat using wire mesh cages (1.5M x 1.5M, 3mm mesh). The macroinvertebrate communities within the cages were then compared to the ambient habitat outside the cages. Fish, mostly Lepomis macrochirus (Bluegill) and Gambusia affinis (Mosquito Fish), colonized the wetland late in the first year of the study, and became common by year two. Also in year two, Rana catesbeiana (Bullfrog) became established. Thus, we were able to explore the variable effects on the macroinvertebrate community of a changing predator complex over a two year period.

  5. Newt orthologue of Growth arrest-specific 6 (NvGas6) is implicated in stress response during newt forelimb regeneration.

    PubMed

    Beug, Shawn; Vascotto, Sandy G; Tsilfidis, Catherine

    2006-03-01

    Red-spotted newts are capable of regenerating various structures and organs through the process of epimorphic regeneration. Receptor tyrosine kinases (RTKs) and their ligands are important for normal cellular development and physiology but most have not yet been characterised during regeneration. We have isolated a newt orthologue of Growth arrest-specific 6 (NvGas6), and examined its expression during forelimb regeneration and within a blastema cell line (B1H1). During limb regeneration, NvGas6 expression increases upon amputation, peaks during maximal blastema cell proliferation, and is subsequently downregulated during redifferentiation. Transcripts are localised to the wound epithelium and distal mesenchymal cells during dedifferentiation and proliferative phases, and scattered within redifferentiating tissues during later stages. In B1H1 cultures, NvGas6 is upregulated under reduced serum conditions and myogenesis. Treatment with mimosine and colchicine or exposure to heat shock or anoxia results in upregulation of NvGas6 expression. Taken together, our findings suggest that during regeneration, NvGas6 expression may be upregulated in response to cellular stress.

  6. Rapid corticosterone-induced impairment of amplectic clasping occurs in the spinal cord of roughskin newts (taricha granulosa).

    PubMed

    Lewis, Christine M; Rose, James D

    2003-01-01

    Courtship clasping, a reproductive behavior in male roughskin newts (Taricha granulosa), is rapidly blocked by an action of corticosterone (CORT) at a specific neuronal membrane receptor. The CORT-induced impairment of clasping in behaving newts appears to be mediated partly by an elimination of clasping-related activity in medullary reticulospinal neurons. Previous studies of rapid CORT actions in Taricha have focused on the brain, so existence of CORT action in the spinal cord or peripheral nervous system has not been assessed. The present study used newts with a high cervical spinal transection to examine potential spinal or peripheral CORT effects on clasping by the hindlimbs in response to pressure on the cloaca. Spinal transection causes clasps elicited by cloacal stimulation to be very sustained beyond the termination of the eliciting stimulus. In spinally transected newts, CORT caused a dose-dependent depression in the duration as well as quality of the clasp that appeared within 10 min of injection. CORT selectively impaired the usual sustained maintenance of a clasp after termination of cloacal stimulation, but not clasp elicitation during stimulation. These effects were not produced by dexamethasone, a synthetic glucocorticoid that binds poorly to the CORT membrane receptor. The CORT effect on clasp maintenance but not clasp elicitation implies selective action on an intraspinal generator for clasping but not on sensory or efferent neuromuscular aspects of the response. These results indicate the presence in the newt spinal cord of the CORT membrane receptor that exerts functional effects distinctly different from those on the brainstem.

  7. Effects of temperature on embryonic and early larval growth and development in the rough-skinned newt (Taricha granulosa).

    PubMed

    Smith, Geoffrey D; Hopkins, Gareth R; Mohammadi, Shabnam; M Skinner, Heather; Hansen, Tyler; Brodie, Edmund D; French, Susannah S

    2015-07-01

    We investigated the effects of temperature on the growth and development of embryonic and early larval stages of a western North American amphibian, the rough-skinned newt (Taricha granulosa). We assigned newt eggs to different temperatures (7, 14, or 21°C); after hatching, we re-assigned the newt larvae into the three different temperatures. Over the course of three to four weeks, we measured total length and developmental stage of the larvae. Our results indicated a strong positive relationship over time between temperature and both length and developmental stage. Importantly, individuals assigned to cooler embryonic temperatures did not achieve the larval sizes of individuals from the warmer embryonic treatments, regardless of larval temperature. Our investigation of growth and development at different temperatures demonstrates carry-over effects and provides a more comprehensive understanding of how organisms respond to temperature changes during early development.

  8. Development of the otolith organs and semicircular canals in the Japanese red-bellied newt, Cynops pyrrhogaster

    NASA Technical Reports Server (NTRS)

    Wiederhold, M. L.; Yamashita, M.; Larsen, K. A.; Batten, J. S.; Koike, H.; Asashima, M.

    1995-01-01

    The sequence in which the otoliths and semicircular canals and their associated sensory epithelia appear and develop in the newt are described. Three-dimensional reconstruction of serial sections through the otic vesicle of newt embryos from stages 31 through 58 demonstrate the first appearance, relative position and growth of the otoliths. A single otolith is first seen in stage 33 embryos (approximately 9 days old); this splits into separate utricular and saccular otoliths at stage 40 (13 days). The lateral semicircular canal is the first to appear, at stage 41 (14 days). The anterior and posterior canals appear approximately one week later and the vestibular apparatus is essentially fully formed at stage 58 (approximately 5 weeks). The data reported here will serve as ground-based controls for fertilized newt eggs flown on the International Microgravity Laboratory-2 Space Shuttle flight, to investigate the influence of microgravity on the development of the gravity-sensing organs.

  9. [Competence factors of retinal pigment epithelium cells for reprogramming in the neuronal direction during retinal regeneration in newts].

    PubMed

    Grigorian, E N

    2015-01-01

    Retinal pigment epithelium (RPE) cells that have the unique ability to reprogram retinal cells @in vivo@ were analyzed in the adult newt. Our own data and that available in the literature on the peculiarities of the biology of these cells (from morphology to molecular profile, which can be associated with the capability of phenotype change) were summarized: It was established that the molecular traits of specialized and poorly differentiated cells are combined in RPE of the adult newt. It was registered that persistent (at a low level) proliferation and rapid change of specific cytoskeleton proteins can contribute to the success of RPE cell reprogramming in the neuronal direction. Each of the considered factors of competence for reprogramming can be found for animal RPE, whose cells are not able @in vivo@ to change the phenotype to a neuronal one; however, their totality (supported by the epigenetic state permissive for conversion) is probably an internal property of only newt RPE.

  10. Non-invasive assessment of otolith formation during development of the Japanese red-bellied newt, Cynops pyrrhogaster

    NASA Technical Reports Server (NTRS)

    Koike, H.; Nakamura, K.; Nishimura, K.; Kashima, I.; Wiederhold, M. L.; Asashima, M.

    1995-01-01

    Pre-mated adult female newts and embryos have been flown on the International Microgravity Laboratory-2 (IML-2) Space Shuttle flight in 1994 (Wiederhold et al., 1992b). With the specimens available from this flight, the calcification of otoliths, ulna, radius and backbone of the flown larvae and adult newts were analyzed. The experiments presented here studied the development of the otoliths on the ground. Otoliths of living newts, from embryo to adult, were observed in situ with the application of a new X-ray and bio-imaging analyzer system. For the establishment of this method, newts at different developmental stages were used. An imaging plate temporarily stores the X-ray energy pattern at the bio-imaging analyzer. A latent image on the imaging plate was transformed into a digital time series signal with an image reader. Acquired digital information was computed with the image processor. The processed information was recorded on film with an image recorder, in order to visualize it on an enlargement computed radiograph. To analyze development of the otoliths, photo-stimulated luminescence level was detected by an image analyzer, using transmitted X-ray photons. A single clump of otoconia could first be seen at stage 33. Stage-36 embryos first have distinguishable otoliths, with the utricle in front and saccule behind. Our results show that this X-ray method detects the otoliths equally as well as sectioning. In the newt, the mandibular/maxillary bone formed before the spine. It is suspected that for the newt embryo, living in water, feeding becomes necessary prior to support of the body.

  11. Derivation and long-term culture of cells from newt adult limbs and limb blastemas.

    PubMed

    Ferretti, Patrizia; Kumar, Anoop

    2015-01-01

    Notwithstanding the key importance of in vivo models for understanding patterning and cellular interactions in the regenerating tailed amphibian (salamander) limb, dissection of molecular mechanisms, as in other species, can be greatly aided by robust in vitro models. This chapter focuses on derivation and maintenance of cell lines from adult post-metamorphic salamanders and in particular cells derived from normal and regenerating limbs. We also describe a protocol for nucleofecting newt cells that can be used both to investigate the gene function in short-term studies and to establish stable cell lines.

  12. Tetrodotoxin and its analogue 6-epitetrodotoxin in newts (Triturus spp.; Urodela, Salamandridae) from southern Germany.

    PubMed

    Yotsu-Yamashita, Mari; Mebs, Dietrich; Kwet, Axel; Schneider, Michael

    2007-08-01

    Tetrodotoxin (TTX) and its analogue 6-epitetrodotoxin (6-epiTTX) were quantitatively assayed in 59 newts representing four Triturus species (Triturus alpestris, Triturus cristatus, Triturus helveticus, Triturus vulgaris) from southern Germany by a post-column fluorescent-HPLC system. Both toxins were detected in only 15 specimens of the four species. The toxins levels varied considerably among individuals (TTX: 0.11-9.0microg/g; 6-epiTTX: 0.05-17.0microg/g). 6-epiTTX was found to be the major component.

  13. Spatial and temporal instability of local biotic community mediate a form of aposematic defense in newts, consisting of carotenoid-based coloration and tetrodotoxin.

    PubMed

    Mochida, Koji; Kitada, Minoru; Ikeda, Koichi; Toda, Mamoru; Takatani, Tomohiro; Arakawa, Osamu

    2013-09-01

    Most animals advertise their unprofitability to potential predators via conspicuous signals. Whether the strength of this aposematic signal indicates the quality and quantity of chemical defenses in animals is controversial. Here, we investigated the relationship between the conspicuousness of an aposematic signal and toxicity, which likely depends, at least in part, on dietary sources, in the newt Cynops pyrrhogaster. Our results indicate that the magnitude of the aposematic signal was not correlated with the amount of tetrodotoxin (TTX) and 6-epi TTX of wild individuals among populations. Using atoxic newts, reared from eggs, we compared the ability to accumulate TTX from diets between mainland and island populations. Newts of a mainland population that exhibited a less conspicuous signal accumulated more TTX than did equivalent newts of an insular population that displayed a more conspicuous signal; this was unrelated to variation in the toxicity of wild individuals of these two populations. We also found toxicity of wild newts changed over approximately one generation (10 years) in both populations. These results indirectly suggest that environmental variance, such as fluctuations in TTX resources in nature, may obscure differences in the ability of wild newts to accumulate TTX, and that this variation may be responsible for a lack of correlation between the strength of a newt's signal and its toxicity in the wild. These results imply that toxicity of wild individuals likely is a phenotypic trait largely dependent on environmental conditions.

  14. Dermocystid infection and associated skin lesions in free-living palmate newts (Lissotriton helveticus) from Southern France.

    PubMed

    González-Hernández, Milagros; Denoël, Mathieu; Duffus, Amanda J L; Garner, Trenton W J; Cunningham, Andrew A; Acevedo-Whitehouse, Karina

    2010-09-01

    Since the early 1900s, mesomycetozoan parasites have been reported in both European anuran and caudate species. These reports have primarily been descriptive, which has made assessing the impact of these parasites on host populations difficult. Anecdotal reports of dermocystidium-like parasites are becoming widespread across Europe, possibly indicating that these mesomycetozoan parasites are increasing in distribution and/or abundance. This highlights the need for further investigations into the occurrence, pathogenesis and effects on host health of these parasitic infections for free-living amphibian populations, particularly those which are already stressed or threatened by other factors. Here we report the results of pathological, microbiological and molecular investigations used to characterize unidentified skin lesions in palmate newts (Lissotriton helveticus) from Larzac, France. We confirm that the lesions are the result of infection with a novel dermocystidium-like parasite, which is related to Amphybiocystidium ranae. We also show that the same parasite is distributed across several newt breeding sites. The lesions that result from infection with this parasite range from single or few vesicular or nodular cutaneous lesions to multiple coalescing skin ulcers with extensive hemorrhages. The latter have not been previously described in amphibians due to mesomycetozoan parasitic infection. Dermocystid DNA was detected only in newts that showed lesions, providing comparative evidence of the parasite's pathogenicity. We discuss the potential significance of the presence of this pathogen in the context of the population health of palmate newts.

  15. Genetic structure in northeastern populations of the Alpine newt (Triturus alpestris): evidence for post-Pleistocene differentiation.

    PubMed

    Pabijan, M; Babik, W

    2006-08-01

    Genetic variation in 13 populations of the Alpine newt, Triturus alpestris, was assessed at the northeastern margin of its range (southern Poland). Variation at six microsatellite loci was scored in 354 newts, and two mitochondrial DNA fragments (c. 2000 bp) were sequenced in a subset of 27 individuals. Significant differences in allele frequencies and the presence of private alleles determined genetic units corresponding to three separate mountain ranges, i.e. the Carpathian, Sudetes and Holy Cross Mountains. F(ST)'s were three times greater in among than in within mountain range pairwise comparisons. An assignment test and pairwise F(ST)'s suggested relatively high levels of gene flow at the local level, although the Sudetes populations revealed some subtle structuring. Genetic variation was lower in the Carpathians and Holy Cross Mountains. The geographic pattern of mitochondrial DNA variation indicated that these newt populations originated from a single glacial refugium/founder population, and that the colonization of southern Poland took place in an easterly direction. The data show that substantial neutral variation and between group divergence has accumulated relatively quickly in these low-vagility organisms. The Alpine newt case exemplifies species history as a factor determining patterns of genetic diversity in marginal populations.

  16. Pigmentation plasticity enhances crypsis in larval newts: associated metabolic cost and background choice behaviour

    PubMed Central

    Polo-Cavia, Nuria; Gomez-Mestre, Ivan

    2017-01-01

    In heterogeneous environments, the capacity for colour change can be a valuable adaptation enhancing crypsis against predators. Alternatively, organisms might achieve concealment by evolving preferences for backgrounds that match their visual traits, thus avoiding the costs of plasticity. Here we examined the degree of plasticity in pigmentation of newt larvae (Lissotriton boscai) in relation to predation risk. Furthermore, we tested for associated metabolic costs and pigmentation-dependent background choice behaviour. Newt larvae expressed substantial changes in pigmentation so that light, high-reflecting environment induced depigmentation whereas dark, low-reflecting environment induced pigmentation in just three days of exposure. Induced pigmentation was completely reversible upon switching microhabitats. Predator cues, however, did not enhance cryptic phenotypes, suggesting that environmental albedo induces changes in pigmentation improving concealment regardless of the perceived predation risk. Metabolic rate was higher in heavily pigmented individuals from dark environments, indicating a high energetic requirement of pigmentation that could impose a constraint to larval camouflage in dim habitats. Finally, we found partial evidence for larvae selecting backgrounds matching their induced phenotypes. However, in the presence of predator cues, larvae increased the time spent in light environments, which may reflect a escape response towards shallow waters rather than an attempt at increasing crypsis. PMID:28051112

  17. Laser irradiation of centrosomes in newt eosinophils: evidence of centriole role in motility

    SciTech Connect

    Koonce, M.P.; Cloney, R.A.; Berns, M.W.

    1984-06-01

    Newt eosinophils are motile granulated leukocytes that uniquely display a highly visible centrosomal area. Electron microscope and tubulin antibody fluorescence confirms the presence of centrioles, pericentriolar material, and radiating microtubules within this visible area. Actin antibodies intensely stain the advancing cell edges and tail but only weakly stain pseudopods being withdrawn into the cell. Randomly activated eosinophils follow a roughly consistent direction with an average rate of 22.5 ..mu..m/min. The position of the centrosome is always located between the trailing cell nucleus and advancing cell edge. If the cell extends more than one pseudopod, the one closest to or containing the centrosome is always the one in which motility continues. Laser irradiation of the visible centrosomal area resulted in rapid cell rounding. After several minutes following irradiation, most cells flattened and movement continued. However, postirradiation motility was uncoordinated and directionless, and the rate decreased to an average of 14.5 ..mu..m/min. Electron microscopy and tubulin immunofluorescence indicated that an initial disorganization of microtubules resulted from the laser microirradiations. After several minutes, organized microtubules reappeared, but the centrioles appeared increasingly damaged. The irregularities in motility due to irradiation are probably related to the damaged centrioles. The results presented in this paper suggest that the centrosome is an important structure in controlling the rate and direction of newt eosinophil motility.

  18. Reintegration of the regenerated and the remaining tissues during joint regeneration in the newt Cynops pyrrhogaster

    PubMed Central

    Inoue, Takeshi; Yamada, Shigehito

    2015-01-01

    Abstract Urodele amphibians, such as newts, can regenerate a functional limb, including joints, after amputation at any level along the proximal−distal axis of the limb. The blastema can regenerate the limb morphology largely independently of the stump after proximal−distal identity has been established, but the remaining and regenerated tissues must be structurally reintegrated (matched in size and shape). Here we used newt joint regeneration as a model to investigate reintegration, because a functionally interlocking joint requires structural integration between its opposing skeletal elements. After forelimbs were amputated at the elbow joint, the joint was regenerated between the remaining and regenerated skeletal elements. The regenerated cartilage was thick around the amputated joint to make a reciprocally interlocking joint structure with the remaining bone. Furthermore, during regeneration, the extracellular matrix of the remaining tissues was lost, suggesting that the remaining tissues might contribute to the morphogenesis of regenerating cartilage. Our results showed that the area of the regenerated cartilage matched the area of the apposed remaining cartilage, thus contributing to formation of a functional structure. PMID:27499865

  19. Predator-Prey Interactions Shape Thermal Patch Use in a Newt Larvae-Dragonfly Nymph Model

    PubMed Central

    Gvoždík, Lumír; Černická, Eva; Van Damme, Raoul

    2013-01-01

    Thermal quality and predation risk are considered important factors influencing habitat patch use in ectothermic prey. However, how the predator’s food requirement and the prey’s necessity to avoid predation interact with their respective thermoregulatory strategies remains poorly understood. The recently developed ‘thermal game model’ predicts that in the face of imminent predation, prey should divide their time equally among a range of thermal patches. In contrast, predators should concentrate their hunting activities towards warmer patches. In this study, we test these predictions in a laboratory setup and an artificial environment that mimics more natural conditions. In both cases, we scored thermal patch use of newt larvae (prey) and free-ranging dragonfly nymphs (predators). Similar effects were seen in both settings. The newt larvae spent less time in the warm patch if dragonfly nymphs were present. The patch use of the dragonfly nymphs did not change as a function of prey availability, even when the nymphs were starved prior to the experiment. Our behavioral observations partially corroborate predictions of the thermal game model. In line with asymmetric fitness pay-offs in predator-prey interactions (the ‘life-dinner’ principle), the prey’s thermal strategy is more sensitive to the presence of predators than vice versa. PMID:23755175

  20. Predator-prey interactions shape thermal patch use in a newt larvae-dragonfly nymph model.

    PubMed

    Gvoždík, Lumír; Černická, Eva; Van Damme, Raoul

    2014-01-01

    Thermal quality and predation risk are considered important factors influencing habitat patch use in ectothermic prey. However, how the predator's food requirement and the prey's necessity to avoid predation interact with their respective thermoregulatory strategies remains poorly understood. The recently developed 'thermal game model' predicts that in the face of imminent predation, prey should divide their time equally among a range of thermal patches. In contrast, predators should concentrate their hunting activities towards warmer patches. In this study, we test these predictions in a laboratory setup and an artificial environment that mimics more natural conditions. In both cases, we scored thermal patch use of newt larvae (prey) and free-ranging dragonfly nymphs (predators). Similar effects were seen in both settings. The newt larvae spent less time in the warm patch if dragonfly nymphs were present. The patch use of the dragonfly nymphs did not change as a function of prey availability, even when the nymphs were starved prior to the experiment. Our behavioral observations partially corroborate predictions of the thermal game model. In line with asymmetric fitness pay-offs in predator-prey interactions (the 'life-dinner' principle), the prey's thermal strategy is more sensitive to the presence of predators than vice versa.

  1. Selective Landscapes in newt Immune Genes Inferred from Patterns of Nucleotide Variation

    PubMed Central

    Fijarczyk, Anna; Dudek, Katarzyna; Babik, Wieslaw

    2016-01-01

    Host–pathogen interactions may result in either directional selection or in pressure for the maintenance of polymorphism at the molecular level. Hence signatures of both positive and balancing selection are expected in immune genes. Because both overall selective pressure and specific targets may differ between species, large-scale population genomic studies are useful in detecting functionally important immune genes and comparing selective landscapes between taxa. Such studies are of particular interest in amphibians, a group threatened worldwide by emerging infectious diseases. Here, we present an analysis of polymorphism and divergence of 634 immune genes in two lineages of Lissotriton newts: L. montandoni and L. vulgaris graecus. Variation in newt immune genes has been shaped predominantly by widespread purifying selection and strong evolutionary constraint, implying long-term importance of these genes for functioning of the immune system. The two evolutionary lineages differ in the overall strength of purifying selection which can partially be explained by demographic history but may also signal differences in long-term pathogen pressure. The prevalent constraint notwithstanding, 23 putative targets of positive selection and 11 putative targets of balancing selection were identified. The latter were detected by composite tests involving the demographic model and further validated in independent population samples. Putative targets of balancing selection encode proteins which may interact closely with pathogens but include also regulators of immune response. The identified candidates will be useful for testing whether genes affected by balancing selection are more prone to interspecific introgression than other genes in the genome. PMID:27702815

  2. Population Genetic Structure of the Endangered Kaiser's Mountain Newt, Neurergus kaiseri (Amphibia: Salamandridae).

    PubMed

    Farasat, Hossein; Akmali, Vahid; Sharifi, Mozafar

    2016-01-01

    Species often exhibit different levels of genetic structuring correlated to their environment. However, understanding how environmental heterogeneity influences genetic variation is difficult because the effects of gene flow, drift and selection are confounded. We investigated the genetic variation and its ecological correlates in an endemic and critically endangered stream breeding mountain newt, Neurergus kaiseri, within its entire range in southwestern Iran. We identified two geographic regions based on phylogenetic relationships using Bayesian inference and maximum likelihood of 779 bp mtDNA (D-loop) in 111 individuals from ten of twelve known breeding populations. This analysis revealed a clear divergence between northern populations, located in more humid habitats at higher elevation, and southern populations, from drier habitats at lower elevations regions. From seven haplotypes found in these populations none was shared between the two regions. Analysis of molecular variance (AMOVA) of N. kaiseri indicates that 94.03% of sequence variation is distributed among newt populations and 5.97% within them. Moreover, a high degree of genetic subdivision, mainly attributable to the existence of significant variance among the two regions is shown (θCT = 0.94, P = 0.002). The positive and significant correlation between geographic and genetic distances (r = 0.61, P = 0.002) following controlling for environmental distance suggests an important influence of geographic divergence of the sites in shaping the genetic variation and may provide tools for a possible conservation based prioritization policy for the endangered species.

  3. Seasonal variation of morph ratio in facultatively paedomorphic populations of the palmate newt Triturus helveticus

    NASA Astrophysics Data System (ADS)

    Denoël, Mathieu

    2006-03-01

    Facultative paedomorphosis is a polyphenism in which individuals may express one of two alternative ontogenetic pathways (metamorphosis vs. paedomorphosis) depending on environmental cues. Previous laboratory experiments showed that drying can cause morph ratio change, suggesting that the maintenance of facultative paedomorphosis is highly dependent on environmental determinants. The aim of this study was to examine seasonal variation in morph ratios in eight ponds from Larzac (southern France) naturally inhabited by palmate newts and to relate it to pond drying. In some ponds, the relative proportion of paedomorphs (i.e. individuals retaining gills at the adult stage) increased after the breeding period, but it remained stable or decreased in other ponds. This seasonal variation in the abundance of the two morphs most probably reflects (1) the emigration of metamorphs leaving the pond to occupy terrestrial habitats and (2) metamorphosis of paedomorphic adults in response to drying of the ponds. This study shows that facultative paedomorphosis in palmate newts is a dynamic process that allows rapid change (i.e. within a single year) in morph ratio to fit environmental variation (i.e. risk of drying) within the aquatic habitats. Long-term studies are needed to model the evolution of the dimorphism according to environmental change.

  4. Analysis of Cell Proliferation in Newt (Pleurodeles waltl) Tissue Regeneration during Spaceflight in Foton M-2

    NASA Technical Reports Server (NTRS)

    Almeida, E. A. C.; Roden, C.; Phillips, J. A.; Yusuf, R.; Globus, R. K.; Searby, N.; Vercoutere, W.; Morey-Holton, E.; Tairbekov, M.; Grigoryan, N.; Domaratskaya, E.; Poplinskaya, V.; Mitashov, V.

    2006-01-01

    Terrestrial organisms exposed to microgravity during spaceflight expe rience musculoskeletal degeneration. It is still not understood if lo nger-term exposures to microgravity induce degeneration in other tiss ues, and if these effects are also observed in neutrally buoyant aqu atic organisms that may be pre-adapted to mechanical unloading. The " Regeneration" experiment conducted collaboratively between Russian an d US scientists for 16 days in the Russian Foton M-2 spaceflight soug ht to test the hypothesis that microgravity alters the proliferation of cells in regenerating tail tissue of the newt Pleurodeles waltl. Our initial results indicate that we successfUlly delivered the proli feration marker 5-bromo-2'-deoxy Uridine (BrdU) during spaceflight, and that it was incorporated in the nuclei of cells in regenerating tis sues. Cells in spaceflight tail regenerates proliferated at a slight ly slower rate and were more undifferentiated than those in ground sy nchronous controls. In addition, the size of regenerating tails from spaceflight was smaller than synchronous controls. However, onboard temperature recordings show that the temperature in spaceflight was a bout 2 C lower than ground synchronous controls, possibly explaining the observed differences. Additional post-facto ground controls at ma tched temperatures will correctly determine the effects of spaceflig ht on regenerative cell proliferation in the newt.

  5. Seasonal acclimation of preferred body temperatures improves the opportunity for thermoregulation in newts.

    PubMed

    Hadamová, Markéta; Gvoždík, Lumír

    2011-01-01

    Seasonal acclimation and thermoregulation represent major components of complex thermal strategies by which ectotherms cope with the heterogeneity of their thermal environment. Some ectotherms possess the acclimatory capacity to shift seasonally their thermoregulatory behavior, but the frequent use of constant acclimation temperatures during experiments and the lack of information about thermal heterogeneity in the field obscures the ecological relevance of this plastic response. We examined the experimentally induced seasonal acclimation of preferred body temperatures (T(p)) in alpine newts Ichthyosaura (formerly Triturus) alpestris subjected to a gradual increase in acclimation temperature from 5°C during the winter to a constant 15°C or diel fluctuations between 10° and 20°C during the spring/summer. Both the mean and range of T(p) followed the increase in mean acclimation temperature without the influence of diel temperature fluctuations. The direction and magnitude of this acclimatory capacity has the potential to increase the time window available for thermoregulation. Although thermoregulation and thermal acclimation are often considered as separate but coadapted adjustments to thermal heterogeneity, their combined response is employed by newts to tackle seasonal variation in a thermoregulatory-challenging aquatic environment.

  6. Formation of otoconia in the Japanese red-bellied newt, Cynops pyrrhogaster

    NASA Technical Reports Server (NTRS)

    Wiederhold, M. L.; Yamashita, M.; Larsen, K.; Asashima, M.

    1994-01-01

    Pre-mated adult female newts and fertilized eggs will be flown on the International Microgravity Laboratory-2 flight, in 1994. One objective of the flight will be to observe the influence of microgravity on the development of the gravity-sensing organs in the inner ear. These organs contain sensory hair cells covered by a layer of dense stones (otoconia). Gravity and linear acceleration exert forces on these masses, leading to excitation of the nerve fibers innervating the hair cells. If the production of the otoliths is regulated to reach an optimal weight, their development might be abnormal in microgravity. Ground-based control experiments are reported describing the developmental sequence in which both the otoliths and their associated sensory epithelium and the semicircular canals appear and develop. Three-dimensional reconstruction of serial sections through the otic vesicle of newt embryos at stages 31 through 58 demonstrate the first appearance, relative position and growth of the otoliths. Reports of experiments in which fertilized frog eggs were flown on a Russian Cosmos mission conclude that the utricular otolith is increased in volume, whereas the saccular otolith maintains normal size, suggesting that at least in the utricle, the weight of the otolith might be regulated.

  7. Reintegration of the regenerated and the remaining tissues during joint regeneration in the newt Cynops pyrrhogaster.

    PubMed

    Tsutsumi, Rio; Inoue, Takeshi; Yamada, Shigehito; Agata, Kiyokazu

    2015-02-01

    Urodele amphibians, such as newts, can regenerate a functional limb, including joints, after amputation at any level along the proximal-distal axis of the limb. The blastema can regenerate the limb morphology largely independently of the stump after proximal-distal identity has been established, but the remaining and regenerated tissues must be structurally reintegrated (matched in size and shape). Here we used newt joint regeneration as a model to investigate reintegration, because a functionally interlocking joint requires structural integration between its opposing skeletal elements. After forelimbs were amputated at the elbow joint, the joint was regenerated between the remaining and regenerated skeletal elements. The regenerated cartilage was thick around the amputated joint to make a reciprocally interlocking joint structure with the remaining bone. Furthermore, during regeneration, the extracellular matrix of the remaining tissues was lost, suggesting that the remaining tissues might contribute to the morphogenesis of regenerating cartilage. Our results showed that the area of the regenerated cartilage matched the area of the apposed remaining cartilage, thus contributing to formation of a functional structure.

  8. Dining dichotomy: aquatic and terrestrial prey capture behavior in the Himalayan newt Tylototriton verrucosus

    PubMed Central

    De Vylder, Marie

    2016-01-01

    ABSTRACT Transitions between aquatic and terrestrial prey capture are challenging. Trophic shifts demand a high degree of behavioral flexibility to account for different physical circumstances between water and air to keep performance in both environments. The Himalayan newt, Tylototriton verrucosus, is mostly terrestrial but becomes aquatic during its short breeding period. Nonetheless, it was assumed that it lacks the capability of trophic behavioral flexibility, only captures prey on land by its tongue (lingual prehension) and does not feed in water. This theory was challenged from stomach content analyses in wild populations that found a variety of aquatic invertebrates in the newts' stomachs during their breeding season. Accordingly, we hypothesized that T. verrucosus actively changes its terrestrial prey capture mechanism to hunt for aquatic prey at least during its aquatic stage. In fact, the kinematic analyses showed that T. verrucosus uses lingual prehension to capture prey on land but changes to suction feeding for aquatic strikes. The statistical analyses revealed that terrestrial and aquatic strikes differ significantly in most kinematic parameters while behavioral variability does not differ between both behaviors. In turn, the movement patterns in suction feeding showed a higher degree of coordination between jaw and hyoid movements compared to the putative primary feeding mode, namely lingual prehension. We conclude that T. verrucosus, though relatively slow compared to trophic specialists, benefits from a high degree of behavioral flexibility that allows exploiting food sources efficiently from two very different habitats. PMID:27612510

  9. Formation of otoconia in the Japanese red-bellied newt, Cynops pyrrhogaster

    NASA Astrophysics Data System (ADS)

    Wiederhold, M. L.; Yamashita, M.; Larsen, K.; Asashima, M.

    1994-08-01

    Pre-mated adult female newts and fertilized eggs will be flown on the International Microgravity Laboratory-2 flight, in 1994. One objective of the flight will be to observe the influence of microgravity on the development of the gravity-sensing organs in the inner ear. These organs contain sensory hair cells covered by a layer of dense stones (otoconia). Gravity and linear acceleration exert forces on these masses, leading to excitation of the nerve fibers innervating the hair cells. If the production of the otoliths is regulated to reach an optimal weight, their development might be abnormal in microgravity. Ground-based control experiments are reported describing the developmental sequence in which both the otoliths and their associated sensory epithelium and the semicircular canals appear and develop. Three-dimensional reconstruction of serial sections through the otic vesicle of newt embryos at stages 31 through 58 demonstrate the first appearance, relative position and growth of the otoliths. Reports of experiments in which fertilized frog eggs were flown on a Russian Cosmos mission conclude that the utricular otolith is increased in volume, whereas the saccular otolith maintains normal size, suggesting that at least in the utricle, the weight of the otolith might be regulated.

  10. Identification of egg-jelly substances triggering sperm acrosome reaction in the newt, Cynops pyrrhogaster.

    PubMed

    Watanabe, Akihiko; Fukutomi, Keiko; Kubo, Hideo; Ohta, Manami; Takayama-Watanabe, Eriko; Onitake, Kazuo

    2009-04-01

    Our previous studies have shown that the acrosome reaction (AR) occurs in egg-jelly of the Japanese newt, Cynops pyrrhogaster. This is analogous to the substances of echinoderms but distinct from those of many other vertebrates derived from the egg envelope or its derivative, the zona pellucida. To identify the AR-inducing substances in newt egg jelly, a monoclonal antibody (mAb) was generated against the jelly by screening the culture supernatants to find the one that best neutralized the AR-inducing activity of the jelly substance. The mAb specifically reacted to protein bands in the jelly. These proteins, with apparent molecular weights of 122 and 90 kDa, exhibited AR-inducing activity, indicating that they are definitely AR-inducing substances. Western blotting using the mAb indicated that the 122 and 90 kDa proteins are present only in the egg jelly's outermost layer, where AR-inducing activity is known to occur. Both proteins were recognized with wheat germ agglutinin (WGA), a lectin that inhibits AR-induction in egg jelly extract. Taken together, these findings indicate that the 122 and 90 kDa proteins are the AR-inducing substances in the egg jelly of C. pyrrhogaster. The WGA recognition of the proteins was lost by N-glycosidase digestion, suggesting that N-linked carbohydrate moieties in these proteins may be responsible for the AR-inducing activity.

  11. Population Genetic Structure of the Endangered Kaiser’s Mountain Newt, Neurergus kaiseri (Amphibia: Salamandridae)

    PubMed Central

    Farasat, Hossein; Akmali, Vahid; Sharifi, Mozafar

    2016-01-01

    Species often exhibit different levels of genetic structuring correlated to their environment. However, understanding how environmental heterogeneity influences genetic variation is difficult because the effects of gene flow, drift and selection are confounded. We investigated the genetic variation and its ecological correlates in an endemic and critically endangered stream breeding mountain newt, Neurergus kaiseri, within its entire range in southwestern Iran. We identified two geographic regions based on phylogenetic relationships using Bayesian inference and maximum likelihood of 779 bp mtDNA (D-loop) in 111 individuals from ten of twelve known breeding populations. This analysis revealed a clear divergence between northern populations, located in more humid habitats at higher elevation, and southern populations, from drier habitats at lower elevations regions. From seven haplotypes found in these populations none was shared between the two regions. Analysis of molecular variance (AMOVA) of N. kaiseri indicates that 94.03% of sequence variation is distributed among newt populations and 5.97% within them. Moreover, a high degree of genetic subdivision, mainly attributable to the existence of significant variance among the two regions is shown (θCT = 0.94, P = 0.002). The positive and significant correlation between geographic and genetic distances (r = 0.61, P = 0.002) following controlling for environmental distance suggests an important influence of geographic divergence of the sites in shaping the genetic variation and may provide tools for a possible conservation based prioritization policy for the endangered species. PMID:26918642

  12. Transcription activator-like effector nucleases efficiently disrupt the target gene in Iberian ribbed newts (Pleurodeles waltl), an experimental model animal for regeneration.

    PubMed

    Hayashi, Toshinori; Sakamoto, Kousuke; Sakuma, Tetsushi; Yokotani, Naoki; Inoue, Takeshi; Kawaguchi, Eri; Agata, Kiyokazu; Yamamoto, Takashi; Takeuchi, Takashi

    2014-01-01

    Regeneration of a lost tissue in an animal is an important issue. Although regenerative studies have a history of research spanning more than a century, the gene functions underlying regulation of the regeneration are mostly unclear. Analysis of knockout animals is a very powerful tool with which to elucidate gene function. Recently, transcription activator-like effector nucleases (TALENs) have been developed as an effective technique for genome editing. This technique enables gene targeting in amphibians such as newts that were previously impossible. Here we show that newts microinjected with TALEN mRNAs designed for targeting the tyrosinase gene in single-cell stage embryos revealed an albino phenotype. Sequence analysis revealed that the tyrosinase genes were effectively disrupted in these albino newts. Moreover, precise genome alteration was achieved using TALENs and single strand oligodeoxyribonucleotides. Our results suggest that TALENs are powerful tools for genome editing for regenerative research in newts.

  13. Peculiarities of lens and tail regeneration detected in newts after spaceflight aboard Foton M3

    NASA Astrophysics Data System (ADS)

    Grigoryan, Eleonora N.; Almeida, Eduardo; Poplinskaya, Valentina; Novikova, Julia; Domaratskaya, Elena; Aleinikova, Karina; Souza, Kenneth; Skidmore, Mike; Grigoryan, Eleonora N.

    In September 2007 the joint, 12 day long experiment was carried out aboard Russian satellite Foton M3. The goal of the experiment was to study eye lens, tail and forelimb toe regeneration in adult 16 newts (Pl. waltl.) operated 10 days before taking-off. In spaceflight and synchronous ground control we used video recording, temperature and irradiation control, as well as constant availability of thymidine analog BrdU for its absorption via animals' skin. New techniques allowed us to analyze animals' behavior in hyperand microgravity periods of time, to take proper account of spaceflight factors, and measure accumulated pools of DNA-synthesizing cells in regenerating tissues. All tissue specimens obtained from animals were isolated in the day of landing and then prepared for morphological, immunochemical and molecular investigations. Synchronous control was shifted for two days and reproduced flight conditions except changes of gravity influence. As a result in flown animals as compared with synchronous ground control we found lens regeneration of 0.5-1 stage speeded up and an increased BrdU+ (S-phase) cell number in eye cornea, growth zone, limbus and newly forming lens. These features of regeneration were accompanied by an increase of FGF2 expression in eye growth zone and heat shock protein (HSP90) induction purely in retinal macroglial cells of regenerating eyes. Toe regeneration rate was equal and achieved the stage of accomplished healing of amputation area in both groups - "flown" and control animals. We found no essential differences in tail regeneration rate and tail regenerate sizes in the newts exposed to space and on ground. In both groups tail regeneration reached the stage IV-V when tail length and square were around 4.4 mm and 15.5 mm2, correspondingly. However we did observe remarkable changes of tail regenerate form and some of pigmentation. Computer morphometrical analysis showed that only in ground control animals the evident dorso

  14. Newt tail regeneration: a model for gravity-dependent morphogenesis and clues to the molecular mechanisms involved.

    NASA Astrophysics Data System (ADS)

    Radugina, Elena A.; Almeida, Eduardo; Grigoryan, Eleonora

    Gravity alterations are widely recognized to influence living systems. They may cause temporary or permanent effects on physiology and development at different levels, from gene expression to morphogenesis. However, the molecular mechanisms underlying these effects are often unclear, and adequate model systems to study them are required. To address this problem we developed a new experimental model of how gravity affects morphogenesis during tail regeneration in the newt Pleurodeles waltl. The effects of increased gravity on newt tail morphogenesis were first documented in two joint Russian-US NASA spaceflight experiments in the Russian Foton-M2 (2005) and Foton-M3 (2007) missions. In these experiments the shape of newt tail regenerate was found to depend on the gravity level, being dorso-ventrally symmetrical in microgravity and in neutrally-buoyant aquarium controls, versus hook-like and bent downward in 1g controls. These 1g controls were conducted in spaceflight habitats using a water-saturated PVA sponge mat. These results were reproducible in multiple spaceflight, and ground laboratory studies, both in the US at NASA ARC and in Russia at IDB RAS, and were characterized in detail using morphometry and histology approaches. The role of hypergravity in shaping morphogenesis was confirmed at NASA ARC with an experiment in the ISS Testbed 8-foot diameter centrifuge operating at 2g. Animals that experienced two-week centrifugation (the period of time used in the Foton flights) developed the same hook-like regenerates as 1g controls, and morphometric analysis revealed no significant difference between 1g and 2g groups, however both were significantly different from aquarium controls. We hypothesize that exposure to 1g or 2g during tail morphogenesis constitutes excessive loading for newts that are adapted to microgravity-like conditions in their aquatic habitat. Because Heat Shock Proteins (HSPs) are stress-induced molecules that respond to a broad variety of

  15. Confirmation of the absence of tetrodotoxin and its analogues in the juveniles of the Japanese fire-bellied newt, Cynops pyrrhogaster, captive-reared from eggs in the laboratory using HILIC-LC-MS.

    PubMed

    Kudo, Yuta; Chiba, Chikafumi; Konoki, Keiichi; Cho, Yuko; Yotsu-Yamashita, Mari

    2015-07-01

    The tetrodotoxin (TTX) contents of the Japanese fire-bellied newt, Cynops pyrrhogaster, captive-reared from eggs to metamorphosed juveniles with a non-toxic diet for 70 weeks, as well as wild-caught juvenile newts, were investigated using a high-resolution hydrophilic interaction chromatography-LC-MS. TTX was detected in 0- to 22-week-old captive-reared juvenile newts but was not detected (<15 ng/g) in the 36- to 70-week-old newts, while significant levels of TTX (1.3-14 μg/g) were detected in the wild-caught juveniles.

  16. Ultraviolet microbeam irradiations of cultured newt lung epithelial cells during mitosis

    SciTech Connect

    Cypher, C.

    1983-01-01

    The mechanism of chromosome movement is unknown. The structural environment for this movement is a birefringent, spindle-shaped array of microtubules. Microbeams of ultraviolet light were used to disrupt the mitotic spindles of newt lung epithelial cells to localize force production within spindles and to evaluate the role of microtubules in force generation or transduction. Time-lapse cinephotomicrographic records of cells were made using phase and polarization microscopy. Irradiation effects were correlated with spindle microtubule structure by immuno-gold antitubulin staining. The results demonstrate the pervasive effects of local irradiations upon spindle structure. The spindle compaction observed after irradiations suggests that each half-spindle is under a compressive force. Since the irradiations locally disassemble microtubules, the results suggest that the birefringent microtubules oppose this compressive force.

  17. Controlling gene loss of function in newts with emphasis on lens regeneration.

    PubMed

    Tsonis, Panagiotis A; Haynes, Tracy; Maki, Nobuyasu; Nakamura, Kenta; Casco-Robles, Martin Miguel; Yamada, Shouta; Miura, Tomoya; Chiba, Chikafumi; Del Rio-Tsonis, Katia

    2011-05-01

    Here we describe a protocol for gene loss of function during regeneration in newts, specifically applied to lens regeneration. Knockdown with the use of morpholinos can be achieved both in vitro and in vivo, depending on the experimental design. These methods achieve desirable levels of gene knockdown, and thus can be compared with methods developed for use in other animals, such as zebrafish. The technology has been applied to study molecular mechanisms during the process of lens regeneration by knocking down genes at specific stages and examining their effects on other genes and lens differentiation. The protocol can take a few days or up to 20 d to complete, depending on the duration of the experiment.

  18. Influence of respirometry methods on intraspecific variation in standard metabolic rates in newts.

    PubMed

    Kristín, Peter; Gvoždík, Lumír

    2012-09-01

    Standard metabolic rate (SMR) is both a highly informative and variable trait. Variation in SMR stems not only from diverse intrinsic and extrinsic factors, but also from the use of diverse methods for metabolic measurements. We measured CO(2) production (VCO(2)) and oxygen consumption rates (VO(2)) using two flow-through respirometry modes, continuous and intermittent (stop-flow), to evaluate their potential contribution to SMR variation in Alpine newts, Ichthyosaura alpestris. Both respirometry modes yielded similar and repeatable VCO(2) values. Although VO(2) was highly repeatable, continuous respirometry produced lower VO(2) than the intermittent method. During intermittent measurements, the total number of activity bouts was higher than during continuous respirometry trials. Statistical correction for disparate activity levels minimized variation in oxygen consumption between respirometry modes. We conclude that use of either method of flow-through respirometry, if properly applied, introduced less noise to SMR estimates than a variation in activity levels.

  19. A case of reproductive character displacement in female palmate newts (Lissotriton helveticus).

    PubMed

    Johanet, Aurélie; Secondi, Jean; Pays, Olivier; Pagano, Alain; Lodé, Thierry; Lemaire, Christophe

    2009-06-01

    Reproductive character displacement is commonly described as larger phenotypic differences between species living in sympatry rather than in allopatry. We investigated this phenomenon on two amphibians found in their contact zone where syntopic and allotopic sites alternate. To test the effect of syntopy with Lissotriton vulgaris on the Lissotriton helveticus phenotype, we studied the morphology of adult males and females while controlling for environmental factors (i.e. land use and flood risk). Using linear mixed-effects models, we found that females of L. helveticus expressed a deeper tail when in the presence of the other species, a pattern consistent with reproductive character displacement. This pattern has been rarely observed in Amphibians. It suggests that male newts incur large mating costs when selecting heterospecific partners. Our study also emphasizes that the evolution of mate recognition systems could occur at a microgeographical scale within a sympatric area.

  20. UV wavelengths experienced during development affect larval newt visual sensitivity and predation efficiency.

    PubMed

    Martin, Mélissa; Théry, Marc; Rodgers, Gwendolen; Goven, Delphine; Sourice, Stéphane; Mège, Pascal; Secondi, Jean

    2016-02-01

    We experimentally investigated the influence of developmental plasticity of ultraviolet (UV) visual sensitivity on predation efficiency of the larval smooth newt, Lissotriton vulgaris. We quantified expression of SWS1 opsin gene (UV-sensitive protein of photoreceptor cells) in the retinas of individuals who had developed in the presence (UV+) or absence (UV-) of UV light (developmental treatments), and tested their predation efficiency under UV+ and UV- light (testing treatments). We found that both SWS1 opsin expression and predation efficiency were significantly reduced in the UV- developmental group. Larvae in the UV- testing environment displayed consistently lower predation efficiency regardless of their developmental treatment. These results prove for the first time, we believe, functional UV vision and developmental plasticity of UV sensitivity in an amphibian at the larval stage. They also demonstrate that UV wavelengths enhance predation efficiency and suggest that the magnitude of the behavioural response depends on retinal properties induced by the developmental lighting environment.

  1. Context-Dependent Plastic Response during Egg-Laying in a Widespread Newt Species

    PubMed Central

    Tóth, Zoltán

    2015-01-01

    Previous research on predator-induced phenotypic plasticity mostly focused on responses in morphology, developmental time and/or behaviour during early life stages, but the potential significance of anticipatory parental responses has been investigated less often. In this study I examined behavioural and maternal responses of gravid female smooth newts, Lissotriton vulgaris, in the presence of chemical cues originating from invertebrate predators, Acilius sulcatus water beetles and Aeshna cyanea dragonfly larvae. More specifically, I tested the extent of oviposition preference, plasticity in egg-wrapping behaviour and plasticity in egg size when females had the possibility to lay eggs at oviposition sites with and without predator cues during overnight trials. I found that individuals did not avoid laying eggs in the environment with predator cues; however, individuals that deposited eggs into both environments adjusted the size of the laid eggs to the perceived environment. Females deposited larger eggs earlier in the season but egg size decreased with time in the absence of predator cues, whereas individuals laid eggs of average size throughout the investigated reproductive period when such cues were present. Also, egg size was found to be positively related to hatching success. Individuals did not adjust their wrapping behaviour to the presence of predator cues, but females differed in the extent of egg-wrapping between ponds. Females’ body mass and tail depth were also different between ponds, whereas their body size was positively associated with egg size. According to these results, female smooth newts have the potential to exhibit activational plasticity and invest differently into eggs depending on temporal and environmental factors. Such an anticipatory response may contribute to the success of this caudate species under a wide range of predator regimes at its natural breeding habitats. PMID:26291328

  2. Tracing glacial refugia of Triturus newts based on mitochondrial DNA phylogeography and species distribution modeling

    PubMed Central

    2013-01-01

    Introduction The major climatic oscillations during the Quaternary Ice Age heavily influenced the distribution of species and left their mark on intraspecific genetic diversity. Past range shifts can be reconstructed with the aid of species distribution modeling and phylogeographical analyses. We test the responses of the different members of the genus Triturus (i.e. the marbled and crested newts) as the climate shifted from the previous glacial period (the Last Glacial Maximum, ~21 Ka) to the current interglacial. Results We present the results of a dense mitochondrial DNA phylogeography (visualizing genetic diversity within and divergence among populations) and species distribution modeling (using two different climate simulations) for the nine Triturus species on composite maps. Conclusions The combined use of species distribution modeling and mitochondrial phylogeography provides insight in the glacial contraction and postglacial expansion of Triturus. The combined use of the two independent techniques yields a more complete understanding of the historical biogeography of Triturus than both approaches would on their own. Triturus newts generally conform to the ‘southern richness and northern purity’ paradigm, but we also find more intricate patterns, such as the absence of genetic variation and suitable area at the Last Glacial Maximum (T. dobrogicus), an ‘extra-Mediterranean’ refugium in the Carpathian Basin (T. cristatus), and areas where species displaced one another postglacially (e.g. T. macedonicus and western T. karelinii). We provide a biogeographical scenario for Triturus, showing the positions of glacial refugia, the regions that were postglacially colonized and the areas where species displaced one another as they shifted their ranges. PMID:23514662

  3. Divergence in the face of gene flow: the case of two newts (amphibia: salamandridae).

    PubMed

    Nadachowska, Krystyna; Babik, Wieslaw

    2009-04-01

    Understanding the process of divergence requires the quantitative characterization of patterns of gene flow between diverging taxa. New and powerful coalescent-based methods give insight into these processes in unprecedented details by enabling the reconstruction of the temporal distribution of past gene flow. Here, we use sequence variation at eight nuclear markers and mitochondrial DNA (mtDNA) in multiple populations to study diversity, divergence, and gene flow between two subspecies of a salamander, the smooth newt (Lissotriton vulgaris kosswigi and Lissotriton vulgaris vulgaris) in Turkey. The ranges of both subspecies encompass mainly the areas of this important glacial refugial area. Populations in refugia where species have been present for a long time and differentiated in situ should better preserve the record of past gene flow than young populations in postglacial expansion areas. Sequence diversity in both subspecies was substantial (nuclear pi(sil) = 0.69% and 1.31%). We detected long-term demographic stability in these refugial populations with large effective population sizes (N(e)) of the order of 1.5-3 x 10(5) individuals. Gene trees and the isolation with migration (IM) analysis complemented by tests of nested IM models showed that despite deep, pre-Pleistocene divergence of the studied newts, asymmetric introgression from vulgaris to kosswigi has occurred, with signatures of recent gene flow in mtDNA and an anonymous nuclear marker, and evidence for more ancient introgression in nuclear introns. The distribution of migration times raises the intriguing possibility that even the initial divergence may have occurred in the face of gene flow.

  4. Hyaluronic acid production and hyaluronidase activity in the newt iris during lens regeneration

    SciTech Connect

    Kulyk, W.M.; Zalik, S.E.; Dimitrov, E.

    1987-09-01

    The process of lens regeneration in newts involves the dedifferentiation of pigmented iris epithelial cells and their subsequent conversion into lens fibers. In vivo this cell-type conversion is restricted to the dorsal region of the iris. We have examined the patterns of hyaluronate accumulation and endogenous hyaluronidase activity in the newt iris during the course of lens regeneration in vivo. Accumulation of newly synthesized hyaluronate was estimated from the uptake of (/sup 3/H)glucosamine into cetylpyridinium chloride-precipitable material that was sensitive to Streptomyces hyaluronidase. Endogenous hyaluronidase activity was determined from the quantity of reducing N-acetylhexosamine released upon incubation of iris tissue extract with exogenous hyaluronate substrate. We found that incorporation of label into hyaluronate was consistently higher in the regeneration-activated irises of lentectomized eyes than in control irises from sham-operated eyes. Hyaluronate labeling was higher in the dorsal (lens-forming) region of the iris than in ventral (non-lens-forming) iris tissue during the regeneration process. Label accumulation into hyaluronate was maximum between 10 and 15 days after lentectomy, the period of most pronounced dedifferentiation in the dorsal iris epithelium. Both normal and regenerating irises demonstrated a high level of endogenous hyaluronidase activity with a pH optimum of 3.5-4.0. Hyaluronidase activity was 1.7 to 2 times higher in dorsal iris tissue than in ventral irises both prior to lentectomy and throughout the regeneration process. We suggest that enhanced hyaluronate accumulation may facilitate the dedifferentiation of iris epithelial cells in the dorsal iris and prevent precocious withdrawal from the cell cycle. The high level of hyaluronidase activity in the dorsal iris may promote the turnover and remodeling of extracellular matrix components required for cell-type conversion.

  5. Changes in microtubule structures during the first cell cycle of physiologically polyspermic newt eggs.

    PubMed

    Iwao, Y; Yasumitsu, K; Narihira, M; Jiang, J; Nagahama, Y

    1997-06-01

    The unfertilized egg of the newt, Cynops pyrrhogaster, has a second meiotic spindle at the animal pole and numerous cortical cytasters. After physiologically polyspermic fertilization, all sperm nuclei incorporated into the egg develop sperm asters, and the cortical cytasters change into bundles of cortical microtubules. The size of the sperm asters in the animal hemisphere is approximately 5.6-fold larger than that in the vegetal hemisphere. Only one sperm nucleus moves toward the center of the animal hemisphere to form a zygote nucleus with the egg nucleus. This movement is inhibited by nocodazole, but not by cytochalasin B. The centrosome in the zygote nucleus divides into two parts to form a bipolar spindle for the first cleavage synchronously with the nuclear cycle, but centrosomes of accessory sperm nuclei in the vegetal hemisphere remained to form monopolar interphase asters and subsequently degenerate around the first cleavage stage. The size of sperm asters in monospermically fertilized Xenopus eggs was approximately 37-fold larger than those in Cynops eggs. Since sperm asters that formed in polyspermically fertilized Xenopus eggs exclude each other, the formation of a zygote nucleus is inhibited. Cynops sperm nuclei form larger asters in Xenopus eggs, whereas Xenopus sperm nuclei form smaller asters in Cynops eggs compared with those in homologous eggs. Since there was no significant difference in the concentration of monomeric tubulin between those eggs, the size of sperm asters is probably regulated by a component(s) in egg cytoplasm. Smaller asters in physiologically polyspermic newt eggs might be useful for selecting only one sperm nucleus to move toward the egg nucleus.

  6. Isolation and structural determination of the first 8-epi-type tetrodotoxin analogs from the newt, Cynops ensicauda popei, and comparison of tetrodotoxin analogs profiles of this newt and the puffer fish, Fugu poecilonotus.

    PubMed

    Kudo, Yuta; Yasumoto, Takeshi; Konoki, Keiichi; Cho, Yuko; Yotsu-Yamashita, Mari

    2012-03-01

    Identification of new tetrodotoxin (TTX) analogs from TTX-possessing animals might provide insight into its biosynthesis and metabolism. In this study, four new analogs, 8-epi-5,6,11-trideoxyTTX, 4,9-anhydro-8-epi-5,6,11-trideoxyTTX, 1-hydroxy-8-epi-5,6,11-trideoxyTTX, and 1-hydroxy-4,4a-anhydro-8-epi-5,6,11-trideoxyTTX, were isolated from the newt, Cynops ensicauda popei, and their structures were determined using spectroscopic methods. These are the first 8-epi-type analogs of TTX that have been found in a natural source. Furthermore, we examined the composition of the TTX analogs in this newt and in the ovary of the puffer fish, Fugu poecilonotus, using LC/MS. The results indicate that TTX and 11-deoxyTTX were present in both sources. However, 6-epiTTX and 8-epi-type analogs were detected only in the newt, while 5,6,11-trideoxyTTX was a specific and major analog in the puffer fish. Such considerable differences among analog compositions might reflect differences in the biosynthesis or metabolism of TTX between these animals.

  7. Signs of Müller cell gliotic response found in the retina of newts exposed to real and simulated microgravity

    NASA Astrophysics Data System (ADS)

    Grigoryan, E. N.; Anton, H. J.; Poplinskaya, V. A.; Aleinikova, K. S.; Domaratskaya, E. I.; Novikova, Y. P.; Almeida, E.

    2012-05-01

    The effects of real and simulated microgravity on the eye tissue regeneration of newts were investigated. For the first time changes in Müller glial cells in the retina of eyes regenerating after retinal detachment were detected in newts exposed to clinorotation. The cells divided, were hypertrophied, and their processes were thickened. Such changes suggested reactive gliosis and were more significant in animals exposed to rotation when compared with desk-top controls. Later experiments onboard the Russian biosatellite Bion-11 showed similar changes in the retinas that were regenerating in a two-week spaceflight. In the Bion-11 animals, GFAP, the major structural protein of retinal macroglial cells, was found to be upregulated. In a more recent experiment onboard Foton-M3 (2007), GFAP expression in retinas of space-flown, ground control (kept at 1 g), and basal control (sacrificed on launch day) newts was quantified, using microscopy, immunohistochemistry, and digital image analysis. A low level of immunoreactivity was observed in basal controls. In contrast, retinas of space-flown animals showed greater GFAP immunoreactivity associated with both an increased cell number and a higher thickness of intermediate filaments. This, in turn, was accompanied by up-regulation of stress protein (HSP90) and growth factor (FGF2) expressions. It can be postulated that such a response of Müller cells was to mitigate the retinal stress in newts exposed to microgravity. Taken together, the data suggest that the retinal population of macroglial cells could be sensitive to gravity changes and that in space it can react by enhancing its neuroprotective function.

  8. An Attempt at Captive Breeding of the Endangered Newt Echinotriton andersoni, from the Central Ryukyus in Japan.

    PubMed

    Igawa, Takeshi; Sugawara, Hirotaka; Tado, Miyuki; Nishitani, Takuma; Kurabayashi, Atsushi; Islam, Mohammed Mafizul; Oumi, Shohei; Katsuren, Seiki; Fujii, Tamotsu; Sumida, Masayuki

    2013-07-31

    Anderson's crocodile newt (Echinotriton andersoni) is distributed in the Central Ryukyu Islands of southern Japan, but environmental degradation and illegal collection over the last several decades have devastated the local populations. It has therefore been listed as a class B1 endangered species in the IUCN Red List, indicating that it is at high risk of extinction in the wild. The species is also protected by law in both Okinawa and Kagoshima prefectures. An artificial insemination technique using hormonal injections could not be applied to the breeding of this species in the laboratory. In this study we naturally bred the species, and tested a laboratory farming technique using several male and female E. andersoni pairs collected from Okinawa, Amami, and Tokunoshima Islands and subsequently maintained in near-biotopic breeding cages. Among 378 eggs derived from 17 females, 319 (84.4%) became normal tailbud embryos, 274 (72.5%) hatched normally, 213 (56.3%) metamorphosed normally, and 141 (37.3%) became normal two-month-old newts; in addition, 77 one- to three-year-old Tokunoshima newts and 32 Amami larvae are currently still growing normally. Over the last five breeding seasons, eggs were laid in-cage on slopes near the waterfront. Larvae were raised in nets maintained in a temperature-controlled water bath at 20 °C and fed live Tubifex. Metamorphosed newts were transferred to plastic containers containing wet sponges kept in a temperature-controlled incubator at 22.5 °C and fed a cricket diet to promote healthy growth. This is the first published report of successfully propagating an endangered species by using breeding cages in a laboratory setting for captive breeding. Our findings on the natural breeding and raising of larvae and adults are useful in breeding this endangered species and can be applied to the preservation of other similarly wild and endangered species such as E. chinhaiensis.

  9. Residues in cutthroat trout (Salmo clarki) and California newts (Tarichia torosa) from a lake treated with technical chlordane.

    PubMed

    Albright, L J; Oloffs, P C; Szeto, S Y

    1980-01-01

    The water of a lake was sprayed with technical chlordane to give a concentration of approximately 10 ppb. Resident California newts (Tarichia torosa) and cutthroat trout (Salmo clarki) were subsequently collected and analyzed for residue concentrations. The newts were collected at 14, 279, 451, and 1,036 days; the trout at 93, 279, 421, and 1,014 days. At first, the concentrations of residues were very high in both species and their composition, except for heptachlor, resembled that of technical chlordane. The heptachlor was quantitatively epoxidized in news after 14 days but in trout, some heptachlor was still present after 93 days. Concentrations of total chlordane in body tissues of both species declined more than 98% with time. Of seven individually determined constituents of technical chlordane, trans-nonachlor was by far the most persistent, accounting for 49 to 55% of total chlordane in specimens collected last. Both animals produced oxychlordane, probably from gamma-chlordane. Heptachlor, heptachlor epoxide and gamma-chlordeine were non-detectable in both species after 279 days. The results strongly suggest that the California newt metabolizes and eliminates chlordane residues more effectively than the cutthroat trout.

  10. Tetrodotoxin concentrations within a clutch and across embryonic development in eggs of the rough-skinned newts (Taricha granulosa).

    PubMed

    Gall, Brian G; Stokes, Amber N; Pett, Jory J; Spivey, Kari L; French, Susannah S; Brodie, Edmund D; Brodie, Edmund D

    2014-11-01

    Tetrodotoxin is an enigmatic neurotoxin that is found in a wide-variety of organisms. Unfortunately, tetrodotoxin (TTX) toxicity across life-history stages is poorly understood in most organisms. Rough-skinned newts (Taricha granulosa) possess the greatest known quantities of TTX of any organism and numerous studies have begun to elucidate these patterns in this species. We conducted a series of studies to answer the following questions: (1) do eggs from a single female's clutch vary in toxicity? (2) does TTX concentration change during embryonic development? and (3) does the jelly coat from newt eggs possess TTX? We found that the amount of TTX in newt eggs depended on the relative "position" of the egg within a clutch; eggs deposited at the beginning of the clutch had substantially more TTX than those at the end. During development egg toxicity remained consistent until hatching. The jelly coat contained small quantities of TTX, but these were not correlated with the toxicity of the embryo. These results clarify several long-held interpretations about embryo toxicity and continue to elucidate the life-history patterns of tetrodotoxin toxicity in this amphibian.

  11. Changes in the olfactory response to amino acids in Japanese newts after transfer from an aquatic to a terrestrial habitat.

    PubMed

    Inoue, Ritsuko; Nakatani, Kei

    2010-04-01

    Amphibians are capable of smelling both volatile and water-soluble (e.g., amino acids) odorants. Adult Japanese newts, Cynops pyrrhogaster, live mostly in water, except during hibernation, but sometimes on land. To examine olfactory responses of the newts to adaptation to a short-term stay on land (land adaptation), we measured the magnitude of the olfactory response at five different time points (land adaptation time: 0, 30, 54, 90, and 114 h after transfer from an aquatic to a terrestrial habitat by using electro-olfactogram (EOG) recordings. Statistical analysis by the weighted linear model (P < 0.05) indicated that the time to land adaptation had a significant effect on the magnitude of the EOG induced by 1 microM and 10 microM amino acid mixtures. Further, the slope estimates of the weighted linear model were significantly positive (P < 0.05). These results indicate that the magnitude of the EOG response to amino acid mixtures (arginine, alanine, proline, and glutamic acid) significantly increases with land adaptation time. On the other hand, we observed no significant relationship between the magnitude of the EOG response induced by an 0.05% volatile odorant mixture (isoamyl acetate, n-amyl acetate, cineole, and limonene) and land adaptation time. Our results indicate that olfactory sensitivity to amino acids significantly increases with land adaptation time in adult Japanese newts.

  12. Frog virus 3-like infections in aquatic amphibian communities.

    PubMed

    Duffus, A L J; Pauli, B D; Wozney, K; Brunetti, C R; Berrill, M

    2008-01-01

    Frog virus 3 (FV3) and FV3-like viruses, are members of the genus Ranavirus (family Iridoviridae), and they have been associated with infectious diseases that may be contributing to amphibian population declines. We examined the mode of transmission of an FV3-like virus, and potential hosts and reservoirs of the virus in a local amphibian community. Using the polymerase chain reaction to detect infected animals, we found an FV3-like virus in south-central Ontario, Canada, amphibian communities, where it infects sympatric amphibian species, including ranid and hylid tadpoles (Rana sylvatica, Hyla versicolor, and Pseudacris spp.), larval salamanders (Ambystoma spp.), and adult eastern-spotted newts (Notophthalmus viridescens). The high prevalence of FV3-like infections in caudate larvae suggests that salamanders are likely to be both hosts and reservoirs. In laboratory FV3 challenges of R. sylvatica, the rate of infection was dependent on the amount of virus to which the animals were exposed. In addition, although vertical transmission was suspected, horizontal transmission through exposure to infected pond water is the most likely route of infection in tadpoles. Based on our observations, a simple model of FV3/FV3-like virus transmission postulates that, in aquatic amphibian communities, transmission of the virus occurs between anuran and urodele species, with ambystomatid salamanders the most likely reservoir for the ranavirus in our study.

  13. The Husting dilemma: A methodological note

    USGS Publications Warehouse

    Nichols, J.D.; Hepp, G.R.; Pollock, K.H.; Hines, J.E.

    1987-01-01

    Recently, Gill (1985) discussed the interpretation of capture history data resulting from his own studies on the red-spotted newt, Notophthalmus viridescens , and work by Husting (1965) on spotted salamanders, Ambystoma maculatum. Gill (1985) noted that gaps in capture histories (years in which individuals were not captured, preceded and followed by years in which they were) could result from either of two very different possibilities: (1) failure of the animal to return to the fenced pond to breed (the alternative Husting (1965) favored), or (2) return of the animal to the breeding pond, but failure of the investigator to capture it and detect its presence. The authors agree entirely with Gill (1985) that capture history data such as his or those of Husting (1965) should be analyzed using models that recognize the possibility of 'census error,' and that it is important to try to distinguish between such 'error' and skipped breeding efforts. The purpose of this note is to point out the relationship between Gill's (1985:347) null model and certain capture-recapture models, and to use capture-recapture models and tests to analyze the original data of Husting (1965).

  14. Multi-Tissue Microarray Analysis Identifies a Molecular Signature of Regeneration

    PubMed Central

    Mercer, Sarah E.; Cheng, Chia-Ho; Atkinson, Donald L.; Krcmery, Jennifer; Guzman, Claudia E.; Kent, David T.; Zukor, Katherine; Marx, Kenneth A.; Odelberg, Shannon J.; Simon, Hans-Georg

    2012-01-01

    The inability to functionally repair tissues that are lost as a consequence of disease or injury remains a significant challenge for regenerative medicine. The molecular and cellular processes involved in complete restoration of tissue architecture and function are expected to be complex and remain largely unknown. Unlike humans, certain salamanders can completely regenerate injured tissues and lost appendages without scar formation. A parsimonious hypothesis would predict that all of these regenerative activities are regulated, at least in part, by a common set of genes. To test this hypothesis and identify genes that might control conserved regenerative processes, we performed a comprehensive microarray analysis of the early regenerative response in five regeneration-competent tissues from the newt Notophthalmus viridescens. Consistent with this hypothesis, we established a molecular signature for regeneration that consists of common genes or gene family members that exhibit dynamic differential regulation during regeneration in multiple tissue types. These genes include members of the matrix metalloproteinase family and its regulators, extracellular matrix components, genes involved in controlling cytoskeleton dynamics, and a variety of immune response factors. Gene Ontology term enrichment analysis validated and supported their functional activities in conserved regenerative processes. Surprisingly, dendrogram clustering and RadViz classification also revealed that each regenerative tissue had its own unique temporal expression profile, pointing to an inherent tissue-specific regenerative gene program. These new findings demand a reconsideration of how we conceptualize regenerative processes and how we devise new strategies for regenerative medicine. PMID:23300656

  15. Müller cell gliotic response in the retina of the newts exposed to real and simulated microgravity

    NASA Astrophysics Data System (ADS)

    Grigoryan, Eleonora N.; Poplinskaya, Valentina; Domaratskaya; Aleinikova, Karina; Novikova, Julia; Anton, Hermann J.; Almeida, Eduardo

    The effects of real and simulated microgravity on the eye tissue regeneration of newts (Pl. waltli) after lens and/or retina removal were investigated. Changes in Müller glial cells in the retina of eyes regenerating after lens extirpation were detected in newts exposed to clinostat-ing. The cells were hypertrophied, and their processes thickened. Such changes were viewed as specific of reactive gliosis [1]. Later experiments onboard the Russian biosatellite Bion-11 showed similar changes in the retinas of newts regenerating after a two-week spaceflight. In the Bion-11 animals, GFAP, the major structural protein of macroglial cells was found to be up-regulated [2]. In more recent experiments onboard Foton-2 (2005) and Foton-M3 (2007), GFAP expression in retinas of space-flown, ground control (kept at 1 g), and basal control (sacrificed on launch day) newts was quantified, using microscopy, immunohistochemistry, and digital image analysis. It was found that Müller cell processes of non-operated animals dis-u played low GFAP immunolabeling. A low level of immunoreactivity was also observed in basal controls. In contrast, retinas of space-flown animals showed greater GFAP immunoreactivity associated with both an increased cell number and a higher density of intermediate filaments [3]. This, in turn, was accompanied by up-regulation of stress protein (HSP90) and growth factor (FGF2) expressions. It can be postulated that such a response of Müller cells was to mitigate the retinal stress in newts exposed to microgravity. Although the exact mechanisms remain unknown, it can be hypothesized that GFAP up-regulation is mediated by HSPs and growth factors, particularly by FGF2. Taken together, these data suggest that the retinal population of macroglial cells is sensitive to gravity changes and that in space it can react by enhancing its neuroprotective function. [1] Grigoryan E.N., Anton H.J., Mitashov V.I. Adv. Space Res. 1998. V. 22. N.2. P. 293-301. [2] Grigoryan E

  16. The Hereptofauna of Letterkenny Army Depot, South-Central Pennsylvania: A Starting Point to the Long-Term Monitoring and Management of Amphibians and Reptiles

    DTIC Science & Technology

    2010-06-01

    Scientific Name 1 2 3 4 Salamanders (21 species) Cryptobranchus alleganiensis Y N N N Necturus maculosus N N N N Ambystoma jeffersonianum Y Y Y Y Ambystoma ...maculatum Y Y Y Y Ambystoma opacum Y Y Y Y Notophthalmus viridescens Y Y Y Y Aneides aeneus** N N N N Desmognathus fuscus Y Y Y Y Desmognathus monticola

  17. The epidermal melanocyte population in the skin of ultraviolet-irradiated crested newt

    SciTech Connect

    Losa, M.; Zavanella, T.; Milani, S.

    1982-02-01

    The response of the epidermal melanocyte population to repeated ultraviolet (UV) exposure (wavelength spectrum 275-350 nm) has been investigated in the crested newt, Triturus cristatus carnifex. The effects of different doses of UV light were studied. The animals were killed 7 months after the first UV exposure. Only a slight decrease in the number of pigment cells was found after 85 sequential irradiations with a total dose of 1.3 x 10(5) J/m2, whereas striking decreases were observed when the same total dose was fractionated into 14 exposures or when a double dose was given in 57 exposures. The relationship between the square roots of the epidermal melanocyte densities and single doses appeared to be roughly linear, at least over the range of doses administered. The main factor in melanocyte damage seemed to be the single dose of irradiation rather than the cumulative dose administered. Decreased melanin content of the keratinocytes was observed in most irradiated animals.

  18. Information-content of morphological and behavioural sexual traits in the Palmate newt (Lissotriton helveticus).

    PubMed

    Cornuau, Jérémie H; Schmeller, Dirk S; Pigeault, Romain; Sibeaux, Adelaïde; Tourat, Audrey; Loyau, Adeline

    2014-10-01

    The question of why females evaluate more than one sexual trait to choose their mates has received increasing attention in recent years. Here, we investigated the information-content of both morphological and behavioural sexual traits that have been identified as predictors of male reproductive success in the palmate newt, Lissotriton helveticus. We examined the co-variation of multiple traits with one aspect of male quality, the male body condition, using both a correlative study and an experimental diet restriction. We found that the development of the three morphological sexual traits (filament length, hind-foot-web size, and crest size) was positively inter-correlated, and was correlated to body condition. In contrast, courtship activity, an important indicator for male reproductive success, was uncorrelated to male body condition. Our results suggest that females likely obtain redundant information on male condition when evaluating filament length, hind-foot-web size and crest size during mate choice. Contrary to our expectations, display activity was not a reliable indicator of male condition, leaving the information-content of this trait unraveled. Our results further suggest that complex, multiple traits may evolve because redundant message, unreliable signals and, possibly, multiple messages can coexist.

  19. The distribution and taxonomy of Lissotriton newts in Turkey (Amphibia, Salamandridae).

    PubMed

    Wielstra, Ben; Bozkurt, Emin; Olgun, Kurtuluş

    2015-01-01

    Two and perhaps three taxa of Lissotriton newt occur in Turkey. Their species status is controversial. The distribution of these taxa and the taxonomic status of each are reviewed and discussed. A database of 128 Turkish Lissotriton localities was compiled and species distribution models were constructed. We reiterate that the presence of Lissotriton (vulgaris) lantzi in Turkey is disputed and needs confirmation. The range of Lissotriton (vulgaris) kosswigi is restricted to north-western Anatolia - given the small global range of this Turkey endemic, a closer look at its conservation status is warranted. The distribution of Lissotritonvulgarisschmidtleri covers western Asiatic and European Turkey. The findings support an allopatric distribution of the Turkish Lissotriton species. We reflect on the biological significance of previously reported morphological intermediates between Lissotriton (vulgaris) kosswigi and Lissotritonvulgarisschmidtleri in the light of the recent proposal to recognize kosswigi at the species level. The available data are in line with species status for Lissotriton (vulgaris) lantzi and Lissotriton (vulgaris) kosswigi. Although Lissotritonvulgarisschmidtleri is a genetically diverged taxon as well, the extent of gene flow with parapatric European Lissotriton taxa is as yet unknown.

  20. The distribution and taxonomy of Lissotriton newts in Turkey (Amphibia, Salamandridae)

    PubMed Central

    Wielstra, Ben; Bozkurt, Emin; Olgun, Kurtuluş

    2015-01-01

    Abstract Two and perhaps three taxa of Lissotriton newt occur in Turkey. Their species status is controversial. The distribution of these taxa and the taxonomic status of each are reviewed and discussed. A database of 128 Turkish Lissotriton localities was compiled and species distribution models were constructed. We reiterate that the presence of Lissotriton (vulgaris) lantzi in Turkey is disputed and needs confirmation. The range of Lissotriton (vulgaris) kosswigi is restricted to north-western Anatolia – given the small global range of this Turkey endemic, a closer look at its conservation status is warranted. The distribution of Lissotriton vulgaris schmidtleri covers western Asiatic and European Turkey. The findings support an allopatric distribution of the Turkish Lissotriton species. We reflect on the biological significance of previously reported morphological intermediates between Lissotriton (vulgaris) kosswigi and Lissotriton vulgaris schmidtleri in the light of the recent proposal to recognize kosswigi at the species level. The available data are in line with species status for Lissotriton (vulgaris) lantzi and Lissotriton (vulgaris) kosswigi. Although Lissotriton vulgaris schmidtleri is a genetically diverged taxon as well, the extent of gene flow with parapatric European Lissotriton taxa is as yet unknown. PMID:25829839

  1. 7alpha-Hydroxypregnenolone acts as a neuronal activator to stimulate locomotor activity of breeding newts by means of the dopaminergic system.

    PubMed

    Matsunaga, Masahiro; Ukena, Kazuyoshi; Baulieu, Etienne-Emile; Tsutsui, Kazuyoshi

    2004-12-07

    It is becoming clear that steroids can be synthesized de novo by the brain and other nervous systems. Such steroids are called neurosteroids, and de novo neurosteroidogenesis from cholesterol is a conserved property of vertebrate brains. In this study, we show that the newt brain actively produces 7alpha-hydroxypregnenolone, a previously undescribed amphibian neurosteroid that stimulates locomotor activity. 7alpha-hydroxypregnenolone was identified as a most abundant amphibian neurosteroid in the newt brain by using biochemical techniques combined with HPLC, TLC, and GC-MS analyses. The production of 7alpha-hydroxypregnenolone in the diencephalon and rhombencephalon was higher than that in the telencephalon and peripheral steroidogenic glands. In addition, 7alpha-hydroxypregnenolone synthesis in the brain showed marked changes during the annual breeding cycle, with a maximal level in the spring breeding period when locomotor activity of the newt increases. Behavioral analysis of newts in the nonbreeding period demonstrated that administration of this previously undescribed amphibian neurosteroid acutely increased locomotor activity. In vitro analysis further revealed that 7alpha-hydroxypregnenolone treatment resulted in a dose-dependent increase in the release of dopamine from cultured brain tissue of nonbreeding newts. The effect of this neurosteroid on locomotion also was abolished by dopamine D(2)-like receptor antagonists. These results indicate that 7alpha-hydroxypregnenolone acts as a neuronal activator to stimulate locomotor activity of breeding newts through the dopaminergic system. This study demonstrates a physiological function of 7alpha-hydroxypregnenolone that has not been described previously in any vertebrate class. This study also provides findings on the regulatory mechanism of locomotor activity from a unique standpoint.

  2. Musculoskeletal architecture of the prey capture apparatus in salamandrid newts with multiphasic lifestyle: does anatomy change during the seasonal habitat switches?

    PubMed

    Heiss, Egon; Handschuh, Stephan; Aerts, Peter; Van Wassenbergh, Sam

    2016-05-01

    Some newt species change seasonally between an aquatic and a terrestrial life as adults, and are therefore repeatedly faced with different physical circumstances that affect a wide range of functions of the organism. For example, it has been observed that seasonally habitat-changing newts display notable changes in skin texture and tail fin anatomy, allowing one to distinguish an aquatic and a terrestrial morphotype. One of the main functional challenges is the switch between efficient aquatic and terrestrial prey capture modes. Recent studies have shown that newts adapt quickly by showing a high degree of behavioral flexibility, using suction feeding in their aquatic stage and tongue prehension in their terrestrial stage. As suction feeding and tongue prehension place different functional demands on the prey capture apparatus, this behavioral flexibility may clearly benefit from an associated morphological plasticity. In this study, we provide a detailed morphological analysis of the musculoskeletal system of the prey capture apparatus in the two multiphasic newt species Ichthyosaura alpestris and Lissotriton vulgaris by using histological sections and micro-computed tomography. We then test for quantitative changes of the hyobranchial musculoskeletal system between aquatic and terrestrial morphotypes, The descriptive morphology of the cranio-cervical musculoskeletal system provides new insights on form and function of the prey capture apparatus in newts, and the quantitative approach shows hypertrophy of the hyolingual musculoskeletal system in the terrestrial morphotype of L. vulgaris but hypertrophy in the aquatic morphotype of I. alpestris. It was therefore concluded that the seasonal habitat shifts are accompanied by a species-dependent muscular plasticity of which the potential effect on multiphasic feeding performance in newts remains unclear.

  3. Mycolactone-producing Mycobacterium marinum infection in captive Hong Kong warty newts and pathological evidence of impaired host immune function.

    PubMed

    Li, Wen-Ta; Chang, Hui-Wen; Pang, Victor Fei; Wang, Fun-In; Liu, Chen-Hsuan; Chen, Ting-Yu; Guo, Jun-Cheng; Wada, Takayuki; Jeng, Chian-Ren

    2017-03-21

    A mass mortality event of captive Hong Kong warty newts Paramesotriton hongkongensis with non-granulomatous necrotic lesions occurred in Taipei Zoo, Taiwan, in 2014. Clinically, the sick newts were lethargic and often covered with water mold Saprolegnia sp. on the skin of the body trunk or extremities. Predominant pathological findings were multifocal non-granulomatous necrotic lesions in the liver, spleen, and kidneys and severe skin infection with Saprolegnia sp., with deep invasion and involvement of underlying muscles. The possibility of ranavirus infection was ruled out by negative PCR results. Unexpectedly, abundant intralesional acid-fast positive bacilli were found in the necrotic lesions of the liver, spleen, and kidney in all 14 sick newts. PCR targeting the hsp65, ITS region, and partial 16S rRNA genes was performed, and the sequence identity from amplified amplicons of hsp65 and partial 16S rRNA genes was 100% identical to that of the corresponding gene fragment of Mycobacterium marinum. Further molecular investigations demonstrated that the current M. marinum was a mycolactone-producing mycobacterium with the presence of esxA/esxB genes. Mycolactone is a plasmid-encoded, immunosuppressive, and cytotoxic toxin. The possible immunosuppression phenomenon characterized by systemic non-granulomatous necrotic lesions caused by M. marinum and the unusual deep invasive infection caused by water mold might be associated with the immunosuppressive effect of mycolactone. Therefore, it should be noted that non-granulomatous necrotic lesions in amphibians can be caused not only by ranavirus infection but also by mycobacteriosis.

  4. Chronic transplantation immunity in newts: temperature susceptibility of an effector phase in allo-skin graft rejection.

    PubMed

    Kinefuchi, Kenjiroh; Kushida, Yoshihiro; Johnouchi, Masato; Shimizu, Yuiko; Ohneda, Hikaru; Fujii, Masato; Hosono, Masamichi

    2011-07-01

    Urodele amphibians are unique due to their greatly reduced immune responsiveness compared to bony fishes, which show acute immune responsiveness. In newts, the mean survival time of allogenic skin grafts in the transplantation immunity was 48.8 ± 8.3 days at 25°C, suggesting that it occurs in a chronic manner. The graft rejection process was categorized into three stages: a latent stage with frequent blood circulation, or the immune induction phase; a vascular stoppage stage with dominant infiltrating cells of T cells; and a rejection stage showing the change of the dominant cells to monocytes/macrophages, probably as effector cells, tetntatively referred to as the immune effector phase. The immune induction phase is susceptible to the cyclophosphamide (CY) mitosis inhibitor, but not to a temperature shift from 18 to 27°C, while the immune effector phase is susceptible to temperature shifts, but not CY-treatment, although the temperature shift failed to shorten the graft survival time to less than 25 days, which nearly equals that of the secondary set of grafts where the lack of complete blood circulation is remarkable and graft rejection is resistant to CY-treatment. In contrast, a very low temperature (5-10°C) completely prevented effector generation in newts; in frogs, however, it is reported that such low temperatures did not prevent the generation of effectors. Taken together, these data suggest that chronic responses in newts are due to effector cells other than cytotoxic T cells; possible effector cells are discussed.

  5. Nuclear markers, mitochondrial DNA and male secondary sexual traits variation in a newt hybrid zone (Triturus vulgaris x T. montandoni).

    PubMed

    Babik, W; Szymura, J M; Rafiński, J

    2003-07-01

    The smooth and the Montandon's newts (Triturus vulgaris and T. montandoni) are genetically similar sister species with highly divergent male secondary sexual traits involved in complex courtship behaviour. Their parapatric ranges overlap at moderate elevations in the Carpathian Mountains where they hybridize readily. Here we present a detailed study of genetic and morphological variation in populations from the area of sympatry. Analysis of variation at seven nuclear markers, mtDNA and male sexual secondary traits was complemented with an ecological survey of breeding sites characteristics. Extensive hybridization was revealed with back-cross individuals similar to either parental species predominating among hybrids. The hybrid zone exhibited a mosaic pattern: the genetic composition of the populations was correlated only weakly with their geographical position. No association with habitat type was found. Departures from Hardy-Weinberg proportions, significant linkage disequilibria and bimodal distribution of genotypes suggest strongly that assortative mating is an important factor shaping the genetic composition of hybrid populations. The pattern of cytonuclear disequilibria did not indicate much asymmetry in interspecific matings. Changes in the frequency of nuclear markers were highly concordant, whereas mtDNA showed much wider bidirectional introgression with 14% excess of T. montandoni haplotype. We argue that the mosaic structure of the newt hybrid zone results mainly from stochastic processes related to extinction and recolonization. Microgeographical differences in mtDNA introgression are explained by historical range shifts. Since morphologically intermediate males were underrepresented when compared to hybrid males identified by genetic markers, sexual selection acting against the morphological intermediates is implied. We discuss the implications of these findings in the context of reinforcement of prezygotic isolation in newts.

  6. Interactions of an insecticide with competition and pond drying in amphibian communities

    USGS Publications Warehouse

    Boone, M.D.; Semlitsch, R.D.

    2002-01-01

    Amphibian populations are often imbedded in agricultural landscapes. Therefore the potential for contamination of their habitat is considerable. Our study examined the effects of an insecticide (carbaryl, a neurotoxin), on larval amphibian communities experiencing natural stresses of competition for resources, predation, and pond drying. In a set of experimental ponds, tadpoles of three anuran species (southern leopard frog [Rana sphenocephala], plains leopard frog [R. blairi], and the Woodhouse's toad [Bufo woodhousii]) were added to 1000-L ponds containing leaf litter, plankton, two newts (Notophthalmus viridescens), and four overwintered green frog (R. clamitans) tadpoles. We manipulated the overall tadpole density (low or high), pond hydroperiod (constant or drying), and chemical exposure (0, 3.5, 5.0, or 7.0 mg/L carbaryl) of the ponds. We measured mass, time, and survival to metamorphosis to determine treatment effects. Carbaryl positively affected Woodhouse's toad survival, although it had a negligible effect on both leopard frog species. Tadpole density interacted with the chemical treatment: Proportionately more Woodhouse's toads survived to metamorphosis in high-density environments than in low-density or control environments. Greater survival may be an indirect effect of increased algal food resources from carbaryl exposure. Most newts lost mass over the course of the experiment, although ponds with drying hydroperiods and high anuran density were the least favorable environments. Overwintered green frogs exposed to carbaryl had longer larval periods on average than did green frogs in control ponds. Our study demonstrated that even sublethal, short-lived contaminants can alter natural communities in ways that cannot be predicted from simple, one-factor studies.

  7. 76 FR 32911 - Endangered and Threatened Wildlife and Plants; 12-Month Finding on a Petition To List the Striped...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-07

    ... North America. These include the eastern red spotted newt (N. viridescens), the black- spotted newt (N... Blanding Training Site. In Georgia, they are found at Joseph Jones Ecological Research Center and Fort... Property, Joseph W. Jones Ecological Research Center (JJERC), Fall Line Sandhills Natural Area, and...

  8. The potential function of prohibitin during spermatogenesis in Chinese fire-bellied newt Cynops orientalis.

    PubMed

    Jin, Jia-Min; Hou, Cong-Cong; Tan, Fu-Qing; Yang, Wan-Xi

    2016-03-01

    Prohibitin proteins are multifunctional proteins located mainly at the inner membrane of mitochondria expressed in universal species. They play a vital role in mitochondria's function, cell proteolysis, senescence, apoptosis and as a substrate for ubiquitination. In this study, we used PCR cloning, protein and nucleotide acids alignment, protein structure prediction, western blot, in situ hybridization and immunofluorescence to study the characteristics of the prohibitin gene and the potential role of prohibitin in spermatogenesis and spermiogenesis processes in the Chinese fire-bellied newt Cynops orientalis. First, we cloned a 1452-bp full-length cDNA from the testis of Cynops orientalis. Second, we found that the 272 amino acids of prohibitin have a SPFH family domain. Thirdly, the western blots showed high expression of prohibitin in testis while the protein size was approximately 32 kDa. Fourthly, the results of in situ hybridization and immunofluorescence experiments showed that most of the prohibitins travelled with the mitochondria's migration in Cynops orientalis. The quantities of mRNA decreased as spermiogenesis proceeded, although the signals of prohibitins existed during the whole period of spermatogenesis and spermiogenesis. In the mature germ cells, the signals of prohibitins were weak and aggregated at the end of the cell. Finally, we discovered that the Sertoli cells had a large quantity of prohibitins and we made several assumptions of prohibitins' potential roles in those cells. This is the first time that the relationship between mitochondria and prohibitin in different stages of the sperm cells in Cynops orientalis has been examined, which also revealed that Sertoli cells have abundant prohibitins.

  9. Homeotic transformations and number changes in the vertebral column of Triturus newts

    PubMed Central

    Slijepčević, Maja; Galis, Frietson; Arntzen, Jan W.

    2015-01-01

    We explored intraspecific variation in vertebral formulae, more specifically the variation in the number of thoracic vertebrae and frequencies of transitional sacral vertebrae in Triturus newts (Caudata: Salamandridae). Within salamandrid salamanders this monophyletic group shows the highest disparity in the number of thoracic vertebrae and considerable intraspecific variation in the number of thoracic vertebrae. Triturus species also differ in their ecological preferences, from predominantly terrestrial to largely aquatic. Following Geoffroy St. Hilaire’s and Darwin’s rule which states that structures with a large number of serially homologous repetitive elements are more variable than structures with smaller numbers, we hypothesized that the variation in vertebral formulae increases in more elongated species with a larger number of thoracic vertebrae. We furthermore hypothesized that the frequency of transitional vertebrae will be correlated with the variation in the number of thoracic vertebrae within the species. We also investigated potential effects of species hybridization on the vertebral formula. The proportion of individuals with a number of thoracic vertebrae different from the modal number and the range of variation in number of vertebrae significantly increased in species with a larger number of thoracic vertebrae. Contrary to our expectation, the frequencies of transitional vertebrae were not correlated with frequencies of change in the complete vertebrae number. The frequency of transitional sacral vertebra in hybrids did not significantly differ from that of the parental species. Such a pattern could be a result of selection pressure against transitional vertebrae and/or a bias towards the development of full vertebrae numbers. Although our data indicate relaxed selection for vertebral count changes in more elongated, aquatic species, more data on different selective pressures in species with different numbers of vertebrae in the two contrasting

  10. One Species, Three Pleistocene Evolutionary Histories: Phylogeography of the Italian Crested Newt, Triturus carnifex

    PubMed Central

    Canestrelli, Daniele; Salvi, Daniele; Maura, Michela; Bologna, Marco A.; Nascetti, Giuseppe

    2012-01-01

    Phylogeographic patterns of temperate species from the Mediterranean peninsulas have been investigated intensively. Nevertheless, as more phylogeographies become available, either unique patterns or new lines of concordance continue to emerge, providing new insights on the evolution of regional biotas. Here, we investigated the phylogeography and evolutionary history of the Italian crested newt, Triturus carnifex, through phylogenetic, molecular dating and population structure analyses of two mitochondrial gene fragments (ND2 and ND4; overall 1273 bp). We found three main mtDNA lineages having parapatric distribution and estimated divergence times between Late Pliocene and Early Pleistocene. One lineage (S) was widespread south of the northern Apennine chain and was further geographically structured into five sublineages, likely of Middle Pleistocene origin. The second lineage (C) was widespread throughout the Padano–Venetian plain and did not show a clear phylogeographic structure. The third lineage (N) was observed in only two populations located on western Croatia/Slovenia. Results of analysis of molecular variance suggested that partitioning populations according to the geographic distribution of these lineages and sublineages explains 76% of the observed genetic variation. The phylogeographic structure observed within T. carnifex and divergence time estimates among its lineages, suggest that responses to Pleistocene environmental changes in this single species have been as diverse as those found previously among several codistributed temperate species combined. Consistent with the landscape heterogeneity, physiographic features, and palaeogeographical evolution of its distribution range, these responses encompass multiple refugia along the Apennine chain, lowland refugia in large peri-coastal plains, and a ‘cryptic’ northern refugium. PMID:22848590

  11. Islands within an island: Population genetic structure of the endemic Sardinian newt, Euproctus platycephalus.

    PubMed

    Ball, Sarah E; Bovero, Stefano; Sotgiu, Giuseppe; Tessa, Giulia; Angelini, Claudio; Bielby, Jon; Durrant, Christopher; Favelli, Marco; Gazzaniga, Enrico; Garner, Trenton W J

    2017-02-01

    The identification of historic and contemporary barriers to dispersal is central to the conservation of endangered amphibians, but may be hindered by their complex life history and elusive nature. The complementary information generated by mitochondrial (mtDNA) and microsatellite markers generates a valuable tool in elucidating population structure and the impact of habitat fragmentation. We applied this approach to the study of an endangered montane newt, Euproctus platycephalus. Endemic to the Mediterranean island of Sardinia, it is threatened by anthropogenic activity, disease, and climate change. We have demonstrated a clear hierarchy of structure across genetically divergent and spatially distinct subpopulations. Divergence between three main mountain regions dominated genetic partitioning with both markers. Mitochondrial phylogeography revealed a deep division dating to ca. 1 million years ago (Mya), isolating the northern region, and further differentiation between the central and southern regions ca. 0.5 Mya, suggesting an association with Pleistocene severe glacial oscillations. Our findings are consistent with a model of southward range expansion during glacial periods, with postglacial range retraction to montane habitat and subsequent genetic isolation. Microsatellite markers revealed further strong population structure, demonstrating significant divergence within the central region, and partial differentiation within the south. The northern population showed reduced genetic diversity. Discordance between mitochondrial and microsatellite markers at this scale indicated a further complexity of population structure, in keeping with male-biased dispersal and female philopatry. Our study underscores the need to elucidate cryptic population structure in the ecology and conservation strategies for endangered island-restricted amphibians, especially in the context of disease and climate change.

  12. Homeotic transformations and number changes in the vertebral column of Triturus newts.

    PubMed

    Slijepčević, Maja; Galis, Frietson; Arntzen, Jan W; Ivanović, Ana

    2015-01-01

    We explored intraspecific variation in vertebral formulae, more specifically the variation in the number of thoracic vertebrae and frequencies of transitional sacral vertebrae in Triturus newts (Caudata: Salamandridae). Within salamandrid salamanders this monophyletic group shows the highest disparity in the number of thoracic vertebrae and considerable intraspecific variation in the number of thoracic vertebrae. Triturus species also differ in their ecological preferences, from predominantly terrestrial to largely aquatic. Following Geoffroy St. Hilaire's and Darwin's rule which states that structures with a large number of serially homologous repetitive elements are more variable than structures with smaller numbers, we hypothesized that the variation in vertebral formulae increases in more elongated species with a larger number of thoracic vertebrae. We furthermore hypothesized that the frequency of transitional vertebrae will be correlated with the variation in the number of thoracic vertebrae within the species. We also investigated potential effects of species hybridization on the vertebral formula. The proportion of individuals with a number of thoracic vertebrae different from the modal number and the range of variation in number of vertebrae significantly increased in species with a larger number of thoracic vertebrae. Contrary to our expectation, the frequencies of transitional vertebrae were not correlated with frequencies of change in the complete vertebrae number. The frequency of transitional sacral vertebra in hybrids did not significantly differ from that of the parental species. Such a pattern could be a result of selection pressure against transitional vertebrae and/or a bias towards the development of full vertebrae numbers. Although our data indicate relaxed selection for vertebral count changes in more elongated, aquatic species, more data on different selective pressures in species with different numbers of vertebrae in the two contrasting

  13. Injury, nerve, and wound epidermis related electrophoretic and fluorographic protein patterns in forelimbs of adult newts

    SciTech Connect

    Garling, D.J.; Tassava, R.A.

    1984-08-01

    Polyacrylamide slab gel electrophoresis and (/sup 35/S)methionine fluorography were used to examine proteins in regenerating newt limbs, amputated denervated limbs, unamputated denervated limbs, and separated blastema mesodermal core and wound epidermis. A total of 27 protein electrophoretic bands were obtained from amputated limbs and 24 bands from unamputated limbs. Amputation resulted in the appearance of 4 new bands and the loss of 1 band as compared to unamputated limbs. These 5 banding differences were apparent on stained gels 3 days postamputation and were maintained through 10 weeks postamputation (complete regenerate stage). Only one band in unamputated limbs was always detectable on fluorographs, whereas virtually all of the stainable bands of amputated limbs were visible on fluorographs. Amputation clearly stimulated a marked, generalized increase in the synthesis of limb proteins. The 5 amputation induced changes were equally evident in stained gels of both innervated and denervated limbs. Amputated denervated limbs possessed a full set of fluorographic bands (including the 5 differences) through 18 days postamputation. However, denervation without amputation was not sufficient to alter the stainable banding pattern. Wound epidermis and mesodermal core both displayed the 5 banding differences and had identical banding patterns with the exception of one epidermal specific band. This band was also present in whole limb skin but was absent in unamputated mesodermal limb tissue. This was the only band of unamputated limbs that was consistently detectable by fluorography. It is concluded that amputation induces nerve independent changes in protein synthesis that are common to both mesodermal core and wound epidermis. These changes may represent preparation for cellular proliferation.

  14. Interspecific hybridization increases MHC class II diversity in two sister species of newts.

    PubMed

    Nadachowska-Brzyska, Krystyna; Zieliński, Piotr; Radwan, Jacek; Babik, Wiesław

    2012-02-01

    Our understanding of the evolutionary mechanisms generating variation within the highly polymorphic major histocompatibility complex (MHC) genes remains incomplete. Assessing MHC variation across multiple populations, of recent and ancient divergence, may facilitate understanding of geographical and temporal aspects of variation. Here, we applied 454 sequencing to perform a large-scale, comprehensive analysis of MHC class II in the closely related, hybridizing newts, Lissotriton vulgaris (Lv) and Lissotriton montandoni (Lm). Our study revealed an extensive (299 alleles) geographically structured polymorphism. Populations at the southern margin of the Lv distribution, inhabited by old and distinct lineages (southern Lv), exhibited moderate MHC variation and strong population structure, indicating little gene flow or extensive local adaptation. Lissotriton vulgaris in central Europe and the northern Balkans (northern Lv) and almost all Lm populations had a high MHC variation. A much higher proportion of MHC alleles was shared between Lm and northern Lv than between Lm and southern Lv. Strikingly, the average pairwise F(ST) between northern Lv and Lm was significantly lower than between northern and southern Lv for MHC, but not for microsatellites. Thus, high MHC variation in Lm and northern Lv may result from gene flow between species. We hypothesize that the interspecific exchange of MHC genes may be facilitated by frequency-dependent selection. A marginally significant correlation between the MHC and microsatellite allelic richness indicates that demographic factors may have contributed to the present-day pattern of MHC variation, but unequivocal signatures of adaptive evolution in MHC class II sequences emphasize the role of selection on a longer timescale.

  15. FINE STRUCTURE OF DESMOSOMES, HEMIDESMOSOMES, AND AN ADEPIDERMAL GLOBULAR LAYER IN DEVELOPING NEWT EPIDERMIS

    PubMed Central

    Kelly, Douglas E.

    1966-01-01

    The skin of late embryonic, larval, and young postmetamorphic newts, Taricha torosa, has been examined with particular reference to areas of cellular attachment. Stereo electron microscopic techniques and special staining methods for extracellular materials were utilized in addition to conventional avenues of ultrastructural study to investigate the fine architecture of desmosomes, hemidesmosomes, their associated filament systems, and extracellular materials. No evidence has been found that continuity of tonofilaments between adjacent cells exists at desmosomes. Rather, most of the tonofilaments which approach desmosomes (and perhaps also hemidesmosomes) course toward the "attachment plaque" and then loop, either outside the plaque or within it, and return into the main filament tracts of the cell. These facts suggest that the filamentous framework provides intracellular tensile support while adhesion is a product of extracellular materials which accumulate at attachment sites. Evidence is presented that the extracellular material is arranged as pillars or partitions which are continuous with or layered upon the outer unit cell membrane leaflets and adjoined in a discontinuous dense midline of the desmosome. A similar analysis has been made of extracellular materials associated with hemidesmosomes along the basal surface of epidermal cells. An adepidermal globular zone, separating the basal cell boundary from the underlying basal lamina and collagenous lamellae during larval stages, has been interpreted from enzyme and solvent extraction study as a lipid-mucopolysaccharide complex, the function of which remains obscure. These observations are discussed in relation to prevailing theories of cellular adhesion and epidermal differentiation. They appear consistent with the concept that a wide range of adhesive specializations exists in nature, and that the more highly organized of these, such as large desmosomes and hemidesmosomes, serve as strong, highly supported

  16. [Retinal regeneration after dissection of the optic nerve in newts exposed on board the Bion-11 biosatellite].

    PubMed

    Grigorian, E N; Tuchkova, S Ia; Poplinskaia, V A; Mitashov, V I

    1999-01-01

    The work brought up initial information on the impacts of space flight (SF) on regeneration of nerve tissues in vertebrata. Summarized are data of analysis of the retinal regeneration following section of the ocular nerve and blood vessels in space-flown adult newts (Pleurodeles waltlii). Two weeks in SF were found not to impede the regeneration of retina as its growth was fully dependent on the same cell sources as in the condition of 1 g. In the newts which had been operated 2 wk prior to launch, recovery of retina in SF proceeded more intensively (phases V-VI) compared with the synchronous controls (phase IV). According to the morphometric analysis, differentiation of regenerates' layers in the space animals was also a more rapid process. The proliferative activity of cells in regenerates estimated with the 3H-timidine radioautography turned to be higher, too: the labeled nuclei index in early non-differentiated regenerates was in 1.2 to 1.5 times higher than in the control. Immunohistochemical array with the help of GFAP antibodies performed at the late phases of regeneration revealed an activating effect of SF on the Muller glia cells. These findings indicate that microgravity can stimulate general retinal regeneration and activate regenerate cells, specifically those involved in morphogenesis.

  17. Changes in the extracellular matrix and glycosaminoglycan synthesis during the initiation of regeneration in adult newt forelimbs

    SciTech Connect

    Mescher, A.L.; Munaim, S.I.

    1986-04-01

    The extracellular matrix (ECM) of the distal tissues in a newt limb stump is completely reorganized in the 2-3-week period following amputation. In view of numerous in vitro studies showing that extracellular material influences cellular migration and proliferation, it is likely that the changes in the limb's ECM are important activities in the process leading to regeneration of such limbs. Using biochemical, autoradiographic, and histochemical techniques we studied temporal and spatial differences in the synthesis of glycosaminoglycans (GAGs) during the early, nerve-dependent phase of limb regeneration. Hyaluronic acid synthesis began with the onset of tissue dedifferentiation, became maximal within 1 weeks, and continued throughout the period of active cell proliferation. Chondroitin sulfate synthesis began somewhat later, increased steadily, and reached very high levels during chondrogenesis. During the first 10 days after amputation, distributions of sulfated and nonsulfated GAGs were both uniform throughout dedifferentiating tissues, except for a heavier localization near the bone. Since nerves are necessary to promote the regenerative process, we examined the neural influence on synthesis and accumulation of extracellular GAGs. Denervation decreased GAG production in all parts of the limb stump by approximately 50%. Newt dorsal root ganglia and brain-derived fibroblast growth factor each produced twofold stimulation of GAG synthesis in cultured 7-day regenerates. The latter effect was primarily on synthesis of hyaluronic acid. The results indicate that the trophic action of nerves on amphibian limb regeneration includes a positive influence on synthesis and extracellular accumulation of GAGs.

  18. Kinetochores capture astral microtubules during chromosome attachment to the mitotic spindle: direct visualization in live newt lung cells

    PubMed Central

    1990-01-01

    When viewed by light microscopy the mitotic spindle in newt pneumocytes assembles in an optically clear area of cytoplasm, virtually devoid of mitochondria and other organelles, which can be much larger than the forming spindle. This unique optical property has allowed us to examine the behavior of individual microtubules, at the periphery of asters in highly flattened living prometaphase cells, by video-enhanced differential interference-contrast light microscopy and digital image processing. As in interphase newt pneumocytes (Cassimeris, L., N. K. Pryer, and E. D. Salmon. 1988. J. Cell Biol. 107:2223-2231), centrosomal (i.e., astral) microtubules in prometaphase cells appear to exhibit dynamic instability, elongating at a mean rate of 14.3 +/- 5.1 microns/min (N = 19) and shortening at approximately 16 microns/min. Under favorable conditions the initial interaction between a kinetochore and the forming spindle can be directly observed. During this process the unattached chromosome is repeatedly probed by microtubules projecting from one of the polar regions. When one of these microtubules contacts the primary constriction the chromosome rapidly undergoes poleward translocation. Our observations on living mitotic cells directly demonstrate, for the first time, that chromosome attachment results from an interaction between astral microtubules and the kinetochore. PMID:2391359

  19. Beyond sodefrin: evidence for a multi-component pheromone system in the model newt Cynops pyrrhogaster (Salamandridae).

    PubMed

    Van Bocxlaer, Ines; Maex, Margo; Treer, Dag; Janssenswillen, Sunita; Janssens, Rik; Vandebergh, Wim; Proost, Paul; Bossuyt, Franky

    2016-03-03

    Sodefrin, a decapeptide isolated from the male dorsal gland of the Japanese fire belly newt Cynops pyrrhogaster, was the first peptide pheromone identified from a vertebrate. The fire belly salamander and sodefrin have become a model for sex pheromone investigation in aquatically courting salamanders ever since. Subsequent studies in other salamanders identified SPF protein courtship pheromones of around 20 kDa belonging to the same gene-family. Although transcripts of these proteins could be PCR-amplified in Cynops, it is currently unknown whether they effectively use full-length SPF pheromones next to sodefrin. Here we combined transcriptomics, proteomics and phylogenetics to investigate SPF pheromone use in Cynops pyrrhogaster. Our data show that not sodefrin transcripts, but multiple SPF transcripts make up the majority of the expression profile in the dorsal gland of this newt. Proteome analyses of water in which a male has been courting confirm that this protein blend is effectively secreted and tail-fanned to the female. By combining phylogenetics and expression data, we show that independent evolutionary lineages of these SPF's were already expressed in ancestral Cynops species before the origin of sodefrin. Extant Cynops species continue to use this multi-component pheromone system, consisting of various proteins in addition to a lineage-specific peptide.

  20. Data concatenation, Bayesian concordance and coalescent-based analyses of the species tree for the rapid radiation of Triturus newts.

    PubMed

    Wielstra, Ben; Arntzen, Jan W; van der Gaag, Kristiaan J; Pabijan, Maciej; Babik, Wieslaw

    2014-01-01

    The phylogenetic relationships for rapid species radiations are difficult to disentangle. Here we study one such case, namely the genus Triturus, which is composed of the marbled and crested newts. We analyze data for 38 genetic markers, positioned in 3-prime untranslated regions of protein-coding genes, obtained with 454 sequencing. Our dataset includes twenty Triturus newts and represents all nine species. Bayesian analysis of population structure allocates all individuals to their respective species. The branching patterns obtained by data concatenation, Bayesian concordance analysis and coalescent-based estimations of the species tree differ from one another. The data concatenation based species tree shows high branch support but branching order is considerably affected by allele choice in the case of heterozygotes in the concatenation process. Bayesian concordance analysis expresses the conflict between individual gene trees for part of the Triturus species tree as low concordance factors. The coalescent-based species tree is relatively similar to a previously published species tree based upon morphology and full mtDNA and any conflicting internal branches are not highly supported. Our findings reflect high gene tree discordance due to incomplete lineage sorting (possibly aggravated by hybridization) in combination with low information content of the markers employed (as can be expected for relatively recent species radiations). This case study highlights the complexity of resolving rapid radiations and we acknowledge that to convincingly resolve the Triturus species tree even more genes will have to be consulted.

  1. Purification and molecular cloning of aspartic proteinases from the stomach of adult Japanese fire belly newts, Cynops pyrrhogaster.

    PubMed

    Nagasawa, Tatsuki; Sano, Kaori; Kawaguchi, Mari; Kobayashi, Ken-Ichiro; Yasumasu, Shigeki; Inokuchi, Tomofumi

    2016-04-01

    Six aspartic proteinase precursors, a pro-cathepsin E (ProCatE) and five pepsinogens (Pgs), were purified from the stomach of adult newts (Cynops pyrrhogaster). On sodium dodecylsulfate-polyacrylamide gel electrophoresis, the molecular weights of the Pgs and active enzymes were 37-38 kDa and 31-34 kDa, respectively. The purified ProCatE was a dimer whose subunits were connected by a disulphide bond. cDNA cloning by polymerase chain reaction and subsequent phylogenetic analysis revealed that three of the purified Pgs were classified as PgA and the remaining two were classified as PgBC belonging to C-type Pg. Our results suggest that PgBC is one of the major constituents of acid protease in the urodele stomach. We hypothesize that PgBC is an amphibian-specific Pg that diverged during its evolutional lineage. PgBC was purified and characterized for the first time. The purified urodele pepsin A was completely inhibited by equal molar units of pepstatin A. Conversely, the urodele pepsin BC had low sensitivity to pepstatin A. In acidic condition, the activation rates of newt pepsin A and BC were similar to those of mammalian pepsin A and C1, respectively. Our results suggest that the enzymological characters that distinguish A- and C-type pepsins appear to be conserved in mammals and amphibians.

  2. The morphogenic features of otoconia during larval development of Cynops pyrrhogaster, the Japanese red-bellied newt

    NASA Technical Reports Server (NTRS)

    Steyger, P. S.; Wiederhold, M. L.; Batten, J.

    1995-01-01

    Otoconia are calcified protein matrices within the gravity-sensing organs of the vertebrate vestibular system. Mammalian otoconia are barrel-shaped with triplanar facets at each end. Reptilian otoconia are commonly prismatic or fusiform in shape. Amphibians have all three otoconial morphologies, barrel-shaped otoconia within the utricle, with prismatic and fusiform otoconia in the saccule. Scanning electron microscopy revealed a sequential appearance of all three otoconial morphologies during larval development of the newt, Cynops pyrrhogaster. The first otoconia appear within a single, developing otolith, and some resemble adult barrel-shaped otoconia. As the larvae hatch, around stages 39-42, the single otolith divides into two anatomically separate regions, the utricle and saccule, and both contain otoconia similar to those seen in the single otolith. Throughout development, these otoconia may have variable morphologies, with serrated surfaces, or circumferential striations with either separated facets or adjacent facets in the triplanar end-regions. Small fusiform otoconia occur later, at stage 51, and only in the saccule. Prismatic otoconia appear later still, at stage 55, and again only in the saccule. Thus, although prismatic otoconia are the most numerous in adult newts, it is the last vestibular otoconial morphology to be expressed.

  3. Ultrastructure of the endolymphatic sac in the larva of the japanese red-bellied newt Cynops pyrrhogaster

    NASA Technical Reports Server (NTRS)

    Gao, W.; Wiederhold, M.; Hejl, R.

    1998-01-01

    The ultrastructure of the endolymphatic sac (ES) of the late stage larva of the Japanese red-bellied newt, Cynops pyrrhogaster (stage 57), was examined by light and transmission electron microscopy. The two endolymphatic sacs are located at the dorsal-medial side of the otic vesicle on the dorsal-lateral side of the midbrain in the cranial cavity. The wall of the sac is composed of a layer of cubical epithelial cells with loose, interposed intercellular spaces. The sac contains a large luminal cavity, in which endolymph and numerous otoconia are present. The epithelial cells of different portions of the sac have a similar structure. These cells contain an abundance of cytoplasmic organelles, including ribosomes, Golgi complexes, and numerous vesicles. Two types of vesicles are found in the epithelial cells: the "floccular" vesicle and the "granular" vesicle. The floccular vesicles are located in the supra- and lateral-nuclear cytoplasm and contain floccular material. The granular vesicles have a fine granular substance and are usually situated apposed to the apical cell membrane. The granular vesicles are suggested to be secreted into the lumen, while the floccular vesicles are thought to be absorbed from the lumen and conveyed to the intercellular spaces by the epithelial cells. The apical surfaces of the epithelial cells bear numerous microvilli. Apparently floating cells, which bear long microvilli on the free surfaces, are observed in the lumen of the ES. Based on the fine structure, the function of the endolymphatic sac of the newt Cynops pyrrhogaster is discussed.

  4. Why are the prevalence and diversity of helminths in the endemic Pyrenean brook newt Calotriton asper (Amphibia, Salamandridae) so low?

    PubMed

    Comas, M; Ribas, A

    2015-03-01

    A cornerstone in parasitology is why some species or populations are more parasitized than others. Here we examine the influence of host characteristics and habitat on parasite prevalence. We studied the helminths parasitizing the Pyrenean brook newt Calotriton asper (n= 167), paying special attention to the relationship between parasites and ecological factors such as habitat, sex, ontogeny, body size and age of the host. We detected two species of parasites, Megalobatrachonema terdentatum (Nematoda: Kathlaniidae) and Brachycoelium salamandrae (Trematoda: Brachycoeliidae), with a prevalence of 5.99% and 1.2%, respectively. Marginally significant differences were found in the prevalence between sexes, with females being more parasitized than males. The present results show significant differences in the body length of paedomorphic and metamorphic individuals, the former being smaller. Nevertheless, no significant correlations between parasite prevalence and either newt body length, ontogenetic stage or age were found. In comparison with other Salamandridae living in ponds, prevalence and diversity values were low. This may be due to a long hibernation period, the species' lotic habitat and its reophilous lifestyle, which probably do not allow for a high parasite load.

  5. Beyond sodefrin: evidence for a multi-component pheromone system in the model newt Cynops pyrrhogaster (Salamandridae)

    PubMed Central

    Van Bocxlaer, Ines; Maex, Margo; Treer, Dag; Janssenswillen, Sunita; Janssens, Rik; Vandebergh, Wim; Proost, Paul; Bossuyt, Franky

    2016-01-01

    Sodefrin, a decapeptide isolated from the male dorsal gland of the Japanese fire belly newt Cynops pyrrhogaster, was the first peptide pheromone identified from a vertebrate. The fire belly salamander and sodefrin have become a model for sex pheromone investigation in aquatically courting salamanders ever since. Subsequent studies in other salamanders identified SPF protein courtship pheromones of around 20 kDa belonging to the same gene-family. Although transcripts of these proteins could be PCR-amplified in Cynops, it is currently unknown whether they effectively use full-length SPF pheromones next to sodefrin. Here we combined transcriptomics, proteomics and phylogenetics to investigate SPF pheromone use in Cynops pyrrhogaster. Our data show that not sodefrin transcripts, but multiple SPF transcripts make up the majority of the expression profile in the dorsal gland of this newt. Proteome analyses of water in which a male has been courting confirm that this protein blend is effectively secreted and tail-fanned to the female. By combining phylogenetics and expression data, we show that independent evolutionary lineages of these SPF’s were already expressed in ancestral Cynops species before the origin of sodefrin. Extant Cynops species continue to use this multi-component pheromone system, consisting of various proteins in addition to a lineage-specific peptide. PMID:26935790

  6. Egg jelly of the newt, Cynops pyrrhogaster contains a factor essential for sperm binding to the vitelline envelope.

    PubMed

    Hiyoshi, Wataru; Sasaki, Takayuki; Takayama-Watanabe, Eriko; Takai, Hiroyuki; Watanabe, Akihiko; Onitake, Kazuo

    2007-06-01

    The acrosome reaction of newt sperm is induced at the surface of egg jelly and the acrosome-reacted sperm acquire the ability to bind to the vitelline envelope. However, because the substance that induces the acrosome reaction has not been identified, the mechanism by which the acrosome-reacted sperm bind to the vitelline envelope remains unclear. We found here that a Dolichos biforus agglutinin (DBA) specifically mimicked the acrosome reaction immediately upon its addition in the presence of milimolar level Ca(2+). Fluorescein isothiocyanate-labeled DBA bound specifically to the acrosomal cap of the intact sperm in the presence of a Ca(2+)-chelating agent, EDTA, suggesting that binding of DBA to the native receptor for the egg jelly substance on the acrosomal region took the place of the egg jelly substance-induced acrosome reaction. In contrast, the sperm that had been acrosome reacted by DBA treatment did not bind to the vitelline envelope of the egg whose jelly layers were removed. Subsequent addition of jelly extract caused the sperm binding to vitelline envelope, indicating that the egg jelly of the newt contains substances that are involved in not only inducing the acrosome reaction but also binding to the vitelline envelope. This is the first demonstration of the involvement of egg jelly substance in the binding of acrosome-reacted sperm to the vitelline envelope.

  7. miR-128 regulates non-myocyte hyperplasia, deposition of extracellular matrix and Islet1 expression during newt cardiac regeneration.

    PubMed

    Witman, Nevin; Heigwer, Jana; Thaler, Barbara; Lui, Weng-Onn; Morrison, Jamie Ian

    2013-11-15

    Cardiovascular disease is a global scourge to society, with novel therapeutic approaches required in order to alleviate the suffering caused by sustained cardiac damage. MicroRNAs (miRNAs) are being touted as one such approach in the fight against heart disease, acting as possible post-transcriptional molecular triggers responsible for invoking cardiac regeneration. To further ones understanding of miRNAs and cardiac regeneration, it is prudent to learn from organisms that can intrinsically regenerate their hearts following injury. Using the red-spotted newt, an adult chordate capable of cardiac regeneration, we decided to delve deeper into the role miRNAs play during this process. RNA isolated from regenerating newt heart samples, was used in a microarray screen, to identify significantly expressed candidate miRNAs during newt cardiac regeneration. We performed quantitative qPCR analysis on several conserved miRNAs and found one in particular, miR-128, to be significantly elevated when cardiac hyperplasia is at its peak following injury. In-situ hybridisation techniques revealed a localised expression pattern for miR-128 in the cardiomyocytes and non-cardiomyocytes in close proximity to the regeneration zone and in vivo knockdown studies revealed a regulatory role for miR-128 in proliferating non-cardiomyocyte populations and extracellular matrix deposition. Finally, 3'UTR reporter assays revealed Islet1 as a biological target for miR-128, which was confirmed further through in vivo Islet1 transcriptional and translational expression analysis in regenerating newt hearts. From these studies we conclude that miR-128 regulates both cardiac hyperplasia and Islet1 expression during newt heart regeneration and that this information could be translated into future mammalian cardiac studies.

  8. Prolactin increases the synthesis of 7alpha-hydroxypregnenolone, a key factor for induction of locomotor activity, in breeding male Newts.

    PubMed

    Haraguchi, Shogo; Koyama, Teppei; Hasunuma, Itaru; Vaudry, Hubert; Tsutsui, Kazuyoshi

    2010-05-01

    We recently found that the Japanese red-bellied newt, Cynops pyrrhogaster, actively produces 7alpha-hydroxypregnenolone, a previously undescribed amphibian neurosteroid. 7alpha-Hydroxypregnenolone stimulates locomotor activity of male newts. Locomotor activity of male newts increases during the breeding period as in other wild animals, but the molecular mechanism for such a change in locomotor activity is poorly understood. Here we show that the adenohypophyseal hormone prolactin (PRL) stimulates 7alpha-hydroxypregnenolone synthesis in the brain, thus increasing locomotor activity of breeding male newts. In this study, cytochrome P450(7alpha) (CYP7B), a steroidogenic enzyme catalyzing the formation of 7alpha-hydroxypregnenolone, was first identified to analyze seasonal changes in 7alpha-hydroxypregnenolone synthesis. Only males exhibited marked seasonal changes in 7alpha-hydroxypregnenolone synthesis and CYP7B expression in the brain, with a maximum level in the spring breeding period when locomotor activity of males increases. Subsequently we identified PRL as a key component of the mechanism regulating 7alpha-hydroxypregnenolone synthesis. Hypophysectomy decreased 7alpha-hydroxypregnenolone synthesis in the male brain, whereas administration of PRL but not gonadotropins to hypophysectomized males caused a dose-dependent increase in 7alpha-hydroxypregnenolone synthesis. To analyze the mode of PRL action, CYP7B and the receptor for PRL were localized in the male brain. PRL receptor was expressed in the neurons expressing CYP7B in the magnocellular preoptic nucleus. Thus, PRL appears to act directly on neurosteroidogenic magnocellular preoptic nucleus neurons to regulate 7alpha-hydroxypregnenolone synthesis, thus inducing seasonal locomotor changes in male newts. This is the first report describing the regulation of neurosteroidogenesis in the brain by an adenohypophyseal hormone in any vertebrate.

  9. Outbreak of common midwife toad virus in alpine newts (Mesotriton alpestris cyreni) and common midwife toads (Alytes obstetricans) in northern Spain: a comparative pathological study of an emerging ranavirus.

    PubMed

    Balseiro, Ana; Dalton, Kevin P; del Cerro, Ana; Márquez, Isabel; Parra, Francisco; Prieto, José M; Casais, R

    2010-11-01

    This report describes the isolation and characterisation of the common midwife toad virus (CMTV) from juvenile alpine newts (Mesotriton alpestris cyreni) and common midwife toad (CMT) tadpoles (Alytes obstetricans) in the Picos de Europa National Park in Northern Spain in August 2008. A comparative pathological and immunohistochemical study was carried out using anti-CMTV polyclonal serum. In the kidneys, glomeruli had the most severe histological lesions in CMT tadpoles, while both glomeruli and renal tubular epithelial cells exhibited foci of necrosis in juvenile alpine newts. Viral antigens were detected by immunohistochemical labelling mainly in the kidneys of CMT tadpoles and in ganglia of juvenile alpine newts. This is the first report of ranavirus infection in the alpine newt, the second known species to be affected by CMTV in the past 2 years.

  10. Development of the endolymphatic sac and duct in the Japanese red-bellied newt, Cynops pyrrhogaster

    NASA Technical Reports Server (NTRS)

    Gao, W.; Wiederhold, M. L.; Harrison, J. L.

    1998-01-01

    The development and maturation of the endolymphatic sac (ES) and duct (ED) were studied in the newt Cynops pyrrhogaster. The ES first appears as an oval capsule at the dorsal-medial tip of the otic vesicle at stage 39, about 11 days after oviposition. The ES consists of polymorphous epithelial cells with a minimum of cytoplasm. The intercellular space (IS) between the epithelial cells is narrow and has a smooth surface. At stage 44, the size of the ES increases as many vacuoles in the IS become filled. At stage 46, 18 days after oviposition, the ES elongates markedly and a slit-like lumen is found in the ES. The epithelium contains a few cell organelles which are scattered in the cytoplasm. The vacuoles in the IS are fused, which expands the IS. Two days later (stage 48), floccular material (endolymph) is present in the expanded lumen. The IS dilates and has a wide and irregular appearance. At stage 50, approximately 26 days after oviposition, the ES extends and expands significantly and crystals (otoconia) can now be seen in the widened lumen of the ES. The cytoplasm of the cuboidal epithelial cells contains an abundance of vesicles surrounded by ribosomes and Golgi complexes. Intercellular digitations are formed in the expanded IS. At stage 54, the ES forms a large bellow-like pouch. Numerous otoconia accumulate in the lumen. Free floating cells and cell debris can be seen in the lumen at this stage. The epithelial cells contain numerous cytoplasmic organelles which are evenly distributed in the cytoplasm. Granules are found in the apical and lateral cytoplasm. The IS is loose and displays a labyrinthine appearance. The primitive ED first appears as a connection between the ES and the saccule but no lumen is present inside at stage 39. At stage 46, a narrow lumen is formed in the ED, which corresponds to the formation of the ES lumen. At stage 50, as the ED extends, floccular material is seen in the lumen. At stage 54, the ED bears numerous microvilli on its

  11. Kinetics of phototransduction in retinal rods of the newt Triturus cristatus.

    PubMed Central

    Forti, S; Menini, A; Rispoli, G; Torre, V

    1989-01-01

    1. The kinetics of photoresponses to flashes and steps of light of rods, from the retina of the newt Triturus cristatus, were analysed by recording the membrane current with a suction electrode. 2. In dark-adapted conditions the relation between the normalized amplitude of the photoresponse at a fixed time 1 s after the onset of light and the light intensity could be fitted by an exponential or a polynomial relation. In the presence of a steady bright light the same relation could be fitted by a Michaelis-Menten relation. 3. The kinetics of photoresponses to light stimuli was reconstructed using a model in which: (i) three molecules of guanosine 3'.5'-cyclic monophosphate (cyclic GMP) open a light-sensitive channel; (ii) light activates the enzyme phosphodiesterase, which hydrolyses cyclic GMP, thus closing light-sensitive channels: (iii) Ca2+ ions permeate through light-sensitive channels: and (iv) intracellular Ca2+ inhibits, in a co-operative way, the enzyme cyclase, which synthesizes cyclic GMP. 4. The model reproduces the shortening of the time to peak of brief flash photoresponses from about 1080 ms to about 690 ms with brighter lights. The model also explains the shortening of the time to peak to 350 ms observed in the presence of a steady light and the lack of a further acceleration with brighter flashes of lights. 5. The presence in the model of an intracellular calcium buffer accounts for the partial reactivation of the photocurrent following a step of light, lasting several seconds. The time course of this reactivation is not accelerated by a steady bright light both experimentally and in the model. 6. After the extinction to a long step of light the photocurrent showed a rapid partial reactivation, which was followed by a slow component of the photoresponse which extinguished with a rate constant of about 0.05 s-1. The model explains the origin of this slow component by assuming that the inactivation of excited rhodopsin is partially reversible. 7. The

  12. Computational Modeling of the Ames 11-Ft Transonic Wind Tunnel in Conjunction with IofNEWT

    NASA Technical Reports Server (NTRS)

    Djomehri, M. Jahed; Buning, Pieter G.; Erickson, Larry L.; George, Michael W. (Technical Monitor)

    1995-01-01

    Technical advances in Computational Fluid Dynamics have now made it possible to simulate complex three-dimensional internal flows about models of various size placed in a Transonic Wind Tunnel. TWT wall interference effects have been a source of error in predicting flight data from actual wind tunnel measured data. An advantage of such internal CFD calculations is to directly compare numerical results with the actual tunnel data for code assessment and tunnel flow analysis. A CFD capability has recently been devised for flow analysis of the NASA/Ames 11-Ft TWT facility. The primary objectives of this work are to provide a CFD tool to study the NASA/Ames 11-Ft TWT flow characteristics, to understand the slotted wall interference effects, and to validate CFD codes. A secondary objective is to integrate the internal flowfield calculations with the Pressure Sensitive Paint data, a surface pressure distribution capability in Ames' production wind tunnels. The effort has been part of the Ames IofNEWT, Integration of Numerical and Experimental Wind Tunnels project, which is aimed at providing further analytical tools for industrial application. We used the NASA/Ames OVERFLOW code to solve the thin-layer Navier-Stokes equations. Viscosity effects near the model are captured by Baldwin-Lomax or Baldwin-Barth turbulence models. The solver was modified to model the flow behavior in the vicinity of the tunnel longitudinal slotted walls. A suitable porous type wall boundary condition was coded to account for the cross-flow through the test section. Viscous flow equations were solved in generalized coordinates with a three-factor implicit central difference scheme in conjunction with the Chimera grid procedure. The internal flow field about the model and the tunnel walls were descretized by the Chimera overset grid system. This approach allows the application of efficient grid generation codes about individual components of the configuration; separate minor grids were developed

  13. Crest evolution in newts: implications for reconstruction methods, sexual selection, phenotypic plasticity and the origin of novelties.

    PubMed

    Wiens, J J; Sparreboom, M; Arntzen, J W

    2011-10-01

    The dorsal crest of newts (Salamandridae) is a novel, phenotypically plastic, sexually selected trait that may evolve in association with complex courtship behaviours. We estimated a near-comprehensive, time-calibrated phylogeny for salamandrids and analysed the evolution of their crests and display behaviour. Different models give conflicting reconstructions for crest evolution, showing that likelihood can estimate incorrect ancestral states with strong statistical support. The best-fitting model suggests that crests evolved once and were lost repeatedly, supporting the hypothesis that sexually selected traits may be frequently lost. We demonstrate the correlated evolution of crests and courtship behaviour and show that species with larger numbers of crest-related traits have larger repertoires of behaviours. We also show that phenotypically plastic morphological traits can be maintained over long macroevolutionary timescales (∼25-48 Myr). Finally, we use salamandrids to address how novel structures may arise, and support a model involving the expansion and subdivision of pre-existing structures.

  14. Kinetochores are transported poleward along a single astral microtubule during chromosome attachment to the spindle in newt lung cells

    PubMed Central

    1990-01-01

    During mitosis in cultured newt pneumocytes, one or more chromosomes may become positioned well removed (greater than 50 microns) from the polar regions during early prometaphase. As a result, these chromosomes are delayed for up to 5 h in forming an attachment to the spindle. The spatial separation of these chromosomes from the polar microtubule- nucleating centers provides a unique opportunity to study the initial stages of kinetochore fiber formation in living cells. Time-lapse Nomarski-differential interference contrast videomicroscopic observations reveal that late-attaching chromosomes always move, upon attachment, into a single polar region (usually the one closest to the chromosome). During this attachment, the kinetochore region of the chromosome undergoes a variable number of transient poleward tugs that are followed, shortly thereafter, by rapid movement of the chromosome towards the pole. Anti-tubulin immunofluorescence and serial section EM reveal that the kinetochores and kinetochore regions of nonattached chromosomes lack associated microtubules. By contrast, these methods reveal that the attachment and subsequent poleward movement of a chromosome correlates with the association of a single long microtubule with one of the kinetochores of the chromosome. This microtubule traverses the entire distance between the spindle pole and the kinetochore and often extends well past the kinetochore. From these results, we conclude that the initial attachment of a chromosome to the newt pneumocyte spindle results from an interaction between a single polar-nucleated microtubule and one of the kinetochores on the chromosome. Once this association is established, the kinetochore is rapidly transported poleward along the surface of the microtubule by a mechanism that is not dependent on microtubule depolymerization. Our results further demonstrate that the motors for prometaphase chromosome movement must be either on the surface of the kinetochore (i.e., within the

  15. Effects of water contamination on site selection by amphibians: experiences from an arena approach with European frogs and newts.

    PubMed

    Wagner, Norman; Lötters, Stefan

    2013-07-01

    Pesticide residues in breeding ponds can cause avoidance by at least some amphibian species. So far, outdoor experiments have been performed only with artificial pools in areas where the focus species usually occur and new colonization has been observed. Results of this kind of study are potentially influenced by natural disturbances and therefore are of limited comparability. We used an easily manufactured and standardizable arena approach, in which animals in reproductive condition for some hours had a choice among pools with different concentrations of a contaminant. Because there has been much debate on the potential environmental impacts of glyphosate-based herbicides, we investigated the impact of glyphosate isopropylamine salt (GLY-IS), Roundup LB PLUS (RU-LB-PLUS), and glyphosate's main metabolite aminomethylphosphonic acid (AMPA) on individual residence time in water. The following European amphibian species were tested: Common frog (Rana temporaria), Palmate newt (Lissotriton helveticus), and Alpine newt (Ichthyosaura alpestris). The residence time in water was not significantly affected by concentrations below or slightly above the European Environmental Quality Standards for AMPA or the German "worst-case" expected environmental concentrations for GLY-IS and RU-LB-PLUS. Occasionally, microclimatic cofactors (nightly minimum ground temperature, water temperature) apparently influenced the residence time. The major drawback of such quick behavior studies is that results can only be transferred to perception and avoidance of contaminated water but not easily to site selection by amphibians. For example, testing oviposition site selection requires more natural water bodies and more time. Hence, to develop a standard procedure in risk assessment, an intermediate design between an arena approach, as presented here, and previously performed field studies should be tested.

  16. Why does the yellow-eyed Ensatina have yellow eyes? Batesian mimicry of Pacific newts (genus Taricha) by the salamander Ensatina eschscholtzii xanthoptica.

    PubMed

    Kuchta, Shawn R; Krakauer, Alan H; Sinervo, Barry

    2008-04-01

    Color patterns commonly vary geographically within species, but it is rare that such variation corresponds with divergent antipredator strategies. The polymorphic salamander Ensatina eschscholtzii, however, may represent such a case. In this species, most subspecies are cryptically colored, whereas E. e. xanthoptica, the Yellow eyed ensatina, is hypothesized to be an aposematic mimic of highly toxic Pacific newts (genus Taricha). To test the mimicry hypothesis, we conducted feeding trials using Western Scrub-Jays, Aphelocoma californica. In every feeding trial, we found that jays, following presentation with the presumed model (T. torosa), were more hesitant to contact the presumed mimic (E. e. xanthoptica) than a control subspecies lacking the postulated aposematic colors (E. e. oregonensis). The median time to contact was 315 sec for the mimic and 52 sec for the control. These results support the mimicry hypothesis, and we suggest that E. e. xanthoptica is likely a Batesian mimic, rather a Müllerian or quasi-Batesian mimic, of Pacific newts.

  17. Parallel tagged amplicon sequencing of transcriptome-based genetic markers for Triturus newts with the Ion Torrent next-generation sequencing platform

    PubMed Central

    Wielstra, B; Duijm, E; Lagler, P; Lammers, Y; Meilink, W R M; Ziermann, J M; Arntzen, J W

    2014-01-01

    Next-generation sequencing is a fast and cost-effective way to obtain sequence data for nonmodel organisms for many markers and for many individuals. We describe a protocol through which we obtain orthologous markers for the crested newts (Amphibia: Salamandridae: Triturus), suitable for analysis of interspecific hybridization. We use transcriptome data of a single Triturus species and design 96 primer pairs that amplify c. 180 bp fragments positioned in 3-prime untranslated regions. Next, these markers are tested with uniplex PCR for a set of species spanning the taxonomical width of the genus Triturus. The 52 markers that consistently show a single band of expected length at gel electrophoreses for all tested crested newt species are then amplified in five multiplex PCRs (with a plexity of ten or eleven) for 132 individual newts: a set of 84 representing the seven (candidate) species and a set of 48 from a presumed hybrid population. After pooling multiplexes per individual, unique tags are ligated to link amplicons to individuals. Subsequently, individuals are pooled equimolar and sequenced on the Ion Torrent next-generation sequencing platform. A bioinformatics pipeline identifies the alleles and recodes these to a genotypic format. Next, we test the utility of our markers. baps allocates the 84 crested newt individuals representing (candidate) species to their expected (candidate) species, confirming the markers are suitable for species delineation. newhybrids, a hybrid index and hiest confirm the 48 individuals from the presumed hybrid population to be genetically admixed, illustrating the potential of the markers to identify interspecific hybridization. We expect the set of markers we designed to provide a high resolving power for analysis of hybridization in Triturus. PMID:24571307

  18. Parallel tagged amplicon sequencing of transcriptome-based genetic markers for Triturus newts with the Ion Torrent next-generation sequencing platform.

    PubMed

    Wielstra, B; Duijm, E; Lagler, P; Lammers, Y; Meilink, W R M; Ziermann, J M; Arntzen, J W

    2014-09-01

    Next-generation sequencing is a fast and cost-effective way to obtain sequence data for nonmodel organisms for many markers and for many individuals. We describe a protocol through which we obtain orthologous markers for the crested newts (Amphibia: Salamandridae: Triturus), suitable for analysis of interspecific hybridization. We use transcriptome data of a single Triturus species and design 96 primer pairs that amplify c. 180 bp fragments positioned in 3-prime untranslated regions. Next, these markers are tested with uniplex PCR for a set of species spanning the taxonomical width of the genus Triturus. The 52 markers that consistently show a single band of expected length at gel electrophoreses for all tested crested newt species are then amplified in five multiplex PCRs (with a plexity of ten or eleven) for 132 individual newts: a set of 84 representing the seven (candidate) species and a set of 48 from a presumed hybrid population. After pooling multiplexes per individual, unique tags are ligated to link amplicons to individuals. Subsequently, individuals are pooled equimolar and sequenced on the Ion Torrent next-generation sequencing platform. A bioinformatics pipeline identifies the alleles and recodes these to a genotypic format. Next, we test the utility of our markers. baps allocates the 84 crested newt individuals representing (candidate) species to their expected (candidate) species, confirming the markers are suitable for species delineation. newhybrids, a hybrid index and hiest confirm the 48 individuals from the presumed hybrid population to be genetically admixed, illustrating the potential of the markers to identify interspecific hybridization. We expect the set of markers we designed to provide a high resolving power for analysis of hybridization in Triturus.

  19. Mitochondrial genomes and divergence times of crocodile newts: inter-islands distribution of Echinotriton andersoni and the origin of a unique repetitive sequence found in Tylototriton mt genomes.

    PubMed

    Kurabayashi, Atsushi; Nishitani, Takuma; Katsuren, Seiki; Oumi, Shohei; Sumida, Masayuki

    2012-01-01

    Crocodile newts, which constitute the genera Echinotriton and Tylototriton, are known as living fossils, and these genera comprise many endangered species. To identify mitochondrial (mt) genes suitable for future population genetic analyses for endangered taxa, we determined the complete nucleotide sequences of the mt genomes of the Japanese crocodile newt Echinotriton andersoni and Himalayan crocodile newt Tylototriton verrucosus. Although the control region (CR) is known as the most variable mtDNA region in many animal taxa, the CRs of crocodile newts are highly conservative. Rather, the genes of NADH dehydrogenase subunits and ATPase subunit 6 were found to have high sequence divergences and to be usable for population genetics studies. To estimate the inter-population divergence ages of E. andersoni endemic to the Ryukyu Islands, we performed molecular dating analysis using whole and partial mt genomic data. The estimated divergence ages of the inter-island individuals are older than the paleogeographic segmentation ages of the islands, suggesting that the lineage splits of E. andersoni populations were not caused by vicariant events. Our phylogenetic analysis with partial mt sequence data also suggests the existence of at least two more undescribed species in the genus Tylototriton. We also found unusual repeat sequences containing the 3' region of cytochrome apoenzyme b gene, whole tRNA-Thr gene, and a noncoding region (the T-P noncoding region characteristic in caudate mtDNAs) from T. verrucosus mtDNA. Similar repeat sequences were found in two other Tylototriton species. The Tylototriton taxa with the repeats become a monophyletic group, indicating a single origin of the repeat sequences. The intra-and inter-specific comparisons of the repeat sequences suggest the occurrences of homologous recombination-based concerted evolution among the repeat sequences.

  20. The effects of sex steroids and vasotocin on behavioral responses to visual and olfactory sexual stimuli in ovariectomized female roughskin newts.

    PubMed

    Thompson, R R; Moore, F L

    2003-11-01

    Previous studies have found that vasotocin (AVT) administration to male roughskin newts (Taricha granulosa) enhances courtship clasping as well as appetitive responses to specific sexual stimuli and that treating female newts with androgens plus AVT induces the expression of male-typical courtship clasping (the selective clasping of females). However, the unique and/or interactive effects of sex steroids and AVT on appetitive responses to specific sexual stimuli have not yet been determined. To first identify male-typical, sexually dimorphic appetitive responses to female sexual stimuli, we tested intact newts during the breeding season and found that males, but not females, are attracted to female visual and pheromonal sexual stimuli. We then used ovariectomized (ovx) females implanted with empty silastic capsules (Blk) or with capsules containing testosterone (T), dihydrotestosterone (DHT), or estradiol (E2) and then injected with either saline or AVT to determine the effects of steroids and AVT, alone or in combination with each other, on male-typical behavioral responses to those stimuli. E2 treatment depressed responses toward female visual stimuli independently of AVT. On the other hand, only T-implanted, AVT-injected females displayed male-typical behavioral responses toward female olfactory stimuli, preferring to spend more time in proximity to female-scented than unscented newt models and selectively clasping the female-scented models. Together, these results support the conclusion that sex steroids and AVT influence behavioral responses to sexual stimuli via sensory-specific mechanisms. Furthermore, they suggest that T and AVT interact within the brain to influence sensorimotor processing in the pathways that integrate olfactory sexual stimuli into male-typical courtship behaviors.

  1. Effects of ghrelin and motilin on smooth muscle contractility of the isolated gastrointestinal tract from the bullfrog and Japanese fire belly newt.

    PubMed

    Kitazawa, Takio; Shimazaki, Misato; Kikuta, Ayumi; Yaosaka, Noriko; Teraoka, Hiroki; Kaiya, Hiroyuki

    2016-06-01

    Ghrelin has been identified in some amphibians and is known to stimulate growth hormone release and food intake as seen in mammals. Ghrelin regulates gastrointestinal motility in mammals and birds. The aim of this study was to determine whether ghrelin affects gastrointestinal smooth muscle contractility in bullfrogs (anuran) and Japanese fire belly newts (urodelian) in vitro. Neither bullfrog ghrelin nor rat ghrelin affected longitudinal smooth muscle contractility of gastrointestinal strips from the bullfrog. Expression of growth hormone secretagogue receptor 1a (GHS-R1a) mRNA was confirmed in the bullfrog gastrointestinal tract, and the expression level in the gastric mucosa was lower than that in the intestinal mucosa. In contrast, some gastrointestinal peptides, including substance P, neurotensin and motilin, and the muscarinic receptor agonist carbachol showed marked contraction, indicating normality of the smooth muscle preparations. Similar results were obtained in another amphibian, the Japanese fire belly newt. Newt ghrelin and rat ghrelin did not cause any contraction in gastrointestinal longitudinal muscle, whereas substance P and carbachol were effective causing contraction. In conclusion, ghrelin does not affect contractility of the gastrointestinal smooth muscle in anuran and urodelian amphibians, similar to results for rainbow trout and goldfish (fish) but different from results for rats and chickens. The results suggest diversity of ghrelin actions on the gastrointestinal tract across animals. This study also showed for the first time that motilin induces gastrointestinal contraction in amphibians.

  2. The alpha1 isoform of the Na+/K+ ATPase is up-regulated in dedifferentiated progenitor cells that mediate lens and retina regeneration in adult newts.

    PubMed

    Vergara, M Natalia; Smiley, Laura K; Del Rio-Tsonis, Katia; Tsonis, Panagiotis A

    2009-02-01

    Adult newts are able to regenerate their retina and lens after injury or complete removal through transdifferentiation of the pigmented epithelial tissues of the eye. This process needs to be tightly controlled, and several different mechanisms are likely to be recruited for this function. The Na(+)/K(+) ATPase is a transmembrane protein that establishes electrochemical gradients through the transport of Na(+) and K(+) and has been implicated in the modulation of key cellular processes such as cell division, migration and adhesion. Even though it is expressed in all cells, its isoform composition varies with cell type and is tightly controlled during development and regeneration. In the present study we characterize the expression pattern of Na(+)/K(+) ATPase alpha1 in the adult newt eye and during the process of lens and retina regeneration. We show that this isoform is up-regulated in undifferentiated cells during transdifferentiation. Such change in composition could be one of the mechanisms that newt cells utilize to modulate this process.

  3. Studies on hemopoietic tissue of ribbed newt, Pleurodeles waltl after the flight on board Russian satellite "Foton- M2" in 2005

    NASA Astrophysics Data System (ADS)

    Domaratskaya, E.; Payushina, O.; Butorina, N.; Nikonova, T.; Grigoryan, E.; Mitashov, V.; Almeida, E.; Tairbekov, M.; Khrushchov, N.

    The effect of 16-day spaceflight aboard the Foton-M2 satellite on the hematopoietic tissue of P waltl newts was studied in flown intact animals F-int and in animals used in experiments on tail and lens regeneration under spaceflight conditions F-reg In addition to the flown animals studies were performed on synchronous and aquarial controls in the case of non-operated animals and on synchronous and basal controls in the case of operated newts The main hematopoietic organs of urodelian species are the liver spleen and peripheral blood Therefore we determined differential blood counts estimated the weight of the liver and the content of its hematopoietic cells and histologically assessed spleen and liver in the above experimental groups and the corresponding control groups of animals No significant differences between these groups were revealed with respect to the structure of hematopoietic zones of the liver the content of hematopoietic cells in the liver and spleen morphology However liver weight in newts of the F-reg group was significantly greater than in the F-int group In the peripheral blood neutrophils eosinophils basophils lymphocytes and monocytes were found Lymphocytes L and neutrophils N prevailed accounting for about 50 and 38 of white blood cells respectively Among neutrophils cells differing in the degree of maturity were distinguished myelocytes M metamyelocytes Mm band B and segmented forms S For each group of animals we determined the ratio of maturing M Mm B to mature S

  4. On the amphibious food uptake and prey manipulation behavior in the Balkan-Anatolian crested newt (Triturus ivanbureschi, Arntzen and Wielstra, 2013).

    PubMed

    Lukanov, Simeon; Tzankov, Nikolay; Handschuh, Stephan; Heiss, Egon; Naumov, Borislav; Natchev, Nikolay

    2016-06-01

    Feeding behavior in salamanders undergoing seasonal habitat shifts poses substantial challenges caused by differences in the physical properties of air and water. Adapting to these specific environments, urodelans use suction feeding predominantly under water as opposed to lingual food prehension on land. This study aims to determine the functionality of aquatic and terrestrial feeding behavior in the Balkan-Anatolian crested newt (Triturus ivanbureschi) in its terrestrial stage. During the terrestrial stage, these newts feed frequently in water where they use hydrodynamic mechanisms for prey capture. On land, prey apprehension is accomplished mainly by lingual prehension, while jaw prehension seems to be the exception (16.67%) in all terrestrial prey capture events. In jaw prehension events there was no detectable depression of the hyo-lingual complex. The success of terrestrial prey capture was significantly higher when T. ivanbureschi used lingual prehension. In addition to prey capture, we studied the mechanisms involved in the subduction of prey. In both media, the newts frequently used a shaking behavior to immobilize the captured earthworms. Apparently, prey shaking constitutes a significant element in the feeding behavior of T. ivanbureschi. Prey immobilization was applied more frequently during underwater feeding, which necessitates a discussion of the influence of the feeding media on food manipulation. We also investigated the osteology of the cranio-cervical complex in T. ivanbureschi to compare it to that of the predominantly terrestrial salamandrid Salamandra salamandra.

  5. Egg activation in physiologically polyspermic newt eggs: involvement of IP₃ receptor, PLCγ, and microtubules in calcium wave induction.

    PubMed

    Ueno, Tomoyo; Ohgami, Takehiro; Harada, Yuichirou; Ueno, Shuichi; Iwao, Yasuhiro

    2014-01-01

    The egg of the polyspermic newt is activated by Ca(2+) waves induced by several sperm at fertilization. A major component of the sperm factor for egg activation is the sperm-specific citrate synthase (CS), which is introduced into the egg cytoplasm after sperm-egg fusion. We tried to clarify the mechanism for sperm-specific CS to induce [Ca(2+)]i increase in egg cytoplasm. The injection of the sperm factor into the unfertilized egg induces a [Ca(2+)]i increase that propagates over the whole egg surface as a Ca(2+) wave. The propagation of the Ca(2+) wave is inhibited by depolymerization of microtubules in the egg cytoplasm. The sperm-specific CS is highly phosphorylated and binds the component containing microtubules and the IP3 receptor. The sperm CS localized in the midpiece region was dispersed in the egg cytoplasm, but most of the CS accumulates at the sperm entry site and is distributed in association with the microtubules around the midpiece region and the nucleus. Phospholipase C (PLC) γ in egg cytoplasm also accumulates around the midpiece region in association with the sperm CS. Thus, CS at the initiation site of the Ca(2+) wave forms a complex of microtubules and endoplasmic reticulum (ER) with the IP3 receptor, in addition to PLCγ, indicating close involvement of those complexes in Ca(2+) releases from the ER by the sperm factor.

  6. Predicting environmental suitability for a rare and threatened species (Lao newt, Laotriton laoensis) using validated species distribution models.

    PubMed

    Chunco, Amanda J; Phimmachak, Somphouthone; Sivongxay, Niane; Stuart, Bryan L

    2013-01-01

    The Lao newt (Laotriton laoensis) is a recently described species currently known only from northern Laos. Little is known about the species, but it is threatened as a result of overharvesting. We integrated field survey results with climate and altitude data to predict the geographic distribution of this species using the niche modeling program Maxent, and we validated these predictions by using interviews with local residents to confirm model predictions of presence and absence. The results of the validated Maxent models were then used to characterize the environmental conditions of areas predicted suitable for L. laoensis. Finally, we overlaid the resulting model with a map of current national protected areas in Laos to determine whether or not any land predicted to be suitable for this species is coincident with a national protected area. We found that both area under the curve (AUC) values and interview data provided strong support for the predictive power of these models, and we suggest that interview data could be used more widely in species distribution niche modeling. Our results further indicated that this species is mostly likely geographically restricted to high altitude regions (i.e., over 1,000 m elevation) in northern Laos and that only a minute fraction of suitable habitat is currently protected. This work thus emphasizes that increased protection efforts, including listing this species as endangered and the establishment of protected areas in the region predicted to be suitable for L. laoensis, are urgently needed.

  7. Light-dependent magnetic compass in Iberian green frog tadpoles

    NASA Astrophysics Data System (ADS)

    Diego-Rasilla, Francisco Javier; Luengo, Rosa Milagros; Phillips, John B.

    2010-12-01

    Here, we provide evidence for a wavelength-dependent effect of light on magnetic compass orientation in Pelophylax perezi (order Anura), similar to that observed in Rana catesbeiana (order Anura) and Notophthalmus viridescens (order Urodela), and confirm for the first time in an anuran amphibian that a 90° shift in the direction of magnetic compass orientation under long-wavelength light (≥500 nm) is due to a direct effect of light on the underlying magnetoreception mechanism. Although magnetic compass orientation in other animals (e.g., birds and some insects) has been shown to be influenced by the wavelength and/or intensity of light, these two amphibian orders are the only taxa for which there is direct evidence that the magnetic compass is light-dependent. The remarkable similarities in the light-dependent magnetic compasses of anurans and urodeles, which have evolved as separate clades for at least 250 million years, suggest that the light-dependent magnetoreception mechanism is likely to have evolved in the common ancestor of the Lissamphibia (Early Permian, ~294 million years) and, possibly, much earlier. Also, we discuss a number of similarities between the functional properties of the light-dependent magnetic compass in amphibians and blue light-dependent responses to magnetic stimuli in Drosophila melanogaster, which suggest that the wavelength-dependent 90° shift in amphibians may be due to light activation of different redox forms of a cryptochrome photopigment. Finally, we relate these findings to earlier studies showing that the pineal organ of newts is the site of the light-dependent magnetic compass and recent neurophysiological evidence showing magnetic field sensitivity in the frog frontal organ (an outgrowth of the pineal).

  8. A New Species of Eimeria (Apicomplexa: Eimeriidae) from the marbled salamander, Ambystoma opacum (Caudata: Ambystomatidae), from northern Louisiana.

    PubMed

    McAllister, Chris T; Upton, Steve J

    2008-06-01

    Between December 2002 and June 2004, 10 marbled salamanders, Ambystoma opacum, were examined for coccidian parasites. Salamanders were collected in Bradley (n = 2), Little River (n = 1), Miller (n = 1), and Sevier (n = 1) Counties, Arkansas; Webster Parish, Louisiana (n = 2); and Bowie (n = 1) and Nacogdoches (n = 2) Counties, Texas. Two of 10 (20%) A. opacum from Louisiana harbored an undescribed species of Eimeria. Oocysts of Eimeria trauthi n. sp. were ellipsoidal, 36.6 x 33.1 (33-40 x 29-37) microm, with a thin, single-layered wall; shape index 1.1. Polar granule(s) and micropyle were absent. Oocyst residuum was composed of hundreds of loosely packed homogenous granules of various sizes enclosing a vacuole. Sporocysts were elongate-ellipsoidal, 20.8 x 8.1 (19-22 x 7-9) microm; shape index 2.6. Sporocyst residuum was spherical and composed of a cluster of granules often membrane-bound. This is the first time a coccidium has been reported from an amphibian species in Louisiana and the second time a coccidium has been described from this salamander host. In addition, the following 26 salamanders from various counties in Arkansas, Oklahoma, and Texas were surveyed during the study period and were negative for coccidia: Ambystomatidae, 4 spotted salamanders (Ambystoma maculatum) and 7 mole salamanders (Ambystoma talpoideum); Cryptobranchidae, 4 Ozark hellbenders (Cryptobranchus alleganiensis bishopi); Plethodontidae, 6 spotted dusky salamanders (Desmognathus conanti) and 3 many-ribbed salamanders (Eurycea multiplicata multiplicata); and Salamandridae, 2 central newts (Notophthalmus viridescens louisianensis).

  9. Most of the Dominant Members of Amphibian Skin Bacterial Communities Can Be Readily Cultured

    PubMed Central

    Becker, Matthew H.; Hughey, Myra C.; Swartwout, Meredith C.; Jensen, Roderick V.; Belden, Lisa K.

    2015-01-01

    Currently, it is estimated that only 0.001% to 15% of bacteria in any given system can be cultured by use of commonly used techniques and media, yet culturing is critically important for investigations of bacterial function. Despite this situation, few studies have attempted to link culture-dependent and culture-independent data for a single system to better understand which members of the microbial community are readily cultured. In amphibians, some cutaneous bacterial symbionts can inhibit establishment and growth of the fungal pathogen Batrachochytrium dendrobatidis, and thus there is great interest in using these symbionts as probiotics for the conservation of amphibians threatened by B. dendrobatidis. The present study examined the portion of the culture-independent bacterial community (based on Illumina amplicon sequencing of the 16S rRNA gene) that was cultured with R2A low-nutrient agar and whether the cultured bacteria represented rare or dominant members of the community in the following four amphibian species: bullfrogs (Lithobates catesbeianus), eastern newts (Notophthalmus viridescens), spring peepers (Pseudacris crucifer), and American toads (Anaxyrus americanus). To determine which percentage of the community was cultured, we clustered Illumina sequences at 97% similarity, using the culture sequences as a reference database. For each amphibian species, we cultured, on average, 0.59% to 1.12% of each individual's bacterial community. However, the average percentage of bacteria that were culturable for each amphibian species was higher, with averages ranging from 2.81% to 7.47%. Furthermore, most of the dominant operational taxonomic units (OTUs), families, and phyla were represented in our cultures. These results open up new research avenues for understanding the functional roles of these dominant bacteria in host health. PMID:26162880

  10. Masters of change: seasonal plasticity in the prey-capture behavior of the Alpine newt Ichthyosaura alpestris (Salamandridae).

    PubMed

    Heiss, Egon; Aerts, Peter; Van Wassenbergh, Sam

    2013-12-01

    Transitions between aquatic and terrestrial environments are significant steps in vertebrate evolution. These transitions require major changes in many biological functions, including food uptake and transport. The Alpine newt, Ichthyosaura alpestris, is known to show a 'multiphasic lifestyle' where the adult shifts from a terrestrial to an aquatic lifestyle and then back to a terrestrial lifestyle every year as a result of its breeding activity. These transitions correspond to dramatic changes in morphology, physiology and behavior, resulting in distinct aquatic and terrestrial morphotypes. We hypothesized that these shifts go along with changes in prey-capture mechanics to maintain a sufficiently high performance in both environments. We analyzed the prey-capture kinematics in the four possible modes: aquatic strikes in the aquatic phase, terrestrial strikes in the terrestrial phase, aquatic strikes in the terrestrial phase and terrestrial strikes in the aquatic phase. A multivariate comparison detected significant kinematic differences between the phase-specific feeding modes. In both the aquatic and the terrestrial phase, I. alpestris uses a suction-feeding mechanism for capturing prey in water. By contrast, I. alpestris uses a jaw-based grasping mechanism with a kinematic profile similar to the aquatic modes for terrestrial prey-capture in its aquatic phase but an elaborate lingual-based prehension mechanism to capture terrestrial prey in the terrestrial phase. These results exhibit a so-far unknown amount of behavioral plasticity in prey-capture behavior that is tuned to the seasonal demands of performance, and exemplify functional mechanisms behind aquatic-terrestrial transitions in vertebrates.

  11. Male Attractiveness Is Influenced by UV Wavelengths in a Newt Species but Not in Its Close Relative

    PubMed Central

    Secondi, Jean; Lepetz, Virginie; Théry, Marc

    2012-01-01

    Background Functional communication in the UV range has been reported in Invertebrates and all major groups of Vertebrates but Amphibians. Although perception in this wavelength range has been shown in a few species, UV signalling has not been demonstrated in this group. One reason may be that in lentic freshwater habitats, litter decomposition generates dissolved organic carbon that absorbs UV radiation and thus hinders its use for visual signalling. We tested the effect of male UV characteristics on female sexual preference in two newt species that experience contrasting levels of UV water transmission when breeding. Methodology/Principal Findings We analysed water spectral characteristics of a sample of breeding ponds in both species. We quantified male ventral coloration and measured male attractiveness under two lighting conditions (UV present, UV absent) using a no-choice female preference design. UV transmission was higher in Lissotriton vulgaris breeding sites. Male UV patterns also differed between experimental males of the two species. We observed a first common peak around 333 nm, higher in L. vulgaris, and a second peak around 397 nm, more frequent and higher in L. helveticus. Male attractiveness was significantly reduced in L. vulgaris when UV was not available but not in L. helveticus. Male attractiveness depended on the hue of the first UV peak in L. vulgaris. Conclusion/Significance Our study is the first report of functional UV-based communication in Amphibians. Interestingly, male spectral characteristics and female preferences were consistent with the differences in habitat observed between the two species as L. helveticus often breeds in ponds containing more UV blocking compounds. We discuss the three hypotheses proposed so far for UV signalling in animals (enhanced signal detectability, private communication channel, indicator of individual quality). PMID:22272342

  12. The egg nucleus regulates the behavior of sperm nuclei as well as cycling of MPF in physiologically polyspermic newt eggs.

    PubMed

    Iwao, Y; Sakamoto, N; Takahara, K; Yamashita, M; Nagahama, Y

    1993-11-01

    The possible role of the egg nucleus in regulating the behavior of sperm nuclei and the cycling of maturation-promoting factor (MPF) was investigated in the physiologically polyspermic eggs of the newt Cynops pyrrhogaster. Many sperm entered all areas of the egg, but only one sperm pronucleus, the principal sperm pronucleus, moved to the center of the animal hemisphere to form a zygote nucleus with the egg pronucleus. All sperm and egg pronuclei synthesized DNA, but the zygote nucleus completed the synthesis of DNA 0.5-1 hr earlier than the accessory sperm nuclei. Entrance into M phase by the accessory sperm nuclei was delayed to a greater and greater extent with increasing distance of these nuclei from the zygote nucleus. When DNA in the egg nucleus was damaged by uv irradiation, not only were both prophase and M phase in the zygote nucleus prolonged, but also the MPF cycle was delayed. Some accessory sperm nuclei in the animal hemisphere escaped degeneration to form additional bipolar spindles, so that delayed multipolar cleavage occurred. The MPF activity in the vegetal hemisphere was less than 25% of that found in the animal hemisphere at M phase in normally fertilized eggs. The levels of immunologically detectable proteins that contained the sequence PSTAIR in vegetal hemispheres were less than 25% of those in animal hemispheres. These results indicate that the egg nucleus of the Cynops egg is involved in the control of the activation of MPF and that the accessory sperm nuclei in the vegetal hemisphere degenerate as a result of the lack of components that are indispensable for entry into M phase.

  13. In silico identification of the genes for sperm-egg interaction in the internal fertilization of the newt Cynops pyrrhogaster.

    PubMed

    Watanabe, Akihiko; Takayama-Watanabe, Eriko

    2014-01-01

    A specific sperm-egg interaction in the oviductal matrix is crucial for internal fertilization of the red-bellied newt, Cynops pyrrhogaster. An understanding of the molecular basis of this interaction is expected to elucidate the evolutionary history of internal fertilization in amphibians. Recently, deep sequencing technology has provided global gene information even in nonmodel animals, allowing us to understand specific features of the molecular mechanisms underlying fertilization in C. pyrrhogaster. In the present study, we screened de novo assembled RNAseq from ovary, testis, and oviduct samples in C. pyrrhogaster and identified the base sequences encoding zona pellucida (ZP) proteins, voltage-dependent Ca(2+) channels, and cysteine-rich secretory proteins (CRISPs), which respectively are sperm receptors for egg envelopes, major mediators of sperm intracellular signaling, and expected extracellular modulators for sperm function in the female reproductive tract. In the ovary, ZP homologues of all six subgroups were found, including a ZP1 homologue that was newly found in amphibians, a ZP4 homologue, and six ZPC homologues. The unique combination of ZP proteins suggests a new mechanism for sperm binding to egg envelopes in the internal fertilization of C. pyrrhogaster. In the testis, CaV1.1, 1.2, and 3.2, which are L- and T-type voltage-dependent Ca(2+) channels, were found as potential mediators for the internal fertilization-specific sperm-egg interaction. We also found CRISP 2 in the oviduct, which is speculated to participate in the sperm-egg interaction. These results indicate that the de novo assembled RNAseq is a powerful tool allowing analysis of the specific sperm-egg interactions in C. pyrrhogaster.

  14. Phylogeography and evolution of the Red Salamander (Pseudotriton ruber).

    PubMed

    Folt, Brian; Garrison, Nicole; Guyer, Craig; Rodriguez, Juanita; Bond, Jason E

    2016-05-01

    Phylogeographic studies frequently result in the elevation of subspecific taxa to species given monophyly, or the synonymy of subspecies that are not monophyletic. However, given limited or incongruent datasets, retention of subspecies can be useful to describe hypothesized incipient species or to illustrate interesting biological phenomena driving morphological diversity. Four subspecific taxa have been used to describe largely allopatric geographic variation within the species Pseudotriton ruber, a plethodontid salamander occupying stream and spring habitats across eastern North America: P. r. vioscai occurs in lowland Coastal Plain habitats, while P. r. ruber, P. r. nitidus, and P. r. schencki occupy upland regions in and around the Appalachian Mountains. Pseudotriton ruber co-occurs through its distribution with the aposematic newt Notophthalmus viridescens, and both species are hypothesized to be part of a Müllerian mimicry complex. In this study, we sequenced regions of two mitochondrial (cytochrome b, NADH dehydrogenase subunit 2) and one single copy nuclear protein-coding gene (pro-opiomelanocortin) from individuals sampled across much of the distribution of P. ruber and then used maximum-likelihood and Bayesian phylogenetic inference to test the monophyly of subspecies, reconstruct biogeographic history, and make inferences about morphological evolution. Phylogeographic hypotheses from mitochondrial and nuclear datasets described structure among populations of P. ruber which separated Coastal Plain and upland Appalachian populations, but subspecies were not monophyletic. Biogeographic reconstruction estimated the ancestor of all populations to have occupied and initially diverged in the Coastal Plain during the Pliocene (∼3.6mya), before one lineage subsequently invaded upland areas of Appalachia. Bold bright coloration of high elevation subspecies P. r. nitidus and P. r. schencki appears to have evolved twice. We hypothesize that the Müllerian mimicry

  15. Single nucleotide polymorphisms reveal genetic structuring of the carpathian newt and provide evidence of interspecific gene flow in the nuclear genome.

    PubMed

    Zieliński, Piotr; Dudek, Katarzyna; Stuglik, Michał Tadeusz; Liana, Marcin; Babik, Wiesław

    2014-01-01

    Genetic variation within species is commonly structured in a hierarchical manner which may result from superimposition of processes acting at different spatial and temporal scales. In organisms of limited dispersal ability, signatures of past subdivision are detectable for a long time. Studies of contemporary genetic structure in such taxa inform about the history of isolation, range changes and local admixture resulting from geographically restricted hybridization with related species. Here we use a set of 139 transcriptome-derived, unlinked nuclear single nucleotide polymorphisms (SNP) to assess the genetic structure of the Carpathian newt (Lissotriton montandoni, Lm) and introgression from its congener, the smooth newt (L. vulgaris, Lv). Two substantially differentiated groups of Lm populations likely originated from separate refugia, both located in the Eastern Carpathians. The colonization of the present range in north-western and south-western directions was accompanied by a modest loss of variation; admixture between the two groups has occurred in the middle of the Eastern Carpathians. Local, apparently recent introgression of Lv alleles into several Lm populations was detected, demonstrating increased power for admixture detection in comparison to a previous study based on a limited number of microsatellite markers. The level of introgression was higher in Lm populations classified as admixed than in syntopic populations. We discuss the possible causes and propose further tests to distinguish between alternatives. Several outlier loci were identified in tests of interspecific differentiation, suggesting genomic heterogeneity of gene flow between species.

  16. Increased frequency and severity of developmental deformities in rough-skinned newt (Taricha granulosa) embryos exposed to road deicing salts (NaCl & MgCl2).

    PubMed

    Hopkins, Gareth R; French, Susannah S; Brodie, Edmund D

    2013-02-01

    Road-side aquatic ecosystems in North America are annually polluted with millions of tons of road deicing salts, which threaten the survival of amphibians which live and breed in these habitats. While much is known of the effects of NaCl, little is known of the second most-commonly used deicer, MgCl(2), which is now used exclusively in parts of the continent. Here we report that environmentally relevant concentrations of both NaCl and MgCl(2) cause increased incidence of developmental deformities in rough-skinned newt hatchlings that developed embryonically in these salts. In addition, we provide some of the first quantification of severity of different deformities, and reveal that increased salt concentrations increase both deformity frequency and severity. Our work contributes to the growing body of literature that suggests salamanders and newts are particularly vulnerable to salt, and that the emerging pollutant, MgCl(2) is comparable in its effects to the more traditionally-used NaCl.

  17. FSH-initiated differentiation of newt spermatogonia to primary spermatocytes in germ-somatic cell reaggregates cultured within a collagen matrix.

    PubMed

    Ito, R; Abé, S I

    1999-03-01

    We previously cultured fragments of newt testes in chemically defined media and showed that mammalian follicle-stimulating hormone (FSH) stimulates proliferation of spermatogonia as well as their differentiation into primary spermatocytes (Ji et al., 1992; Abe and Ji, 1994). Next, we indicated in cultures composed of spermatogonia and somatic cells (mainly Sertoli cells) that FSH stimulates germ cell proliferation via Sertoli cells (Maekawa et al., 1995). However, the spermatogonia did not differentiate into primary spermatocytes, but instead died. In the present study, we embedded large reaggregates of spermatogonia and somatic cells (mainly Sertoli cells) within a collagen matrix and cultured the reaggregates on a filter that floated on chemically defined media containing FSH; in this revised culture system, spermatogonia proliferated and differentiated into primary spermatocytes. The viability and percentage of germ cells differentiating into primary spermatocytes were proportional to the percentage of somatic cells in the culture, indicating that differentiation of spermatogonia into primary spermatocytes is mediated by Sertoli cells.

  18. Acute stress increases the synthesis of 7α-hydroxypregnenolone, a new key neurosteroid stimulating locomotor activity, through corticosterone action in newts.

    PubMed

    Haraguchi, Shogo; Koyama, Teppei; Hasunuma, Itaru; Okuyama, Shin-ichiro; Ubuka, Takayoshi; Kikuyama, Sakae; Do Rego, Jean-Luc; Vaudry, Hubert; Tsutsui, Kazuyoshi

    2012-02-01

    7α-Hydroxypregnenolone (7α-OH PREG) is a newly identified bioactive neurosteroid stimulating locomotor activity in the brain of newt, a wild animal, which serves as an excellent model to investigate the biosynthesis and biological action of neurosteroids. Here, we show that acute stress increases 7α-OH PREG synthesis in the dorsomedial hypothalamus (DMH) through corticosterone (CORT) action in newts. A 30-min restraint stress increased 7α-OH PREG synthesis in the brain tissue concomitant with the increase in plasma CORT concentrations. A 30-min restraint stress also increased the expression of cytochrome P450(7α) (CYP7B), the steroidogenic enzyme of 7α-OH PREG formation, in the DMH. Decreasing plasma CORT concentrations by hypophysectomy or trilostane administration decreased 7α-OH PREG synthesis in the diencephalon, whereas administration of CORT to these animals increased 7α-OH PREG synthesis. Glucocorticoid receptor was present in DMH neurons expressing CYP7B. Thus, CORT appears to act directly on DMH neurons to increase 7α-OH PREG synthesis. We further investigated the biological action of 7α-OH PREG in the brain under stress. A 30-min restraint stress or central administration of 7α-OH PREG increased serotonin concentrations in the diencephalon. Double immunolabeling further showed colocalization of CYP7B and serotonin in the DMH. These results indicate that acute stress increases the synthesis of 7α-OH PREG via CORT action in the DMH, and 7α-OH PREG activates serotonergic neurons in the DMH that may coordinate behavioral responses to stress. This is the first demonstration of neurosteroid biosynthesis regulated by peripheral steroid hormone and of neurosteroid action in the brain under stress in any vertebrate class.

  19. An Extremely Peramorphic Newt (Urodela: Salamandridae: Pleurodelini) from the Latest Oligocene of Germany, and a New Phylogenetic Analysis of Extant and Extinct Salamandrids.

    PubMed

    Marjanović, David; Witzmann, Florian

    2015-01-01

    We describe an Oligocene newt specimen from western Germany that has gone practically unnoticed in the literature despite having been housed in the Museum für Naturkunde (Berlin) for a century. It is referable to the coeval Chelotriton, but is unusually peramorphic; for many characters it is more peramorphic than all other caudates or even all other lissamphibians. Most noticeable are the position of the jaw joints far caudal to the occiput, the honeycombed sculpture on the maxilla, and the possible presence of a septomaxilla (which would be unique among salamandrids). Referral to a species would require a revision of the genus, but the specimen likely does not belong to the type species. A phylogenetic analysis of nonmolecular characters of Salamandridae, far larger than all predecessors, confirms the referral to Chelotriton. It further loosely associates the Oligocene Archaeotriton and the Miocene Carpathotriton with the extant Lissotriton, though the former may alternatively lie outside Pleurodelinae altogether. The Miocene? I. randeckensis may not belong to the extant Ichthyosaura. The Miocene "Triturus" roehrsi is found neither with the extant Ommatotriton nor with Lissotriton, but inside an Asian/aquatic clade or, when geographic distribution is included as a character, as the sister-group to all other European molgins. The main cause for discrepancies between the results and the molecular consensus is not heterochrony, but adaptations to a life in mountain streams; this is the most likely reason why the Paleocene Koalliella from western Europe forms the sister-group to some or all of the most aquatic extant newts in different analyses. We would like to urge neontologists working on salamandrids to pay renewed attention to the skeleton, not limited to the skull, as a source of diagnostic and phylogenetically informative characters.

  20. Neuronal regeneration in the newt: a model to study the partly reconstruction of the neural tissue in real and simulated weightles sness

    NASA Astrophysics Data System (ADS)

    Anton, H.; Grigoryan, E.; Mitashov, V.

    The micro -"g" effect on nervous tissue regeneration in newts has been investigated by our group for many years. It has been performed in real and in simulated microgravity with a clinostat. During limb regeneration the motor - and sensory nerves regrow perfectly within the newly formed limb. Like in `1g' conditions they are responsible for the initiation of blastema formation and continuity of g owth andr differentiation. Except for a general acceleration of growth and differentiation processes no differences became visible. Tail regeneration, which is perfectly regulated in newts during their whole life, includes the restoration of the spinal cord and dorsal root ganglia. They follow or initiate an accelerated growth. Up to the present the cellular derivation of the sensory neurones within the regenerate has not yet been clarified. But growth acceleration comprises the whole nervous system. That means a totally new formation of the sensory connection from the periphery to the whole spinal cord. Regeneration must be initiated by the outgrowth of nerve fibres into the wound area. This may be performed by the remaining cut sensory fibres of the last stump segment and should be followed by the differentiation of undifferentiated cells of neural crest origin nearby the amputation area. Such cells are present in the form of meningeal cells which are the origin of mantle and Schwann cells too. Corresponding to the well proved growth acceleration of lens, retina, connective tissue, muscle and skin, the real and simulated microgravity affects the nervous system in the same manner. Tissues and organs of adult organisms have no chance to remain unaffected by the microgravity effect. We try to find the trigger which initiates the accelerated proliferation of the stem cells of sensory neurons, mantle and sheath cells under micro-"g" conditions.

  1. An Extremely Peramorphic Newt (Urodela: Salamandridae: Pleurodelini) from the Latest Oligocene of Germany, and a New Phylogenetic Analysis of Extant and Extinct Salamandrids

    PubMed Central

    Marjanović, David; Witzmann, Florian

    2015-01-01

    We describe an Oligocene newt specimen from western Germany that has gone practically unnoticed in the literature despite having been housed in the Museum für Naturkunde (Berlin) for a century. It is referable to the coeval Chelotriton, but is unusually peramorphic; for many characters it is more peramorphic than all other caudates or even all other lissamphibians. Most noticeable are the position of the jaw joints far caudal to the occiput, the honeycombed sculpture on the maxilla, and the possible presence of a septomaxilla (which would be unique among salamandrids). Referral to a species would require a revision of the genus, but the specimen likely does not belong to the type species. A phylogenetic analysis of nonmolecular characters of Salamandridae, far larger than all predecessors, confirms the referral to Chelotriton. It further loosely associates the Oligocene Archaeotriton and the Miocene Carpathotriton with the extant Lissotriton, though the former may alternatively lie outside Pleurodelinae altogether. The Miocene? I. randeckensis may not belong to the extant Ichthyosaura. The Miocene “Triturus” roehrsi is found neither with the extant Ommatotriton nor with Lissotriton, but inside an Asian/aquatic clade or, when geographic distribution is included as a character, as the sister-group to all other European molgins. The main cause for discrepancies between the results and the molecular consensus is not heterochrony, but adaptations to a life in mountain streams; this is the most likely reason why the Paleocene Koalliella from western Europe forms the sister-group to some or all of the most aquatic extant newts in different analyses. We would like to urge neontologists working on salamandrids to pay renewed attention to the skeleton, not limited to the skull, as a source of diagnostic and phylogenetically informative characters. PMID:26421432

  2. Sperm motility-initiating substance in newt egg-jelly induces differential initiation of sperm motility based on sperm intracellular calcium levels.

    PubMed

    Watanabe, Akihiko; Takayama-Watanabe, Eriko; Vines, Carol A; Cherr, Gary N

    2011-01-01

    Sperm motility-initiating substance (SMIS), a novel motility inducer from newt egg-jelly, is activated by the release from associated jelly substances at the beginning of internal fertilization and affects female-stored sperm. We examined motility initiation kinetics of newt sperm in response to SMIS by monitoring the changes of sperm intracellular calcium ([Ca²(+)](i)). In quiescent non-motile sperm loaded with the Ca²(+) indicator Fluo-4, intracellular free Ca²(+) was observed around mitochondria using confocal scanning laser microscopy. A slight increase in [Ca²(+)](i) occurred simultaneously and transiently at motility initiation in sperm treated with either heated jelly extract (hJE) containing activated SMIS, or a low osmotic solution, which naturally initiates motility in externally-fertilizing amphibians and can initiate motility in urodele sperm. When the increase of [Ca²(+)](i) at motility-initiation was monitored using spectrofluorometry, large increases in [Ca²(+)](i) occurred immediately in the low osmotic solution and within 1.5 min in the hJE. In the intact jelly extract (no heating), small increases of [Ca²(+)](i) irregularly occurred from around 1 min and for about 4 min, during which motility was differentially initiated among sperm. These results indicate that the SMIS induces differential initiation of sperm motility depending on the activational states of the SMIS and its overall activity. The motility initiation in the jelly extract was delayed in sperm whose intracellular Ca²(+) had been chelated with BAPTA-AM. The relative levels of [Ca²(+)](i) were variable with a mean of 414 ± 256 nmol/L among resting sperm, suggesting that the level of [Ca²(+)](i) in the resting sperm modulates the responsiveness to the SMIS.

  3. Distinct Ca2+ channels maintain a high motility state of the sperm that may be needed for penetration of egg jelly of the newt, Cynops pyrrhogaster.

    PubMed

    Takahashi, Tomoe; Kutsuzawa, Megumi; Shiba, Kogiku; Takayama-Watanabe, Eriko; Inaba, Kazuo; Watanabe, Akihiko

    2013-09-01

    Activation state of sperm motility named "hyperactivation" enables mammalian sperm to progress through the oviductal matrix, although a similar state of sperm motility is unknown in non-mammalian vertebrates at fertilization. Here, we found a high motility state of the sperm in the newt Cynops pyrrhogaster. It was predominantly caused in egg jelly extract (JE) and characterized by a high wave velocity of the undulating membrane (UM) that was significantly higher at the posterior midpiece. An insemination assay suggested that the high motility state might be needed for sperm to penetrate the egg jelly, which is the accumulated oviductal matrix. Specific characteristics of the high motility state were completely abrogated by a high concentration of verapamil, which blocks the L-type and T-type voltage-dependent Ca(2+) channels (VDCCs). Mibefradil, a dominant blocker of T-type VDCCs, suppressed the wave of the UM at the posterior midpiece with separate wave propagation from both the anterior midpiece and the posterior principal piece. In addition, nitrendipine, a dominant L-type VDCC blocker, weakened the wave of the UM, especially in the anterior midpiece. Live Ca(2+) imaging showed that, compared with the intact sperm in the JE, the relative intracellular Ca(2+) level changed especially in the anterior and posterior ends of the midpiece of the blocker-treated sperm. These suggest that different types of Ca(2+) channels mediate the intracellular Ca(2+) level predominantly in the anterior and posterior ends of the midpiece to maintain the high motility state of the newt sperm.

  4. Production of otoconia in the endolymphatic sac in the Japanese red-bellied newt, Cynops pyrrhogaster: light and transmission electron microscopic study

    NASA Technical Reports Server (NTRS)

    Gao, W.; Wiederhold, M. L.; Hejl, R.

    1998-01-01

    The formation of otoconia in the endolymphatic sac (ES) of the larval newt, Cynops pyrrhogaster, has been studied by light and transmission electron microscopy. Some of the epithelial cells of the ES contain an abundance of swollen vesicles, Golgi complexes, rough endoplasmic reticula and ribosomes at the late larval stages 50 and 51, approximately 26-30 days after eggs are laid. Five days later, at stage 52, crystals are present in the vacuoles between the epithelial cells. Serial sections indicate that these vacuoles actually form small canals which lie in the wall and join the lumen of the ES. Reconstruction of the ES shows that several canals are contained in the ES wall. At stage 56, about 72 days after eggs are laid, a large number of otoconia are present in the ES lumen, while the otoconia disappear from the canals. It appears that the otoconia are first produced in the canals and then released to the lumen. Some epithelial cells of the ES are thought to expel the organic and inorganic material to the canals to form the otoconia in situ. The process of formation of the otoconia in the ES is discussed.

  5. Sperm motility initiation by egg jelly of the anuran, Discoglossus pictus may be mediated by sperm motility-initiating substance of the internally-fertilizing newt, Cynops pyrrhogaster.

    PubMed

    Takayama-Watanabe, Eriko; Campanella, Chiara; Kubo, Hideo; Watanabe, Akihiko

    2012-11-01

    The egg jelly of Discoglossus pictus contains sperm motility-activating activity, the molecular basis of which has not been studied. Discoglossus pictus sperm initiated motility immediately after immersion in egg-jelly extract, as well as after immersion in hyposmotic solution, which initiates sperm motility in the external fertilization of anuran amphibians. Sequential treatment of the D. pictus sperm with these two solutions revealed the predominant effect of hyposmolality in initiation of motility. The motility initiation induced by jelly extract was suppressed by a monoclonal antibody (mAb) that is specific for the 34 kDa sperm motility-initiating substance (SMIS) in the egg jelly of the newt, Cynops pyrrhogaster. Immunoblotting using the anti-SMIS mAb revealed several antigenic proteins that included major ones with sizes of 18- and 34-kDa in D. pictus jelly extract. Scanning electron microscopic observation revealed that granules of jelly matrix, in which SMIS localizes and which have a critical role in the internal fertilization of C. pyrrhogaster, were not observed near the surface of the D. pictus egg jelly. These results suggest that sperm motility-activating activity in egg jelly of D. pictus may be mediated by SMIS homologous proteins that act through a mechanism that is partially different from that of C. pyrrhogaster.

  6. [The comparative characteristics of crystalline lens and limb regeneration in newts operated on before and after the completion of an orbital space flight].

    PubMed

    Tuchkova, S Ia; Brushlinskaia, N V; Grigorian, E N; Mitashov, V I

    1994-01-01

    It has been already established that a tendency towards synchronization and acceleration of the forelimb and lens regeneration is observed in Pleurodeles waltlii under the effect of space flight factors. Here we present the results obtained after 16-day space flight of two groups of newts. In animals of group I forelimbs were amputated and lenses were removed 14 and 7 days before the space flight, respectively. Intact animals of group II were operated on the day of the sputnik landing. Regenerates of the flight and corresponding control animals were fixed at the same time after the operation. For evaluation of the regeneration rate morphological criteria were used: morphological stages of regeneration were compared in the experiment and the control. For quantitative assay of the regeneration rate we determined the index of nuclei labelled with 3H-thymidine in the blastema and lens rudiment cells and used morphometry of the lens regenerates. Acceleration of forelimb and lens regeneration was observed in both groups of animals. In group II more than two-fold increase of the index of labelled nuclei was found in the blastema cells at the comparable stages of development. The size of lens regenerates in flight groups I and II exceeded reliably those in the control animals. The results obtained suggest a prolonged effect of the space flight factors on forelimb and lens regeneration. Under the conditions of space flight the lens regenerates reached more advanced stages of regeneration, as compared with the control animals operated after the space flight. These results also suggest acceleration of regeneration in lower vertebrates.

  7. Variation in food availability mediate the impact of density on cannibalism, growth, and survival in larval yellow spotted mountain newts (Neurergus microspilotus): Implications for captive breeding programs.

    PubMed

    Vaissi, Somaye; Sharifi, Mozafar

    2016-11-01

    In this study, we examined cannibalistic behavior, growth, metamorphosis, and survival in larval and post-metamorph endangered yellow spotted mountain newts Neurergus microspilotus hatched and reared in a captive breeding facility. We designed a 2 × 2 factorial experiment, crossing two levels of food with two levels of density including high food/high density, high food/low density, low food/high density, and low food/low density. The level of cannibalistic behavior (including the loss of fore and hind limbs, missing toes, tail, gills, body damage, and whole body consumption) changed as the larvae grew, from a low level during the first 4 weeks, peaking from weeks 7 to 12, and then dropped during weeks 14-52. Both food level and density had a significant effect on cannibalism. The highest frequency of cannibalism was recorded for larvae reared in the low food/high density and lowest in high food/low density treatments. Growth, percent of larval metamorphosed, and survival were all highest in the high food/low density and lowest in low food/high density treatment. Food level had a significant effect on growth, metamorphosis, and survival. However, the two levels of density did not influence growth and metamorphosis but showed a significant effect on survival. Similarly, combined effects of food level and density showed significant effects on growth, metamorphosis, and survival over time. Information obtained from current experiment could improve productivity of captive breeding facilities to ensure the release of adequate numbers of individuals for reintroduction programs. Zoo Biol. 35:513-521, 2016. © 2016 The Authors. Zoo Biology published by Wiley Periodicals, Inc.

  8. A revised taxonomy of crested newts in the Triturus karelinii group (Amphibia: Caudata: Salamandridae), with the description of a new species.

    PubMed

    Wielstra, B; Litvinchuk, S N; Naumov, B; Tzankov, N; Arntzen, J W

    2013-01-01

    We present a taxonomic revision of the crested newt Triturus karelinii sensu lato. Based on the presence of discrete nuclear DNA gene pools, deep genetic divergence of mitochondrial and nuclear DNA, and no indication of gene flow, we interpret this taxon as comprising two species: one covering the southern Caspian Sea shore, the Caucasus and the Crimea, i.e. the eastern part of the total range and another covering northern Asiatic Turkey and western Asiatic Turkey plus the southeastern Balkan Peninsula, i.e. the central and western part of the total range. We acknowledge that the central/western species should likely be further subdivided into a central and a western taxon, but we prefer to await a more detailed genetic analysis of the putative contact zone, positioned in northwestern Asiatic Turkey. The name T. karelinii (Strauch, 1870) applies to the eastern species as the type locality is positioned along the coast of the Gulf of Gorgan, Iran. The name T. arntzeni has been applied to the central/western species with Vrtovać, Serbia as the type locality. We show that not T. karelinii sensu lato but T. macedonicus occurs at Vrtovać. Hence, the name T. arntzeni Litvinchuk, Borkin, Dzukić and Kalezić, 1999 (in Litvinchuk et al., 1999) is a junior synonym of T. macedonicus (Karaman, 1922) and should not be used for the central/western species. We propose the name T. ivanbureschi sp. nov. for the central/western species and provide a formal species description.

  9. Corticosterone suppresses vasotocin-enhanced clasping behavior in male rough-skinned newts by novel mechanisms interfering with V1a receptor availability and receptor-mediated endocytosis.

    PubMed

    Davis, Audrey; Abraham, Emily; McEvoy, Erin; Sonnenfeld, Sarah; Lewis, Christine; Hubbard, Catherine S; Dolence, E Kurt; Rose, James D; Coddington, Emma

    2015-03-01

    In rough-skinned newts, Taricha granulosa, exposure to an acute stressor results in the rapid release of corticosterone (CORT), which suppresses the ability of vasotocin (VT) to enhance clasping behavior. CORT also suppresses VT-induced spontaneous activity and sensory responsiveness of clasp-controlling neurons in the rostromedial reticular formation (Rf). The cellular mechanisms underlying this interaction remain unclear. We hypothesized that CORT blocks VT-enhanced clasping by interfering with V1a receptor availability and/or VT-induced endocytosis. We administered a physiologically active fluorescent VT conjugated to Oregon Green (VT-OG) to the fourth ventricle 9 min after an intraperitoneal injection of CORT (0, 10, 40 μg/0.1mL amphibian Ringers). The brains were collected 30 min post-VT-OG, fixed, and imaged with confocal microscopy. CORT diminished the number of endocytosed vesicles, percent area containing VT-OG, sum intensity of VT-OG, and the amount of VT-V1a within each vesicle; indicating that CORT was interfering with V1a receptor availability and VT-V1a receptor-mediated endocytosis. CORT actions were brain location-specific and season-dependent in a manner that is consistent with the natural and context-dependent expression of clasping behavior. Furthermore, the sensitivity of the Rf to CORT was much higher in animals during the breeding season, arguing for ethologically appropriate seasonal variation in CORT's ability to prevent VT-induced endocytosis. Our data are consistent with the time course and interaction effects of CORT and VT on clasping behavior and neurophysiology. CORT interference with VT-induced endocytosis may be a common mechanism employed by hormones across taxa for mediating rapid context- and season-specific behavioral responses.

  10. No signs of inbreeding despite long-term isolation and habitat fragmentation in the critically endangered Montseny brook newt (Calotriton arnoldi).

    PubMed

    Valbuena-Ureña, E; Soler-Membrives, A; Steinfartz, S; Orozco-terWengel, P; Carranza, S

    2017-01-11

    Endemic species with restricted geographic ranges potentially suffer the highest risk of extinction. If these species are further fragmented into genetically isolated subpopulations, the risk of extinction is elevated. Habitat fragmentation is generally considered to have negative effects on species survival, despite some evidence for neutral or even positive effects. Typically, non-negative effects are ignored by conservation biology. The Montseny brook newt (Calotriton arnoldi) has one of the smallest distribution ranges of any European amphibian (8 km(2)) and is considered critically endangered by the International Union for Conservation of Nature. Here we apply molecular markers to analyze its population structure and find that habitat fragmentation owing to a natural barrier has resulted in strong genetic division of populations into two sectors, with no detectable migration between sites. Although effective population size estimates suggest low values for all populations, we found low levels of inbreeding and relatedness between individuals within populations. Moreover, C. arnoldi displays similar levels of genetic diversity to its sister species Calotriton asper, from which it separated around 1.5 million years ago and which has a much larger distribution range. Our extensive study shows that natural habitat fragmentation does not result in negative genetic effects, such as the loss of genetic diversity and inbreeding on an evolutionary timescale. We hypothesize that species in such conditions may evolve strategies (for example, special mating preferences) to mitigate the effects of small population sizes. However, it should be stressed that the influence of natural habitat fragmentation on an evolutionary timescale should not be conflated with anthropogenic habitat loss or degradation when considering conservation strategies.Heredity advance online publication, 11 January 2017; doi:10.1038/hdy.2016.123.

  11. Differential proteome analysis of the cell differentiation regulated by BCC, CRH, CXCR4, GnRH, GPCR, IL1 signaling pathways in Chinese fire-bellied newt limb regeneration.

    PubMed

    Geng, Xiaofang; Xu, Tiantian; Niu, Zhipeng; Zhou, Xiaochun; Zhao, Lijun; Xie, Zhaohui; Xue, Deming; Zhang, Fuchun; Xu, Cunshuan

    2014-01-01

    Following amputation, the newt has the remarkable ability to regenerate its limb, and this process involves dedifferentiation, proliferation and differentiation. To investigate the potential proteome during a dynamic network of Chinese fire-bellied newt limb regeneration (CNLR), two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) and mass spectrum (MS) were applied to examine changes in the proteome that occurred at 11 time points after amputation. Meanwhile, several proteins were selected to validate their expression levels by Western blot. The results revealed that 1476 proteins had significantly changed as compared to the control group. Gene Ontology annotation and protein network analysis by Ingenuity Pathway Analysis 9.0 (IPA) software suggested that the differentially expressed proteins were involved in 33 kinds of physiological activities including signal transduction, cell proliferation, cell differentiation, etc. Among these proteins, 407 proteins participated in cell differentiation with 212 proteins in the differentiation of skin cell, myocyte, neurocyte, chondrocyte and osteocyte, and 37 proteins participated in signaling pathways of BCC, CRH, CXCR4, GnRH, GPCR and IL1 which regulated cell differentiation and redifferentiation. On the other hand, the signal transduction activity and cell differentiation activity were analyzed by IPA based on the changes in the expression of these proteins. The results showed that BCC, CRH, CXCR4, GnRH, GPCR and IL1 signaling pathways played an important role in regulating the differentiation of skin cell, myocyte, neurocyte, chondrocyte and osteocyte during CNLR.

  12. New effects of Roundup on amphibians: predators reduce herbicide mortality; herbicides induce antipredator morphology.

    PubMed

    Relyea, Rick A

    2012-03-01

    The use of pesticides is important for growing crops and protecting human health by reducing the prevalence of targeted pest species. However, less attention is given to the potential unintended effects on nontarget species, including taxonomic groups that are of current conservation concern. One issue raised in recent years is the potential for pesticides to become more lethal in the presence of predatory cues, a phenomenon observed thus far only in the laboratory. A second issue is whether pesticides can induce unintended trait changes in nontarget species, particularly trait changes that might mimic adaptive responses to natural environmental stressors. Using outdoor mesocosms, I created simple wetland communities containing leaf litter, algae, zooplankton, and three species of tadpoles (wood frogs [Rana sylvatica or Lithobates sylvaticus], leopard frogs [R. pipiens or L. pipiens], and American toads [Bufo americanus or Anaxyrus americanus]). I exposed the communities to a factorial combination of environmentally relevant herbicide concentrations (0, 1, 2, or 3 mg acid equivalents [a.e.]/L of Roundup Original MAX) crossed with three predator-cue treatments (no predators, adult newts [Notophthalmus viridescens], or larval dragonflies [Anax junius]). Without predator cues, mortality rates from Roundup were consistent with past studies. Combined with cues from the most risky predator (i.e., dragonflies), Roundup became less lethal (in direct contrast to past laboratory studies). This reduction in mortality was likely caused by the herbicide stratifying in the water column and predator cues scaring the tadpoles down to the benthos where herbicide concentrations were lower. Even more striking was the discovery that Roundup induced morphological changes in the tadpoles. In wood frog and leopard frog tadpoles, Roundup induced relatively deeper tails in the same direction and of the same magnitude as the adaptive changes induced by dragonfly cues. To my knowledge, this

  13. Effects of light on the cytotoxicity and genotoxicity of benzo(a)pyrene and an oil refinery effluent in the newt

    SciTech Connect

    Fernandez, M.; l`Haridon, J.

    1994-12-31

    The genotoxicity and/or toxicity of benzo(a)pyrene (BaP) were evaluated under different lighting conditions in larvae and embryos of the newt Pleurodeles waltl. Visible light alone, UVA alone, or BaP alone had no toxic effects on the larvae. Conversely, toxic effects were observed in animals exposed to BaP + daylight, or BaP + UVA. The genotoxicity of BaP (50 ppb) was halved by its previous exposure to UVA, and was abolished at the lowest concentration (12.5 ppb). In other experiments, the larvae were exposed alternatively to BaP or Irr BaP (18 hours in dark) and UVA (6 hr in water), every day for 8 days. All animals that had accumulated non-irradiated BaP (50 ppb) showed signs of severe toxicity, and 90% died before the end of the test. On the other hand, irradiated BaP (50 ppb) was a 4-fold less toxic and half as genotoxic as non-irradiated BaP. In addition, exposure of the animals to UVA alone for 4 days prior to treatment with BaP did not affect the genotoxicity or toxicity of this hydrocarbon. In the dark, the embryotoxicity of BaP was markedly attenuated by the presence of the jelly coats. Although UVA alone did not affect growth of the embryos, the toxicity of BaP was enhanced by the combined action of the two agents together or in succession (BaP + UVA or BaP then UVA). Larvae were treated with an oil refinery effluent (EF). At 125 ml/l, EF was not found to be genotoxic in the dark. However, in animals exposed to both EF and UVA, there was a progressive increase in level of micronucleated erythrocytes with increasing duration of daily exposure to UVA. Moreover, the genotoxic potential of irradiated EF + UVA was systematically below that of non-irradiated EF + UVA for all durations of exposure to ultraviolet light. Irradiation of this type of effluent might help reduce its harmful effects on aquatic species. Our results also suggest that metabolic activation is not necessary for hydrocarbons to induce toxic effects. 51 refs., 5 tabs., 3 figs.

  14. Micronuclei in red blood cells of the newt Pleurodeles waltl after treatment with benzo(a)pyrene: dependence on dose, length of exposure, posttreatment time, and uptake of the drug

    SciTech Connect

    Grinfeld, S.; Jaylet, A.; Siboulet, R.; Deparis, P.; Chouroulinkov, I.

    1986-01-01

    Aquatic larvae of the newt Pleurodeles waltl were exposed to different concentrations of benzo(a)pyrene (BaP) for various lengths of time. Frequencies of micronuclei in circulating erythrocytes were determined at different times after termination of the treatment. The incidence of micronuclei in larvae kept for 8 days in BaP-containing water displayed a marked increase with dose up to 0.075 ppm and a more gradual one with higher doses, reaching 158 per 1000 at 0.75 ppm. The lowest dose at which a significant increase could be discerned was 0.01 ppm. Short periods of exposure, less than 2 days, did not result in a marked increase in micronuclei. Uptake and release was studied with tritiated BaP. Larvae concentrated BaP rapidly, attaining maximal levels after 12 hr. Radioactive larvae placed in regularly renewed noncontaminated water lost 99% of the label after 100 hr. It is concluded that pleurodele larvae are a promising model for the detection of genotoxic activity in the aquatic environment.

  15. A molecular assessment of phylogenetic relationships and lineage accumulation rates within the family Salamandridae (Amphibia, Caudata).

    PubMed

    Weisrock, David W; Papenfuss, Theodore J; Macey, J Robert; Litvinchuk, Spartak N; Polymeni, Rosa; Ugurtas, Ismail H; Zhao, Ermi; Jowkar, Houman; Larson, Allan

    2006-11-01

    We examine phylogenetic relationships among salamanders of the family Salamandridae using approximately 2700 bases of new mtDNA sequence data (the tRNALeu, ND1, tRNAIle, tRNAGln, tRNAMet, ND2, tRNATrp, tRNAAla, tRNAAsn, tRNACys, tRNATyr, and COI genes and the origin for light-strand replication) collected from 96 individuals representing 61 of the 66 recognized salamandrid species and outgroups. Phylogenetic analyses using maximum parsimony and Bayesian analysis are performed on the new data alone and combined with previously reported sequences from other parts of the mitochondrial genome. The basal phylogenetic split is a polytomy of lineages ancestral to (1) the Italian newt Salamandrina terdigitata, (2) a strongly supported clade comprising the "true" salamanders (genera Chioglossa, Mertensiella, Lyciasalamandra, and Salamandra), and (3) a strongly supported clade comprising all newts except S. terdigitata. Strongly supported clades within the true salamanders include monophyly of each genus and grouping Chioglossa and Mertensiella as the sister taxon to a clade comprising Lyciasalamandra and Salamandra. Among newts, genera Echinotriton, Pleurodeles, and Tylototriton form a strongly supported clade whose sister taxon comprises the genera Calotriton, Cynops, Euproctus, Neurergus, Notophthalmus, Pachytriton, Paramesotriton, Taricha, and Triturus. Our results strongly support monophyly of all polytypic newt genera except Paramesotriton and Triturus, which appear paraphyletic, and Calotriton, for which only one of the two species is sampled. Other well-supported clades within newts include (1) Asian genera Cynops, Pachytriton, and Paramesotriton, (2) North American genera Notophthalmus and Taricha, (3) the Triturus vulgaris species group, and (4) the Triturus cristatus species group; some additional groupings appear strong in Bayesian but not parsimony analyses. Rates of lineage accumulation through time are evaluated using this nearly comprehensive sampling of

  16. Phylogeny and biogeography of the family Salamandridae (Amphibia: Caudata) inferred from complete mitochondrial genomes.

    PubMed

    Zhang, Peng; Papenfuss, Theodore J; Wake, Marvalee H; Qu, Lianghu; Wake, David B

    2008-11-01

    Phylogenetic relationships of members of the salamander family Salamandridae were examined using complete mitochondrial genomes collected from 42 species representing all 20 salamandrid genera and five outgroup taxa. Weighted maximum parsimony, partitioned maximum likelihood, and partitioned Bayesian approaches all produce an identical, well-resolved phylogeny; most branches are strongly supported with greater than 90% bootstrap values and 1.0 Bayesian posterior probabilities. Our results support recent taxonomic changes in finding the traditional genera Mertensiella, Euproctus, and Triturus to be non-monophyletic species assemblages. We successfully resolved the current polytomy at the base of the salamandrid tree: the Italian newt genus Salamandrina is sister to all remaining salamandrids. Beyond Salamandrina, a clade comprising all remaining newts is separated from a clade containing the true salamanders. Among these newts, the branching orders of well-supported clades are: primitive newts (Echinotriton, Pleurodeles, and Tylototriton), New World newts (Notophthalmus-Taricha), Corsica-Sardinia newts (Euproctus), and modern European newts (Calotriton, Lissotriton, Mesotriton, Neurergus, Ommatotriton, and Triturus) plus modern Asian newts (Cynops, Pachytriton, and Paramesotriton).Two alternative sets of calibration points and two Bayesian dating methods (BEAST and MultiDivTime) were used to estimate timescales for salamandrid evolution. The estimation difference by dating methods is slight and we propose two sets of timescales based on different calibration choices. The two timescales suggest that the initial diversification of extant salamandrids took place in Europe about 97 or 69Ma. North American salamandrids were derived from their European ancestors by dispersal through North Atlantic Land Bridges in the Late Cretaceous ( approximately 69Ma) or Middle Eocene ( approximately 43Ma). Ancestors of Asian salamandrids most probably dispersed to the eastern Asia

  17. Mediation of chemoattractant-induced changes in [Ca2+]i and cell shape, polarity, and locomotion by InsP3, DAG, and protein kinase C in newt eosinophils

    PubMed Central

    1994-01-01

    During chemotaxis large eosinophils from newts exhibit a gradient of [Ca2+]i from rear to front. The direction of the gradient changes on relocation of the chemoattractant source, suggesting that the Ca2+ signal may trigger the cytoskeletal reorganization required for cell reorientation during chemotaxis. The initial stimulatory effect of chemoattractant on [Ca2+]i and the opposite orientations of the intracellular Ca2+ gradient and the external stimulus gradient suggest that more than one chemoattractant-sensitive messenger pathway may be responsible for the generation of spatially graded Ca2+ signals. To identify these messengers, Ca2+ changes were measured in single live cells stimulated with spatially uniform chemoattractant. On stimulation spatially averaged [Ca2+]i increased rapidly from < or = 100 nM to > or = 400 nM and was accompanied by formation of lamellipods. Subsequently cells flattened, polarized and crawled, and [Ca2+]i fluctuated around a mean value of approximately 200 nM. The initial Ca2+ spike was insensitive acutely to removal of extracellular Ca2+ but was abolished by treatments expected to deplete internal Ca2+ stores and by blocking receptors for inositol-trisphosphate, indicating that it is produced by discharge of internal stores, at least some of which are sensitive to InsP3. Activators of protein kinase C (PKC) (diacyl glycerol and phorbol ester) induced flattening and lamellipod activity and suppressed the Ca2+ spike, while cells injected with PKC inhibitors (an inhibitory peptide and low concentrations of heparin-like compounds) produced an enhanced Ca2+ spike on stimulation. Although cell flattening and lamellipod activity were induced by chemoattractant when the normal Ca2+ response was blocked, cells failed to polarize and crawl, indicating that Ca2+ homeostasis is required for these processes. We conclude that InsP3 acting on Ca2+ stores and DAG acting via PKC regulate chemoattractant-induced changes in [Ca2+]i, which in turn

  18. The new ATLAS track reconstruction (NEWT)

    NASA Astrophysics Data System (ADS)

    Cornelissen, T.; Elsing, M.; Gavrilenko, I.; Liebig, W.; Moyse, E.; Salzburger, A.

    2008-07-01

    The track reconstruction of modern high energy physics experiments is a very complex task that puts stringent requirements onto the software realisation. The ATLAS track reconstruction software has been in the past dominated by a collection of individual packages, each of which incorporating a different intrinsic event data model, different data flow sequences and calibration data. Recently, the ATLAS track reconstruction has undergone a major design revolution to ensure maintainability during the long lifetime of the ATLAS experiment and the flexibility needed for the startup phase. The entire software chain has been re-organised in modular components and a common event data model has been deployed. A complete new track reconstruction that concentrates on common tools aimed to be used by both ATLAS tracking devices, the Inner Detector and the Muon System, has been established. It has been already used during many large scale tests with data from Monte Carlo simulation and from detector commissioning projects such as the combined test beam 2004 and cosmic ray events. This document concentrates on the technical and conceptual details of the newly developed track reconstruction.

  19. Predator perception of Batesian mimicry and conspicuousness in a salamander.

    PubMed

    Kraemer, Andrew C; Adams, Dean C

    2014-04-01

    In Batesian mimicry a palatable mimic deceives predators by resembling an unpalatable model. The evolution of Batesian mimicry relies on the visual capabilities of the potential predators, as prey detection provides the selective force driving evolutionary change. We compared the visual capabilities of several potential predators to test predictions stemming from the hypothesis of Batesian mimicry between two salamanders: the model species Notophthalmus viridescens, and polymorphic mimic, Plethodon cinereus. First, we found mimicry to be restricted to coloration, but not brightness. Second, only bird predators appeared able to discriminate between the colors of models and nonmimic P. cinereus. Third, estimates of salamander conspicuousness were background dependent, corresponding to predictions only for backgrounds against which salamanders are most active. These results support the hypothesis that birds influence the evolution of Batesian mimicry in P. cinereus, as they are the only group examined capable of differentiating N. viridescens and nonmimetic P. cinereus. Additionally, patterns of conspicuousness suggest that selection from predators may drive the evolution of conspicuousness in this system. This study confirms the expectation that the visual abilities of predators may influence the evolution of Batesian mimicry, but the role of conspicuousness may be more complex than previously thought.

  20. Amphibians have immunoglobulins similar to ancestral IgD and IgA from Amniotes.

    PubMed

    Estevez, Olivia; Garet, Elina; Olivieri, David; Gambón-Deza, Francisco

    2016-01-01

    We studied the immunoglobulin genes from either the genomes or RNAs of amphibians. In particular, we obtained data from one frog genome (Nanorana parkeri) and three transcriptomes of the Caudata order (Andrias davidianus, Notophthalmus viridescens and Cynops pyrrhogaster). Apart from the immunoglobulins IgM and IgY previously described, we identified several IgD related immunoglobulins. The species N. parkeri, N. viridescens and C. pyrrhogaster have two IgD genes, while Andrias davidianus has three such genes. The three Caudata species have long IgD immunoglobulins similar to IgD of reptiles, and could be an ancient relic from the common ancestor of IgD of all mammals and reptiles. We also found two IgA isotypes. The results suggest that one of the IgA may be the ancestor of IgA in crocodiles and birds, while the other could be the ancestor IgA found in mammals. These results provide information that could help understand the evolution of immunoglobulins in terrestrial vertebrates.

  1. Synonymy of Katianna coeruleocephala Handschin, 1920 (Collembola: Katiannidae) with Bourletiella viridescens (Bourletiellidae).

    PubMed

    Greenslade, Penelope

    2016-01-12

    Katianna coeruleocephala was described by Handschin in 1920 from Poespo, Java. It was collected in December, 1896 by Dr. Zehntner with the collecting details given as rotten "Louv" (leaves?) from live orchard. Handschin (1920) labelled his figures of the species (p. 146) as Katianna coerulescephala but the first spelling of the species name (p. 145) has priority. Katianna coeruleocephala has never been recollected. The only mention of the species in the literature since 1920 has been by Suhardjono (1989) in a check list for Indonesia and Suhardjono (2012) who listed it as present on Java and provided the main characteristics of the genus Katianna Börner, 1923. She stated it was a "new" (translate as endemic?) species in Java with a preferred habitat in cold and damp litter but no comment was made on the taxonomic status of the Indonesian species.

  2. Evolutionary ecology of facultative paedomorphosis in newts and salamanders.

    PubMed

    Denoël, Mathieu; Joly, Pierre; Whiteman, Howard H

    2005-11-01

    Facultative paedomorphosis is an environmentally induced polymorphism that results in the coexistence of mature, gilled, and fully aquatic paedomorphic adults and transformed, terrestrial, metamorphic adults in the same population. This polymorphism has been of interest to scientists for decades because it occurs in a large number of caudate amphibian taxa as well as in a large diversity of habitats. Numerous experimental and observational studies have been conducted to explain the proximate and ultimate factors affecting these heterochronic variants in natural populations. The production of each alternative phenotype is based on a genotypexenvironment interaction and research suggests that differences in the environment can produce paedomorphs through several ontogenetic pathways. No single advantage accounts for the maintenance of this polymorphism. Rather, the interplay of different costs and benefits explains the success of the polyphenism across variable environments. Facultative paedomorphosis allows individuals to cope with habitat variation, to take advantage of environmental heterogeneity in the presence of open niches, and to increase their fitness. This process is expected to constitute a first step towards speciation events, and is also an example of biodiversity at the intraspecific level. The facultative paedomorphosis system is thus ripe for future studies encompassing ecology, evolution, behaviour, endocrinology, physiology, and conservation biology. Few other systems have been broad enough to provide varied research opportunities on topics as diverse as phenotypic plasticity, speciation, mating behaviour, and hormonal regulation of morphology. Further research on facultative paedomorphosis will provide needed insight into these and other important questions facing biologists.

  3. Batesian mimics influence the evolution of conspicuousness in an aposematic salamander.

    PubMed

    Kraemer, A C; Serb, J M; Adams, D C

    2015-05-01

    Conspicuousness, or having high contrast relative to the surrounding background, is a common feature of unpalatable species. Several hypotheses have been proposed to explain the occurrence of conspicuousness, and while most involve the role of conspicuousness as a direct signal of unpalatability to potential predators, one hypothesis suggests that exaggerated conspicuousness may evolve in unpalatable species to reduce predator confusion with palatable species (potential Batesian mimics). This hypothesis of antagonistic coevolution between palatable and unpalatable species hinges on the 'cost of conspicuousness', in which conspicuousness increases the likelihood of predation more in palatable species than in unpalatable species. Under this mimicry scenario, four patterns are expected: (i) mimics will more closely resemble local models than models from other localities, (ii) there will be a positive relationship between mimic and model conspicuousness, (iii) models will be more conspicuous in the presence of mimics, and (iv) when models and mimics differ in conspicuousness, mimics will be less conspicuous than models. We tested these predictions in the salamander mimicry system involving Notophthalmus viridescens (model) and one colour morph of Plethodon cinereus (mimic). All predictions were supported, indicating that selection for Batesian mimicry not only influences the evolution of mimics, but also the evolution of the models they resemble. These findings indicate that mimicry plays a large role in the evolution of model warning signals, particularly influencing the evolution of conspicuousness.

  4. Re-regeneration of lower jaws and the dental lamina in adult urodeles.

    PubMed

    Graver, H T

    1978-09-01

    Transverse amputations were carried out through one-third fully regenerated jaw segments and through normal tissue of the mandible on the same and opposite sides of the jaw in adults of Notophthalmus viridescens. Collectively the results suggest that, in adult urodeles, the mandible and the dental lamina can be replaced in an identical manner more than one time. Although the major histological events are the same in jaw regeneration and re-regeneration, regrowth is more rapid in re-regeneration. It appears that recently differentiated tissues of the regenerate have a higher capacity for regeneration than normal tissues amputated for the first time. Re-regeneration of the jaw occurs by growth of the original regenerate cartilage which has undergone reorganization. In re-regeneration, the skeletal elements exhibit no polarity and regrowth occurs in both directions, while the dental lamina possesses an anterior-posterior polarity and can regrow in an anterior direction only. Information concerning the mechanisms involved in the regenerative events remain to be determined.

  5. Herpetofaunal Community Change in Multiple Habitats after Fifteen Years in a Southwest Florida Preserve, USA

    PubMed Central

    Cassani, John R.; Croshaw, Dean A.; Bozzo, Joseph; Brooks, Brenda; Everham, Edwin M.; Ceilley, David W.; Hanson, Deborah

    2015-01-01

    Herpetofaunal declines have been documented globally, and southern Florida, USA, is an especially vulnerable region because of high impacts from hydrological perturbations and nonindigenous species. To assess the extent of recent change in herpetofauna community composition, we established a baseline inventory during 1995-97 at a managed preserve in a habitat rich area of southwest Florida, and repeated our sampling methods fifteen years later (2010-11). Nine drift fence arrays were placed in four habitat types: mesic flatwood, mesic hammock, depression marsh, and wet prairie. Trapping occurred daily for one week during 7-8 sampling runs in each period (57 and 49 total sampling days, respectively). Species richness was maintained in mesic hammock habitats but varied in the others. Catch rates of several native species (Anaxyrus terrestris, Lithobates grylio, Anolis carolinensis, Nerodia fasciata) declined significantly. Other native species (Lithobates sphenocephalus, Siren lacertian, and Notophthalmus viridescens piaropicola) that were abundant in 1995-97 declined by greater than 50%. Catch rate of only two species (the nonindigenous Anolis sagrei and the native Diadophis punctatus) increased significantly. Hierarchical cluster analysis indicated similarity within habitat types but significant dissimilarity between sampling periods, confirming shifts in community composition. Analysis of individual species’ contributions to overall similarity across habitats shows a shift from dominance of native species in the 1990s to increased importance of nonindigenous species in 2010-11. Although natural population fluctuations may have influenced differences between the two sampling periods, our results suggest considerable recent change in the structure and composition of this southwest Florida herpetofaunal community. The causes are unknown, but hydrological shifts and ecological impacts of nonindigenous species may have contributed. PMID:26016475

  6. Widespread occurrence of the amphibian chytrid fungus Batrachochytrium dendrobatidis in the southeastern USA

    USGS Publications Warehouse

    Rothermel, B.B.; Walls, S.C.; Mitchell, J.C.; Dodd, C.K.; Irwin, L.K.; Green, D.E.; Vazquez, Victoria M.; Petranka, James W.; Stevenson, Dirk J.

    2008-01-01

    From 1999 to 2006, we sampled >1200 amphibians for the fungal pathogen Batrachochytnum dendrobatidis (Bd) at 30 sites in the southeastern USA. Using histological techniques or PCR assays, we detected chytrid infection in 10 species of aquatic-breeding amphibians in 6 states. The prevalence of chytrid infection was 17.8% for samples of postmetamorphic amphibians examined using skin swab-PCR assays (n = 202 samples from 12 species at 4 sites). In this subset of samples, anurans had a much higher prevalence of infection than caudates (39.2% vs. 5.5%, respectively). Mean prevalence in ranid frogs was 40.7 %. The only infected salamanders were Notophthalmus viridescens at 3 sites. We found infected amphibians from late winter through late spring and in 1 autumn sample. Although we encountered moribund or dead amphibians at 9 sites, most mortality events were not attributed to Bd. Chytridiomycosis was established as the probable cause of illness or death in fewer than 10 individuals. Our observations suggest a pattern of widespread and subclinical infections. However, because most of the sites in our study were visited only once, we cannot dismiss the possibility that chytridiomycosis is adversely affecting some populations. Furthermore, although there is no evidence of chytrid-associated declines in our region, the presence of this pathogen is cause for concern given global climate change and other stressors. Although presence-absence surveys may still be needed for some taxa, such as bufonids, we recommend that future researchers focus on potential population-level effects at sites where Bd is now known to occur. ?? Inter-Research 2008.

  7. Widespread occurrence of the amphibian chytrid fungus Batrachochytrium dendrobatidis in the southeastern USA

    USGS Publications Warehouse

    Rothermel, Betsie B.; Walls, Susan C.; Mitchell, Joseph C.; Dodd, C. Kenneth; Irwin, Lisa K.; Green, David E.; Vazquez, Victoria M.; Petranka, James W.; Stevenson, Dirk J.

    2008-01-01

     From 1999 to 2006, we sampled >1200 amphibians for the fungal pathogen Batrachochytrium dendrobatidis(Bd) at 30 sites in the southeastern USA. Using histological techniques or PCR assays, we detected chytrid infection in 10 species of aquatic-breeding amphibians in 6 states. The prevalence of chytrid infection was 17.8% for samples of postmetamorphic amphibians examined using skin swab-PCR assays (n = 202 samples from 12 species at 4 sites). In this subset of samples, anurans had a much higher prevalence of infection than caudates (39.2% vs. 5.5%, respectively). Mean prevalence in ranid frogs was 40.7%. The only infected salamanders were Notophthalmus viridescens at 3 sites. We found infected amphibians from late winter through late spring and in 1 autumn sample. Although we encountered moribund or dead amphibians at 9 sites, most mortality events were not attributed to Bd. Chytridiomycosis was established as the probable cause of illness or death in fewer than 10 individuals. Our observations suggest a pattern of widespread and subclinical infections. However, because most of the sites in our study were visited only once, we cannot dismiss the possibility that chytridiomycosis is adversely affecting some populations. Furthermore, although there is no evidence of chytrid-associated declines in our region, the presence of this pathogen is cause for concern given global climate change and other stressors. Although presence-absence surveys may still be needed for some taxa, such as bufonids, we recommend that future researchers focus on potential population-level effects at sites where Bd is now known to occur.

  8. The mesencephalic locomotor region sends a bilateral glutamatergic drive to hindbrain reticulospinal neurons in a tetrapod

    PubMed Central

    Ryczko, Dimitri; Auclair, Francois; Cabelguen, Jean‐Marie

    2015-01-01

    In vertebrates, stimulation of the mesencephalic locomotor region (MLR) on one side evokes symmetrical locomotor movements on both sides. How this occurs was previously examined in detail in a swimmer using body undulations (lamprey), but in tetrapods the downstream projections from the MLR to brainstem neurons are not fully understood. Here we examined the brainstem circuits from the MLR to identified reticulospinal neurons in the salamander Notophthalmus viridescens. Using neural tracing, we show that the MLR sends bilateral projections to the middle reticular nucleus (mRN, rostral hindbrain) and the inferior reticular nucleus (iRN, caudal hindbrain). Ca2+ imaging coupled to electrophysiology in in vitro isolated brains revealed very similar responses in reticulospinal neurons on both sides to a unilateral MLR stimulation. As the strength of MLR stimulation was increased, the responses increased in size in reticulospinal neurons of the mRN and iRN, but the responses in the iRN were smaller. Bath‐application or local microinjections of glutamatergic antagonists markedly reduced reticulospinal neuron responses, indicating that the MLR sends glutamatergic inputs to reticulospinal neurons. In addition, reticulospinal cells responded to glutamate microinjections and the size of the responses paralleled the amount of glutamate microinjected. Immunofluorescence coupled with anatomical tracing confirmed the presence of glutamatergic projections from the MLR to reticulospinal neurons. Overall, we show that the brainstem circuits activated by the MLR in the salamander are organized similarly to those previously described in lampreys, indicating that the anatomo‐physiological features of the locomotor drive are well conserved in vertebrates. J. Comp. Neurol. 524:1361–1383, 2016. © 2015 The Authors The Journal of Comparative Neurology Published by Wiley Periodicals, Inc. PMID:26470600

  9. Use of stable isotopes to differentiate between multiple groundwater contaminant sources

    SciTech Connect

    Kim, P.Y.; Bovitz, P.; VanDerveer, B.; Donohue, M.; Sprenger, M.; Munney, K.

    1994-12-31

    A wildlife kill in a northeastern freshwater pond, downgradient of a municipal landfill, was investigated. Chemical analyses of water, sediment, minnow (Pimephales sp.), and newt (Notophthalmus sp.) tissue was conducted in conjunction with histopathological analyses, toxicity evaluations, and a site reconnaissance. Elevated levels of volatile organic compounds (VOCs), Aroclor 1248, cyanide, and metals in water, sediment, and tissue suggested that contaminants were released into the pond from an upgradient source. In addition, the presence of a floating oil on the pond surface (originating from an upgradient source) exceeded the US EPA Ambient Water Quality Criterion for oil and grease. Bacterial, parasitological, and histopathological tests conducted on minnow tissue did not implicate any pathogenic organism to be associated with mortality. Results of the toxicity evaluation of seep water from the upgradient source revealed a significant (p < 0.05) reduction in survival and growth of fathead minnows (Pimephales promelas) from the control. Water quality parameters measured at the time of the field investigation revealed normal conditions.

  10. Movement patterns and the conservation of amphibians breeding in small, temporary wetlands

    USGS Publications Warehouse

    Dodd, C.K.; Cade, B.S.

    1998-01-01

    Many amphibians breed in water but live most of their lives in terrestrial habitats. Little is known, however, about the spatial distribution of these habitats or of the distances and directions amphibians move to reach breeding sites. The amphibian community at a small, temporary pond in northcentral Florida was monitored for 5 years. Based on captures and recaptures of more than 2500 striped newts (Notophthalmus perstriatus) and 5700 eastern narrow-mouthed toads (Gastrophryne carolinensis), we tabulated the angles of orientation that these amphibians entered and exited the pond basin. Our results showed that movements of these species between the pond and terrestrial habitats were nonrandom in orientation, but that narrow corridors did not appear to be used. Differences between the species likely reflect differences in habitat preferences, whereas intraspecific differences among years and between the sexes likely reflect variation among individuals. For terrestrial buffer zones to be effective at conserving pond-breeding amphibian communities, they need both a distance and a directional component. The determination of a directional component may be obscured if studies are carried out over a short time span. Conservation efforts for wetland-breeding amphibians that concentrate solely on the wetland likely will fail without consideration of the adjacent terrestrial habitat.

  11. Tadpoles balance foraging and predator avoidance: Effects of predation, pond drying, and hunger

    USGS Publications Warehouse

    Bridges, C.M.

    2002-01-01

    Organisms are predicted to make trade-offs when foraging and predator avoidance behaviors present conflicting demands. Balancing conflicting demands is important to larval amphibians because adult fitness can be strongly influenced by size at metamorphosis and duration of the larval period. Larvae in temporary ponds must maximize growth within a short time period to achieve metamorphosis before ponds dry, while simultaneously avoiding predators. To determine whether tadpoles trade off between conflicting demands, I examined tadpole (Pseudacris triseriata) activity and microhabitat use in the presence of red-spotted newts (Notopthalmus viridescens) under varying conditions of pond drying and hunger. Tadpoles significantly decreased activity and increased refuge use when predators were present. The proportion of active time tadpoles spent feeding was significantly greater in predator treatments, suggesting tadpoles adaptively balance the conflicting demands of foraging and predator avoidance without making apparent trade-offs. Tadpoles responded to simulated drying conditions by accelerating development. Pond drying did not modify microhabitat use or activity in the presence of predators, suggesting tadpoles perceived predation and hunger as greater immediate threats than desiccation, and did not take more risks.

  12. Gamma ray astronomy beyond 2001: What instruments for the newt challenges?

    NASA Astrophysics Data System (ADS)

    Vedrenne, G.

    2001-03-01

    In spite of the recent successes of SIGMA, RXTE and Compton GRO, and the launch of INTEGRAL in 2001, a lot of questions will stay opened for the next decades in gamma-ray astronomy. In this context we have to think about future instrument concepts which will allow a new step in the understanding of high-energy phenomena at work in many exciting objects: binary systems with compact objects, active galactic nuclei, supernovae and novae, gamma ray bursters... A short overview of these new types of instruments will be given.

  13. Description of a new species of crested newt, previously subsumed in Triturus ivanbureschi (Amphibia: Caudata: Salamandridae).

    PubMed

    Wielstra, B; Arntzen, J W

    2016-05-05

    Multilocus molecular data play a pivotal role in diagnosing cryptic species (i.e. genetically distinct but morphologically similar species). A multilocus phylogeographic survey has provided compelling evidence that Triturus ivanbureschi sensu lato comprises two distinct gene pools with restricted gene flow. We conclude that this taxon had better be treated as two distinct (albeit morphologically cryptic) species. The name T. ivanbureschi should be restricted to the western species, which is distributed in western Asiatic Turkey plus the south-eastern Balkan Peninsula. No name is as yet available for the eastern species, which is distributed in northern Asiatic Turkey. We propose the name T. anatolicus sp. nov. for the eastern species and provide a formal species description.

  14. Assessment of environmental DNA for detecting presence of imperiled aquatic amphibian species in isolated wetlands

    USGS Publications Warehouse

    Mckee, Anna; Calhoun, Daniel L.; Barichivich, William J.; Spear, Stephen F.; Goldberg, Caren S.; Glenn, Travis C

    2015-01-01

    Environmental DNA (eDNA) is an emerging tool that allows low-impact sampling for aquatic species by isolating DNA from water samples and screening for DNA sequences specific to species of interest. However, researchers have not tested this method in naturally acidic wetlands that provide breeding habitat for a number of imperiled species, including the frosted salamander (Ambystoma cingulatum), reticulated flatwoods salamanders (Ambystoma bishopi), striped newt (Notophthalmus perstriatus), and gopher frog (Lithobates capito). Our objectives for this study were to develop and optimize eDNA survey protocols and assays to complement and enhance capture-based survey methods for these amphibian species. We collected three or more water samples, dipnetted or trapped larval and adult amphibians, and conducted visual encounter surveys for egg masses for target species at 40 sites on 12 different longleaf pine (Pinus palustris) tracts. We used quantitative PCRs to screen eDNA from each site for target species presence. We detected flatwoods salamanders at three sites with eDNA but did not detect them during physical surveys. Based on the sample location we assumed these eDNA detections to indicate the presence of frosted flatwoods salamanders. We did not detect reticulated flatwoods salamanders. We detected striped newts with physical and eDNA surveys at two wetlands. We detected gopher frogs at 12 sites total, three with eDNA alone, two with physical surveys alone, and seven with physical and eDNA surveys. We detected our target species with eDNA at 9 of 11 sites where they were present as indicated from traditional surveys and at six sites where they were not detected with traditional surveys. It was, however, critical to use at least three water samples per site for eDNA. Our results demonstrate eDNA surveys can be a useful complement to traditional survey methods for detecting imperiled pond-breeding amphibians. Environmental DNA may be particularly useful in situations

  15. Pond Identification, Classification, and Inundation Dynamics at St. Marks National Wildlife Refuge in northwest Florida, USA

    NASA Astrophysics Data System (ADS)

    Riley, J. W.; Calhoun, D.; Barichivich, J.

    2012-12-01

    The persistence and resilience of amphibian communities is largely dependent on adequate breeding habitat. This is especially important for threatened and endangered species that may often exist as isolated populations and have specific requirements for breeding. A study currently being conducted by the U.S. Geological Survey is investigating the feasibility of a repatriation effort of the Striped Newt (Notophthalmus perstriatus), a federal candidate species, within the St. Marks National Wildlife Refuge (SMNWR) in northwest Florida. This amphibian species requires ponds that are free of fishes and, for this reason, generally chooses ephemeral ponds as breeding sites. The delineation of potential breeding habitat is a first step in selecting candidate areas for repatriation. To achieve this, a LIDAR (Light Detection and Ranging) derived digital elevation model (DEM) and a topographic position index (TPI) classification scheme was used to identify and classify isolated depressions across the landscape. The TPI evaluates the difference in elevation from a central DEM cell to the mean elevation of a neighborhood of surrounding DEM cells and is a robust tool for locating depressional features within a landscape. These candidate depression features were then screened to remove large perennial ponds and smaller connected ponds from further consideration. In addition, the perimeters of twenty-two field identified ephemeral ponds were surveyed with a high precision RTK GPS (Real Time Kinematic Global Positioning System) unit to provide a calibration dataset to evaluate the performance of the feature identification method. This set of ponds was also instrumented with water-level recorders to investigate inundation dynamics across a wide range of hydrologic conditions. We anticipate being able to classify pond hydroperiod—thus each pond's potential as breeding habitat—at the monitored locations through this combination of approaches. Using estimates of pond size

  16. Effects of noradrenaline administration on the interrenal gland of the newt, Triturus carnifex: evidence of intra-adrenal paracrine interactions.

    PubMed

    Capaldo, A; Gay, F; Valiante, S; Laforgia, V; Varano, L

    2004-01-01

    The existence of paracrine control of steroidogenic activity by adrenochromaffin cells in Triturus carnifex was investigated by in vivo noradrenaline (NA) administration. The effects were evaluated by examination of the ultrastructural morphological and morphometrical features of the tissues as well as the serum levels of aldosterone, NA, and adrenaline (A). In March and July, NA administration increased aldosterone release (from 187.23 +/- 2.93 pg/ml to 878.31 +/- 6.13 pg/ml in March; from 314.60 +/- 1.34 pg/ml to 622.51 +/- 2.65 pg/ml in July) from steroidogenic cells. The cells showed clear signs of stimulation, as evidenced by a strong reduction of lipid content. Moreover, NA administration decreased the mean total number of secretory vesicles in the chromaffin cells in March (from 7.24 +/- 0.18 granules/micro2 to 5.57 +/- 1.88 granules/micro2) and July (from 7.74 +/- 0.74 granules/micro2 to 6.04 +/- 1.13 granules/micro2). In March, however, when T. carnifex chromaffin cells contain both catecholamines, NA (3.88 +/- 0.13 granules/micro2) and A (3.36 +/- 0.05 granules/micro2) in almost equal quantities, NA administration reduced A content (1.29 +/- 1.04 granules/micro2) in the chromaffin cells, enhancing adrenaline secretion (from 681.27 +/- 1.83 pg/ml to 1527.02 +/- 2.11 pg/ml). In July, when the chromaffin cells contain almost exclusively NA granules (NA: 7.42 +/- 0.86 granules/micro2; A: 0.32 +/- 0.13 granules/micro2), NA administration reduced the number of NA granules (5.45 +/- 1.10 granules/micro2), thereby increasing noradrenaline release from the chromaffin cells (from 640.19 +/- 1.65 pg/ml to 1217.0 +/- 1.14 pg/ml). The results of this study indicate that NA influences the steroidogenic cells, eliciting aldosterone release. Noradrenalin effects on the chromaffin cells, increase of NA or A secretion, according to the period of chromaffin cell functional cycle, may be direct and/or mediated through the steroidogenic cells. The existence of intra-adrenal paracrine interactions in T. carnifex is discussed.

  17. Effect of hypophysectomy and starvation on the fine structure of vitellogenic oocytes in the newt, Triturus pyrrhogaster (Laur).

    PubMed

    Dutt, N H; Inoue, S

    1982-01-01

    Hypophysectomy and starvation in Triturus pyrrhogaster result in a similar ultrastructural pattern of follicular atresia. The first detectable change in the oocytes is decrease in the size and number of microvilli. Subsequently the yolk precursor bodies (YPB) disappear from the micropinocytotic vesicles and the mitochondria degenerate. Finally the yolk platelets undergo decomposition. The smaller yolk platelets disintegrate by granulation, vacuolation and lobule formation. The larger platelets, after losing their superficial layer and the inner crystalline lattice, are surrounded by a laminated membrane complex. The pattern of yolk breakdown is comparable to that during development. A rather delayed effect is observed on the nucleolus of the oocytes. Pigment granules seem to play an important role in the proteolysis of the yolk.

  18. Increased slow transport in axons of regenerating newt limbs after a nerve conditioning lesion made prior to amputation

    SciTech Connect

    Maier, C.E.

    1989-01-01

    The first part of this study shows that axonal density is constant in the limb stump of the next proximal to the area of traumatic nerve degeneration caused by limb amputation. The results of the second part of this work reveal that a nerve conditioning lesion made two weeks prior to amputation is associated with accelerated limb regeneration and that this accelerated limb regeneration is accompanied by an earlier arrival of axons. This is the first demonstration of naturally occurring limb regeneration being enhanced. In this study SCb cytoskeletal proteins were identified and measured using SDS-PAGE and liquid scintillation counting. Proteins were measured at 7, 14, 21, and 28 days after {sup 35}S-methionine injection and the normal rate of SCb transport determined to be 0.19 mm/day. A single axotomy does not enhance the rate of SCb transport but does increase the amount of labeled SCb proteins that are transported. When a conditioning lesion is employed prior to limb amputation and SCb proteins are measured at 7, 14, and 21 days after injection, there is a twofold acceleration in the rate of SCb transport and an increase in the amount of SCb proteins transported in conditioned axons.

  19. [The effect of space flight factors on the cellular proliferative activity of different eye tissues during lens regeneration in the Spanish newt Pleurodeles waltlii].

    PubMed

    Brushlinskaia, N V

    1995-01-01

    The proliferative activity of the cells of various eye tissues was studied during lens regeneration in Pleurodeles waltlii under the influence of space-flight factors. After space-flight termination, the index of 3H-thymidine labelled nuclei increased reliably in the lens regenerate, in the ciliary zone of the iris, and in the growth zone of the retina, i.e., in the eye tissues that are not directly involved in formation of the regenerate cell population. The rate of increase in regenerate size was higher in the flight group than in the control. Enhancement of the proliferative activity of eye tissues, acceleration of lens regeneration, and the larger size of the regenerates are related to hormonal changes arising under the effect of space-flight factors. We propose that changes in calcium metabolism under the conditions of microgravity (in particular, increased prolactin production) accelerates the regeneration of both lens and limb in P. waltlii.

  20. Agency talk. With apologies to Mark Twain (and, for that matter, Newt Gingrich), reports of HCFA's death have been greatly exaggerated.

    PubMed

    MacPherson, P

    1996-01-20

    The Health Care Financing Administration continues to plug alone while it awaits word on what sort of job it will be required to do in the future. The ongoing battle over the scope of federal authority over Medicaid, as well as managed care-driven changes in Medicare, will reshape the agency. Whatever the specifics, change is imminent.

  1. Annual changes in the number, testosterone content and ultrastructure of glandular tissue cells of the testis in the marbled newt Triturus marmoratus.

    PubMed Central

    Fraile, B; Paniagua, R; Rodríguez, M C; Sáez, F J; Jimenez, A

    1989-01-01

    The testes of 8 specimens of Triturus marmoratus were collected during each month of 1987 and processed for electron microscopy and light microscopy demonstration of testosterone (T) following the ABC (avidin-biotin peroxidase complex) method. According to their staining affinity for anti-T antibodies, the glandular tissue cells were classified as T-, T+, T++, and T and the annual changes in the numbers of these cell populations, as well as in the volume occupied by the glandular tissue, were calculated. The volume occupied by the glandular tissue increases from September to December; it begins to decrease in April and disappears from June to August. The glandular tissue is formed from the interstitial cells that surround the lobules containing differentiating germ cells. During the spermatogenic process, the interstitial cells do not show staining affinity for anti-T antibodies. In August-September, the interstitial cells around the lobules that have completed spermatogenesis become positively stained (T+) and form the glandular tissue when the spermatozoa leave the testis. The numbers of intensely stained cells in the glandular tissue (T++ and T ) increase from September to November; begin to decrease in December; disappear in January-February; increase again in March and decrease again in April until they disappear in June-September. The interstitial cells, before their transformation in glandular tissue, are ultrastructurally similar to fibroblasts. After their transformation these cells increase in size and develop abundant smooth endoplasmic reticulum, mitochondria with tubular cristae and lipid droplets. This morphological pattern is maintained in the glandular tissue from September to April in spite of the changes in staining affinity during this period. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 PMID:2630543

  2. STS-65 Mission Onboard Photograph

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Astronaut Donald Thomas conducts the Fertilization and Embryonic Development of Japanese Newt in Space (AstroNewt) experiment at the Aquatic Animal Experiment Unit (AAEU) inside the International Microgravity Laboratory-2 (IML-2) science module. The AstroNewt experiment aims to know the effects of gravity on the early developmental process of fertilized eggs using a unique aquatic animal, the Japanese red-bellied newt. The newt egg is a large single cell at the begirning of development. The Japanese newt mates in spring and autumn. In late autumn, female newts enter hibernation with sperm in their body cavity and in spring lay eggs and fertilize them with the stored sperm. The experiment takes advantage of this feature of the newt. Groups of newts were sent to the Kennedy Space Center and kept in hibernation until the mission. The AAEU cassettes carried four newts aboard the Space Shuttle. Two newts in one cassette are treated by hormone injection on the ground to simulate egg laying. The other two newts are treated on orbit by the crew. The former group started maturization of eggs before launch. The effects of gravity on that early process were differentiated by comparison of the two groups. The IML-2 was the second in a series of Spacelab flights designed to conduct research by the international science community in a microgravity environment. Managed by the Marshall Space Flight Center, the IML-2 was launched on July 8, 1994 aboard the STS-65 Space Shuttle mission, Orbiter Columbia.

  3. STS-65 Mission Onboard Photograph

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Astronaut Donald Thomas conducts the Fertilization and Embryonic Development of Japanese Newt in Space (AstroNewt) experiment at the Aquatic Animal Experiment Unit (AAEU) inside the International Microgravity Laboratory-2 (IML-2) science module. The AstroNewt experiment aims to know the effects of gravity on the early developmental process of fertilized eggs using a unique aquatic animal, the Japanese red-bellied newt. The newt egg is a large single cell at the begirning of development. The Japanese newt mates in spring and autumn. In late autumn, female newts enter hibernation with sperm in their body cavity and in spring lay eggs and fertilized them with the stored sperm. The experiment takes advantage of this feature of the newt. Groups of newts were sent to the Kennedy Space Center and kept in hibernation until the mission. The AAEU cassettes carried four newts aboard the Space Shuttle. Two newts in one cassette are treated by hormone injection on the ground to simulate egg laying. The other two newts are treated on orbit by the crew. The former group started maturization of eggs before launch. The effects of gravity on that early process were differentiated by comparison of the two groups. The IML-2 was the second in a series of Spacelab flights designed to conduct research by the international science community in a microgravity environment. Managed by the Marshall Space Flight Center, the IML-2 was launch on July 8, 1994 aboard the STS-65 Space Shuttle Orbiter Columbia mission.

  4. Navy Pre-Deployment Training at Eglin AFB, Florida Final Environmental Assessment

    DTIC Science & Technology

    2004-02-10

    a target area of a military shooting range showed acute lead poisoning that included symptoms of maniacal movements, drooling, rolling eyes, and... NEWT Navy Expeditionary Warfare Training NHPA National Historic Preservation Act NN Number of Events During Nighttime NO2 Nitrogen Dioxide NOAEL...Final Environmental Assessment Navy Expeditionary Warfare Training ( NEWT ). NEWT includes activities similar to those proposed for ARG/MEU

  5. Fish predation on sea urchins on the Great Barrier Reef

    NASA Astrophysics Data System (ADS)

    Young, M. A. L.; Bellwood, D. R.

    2012-09-01

    Predators are important for regulating adult sea urchin densities. Here, we employ remote underwater video cameras to record diurnal predation on tethered sea urchins at Lizard Island on the Great Barrier Reef (GBR). We identified four fish predators of adult sea urchins ( Balistoides viridescens, Balistapus undulatus, Lethrinus atkinsoni and Choerodon schoenleinii). Predator activity appeared to be site-specific. Balistoides viridescens and B. undulatus (f: Balistidae) were the two most important predators of Echinometra mathaei with the former handling E. mathaei significantly faster (mean 0.7 min) than B. undulatus (5.2 min). Balistoides viridescens also successfully preyed on 70 % of detections, while C. schoenleinii, B. undulatus and L. atkinsoni preyed on just 33, 17 and <1 %, respectively. Additionally, B. viridescens were behaviourally dominant among predator species and were observed as aggressors in 30 encounters with B. undulatus and 8 encounters with L. atkinsoni. In only one encounter was B. viridescens the recipient of any aggression (from B. undulatus). In terms of relative vulnerability, of the three sea urchin species examined, E. mathaei were more vulnerable to predation than Diadema setosum or Echinothrix calamaris, with mean handling times of 1.2, 4.8 and 10.3 min, respectively. Balistoides viridescens and B. undulatus both appear to be able to play an important role as predators of sea urchins on the relatively intact coral reefs of Lizard Island. However, B. viridescens emerge as the most efficient predator in terms of handling speed and the proportion of detections preyed upon. They were also the behaviourally dominant predator. This preliminary study of the predators of sea urchins on the GBR highlights the potential significance of relatively scarce but functionally important species.

  6. What remains from a 454 run: estimation of success rates of microsatellite loci development in selected newt species (Calotriton asper, Lissotriton helveticus, and Triturus cristatus) and comparison with Illumina-based approaches

    PubMed Central

    Drechsler, Axel; Geller, Daniel; Freund, Katharina; Schmeller, Dirk S; Künzel, Sven; Rupp, Oliver; Loyau, Adeline; Denoël, Mathieu; Valbuena-Ureña, Emilio; Steinfartz, Sebastian

    2013-01-01

    The development of microsatellite loci has become more efficient using next-generation sequencing (NGS) approaches, and many studies imply that the amount of applicable loci is large. However, few studies have sought to quantify the number of loci that are retained for use out of the thousands of sequence reads initially obtained. We analyzed the success rate of microsatellite loci development for three amphibian species using a 454 NGS approach on tetra-nucleotide motif-enriched species-specific libraries. The number of sequence reads obtained differed strongly between species and ranged from 19,562 for Triturus cristatus to 55,626 for Lissotriton helveticus, with 52,075 reads obtained for Calotriton asper. PHOBOS was used to identify sequences with tetra-nucleotide repeat motifs with a minimum repeat number of ten and high quality primer binding sites. Of 107 sequences for T. cristatus, 316 for C. asper and 319 for L. helveticus, we tested the amplification success, polymorphism, and degree of heterozygosity for 41 primer combinations each for C. asper and T. cristatus, and 22 for L. helveticus. We found 11 polymorphic loci for T. cristatus, 20 loci for C. asper, and 15 loci for L. helveticus. Extrapolated, the number of potentially amplifiable loci (PALs) resulted in estimated species-specific success rates of 0.15% (T. cristatus), 0.30% (C. asper), and 0.39% (L. helveticus). Compared with representative Illumina NGS approaches, our applied 454-sequencing approach on specifically enriched sublibraries proved to be quite competitive in terms of success rates and number of finally applicable loci. PMID:24198952

  7. Effects of natural flooding and manual trapping on the facilitation of invasive crayfish-native amphibian coexistence in a semi-arid perennial stream

    USGS Publications Warehouse

    Kats, Lee B.; Bucciarelli, Gary; Vandergon, Thomas L.; Honeycutt, Rodney L.; Mattiasen, Evan; Sanders, Arthur; Riley, Seth P.D.; Kerby, Jacob L.; Fisher, Robert N.

    2013-01-01

    Aquatic amphibians are known to be vulnerable to a myriad of invasive predators. Invasive crayfish are thought to have eliminated native populations of amphibians in some streams in the semi-arid Santa Monica Mountains of southern California. Despite their toxic skin secretions that defend them from native predators, newts are vulnerable to crayfish attacks, and crayfish have been observed attacking adult newts, and eating newt egg masses and larvae. For 15 years, we have observed invasive crayfish and native California newts coexisting in one stream in the Santa Monica Mountains. During that period, we monitored the densities of both crayfish and newt egg mass densities and compared these to annual rainfall totals. After three seasons of below average rainfall, we reduced crayfish numbers by manual trapping. Our long-term data indicated that crayfish did not fare well in years when rainfall is above the historic average. This invasive predator did not evolve with high velocity streams, and observations indicated that southern California storm events washed crayfish downstream, killing many of them. Newts exhibit increased reproduction in years when crayfish numbers were reduced. A comparison with a nearby stream that does not contain crayfish indicated that newt reproduction positively responded to increased rainfall, but that fluctuations were much greater in the stream that contains crayfish. We suggest that rainfall patterns help explain invasive crayfish/newt coexistence and that management for future coexistence may benefit from manual trapping.

  8. 75 FR 13720 - Endangered and Threatened Wildlife and Plants; 90-Day Finding on a Petition to List the Striped...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-23

    .... The striped newt has one of the most complex life cycles of any amphibian (Johnson 2002, p. 384... striped newt. Population models of an amphibian (California tiger salamander) with a life cycle similar to... populations. This is supported by a review conducted in Florida on the commercial harvest of amphibians...

  9. "In The Dark": Military Planning for a Catastrophic Critical Infrastructure Event

    DTIC Science & Technology

    2011-05-01

    issue. Q: Can you share some medical stories that inspired the book [One Second After]? A: Newt Gingrich provided a real life story. Shortly after...meeting with Newt , a man told him of his father who was in the final weeks of his life, going out like a great cavalry fighter. A storm blew out the

  10. The Few and the Proud: Veterans in Congress on Defense Issues

    DTIC Science & Technology

    2013-04-15

    Language in Society 35, no 4 (September 2006), 467. 32 John J. Pitney, “Tongue of Newt : The Political Power of Language,” Reason 30, no 9 (February...Pitney Jr., John J. "Tongue of Newt : The Political Power of Language." Reason, Feb 1999, 50- 51, http://search.proquest.com.lomc.idm.oclc.org/docview

  11. Hypocrea rufa/Trichoderma viride: a reassessment, and description of five closely related species with and without warted conidia

    PubMed Central

    Jaklitsch, Walter M.; Samuels, Gary J.; Dodd, Sarah L.; Lu, Bing-Sheng; Druzhinina, Irina S.

    2006-01-01

    The type species of the genus Hypocrea (Hypocreaceae, Hypocreales, Ascomycota, Fungi), H. rufa, is re-defined and epitypified using a combination of phenotype (morphology of teleomorphs and anamorphs, and characteristics in culture) and phylogenetic analyses of the translation-elongation factor 1α gene. Its anamorph, T. viride, the type species of Trichoderma, is re-described and epitypified. Eidamia viridescens is combined as Trichoderma viridescens and is recognised as one of the most morphologically and phylogenetically similar relatives of T. viride. Its teleomorph is newly described as Hypocrea viridescens. Contrary to frequent citations of H. rufa and T. viride in the literature, this species is relatively rare. Although both T. viride and T. viridescens have a wide geographic distribution, their greatest genetic diversity appears to be in Europe and North America. Hypocrea vinosa is characterised and its anamorph, T. vinosum sp. nov., is described. Conidia of T. vinosum are subglobose and warted. The new species T. gamsii is proposed. It shares eidamia-like morphology of conidiophores with T. viridescens, but it has smooth, ellipsoidal conidia that have the longest L/W ratio that we have seen in Trichoderma. Trichoderma scalesiae, an endophyte of trunks of Scalesia pedunculata in the Galapagos Islands, is described as new. It only produces conidia on a low-nutrient agar to which filter paper has been added. Additional phylogenetically distinct clades are recognised and provisionally delimited from the species here described. Trichoderma neokoningii, a T. koningii-like species, is described from a collection made in Peru on a fruit of Theobroma cacao infected with Moniliophthora roreri. PMID:18490991

  12. Spaceflight Effects on Hemopoiesis of Lower Vertebrates Flown on Foton-M2

    NASA Technical Reports Server (NTRS)

    Domaratskaya, E. I.; Payushina, O. V.; Butorina, M. N.; Nikonova, T. M.; Grigorian, E. N.; Mitashov, V. I.; Tairbekov, M. G.; Almeida, E.; Khrushchov, N. G.

    2006-01-01

    Intact and operated newts Pleumdeles waltl flown on Foton-M2 for 16 days were used to study the effects of spaceflight as well as tail amputation and lensectomy on their hemopoiesis. The flight did not produce noticeable changes in the peripheral blood of nonoperated newts. However, in operated animals, the number of lymphocytes increased whereas that of neutrophils decreased. There were no morphological differences in hemopoietic organs (liver and spleen) between flown non-operated and operated animals or their controls. However, in both non-operated and operated newts the liver weight and the number of hemopoietic cells in it increased. In contrast to nonoperated newts, space-flown mammals typically showed significant changes in blood cell counts. Experiments with BrdU incorporation revealed labeled cells in the hemopoietic area of the liver as well as in blood and spleen. This observation gives evidence that the BrdU label can be used to study proliferation of hemopoietic cells.

  13. Comparison and evolution of the lagena in various animal species.

    PubMed

    Harada, Y; Kasuga, S; Tamura, S

    2001-04-01

    The structure of the vestibular organs of the teleost fish (bluegill), newts (Japanese fire-belly newt), frogs (black-spotted pond frog), snapping turtles and birds (chicks) was morphologically compared, with particular attention to the lagena macula, and the differences between animal species with relation to evolution were considered. Teleost fish had no striola on the lagena macula. The striola of newts were short and restricted to the central area of the macula, but those of frogs, snapping turtles and chicks extended from the anterior to posterior edges of the macula. This indicates that the frog is more highly evolved than the newt. The length of the kinocilium of sensory hairs was equal to that of the longest stereocilium in teleost fish and newts, but the kinocilia of frogs, snapping turtles and chicks were longer than the longest stereocilium. This indicates that the function of the lagena of teleost fish and newts is for hearing whilst in the other animals they are for posture. The diameter of the sensory hair bundles is small in teleost fish and frogs, but large in newts and snapping turtles. This indicates that the sensitivity of the sensory cells of the lagena towards outer force is low in teleost fish and frogs, high in newts and snapping turtles and intermediate in birds. The lagena of snapping turtles protrudes from the basilar papilla into the vestibule but the lagena of chicks lies on the tip of the long projecting basilar papilla. From observation of the locations of lagenae it is natural to speculate that there must have been some species of animal now extinct that had the evolving location of the lagena prior to that of chicks. In future it will be very interesting and useful to identify this extinct animal using DNA techniques.

  14. Introduced Goldfish Affect Amphibians through Inhibition of Sexual Behaviour in Risky Habitats: an Experimental Approach

    PubMed Central

    Winandy, Laurane; Denoël, Mathieu

    2013-01-01

    The introduction of alien species is one of the major causes of current and global biodiversity loss. The introduction of fish can be a particular threat to native amphibian populations, which are declining worldwide. One way for amphibians to persist in such altered environments is to adopt anti-predator strategies especially at the behavioural level. However, although it has been shown that avoidance behaviour may decrease the probability of being detected by a potential predator, little is known on the consequences on sexual behaviour. In this study, we tested the hypothesis that adult Alpine newts (Ichthyosaura alpestris) use shelters more often and exhibit less sexual activity in the presence of goldfish (Carassius auratus) and that they reduce sexual activity more in risky micro-habitats than in safe environments. To this end, we assessed behavioural patterns of adult newts in a replicated laboratory design. Goldfish were present in direct contact with newts in half of the tanks. Consistently throughout the study period, significantly more newts used shelter in the presence of fish than in their absence. Newts also significantly decreased their sexual activity level overall, but specially outside the shelter when they were in direct contact with fish. These results show that fish presence can affect newts in complex ways, such as through inhibition of their reproduction. Our work highlights that integrating behaviour in conservation studies is essential to understanding the patterns of coexistence and exclusion between introduced fish and amphibians. PMID:24312432

  15. Introduced goldfish affect amphibians through inhibition of sexual behaviour in risky habitats: an experimental approach.

    PubMed

    Winandy, Laurane; Denoël, Mathieu

    2013-01-01

    The introduction of alien species is one of the major causes of current and global biodiversity loss. The introduction of fish can be a particular threat to native amphibian populations, which are declining worldwide. One way for amphibians to persist in such altered environments is to adopt anti-predator strategies especially at the behavioural level. However, although it has been shown that avoidance behaviour may decrease the probability of being detected by a potential predator, little is known on the consequences on sexual behaviour. In this study, we tested the hypothesis that adult Alpine newts (Ichthyosaura alpestris) use shelters more often and exhibit less sexual activity in the presence of goldfish (Carassius auratus) and that they reduce sexual activity more in risky micro-habitats than in safe environments. To this end, we assessed behavioural patterns of adult newts in a replicated laboratory design. Goldfish were present in direct contact with newts in half of the tanks. Consistently throughout the study period, significantly more newts used shelter in the presence of fish than in their absence. Newts also significantly decreased their sexual activity level overall, but specially outside the shelter when they were in direct contact with fish. These results show that fish presence can affect newts in complex ways, such as through inhibition of their reproduction. Our work highlights that integrating behaviour in conservation studies is essential to understanding the patterns of coexistence and exclusion between introduced fish and amphibians.

  16. Nodal energy weighted transformation: A mistuning projection and its application to FLADE™ turbines

    NASA Astrophysics Data System (ADS)

    Fitzner, Colin; Epureanu, Bogdan I.; Filippi, Sergio

    2014-01-01

    In recent years, several researchers have developed reduced-order models (ROMs) to efficiently and accurately calculate the forced response of blisks with known small mistuning. Small mistuning consists of the small blade-to-blade structural differences which destroy the inherent cyclic symmetry of the structure. This paper presents a nodal energy weighted transformation (NEWT) which can be used to construct ROMs of mistuned blisks and dual flow path systems, such as FLADE™ turbines. The NEWT approach can be interpreted as a hybrid of two existing techniques: component mode mistuning (CMM) and the subset of nominal modes (SNM). Similar to the previous methods, NEWT assumes that the mistuned modes of the system are a linear combination of tuned modes. However, NEWT differs from its predecessors in the blisk substructuring and in the mistuning projection. Numerical results obtained using full order models, CMM, and NEWT are presented and compared over multiple frequency ranges for a finite element model of a blisk and that of a FLADE™ turbine. These results show that ROMs based on NEWT have several attractive features: (a) the accuracy of the ROMs is comparable to ROMs based on CMM, and can be improved by increasing the size of the projection mode subset; (b) no necessary modifications are needed to analyze FLADE™ turbines; and (c) the response of all modes can be predicted well even if they are not blade dominated.

  17. Parametrizing Finite Frames and Optimal Frame Completions

    DTIC Science & Technology

    2012-12-01

    p = P:-1:2 newT = T(:,:,p); newT (find(tril( newT )))=0; 146 nu(M,1)=mu(p); for j = M:-1:1 for k = M-j+1:-1:1 if k==(M-j+1) delta = min(nu(j-1+k,k), T(j...1+k,k,p)); else delta = min(nu(j-1+k,k), T(j-1+k,k,p)-T(j+k,k,p)); end newT (j-1+k,k) = T(j-1+k,k,p)-delta; if k>1 nu(j-2+k,k-1) = nu(j-1+k,k) - delta...else nu(M,M-j+2) = nu(j-1+k,k) - delta; end end end eigensteps(:,p) = flipud(sum( newT ,2)); T(:,:,p-1) = newT ; end 147 Bibliography [1] Antezana, J

  18. Functional convergence of signalling by GPI-anchored and anchorless forms of a salamander protein implicated in limb regeneration.

    PubMed

    Blassberg, Robert A; Garza-Garcia, Acely; Janmohamed, Azara; Gates, Phillip B; Brockes, Jeremy P

    2011-01-01

    The GPI-anchor is an established determinant of molecular localisation and various functional roles have been attributed to it. The newt GPI-anchored three-finger protein (TFP) Prod1 is an important regulator of cell behaviour during limb regeneration, but it is unclear how it signals to the interior of the cell. Prod1 was expressed by transfection in cultured newt limb cells and activated transcription and expression of matrix metalloproteinase 9 (MMP9) by a pathway involving ligand-independent activation of epidermal growth factor receptor (EGFR) signalling and phosphorylation of extracellular regulated kinase 1 and 2 (ERK1/2). This was dependent on the presence of the GPI-anchor and critical residues in the α-helical region of the protein. Interestingly, Prod1 in the axolotl, a salamander species that also regenerates its limbs, was shown to activate ERK1/2 signalling and MMP9 transcription despite being anchorless, and both newt and axolotl Prod1 co-immunoprecipitated with the newt EGFR after transfection. The substitution of the axolotl helical region activated a secreted, anchorless version of the newt molecule. The activity of the newt molecule cannot therefore depend on a unique property conferred by the anchor. Prod1 is a salamander-specific TFP and its interaction with the phylogenetically conserved EGFR has implications for our view of regeneration as an evolutionary variable.

  19. Some Slime-Forming Heterofermentative Species of the Genus Lactobacillus

    PubMed Central

    Sharpe, M. Elisabeth; Garvie, Ellen I.; Tilbury, R. H.

    1972-01-01

    Lactobacillus coprophilus subsp. confusus (NCDO 1586) and 18 other strains of slime-forming heterofermentative lactobacilli obtained from diverse sources are considered to form a new species on the basis of their physiological characteristics and similarities of their pyruvate reductases and lactate dehydrogenases. It is suggested that these strains should be named Lactobacillus confusus (Holzapfel & Kandler) comb. nov. (L. coprophilus subsp. confusus Holzapfel & Kandler), reasons being given. The type strain is NCDO 1586 (NCIB 9311, ATCC 10881). Strains of Lactobacillus vermiforme and Lactobacillus viridescens also form slime. However, L. vermiforme was readily separated from the other two by the criteria used. Although physiological characteristics separated L. viridescens from L. confusus, a relationship between these two species and also between them and the leuconostocs was indicated by the properties of the pyruvate reductases and lactate dehydrogenases. The slime produced by all species was found to be a glucan, probably a dextran, containing primarily α-1-6-glycosidic linkages. PMID:4259626

  20. Effects of Lactic Acid Bacteria on Residual Nitrite in a Summer Style Sausage.

    DTIC Science & Technology

    1984-01-01

    Lactobacillus leichmannii, Streptococcus faecalis, and several atypical lactobacilli isolated from fresh beef and mutton reduced 200-1000 ppm nitrite...faecalis and an atypical lactobacillus isolated from beef) showed abilities to reduce pH and residual nitrite to levels similar to L. plantarum and P...Leuconostoc mesenteroides reduced nitrite at a faster rate than either Lactobacillus plantarum or Lactobacillus viridescens, while Lactobacillus

  1. Cloning proenkephalin from the brain of a urodele amphibian (Taricha granulosa) using a DOR-specific primer in a 3'RACE reaction.

    PubMed

    Walthers, Eliza A; Moore, Frank L

    2005-07-01

    A large cDNA fragment that codes for proenkephalin (PENK) was cloned from the rough-skinned newt, Taricha granulosa (GenBank Accession: AY817670). This 1299-bp PENK cDNA extends from the poly(A) sequence on the 3' end into the 5'-UTR (221bp) upstream of an open reading frame that codes for 264 amino acids and a stop codon. Within the precursor are five Met-enkephalin sequences and two C-terminally extended forms of Met-enkephalin (YGGFMRGV and YGGFMRY). The organization of the opioid core sequences within the newt PENK closely resembles that reported for other vertebrates. In this urodele amphibian, as in anurans, PENK does not contain the penultimate Leu-enkephalin opioid sequence found in mammals, and instead has in this position Met-enkephalin. PENK cDNA was amplified from newt brain in a RACE PCR targeting the 3' end of the newt delta opioid receptor (DOR). It remains to be determined whether generating the cDNA for the newt PENK while cloning its receptor was serendipitous or the result of a meaningful coincidence between the DOR and PENK sequences.

  2. Efficient regeneration by activation of neurogenesis in homeostatically quiescent regions of the adult vertebrate brain.

    PubMed

    Berg, Daniel A; Kirkham, Matthew; Beljajeva, Anna; Knapp, Dunja; Habermann, Bianca; Ryge, Jesper; Tanaka, Elly M; Simon, András

    2010-12-01

    In contrast to mammals, salamanders and teleost fishes can efficiently repair the adult brain. It has been hypothesised that constitutively active neurogenic niches are a prerequisite for extensive neuronal regeneration capacity. Here, we show that the highly regenerative salamander, the red spotted newt, displays an unexpectedly similar distribution of active germinal niches with mammals under normal physiological conditions. Proliferation zones in the adult newt brain are restricted to the forebrain, whereas all other regions are essentially quiescent. However, ablation of midbrain dopamine neurons in newts induced ependymoglia cells in the normally quiescent midbrain to proliferate and to undertake full dopamine neuron regeneration. Using oligonucleotide microarrays, we have catalogued a set of differentially expressed genes in these activated ependymoglia cells. This strategy identified hedgehog signalling as a key component of adult dopamine neuron regeneration. These data show that brain regeneration can occur by activation of neurogenesis in quiescent brain regions.

  3. Exogenous Abscisic Acid Mimics Cold Acclimation for Cacti Differing in Freezing Tolerance.

    PubMed Central

    Loik, M. E.; Nobel, P. S.

    1993-01-01

    The responses to low temperature were determined for two species of cacti sensitive to freezing, Ferocactus viridescens and Opuntia ficus-indica, and a cold hardy species, Opuntia fragilis. Fourteen days after shifting the plants from day/night air temperatures of 30/20[deg]C to 10/0[deg]C, the chlorenchyma water content decreased only for O. fragilis. This temperature shift caused the freezing tolerance (measured by vital stain uptake) of chlorenchyma cells to be enhanced only by about 2.0[deg]C for F. viridescens and O. ficus-indica but by 14.6[deg]C for O. fragilis. Also, maintenance of high water content by injection of water into plants at 10/0[deg]C reversed the acclimation. The endogenous abscisic acid (ABA) concentration was below 0.4 pmol g-1 fresh weight at 30/20[deg]C, but after 14 d at 10/0[deg]C it increased to 84 pmol g-1 fresh weight for O. ficus-indica and to 49 pmol g-1 fresh weight for O. fragilis. Four days after plants were sprayed with 7.5 x 10-5 M ABA at 30/20[deg]C, freezing tolerance was enhanced by 0.5[deg]C for F. viridescens, 4.1[deg]C for O. ficus-indica, and 23.4[deg]C for O. fragilis. Moreover, the time course for the change in freezing tolerance over 14 d was similar for plants shifted to low temperatures as for plants treated with exogenous ABA at moderate temperatures. Decreases in plant water content and increases in ABA concentration may be important for low-temperature acclimation by cacti, especially O. fragilis, which is widely distributed in Canada and the United States. PMID:12231985

  4. The influence of different preservation methods on spoilage bacteria populations inoculated in morcilla de Burgos during anaerobic cold storage.

    PubMed

    Diez, Ana M; Jaime, Isabel; Rovira, Jordi

    2009-06-30

    Blood sausage is a widely consumed traditional product that would benefit from an extended shelf life. The two main spoilage bacteria in vacuum-packaged morcilla de Burgos are Weissella viridescens and Leuconostoc mesenteroides. This study examines the way in which three preservation treatments--organic acid salts (OAS), high-pressure processing (HPP) and pasteurization--influence these bacterial populations and their spoilage behaviour. HPP and pasteurization treatments were found to inhibit growth of the inoculated species and delay sensory spoilage of the product. In both treatments, L. mesenteroides was observed to have a longer recovery time; even so, once its growth started, it grew faster than W. viridescens. This longer recovery time might be due to metabolic modification following treatment, which would affect the production of metabolites such as acetic acid and some aldehydes. W. viridescens was the first strain to recover from the two treatments. It preserved its spoilage behaviour and even increased the production of certain compounds such as acetoin or ethanol. The extended product shelf life following HPP and pasteurization treatments might be due to a combination of various factors such as the fall in both microbial populations, as well as the delay in spoilage caused by damage to L. mesenteroides cells, as this strain is the fastest-acting, most intensive spoilage microorganism. It was observed that the addition of organic salts neither diminished nor delayed the growth of the two inoculated species. Nevertheless, the results also indicate that this treatment inhibits the metabolic activity of L. mesenteroides, resulting once again in an extended product shelf life.

  5. Exogenous Abscisic Acid Mimics Cold Acclimation for Cacti Differing in Freezing Tolerance.

    PubMed

    Loik, M. E.; Nobel, P. S.

    1993-11-01

    The responses to low temperature were determined for two species of cacti sensitive to freezing, Ferocactus viridescens and Opuntia ficus-indica, and a cold hardy species, Opuntia fragilis. Fourteen days after shifting the plants from day/night air temperatures of 30/20[deg]C to 10/0[deg]C, the chlorenchyma water content decreased only for O. fragilis. This temperature shift caused the freezing tolerance (measured by vital stain uptake) of chlorenchyma cells to be enhanced only by about 2.0[deg]C for F. viridescens and O. ficus-indica but by 14.6[deg]C for O. fragilis. Also, maintenance of high water content by injection of water into plants at 10/0[deg]C reversed the acclimation. The endogenous abscisic acid (ABA) concentration was below 0.4 pmol g-1 fresh weight at 30/20[deg]C, but after 14 d at 10/0[deg]C it increased to 84 pmol g-1 fresh weight for O. ficus-indica and to 49 pmol g-1 fresh weight for O. fragilis. Four days after plants were sprayed with 7.5 x 10-5 M ABA at 30/20[deg]C, freezing tolerance was enhanced by 0.5[deg]C for F. viridescens, 4.1[deg]C for O. ficus-indica, and 23.4[deg]C for O. fragilis. Moreover, the time course for the change in freezing tolerance over 14 d was similar for plants shifted to low temperatures as for plants treated with exogenous ABA at moderate temperatures. Decreases in plant water content and increases in ABA concentration may be important for low-temperature acclimation by cacti, especially O. fragilis, which is widely distributed in Canada and the United States.

  6. Effects of Temperature and Precipitation on Breeding Migrations of Amphibian Species in Southeastern Norway

    PubMed Central

    Dervo, Børre K.; Bærum, Kim Magnus; Skurdal, Jostein; Museth, Jon

    2016-01-01

    To reveal the effects of climate, a generalized linear mixed model was used to explore the variation in onset of spawning migration for the two newt species T. cristatus and L. vulgaris in southern Norway. Amphibians are highly influenced by the physical environment, such as temperature and rainfall. The first migrating newts were observed subsequently to the three first consecutive days with mean temperature close to or above 4°C. Further, migration of L. vulgaris was facilitated at lower temperatures compared to T. cristatus, but the migration was dependent on higher precipitation levels. Northern populations of T. cristatus and L. vulgaris may already benefit from a warmer climate due to increased recruitment and juvenile survival. However, an offset in the migration phenology due to climate change might further alter the recruitment and survival rates with either positive or negative outcome. Thus, variations in migration phenology for newts due to climate change may have implications for management and protection status in many systems. In a general context, we should increase emphasis on protecting newts and support increased populations and distribution. PMID:27239371

  7. New Host and Distribution Records of the Leech Placobdella sophieaeOceguera-Figueroa et al., 2010 (Hirudinida: Glossiphoniidae)

    USGS Publications Warehouse

    Moser, William E.; Bowerman, Jay; Hovingh, Peter; Pearl, Christopher A.; Oceguera-Figueroa, Alajandro

    2014-01-01

    Placobdella sophieae Oceguera-Figueroa et al., 2010 (Hirudinida: Glossiphoniidae) is reported from Oregon, California, and British Columbia for the first time. New hosts reported for P. sophieae include Taricha granulosa (rough-skinned newt), Rana pretiosa (Oregon spotted frog), and Anaxyrus boreas (western toad). Placobdella sophieae exhibits relatively low host specificity and all amphibians occurring in the Pacific Northwest are potential hosts.

  8. Validation of standardized computer analyses for licensing evaluation/TRITON two-dimensional and three-dimensional models for light water reactor fuel

    SciTech Connect

    Bowman, S. M.; Gill, D. F.

    2006-07-01

    The isotopic depletion capabilities of the new Standardized Computer Analyses for Licensing Evaluation control module TRITON, coupled with ORIGEN-S, were evaluated using spent fuel assays from several commercial light water reactors with both standard and mixed-oxide fuel assemblies. Calculations were performed using the functional modules NEWT and KENO-VI. NEWT is a two-dimensional, arbitrary-geometry, discrete-ordinates transport code, and KENO-VI is a three-dimensional Monte Carlo transport code capable of handling complex three-dimensional geometries. To validate the codes and data used in depletion calculations, numerical predictions were compared with experimental measurements for a total of 29 samples taken from the Calvert Cliffs, Obrigheim, and San Onofre pressurized water reactors and the Gundremmingen boiling water reactor. Similar comparisons have previously been performed at the Oak Ridge National Laboratory for the one-dimensional SAS2H control module. The SAS2H, TRITON/KENO-VI, and TRITON/NEWT results were compared for corresponding samples. All analyses showed that TRITON/KENO-VI and TRITON/NEWT produced typically similar or better results than SAS2H. The calculations performed in this validation study demonstrate that the depletion capabilities of TRITON accurately model spent fuel depletion and decay. (authors)

  9. Oocyte-type linker histone B4 is required for transdifferentiation of somatic cells in vivo.

    PubMed

    Maki, Nobuyasu; Suetsugu-Maki, Rinako; Sano, Shozo; Nakamura, Kenta; Nishimura, Osamu; Tarui, Hiroshi; Del Rio-Tsonis, Katia; Ohsumi, Keita; Agata, Kiyokazu; Tsonis, Panagiotis A

    2010-09-01

    The ability to reprogram in vivo a somatic cell after differentiation is quite limited. One of the most impressive examples of such a process is transdifferentiation of pigmented epithelial cells (PECs) to lens cells during lens regeneration in newts. However, very little is known of the molecular events that allow newt cells to transdifferentiate. Histone B4 is an oocyte-type linker histone that replaces the somatic-type linker histone H1 during reprogramming mediated by somatic cell nuclear transfer (SCNT). We found that B4 is expressed and required during transdifferentiation of PECs. Knocking down of B4 decreased proliferation and increased apoptosis, which resulted in considerable smaller lens. Furthermore, B4 knockdown altered gene expression of key genes of lens differentiation and nearly abolished expression of gamma-crystallin. These data are the first to show expression of oocyte-type linker histone in somatic cells and its requirement in newt lens transdifferentiation and suggest that transdifferentiation in newts might share common strategies with reprogramming after SCNT.

  10. [Biologically Active Peptides of King Crab Hepatopancreas].

    PubMed

    Bogdanov, V V; Berezin, B B; Il'ina, A P; Yamskova, V P; Yamskov, I A

    2015-01-01

    Substances of a peptide nature isolated from the hepatopancreas of the king crab Paralithodes camtschaticus exhibited physicochemical properties and membranotropic and specific activities similar to those of membranotropic homeostatic tissue-specific bioregulators previously found in different mammalian and plant tissues. Their biological effect on vertebrate tissues was demonstrated on a model of roller organotypic cultivation of Pleurodeles waltl newt liver tissue.

  11. Phase-II conjugation ability for PAH metabolism in amphibians: characteristics and inter-species differences.

    PubMed

    Ueda, Haruki; Ikenaka, Yoshinori; Nakayama, Shouta M M; Tanaka-Ueno, Tomoko; Ishizuka, Mayumi

    2011-10-01

    The present study examines amphibian metabolic activity - particularly conjugation - by analysis of pyrene (a four ring, polycyclic aromatic hydrocarbon) metabolites using high-performance liquid chromatography (HPLC) with fluorescence detector (FD), a mass spectrometry detector (MS) system and kinetic analysis of conjugation enzymes. Six amphibian species were exposed to pyrene (dissolved in water): African claw frog (Xenopus laevis); Tago's brown frog (Rana tagoi); Montane brown frog (Rana ornativentris); Wrinkled frog (Rana rugosa); Japanese newt (Cynops pyrrhogaster); and Clouded salamander (Hynobius nebulosus); plus one fish species, medaka (Oryzias latipes); and a fresh water snail (Clithon retropictus), and the resultant metabolites were collected. Identification of pyrene metabolites by HPLC and ion-trap MS system indicated that medaka mainly excreted pyrene-1-glucuronide (PYOG), while pyrene-1-sulfate (PYOS) was the main metabolite in all amphibian species. Pyrene metabolites in amphibians were different from those in invertebrate fresh water snails. Inter-species differences were also observed in pyrene metabolism among amphibians. Metabolite analysis showed that frogs relied more strongly on sulfate conjugation than did Japanese newts and clouded salamanders. Furthermore, urodelan amphibians, newts and salamanders, excreted glucose conjugates of pyrene that were not detected in the anuran amphibians. Kinetic analysis of conjugation by hepatic microsomes and cytosols indicated that differences in excreted metabolites reflected differences in enzymatic activities. Furthermore, pyrenediol (PYDOH) glucoside sulfate was detected in the Japanese newt sample. This novel metabolite has not been reported previously to this report, in which we have identified unique characteristics of amphibians in phase II pyrene metabolism.

  12. All about Amphibians. Animal Life for Children. [Videotape].

    ERIC Educational Resources Information Center

    2000

    This videotape teaches children about their favorite amphibious creatures, as well as amphibians' nearest cousins--toads, newts, and salamanders. Young students discover how these amazing creatures can live both in and out of water, learn about the amphibious life cycle, and compare the differences between amphibians and reptiles. This videotape…

  13. Space: The Final Frontier!

    ERIC Educational Resources Information Center

    Roy, Ken

    2003-01-01

    Discusses the importance of laboratory safety in science classrooms. Urges middle school teachers to address class size in an effort to establish and maintain a safe working environment. Answers a teacher's question related to having newts and salamanders in the classroom. (SOE)

  14. Studies on clonogenic hemopoietic cells of vertebrate in space: problems and perspectives

    NASA Astrophysics Data System (ADS)

    Domaratskaya, E. I.; Michurina, T. V.; Bueverova, E. I.; Bragina, E. V.; Nikonova, T. A.; Starostin, V. I.; Khrushchov, N. G.

    Hemopoietic tissues were studied in vertebrates launched aboard the Soviet (Russian) biosatellites ("Cosmos-1129, 1514, 1667, 1887 and 2044"; "Bion-10 and 11") between 1980 and 1996. In the bone marrow of rats exposed to spaceflight conditions, a statistically significant decrease in cell number was revealed in the progenitor cell compartment accounting for the compensatory response of granulocyte—macrophage (CFU-gm) and erythrocyte lineages (BFU-e and CFU-e) and in the compartment of multipotent hemopoietic stem cells (CFU-s), which is responsible for the permanent renewal of hemopoietic tissue. The number of stromal fibroblastic progenitors (CFC-f) in the bone marrow of these rats was also reduced. Apparently, changes in the hemopoietic stroma damage the hemopoietic microenvironment and, hence, may be responsible for changes observed in the hemopoietic tissue proper. Attempts were made to develop methods for analyzing morphologically indiscernible clonogenic hemopoietic cells of newts, and studies on the effects of spaceflight factors on these cells were performed. The results showed that the numbers of clonogenic cells in newts of the flight group newts were significantly lower than in control newts. The data obtained are used as the basis for formulating the problems to be studied, drawing up a program for further research on the effects of spaceflight factors on stem and other clonogenic hemopoietic cells, and developing new experimental models for analyzing stem cells, the state of the hemopoietic stroma, etc.

  15. Slouching toward Bork: The Culture Wars and Self-Criticism in Hip-Hop Music.

    ERIC Educational Resources Information Center

    Ogbar, Jeffrey O. G.

    1999-01-01

    Examined the marginalized voices of hip-hop artists in the culture war debates of the 1990s. Explores the efficacy of those voices and reveals how they differ from the typical parameter of public debate. Discusses the attacks on rap by right wing thinkers, such as Newt Gingrich and Robert Bork. (SLD)

  16. Extracellular Control of Limb Regeneration

    NASA Astrophysics Data System (ADS)

    Calve, S.; Simon, H.-G.

    Adult newts possess the ability to completely regenerate organs and appendages. Immediately after limb loss, the extracellular matrix (ECM) undergoes dramatic changes that may provide mechanical and biochemical cues to guide the formation of the blastema, which is comprised of uncommitted stem-like cells that proliferate to replace the lost structure. Skeletal muscle is a known reservoir for blastema cells but the mechanism by which it contributes progenitor cells is still unclear. To create physiologically relevant culture conditions for the testing of primary newt muscle cells in vitro, the spatio-temporal distribution of ECM components and the mechanical properties of newt muscle were analyzed. Tenascin-C and hyaluronic acid (HA) were found to be dramatically upregulated in the amputated limb and were co-expressed around regenerating skeletal muscle. The transverse stiffness of muscle measured in situ was used as a guide to generate silicone-based substrates of physiological stiffness. Culturing newt muscle cells under different conditions revealed that the cells are sensitive to both matrix coating and substrate stiffness: Myoblasts on HA-coated soft substrates display a rounded morphology and become more elongated as the stiffness of the substrate increases. Coating of soft substrates with matrigel or fibronectin enhanced cell spreading and eventual cell fusion.

  17. Perspectives: Readings on Contemporary American Government [and] Teacher's Guide.

    ERIC Educational Resources Information Center

    Close Up Foundation, Alexandria, VA.

    This student reader accompanies a teacher's guide of the same name. The essays in this book provide firsthand perspectives on how the federal government works. Essays by President Bill Clinton, Speaker of the House Newt Gingrich, justices of the Supreme Court, journalists, lobbyists, and others who take an active role in this nation's democracy…

  18. Expression of sexual ornaments in a polymorphic species: phenotypic variation in response to environmental risk.

    PubMed

    Winandy, L; Denoël, M

    2015-05-01

    Secondary sexual traits may evolve under the antagonistic context of sexual and natural selection. In some polymorphic species, these traits are only expressed during the breeding period and are differently expressed in alternative phenotypes. However, it is unknown whether such phenotypes exhibit phenotypic plasticity of seasonal ornamentations in response to environmental pressures such as in the presence of fish (predation risk). This is an important question to understand the evolution of polyphenisms. We used facultative paedomorphosis in newts as a model system because it involves the coexistence of paedomorphs that retain gills in the adult stage with metamorphs that have undergone metamorphosis, but also because newts exhibit seasonal sexual traits. Our aim was therefore to determine the influence of fish on the development of seasonal ornamentation in the two phenotypes of the palmate newt (Lissotriton helveticus). During the entire newt breeding period, we assessed the importance of phenotype and fish presence with an information-theoretic approach. Our results showed that paedomorphs presented much less developed ornamentation than metamorphs and those ornamentations varied over time. Fish inhibited the development of sexual traits but differently between phenotypes: in contrast to metamorphs, paedomorphs lack the phenotypic plasticity of sexual traits to environmental risk. This study points out that internal and external parameters act in complex ways in the expression of seasonal sexual ornamentations and that similar environmental pressure can induce a contrasted evolution in alternative phenotypes.

  19. Fine-scale selection by ovipositing females increases egg survival

    PubMed Central

    Gall, Brian G; Brodie, Edmund D; Brodie, Edmund D

    2012-01-01

    One of the most important defenses for the eggs of ovipositing female organisms is to avoid being laid in the same habitat as their predators. However, for most organisms, completely avoiding an offspring's predators is not possible. One mechanism that has been largely overlooked is for females to partition an oviposition site into microhabitats that differ in quality for offspring survival. We conducted a series of experiments to examine whether female newts avoid microhabitats utilized by their offspring's primary predator, caddisfly larvae. Female newts avoided laying eggs near predatory caddisflies and shifted egg laying upward in the water column when provided with a vertical dimension. Caddisflies were attracted to chemical stimuli from female newts and their eggs, yet primarily used benthic areas in experimental chambers. Finally, results from a field experiment indicate that the behavioral strategy employed by female newts increases offspring survival. This subset of non-genetic maternal effects, micro-oviposition avoidance, is likely an important yet underexplored mechanism by which females increase offspring survival. PMID:23170211

  20. Physiological Responses to Salinity Vary with Proximity to the Ocean in a Coastal Amphibian.

    PubMed

    Hopkins, Gareth R; Brodie, Edmund D; Neuman-Lee, Lorin A; Mohammadi, Shabnam; Brusch, George A; Hopkins, Zoë M; French, Susannah S

    2016-01-01

    Freshwater organisms are increasingly exposed to elevated salinity in their habitats, presenting physiological challenges to homeostasis. Amphibians are particularly vulnerable to osmotic stress and yet are often subject to high salinity in a variety of inland and coastal environments around the world. Here, we examine the physiological responses to elevated salinity of rough-skinned newts (Taricha granulosa) inhabiting a coastal stream on the Pacific coast of North America and compare the physiological responses to salinity stress of newts living in close proximity to the ocean with those of newts living farther upstream. Although elevated salinity significantly affected the osmotic (body weight, plasma osmolality), stress (corticosterone), and immune (bactericidal ability) responses of newts, animals found closer to the ocean were generally less reactive to salt stress than those found farther upstream. Our results provide possible evidence for some physiological tolerance in this species to elevated salinity in coastal environments. As freshwater environments become increasingly saline and more stressful, understanding the physiological tolerances of vulnerable groups such as amphibians will become increasingly important to our understanding of their abilities to respond, to adapt, and, ultimately, to survive.

  1. A comparative study of gland cells implicated in the nerve dependence of salamander limb regeneration.

    PubMed

    Kumar, Anoop; Nevill, Graham; Brockes, Jeremy P; Forge, Andrew

    2010-07-01

    Limb regeneration in salamanders proceeds by formation of the blastema, a mound of proliferating mesenchymal cells surrounded by a wound epithelium. Regeneration by the blastema depends on the presence of regenerating nerves and in earlier work it was shown that axons upregulate the expression of newt anterior gradient (nAG) protein first in Schwann cells of the nerve sheath and second in dermal glands underlying the wound epidermis. The expression of nAG protein after plasmid electroporation was shown to rescue a denervated newt blastema and allow regeneration to the digit stage. We have examined the dermal glands by scanning and transmission electron microscopy combined with immunogold labelling of the nAG protein. It is expressed in secretory granules of ductless glands, which apparently discharge by a holocrine mechanism. No external ducts were observed in the wound epithelium of the newt and axolotl. The larval skin of the axolotl has dermal glands but these are absent under the wound epithelium. The nerve sheath was stained post-amputation in innervated but not denervated blastemas with an antibody to axolotl anterior gradient protein. This antibody reacted with axolotl Leydig cells in the wound epithelium and normal epidermis. Staining was markedly decreased in the wound epithelium after denervation but not in the epidermis. Therefore, in both newt and axolotl the regenerating axons induce nAG protein in the nerve sheath and subsequently the protein is expressed by gland cells, under (newt) or within (axolotl) the wound epithelium, which discharge by a holocrine mechanism. These findings serve to unify the nerve dependence of limb regeneration.

  2. The spoilage microflora of cured, cooked turkey breasts prepared commercially with or without smoking.

    PubMed

    Samelis, J; Kakouri, A; Rementzis, J

    2000-06-01

    Lactobacillus sakei subsp. carnosus was predominant in the spoilage flora of sliced, vacuum-packed, smoked, oven-cooked turkey breast fillets which developed mild, sour spoilage flavors after 4 weeks storage at 4 degrees C. In contrast, Leuconostoc mesenteroides subsp. mesenteroides predominated in the spoilage flora of sliced, vacuum-packed, unsmoked, boiled turkey breast fillets from the same plant which were also stored at 4 degrees C. The spoilage flora of the unsmoked breasts grew faster than that of the smoked breasts and was more diverse. Lactobacillus sakei, Weissella viridescens and an atypical group of leuconostoc-like bacteria were also members of the unsmoked turkey breasts flora. Consequently, the unsmoked breasts spoiled after 2 weeks at 4 degrees C: the packs swelled and the meat developed strong sour odors and flavors and abundant slime. Except for the unidentified leuconostocs, which apparently survived boiling of the unsmoked turkey, all the spoilage organisms contaminated the meats during the slicing and vacuum packaging operations. From their biochemical reactions and cellular fatty acid profiles, the atypical leuconostocs were more closely related to Leuconostoc carnosum than W. viridescens. Carnobacteria and Brochothrix thermosphacta were present in relatively large numbers on the raw turkey, but were not numerous in the spoilage flora of the cooked, vacuum-packed meat products.

  3. Effect of high pressure on the microbiological quality of cooked chicken during storage at normal and abuse refrigeration temperatures.

    PubMed

    Patterson, Margaret F; McKay, Alan M; Connolly, Malachy; Linton, Mark

    2010-04-01

    Vacuum-packaged cooked poultry meat was treated at a range of pressures (400-600 MPa) and hold times (1, 2 and 10 min), followed by storage at 4 degrees , 8 degrees or 12 degrees C for up to 35 days. Weissella viridescens was found to be the dominant microorganism in the pressure-treated meat, constituting 100% of the microflora identified at 500 and 600 MPa. None of the pressure-treated samples had obvious signs of spoilage during the 35 day storage period, even when the Weissella count was >7 log(10) cfu/g. Studies on a typical W. viridescens isolate showed it to be relatively pressure-resistant in poultry meat, with <1 log reduction in numbers after a treatment of 2 min at 600 MPa. Agar diffusion assays showed that the isolate also caused the inhibition of a number of Gram-positive and Gram-negative pathogens, including strains of Clostridium botulinum, Listeria monocytogenes, Bacillus cereus and Escherichia coli. The selection of a pressure-resistant organism, such as this Weissella sp. could be advantageous in extending the shelf-life, and also microbiological safety, of the cooked meat, as it could give protection in addition to the pressure treatment itself.

  4. Use of Potential Probiotic Lactic Acid Bacteria (LAB) Biofilms for the Control of Listeria monocytogenes, Salmonella Typhimurium, and Escherichia coli O157:H7 Biofilms Formation.

    PubMed

    Gómez, Natacha C; Ramiro, Juan M P; Quecan, Beatriz X V; de Melo Franco, Bernadette D G

    2016-01-01

    Use of probiotic biofilms can be an alternative approach for reducing the formation of pathogenic biofilms in food industries. The aims of this study were (i) to evaluate the probiotic properties of bacteriocinogenic (Lactococcus lactis VB69, L. lactis VB94, Lactobacillus sakei MBSa1, and Lactobacillus curvatus MBSa3) and non-bacteriocinogenic (L. lactis 368, Lactobacillus helveticus 354, Lactobacillus casei 40, and Weissela viridescens 113) lactic acid bacteria (LAB) isolated from Brazilian's foods and (ii) to develop protective biofilms with these strains and test them for exclusion of Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella Typhimurium. LAB were tested for survival in acid and bile salt conditions, surface properties, biosurfactant production, β-galactosidase and gelatinase activity, antibiotic resistance and presence of virulence genes. Most strains survived exposure to pH 2 and 4% bile salts. The highest percentages of auto-aggregation were obtained after 24 h of incubation. Sixty-seven percentage auto-aggregation value was observed in W. viridescens 113 and Lactobacillus curvatus MBSa3 exhibited the highest co-aggregation (69% with Listeria monocytogenes and 74.6% with E. coli O157:H7), while the lowest co-aggregation was exhibited by W. viridescens 113 (53.4% with Listeria monocytogenes and 38% with E. coli O157:H7). Tests for hemolytic activity, bacterial cell adherence with xylene, and drop collapse confirmed the biosurfactant-producing ability of most strains. Only one strain (L. lactis 368) produced β-galactosidase. All strains were negative for virulence genes cob, ccf, cylLL, cylLs, cyllM, cylB, cylA and efaAfs and gelatinase production. The antibiotic susceptibility tests indicated that the MIC for ciprofloxacin, clindamycin, gentamicin, kanamycin, and streptomycin did not exceed the epidemiological cut-off suggested by the European Food Safety Authority. Some strains were resistant to one or more antibiotics and resistance

  5. Use of Potential Probiotic Lactic Acid Bacteria (LAB) Biofilms for the Control of Listeria monocytogenes, Salmonella Typhimurium, and Escherichia coli O157:H7 Biofilms Formation

    PubMed Central

    Gómez, Natacha C.; Ramiro, Juan M. P.; Quecan, Beatriz X. V.; de Melo Franco, Bernadette D. G.

    2016-01-01

    Use of probiotic biofilms can be an alternative approach for reducing the formation of pathogenic biofilms in food industries. The aims of this study were (i) to evaluate the probiotic properties of bacteriocinogenic (Lactococcus lactis VB69, L. lactis VB94, Lactobacillus sakei MBSa1, and Lactobacillus curvatus MBSa3) and non-bacteriocinogenic (L. lactis 368, Lactobacillus helveticus 354, Lactobacillus casei 40, and Weissela viridescens 113) lactic acid bacteria (LAB) isolated from Brazilian’s foods and (ii) to develop protective biofilms with these strains and test them for exclusion of Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella Typhimurium. LAB were tested for survival in acid and bile salt conditions, surface properties, biosurfactant production, β-galactosidase and gelatinase activity, antibiotic resistance and presence of virulence genes. Most strains survived exposure to pH 2 and 4% bile salts. The highest percentages of auto-aggregation were obtained after 24 h of incubation. Sixty-seven percentage auto-aggregation value was observed in W. viridescens 113 and Lactobacillus curvatus MBSa3 exhibited the highest co-aggregation (69% with Listeria monocytogenes and 74.6% with E. coli O157:H7), while the lowest co-aggregation was exhibited by W. viridescens 113 (53.4% with Listeria monocytogenes and 38% with E. coli O157:H7). Tests for hemolytic activity, bacterial cell adherence with xylene, and drop collapse confirmed the biosurfactant-producing ability of most strains. Only one strain (L. lactis 368) produced β-galactosidase. All strains were negative for virulence genes cob, ccf, cylLL, cylLs, cyllM, cylB, cylA and efaAfs and gelatinase production. The antibiotic susceptibility tests indicated that the MIC for ciprofloxacin, clindamycin, gentamicin, kanamycin, and streptomycin did not exceed the epidemiological cut-off suggested by the European Food Safety Authority. Some strains were resistant to one or more antibiotics and

  6. Correlations of geographic distribution and temperature of embryonic development with the nuclear DNA content in the Salamandridae (Urodela, Amphibia).

    PubMed

    Litvinchuk, Spartak N; Rosanov, Jury M; Borkin, Leo J

    2007-04-01

    We used flow cytometry to measure the nuclear DNA content in erythrocytes of 27 salamandrid species. Across these species, diploid genome size varied more than 2 fold (51.3-104.4 pg). According to genome size and geographic distribution, 3 groups of newt species were recognized: West Palearctics with smaller amounts of nuclear DNA; Nearctic, with intermediate values; and East Asiatic, with higher genome sizes. Viviparous West Palearctic salamanders differed from most of the oviparous West Palearctic newts in possessing larger genome sizes. The nuclear DNA content strongly correlates with species range limits. At the same temperature, embryos of salamandrid species with larger genome sizes have a markedly longer developmental time than those with smaller genomes. We present an analysis of the relationships between the amount of nuclear DNA and water temperature at the breeding sites.

  7. [Peptide-containing fraction from a culture medium of Fusarium sambucinum: composition and biological effects].

    PubMed

    Bogdanov, V V; Fatkulina, É F; Berezin, B B; Il'ina, A P; Iamskova, V P; Iamskov, I A

    2014-01-01

    The culture fluid of the fungus Fusarium sambucinum was investigated for the presence of new peptide-containing bioregulators, previously identified in various mammalian and plant tissues. A fraction containing peptides with molecular weights from 1000 to 2000 Da, which exhibited specific membranotropic activity and a number of physical and chemical properties characteristic of this group of bioregulators, was obtained. The effects of this fraction on the model roller organotypic cultivation of liver tissue of the Pleurodeles waltl newt in vitro were investigated for the first time. This fraction caused the additional activation of pigmented liver cells of newt (analogues to Kupffer cells of the liver of mammals) and provided the maintenance of cell-cell adhesive interactions in tissues. The results show that a new group of peptide bioregulators was present in the culture medium of the fungus F. sambucinum.

  8. NASDA aquatic animal experiment facilities for Space Shuttle.

    PubMed

    Sakimura, T; Suzuki, T; Matsubara, S; Uchida, S; Kato, M; Tanemura, R; Honda, S

    1999-12-01

    National Space Development Agency of Japan (NASDA) has been developed aquatic animal experiment facilities for space experiments using NASA Space Shuttle. Vestibular Function Experiment Unit (VFEU) has been firstly designed and developed for Spacelab-J mission (STS-47), and 8 days space experiment with carp has been performed. Following, the VFEU, Aquatic Animal Experiment Unit (AAEU) has been developed to accommodate small aquatic animals second International Microgravity Laboratory mission (IML-2, STS-65). Four kinds of space experiments with goldfish, medaka, newt, and newt eggs have been performed for 15 days mission duration. Then, VFEU has been improved to accommodate marine fish under low temperature condition for Neurolab (STS-90) and STS-95 missions. 17 days (STS-90) and 9 days (STS-95) experiments with oyster toadfish have been performed by using the VFEU. This report summarizes the outline of these aquatic animal experiment facilities.

  9. Interactive influence of biotic and abiotic cues on the plasticity of preferred body temperatures in a predator-prey system.

    PubMed

    Smolinský, Radovan; Gvoždík, Lumír

    2012-09-01

    The ability to modify phenotypes in response to heterogeneity of the thermal environment represents an important component of an ectotherm's non-genetic adaptive capacity. Despite considerable attention being dedicated to the study of thermally-induced developmental plasticity, whether or not interspecific interactions shape the plastic response in both a predator and its prey remains unknown. We tested several predictions about the joint influence of predator/prey scents and thermal conditions on the plasticity of preferred body temperatures (T (p)) in both actors of this interaction, using a dragonfly nymphs-newt larvae system. Dragonfly nymphs (Aeshna cyanea) and newt eggs (Ichthyosaura alpestris) were subjected to fluctuating cold and warm thermal regimes (7-12 and 12-22°C, respectively) and the presence/absence of a predator or prey chemical cues. Preferred body temperatures were measured in an aquatic thermal gradient (5-33°C) over a 24-h period. Newt T (p) increased with developmental temperature irrespective of the presence/absence of predator cues. In dragonflies, thermal reaction norms for T (p) were affected by the interaction between temperature and prey cues. Specifically, the presence of newt scents in cold regime lowered dragonfly T (p). We concluded that predator-prey interactions influenced thermally-induced plasticity of T (p) but not in a reciprocal fashion. The occurrence of frequency-dependent thermal plasticity may have broad implications for predator-prey population dynamics, the evolution of thermal biology traits, and the consequences of sustaining climate change within ecological communities.

  10. International Drug Trafficking--a Growing National Security Concern for Low Intensity Conflict

    DTIC Science & Technology

    1990-03-01

    aptly noted by Representative Newt Gingrich, "...using the military in a long-term war against corruption will corrupt them." Is continued military...terms with the drug problem In its essence: use Itself. Worthy !fibrts to alleviate the symptoms of epidemic drug abuse - crime and disease, for...keep those Americans - and their children after them - safe and secure from the poison of drug trafficking and drug use. But government also has an

  11. 78 FR 26359 - FFP Project 111, LLC; Notice of Preliminary Permit Application Accepted for Filing and Soliciting...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-06

    ... wall; (2) a 100-foot-long overflow bank extension connecting the dam to the powerhouse; (3) a 140-foot...; (4) a 1,000-foot-long, 220-foot-wide tailrace with a 40- foot-long retaining wall; (5) a 4.16/99 kilo... annual generation of 32, 300 megawatt-hours, and utilize surplus water from the Newt Graham Lock and...

  12. Flight Model Discharge System.

    DTIC Science & Technology

    1987-04-01

    will immediately remove the charge from the front surface of the dielectric and return it to ground. The 2-hour time constant network will then reset the...ATDP programs. NEWT5 permits the digitized input of board and component position data, while ATDP automates certain phases of input and output table...format. 8.5 RESULTS The system-level results are presented as curves of AR (normalized radiator area) versus THOT and as curves of Q (heater

  13. Global Entrepreneurship and the United States

    DTIC Science & Technology

    2010-09-01

    number of extraordinary high-growth entrepreneurial 4 ventures, called “ gazelles .”2 2.1. Assessing Entrepreneurship At the outset of this paper, we...production processes is another important feature of businesses with high growth potential (Acs and Varga 2005). The role of “ gazelles ” or high-growth...0.80 0.90 1.00 OPPORTUNITY SKILL NONFEAR KNOWENT CARSTAT TEAOPPORT TECHSECT HIGHEDUC COMPET NEWP NEWT GAZELLE EXPORT INFINV INDIVIDUAL

  14. New animal model to study epigenetic mechanisms mediating altered gravity effects upon cell growth and morphogenesis

    NASA Astrophysics Data System (ADS)

    Grigoryan, Eleonora N.; Dvorochkin, Natasha; Radugina, Elena A.; Poplinskaya, Valentina; Novikova, Julia; Almeida, Eduardo

    The gravitational field and its variations act as a major environmental factor that can impact morphogenesis developing through epigenetic molecular mechanisms. The mechanisms can be thoroughly investigated by using adequate animal models that reveal changes in the morpho-genesis of a growing organ as a function of gravitational effects. Two cooperative US/Russian experiments on Foton-M2 (2005) and Foton-M3 (2007) were the first to demonstrate differences in the shape of regenerating tails of space-flown and ground control newts. The space-flown and aquarium (simulated microgravity) animals developed lancet-shaped tails whereas 1 g con-trols (kept in space-type habitats) showed hook-like regenerates. These visual observations were supported by computer-aided processing of the images and statistical analysis of the results. Morphological examinations and cell proliferation measurements using BrdU demon-strated dorsal-ventral asymmetry as well as enhanced epithelial growth on the dorsal area of regenerating tails in 1 g newts. These findings were reproduced in laboratory tests on newts kept at 1 g and in large water tanks at cut g. The 1 g animals showed statistically significant deviations of the lancet-like tail shape typically seen in aquarium animals. Such modifications were found as early as regeneration stages III-IV and proved irreversible. The authors believe that the above phenomenon detected in newts used in many space experiments can serve as an adequate model for studying molecular mechanisms underlying gravitational effects upon animal morphogenesis.

  15. Three-dimensional holographic reconstruction of two-dimensional image information from serial sections and its applications in biomedicine

    NASA Astrophysics Data System (ADS)

    Zhou, Guo-Ping

    1985-02-01

    An experimental study to synthesize holographically two-dimensional projections of serial sections at various depths into three-dimensional images is described. The effects caused by the position, size and resolution of virtual images during reconstruction are analysed, and the advantages and limitations of this method are discussed. An application of this experimental method — the three-dimensional reconstruction of serial sections of a newt embryo — is presented.

  16. Regeneration of organs and tissues in lower vertebrates during and after space flight

    NASA Astrophysics Data System (ADS)

    Mitashov, V. I.; Brushlinskaya, N. V.; Grigoryan, E. N.; Tuchkova, S. Ya.; Anton, H. J.

    In this paper most important data obtained in studies on the effect of space flight conditions on regeneration in the adult newt are summarized. We demonstrate a phenomenon of synchronization of limb and lens regeneration and increase in its rate during and after space flight. We also describe a peculiarities of cell proliferation in lens, limb and tail regenerates and of the process of minced muscle regeneration.

  17. STS-65 onboard: IML-2

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Onboard Space Shuttle Columbia (STS-65) Mission specialist Leroy Chiao is seen in the International Microgravity Laboratory 2 (IML-2) spacelab science moduel in front of Rack 3 and above center aisle equipment. Chiao has just made an observation of the goldfish container (silver apparatus on left beween his right hand and knee) . The Rack 3 Aquatic Animal Experiment Unit (AAEU) also contains Medaka and newts. Chiao joined five other NASA astronauts and a Japanese payload specialist for two weeks of experimenting.

  18. Development of Gravity-Sensing Organs in Altered Gravity

    NASA Technical Reports Server (NTRS)

    Wiederhold, M. L.; Gao, W. Y.; Harrison, J. L.; Hejl, R.

    1996-01-01

    Experiments are described in which the development of the gravity-sensing organs was studied in newt larvae reared in micro-g on the IML-2 mission and in Aplysia embryos and larvae reared on a centrifuge at 1 to 5 g. In Aplysia embryos, the statolith (single dense mass on which gravity and linear acceleration act) was reduced in size in a graded fashion at increasing g. In early post-metamorphic Aplysia or even in isolated statocysts from such animals, the number of statoconia produced is reduced at high gravity Newt larvae launched before any of the otoconia were formed and reared for 15 days in micro-gravity had nearly adult labyrinths at the end of the IML-2 mission. The otoliths of the saccule and utricle were the same size in flight and ground-reared larvae. However, the system of aragonitic otoconia produced in the endolymphatic sac in amphibians was much larger and developed earlier in the flight-reared larvae. At later developmental stages, the aragonitic otoconia enter and fill the saccule. One flight-reared larva was maintained for nine months post-flight and the size of the saccular otolith, as well as the volume of otoconia within the endolymphatic sac, were considerably larger than in age-matched, ground-reared newts. This suggests that rearing in micro-gravity initiates a process that continues for several months after introduction to 1-g, which greatly increases the volume of otoconia. The flight-reared animal had abnormal posture, pointing its head upward, whereas normal ground-reared newts always keep their head horizontal. This suggests that rearing for even a short period in micro-gravity can have lasting functional consequences in an animal subsequently reared in 1-g conditions on Earth.

  19. Development of gravity-sensing organs in altered gravity

    NASA Technical Reports Server (NTRS)

    Wiederhold, M. L.; Gao, W. Y.; Harrison, J. L.; Hejl, R.

    1997-01-01

    Experiments are described in which the development of the gravity-sensing organs was studied in newt larvae reared in microgravity on the IML-2 mission and in Aplysia embryos and larvae reared on a centrifuge at 1 to 5 g. In Aplysia embryos, the statolith (single dense mass on which gravity and linear acceleration act) was reduced in size in a graded fashion at increasing g. In early post-metamorphic Aplysia or even in isolated statocysts from such animals, the number of statoconia produced is reduced at high g. Newt larvae launched before any of the otoconia were formed and reared for 15 days in microgravity had nearly adult labyrinths at the end of the IML-2 mission. The otoliths of the saccule and utricle were the same size in flight and ground-reared larvae. However, the system of aragonitic otoconia produced in the endolymphatic sac in amphibians was much larger and developed earlier in the flight-reared larvae. At later developmental stages, the aragonitic otoconia enter and fill the saccule. One flight-reared larva was maintained for nine months post-flight and the size of the saccular otolith, as well as the volume of otoconia within the endolymphatic sac, were considerably larger than in age-matched, ground-reared newts. This suggests that rearing in microgravity initiates a process that continues for several months after introduction to 1-g, which greatly increases the volume of otoconia. The flight-reared animal had abnormal posture, pointing its head upward, whereas normal ground-reared newts always keep their head horizontal. This suggests that rearing for even a short period in microgravity can have lasting functional consequences in an animal subsequently reared in 1-g conditions on Earth.

  20. India as a Responsible Nuclear Power: A Strategy for Stability

    DTIC Science & Technology

    2002-12-01

    Westview Press, Inc.,1991) 306 & 308. 70 Ibid., 12. 71 Newt Gingrich, quoted in Barbara Conry “U.S. "Global Leadership": A Euphemism for World...unable to link its Kargil caper with a nuclear flashpoint, though some foreign observers believe it was a near thing” The Kargil Review Committee...On-line. Internet. Available from http://www.rand.org// Conry, Barbara , U.S. "Global Leadership":A Euphemism for World Policeman . Policy

  1. Program Aids Analysis And Optimization Of Design

    NASA Technical Reports Server (NTRS)

    Rogers, James L., Jr.; Lamarsh, William J., II

    1994-01-01

    NETS/ PROSSS (NETS Coupled With Programming System for Structural Synthesis) computer program developed to provide system for combining NETS (MSC-21588), neural-network application program and CONMIN (Constrained Function Minimization, ARC-10836), optimization program. Enables user to reach nearly optimal design. Design then used as starting point in normal optimization process, possibly enabling user to converge to optimal solution in significantly fewer iterations. NEWT/PROSSS written in C language and FORTRAN 77.

  2. A critical role for thrombin in vertebrate lens regeneration.

    PubMed Central

    Imokawa, Yutaka; Simon, András; Brockes, Jeremy P

    2004-01-01

    Lens regeneration in urodele amphibians such as the newt proceeds from the dorsal margin of the iris where pigment epithelial cells (PEC) re-enter the cell cycle and transdifferentiate into lens. A general problem in regeneration research is to understand how the events of tissue injury or removal are coupled to the activation of plasticity in residual differentiated cells or stem cells. Thrombin, a pivotal regulator of the injury response, has been implicated as a regulator of cell cycle re-entry in newt myotubes, and also in newt iris PEC. After removal of the lens, thrombin was activated on the dorsal margin for 5-7 days. Inactivation of thrombin by either of two different inhibitors essentially blocked S-phase re-entry by PEC at this location. The axolotl, a related species which can regenerate its limb but not its lens, can activate thrombin after amputation but not after lens removal. These data support the hypothesis that thrombin is a critical signal linking injury to regeneration, and offer a new perspective on the evolutionary and phylogenetic questions about regeneration. PMID:15293804

  3. Expression of pax-6 during urodele eye development and lens regeneration.

    PubMed Central

    Del Rio-Tsonis, K; Washabaugh, C H; Tsonis, P A

    1995-01-01

    Regeneration of eye tissues, such as lens, seen in some urodeles involves dedifferentiation of the dorsal pigmented epithelium and subsequent differentiation to lens cells. Such spatial regulation implies possible action of genes known to be specific for particular cell lineages and/or axis. Hox genes have been the best examples of genes for such actions. We have, therefore, investigated the possibility that such genes are expressed during lens regeneration in the newt. The pax-6 gene (a gene that contains a homeobox and a paired box) has been implicated in the development of the eye and lens determination in various species ranging from Drosophila to human and, because of these properties, could be instrumental in the regeneration of the urodele eye tissues as well. We present data showing that pax-6 transcripts are present in the developing and the regenerating eye tissues. Furthermore, expression in eye tissues, such as in retina, declines when a urodele not capable of lens regeneration (axolotl) surpasses the embryonic stages. Such a decline is not seen in adult newts capable of lens regeneration. This might indicate a vital role of pax-6 in newt lens regeneration. Images Fig. 2 Fig. 3 PMID:7761453

  4. Identification of a retroviroid-like element from plants.

    PubMed

    Daròs, J A; Flores, R

    1995-07-18

    The biological nature of carnation small viroid-like RNA (CarSV RNA), a 275-nt circular molecule with self-cleaving hammerhead structures in its strands of both polarities, was investigated. The lack of infectivity observed in a series of transmission assays in carnation indicates that CarSV RNA, in spite of sharing structural similarities with viroid and viroid-like satellite RNAs from plants, does not belong to either of these two groups. Additional evidence in this direction comes from the observation that CarSV RNA also exists in carnation plants as DNA tandem repeats. In this respect, CarSV RNA is similar to a small transcript of a tandemly repeated DNA sequence of the newt genome. Moreover, CarSV and newt RNAs have similarities in their sequences as well as in some characteristics of their corresponding hammerhead structures. Further analyses have revealed that CarSV DNA is found directly fused to DNA sequences of carnation etched ring caulimovirus, a pararetrovirus, most likely in the form of an extrachromosomal element. The properties of the CarSV RNA/DNA system are those of a retroviroid-like element having some features in common with viroid and viroid-like satellite RNAs from plants and others with the newt transcript.

  5. Detrimental effect of temperature increase on the fitness of an amphibian ( Lissotriton helveticus)

    NASA Astrophysics Data System (ADS)

    Galloy, Valérie; Denoël, Mathieu

    2010-03-01

    Increases of global temperatures have resulted in measurable shifts in the distribution, phenology and survival of some plant and animal species. However, the mechanisms showing links between global warming and biodiversity declines remain unclear. The aim of this study was to examine whether a key parameter of fitness, i.e. offspring number, could be affected by a temperature increase. To this end, we compared egg-laying traits at naturally occurring temperatures (14 °C, 18 °C and 22 °C) in palmate newts, Lissotriton helveticus. Our study suggests that water temperature increase has a negative effect on the fecundity of female newts. Females lay half as many eggs at high temperatures as they do at low temperatures, which results in a lower number of hatchlings. This study shows that global warming would affect amphibian populations. It complements other studies in pointing out that changes in phenology may not be driven only by warmer earlier temperatures but also by counter-selection during late-breeding, particularly in long-term breeders such as newts. More experimental studies should be carried out to understand the complex consequences of global warming and the proximate mechanisms of amphibian decline.

  6. The benefits of heterospecific oophagy in a top predator

    NASA Astrophysics Data System (ADS)

    Denoël, Mathieu; Demars, Bertrand

    2008-07-01

    Oophagy is a behavioural pattern that has been found in a large variety of predator species in the animal kingdom. In contrast to other modes of feeding, it is peculiar in that it involves the detection, capture and ingestion of immobile prey. Several hypotheses have been proposed to explain the evolutionary origin and persistence of this pattern, but they have rarely been tested. The aim of this study was to compare the benefits of a heterospecific oophagous tactic over a non-oophageous diet in terms of biomass intake. To this end, stomach contents were gathered by flushing the stomachs of male and female Alpine newts ( Mesotriton alpestris) found in forestry ruts (i.e. pools caused by traffic) during their reproductive period. Prey items were identified, classified into functional categories and their dry mass determined. Frog ( Rana temporaria) eggs are valuable prey items that give a higher biomass intake to individuals foraging on them than on those relying on invertebrates. Both sexes of newts practice oophagy but frog eggs are a transient resource that is only available during a part of their aquatic phase. Consequently, the newts adjust their diet to invertebrate predation later in the season after the peak of the frogs' breeding season. Oophagy is thus facultative and not obligate in the study species. The correlated occurrence of prey and predator, similarities between frog eggs and mobile potential prey (tadpoles), and high resource intake are all in favour of the occurrence and persistence of an oophagous feeding tactic.

  7. Evidence of light-dependent magnetic compass orientation in urodele amphibian larvae.

    PubMed

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

    2015-09-01

    Experiments were conducted to investigate whether larval palmate newts undertake orientation toward or away from the home shoreline (y-axis orientation) using the geomagnetic field to steer the most direct route, and if they accomplish this task through a light-dependent magnetoreception mechanism similar to that found in anuran tadpoles and adult newts. Larval palmate newts trained and then tested under full-spectrum light showed bimodal magnetic compass orientation that coincided with the magnetic direction of the trained y-axis. In contrast, larvae trained under long-wavelength (≥500nm) light and then tested under full-spectrum light displayed bimodal orientation perpendicular to the trained y-axis direction. These results offer evidence for the use of magnetic compass cues in orienting urodele amphibian larvae, and provide additional support for the light-dependent magnetoreception mechanism since they are in complete agreement with earlier studies showing that the observed 90° shift in the direction of magnetic compass orientation under long-wavelength light (≥500nm) is due to a direct effect of light on the underlying magnetoreception mechanism. This study is the first to provide evidence of a light-dependent magnetic compass in larval urodeles.

  8. How the transition frequencies of microtubule dynamic instability (nucleation, catastrophe, and rescue) regulate microtubule dynamics in interphase and mitosis: analysis using a Monte Carlo computer simulation.

    PubMed Central

    Gliksman, N R; Skibbens, R V; Salmon, E D

    1993-01-01

    Microtubules (MTs) in newt mitotic spindles grow faster than MTs in the interphase cytoplasmic microtubule complex (CMTC), yet spindle MTs do not have the long lengths or lifetimes of the CMTC microtubules. Because MTs undergo dynamic instability, it is likely that changes in the durations of growth or shortening are responsible for this anomaly. We have used a Monte Carlo computer simulation to examine how changes in the number of MTs and changes in the catastrophe and rescue frequencies of dynamic instability may be responsible for the cell cycle dependent changes in MT characteristics. We used the computer simulations to model interphase-like or mitotic-like MT populations on the basis of the dynamic instability parameters available from newt lung epithelial cells in vivo. We started with parameters that produced MT populations similar to the interphase newt lung cell CMTC. In the simulation, increasing the number of MTs and either increasing the frequency of catastrophe or decreasing the frequency of rescue reproduced the changes in MT dynamics measured in vivo between interphase and mitosis. Images PMID:8298190

  9. Limited immune diversity in urodela: chronic transplantation responses occur even with family-disparate xenografts.

    PubMed

    Kinefuchi, Kenjiroh; Kushida, Yoshihiro; Touma, Maki; Hosono, Masamichi

    2013-07-01

    Urodele amphibians are thought to have poorer immune responses than evolutionary more ancestral vertebrate classes, such as bony fish. We investigated skin graft rejection and transplantation immunity in Urodele amphibians, Japanese newts, and Asiatic salamanders, and compared these findings to those from transplants in several species of frogs. The skin grafts used in this study were either allogeneic or xenogeneic. The mean survival time of the first set of allografts at 20°C was approximately 60 days for chronic responses in Urodela and 20 days for acute responses in Anura. As the graft survival times of urodeles were significantly longer than those of anurans, even when urodeles were repeatedly grafted from identical donors, there appear to be substantial differences in transplantation immunity between Urodela and Anura. These slow responses in Urodela may not be accompanied by the expansion of cytotoxic T cells, as observed in fish and anuran species, which are known to have functional major histocompatibility complex (MHC)-class I systems. In our study, approximately five histo-incompatible immunogenic components were found to be involved in chronic responses in newts. Similar chronic responses were also observed in xenograft rejection in newts. In contrast, xenografts were rejected in frogs due to an accelerated acute response, possibly involving natural killer cells. Our findings that some anti-allogeneic components appear to be shared with xenogeneic components indicate that the diversification of the acquired immune system is poorly developed in Urodela.

  10. A putative amino acid transporter determines sensitivity to the two-peptide bacteriocin plantaricin JK.

    PubMed

    Oppegård, Camilla; Kjos, Morten; Veening, Jan-Willem; Nissen-Meyer, Jon; Kristensen, Tom

    2016-08-01

    Lactobacillus plantarum produces a number of antimicrobial peptides (bacteriocins) that mostly target closely related bacteria. Although bacteriocins are important for the ecology of these bacteria, very little is known about how the peptides target sensitive cells. In this work, a putative membrane protein receptor of the two-peptide bacteriocin plantaricin JK was identified by comparing Illumina sequence reads from plantaricin JK-resistant mutants to a crude assembly of the sensitive wild-type Weissella viridescens genome using the polymorphism discovery tool VAAL. Ten resistant mutants harbored altogether seven independent mutations in a gene encoding an APC superfamily protein with 12 transmembrane helices. The APC superfamily transporter thus is likely to serve as a target for plantaricin JK on sensitive cells.

  11. STUDIES ON AMPHIBIAN YOLK

    PubMed Central

    Karasaki, Shuichi

    1963-01-01

    The yolk platelets of mature eggs and young embryonic cells of all amphibian species studied (Rana pipiens, Triturus pyrrhogaster, Diemictylus viridescens, Rana nigromaculata, and Bufo vulgaris) have a superficial layer of fine particles or fibrils (ca. 50 A in diameter), a central main body with a crystalline lattice structure, and an enclosing membrane approximately 70 A in thickness. Electron micrographs of the main body reveal hexagonal net (spacing ca. 70 A), square net (spacing ca. 80 A), and parallel band (spacing from 35 to 100 A but most frequent at ca. 70 A) patterns. The crystalline structure is believed to be a simple hexagonal lattice made of closely packed cylindrical rods. Each rod is estimated to be about 80 A in diameter and 160 A in length. PMID:13962448

  12. Identification and evaluation of the probiotic potential of lactobacilli isolated from canine milk.

    PubMed

    Martín, Rocío; Olivares, Mónica; Pérez, Manuela; Xaus, Jordi; Torre, Celina; Fernández, Leonides; Rodríguez, Juan M

    2010-08-01

    Canine milk protects puppies against infectious diseases through a variety of mechanisms. In this study, the presence of potentially probiotic lactic acid bacteria grown on MRS-Cys agar plates from milk of nine bitches was investigated. The Gram positive catalase negative bacilli identified in this study belonged to four Lactobacillus species (Lactobacillus reuteri, Lactobacillus fermentum, Lactobacillus murinus, Lactobacillus animalis), as well as one isolate that was identified as Weissella viridescens. Random amplified polymorphic DNA profiling revealed 28 different genetic profiles among the lactobacilli isolates. Their probiotic potential was evaluated through different assays, including survival in conditions that resemble those existing in the gastrointestinal tract, production of antimicrobial compounds, adherence to intestinal mucin, degradation of mucin and pattern of antibiotic sensitivity. Some strains showed potential for future applications as canine probiotics.

  13. Static friction of biomimetic surface microstructure of PDMS under wet and dry conditions

    NASA Astrophysics Data System (ADS)

    Yu, Haiwu; Jia, Hongduo; Gong, Ling; Li, Rong; Wang, Caiping; Wang, Xiaojie

    2016-04-01

    Smooth adhesive pad found among arthropods, amphibians, particularly tree frogs, are usually covered with surface microstructure of different shape to enhance the attachment abilities on the smooth substrate. During the last decade, it has gained more attentions in the development of anti-slippery systems by mimicking these unique characteristics. In this paper, we studied a new amphibian species newt by observing their climbing abilities on wet and dry vertical smooth surface, and found that the newts can even hang on the surface with an inclination angle more than 90° without falling. We investigated the toe pad micro-structured surface of the newt by using scanning electron microscopy (SEM), and found that an array of hexagonal cells with micro-ridges on cell borders exists for the larvae; while an array of hexagonal cells separated by microgrooves is for the adult. Inspired by these features, the biomimetic micro-structured surfaces were fabricated using a soft elastomeric material polydimethysiloxane (PDMS). Four different microstructures were chosen to study their tribological properties with a solid substrate under wet and dry conditions. The patterns of the microstructures include round pillar, hexagonal pillar, round pillars surrounded by a closed hexagonal ridge, and round pillars surrounded by a semi-closed hexagonal ridge. The static friction tests were carried out using the multi-functional surface meter TYPE12. The results showed that the area ratio of the micro pillar plays a major role in enhancing the static friction for both wet and dry conditions, while the numerical density of the micro pillar has less effect on the friction enhancement. Among the four kind specimens, the specimen with hexagonal pillars would increase the static friction more than others at the same test conditions when the pillar area ratio is lower than 40%.

  14. Regeneration of eye tissues is modulated by altered levels of gravity at 1g, 2g, and in microgravity during spaceflight

    NASA Astrophysics Data System (ADS)

    Grigoryan, Eleonora; Almeida, Eduardo; Mitashov, Victor

    The pursuit of human space exploration requires detailed knowledge of microgravity-related changes in fundamental biological processes, and their effects on health. Normal regeneration of organs and tissues is one such fundamental process that allows maintenance of vitality and function of living organisms. Animal models of tissue regeneration include the newt (Pleurodeles waltl, Urodela) eye, which has been extensively used by our team in Russian Bion and Foton microgravity experiments since 1985, and in recent NASA 2.5 meter diameter centrifuge hypergravity experiments. In total, these experiments allow us to draw several broad conclusions: Newt lens regeneration is significantly altered in microgravity and hypergravity relative to 1g controls. Lenses formed in microgravity are larger and more developed than those regenerated in 1g controls; Microgravity alterations of lens regeneration can persist after spaceflight, and continue to affect repeated removal and regeneration of the lens after return to 1g; Microgravity increases the numbers of early stage regenerative proliferating BrdU-labeled cells in dorsal iris progenitors and in the lens regenerate. Regeneration under hypergravity conditions at 2g inhibits lens regeneration, and often causes retinal detachment. Molecular mechanisms regulating lens regeneration rate include FGF2 signaling, (a key pathway for eye tissue development and regeneration), and an expression of stress-related proteins - HSPs. In conclusion, regeneration of lens and other eye tissues in the newt is sensitive to, and regulated by the level of gravity mechanotransduction and developmental signaling pathways, with microgravity favoring stem cell progenitor proliferation, and gravity at 1g promoting terminal differentiation, while hypergravity at 2g often causes damage of delicate regenerating tissues.

  15. The Soviet Union and China,

    DTIC Science & Technology

    1980-03-01

    eel)ly d is tulrbed by thle sp ic tarn L I a r , newt 1h o f t ht, Sax’ i vt - Cuban mitlitary role and Soviet political in I nnce in P%’rica m ici...perception is also fed by What the Chinese see as other symptoms of the incremental growth of the Soviet political and miii- tarv presence in the Trhird World...indefinitely poisoned . Soviet Economic Courting of Beijing. The net result of these experiences has been a long series of rebuffs to sporadic Soviet

  16. Analysis of Special Forces Medic (18D) Attrition

    DTIC Science & Technology

    1994-08-01

    Disorders of Heart Rate and P hythm System Low Back Pain Common Arthritic Disorders Sick Call Practice Exercise Endocrine Diseases Hepotitis Poisoning ...termination of their newt tour, 1 a Strongly Disagree 5 m Strongly Agree 1.9 1.6 1i8 (1,1) (1.0) (1.1) 94, Regardless of "critical shortages", one’s...disillusioned 18D’s is part of the symptom of a greater problem. The idea of special forces is just about dead in the water. We promote incompetence from

  17. From fish to amphibians to mammals: in search of novel strategies to optimize cardiac regeneration.

    PubMed

    Ausoni, Simonetta; Sartore, Saverio

    2009-02-09

    Different vertebrate species have different cardiac regeneration rates: high in teleost fish, moderate in urodele amphibians, and almost negligible in mammals. Regeneration may occur through stem and progenitor cell differentiation or via dedifferentiation with residual cardiomyocytes reentering the cell cycle. In this review, we will examine the ability of zebrafish and newts to respond to cardiac damage with de novo cardiogenesis, whereas rodents and humans respond with a marked fibrogenic response and virtually no cardiomyocyte regeneration. Concerted strategies are needed to overcome this evolutionarily imposed barrier and optimize cardiac regeneration in mammals.

  18. Could we also be regenerative superheroes, like salamanders?

    PubMed

    Dall'Agnese, Alessandra; Puri, Pier Lorenzo

    2016-09-01

    Development of methods to reawaken the semi-dormant regenerative potential that lies within adult human tissues would hold promise for the restoration of diseased or damaged organs and tissues. While most of the regeneration potential is suppressed in many vertebrates, including humans, during adult life, urodele amphibians (salamanders) retain their regenerative ability throughout adulthood. Studies in newts and axolotls, two salamander models, have provided significant knowledge about adult limb regeneration. In this review, we present a comparative analysis of salamander and mammalian regeneration and discuss how evolutionarily altered properties of the regenerative environment can be exploited to restore full regenerative potential in the human body.

  19. [Biologically Active Peptides Isolated from Dill Anethum graveolens L].

    PubMed

    Kulikova, O G; Maltsev, D I; Ilyina, A P; Burdina, A V; Yamskova, V P; Yamskov, I A

    2015-01-01

    Peptide mixtures with molecular weights of 1000-2000 Da and in vivo membrano-trophic activity against mouse hepatocyte culture at very low concentrations were isolated from dill Anethum graveolens L. leaves. It has been found that plant peptides in aqueous solution formed larger nanosized particles of approximately 90 nm with a secondary structure mainly composed of β-structures and random coil structures. We demonstrated that peptides isolated from A. graveolens in vitro at an ultra-low dosage affected the size of the area of pigmented cells of amphibian liver, which are analogous to Kupffer cells of the mammalian liver, using roller organotypic newt liver culture models.

  20. Internet censorship: Congress moves toward final decision.

    PubMed

    Mirken, B

    1995-12-01

    The House and the Senate have passed proposals restricting the online access to obscene or indecent information. AIDS activists and service organizations fear that the proposals will restrict the distribution of HIV/AIDS information. A House/Senate conference committee soon will meet for a final decision. Religious right organizations are pressing for additional restrictions, while civil liberties, arts, and libertarian groups have expressed opposition on freedom-of-speech grounds. Some conservatives, including Newt Gingrich (R-GA), believe that the proposals may retard the growth of online communication.

  1. Suppression of Odorant Responses by Odorants in Olfactory Receptor Cells

    NASA Astrophysics Data System (ADS)

    Kurahashi, Takashi; Lowe, Graeme; Gold, Geoffrey H.

    1994-07-01

    Odorants activate an inward current in vertebrate olfactory receptor cells. Here it is shown, in receptor cells from the newt, that odorants can also suppress this current, by a mechanism that is distinct from inhibition and adaptation. Suppression provides a simple explanation for two seemingly unrelated phenomena: the anomalously long latency of olfactory transduction and the existence of an "off response" at the end of a prolonged stimulus. Suppression may influence the perception of odorants by masking odorant responses and by sharpening the odorant specificities of single cells.

  2. SCALE 5.1 Predictions of PWR Spent Nuclear Fuel Isotopic Compositions

    SciTech Connect

    Radulescu, Georgeta; Gauld, Ian C; Ilas, Germina

    2010-03-01

    The purpose of this calculation report is to document the comparison to measurement of the isotopic concentrations for pressurized water reactor (PWR) spent nuclear fuel determined with the Standardized Computer Analysis for Licensing Evaluation (SCALE) 5.1 (Ref. ) epletion calculation method. Specifically, the depletion computer code and the cross-section library being evaluated are the twodimensional (2-D) transport and depletion module, TRITON/NEWT,2, 3 and the 44GROUPNDF5 (Ref. 4) cross-section library, respectively, in the SCALE .1 code system.

  3. Tail regeneration in Urodela: old model and new perspectives in studies

    NASA Astrophysics Data System (ADS)

    Grigoryan, E.; Anton, H.; Mitashov, V.

    For better understanding of micro-"g" effect on nervous tissue regeneration we have chosen the regeneration of the Urodele tail, because it utilizes many developmental processes and represents the most convenient model for experiments in Space. The special interesting aspect lies in the ability of regenerates to differentiate the spinal cord (SC) and this, in turn, has a potential of practical application. Meanwhile there are conclusive evidences suggesting the production by SC cells the neurotrophic factors promoting cell proliferation and differentiation in growing tail regenerate. Previously our studies on tail regeneration in the adult newt showed that the force of gravity clearly inf luences the events underlying the regeneration. We reported the significant increase of tail regeneration rate and tissue volume of tail regenerates in the newts exposed to real and simulated low "g". In Bion 11 mission animals that were exposed 14 days in microgravity and whose tails were operated two and four weeks before launch demonstrated the regenerates achieved 1.5 - 2 times the volume of those in 1"g" control. Results of this experiment indicated also that the regeneration of central and peripheral neurons and nerve fibers was carrying out faster under low "g" conditions than in 1 "g" control. Similar data were obtained in several experiments remodeling physiological weightlessness by mean of the clinostat. It led us to the hypothesis that the stimulation of tail regeneration is linked with an over activation of neurotrophic factors produced by quickly growing SC neurons. Now we've completed the experiment on tail regeneration in the newts Tr. alpestris subjected to 5 day long clinorotation after 6 days post tail amputation. The rate of primary- and secondary regeneration was evaluated at different time points after treatment. Cell proliferation, differentiation and expression of neurotrophic proteins in SC and other major tissue-type of regenerate were investigated by

  4. STS-65 Mission Specialist Chiao in front of IML-2 Rack 3 aboard OV-102

    NASA Technical Reports Server (NTRS)

    1994-01-01

    STS-65 Mission Specialist Leroy Chiao is seen in the International Microgravity Laboratory 2 (IML-2) spacelab science module in front of Rack 3 and above center aisle equipment. Chiao has just made an observation of the goldfish container (silver apparatus on left between his right hand and knee). The Rack 3 Aquatic Animal Experiment Unit (AAEU) also contains Medaka and newts. Chiao joined five other NASA astronauts and a Japanese payload specialist for two weeks of experimenting onboard the Space Shuttle Columbia, Orbiter Vehicle (OV) 102, in Earth orbit.

  5. Pheromone communication in amphibians and reptiles.

    PubMed

    Houck, Lynne D

    2009-01-01

    This selective review considers herpetological papers that feature the use of chemical cues, particularly pheromones involved in reproductive interactions between potential mates. Primary examples include garter snake females that attract males, lacertid lizards and the effects of their femoral gland secretions, aquatic male newts that chemically attract females, and terrestrial salamander males that chemically persuade a female to mate. Each case study spans a number of research approaches (molecular, biochemical, behavioral) and is related to sensory processing and the physiological effects of pheromone delivery. These and related studies show that natural pheromones can be identified, validated with behavioral tests, and incorporated in research on vomeronasal functional response.

  6. Cardiovascular physiology and diseases of amphibians.

    PubMed

    Heinz-Taheny, Kathleen M

    2009-01-01

    The class Amphibia includes three orders of amphibians: the anurans (frogs and toads), urodeles (salamanders, axolotls, and newts), and caecilians. The diversity of lifestyles across these three orders has accompanying differences in the cardiovascular anatomy and physiology allowing for adaptations to aquatic or terrestrial habitats, pulmonic or gill respiration, hibernation, and body elongation (in the caecilian). This article provides a review of amphibian cardiovascular anatomy and physiology with discussion of unique species adaptations. In addition, amphibians as cardiovascular animal models and commonly encountered natural diseases are covered.

  7. Pyrosequencing vs. culture-dependent approaches to analyze lactic acid bacteria associated to chicha, a traditional maize-based fermented beverage from Northwestern Argentina.

    PubMed

    Elizaquível, Patricia; Pérez-Cataluña, Alba; Yépez, Alba; Aristimuño, Cecilia; Jiménez, Eugenia; Cocconcelli, Pier Sandro; Vignolo, Graciela; Aznar, Rosa

    2015-04-02

    The diversity of lactic acid bacteria (LAB) associated with chicha, a traditional maize-based fermented alcoholic beverage from Northwestern Argentina, was analyzed using culture-dependent and culture-independent approaches. Samples corresponding to 10 production steps were obtained from two local producers at Maimará (chicha M) and Tumbaya (chicha T). Whereas by culture-dependent approach a few number of species (Lactobacillus plantarum and Weissella viridescens in chicha M, and Enterococcus faecium and Leuconostoc mesenteroides in chicha T) were identified, a higher quantitative distribution of taxa was found in both beverages by pyrosequencing. The relative abundance of OTUs was higher in chicha M than in chicha T; six LAB genera were common for chicha M and T: Enterococcus, Lactococcus, Streptococcus, Weissella, Leuconostoc and Lactobacillus while Pediococcus only was detected in chicha M. Among the 46 identified LAB species, those of Lactobacillus were dominant in both chicha samples, exhibiting the highest diversity, whereas Enterococcus and Leuconostoc were recorded as the second dominant genera in chicha T and M, respectively. Identification at species level showed the predominance of Lb. plantarum, Lactobacillus rossiae, Leuconostoc lactis and W. viridescens in chicha M while Enterococcus hirae, E. faecium, Lc. mesenteroides and Weissella confusa predominated in chicha T samples. In parallel, when presumptive LAB isolates (chicha M: 146; chicha T: 246) recovered from the same samples were identified by ISR-PCR and RAPD-PCR profiles, species-specific PCR and 16S rRNA gene sequencing, most of them were assigned to the Leuconostoc genus (Lc. mesenteroides and Lc. lactis) in chicha M, Lactobacillus, Weissella and Enterococcus being also present. In contrast, chicha T exhibited the presence of Enterococcus and Leuconostoc, E. faecium being the most representative species. Massive sequencing approach was applied for the first time to study the diversity and

  8. Functional joint regeneration is achieved using reintegration mechanism in Xenopus laevis

    PubMed Central

    Yamada, Shigehito

    2016-01-01

    Abstract A functional joint requires integration of multiple tissues: the apposing skeletal elements should form an interlocking structure, and muscles should insert into skeletal tissues via tendons across the joint. Whereas newts can regenerate functional joints after amputation, Xenopus laevis regenerates a cartilaginous rod without joints, a “spike.” Previously we reported that the reintegration mechanism between the remaining and regenerated tissues has a significant effect on regenerating joint morphogenesis during elbow joint regeneration in newt. Based on this insight into the importance of reintegration, we amputated frogs’ limbs at the elbow joint and found that frogs could regenerate a functional elbow joint between the remaining tissues and regenerated spike. During regeneration, the regenerating cartilage was partially connected to the remaining articular cartilage to reform the interlocking structure of the elbow joint at the proximal end of the spike. Furthermore, the muscles of the remaining part inserted into the regenerated spike cartilage via tendons. This study might open up an avenue for analyzing molecular and cellular mechanisms of joint regeneration using Xenopus. PMID:27499877

  9. Application of local gene induction by infrared laser-mediated microscope and temperature stimulator to amphibian regeneration study.

    PubMed

    Kawasumi-Kita, Aiko; Hayashi, Toshinori; Kobayashi, Takuya; Nagayama, Chikashi; Hayashi, Shinichi; Kamei, Yasuhiro; Morishita, Yoshihiro; Takeuchi, Takashi; Tamura, Koji; Yokoyama, Hitoshi

    2015-12-01

    Urodele amphibians (newts and salamanders) and anuran amphibians (frogs) are excellent research models to reveal mechanisms of three-dimensional organ regeneration since they have exceptionally high regenerative capacity among tetrapods. However, the difficulty in manipulating gene expression in cells in a spatially restricted manner has so far hindered elucidation of the molecular mechanisms of organ regeneration in amphibians. Recently, local heat shock by laser irradiation has enabled local gene induction even at the single-cell level in teleost fishes, nematodes, fruit flies and plants. In this study, local heat shock was made with infrared laser irradiation (IR-LEGO) by using a gene expression inducible system in transgenic animals containing a heat shock promoter, and gene expression was successfully induced only in the target region of two amphibian species, Xenopus laevis and Pleurodeles waltl (a newt), at postembryonic stages. Furthermore, we induced spatially restricted but wider gene expression in Xenopus laevis tadpoles and froglets by applying local heat shock by a temperature-controlled metal probe (temperature stimulator). The local gene manipulation systems, the IR-LEGO and the temperature stimulator, enable us to do a rigorous cell lineage trace with the combination of the Cre-LoxP system as well as to analyze gene function in a target region or cells with less off-target effects in the study of amphibian regeneration.

  10. Tracking the amphibian pathogens Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans using a highly specific monoclonal antibody and lateral-flow technology.

    PubMed

    Dillon, Michael J; Bowkett, Andrew E; Bungard, Michael J; Beckman, Katie M; O'Brien, Michelle F; Bates, Kieran; Fisher, Matthew C; Stevens, Jamie R; Thornton, Christopher R

    2017-03-01

    The fungus Batrachochytrium dendrobatidis (Bd) causes chytridiomycosis, a lethal epizootic disease of amphibians. Rapid identification of the pathogen and biosecurity is essential to prevent its spread, but current laboratory-based tests are time-consuming and require specialist equipment. Here, we describe the generation of an IgM monoclonal antibody (mAb), 5C4, specific to Bd as well as the related salamander and newt pathogen Batrachochytrium salamandrivorans (Bsal). The mAb, which binds to a glycoprotein antigen present on the surface of zoospores, sporangia and zoosporangia, was used to develop a lateral-flow assay (LFA) for rapid (15 min) detection of the pathogens. The LFA detects known lineages of Bd and also Bsal, as well as the closely related fungus Homolaphlyctis polyrhiza, but does not detect a wide range of related and unrelated fungi and oomycetes likely to be present in amphibian habitats. When combined with a simple swabbing procedure, the LFA was 100% accurate in detecting the water-soluble 5C4 antigen present in skin, foot and pelvic samples from frogs, newts and salamanders naturally infected with Bd or Bsal. Our results demonstrate the potential of the portable LFA as a rapid qualitative assay for tracking these amphibian pathogens and as an adjunct test to nucleic acid-based detection methods.

  11. Total DNA transcription in vitro: a procedure to detect highly repetitive and transcribable sequences with tRNA-like structures

    SciTech Connect

    Endoh, H.; Okada, N.

    1986-01-01

    Total DNAs from various animals were transcribed in vitro in a HeLa cell extract, and it was found that one to several discrete RNAs were transcribed by RNA polymerase III. With tortoise (Geoclemys reevessi) and newt (Cynops pyrrhogaster), distinct 6.5S and 8S RNAs were transcribed from these respective DNAs. Representative phage clones carrying the 6.5S and 8S RNA genes were isolated from genomic libraries of these animals, and the sequences of these genes were determined. The 5' parts of highly repetitive and transcribable sequences of tortoise and newt were found to have close resemblance to tRNA/sub 1//sup Lys/ (rabbit) gene (78% homology) and a tRNA/sup Glu/ (Drosophila) gene (74% homology, not counting the aminoacyl stem region), respectively. The homologies extended to secondary structures, homologous nucleotides being located on similar secondary structures. It is proposed that many, if not all, highly repetitive and transcribable sequences detected by total DNA transcription have specific tRNA genes as their progenitors.

  12. Seasonal variation in environmental DNA in relation to population size and environmental factors

    PubMed Central

    Buxton, Andrew S.; Groombridge, Jim J.; Zakaria, Nurulhuda B.; Griffiths, Richard A.

    2017-01-01

    Analysing DNA that organisms release into the environment (environmental DNA, or eDNA) has enormous potential for assessing rare and cryptic species. At present the method is only reliably used to assess the presence-absence of species in natural environments, as seasonal influences on eDNA in relation to presence, abundance, life stages and seasonal behaviours are poorly understood. A naturally colonised, replicated pond system was used to show how seasonal changes in eDNA were influenced by abundance of adults and larvae of great crested newts (Triturus cristatus). Peaks in eDNA were observed in early June when adult breeding was coming to an end, and between mid-July and mid-August corresponding to a peak in newt larval abundance. Changes in adult body condition associated with reproduction also influenced eDNA concentrations, as did temperature (but not rainfall or UV). eDNA concentration fell rapidly as larvae metamorphosed and left the ponds. eDNA concentration may therefore reflect relative abundance in different ponds, although environmental factors can affect the concentrations observed. Nevertheless, eDNA surveys may still represent an improvement over unadjusted counts which are widely used in population assessments but have unreliable relationships with population size. PMID:28393885

  13. Microelasticity of Single Mitotic Chromosomes

    NASA Astrophysics Data System (ADS)

    Poirier, Michael; Eroglu, Sertac; Chatenay, Didier; Marko, John F.; Hirano, Tatsuya

    2000-03-01

    The force-extension behavior of mitotic chromosomes from the newt TVI tumor cell line was studied using micropipette manipulation and force measuring techniques. Reversible, linear elastic response was observed for extensions up to 5 times the native length; the force required to double chromosome length was 1 nanonewton (nN). For further elongations, the linear response teminates at a force plateau of 15 nN and at an extension of 20x. Beyond this extension, the chromosome breaks at elongations between 20x and 70x. These results will be compared to the similar behavior of mitotic chromosomes from explanted newt cells (Poirier, Eroglu, Chatenay and Marko, Mol. Biol. Cell, in press). Also, the effect of biochemical modifications on the elasticity was studied. Ethidium Bromide, which binds to DNA, induces up to a 10 times increase in the Young's modulus. Anti-XCAP-E, which binds to a putative chromosome folding protein, induces up to a 2 times increase in the Young's modulus. Preliminary results on the dynamical relaxation of chromosomes will also be presented. Support of this research through a Biomedical Engineering Research Grant from The Whitaker Foundation is gratefully acknowledged.

  14. Zooplankton Successions in Neighboring Lakes with Contrasting Impacts of Amphibian and Fish Predators

    NASA Astrophysics Data System (ADS)

    Schabetsberger, Robert; Grill, Susanne; Hauser, Gabriele; Wukits, Petra

    2006-06-01

    Two pairs of neighboring subalpine lakes located in the Northern Calcareous Alps of Austria were investigated. Each pair comprised a deeper lake containing European minnows (Phoxinus phoxinus ), and a corresponding shallower lake harboring Alpine newts (Triturus alpestris ) as top predators. Plankton successions within fish and amphibian lakes differed markedly from each other. Throughout the year rotifers numerically dominated within the minnow lakes, while pigmented copepods (Genera Heterocope, Acanthodiaptomus , Arctodiaptomus , Mixodiaptomus ) and Daphnia were prominent in the amphibian lakes, at least early during the ice-free period. We argue that size-selective predation by minnows was the ultimate reason for this predominance of smaller zooplankton. While one of the minnow lakes was characterized by a succession of spatially and temporally segregated rotifer species, the other minnow lake permitted the development of populations of small-sized Bosmina and Ceriodaphnia during summer, probably due to the existence of a strong oxycline allowing zooplankton crustaceans to avoid predation from shore-based shoals of minnows. Once trout were introduced into this lake, minnows were visibly reduced in abundance. Bosmina and Ceriodaphnia disappeared and Daphnia together with a predacious copepod (Heterocope ) emerged either from egg banks or arrived from nearby source populations. We argue that the crustacean communities within the fishless lakes were adapted to the comparatively weak predation rates of Alpine newts.

  15. Experiment "Regeneration" Performed Aboard the Russian Spacecraft Foton-M2 in 2005

    NASA Technical Reports Server (NTRS)

    Grigoryan, Elonora; Almeida, Eduardo; Domaratskaya, Elena; Poplinskaya, Valentina; Aleinikova, Karina; Tairbekov, Murad; Mitashov, Victor

    2006-01-01

    The experiments on the newts performed earlier aboard Russian biosate llites showed that the rate of lens and tail regeneration in space wa s greater than on the ground. In parallel it was found that the numbe r of cells in S-phase was greater in space-flown animals than in the ground controls. However, it was unclear whether cell proliferation stimulation was induced by micro-g per se. Molecular mechanisms under lying the change also remained obscure. These issues were addressed b y the joint Russian-American experiment "Regeneration" flown on Foton -M2 in 2005. The method for in-flight delivering DNA precursor BrdU was developed. The experiment showed that during the flight the numbe r of S-phase cells in the regenerating eyes and tails increased. Thes e data together with those obtained earlier suggest that cell prolife ration increases in response to the effects of both micro-g and 1-g a fter return to Earth. The expression of bFGF in regenerating tissues of "flown" newts and ground controls was examined using immuno-histo chemistry. Obtained results suggest that this growth factor is a part icipant of the promotional effect of space flight upon cell prolifera tion in lens and tail regenerates.

  16. High gene flow between alternative morphs and the evolutionary persistence of facultative paedomorphosis

    PubMed Central

    Oromi, Neus; Michaux, Johan; Denoël, Mathieu

    2016-01-01

    Paedomorphosis and metamorphosis are two major developmental processes that characterize the evolution of complex life cycles in many lineages. Whereas these processes were fixed in some taxa, they remained facultative in others, with alternative phenotypes expressed in the same populations. From a genetic perspective, it is still unknown whether such phenotypes form a single population or whether they show some patterns of isolation in syntopy. This has deep implications for understanding the evolution of the phenotypes, i.e. towards their persistence or their fixation and speciation. Newts and salamanders are excellent models to test this hypothesis because they exhibit both developmental processes in their populations: the aquatic paedomorphs retain gills, whereas the metamorphs are able to colonize land. Using microsatellite data of coexisting paedomorphic and metamorphic palmate newts (Lissotriton helveticus), we found that they formed a panmictic population, which evidences sexual compatibility between the two phenotypes. The high gene flow could be understood as an adaptation to unstable habitats in which phenotypic plasticity is favored over the fixation of developmental alternatives. This makes then possible the persistence of a polyphenism: only metamorphosis could be maintained in case of occasional drying whereas paedomorphosis could offer specific advantages in organisms remaining in water. PMID:27534370

  17. Characterization and localization of arginine vasotocin receptors in the brain and kidney of an amphibian

    SciTech Connect

    Boyd, S.K.

    1987-01-01

    Because arginine vasotocin (AVT) activates male sexual behaviors in the rough-skinned newt (Taricha granulosa), quantitative autoradiography with radiolabeled arginine vasopressin (/sup 3/H-AVP) was used to localize and characterize putative AVT receptors in the brain of this amphibian. Binding of /sup 3/H-AVP to sites within the medial pallium was saturable, specific, reversible, of high affinity and low capacity. These binding sites appear to represent authentic central nervous system receptors for AVT. Furthermore, ligand specificity for the binding sites in this amphibian differs from that reported for AVP binding sites in rat brains. Dense concentrations of specific binding sites were located in the olfactory nerve as it entered the olfactory bulb within the medial pallium, dorsal pallium, and amygdala pars lateralis of the telencephalon, and in the tegmental region of the medulla. Concentrations of binding sites differed significantly among various brain regions. A comparison of male and female newts collected during the breeding season revealed no sexual dimorphism. These areas may represent site(s) of action where AVT elicits sexual behaviors in male T. granulosa.

  18. Foton-M3 Unmanned Russian Research Satellite- Development, Implementation and Operations

    NASA Astrophysics Data System (ADS)

    Ilyin, Eugene A.; Skidmore, Michael G.

    2008-06-01

    The Foton-M3 spacecraft launched from Baikonur Cosmodrome (Kazakhstan) on 14 September 2007 and landed 12 days later approximately 130 km south of Kustanay, Northern Kazakhstan. Following the successful National Aeronautics and Space Administration (NASA) and Institute for Biomedical Problems (IMBP) collaboration on the Russian Foton-M2 spaceflight (June 2005), IMBP invited NASA to continue and broaden its participation in four Russian biomedical studies on the Foton-M3 spaceflight. Where the Foton-M2 collaboration had been accomplished without an exchange of funds, the basis for the ongoing bilateral interaction on Foton-M3 was both a cooperative Space Act Agreement and a NASA contract with IMBP. As in Foton-M2, NASA scientists agreed to focus their efforts on research that would be complementary and would facilitate the accomplishment of the original Russian science goals. Foton-M3 hardware enhancements included NASA inserts installed in the IMBP flight hardware to provide programmable in-flight video recording for newts and geckos, drinking water for the geckos, and a preflight "shower" of Bromodeoxyuridine (BrdU) for the newts.

  19. An advanced deterministic method for spent fuel criticality safety analysis

    SciTech Connect

    DeHart, M.D.

    1998-01-01

    Over the past two decades, criticality safety analysts have come to rely to a large extent on Monte Carlo methods for criticality calculations. Monte Carlo has become popular because of its capability to model complex, non-orthogonal configurations or fissile materials, typical of real world problems. Over the last few years, however, interest in determinist transport methods has been revived, due shortcomings in the stochastic nature of Monte Carlo approaches for certain types of analyses. Specifically, deterministic methods are superior to stochastic methods for calculations requiring accurate neutron density distributions or differential fluxes. Although Monte Carlo methods are well suited for eigenvalue calculations, they lack the localized detail necessary to assess uncertainties and sensitivities important in determining a range of applicability. Monte Carlo methods are also inefficient as a transport solution for multiple pin depletion methods. Discrete ordinates methods have long been recognized as one of the most rigorous and accurate approximations used to solve the transport equation. However, until recently, geometric constraints in finite differencing schemes have made discrete ordinates methods impractical for non-orthogonal configurations such as reactor fuel assemblies. The development of an extended step characteristic (ESC) technique removes the grid structure limitations of traditional discrete ordinates methods. The NEWT computer code, a discrete ordinates code built upon the ESC formalism, is being developed as part of the SCALE code system. This paper will demonstrate the power, versatility, and applicability of NEWT as a state-of-the-art solution for current computational needs.

  20. Experiment aboard Russian satellite "Foton M2" in 2005: new approaches for study on stimulating effect of space flight on cell proliferation and regeneration in Urodela

    NASA Astrophysics Data System (ADS)

    Grigoryan, E.; Almeida, E.; Domaratskaya, E.; Tairbekov, M.; Aleinikova, K.; Mitashov, V.

    A study on space flight effect upon processes of regeneration is due to the necessity to know their characteristics in animals and human exposed to space and earth conditions shortly after flight Several experiments on the newts performed earlier aboard Russian biosatellites showed that the rate of organ and tissue regeneration in space was greater than that on the ground Space flight effect stimulating regeneration was enduring and apparent not only just after flight but long time later as well This observation found support in studies simulated physiological weightlessness by means of fast-rotating clinostat It was shown also that the higher rate of regeneration was associated with enhanced cell proliferation For instance we found that the number of cells in S-phase in regenerating tissues was significantly greater in space-flown animals than in the ground controls However it was unclear whether cell proliferation stimulation was induced by micro- g per se or by conditions of hyper- g during launching and re-adaptation on the earth Molecular mechanisms underlying the change also remained obscure These issues were addressed by the joint Russian-USA experiment Regeneration performed on Foton-M2 in 2005 In 16- day flight we used two well-known models of regeneration lens regeneration after lensectomy and tail regeneration after amputation in adult newts Pleurodeles walt Urodela In order to evaluate cell proliferative activity in time limits of microgravity influence the original method for in-flight delivering DNA precursor BrdU

  1. Le protée est-il équipé pour le magnétotactisme ?

    NASA Astrophysics Data System (ADS)

    Bouquerel, Hélène; Valet, Jean-Pierre

    2005-07-01

    It was suggested that the proteus blind cave salamander can sense the geomagnetic field using magnetic crystals (like magnetite). We attempted to check this hypothesis by measuring the magnetization and the magnetic mineralogy of proteus from the Moulis CNRS underground laboratory. The abdomen and the rear legs of the animals were the unique body parts that revealed a detectable saturation magnetization in the order of 10 -9 A m 2. Because this magnetization was carried by magnetite crystals that have the same magnetic properties as the soil sampled in the cave, it is likely that they were ingested by the animals. Thus these experiments did not detect any crystal that would be responsible for magnetotactism. These results are in contrast with those published for the newt [J. Brassart, J.L. Kirschvink, J.B. Phillips, S.C. Borland, Ferromagnetic material in the eastern red-spotted newt, J. Exp. Biol. 202 (1999) 3155]. However the cryogenic magnetometers do not allow us to detect very small amounts of monodomain grains. This prevents us from any definite conclusion until the construction of a very sensitive cryogenic gradiometer. To cite this article: H. Bouquerel, J.-P. Valet, C. R. Geoscience 337 (2005).

  2. Urodelean amphibians in studies on microgravity: effects upon organ and tissue regeneration

    NASA Astrophysics Data System (ADS)

    Grigoryan, E. N.; Mitashov, V. I.; Anton, H. J.

    Results obtained from nine experiments performed onboard Russian biosatellites have shown that microgravity promotes tissue regeneration in the newt, Pleurodeles waltl. The effect has been reproduced in all flights and on a clinostat as well for eye tissues (lens and retina), limbs and tail. The effect was demonstrated in 1.5- to 2 -fold increase in cell proliferation in the early stages of regeneration in space flight. Animals "flown" intact and operated after flight regenerated faster than control ones and showed long-lasting micro-"g" effect. The most recent experiment flew aboard the Bion-11 biosatellite. This test was performed for study on microgravity effect on neural retina regeneration after optic nerve lesioning in the newt. Obtained results confirmed our previous information about intensification of regenerative processes in detached neural retina in urodela exposed to simulated weightlessness (Grigoryan et al., 1998). In particular, we found the increase and activation of cell populations participating in neural retina restoration and maintenance of retinal structure. Our findings suggest that promoting effect of microgravity upon regeneration could be influenced by several factors, largely influenced by a response of the whole organism to changed gravity vector. We hypothesized the synthesis of the specific range of stress proteins induced by micro-"g" and their regulative role in cell proliferation. Such a hypothesis for the existence of "altered gravity stress proteins" is discussed.

  3. The ontogenetic origins of skull shape disparity in the Triturus cristatus group.

    PubMed

    Cvijanović, Milena; Ivanović, Ana; Kalezić, Miloš L; Zelditch, Miriam L

    2014-09-01

    Comparative studies of ontogenies of closely related species provide insights into the mechanisms responsible for morphological diversification. Using geometric morphometrics, we investigated the ontogenetic dynamics of postlarval skull shape and disparity in three closely related crested newt species. The skull shapes of juveniles just after metamorphosis (hereafter metamorphs) and adult individuals were sampled by landmark configurations that describe the shape of the dorsal and ventral side of the newt skull, and analyzed separately. The three species differ in skull size and shape in metamorphs and adults. The ontogenies of dorsal and ventral skull differ in the orientation but not lengths of the ontogenetic trajectories. The disparity of dorsal skull shape increases over ontogeny, but that of ventral skull shape does not. Thus, modifications of ontogenetic trajectories can, but need not, increase the disparity of shape. In species with biphasic life-cycles, when ontogenetic trajectories for one stage can be decoupled from those of another, increases and decreases in disparity are feasible, but our results show that they need not occur.

  4. Serotonin (5-hydroxytryptamine, 5-HT) immunoreactive endocrine and neural elements in the chromaffin enteropancreatic system of amphibians and reptiles.

    PubMed

    Trandaburu, Tiberiu; Trandaburu, Ioana

    2007-01-01

    The diffuse chromaffin enteropancreatic system of nine species of amphibians (newts, frogs) and reptiles (turtles, lizards, snakes) was investigated immunohistochemically for the presence and topographic distribution of serotonin (5-hydroxytryptamine, 5-HT). The study revealed various numbers of serotonin-producing cells in the pancreas and intestinal epithelium and also immunolabelled nerve profiles in the villi of all species studied. In addition, two different morphological populations of serotonin cells ("open" and "closed") were localized in the functional segments of the intestines in the representative species of all the taxa investigated. Semi-quantitative evaluation of the immunolabelled pancreatic and enteric cells revealed significantly different mean numbers of labelled cells in different amphibian and reptilian taxa, and also between the various successive gut segments of each taxon. The ratio between "open" and "closed" varieties of serotonin cells recorded along the intestines followed a decreasing trend, progressive in lizards and snakes and more abrupt in newts, frogs and turtles. The above findings may help resolve several key stages of the phylogenetic evolution of poikilothermic vertebrates.

  5. Potential for local adaptation in response to an anthropogenic agent of selection: effects of road deicing salts on amphibian embryonic survival and development.

    PubMed

    Hopkins, Gareth R; French, Susannah S; Brodie, Edmund D

    2013-02-01

    The application of millions of tons of road deicing salts every winter in North America presents significant survival challenges to amphibians inhabiting roadside habitats. While much is known of the effects of NaCl on anuran tadpoles, less is known of effects on amphibian eggs, or any caudate life stage. In addition, little is known of the effects of MgCl2, which is now the 2nd most commonly used road deicer. Most studies have considered amphibians to be helpless victims of deicing salts, and ignore the possibility of the evolution of local adaptation to this stressor. We attempt to address these knowledge gaps and explore this evolutionary potential by examining the effects of NaCl and MgCl2 on the survival and development of eggs from different female rough-skinned newts (Taricha granulosa) from the same population. We demonstrate that both salts, at environmentally relevant concentrations, severely affect the embryonic survival and development of this amphibian, but that the effects of the salt are dependent on the identity of the mother. This female × treatment interaction results in substantial variation in tolerance to road deicing salts among newt families, providing the raw material necessary for natural selection and the evolution of local adaptation in this amphibian.

  6. Developmental and Evolutionary History Affect Survival in Stressful Environments

    PubMed Central

    Hopkins, Gareth R.; Brodie, Edmund D.; French, Susannah S.

    2014-01-01

    The world is increasingly impacted by a variety of stressors that have the potential to differentially influence life history stages of organisms. Organisms have evolved to cope with some stressors, while with others they have little capacity. It is thus important to understand the effects of both developmental and evolutionary history on survival in stressful environments. We present evidence of the effects of both developmental and evolutionary history on survival of a freshwater vertebrate, the rough-skinned newt (Taricha granulosa) in an osmotically stressful environment. We compared the survival of larvae in either NaCl or MgCl2 that were exposed to salinity either as larvae only or as embryos as well. Embryonic exposure to salinity led to greater mortality of newt larvae than larval exposure alone, and this reduced survival probability was strongly linked to the carry-over effect of stunted embryonic growth in salts. Larval survival was also dependent on the type of salt (NaCl or MgCl2) the larvae were exposed to, and was lowest in MgCl2, a widely-used chemical deicer that, unlike NaCl, amphibian larvae do not have an evolutionary history of regulating at high levels. Both developmental and evolutionary history are critical factors in determining survival in this stressful environment, a pattern that may have widespread implications for the survival of animals increasingly impacted by substances with which they have little evolutionary history. PMID:24748021

  7. Adapting biodegradable oligo(poly(ethylene glycol) fumarate) hydrogels for pigment epithelial cell encapsulation and lens regeneration.

    PubMed

    Zhang, Mimi W; Park, Hansoo; Guo, Xuan; Nakamura, Kenta; Raphael, Robert M; Kasper, F Kurtis; Mikos, Antonios G; Tsonis, Panagiotis A

    2010-04-01

    This study investigated the encapsulation of newt iris pigment epithelial cells (PECs), which have the ability to regenerate a lens by trans-differentiation in vivo, within a biodegradable hydrogel of oligo(poly(ethylene glycol) fumarate) crosslinked with poly(ethylene glycol)-diacrylate. Hydrogel beads of initial diameter of 1 mm were fabricated by a molding technique. The swelling ratio and degradation rate of the hydrogel beads decreased with increasing crosslinking ratios. Confocal microscopy confirmed the cytocompatibility of crosslinking hydrogel formulations as evidenced by the viability of an encapsulated model cell line within a crosslinked hydrogel bead. Hydrogel beads encapsulating iris PECs were also implanted into lentectomized newts in vivo; histological evaluation of explants after 30 days revealed a regenerated lens, thus demonstrating that the presence of degrading hydrogel did not adversely affect lens regeneration. The results of this study suggest the potential of a method for lens regeneration involving oligo(poly(ethylene glycol) fumarate) hydrogels for iris PEC encapsulation and transplantation.

  8. Functional joint regeneration is achieved using reintegration mechanism in Xenopus laevis.

    PubMed

    Tsutsumi, Rio; Yamada, Shigehito; Agata, Kiyokazu

    2016-02-01

    A functional joint requires integration of multiple tissues: the apposing skeletal elements should form an interlocking structure, and muscles should insert into skeletal tissues via tendons across the joint. Whereas newts can regenerate functional joints after amputation, Xenopus laevis regenerates a cartilaginous rod without joints, a "spike." Previously we reported that the reintegration mechanism between the remaining and regenerated tissues has a significant effect on regenerating joint morphogenesis during elbow joint regeneration in newt. Based on this insight into the importance of reintegration, we amputated frogs' limbs at the elbow joint and found that frogs could regenerate a functional elbow joint between the remaining tissues and regenerated spike. During regeneration, the regenerating cartilage was partially connected to the remaining articular cartilage to reform the interlocking structure of the elbow joint at the proximal end of the spike. Furthermore, the muscles of the remaining part inserted into the regenerated spike cartilage via tendons. This study might open up an avenue for analyzing molecular and cellular mechanisms of joint regeneration using Xenopus.

  9. Micronucleus test on Triturus carnifex as a tool for environmental biomonitoring.

    PubMed

    Udroiu, I; Sgura, A; Vignoli, L; Bologna, M A; D'Amen, M; Salvi, D; Ruzza, A; Antoccia, A; Tanzarella, C

    2015-05-01

    The amphibian micronucleus test has been widely used during the last 30 years to test the genotoxic properties of several chemicals and as a tool for ecogenotoxic monitoring. The vast majority of these studies were performed on peripheral blood of urodelan larvae and anuran tadpoles and to a lesser extent adults were also used. In this study, we developed protocols for measuring micronuclei in adult shed skin cells and larval gill cells of the Italian crested newt (Triturus carnifex). Amphibians were collected from ponds in two protected areas in Italy that differed in their radon content. Twenty-three adult newts and 31 larvae were captured from the radon-rich pond, while 20 adults and 27 larvae were taken from the radon-free site. The animals were brought to the laboratory and the micronucleus test was performed on peripheral blood and shed skins taken from the adults and on larval gills. Samples from the radon-rich site showed micronucleus frequencies higher than those from the radon-free site and the difference was statistically significant in gill cells (P < 0.00001). Moreover, the larval gills seem to be more sensitive than the adult tissues. This method represents an easy (and noninvasive in the case of the shed skin) application of the micronucleus assay that can be useful for environmental studies in situ.

  10. Side-by-side secretion of Late Palaeozoic diverged courtship pheromones in an aquatic salamander

    PubMed Central

    Van Bocxlaer, Ines; Treer, Dag; Maex, Margo; Vandebergh, Wim; Janssenswillen, Sunita; Stegen, Gwij; Kok, Philippe; Willaert, Bert; Matthijs, Severine; Martens, Erik; Mortier, Anneleen; de Greve, Henri; Proost, Paul; Bossuyt, Franky

    2015-01-01

    Males of the advanced salamanders (Salamandroidea) attain internal fertilization without a copulatory organ by depositing a spermatophore on the substrate in the environment, which females subsequently take up with their cloaca. The aquatically reproducing modern Eurasian newts (Salamandridae) have taken this to extremes, because most species do not display close physical contact during courtship, but instead largely rely on females following the male track at spermatophore deposition. Although pheromones have been widely assumed to represent an important aspect of male courtship, molecules able to induce the female following behaviour that is the prelude for successful insemination have not yet been identified. Here, we show that uncleaved sodefrin precursor-like factor (SPF) protein pheromones are sufficient to elicit such behaviour in female palmate newts (Lissotriton helveticus). Combined transcriptomic and proteomic evidence shows that males simultaneously tail-fan multiple ca 20 kDa glycosylated SPF proteins during courtship. Notably, molecular dating estimates show that the diversification of these proteins already started in the late Palaeozoic, about 300 million years ago. Our study thus not only extends the use of uncleaved SPF proteins outside terrestrially reproducing plethodontid salamanders, but also reveals one of the oldest vertebrate pheromone systems. PMID:25694622

  11. Potential for local adaptation in response to an anthropogenic agent of selection: effects of road deicing salts on amphibian embryonic survival and development

    PubMed Central

    Hopkins, Gareth R; French, Susannah S; Brodie, Edmund D

    2013-01-01

    The application of millions of tons of road deicing salts every winter in North America presents significant survival challenges to amphibians inhabiting roadside habitats. While much is known of the effects of NaCl on anuran tadpoles, less is known of effects on amphibian eggs, or any caudate life stage. In addition, little is known of the effects of MgCl2, which is now the 2nd most commonly used road deicer. Most studies have considered amphibians to be helpless victims of deicing salts, and ignore the possibility of the evolution of local adaptation to this stressor. We attempt to address these knowledge gaps and explore this evolutionary potential by examining the effects of NaCl and MgCl2 on the survival and development of eggs from different female rough-skinned newts (Taricha granulosa) from the same population. We demonstrate that both salts, at environmentally relevant concentrations, severely affect the embryonic survival and development of this amphibian, but that the effects of the salt are dependent on the identity of the mother. This female × treatment interaction results in substantial variation in tolerance to road deicing salts among newt families, providing the raw material necessary for natural selection and the evolution of local adaptation in this amphibian. PMID:23467723

  12. Cardiomyocyte proliferation in cardiac development and regeneration: a guide to methodologies and interpretations.

    PubMed

    Leone, Marina; Magadum, Ajit; Engel, Felix B

    2015-10-01

    The newt and the zebrafish have the ability to regenerate many of their tissues and organs including the heart. Thus, a major goal in experimental medicine is to elucidate the molecular mechanisms underlying the regenerative capacity of these species. A wide variety of experiments have demonstrated that naturally occurring heart regeneration relies on cardiomyocyte proliferation. Thus, major efforts have been invested to induce proliferation of mammalian cardiomyocytes in order to improve cardiac function after injury or to protect the heart from further functional deterioration. In this review, we describe and analyze methods currently used to evaluate cardiomyocyte proliferation. In addition, we summarize the literature on naturally occurring heart regeneration. Our analysis highlights that newt and zebrafish heart regeneration relies on factors that are also utilized in cardiomyocyte proliferation during mammalian fetal development. Most of these factors have, however, failed to induce adult mammalian cardiomyocyte proliferation. Finally, our analysis of mammalian neonatal heart regeneration indicates experiments that could resolve conflicting results in the literature, such as binucleation assays and clonal analysis. Collectively, cardiac regeneration based on cardiomyocyte proliferation is a promising approach for improving adult human cardiac function after injury, but it is important to elucidate the mechanisms arresting mammalian cardiomyocyte proliferation after birth and to utilize better assays to determine formation of new muscle mass.

  13. Contributions to the functional morphology of caudate skulls: kinetic and akinetic forms

    PubMed Central

    Handschuh, Stephan; Lukanov, Simeon; Naumov, Borislav

    2016-01-01

    A strongly ossified and rigid skull roof, which prevents parietal kinesis, has been reported for the adults of all amphibian clades. Our μ-CT investigations revealed that the Buresch’s newt (Triturus ivanbureschi) possess a peculiar cranial construction. In addition to the typical amphibian pleurokinetic articulation between skull roof and palatoquadrate associated structures, we found flexible connections between nasals and frontals (prokinesis), vomer and parasphenoid (palatokinesis), and between frontals and parietals (mesokinesis). This is the first description of mesokinesis in urodelans. The construction of the skull in the Buresch’s newts also indicates the presence of an articulation between parietals and the exocipitals, discussed as a possible kind of metakinesis. The specific combination of pleuro-, pro-, meso-, palato-, and metakinetic skull articulations indicate to a new kind of kinetic systems unknown for urodelans to this date. We discuss the possible neotenic origin of the skull kinesis and pose the hypothesis that the kinesis in T. ivanbureschi increases the efficiency of fast jaw closure. For that, we compared the construction of the skull in T. ivanbureschi to the akinetic skull of the Common fire salamander Salamandra salamandra. We hypothesize that the design of the skull in the purely terrestrial living salamander shows a similar degree of intracranial mobility. However, this mobility is permitted by elasticity of some bones and not by true articulation between them. We comment on the possible relation between the skull construction and the form of prey shaking mechanism that the species apply to immobilize their victims. PMID:27688958

  14. Amphibian and reptile abundance in riparian and upslope areas of five forest types in western Oregon

    USGS Publications Warehouse

    Gomez, D.M.; Anthony, R.G.

    1996-01-01

    We compared species composition and relative abundance of herpetofauna between riparian and upslope habitats among 5 forest types (shrub, open sapling-pole, large sawtimber and old-growth conifer forests, and deciduous forests) in Western Oregon. Riparian- and upslope- associated species were identified based on capture frequencies from pitfall trapping. Species richness was similar among forest types but slightly greater in the shrub stands. The abundances of 3 species differed among forest types. Total captures was highest in deciduous forests, intermediate in the mature conifer forests, and lowest in the 2 young coniferous forests. Species richness was similar between stream and upslope habitats; however, captures were higher in riparian than upslope habitat. Tailed frogs (Ascaphus truei), Dunn's salamanders (Plethodon dunni), roughskin newts(Tanicha granulosa), Pacific giant salamanders (Dicamptodon tenebrosus) and red-legged frogs(Rana aurora) were captured more frequently in riparian than upslope habitats. Of these species the red-legged frog and Pacific giant salamander may depend on riparian habitat for at least part of their life requirements, while tailed frogs, Dunn's salamanders and roughskin newts appear to be riparian associated species. In addition, we found Oregon salamanders (Ensatina eschscholtzi) were associated with upslope habitats. We suggest riparian management zones should be al least 75-100 m on each side of the stream and that management for upslope/and or old forest associates may be equally as important as for riparian species.

  15. Side-by-side secretion of Late Palaeozoic diverged courtship pheromones in an aquatic salamander.

    PubMed

    Van Bocxlaer, Ines; Treer, Dag; Maex, Margo; Vandebergh, Wim; Janssenswillen, Sunita; Stegen, Gwij; Kok, Philippe; Willaert, Bert; Matthijs, Severine; Martens, Erik; Mortier, Anneleen; de Greve, Henri; Proost, Paul; Bossuyt, Franky

    2015-03-22

    Males of the advanced salamanders (Salamandroidea) attain internal fertilization without a copulatory organ by depositing a spermatophore on the substrate in the environment, which females subsequently take up with their cloaca. The aquatically reproducing modern Eurasian newts (Salamandridae) have taken this to extremes, because most species do not display close physical contact during courtship, but instead largely rely on females following the male track at spermatophore deposition. Although pheromones have been widely assumed to represent an important aspect of male courtship, molecules able to induce the female following behaviour that is the prelude for successful insemination have not yet been identified. Here, we show that uncleaved sodefrin precursor-like factor (SPF) protein pheromones are sufficient to elicit such behaviour in female palmate newts (Lissotriton helveticus). Combined transcriptomic and proteomic evidence shows that males simultaneously tail-fan multiple ca 20 kDa glycosylated SPF proteins during courtship. Notably, molecular dating estimates show that the diversification of these proteins already started in the late Palaeozoic, about 300 million years ago. Our study thus not only extends the use of uncleaved SPF proteins outside terrestrially reproducing plethodontid salamanders, but also reveals one of the oldest vertebrate pheromone systems.

  16. Biodiversity of Trichoderma Community in the Tidal Flats and Wetland of Southeastern China

    PubMed Central

    Saravanakumar, Kandasamy; Yu, Chuanjin; Dou, Kai; Wang, Meng; Li, Yaqian; Chen, Jie

    2016-01-01

    To investigate the biodiversity of Trichoderma (Hypocreaceae) and their relation to sediment physical and chemical properties, we collected a total of 491 sediment samples from coastal wetlands (tidal flat and wetland) in Southeast China. Further, we applied two types of molecular approaches such as culture dependent and independent methods for identification of Trichoderma spp. A total of 254 isolates were obtained and identified to 13 species such as T. aureoviride, T. asperellum, T. harzianum, T. atroviride, T. koningiopsis, T. longibrachiatum, T. koningii. T. tawa, T. viridescens, T. virens, T. hamatum, T. viride, and T. velutinum by the culture-dependent (CD) method of these, T. tawa was newly described in China. Subsequently, the culture indepented method of 454 pyrosequencing analysis revealed a total of six species such as T. citrinoviride, T. virens, T. polysporum, T. harzianum/Hypocrea lixii and two unknown species. Notably, T. citrinoviride and T. polysporum were not found by the CD method. Therefore, this work revealed that the combination of these two methods could show the higher biodiversity of Trichoderma spp., than either of this method alone. Among the sampling sites, Hangzhou, Zhejiang Province, exhibited rich biodiversity and low in Fengxian. Correlation and Redundancy discriminant analysis (RDA) revealed that sediment properties of temperature, redox potential (Eh) and pH significantly influenced the biodiversity of Trichoderma spp. PMID:28002436

  17. Blue pigment in Hypocrea caerulescens sp. nov. and two additional new species in sect. Trichoderma

    PubMed Central

    Jaklitsch, Walter M.; Stadler, Marc; Voglmayr, Hermann

    2012-01-01

    Three new species of Hypocrea/Trichoderma sect. Trichoderma (Hypocreaceae, Hypocreales, Ascomycota, Fungi) are described from recent collections in southern Europe and the Canary Islands. They have been characterized by morphological and molecular methods, including microscopic examination of the teleomorph in thin sections, the anamorph, growth rate experiments and phylogenetic analyses based on a part of the translation elongation factor 1-alpha encoding gene (tef1) containing the two last introns and a part of the rpb2 gene, encoding the second largest RNA polymerase subunit. Analyses involving tef1 did not unequivocally resolve the sister clade relationship of Hypocrea caerulescens relative to the Koningii and Viride clades, while analyses based on rpb2 clearly suggest a close relationship with the former, although the phenotype of H. caerulescens is similar to H. viridescens, particularly by its warted conidia and a coconut-like odor in CMD culture. Hypocrea hispanica and T. samuelsii however are clearly related to the Viride clade by both phylogenetic markers, despite their morphological similarity to H. koningii and its relatives. An apparently specific blue pigment is formed in CMD cultures by Hypocrea caerulescens but could not be obtained by extraction with organic solvents. PMID:22453122

  18. Identification of lactic acid bacteria involved in the spoilage of pasteurized "foie gras" products.

    PubMed

    Matamoros, S; André, S; Hue, I; Prévost, H; Pilet, M F

    2010-07-01

    The spoiling microflora of a re-packaged French "foie gras" product was studied. A total of 54 isolates, originating from two different factories, were identified using phenotypical and molecular methods (partial 16S rDNA sequencing). Weissella viridescens was the main species detected in the products from factory 1 (64% of the isolates). These products had a low lactic acid concentration and were considered as non-spoiled. The microflora of factory 2 was dominated mainly by the genus Lactobacillus (95% of the isolates), and the high lactic acid concentration of these products was linked with a strong spoilage. Among the 30 Lactobacillus strains, three species were predominant: Lactobacillus sakei (nine isolates), Lactobacillus coryniformis (eight isolates) and Lactobacillus paraplantarum (five isolates). Challenge tests were performed to confirm the involvement of the Lactobacillus strains in the spoilage of the product. Sterile "foie gras" samples were inoculated with 14 LAB strains from the collection. The most acidifying strains belonged to the species L. sakei, Lactobacillus plantarum and L. paraplantarum. This confirmed the role of the strains from the Lactobacillus genus as the main spoilers of "foie gras" products and will be useful to design new quality protocols and extend the shelf-life of these products.

  19. Biodiversity of Trichoderma Community in the Tidal Flats and Wetland of Southeastern China.

    PubMed

    Saravanakumar, Kandasamy; Yu, Chuanjin; Dou, Kai; Wang, Meng; Li, Yaqian; Chen, Jie

    2016-01-01

    To investigate the biodiversity of Trichoderma (Hypocreaceae) and their relation to sediment physical and chemical properties, we collected a total of 491 sediment samples from coastal wetlands (tidal flat and wetland) in Southeast China. Further, we applied two types of molecular approaches such as culture dependent and independent methods for identification of Trichoderma spp. A total of 254 isolates were obtained and identified to 13 species such as T. aureoviride, T. asperellum, T. harzianum, T. atroviride, T. koningiopsis, T. longibrachiatum, T. koningii. T. tawa, T. viridescens, T. virens, T. hamatum, T. viride, and T. velutinum by the culture-dependent (CD) method of these, T. tawa was newly described in China. Subsequently, the culture indepented method of 454 pyrosequencing analysis revealed a total of six species such as T. citrinoviride, T. virens, T. polysporum, T. harzianum/Hypocrea lixii and two unknown species. Notably, T. citrinoviride and T. polysporum were not found by the CD method. Therefore, this work revealed that the combination of these two methods could show the higher biodiversity of Trichoderma spp., than either of this method alone. Among the sampling sites, Hangzhou, Zhejiang Province, exhibited rich biodiversity and low in Fengxian. Correlation and Redundancy discriminant analysis (RDA) revealed that sediment properties of temperature, redox potential (Eh) and pH significantly influenced the biodiversity of Trichoderma spp.

  20. Identification and significance of Weissella species infections

    PubMed Central

    Kamboj, Kamal; Vasquez, Amber; Balada-Llasat, Joan-Miquel

    2015-01-01

    Weissella spp. are non-spore forming, catalase-negative, gram-positive coccobacilli. They are often misidentified by traditional and commercial phenotypic identification methods as Lactobacillus spp. or Lactobacillus-like organisms. Weissella spp. were previously grouped along with Lactobacillus spp., Leuconostoc spp., and Pediococcus spp. Utilization of more sensitive methods like DNA sequencing or Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) has facilitated identification of Weissella as a unique genus. Nineteen species have been identified to date. W. confusa, W. cibaria, and W. viridescens are the only species isolated from humans. The true prevalence of Weissella spp. continues to be probably underestimated. Weissella spp. strains have been isolated from a wide range of habitats including raw milk, feces, fermented cereals, and vegetables. Weisella is believed to be a rare cause of usually nonfatal infections in humans, and is often considered a contaminant. However, in recent years, Weissella spp. have been implicated in bacteremia, abscesses, prosthetic joint infections, and infective endocarditis. Alterations of the gut flora from surgery or chemotherapy are believed to facilitate translocation of Weissella spp. due to disruption of the mucosal barrier, predisposing the host to infection with this organism. Implications of the isolation of Weissella spp. from blood must be interpreted in context of underlying risk factors. Weissella spp. are inherently resistant to vancomycin. Therefore, early consideraton of the pathogenic role of this bacteria and choice of alternate therapy is important to assure better outcomes. PMID:26583007

  1. Trichoderma species occurring on wood with decay symptoms in mountain forests in Central Europe: genetic and enzymatic characterization.

    PubMed

    Błaszczyk, Lidia; Strakowska, Judyta; Chełkowski, Jerzy; Gąbka-Buszek, Agnieszka; Kaczmarek, Joanna

    2016-08-01

    The aim of this study was to explore the species diversity of Trichoderma obtained from samples of wood collected in the forests of the Gorce Mountains (location A), Karkonosze Mountains (location B) and Tatra Mountains (location C) in Central Europe and to examine the cellulolytic and xylanolytic activity of these species as an expression of their probable role in wood decay processes. The present study has led to the identification of the following species and species complex: Trichoderma atroviride P. Karst., Trichoderma citrinoviride Bissett, Trichoderma cremeum P. Chaverri & Samuels, Trichoderma gamsii Samuels & Druzhin., Trichoderma harzianum complex, Trichoderma koningii Oudem., Trichoderma koningiopsis Samuels, C. Suárez & H.C. Evans, Trichoderma longibrachiatum Rifai, Trichoderma longipile Bissett, Trichoderma sp. (Hypocrea parapilulifera B.S. Lu, Druzhin. & Samuels), Trichoderma viride Schumach. and Trichoderma viridescens complex. Among them, T. viride was observed as the most abundant species (53 % of all isolates) in all the investigated locations. The Shannon's biodiversity index (H), evenness (E), and the Simpson's biodiversity index (D) calculations for each location showed that the highest species diversity and evenness were recorded for location A-Gorce Mountains (H' = 1.71, E = 0.82, D = 0.79). The preliminary screening of 119 Trichoderma strains for cellulolytic and xylanolytic activity showed the real potential of all Trichoderma species originating from wood with decay symptoms to produce cellulases and xylanases-the key enzymes in plant cell wall degradation.

  2. Isolation of lactic acid bacteria bound to the porcine intestinal mucosa and an analysis of their moonlighting adhesins

    PubMed Central

    KINOSHITA, Hideki; OHUCHI, Satoko; ARAKAWA, Kensuke; WATANABE, Masamichi; KITAZAWA, Haruki; SAITO, Tadao

    2016-01-01

    The adhesion of lactic acid bacteria (LAB) to the intestinal mucosa is one of the criteria in selecting for probiotics. Eighteen LAB were isolated from porcine intestinal mucin (PIM): ten strains of Lactobacillus, six strains of Weissella, and two strains of Streptococcus. Using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) for phosphate-buffered saline (PBS) extracts from the LAB, many bands were detected in half of the samples, while a few and/or no clear bands were detected in the other half. All six of the selected LAB showed adhesion to PIM. L. johnsonii MYU 214 and MYU 221 showed adhesion at more than 10%. W. viridescens MYU 208, L. reuteri MYU 213, L. mucosae MYU 225, and L. agilis MYU 227 showed medium levels of adhesion at 5.9–8.3%. In a comprehensive analysis for the adhesins in the PBS extracts using a receptor overlay analysis, many moonlighting proteins were detected and identified as candidates for adhesins: GroEL, enolase, and elongation factor Tu in MYU 208; peptidase C1, enolase, formyl-CoA transferase, phosphoglyceromutase, triosephosphate isomerase, and phosphofructokinase in MYU 221; and DnaK, enolase, and phosphoglycerate kinase in MYU 227. These proteins in the PBS extracts, which included such things as molecular chaperones and glycolytic enzymes, may play important roles as adhesins. PMID:27867805

  3. Chromosome motion during attachment to the vertebrate spindle: initial saltatory-like behavior of chromosomes and quantitative analysis of force production by nascent kinetochore fibers

    PubMed Central

    1991-01-01

    Before forming a monopolar attachment to the closest spindle pole, chromosomes attaching in newt (Taricha granulosa) pneumocytes generally reside in an optically clear region of cytoplasm that is largely devoid of cytoskeletal components, organelles, and other chromosomes. We have previously demonstrated that chromosome attachment in these cells occurs when an astral microtubule contacts one of the kinetochores (Hayden, J., S. S. Bowser, and C. L. Rieder. 1990. J. Cell Biol. 111:1039-1045), and that once this association is established the chromosome can be transported poleward along the surface of the microtubule (Rieder, C. L., and S. P. Alexander. 1990. J. Cell Biol. 110:81-95). In the study reported here we used video enhanced differential interference contrast light microscopy and digital image processing to compare, at high spatial and temporal resolution (0.1 microns and 0.93 s, respectively), the microtubule-mediated poleward movement of attaching chromosomes and poleward moving particles on the spindle. The results of this analysis demonstrate obvious similarities between minus end-directed particle motion on the newt pneumocyte spindle and the motion of attaching chromosomes. This is consistent with the hypothesis that both are driven by a similar force-generating mechanism. We then used the Brownian displacements of particles in the vicinity of attaching chromosomes to calculate the apparent viscosity of cytoplasm through which the chromosomes were moving. From these data, and that from our kinetic analyses and previous work, we calculate the force-producing potential of nascent kinetochore fibers in newt pneumocytes to be approximately 0.1-7.4 x 10(-6) dyn/microtubule) This is essentially equivalent to that calculated by Nicklas (Nicklas, R.B. 1988. Annu. Rev. Biophys. Biophys. Chem. 17:431- 449) for prometaphase (4 x 10(-6) dyn/microtubule) and anaphase (5 x 10(-6) dyn/microtubule) chromosomes in Melanoplus. Thus, within the limits of experimental

  4. Neurosteroid Biosynthesis in the Brain of Amphibians

    PubMed Central

    Vaudry, Hubert; Do Rego, Jean-Luc; Burel, Delphine; Luu-The, Van; Pelletier, Georges; Vaudry, David; Tsutsui, Kazuyoshi

    2011-01-01

    Amphibians have been widely used to investigate the synthesis of biologically active steroids in the brain and the regulation of neurosteroid production by neurotransmitters and neuropeptides. The aim of the present review is to summarize the current knowledge regarding the neuroanatomical distribution and biochemical activity of steroidogenic enzymes in the brain of anurans and urodeles. The data accumulated over the past two decades demonstrate that discrete populations of neurons and/or glial cells in the frog and newt brains express the major steroidogenic enzymes and are able to synthesize de novo a number of neurosteroids from cholesterol/pregnenolone. Since neurosteroidogenesis has been conserved during evolution from amphibians to mammals, it appears that neurosteroids must play important physiological functions in the central nervous system of vertebrates. PMID:22649387

  5. Comparative analysis of ear-hole closure identifies epimorphic regeneration as a discrete trait in mammals.

    PubMed

    Gawriluk, Thomas R; Simkin, Jennifer; Thompson, Katherine L; Biswas, Shishir K; Clare-Salzler, Zak; Kimani, John M; Kiama, Stephen G; Smith, Jeramiah J; Ezenwa, Vanessa O; Seifert, Ashley W

    2016-04-25

    Why mammals have poor regenerative ability has remained a long-standing question in biology. In regenerating vertebrates, injury can induce a process known as epimorphic regeneration to replace damaged structures. Using a 4-mm ear punch assay across multiple mammalian species, here we show that several Acomys spp. (spiny mice) and Oryctolagus cuniculus completely regenerate tissue, whereas other rodents including MRL/MpJ 'healer' mice heal similar injuries by scarring. We demonstrate ear-hole closure is independent of ear size, and closure rate can be modelled with a cubic function. Cellular and genetic analyses reveal that injury induces blastema formation in Acomys cahirinus. Despite cell cycle re-entry in Mus musculus and A. cahirinus, efficient cell cycle progression and proliferation only occurs in spiny mice. Together, our data unite blastema-mediated regeneration in spiny mice with regeneration in other vertebrates such as salamanders, newts and zebrafish, where all healthy adults regenerate in response to injury.

  6. Sox2-mediated regulation of adult neural crest precursors and skin repair.

    PubMed

    Johnston, Adam P W; Naska, Sibel; Jones, Karen; Jinno, Hiroyuki; Kaplan, David R; Miller, Freda D

    2013-01-01

    Nerve-derived neural crest cells are essential for regeneration in certain animals, such as newts. Here, we asked whether they play a similar role during mammalian tissue repair, focusing on Sox2-positive neural crest precursors in skin. In adult skin, Sox2 was expressed in nerve-terminal-associated neural crest precursor cells (NCPCs) around the hair follicle bulge, and following injury was induced in nerve-derived cells, likely dedifferentiated Schwann cell precursors. At later times postinjury, Sox2-positive cells were scattered throughout the regenerating dermis, and lineage tracing showed that these were all neural-crest-derived NCPCs. These Sox2-positive NCPCs were functionally important, since acute deletion of Sox2 prior to injury caused a decrease of NCPCs in the wound and aberrant skin repair. These data demonstrate that Sox2 regulates skin repair, likely by controlling NCPCs, and raise the possibility that nerve-derived NCPCs may play a general role in mammalian tissue repair.

  7. Utilization of ontology look-up services in information retrieval for biomedical literature.

    PubMed

    Vishnyakova, Dina; Pasche, Emilie; Lovis, Christian; Ruch, Patrick

    2013-01-01

    With the vast amount of biomedical data we face the necessity to improve information retrieval processes in biomedical domain. The use of biomedical ontologies facilitated the combination of various data sources (e.g. scientific literature, clinical data repository) by increasing the quality of information retrieval and reducing the maintenance efforts. In this context, we developed Ontology Look-up services (OLS), based on NEWT and MeSH vocabularies. Our services were involved in some information retrieval tasks such as gene/disease normalization. The implementation of OLS services significantly accelerated the extraction of particular biomedical facts by structuring and enriching the data context. The results of precision in normalization tasks were boosted on about 20%.

  8. Phyllodistomum kanae sp. nov. (Trematoda: Gorgoderidae), a bladder fluke from the Ezo salamander Hynobius retardatus.

    PubMed

    Nakao, Minoru

    2015-10-01

    The Ezo salamander, Hynobius retardatus, is endemic only to Hokkaido, the northernmost island of Japan. Gravid flukes of the family Gorgoderidae were discovered from the urinary bladder of H. retardatus. The parasites were identified as a new species named Phyllodistomum kanae sp. nov. In the neighboring Honshu island another bladder fluke, Phyllodistomum patellare, has already been found from the Japanese newt. The new species clearly differs from P. patellare in having a spherical ovary and very weakly lobed testes. The discovery of species of Phyllodistomum from urodelan amphibians is very uncommon in Eurasia. A molecular phylogeny based on 28S ribosomal DNA suggests that sphaeriid bivalves may serve as the first intermediate host for the new species.

  9. Exploring the Effect of Asymmetric Mitochondrial DNA Introgression on Estimating Niche Divergence in Morphologically Cryptic Species

    PubMed Central

    Wielstra, Ben; Arntzen, Jan W.

    2014-01-01

    If potential morphologically cryptic species, identified based on differentiated mitochondrial DNA, express ecological divergence, this increases support for their treatment as distinct species. However, mitochondrial DNA introgression hampers the correct estimation of ecological divergence. We test the hypothesis that estimated niche divergence differs when considering nuclear DNA composition or mitochondrial DNA type as representing the true species range. We use empirical data of two crested newt species (Amphibia: Triturus) which possess introgressed mitochondrial DNA from a third species in part of their ranges. We analyze the data in environmental space by determining Fisher distances in a principal component analysis and in geographical space by determining geographical overlap of species distribution models. We find that under mtDNA guidance in one of the two study cases niche divergence is overestimated, whereas in the other it is underestimated. In the light of our results we discuss the role of estimated niche divergence in species delineation. PMID:24743746

  10. Mechanisms of adaptation in a predator-prey arms race: TTX-resistant sodium channels.

    PubMed

    Geffeney, Shana; Brodie, Edmund D; Ruben, Peter C; Brodie, Edmund D

    2002-08-23

    Populations of the garter snake Thamnophis sirtalis have evolved geographically variable resistance to tetrodotoxin (TTX) in a coevolutionary arms race with their toxic prey, newts of the genus Taricha. Here, we identify a physiological mechanism, the expression of TTX-resistant sodium channels in skeletal muscle, responsible for adaptive diversification in whole-animal resistance. Both individual and population differences in the ability of skeletal muscle fibers to function in the presence of TTX correlate closely with whole-animal measures of TTX resistance. Demonstration of individual variation in an essential physiological function responsible for the adaptive differences among populations is a step toward linking the selective consequences of coevolutionary interactions to geographic and phylogenetic patterns of diversity.

  11. From healing to witchcraft: on ritual speech and roboticization in the hospital.

    PubMed

    Pine, Adrienne

    2011-06-01

    Healthcare Information Technology (HIT), touted as a panacea by U.S. political actors ranging from Newt Gingrich to Barack Obama, is central to emerging forms of healthcare governance which Holmes et al.-in their critique of the institutionalization of magical thinking brought about by Orwellian techno-Newspeak-have provocatively labeled fascistic. Drawing from data collected over 3 years of working with and teaching continuing education (CE) courses for thousands of registered nurses as lead political educator for the California Nurses Association/National Nurses Organizing Committee (CNA/NNOC), I argue that HIT is an integral component of a broader technological restructuring of healthcare and thus society, both of which are part of a social discourse that is tied to a transformative system of ritual speech, with profound implications for healthcare work, patient health, and democracy.

  12. [Biological experiments in flights of unmanned space craft Foton-M2 and Foton-M3].

    PubMed

    Ilyin, E A

    2013-01-01

    Missions of unmanned spacecraft Foton-M2 (2005) and Foton-M3 (2007) of 16 and 12 days in duration, respectively, provided an opportunity to conduct the Russian/US experiments with snails (Helix lucorum and Helix aspera), newts (Pleurodeles waltli), geckos (Pachydactilus turneri) and microorganisms (Streptomyces lividans 66, E. coli and others). Besides, Foton-M3 carried a Russian experiment with Mongolian gerbils (Meriones unguiculatus). Objectives of the space experiments were to study the micro-g effects on the living systems' behavior, structure and functioning, post-traumatic regeneration of bone and organs, stable inheritance of plasmid pIJ 702, and melanin pigment synthesis by streptomycets. The survey paper presents the major findings of a large team of investigators.

  13. Influence of longitudinal whole animal clinorotation on lens, tail, and limb regeneration in urodeles

    NASA Astrophysics Data System (ADS)

    Anton, H. J.; Grigoryan, E. N.; Mitashov, V. I.

    Two species of newts (Urodela) and two types of clinostats for fast clinorotation (60 rpm) were used to investigate the influence of simulated weightlessness on regeneration and to compare results obtained with data from spaceflight experiments. Seven or fourteen days of weightlessness in Russian biosatellites caused acceleration of lens and limb regeneration by an increase in cell proliferation, differentiation, and rate of morphogenesis in comparison with ground controls. After a comparable time of clinorotation the results obtained with Triturus vulgaris using a horizontal clinostat were similar to those found in spaceflight. In contrast, in Pleurodeles waltl using both horizontal and radial clinostats the results were contradictionary compared to Triturus. We speculate that different levels of gravity or/and species specific thresholds for gravitational sensitivity could be responsible for these contradictionary results.

  14. Wake Management Strategies for Reduction of Turbomachinery Fan Noise

    NASA Technical Reports Server (NTRS)

    Waitz, Ian A.

    1998-01-01

    The primary objective of our work was to evaluate and test several wake management schemes for the reduction of turbomachinery fan noise. Throughout the course of this work we relied on several tools. These include 1) Two-dimensional steady boundary-layer and wake analyses using MISES (a thin-shear layer Navier-Stokes code), 2) Two-dimensional unsteady wake-stator interaction simulations using UNSFLO, 3) Three-dimensional, steady Navier-Stokes rotor simulations using NEWT, 4) Internal blade passage design using quasi-one-dimensional passage flow models developed at MIT, 5) Acoustic modeling using LINSUB, 6) Acoustic modeling using VO72, 7) Experiments in a low-speed cascade wind-tunnel, and 8) ADP fan rig tests in the MIT Blowdown Compressor.

  15. Cold-induced changes in amphibian oocytes

    SciTech Connect

    Angelier, N.; Moreau, N.A.; N'Da, E.A.; Lautredou, N.F. )

    1989-08-01

    Female Pleurodeles waltl newts (Amphibia, urodele), usually raised at 20 degrees C, were submitted to low temperatures; oocytes responded to this cold stress by drastic changes both in lampbrush chromosome structure and in protein pattern. Preexisting lateral loops of lampbrush chromosomes were reduced in size and number, while cold-induced loops which were tremendously developed, occurred on defined bivalents of the oocyte at constant, reproducible sites. A comparison of protein patterns in control and stressed oocytes showed two main differences: in stressed oocytes, overall protein synthesis was reduced, except for a set of polypeptides, the cold-stress proteins; second, there was a striking inversion of the relative amount of beta- and gamma-actin found in the oocyte nucleus before and after cold stress. Whereas beta-actin was the predominant form in control oocytes, gamma-actin became the major form in stressed oocytes.

  16. A Deterministic Study of the Deficiency of the Wigner-Seitz Approximation for Pu/MOX Fuel Pins

    SciTech Connect

    DeHart, M.D.

    1999-09-27

    The Wigner-Seitz pin-cell approximation has long been applied as a modeling approximation in analysis of UO2 lattice fuel cells. In the past, this approximation has been appropriate for such fuel. However, with increasing attention drawn to mixed-oxide (MOX) fuels with significant plutonium content, it is important to understand the implications of the approximation in a uranium-plutonium matrix. The special geometric capabilities of the deterministic NEWT computer code have been used to assess the adequacy of the Wigner-Seitz cell in such an environment, as part of a larger study of computational aspects of MOX fuel modeling. Results of calculations using various approximations and boundary conditions are presented, and are validated by comparison to results obtained using KENO V.a and XSDRNPM.

  17. Investigations onboard the biosatellite Cosmos-1667

    NASA Astrophysics Data System (ADS)

    Gazenko, O. G.; Ilyin, E. A.

    The program of the 7-day flight of the biosatellite Cosmos-1667 launched in July 1985 included experiments on two rhesus monkeys, ten Wistar SPF rats, ten newts, Drosophila flies, maize seedlings, lettuce sprouts, and unicellular organisms - Tetrahymena. The primate study demonstrated that transition to orbital flight was accompanied by a greater excitability of the vestibular apparatus and an increased linear blood flow velocity in the common carotid artery. The rat studies showed that atrophy of antigravity muscles and osteoporosis of limb bones developed even during short-term exposure to microgravity. The experiments on other living systems revealed no microgravity effects on the cell division rate, proliferative activity of cells of regenerating tissues and organs, energy metabolism of developing insects, structure or chemical composition of higher plant seedlings.

  18. A phylogeny of the Tylototriton asperrimus group (Caudata: Salamandridae) based on a mitochondrial study: suggestions for a taxonomic revision.

    PubMed

    Yuan, Zhi-Yong; Jiang, Ke; Lü, Shun-Qing; Yang, Jun-Xiao; Nguyen, Quang Truong; Nguyen, Thien Tao; Jin, Jie-Qiong; Che, Jing

    2011-12-01

    A phylogenetic hypothesis for the Asian newts of the Tylototriton asperrimus group was generated using data from two mitochondrial fragments including COI and the ND1-ND2 regions. Four distinct clades (A, B, C, D) were resolved with high nodal support within this monophyletic group. Clade A included T. asperrimus, T. hainanensis, T. notialis, "T. vietnamensis", and two unnamed salamander populations from Vietnam. Clade A, constituted the sister group of clades B + C. Newly identified clade C likely represents a new cryptic species. Clade C was the sister group of T. wenxianensis. The true T. vietnamensis exclusively constituted clade D. Our results bring into question some previous taxonomic decisions, and a revision is required. This study illustrates the necessity to include samples from type localities in taxonomic studies, and highlights the importance of fine-grained geographical sampling.

  19. Trophic specialisations in alternative heterochronic morphs

    NASA Astrophysics Data System (ADS)

    Denoël, Mathieu; Schabetsberger, Robert; Joly, Pierre

    Polymorphisms are suspected of reducing competition among conspecifics in heterogeneous environments by allowing differential resource use. However the adaptive significance of alternative morphs has been poorly documented. The aim of this study is to determine food partitioning of two heterochronic morphs of the Alpine newt, Triturus alpestris, in mountain lakes. The morphs differ in the functional morphology of their feeding apparatus. Only paedomorphs are able to expel water during prey suction behind the mouth through gill slits. We observed a substantial trophic differentiation between morphs in all lakes. Paedomorphs preyed mainly on plankton, whereas metamorphs foraged on terrestrial invertebrates that fell upon the water surface. This resource partitioning may facilitate the coexistence of the alternative morphs in lakes devoid of vertebrate competitors. Food diversity may thus favour the evolutionary maintenance of facultative polymorphism in natural populations.

  20. NASDA aquatic animal experiment facilities for space shuttle and ISS

    NASA Astrophysics Data System (ADS)

    Uchida, Satoko; Masukawa, Mitsuyo; Kamigaichi, Shigeki

    National Space Development Agency of Japan (NASDA) has developed aquatic animal experiment facilities for NASA Space Shuttle use. Vestibular Function Experiment Unit (VFEU) was firstly designed and developed for physiological research using carp in Spacelab-J (SL-J, STS-47) mission. It was modified as Aquatic Animal Experiment Unit (AAEU) to accommodate small aquatic animals, such as medaka and newt, for second International Microgravity Laboratory (IML-2, STS-65) mission. Then, VFEU was improved to accommodate marine fish and to perform neurobiological experiment for Neurolab (STS-90) and STS-95 missions. We have also developed and used water purification system which was adapted to each facility. Based on these experiences of Space Shuttle missions, we are studying to develop advanced aquatic animal experiment facility for both Space Shuttle and International Space Station (ISS).

  1. NASDA aquatic animal experiment facilities for Space Shuttle and ISS.

    PubMed

    Uchida, Satoko; Masukawa, Mitsuyo; Kamigaichi, Shigeki

    2002-01-01

    National Space Development Agency of Japan (NASDA) has developed aquatic animal experiment facilities for NASA Space Shuttle use. Vestibular Function Experiment Unit (VFEU) was firstly designed and developed for physiological research using carp in Spacelab-J (SL-J, STS-47) mission. It was modified as Aquatic Animal Experiment Unit (AAEU) to accommodate small aquatic animals, such as medaka and newt, for second International Microgravity Laboratory (IML-2, STS-65) mission. Then, VFEU was improved to accommodate marine fish and to perform neurobiological experiment for Neurolab (STS-90) and STS-95 missions. We have also developed and used water purification system which was adapted to each facility. Based on these experiences of Space Shuttle missions, we are studying to develop advanced aquatic animal experiment facility for both Space Shuttle and International Space Station (ISS).

  2. Magnetic maps in animals: nature's GPS.

    PubMed

    Lohmann, Kenneth J; Lohmann, Catherine M F; Putman, Nathan F

    2007-11-01

    Diverse animals detect the Earth's magnetic field and use it as a cue in orientation and navigation. Most research on magnetoreception has focused on the directional or ;compass' information that can be extracted from the Earth's field. Because the field varies predictably across the surface of the globe, however, it also provides a potential source of positional or 'map' information, which some animals use to steer themselves along migratory pathways or to navigate toward specific target areas. The use of magnetic positional information has been demonstrated in several diverse animals including sea turtles, spiny lobsters, newts and birds, suggesting that such systems are phylogenetically widespread and can function over a wide range of spatial scales. These ;magnetic maps' have not yet been fully characterized. They may be organized in several fundamentally different ways, some of which bear little resemblance to human maps, and they may also be used in conjunction with unconventional navigational strategies.

  3. Conjecture: Can continuous regeneration lead to immortality? Studies in the MRL mouse.

    PubMed

    Heber-Katz, Ellen; Leferovich, John; Bedelbaeva, Khamilia; Gourevitch, Dmitri; Clark, Lise

    2006-01-01

    A particular mouse strain, the MRL mouse, has been shown to have unique healing properties that show normal replacement of tissue without scarring. The serendipitous discovery that the MRL mouse has a profound capacity for regeneration in some ways rivaling the classic newt and axolotl species raises the possibility that humans, too, may have an innate regenerative ability. We propose this mouse as a model for continuous regeneration with possible life-extending properties. We will use the classical "immortal" organism, the hydra, for comparison and examine those key phenotypes that contribute to their immortality as they are expressed in the MRL mouse versus control mouse strains. The phenotypes to be examined include the rate of proliferation and the rate of cell death, which leads to a continual turnover in cells without an increase in mass.

  4. Diversity and distribution of fish tapeworms of the "Bothriocephalidea" (Eucestoda).

    PubMed

    Kuchta, R; Scholz, T

    2007-09-01

    Recent studies have demonstrated the invalidity of the Pseudophyllidea, a long-term recognised order of tapeworms (Platyhelminthes: Cestoda), typical in possessing two dorsoventrally situated attachment organs called bothria. In fact, cestodes parasitic in tetrapods, especially mammals including man, form a relatively basal group called provisionally the "Diphyllobothriidea", whereas tapeworms occurring in freshwater and marine fish, with a few taxa known from amphibians (frogs and newts), belong to a more derived clade, for which the name "Bothriocephalidea" is tentatively proposed. Revision of the "Bothriocephalidea", based on literary data, study of type- and voucher specimens and extensive newly collected material made it possible to critically review the species composition of the group and to prepare a tentative list of its valid species. Out of 305 nominal taxa, only 125 species are considered to be valid. In addition, the spectrum of definitive hosts and geographical distribution of bothriocephalideans are briefly discussed.

  5. The corporate assault on the Food and Drug Administration.

    PubMed

    Nixon, R

    1996-01-01

    Current "regulatory reform" in the U.S. Congress is seeking to eliminate the Food and Drug Administration. The author discusses the forces behind this reform and traces the impact of campaign contributions from various industries opposed to FDA regulations, stock held by members of Congress in companies regulated by the FDA, and a variety of organizations with ties to House Speaker Newt Gingrich that have received donations from industries that Gingrich has helped in their efforts to loosen FDA regulations. The article also examines the myth that the FDA is an overzealous watchdog imposing unnecessary burdens on the companies that it regulates. The controversy over the cow hormone rBGH is given as an example.

  6. [Biological experiments on "Kosmos-1887"].

    PubMed

    Alpatov, A M; I'lin, E A; Antipov, V V; Tairbekov, M G

    1989-01-01

    In the 13-ray space flight on Kosmos-1887 various experiments in the field of cell biology, genetics, biorhythm, developmental biology and regeneration were performed using bacteria, protozoa, plants, worms, insects, fish and amphibia. Paramecia showed enhanced cell proliferation, spheroidization and diminished protein content. Experiments on fruit-flies, newt oocytes and primate lymphocytes confirmed involvement of the cell genetic apparatus in responses to microgravity. Beetles exhibited a reduction of the length of the spontaneous period of freely running circadian rhythms. Carausius morosus developed latent changes in early embryogenesis which manifested at later stages of ontogenesis. Exposure to microgravity did not prevent recovery of injured tissues; moreover their regeneration may be accelerated after recovery. Biology research programs in future biosatellite flights are discussed.

  7. Weak bases inhibit cleavage and embryogenesis in amphibians and echinoderms.

    PubMed

    Webb, D J; Charbonneau, M

    1987-01-01

    The action of weak bases was studied on the early embryonic development of a number of species. Gastrulation was disrupted in the frog, Xenopus laevis, the newt, Pleurodeles watlii, the sea urchins, Paracentrotus lividus and Sphaerechinus granularis and the starfish, Asterias rubens. This required only submillimolar amounts of either NH+4 (pH 9.0) or procaine (pH 8.2). At higher concentrations even early cell division was inhibited in all the species with furrow regression particularly noticeable in Xenopus eggs. A similar action of the weak bases on early development, the lack of any action at lower extracellular pH, and the counteracting action of NH+4 on acidity-induced disruption of sea urchin development, all implicate an elevation of intracellular pH. However, a more direct intracellular action of the weak bases cannot be ruled out.

  8. Wildlife disease. Recent introduction of a chytrid fungus endangers Western Palearctic salamanders.

    PubMed

    Martel, A; Blooi, M; Adriaensen, C; Van Rooij, P; Beukema, W; Fisher, M C; Farrer, R A; Schmidt, B R; Tobler, U; Goka, K; Lips, K R; Muletz, C; Zamudio, K R; Bosch, J; Lötters, S; Wombwell, E; Garner, T W J; Cunningham, A A; Spitzen-van der Sluijs, A; Salvidio, S; Ducatelle, R; Nishikawa, K; Nguyen, T T; Kolby, J E; Van Bocxlaer, I; Bossuyt, F; Pasmans, F

    2014-10-31

    Emerging infectious diseases are reducing biodiversity on a global scale. Recently, the emergence of the chytrid fungus Batrachochytrium salamandrivorans resulted in rapid declines in populations of European fire salamanders. Here, we screened more than 5000 amphibians from across four continents and combined experimental assessment of pathogenicity with phylogenetic methods to estimate the threat that this infection poses to amphibian diversity. Results show that B. salamandrivorans is restricted to, but highly pathogenic for, salamanders and newts (Urodela). The pathogen likely originated and remained in coexistence with a clade of salamander hosts for millions of years in Asia. As a result of globalization and lack of biosecurity, it has recently been introduced into naïve European amphibian populations, where it is currently causing biodiversity loss.

  9. Interfamily variation in amphibian early life-history traits: raw material for natural selection?

    PubMed Central

    Hopkins, Gareth R; Gall, Brian G; French, Susannah S; Brodie, Edmund D

    2012-01-01

    The embryonic development and time to hatching of eggs can be highly adaptive in some species, and thus under selective pressure. In this study, we examined the underlying interfamily variation in hatching timing and embryonic development in a population of an oviparous amphibian, the rough-skinned newt (Taricha granulosa). We found significant, high variability in degree of embryonic development and hatching timing among eggs from different females. Patterns of variation were present regardless of temperature. We also could not explain the differences among families by morphological traits of the females or their eggs. This study suggests that the variation necessary for natural selection to act upon is present in the early life history of this amphibian. PMID:22957168

  10. Salamander-derived, human-optimized nAG protein suppresses collagen synthesis and increases collagen degradation in primary human fibroblasts.

    PubMed

    Al-Qattan, Mohammad M; Shier, Medhat K; Abd-Alwahed, Mervat M; Mawlana, Ola H; El-Wetidy, Mohammed S; Bagayawa, Reginald S; Ali, Hebatallah H; Al-Nbaheen, May S; Aldahmash, Abdullah M

    2013-01-01

    Unlike humans, salamanders regrow their amputated limbs. Regeneration depends on the presence of regenerating axons which upregulate the expression of newt anterior gradient (nAG) protein. We had the hypothesis that nAG might have an inhibitory effect on collagen production since excessive collagen production results in scarring, which is a major enemy to regeneration. nAG gene was designed, synthesized, and cloned. The cloned vector was then transfected into primary human fibroblasts. The results showed that the expression of nAG protein in primary human fibroblast cells suppresses the expression of collagen I and III, with or without TGF- β 1 stimulation. This suppression is due to a dual effect of nAG both by decreasing collagen synthesis and by increasing collagen degradation. Furthermore, nAG had an inhibitory effect on proliferation of transfected fibroblasts. It was concluded that nAG suppresses collagen through multiple effects.

  11. An orphan gene is necessary for preaxial digit formation during salamander limb development.

    PubMed

    Kumar, Anoop; Gates, Phillip B; Czarkwiani, Anna; Brockes, Jeremy P

    2015-10-26

    Limb development in salamanders differs from other tetrapods in that the first digits to form are the two most anterior (preaxial dominance). This has been proposed as a salamander novelty and its mechanistic basis is unknown. Salamanders are the only adult tetrapods able to regenerate the limb, and the contribution of preaxial dominance to limb regeneration is unclear. Here we show that during early outgrowth of the limb bud, a small cohort of cells express the orphan gene Prod1 together with Bmp2, a critical player in digit condensation in amniotes. Disruption of Prod1 with a gene-editing nuclease abrogates these cells, and blocks formation of the radius and ulna, and outgrowth of the anterior digits. Preaxial dominance is a notable feature of limb regeneration in the larval newt, but this changes abruptly after metamorphosis so that the formation of anterior and posterior digits occurs together within the autopodium resembling an amniote-like pattern.

  12. Subtractive screen of potential limb regeneration related genes from Pachytriton brevipes.

    PubMed

    Jiang, Dan; Zhu, Xiao-Long; Zhao, Jun-Fang; Zhou, Yan-Kuan; Zhong, Chao; Zhang, Ji; Huang, Xiao

    2014-02-01

    Regeneration capacity varies greatly among different animal species. In vertebrate, amphibian especially the Urodela, has been used as a powerful model system to study the mechanism of tissue regeneration because of the strong ability to regenerate their damaged or lost appendages. Pachytriton brevipes, a species of newt, which is widely distributed in south of China, can completely restore their damaged limbs within several months. In this study, we use modified suppression subtractive hybridization assay and dot-blot screening to identify candidate genes involved in tissue regeneration in P. brevipes. We successfully isolated 81 ESTs from a forward regeneration subtraction library. And we further verified the differential expression of four candidate genes, Rpl11, Cirbp, Ag2 and Trimx, between regenerating blastema and non-regeneration tissues by in situ hybridization. These genes were also be further characterized by phylogenetic and bioinformatic analysis. In general, we provided a comparative experimental approach to study the mechanisms of vertebrate regeneration.

  13. Recombinant nAG (a salamander-derived protein) decreases the formation of hypertrophic scarring in the rabbit ear model.

    PubMed

    Al-Qattan, Mohammad M; Abd-Al Wahed, Mervat M; Hawary, Khalid; Alhumidi, Ahmed A; Shier, Medhat K

    2014-01-01

    nAG (newt-Anterrior Gradient) protein is the key mediator of regrowth of amputated limbs in salamanders. In a previous work in our lab, a new nAG gene (suitable for humans) was designed and cloned. The cloned vector was transfected into primary human fibroblasts. The expression of nAG in human primary fibroblasts was found to suppress collagen expression. The current study shows that local injection of recombinant nAG reduces scar hypertrophy in the rabbit ear model. This is associated with lower scar elevation index (SEI), lower levels of collagen I & III, higher levels of MMP1, and a higher degree of scar maturation in experimental wounds compared to controls.

  14. An orphan gene is necessary for preaxial digit formation during salamander limb development

    PubMed Central

    Kumar, Anoop; Gates, Phillip B.; Czarkwiani, Anna; Brockes, Jeremy P.

    2015-01-01

    Limb development in salamanders differs from other tetrapods in that the first digits to form are the two most anterior (preaxial dominance). This has been proposed as a salamander novelty and its mechanistic basis is unknown. Salamanders are the only adult tetrapods able to regenerate the limb, and the contribution of preaxial dominance to limb regeneration is unclear. Here we show that during early outgrowth of the limb bud, a small cohort of cells express the orphan gene Prod1 together with Bmp2, a critical player in digit condensation in amniotes. Disruption of Prod1 with a gene-editing nuclease abrogates these cells, and blocks formation of the radius and ulna, and outgrowth of the anterior digits. Preaxial dominance is a notable feature of limb regeneration in the larval newt, but this changes abruptly after metamorphosis so that the formation of anterior and posterior digits occurs together within the autopodium resembling an amniote-like pattern. PMID:26498026

  15. Communication System Simulation Workstation

    DTIC Science & Technology

    1990-01-30

    MLUSBICAYCR AO L)FLIVEPTZ 2 WEEK~S NEWT 30 days pp ’. HAMMfl P’AiJA1.C CU T Ii 2 Brix 1000-V Block Oriented Syutert $ 200.00 $ 400.00 SAiulator (OUSS) for VAX...rIA~ff (.011 A(;,:A 1aitoflance TOTAL A \\ (.I(Fr) WITH tnvr ?I pps -V ID I 1A Y OILIGARSI. 4.0O * 80 FECHA UE CARTA CON ESTAGION COMEN tAIIIOS FECIIA DE...LLAMADA PERSONA CON OUIF 14 HAfTLO0) NUM DC TELFFONI) Modelo 105/ Rev Julio I 9J UNIVERSIDAD DE PUERTO RICO RUM 1. Unidad Instilucional Clr -3 32 91

  16. PWR core and spent fuel pool analysis using scale and nestle

    SciTech Connect

    Murphy, J. E.; Maldonado, G. I.; St Clair, R.; Orr, D.

    2012-07-01

    The SCALE nuclear analysis code system [SCALE, 2011], developed and maintained at Oak Ridge National Laboratory (ORNL) is widely recognized as high quality software for analyzing nuclear systems. The SCALE code system is composed of several validated computer codes and methods with standard control sequences, such as the TRITON/NEWT lattice physics sequence, which supplies dependable and accurate analyses for industry, regulators, and academia. Although TRITON generates energy-collapsed and space-homogenized few group cross sections, SCALE does not include a full-core nodal neutron diffusion simulation module within. However, in the past few years, the open-source NESTLE core simulator [NESTLE, 2003], originally developed at North Carolina State Univ. (NCSU), has been updated and upgraded via collaboration between ORNL and the Univ. of Tennessee (UT), so it now has a growingly seamless coupling to the TRITON/NEWT lattice physics [Galloway, 2010]. This study presents the methodology used to couple lattice physics data between TRITON and NESTLE in order to perform a three-dimensional full-core analysis employing a 'real-life' Duke Energy PWR as the test bed. The focus for this step was to compare the key parameters of core reactivity and radial power distribution versus plant data. Following the core analysis, following a three cycle burn, a spent fuel pool analysis was done using information generated from NESTLE for the discharged bundles and was compared to Duke Energy spent fuel pool models. The KENO control module from SCALE was employed for this latter stage of the project. (authors)

  17. Genetic fingerprinting proves cross-correlated automatic photo-identification of individuals as highly efficient in large capture–mark–recapture studies

    PubMed Central

    Drechsler, Axel; Helling, Tobias; Steinfartz, Sebastian

    2015-01-01

    Capture–mark–recapture (CMR) approaches are the backbone of many studies in population ecology to gain insight on the life cycle, migration, habitat use, and demography of target species. The reliable and repeatable recognition of an individual throughout its lifetime is the basic requirement of a CMR study. Although invasive techniques are available to mark individuals permanently, noninvasive methods for individual recognition mainly rest on photographic identification of external body markings, which are unique at the individual level. The re-identification of an individual based on comparing shape patterns of photographs by eye is commonly used. Automated processes for photographic re-identification have been recently established, but their performance in large datasets (i.e., > 1000 individuals) has rarely been tested thoroughly. Here, we evaluated the performance of the program AMPHIDENT, an automatic algorithm to identify individuals on the basis of ventral spot patterns in the great crested newt (Triturus cristatus) versus the genotypic fingerprint of individuals based on highly polymorphic microsatellite loci using GENECAP. Between 2008 and 2010, we captured, sampled and photographed adult newts and calculated for 1648 samples/photographs recapture rates for both approaches. Recapture rates differed slightly with 8.34% for GENECAP and 9.83% for AMPHIDENT. With an estimated rate of 2% false rejections (FRR) and 0.00% false acceptances (FAR), AMPHIDENT proved to be a highly reliable algorithm for CMR studies of large datasets. We conclude that the application of automatic recognition software of individual photographs can be a rather powerful and reliable tool in noninvasive CMR studies for a large number of individuals. Because the cross-correlation of standardized shape patterns is generally applicable to any pattern that provides enough information, this algorithm is capable of becoming a single application with broad use in CMR studies for many

  18. Variation in voxel value distribution and effect of time between exposures in six CBCT units.

    PubMed

    Spin-Neto, R; Gotfredsen, E; Wenzel, A

    2014-01-01

    The aim of this study is to assess the variation in voxel value distribution in volumetric data sets obtained by six cone beam CT (CBCT) units, and the effect of time between exposures. Six CBCT units [Cranex(®) 3D (CRAN; Soredex Oy, Tuusula, Finland), Scanora(®) 3D (SCAN; Soredex Oy), NewTom™ 5G (NEWT; QR Srl, Verona, Italy), Promax(®) Dimax 3 (Planmeca Oy, Helsinki, Finland), i-CAT (Imaging Sciences International, Hatfield, PA) and 3D Accuitomo FPD80 (Morita, Kyoto, Japan)] were tested. Two volumetric data sets of a dry human skull embedded in acrylic were acquired by each CBCT unit in two sessions on separate days. Each session consisted of 20 exposures: 10 acquired with 30 min between exposures and 10 acquired immediately one after the other. CBCT data were exported as digital imaging and communications in medicine (DICOM) files and converted to text files. The text files were re-organized to contain x-, y- and z-position and grey shade for each voxel. The files were merged to contain 1 record per voxel position, including the voxel values from the 20 exposures in a session. For each voxel, subtractions were performed between Data Set 1 and the remaining 19 data sets (1 - 2, 1 - 3, etc) in a session. Means, medians, ranges and standard deviations for grey shade variation in the subtraction data sets were calculated for each unit and session. For all CBCT units, variation in voxel values was observed throughout the 20 exposures. A "fingerprint" for the grey shade variation was observed for CRAN, SCAN and NEWT. For the other units, the variation was (apparently) randomly distributed. Large discrepancies in voxel value distribution are seen in CBCT images. This variation should be considered in studies that assess minute changes in CBCT images.

  19. Neural retinal regeneration in the anuran amphibian Xenopus laevis post-metamorphosis: transdifferentiation of retinal pigmented epithelium regenerates the neural retina.

    PubMed

    Yoshii, Chika; Ueda, Yoko; Okamoto, Mitumasa; Araki, Masasuke

    2007-03-01

    In urodele amphibians like the newt, complete retina and lens regeneration occurs throughout their lives. In contrast, anuran amphibians retain this capacity only in the larval stage and quickly lose it during metamorphosis. It is believed that they are unable to regenerate these tissues after metamorphosis. However, contrary to this generally accepted notion, here we report that both the neural retina (NR) and lens regenerate following the surgical removal of these tissues in the anuran amphibian, Xenopus laevis, even in the mature animal. The NR regenerated both from the retinal pigment epithelial (RPE) cells by transdifferentiation and from the stem cells in the ciliary marginal zone (CMZ) by differentiation. In the early stage of NR regeneration (5-10 days post operation), RPE cells appeared to delaminate from the RPE layer and adhere to the remaining retinal vascular membrane. Thereafter, they underwent transdifferentiation to regenerate the NR layer. An in vitro culture study also revealed that RPE cells differentiated into neurons and that this was accelerated by the presence of FGF-2 and IGF-1. The source of the regenerating lens appeared to be remaining lens epithelium, suggesting that this is a kind of repair process rather than regeneration. Thus, we show for the first time that anuran amphibians retain the capacity for retinal regeneration after metamorphosis, similarly to urodeles, but that the mode of regeneration differs between the two orders. Our study provides a new tool for the molecular analysis of regulatory mechanisms involved in retinal and lens regeneration by providing an alternative animal model to the newt, the only other experimental model.

  20. The Effect of Human Impact on Batrachochytrium dendrobatidis prevalence in Taricha torosa

    NASA Astrophysics Data System (ADS)

    Deng, V.; Macario, E.; Tumey, C.

    2014-12-01

    Batrachochytrium dendrobatidis (Bd) is emerging as a major cause of the amphibian extinction. As amphibians serve an important role as indicator species in their ecosystem and play a vital role in the food chain, Bd will not only affect the amphibian population but also the health of the environment. Bd is an aquatic fungus that blocks the porous skin of amphibians which interrupts electrolyte, gas and water transfer. This imbalances the electrolyte system which causes cells and organs to malfunction, therefore killing the amphibian. While frogs are more common for Bd, it is not often found in newts. However, Dr. Vance Vredenburg recently found an outbreak of Bd in Taricha torosa in Marin Headlands, California. This location was used in the research as the sample site with most human impact and was expected to have the highest prevalence according to the proposed hypothesis that more human impact will correspond with a higher prevalence of Bd. Decreasing the level of human impact, Fairfield Osborn Preserve and Galbreath Preserve were picked as the other sample sites. After the samples went through qPCR, all of them came back negative for Bd. These results did not support the hypothesis, however, it contributed data to explaining the dynamics of Bd when combined with Dr. Vance Vredenburg's data from 2 months earlier. Within the two months, there was a huge difference in the prevalence of Bd as it dropped from 88% to 0%. This shows that Taricha torosa does in fact get Bd. However, it is rarely detected because Bd is fast-acting and has high mortality rates. Therefore, it is least likely for current nonspecific surveys to swab the newts during a short but lethal Bd outbreak.

  1. A missing geographic link in the distribution of the genus Echinotriton (Caudata: Salamandridae) with description of a new species from southern China.

    PubMed

    Hou, Mian; Wu, Yunke; Yang, Kelin; Zheng, Sheng; Yuan, Zhiyong; Li, Pipeng

    2014-12-12

    Disjunct geographic distribution of a species or a group of species is the product of long-term interaction between organisms and the environment. Filling the distributional gap by discovery of a new population or a species has significant biogeographic implications, because it suggests a much wider past distribution and provides evidence for the route of range expansion/contraction. The salamandrid genus Echinotriton (commonly known as spiny salamanders, spiny newts, or crocodile newts) has two species that are restricted to two widely separated areas, one in eastern Zhejiang province, China and the other in the Ryukyu Archipelago of Japan. It has been hypothesized that Echinotriton was once continuously distributed between the two areas through a historical land bridge that connected mainland China, Taiwan, and the archipelago. Finding fossils or relic populations along the postulated distribution are strong evidence for the hypothesis. Hundred-twenty-two years after the description of E. andersoni and eight-one years after that of E. chinhaiensis, we discover a third species of Echinotriton in southern China, which fills the distributional gap of the former two species. Species status of the new species is confirmed through molecular phylogenetic analysis and morphological comparison. Mitochondrial DNA indicates that the new species is sister to E. chinhaiensis, while nuclear DNA does not support this relationship. The new species has a very large quadrate projection, a single line of lateral warts pierced by distal rib extremities, normally developed 5th toes, and conical skin tubercles. Our discovery supports the hypothesis that there was a continuous distribution of Echinotriton from eastern coastal China to the Ryukyu Archipelago. We suggest that other species of this genus may also be found in Taiwan. Due to the rarity of this new species, we urge all hobbyists to refrain themselves from collecting this salamander or leaking locality information if

  2. Tissue Regeneration in Urodela on Foton-M3

    NASA Astrophysics Data System (ADS)

    Grigoryan, E. N.; Poplinskaya, V. A.; Domaratskaya, E. I.; Novikova, Y. P.; Aleinikova, K. S.; Dvorochkin, N.; Almeida, E. A. C.

    2008-06-01

    In the experiment "Regeneration" flown on Foton-M3 in 2007 we continued our study of tissue and organ regeneration in Urodela. Special attention was given to the regulatory mechanisms that could induce peculiarities of regeneration during the spaceflight. The results obtained showed that lens regeneration in space-flown animals was synchronized and about 0.5 to 1 stage more advanced than in synchronous 1g controls. In both groups of animals cytokine FGFb expression increased in parallel with lens cell mitotic activity and was localized in the growth zone and iris of regenerating eyes. Lens regeneration was also accompanied by an increase of stress protein (HSP90) expression in retinal macroglia. Evaluation of HSP90 and FGFb expression by immuno-staining showed that it was higher in the eyes of space-flown animals than in synchronous controls. BrdU assay demonstrated incorporation of the precursor into populations of DNA synthesizing cells in both animal groups and mirrored cell growth in regenerating tissues. Tail regeneration in space-flown and synchronous control animals reached the stages IV to V. Computer morphometry showed that tail size parameters were similar though the tail area was slightly decreased in the space-flown newts. In contrast, remarkable changes in tail tip morphology were found between animal groups: flight and aquarium-control tail regenerates were identical in shape, while synchronous controls developed distinct dorsoventral asymmetry. Histological examinations suggested that morphogenetic differences were caused by different rates of epidermal cell growth in tail regenerates of newts exposed to microgravity and 1 g.

  3. A Complex-Geometry Validation Experiment for Advanced Neutron Transport Codes

    SciTech Connect

    David W. Nigg; Anthony W. LaPorta; Joseph W. Nielsen; James Parry; Mark D. DeHart; Samuel E. Bays; William F. Skerjanc

    2013-11-01

    The Idaho National Laboratory (INL) has initiated a focused effort to upgrade legacy computational reactor physics software tools and protocols used for support of core fuel management and experiment management in the Advanced Test Reactor (ATR) and its companion critical facility (ATRC) at the INL.. This will be accomplished through the introduction of modern high-fidelity computational software and protocols, with appropriate new Verification and Validation (V&V) protocols, over the next 12-18 months. Stochastic and deterministic transport theory based reactor physics codes and nuclear data packages that support this effort include MCNP5[1], SCALE/KENO6[2], HELIOS[3], SCALE/NEWT[2], and ATTILA[4]. Furthermore, a capability for sensitivity analysis and uncertainty quantification based on the TSUNAMI[5] system has also been implemented. Finally, we are also evaluating the Serpent[6] and MC21[7] codes, as additional verification tools in the near term as well as for possible applications to full three-dimensional Monte Carlo based fuel management modeling in the longer term. On the experimental side, several new benchmark-quality code validation measurements based on neutron activation spectrometry have been conducted using the ATRC. Results for the first four experiments, focused on neutron spectrum measurements within the Northwest Large In-Pile Tube (NW LIPT) and in the core fuel elements surrounding the NW LIPT and the diametrically opposite Southeast IPT have been reported [8,9]. A fifth, very recent, experiment focused on detailed measurements of the element-to-element core power distribution is summarized here and examples of the use of the measured data for validation of corresponding MCNP5, HELIOS, NEWT, and Serpent computational models using modern least-square adjustment methods are provided.

  4. Genetic fingerprinting proves cross-correlated automatic photo-identification of individuals as highly efficient in large capture-mark-recapture studies.

    PubMed

    Drechsler, Axel; Helling, Tobias; Steinfartz, Sebastian

    2015-01-01

    Capture-mark-recapture (CMR) approaches are the backbone of many studies in population ecology to gain insight on the life cycle, migration, habitat use, and demography of target species. The reliable and repeatable recognition of an individual throughout its lifetime is the basic requirement of a CMR study. Although invasive techniques are available to mark individuals permanently, noninvasive methods for individual recognition mainly rest on photographic identification of external body markings, which are unique at the individual level. The re-identification of an individual based on comparing shape patterns of photographs by eye is commonly used. Automated processes for photographic re-identification have been recently established, but their performance in large datasets (i.e., > 1000 individuals) has rarely been tested thoroughly. Here, we evaluated the performance of the program AMPHIDENT, an automatic algorithm to identify individuals on the basis of ventral spot patterns in the great crested newt (Triturus cristatus) versus the genotypic fingerprint of individuals based on highly polymorphic microsatellite loci using GENECAP. Between 2008 and 2010, we captured, sampled and photographed adult newts and calculated for 1648 samples/photographs recapture rates for both approaches. Recapture rates differed slightly with 8.34% for GENECAP and 9.83% for AMPHIDENT. With an estimated rate of 2% false rejections (FRR) and 0.00% false acceptances (FAR), AMPHIDENT proved to be a highly reliable algorithm for CMR studies of large datasets. We conclude that the application of automatic recognition software of individual photographs can be a rather powerful and reliable tool in noninvasive CMR studies for a large number of individuals. Because the cross-correlation of standardized shape patterns is generally applicable to any pattern that provides enough information, this algorithm is capable of becoming a single application with broad use in CMR studies for many species.

  5. Parallel Evolution of Tetrodotoxin Resistance in Three Voltage-Gated Sodium Channel Genes in the Garter Snake Thamnophis sirtalis

    PubMed Central

    McGlothlin, Joel W.; Chuckalovcak, John P.; Janes, Daniel E.; Edwards, Scott V.; Feldman, Chris R.; Brodie, Edmund D.; Pfrender, Michael E.; Brodie, Edmund D.

    2014-01-01

    Members of a gene family expressed in a single species often experience common selection pressures. Consequently, the molecular basis of complex adaptations may be expected to involve parallel evolutionary changes in multiple paralogs. Here, we use bacterial artificial chromosome library scans to investigate the evolution of the voltage-gated sodium channel (Nav) family in the garter snake Thamnophis sirtalis, a predator of highly toxic Taricha newts. Newts possess tetrodotoxin (TTX), which blocks Nav’s, arresting action potentials in nerves and muscle. Some Thamnophis populations have evolved resistance to extremely high levels of TTX. Previous work has identified amino acid sites in the skeletal muscle sodium channel Nav1.4 that confer resistance to TTX and vary across populations. We identify parallel evolution of TTX resistance in two additional Nav paralogs, Nav1.6 and 1.7, which are known to be expressed in the peripheral nervous system and should thus be exposed to ingested TTX. Each paralog contains at least one TTX-resistant substitution identical to a substitution previously identified in Nav1.4. These sites are fixed across populations, suggesting that the resistant peripheral nerves antedate resistant muscle. In contrast, three sodium channels expressed solely in the central nervous system (Nav1.1–1.3) showed no evidence of TTX resistance, consistent with protection from toxins by the blood–brain barrier. We also report the exon–intron structure of six Nav paralogs, the first such analysis for snake genes. Our results demonstrate that the molecular basis of adaptation may be both repeatable across members of a gene family and predictable based on functional considerations. PMID:25135948

  6. Amphibian occurrence and aquatic invaders in a changing landscape: Implications for wetland mitigation in the Willamette Valley, Oregon

    USGS Publications Warehouse

    Pearl, Christopher A.; Adams, Michael J.; Leuthold, N.; Bury, R. Bruce

    2005-01-01

    Despite concern about the conservation status of amphibians in western North America, few field studies have documented occurrence patterns of amphibians relative to potential stressors. We surveyed wetland fauna in Oregon's Willamette Valley and used an information theoretic approach (AIC) to rank the associations between native amphibian breeding occurrence and wetland characteristics, non-native aquatic predators, and landscape characteristics in a mixed urban-agricultural landscape. Best predictors varied among the five native amphibians and were generally consistent with life history differences. Pacific tree frog (Pseudacris regilla) and long-toed salamander (Ambystoma macrodactylum) occurrence was best predicted by the absence of non-native fish. Northern red-legged frog (Rana a. aurora) and northwestern salamander (Ambystoma gracile) were most strongly related to wetland vegetative characteristics. The occurrence of rough-skinned newts (Taricha granulosa), a migratory species that makes extensive use of terrestrial habitats, was best predicted by greater forest cover within 1 km. The absence of non-native fish was a strong predictor of occurrence for four of the five native species. In contrast, amphibians were not strongly related to native fish presence. We found little evidence supporting negative effects of the presence of breeding populations of bullfrog (Rana catesbeiana) on any native species. Only the two Ambystoma salamanders were associated with wetland permanence. Northwestern salamanders (which usually have a multi-year larval stage) were associated with permanent waters, while long-toed salamanders were associated with temporary wetlands. Although all the species make some use of upland habitats, only one (rough-skinned newt) was strongly associated with surrounding landscape conditions. Instead, our analysis suggests that within-wetland characteristics best predict amphibian occurrence in this region. We recommend that wetland preservation and

  7. Application of multigene phylogenetics and site-stripping to resolve intraordinal relationships in the Rhodymeniales (Rhodophyta).

    PubMed

    Filloramo, Gina V; Saunders, Gary W

    2016-06-01

    Previous molecular assessments of the red algal order Rhodymeniales have confirmed its monophyly and distinguished the six currently recognized families (viz. Champiaceae, Faucheaceae, Fryeellaceae, Hymenocladiaceae, Lomentariaceae, and Rhodymeniaceae); however, relationships among most of these families have remained unresolved possibly as a result of substitution saturation at deeper phylogenetic nodes. The objective of the current study was to improve rhodymenialean systematics by increasing taxonomic representation and using a more robust multigene dataset of mitochondrial (COB, COI/COI-5P), nuclear (LSU, EF2) and plastid markers (psbA, rbcL). Additionally, we aimed to prevent phylogenetic inference problems associated with substitution saturation (particularly at the interfamilial nodes) by removing fast-evolving sites and analyzing a series of progressively more conservative alignments. The Rhodymeniales was resolved as two major lineages: (i) the Fryeellaceae as sister to the Faucheaceae and Lomentariaceae; and (ii) the Rhodymeniaceae allied to the Champiaceae and Hymenocladiaceae. Support at the interfamilial nodes was highest when 20% of variable sites were removed. Inclusion of Binghamiopsis, Chamaebotrys, and Minium, which were absent in previous phylogenetic investigations, established their phylogenetic affinities while assessment of two genera consistently polyphyletic in phylogenetic analyses, Erythrymenia and Lomentaria, resulted in the proposition of the novel genera Perbella and Fushitsunagia. The taxonomic position of Drouetia was reinvestigated with re-examination of holotype material of D. coalescens to clarify tetrasporangial development in this genus. In addition, we added three novel Australian species to Drouetia as a result of ongoing DNA barcoding assessments-D. aggregata sp. nov., D. scutellata sp. nov., and D. viridescens sp. nov.

  8. New synonymies and new records of Afrotropical and Madagascan Pentatominae (Hemiptera: Heteroptera: Pentatomidae).

    PubMed

    Kment, Petr; Jindra, Zdeněk; Rider, David A

    2014-09-24

    The following new synonymies within the family Pentatomidae, subfamily Pentatominae, are established: Aesula Stål, 1876 = Pseudacrosternum Day, 1965, syn. nov. (Nezarini), Aesula viridissima (Signoret, 1861) = Aesula signoretiana Kirkaldy, 1909, syn. nov. = Pseudacrosternum cachani Day, 1965, syn. nov. = Pseudacrosternum cachani var. scutellatum Day, 1965, syn. nov., and Andocides vittaticeps (Stål, 1858) = Andocides vittaticeps var. viridescens Schumacher, 1913, syn. nov. Afrania brachyptera (Schaum, 1853), stat. restit., is restored as the oldest available name for that species, with Afrania wahlbergi Stål, 1854, syn. restit., being its junior synonym. Lectotype of Pentatoma viridissima Signoret, 1861 is designated, and lectotype designation of Pseudolerida incerta (Schouteden, 1909) is commented. The following new or confirmed state records are provided: Cappaeini: Leridella kenyensis Jeannel, 1913 (Cameroon), Paralerida bolivari (Schouteden, 1904) (Republic of the Congo, Uganda), P. niokana Linnavuori, 1982 (Uganda), Tripanda (Tripanda) dispar Schouteden, 1964 (Cameroon, Ghana, Liberia), T. (T.) horacekorum Kment & Jindra, 2009 (Cameroon, Guinea), T. (T.) jurickorum Kment & Jindra, 2009 (Gabon, Ivory Coast), T. (T.) longiceps (Villiers, 1967) (Democratic Republic of the Congo, Gabon), T. (T.) signitenens (Distant, 1898) (Democratic Republic of the Congo, Mozambique), T. (Tenerva) decorata (Jensen-Haarup, 1937) (Kenya, Oman, Tanzania); Carpocorini: Andocides vittaticeps (Angola); Diploxyini: Acoloba lanceolata (Fabricius, 1803) (Angola, Central African Republic, Zambia, Zimbabwe); Eysarcorini: Pseudolerida bitalensis Schouteden, 1958 (Cameroon), Pseudolerida incerta (Equatorial Guinea: Bioko Island, Tanzania, Uganda); Myrocheini: Humria bimaculicollis Linnavuori, 1975 (Botswana, Democratic Republic of the Congo, Guinea, Kenya, Mozambique, Namibia, South Africa, Zambia, Zimbabwe); Strachiini: Afrania brachyptera (Schaum, 1853) (Botswana, Democratic Republic of

  9. A revision of the Neotropical species of Bolitogyrus Chevrolat, a geographically disjunct lineage of Staphylinini (Coleoptera, Staphylinidae)

    PubMed Central

    Brunke, Adam J.; Solodovnikov, Alexey

    2014-01-01

    Abstract The Neotropical species of the rarely collected genus Bolitogyrus (Coleoptera: Staphylinidae: Staphylininae: Staphylinini) are revised. The genus exhibits an uncommon, disjunct distribution between the Neotropical and Oriental Regions and is of unknown phylogenetic position within Staphylinini. Morphological evolution remarkable for Staphylinini was discovered within Bolitogyrus, including sexually dimorphic modifications of the pronotum that may be involved in male competition for females. rSEM interactive animations were used to establish morphological species boundaries between two highly variable species and are provided to illustrate diagnostic characters of the genitalia in unconventional views. The genus is redescribed based on the world fauna and twenty-eight Neotropical species are considered valid. Of these, nineteen are described as new to science: Bolitogyrus ashei sp. n.; B. apicofasciatus sp. n.; B. brevistellus sp. n.; B. bufo sp. n.; B. cheungi sp. n.; B. cornutus sp. n.; B. divisus sp. n.; B. falini sp. n.; B. gracilis sp. n.; B. inexspectatus sp. n.; B. longistellus sp. n.; B. marquezi sp. n.; B. newtoni sp. n.; B. pseudotortifolius sp. n.; B. pulchrus sp. n.; B. silex sp. n.; B. thomasi sp. n.; B. tortifolius sp. n.; and B. viridescens sp. n. Bolitogyrus sallei (Kraatz), stat. r. is removed from synonymy with B. buphthalmus (Erichson) and the following new synonyms are proposed: Cyrtothorax cyanescens Sharp, 1884, syn. n. = Quedius buphthalmus Erichson, 1840; C. nevermanni Scheerpeltz, 1974, syn. n. = C. costaricensis Wendeler, 1927. A summary of all available bionomic and distributional data, as well as an illustrated identification key to and diagnoses of all Neotropical species are provided. PMID:25061393

  10. Influence of wavelength on the laser removal of lichens colonizing heritage stone

    NASA Astrophysics Data System (ADS)

    Sanz, M.; Oujja, M.; Ascaso, C.; Pérez-Ortega, S.; Souza-Egipsy, V.; Fort, R.; de los Rios, A.; Wierzchos, J.; Cañamares, M. V.; Castillejo, M.

    2017-03-01

    Laser irradiation of lichen thalli on heritage stones serves for the control of epilithic and endolithic biological colonizations. In this work we investigate rock samples from two quarries traditionally used as source of monumental stone, sandstone from Valonsadero (Soria, Spain) and granite from Alpedrete (Madrid, Spain), in order to find conditions for efficient laser removal of lichen thalli that ensure preservation of the lithic substrate. The samples presented superficial areas colonized by different types of crustose lichens, i.e. Candelariella vitellina, Aspicilia viridescens, Rhizocarpon disporum and Protoparmeliopsis muralis in Valonsadero samples and P. cf. bolcana and A. cf. contorta in Alpedrete samples. A comparative laser cleaning study was carried out on the mentioned samples with ns Q-switched Nd:YAG laser pulses of 1064 nm (fundamental radiation), 355 nm (3rd harmonic) and 266 nm (4th harmonic) and sequences of IR-UV pulses. A number of techniques such as UV-Vis absorption spectroscopy, stereomicroscopy, scanning electron microscopy (SEM) at low vacuum, SEM with backscattered electron imaging (SEM-BSE), electron dispersive spectroscopy (EDS) and FT-Raman spectroscopy were employed to determine the best laser irradiation conditions and to detect possible structural, morphological and chemical changes on the irradiated surfaces. The results show that the laser treatment does not lead to the complete removal of the studied lichen thalli, although clearly induces substantial damage, in the form of loss of the lichen upper cortex and damage to the algal layer. In the medium term these alterations could result in the destruction of the lichen thalli, thus providing a degree of control of the biodeterioration processes of the lithic substrate and reducing the chances of subsequent lichen recolonization.

  11. Idiosyncratic features in tRNAs participating in bacterial cell wall synthesis

    PubMed Central

    Villet, Régis; Fonvielle, Matthieu; Busca, Patricia; Chemama, Maryline; Maillard, Antoine P.; Hugonnet, Jean-Emmanuel; Dubost, Lionel; Marie, Arul; Josseaume, Nathalie; Mesnage, Stéphane; Mayer, Claudine; Valéry, Jean-Marc; Ethève-Quelquejeu, Mélanie; Arthur, Michel

    2007-01-01

    The FemXWv aminoacyl transferase of Weissella viridescens initiates the synthesis of the side chain of peptidoglycan precursors by transferring l-Ala from Ala-tRNAAla to UDP-MurNAc-pentadepsipeptide. FemXWv is an attractive target for the development of novel antibiotics, since the side chain is essential for the last cross-linking step of peptidoglycan synthesis. Here, we show that FemXWv is highly specific for incorporation of l-Ala in vivo based on extensive analysis of the structure of peptidoglycan. Comparison of various natural and in vitro-transcribed tRNAs indicated that the specificity of FemXWv depends mainly upon the sequence of the tRNA although additional specificity determinants may include post-transcriptional modifications and recognition of the esterified amino acid. Site-directed mutagenesis identified cytosines in the G1–C72 and G2–C71 base pairs of the acceptor stem as critical for FemXWv activity in agreement with modeling of tRNAAla in the catalytic cavity of the enzyme. In contrast, semi-synthesis of Ala-tRNAAla harboring nucleotide substitutions in the G3–U70 wobble base pair showed that this main identity determinant of alanyl-tRNA synthetase is non-essential for FemXWv. The different modes of recognition of the acceptor stem indicate that specific inhibition of FemXWv could be achieved by targeting the distal portion of tRNAAla for the design of substrate analogues. PMID:17932062

  12. Golf courses and wetland fauna.

    PubMed

    Colding, Johan; Lundberg, Jakob; Lundberg, Stefan; Andersson, Erik

    2009-09-01

    Golf courses are often considered to be chemical-intensive ecosystems with negative impacts on fauna. Here we provide evidence that golf courses can contribute to the support and conservation of wetland fauna, i.e., amphibians and macroinvertebrates. Comparisons of amphibian occurrence, diversity of macroinvetebrates, and occurrence of species of conservation concern were made between permanent freshwater ponds surveyed on golf courses around Sweden's capital city, Stockholm, and off-course ponds in nature-protected areas and residential parklands. A total of 71 macroinvertebrate species were recorded in the field study, with no significant difference between golf course ponds and off-course ponds at the species, genus, or family levels. A within-group similarities test showed that golf course ponds have a more homogenous species composition than ponds in nature-protected areas and ponds in residential parkland. Within the macroinvertebrate group, a total of 11 species of odonates were identified, with no difference detected between the categories of ponds, nor any spatial autocorrelation. Significant differences were found between pond categories in the occurrence of five species of amphibians, although anuran occurrence did not differ between ponds. The great crested newt (Triturus cristatus) was significantly associated with golf course ponds, but the smooth newt (Triturus vulgaris) was not. We found no evidence of any correlation between pond size and occurrence of amphibians. Among the taxa of conservation concern included in the sample, all amphibians are nationally protected in Sweden, with the internationally threatened T. cristatus more frequently found in golf course ponds. Among macroinveterbrates of conservation status, the large white-faced darter dragonfly (Leucorrhinia pectoralis) was only detected in golf course ponds, and Tricholeiochiton fagesi (Trichoptera) was only found in one off-course pond. GIS results revealed that golf courses provide over

  13. Wound keratins in the regenerating epidermis of lizard suggest that the wound reaction is similar in the tail and limb.

    PubMed

    Alibardi, Lorenzo; Toni, Mattia

    2005-10-01

    The keratin cytoskeleton of the wound epidermis of lizard limb (which does not regenerate) and tail (which regenerates) hase been studied by qualitative ultrastructural, immunocytochemical, and immunoblotting methods. The process of re-epithelialization is much shorter in the tail than in the limb. In the latter, a massive tissue destruction of bones, and the shrinkage of the old skin over the stump surface, delay wound closure, maintain inflammation, reduce blastemal cell population, resulting in inhibition of regeneration. The expression of special wound keratins found in the newt epidermis (W6) or mammalian epidermis (K6, K16, and K17) is present in the epidermis of both tail and limb of the lizard. These keratins are not immunolocalized in the migrating epithelium or normal (resting) epidermis but only after it has formed the thick wound epithelium, made of lacunar cells. The latter are proliferating keratinocytes produced during the cyclical renewal or regeneration of lizard epidermis. W6-immunolabeled proteic bands mainly at 45-47 kDa are detected by immunoblotting in normal, regenerating, and scarring epidermis of the tail and limb. Immunolabeled proteic bands at 52, 62-67 kDa (with K6), at 44-47, 60, 65 kDa (with K16), and at 44-47 kDa (with K17) were detected in normal and regenerating epidermis. It is suggested that: (1) these keratins constitute normal epidermis, especially where the lacunar layer is still differentiating; (2) the wound epidermis is similar in the limb and tail in terms of morphology and keratin content; (3) the W6 antigen is similar to that of the newt, and is associated with tonofilaments; (4) lizard K6 and K17 have molecular weights similar to mammalian keratins; (5) K16 shows some isoforms or degradative products with different molecular weight from those of mammals; (6) K17 increases in wound keratinocytes and localizes over sparse filaments or small bundles of short filaments, not over tonofilaments joined to desmosomes; and (7

  14. Continuous energy, multi-dimensional discrete ordinates transport calculations for problem dependent resonance treatment

    NASA Astrophysics Data System (ADS)

    Zhong, Zhaopeng

    In the past twenty 20 years considerable progress has been made in developing new methods for solving the multi-dimensional transport problem. However the effort devoted to the resonance self-shielding calculation has lagged, and much less progress has been made in enhancing resonance-shielding techniques for generating problem-dependent multi-group cross sections (XS) for the multi-dimensional transport calculations. In several applications, the error introduced by self-shielding methods exceeds that due to uncertainties in the basic nuclear data, and often they can be the limiting factor on the accuracy of the final results. This work is to improve the accuracy of the resonance self-shielding calculation by developing continuous energy multi-dimensional transport calculations for problem dependent self-shielding calculations. A new method has been developed, it can calculate the continuous-energy neutron fluxes for the whole two-dimensional domain, which can be utilized as weighting function to process the self-shielded multi-group cross sections for reactor analysis and criticality calculations, and during this process, the two-dimensional heterogeneous effect in the resonance self-shielding calculation can be fully included. A new code, GEMINEWTRN (Group and Energy-Pointwise Methodology Implemented in NEWT for Resonance Neutronics) has been developed in the developing version of SCALE [1], it combines the energy pointwise (PW) capability of the CENTRM [2] with the two-dimensional discrete ordinates transport capability of lattice physics code NEWT [14]. Considering the large number of energy points in the resonance region (typically more than 30,000), the computational burden and memory requirement for GEMINEWTRN is tremendously large, some efforts have been performed to improve the computational efficiency, parallel computation has been implemented into GEMINEWTRN, which can save the computation and memory requirement a lot; some energy points reducing

  15. The genus Weissella: taxonomy, ecology and biotechnological potential

    PubMed Central

    Fusco, Vincenzina; Quero, Grazia M.; Cho, Gyu-Sung; Kabisch, Jan; Meske, Diana; Neve, Horst; Bockelmann, Wilhelm; Franz, Charles M. A. P.

    2015-01-01

    Bacteria assigned to the genus Weissella are Gram-positive, catalase-negative, non-endospore forming cells with coccoid or rod-shaped morphology (Collins et al., 1993; Björkroth et al., 2009, 2014) and belong to the group of bacteria generally known as lactic acid bacteria. Phylogenetically, the Weissella belong to the Firmicutes, class Bacilli, order Lactobacillales and family Leuconostocaceae (Collins et al., 1993). They are obligately heterofermentative, producing CO2 from carbohydrate metabolism with either d(−)-, or a mixture of d(−)- and l(+)- lactic acid and acetic acid as major end products from sugar metabolism. To date, there are 19 validly described Weissella species known. Weissella spp. have been isolated from and occur in a wide range of habitats, e.g., on the skin and in the milk and feces of animals, from saliva, breast milk, feces and vagina of humans, from plants and vegetables, as well as from a variety of fermented foods such as European sourdoughs and Asian and African traditional fermented foods. Thus, apart from a perceived technical role of certain Weissella species involved in such traditional fermentations, specific Weissella strains are also receiving attention as potential probiotics, and strain development of particularly W. cibaria strains is receiving attention because of their high probiotic potential for controlling periodontal disease. Moreover, W. confusa and W. cibaria strains are known to produce copius amounts of novel, non-digestible oligosaccharides and extracellular polysaccharides, mainly dextran. These polymers are receiving increased attention for their potential application as prebiotics and for a wide range of industrial applications, predominantly for bakeries and for the production of cereal-based fermented functional beverages. On the detrimental side, strains of certain Weissella species, e.g., of W. viridescens, W. cibaria and W. confusa, are known as opportunistic pathogens involved in human infections while

  16. Production of Antilisterial Bacteriocins from Lactic Acid Bacteria in Dairy-Based Media: A Comparative Study.

    PubMed

    Ünlü, Gülhan; Nielsen, Barbara; Ionita, Claudia

    2015-12-01

    One hundred and eight strains of lactic acid bacteria (LAB) were screened for bacteriocin production by the modified deferred antagonism and agar well diffusion methods. When the modified deferred antagonism method was employed, 82 LAB strains showed inhibitory action against Listeria monocytogenes v7 ½a, whereas 26 LAB strains expressed no inhibition. Only 12 LAB strains exhibited inhibitory activity when the agar well diffusion method was used, 11 of which had been previously recognized as bacteriocin production positive (Bac(+)). Lactobacillus viridescens NRRL B-1951 was determined, for the first time, to produce an inhibitory compound with a proteinaceous nature. The inhibitory activity was observed in the presence of lipase, α-chymotrypsin, and trypsin, but no inhibition zone could be detected in the presence of proteinase K, indicating the proteinaceous nature of the inhibitory compound. The inhibitory compound was active against Lact. sake ATCC 15521 and Lact. plantarum NCDO 995. Bacteriocin production by the Bac(+) LAB strains was assessed in Lactobacillus MRS Broth as well as in dairy-based media such as nonfat milk, demineralized whey powder, and cheddar cheese whey supplemented with complex nutrient sources that are rich in nitrogen. Lact. sake ATCC 15521 and L. monocytogenes CWD 1002, CWD 1092, CWD 1157, CWD 1198, and v7 ½a were used as indicators. The inhibitory activities of the bacteriocins varied depending on the indicator strains and the growth media used. The LAB indicator strains were found to be more sensitive to inhibition by bacteriocins when compared to the listerial indicator strains. Among the listerial indicators, L. monocytogenes CWD 1002 and CWD 1198 were the most sensitive strains to the bacteriocins investigated in this study. Media composition had a significant influence on bacteriocin production and activity. When compared to demineralized whey powder medium and cheddar cheese whey medium supplemented with whey protein concentrate

  17. A Molecular Assessment of Phylogenetic Relationships and LineageDiversification Within the Family Salamandridae (Amphibia, Caudata)

    SciTech Connect

    Weisrock, David W.; Papenfuss, Theodore J.; Macey, J. Robert; Litvinchuk, Spartak N.; Polymeni, Rosa; Ugurtas, Ismail H.; Zhao, Ermi; Larson, Allan

    2005-08-08

    Phylogenetic relationships among species of the salamanderfamily Salamandridae are investigated using nearly 3000 nucleotide basesof newly reported mitochondrial DNA sequence data from the mtDNA genicregion spanning the genes tRNALeu-COI. This study uses nearlycomprehensive species-level sampling to provide the first completephylogeny for the Salamandridae. Deep phylogenetic relationships amongthe three most divergent lineages in the family Salamandrina terdigitata,a clade comprising the "True" salamanders, and a clade comprising allnewts except S. terdigitata are difficult to resolve. However, mostrelationships within the latter two lineages are resolved with robustlevels of branch support. The genera Euproctus and Triturus arestatistically shown to be nonmonophyletic, instead each contains adiverse set of lineages positioned within the large newt clade. The genusParamesotriton is also resolve as a nonmonophyletic group, with the newlydescribed species P. laoensis constituting a divergent lineage placed ina sister position to clade containing all Pachytriton species and allremaining Paramesotriton species. Sequence divergences between P.laoensis and other Paramesotriton species are as great as those comparingP. laoensis and species of the genera Cynops and Pachytriton. Analyses oflineage diversification across the Salamandridae indicate that, despiteits exceptional diversity, lineage accumulation appears to have beenconstant across time, indicating that it does not represent a truespecies radiation.

  18. Hedgehog Signaling during Appendage Development and Regeneration

    PubMed Central

    Singh, Bhairab N.; Koyano-Nakagawa, Naoko; Donaldson, Andrew; Weaver, Cyprian V.; Garry, Mary G.; Garry, Daniel J.

    2015-01-01

    Regulatory networks that govern embryonic development have been well defined. While a common hypothesis supports the notion that the embryonic regulatory cascades are reexpressed following injury and tissue regeneration, the mechanistic regulatory pathways that mediate the regenerative response in higher organisms remain undefined. Relative to mammals, lower vertebrates, including zebrafish and newts, have a tremendous regenerative capacity to repair and regenerate a number of organs including: appendages, retina, heart, jaw and nervous system. Elucidation of the pathways that govern regeneration in these lower organisms may provide cues that will enhance the capacity for the regeneration of mammalian organs. Signaling pathways, such as the hedgehog pathway, have been shown to play critical functions during development and during regeneration in lower organisms. These signaling pathways have been shown to modulate multiple processes including cellular origin, positional identity and cellular maturation. The present review will focus on the cellular and molecular regulation of the hedgehog (HH) signaling pathway and its interaction with other signaling factors during appendage development and regeneration. PMID:26110318

  19. Comparison of PWR - Burnup calculations with SCALE 5.0/TRITON other burnup codes and experimental results

    SciTech Connect

    Oberle, P.; Broeders, C. H. M.; Dagan, R.

    2006-07-01

    The increasing tendency towards fuel lifetime extension in thermal nuclear reactors motivated validation work for available evaluation tools for nuclear fuel burnup calculations. In this study two deterministic codes with different transport solvers and one Monte Carlo method are investigated. The code system KAPROS/KARBUS uses the classical deterministic First Collision Probability method utilizing a cylinderized Wigner-Seitz cell. In the SCALES.0/TRITON/NEWT code the Extended Step Characteristic method is applied. In a first step the two deterministic codes are compared with experimental results from the KWO-Isotope Correlation Experiment up to 30 MWD/kg HM burnup, published in 1981. Two pin cell calculations are analyzed by comparison of calculated and experimental results for important heavy isotope vectors. The results are very satisfactory. Subsequently, further validation at higher burnup (< 80 MWD/kg HM) is provided by comparison of the two deterministic codes and the Monte Carlo based burnup code MONTEBURNS for PWR UO{sub 2} fuel assembly calculations. Possible reasons for differences in the results are analyzed and discussed. Especially the influence of cross section data and processing is presented. (authors)

  20. DISTRIBUTION OF LEUCINE-3H DURING AXOPLASMIC TRANSPORT WITHIN REGENERATING NEURONS AS DETERMINED BY ELECTRON-MICROSCOPE RADIOAUTOGRAPHY

    PubMed Central

    Lentz, Thomas L.

    1972-01-01

    The distribution of leucine-3H in neurons was determined by electron-microscope radioautography after infusion of label into the spinal cord or sensory ganglia of regenerating newts. In the nerve cell bodies 3 days after infusion, the highest concentration of label per unit area occurred over the rough-surfaced endoplasmic reticulum. In the large brachial nerves, the silver grains were not distributed uniformly in the axoplasm, indicating that the labeled materials are restricted in their movement to certain regions of the axon. Almost all of the radioautographic grains observed in myelinated nerves could be accounted for by the presence of a uniformly labeled band occupying the area 1500–9000 A inside the axolemma. This region of the axon was rich in microtubules and organelles while the unlabeled central core of the axon contained mainly neurofilaments. This observation supports the hypothesis that microtubules are related to axonal transport. In small, vesicle-filled nerve terminals in the blastema, labeled material was restricted to a thin zone a short distance beneath the plasma membrane while the central region of the terminal was largely unlabeled. The peripheral pattern of labeling in the nerve endings is consistent with successive addition of newly synthesized proteins at the periphery of the growth cone and release of substances such as trophic factors at the nerve terminal. PMID:4109691

  1. Dimorphisms of the proteasome subunit beta type 8 gene (PSMB8) of ectothermic tetrapods originated in multiple independent evolutionary events.

    PubMed

    Huang, Ching-Huei; Tanaka, Yuta; Fujito, Naoko T; Nonaka, Masaru

    2013-11-01

    The proteasome subunit beta type 8 gene (PSMB8) encodes one of the beta subunits of the immunoproteasome responsible for the generation of peptides presented by major histocompatibility complex class I molecules. Dimorphic alleles of the PSMB8 gene, termed A and F types, based on the deduced 31st amino acid residue of the mature protein have been reported from various vertebrates. Phylogenetic analysis revealed the presence of dichotomous ancient lineages, one comprising the F-type PSMB8 of basal ray-finned fishes, and the other comprising the A-type PSMB8 of these animals and both the F- and A-type PSMB8 of Xenopus and acanthopterygians, indicating that evolutionary history of the PSMB8 dimorphism was not straightforward. We analyzed the PSMB8 gene of five reptile and one amphibian species and found both the A and F types from all six. Phylogenetic analysis indicated that the PSMB8 F type was apparently regenerated from the PSMB8 A type at least five times independently during tetrapod evolution. Genomic typing of wild individuals of geckos and newts indicated that the frequencies of the A- and F-type alleles are not highly biased in these species. Phylogenetic analysis of each exon of the reptile PSMB8 gene suggested interallelic sequence homogenization as a possible evolutionary mechanism for the apparent recurrent regeneration of PSMB8 dimorphism in tetrapods. An extremely strong balancing selection acting on PSMB8 dimorphism was implicated in an unprecedented pattern of allele evolution.

  2. Invasive hybrid tiger salamander genotypes impact native amphibians

    PubMed Central

    Ryan, Maureen E.; Johnson, Jarrett R.; Fitzpatrick, Benjamin M.

    2009-01-01

    Although the ecological consequences of species invasions are well studied, the ecological impacts of genetic introgression through hybridization are less understood. This is particularly true of the impacts of hybridization on “third party” community members not genetically involved in hybridization. We also know little about how direct interactions between hybrid and parental individuals influence fitness. Here, we examined the ecological effects of hybridization between the native, threatened California Tiger Salamander (Ambystoma californiense) and the introduced Barred Tiger Salamander (Ambystoma tigrinum mavortium). Native x introduced hybrids are widespread in California, where they are top predators in seasonal ponds. We examined the impacts of early generation hybrids (first 2 generations of parental crosses) and contemporary hybrids derived from ponds where hybrids have been under selection in the wild for 20 generations. We found that most classes of hybrid tiger salamander larvae dramatically reduced survival of 2 native community members, the Pacific Chorus Frog (Pseudacris regilla) and the California Newt (Taricha torosa). We also found that native A. californiense larvae were negatively impacted by the presence of hybrid larvae: Native survival and size at metamorphosis were reduced and time to metamorphosis was extended. We also observed a large influence of Mendelian dominance on size, metamorphic timing and predation rate of hybrid tiger salamanders. These results suggest that both genetic and ecological factors are likely to influence the dynamics of admixture, and that tiger salamander hybridization might constitute a threat to additional pond-breeding species of concern in the region. PMID:19564601

  3. Invasive hybrid tiger salamander genotypes impact native amphibians.

    PubMed

    Ryan, Maureen E; Johnson, Jarrett R; Fitzpatrick, Benjamin M

    2009-07-07

    Although the ecological consequences of species invasions are well studied, the ecological impacts of genetic introgression through hybridization are less understood. This is particularly true of the impacts of hybridization on "third party" community members not genetically involved in hybridization. We also know little about how direct interactions between hybrid and parental individuals influence fitness. Here, we examined the ecological effects of hybridization between the native, threatened California Tiger Salamander (Ambystoma californiense) and the introduced Barred Tiger Salamander (Ambystoma tigrinum mavortium). Native x introduced hybrids are widespread in California, where they are top predators in seasonal ponds. We examined the impacts of early generation hybrids (first 2 generations of parental crosses) and contemporary hybrids derived from ponds where hybrids have been under selection in the wild for 20 generations. We found that most classes of hybrid tiger salamander larvae dramatically reduced survival of 2 native community members, the Pacific Chorus Frog (Pseudacris regilla) and the California Newt (Taricha torosa). We also found that native A. californiense larvae were negatively impacted by the presence of hybrid larvae: Native survival and size at metamorphosis were reduced and time to metamorphosis was extended. We also observed a large influence of Mendelian dominance on size, metamorphic timing and predation rate of hybrid tiger salamanders. These results suggest that both genetic and ecological factors are likely to influence the dynamics of admixture, and that tiger salamander hybridization might constitute a threat to additional pond-breeding species of concern in the region.

  4. PWR Cross Section Libraries for ORIGEN-ARP

    SciTech Connect

    McGraw, Carolyn; Ilas, Germina

    2012-01-01

    New pressurized water reactor (PWR) cross-section libraries were generated for use with the ORIGEN-ARP depletion sequence in the SCALE nuclear analysis code system. These libraries are based on ENDF/B-VII nuclear data and were generated using the two-dimensional depletion sequence, TRITON/NEWT, in SCALE 6.1. The libraries contain multiple burnup-dependent cross-sections for seven PWR fuel designs, with enrichments ranging from 1.5 to 6 wt% 235U. The burnup range has been extended from the 72 GWd/MTU used in previous versions of the libraries to 90 GWd/MTU. Validation of the libraries using radiochemical assay measurements and decay heat measurements for PWR spent fuel showed good agreement between calculated and experimental data. Verification against detailed TRITON simulations for the considered assembly designs showed that depletion calculations performed in ORIGEN-ARP with the pre-generated libraries provide similar results as obtained with direct TRITON depletion, while greatly reducing the computation time.

  5. SCALE Continuous-Energy Monte Carlo Depletion with Parallel KENO in TRITON

    SciTech Connect

    Goluoglu, Sedat; Bekar, Kursat B; Wiarda, Dorothea

    2012-01-01

    The TRITON sequence of the SCALE code system is a powerful and robust tool for performing multigroup (MG) reactor physics analysis using either the 2-D deterministic solver NEWT or the 3-D Monte Carlo transport code KENO. However, as with all MG codes, the accuracy of the results depends on the accuracy of the MG cross sections that are generated and/or used. While SCALE resonance self-shielding modules provide rigorous resonance self-shielding, they are based on 1-D models and therefore 2-D or 3-D effects such as heterogeneity of the lattice structures may render final MG cross sections inaccurate. Another potential drawback to MG Monte Carlo depletion is the need to perform resonance self-shielding calculations at each depletion step for each fuel segment that is being depleted. The CPU time and memory required for self-shielding calculations can often eclipse the resources needed for the Monte Carlo transport. This summary presents the results of the new continuous-energy (CE) calculation mode in TRITON. With the new capability, accurate reactor physics analyses can be performed for all types of systems using the SCALE Monte Carlo code KENO as the CE transport solver. In addition, transport calculations can be performed in parallel mode on multiple processors.

  6. ENDF/B-VII Nuclear Data Libraries for SCALE-6.0

    SciTech Connect

    Williams, Mark L; Ilas, Germina

    2009-01-01

    Version 6 of the SCALE (Standardized Computer Analyses for Licensing Evaluation) code system was released in February 2009. SCALE provides a comprehensive, integrated package of modular programs and nuclear data for a wide range of applications, including reactor physics, criticality safety, shielding, sensitivity/uncertainty analysis, and isotopic transmutation and radiation source term determination. SCALE computational modules are executed by automated control sequences that prepare input and call the desired modules in a particular order, linking output from one calculation to the next in series. The SCALE lattice physics sequence TRITON generates few-group, assembly-homogenized cross sections, as a function of burnup and branch states, which can be input to core simulator codes. TRITON couples the ORIGEN-S depletion module with either the NEWT (NEW Transport algorithm) two-dimensional (2D) arbitrary-geometry transport code or the three-dimensional Monte Carlo KENO code. Fluxes from the transport solution, along with self-shielded multigroup (MG) cross sections, are passed to ORIGEN-S, which computes the time-dependent isotopic concentrations of more than 1400 nuclides. One of the major advancements in SCALE 6 is the availability of new nuclear data libraries based on ENDF/B-VII for neutron transport calculations. In this paper we describe the SCALE ENDF/B-VII (designated here as V7) libraries and present some validation results for critical benchmarks and isotopic depletion experiments.

  7. PWR ENDF/B-VII cross-section libraries for ORIGEN-ARP

    SciTech Connect

    McGraw, C.; Ilas, G.

    2012-07-01

    New pressurized water reactor (PWR) cross-section libraries were generated for use with the ORIGEN-ARP depletion sequence in the SCALE nuclear analysis code system. These libraries are based on ENDF/B-VII nuclear data and were generated using the two-dimensional depletion sequence, TRITON/NEWT, in SCALE 6.1. The libraries contain multiple burnup-dependent cross-sections for seven PWR fuel designs, with enrichments ranging from 1.5 to 6 wt% {sup 235}U. The burnup range has been extended from the 72 GWd/MTU used in previous versions of the libraries to 90 GWd/MTU. Validation of the libraries using radiochemical assay measurements and decay heat measurements for PWR spent fuel showed good agreement between calculated and experimental data. Verification against detailed TRITON simulations for the considered assembly designs showed that depletion calculations performed in ORIGEN-ARP with the pre-generated libraries provide similar results as obtained with direct TRITON depletion, while greatly reducing the computation time. (authors)

  8. Molecular cloning and characterization of ligand- and species-specificity of amphibian estrogen receptors.

    PubMed

    Katsu, Yoshinao; Taniguchi, Ena; Urushitani, Hiroshi; Miyagawa, Shinichi; Takase, Minoru; Kubokawa, Kaoru; Tooi, Osamu; Oka, Tomohiro; Santo, Noriaki; Myburgh, Jan; Matsuno, Akira; Iguchi, Taisen

    2010-09-01

    Estrogens are essential for normal reproductive activity in both males and females as well as for ovarian differentiation during a critical developmental stage in most vertebrates. To understand the molecular mechanisms of estrogen action and to evaluate estrogen receptor ligand interactions in amphibians, we isolated cDNAs encoding the estrogen receptors (ERalpha and ERbeta) from the Japanese firebelly newt (Cynops pyrrhogaster), Tokyo salamander (Hynobius tokyoensis), axolotl (Ambystoma mexicanum), and Raucous toad (Bufo rangeri). Full-length amphibian ER cDNAs were obtained using 5' and 3' rapid amplification of cDNA ends. The predicted amino acid sequences of these amphibian ERs showed a high degree of amino acid sequence identity (over 70%) to each other. We analyzed the relationships of these amphibian ER sequences to other vertebrate ER sequences by constructing a phylogenetic tree. We verified that these were bona fide estrogen receptors using receptor dependent reporter gene assays. We analyzed the effects of natural estrogens, ethinylestradiol, and DDT and its metabolites on the transactivation of the four amphibian species listed above, and Xenopus tropicalis ERs and found that there were species-specific differences in the sensitivity of these ERs to hormones and environmental chemicals. These findings will expand our knowledge of endocrine-disrupting events in amphibians.

  9. IgX antibodies in the urodele amphibian Ambystoma mexicanum.

    PubMed

    Schaerlinger, Bérénice; Frippiat, Jean-Pol

    2008-01-01

    Until recently, it was believed that urodele amphibians are able to synthesize only two immunoglobulin isotypes, IgM and IgY. We reinvestigated this issue in the Iberian ribbed newt Pleurodeles waltl and reported recently that this urodele expresses at least three isotypes: IgM, IgP and IgY. In this study, we demonstrate that another urodele, Ambystoma mexicanum, has also a third isotype whose amino acid sequence presents the highest homology with the amino acid sequence of Xenopus IgX. This isotype has typical Ig H-chain characteristics, could form multimers and is mainly expressed in mucosal tissues thereby indicating that it is likely the physiological counterpart of Xenopus IgX and mammalian IgA. Interestingly, no IgP could be found in A. mexicanum, in contrast to P. waltl, in which IgX was not found in previous investigations. These data indicate, for the first time, that different families of urodeles can express different immunoglobulin isotypes.

  10. Modulation of Pleurodeles waltl DNA Polymerase mu Expression by Extreme Conditions Encountered during Spaceflight

    PubMed Central

    Baatout, Sarah; Frippiat, Jean-Pol

    2013-01-01

    DNA polymerase µ is involved in DNA repair, V(D)J recombination and likely somatic hypermutation of immunoglobulin genes. Our previous studies demonstrated that spaceflight conditions affect immunoglobulin gene expression and somatic hypermutation frequency. Consequently, we questioned whether Polμ expression could also be affected. To address this question, we characterized Polμ of the Iberian ribbed newt Pleurodeles waltl and exposed embryos of that species to spaceflight conditions or to environmental modifications corresponding to those encountered in the International Space Station. We noted a robust expression of Polμ mRNA during early ontogenesis and in the testis, suggesting that Polμ is involved in genomic stability. Full-length Polμ transcripts are 8–9 times more abundant in P. waltl than in humans and mice, thereby providing an explanation for the somatic hypermutation predilection of G and C bases in amphibians. Polμ transcription decreases after 10 days of development in space and radiation seem primarily involved in this down-regulation. However, space radiation, alone or in combination with a perturbation of the circadian rhythm, did not affect Polμ protein levels and did not induce protein oxidation, showing the limited impact of radiation encountered during a 10-day stay in the International Space Station. PMID:23936065

  11. Composition of the Cutaneous Bacterial Community in Japanese Amphibians: Effects of Captivity, Host Species, and Body Region.

    PubMed

    Sabino-Pinto, Joana; Bletz, Molly Catherine; Islam, Mohammed Mafizul; Shimizu, Norio; Bhuju, Sabin; Geffers, Robert; Jarek, Michael; Kurabayashi, Atsushi; Vences, Miguel

    2016-08-01

    The cutaneous microbiota plays a significant role in the biology of their vertebrate hosts, and its composition is known to be influenced both by host and environment, with captive conditions often altering alpha diversity. Here, we compare the cutaneous bacterial communities of 61 amphibians (both wild and captive) from Hiroshima, Japan, using high-throughput amplicon sequencing of a segment of the 16S rRNA gene. The majority of these samples came from a captive breeding facility at Hiroshima University where specimens from six species are maintained under highly standardized conditions for several generations. This allowed to identify host effects on the bacterial communities under near identical environmental conditions in captivity. We found the structure of the cutaneous bacterial community significantly differing between wild and captive individuals of newts, Cynops pyrrhogaster, with a higher alpha diversity found in the wild individuals. Community structure also showed distinct patterns when comparing different species of amphibians kept under highly similar conditions, revealing an intrinsic host effect. Bacterial communities of dorsal vs. ventral skin surfaces did not significantly differ in most species, but a trend of higher alpha diversity on the ventral surface was found in Oriental fire-bellied toads, Bombina orientalis. This study confirms the cutaneous microbiota of amphibians as a highly dynamic system influenced by a complex interplay of numerous factors.

  12. Impact of asynchronous emergence of two lethal pathogens on amphibian assemblages

    PubMed Central

    Rosa, Gonçalo M.; Sabino-Pinto, Joana; Laurentino, Telma G.; Martel, An; Pasmans, Frank; Rebelo, Rui; Griffiths, Richard A.; Stöhr, Anke C.; Marschang, Rachel E.; Price, Stephen J.; Garner, Trenton W. J.; Bosch, Jaime

    2017-01-01

    Emerging diseases have been increasingly associated with population declines, with co-infections exhibiting many types of interactions. The chytrid fungus (Batrachochytrium dendrobatidis) and ranaviruses have extraordinarily broad host ranges, however co-infection dynamics have been largely overlooked. We investigated the pattern of co-occurrence of these two pathogens in an amphibian assemblage in Serra da Estrela (Portugal). The detection of chytridiomycosis in Portugal was linked to population declines of midwife-toads (Alytes obstetricans). The asynchronous and subsequent emergence of a second pathogen - ranavirus - caused episodes of lethal ranavirosis. Chytrid effects were limited to high altitudes and a single host, while ranavirus was highly pathogenic across multiple hosts, life-stages and altitudinal range. This new strain (Portuguese newt and toad ranavirus – member of the CMTV clade) caused annual mass die-offs, similar in host range and rapidity of declines to other locations in Iberia affected by CMTV-like ranaviruses. However, ranavirus was not always associated with disease, mortality and declines, contrasting with previous reports on Iberian CMTV-like ranavirosis. We found little evidence that pre-existing chytrid emergence was associated with ranavirus and the emergence of ranavirosis. Despite the lack of cumulative or amplified effects, ranavirus drove declines of host assemblages and changed host community composition and structure, posing a grave threat to all amphibian populations. PMID:28240267

  13. Phylogenetic distribution of apolipoproteins A-I and E in vertebrates as determined by Western blot analysis.

    PubMed

    Duggan, A E; Callard, I P

    2001-08-01

    A putative apolipoprotein E (apoE) has been identified in the HDL and VHDL fractions of the turtle. This observation is of particular interest considering apoE has been reported absent in the domestic hen (Hermier et al., '95; Biochim Biophys Acta: 105-118, 1995) and thus presumed absent in nonmammalian vertebrates altogether. As a result, partial amino acid sequencing of this protein was performed and revealed that one fragment shared 41% sequence identity to human apoE. Western blot analysis using antisera to apoE demonstrated cross-reactivity to a 34-kDa protein (putative apoE) in turtle plasma. Further investigation using anti-apoE antibody in Western blot analysis detected immunoreactive apoE in the plasma of lamprey, spiny dogfish, skate, and alligator, but not in flounder, newt or python; its absence in several species of birds was confirmed. Using anti-apoA-I antibody, apoA-I was detected in all vertebrate groups except a representative teleost (flounder). Apo-A-I antibody cross-reacted weakly with some putative apoE proteins (chicken, spiny dogfish and skate) and the reverse was true for anti-apoE, which cross-reacted with putative apoA-I in birds, reptiles, and elasmobranchs, confirming the molecular similarity and phylogenetic relatedness of these two proteins.

  14. Comparative analysis of ear-hole closure identifies epimorphic regeneration as a discrete trait in mammals

    PubMed Central

    Gawriluk, Thomas R.; Simkin, Jennifer; Thompson, Katherine L.; Biswas, Shishir K.; Clare-Salzler, Zak; Kimani, John M.; Kiama, Stephen G.; Smith, Jeramiah J.; Ezenwa, Vanessa O.; Seifert, Ashley W.

    2016-01-01

    Why mammals have poor regenerative ability has remained a long-standing question in biology. In regenerating vertebrates, injury can induce a process known as epimorphic regeneration to replace damaged structures. Using a 4-mm ear punch assay across multiple mammalian species, here we show that several Acomys spp. (spiny mice) and Oryctolagus cuniculus completely regenerate tissue, whereas other rodents including MRL/MpJ ‘healer' mice heal similar injuries by scarring. We demonstrate ear-hole closure is independent of ear size, and closure rate can be modelled with a cubic function. Cellular and genetic analyses reveal that injury induces blastema formation in Acomys cahirinus. Despite cell cycle re-entry in Mus musculus and A. cahirinus, efficient cell cycle progression and proliferation only occurs in spiny mice. Together, our data unite blastema-mediated regeneration in spiny mice with regeneration in other vertebrates such as salamanders, newts and zebrafish, where all healthy adults regenerate in response to injury. PMID:27109826

  15. The RNA-binding protein xCIRP2 is involved in apoptotic tail regression during metamorphosis in Xenopus laevis tadpoles.

    PubMed

    Eto, Ko; Iwama, Tomoyuki; Tajima, Tatsuya; Abe, Shin-ichi

    2012-10-01

    Frog metamorphosis induced by thyroid hormone (TH) involves not only cell proliferation and differentiation in reconstituted organs such as limbs, but also apoptotic cell death in degenerated organs such as tails. However, the molecular mechanisms directing the TH-dependent cell fate determination remain unclear. We have previously identified from newts an RNA-binding protein (nRBP) acting as the regulator governing survival and death in germ cells during spermatogenesis. To investigate the molecular events leading the tail resorption during metamorphosis, we analyzed the expression, the functional role in apoptosis, and the regulation of xCIRP2, a frog homolog of nRBP, in tails of Xenopus laevis tadpoles. At the prometamorphic stage, xCIRP2 protein is expressed in fibroblast, epidermal, nerve, and muscular cells and localized in their cytoplasm. When spontaneous metamorphosis progressed, the level of xCIRP2 mRNA remained unchanged but the amount of the protein decreased. In organ cultures of tails at the prometamorphic stage, xCIRP2 protein decreased before their lengths shortened during TH-dependent metamorphosis. The inhibition of calpain or proteasome attenuated the TH-induced decrease of xCIRP2 protein in tails, impairing their regression. These results suggest that xCIRP2 protein is downregulated through calpain- and proteasome-mediated proteolysis in response to TH at the onset of metamorphosis, inducing apoptosis in tails and thereby degenerating them.

  16. Purification and characterization of cholecystokinin from the skin of salamander Tylototriton verrucosus.

    PubMed

    Jiang, Wen-Bin; Hakim, Ma; Luo, Lei; Li, Bo-Wen; Yang, Shi-Long; Song, Yu-Zhu; Lai, Ren; Lu, Qiu-Min

    2015-05-18

    As a group of intestinal hormones and neurotransmitters, cholecystokinins (CCKs) regulate and affect pancreatic enzyme secretion, gastrointestinal motility, pain hypersensitivity, digestion and satiety, and generally contain a DYMGWMDFG sequence at the C-terminus. Many CCKs have been reported in mammals. However, only a few have been reported in amphibians, such as Hyla nigrovittata, Xenopus laevis, and Rana catesbeiana, with none reported in urodele amphibians like newts and salamanders. Here, a CCK called CCK-TV was identified and characterized from the skin of the salamander Tylototriton verrucosus. This CCK contained an amino acid sequence of DYMGWMDF-NH2 as seen in other CCKs. A cDNA encoding the CCK precursor containing 129 amino acid residues was cloned from the cDNA library of T. verrucosus skin. The CCK-TV had the potential to induce the contraction of smooth muscle strips isolated from porcine gallbladder, eliciting contraction at a concentration of 5.0 x 10⁻¹¹ mol/L and inducing maximal contraction at a concentration of 2.0 x 10⁻⁶ mol/L. The EC50 was 13.6 nmol/L. To the best of our knowledge, this is the first report to identify the presence of a CCK in an urodele amphibian.

  17. Inflammation and Its Correlates in Regenerative Wound Healing: An Alternate Perspective.

    PubMed

    Gourevitch, Dmitri; Kossenkov, Andrew V; Zhang, Yong; Clark, Lise; Chang, Celia; Showe, Louise C; Heber-Katz, Ellen

    2014-09-01

    Objective: The wound healing response may be viewed as partially overlapping sets of two physiological processes, regeneration and wound repair with the former overrepresented in some lower species such as newts and the latter more typical of mammals. A robust and quantitative model of regenerative healing has been described in Murphy Roths Large (MRL) mice in which through-and-through ear hole wounds in the ear pinna leads to scarless healing and replacement of all tissue through blastema formation and including cartilage. Since these mice are naturally autoimmune and display many aspects of an enhanced inflammatory response, we chose to examine the inflammatory status during regenerative ear hole closure and observed that inflammation has a clear positive effect on regenerative healing. Approach: The inflammatory gene expression patterns (Illumina microarrays) of early healing ear tissue from regenerative MRL and nonregenerative C57BL/6 (B6) strains are presented along with a survey of innate inflammatory cells found in this tissue type pre and postinjury. The role of inflammation on healing is tested using a COX-2 inhibitor. Innovation and Conclusion: We conclude that (1) enhanced inflammation is consistent with, and probably necessary, for a full regenerative response and (2) the inflammatory gene expression and cell distribution patterns suggest a novel mast cell population with markers found in both immature and mature mast cells that may be a key component of regeneration.

  18. Evolutionary diversification of TTX-resistant sodium channels in a predator-prey interaction.

    PubMed

    Geffeney, Shana L; Fujimoto, Esther; Brodie, Edmund D; Brodie, Edmund D; Ruben, Peter C

    2005-04-07

    Understanding the molecular genetic basis of adaptations provides incomparable insight into the genetic mechanisms by which evolutionary diversification takes place. Whether the evolution of common traits in different lineages proceeds by similar or unique mutations, and the degree to which phenotypic evolution is controlled by changes in gene regulation as opposed to gene function, are fundamental questions in evolutionary biology that require such an understanding of genetic mechanisms. Here we identify novel changes in the molecular structure of a sodium channel expressed in snake skeletal muscle, tsNa(V)1.4, that are responsible for differences in tetrodotoxin (TTX) resistance among garter snake populations coevolving with toxic newts. By the functional expression of tsNa(V)1.4, we show how differences in the amino-acid sequence of the channel affect TTX binding and impart different levels of resistance in four snake populations. These results indicate that the evolution of a physiological trait has occurred through a series of unique functional changes in a gene that is otherwise highly conserved among vertebrates.

  19. Convergent Evolution of Tetrodotoxin-Resistant Sodium Channels in Predators and Prey.

    PubMed

    Toledo, G; Hanifin, C; Geffeney, S; Brodie, E D

    2016-01-01

    Convergent evolution of similar adaptive traits may arise from either common or disparate molecular and physiological mechanisms. The forces that determine the degree of underlying mechanistic similarities across convergent phenotypes are highly debated and poorly understood. Some garter snakes are able to consume newts that possess the channel blocking compound tetrodotoxin (TTX). Despite belonging to unrelated lineages, both the predators and prey have independently evolved remarkably similar physiological mechanisms of resistance to TTX that involve chemical and structural changes in voltage-gated sodium channels (NaV). The evolution of TTX resistance in this predator-prey pair cons