'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

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).

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.

Hair cell regeneration in sensory epithelia from the inner ear of a urodele amphibian.

PubMed

Taylor, Ruth R; Forge, Andrew

2005-03-28

The capacity of urodele amphibians to regenerate a variety of body parts is providing insight into mechanisms of tissue regeneration in vertebrates. In this study the ability of the newt, Notophthalmus viridescens, to regenerate inner ear hair cells in vitro was examined. Intact otic capsules were maintained in organotypic culture. Incubation in 2 mM gentamicin for 48 hours resulted in ablation of all hair cells from the saccular maculae. Thus, any hair cell recovery was not due to repair of damaged hair cells. Immature hair cells were subsequently observed at approximately 12 days posttreatment. Their number increased over the following 7-14 days to reach approximately 30% of the normal number. Following incubation of damaged tissue with bromodeoxyuridine (BrdU), labeled nuclei were confined strictly within regions of hair cell loss, indicating that supporting cells entered S-phase. Double labeling of tissue with two different hair cell markers and three different antibodies to BrdU in various combinations, however, all showed that the nuclei of cells that labeled with hair cell markers did not label for BrdU. This suggested that the new hair cells were not derived from those cells that had undergone mitosis. When mitosis was blocked with aphidicolin, new hair cells were still generated. The results suggest that direct phenotypic conversion of supporting cells into hair cells without an intervening mitotic event is a major mechanism of hair cell regeneration in the newt. A similar mechanism has been proposed for the hair cell recovery phenomenon observed in the vestibular organs of mammals. Copyright 2005 Wiley-Liss, Inc.

Isolation and Characterization of Viruses from the Kidneys of Rana pipiens with Renal Adenocarcinoma Before and After Passage in the Red Eft (Triturus viridescens)

PubMed Central

Clark, H. Fred; Brennan, James C.; Zeigel, Robert F.; Karzon, David T.

1968-01-01

Viruses were isolated from kidneys of normal and renal tumor-bearing Vermont Rana pipiens after subinoculation into red eft newts (Triturus viridescens). Organs of efts inoculated with viable cell suspensions from four of seven tumor-bearing kidneys yielded virus (LT-1, -2, -3, -4) when inoculated into TH-1 (Terrapene heart) cell culture. One tumor-bearing kidney also yielded virus (L-4) by direct inoculation into TH-1 cells. An additional isolate (L-5) was obtained from 1 of 52 normal Vermont frog kidneys inoculated directly into TH-1 cells. LT-1 was propagated with cytopathic effect (CPE) in each of 38 cell types tested, of fish, amphibian, reptilian, avian, and mammalian origin, at 23 or 30 C. LT-1 through LT-4, L-4 and L-5, and FV-1 through FV-3 each induced similar CPE in all cells tested. LT-2, however, induced CPE that progressed at a slower rate than that caused by the other isolates and produced smaller plaques (<0.8 mm) under starch gel overlay. Each of the viruses replicated to high titer in embryonated eggs incubated at 30 C. The viruses also grew in efts and adult newts, but not in bullfrog (Rana catesbeiana) tadpoles or adult leopard frogs. Tumor induction in adult leopard frogs inoculated with LT-1 was not demonstrated. Electron microscopic observations of LT-1 and LT-2 viruses revealed cytoplasmic particles, hexagonal in cross section, approximately 120 to 140 mμ in diameter, containing a dense nucleoid. LT-1 and LT-2 viruses were indistinguishable from FV-1 and Tipula iridescent virus. LT-1 was presumed to be a deoxyribonucleic acid virus on the basis of 5-bromodeoxyuridine inhibition. The isolates were ether-sensitive. On the basis of biological, physicochemical, and antigenic similarities, LT-1 through LT-4, L-4, L-5, FV-1 through FV-3, and isolates recently recovered from the bullfrog and the newt may represent strains of the same amphibian cytoplasmic virus. Images PMID:4972302

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).

Effects of cadmium exposure on Iberian ribbed newt (Pleurodeles waltl) testes

PubMed Central

Hirako, Ayano; Takeoka, Yuki; Hayashi, Toshinori; Takeuchi, Takashi; Furukawa, Satoshi; Sugiyama, Akihiko

2017-01-01

To characterize the histomorphologic effects of cadmium on adult newt testes, male Iberian ribbed newts (6 months post-hatching) were intraperitoneally exposed to a single dose of 50 mg/kg of cadmium, with histologic analysis of the testes at 24, 48, 72, and 96 h. Beginning 24 h after cadmium exposure, apoptosis of spermatogonia and spermatocytes was observed, and congestion was observed in the interstitial vessels of the testes. Throughout the experimental period, the rates of pyknotic cells and TUNEL and cleaved caspase-3 positivity were significantly higher in the spermatogonia and spermatocytes of cadmium-treated newts compared with control newts. There were no significant differences between cadmium-treated and control newts in phospho-histone H3 positivity in the spermatogonia and spermatocytes. These results suggest that spermatogonia and spermatocytes in adult Iberian ribbed newts are highly sensitive to cadmium. This is the first report of the histomorphologic characteristics of cadmium-induced testicular dysfunction in newts. PMID:29097846

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.

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

USGS Publications Warehouse

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

2017-01-01

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.

Corresponding Mitochondrial DNA and Niche Divergence for Crested Newt Candidate Species

PubMed Central

Wielstra, Ben; Beukema, Wouter; Arntzen, Jan W.; Skidmore, Andrew K.; Toxopeus, Albertus G.; Raes, Niels

2012-01-01

Genetic divergence of mitochondrial DNA does not necessarily correspond to reproductive isolation. However, if mitochondrial DNA lineages occupy separate segments of environmental space, this supports the notion of their evolutionary independence. We explore niche differentiation among three candidate species of crested newt (characterized by distinct mitochondrial DNA lineages) and interpret the results in the light of differences observed for recognized crested newt species. We quantify niche differences among all crested newt (candidate) species and test hypotheses regarding niche evolution, employing two ordination techniques (PCA-env and ENFA). Niche equivalency is rejected: all (candidate) species are found to occupy significantly different segments of environmental space. Furthermore, niche overlap values for the three candidate species are not significantly higher than those for the recognized species. As the three candidate crested newt species are, not only in terms of mitochondrial DNA genetic divergence, but also ecologically speaking, as diverged as the recognized crested newt species, our findings are in line with the hypothesis that they represent cryptic species. We address potential pitfalls of our methodology. PMID:23029564

The newt (Cynops pyrrhogaster) RPE65 promoter: molecular cloning, characterization and functional analysis.

PubMed

Casco-Robles, Martin Miguel; Miura, Tomoya; Chiba, Chikafumi

2015-06-01

The adult newt has the ability to regenerate the neural retina following injury, a process achieved primarily by the retinal pigment epithelium (RPE). To deliver exogenous genes to the RPE for genetic manipulation of regenerative events, we isolated the newt RPE65 promoter region by genome walking. First, we cloned the 2.8 kb RPE65 promoter from the newt, Cynops pyrrhogaster. Sequence analysis revealed several conserved regulatory elements described previously in mouse and human RPE65 promoters. Second, having previously established an I-SceI-mediated transgenic protocol for the newt, we used it here to examine the -657 bp proximal promoter of RPE65. The promoter assay used with F0 transgenic newts confirmed transgene expression of mCherry fluorescent protein in the RPE. Using bioinformatic tools and the TRANSFAC database, we identified a 340 bp CpG island located between -635 and -296 bp in the promoter; this region contains response elements for the microphthalmia-associated transcription factor known as MITF (CACGTG, CATGTG), and E-boxes (CANNTG). Sex-determining region box 9 (or SOX9) response element previously reported in the regulation of RPE genes (including RPE65) was also identified in the newt RPE65 promoter. Third, we identified DNA motif boxes in the newt RPE65 promoter that are conserved among other vertebrates. The newt RPE65 promoter is an invaluable tool for site-specific delivery of exogenous genes or genetic manipulation systems for the study of retinal regeneration in this animal.

Newt cells secrete extracellular vesicles with therapeutic bioactivity in mammalian cardiomyocytes.

PubMed

Middleton, Ryan C; Rogers, Russell G; De Couto, Geoffrey; Tseliou, Eleni; Luther, Kristin; Holewinski, Ronald; Soetkamp, Daniel; Van Eyk, Jennifer E; Antes, Travis J; Marbán, Eduardo

2018-01-01

Newts can regenerate amputated limbs and cardiac tissue, unlike mammals which lack broad regenerative capacity. Several signaling pathways involved in cell proliferation, differentiation and survival during newt tissue regeneration have been elucidated, however the factors that coordinate signaling between cells, as well as the conservation of these factors in other animals, are not well defined. Here we report that media conditioned by newt limb explant cells (A1 cells) protect mammalian cardiomyocytes from oxidative stress-induced apoptosis. The cytoprotective effect of A1-conditioned media was negated by exposing A1 cells to GW4869, which suppresses the generation of extracellular vesicles (EVs). A1-EVs are similar in diameter (~100-150 nm), structure, and share several membrane surface and cargo proteins with mammalian exosomes. However, isolated A1-EVs contain significantly higher levels of both RNA and protein per particle than mammalian EVs. Additionally, numerous cargo RNAs and proteins are unique to A1-EVs. Of particular note, A1-EVs contain numerous mRNAs encoding nuclear receptors, membrane ligands, as well as transcription factors. Mammalian cardiomyocytes treated with A1-EVs showed increased expression of genes in the PI3K/AKT pathway, a pivotal player in survival signaling. We conclude that newt cells secrete EVs with diverse, distinctive RNA and protein contents. Despite ~300 million years of evolutionary divergence between newts and mammals, newt EVs confer cytoprotective effects on mammalian cardiomyocytes.

A resistant predator and its toxic prey: persistence of newt toxin leads to poisonous (not venomous) snakes.

PubMed

Williams, Becky L; Brodie, Edmund D; Brodie, Edmund D

2004-10-01

The common garter snake (Thamnophis sirtalis) preys upon the rough-skinned newt (Taricha granulosa), which contains the neurotoxin tetrodotoxin (TTX) in the skin. TTX is toxic, large quantities are present in a newt, and highly resistant snakes have the ability to ingest multiple newts; subsequently snakes harbor significant amounts of active toxin in their own tissues after consuming a newt. Snakes harbor TTX in the liver for 1 mo or more after consuming just one newt, and at least 7 wk after consuming a diet of newts. Three weeks after eating one newt, snakes contained an average of 42 microg of TTX in the liver. This amount could severely incapacitate or kill avian predators, and mammalian predators may be negatively affected as well.

Tetrodotoxin levels of the rough-skin newt, Taricha granulosa, increase in long-term captivity.

PubMed

Hanifin, Charles T; Brodie, Edmund D; Brodie, Edmund D

2002-08-01

We investigated the persistence of the neurotoxin tetrodotoxin (TTX) in individual captive newts (Taricha granulosa) from the Willamette Valley of Oregon using a non-lethal sampling technique. We found that the TTX levels of newts held in the laboratory for 1 yr increased. TTX stereoisomer-analog profiles were not affected by captive husbandry. Levels of TTX were high in newts from our study population and we observed substantial within population variation in quantitative levels of TTX. Females possessed more TTX than males, but the response of TTX levels to captivity did not differ between females and males. The stability of TTX toxicity in newts is consistent with other amphibian species where TTX is present and may indicate that exogenous factors play a less important role in TTX toxicity of newts than previously thought.

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.

Comparative and developmental patterns of amphibious auditory function in salamanders.

PubMed

Zeyl, Jeffrey N; Johnston, Carol E

2016-12-01

Early amphibious tetrapods may have detected aquatic sound pressure using sound-induced lung vibrations, but their lack of tympanic middle ears would have restricted aerial sensitivity. Sharing these characteristics, salamanders could be models for the carryover of auditory function across an aquatic-terrestrial boundary without tympanic middle ears. We measured amphibious auditory evoked potential audiograms in five phylogenetically and ecologically distinct salamanders (Amphiuma means, Notophthalmus viridescens, Ambystoma talpoideum, Eurycea spp., and Plethodon glutinosus) and tested whether metamorphosis and terrestrial niche were linked to aerial sensitivity. Threshold differences between media varied between species. A. means' relative aerial sensitivity was greatest at 100 Hz and decreased with increasing frequency. In contrast, all other salamanders retained greater sensitivity up to 500 Hz, and in A. talpoideum and Eurycea, relative sensitivity at 500 Hz was higher than at 100 Hz. Aerial thresholds of terrestrial P. glutinosus above 200 Hz were similar to A. talpoideum and Eurycea, but lower than N. viridescens and A. means. Metamorphosis did not affect aerial sensitivity in N. viridescens or A. talpoideum. These results fail to support a hypothesis of terrestrial hearing specialization across ontogeny or phylogeny. We discuss methodological limitations to our amphibious comparisons and factors affecting variation in amphibious performance.

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. © 2017. Published by The Company of Biologists Ltd.

Unraveling the rapid radiation of crested newts (Triturus cristatus superspecies) using complete mitogenomic sequences.

PubMed

Wielstra, Ben; Arntzen, Jan W

2011-06-14

The rapid radiation of crested newts (Triturus cristatus superspecies) comprises four morphotypes: 1) the T. karelinii group, 2) T. carnifex - T. macedonicus, 3) T. cristatus and 4) T. dobrogicus. These vary in body build and the number of rib-bearing pre-sacral vertebrae (NRBV). The phylogenetic relationships of the morphotypes have not yet been settled, despite several previous attempts, employing a variety of molecular markers. We here resolve the crested newt phylogeny by using complete mitochondrial genome sequences. Bayesian inference based on the mitogenomic data yields a fully bifurcating, significantly supported tree, though Maximum Likelihood inference yields low support values. The internal branches connecting the morphotypes are short relative to the terminal branches. Seen from the root of Triturus (NRBV = 13), a basal dichotomy separates the T. karelinii group (NRBV = 13) from the remaining crested newts. The next split divides the latter assortment into T. carnifex - T. macedonicus (NRBV = 14) versus T. cristatus (NRBV = 15) and T. dobrogicus (NRBV = 16 or 17). We argue that the Bayesian full mitochondrial DNA phylogeny is superior to previous attempts aiming to recover the crested newt species tree. Furthermore, our new phylogeny involves a maximally parsimonious interpretation of NRBV evolution. Calibrating the phylogeny allows us to evaluate potential drivers for crested newt cladogenesis. The split between the T. karelinii group and the three other morphotypes, at ca. 10.4 Ma, is associated with the separation of the Balkan and Anatolian landmasses (12-9 Ma). No currently known vicariant events can be ascribed to the other two splits, first at ca. 9.3 Ma, separating T. carnifex - T. macedonicus, and second at ca. 8.8 Ma, splitting T. cristatus and T. dobrogicus. The crested newt morphotypes differ in the duration of their annual aquatic period. We speculate on the role that this ecological differentiation could have played during speciation.

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

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

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.

Love Is Blind: Indiscriminate Female Mating Responses to Male Courtship Pheromones in Newts (Salamandridae)

PubMed Central

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. PMID:23457580

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.

Modeling the growth of Lactobacillus viridescens under non-isothermal conditions in vacuum-packed sliced ham.

PubMed

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

2017-01-02

Lactic acid bacteria (LAB) are responsible for spoiling vacuum-packed meat products, such as ham. Since the temperature is the main factor affecting the microbial dynamic, the use of mathematical models describing the microbial behavior into a non-isothermal environment can be very useful for predicting food shelf life. In this study, the growth of Lactobacillus viridescens was measured in vacuum-packed sliced ham under non-isothermal conditions, and the predictive ability of primary (Baranyi and Roberts, 1994) and secondary (Square Root) models were assessed using parameters estimated in MRS culture medium under isothermal conditions (between 4 and 30°C). Fresh ham piece was sterilized, sliced, inoculated, vacuum-packed, and stored in a temperature-controlled incubator at five different non-isothermal conditions (between 4 and 25°C) and one isothermal condition (8°C). The mathematical models obtained in MRS medium were assessed by comparing predicted values with L. viridescens growth data in vacuum-packed ham. Its predictive ability was assessed through statistical indexes, with good results (bias factor between 0.95 and 1.03; accuracy factor between 1.04 and 1.07, and RMSE between 0.76 and 1.33), especially in increasing temperature, which predictions were safe. The model parameters obtained from isothermal growth data in MRS medium enabled to estimate the shelf life of a commercial ham under non-isothermal conditions in the temperature range analyzed. Copyright © 2016 Elsevier B.V. All rights reserved.

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

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

Noxious newts and their natural enemies: Experimental effects of tetrodotoxin exposure on trematode parasites and aquatic macroinvertebrates.

PubMed

Calhoun, Dana M; Bucciarelli, Gary M; Kats, Lee B; Zimmer, Richard K; Johnson, Pieter T J

2017-10-01

The dermal glands of many amphibian species secrete toxins or other noxious substances as a defense strategy against natural enemies. Newts in particular possess the potent neurotoxin tetrodotoxin (TTX), for which the highest concentrations are found in species within the genus Taricha. Adult Taricha are hypothesized to use TTX as a chemical defense against vertebrate predators such as garter snakes (Thamnophis spp.). However, less is known about how TTX functions to defend aquatic-developing newt larvae against natural enemies, including trematode parasites and aquatic macroinvertebrates. Here we experimentally investigated the effects of exogenous TTX exposure on survivorship of the infectious stages (cercariae) of five species of trematode parasites that infect larval amphibians. Specifically, we used dose-response curves to test the sensitivity of trematode cercariae to progressively increasing concentrations of TTX (0.0 [control], 0.63, 3.13, 6.26, 31.32, and 62.64 nmol L -1 ) and how this differed among parasite species. We further compared these results to the effects of TTX exposure (0 and 1000 nmolL -1 ) over 24 h on seven macroinvertebrate taxa commonly found in aquatic habitats with newt larvae. TTX significantly reduced the survivorship of trematode cercariae for all species, but the magnitude of such effects varied among species. Ribeiroia ondatrae - which causes mortality and limb malformations in amphibians - was the least sensitive to TTX, whereas the kidney-encysting Echinostoma trivolvis was the most sensitive. Among the macroinvertebrate taxa, only mayflies (Ephemeroptera) showed a significant increase in mortality following exogenous TTX exposure, despite the use of a concentration 16x higher than the maximum used for trematodes. Our results suggest that maternal investment of TTX into larval newts may provide protection against certain trematode infections and highlight the importance of future work assessing the effects of newt toxicity on

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

Parallel arms races between garter snakes and newts involving tetrodotoxin as the phenotypic interface of coevolution.

PubMed

Brodie, Edmund D; Feldman, Chris R; Hanifin, Charles T; Motychak, Jeffrey E; Mulcahy, Daniel G; Williams, Becky L; Brodie, Edmund D

2005-02-01

Parallel "arms races" involving the same or similar phenotypic interfaces allow inference about selective forces driving coevolution, as well as the importance of phylogenetic and phenotypic constraints in coevolution. Here, we report the existence of apparent parallel arms races between species pairs of garter snakes and their toxic newt prey that indicate independent evolutionary origins of a key phenotype in the interface. In at least one area of sympatry, the aquatic garter snake, Thamnophis couchii, has evolved elevated resistance to the neurotoxin tetrodotoxin (TTX), present in the newt Taricha torosa. Previous studies have shown that a distantly related garter snake, Thamnophis sirtalis, has coevolved with another newt species that possesses TTX, Taricha granulosa. Patterns of within population variation and phenotypic tradeoffs between TTX resistance and sprint speed suggest that the mechanism of resistance is similar in both species of snake, yet phylogenetic evidence indicates the independent origins of elevated resistance to TTX.

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.

Reconstitution of the myocardium in regenerating newt hearts is preceded by transient deposition of extracellular matrix components.

PubMed

Piatkowski, Tanja; Mühlfeld, Christian; Borchardt, Thilo; Braun, Thomas

2013-07-01

Adult newts efficiently regenerate the heart after injury in a process that involves proliferation of cardiac muscle and nonmuscle cells and repatterning of the myocardium. To analyze the processes that underlie heart regeneration in newts, we characterized the structural changes in the myocardium that allow regeneration after mechanical injury. We found that cardiomyocytes in the damaged ventricle mainly die by necrosis and are removed during the first week after injury, paving the way for the extension of thin myocardial trabeculae, which initially contain only very few cardiomyocytes. During the following 200 days, these thin trabeculae fill up with new cardiomyocytes until the myocardium is fully reconstituted. Interestingly, reconstruction of the newly formed trabeculated network is accompanied by transient deposition of extracellular matrix (ECM) components such as collagen III. We conclude that the ECM is a critical guidance cue for outgrowing and branching trabeculae to reconstruct the trabeculated network, which represents a hallmark of uninjured cardiac tissue in newts.

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

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.

Spatio-temporal neural stem cell behavior that leads to both perfect and imperfect structural brain regeneration in adult newts.

PubMed

Urata, Yuko; Yamashita, Wataru; Inoue, Takeshi; Agata, Kiyokazu

2018-06-14

Adult newts can regenerate large parts of their brain from adult neural stem cells (NSCs), but how adult NSCs reorganize brain structures during regeneration remains unclear. In development, elaborate brain structures are produced under broadly coordinated regulations of embryonic NSCs in the neural tube, whereas brain regeneration entails exquisite control of the reestablishment of certain brain parts, suggesting a yet-unknown mechanism directs NSCs upon partial brain excision. Here we report that upon one-quarter excision of the adult newt ( Pleurodeles waltl ) mesencephalon, active participation of local NSCs around specific brain subregions' boundaries leads to some imperfect and some perfect brain regeneration along an individual's rostrocaudal axis. Regeneration phenotypes depend on how the wound closing occurs using local NSCs, and perfect regeneration replicates development-like processes but takes more than one year. Our findings indicate that newt brain regeneration is supported by modularity of boundary-domain NSCs with self-organizing ability in neighboring fields. © 2018. Published by The Company of Biologists Ltd.

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

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.

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

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. Copyright © 2009 Elsevier Ltd. All rights reserved.

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.

Characterization of a tandemly repeated DNA sequence family originally derived by retroposition of tRNA(Glu) in the newt.

PubMed

Nagahashi, S; Endoh, H; Suzuki, Y; Okada, N

1991-11-20

A previous report from this laboratory showed that in vitro transcription of total genomic DNA of the newt Cynopus pyrrhogaster resulted in a discrete sized 8 S RNA, which represented highly repetitive and transcribable sequences with a glutamic acid tRNA-like structure in the newt genome. We isolated four independent clones from a newt genomic library and determined the complete sequences of three 2000 to 2400 base-pair PstI fragments spanning the 8 S RNA gene. The glutamic acid tRNA-related segment in the 8 S RNA gene contains the CCA sequence expected as the 3' terminus of a tRNA molecule. Further, the 11 nucleotides located 13 nucleotides upstream from one of the two transcription initiation sites of the 8 S RNA were found to be repeated in the region upstream from the termination site, suggesting that the original unit, which is shorter than the 8 S RNA, was retrotransposed via cDNA intermediates from the PolIII transcript. In the upstream region of the 8 S RNA gene, a 360 nucleotide unit containing the glutamic acid tRNA-related segment was found to be duplicated (clones NE1 and NE10) or triplicated (clone NE3). Except for the difference in the number of the 360 nucleotide unit, the three sequences of the 2000 to 2400 base-pair PstI fragment were essentially the same with only a few mutations and minor deletions. Inverse polymerase chain reaction and sequence determination of the products, together with a Southern hybridization experiment, demonstrated that the family consists of a tandemly repeated unit of 3300, 3700 or 4100 base-pairs. Thus during evolution, this family in the newt was created by retroposition via cDNA intermediates, followed by duplication or triplication of the 360 nucleotide unit and multiplication of the 3300 to 4100 base-pair region at the DNA level.

Endocrine-disrupting effects of nonylphenol in the newt, Triturus carnifex (Amphibia, Urodela).

PubMed

Capaldo, Anna; Gay, Flaminia; Valiante, Salvatore; De Falco, Maria; Sciarrillo, Rosaria; Maddaloni, Massimo; Laforgia, Vincenza

2012-03-01

The aim of our study was to verify whether environmental concentrations of nonylphenol influenced the adrenal gland of Triturus carnifex. Newts were exposed to 19 μg/L nominal concentration of nonylphenol throughout the periods of December-January and March-April, corresponding to different stages of the chromaffin cell functional cycle. The morphological features of the steroidogenic and chromaffin tissues, and the serum levels of ACTH, aldosterone, corticosterone, norepinephrine and epinephrine were evaluated. Nonylphenol did not influence ACTH serum levels. During the two periods examined, the steroidogenic tissue had the same reaction: the quantity of cytoplasmic lipids, and the corticosteroid serum levels, decreased, suggesting the inhibition of synthesis and release of corticosteroids. During the two periods examined, the chromaffin tissue reacted differently to nonylphenol. During December-January, the numeric ratio of norepinephrine granules to epinephrine granules, and the epinephrine serum levels, increased, suggesting the stimulation of epinephrine release. During March-April, the numeric ratio of norepinephrine granules to epinephrine granules did not change, and the norepinephrine serum levels decreased, suggesting the inhibition of norepinephrine release. Our results show that nonylphenol influences the activity of the newt adrenal gland; considering the physiological role of this gland, our results suggest that nonylphenol may contribute to amphibian decline. Copyright © 2011. Published by Elsevier Inc.

Serum Proteases Potentiate BMP-Induced Cell Cycle Re-entry of Dedifferentiating Muscle Cells during Newt Limb Regeneration.

PubMed

Wagner, Ines; Wang, Heng; Weissert, Philipp M; Straube, Werner L; Shevchenko, Anna; Gentzel, Marc; Brito, Goncalo; Tazaki, Akira; Oliveira, Catarina; Sugiura, Takuji; Shevchenko, Andrej; Simon, András; Drechsel, David N; Tanaka, Elly M

2017-03-27

Limb amputation in the newt induces myofibers to dedifferentiate and re-enter the cell cycle to generate proliferative myogenic precursors in the regeneration blastema. Here we show that bone morphogenetic proteins (BMPs) and mature BMPs that have been further cleaved by serum proteases induce cell cycle entry by dedifferentiating newt muscle cells. Protease-activated BMP4/7 heterodimers that are present in serum strongly induced myotube cell cycle re-entry with protease cleavage yielding a 30-fold potency increase of BMP4/7 compared with canonical BMP4/7. Inhibition of BMP signaling via muscle-specific dominant-negative receptor expression reduced cell cycle entry in vitro and in vivo. In vivo inhibition of serine protease activity depressed cell cycle re-entry, which in turn was rescued by cleaved-mimic BMP. This work identifies a mechanism of BMP activation that generates blastema cells from differentiated muscle. Copyright © 2017 Elsevier Inc. All rights reserved.

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

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

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

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.

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. Copyright © 2016 Elsevier GmbH. All rights reserved.

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

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. Copyright © 2015 Elsevier Inc. All rights reserved.

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.;

Kicking Triturus arntzeni when it's down: large-scale nuclear genetic data confirm that newts from the type locality are genetically admixed.

PubMed

Wielstra, B; Arntzen, J W

2014-05-27

We collected nuclear DNA data (52 markers) with next-generation sequencing for nine Triturus newt specimens, including the holotype and two of the paratypes of T. arntzeni, from the type locality at Vrtovać in eastern Serbia. We compare these data to a reference set composed of the four crested newt species distributed in eastern Serbia namely T. cristatus, T. dobrogicus, T. ivanbureschi and T. macedonicus to determine to which of these species the newts from the type locality of T. arntzeni should be attributed. The majority of alleles in individuals from Vrtovać is derived from T. macedonicus, but a considerable number of T. ivanbureschi alleles is also present; alleles typical for T. cristatus and T. dobrogicus are found at low frequency. Accordingly, we interpret Vrtovać as a T. macedonicus - T. ivanbureschi hybrid population, albeit not composed of F1 hybrids but of genetically admixed individuals derived through multiple generations of backcrossing. The data support the notion that the name T. arntzeni should not be applied to a species newly distinguished in T. karelinii sensu lato (to which the name T. ivanbureschi has been given). We conclude that because of the hybrid nature of the individuals from Vrtovać, the name T. arntzeni should be placed not only in the synonymy of T. macedonicus but also in the synonymy of T. ivanbureschi. In this study we demonstrate that next-generation sequencing can provide high quality data for type material with degraded DNA and therefore can play an important role in taxonomy.

Comparison and characterization of biosorption by Weissella viridescens MYU 205 of periodic group 12 metal ions.

PubMed

Kinoshita, Hideki; Ohtake, Fumika; Ariga, Yuuki; Kimura, Kazuhiko

2016-02-01

Because heavy metals cause various health hazards, we studied biosorption by Weissella viridescens MYU 205. MYU 205 showed high biosorption for Cd (II) and Hg (II) and was low for Zn (II). The Hg (II) biosorption rate was high at about 80%. Different biosorptions were shown for each metal after successive incubation. About 20% of the Zn (II) biosorption was observed after 3 h. Cd (II) biosorption increased in a time-dependent manner until 3 h, then gradually decreased. Hg (II) was immediately sorbed at 79.6 ± 4.7% and decreased at 3 h to 52.9 ± 2.6%, and then gradually increased to 77.8 ± 3.6%. Using heat-killed cells, the rate of biosorption of Zn (II) and Cd (II) decreased whereas Hg (II) tended to increase. The metal resistance was high, that is Zn (II) > Cd (II) > Hg (II); while the affinity was opposite where MYU 205 showed high affinity to Hg (II) and low affinity to Zn (II). Our data shows lactic acid bacteria may be powerful heavy metal sorbents for detoxification. © 2015 Japanese Society of Animal Science.

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

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

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

PubMed

Wielstra, Ben; Crnobrnja-Isailović, Jelka; Litvinchuk, Spartak N; Reijnen, Bastian T; Skidmore, Andrew K; Sotiropoulos, Konstantinos; Toxopeus, Albertus G; Tzankov, Nikolay; Vukov, Tanja; Arntzen, Jan W

2013-03-20

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. 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. 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.

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.

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

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 T min (±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 T min =-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 T min =-0.24 (±0.55) [°C], with R 2 =0.990 and RMSE=0.436. The parameters obtained from OED approach

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

PubMed Central

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

2016-01-01

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. PMID:26711235

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.

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. © The Authors 2015. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

Progenitor cell dynamics in the Newt Telencephalon during homeostasis and neuronal regeneration.

PubMed

Kirkham, Matthew; Hameed, L Shahul; Berg, Daniel A; Wang, Heng; Simon, András

2014-04-08

The adult newt brain has a marked neurogenic potential and is highly regenerative. Ventricular, radial glia-like ependymoglia cells give rise to neurons both during normal homeostasis and after injury, but subpopulations among ependymoglia cells have not been defined. We show here that a substantial portion of GFAP(+) ependymoglia cells in the proliferative hot spots of the telencephalon has transit-amplifying characteristics. In contrast, proliferating ependymoglia cells, which are scattered along the ventricular wall, have stem cell features in terms of label retention and insensitivity to AraC treatment. Ablation of neurons remodels the proliferation dynamics and leads to de novo formation of regions displaying features of neurogenic niches, such as the appearance of cells with transit-amplifying features and proliferating neuroblasts. The results have implication both for our understanding of the evolutionary diversification of radial glia cells as well as the processes regulating neurogenesis and regeneration in the adult vertebrate brain.

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.

Steroids, aromatase and sex differentiation of the newt Pleurodeles waltl.

PubMed

Kuntz, S; Chardard, D; Chesnel, A; Grillier-Vuissoz, I; Flament, S

2003-01-01

In the newt Pleurodeles waltl, genetic sex determination obeys female heterogamety (female ZW, male ZZ). In this species as in most of non-mammalian vertebrates, steroid hormones play a key role in sexual differentiation of gonads. In that context, male to female sex reversal can be obtained by treatment of ZZ larvae with estradiol. Male to female sex reversal has also been observed following treatment of ZZ larvae with testosterone, a phenomenon that was called the "paradoxical effect". Female to male sex reversal occurs when ZW larvae are reared at 32 degrees C during a thermosensitive period (TSP) that takes place from stage 42 to stage 54 of development. Since steroids play an important part in sex differentiation, we focussed our studies on the estrogen-producing enzyme aromatase during normal sex differentiation as well as in experimentally induced sex reversal situations. Our results based on treatment with non-aromatizable androgens, aromatase activity measurements and aromatase expression studies demonstrate that aromatase (i) is differentially active in ZZ and ZW larvae, (ii) is involved in the paradoxical effect and (iii) might be a target of temperature. Thus, the gene encoding aromatase might be one of the master genes in the process leading to the differentiation of the gonad in Pleurodeles waltl. Copyright 2003 S. Karger AG, Basel

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.

Morphological and immunohistochemical reactions of the larval epidermis in the Italian newt (Lissotriton italicus) after exposure to low pH.

PubMed

Brunelli, Elvira

2018-02-01

Mounting evidence suggests that amphibians are globally and currently the most threatened group of vertebrates and different causes might be responsible for this phenomenon. Acidification of water bodies is a global environmental issue that has been proposed as a possible cause for amphibian populations decline. Indeed, it has been widely demonstrated that low pH may exert harmful effects on amphibians, either directly or by increasing the adverse effects of other stressors. Surprisingly only few studies documented the response of amphibian integument to acidic pH conditions and no data are available on the effects of a non-lethal level of pH onto the amphibian larval epidermis. The present study showed that acidic pH (4.5) condition has severe effects on the epidermis of the Italian newt (Lissotriton italicus, formerly Triturus italicus) inducing both morphological and functional alterations. The increase of mucus is the first evident effect of acid injury, followed by the flattening of the epithelium and the appearance of a keratinized shedding layer. The immunolabeling of cytokeratins substantially changes acquiring an adult-like pattern. Also aquaporin 3 and iNOS expression modify their distribution according to a change of the histological features of the epidermis. These results clearly indicate that a short-term exposure to a sub-lethal pH disrupts the epidermis morphology and function in L. italicus larvae. Since the skin exerts a prominent role in both respiration and osmoregulation, the described alterations may adversely affect the overall ionic balance, with a long chain of cascading effects significantly decreasing newts survival probabilities when environmental pH lowering occurs. Copyright © 2018 Elsevier GmbH. All rights reserved.

Unraveling climate influences on the distribution of the parapatric newts Lissotriton vulgaris meridionalis and L. italicus.

PubMed

Iannella, Mattia; Cerasoli, Francesco; Biondi, Maurizio

2017-01-01

Climate is often considered as a key ecological factor limiting the capability of expansion of most species and the extent of suitable habitats. In this contribution, we implement Species Distribution Models (SDMs) to study two parapatric amphibians, Lissotriton vulgaris meridionalis and L. italicus , investigating if and how climate has influenced their present and past (Last Glacial Maximum and Holocene) distributions. A database of 901 GPS presence records was generated for the two newts. SDMs were built through Boosted Regression Trees and Maxent, using the Worldclim bioclimatic variables as predictors. Precipitation-linked variables and the temperature annual range strongly influence the current occurrence patterns of the two Lissotriton species analyzed. The two newts show opposite responses to the most contributing variables, such as BIO7 (temperature annual range), BIO12 (annual precipitation), BIO17 (precipitation of the driest quarter) and BIO19 (precipitation of the coldest quarter). The hypothesis of climate influencing the distributions of these species is also supported by the fact that the co-occurrences within the sympatric area fall in localities characterized by intermediate values of these predictors. Projections to the Last Glacial Maximum and Holocene scenarios provided a coherent representation of climate influences on the past distributions of the target species. Computation of pairwise variables interactions and the discriminant analysis allowed a deeper interpretation of SDMs' outputs. Further, we propose a multivariate environmental dissimilarity index (MEDI), derived through a transformation of the multivariate environmental similarity surface (MESS), to deal with extrapolation-linked uncertainties in model projections to past climate. Finally, the niche equivalency and niche similarity tests confirmed the link between SDMs outputs and actual differences in the ecological niches of the two species. The different responses of the two

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.

Molecular cloning of pepsinogens A and C from adult newt (Cynops pyrrhogaster) stomach.

PubMed

Inokuchi, Tomofumi; Ikuzawa, Masayuki; Yamazaki, Shin; Watanabe, Yukari; Shiota, Koushiro; Katoh, Takuma; Kobayashi, Ken-Ichiro

2013-08-01

The full-length cDNAs of three pepsinogens (Pgs) were cloned from the stomach of newt, Cynops pyrrhogaster, and nucleotide sequences of the full-length cDNAs were determined. Molecular phylogenetic analysis showed that two Pgs, named PgC1 and PgC2, belong to the pepsinogen C group, and one Pg, named PgA, belongs to the pepsinogen A group. The sequences contain an open reading frame (ORF) encoding 385 amino acid residues for PgC1, 383 amino acid residues for PgC2 and 377 amino acid residues for PgA. In addition, all of the three amino acid sequences conserve some unique characteristics such as six cysteine residues and putative active site two aspartic acid residues. All of the pepsinogen mRNAs were detected in the stomach by RT-PCR but not in other organs. Although a slight difference at the time of the start of expression was seen among the three pepsinogen genes, all of them were expressed in the larval stage after hatching. This is the first report on cloning of pepsinogens from urodele stomach. Copyright © 2013 Elsevier Inc. All rights reserved.

Pheromones enhance somatosensory processing in newt brains through a vasotocin-dependent mechanism.

PubMed

Thompson, R R; Dickinson, P S; Rose, J D; Dakin, K A; Civiello, G M; Segerdahl, A; Bartlett, R

2008-07-22

We tested whether the sex pheromones that stimulate courtship clasping in male roughskin newts do so, at least in part, by amplifying the somatosensory signals that directly trigger the motor pattern associated with clasping and, if so, whether that amplification is dependent on endogenous vasotocin (VT). Female olfactory stimuli increased the number of action potentials recorded in the medulla of males in response to tactile stimulation of the cloaca, which triggers the clasp motor reflex, as well as to tactile stimulation of the snout and hindlimb. That enhancement was blocked by exposing the medulla to a V1a receptor antagonist before pheromone exposure. However, the antagonist did not affect medullary responses to tactile stimuli in the absence of pheromone exposure, suggesting that pheromones amplify somatosensory signals by inducing endogenous VT release. The ability of VT to couple sensory systems together in response to social stimulation could allow this peptide to induce variable behavioural outcomes, depending on the immediate context of the social interaction and thus on the nature of the associated stimuli that are amplified. If widespread in vertebrates, this mechanism could account for some of the behavioural variability associated with this and related peptides both within and across species.

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.

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.

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

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

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.

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.

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. Copyright © 2014 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.

[Determination of mRNA-transcripts and heat shock proteins HSP70 and HSP90 in retina of the adult Spanish Ribbed Newt Pleurodeles waltl].

PubMed

Avdonin, P P; Markitantova, Yu V; Poplinskaya, V A; Grigoryan, E N

2013-01-01

Expression of genes and heat shock proteins in normal intact retina of the Spanish Ribbed Newt Pleurodeles waltl was studied using polymerase chain reaction, Western blot hybridization, and immunohistochemistry. It was shown that the proteins HSP70 and HSP90, as well as their encoding transcripts of relevant genes, are constitutively expressed in eye tissues. These proteins were distributed differentially, and they were characterized by expression of different levels in the retina: HSP70 dominated in the external retina, while HSP90 dominated in the internal one, in particular, in Muller glial cells and the optic nerve. Transcripts and heat shock proteins HSP70 and HSP90 were also found in the retinal pigment epithelium and eye growth zone.

Size does matter - Intraspecific variation of feeding mechanics in the crested newt Triturus dobrogicus (Kiritzescu, 1903)

NASA Astrophysics Data System (ADS)

Kucera, Florian; Beisser, Christian J.; Lemell, Patrick

2018-03-01

Many studies have yet been conducted on suction feeding in aquatic salamander species. Within the Salamandridae, the crested newt Triturus dobrogicus (Kiritzescu, 1903), occurring from the Austrian Danube floodplains to the Danube Delta, was not subject of investigations so far. The present study examines the kinematics of aquatic suction feeding in this species by means of high-speed videography. Recordings of five individuals of different size and sex while feeding on bloodworms were conducted, in order to identify potential discrepancies among individuals and sizes. Five coordinate points were digitized from recordings of prey capture and twelve time- and velocity-determined variables were evaluated. All specimens follow a typical inertial suction feeding process, where rapid hyoid depression expands the buccal cavity. Generated negative pressure within the buccal cavity causes influx of water along with the prey item into the mouth. Results demonstrate higher distance values and angles for gape in individuals with smaller size. In addition, hyoid depression is maximized in smaller individuals. While Triturus dobrogicus resembles a typical inertial suction feeder in its functional morphology, intraspecific differences could be found regarding the correlation of different feeding patterns and body size.

A decay of gap junctions associated with ganglion cell differentiation during retinal regeneration of the adult newt.

PubMed

Oi, Hanako; Chiba, Chikafumi; Saito, Takehiko

2003-12-01

Changes in the gap junctional coupling and maturation of voltage-activated Na(+) currents during regeneration of newt retinas were examined by whole-cell patch-clamping in slice preparations. Progenitor cells in regenerating retinas did not exhibit Na(+) currents but showed prominent electrical and tracer couplings. Cells identified by LY-fills were typically slender. Na(+) currents were detected in premature ganglion cells with round somata in the 'intermediate-II' regenerating retina. No electrical and tracer couplings were observed between these cells. Mature ganglion cells did not exhibit electrical coupling, but showed tracer coupling. On average, the maximum Na(+) current amplitude recorded from premature ganglion cells was roughly 2.5-fold smaller than that of mature ganglion cells. In addition, the activation threshold of the Na(+) current was nearly 11 mV more positive than that of mature cells. We provide morphological and physiological evidence showing that loss of gap junctions between progenitor cells is associated with ganglion cell differentiation during retinal regeneration and that new gap junctions are recreated between mature ganglion cells. Also we provide evidence suggesting that the loss of gap junctions correlates with the appearance of voltage-activated Na(+) currents in ganglion cells.

Divergence history of the Carpathian and smooth newts modelled in space and time.

PubMed

Zieliński, P; Nadachowska-Brzyska, K; Dudek, K; Babik, W

2016-08-01

Information about demographic history is essential for the understanding of the processes of divergence and speciation. Patterns of genetic variation within and between closely related species provide insights into the history of their interactions. Here, we investigated historical demography and genetic exchange between the Carpathian (Lissotriton montandoni, Lm) and smooth (L. vulgaris, Lv) newts. We combine an extensive geographical sampling and multilocus nuclear sequence data with the approximate Bayesian computation framework to test alternative scenarios of divergence and reconstruct the temporal and spatial pattern of gene flow between species. A model of recent (last glacial period) interspecific gene flow was favoured over alternative models. Thus, despite the relatively old divergence (4-6 mya) and presumably long periods of isolation, the species have retained the ability to exchange genes. Nevertheless, the low migration rates (ca. 10(-6) per gene copy per generation) are consistent with strong reproductive isolation between the species. Models allowing demographic changes were favoured, suggesting that the effective population sizes of both species at least doubled as divergence reaching the current ca. 0.2 million in Lm and 1 million in Lv. We found asymmetry in rates of interspecific gene flow between Lm and one evolutionary lineage of Lv. We suggest that intraspecific polymorphism for hybrid incompatibilities segregating within Lv could explain this pattern and propose further tests to distinguish between alternative explanations. Our study highlights the importance of incorporating intraspecific genetic structure into the models investigating the history of divergence. © 2016 John Wiley & Sons Ltd.

Asymmetric viability of reciprocal-cross hybrids between crested and marbled newts (Triturus cristatus and T. Marmoratus).

PubMed

Arntzen, Jan W; Jehle, Robert; Bardakci, Fevzi; Burke, Terry; Wallis, Graham P

2009-05-01

Hybridization between divergent lineages often results in reduced hybrid viability. Here we report findings from a series of independent molecular analyses over several seasons on four life stages of F1 hybrids between the newts Triturus cristatus and T. marmoratus. These two species form a bimodal hybrid zone of broad overlap in France, with F1 hybrids making up about 4% of the adult population. We demonstrate strong asymmetry in the direction of the cross, with one class (cristatus-mothered) making up about 90% of F1 hybrids. By analyzing embryos and hatchlings, we show that this asymmetry is not due to prezygotic effects, as both classes of hybrid embryos are present at similar frequencies, implicating differential selection on the two hybrid classes after hatching. Adult F1 hybrids show a weak Haldane effect overall, with a 72% excess of females. The rarer marmoratus-mothered class, however, consists entirely of males. The absence of females from this class of adult F1 hybrids is best explained by an incompatibility between the cristatus X chromosome and marmoratus cytoplasm. It is thus important to distinguish the two classes of reciprocal-cross hybrids before making general statements about whether Haldane's rule is observed.

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.

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

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

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

Validation of Bateman's principles: a genetic study of sexual selection and mating patterns in the rough-skinned newt.

PubMed Central

Jones, Adam G; Arguello, J Roman; Arnold, Stevan J

2002-01-01

Few studies have influenced thought on the nature of sexual selection to the extent of the classic paper of A. J. Bateman on mating patterns in Drosophila. However, interpretation of his study remains controversial, and a lack of modern empirical evidence prevents a consensus with respect to the perceived utility of Bateman's principles in the study of sexual selection. Here, we use a genetic study of natural mating patterns in the rough-skinned newt, Taricha granulosa, to investigate the concordance between Bateman's principles and the intensity of sexual selection. We found that males experienced strong sexual selection on tail height and body size, while sexual selection was undetectable in females. This direct quantification of sexual selection agreed perfectly with inferences that are based on Bateman's principles. Specifically, males (in comparison with females) exhibited greater standardized variances in reproductive and mating success, as well as a stronger relationship between mating success and reproductive success. Overall, our results illustrate that Bateman's principles provide the only quantitative measures of the mating system with explicit connections to formal selection theory and should be the central focus of studies of mating patterns in natural populations. PMID:12573067

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.

Spacelab

NASA Image and Video Library

1994-07-01

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.

Spacelab

NASA Image and Video Library

1994-07-01

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.

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

Secondary compounds from exotic tree plantations change female mating preferences in the palmate newt (Lissotriton helveticus).

PubMed

Iglesias-Carrasco, M; Head, M L; Jennions, M D; Cabido, C

2017-10-01

Selection can favour phenotypic plasticity in mate choice in response to environmental factors that alter the costs and benefits of being choosy, or of choosing specific mates. Human-induced environmental change could alter sexual selection by affecting the costs of mate choice, or by impairing the ability of individuals to identify preferred mates. For example, variation in mate choice could be driven by environmentally induced differences in body condition (e.g. health) that change the cost of choosiness, or by environmental effects on the ability to detect or discriminate sexual signals. We teased apart these possibilities experimentally, by comparing female mate choice in the palmate newt Lissotriton helveticus between environments that mimic water from either native oak forests or exotic eucalypt plantations. In laboratory two-choice mate trials in clean water, females with prolonged exposure (21 days) to waterborne chemicals leached from eucalypt leaves did not preferentially associate with the male with a stronger immune response, but females exposed to water with chemicals from oak leaves did. In contrast, female choice was unaffected by the immediate presence or absence of eucalypt leachates during mate choice (using only females previously held in oak-treated water). The habitat-related change in female choice we observed is likely to be driven by effects of eucalypt leachates on female physiology, rather than immediate inhibition of pheromone transmission or blocking of pheromone reception. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

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.

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.

Phylogenetic surveys on the newt genus Tylototriton sensu lato (Salamandridae, Caudata) reveal cryptic diversity and novel diversification promoted by historical climatic shifts.

PubMed

Wang, Bin; Nishikawa, Kanto; Matsui, Masafumi; Nguyen, Truong Quang; Xie, Feng; Li, Cheng; Khatiwada, Janak Raj; Zhang, Baowei; Gong, Dajie; Mo, Yunming; Wei, Gang; Chen, Xiaohong; Shen, Youhui; Yang, Daode; Xiong, Rongchuan; Jiang, Jianping

2018-01-01

Global climatic transitions and Tibetan Plateau uplifts are hypothesized to have profoundly impacted biodiversity in southeastern Asia. To further test the hypotheses related to the impacts of these incidents, we investigated the diversification patterns of the newt genus Tylototriton sensu lato , distributed across the mountain ranges of southeastern Asia. Gene-tree and species-tree analyses of two mitochondrial genes and two nuclear genes revealed five major clades in the genus, and suggested several cryptic species. Dating estimates suggested that the genus originated in the early-to-middle Miocene. Under different species delimitating scenarios, diversification analyses with birth-death likelihood tests indicated that the genus held a higher diversification rate in the late Miocene-to-Pliocene era than that in the Pleistocene. Ancestral area reconstructions indicated that the genus originated from the northern Indochina Peninsula. Accordingly, we hypothesized that the Miocene Climatic Transition triggered the diversification of the genus, and the reinforcement of East Asian monsoons associated with the stepwise uplifts of the Tibetan Plateau promoted the radiation of the genus in southeastern Asia during the Miocene-to-Pliocene period. Quaternary glacial cycles likely had limited effects on speciation events in the genus, but mainly had contributions on their intraspecific differentiations.

Phylogenetic surveys on the newt genus Tylototriton sensu lato (Salamandridae, Caudata) reveal cryptic diversity and novel diversification promoted by historical climatic shifts

PubMed Central

Wang, Bin; Nishikawa, Kanto; Matsui, Masafumi; Nguyen, Truong Quang; Xie, Feng; Li, Cheng; Khatiwada, Janak Raj; Zhang, Baowei; Gong, Dajie; Mo, Yunming; Wei, Gang; Chen, Xiaohong; Shen, Youhui; Yang, Daode; Xiong, Rongchuan

2018-01-01

Global climatic transitions and Tibetan Plateau uplifts are hypothesized to have profoundly impacted biodiversity in southeastern Asia. To further test the hypotheses related to the impacts of these incidents, we investigated the diversification patterns of the newt genus Tylototriton sensu lato, distributed across the mountain ranges of southeastern Asia. Gene-tree and species-tree analyses of two mitochondrial genes and two nuclear genes revealed five major clades in the genus, and suggested several cryptic species. Dating estimates suggested that the genus originated in the early-to-middle Miocene. Under different species delimitating scenarios, diversification analyses with birth-death likelihood tests indicated that the genus held a higher diversification rate in the late Miocene-to-Pliocene era than that in the Pleistocene. Ancestral area reconstructions indicated that the genus originated from the northern Indochina Peninsula. Accordingly, we hypothesized that the Miocene Climatic Transition triggered the diversification of the genus, and the reinforcement of East Asian monsoons associated with the stepwise uplifts of the Tibetan Plateau promoted the radiation of the genus in southeastern Asia during the Miocene-to-Pliocene period. Quaternary glacial cycles likely had limited effects on speciation events in the genus, but mainly had contributions on their intraspecific differentiations. PMID:29576937

Postglacial species displacement in Triturus newts deduced from asymmetrically introgressed mitochondrial DNA and ecological niche models

PubMed Central

2012-01-01

Background If the geographical displacement of one species by another is accompanied by hybridization, mitochondrial DNA can introgress asymmetrically, from the outcompeted species into the invading species, over a large area. We explore this phenomenon using the two parapatric crested newt species, Triturus macedonicus and T. karelinii, distributed on the Balkan Peninsula in south-eastern Europe, as a model. Results We first delimit a ca. 54,000 km2 area in which T. macedonicus contains T. karelinii mitochondrial DNA. This introgression zone bisects the range of T. karelinii, cutting off a T. karelinii enclave. The high similarity of introgressed mitochondrial DNA haplotypes with those found in T. karelinii suggests a recent transfer across the species boundary. We then use ecological niche modeling to explore habitat suitability of the location of the present day introgression zone under current, mid-Holocene and Last Glacial Maximum conditions. This area was inhospitable during the Last Glacial Maximum for both species, but would have been habitable at the mid-Holocene. Since the mid-Holocene, habitat suitability generally increased for T. macedonicus, whereas it decreased for T. karelinii. Conclusion The presence of a T. karelinii enclave suggests that T. karelinii was the first to colonize the area where the present day introgression zone is positioned after the Last Glacial Maximum. Subsequently, we propose T. karelinii was outcompeted by T. macedonicus, which captured T. karelinii mitochondrial DNA via introgressive hybridization in the process. Ecological niche modeling suggests that this replacement was likely facilitated by a shift in climate since the mid-Holocene. We suggest that the northwestern part of the current introgression zone was probably never inhabited by T. karelinii itself, and that T. karelinii mitochondrial DNA spread there through T. macedonicus exclusively. Considering the spatial distribution of the introgressed mitochondrial DNA and

Postglacial species displacement in Triturus newts deduced from asymmetrically introgressed mitochondrial DNA and ecological niche models.

PubMed

Wielstra, Ben; Arntzen, Jan W

2012-08-30

If the geographical displacement of one species by another is accompanied by hybridization, mitochondrial DNA can introgress asymmetrically, from the outcompeted species into the invading species, over a large area. We explore this phenomenon using the two parapatric crested newt species, Triturus macedonicus and T. karelinii, distributed on the Balkan Peninsula in south-eastern Europe, as a model. We first delimit a ca. 54,000 km(2) area in which T. macedonicus contains T. karelinii mitochondrial DNA. This introgression zone bisects the range of T. karelinii, cutting off a T. karelinii enclave. The high similarity of introgressed mitochondrial DNA haplotypes with those found in T. karelinii suggests a recent transfer across the species boundary. We then use ecological niche modeling to explore habitat suitability of the location of the present day introgression zone under current, mid-Holocene and Last Glacial Maximum conditions. This area was inhospitable during the Last Glacial Maximum for both species, but would have been habitable at the mid-Holocene. Since the mid-Holocene, habitat suitability generally increased for T. macedonicus, whereas it decreased for T. karelinii. The presence of a T. karelinii enclave suggests that T. karelinii was the first to colonize the area where the present day introgression zone is positioned after the Last Glacial Maximum. Subsequently, we propose T. karelinii was outcompeted by T. macedonicus, which captured T. karelinii mitochondrial DNA via introgressive hybridization in the process. Ecological niche modeling suggests that this replacement was likely facilitated by a shift in climate since the mid-Holocene. We suggest that the northwestern part of the current introgression zone was probably never inhabited by T. karelinii itself, and that T. karelinii mitochondrial DNA spread there through T. macedonicus exclusively. Considering the spatial distribution of the introgressed mitochondrial DNA and the signal derived from

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

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

Transient outward currents and changes of their gating properties after cell activation in thrombocytes of the newt.

PubMed Central

Kawa, K

1987-01-01

1. The electrical properties of the cell membrane of thrombocytes in the newt, Triturus pyrrhogaster, were studied using the whole-cell variation of the patch-electrode voltage-clamp technique. 2. In medium containing Ca2+ (1.8 mM), activated thrombocytes became round and then spread on the glass. Activation of thrombocytes was inhibited by the removal of external Ca2+ and addition of 1 w/v% albumin to the external media. 3. For thrombocytes kept in the resting state, depolarizations more positive than -30 mV evoked transient outward currents which decayed completely during the duration of the depolarization (150 ms). The half-decay time of the currents became smaller as the depolarizing pulse strengthened, reaching about 20 ms at +30 mV (20 degrees C). 4. The outward currents are identified as K+ currents, since (1) their reversal potential depended on extracellular K+ concentration and (2) the outward currents were suppressed either by external application of 4-aminopyridine (1 mM) or by internal application of Cs+ (120 mM). The monovalent cation selectivities of the K+ channels were evaluated from the reversal potential as Tl (1.68) greater than K(1.0) greater than Rb (0.89) greater than NH4 (0.13) greater than Na(less than 0.03). 5. When the thrombocytes had been activated, depolarization again evoked K+ currents. The currents, however, showed negligible or small decay during the duration of the depolarization (150 ms). The rate of recovery from preceding depolarization was also reduced to about one-sixth. 6. The sensitivity to 4-aminopyridine and the selectivity of the K+ channels were not changed by cell activation. 7. We conclude that during activation of thrombocytes the inactivation of the K+ channels is almost eliminated. Removal of inactivation of the K+ channels was also induced in resting thrombocytes by intracellular application of 4-bromoacetamide (50 microM). PMID:2443665

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

PubMed Central

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

2017-01-01

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 km2) 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. PMID:28074844

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

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

Spinal cord neuron classes in embryos of the smooth newt Triturus vulgaris: a horseradish peroxidase and immunocytochemical study.

PubMed

Harper, C E; Roberts, A

1993-04-29

Spinal cord neurons were investigated in embryos of Triturus vulgaris, the smooth newt, just prior to hatching. These embryos can swim if freed from their egg membranes. Horseradish peroxidase (HRP) labelling, together with GABA and glycine immunocytochemistry (ICC), revealed nine distinct anatomical classes of neuron. 1. Ventrolateral motoneurons with mainly dorsal dendrites, sometimes a descending central axon and peripheral axon innervating the trunk muscles. 2. Dorsal primary sensory Rohon-Beard neurons innervating skin and with dorsal ascending and descending axons in spinal cord. 3. Commissural interneurons with mid-cord unipolar soma, glycine-like immunoreactivity, dendrites on initial segment of ventral axon which crosses cord to ascend or branch. 4. Dorsolateral commissural interneurons with multipolar soma in dorsolateral position with dorsal dendrites and ventral axon which crosses and ascends or branches. 5. Giant dorsolateral commissural interneurons with large dorsolateral somata widely spaced (130-250 microns spacing) with process projecting dorsally to other side, dorsolateral dendrites and ventral axon which crosses to ascend and branch. 6. Dorsolateral ascending interneurons in dorsolateral position with multipolar soma and ascending axon on same side. 7. Ascending interneurons with unipolar soma, GABA-like immunoreactivity and ascending axon on same side. 8. Descending interneurons with bi- or multi-polar soma, extensive dorsal and ventral dendrites, and descending axon on same side. They may also have ascending axons. 9. Kolmer-Agduhr cerebrospinal fluid contacting neurons with cilia and microvilli in lateral corners of neural canal. GABA-like immunoreactivity, no dendrites and ascending axon. Eight of the nine cells classes were found to bear a marked resemblance to neurons previously described in zebrafish and Xenopus embryos in terms of their anatomy, distribution and immunoreactivity to GABA and glycine. Homologies and possible functions are

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.

[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.

The Near East as a cradle of biodiversity: A phylogeography of banded newts (genus Ommatotriton) reveals extensive inter- and intraspecific genetic differentiation.

PubMed

van Riemsdijk, Isolde; Arntzen, Jan W; Bogaerts, Sergé; Franzen, Michael; Litvinchuk, Spartak N; Olgun, Kurtuluş; Wielstra, Ben

2017-09-01

The banded newt (genus Ommatotriton) is widely distributed in the Near East (Anatolia, Caucasus and the Levant) - an understudied region from the perspective of phylogeography. The genus is polytypic, but the number of species included and the phylogenetic relationships between them are not settled. We sequenced two mitochondrial and two nuclear DNA markers throughout the range of Ommatotriton. For mtDNA we constructed phylogenetic trees, estimated divergence times using fossil calibration, and investigated changes in effective population size with Bayesian skyline plots and mismatch analyses. For nuDNA we constructed phylogenetic trees and haplotype networks. Species trees were constructed for all markers and nuDNA only. Species distribution models were projected on current and Last Glacial Maximum climate layers. We confirm the presence of three Ommatotriton species: O. nesterovi, O. ophryticus and O. vittatus. These species are genetically distinct and their most recent common ancestor was dated at ∼25Ma (Oligocene). No evidence of recent gene flow between species was found. The species show deep intraspecific genetic divergence, represented by geographically structured clades, with crown nodes of species dated ∼8-13Ma (Miocene to Early Quaternary); evidence of long-term in situ evolution and survival in multiple glacial refugia. While a species tree based on nuDNA suggested a sister species relationship between O. vittatus and O. ophryticus, when mtDNA was included, phylogenetic relationships were unresolved, and we refrain from accepting a particular phylogenetic hypothesis at this stage. While species distribution models suggest reduced and fragmented ranges during the Last Glacial Maximum, we found no evidence for strong population bottlenecks. We discuss our results in the light of other phylogeographic studies from the Near East. Our study underlines the important role of the Near East in generating and sustaining biodiversity. Copyright © 2017

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.

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.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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), everymore » 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.« less

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. © 2016 The Authors. Zoo Biology published by Wiley Periodicals, Inc.

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

DTIC Science & Technology

1984-01-01

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 ... Lactobacillus plantarum 4008 Lactobacillus bulgaricus 11842 Lactobacillus fermentum 9338 Lactobacillus casei subsp. rhamnosus 7469 Pediococcus acidilactici

An amphibian chemical defense phenotype is inducible across life history stages.

PubMed

Bucciarelli, Gary M; Shaffer, H Bradley; Green, David B; Kats, Lee B

2017-08-15

Inducible phenotypic responses to environmental variation are ubiquitous across the tree of life, but it remains an open question whether amphibian chemical defense phenotypes are inducible. Tetrodotoxin (TTX) is a key chemical defense trait in North American and Eurasian newts (Salamandridae). We tested if TTX can be induced by exposing populations of adult and larval California newts (Taricha torosa) to sustained stressful conditions while longitudinally quantifying TTX concentrations. Adult newts rapidly increased chemical defenses in response to simulated predator attacks and consistently maintained elevated TTX concentrations relative to wild, non-captive individuals. We also found that laboratory-reared larvae maintained chemical defenses nearly three-fold greater than those of siblings reared in streams. Collectively, our results indicate that amphibian chemical defenses are not fixed. Instead, toxins are maintained at a baseline concentration that can quickly be increased in response to perceived risk with substantial increases to toxicity. Therefore, it is crucial that inducible variation be accounted for when considering ecological dynamics of chemically defended animals and coevolutionary predator-prey and mimic-model relationships.

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.

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.

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.

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.

Species identification by conservation practitioners using online images: accuracy and agreement between experts.

PubMed

Austen, Gail E; Bindemann, Markus; Griffiths, Richard A; Roberts, David L

2018-01-01

Emerging technologies have led to an increase in species observations being recorded via digital images. Such visual records are easily shared, and are often uploaded to online communities when help is required to identify or validate species. Although this is common practice, little is known about the accuracy of species identification from such images. Using online images of newts that are native and non-native to the UK, this study asked holders of great crested newt ( Triturus cristatus ) licences (issued by UK authorities to permit surveying for this species) to sort these images into groups, and to assign species names to those groups. All of these experts identified the native species, but agreement among these participants was low, with some being cautious in committing to definitive identifications. Individuals' accuracy was also independent of both their experience and self-assessed ability. Furthermore, mean accuracy was not uniform across species (69-96%). These findings demonstrate the difficulty of accurate identification of newts from a single image, and that expert judgements are variable, even within the same knowledgeable community. We suggest that identification decisions should be made on multiple images and verified by more than one expert, which could improve the reliability of species data.

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

Biosorption of heavy metals by lactic acid bacteria and identification of mercury binding protein.

PubMed

Kinoshita, Hideki; Sohma, Yui; Ohtake, Fumika; Ishida, Mitsuharu; Kawai, Yasushi; Kitazawa, Haruki; Saito, Tadao; Kimura, Kazuhiko

2013-09-01

Heavy metals cause various health hazards. Using lactic acid bacteria (LAB), we tested the biosorption of heavy metals e.g. cadmium (Cd) (II), lead (Pb) (II), arsenic (As) (III), and mercury (Hg) (II). Cd (II) sorption was tested in 103 strains using atomic absorption spectrophotometery (AAS). Weissella viridescens MYU 205 (1 × 10(8) cells/ml) decreased Cd (II) levels in citrate buffer (pH 6.0) from one ppm to 0.459 ± 0.016 ppm, corresponding to 10.46 μg of Cd (II). After screening, 11 LAB strains were tested using various pH (pH 4.0, 5.0, 6.0, 7.0) showing the sorption was acid sensitive; and was cell concentration dependent, where the Cd (II) concentration decreased from one ppm to 0.042 (max)/0.255 (min) ppm at 1 × 10(10) cells/ml. Additionally, the biosorption of Pb (II), As (III), and Hg (II) were tested using an inductively coupled plasma mass spectrometer (ICP-MS). The Hg (II) concentration was reduced the most followed by Pb (II) and As (III). Many of the bacterial cell surface proteins of W. viridescens MYU 205 showed binding to Hg (II) using the Hg (II) column assay. Having a CXXC motif, a ∼14 kDa protein may be one of the Hg (II) binding proteins. LAB biosorption may aid the detoxification of people exposed to heavy metals. Copyright © 2013 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

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

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)

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.

Interacting stressors and the potential for adaptation in a changing world: responses of populations and individuals

PubMed Central

French, Susannah S.; Brodie, Edmund D.

2017-01-01

To accurately predict the impact of environmental change, it is necessary to assay effects of key interacting stressors on vulnerable organisms, and the potential resiliency of their populations. Yet, for the most part, these critical data are missing. We examined the effects of two common abiotic stressors predicted to interact with climate change, salinity and temperature, on the embryonic survival and development of a model freshwater vertebrate, the rough-skinned newt (Taricha granulosa) from different populations. We found that salinity and temperature significantly interacted to affect newt embryonic survival and development, with the negative effects of salinity most pronounced at temperature extremes. We also found significant variation among, and especially within, populations, with different females varying in the performance of their eggs at different salinity–temperature combinations, possibly providing the raw material for future natural selection. Our results highlight the complex nature of predicting responses to climate change in space and time, and provide critical data towards that aim. PMID:28680662

Body size, swimming speed, or thermal sensitivity? Predator-imposed selection on amphibian larvae.

PubMed

Gvoždík, Lumír; Smolinský, Radovan

2015-11-02

Many animals rely on their escape performance during predator encounters. Because of its dependence on body size and temperature, escape velocity is fully characterized by three measures, absolute value, size-corrected value, and its response to temperature (thermal sensitivity). The primary target of the selection imposed by predators is poorly understood. We examined predator (dragonfly larva)-imposed selection on prey (newt larvae) body size and characteristics of escape velocity using replicated and controlled predation experiments under seminatural conditions. Specifically, because these species experience a wide range of temperatures throughout their larval phases, we predict that larvae achieving high swimming velocities across temperatures will have a selective advantage over more thermally sensitive individuals. Nonzero selection differentials indicated that predators selected for prey body size and both absolute and size-corrected maximum swimming velocity. Comparison of selection differentials with control confirmed selection only on body size, i.e., dragonfly larvae preferably preyed on small newt larvae. Maximum swimming velocity and its thermal sensitivity showed low group repeatability, which contributed to non-detectable selection on both characteristics of escape performance. In the newt-dragonfly larvae interaction, body size plays a more important role than maximum values and thermal sensitivity of swimming velocity during predator escape. This corroborates the general importance of body size in predator-prey interactions. The absence of an appropriate control in predation experiments may lead to potentially misleading conclusions about the primary target of predator-imposed selection. Insights from predation experiments contribute to our understanding of the link between performance and fitness, and further improve mechanistic models of predator-prey interactions and food web dynamics.

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.

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…

Agricultural Products | National Agricultural Library

Science.gov Websites

Skip to main content Home National Agricultural Library United States Department of Agriculture Ag News Contact Us Search  Log inRegister Home Home Agricultural Products NEWT: National Extension Web , tables, graphs), Agricultural Products html National Animal Nutrition Program (NANP) Feed Composition

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

... areas of pond where light penetrates and rooted plants occur) of breeding sites have been destroyed by...-0007] [MO 92210-0-0008-B2] Endangered and Threatened Wildlife and Plants; 90-Day Finding on a Petition... substantial scientific or commercial information indicating that listing the striped newt may be warranted...

Characterization and localization of arginine vasotocin receptors in the brain and kidney of an amphibian

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 inmore » 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.« less

Developmental alterations in centrosome integrity contribute to the post-mitotic state of mammalian cardiomyocytes

PubMed Central

Zebrowski, David C; Vergarajauregui, Silvia; Wu, Chi-Chung; Piatkowski, Tanja; Becker, Robert; Leone, Marina; Hirth, Sofia; Ricciardi, Filomena; Falk, Nathalie; Giessl, Andreas; Just, Steffen; Braun, Thomas; Weidinger, Gilbert; Engel, Felix B

2015-01-01

Mammalian cardiomyocytes become post-mitotic shortly after birth. Understanding how this occurs is highly relevant to cardiac regenerative therapy. Yet, how cardiomyocytes achieve and maintain a post-mitotic state is unknown. Here, we show that cardiomyocyte centrosome integrity is lost shortly after birth. This is coupled with relocalization of various centrosome proteins to the nuclear envelope. Consequently, postnatal cardiomyocytes are unable to undergo ciliogenesis and the nuclear envelope adopts the function as cellular microtubule organizing center. Loss of centrosome integrity is associated with, and can promote, cardiomyocyte G0/G1 cell cycle arrest suggesting that centrosome disassembly is developmentally utilized to achieve the post-mitotic state in mammalian cardiomyocytes. Adult cardiomyocytes of zebrafish and newt, which are able to proliferate, maintain centrosome integrity. Collectively, our data provide a novel mechanism underlying the post-mitotic state of mammalian cardiomyocytes as well as a potential explanation for why zebrafish and newts, but not mammals, can regenerate their heart. DOI: http://dx.doi.org/10.7554/eLife.05563.001 PMID:26247711

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

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. © 2014 Wiley Periodicals, Inc.

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.

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.

The 'male escape hypothesis': sex-biased metamorphosis in response to climatic drivers in a facultatively paedomorphic amphibian.

PubMed

Mathiron, Anthony G E; Lena, Jean-Paul; Baouch, Sarah; Denoël, Mathieu

2017-04-26

Paedomorphosis is a major evolutionary process that bypasses metamorphosis and allows reproduction in larvae. In newts and salamanders, it can be facultative with paedomorphs retaining gills and metamorphs dispersing. The evolution of these developmental processes is thought to have been driven by the costs and benefits of inhabiting aquatic versus terrestrial habitats. In this context, we aimed at testing the hypothesis that climatic drivers affect phenotypic transition and the difference across sexes because sex-ratio is biased in natural populations. Through a replicated laboratory experiment, we showed that paedomorphic palmate newts ( Lissotriton helveticus ) metamorphosed at a higher frequency when water availability decreased and metamorphosed earlier when temperature increased in these conditions. All responses were sex-biased, and males were more prone to change phenotype than females. Our work shows how climatic variables can affect facultative paedomorphosis and support theoretical models predicting life on land instead of in water. Moreover, because males metamorphose and leave water more often and earlier than females, these results, for the first time, give an experimental explanation for the rarity of male paedomorphosis (the 'male escape hypothesis') and suggest the importance of sex in the evolution of paedomorphosis versus metamorphosis. © 2017 The Author(s).

The ‘male escape hypothesis’: sex-biased metamorphosis in response to climatic drivers in a facultatively paedomorphic amphibian

PubMed Central

Mathiron, Anthony G. E.; Lena, Jean-Paul; Baouch, Sarah

2017-01-01

Paedomorphosis is a major evolutionary process that bypasses metamorphosis and allows reproduction in larvae. In newts and salamanders, it can be facultative with paedomorphs retaining gills and metamorphs dispersing. The evolution of these developmental processes is thought to have been driven by the costs and benefits of inhabiting aquatic versus terrestrial habitats. In this context, we aimed at testing the hypothesis that climatic drivers affect phenotypic transition and the difference across sexes because sex-ratio is biased in natural populations. Through a replicated laboratory experiment, we showed that paedomorphic palmate newts (Lissotriton helveticus) metamorphosed at a higher frequency when water availability decreased and metamorphosed earlier when temperature increased in these conditions. All responses were sex-biased, and males were more prone to change phenotype than females. Our work shows how climatic variables can affect facultative paedomorphosis and support theoretical models predicting life on land instead of in water. Moreover, because males metamorphose and leave water more often and earlier than females, these results, for the first time, give an experimental explanation for the rarity of male paedomorphosis (the ‘male escape hypothesis’) and suggest the importance of sex in the evolution of paedomorphosis versus metamorphosis. PMID:28424346

Occurrence of amphibians in northern California coastal dune drainages

USGS Publications Warehouse

Halstead, Brian J.; Kleeman, Patrick M.

2017-01-01

Many coastal dune ecosystems have been degraded by non-native dune vegetation, but these systems might still provide valuable habitat for some taxa, including amphibians. Because restoration of degraded dune systems is occurring and likely to continue, we examined the occurrence of amphibians in drainages associated with a coastal dune ecosystem degraded by invasive plants (European Beachgrass, Ammophila arenaria, and Iceplant, Carpobrotus edulis). We found that occupancy of 3 amphibian species (California Red-legged Frog, Rana draytonii; Sierran Treefrog, Hyliola sierra; and Rough-skinned Newt, Taricha granulosa) among 21 coastal-dune drainages was high, with most coastal-dune drainages occupied by all 3 species. Furthermore, reproduction of Sierran Treefrogs and California Red-legged Frogs was estimated to occur in approximately ½ and ⅓ of the drainages, respectively. The probability of occurrence of Rough-skinned Newts and pre-metamorphic life stages of both anurans decreased during the study, perhaps because of ongoing drought in California or precipitation-induced changes in phenology during the final year of the study. Maintaining structural cover and moist features during dune restoration will likely benefit native amphibian populations inhabiting coastal-dune ecosystems.

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.

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

JPRS Report Science & Technology Japan

DTIC Science & Technology

1989-10-20

plant callus o Adaptation of protozoans to microgravity o Fertilization and embryogeny of newt in space o Fertilization and embryogeny of sea urchin ...for by the mining and manufacturing branch. Moreover, about 50 percent of the energy consumed is exhausted to air, river, sea , etc., as waste heat...Cross section of substrate Figure 6. Photo of Cross Section of Coating Film Taken by Scanning Electron Microscope ( SEM ) It was heated for 60 hours

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.

Vertebral shape and body elongation in Triturus newts.

PubMed

Urošević, Aleksandar; Slijepčević, Maja D; Arntzen, Jan W; Ivanović, Ana

2016-10-01

Body elongation in vertebrates is often related to a lengthening of the vertebrae and an increase in their number. Changes in the number and shape of vertebrae are not necessarily linked. In tailed amphibians, a change in body shape is mostly associated with an increase in the number of trunk and tail vertebrae. Body elongation without a numerical change of vertebrae is rare. In Triturus aquatic salamanders body elongation is achieved by trunk elongation through an increase in the number of trunk vertebrae. We used computed microtomography and three-dimensional geometric morphometrics to document the size, shape and number of trunk vertebrae in seven Triturus species. The data suggest that body elongation has occurred more frequently than body shortening, possibly related to a more aquatic versus a more terrestrial locomotor style. Our results show that body elongation is achieved through an increase in the number of trunk vertebrae, and that interspecific differences in vertebral shape are correlated with this pattern of elongation. More gracile trunk vertebrae were found in the more elongated species. The shape differences are such that single trunk vertebrae can be used for the identification of species with a possible application in the identification of subfossil and fossil material. Copyright © 2016 Elsevier GmbH. All rights reserved.

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

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.

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.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rouxelin, Pascal Nicolas; Strydom, Gerhard

Best-estimate plus uncertainty analysis of reactors is replacing the traditional conservative (stacked uncertainty) method for safety and licensing analysis. To facilitate uncertainty analysis applications, a comprehensive approach and methodology must be developed and applied. High temperature gas cooled reactors (HTGRs) have several features that require techniques not used in light-water reactor analysis (e.g., coated-particle design and large graphite quantities at high temperatures). The International Atomic Energy Agency has therefore launched the Coordinated Research Project on HTGR Uncertainty Analysis in Modeling to study uncertainty propagation in the HTGR analysis chain. The benchmark problem defined for the prismatic design is represented bymore » the General Atomics Modular HTGR 350. The main focus of this report is the compilation and discussion of the results obtained for various permutations of Exercise I 2c and the use of the cross section data in Exercise II 1a of the prismatic benchmark, which is defined as the last and first steps of the lattice and core simulation phases, respectively. The report summarizes the Idaho National Laboratory (INL) best estimate results obtained for Exercise I 2a (fresh single-fuel block), Exercise I 2b (depleted single-fuel block), and Exercise I 2c (super cell) in addition to the first results of an investigation into the cross section generation effects for the super-cell problem. The two dimensional deterministic code known as the New ESC based Weighting Transport (NEWT) included in the Standardized Computer Analyses for Licensing Evaluation (SCALE) 6.1.2 package was used for the cross section evaluation, and the results obtained were compared to the three dimensional stochastic SCALE module KENO VI. The NEWT cross section libraries were generated for several permutations of the current benchmark super-cell geometry and were then provided as input to the Phase II core calculation of the stand alone neutronics

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.

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

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

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.

Structure of rat acidic fibroblast growth factor at 1.4 Å resolution

PubMed Central

Kulahin, Nikolaj; Kiselyov, Vladislav; Kochoyan, Arthur; Kristensen, Ole; Kastrup, Jette Sandholm; Berezin, Vladimir; Bock, Elisabeth; Gajhede, Michael

2007-01-01

Fibroblast growth factors (FGFs) constitute a family of 22 structurally related heparin-binding polypeptides that are involved in the regulation of cell growth, survival, differentiation and migration. Here, a 1.4 Å resolution X-ray structure of rat FGF1 is presented. Two molecules are present in the asymmetric unit of the crystal and they coordinate a total of five sulfate ions. The structures of human, bovine and newt FGF1 have been published previously. Human and rat FGF1 are found to have very similar structures. PMID:17277441

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

DESIGN CHARACTERISTICS OF THE IDAHO NATIONAL LABORATORY HIGH-TEMPERATURE GAS-COOLED TEST REACTOR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sterbentz, James; Bayless, Paul; Strydom, Gerhard

2016-11-01

Uncertainty and sensitivity analysis is an indispensable element of any substantial attempt in reactor simulation validation. The quantification of uncertainties in nuclear engineering has grown more important and the IAEA Coordinated Research Program (CRP) on High-Temperature Gas Cooled Reactor (HTGR) initiated in 2012 aims to investigate the various uncertainty quantification methodologies for this type of reactors. The first phase of the CRP is dedicated to the estimation of cell and lattice model uncertainties due to the neutron cross sections co-variances. Phase II is oriented towards the investigation of propagated uncertainties from the lattice to the coupled neutronics/thermal hydraulics core calculations.more » Nominal results for the prismatic single block (Ex.I-2a) and super cell models (Ex.I-2c) have been obtained using the SCALE 6.1.3 two-dimensional lattice code NEWT coupled to the TRITON sequence for cross section generation. In this work, the TRITON/NEWT-flux-weighted cross sections obtained for Ex.I-2a and various models of Ex.I-2c is utilized to perform a sensitivity analysis of the MHTGR-350 core power densities and eigenvalues. The core solutions are obtained with the INL coupled code PHISICS/RELAP5-3D, utilizing a fixed-temperature feedback for Ex. II-1a.. It is observed that the core power density does not vary significantly in shape, but the magnitude of these variations increases as the moderator-to-fuel ratio increases in the super cell lattice models.« less

The scent of danger: arginine as an olfactory cue of reduced predation risk.

PubMed

Ferrer, Ryan P; Zimmer, Richard K

2007-05-01

Animal perception of chemosensory cues is a function of ecological context. Larvae of the California newt (Taricha torosa), for example, exhibit predator-avoidance behavior in response to a chemical from cannibalistic adults. The poison tetrodotoxin (TTX), well known as an adult chemical defense, stimulates larval escape to refuges. Although they are cannibals, adult newts feed preferentially on worms (Eisenia rosea) over conspecific young. Hence, larval avoidance reactions to TTX are suppressed in the presence of odor from these alternative prey. The free amino acid, arginine, is abundant in fluids emitted by injured worms. Here, we demonstrate that arginine is a natural suppressant of TTX-stimulated larval escape behavior. Compared to a tapwater control, larvae initiated vigorous swimming in response to 10(-7) mol l(-1) TTX. This excitatory response was eliminated when larval nasal cavities were blocked with an inert gel, but not when gel was placed on the forehead (control). In additional trials, a binary mixture of arginine and 10(-7) mol l(-1) TTX failed to induce larval swimming. The inhibitory effect of arginine was, however, dose dependent. An arginine concentration as low as 0.3-times that of TTX was significantly suppressant. Further analysis showed that suppression by arginine of TTX-stimulated behavior was eliminated by altering the positively-charged guanidinium moiety, but not by modifying the carbon chain, carboxyl group, or amine group. These results are best explained by a mechanism of competitive inhibition between arginine and TTX for common, olfactory receptor binding sites. Although arginine alone has no impact on larval behavior, it nevertheless signals active adult predation on alternative prey, and hence, reduced cannibalism risk.

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.

What do Hillary Rodham Clinton and Newt Gingrich have in common?

PubMed

Drake, D F

1995-10-25

In a somewhat tongue-in-cheek style, this article tries to persuade conservatives that it might be in their best interests to consider broader health system reform alternatives in their quest to reduce the cost of federal health entitlements for a balanced budget by 2002. The conventional means for reducing the federal budget by $450 billion in 7 years will inflict much pain on many voters. The substitution of a new, more targeted entitlement, prospectively, for all Americans represents an alternative that provides much gain to many and only some pain to a few.

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

Genetic architecture of a feeding adaptation: garter snake (Thamnophis) resistance to tetrodotoxin bearing prey.

PubMed

Feldman, Chris R; Brodie, Edmund D; Brodie, Edmund D; Pfrender, Michael E

2010-11-07

Detailing the genetic basis of adaptive variation in natural populations is a first step towards understanding the process of adaptive evolution, yet few ecologically relevant traits have been characterized at the genetic level in wild populations. Traits that mediate coevolutionary interactions between species are ideal for studying adaptation because of the intensity of selection and the well-characterized ecological context. We have previously described the ecological context, evolutionary history and partial genetic basis of tetrodotoxin (TTX) resistance in garter snakes (Thamnophis). Derived mutations in a voltage-gated sodium channel gene (Na(v)1.4) in three garter snake species are associated with resistance to TTX, the lethal neurotoxin found in their newt prey (Taricha). Here we evaluate the contribution of Na(v)1.4 alleles to TTX resistance in two of those species from central coastal California. We measured the phenotypes (TTX resistance) and genotypes (Na(v)1.4 and microsatellites) in a local sample of Thamnophis atratus and Thamnophis sirtalis. Allelic variation in Na(v)1.4 explains 23 per cent of the variation in TTX resistance in T. atratus while variation in a haphazard sample of the genome (neutral microsatellite markers) shows no association with the phenotype. Similarly, allelic variation in Na(v)1.4 correlates almost perfectly with TTX resistance in T. sirtalis, but neutral variation does not. These strong correlations suggest that Na(v)1.4 is a major effect locus. The simple genetic architecture of TTX resistance in garter snakes may significantly impact the dynamics of phenotypic coevolution. Fixation of a few alleles of major effect in some garter snake populations may have led to the evolution of extreme phenotypes and an 'escape' from the arms race with newts.

Parallel evolution of tetrodotoxin resistance in three voltage-gated sodium channel genes in the garter snake Thamnophis sirtalis.

PubMed

McGlothlin, Joel W; Chuckalovcak, John P; Janes, Daniel E; Edwards, Scott V; Feldman, Chris R; Brodie, Edmund D; Pfrender, Michael E; Brodie, Edmund D

2014-11-01

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. © The Author 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

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.

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

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

Morphogenesis and gravity in a whole amphibian embryo and in isolated blastomeres of sea urchins.

PubMed

Izumi-Kurotani, Akemi; Kiyomoto, Masato

2003-01-01

Fertilization and subsequent embryogenesis of newts occurred normally under microgravity in two Astronewt flight experiments. By accumulation of the results from the amphibian flight experiments including 'Astronewt', it is considered that gravity has rather small effects on the early development of amphibian eggs. However, some temporary abnormalities, which recover in the course of the further developmental process, have been observed. Some regulations may occur in whole embryos. For a thorough knowledge about the role of gravity in morphogenesis, we need to investigate the gravitational effects on a single cell in a whole embryo. We propose a new experimental system with sea urchin embryos and micromeres for further studies at a cellular level of the effects of gravity on morphogenesis.

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%.

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.

Recent introduction of a chytrid fungus endangers Western Palearctic salamanders

PubMed Central

Martel, A.; 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.

2018-01-01

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. PMID:25359973

[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.

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

Ranavirus-associated mass mortality in wild amphibians, the Netherlands, 2010: a first report.

PubMed

Kik, Marja; Martel, An; Sluijs, Annemarieke Spitzen-van der; Pasmans, Frank; Wohlsein, Peter; Gröne, Andrea; Rijks, Jolianne M

2011-11-01

In 2010, a mass die-off of over 1000 wild water frogs (Pelophylax spp.) and at least 10 common newts (Lissotriton vulgaris) occurred in a pond in The Netherlands. Haemorrhagic disease with hepatomegaly and splenomegaly was evident. Microscopically, multiple organs presented cells with multifocal intracytoplasmic inclusion bodies, in which ranavirus-like particles were demonstrated ultrastructurally. All specimens examined tested positive for ranavirus by PCR. The sequence obtained showed a 100% identity with the one deposited for common midwife toad virus (CMTV). This is the first report of ranavirus-associated mortality in wild amphibian populations in The Netherlands. It is also the first time CMTV or a CMTV-like virus has been reported in these two species in the adult stage and outside of Spain. Copyright © 2011 Elsevier Ltd. All rights reserved.

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.

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.

Cryptic chytridiomycosis linked to climate and genetic variation in amphibian populations of the southeastern United States

PubMed Central

Hoffman, Eric A.; Tye, Matthew R.; Hether, Tyler D.; Savage, Anna E.

2017-01-01

North American amphibians have recently been impacted by two major emerging pathogens, the fungus Batrachochytrium dendrobatidis (Bd) and iridoviruses in the genus Ranavirus (Rv). Environmental factors and host genetics may play important roles in disease dynamics, but few studies incorporate both of these components into their analyses. Here, we investigated the role of environmental and genetic factors in driving Bd and Rv infection prevalence and severity in a biodiversity hot spot, the southeastern United States. We used quantitative PCR to characterize Bd and Rv dynamics in natural populations of three amphibian species: Notophthalmus perstriatus, Hyla squirella and Pseudacris ornata. We combined pathogen data, genetic diversity metrics generated from neutral markers, and environmental variables into general linear models to evaluate how these factors impact infectious disease dynamics. Occurrence, prevalence and intensity of Bd and Rv varied across species and populations, but only one species, Pseudacris ornata, harbored high Bd intensities in the majority of sampled populations. Genetic diversity and climate variables both predicted Bd prevalence, whereas climatic variables alone predicted infection intensity. We conclude that Bd is more abundant in the southeastern United States than previously thought and that genetic and environmental factors are both important for predicting amphibian pathogen dynamics. Incorporating both genetic and environmental information into conservation plans for amphibians is necessary for the development of more effective management strategies to mitigate the impact of emerging infectious diseases. PMID:28448517

Condition-dependent trade-offs between sexual traits, body condition and immunity: the effect of novel habitats.

PubMed

Iglesias-Carrasco, Maider; Head, Megan L; Jennions, Michael D; Cabido, Carlos

2016-06-21

The optimal allocation of resources to sexual signals and other life history traits is usually dependent on an individual's condition, while variation in the expression of sexual traits across environments depends on the combined effects of local adaptation, mean condition, and phenotypic responses to environment-specific cues that affect resource allocation. A clear contrast can often be drawn between natural habitats and novel habitats, such as forest plantations and urban areas. In some species, males seem to change their sexual signals in these novel environments, but why this occurs and how it affects signal reliability is still poorly understood. The relative size of sexual traits and level of immune responses were significantly lower for male palmate newts Lissotriton helveticus caught in pine and eucalyptus plantations compared to those caught in native forests, but there was no habitat-dependent difference in body condition (n = 18 sites, 382 males). The reliability with which sexual traits signalled body condition and immune responses was the same in all three habitats. Finally, we conducted a mesocosm experiment in which males were maintained in pine, eucalypt or oak infused water for 21 days. Males in plantation-like water (pine or eucalypt) showed significantly lower immune responses but no change in body condition. This matches the pattern seen for field-caught males. Unlike field-caught males, however, there was no relationship between water type and relative sexual trait size. Pine and eucalyptus plantations are likely to be detrimental to male palmate newt because they are associated with reduced immune function and smaller sexual traits. This could be because ecological aspects of these novel habitats, such as high water turbidity or changes in male-male competition, drive selection for reduced investment into sexual traits. However, it is more probable that there are differences in the ease of acquisition, hence optimal allocation, of

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). c2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

Terrestrial pesticide exposure of amphibians: an underestimated cause of global decline?

PubMed

Brühl, Carsten A; Schmidt, Thomas; Pieper, Silvia; Alscher, Annika

2013-01-01

Amphibians, a class of animals in global decline, are present in agricultural landscapes characterized by agrochemical inputs. Effects of pesticides on terrestrial life stages of amphibians such as juvenile and adult frogs, toads and newts are little understood and a specific risk assessment for pesticide exposure, mandatory for other vertebrate groups, is currently not conducted. We studied the effects of seven pesticide products on juvenile European common frogs (Rana temporaria) in an agricultural overspray scenario. Mortality ranged from 100% after one hour to 40% after seven days at the recommended label rate of currently registered products. The demonstrated toxicity is alarming and a large-scale negative effect of terrestrial pesticide exposure on amphibian populations seems likely. Terrestrial pesticide exposure might be underestimated as a driver of their decline calling for more attention in conservation efforts and the risk assessment procedures in place do not protect this vanishing animal group.

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.

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.

Exploring the effect of asymmetric mitochondrial DNA introgression on estimating niche divergence in morphologically cryptic species.

PubMed

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.

The evolutionary origins of beneficial alleles during the repeated adaptation of garter snakes to deadly prey.

PubMed

Feldman, Chris R; Brodie, Edmund D; Brodie, Edmund D; Pfrender, Michael E

2009-08-11

Where do the genetic variants underlying adaptive change come from? Are currently adaptive alleles recruited by selection from standing genetic variation within populations, moved through introgression from other populations, or do they arise as novel mutations? Here, we examine the molecular basis of repeated adaptation to the toxin of deadly prey in 3 species of garter snakes (Thamnophis) to determine whether adaptation has evolved through novel mutations, sieving of existing variation, or transmission of beneficial alleles across species. Functional amino acid substitutions in the skeletal muscle sodium channel (Na(v)1.4) are largely responsible for the physiological resistance of garter snakes to tetrodotoxin found in their newt (Taricha) prey. Phylogenetic analyses reject the hypotheses that the unique resistance alleles observed in multiple Thamnophis species were present before the split of these lineages, or that alleles were shared among species through occasional hybridization events. Our results demonstrate that adaptive evolution has occurred independently multiple times in garter snakes via the de novo acquisition of beneficial mutations.

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

The scarless heart and the MRL mouse.

PubMed

Heber-Katz, Ellen; Leferovich, John; Bedelbaeva, Khamilia; Gourevitch, Dmitri; Clark, Lise

2004-05-29

The ability to regenerate tissues and limbs in its most robust form is seen in many non-mammalian species. The serendipitous discovery that the MRL mouse has a profound capacity for regeneration in some ways rivalling the classic newt and axolotl species raises the possibility that humans, too, may have an innate regenerative ability. The adult MRL mouse regrows cartilage, skin, hair follicles and myocardium with near perfect fidelity and without scarring. This is seen in the ability to close through-and-through ear holes, which are generally used for lifelong identification of mice, and the anatomic and functional recovery of myocardium after a severe cryo-injury. We present histological, biochemical and genetic data indicating that the enhanced breakdown of scar-like tissue may be an underlying factor in the MRL regenerative response. Studies as to the source of the cells in the regenerating MRL tissue are discussed. Such studies appear to support multiple mechanisms for cell replacement.

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.

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

Genetic and metabolic biodiversity of Trichoderma from Colombia and adjacent neotropic regions.

PubMed

Hoyos-Carvajal, Lilliana; Orduz, Sergio; Bissett, John

2009-09-01

The genus Trichoderma has been studied for production of enzymes and other metabolites, as well as for exploitation as effective biological control agents. The biodiversity of Trichoderma has seen relatively limited study over much of the neotropical region. In the current study we assess the biodiversity of 183 isolates from Mexico, Guatemala, Panama, Ecuador, Peru, Brazil and Colombia, using morphological, metabolic and genetic approaches. A comparatively high diversity of species was found, comprising 29 taxa: Trichoderma asperellum (60 isolates), Trichoderma atroviride (3), Trichoderma brevicompactum (5), Trichoderma crassum (3), Trichoderma erinaceum (3), Trichoderma gamsii (2), Trichoderma hamatum (2), Trichoderma harzianum (49), Trichoderma koningiopsis (6), Trichoderma longibrachiatum (3), Trichoderma ovalisporum (1), Trichoderma pubescens (2), Trichoderma rossicum (4), Trichoderma spirale (1), Trichoderma tomentosum (3), Trichoderma virens (8), Trichoderma viridescens (7) and Hypocrea jecorina (3) (anamorph: Trichoderma reesei), along with 11 currently undescribed species. T. asperellum was the prevalent species and was represented by two distinct genotypes with different metabolic profiles and habitat preferences. The second predominant species, T. harzianum, was represented by three distinct genotypes. The addition of 11 currently undescribed species is evidence of the considerable unresolved biodiversity of Trichoderma in neotropical regions. Sequencing of the internal transcribed spacer regions (ITS) of the ribosomal repeat could not differentiate some species, and taken alone gave several misidentifications in part due to the presence of nonorthologous copies of the ITS in some isolates.

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.

Molecular signatures that correlate with induction of lens regeneration in newts: lessons from proteomic analysis.

PubMed

Sousounis, Konstantinos; Bhavsar, Rital; Looso, Mario; Krüger, Marcus; Beebe, Jessica; Braun, Thomas; Tsonis, Panagiotis A

2014-12-11

Amphibians have the remarkable ability to regenerate missing body parts. After complete removal of the eye lens, the dorsal but not the ventral iris will transdifferentiate to regenerate an exact replica of the lost lens. We used reverse-phase nano-liquid chromatography followed by mass spectrometry to detect protein concentrations in dorsal and ventral iris 0, 4, and 8 days post-lentectomy. We performed gene expression comparisons between regeneration and intact timepoints as well as between dorsal and ventral iris. Our analysis revealed gene expression patterns associated with the ability of the dorsal iris for transdifferentiation and lens regeneration. Proteins regulating gene expression and various metabolic processes were enriched in regeneration timepoints. Proteins involved in extracellular matrix, gene expression, and DNA-associated functions like DNA repair formed a regeneration-related protein network and were all up-regulated in the dorsal iris. In addition, we investigated protein concentrations in cultured dorsal (transdifferentiation-competent) and ventral (transdifferentiation-incompetent) iris pigmented epithelial (IPE) cells. Our comparative analysis revealed that the ability of dorsal IPE cells to keep memory of their tissue of origin and transdifferentiation is associated with the expression of proteins that specify the dorso-ventral axis of the eye as well as with proteins found highly expressed in regeneration timepoints, especially 8 days post-lentectomy. The study deepens our understanding in the mechanism of regeneration by providing protein networks and pathways that participate in the process.

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.

Brazilian artisanal ripened cheeses as sources of proteolytic lactic acid bacteria capable of reducing cow milk allergy.

PubMed

Biscola, V; Choiset, Y; Rabesona, H; Chobert, J-M; Haertlé, T; Franco, B D G M

2018-04-13

The objective was to obtain lactic acid bacteria (LAB) capable of hydrolysing immunoreactive proteins in milk, to optimize the hydrolysis, to determine the proteolysis kinetics and to test the safety of the best hydrolytic strain. Brazilian cheese was used as source of LAB capable of hydrolysing main milk allergens. Proteolytic isolates were submitted to RAPD-PCR for the characterization of clonal diversity. Optimized hydrolysis was strain and protein fraction dependent. 16S rDNA sequencing identified three proteolytic strains: Enterococcus faecalis VB43, that hydrolysed α S1 -, α S2 - and β-caseins, α-lactalbumin and β-lactoglobulin (partial hydrolysis), and Pediococcus acidilactici VB90 and Weissella viridescens VB111, that caused partial hydrolysis of α S1 - and α S2 -caseins. Enterococcus faecalis VB43 tested negative for virulence genes asa1, agg, efaA, hyl, esp, cylL L and cylL S but positive for genes ace and gelE. Ethylenediamine tetra-acetic acid inhibited the proteolysis, indicating that the main proteases of E. faecalis VB43 are metalloproteases. Brazilian artisanal cheese is a good source of LAB capable of hydrolysing allergenic proteins in milk. One isolate (E. faecalis VB43) presented outstanding activity against these proteins and lacked most of the tested virulence genes. Enterococcus faecalis VB43 presents good potential for the manufacture of hypoallergenic dairy products. © 2018 The Society for Applied Microbiology.

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.

Characterisation of lactic acid bacteria isolated from naturally fermented Greek dry salami.

PubMed

Samelis, J; Maurogenakis, F; Metaxopoulos, J

1994-10-01

A total of 348 lactic acid bacteria isolated from five batches of naturally fermented dry salami at various stages of ripening were characterised. The majority of the strains were assigned to two main phylogenetic groups of species: (i) the psychrotrophic, formerly called atypical, meat streptobacteria (169 strains) and (ii) a new genus Weissella (120), which was recently proposed (Collins et al., 1993) to include Leuconostoc paramesenteroides and some other closely related species. Meat streptobacteria were identified as Lactobacillus curvatus (88 strains) and L. sake (76), whereas 5 strains were indistinguishable and, thus designated L. sake/curvatus. Non-psychrotrophic streptobacteria were also isolated and identified as L. plantarum (34 strains), L. farciminis (10), L. coryniformis (1) and L. casei subsp. pseudoplantarum (1). The majority of the Weissella strains (86) were leuconostoc-like bacteria; four of them were identified as W. viridescens, 11 belonged to the newly described W. hellenica (Collins et al., 1993), another 11 resembled W. paramesenteroides, whereas 60 isolates were not classified to any species. The latter group comprised strains that produced D(L)-lactate. The remaining Weissella were gas-forming, arginine-positive rods assigned to W. minor (31) and W. halotolerans (3). Other species identified were Enterococcus faecium (10), Leuconostoc mesenteroides (1), L. brevis (1) and Pediococcus sp. (1). The main criteria used to distinguish between above species as well as their distribution on the five salami batches in relation to their succession with time and suitability as starters were discussed.

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.

The effect of hypergravity on the lens, cornea and tail regeneration in Urodela

NASA Astrophysics Data System (ADS)

Grigoryan, E. N.; Dvorochkin, N.; Poplinskaya, V. A.; Yousuf, R.; Radugina, E. A.; Almeida, E. A.

2017-09-01

In previous experiments onboard Russian Bion/Foton satellites it was found that exposure to microgravity causes changes in eye lens regeneration of Urodela. The changes included higher rate of regeneration, increased cell proliferation in lens anlage, and synchronization of lens restoration. Similar changes were observed regarding tail regeneration. Recently, investigations were performed to find out whether exposure to hypergravity could also alter lens, cornea and tail regeneration in the newt P. waltl. Nine days prior to exposure the left lens was surgically removed through corneal incision and distal 1/3 of the tail was amputated, thus initiating regeneration. The experimental animals were allowed to recover for 9 days at 1 g and then exposed to 2 g for 12 days in an 8 ft diameter centrifuge at NASA Ames Research Center. The experimental animals were divided into 1 g controls, 2 g centrifugation animals, basal controls, and aquarium controls. Lens and corneal regeneration appeared to be inhibited in 2 g group compared to 1 g animals. In all 1 g controls, lens regeneration reached stages VII-IX in a synchronous fashion and corneal regeneration was nearly complete. In the 2 g newts, neural retinal detachment from the pigmented epithelium was seen in most operated eyes. It was also observed in the non-operated (right) eyes of the animals exposed to 2 g. The level of retinal detachment varied and could have been caused by hypergravity-induced high intraocular pressure. Regeneration (when it could be assessed) proceeded asynchronously, reaching stages from II to IX. Corneal restoration was also noticeably delayed and corneal morphology changed. Cell proliferation was measured using BrdU; the results were not comparable to the 1 g data because of retinal detachment. Previous investigations demonstrated that lens regeneration was controlled by the neural retina; therefore, lower regeneration rate at 2 g was, at least in part, associated with retinal detachment. FGF2

Sperm storage influences the potential for spontaneous acrosome reaction of the sperm in the newt Cynops pyrrhogaster.

PubMed

Kon, Shinnosuke; Sato, Tae; Endo, Daisuke; Takahashi, Tomoe; Takaku, Akio; Nakauchi, Yuni; Toyama, Fubito; Meyer-Rochow, Victor B; Takayama-Watanabe, Eriko; Watanabe, Akihiko

2017-12-01

Sperm storage is supposed to influence sperm quality, although the details remain unclear. In the present study, we found that sperm stored in a sperm storage site, the vas deferens of Cynops pyrrhogaster, spontaneously undergo acrosome reaction following incubation in Steinberg's salt solution (ST). Percentages of acrosome-reacted sperm increased time-dependently to about 60% in 24 hr. The concentration of cyclic adenosine monophosphate (cAMP) was elevated after incubating sperm in ST, while dibutylyl cAMP induced an acrosome reaction. Chelating of extracellular Ca 2+ suppressed the dibutylyl cAMP-induced acrosome reaction as well as spontaneous acrosome reaction in ST. These results suggest that cAMP elevation driven by Ca 2+ influx can be a cue for spontaneous acrosome reaction. Relatively low Ca 2+ concentration and pH in the vas deferens were sufficient to suppress spontaneous acrosome reaction within 1 hr. In addition, the cysteine rich secretory protein 2 gene was expressed in the vas deferens, indicating that it may be involved in the continuous suppression of spontaneous acrosome reaction. Sperm that underwent spontaneous acrosome reaction in ST was significantly increased when stored in the vas deferens for longer periods, or by males experiencing temperatures in excess of 12°C during hibernation conditions. Percentages of the spontaneously acrosome-reacted sperm were found to differ among males even though they were of identical genetic background. Taken together, C. pyrrhogaster sperm possess the potential for spontaneous acrosome reaction that does not become obvious in the vas deferens, unless promoted in correlation with sperm storage. © 2017 Wiley Periodicals, Inc.

Combination of culture-dependent and culture-independent molecular methods for the determination of lactic microbiota in sucuk.

PubMed

Kesmen, Z; Yetiman, A E; Gulluce, A; Kacmaz, N; Sagdic, O; Cetin, B; Adiguzel, A; Sahin, F; Yetim, H

2012-02-15

In this study, the culture-dependent and culture-independent molecular methods were used for the identification of lactic acid bacteria (LAB) in sucuk a Turkish fermented dry sausage. On the one hand, the PCR-DGGE method targetting the V1 and V3 regions of 16S DNA was applied to DNA that was directly extracted from sucuk samples. On the other hand, rep-PCR fingerprinting was performed for the primary differentiation and grouping of the isolates, and the results were confirmed by sequencing of the 16S rDNA and 16S-23S rDNA intergenic spacer region. As a result of the PCR-DGGE analysis of all the samples, total 8 different lactic acid bacteria were identified, and Lactobacillus sakei, Lactobacillus curvatus and Weissella viridescens were the dominant microbiota among these bacteria. The culture-dependent approach indicated that the majority of the strains belonged to the Lactobacillus genera including Lb. sakei, Lactobacillus plantarum, Lb. curvatus, Lactobacillus brevis, Lactobacillus farciminis and Lactobacillus alimentarius. However, Leuconostoc and Weisella were also detected as minor genera. Again, Lactococcus piscium, Weissella halotolerans, Staphylococcus succinus and the comigrated Staphylococcus piscifermentans/Staphylococcus condimenti/Staphylococcus carnosus group were detected only with the culture-independent method while Lb. plantarum, Leuconostoc mesenteroides and Leuconostoc citreum were identified only by using the culture-dependent method. In the results, it was concluded that the combination of culture-dependent and culture-independent methods was necessary for reliable and detailed investigation of LAB communities in fermented food products. Copyright © 2011 Elsevier B.V. All rights reserved.

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

Suppressive Effect of Trichoderma spp. on toxigenic Fusarium species.

PubMed

Błaszczyk, Lidia; Basińska-Barczak, Aneta; Ćwiek-Kupczyńska, Hanna; Gromadzka, Karolina; Popiel, Delfina; Stępień, Łukasz

2017-03-30

The aim of the present study was to examine the abilities of twenty-four isolates belonging to ten different Trichoderma species (i.e., Trichoderma atroviride, Trichoderma citrinoviride, Trichoderma cremeum, Trichoderma hamatum, Trichoderma harzianum, Trichoderma koningiopsis, Trichoderma longibrachiatum, Trichoderma longipile, Trichoderma viride and Trichoderma viridescens) to inhibit the mycelial growth and mycotoxin production by five Fusarium strains (i.e., Fusarium avenaceum, Fusarium cerealis, Fusarium culmorum, Fusarium graminearum and Fusarium temperatum). Dual-culture bioassay on potato dextrose agar (PDA) medium clearly documented that all of the Trichoderma strains used in the study were capable of influencing the mycelial growth of at least four of all five Fusarium species on the fourth day after co-inoculation, when there was the first apparent physical contact between antagonist and pathogen. The qualitative evaluation of the interaction between the colonies after 14 days of co-culturing on PDA medium showed that ten Trichoderma strains completely overgrew and sporulated on the colony at least one of the tested Fusarium species. Whereas, the microscopic assay provided evidence that only T. atroviride AN240 and T. viride AN255 formed dense coils around the hyphae of the pathogen from where penetration took place. Of all screened Trichoderma strains, T. atroviride AN240 was also found to be the most efficient (69-100% toxin reduction) suppressors of mycotoxins (deoxynivalenol, 3-acetyl-deoxynivalenol, 15-acetyl-deoxynivalenol, nivalenol, zearalenone, beauvericin, moniliformin) production by all five Fusarium species on solid substrates. This research suggests that T. atroviride AN240 can be a promising candidate for the biological control of toxigenic Fusarium species.

The battle over workers' compensation.

PubMed

Ellenberger, J N

2000-01-01

Faced with lower profits and rapidly increasing premium costs in the 1980s, insurers and employer organizations cleverly parlayed the public perception of worker fraud and abuse in the workers' compensation system (that they helped to create) into massive legislative changes. Over the last decade, state legislators and governors, Republican and Democrat alike, have jumped on this bandwagon, one that workers and their allies have dubbed the workers' compensation "deform" movement. Alleging a "game plan" and a calculated campaign on the part of insurers and employers, the author looks at the major components of changes that were made, examines the elements of workers' compensation over which employers and insurers have gained control, and discusses Newt Gingrich's efforts to capitalize on employer and insurer fervor over the system. This campaign whistled through the country until it goaded the labor movement, injured workers, the trial bar, and others in Ohio in 1997 to organize themselves to stand up to employers by defeating the deform law through a ballot initiative. The article details that battle and suggests that similar voices can be achieved through a return to grassroots organizing and mobilization.

Genomic analysis of a new mammalian distal-less gene: Dlx7.

PubMed

Nakamura, S; Stock, D W; Wydner, K L; Bollekens, J A; Takeshita, K; Nagai, B M; Chiba, S; Kitamura, T; Freeland, T M; Zhao, Z; Minowada, J; Lawrence, J B; Weiss, K M; Ruddle, F H

1996-12-15

We have cloned a new Dlx gene (Dlx7) from human and mouse that may represent the mammalian orthologue of the newt gene NvHBox-5. The homeodomains of these genes are highly similar to all other vertebrate Dlx genes, and regions of similarity also exist between mammalian Dlx7 and a subset of vertebrate Dlx genes downstream of the homeodomain. The sequence divergence between human and mouse Dlx7 in these regions is greater than that predicted from comparisons of other vertebrate Dlx genes, however, and there is little sequence similarity upstream of the homeodomain both between these two genes and with other Dlx genes. We present evidence for alternative splicing of mouse Dlx7 upstream of the homeodomain that may account for some of this divergence. We have mapped human DLX7 distal to the 5' end of the HOXB cluster at an estimated distance of between 1 and 2 Mb by FISH. Both the human and the mouse Dlx7 are shown to be closely linked to Dlx3 in a convergently transcribed orientation. These mapping results support the possibility that vertebrate distal-less genes have been duplicated in concert with the Hox clusters.

Gravity changes during animal development affect IgM heavy-chain transcription and probably lymphopoiesis.

PubMed

Huin-Schohn, Cécile; Guéguinou, Nathan; Schenten, Véronique; Bascove, Matthieu; Koch, Guillemette Gauquelin; Baatout, Sarah; Tschirhart, Eric; Frippiat, Jean-Pol

2013-01-01

Our previous research demonstrated that spaceflight conditions affect antibody production in response to an antigenic stimulation in adult amphibians. Here, we investigated whether antibody synthesis is affected when animal development occurs onboard a space station. To answer this question, embryos of the Iberian ribbed newt, Pleurodeles waltl, were sent to the International Space Station (ISS) before the initiation of immunoglobulin heavy-chain expression. Thus, antibody synthesis began in space. On landing, we determined the effects of spaceflight on P. waltl development and IgM heavy-chain transcription. Results were compared with those obtained using embryos that developed on Earth. We find that IgM heavy-chain transcription is doubled at landing and that spaceflight does not affect P. waltl development and does not induce inflammation. We also recreated the environmental modifications encountered by the embryos during their development onboard the ISS. This strategy allowed us to demonstrate that gravity change is the factor responsible for antibody heavy-chain transcription modifications that are associated with NF-κB mRNA level variations. Taken together, and given that the larvae were not immunized, these data suggest a modification of lymphopoiesis when gravity changes occur during ontogeny.

Marine Biotoxins: Occurrence, Toxicity, and Detection Methods

NASA Astrophysics Data System (ADS)

Asakawa, M.

2017-04-01

This review summarizes the role of marine organisms as vectors of marine biotoxins, and discusses the need for surveillance to protect public health and ensure the quality of seafood. I Paralytic shellfish poison (PSP) and PSP-bearing organisms-PSP is produced by toxic dinoflagellates species belonging to the genera Alexandrium, Gymnodinium, and Pyrodinium. Traditionally, PSP monitoring programs have only considered filter-feeding molluscs that concentrate these toxic algae, however, increasing attention is now being paid to higher-order predators that carry PSP, such as carnivorous gastropods and crustaceans. II. Tetrodotoxin (TTX) and TTX-bearing organisms - TTX is the most common natural marine toxin that causes food poisonings in Japan, and poses a serious public health risk. TTX was long believed to be present only in pufferfish. However, TTX was detected in the eggs of California newt Taricha torosa in 1964, and since then it has been detected in a wide variety of species belonging to several different phyla. In this study, the main toxic components in the highly toxic ribbon worm Cephalothrix simula and the greater blue-ringed octopus Hapalochlaena lunulata from Japan were purified and analysed.

Lens regeneration from the cornea requires suppression of Wnt/β-catenin signaling.

PubMed

Hamilton, Paul W; Sun, Yu; Henry, Jonathan J

2016-04-01

The frog, Xenopus laevis, possesses a high capacity to regenerate various larval tissues, including the lens, which is capable of complete regeneration from the cornea epithelium. However, the molecular signaling mechanisms of cornea-lens regeneration are not fully understood. Previous work has implicated the involvement of the Wnt signaling pathway, but molecular studies have been very limited. Iris-derived lens regeneration in the newt (Wolffian lens regeneration) has shown a necessity for active Wnt signaling in order to regenerate a new lens. Here we provide evidence that the Wnt signaling pathway plays a different role in the context of cornea-lens regeneration in Xenopus. We examined the expression of frizzled receptors and wnt ligands in the frog cornea epithelium. Numerous frizzled receptors (fzd1, fzd2, fzd3, fzd4, fzd6, fzd7, fzd8, and fzd10) and wnt ligands (wnt2b.a, wnt3a, wnt4, wnt5a, wnt5b, wnt6, wnt7b, wnt10a, wnt11, and wnt11b) are expressed in the cornea epithelium, demonstrating that this tissue is transcribing many of the ligands and receptors of the Wnt signaling pathway. When compared to flank epithelium, which is lens regeneration incompetent, only wnt11 and wnt11b are different (present only in the cornea epithelium), identifying them as potential regulators of cornea-lens regeneration. To detect changes in canonical Wnt/β-catenin signaling occurring within the cornea epithelium, axin2 expression was measured over the course of regeneration. axin2 is a well-established reporter of active Wnt/β-catenin signaling, and its expression shows a significant decrease at 24 h post-lentectomy. This decrease recovers to normal endogenous levels by 48 h. To test whether this signaling decrease was necessary for lens regeneration to occur, regenerating eyes were treated with either 6-bromoindirubin-3'-oxime (BIO) or 1-azakenpaullone - both activators of Wnt signaling - resulting in a significant reduction in the percentage of cases with successful

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

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.

Evolutionary history of a complex adaptation: Tetrodotoxin resistance in salamanders

PubMed Central

Hanifin, Charles T.; Gilly, William F.

2017-01-01

Understanding the processes that generate novel adaptive phenotypes is central to evolutionary biology. We used comparative analyses to reveal the history of tetrodotoxin (TTX) resistance in TTX-bearing salamanders. Resistance to TTX is a critical component of the ability to use TTX defensively but the origin of the TTX-bearing phenotype is unclear. Skeletal muscle of TTX-bearing salamanders (modern newts, family: Salamandridae) is unaffected by TTX at doses far in excess of those that block action potentials in muscle and nerve of other vertebrates. Skeletal muscle of non-TTX-bearing salamandrids is also resistant to TTX but at lower levels. Skeletal muscle TTX resistance in the Salamandridae results from the expression of TTX-resistant variants of the voltage-gated sodium channel NaV 1.4 (SCN4a). We identified four substitutions in the coding region of salSCN4a that are likely responsible for the TTX resistance measured in TTX-bearing salamanders and variation at one of these sites likely explains variation in TTX resistance among other lineages. Our results suggest that exaptation has played a role in the evolution of the TTX-bearing phenotype and provide empirical evidence that complex physiological adaptations can arise through the accumulation of beneficial mutations in the coding region of conserved proteins. PMID:25346116

A signature of dynamic biogeography: enclaves indicate past species replacement.

PubMed

Wielstra, B; Burke, T; Butlin, R K; Arntzen, J W

2017-12-13

Understanding how species have replaced each other in the past is important to predicting future species turnover. While past species replacement is difficult to detect after the fact, the process may be inferred from present-day distribution patterns. Species with abutting ranges sometimes show a characteristic distribution pattern, where a section of one species range is enveloped by that of the other. Such an enclave could indicate past species replacement: when a species is partly supplanted by a competitor, but a population endures locally while the invading species moves around and past it, an enclave forms. If the two species hybridize and backcross, the receding species is predicted to leave genetic traces within the expanding one under a scenario of species replacement. By screening dozens of genes in hybridizing crested newts, we uncover genetic remnants of the ancestral species, now inhabiting an enclave, in the range of the surrounding invading species. This independent genetic evidence supports the past distribution dynamics we predicted from the enclave. We suggest that enclaves provide a valuable tool in understanding historical species replacement, which is important because a major conservation concern arising from anthropogenic climate change is increased species replacement in the future. © 2017 The Authors.

Spinal cord regeneration in Xenopus tadpoles proceeds through activation of Sox2-positive cells

PubMed Central

2012-01-01

Background In contrast to mammals, amphibians, such as adult urodeles (for example, newts) and anuran larvae (for example, Xenopus) can regenerate their spinal cord after injury. However, the cellular and molecular mechanisms involved in this process are still poorly understood. Results Here, we report that tail amputation results in a global increase of Sox2 levels and proliferation of Sox2+ cells. Overexpression of a dominant negative form of Sox2 diminished proliferation of spinal cord resident cells affecting tail regeneration after amputation, suggesting that spinal cord regeneration is crucial for the whole process. After spinal cord transection, Sox2+ cells are found in the ablation gap forming aggregates. Furthermore, Sox2 levels correlated with regenerative capabilities during metamorphosis, observing a decrease in Sox2 levels at non-regenerative stages. Conclusions Sox2+ cells contribute to the regeneration of spinal cord after tail amputation and transection. Sox2 levels decreases during metamorphosis concomitantly with the lost of regenerative capabilities. Our results lead to a working hypothesis in which spinal cord damage activates proliferation and/or migration of Sox2+ cells, thus allowing regeneration of the spinal cord after tail amputation or reconstitution of the ependymal epithelium after spinal cord transection. PMID:22537391

Biophysical costs associated with tetrodotoxin resistance in the sodium channel pore of the garter snake, Thamnophis sirtalis.

PubMed

Lee, Chong Hyun; Jones, David K; Ahern, Christopher; Sarhan, Maen F; Ruben, Peter C

2011-01-01

Tetrodotoxin (TTX) is a potent toxin that specifically binds to voltage-gated sodium channels (NaV). TTX binding physically blocks the flow of sodium ions through NaV, thereby preventing action potential generation and propagation. TTX has different binding affinities for different NaV isoforms. These differences are imparted by amino acid substitutions in positions within, or proximal to, the TTX-binding site in the channel pore. These substitutions confer TTX-resistance to a variety of species. The garter snake Thamnophis sirtalis has evolved TTX-resistance over the course of an arms race, allowing some populations of snakes to feed on tetrodotoxic newts, including Taricha granulosa. Different populations of the garter snake have different degrees of TTX-resistance, which is closely related to the number of amino acid substitutions. We tested the biophysical properties and ion selectivity of NaV of three garter snake populations from Bear Lake, Idaho; Warrenton, Oregon; and Willow Creek, California. We observed changes in gating properties of TTX-resistant (TTXr) NaV. In addition, ion selectivity of TTXr NaV was significantly different from that of TTX-sensitive NaV. These results suggest TTX-resistance comes at a cost to performance caused by changes in the biophysical properties and ion selectivity of TTXr NaV.

Org-1-dependent lineage reprogramming generates the ventral longitudinal musculature of the Drosophila heart.

PubMed

Schaub, Christoph; März, Johannes; Reim, Ingolf; Frasch, Manfred

2015-02-16

Only few examples of transdifferentiation, which denotes the conversion of one differentiated cell type to another, are known to occur during normal development, and more often, it is associated with regeneration processes. With respect to muscles, dedifferentiation/redifferentiation processes have been documented during post-traumatic muscle regeneration in blastema of newts as well as during myocardial regeneration. As shown herein, the ventral longitudinal muscles of the adult Drosophila heart arise from specific larval alary muscles in a process that represents the first known example of syncytial muscle transdifferentiation via dedifferentiation into mononucleate myoblasts during normal development. We demonstrate that this unique process depends on the reinitiation of a transcriptional program previously employed for embryonic alary muscle development, in which the factors Org-1 (Drosophila Tbx1) and Tailup (Drosophila Islet1) are key components. During metamorphosis, the action of these factors is combined with cell-autonomous inputs from the ecdysone steroid and the Hox gene Ultrabithorax, which provide temporal and spatial specificity to the transdifferentiation events. Following muscle dedifferentiation, inductive cues, particularly from the remodeling heart tube, are required for the redifferentiation of myoblasts into ventral longitudinal muscles. Our results provide new insights into mechanisms of lineage commitment and cell-fate plasticity during development. Copyright © 2015 Elsevier Ltd. All rights reserved.

Uncertainty in the delayed neutron fraction in fuel assembly depletion calculations

NASA Astrophysics Data System (ADS)

Aures, Alexander; Bostelmann, Friederike; Kodeli, Ivan A.; Velkov, Kiril; Zwermann, Winfried

2017-09-01

This study presents uncertainty and sensitivity analyses of the delayed neutron fraction of light water reactor and sodium-cooled fast reactor fuel assemblies. For these analyses, the sampling-based XSUSA methodology is used to propagate cross section uncertainties in neutron transport and depletion calculations. Cross section data is varied according to the SCALE 6.1 covariance library. Since this library includes nu-bar uncertainties only for the total values, it has been supplemented by delayed nu-bar uncertainties from the covariance data of the JENDL-4.0 nuclear data library. The neutron transport and depletion calculations are performed with the TRITON/NEWT sequence of the SCALE 6.1 package. The evolution of the delayed neutron fraction uncertainty over burn-up is analysed without and with the consideration of delayed nu-bar uncertainties. Moreover, the main contributors to the result uncertainty are determined. In all cases, the delayed nu-bar uncertainties increase the delayed neutron fraction uncertainty. Depending on the fuel composition, the delayed nu-bar values of uranium and plutonium in fact give the main contributions to the delayed neutron fraction uncertainty for the LWR fuel assemblies. For the SFR case, the uncertainty of the scattering cross section of U-238 is the main contributor.

Tail regeneration and other phenomena of wound healing and tissue restoration in lizards.

PubMed

Jacyniak, Kathy; McDonald, Rebecca P; Vickaryous, Matthew K

2017-08-15

Wound healing is a fundamental evolutionary adaptation with two possible outcomes: scar formation or reparative regeneration. Scars participate in re-forming the barrier with the external environment and restoring homeostasis to injured tissues, but are well understood to represent dysfunctional replacements. In contrast, reparative regeneration is a tissue-specific program that near-perfectly replicates that which was lost or damaged. Although regeneration is best known from salamanders (including newts and axolotls) and zebrafish, it is unexpectedly widespread among vertebrates. For example, mice and humans can replace their digit tips, while many lizards can spontaneously regenerate almost their entire tail. Whereas the phenomenon of lizard tail regeneration has long been recognized, many details of this process remain poorly understood. All of this is beginning to change. This Review provides a comparative perspective on mechanisms of wound healing and regeneration, with a focus on lizards as an emerging model. Not only are lizards able to regrow cartilage and the spinal cord following tail loss, some species can also regenerate tissues after full-thickness skin wounds to the body, transections of the optic nerve and even lesions to parts of the brain. Current investigations are advancing our understanding of the biological requirements for successful tissue and organ repair, with obvious implications for biomedical sciences and regenerative medicine. © 2017. Published by The Company of Biologists Ltd.

The relationship between RNA catalytic processes

NASA Astrophysics Data System (ADS)

Cedergren, Robert; Lang, B. Franz; Gravel, Denis

1988-09-01

Proposals that an RNA-based genetic system preceeded DNA, stem from the ability of RNA to store genetic information and to promote simple catalysis. However, to be a valid basis for the RNA world, RNA catalysis must demonstrate or be related to intrinsic chemical properties which could have existed in primordial times. We analyze this question by first classifying RNA catalysis and related processes according to their mechanism. We define: (A) thedisjunct nucleophile class which leads to 5'-phosphates. These include Group I and II intron splicing, nuclear mRNA splicing and RNase P reactions. Although Group I introns and its excision mechanism is likely to have existed in primordial times, present-day examples have arisen independently in different phyla much more recently. Comparative methodology indicates that RNase P catalysis originated before the divergence of the major kingdoms. In addition, alldisjunct nucleophile reactions can be interrelated by a proposed mechanism involving a distant 2-OH nucleophile. (B) theconjunct nucleophile class leading to 3'-phosphates. This class is composed of self-cleaving RNAs found in plant viruses and the newt. We propose that tRNA splicing is related to this mechanism rather than the previous one. The presence of introns in tRNA genes of eukaryotes and archaebacteria supports the idea that tRNA splicing predates the divergence of these cell types.

I Environmental DNA sampling is more sensitive than a traditional survey technique for detecting an aquatic invader.

PubMed

Smart, Adam S; Tingley, Reid; Weeks, Andrew R; van Rooyen, Anthony R; McCarthy, Michael A

2015-10-01

Effective management of alien species requires detecting populations in the early stages of invasion. Environmental DNA (eDNA) sampling can detect aquatic species at relatively low densities, but few studies have directly compared detection probabilities of eDNA sampling with those of traditional sampling methods. We compare the ability of a traditional sampling technique (bottle trapping) and eDNA to detect a recently established invader, the smooth newt Lissotriton vulgaris vulgaris, at seven field sites in Melbourne, Australia. Over a four-month period, per-trap detection probabilities ranged from 0.01 to 0.26 among sites where L. v. vulgaris was detected, whereas per-sample eDNA estimates were much higher (0.29-1.0). Detection probabilities of both methods varied temporally (across days and months), but temporal variation appeared to be uncorrelated between methods. Only estimates of spatial variation were strongly correlated across the two sampling techniques. Environmental variables (water depth, rainfall, ambient temperature) were not clearly correlated with detection probabilities estimated via trapping, whereas eDNA detection probabilities were negatively correlated with water depth, possibly reflecting higher eDNA concentrations at lower water levels. Our findings demonstrate that eDNA sampling can be an order of magnitude more sensitive than traditional methods, and illustrate that traditional- and eDNA-based surveys can provide independent information on species distributions when occupancy surveys are conducted over short timescales.

Tetrodotoxin – Distribution and Accumulation in Aquatic Organisms, and Cases of Human Intoxication

PubMed Central

Noguchi, Tamao; Arakawa, Osamu

2008-01-01

Many pufferfish of the family Tetraodontidae possess a potent neurotoxin, tetrodotoxin (TTX). In marine pufferfish species, toxicity is generally high in the liver and ovary, whereas in brackish water and freshwater species, toxicity is higher in the skin. In 1964, the toxin of the California newt was identified as TTX as well, and since then TTX has been detected in a variety of other organisms. TTX is produced primarily by marine bacteria, and pufferfish accumulate TTX via the food chain that begins with these bacteria. Consequently, pufferfish become non-toxic when they are fed TTX-free diets in an environment in which the invasion of TTX-bearing organisms is completely shut off. Although some researchers claim that the TTX of amphibians is endogenous, we believe that it also has an exogenous origin, i.e., from organisms consumed as food. TTX-bearing animals are equipped with a high tolerance to TTX, and thus retain or accumulate TTX possibly as a biologic defense substance. There have been many cases of human intoxication due to the ingestion of TTX-bearing pufferfish, mainly in Japan, China, and Taiwan, and several victims have died. Several cases of TTX intoxication due to the ingestion of small gastropods, including some lethal cases, were recently reported in China and Taiwan, revealing a serious public health issue. PMID:18728726

Chemosignals, hormones, and amphibian reproduction.

PubMed

Woodley, Sarah

2015-02-01

This article is part of a Special Issue "Chemosignals and Reproduction". Amphibians are often thought of as relatively simple animals especially when compared to mammals. Yet the chemosignaling systems used by amphibians are varied and complex. Amphibian chemosignals are particularly important in reproduction, in both aquatic and terrestrial environments. Chemosignaling is most evident in salamanders and newts, but increasing evidence indicates that chemical communication facilitates reproduction in frogs and toads as well. Reproductive hormones shape the production, dissemination, detection, and responsiveness to chemosignals. A large variety of chemosignals have been identified, ranging from simple, invariant chemosignals to complex, variable blends of chemosignals. Although some chemosignals elicit straightforward responses, others have relatively subtle effects. Review of amphibian chemosignaling reveals a number of issues to be resolved, including: 1) the significance of the complex, individually variable blends of courtship chemosignals found in some salamanders, 2) the behavioral and/or physiological functions of chemosignals found in anuran "breeding glands", 3) the ligands for amphibian V2Rs, especially V2Rs expressed in the main olfactory epithelium, and 4) the mechanism whereby transdermal delivery of chemosignals influences behavior. To date, only a handful of the more than 7000 species of amphibians has been examined. Further study of amphibians should provide additional insight to the role of chemosignals in reproduction. Copyright © 2014 Elsevier Inc. All rights reserved.

‘Monster… -omics’: on segmentation, re-segmentation, and vertebrae formation in amphibians and other vertebrates

PubMed Central

2013-01-01

Background The axial skeleton is one of the defining evolutionary landmarks of vertebrates. How this structure develops and how it has evolved in the different vertebrate lineages is, however, a matter of debate. Vertebrae and vertebral structures are derived from the embryonic somites, although the mechanisms of development are different between lineages. Discussion Using the anecdotal description of a teratological newt (Triturus dobrogicus) with an unusual malformation in its axial skeleton, we review, compare, and discuss the development of vertebral structures and, in particular, the development of centra from somitic cellular domains in different vertebrate groups. Vertebrae development through re-segmentation of the somitic sclerotomal cells is considered the general mechanism among vertebrates, which has been generalized from studies in amniotic model organisms. The prevalence of this mechanism among anamniotes is, however, controversial. We propose alternative developmental mechanisms for vertebrae formation that should be experimentally tested. Summary Research in model organisms, especially amniotes, is laying the foundations for a thorough understanding of the mechanisms of development of the axial skeleton in vertebrates, foundations that should expand the extent of future comparative studies. Although immersed in the ‘-omics’ era, we emphasize the need for an integrative and organismal approach in evolutionary developmental biology for a better understanding of the causal role of development in the evolution of morphological diversity in nature. PMID:23577917

Myxozoan infections of caecilians demonstrate broad host specificity and indicate a link with human activity.

PubMed

Hartigan, Ashlie; Wilkinson, Mark; Gower, David J; Streicher, Jeffrey W; Holzer, Astrid S; Okamura, Beth

2016-05-01

Myxozoans are parasitic cnidarians that infect a wide variety of hosts. Vertebrates typically serve as intermediate hosts whereas definitive hosts are invertebrates, including annelids and bryozoans. Myxozoans are known to exploit species in two of the three extant amphibian orders (Anura: frogs and toads; Caudata: newts and salamanders). Here we use museum collections to determine, to our knowledge for the first time, whether myxozoans also exploit the third amphibian order (Gymnophiona: caecilians). Caecilians are a poorly known group of limbless amphibians, the ecologies of which range from aquatic to fully terrestrial. We examined 12 caecilian species in seven families (148 individuals total) characterised by a diversity of ecologies and life histories. Using morphological and molecular surveys, we discovered the presence of the myxozoan Cystodiscus axonis in two South American species (one of seven examined families) of aquatic caecilians - Typhlonectes natans and Typhlonectes compressicauda. All infected caecilians had been maintained in captivity in the United Kingdom prior to their preservation. Cystodiscus axonis is known from several Australian frog species and its presence in caecilians indicates a capacity for infecting highly divergent amphibian hosts. This first known report of myxozoan infections in caecilians provides evidence of a broad geographic and host range. However, the source of these infections remains unknown and could be related to exposure in South America, the U.K. or to conditions in captivity. Copyright © 2016 Australian Society for Parasitology Inc. All rights reserved.

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. Copyright © 2012 Elsevier Inc. All rights reserved.

The microsomal mixed function oxidase system of amphibians and reptiles: components, activities and induction.

PubMed

Ertl, R P; Winston, G W

1998-11-01

This article reviews current research in amphibian and reptilian cytochromes P450, important to the overall understanding of xenobiotic metabolism in the ecosystem and the evolution of P450s. Amphibians and reptilians contain the normal mixed function oxidase system (MFO). In general the MFO content and activities are less than those found in mammals, but only a few of the known activities have been examined in these vertebrate classes. Research to date has focused on two families of cytochromes P450, CYP1 and 2. The isoforms examined catalyze the classic activities but there have been notable absences. The total number of isoforms present and the breadth of substrates metabolized are yet unknown. Induction by foreign compounds (xenobiotics) is lengthier and yields lower levels of induced activity than is typically found in mammals. When these animals are pretreated with 3-methylcholanthrene (3MC) and beta-naphthaflavone (BNF), which are known to induce the same isoform in mammals, multiple isoforms are induced with different activities. Phenobarbital-pretreatment in turtles and alligators induces cytochromes P450 and suggestive data indicates induction in the lizard Agama lizard and the newt Pleurodeles waltl. In amphibians and reptiles a CYP2B protein does appear to be present along with constitutive activities associated with the 2 family of cytochromes P450. The markedly different response to classic inducers combined with lower or absent activities alters the view of how amphibians and reptilians respond to xenobiotic challenges.

Convergent adaptation to dangerous prey proceeds through the same first-step mutation in the garter snake Thamnophis sirtalis.

PubMed

Hague, Michael T J; Feldman, Chris R; Brodie, Edmund D; Brodie, Edmund D

2017-06-01

Convergent phenotypes often result from similar underlying genetics, but recent work suggests convergence may also occur in the historical order of substitutions en route to an adaptive outcome. We characterized convergence in the mutational steps to two independent outcomes of tetrodotoxin (TTX) resistance in separate geographic lineages of the common garter snake (Thamnophis sirtalis) that coevolved with toxic newts. Resistance is largely conferred by amino acid changes in the skeletal muscle sodium channel (Na V 1.4) that interfere with TTX-binding. We sampled variation in Na V 1.4 throughout western North America and found clear evidence that TTX-resistant changes in both lineages began with the same isoleucine-valine mutation (I1561V) within the outer pore of Na V 1.4. Other point mutations in the pore, shown to confer much greater resistance, accumulate later in the evolutionary progression and always occur together with the initial I1561V change. A gene tree of Na V 1.4 suggests the I1561V mutations in each lineage are not identical-by-decent, but rather they arose independently. Convergence in the evolution of channel resistance is likely the result of shared biases in the two lineages of T. sirtalis-only a few mutational routes can confer TTX resistance while maintaining the conserved function of voltage-gated sodium channels. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

Detection of spring viraemia of carp virus in imported amphibians reveals an unanticipated foreign animal disease threat

USGS Publications Warehouse

Ip, Hon S.; Lorch, Jeffrey M.; Blehert, David

2016-01-01

Global translocation of plants and animals is a well-recognized mechanism for introduction of pathogens into new regions. To mitigate this risk, various tools such as preshipment health certificates, quarantines, screening for specific disease agents and outright bans have been implemented. However, such measures only target known infectious agents and their hosts and may fail to prevent translocation of even well-recognized pathogens if they are carried by novel host species. In a recent example, we screened an imported shipment of Chinese firebelly newts (Cynops orientalis) for Batrachochytrium salamandrivorans, an emergent fungal pathogen of salamanders. All animals tested negative for the fungus. However, a virus was cultured from internal organs from 7 of the 11 individual dead salamanders and from two pools of tissues from four additional dead animals. Sequencing of a portion of the glycoprotein gene from all viral isolates indicated 100% identity and that they were most closely related to spring viraemia of carp virus (SVCV). Subsequently, SVCV-specific PCR testing indicated the presence of virus in internal organs from each of the four animals previously pooled, and whole-genome sequencing of one of the viral isolates confirmed genomic arrangement characteristic of SVCV. SVCV is a rhabdovirus pathogen of cyprinid fish that is listed as notifiable to the Office International des Epizooties. This discovery reveals a novel route for potential spillover of this economically important pathogen as rhabdovirus has not previously been documented in amphibians.

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

Development of the Gecko (Pachydactylus turneri) Animal Model during Foton M-2 to Study Comparative Effects of Microgravity in Terrestrial and Aquatic Organisms

NASA Technical Reports Server (NTRS)

Almeida, E. A.; Roden, C.; Phillips, J. A.; Globus, R. K.; Searby, N.; Vercoutere, W.; Morey-Holton, E.; Gulimova, V.; Saveliev, S.; Tairbekov, M.;

Adaptive evolution of voltage-gated sodium channels: The first 800 million years

PubMed Central

Zakon, Harold H.

2012-01-01

Voltage-gated Na+-permeable (Nav) channels form the basis for electrical excitability in animals. Nav channels evolved from Ca2+ channels and were present in the common ancestor of choanoflagellates and animals, although this channel was likely permeable to both Na+ and Ca2+. Thus, like many other neuronal channels and receptors, Nav channels predated neurons. Invertebrates possess two Nav channels (Nav1 and Nav2), whereas vertebrate Nav channels are of the Nav1 family. Approximately 500 Mya in early chordates Nav channels evolved a motif that allowed them to cluster at axon initial segments, 50 million years later with the evolution of myelin, Nav channels “capitalized” on this property and clustered at nodes of Ranvier. The enhancement of conduction velocity along with the evolution of jaws likely made early gnathostomes fierce predators and the dominant vertebrates in the ocean. Later in vertebrate evolution, the Nav channel gene family expanded in parallel in tetrapods and teleosts (∼9 to 10 genes in amniotes, 8 in teleosts). This expansion occurred during or after the late Devonian extinction, when teleosts and tetrapods each diversified in their respective habitats, and coincided with an increase in the number of telencephalic nuclei in both groups. The expansion of Nav channels may have allowed for more sophisticated neural computation and tailoring of Nav channel kinetics with potassium channel kinetics to enhance energy savings. Nav channels show adaptive sequence evolution for increasing diversity in communication signals (electric fish), in protection against lethal Nav channel toxins (snakes, newts, pufferfish, insects), and in specialized habitats (naked mole rats). PMID:22723361

Mismatched anti-predator behavioral responses in predator-naïve larval anurans.

PubMed

Albecker, Molly; Vance-Chalcraft, Heather D

2015-01-01

Organisms are adept at altering behaviors to balance the tradeoff between foraging and predation risk in spatially and temporally shifting predator environments. In order to optimize this tradeoff, prey need to be able to display an appropriate response based on degree of predation risk. To be most beneficial in the earliest life stages in which many prey are vulnerable to predation, innate anti-predator responses should scale to match the risk imposed by predators until learned anti-predator responses can occur. We conducted an experiment that examined whether tadpoles with no previous exposure to predators (i.e., predator-naive) exhibit innate antipredator behavioral responses (e.g., via refuge use and spatial avoidance) that match the actual risk posed by each predator. Using 7 treatments (6 free-roaming, lethal predators plus no-predator control), we determined the predation rates of each predator on Lithobates sphenocephalus tadpoles. We recorded behavioral observations on an additional 7 nonlethal treatments (6 caged predators plus no-predator control). Tadpoles exhibited innate responses to fish predators, but not non-fish predators, even though two non-fish predators (newt and crayfish) consumed the most tadpoles. Due to a mismatch between innate response and predator consumption, tadpoles may be vulnerable to greater rates of predation at the earliest life stages before learning can occur. Thus, naïve tadpoles in nature may be at a high risk to predation in the presence of a novel predator until learned anti-predator responses provide additional defenses to the surviving tadpoles.

Mismatched anti-predator behavioral responses in predator-naïve larval anurans

PubMed Central

Vance-Chalcraft, Heather D.

2015-01-01

Organisms are adept at altering behaviors to balance the tradeoff between foraging and predation risk in spatially and temporally shifting predator environments. In order to optimize this tradeoff, prey need to be able to display an appropriate response based on degree of predation risk. To be most beneficial in the earliest life stages in which many prey are vulnerable to predation, innate anti-predator responses should scale to match the risk imposed by predators until learned anti-predator responses can occur. We conducted an experiment that examined whether tadpoles with no previous exposure to predators (i.e., predator-naive) exhibit innate antipredator behavioral responses (e.g., via refuge use and spatial avoidance) that match the actual risk posed by each predator. Using 7 treatments (6 free-roaming, lethal predators plus no-predator control), we determined the predation rates of each predator on Lithobates sphenocephalus tadpoles. We recorded behavioral observations on an additional 7 nonlethal treatments (6 caged predators plus no-predator control). Tadpoles exhibited innate responses to fish predators, but not non-fish predators, even though two non-fish predators (newt and crayfish) consumed the most tadpoles. Due to a mismatch between innate response and predator consumption, tadpoles may be vulnerable to greater rates of predation at the earliest life stages before learning can occur. Thus, naïve tadpoles in nature may be at a high risk to predation in the presence of a novel predator until learned anti-predator responses provide additional defenses to the surviving tadpoles. PMID:26664805

Proliferative events experimentally induced by a transient cold shock in the brain of adult terrestrial heterothermic vertebrates: preliminary analysis of PCNA expression in Podarcis sicula.

PubMed

Margotta, Vito

2014-01-01

In past studies on the encephalic regenerative phenomena some authors adopted a pre-surgi- cal stratagem (drastic, sudden, transient thermal stimulus) to adult brain-injured newts to limit death rate upon surgery and with this method, unexpected tissue reparation was obtained. This procedure became a routine technicality also in frog and lizard to stimulate an increase in the neurogenesis, attributable to putative stem cells which appear either in clusters ("matrix areas" or "matrix zones"), mostly at or near the telencephalic ventricular surfaces, or scattered ("matrix cells") within other cerebral districts. On the basis of this literature background, planning an immunocytochemical re-evaluation of the survival of latent proliferative properties in these adult cold shocked organisms, as already studied in Triturus carnifex, the actual investigation was carried out on the brain of Podarcis sicula not subjected to cerebral injury. The immunohistochem- ical expression of the proliferating cell nuclear antigen (PCNA) seemed moderate only in those encephalic portions better provided with cells in stand-by: the olfactory peduncles and the telen- cephalic zonae germinativae ventrales. This scenario appeared rather disappointed and inadequate with respect to the unexpected, widespread restoration of the removed portions observed by previous authors. These findings could be due both to a small effectiveness of a relatively mild thermal stress, depending on the difference between the applied temperature and seasonal one, to the lack of other experimental conditions (surgical trauma, encephalic injury) adopted in the past, and to the interspecific differences in sensitivity, since lacertilian Reptiles are less endowed with proliferative/regenerative power than Amphibians, mainly Urodela, and Teleosts.

Comparing the Natural and Anthropogenic Sodium Channel Blockers Tetrodotoxin and Indoxacarb in Garter Snakes.

PubMed

Neuman-Lee, Lorin A; Brodie, Edmund D; Hansen, Tyler; Brodie, Edmund D; French, Susannah S

2016-04-01

Synthetic chemicals, such as pesticides, are used in a variety of ways in the agricultural industry. Anthropogenic chemicals pose a unique challenge to organisms because of the lack of evolutionary history between the chemical and the organism. However, research has shown that some organisms have a resistance to these synthetic chemicals due to their evolved resistance to a natural compound with a similar structure or mode of action. Indoxacarb (INDOX) is a relatively new pesticide with a similar mode of action to that of tetrodotoxin (TTX). Tetrodotoxin is a naturally occurring toxin that is used as an antipredator defense in the rough-skinned newt (Taricha granulosa). Some populations of the common garter snake (Thamnophis sirtalis) have developed a resistance to tetrodotoxin. Here, we investigated the correlation between TTX and INDOX resistance in snakes. We hypothesized that INDOX would induce a much higher stress response than the naturally occurring TTX. We injected each snake with tetrodotoxin (1 mass-adjusted mouse unit). We did the same with mass-adjusted units of INDOX. We measured corticosterone, testosterone, and bactericidal ability. Our results show an acute stress response to INDOX, but not TTX through an elevate corticosterone and innate immune response, although there was no difference in testosterone concentration. These results suggest that, although INDOX may have a similar mechanism of action, garter snakes do not react in a similar manner as to TTX. This research gives a physiological perspective on the differences between naturally occurring compounds and synthetic compounds. © 2016 Wiley Periodicals, Inc.

Phenotypic Mismatches Reveal Escape from Arms-Race Coevolution

PubMed Central

Hanifin, Charles T; Brodie, Edmund D; Brodie, Edmund D

2008-01-01

Because coevolution takes place across a broad scale of time and space, it is virtually impossible to understand its dynamics and trajectories by studying a single pair of interacting populations at one time. Comparing populations across a range of an interaction, especially for long-lived species, can provide insight into these features of coevolution by sampling across a diverse set of conditions and histories. We used measures of prey traits (tetrodotoxin toxicity in newts) and predator traits (tetrodotoxin resistance of snakes) to assess the degree of phenotypic mismatch across the range of their coevolutionary interaction. Geographic patterns of phenotypic exaggeration were similar in prey and predators, with most phenotypically elevated localities occurring along the central Oregon coast and central California. Contrary to expectations, however, these areas of elevated traits did not coincide with the most intense coevolutionary selection. Measures of functional trait mismatch revealed that over one-third of sampled localities were so mismatched that reciprocal selection could not occur given current trait distributions. Estimates of current locality-specific interaction selection gradients confirmed this interpretation. In every case of mismatch, predators were “ahead” of prey in the arms race; the converse escape of prey was never observed. The emergent pattern suggests a dynamic in which interacting species experience reciprocal selection that drives arms-race escalation of both prey and predator phenotypes at a subset of localities across the interaction. This coadaptation proceeds until the evolution of extreme phenotypes by predators, through genes of large effect, allows snakes to, at least temporarily, escape the arms race. PMID:18336073

Anterior gradient 2 is induced in cutaneous wound and promotes wound healing through its adhesion domain.

PubMed

Zhu, Qi; Mangukiya, Hitesh Bhagavanbhai; Mashausi, Dhahiri Saidi; Guo, Hao; Negi, Hema; Merugu, Siva Bharath; Wu, Zhenghua; Li, Dawei

2017-09-01

Anterior gradient 2 (AGR2), a member of protein disulfide isomerase (PDI) family, is both located in cytoplasm and secreted into extracellular matrix. The orthologs of AGR2 have been linked to limb regeneration in newt and wound healing in zebrafish. In mammals, AGR2 influences multiple cell signaling pathways in tumor formation and in normal cell functions related to new tissue formation like angiogenesis. However, the function of AGR2 in mammalian wound healing remains unknown. This study aimed to investigate AGR2 expression and its function during skin wound healing and the possible application of external AGR2 in cutaneous wound to accelerate the healing process. Our results showed that AGR2 expression was induced in the migrating epidermal tongue and hyperplastic epidermis after skin excision. Topical application of recombinant AGR2 significantly accelerated wound-healing process by increasing the migration of keratinocytes (Kera.) and the recruitment of fibroblasts (Fibro.) near the wounded area. External AGR2 also promoted the migration of Kera. and Fibro. in vitro in a dose-dependent manner. The adhesion domain of AGR2 was required for the formation of focal adhesions in migrating Fibro., leading to the directional migration along AGR2 gradient. These results indicate that recombinant AGR2 accelerates skin wound healing through regulation of Kera. and Fibro. migration, thus demonstrating its potential utility as an alternative strategy of the therapeutics to accelerate the healing of acute or chronic skin wounds. © 2017 Federation of European Biochemical Societies.

Group III metabotropic glutamate receptors and exocytosed protons inhibit L-type calcium currents in cones but not in rods.

PubMed

Hosoi, Nobutake; Arai, Itaru; Tachibana, Masao

2005-04-20

Light responses of photoreceptors (rods and cones) are transmitted to the second-order neurons (bipolar cells and horizontal cells) via glutamatergic synapses located in the outer plexiform layer of the retina. Although it has been well established that postsynaptic group III metabotropic glutamate receptors (mGluRs) of ON bipolar cells contribute to generating the ON signal, presynaptic roles of group III mGluRs remain to be elucidated at this synaptic connection. We addressed this issue by applying the slice patch-clamp technique to the newt retina. OFF bipolar cells and horizontal cells generate a steady inward current in the dark and a transient inward current at light offset, both of which are mediated via postsynaptic non-NMDA receptors. A group III mGluR-specific agonist, L-2-amino-4-phosphonobutyric acid (L-AP-4), inhibited both the steady and off-transient inward currents but did not affect the glutamate-induced current in these postsynaptic neurons. L-AP-4 inhibited the presynaptic L-type calcium current (ICa) in cones by shifting the voltage dependence of activation to more positive membrane potentials. The inhibition of ICa was most prominent around the physiological range of cone membrane potentials. In contrast, L-AP-4 did not affect L-type ICa in rods. Paired recordings from photoreceptors and the synaptically connected second-order neurons confirmed that L-AP-4 inhibited both ICa and glutamate release in cones but not in rods. Furthermore, we found that exocytosed protons also inhibited ICa in cones but not in rods. Selective modulation of ICa in cones may help broaden the dynamic range of synaptic transfer by controlling the amount of transmitter release from cones.

Performance of U3Si2 Fuel in a Reactivity Insertion Accident

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheng, Lap Y.; Cuadra, Arantxa; Todosow, Michael

In this study we examined the performance of the U3Si2 fuel cladded with Zircaloy (Zr) in a reactivity insertion accident (RIA) in a PWR core. The power excursion as a result of a $1 reactivity insertion was calculated by a TRACE PWR plant model using point-kinetics, for alternative cores with UO2 and U3Si2 fuel assemblies. The point-kinetics parameters (feedback coefficients, prompt-neutron lifetime and group constants for six delayed-neutron groups) were obtained from beginning-of-cycle equilibrium full core calculations with PARCS. In the PARCS core calculations, the few-group parameters were developed utilizing the TRITON/NEWT tools in the SCALE package. In order tomore » assess the fuel response in finer detail (e.g. the maximum fuel temperature) the power shape and thermal boundary conditions from the TRACE/PARCS calculations were used to drive a BISON model of a fuel pin with U3Si2 and UO2 respectively. For a $1 reactivity transient both TRACE and BISON predicted a higher maximum fuel temperature for the UO2 fuel than the U3Si2 fuel. Furthermore, BISON is noted to calculate a narrower gap and a higher gap heat transfer coefficient than TRACE. This resulted in BISON predicting consistently lower fuel temperatures than TRACE. This study also provides a systematic comparison between TRACE and BISON using consistent transient boundary conditions. The TRACE analysis of the RIA only reflects the core-wide response in power. A refinement to the analysis would be to predict the local peaking in a three-dimensional core as a result of control rod ejection.« less

Egg-laying environment modulates offspring responses to predation risk in an amphibian.

PubMed

Tóth, Zoltán; Hettyey, Attila

2018-05-01

Predator-induced plasticity has been in the focus of evolutionary ecological research in the last decades, but the consequences of temporal variation in the presence of cues predicting offspring environment have remained controversial. This is partly due to the fact that the role of early environmental effects has scarcely been scrutinized in this context while also controlling for potential maternal effects. In this study, we investigated how past environmental conditions, that is different combinations of risky or safe adult (prenatal) and oviposition (early post-natal) environments, affected offspring's plastic responses in hatching time and locomotor activity to predation risk during development in the smooth newt (Lissotriton vulgaris). We found that females did not adjust their reproductive investment to the perceived level of risk in the adult environment, and this prenatal environment had generally negligible effect on offspring phenotype. However, when predator cues were absent during oviposition, larvae raised in the presence of predator cues delayed their hatching and exhibited a decreased activity compared to control larvae developing without predator cues, which responses are advantageous when predators pose a threat to hatched larvae. In the presence of predator cues during oviposition, the difference in hatching time persisted, but the difference in general locomotor activity disappeared between risk-exposed and control larvae. Our findings provide clear experimental evidence that fine-scale temporal variation in a predictive cue during and after egg-laying interactively affects offspring phenotype, and highlight the importance of the early post-natal environment, which may exert a substantial influence on progeny's phenotype also under natural conditions. © 2018 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2018 European Society For Evolutionary Biology.

Effects of urbanization on the distribution and abundance of amphibians and invasive species in southern California streams

USGS Publications Warehouse

Riley, S.P.D.; Busteed, G.T.; Kats, L.B.; Vandergon, T.L.; Lee, L.F.S.; Dagit, R.G.; Kerby, J.L.; Fisher, R.N.; Sauvajot, R.M.

2005-01-01

Urbanization negatively affects natural ecosystems in many ways, and aquatic systems in particular. Urbanization is also cited as one of the potential contributors to recent dramatic declines in amphibian populations. From 2000 to 2002 we determined the distribution and abundance of native amphibians and exotic predators and characterized stream habitat and invertebratecommunities in 35 streams in an urbanized landscape north of Los Angeles (U.S.A.). We measured watershed development as the percentage of area within each watershed occupied by urban land uses. Streams in more developed watersheds often had exotic crayfish (Procambarus clarkii) and fish, and had fewer native species such as California newts (Taricha torosa) and California treefrogs (Hyla cadaverina). These effects seemed particularly evident above 8% development, a result coincident with other urban stream studies that show negative impacts beginning at 10-15% urbanization. For Pacific treefrogs (H. regilla), the most widespread native amphibian, abundance was lower in the presence of exotic crayfish, although direct urbanization effects were not found. Benthic macroinvertebrate communities were also less diverse in urban streams, especially for sensitive species. Faunal community changes in urban streams may be related to changes in physical stream habitat, such as fewer pool and more run habitats and increased water depth and flow, leading to more permanent streams. Variation in stream permanence was particularly evident in 2002, a dry year when many natural streams were dry but urban streams were relatively unchanged. Urbanization has significantly altered stream habitat in this region and may enhance invasion by exotic species and negatively affect diversity and abundance of native amphibians. ??2005 Society for Conservation Biology.

THE RESPONSE OF X-IRRADIATED LIMBS OF ADULT URODELES TO NORMAL TISSUE GRAFTS. I. EFFECTS OF AUTOGRAFTS OF SIXTY-DAY FOREARM REGENERATES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stinson, B.D.

1963-06-01

Results are reported of autoplastic transplantation of parts of nonirradiated, regenerated forelimb to the contralateral x-irradiated forelimb in adult Triturus viridescens. The right forelimbs were exposed to various doses of localized irradiation (1000 to 5000 r) followed by amputation of both left and right forelimbs through the mid forearm. Left limbs regenerated normally, but irradiated right limbs failed to exhibit any significant degree of regenerative activity over a 3-month period. Both forelimbs were reamputated through the distal humerus and observed for an additional two months. Left limbs produced normal regenerates, but irradiated right limbs gave no gross evidence of regenerationmore » at any of the radiation dose levels. Normal left regenerates were reamputated immediately distal to the elbow on the 60th day after the second amputation; the severed forearm was trimmed with scissors along anterior and posterior borders and denuded of skin over its proximal half, leaving an essentially complete forearm region as a normal autograft. This was implanted into the irradiated right upper arm stump, after ablation of the distal half of its humerus, with normal proximodistal polarity in all cases. The irradiated stump was reamputated through the distal portion of the implanted normal autograft two weeks after implantation, and was observed for four months. Periodic gross observations showed that over 90% of irradiated upper arms formed regenerates at a rate which paralleled that of nonirradiated controls. However, regenerates formed on irradiated upper arms exhibited a restriction of morphogenetic capacity, only 60% attaining 3- and 4-digit stages. Most of the morphologically more complex regenerates which developed on the irradiated upper arm stumps manifested left limb asymmetry despite their formation on right irradiated stumps, suggesting a relation between the asymmetry of the normal graft and that of the resulting regenerate. All regenerates which

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

Haloacetonitriles: metabolism and toxicity.

PubMed

Lipscomb, John C; El-Demerdash, Ebtehal; Ahmed, Ahmed E

2009-01-01

bioactivation process, depending on the particular HAN and the enzyme involved. HANs can inhibit CYP2E1-mediated metabolism, an effect which may be dependent on a covalent interaction with the enzyme. In addition, HAN compounds inhibit GST-mediated conjugation, but this effect is reversible upon dialysis, indicating that the interaction does not represent covalent binding. No subchronic studies of HAN toxicity are available in the literature. However, studies show that HANs produce developmental toxicity in experimental animals. The nature of developmental toxicity is affected by the type of administration vehicle, which renders interpretation of results more difficult. Skin tumors have been found following dermal application of HANs, but oral studies for carcinogenicity are negative. Pulmonary adenomas were increased following oral administration of HANs, but the A/J strain of mice employed has a characteristically high background rate of such tumors. HANs interact with DNA to produce unscheduled DNA repair, SCE and reverse mutations in Salmonella. HANs did not induce micronuclei or cause alterations in sperm head morphology in mice, but did induce micronuclei in newts. Thus, there is concern for the potential carcinogenicity of HANs. It would be valuable to delineate any relationship between the apparent threshold for micronuclei formation in newts and the potential mechanism of toxicity involving HAN-induced oxidative stress. Dose-response studies in rodents may provide useful information on toxicity mechanisms and dose selection for longer term toxicity studies. Additional studies are warranted before drawing firm conclusions on the hazards of HAN exposure. Moreover, additional studies on HAN-DNA and HAN-protein interaction mechanisms, are needed. Such studies can better characterize the role of metabolism in toxicity of individual HANs, and delineate the role of oxidative stress, both of which enhance the capacity to predict risk. Most needed, now, are new subchronic (and

Anti-choice groups target reproductive rights in Congress.

PubMed

1995-06-16

In a May 3 memo, the GOP "Family Caucus" presented its legislative agenda for the remainder of the 104th Congress. Chaired by Representative Tom Coburn (R-OK), the anti-choice caucus promotes family and social issues, and emphasizes religious liberty and parental rights. It is seeking to eliminate funding for Title X of the Public Health Service Act, which provides grants to domestic family planning providers; repeal the Freedom of Access to Clinic Entrances Act (FACE); curtail fetal tissue research; restrict the production and sale of RU486; reduce funding for the US Agency for International Development (USAID); and hinder US representation at the UN Fourth World Conference on Women. On May 17, the Virginia-based Christian Coalition unveiled a ten-point "Contract with the American Family," which targets reproductive health care by restricting late-term abortions, reversing the Medicaid requirement that states cover abortions in cases of rape or incest, and eliminating funding for Title X and international family planning. Director Ralph Reed was joined at the group's press conference in the Capitol by Speaker of the House Newt Gingrich (R-GA) and Senator Phil Gramm (R-TX), both of whom are anti-abortion. Senate Majority Leader Robert Dole (R-KS), who is also anti-choice, met with Reed in his office later that day. Anti-choice representatives and senators met with some success in the last month in restricting US funding for family planning programs abroad, US participation in international meetings, and the performance of abortions at military facilities. Representative Charles Canady (R-FL) has introduced a bill banning modified dilation and evacuation abortions, and Representative Robert Dornan (R-CA) has introduced the "Family Planning Programs Repeal Act" (HR 1623).

Evolutionary history of Lissotriton helveticus: multilocus assessment of ancestral vs. recent colonization of the Iberian Peninsula.

PubMed

Recuero, Ernesto; García-París, Mario

2011-07-01

The Pleistocene was characterized by climatic changes that greatly altered the distribution of organisms. Population extinctions, bottlenecks, isolation, range expansions and contractions were often associated with glaciations, leaving signatures in the spatial patterns of genetic diversity across species. Lissotriton helveticus belongs to a Pan-European lineage of newts that were strongly affected by glaciations and represent an excellent model to analyse the effect of generalized climatic changes in phylogeographic patterns. We studied the genetic diversity of the species using data from two mitochondrial and three nuclear genes analyzed in a Bayesian phylogenetic framework to investigate the historical processes shaping spatial patterns of genetic diversity. Mitochondrial haplotypes cluster in four different groups present in the Iberian Peninsula and of Pleistocene origin, probably by allopatric fragmentation. Nuclear genes present no obvious geographic structure patterns, suggesting gene flow and generalized incomplete lineage sorting. Populations north of the Pyrenees are closely related to those from northeastern Iberia, suggesting recent range expansion from this region. Historical demographic analyses indicate a demographic expansion starting about 100,000years ago and more recent population declines. Compared to other Lissotriton species, L. helveticus includes only relatively young genetic lineages, suggesting a Central European pre-Pleistocene distribution followed by complete extirpation of the species during glaciations in that area. Historical demographic trends in the Iberian Peninsula are reversed with respect to the more Mediterranean species Lissotriton boscai, indicating different responses of both species to climate changes. Diversity patterns among Lissotriton species seem to be defined by four main factors: ancestral distributions, colonization capabilities, interactions with other species and effective population sizes. Differences in these

Effects of a glyphosate-based herbicide and predation threat on the behaviour of agile frog tadpoles.

PubMed

Mikó, Zsanett; Ujszegi, János; Gál, Zoltán; Hettyey, Attila

2017-06-01

The widespread application of pesticides emphasises the importance of understanding the impacts of these chemicals on natural communities. The most commonly applied broad-spectrum herbicides in the world are glyphosate-based herbicides, which have been suggested to induce significant behavioural changes in non-target organisms even at low environmental concentrations. To scrutinize the behavioural effects of herbicide-exposure we exposed agile frog (Rana dalmatina) tadpoles in an outdoor mesocosm experiment to three concentrations of a glyphosate-based herbicide (0, 2 and 6.5mg acid equivalent (a.e.) / L). To assess whether anti-predator behaviour is affected by the pesticide, we combined all levels of herbicide-exposure with three predator treatments (no predator, caged Aeshna cyanea dragonfly larvae or Lissotriton vulgaris newt adults) in a full factorial design. We observed hiding, activity, proximity to the predator cage and vertical position of tadpoles. We found that at the higher herbicide concentration tadpoles decreased their activity and more tadpoles were hiding, and at least at the lower concentration their vertical position was closer to the water surface than in tadpoles of the control treatment. Tadpoles also decreased their activity in the presence of dragonfly larvae, but did not hide more in response to either predator, nor did tadpoles avoid predators spatially. Further, exposure to the herbicide did not significantly influence behavioural responses to predation threat. Our study documents a definite influence of glyphosate-based herbicides on the behaviour of agile frog tadpoles and indicates that some of these changes are similar to those induced by dangerous predators. This may suggest that the underlying physiological mechanisms or the adaptive value of behavioural changes may similar. Copyright © 2017 Elsevier Inc. All rights reserved.

Development of Gravity-Sensing Organs in Altered Gravity Conditions: Opposite Conclusions From an Amphibian and a Molluscan Preparation

NASA Technical Reports Server (NTRS)

Wiederhold, Michael L.; Pedrozo, Hugo A.; Harrison, Jeffrey L.; Hejl, Robert; Gao, Wenyuan

1997-01-01

Several components of the systems animals use to orient to gravity might develop differently in micrograms. If the growth of the "test masses" on which gravity acts (otoliths, in vertebrates, statoliths or statoconia in most invertebrates) is controlled on the basis of their weight, larger otoliths (or their analogs) would be expected to develop in micrograms. The vestibular systems in animals reared in altered gravity have been studied in several species, with varied results being reported. Early Russian reports of Xenopus larvae reared in space indicated no qualitative differences in the vestibular organs, compared to ground-reared controls. A similar lack of differences in Xenopus were reported. The ultricular otolith was 30% larger in space-reared Xenopus. No differences in saccular otolith volume between centrifuged and control adult rats were found. A delay in otoconial development in chick embryos reared at 2 grams on a centrifuge was reported but in a later report, no differences in otolith weight between 2 grams and control chicks were found. Increased optokinetic responses in flight-reared Xenopus tadpoles, suggesting that the animals reared in the absence of gravity made greater relative use of their visual system, rather than the vestibular system, in orienting to a moving stimulus was reported. To test early Japanese newt, CYnops pyrrhogaster, were maintained in orbit for 15 days on the IML-2 mission in 1994. All specimens reached orbit before any otoconia were formed and all major components of the inner ear were formed by the end of the flight. In ground-based studies of he Aplysia statocyst, the volume of the statolith in embryos and the number statoconia in post-metamorphic animals were compared between 1-gram controls and specimens reared at 2 to 5.7 grams.

Is the detection of aquatic environmental DNA influenced by substrate type?

PubMed

Buxton, Andrew S; Groombridge, Jim J; Griffiths, Richard A

2017-01-01

The use of environmental DNA (eDNA) to assess the presence-absence of rare, cryptic or invasive species is hindered by a poor understanding of the factors that can remove DNA from the system. In aquatic systems, eDNA can be transported out either horizontally in water flows or vertically by incorporation into the sediment. Equally, eDNA may be broken down by various biotic and abiotic processes if the target organism leaves the system. We use occupancy modelling and a replicated mesocosm experiment to examine how detection probability of eDNA changes once the target species is no longer present. We hypothesise that detection probability falls faster with a sediment which has a large number of DNA binding sites such as topsoil or clay, over lower DNA binding capacity substrates such as sand. Water removed from ponds containing the target species (the great crested newt) initially showed high detection probabilities, but these fell to between 40% and 60% over the first 10 days and to between 10% and 22% by day 15: eDNA remained detectable at very low levels until day 22. Very little difference in detection was observed between the control group (no substrate) and the sand substrate. A small reduction in detection probability was observed between the control and clay substrates, but this was not significant. However, a highly significant reduction in detection probability was observed with a topsoil substrate. This result is likely to have stemmed from increased levels of PCR inhibition, suggesting that incorporation of DNA into the sentiment is of only limited importance. Surveys of aquatic species using eDNA clearly need to take account of substrate type as well as other environmental factors when collecting samples, analysing data and interpreting the results.

Cell Therapy Trials in Congenital Heart Disease.

PubMed

Oh, Hidemasa

2017-04-14

Dramatic evolution in medical and catheter interventions and complex surgeries to treat children with congenital heart disease (CHD) has led to a growing number of patients with a multitude of long-term complications associated with morbidity and mortality. Heart failure in patients with hypoplastic left heart syndrome predicated by functional single ventricle lesions is associated with an increase in CHD prevalence and remains a significant challenge. Pathophysiological mechanisms contributing to the progression of CHD, including single ventricle lesions and dilated cardiomyopathy, and adult heart disease may inevitably differ. Although therapeutic options for advanced cardiac failure are restricted to heart transplantation or mechanical circulatory support, there is a strong impetus to develop novel therapeutic strategies. As lower vertebrates, such as the newt and zebrafish, have a remarkable ability to replace lost cardiac tissue, this intrinsic self-repair machinery at the early postnatal stage in mice was confirmed by partial ventricular resection. Although the underlying mechanistic insights might differ among the species, mammalian heart regeneration occurs even in humans, with the highest degree occurring in early childhood and gradually declining with age in adulthood, suggesting the advantage of stem cell therapy to ameliorate ventricular dysfunction in patients with CHD. Although effective clinical translation by a variety of stem cells in adult heart disease remains inconclusive with respect to the improvement of cardiac function, case reports and clinical trials based on stem cell therapies in patients with CHD may be invaluable for the next stage of therapeutic development. Dissecting the differential mechanisms underlying progressive ventricular dysfunction in children and adults may lead us to identify a novel regenerative therapy. Future regenerative technologies to treat patients with CHD are exciting prospects for heart regeneration in general

Otoliths developed in microgravity

NASA Technical Reports Server (NTRS)

Wiederhold, M. L.; Harrison, J. L.; Parker, K.; Nomura, H.

2000-01-01

Little is known about mechanisms that regulate the development of the otoliths in the gravity-sensing organs. Several reported experiments suggest that the growth of the otoliths is adjusted to produce a test mass of the appropriate weight. If this is the case, larger than normal otoliths would be expected in animals reared in reduced gravity and a reduced mass, relative to 1-g controls, would be expected in animals reared at elevated g. In gastropod mollusks, the gravity-sensing organ is the statocyst, a spherical organ whose wall is made largely of sensory receptor cells with motile cilia facing the lumen. Dense statoconia in the cyst lumen interact with cilia of receptor cells at the bottom of the cyst and action potentials in their axons carry information on direction and magnitude of gravity and linear acceleration. In the marine mollusk, Aplysia californica, larvae reared at 2 to 5-g, the volume of statoconia was reduced in a graded manner, compared to 1-g control animals. In the statocyst of the fresh-water pond snail, Biomphalaria glabrata, reared in space in the Closed Equilibrated Biological Aquatic System (CEBAS), the number and total volume of statoconia was increased approximately 50%, relative to ground-reared controls. Lychakov found the utricular otolith to be 30% larger in space-reared Xenopus, whereas we found the saccular otolith to be significantly larger in newt larvae reared in space. In cichlid fish reared on a centrifuge, the saccular otolith was smaller than in 1-g controls. Here, we demonstrate that the otoliths of late-stage embryos of the swordtail fish, Xiphophorus helleri, reared in space on STS-89 and STS-90 (Neurolab) were significantly larger than those of ground-controls reared in functionally identical hardware.

Draft Genome Sequences of Nine Strains of Brochothrix thermosphacta, Carnobacterium divergens, Lactobacillus algidus, Lactobacillus fuchuensis, Lactococcus piscium, Leuconostoc gelidum subsp. gasicomitatum, Pseudomonas lundensis, and Weissella viridescens, a Collection of Psychrotrophic Species Involved in Meat and Seafood Spoilage.

PubMed

Poirier, Simon; Coeuret, Gwendoline; Champomier-Vergès, Marie-Christine; Chaillou, Stéphane

2018-06-14

In this study, we present the draft genome sequences of nine strains from various psychrotrophic species identified in meat products and being recognized as important emerging food spoilers. Many of these species have only one or few strains being sequenced, and this work will contribute to the improvement of the overall genomic knowledge about them. Copyright © 2018 Poirier et al.

Integrative inference of population history in the Ibero-Maghrebian endemic Pleurodeles waltl (Salamandridae).

PubMed

Gutiérrez-Rodríguez, Jorge; Barbosa, A Márcia; Martínez-Solano, Íñigo

2017-07-01

Inference of population histories from the molecular signatures of past demographic processes is challenging, but recent methodological advances in species distribution models and their integration in time-calibrated phylogeographic studies allow detailed reconstruction of complex biogeographic scenarios. We apply an integrative approach to infer the evolutionary history of the Iberian ribbed newt (Pleurodeles waltl), an Ibero-Maghrebian endemic with populations north and south of the Strait of Gibraltar. We analyzed an extensive multilocus dataset (mitochondrial and nuclear DNA sequences and ten polymorphic microsatellite loci) and found a deep east-west phylogeographic break in Iberian populations dating back to the Plio-Pleistocene. This break is inferred to result from vicariance associated with the formation of the Guadalquivir river basin. In contrast with previous studies, North African populations showed exclusive mtDNA haplotypes, and formed a monophyletic clade within the Eastern Iberian lineage in the mtDNA genealogy. On the other hand, microsatellites failed to recover Moroccan populations as a differentiated genetic cluster. This is interpreted to result from post-divergence gene flow based on the results of IMA2 and Migrate analyses. Thus, Moroccan populations would have originated after overseas dispersal from the Iberian Peninsula in the Pleistocene, with subsequent gene flow in more recent times, implying at least two trans-marine dispersal events. We modeled the distribution of the species and of each lineage, and projected these models back in time to infer climatically favourable areas during the mid-Holocene, the last glacial maximum (LGM) and the last interglacial (LIG), to reconstruct more recent population dynamics. We found minor differences in climatic favourability across lineages, suggesting intraspecific niche conservatism. Genetic diversity was significantly correlated with the intersection of environmental favourability in the LIG and

Microgravity can activate signals urging cells to S-phase entry during tissue and organ regeneration in Urodele amphibians exposed to real and simulated microgravity

NASA Astrophysics Data System (ADS)

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

Regenerative response following local injury or tissue removal in urodele amphibians is dependent on cell cycle entry of cells sources for regeneration in the remaining tissue. In a number of our experiments performed aboard biosatellites in orbital flights and fast rotated clinostat we found enhanced proliferative activity and, as a result, regeneration quicker than that in controls. In each investigated case an activity of cell proliferation evaluated by 3H-thymidine radioautography and BrdU assay at the early stages of lens, retina, forelimb and tail regeneration in newts was about 1,2-1,7 fold higher both under conditions of real and physiological weightlessness as compared with controls. Faster S-phase entry under conditions of micro- g was demonstrated by cycling multipotent cells as well as by differentiated postmitotic cells both participated in regeneration. Important, that cycling cells outside areas of regeneration were also found as displayed faster cellular growth. In our papers (1,2,3,4) we offered some hypothesis that could explain mechanisms of low g stimulating effect upon cell growth in regeneration in Urodela. In particular, changes in expression of some growth factors and their receptors, as well as the synthesis of specific range of generalized stress proteins (AGSPs) were proposed. However, in fact, molecular mechanisms of micro- g effect upon cell proliferation are mediated by changes on organismic level induced by micro- g environment. Some of them which are able to trigger off signaling changes on the cellular level that, in turn, evoke cells to grow faster would be represented in our report. 1. Mitashov V. et al. Adv. Space Res. 1996. 17 (6/7): 241-255 2. Anton H.-J. et al. Adv. Space Res. 1996. 17 (6/7): 55-65 3. Grigoryan E. et al. Adv. Space Res. 1998. 22 (2): 293-301 4. Grigoryan E. et al. Adv. Space Res. 2002. 30 (4): 757-764

Diversity of pulsed-field gel electrophoresis pulsotypes, serovars, and antibiotic resistance among Salmonella isolates from wild amphibians and reptiles in the California Central Coast.

PubMed

Gorski, Lisa; Jay-Russell, Michele T; Liang, Anita S; Walker, Samarpita; Bengson, Yingjia; Govoni, Jessica; Mandrell, Robert E

2013-06-01

A survey of cold-blooded vertebrates and associated surface waters in a produce-growing region on the Central California Coast was done between May and September 2011 to determine the diversity of Salmonella. Samples from 460 amphibians and reptiles and 119 water samples were collected and cultured for Salmonella. Animals sampled were frogs (n=331), lizards (n=59), newts (n=5), salamanders (n=6), snakes (n=39), and toads (n=20). Salmonella was isolated from 37 individual animals, including frogs, lizards, snakes, and toads. Snakes were the most likely to contain Salmonella, with 59% testing positive followed by 15.3% of lizards, 5% of toads, and 1.2% of frogs. Fifteen water samples (12.6%) were positive. Twenty-two different serovars were identified, and the majority of isolates were S. enterica subsp. IIIb, with subsp. I, II, and IIIa also found. The serovar isolated most frequently was S. enterica subsp. IIIb 16:z₁₀:e,n,x,z₁₅, from snakes and frogs in five different locations. S. enterica subsp. I serovar Typhimurium and the monophasic I 6,8:d:- were isolated from water, and subspecies I Duisburg and its variants were found in animals and water. Some samples contained more than one type of Salmonella. Analysis of pulsed-field gel electrophoresis pulsotypes indicated that some strains persisted in animals and water collected from the same location. Sixty-six isolates displayed antibiotic resistance, with 27 isolates resistant to more than one antibiotic, including a subspecies IIIb isolate from snake having resistance to five different antibiotics. Twenty-three isolates were resistant to more than one class of antibiotic, and six isolates were resistant to three classes. While these subspecies of IIIa and IIIb cause fewer instances of human illness, they may serve as reservoirs of antibiotic resistance, determinants in the environment, and be sources of contamination of leafy greens associated with product recalls.

One hundred and one new species of Trigonopterus weevils from New Guinea

PubMed Central

Riedel, Alexander; Sagata, Katayo; Surbakti, Suriani; Rene Tänzler;  Michael Balke

2013-01-01

., Trigonopterus montivagus sp. n., Trigonopterus moreaorum sp. n., Trigonopterus myops sp. n., Trigonopterus nangiorum sp. n., Trigonopterus nothofagorum sp. n., Trigonopterus ovatus sp. n., Trigonopterus oviformis sp. n., Trigonopterus parumsquamosus sp. n., Trigonopterus parvulus sp. n., Trigonopterus phoenix sp. n., Trigonopterus plicicollis sp. n., Trigonopterus politoides sp. n., Trigonopterus pseudogranum sp. n., Trigonopterus pseudonasutus sp. n., Trigonopterus ptolycoides sp. n., Trigonopterus punctulatus sp. n., Trigonopterus ragaorum sp. n., Trigonopterus rhinoceros sp. n., Trigonopterus rhomboidalis sp. n., Trigonopterus rubiginosus sp. n., Trigonopterus rubripennis sp. n., Trigonopterus rufibasis sp. n., Trigonopterus scabrosus sp. n., Trigonopterus scissops sp. n., Trigonopterus scharfi sp. n., Trigonopterus signicollis sp. n., Trigonopterus simulans sp. n., Trigonopterus soiorum sp. n., T sordidus sp. n., Trigonopterus squamirostris sp. n., Trigonopterus striatus sp. n., Trigonopterus strigatus sp. n., Trigonopterus strombosceroides sp. n., Trigonopterus subglabratus sp. n., Trigonopterus sulcatus sp. n., Trigonopterus taenzleri sp. n., Trigonopterus talpa sp. n., Trigonopterus taurekaorum sp. n., Trigonopterus tialeorum sp. n., Trigonopterus tibialis sp. n., Trigonopterus tridentatus sp. n., Trigonopterus uniformis sp. n., Trigonopterus variabilis sp. n., Trigonopterus velaris sp. n., Trigonopterus verrucosus sp. n., Trigonopterus violaceus sp. n., Trigonopterus viridescens sp. n., Trigonopterus wamenaensis sp. n., Trigonopterus wariorum sp. n., Trigonopterus zygops sp. n.. All new species are authored by the taxonomist-in-charge, Alexander Riedel. PMID:23794832

One hundred and one new species of Trigonopterus weevils from New Guinea.

PubMed

Riedel, Alexander; Sagata, Katayo; Surbakti, Suriani; Rene Tänzler; Michael Balke

2013-01-01

montivagus sp. n., Trigonopterus moreaorum sp. n., Trigonopterus myops sp. n., Trigonopterus nangiorum sp. n., Trigonopterus nothofagorum sp. n., Trigonopterus ovatus sp. n., Trigonopterus oviformis sp. n., Trigonopterus parumsquamosus sp. n., Trigonopterus parvulus sp. n., Trigonopterus phoenix sp. n., Trigonopterus plicicollis sp. n., Trigonopterus politoides sp. n., Trigonopterus pseudogranum sp. n., Trigonopterus pseudonasutus sp. n., Trigonopterus ptolycoides sp. n., Trigonopterus punctulatus sp. n., Trigonopterus ragaorum sp. n., Trigonopterus rhinoceros sp. n., Trigonopterus rhomboidalis sp. n., Trigonopterus rubiginosus sp. n., Trigonopterus rubripennis sp. n., Trigonopterus rufibasis sp. n., Trigonopterus scabrosus sp. n., Trigonopterus scissops sp. n., Trigonopterus scharfi sp. n., Trigonopterus signicollis sp. n., Trigonopterus simulans sp. n., Trigonopterus soiorum sp. n., T sordidus sp. n., Trigonopterus squamirostris sp. n., Trigonopterus striatus sp. n., Trigonopterus strigatus sp. n., Trigonopterus strombosceroides sp. n., Trigonopterus subglabratus sp. n., Trigonopterus sulcatus sp. n., Trigonopterus taenzleri sp. n., Trigonopterus talpa sp. n., Trigonopterus taurekaorum sp. n., Trigonopterus tialeorum sp. n., Trigonopterus tibialis sp. n., Trigonopterus tridentatus sp. n., Trigonopterus uniformis sp. n., Trigonopterus variabilis sp. n., Trigonopterus velaris sp. n., Trigonopterus verrucosus sp. n., Trigonopterus violaceus sp. n., Trigonopterus viridescens sp. n., Trigonopterus wamenaensis sp. n., Trigonopterus wariorum sp. n., Trigonopterus zygops sp. n.. All new species are authored by the taxonomist-in-charge, Alexander Riedel.

Do hormone-modulating chemicals impact on reproduction and development of wild amphibians?

PubMed

Orton, Frances; Tyler, Charles R

2015-11-01

Globally, amphibians are undergoing a precipitous decline. At the last estimate in 2004, 32% of the approximately 6000 species were threatened with extinction and 43% were experiencing significant declines. These declines have been linked with a wide range of environmental pressures from habitat loss to climate change, disease and pollution. This review evaluates the evidence that endocrine-disrupting contaminants (EDCs) - pollutants that affect hormone systems - are impacting on wild amphibians and contributing to population declines. The review is limited to anurans (frogs and toads) as data for effects of EDCs on wild urodeles (salamanders, newts) or caecilians (limbless amphibians) are extremely limited. Evidence from laboratory studies has shown that a wide range of chemicals have the ability to alter hormone systems and affect reproductive development and function in anurans, but for the most part only at concentrations exceeding those normally found in natural environments. Exceptions can be found for exposures to the herbicide atrazine and polychlorinated biphenyls in leopard frogs (Rana pipiens) and perchlorate in African clawed frogs (Xenopus laevis). These contaminants induce feminising effects on the male gonads (including 'intersex' - oocytes within testes) at concentrations measured in some aquatic environments. The most extensive data for effects of an EDC in wild amphibian populations are for feminising effects of atrazine on male gonad development in regions across the USA. Even where strong evidence has been provided for feminising effects of EDCs, however, the possible impact of these effects on fertility and breeding outcome has not been established, making inference for effects on populations difficult. Laboratory studies have shown that various chemicals, including perchlorate, polychlorinated biphenyls and bromodiphenylethers, also act as endocrine disrupters through interfering with thyroid-dependent processes that are fundamental for

Spatial scales of carbon flow in a river food web

USGS Publications Warehouse

Finlay, J.C.; Khandwala, S.; Power, M.E.

2002-01-01

Spatial extents of food webs that support stream and river consumers are largely unknown, but such information is essential for basic understanding and management of lotic ecosystems. We used predictable variation in algal ??13C with water velocity, and measurements of consumer ??13C and ??15N to examine carbon flow and trophic structure in food webs of the South Fork Eel River in Northern California. Analyses of ??13C showed that the most abundant macroinvertebrate groups (collector-gatherers and scrapers) relied on algae from local sources within their riffle or shallow pool habitats. In contrast, filter-feeding invertebrates in riffles relied in part on algal production derived from upstream shallow pools. Riffle invertebrate predators also relied in part on consumers of pool-derived algal carbon. One abundant taxon drifting from shallow pools and riffles (baetid mayflies) relied on algal production derived from the habitats from which they dispersed. The trophic linkage from pool algae to riffle invertebrate predators was thus mediated through either predation on pool herbivores dispersing into riffles, or on filter feeders. Algal production in shallow pool habitats dominated the resource base of vertebrate predators in all habitats at the end of the summer. We could not distinguish between the trophic roles of riffle algae and terrestrial detritus, but both carbon sources appeared to play minor roles for vertebrate consumers. In shallow pools, small vertebrates, including three-spined stickleback (Gasterosteus aculeatus), roach (Hesperoleucas symmetricus), and rough-skinned newts (Taricha granulosa), relied on invertebrate prey derived from local pool habitats. During the most productive summer period, growth of all size classes of steelhead and resident rainbow trout (Oncorhynchus mykiss) in all habitats (shallow pools, riffles, and deep unproductive pools) was largely derived from algal production in shallow pools. Preliminary data suggest that the strong

Diseases of frogs and toads

USGS Publications Warehouse

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

2005-01-01

(Rana pipiens). Other interesting diseases could have been presented, such as a wart-like virus infection of Japanese newts and a group of protistan parasites, referred to as Dermocystidium and Dermomycoides, in European frogs and toads. The reader is referred to Green (2001) for a review of these diseases. Amphibians have a rich diversity of helminthic parasites (Poynton and Whitaker, 2001). In general, most cestodes, trematodes and nematodes of amphibians are innocuous and not linked to specific clinical signs ('symptoms') or mortalities. An important major exception to this generalization is the trematode, Ribeiroia, which has been linked to numerous and bizarre malformations of frogs, toads and salamanders (Johnson et al., 1999, Johnson et al., 2001, Schotthoefer et al., 2003). Two genera of trematodal parasites are discussed in this chapter: Ribeiroia because they cause malformations and Clinostomum because they are large and produce visible lumps in the skin. For a review of amphibian helminths, the reader is referred to the text by Flynn (1973).

Evolutionary history of Ichthyosaura alpestris (Caudata, Salamandridae) inferred from the combined analysis of nuclear and mitochondrial markers.

PubMed

Recuero, Ernesto; Buckley, David; García-París, Mario; Arntzen, Jan W; Cogălniceanu, Dan; Martínez-Solano, Iñigo

2014-12-01

Widespread species with morphologically and ecologically differentiated populations are key to understand speciation because they allow investigating the different stages of the continuous process of population divergence. The alpine newt, Ichthyosaura alpestris, with a range that covers a large part of Central Europe as well as isolated regions in all three European Mediterranean peninsulas, and with strong ecological and life-history differences among populations, is an excellent system for such studies. We sampled individuals across most of the range of the species, and analyzed mitochondrial (1442 bp) and nuclear (two nuclear genes -1554 bp- and 35 allozyme loci) markers to produce a time-calibrated phylogeny and reconstruct the historical biogeography of the species. Phylogenetic analyses of mtDNA data produced a fully resolved topology, with an endemic, Balkan clade (Vlasina) which is sister to a clade comprising an eastern and a western group. Within the former, one clade (subspecies I. a. veluchiensis) is sister to a clade containing subspecies I. a. montenegrina and I. a. serdara as well as samples from southern Romania, Bosnia-Herzegovina, Serbia and Bulgaria (subspecies I. a. reiseri and part of I. a. alpestris). Within the western group, populations from the Italian peninsula (subspecies I. a. apuana and I. a. inexpectata) are sister to a clade containing samples from the Iberian Peninsula (subspecies I. a. cyreni) and the remainder of the samples from subspecies I. a. alpestris (populations from Hungary, Austria, Poland, France, Germany and the larger part of Romania). Results of (∗)BEAST analyses on a combined mtDNA and nDNA dataset consistently recovered with high statistical support four lineages with unresolved inter-relationships: (1) subspecies I. a. veluchiensis; (2) subspecies I. a. apuana+I. a. inexpectata; (3) subspecies I. a. cyreni+part of subspecies I. a. alpestris (the westernmost populations, plus most Romanian populations); and (4

Advanced Test Reactor Core Modeling Update Project Annual Report for Fiscal Year 2011

DOE Office of Scientific and Technical Information (OSTI.GOV)

David W. Nigg; Devin A. Steuhm

2011-09-01

Legacy computational reactor physics software tools and protocols currently used for support of Advanced Test Reactor (ATR) core fuel management and safety assurance and, to some extent, experiment management are obsolete, inconsistent with the state of modern nuclear engineering practice, and are becoming increasingly difficult to properly verify and validate (V&V). Furthermore, the legacy staff knowledge required for application of these tools and protocols from the 1960s and 1970s is rapidly being lost due to staff turnover and retirements. In 2009 the Idaho National Laboratory (INL) initiated a focused effort to address this situation through the introduction of modern high-fidelitymore » computational software and protocols, with appropriate V&V, within the next 3-4 years via the ATR Core Modeling and Simulation and V&V Update (or 'Core Modeling Update') Project. This aggressive computational and experimental campaign will have a broad strategic impact on the operation of the ATR, both in terms of improved computational efficiency and accuracy for support of ongoing DOE programs as well as in terms of national and international recognition of the ATR National Scientific User Facility (NSUF). The ATR Core Modeling Update Project, targeted for full implementation in phase with the anticipated ATR Core Internals Changeout (CIC) in the 2014 time frame, began during the last quarter of Fiscal Year 2009, and has just completed its first full year. Key accomplishments so far have encompassed both computational as well as experimental work. A new suite of stochastic and deterministic transport theory based reactor physics codes and their supporting nuclear data libraries (SCALE, KENO-6, HELIOS, NEWT, and ATTILA) have been installed at the INL under various permanent sitewide license agreements and corresponding baseline models of the ATR and ATRC are now operational, demonstrating the basic feasibility of these code packages for their intended purpose. Furthermore

Advanced Test Reactor Core Modeling Update Project Annual Report for Fiscal Year 2012

DOE Office of Scientific and Technical Information (OSTI.GOV)

David W. Nigg, Principal Investigator; Kevin A. Steuhm, Project Manager

Legacy computational reactor physics software tools and protocols currently used for support of Advanced Test Reactor (ATR) core fuel management and safety assurance, and to some extent, experiment management, are inconsistent with the state of modern nuclear engineering practice, and are difficult, if not impossible, to properly verify and validate (V&V) according to modern standards. Furthermore, the legacy staff knowledge required for application of these tools and protocols from the 1960s and 1970s is rapidly being lost due to staff turnover and retirements. In late 2009, the Idaho National Laboratory (INL) initiated a focused effort, the ATR Core Modeling Updatemore » Project, to address this situation through the introduction of modern high-fidelity computational software and protocols. This aggressive computational and experimental campaign will have a broad strategic impact on the operation of the ATR, both in terms of improved computational efficiency and accuracy for support of ongoing DOE programs as well as in terms of national and international recognition of the ATR National Scientific User Facility (NSUF). The ATR Core Modeling Update Project, targeted for full implementation in phase with the next anticipated ATR Core Internals Changeout (CIC) in the 2014-2015 time frame, began during the last quarter of Fiscal Year 2009, and has just completed its third full year. Key accomplishments so far have encompassed both computational as well as experimental work. A new suite of stochastic and deterministic transport theory based reactor physics codes and their supporting nuclear data libraries (HELIOS, KENO6/SCALE, NEWT/SCALE, ATTILA, and an extended implementation of MCNP5) has been installed at the INL under various licensing arrangements. Corresponding models of the ATR and ATRC are now operational with all five codes, demonstrating the basic feasibility of the new code packages for their intended purpose. Of particular importance, a set of as

SCALE Code System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jessee, Matthew Anderson

MAVRIC,• CE depletion with TRITON (T5-DEPL/T6-DEPL),• CE sensitivity/uncertainty analysis with TSUNAMI-3D,• Simplified and efficient LWR lattice physics with Polaris,• Large scale detailed spent fuel characterization with ORIGAMI and ORIGAMI Automator,• Advanced fission source convergence acceleration capabilities with Sourcerer,• Nuclear data library generation with AMPX, and• Integrated user interface with Fulcrum.Enhanced capabilities include:• Accurate and efficient CE Monte Carlo methods for eigenvalue and fixed source calculations,• Improved MG resonance self-shielding methodologies and data,• Resonance self-shielding with modernized and efficient XSProc integrated into most sequences,• Accelerated calculations with TRITON/NEWT (generally 4x faster than SCALE 6.1),• Spent fuel characterization with 1470 new reactor-specific libraries for ORIGEN,• Modernization of ORIGEN (Chebyshev Rational Approximation Method [CRAM] solver, API for high-performance depletion, new keyword input format)• Extension of the maximum mixture number to values well beyond the previous limit of 2147 to ~2 billion,• Nuclear data formats enabling the use of more than 999 energy groups,• Updated standard composition library to provide more accurate use of natural abundances, andvi• Numerous other enhancements for improved usability and stability.« less

Outstanding scientist of the year 2006: Rogel Patawaran, BS.

PubMed

Rubin, Robert A; Hazirjian, Courtney L

2006-01-01

Rogel Patawaran is cofounder of iQSecure Solutions, Inc., a secure web mail company, which began in 2002 and is currently based in Santa Monica, California. Its unique service enables hospitals, clinics, and doctors' offices the opportunity to have secure web-based video and telephone conferencing by simply switching online services offered by this innovative company. In addition, he is cofounder of AuthoTecq, based in Long Beach, California, and inventor of the AuthoTecq system in 1999. The AuthoTecq system is an online credit card processing company. Rogel Patawaran sought to remedy one of the problems facing users of internet transactions. Because internet merchants act as their own gateway for financial transactions, they have been storing credit card numbers in their own databases, thereby failing to address the necessary security provisions involved in the storage of such sensitive information. AuthoTecq removes this responsibility from the merchant by processing financial transactions on behalf of the merchants. Its system dramatically reduces credit card theft, and thereby decreases the amount of credit card fraud. In his landmark book Saving Lives & Saving Money, Newt Gingrich, former Speaker of House of Representatives, describes a new approach to the challenge of creating a better system of personal health and health care for the 21st century, a system that saves lives and saves money. He indicates that you could be visiting a clinic with electronic medical records, electronic laboratory reports, and electronic drug prescriptions. This entirely electronic clinic saves money and lives because it is far more accurate than a paper system. Such clinics exist at the Kaiser Permanente Hospitals, the Mayo Clinic in Jacksonville, Florida, the Cleveland Clinic, many Harvard hospitals, and all Veteran Administration hospitals in the US. He indicates that healthcare is the only industry in America that can give you a disease and then charge you to cure it. He