| incomplete antibodies and immunoglobulin characterization in adult urodeles, pleurodeles waltlii michah. and triturus alpestris laur. | humoral immunoglobulin synthesis has been studied in two adult urodeles, pleurodeles waltlii michah. and triturus alpestris laur. following srbc immunization. the specific antibody response is detected after a long period of immunization and is due exclusively to 'incomplete' antibodies which are unable to induce agglutination. the antibody titre is essentially dependent on the number of stimulations rather than on the dose or nature of the antigen (papainized or normal erythrocytes). antibodies ... | 1975 | 49296 |
| microfilaments in the external surface layer of the early amphibian embryo. | a comparison was made by transmission electron microscopy of the microfilaments in the surface layers of the early embryos of triturus alpestris and xenopus laevis at stages of development up to neurulation. actin-like filaments which bound heavy meromyosin (hmm) were found in cell extracts of all stages, but were comparatively rare in the newly fertilized egg. ten nm microfilaments were present throughout development in xenopus, and from the mid-neurula stage in triturus. both kinds of microfil ... | 1975 | 50397 |
| changes of nucleosome frequency in nucleolar and non-nucleolar chromatin as a function of transcription: an electron microscopic study. | the morphology of nucleolar and non-nucleolar (lampbrush chromosome loops) chromatin was studied in the electron microscope during states of reduced transcriptional activity in amphibian oocytes (xenopus laevis, triturus alpestris, t. cristatus). reduced transcriptional activity was observed in maturing stages of oocyte development and after treatment with an inhibitor, actinomycin d. strands of nucleolar chromatin appear smooth and thin, and contain only few, if any, nucleosomal particles in th ... | 1978 | 566162 |
| a proteoglycan with affinity for the vegetalizing factor: characterization by density gradient centrifugation. | a crude proteoglycan fraction isolated from chicken embryos has an affinity for the vegetalizing factor, which induces mesodermal and endodermal tissues in gastrula ectoderm of triturus alpestris. binding of the factor to the crude proteoglycan results in inactivation of the vegetalizing factor. the crude proteoglycan was centrifuged in cscl and cscl-urea density gradients. most of the inactivating material was recovered from the gradients in the high density proteoglycan fraction. part of the i ... | 1978 | 732367 |
| [activity and isoenzymes of lactate dehydrogenase in tissues of amphibians (xenopus laevis, ambystoma mexicanum, triturus alpestris and vulgaris) and the response in the fat body of xenopus males to gonadotropin injection (author's transl)]. | lactate-dehydrogenase activity was determined by the optical test method using pyruvate as substrate and the isoenzymes were separated by vertical starch gel electrophoresis. species-specific and organ-specific characteristics of the total activity and the isoenzyme patterns of the four amphibian species are compared with those of rat and mouse. application of gonadotropin increases the amount of soluble protein and the lactate-dehydrogenase activity in the fat body of xenopus and the isoenzyme ... | 1975 | 1176091 |
| topographical relationships between catecholamine- and neuropeptide-containing fibers in the median eminence of the newt, triturus alpestris. an ultrastructural immunocytochemical study. | dopaminergic and peptidergic nerve fibers were simultaneously demonstrated with a double-labeling technique at the ultrastructural level. the first antibody, raised against tyrosine hydroxylase, was applied during the preembedding phase and visualized with the peroxidase method. the second antibody, raised against one of the peptides met-enkephalin, somatostatin or gonadotropin-releasing hormone (gnrh), was applied to the ultrathin sections and visualized with gold-labeled goat anti-rabbit igg. ... | 1990 | 1969331 |
| isolation of a vegetalizing inducing factor after extraction with acid ethanol. concentration-dependent inducing capacity of the factor. | a vegetalizing factor has been isolated from chicken embryos by an improved method. the factor is extracted with acid/ethanol and finally purified by four consecutive steps of reversed phase hplc. the molecular mass is about 25 kda. the factor dissociates after reduction with dithiothreitol into two subunits of about 13 kda. the factor was tested on triturus alpestris by the implantation method, and on isolated ectoderm of xenopus laevis in solution. the factor induces as the crude fractions all ... | 1990 | 2090330 |
| activation of masked neural determinants in amphibian eggs and embryos and their release from the inducing tissue. | the neural-archencephalic (forehead) inducing activity of the microsomes and the high speed supernatant from xenopus laevis ovaries and eggs was tested on gastrula ectoderm of triturus alpestris. both fractions have a very small inducing activity which increases considerably after autolysis or treatment with dissociating agents. a comparison with the inducing activity of the high speed supernatant from gastrulae suggests that neural inducing factors are synthesized in the ovary, stored in a mask ... | 1989 | 2766041 |
| [rosette formation in splenic cells of the urodele amphibia triturus alpestris laur. and pleurodeles waltlii michah]. | | 1972 | 4631124 |
| a reinvestigation of some of the tissue movements involved in the formation of the neural tube and the eye/lens system of triturus alpestris and xenopus laevis. | | 1966 | 5962694 |
| partially purified factor from embryonic chick brain can provoke neuralization of rana temporaria and triturus alpestris but not xenopus laevis early gastrula ectoderm. | a high neuralizing activity has been determined in forebrain of 7.5-day old chick embryos using rana temporaria early gastrula ectoderm as reacting tissue (mikhailov and gorgolyuk, soviet scientific reviews, section of physiology and general biology, vol. 1: 267-306, 1987). the corresponding protease-sensitive agent was extracted, partially purified by chromatography on deae-toyopearl and heparin-ultragel columns, and its neuralizing activity was tested in vitro on ectoderm isolated from early g ... | 1995 | 7669544 |
| neural crest cell migration and pigment pattern formation in urodele amphibians. | this review deals with research on the development and differentiation of the neural crest (nc) in amphibians carried out during the past twenty years. first, earlier studies on the migration and differentiation of nc cells in vitro are summarized. these studies include the modes of nc cell migration and their differentiation into chondroblasts, perichondral cells, neurons, schwann cells and pigment cells (melanophores and xanthophores). then a summary is given on the development of cranial sens ... | 1996 | 8735933 |
| planar signalling is not sufficient to generate a specific anterior/posterior neural pattern in pseudoexogastrula explants from xenopus and triturus. | early observations on the morphology of total exogastrulae from urodeles (axolotl) had provided evidence for essential vertical signalling mechanisms in the process of neural induction. conversely, more recent studies with anurans (xenopus laevis) making use of molecular markers for neural-specific gene expression appear to support the idea of planar signalling as providing sufficient information for neural differentiation along the anterior-posterior axis. in an attempt to resolve this apparent ... | 2000 | 10585562 |
| tetrodotoxin and its analogue 6-epitetrodotoxin in newts (triturus spp.; urodela, salamandridae) from southern germany. | tetrodotoxin (ttx) and its analogue 6-epitetrodotoxin (6-epittx) were quantitatively assayed in 59 newts representing four triturus species (triturus alpestris, triturus cristatus, triturus helveticus, triturus vulgaris) from southern germany by a post-column fluorescent-hplc system. both toxins were detected in only 15 specimens of the four species. the toxins levels varied considerably among individuals (ttx: 0.11-9.0microg/g; 6-epittx: 0.05-17.0microg/g). 6-epittx was found to be the major co ... | 2007 | 17507070 |
| 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. | 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 an ... | 2010 | 19703784 |
| topologic and connectional analysis of the dorsal thalamus of triturus alpestris (amphibia, urodela, salamandridae). | a morphological and connectional analysis was performed on the dorsal thalamus of the alpine newt, triturus alpestris. we have used a graphic reconstruction technique for the evaluation of the connectional (hrp) data. on the basis of these reconstructions, we propose a subdivision of the salamandrid dorsal thalamus into subhabenular, anteroventral, and posterodorsal zones. each of these zones is defined by its telencephalic projections ("ascending thalamofugal systems"). the posterodorsal zone p ... | 2012 | 3346376 |
| autoradiographic evaluation of vitamin a effects on triturus alpestris blastema cells. | autoradiographic studies on triturus alpestris regenerates treated with vitamin a palmitate for 4, 7, 11 and 14 days after amputation, reveal a considerable diminution in the percentage of cells duplicating dna, as judged by measurements of labelling indices. based on previous observations, that vitamin a promotes dna-synthesis, mitosis and growth of regenerates, we conclude that the lower labelling indices calculated are due to an acceleration of s-phase processes, resulting in a concomitant re ... | 2009 | 3401931 |
| [quantitative histochemistry of glandular secretion of the oviduct in the sexually mature triturus alpestris laur]. | | 2016 | 4917893 |
| geographic distribution of the chytrid pathogen batrachochytrium dendrobatidis among mountain amphibians along the italian peninsula. | the amphibian chytrid pathogen batrachochytrium dendrobatidis (bd) is considered a major cause of amphibian population declines, particularly in montane areas. here, we investigated the presence and distribution of bd among populations of 3 mid- to high-altitude species spanning the entire italian peninsula (486 individuals from 39 sites overall): the stream frog rana italica, the fire salamander salamandra salamandra gigliolii, and the alpine newt mesotriton alpestris apuanus. we found bd in al ... | 2013 | 24270024 |
| batrachochytrium dendrobatidis in germany: distribution, prevalences, and prediction of high risk areas. | in germany, the pathogenic fungus batrachochytrium dendrobatidis (bd) was detected in 11 indigenous frog species, 4 newt species, and 1 salamander species in 64 out of the 181 locations (35%) investigated. among the 3450 samples collected between 2003 and 2011, 284 (8.2%) were positive for bd infections. the highest prevalences were observed in alytes obstetricans (17.8% of individuals, 20% of populations), followed by ichthyosaura alpestris (14.7%, 22.2%), bombina variegata (13.9%, 38.5%), and ... | 2013 | 24270023 |
| demonstration of sensory-motor innervation of postmetamorphic forelimb regenerates of triturus alpestris (urodela) on cryotome serial sections using horseradish peroxidase. | a method has been developed to obtain horseradish peroxidase-treated serial sections containing spinal cord as well as bilateral ventral and dorsal roots, dorsal root ganglia and spinal nerves. young postmetamorphic newts (triturus alpestris) served as experimental animals. after cryotome cross sectioning the forelimb region of the trunk, slices 80 microns in thickness were mounted serially with up to 15 sections per slide. this facilitated subsequent staining manipulations and made partial loss ... | 1990 | 2378008 |
| development of retinofugal neuropil areas in the brain of the alpine newt, triturus alpestris. ii. topographic organization and formation of projections. | the development of retinal projections and the formation of their retinotopic organization were studied by means of anterograde transport of horseradish peroxidase in the newt, triturus alpestris. all tracts found in the adult on the contralateral brain side are established during embryonic stages. at this stage a few uncrossed fibers are also detectable. retinal fibers project first to the contralateral optic tectum. these are followed by contralateral projections to the thalamic recipient area ... | 1988 | 2833132 |
| two thalamo-telencephalic pathways in a urodele, triturus alpestris. | ascending thalamo-telencephalic projection systems have been investigated in an urodele, triturus alpestris, using the horseradish peroxidase technique. two separate dorsal thalamic projections onto the telencephalon have been identified; one arises from the posterior dorsal thalamus and terminates in the ipsilateral striatum, the other originates from anterior dorsal thalamic cells and reaches the medial pallium and a part of the dorsal pallium bilaterally. both systems, which are spatially wel ... | 1986 | 3014400 |
| development of retinofugal neuropil areas in the brain of the alpine newt, triturus alpestris. | the development of the retinofugal projection areas of the brain has been studied in larvae of triturus alpestris by means of anterograde transported horseradish peroxidase. the optic tract establishes contacts with the optic tectum prior to the onset of robust terminal formation in the diencephalon. the tectum becomes covered by the retinofugal projection in a rostro-caudal direction. the basal optic neuropil develops synchronously with the oculomotor neurons. their dendrites extend into this n ... | 1981 | 7283179 |
| introduced goldfish affect amphibians through inhibition of sexual behaviour in risky habitats: an experimental approach. | 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 kn ... | 2013 | 24312432 |
| amphibian skin microbiota exhibits temporal variation in community structure but stability of predicted bd-inhibitory function. | host-associated microbiomes are increasingly recognized to contribute to host disease resistance; the temporal dynamics of their community structure and function, however, are poorly understood. we investigated the cutaneous bacterial communities of three newt species, ichthyosaura alpestris, lissotriton vulgaris and triturus cristatus, at approximately weekly intervals for 3 months using 16s ribosomal rna amplicon sequencing. we hypothesized cutaneous microbiota would vary across time, and that ... | 2017 | 28387770 |
| the role of vertical and planar signals during the early steps of neural induction. | the classical einsteck-test (spemann and mangold, roux arch. dev. biol. 100: 599-638, 1924) and data from total exogastrulae (holtfreter, 1933) suggest that vertical signals are transmitted between the chordamesoderm (organizer) and reacting ectoderm in the early phase of neural induction. in contrast to these results with axoloti (urodeles), several authors observed the expression of neural specific genes in xenopus exogastrulae, isolated dorsal blastopore lip with adjacent ectoderm (open-face ... | 1995 | 7577445 |
| the development of the larval pigment patterns in triturus alpestris and ambystoma mexicanum. | 1. melanophores and xanthophores are pigment cell derivatives of the nc. in amphibian embryos they migrate from their original position on the neural tube dorsally (into the dorsal fin) as well as laterally (between somites and epidermis) and arrange themselves into typical pigment patterns of the skin. we investigated pigment pattern formation in two species of tailed amphibians, triturus alpestris (alpine newt) and ambystoma mexicanum (mexican axolotl). in larvae of t. alpestris alternating lo ... | 1990 | 2368640 |
| identification of pigment cells during early amphibian development (triturus alpestris, ambystoma mexicanum). | the purpose of the present investigation was to provide and apply a methodological manual with which the distribution, patterning and relationship of melanophores and xanthophores can be analyzed during early amphibian development. for demonstration of the methods, which include ultrastructural, histochemical and biochemical approaches, triturus alpestris and ambystoma mexicanum (axolotl) embryos are used. these two species differ conspicuously in their larval pigment patterns, showing alternati ... | 1988 | 3141059 |
| embryonic induction and cation concentrations in amphibian embryos. | explanted ectoderm from early gastrulae of triturus alpestris was treated with the na-k ionophore gramicidin (10(-9) to 10(-5) m) and the ca-ionophore a 23187 (10(-7) to 10(-5) m). the ectoderm developed almost exclusively to atypical epidermis as in the control explants. when the ectoderm was treated with ouabain (10(-4) m), intracellular na+ increased about 4.4-fold and k+ was reduced by half. mesenchyme cells in small number differentiated in about 40% of the ouabain-treated explants. the tim ... | 1985 | 2416476 |
| [studies of the activity and the isoenzyme patterns of ldh during the development ofxenopus laevis, triturus alpestris andvulgaris andambystoma mexicanum]. | the present paper deals with studies of the activity and the isoenzyme patterns of ldh during the development ofxenopus laevis, triturus alpestris andvulgaris andambystoma mexicanum. activity measurements have been performed with the optical test method using pyruvate as substrate and the isoenzymes have been separated by vertical starch gel electrophoresis. a) substrate optima for enzyme extracts from embryonic stages 1-38 are identical in the three speciestriturus alpestris, ambystoma mexicanu ... | 1975 | 28304825 |
| [evolution of xenografts of embryonic gonads and juvenile ovaries from ambystoma mexicanum shaw, transplanted into triturus alpestris laur]. | gonad primordium of ambystoma mexicanum when grafted at tail-bud stage on triturus alpestris is indefinately tolerated. testis or ovaries derived from those grafted embryonic gonads follow their differentiaion and reach sexual maturity. axolotl juvenile ovaries transplanted in triturus alpestris are also tolerated; the ovocytes achieve the entire vitellogenesis but are not able to be laid. | 1975 | 809199 |
| [relative antigenicity of tegument embryonic heterografts in urodele amphibians: ambystoma mexicanum shaw, triturus helveticus raz., triturus alpestris laur. and pleurodeles waltlii michah]. | | 1969 | 4979133 |
| [embryonic skin grafts between ambystoma mexicanum shaw, pleurodeles waltlii michah and triturus alpestris laur; phenomena of tolerance and rejection]. | | 1967 | 4989164 |
| [embryonal skin grafts between ambystoma mexicanum shaw, pleurodeles waltlii michah. and triturus alpestris laur.; phenomena of tolerance and rejection]. | | 1967 | 4963534 |
| skin swabbing as a new efficient dna sampling technique in amphibians, and 14 new microsatellite markers in the alpine newt (ichthyosaura alpestris). | this study introduces a novel dna sampling method in amphibians using skin swabs. we assessed the relevancy of skin swabs relevancy for genetic studies by amplifying a set of 17 microsatellite markers in the alpine newt ichthyosaura alpestris, including 14 new polymorphic loci, and a set of 11 microsatellite markers in hyla arborea, from dna collected with buccal swabs (the standard swab method), dorsal skin swabs and ventral skin swabs. we tested for quality and quantity of collected dna with e ... | 2012 | 22248363 |
| robustness of newt heads in condition of co-existence: a case of the carpathian newt and the alpine newt. | co-existence between potentially competing newt species can lead to niche differentiation (e.g., in terms of diet shifts). this may cause adaptive responses involving changes in head shape. here, we tested the hypothesis: the head shape of lissotriton montandoni is different in conditions of co-occurrence with ichthyosaura alpestris than in conditions in which other newt species are absent. we analysed images depicting head shape of specimens of i. alpestris and l. montandoni from a museum colle ... | 2017 | 29104358 |
| divergence of species-specific protein sex pheromone blends in two related, nonhybridizing newts (salamandridae). | in animals that use chemical communication during courtship and reproduction, speciation is often associated with divergence of their sex pheromones. in multicomponent pheromone systems, divergence can be obtained either by adding or deleting components, or by altering the relative contribution of individual components to the mixture. protein pheromone systems can additionally evolve by amino acid sequence divergence to produce pheromones with a species-specific effect. the sodefrin precursor-li ... | 2017 | 29087032 |
| costly neighbours: heterospecific competitive interactions increase metabolic rates in dominant species. | the energy costs of self-maintenance (standard metabolic rate, smr) vary substantially among individuals within a population. despite the importance of smr for understanding life history strategies, ecological sources of smr variation remain only partially understood. stress-mediated increases in smr are common in subordinate individuals within a population, while the direction and magnitude of the smr shift induced by interspecific competitive interactions is largely unknown. using laboratory e ... | 2017 | 28701786 |
| morphological integration and alternative life history strategies: a case study in a facultatively paedomorphic newt. | tetrapod limbs are serially homologous structures that represent a particularly interesting model for studies on morphological integration, i.e. the tendency of developmental systems to produce correlated variation. in newts, limbs develop at an early larval stage and grow continuously, including after the habitat transition from water to land following metamorphosis. however, aquatic and terrestrial environments impose different constraints and locomotor modes that could affect patterns of morp ... | 2017 | 28664626 |
| quaternary history, population genetic structure and diversity of the cold-adapted alpine newt ichthyosaura alpestris in peninsular italy. | mediterranean peninsulas are major biodiversity hotspots, and cold-adapted species are an important component of this biodiversity. however, cold-adapted species contributed surprisingly little to our knowledge of the intimate links between quaternary environmental changes, species' responses to these changes, and current patterns of intraspecific biodiversity. here, we investigated the genetic structure and evolutionary history of a cold-adapted amphibian, the alpine newt ichthyosaura alpestris ... | 2017 | 28592856 |
| skin microbiota differs drastically between co-occurring frogs and newts. | diverse microbial assemblages inhabit amphibian skin and are known to differ among species; however, few studies have analysed these differences in systems that minimize confounding factors, such as season, location or host ecology. we used high-throughput amplicon sequencing to compare cutaneous microbiotas among two ranid frogs (rana dalmatina, r. temporaria) and four salamandrid newts (ichthyosaura alpestris, lissotriton helveticus, l. vulgaris, triturus cristatus) breeding simultaneously in ... | 2017 | 28484639 |
| economic thermoregulatory response explains mismatch between thermal physiology and behaviour in newts. | 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 ... | 2017 | 28082616 |
| influence of temperature on female, embryonic and hatchling traits in syntopic newts, ichthyosaura alpestris and lissotriton vulgaris. | 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, a ... | 2017 | 28010812 |
| variation in winter metabolic reduction between sympatric amphibians. | distribution and abundance of temperate ectotherms is determined, in part, by the depletion of their limited caloric reserves during wintering. the magnitude of winter energy drain depends on the species-specific capacity to seasonally modify the minimal maintenance costs. we examined seasonal variation of minimum oxygen consumption between two newt species, ichthyosaura alpestris and lissotriton vulgaris. oxygen consumption was measured in both species during their active season (daily temperat ... | 2016 | 27418441 |
| expanding distribution of lethal amphibian fungus batrachochytrium salamandrivorans in europe. | emerging fungal diseases can drive amphibian species to local extinction. during 2010-2016, we examined 1,921 urodeles in 3 european countries. presence of the chytrid fungus batrachochytrium salamandrivorans at new locations and in urodeles of different species expands the known geographic and host range of the fungus and underpins its imminent threat to biodiversity. | 2016 | 27070102 |
| do female newts modify thermoregulatory behavior to manipulate egg size? | reproductive females manipulate offspring phenotypes by modifying conditions during embryogenesis. in ectotherms, the environmental control over embryogenesis is often realized by changes in maternal thermoregulation during gravidity. to determine if reproduction influences thermoregulatory behavior in species where females lay eggs shortly after fertilization (strict oviparity), we compared preferred body temperatures (tp) between reproductive (egg-laying) and non-reproductive female newts, ich ... | 2016 | 27033041 |
| musculoskeletal architecture of the prey capture apparatus in salamandrid newts with multiphasic lifestyle: does anatomy change during the seasonal habitat switches? | some newt species change seasonally between an aquatic and a terrestrial life as adults, and are therefore repeatedly faced with different physical circumstances that affect a wide range of functions of the organism. for example, it has been observed that seasonally habitat-changing newts display notable changes in skin texture and tail fin anatomy, allowing one to distinguish an aquatic and a terrestrial morphotype. one of the main functional challenges is the switch between efficient aquatic a ... | 2016 | 26892189 |
| flexibility is everything: prey capture throughout the seasonal habitat switches in the smooth newt lissotriton vulgaris. | transitions between aquatic and terrestrial habitats are significant steps in vertebrate evolution. due to the different biophysical demands on the whole organism in water and air, such transitions require major changes of many physiological functions, including feeding. accordingly, the capability to modulate the pre-programmed chain of prey-capture movements might be essential to maintain performance in a new environment. newts are of special interest in this regard as they show a multiphasic ... | 2017 | 26097413 |
| can newts cope with the heat? disparate thermoregulatory strategies of two sympatric species in water. | 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 vu ... | 2015 | 25993482 |
| females have larger ratio of second-to-fourth digits than males in four species of salamandridae, caudata. | digit ratio (2d:4d) denotes the relative length of the second and fourth digits. it is considered to be a suitable biomarker of the in utero balance of fetal sex hormones, which affect early development of individuaĺs behavioral and morphological characteristics. in recent decades, digit ratio attracted a great attention in biology and psychology. however, for unmasking the biological basis of the phenomenon, extensive studies on non-human animals are necessary. despite it was hypothesized that ... | 2015 | 25704339 |
| evolutionary history of ichthyosaura alpestris (caudata, salamandridae) inferred from the combined analysis of nuclear and mitochondrial markers. | 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 su ... | 2014 | 25263421 |
| masters of change: seasonal plasticity in the prey-capture behavior of the alpine newt ichthyosaura alpestris (salamandridae). | transitions between aquatic and terrestrial environments are significant steps in vertebrate evolution. these transitions require major changes in many biological functions, including food uptake and transport. the alpine newt, ichthyosaura alpestris, is known to show a 'multiphasic lifestyle' where the adult shifts from a terrestrial to an aquatic lifestyle and then back to a terrestrial lifestyle every year as a result of its breeding activity. these transitions correspond to dramatic changes ... | 2013 | 24259258 |
| optimizing the trade-off between spatial and genetic sampling efforts in patchy populations: towards a better assessment of functional connectivity using an individual-based sampling scheme. | genetic data are increasingly used in landscape ecology for the indirect assessment of functional connectivity, that is, the permeability of landscape to movements of organisms. among available tools, matrix correlation analyses (e.g. mantel tests or mixed models) are commonly used to test for the relationship between pairwise genetic distances and movement costs incurred by dispersing individuals. when organisms are spatially clustered, a population-based sampling scheme (pss) is usually perfor ... | 2013 | 24118539 |
| love is blind: indiscriminate female mating responses to male courtship pheromones in newts (salamandridae). | 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. beha ... | 2013 | 23457580 |
| effects of water contamination on site selection by amphibians: experiences from an arena approach with european frogs and newts. | pesticide residues in breeding ponds can cause avoidance by at least some amphibian species. so far, outdoor experiments have been performed only with artificial pools in areas where the focus species usually occur and new colonization has been observed. results of this kind of study are potentially influenced by natural disturbances and therefore are of limited comparability. we used an easily manufactured and standardizable arena approach, in which animals in reproductive condition for some ho ... | 2013 | 23377318 |
| permeability of the landscape matrix between amphibian breeding sites. | for organisms that reproduce in discrete habitat patches, land cover between patches (known as the matrix) is important for dispersal among breeding sites. models of patchy populations often incorporate information on the permeability of the matrix to dispersal, sometimes based on expert opinion. i estimated the relative resistance to gene flow of land cover types and barriers using f(st) calculated from microsatellite markers in two amphibians, within an 800-km(2) area in northern switzerland. ... | 2012 | 23301180 |
| influence of respirometry methods on intraspecific variation in standard metabolic rates in newts. | standard metabolic rate (smr) is both a highly informative and variable trait. variation in smr stems not only from diverse intrinsic and extrinsic factors, but also from the use of diverse methods for metabolic measurements. we measured co(2) production (vco(2)) and oxygen consumption rates (vo(2)) using two flow-through respirometry modes, continuous and intermittent (stop-flow), to evaluate their potential contribution to smr variation in alpine newts, ichthyosaura alpestris. both respirometr ... | 2012 | 22643334 |
| interactive influence of biotic and abiotic cues on the plasticity of preferred body temperatures in a predator-prey system. | the ability to modify phenotypes in response to heterogeneity of the thermal environment represents an important component of an ectotherm's non-genetic adaptive capacity. despite considerable attention being dedicated to the study of thermally-induced developmental plasticity, whether or not interspecific interactions shape the plastic response in both a predator and its prey remains unknown. we tested several predictions about the joint influence of predator/prey scents and thermal conditions ... | 2012 | 22358997 |
| non-interactive multiple predator effects on tadpole survival. | interactions among and within three species of predators were estimated in terms of their effects on prey survival using short-term predation experiments. the prey were tadpoles (rana temporaria), and the predators were dragonfly larvae (anax imperator), newts (triturus alpestris), and backswimmers (notonecta glauca). mortality rate per predator imposed by triturus and notonecta did not decline with predator density, whereas the predation rate of anax was strongly reduced when the number of pred ... | 2012 | 22159918 |
| morphing of the phylogeographic lineages of the balkan alpine newts (ichthyosaura alpestris, caudata, salamandridae): in situ morphological diversification. | numerous alpine newt (ichthyosaura alpestris) populations from the balkans, representing all the previously established phylogeographic lineages, were studied for variations in various morphological characteristics (body size and shape, skull qualitative traits and number of trunk vertebrae). here, we present a decoupling of morphological and mtdna phylogeographic substructuring in the alpine newt on the balkan peninsula. in sharp contrast to other european newts (triturus spp., lissotriton spp. ... | 2011 | 22123091 |
| mothers matter too: benefits of temperature oviposition preferences in newts. | the maternal manipulation hypothesis states that ectothermic females modify thermal conditions during embryonic development to benefit their offspring (anticipatory maternal effect). however, the recent theory suggests that the ultimate currency of an adaptive maternal effect is female fitness that can be maximized also by decreasing mean fitness of individual offspring. we evaluated benefits of temperature oviposition preferences in alpine newts (ichthyosaura [formerly triturus] alpestris) by c ... | 2011 | 21887330 |
| seasonal acclimation of preferred body temperatures improves the opportunity for thermoregulation in newts. | seasonal acclimation and thermoregulation represent major components of complex thermal strategies by which ectotherms cope with the heterogeneity of their thermal environment. some ectotherms possess the acclimatory capacity to shift seasonally their thermoregulatory behavior, but the frequent use of constant acclimation temperatures during experiments and the lack of information about thermal heterogeneity in the field obscures the ecological relevance of this plastic response. we examined the ... | 2011 | 21460527 |
| aspects on the relief of living surfaces using atomic force microscopy allow "art" to imitate nature. | the visualization of the surface of biological samples using an atomic force microscope reveals features of the external relief and can resolve very fine and detailed features of the surface. we examined specimens from the skin of the amphibians salamandra salamandra linnaeus, 1758, lyciasalamandra luschani basoglui baran & atatür, 1980 and mesotriton alpestris laurenti, 1768, and from the surface of pollen grains of the plant species cyclamen graecum link, 1835 and cistus salviifolius linnaeus, ... | 2010 | 21392340 |
| the use of visual and automatized behavioral markers to assess methodologies: a study case on pit-tagging in the alpine newt. | in various research fields, biomarkers are now widely used as tools for assessing individual integrity. the recent advances in quantification methods for behavioral patterns, such as computerized video-tracking procedures, make them valuable biomarkers. however, the corollary of these novelties is that they remain relatively unknown and unused. in this study, we show that such tools can assess the validity of research methods, such as individual recognition. to demonstrate this, we employed, as ... | 2011 | 21359908 |
| testing the hypothesis of morphological integration on a skull of a vertebrate with a biphasic life cycle: a case study of the alpine newt. | in this article, we explore the possible influences of the developmental and functional relationships between skeletal elements on the pattern of morphological integration in the adult skull of the alpine newt. like many tailed amphibians, the alpine newt has a biphasic life cycle, which implies the possibility that two distinct sets of constraints on development and function of the cranial skeleton may act at different times. we study how trait covariation, resulting from processes early in dev ... | 2010 | 23939712 |
| sperm morphology of salamandrids (amphibia, urodela): implications for phylogeny and fertilization biology. | mature spermatozoa belonging to four salamander species, salamandrina terdigitata, triturus alpestris, triturus carnifex and triturus vulgaris, have been investigated by electron microscopy. the sperm ultrastructure of these species was compared with that of previously examined urodeles (36 species and 20 genera) and with that of anurans and caecilians. many phylogenetic considerations may be inferred as a consequence of comparative spermatology. urodela appears to be a monophyletic order charac ... | 1997 | 18627832 |
| patterns of morphometric variation in the alpine newt (mesotriton alpestris) at the southern limit of its distribution: environmental correlates. | we applied multivariate analyses to an array of body measures of alpine newt specimens derived from 11 local populations in greece to describe, analyse and detect patterns and putative causes of within-population and among-population morphometric variation. the observed morphometric variation was partitioned into several independently varying aspects of the external phenotype, frequently following variation patterns in different environmental factors. the size and features of the aquatic habitat ... | 2008 | 21396060 |
| contrasting patterns of variation in mhc loci in the alpine newt. | major histocompatibility complex (mhc) genes are essential in pathogen recognition and triggering an adaptive immune response. although they are the most polymorphic genes in vertebrates, very little information on mhc variation and patterns of evolution are available for amphibians, a group known to be declining rapidly worldwide. as infectious diseases are invoked in the declines, information on mhc variation should contribute to devising appropriate conservation strategies. in this study, we ... | 2008 | 18422929 |
| sperm transport after insemination in the alpine newt (triturus alpestris, caudata, salamandridae). | the goal of this study was to test if sperm transport to the spermathecae in the alpine newt (triturus alpestris) requires active co-operation of the female. artificial insemination of anaesthetised female newts was conducted using spermatophores collected from courting males and with sperm duct contents collected from sacrificed males. sperm was present in the spermathecae of 9 out of 10 females inseminated with the spermatophores but in only 1 out of 8 females inseminated with sperm duct conte ... | 2007 | 18274253 |
| is the prefrontal bone in alpine newt (triturus alpestris laurenti, 1768) of dual origin? | according to current knowledge, only the prefrontal bone (os prefrontale) of the circumorbital series is preserved in the family salamandridae. however, the exact origin and number of ossification centres creating this bone is unknown. detailed examination of the prefrontal bone during ontogeny of juvenile and adult specimens of the alpine newt (triturus alpestris) indicates its dual origin (prefrontal and lacrimal). we found that the prefrontal bone originates from four ossification centres, i. ... | 2007 | 17645458 |
| structural diversification of the gustatory organs during metamorphosis in the alpine newt triturus alpestris. | gustatory organs of the taste bud type occur in the epithelial lining of the oropharyngeal cavity of alpine newt larvae. they resemble the taste buds of bony fish, both in appearance (as revealed by scanning electron microscopy) and in detailed internal structure (seen on transmission electron micropscopy). during metamorphosis, at stage 55 of development, the secondary tongue (i.e. the soft tongue) is well formed and the anlages of taste discs are clearly apparent. somewhat later, taste discs a ... | 2007 | 17578451 |
| landscape-level thresholds, and newt conservation. | ecological thresholds are defined as points or zones at which a rapid change occurs from one ecological condition to another. the existence of thresholds in species-habitat relationships has important implications for management, but the lack of concordance across studies and the wide range of methods used make generalizations difficult. we used two different statistical methods to test for the existence of thresholds for both individual species and the whole community, using three newt species ... | 2007 | 17479853 |
| phylogeny and biogeography of the alpine newt mesotriton alpestris (salamandridae, caudata), inferred from mtdna sequences. | in this paper, we performed phylogenetic analyses of mesotriton alpestris populations from the entire range of species distribution, using fragments of two mtdna genes, cytochrome b (309bp) and 16s rrna ( approximately 500bp). sequence diversity patterns and phylogenetic analyses reveal the existence of a relict lineage (clade a) of late miocene origin, comprising populations from south-eastern serbia. this lineage is proposed to be ancestor to a western and an eastern lineage, which diverged du ... | 2007 | 17467298 |
| structure elucidation of neuac, neugc and kdn-containing o-glycans released from triturus alpestris oviductal mucins. characterization of the poly lacdinac sequence: hso3(4)(galnacbeta1-4glcnacbeta1-3)1-3galnacbeta1-4(glcnacbeta1-3)0-1glcnacbeta1-6galnac-ol. | eggs from amphibia are surrounded by several layers of jelly that are needed for proper fertilization. jelly coat is composed of highly glycosylated mucin-type glycoproteins containing up to 60% of carbohydrates, which display a remarkable species-specificity. this material obtained from triturus alpestris was submitted to reductive beta-elimination and the released oligosaccharide-alditols were further fractionated by hplc. structural characterization was performed through a combination of two ... | 2006 | 16897180 |
| genetic structure in northeastern populations of the alpine newt (triturus alpestris): evidence for post-pleistocene differentiation. | genetic variation in 13 populations of the alpine newt, triturus alpestris, was assessed at the northeastern margin of its range (southern poland). variation at six microsatellite loci was scored in 354 newts, and two mitochondrial dna fragments (c. 2000 bp) were sequenced in a subset of 27 individuals. significant differences in allele frequencies and the presence of private alleles determined genetic units corresponding to three separate mountain ranges, i.e. the carpathian, sudetes and holy c ... | 2006 | 16842414 |
| display lateralisation in the courtship behaviour of the alpine newt (triturus alpestris). | among urodelan amphibians, european newts of the genus triturus have evolved a complex sequence of displays to the effect of stimulating the female to actively pick up the spermatophore deposited by the male. courtship is varied, with plenty of potential for asymmetric uses of tails and of asymmetric turns. the analysis of the temporal structure of the behavioural sequences showed that both males and females significantly utilise the same side during a single courtship sequence. moreover, if an ... | 2002 | 15513203 |
| trophic specialisations in alternative heterochronic morphs. | polymorphisms are suspected of reducing competition among conspecifics in heterogeneous environments by allowing differential resource use. however the adaptive significance of alternative morphs has been poorly documented. the aim of this study is to determine food partitioning of two heterochronic morphs of the alpine newt, triturus alpestris, in mountain lakes. the morphs differ in the functional morphology of their feeding apparatus. only paedomorphs are able to expel water during prey sucti ... | 2004 | 14991145 |
| relatedness, body size and paternity in the alpine newt, triturus alpestris. | sexual selection has traditionally been investigated assuming that male quality is as skewed as patterns of male reproductive success can sometimes be. recently, female choice has been investigated under the model of genetic compatibility, which assumes that each individual female has her own 'best' mate and there is no overall optimal choice for all females. we investigated female mate choice in the newt species triturus alpestris, a member of a genus where female choice has been investigated o ... | 2003 | 12769462 |
| neoteny and progenesis as two heterochronic processes involved in paedomorphosis in triturus alpestris (amphibia: caudata). | current theories on the evolution of paedomorphosis suppose that several ontogenetic pathways have appeared according to different selective pressures. the aim of this study was to find out whether two distinct processes can lead to paedomorphosis in the alpine newt, triturus alpestris. in this respect, we compared age structures of paedomorphic and metamorphic individuals in two newt populations where the two forms lived syntopically. whereas paedomorphosis resulted in a slower rate of somatic ... | 2000 | 10983835 |
| paedogenesis in european newts (triturus: salamandridae): cranial morphology during ontogeny. | a cross-sectional analysis using different ontogenetic stages (larvae, juveniles, paedotypic, and metamorphic adults) of the smooth newt, triturus vulgaris, and the alpine newt, t.alpestris, revealed a broad spectrum of perennibranchiation influences on cranial ontogeny in european newts, more pronounced than previously thought. these influences included marked variation in ossification levels, pronounced morphometric variability of many cranial elements, and considerable skull shape changes in ... | 2000 | 10658197 |
| effects of ultraviolet radiation on early larval stages of the alpine newt, triturus alpestris, under natural and laboratory conditions. | although alpine newts (triturus alpestris) are found at altitudes up to 2500 m, their larvae proved to be extremely sensitive to uv radiation when exposed in clear tapwater to natural sunlight or to comparable artificial uv-b radiation in the laboratory. the experiments revealed severe skin damages (lysis of epithelial cells) and mortality after a few days of exposure. in their natural habitats above the timberline, however, the larvae are protected by the high concentration of dissolved organic ... | 1997 | 28307243 |
| [mirror symmetrical and "left dominant" organization in the gastrula stage molted parabiotic larva of mountain salamander]. | gastrulae of triturus alpestris were laterally fused (body axes in equal directions). the parabiotic larvae mostly showed an undivided body with tail, but exhibited two heads. defects of organogenesis were frequently observed in the gut, and, to some fewer extent, in the heart. the gut mostly develops undivided, the heart in singular or (with transitions) as two organs. the number of organ-inversions and partial inversions was high (table 1). in addition a transindividual organ-symmetry (mirror- ... | 1995 | 7625609 |
| [the symmetrical relation of intestines, the habenular nuclei and the intestinal venous system in dorsal-doral and ventral-ventral grown parabiontic larva of mountain salamanders (triturus alpestris)]. | embryos of the newt triturus alpestris were fused in their dorsal regions (dd-parabionts) of their ventral regions (vv-parabionts), while the longitudinal axes were in equal direction. in these parabionts situs and symmetry of the gut, the heart, the habenular nuclei and the vitelline vein were studied. the fusion of the embryos of the dd-parabionts was performed in three developmental stages (after harrison): phase of neurulation (14-18, n-parabionts), late phase of neurulation (19-22, e-parabi ... | 1995 | 7872498 |
| basic fibroblast growth factor can induce exclusively neural tissue in triturus ectoderm explants. | ectoderm was isolated from early gastrulae of triturus alpestris and induced with recombinant basic fibroblast growth factor (b-fgf). neural tissue differentiated in about 38% of the explants which were induced by 2,5 μg/ml fgf. these explants do not contain other tissues, or contain only small amounts of mesenchyme and melanophores which are probably derived from induced neural crest. it is therefore unlikely that these neural tissues are secondarily induced. the other explants contain predomin ... | 1994 | 28305823 |
| distribution of catecholaminergic and serotoninergic systems in forebrain and midbrain of the newt, triturus alpestris (urodela). | mapping of monoaminergic systems in the brain of the newt triturus alpestris was achieved with antisera against (1) thyrosine hydroxylase (th), (2) formaldehyde-conjugated dopamine (da), and (3) formaldehyde-conjugated serotonin (5-ht). in the telencephalon, the striatum was densely innervated by a large number of 5-ht-, da- and th-immunoreactive (ir) fibers; ir fibers were more scattered in the amygdala, the medial and lateral forebrain bundles, and the anterior commissure. in the anterior and ... | 1992 | 1352186 |
| sem observations on polar body elimination and changes of the oocyte surface during egg maturation in the newt triturus alpestris (amphibia, urodela). | we have studied the surface of the animal half of ovulated newt eggs recovered from different portions of the oviduct. the germinative area, about 40 μm diameter, is localized in the region of the whitish polar spot, about 450 μm diameter. the structural changes in the germinative area are connected with the formation and extrusion of the first and second polar bodies. of the two types of oviductal eggs observed, those covered with microvilli (type 1) were found only in the ostial portions of th ... | 1991 | 28306020 |
| effect of vitamin a on wound epidermis during forelimb regeneration in adult newts. | the effects of vitamin a on blastemal epidermis were studied during the early postamputational period of forelimb regeneration in triturus alpestris. vitamin a was administered through oral intubation at a dose of 250 iu per gram of body weight per day. the results were evaluated by morphometry, histology, and autoradiography. after 7, 11 and 14 days of treatment, several alterations were observed in the wound epidermis: a) reversal of keratinization; fewer keratinized cells were counted in sect ... | 1990 | 1705139 |
| telencephalic structures are involved in learning and memory in the newt triturus alpestris. | | 1990 | 2377236 |
| characterization of heterochromatic regions in two triturus alpestris subspecies (urodela: salamandridae). | the fluorescence analysis carried out in triturus alpestris alpestris and triturus alpestris cyreni subspecies has revealed differences related to the content and distribution of at-rich, gc-rich and non-fluorescent heterochromatic bands. these results provide new evidence on the chromosome differentiation undergone in their phylogenetic splitting. | 1989 | 2767986 |
| fidelity to the breeding site in the alpine newt triturus alpestris. | in a context of several closed breeding sites (archipelago model), the great majority of alpine newts are sedentary, visiting the same site during two successive years. a homing experiment offered the animals a choice between two breeding sites, one from which they came and the other which was inhabited by another population. this experiment demonstrates the fidelity of a great majority of newts for their site of origin. fidelity was stronger when sites were distant (150 m) than when nearer (25 ... | 1989 | 24895901 |
| thermal behaviour of a4 lactate dehydrogenase purified from the heterothermic and sympatric vertebrate species brook lamprey (lampetra planeri), tench (tenca tenca), smooth (triturus vulgaris) and alpine newt (triturus alpestris). | 1. the a4 lactate dehydrogenase isozyme was purified to homogeneity from the tissues of brook lamprey (lampetra planeri), tench (tenca tenca), smooth newt (triturus vulgaris) and alpine newt (t. alpestris). 2. these four species share their geographical distribution in the same freshwater habitats, often live together in the same station and two of them are congeneric. steady-state kinetic investigations have shown that: 3. km (apparent) for pyruvate vs. temperature and (apparent) product ki (py ... | 1989 | 2620488 |
| putative neurotransmitters in the retinae of three urodele species (triturus alpestris, salamandra salamandra, pleurodeles waltli). | the immunocytochemical localization of several substances with putative neurotransmitter or modulator properties was investigated in the retinae of three urodele species. gamma-aminobutyric acid-like immunoreactive labelling appeared in different types of amacrine and horizontal cells. in addition, labelled fibres in the optic nerve were detected. it was not possible to determine whether these fibres were ganglion-cell axons or part of an efferent projection. endogenous serotonin was found in se ... | 1988 | 2898293 |
| intercalary regeneration in postmetamorphic forelimbs of triturus alpestris. | | 1988 | 3412342 |
| intercalary regeneration in the different hindlimb stages of triturus alpestris larvae. | | 1988 | 3412341 |
| influence of vitamin a on proximal and distal blastemata of triturus alpestris--a morphological and cytophotometrical study. | | 1988 | 3412338 |
| vitamin a induced bilateral asymmetries in triturus forelimb regenerates. | after amputation of both forelimb of young, postmetamorphic triturus alpestris through the middle of the zeugopod, the left and right regenerates grew asynchronously. as a result of oral administration of vitamin a palmitate (250 iu/gbw/day), from the 4th to the 13th dpa, the growth rate of the right regenerates was relatively higher than that of the left ones. moreover, the percentage of skeletal abnormalities as well as proximodistal duplications (proximalizations), induced by vitamin a, was n ... | 1988 | 3401522 |
| influence of vitamin a palmitate on the growth of regenerating triturus alpestris forelimbs. | the objective of this investigation was to analyse the effects of vitamin a palmitate orally administered to young postmetamorphic triturus alpestris on the growth of regenerates. vitamin a was administered for 4, 7, 11 and 14 days after amputation at the middle of the right zeugopod. growth of regenerates was evaluated on the basis of external size measurements and blastema cell proliferation. calculation of the percentages of cells in each cell-cycle phase and estimation of mitotic indices dur ... | 1988 | 3196784 |
| the monoaminergic system in the diencephalon of the newt tadpole, triturus alpestris (mert). a histofluorescence study. | the distribution of monoamines in the brain of triturus alpestris tadpoles was investigated with the falck-hillarp histofluorescence method. this study concerns especially the diencephalon where is observed the major part of the monoaminergic (ma) neurons. ma fiber tracts are found in the striatum, the septal nucleus and the medial and lateral forebrain bundles of the telencephalon. in the anterior diencephalon cerebrospinal fluid (csf)--contacting catecholaminergic cells are localized within th ... | 1988 | 3183361 |
| vitamin a promotes dna synthesis and mitosis in blastemas of triturus alpestris. | vitamin a palmitate orally administered to young, post-metamorphic triturus alpestris (amphibia-urodela), for 4 and 7 days after bilateral forelimb amputation at the middle of the zeugopodium, enhanced the mean dna content of the blastema cells. moreover, the number of cells in mitosis was nearly twice as high in vitamin a treated animals than in control ones. | 1987 | 3690680 |