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enzyme activity in anuran spermatozoa upon induction of the acrosome reaction.at the time of sperm-egg fusion in discoglossus pictus, a large amount of electron-dense material of an unknown nature is liberated from the sperm. in the present work we studied this material in d. pictus sperm, using an assay utilising strips of autoradiographic film as a gelatin substrate for proteolytic enzymes. upon treatment with a23187, d. pictus sperm produced a large halo on the gelatin substrate, indicating the presence of enzymes released by the sperm at the time of the acrosome react ...200111771895
sulphated glycoconjugates are powerful inhibitors of spermatozoa binding to the vitelline envelope in amphibian eggs.in amphibians, the role of sulphated glycans has not been determined in spermatozoa-egg interaction, although they are known to be involved in other systems. in previous studies, it was found that, in discoglossus pictus, a ve (vitelline envelope) glycoprotein of 63 kda exhibits high homology to xenopus laevis gp69/gp64 and to zp2 of mammals. gp63 and a glycoprotein of 75 kda are both capable of binding the spermatozoa in in vitro assays and, having similar peptide maps and different glycosylati ...200515859944
dorsal striatopallidal system in anurans.the dorsal striatopallidal system of tetrapods consists of the dorsal striatum (caudate-putamen in mammals) and the dorsal pallidum. although the existence of striatal and pallidal structures has been well documented in anuran amphibians, the exact boundaries of these structures have so far been a matter of debate. to delineate precisely the dorsal striatopallidal system of anurans, we used quantitative analysis of leucine-enkephalin immunohistochemistry (in bombina orientalis, discoglossus pict ...200414648686
fatal chytridiomycosis in the tyrrhenian painted frog.batrachochytrium dendrobatidis (bd), the causative agent of the amphibian disease chytridiomycosis, is an important factor in the global decline of amphibians. within europe, animals that exhibit clinical signs of the disease have only been reported in spain despite the pathogen's wide, but patchy, distribution on the continent. recently, another occurrence of chytridiomycosis was reported in euproctus platycephalus, the sardinian brook newt, on the mediterranean island of sardinia, but without ...200919418096
chemoarchitecture of the anuran auditory midbrain.the anuran torus semicircularis consists of several subnuclei that are part of the ascending auditory pathway as well as audiomotor interface structures. additionally, recent anatomical studies suggest that the midbrain tegmentum is an integral part of the audiomotor network. to describe the chemoarchitecture of these nuclei, taking into account the toral subdivisions, we investigated the distribution of serotonin, leucine-enkephalin, substance p, tyrosine-hydroxylase, dopamine d2-receptor, parv ...200011011065
vitelline envelope gps 63 and 75 specifically bind sperm in "in vitro" assays in discoglossus pictus.in xenopus, conflicting data related to sperm-vitelline envelope (ve) binding suggest that further experiments should be performed to study the role of ve glycoproteins in sperm binding. in this article, we studied the ve of discoglossus pictus, where gp63, the product of the dp zp2 gene, has high molecular identity to xenopus gp69/64 and to mouse zp2 and only a23187-treated sperm bind to ve. sperm bind to ve all over the egg, yet a sperm tuft was found only in the animal half of the egg, where ...200415095343
a novel protein cross-reacting with antibodies against spectrin is localised in the nucleoli of amphibian oocytes.cytoskeletal proteins such as actin and myosin are important constituents of the nucleoplasm. spectrin is an actin binding protein typically related to plasma membrane; recently, it has been found that it is widespread and forms distinct membrane protein domains in such organelles as the golgi. in this paper, the large germinal vesicle of amphibian oocytes was chosen as a particularly suitable system to investigate the presence and location of spectrin in the nucleus. we manually isolated the ge ...19979427386
comparative acid phosphatase distribution in the suprarenal gland of discoglossus pictus, xenopus laevis and bufo bufo (anurans, amphibia).acid phosphatase activity was found to have a similar distribution in the suprarenal glands of discoglossus pictus, xenopus laevis and bufo bufo (anurans, amphibia) as determined by light and electron histochemical localization. the enzymatic activity is localized in the lysosomes of both the interrenal cells and the chromaffin cells. it is, moreover, positive on the granule membranes of the adrenaline cells whereas it appears only occasionally on the granule membranes of the noradrenaline cells ...19816802124
aluminium localization in amphibian skin with the electron microprobe and ion microanalyzer.emp and ima studies show the presence of a1 in the epidermis of larvae and young adults of discoglossus pictus and rana esculenta, which disappears during later stages of development. a1 is practically absent in the epidermis of xenopus laevis and pleurodeles waltlii. the localization of a1 with emp and ima supports the biochemical results. the function of a1 in the epidermis is not known at present.19761083571
the role of glycosaminoglycans in anuran pigment cell migration.the migratory pathways of neural crest-derived pigment cells were examined in two anurans, xenopus laevis and discoglossus pictus, and correlated with the distribution of glycosaminoglycans (gag) in the extracellular matrix (ecm) of these pathways. in xenopus, melanophores in the trunk reach the dermis by initially migrating ventrally, between the neural tube and somites, and then by migrating through the somites to reach the subectodermal space. in discoglossus, melanophores, iridophores, and x ...19863723060
the area acustico-vestibularis of discoglossus pictus. i. cytoarchitecture and ultrastructure features.the cytoarchitecture of the area acustico-vestibularis (aav) in discoglossus pictus is studied by means of normal stained material. in addition, the main ultrastructural features of the cells in the aav are described. basically, three different components are found: the dorsal, ventral and medial cell columns. while the two former are made up by the dorsal and ventral nuclei respectively, the medial column is formed by a rostrally located cerebellar nucleus and a caudal nucleus, which extends up ...20123263414
[action of thyroxine on discoglossus pictus otth larvae treated with actinomycin d and chloramphenicol]. 20154973701
[estradiol-17 receptors in the liver of chicken and the amphibian discoglossus pictus]. 19734348321
development of the retinotectal system in the direct-developing frog eleutherodactylus coqui in comparison with other anurans.abstract:200818573199
development of the retina is altered in the directly developing frog eleutherodactylus coqui (leptodactylidae).the loss of a free-living larval stage during the evolution of directly developing frogs of the genus eleutherodactylus resulted in dramatic alterations in ontogeny. immunostaining for proliferating cell nuclear antigen reveals that in the directly developing frog eleutherodactylus coqui pervasive cell proliferation occurs throughout the retina even after the plexiform layers have formed. in striking contrast to biphasically developing frogs (e.g. discoglossus pictus or xenopus laevis), in e. co ...19979131659
mosaic evolution of neural development in anurans: acceleration of spinal cord development in the direct developing frog eleutherodactylus coqui.previous studies have shown that spinal cord development in direct developing frogs of the genus eleutherodactylus, which have evolutionarily lost the tadpole stage, differs from that in biphasically developing anurans (with the larval and the adult stage separated by metamorphosis). the present study of spinal cord development in eleutherodactylus coqui provides additional information about neurogenesis, neuronal differentiation and growth analyzed by immunostaining for proliferating cell nucle ...200312592573
globin evolution in some species of the genus bufo.the globins of 10 species of toads of the genus bufo have been analysed. from the values of the reciprocal rates between their amino acid residues a 'dissimilarity matrix' was made. in this have been included the values related to discoglossus pictus and xenopus laevis. the numerical data, derived from a computer program, gave a dendrogram representing the evolution of the analysed globins. this appears correlated to the geographical distribution and to the metabolic adaptation of the correspond ...19846744827
ontogeny of ocular serotonin n-acetyltransferase activity daily rhythm in four anuran species.the profile of daily ocular serotonin n-acetyltransferase (nat) rhythm has been examined during the development of four anuran amphibians in different environments and of varying phylogenetic origins: xenopus laevis, discoglossus pictus, rana perezi, and bufo calamita. a significant day/night rhythm of ocular nat with the acrophase at midnight was first detected at stages 43/44 and 25 in x. laevis and r. perezi, respectively. total enzymatic activity increased with body weight throughout develop ...19947926643
[ionic determinism of sex formation, studied in an anourous batrachian: discoglossus pictus (otth), and in the animal kingdom]. 19704248219
catalase enzymatic activity and electrophoretic patterns in adult amphibians--a comparative study.catalase electrophoretic patterns and enzymatic activities were measured in four organs of two anuran species, rana ridibunda perezii and discoglossus pictus. the d. pictus enzyme appeared as two distinguishable bands, whereas r. ridibunda catalase was monomorphic. electrophoretic mobility of the major d. pictus catalase band was greater than that of r. ridibunda. enzymes from both species showed slower mobility than that from bovine liver. catalase activities did not show significant difference ...19853995926
the area acustico-vestibularis of discoglossus pictus. ii. the primary afferent projections.in the present report the primary projections to the dorsal rhombencephalic alar plate (area acustico-vestibularis, aav) of the adult anuran amphibian discoglossus pictus have been studied by means of the anterograde transport of horseradish peroxidase (hrp). as in alytes cisternasii, other member of the family discoglossidae, no primary afferent fibers to the aav were found from nerves other than the viiith cranial nerve. no remanent of the lateral line system in the adult stage is present. the ...19883263415
impact of ammonium nitrate on growth and survival of six european amphibians.we conducted static experiments to assess the effects of ammonium nitrate fertilizer on embryos and larvae of six european amphibians: sharp-ribbed salamander (pleurodeles waltl), iberian painted frog (discoglossus galganoi), western spadefoot toad (pelobates cultripes), common toad (bufo bufo), natterjack toad (bufo calamita), and common tree frog (hyla arborea). embryos were exposed to different and environmentally relevant concentrations of ammonium nitrate (0 to 200 mg no(3)(-)/l) for 15 day ...200415386149
geographical variations in adult body size and reproductive life history traits in an invasive anuran, discoglossus pictus.variability in life history traits positively affects the establishment and expansive potential of invasive species. in the present study, we analysed the variation of body size in seven populations - two native and five invasive - of the painted frog (discoglossus pictus, anura: discoglossidae), native to north africa and introduced in southern france and the north-east of the iberian peninsula. other life history traits (age at maturity, size at maturity, longevity, median age and potential re ...201626995099
transformation of the pectoral girdle in the evolutionary origin of frogs: insights from the primitive anuran discoglossus.using cleared-and-stained whole mounts and computer-aided three-dimensional reconstructions made from serial histological sections, we studied the development of the pectoral girdle in discoglossus pictus, an extant member of an ancient frog lineage, represented for example by eodiscoglossus from the middle jurassic to early cretaceous periods in europe. basic developmental features were compared with those of extinct temnospondyli, considered to be the most probable anuran ancestors, and with t ...200616822264
living quarters of a living fossil-uncovering the current distribution pattern of the rediscovered hula painted frog (latonia nigriventer) using environmental dna.one of the greatest challenges of effective conservation measures is the correct identification of sites where rare and elusive organisms reside. the recently rediscovered hula painted frog (latonia nigriventer) has not been seen for many decades and was therefore categorized extinct. since its rediscovery in 2011, individuals from the critically endangered species have been found, with great effort, only in four restricted sites. we applied the environmental dna (edna) approach to search for ne ...201729117632
primary structure and developmental expression of dp zp2, a vitelline envelope glycoprotein homolog of mouse zp2, in discoglossus pictus, one of the oldest living anuran species.a glycoprotein of the xenopus vitelline envelope, gp 69/64, which mediates sperm binding, is closely related to the components of zpa family, such as the mouse zona pellucida zp2. to test the generality of these findings, we studied discoglossus pictus, a species evolutionary distant from xenopus and identified as a protein of 63 kda in the vitelline envelope. preliminary studies suggest that this protein may bind sperm at fertilization. we found that the 63-kda protein is glycosylated and conta ...200111389548
effects of a commonly used glyphosate-based herbicide formulation on early developmental stages of two anuran species.environmental contamination, especially due to the increasing use of pesticides, is suggested to be one out of six main reasons for the global amphibian decline. adverse effects of glyphosate-based herbicides on amphibians have been already discussed in several studies with different conclusions, especially regarding sublethal effects at environmentally relevant concentrations. therefore, we studied the acute toxic effects (mortality, growth, and morphological changes) of the commonly used glyph ...201727785717
osteological observations on the alytid anura latonia nigriventer with comments on functional morphology, biogeography, and evolutionary history.the hula painted frog (latonia nigriventer) is a rare frog species endemic to the hula valley, israel. the species is the sole relict of a clade that was widespread mainly in europe from the oligocene until the beginning of the pleistocene. the osteological characteristics of l. nigriventer are described based on x-ray microtomography scans of extant specimens and pleistocene bones from the hula valley, to elucidate the evolutionary history of alytidae and more specifically of latonia. based on ...201627188540
[cutaneous granular glands of alytes cisternasii bosca and discoglossus pictus otth (amphibia, anura, discoglossidae): structure, ultrastructure, and certain cytochemical findings]. 2006555299
acute toxic effects of the herbicide formulation focus(®) ultra on embryos and larvae of the moroccan painted frog, discoglossus scovazzi.for regulatory and scientific purposes, there is a need to understand the sensitivity of a wider variety of wild species of amphibians and the sensitivities within their life stages to chemicals of widespread use such as herbicides. we investigated the acute toxic effects of the herbicide formulation focus ultra [with the active ingredient (a.i.) cycloxydim plus solvent naphtha and sodium dioctylsulphosuccinate as added substances] on embryos and early stage larvae of the moroccan painted frog ( ...201526118991
different levels of hyperoxia reversibly induce catalase activity in amphibian tadpoles.studies about the proposed antioxidant physiological role of the catalase (cat) enzyme in relation to different environmental oxygen tensions are reported for the first time in amphibian larvae of discoglossus pictus and rana ridibunda perezi during their development. the cat levels of whole tadpoles increased constantly in both species during the larval period, reaching a maximum during the metamorphic climax. all through development, cat activity levels were always greater in d. pictus than in ...19873666517
[in the near future will women be able to choose the sex of their children by following a diet?].the evidence for the author's hypothesis, that the sex ratio may be altered by the ionic environment during fertilization is presented. in the 1930's, it was discovered that the proportion of males increased as the ratio of potassium to calcium + magnesium ions increased for several marine species: an invertebrate bonellia viridis, aquarium fish aphyosemion microphtalmum, amphibian discoglossus pictus, dinophilus apatris, and some eels. these sex ratios cannot be affected by manipulating the ...19751136075
trophic strategies of a non-native and a native amphibian species in shared ponds.one of the critical factors for understanding the establishment, success and potential impact on native species of an introduced species is a thorough knowledge of how these species manage trophic resources. two main trophic strategies for resource acquisition have been described: competition and opportunism. in the present study our objective was to identify the main trophic strategies of the non-native amphibian discoglossus pictus and its potential trophic impact on the native amphibian bufo ...201526101880
the lateral line system in anuran tadpoles: neuromast morphology, arrangement, and innervation.anuran larvae have been classified into four morphological types which reflect intraordinal macroevolution. at present, complete characterizations of the lateral line system are only available for xenopus laevis (type i) and discoglossus pictus (type iii). we analyzed the morphology, arrangement, and innervation of neuromasts related to the anterodorsal and anteroventral lateral line nerves in 10 anuran species representing types i, ii, and iv with the aim of interpreting the existing variation ...201424863412
the rediscovered hula painted frog is a living fossil.amphibian declines are seen as an indicator of the onset of a sixth mass extinction of life on earth. because of a combination of factors such as habitat destruction, emerging pathogens and pollutants, over 156 amphibian species have not been seen for several decades, and 34 of these were listed as extinct by 2004. here we report the rediscovery of the hula painted frog, the first amphibian to have been declared extinct. we provide evidence that not only has this species survived undetected in i ...201323736869
antispectrin antibodies stain the oocyte nucleus and the site of fertilization channels in the egg of discoglossus pictus (anura).in discoglossus pictus eggs, only the dimple contains ionic channels active at fertilization; in particular, chloride channels are found in the central portion of the dimple, which is also the site of sperm penetration. moreover the dimple hosts an imposing cytoskeleton, consisting of a cortical network and bundles of microfilaments extending from the microvilli. since spectrin cross links actin and is connected through ankyrin to anion transporters in the plasma membrane of erythrocytes as well ...20061695511
following passage through the oviduct, the coelomic envelope of discoglossus pictus (amphibia) acquires fertilizability upon reorganization, conversion of gp 42 to gp 40, extensive glycosylation, and formation of a specific layer.this paper describes the morphological and biochemical changes in discoglossus pictus coelomic oocyte envelope (ce) following passage through the oviduct. as in other anurans, in this species, the transformation of the envelope into vitelline envelope (ve) leads to the acquisition of fertilizability and involves the cleavage of a glycoprotein. in addition, several features, typical of discoglossus pictus, were observed. a new layer, ve-d, forms underneath the ve region facing the site of sperm e ...200111170273
food availability determines the response to pond desiccation in anuran tadpoles.food availability and pond desiccation are two of the most studied factors that condition amphibian metamorphosis. it is well known that, when food is abundant, organisms undergo metamorphosis early and when they are relatively large. the capability of anurans to accelerate their developmental rate in response to desiccation is also common knowledge. these two variables must act together in nature, since we know that, as a pond dries, the per capita resources decrease. we conduct an experiment t ...201323344427
[electrophoretic blood examinations in 2 species of anura tadpoles: discoglossus pictus (otth.) and alytes obstetricans (laur.). comparisons between controls and animals which received cutaneous heterografts]. 196414262530
an immunomodulatory peptide related to frenatin 2 from skin secretions of the tyrrhenian painted frog discoglossus sardus (alytidae).norepinephrine-stimulated skin secretions of the tyrrhenian painted frog discoglossus sardus tschudi, 1837 (alytidae) did not contain any peptide with antimicrobial or hemolytic activity. however, peptidomic analysis of the secretions revealed the presence of an abundant peptide with structural similarity to frenatin 2, previously isolated from the australian frog litoria infrafrenata (hylidae). the primary structure of the peptide, termed frenatin 2d, was established as dllgtlgnlplpfi.nh2 by au ...201323262358
development of the olfactory and vomeronasal organs in discoglossus pictus (discoglossidae, anura).using histological techniques and computer-aided three-dimensional reconstructions of histological serial sections, we studied the development of the olfactory and vomeronasal organs in the discoglossid frog discoglossus pictus. the olfactory epithelium in larval d. pictus represents one continuous unit of tissue not divided into two separate portions. however, a small pouch of olfactory epithelium (the "ventromedial diverticulum") is embedded into the roof of the buccal cavity, anteromedial to ...201322972712
distribution of cranial and rostral spinal nerves in tadpoles of the frog discoglossus pictus (discoglossidae).we studied the peripheral nervous system of early tadpoles of the frog discoglossus pictus using whole-mount immunohistochemistry. double-labeling of muscles and nerves allowed us to determine the innervation of all cranial muscles supplied by the trigeminal, facial, glossopharyngeal, vagal, and hypoglossal nerves. the gross anatomical pattern of visceral, cutaneous, and lateral-line innervation was also assessed. most muscles of the visceral arches are exclusively supplied by posttrematic rami ...19957473767
influence of ammonium nitrate on larval anti-predatory responses of two amphibian species.sublethal effects of toxicants can upset normal behavioural responses to predators, leading to increased predation. for example, sensory capabilities can be impaired by toxicants, leading to difficulty in detecting predators or other threats. alteration of locomotor abilities by pollutants can also explain the difficulty of tadpoles to escape from predators. here we assess the effects of a nitrogenous fertilizer on the response to predators shown by anuran tadpoles. in a first experiment, we chr ...201020493565
effects of induced variation in anuran larval development on postmetamorphic energy reserves and locomotion.anuran larvae exhibit high levels of phenotypic plasticity in growth and developmental rates in response to variation in temperature and food availability. we tested the hypothesis that alteration of developmental pathways during the aquatic larval stage should affect the postmetamorphic performance of the iberian painted frog (discoglossus galganoi). we exposed tadpoles to different temperatures and food types (animal- vs. plant-based diets) to induce variation in the length of the larval perio ...200228547685
unusual chromosomal distribution of a major satellite dna from discoglossus pictus (amphibia, anura).a new highly abundant satellite dna from discoglossus pictus (dp-sat1) was isolated and characterized. the repetitive unit (0.51 kb) has 2 hindiii sites and only one spei site: digestion of genomic dna with hindiii produces 3 fragments: ha (0.17 kb), hb (0.34 kb), and hc = ha + hb (0.51 kb), while digestion with spei produces the whole repetitive unit (0.51 kb) that contains both hindiii sites. sequence analysis of cloned repeats indicates an average a + t content of 71%, with many a- and t-runs ...200920110657
three-dimensional reconstruction of the cranial and anterior spinal nerves in early tadpoles of xenopus laevis (pipidae, anura).xenopus laevis is one of the most widely used model organism in neurobiology. it is therefore surprising, that no detailed and complete description of the cranial nerves exists for this species. using classical histological sectioning in combination with fluorescent whole mount antibody staining and micro-computed tomography we prepared a detailed innervation map and a freely-rotatable three-dimensional (3d) model of the cranial nerves and anterior-most spinal nerves of early x. laevis tadpoles. ...201729218708
immunohistochemical study of the innervation of pulmonary vessels and smooth muscles in the respiratory tract of two frog species.the innervation of the respiratory tract of amphibians is still poorly understood. therefore, the respiratory tracts of the frogs rana esculenta and discoglossus pictus have been investigated in order to describe non-adrenergic non-cholinergic (nanc) and adrenergic innervation, and the localization of neuromediators that are possibly involved. immunohistochemical staining of many bioactive substances was found in neuroepithelial cells of the buccopharynx, larynx, lung septa, nerves and neurons t ...200415186925
morphology and projection pattern of medial and dorsal pallial neurons in the frog discoglossus pictus and the salamander plethodon jordani.in the frog discoglossus pictus and the salamander plethodon jordani, the morphology and axonal projection pattern of neurons in the medial and dorsal pallium were determined by intracellular biocytin labeling. a total of 77 pallial neurons were labeled in the frog and 58 pallial neurons in the salamander. within the medial pallium (mp) of the frog, four types of neurons were identified on the basis of differences in their axonal projection pattern. type i neurons have bilateral projections into ...200211891656
using heterochrony plots to detect the dissociated coevolution of characters.the comparison of developmental sequences among species is notoriously difficult. here, heterochrony plots are introduced as a new graphic method to detect temporal shifts in the development of characters in pair-wise species comparisons. plotting the timing of character development in one species against the timing of character development in another species allows us to compare a principally unlimited number of characters simultaneously and can detect whether suites of characters are dissociat ...200111598916
cytoarchitecture and connectivity of the amphibian medial pallium.we investigated the cytoarchitecture and connectivity of the medial pallium of amphibians by intracellular recording and biocytin labeling. the experiments were carried out in a whole-brain in vitro preparation in the painted frog, discoglossus pictus. four types of neurons with specific axonal projection patterns and position in the medial pallium are distinguished, three types with extratelencephalic and one type with only intratelencephalic projections. our findings corroborate the assumption ...199910342450
neural substrate for motor control of feeding in amphibians.descending pathways to premotor/motor centers and their cell groups of origin were studied by means of retrograde biocytin tracing experiments in the frog discoglossus pictus and the plethodontid salamander plethodon jordani, which differ remarkably in the structure and function of their feeding apparatus and their feeding strategy. labeled neurons were found in 30 major cell groups located in the telencephalon, diencephalon, synencephalon, mesencephalon and rhombencephalon. the number and distr ...19989973634
morphology and axonal projection patterns of auditory neurons in the midbrain of the painted frog, discoglossus pictus.acoustic signals are extensively used for guiding various behaviors in frogs such as vocalization and phonotaxis. while numerous studies have investigated the anatomy and physiology of the auditory system, our knowledge of intrinsic properties and connectivity of individual auditory neurons remains poor. moreover, the neural basis of audiomotor integration still has to be elucidated. we determined basic response patterns, dendritic arborization and axonal projection patterns of auditory midbrain ...19989714570
the role of sodium in the in vivo absorption of glycine by the intestine of the amphibian discoglossus pictus.this work showed that sodium deficit in the incubation medium causes a decrease in oxygen consumption of the isolated intestine. replacement of 33% and 66% sodium by equivalent quantities of potassium provoked respective inhibitions of 43.5% and 44%. total replacement of sodium induced an inhibition of 51.7%. under in vivo conditions, sodium deficit in the luminal fluid led to lower glycine absorption. this inhibition was 7.9% in 5/1000 nacl, from 16.8% in 2.5/1000 nacl and 27.4% when sodium was ...20139796130
sperm-egg interaction in the painted frog (discoglossus pictus): an ultrastructural study.the ultrastructure of sperm changes and penetration in the egg was studied in the anuran discoglossus pictus, whose sperm have an acrosome cap with a typical tip, the apical rod. the first stage of the sperm apical rod and acrosome reaction (ar) consists in vesiculation between the plasma membrane and the outer acrosome membrane. the two components of the acrosome cap are released in sequence. the innermost component (component b) is dispersed first. the next acrosome change is the dispersal of ...19979170112
evolution of nerve development in frogs. ii. modified development of the peripheral nervous system in the direct-developing frog eleutherodactylus coqui (leptodactylidae).we use whole-mount immunohistochemistry to describe the pattern of development of cranial nerves and muscles in the direct-developing leptodactylid frog eleutherodactylus coqui. comparison with nerve development in the biphasically developing frogs physalaemus pustulosus (leptodactylidae) and discoglossus pictus (discoglossidae; described in a companion paper) allows us to infer the ancestral leptodactylid ontogenetic pattern and the extent to which it has been modified during the evolution of d ...19979261555
evolution of nerve development in frogs. i. the development of the peripheral nervous system in discoglossus pictus (discoglossidae).the gross anatomical development of the peripheral nervous system (pns) during embryogenesis and metamorphosis in the frog discoglossus pictus is described based on whole-mount immunostaining for nerves and muscles. in the head, neurite outgrowth starts with the mandibular ramus of the trigeminal nerve at the tailbud stage. cranial muscles are innervated as soon as they differentiate, beginning at mid-embryonic stages. during late embryonic stages, the course of the trigeminal and facial nerves ...19979261554
localization of egg-surface carbohydrates and fertilization in discoglossus pictus (anura).the distribution of carbohydrates on the unfertilized egg surface in regions receptive or refractory to sperm penetration was analysed in the anuran amphibian discoglossus pictus by means of a panel of lectins at the level of both the light and electron microscope. results showed that a gradient of fucosyl-containing glycoconjugates was present at the pre-determined site of sperm entrance and topographically overlapped a similar gradient in sperm entry previously reported. of a number of simple ...19968593646
similarities and differences in the cytoarchitecture of the tectum of frogs and salamanders.frogs exhibit a morphologically complex (multiply laminated) optic tectum, while salamanders have one of the morphologically simplest tecta among vertebrates. in a comparative approach, the morphology of tectal projection neurons is investigated in three salamander species, hydromantes italicus, h. genei and plethodon jordani, and two frog species, discoglossus pictus and eleutherodactylus coqui, by means of retrograde biocytin labeling complemented by intracellular biocytin staining of cells. d ...19969124009
immunohistological localization of tenascin-c in the developing and regenerating retinotectal system of two amphibian species.the expression pattern of the extracellular matrix molecule tenascin-c was investigated in the retinotectal system of the frog discoglossus pictus and the salamander pleurodeles waltl during development and optic nerve regeneration in the adult. in both species, the retina was devoid of tenascin-c immunoreactivity at all ages studied. during development, tenascin-c was distributed in a gradient in the optic nerve, with the highest immunoreactivity in the eye near part of the optic nerve. the mye ...19958801256
silver enhancement of colloidal gold particles in deplasticized semithin epoxy sections.a simple method for light microscope screening of pre-embedded, gold-labeled samples, by silver enhancing deplasticized semithin epoxy sections is presented. this method is of great help in visualizing the topography of gold labeled sites at low magnification and for selecting labeled sample regions for subsequent electron microscope analysis on serial ultrathin sections. the method was developed during a study of lectin binding sites on the egg surface of the anuran amphibian discoglossus pictu ...19957779991
distribution of ncam-180 and polysialic acid in the developing tectum mesencephali of the frog discoglossus pictus and the salamander pleurodeles waltl.the 180 kda component of the neural cell adhesion molecule (ncam-180), total ncam (ncam-total) and the polysialic acid modification of ncam (psa) show similar temporal and spatial regulation in the developing tecta of pleurodeles waltl (salamander) and discoglossus pictus (frog). whereas ncam-total is found throughout the tectal tissue on neurons and glia, ncam-180 is only found on non-proliferating neurons and in fiber layers. psa is expressed by a subset of ncam-180-positive cells. western blo ...19938513482
jelly plug dissolution in discoglossus pictus eggs (anura) involves peroxidase-like activity and oxidative opening of disulphide bonds.in amphibian eggs the formation of a capsular chamber is one of the most striking events occurring either upon oviposition or after fertilisation. in the egg of the anuran discoglossus pictus a capsular chamber forms following fertilisation or activation; the egg with its vitelline envelope rotates in this chamber according to gravity. previous work showed that the chamber is the product of plug dissolution. the plug is a lens-shaped jelly coat, typical of discoglossus, covering only part of the ...19938081802
lipovitellin constitutes the protein backbone of glycoproteins involved in sperm-egg interaction in the amphibian discoglossus pictus.our knowledge of the molecules that interact with sperm at the egg membrane is restricted to a short list. in the eggs of discoglossus pictus, fusion with sperm is limited to a differentiated structure, the dimple, offering several advantages for detecting molecules involved in fertilization. previous studies have identified fucosylated glycoproteins of 200, 260, and 270 kda located at the surface of the dimple that are able to bind sperm in vitro. here, we show that dimple glycoproteins and a p ...201121308852
development of the ethmoidal structures of the endocranium in discoglossus pictus (anura: discoglossidae).we use histological techniques and computer-aided three-dimensional reconstructions made from serial histological sections to describe the ontogeny of the ethmoidal endocranium of discoglossid frog discoglossus pictus. we identify a pattern of development for the suprarostral cartilage that differs from previous findings and probably represents the ancestral anuran pattern. the nasal cartilages, including the inferior prenasal cartilage, are de novo adult structures. the only larva-derived struc ...201020730921
[electrophoretic analysis of intestinal acid phosphatase and n-acetyl-beta-glucosaminidase in the discoglossus tadpole treated by thyroxine].polyacrylamide gel electrophoresis has been used to separate the two isoenzymes of intestional acid phosphatase (pi and p2) and n-acetyl-beta-glucosaminidase (g1 and g2) in discoglossus pictus tadpoles treated by thyroxine. when the isoenzyme activities of each pair are expressed as percentages, the activity of the slower form (p2 or g2) increases significantly when the tadpoles are treated by the hormone.2002134794
different cytoskeletal organization in two maturation stages of discoglossus pictus (anura) oocytes: thickness and stability of actin microfilaments and tropomyosin immunolocalization.in discoglossus pictus oocytes, the germinative area (ga) contains long and irregular microvilli where actin microfilaments are located. in the egg, the funnel-shaped dimple that originates by invagination of the ga is present. in the dimple both microvilli and microfilament bundles have a very orderly appearance. this report extends previous observations (campanella and gabbiani, gamete res 3:99-114, 1980) and shows that ga microfilaments are thinner (36 a average) than dimple microfilaments (6 ...19902178640
fertilization in discoglossus pictus (anura). i. sperm-egg interactions in distinct regions of the dimple and occurrence of a late stage of sperm penetration.the heterogeneity of the egg surface with respect to receptivity to sperm was investigated in discoglossus pictus; in this species fertilization occurs only in an indentation called the dimple, at the center of the animal hemisphere. following insemination sperm are seen in the outermost jelly layers and in the lens-shaped jelly plug, converging to the dimple center, d1. a fertilization potential (fp) is recorded 30 sec following insemination. about 30 min after fertilization, when fertilization ...19883197923
the cortical reaction in the egg of discoglossus pictus: a study of the changes in the endoplasmic reticulum at activation.in discoglossus pictus previous ultrastructural observations have shown that at the animal dimple, where sperm fuse with the egg, cortical granules (cg), vacuoles, and tightly packed clusters of small cisternae are present. at fertilization the clusters open (i.e., become loose) and give rise to longer cisternae arranged in whorls and chains which migrate toward the plasma membrane. the vacuoles fuse to form cisternae and exocytose along with the cg. in the rest of the egg periphery, while exocy ...19883181623
a highly localized activation current yet widespread intracellular calcium increase in the egg of the frog, discoglossus pictus.sperm entry in the egg of the painted frog, discoglossus pictus, occurs only at a specialized region of the animal hemisphere called the animal dimple, a structure not found in other species of frog. an extracellular vibrating electrode was used to measure the activation current to determine if the ion channels that open to generate the fertilization potential are localized in this region. eggs that were activated by microinjecting inositol-1,4,5-trisphosphate (ins(1,4,5)p3) exhibited activation ...19882460387
oxygen regulation capacity in discoglossus pictus tadpoles between moderate hyperoxia and acute hypoxia in water.the oxygen dependence of aquatic oxygen consumption was measured in active and anesthetized stage xviii discoglossus pictus tadpoles (amphibia, anura). the active tadpoles are good oxygen regulators in moderate hyperoxia and moderate hypoxia, whereas they are oxygen conformers in acute hypoxia. critical oxygen pressure was 52 mmhg o2. anesthetizing the larvae changes them to perfect oxygen conformers between moderate hyperoxia and moderate hypoxia (249-63 mmhg o2). at stage xviii the aquatic res ...19883231886
physiological significance of catalase and glutathione peroxidases, and in vivo peroxidation, in selected tissues of the toad discoglossus pictus (amphibia) during acclimation to normobaric hyperoxia.1. various parameters related to oxidative stress were measured in adult discoglossus pictus acclimated for 15 days to either normoxia or hyperoxia (po2 = 710 mmhg). 2. total weight of the toads and total and relative wet weight of liver, kidneys, lungs and heart were not changed by hyperoxic acclimation. 3. in vivo tissue peroxidation increased in lung, decreased in skeletal muscle, and was not changed in liver, kidney, heart and skin after hyperoxic exposure. 4. hyperoxic acclimation increased ...19883249021
comparative data on acetylcholinesterase cytochemistry in various chromaffin cell types of discoglossus pictus (amphibia, anura).the cytochemical localization of acetylcholinesterase (ache) activity was studied in the adrenal chromaffin cells of discoglossus pictus. reaction end-products were associated with all types of chromaffin cells, i.e. adrenaline (a), noradrenaline (n) and small granule chromaffin (sgc-a, sgc-n) cells, and nervous elements present in the gland. the sgc-a and sgc-n showed the same intensity of ache reaction in a and n cells, respectively. on the whole, the a and sgc-a cells were more reactive than ...19872443117
the cortical endoplasmic reticulum and its possible role in activation of discoglossus pictis (anura) eggs.the role of endoplasmic reticulum was investigated in the egg of discoglossus pictus; recent findings suggest that this organelle is the source of ca2+ sequestration and release at activation. in the egg of discoglossus the dimple is the only site where sperm-egg fusion occurs. microvilli containing microfilament bundles penetrate into the dimple cytoplasm and thus define a cortical layer containing cortical granules, tubular cisternae 35 nm thick and vacuoles. in the underlying cytoplasm are cl ...19863825679
[ultrastructural aspects of the amphibian heart (discoglossus pictus pictus)]. 19854074529
post-fertilization changes in discoglossus pictus (anura) eggs result in the formation of a capsular chamber where the egg rotates.discoglossus pictus is one of the few anurans with an egg where a capsular chamber forms as a consequence of fertilization; the egg with its vitelline envelope rotates in this chamber according to gravity. we investigated the formation of the capsular chamber through various experimental cytochemical and ultrastructural approaches, and found that it is the product of plug liquefaction. the plug is a lens-shaped jelly coat typical of discoglossus, and covering only part of the egg animal half. ab ...19921445785
glycine transport by intestinal brush border vesicles of the amphibian discoglossus pictus.1. in order to determine the different components of glycine uptake by the intestine of the frog, discoglossus pictus, we have used brush border membrane vesicles isolated by a classical precipitation technique. 2. enzymatic tests showed that a good purification was obtained. the concentration ratio of alkaline phosphatase was 14.8. 3. glycine entry in vesicles as a function of time, in presence or absence of sodium, indicated an overshoot which decreased when incubation time was prolonged. the ...19911685388
temperature acclimation in amphibians: changes in lactate dehydrogenase activities and isoenzyme patterns in discoglossus pictus pictus (otth.) tadpoles. 1979547616
development of dorsal root iii afferent fibres in postmetamorphic juveniles of the frog discoglossus pictus. 1977333306
[architecture of the visual system of discoglossus pictus (oth)].the retinofugal pathways of an "archaic" anura discogossus pictus were examinated with fink-heimer method following ablation of the retina and after survival times of 5--105 days at 14 degrees c. a description of the diencephalic and mensencephalic architectonics has been done in order to replace the visual system into the general pattern. the scheme of primary optic pathways and centers is similar in discoglossus and rana. however, some retinofugal fibers reach the posterolateral part of the ip ...1977305441
[a new visual pathway in an anour amphibian, discoglossus pictus].the retino-tectai projections of the anura discoglossus pictus were examined on seventeen adult specimens unilaterally enucleated. after a postoperative survival period of 9 to 105 days, the degenerating fibers and terminals were shown by nauta and electromicroscopic techniques. this work points out the existence of a direct ipsilateral retino-tectal pathway in anura. typical terminal degenerations were seen in the postero-medial part of the ipsilateral tectum. the implications of this new anato ...1976822954
[differentiation in vitro of the nasolacrymal canal of discoglossus pictus otth (anuran amphibian)].the nasolacrymal duct of discoglossus pictus is able to differentiate in vitro from prometamorphosis, without thyroxine added to the culture medium if it is taken off late or with thyroxine added to the culture medium if it is taken off earlier (presumptive anlage).1976816524
evolution of lactate dehydrogenase isoenzymes in two types of skeletal muscles and skin tissue in discoglossus pictus (amphibia anura) during embryonic development. 19761020629
diploid gynogenetics in discoglossus pictus. 19761020626
[electrophoretic pattern and activity of lactate dehydrogenase in discoglossus pictus (otth) and rana ridibunda (pallas) skeletal muscle and heart (author's transl)].the electrophoretic isozyme patterns, total and specific activity of lactate dehydrogenase on skeletal and cardiac muscles in discoglossus pictus and rana ridibunda have been studied. the isozymes were separated out in polyacrylamide gels. the ldh activity bands were developed selectively. the percentage of the h subunits are significantly higher in discoglossus than in rana, probably becuase rana is subjected to more severe anaerobic conditions during the hibernation time.1978741060
properties of leucyl-trna synthetase from discoglossus pictus tadpoles. influence of mg-2+ ions on the enzymatic activity. 19751139890
[development of the thalamus in anurans during metamorphosis (author's transl)].a developmental study of the anuran diencephalon from stage 30 to 2 months after metamorphosis has been done. at stage 30 in discoglossus pictus, the diencephalic wall is divided into a superior area and an inferior area, where two kinds of cellular migrations are described. comparison with the urodele diencephalon suggests that the building of a new area (area dorsolateralis) in anurans, by means of an 'external migration', characterizes a level of organization which is related to the optic sys ...19751176849
[action of androgens in the anuran amphibian discoglossus pictus (otth). iii. effects of castration and action of androgens on the ultrastructure of the seminal vesicle]. 19744430441
[measurement of several intestinal lysosomal hydrolase activities, through larval development of discoglossus pictus otth, anuran amphibian].the whole specific activities of 5 lysosomal enzymes (acid phosphatase, n-acetylβ-glucosaminidase,β-glucuronidase, cathepsin and aryl sulphatase) were measured in the guts of discoglossus tadpoles, before and during metamorphosis.for each hydrolase, the activities show the same variation pattern. they significantly increase at the end of prometamorphosis and the beginning of the climax, while there is histolysis of the first (primary) epithelium of the gut.the measured activities decrease at the ...197428304849
[role of the dermis in differentiation of the nasolacrimal duct in discoglossus pictus (anourous amphibian)]. 19744216416
[the in vitro formation of 5 alpha-dihydrotestosterone by the testis of discoglossus pictus]. 19744152107
topography of cutaneous mechanoreceptive neurones in dorsal root ganglia of skin-grafted frogs.1. topographical distribution patterns of dorsal root ganglion (d.r.g.) cutaneous neurones providing innervation to various body surfaces were examined in doublypithed discoglossus pictus frogs.2. using electrophysiological methods, sensory neurones innervating back skin were observed to predominate on the dorsal ganglionic surfaces, while belly skin neurones were most prevalent in the caudal half of the d.r.g. ventral surfaces. flank neurones clustered in the medial half of d.r.g. ventral surfa ...1978366106
[effects of treatment with potassium perchlorate on the development of the intestine in the larvae of discoglossus pictus otth]. 19734123674
[active transport of sodium through seminal vesicles in the anuran discoglossus pictus]. 19734197481
isoenzymes of lactic dehydrogenase in discoglossus pictus. electrophoretic pattern of the adult and variations observed in the course of embryonic development. 19734789488
[partial characterization of a delta 4-3-ketosteroid-5-oxidoreductase in seminal vesicles of the anuran amphibian discoglossus pictus]. 19734149250
[assay of the total acid phosphatase activity of intestinal homogenates from larvae of discoglossus pictus otth treated with thyroxine]. 19724631955
[role of androgens in the anuran amphibian discoglossus pictus. i. in vitro metabolism of testosterone by the seminal vesicles]. 19724405421
a bactericidal protein in bombina variegata pachypus skin venom.the skin venom of the yellow bellied toad bombina variegata pachypus has an antimicrobial activity which seems to be correlated to the presence of a 6700 mol. wt polypeptide. this polypeptide was purified by electroelution from sds-urea-polyacrylamide gels and characterized for its antimicrobial activity. a bactericidal action was detected at concentrations with little or no cytolytic effect. the determination of the minimal inhibitory concentration showed that there was activity against gram po ...19912048146
[xenoplastic transplantation of the caudal bud of urodela embryos on the limb region of anuran embryos (axolotl-discoglossus pictus)]. 195913855773
integration of ascending and descending inputs in the auditory midbrain of anurans.in anurans, the midbrain torus semicircularis is involved in auditory processing and audio-motor integration. in this study, we examined the influence of descending forebrain projections on the auditory response properties and hence the audiomotor transmission of mesencephalic interface neurons. in order to investigate response integration, we performed intracellular recordings from torus neurons in an isolated brain preparation of discoglossus pictus and bombina orientalis and stimulated the au ...201411288824
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