| the activity for the induction of the sperm acrosome reaction localises in the outer layers and exists in the high-molecular-weight components of the egg-jelly of the newt, cynops pyrrhogaster. | localisation of the acrosome reaction inducing activity in egg-jelly was examined in the newt, cynops pyrrhogaster. the jelly has six layers: the j0, j1, j2, j3, j4 and st layers. jelly was mechanically dissected and placed on a millipore filter. when sperm were added from the outer surface side of the jelly, most of them exhibited the acrosome reaction after passing through the jelly. when egg-jelly was divided into four layers, strong activity for the induction of acrosome reaction was detecte ... | 2002 | 11964085 |
| retinotopic analysis of fiber pathways is amphibians. i. the adult newt cynops pyrrhogaster. | the possibility that pathways of retinal fibers within the optic tract and the tectum of the adult newt are retinotopic was examined by selective labeling of the retinal fibers with horseradish peroxidase. within the optic tract fibers from the ventral, temporal and dorsal retinal quadrants were ordered from the dorsal to ventral edges of th optic tract. the nasal retinal fibers exhibited two different pathways. the fibers from the dorsonasal retina ran along the ventral edge of the optic tract, ... | 1981 | 6162523 |
| retinotopic analysis of fiber pathways in the regenerating retinotectal system of the adult newt cynops pyrrhogaster. | retinotopic analysis of the pathways of regenerating retinal fibers within the optic tract and in the tectum of an adult newt was performed by selective labeling of the retinal fibers with horseradish peroxidase. at the tenth week of regeneration, all the regenerating retinal fibers from different retinal quadrants had terminal arbors nearly at the parts of the tectum innervated normally by those quadrants. the pathways for individual retinal fibers, however, were greatly disorganized within the ... | 1981 | 6162521 |
| isolation and characterization of four vip-related peptides from red-bellied newt, cynops pyrrhogaster. | four novel bioactive peptides were isolated from the red-bellied newt, cynops pyrrhogaster, using a bioassay system monitoring the rectum contraction of the japanese quail, coturnix japonica. as these peptides are structurally related to vasoactive intestinal polypeptide (vip), we termed these peptides newt vip-related peptides 1, 2, 3, and 4 (nvrp-1, -2, -3, and -4). the primary sequences of these peptides were determined to be hsdavftdnysrllgktalknyldgalkke (nvrp-1), hsdavftdnysrllaktalknyldga ... | 2004 | 15518909 |
| molecular cloning of newt sex pheromone precursor cdnas: evidence for the existence of species-specific forms of pheromones. | cloning of cdna encoding a decapeptide pheromone (sodefrin) that attracts conspecific female newts was attempted. a cdna clone encoding a protein consisting of 189 amino acid residues including a sodefrin sequence was isolated from a cynops pyrrhogaster abdominal gland cdna library. likewise, a cdna clone encoding a molecule comparable to the sodefrin precursor was obtained from a cynops ensicauda abdominal gland cdna library. this clone encoded a precursor protein of 192 amino acid residues, in ... | 1999 | 10471817 |
| innervation of two peptidergic (substance p and calcitonin gene-related peptide) nerves in the cerebral arteries and choroid plexus of the japanese newt (triturus pyrrhogaster). | the pattern of cerebrovascular substance p (sp) and calcitonin gene-related peptide (cgrp) immunoreactive (-ir) innervation was investigated in the newt. sp-ir nerves supplying the cerebral arterial tree and choroid plexus were positive for cgrp, but negative for vasoactive intestinal polypeptide or neuropeptide y. it is suggested that cerebrovascular sp- and cgrp-ir axons are sensory in nature. the supply of sp- and cgrp-ir nerves to the major cerebral arteries is relatively poor. nevertheless, ... | 1997 | 9409510 |
| proteinaceous pheromone homologs identified from the cloacal gland transcriptome of a male axolotl, ambystoma mexicanum. | pheromones play an important role in modifying vertebrate behavior, especially during courtship and mating. courtship behavior in urodele amphibians often includes female exposure to secretions from the cloacal gland, as well as other scent glands. the first vertebrate proteinaceous pheromone discovered, the decapeptide sodefrin, is a female attracting pheromone secreted by the cloacal gland of male cynops pyrrhogaster. other proteinaceous pheromones in salamanders have been shown to elicit resp ... | 2016 | 26885665 |
| molecular cloning and characterization of ligand- and species-specificity of amphibian estrogen receptors. | estrogens are essential for normal reproductive activity in both males and females as well as for ovarian differentiation during a critical developmental stage in most vertebrates. to understand the molecular mechanisms of estrogen action and to evaluate estrogen receptor ligand interactions in amphibians, we isolated cdnas encoding the estrogen receptors (eralpha and erbeta) from the japanese firebelly newt (cynops pyrrhogaster), tokyo salamander (hynobius tokyoensis), axolotl (ambystoma mexica ... | 2010 | 20064516 |
| neuroepithelial endocrine and nervous system in the respiratory tract of cynops pyrrhogaster with special reference to the distribution of nitric oxide synthase and serotonin. | the respiratory tract of urodeles harbours an intramural nerve network comprising an innervated system of neuroepithelial endocrine (nee) cells. however, striking differences have been noted between phylogenetically closely related species. zamboni- or formaldehyde-fixed whole-mount preparations and sections of the saclike lungs of a japanese salamander, cynops salamander, cynops pyrrhogaster, have been investigated for the immunocytochemical detection of nitric oxide synthase (nos), serotonin ( ... | 1994 | 7529073 |
| composition of the cutaneous bacterial community in japanese amphibians: effects of captivity, host species, and body region. | the cutaneous microbiota plays a significant role in the biology of their vertebrate hosts, and its composition is known to be influenced both by host and environment, with captive conditions often altering alpha diversity. here, we compare the cutaneous bacterial communities of 61 amphibians (both wild and captive) from hiroshima, japan, using high-throughput amplicon sequencing of a segment of the 16s rrna gene. the majority of these samples came from a captive breeding facility at hiroshima u ... | 2016 | 27278778 |
| a novel cysteine knot protein for enhancing sperm motility that might facilitate the evolution of internal fertilization in amphibians. | internal fertilization ensures successful reproduction of tetrapod vertebrates on land, although how this mode of reproduction evolved is unknown. here, we identified a novel gene encoding sperm motility-initiating substance (smis), a key protein for the internal fertilization of the urodele cynops pyrrhogaster by edman degradation of an isolated protein and subsequent reverse transcription polymerase chain reaction. the smis gene encoded a 150 amino-acid sequence including the cysteine knot (ck ... | 2016 | 27579691 |
| expression of g proteins in the olfactory receptor neurons of the newt cynops pyrrhogaster: their unique projection into the olfactory bulbs. | we analyzed the expression of g protein α subunits and the axonal projection into the brain in the olfactory system of the semiaquatic newt cynops pyrrhogaster by immunostaining with antibodies against gαolf and gαo , by in situ hybridization using probes for gαolf , gαo , and gαi2 , and by neuronal tracing with dii and dia. the main olfactory epithelium (oe) consists of two parts, the ventral oe and dorsal oe. in the ventral oe, the gαolf - and gαo -expressing neurons are located in the apical ... | 2014 | 24771457 |
| cloning of cdnas for the pituitary glycoprotein hormone alpha subunit precursor molecules in three amphibian species, bufo japonicus, rana catesbeiana, and cynops pyrrhogaster. | we have isolated cdna clones encoding molecules of putative glycoprotein hormone alpha subunit precursors from their pituitary cdna libraries for a toad, bullfrog and newt. the insert of the isolated toad cdna was 562 bp long containing the 5'-untranlated, coding and 3'-untranslated regions of 38, 363 and 161 bp, respectively. the insert of the bullfrog cdna was 604 bp long containing the 5'-untranslated, coding and 3'-untranslated regions of 70, 366, and 168 bp, respectively. in the newt, a com ... | 1998 | 9748402 |
| the spike component of the fertilization potential in the toad, bufo japonicus: changes during meiotic maturation and absence during cross-fertilization. | immature oocytes of the toad, bufo japonicus, inseminated between first- and second-meiotic metaphase, exhibited polyspermy. monospermy occurred when the oocytes had reached second-meiotic metaphase. electrical recording during insemination of the immature oocyte showed fast-rising and slow-rising spikes followed by a gradual shift to a positive membrane potential. the number of fast spikes in each oocyte corresponded well with the number of sperm observed in cytological sections. mature oocytes ... | 1987 | 3653525 |
| sperm motility initiating substance may be insufficient to induce forward motility of cynops ensicauda sperm. | sperm motility-initiating substance (smis) is a key protein for internal fertilization of the newt, cynops pyrrhogaster, and commonly enhances forward sperm motility in some amphibian species, including external fertilizers. smis action varies among different species in correlation with a species-specific reproductive environment. in the present study, we identified the gene of c. ensicauda smis (cesmis) and examined the mechanism of smis action with reference to that of the closely related cyno ... | 2017 | 28586125 |
| sperm storage influences the potential for spontaneous acrosome reaction of the sperm in the newt cynops pyrrhogaster. | sperm storage is supposed to influence sperm quality, although the details remain unclear. in the present study, we found that sperm stored in a sperm storage site, the vas deferens of cynops pyrrhogaster, spontaneously undergo acrosome reaction following incubation in steinberg's salt solution (st). percentages of acrosome-reacted sperm increased time-dependently to about 60% in 24 hr. the concentration of cyclic adenosine monophosphate (camp) was elevated after incubating sperm in st, while di ... | 2017 | 29235206 |
| dietary administration of tetrodotoxin and its putative biosynthetic intermediates to the captive-reared non-toxic japanese fire-bellied newt, cynops pyrrhogaster. | the origin of tetrodotoxin (ttx) in amphibians has long been disputed. in this study, ttx and its putative biosynthetic intermediates or shunt compounds (4,9-anhydro-10-hemiketal-5-deoxyttx and cep-242) were dietary administered to the captive-reared, non-toxic japanese fire-bellied newt, cynops pyrrhogaster. after 4 weeks, the ingested compounds were detected mainly in the newt body using liquid chromatography-mass spectrometry (lc-ms), while these compounds were not converted into other ttx an ... | 2017 | 28734983 |
| imorin: a sexual attractiveness pheromone in female red-bellied newts (cynops pyrrhogaster). | the male red-bellied newt (cynops pyrrhogaster) approaches the female's cloaca prior to performing any courtship behaviour, as if he is using some released substance to gauge whether she is sexually receptive. therefore, we investigated whether such a female sexual attractiveness pheromone exists. we found that a tripeptide with amino acid sequence ala-glu-phe is secreted by the ciliary cells in the epithelium of the proximal portion of the oviduct of sexually developed newts and confirmed that ... | 2017 | 28120945 |
| generation of albino cynops pyrrhogaster by genomic editing of the tyrosinase gene. | albino animals are useful for in situ hybridization experiments that demonstrate gene expression in embryos and organs, for the immunological rejection of skin grafts transplanted to host animals, and to identify tissues with regenerative ability during limbs and retina regeneration processes. cynops pyrrhogaster has extensive regenerating capacities. to facilitate regenerative research, in the present study, we produced albino c. pyrrhogaster using genomic editing. the dna fragment containing p ... | 2016 | 27268983 |
| beyond sodefrin: evidence for a multi-component pheromone system in the model newt cynops pyrrhogaster (salamandridae). | sodefrin, a decapeptide isolated from the male dorsal gland of the japanese fire belly newt cynops pyrrhogaster, was the first peptide pheromone identified from a vertebrate. the fire belly salamander and sodefrin have become a model for sex pheromone investigation in aquatically courting salamanders ever since. subsequent studies in other salamanders identified spf protein courtship pheromones of around 20 kda belonging to the same gene-family. although transcripts of these proteins could be pc ... | 2016 | 26935790 |
| expression of two classes of pax6 transcripts in reprogramming retinal pigment epithelium cells of the adult newt. | the adult newt has the remarkable ability to regenerate a functional retina from retinal pigment epithelium (rpe) cells, even when the neural retina (nr) is completely lost from the eye. in this system, rpe cells are reprogrammed into a unique state of multipotent cells, named rpescs, in an early phase of retinal regeneration. however, the signals that trigger reprogramming remain unknown. here, to approach this issue we focused on pax6, a transcription factor known to be expressed in rpescs. we ... | 2016 | 26853865 |
| purification and molecular cloning of aspartic proteinases from the stomach of adult japanese fire belly newts, cynops pyrrhogaster. | six aspartic proteinase precursors, a pro-cathepsin e (procate) and five pepsinogens (pgs), were purified from the stomach of adult newts (cynops pyrrhogaster). on sodium dodecylsulfate-polyacrylamide gel electrophoresis, the molecular weights of the pgs and active enzymes were 37-38 kda and 31-34 kda, respectively. the purified procate was a dimer whose subunits were connected by a disulphide bond. cdna cloning by polymerase chain reaction and subsequent phylogenetic analysis revealed that thre ... | 2016 | 26711235 |
| [identification of the gene encoding nucleostemin in the eye tissues of pleurodeles waltl]. | nucleotide sequences were identified in the eye tissues (lens, retina, and retinal pigment epithelium) of the adult newt pleurodeles waltl by the polymerase chain reaction with primers for the ns gene. sequencing showed that these nucleotide sequences belong to the ns gene of the newt p. walt, which encodes the nucleolar protein nucleostemin. structural analysis revealed a high homology of ns nucleotide sequences of p. walt! with those of newts. cynops pyrrhogaster and notophthalmus viridescens. ... | 2016 | 26638232 |
| ghrelin receptor in japanese fire belly newt, cynops pyrrhogaster. | we identified cdna encoding a functional ghrelin receptor (growth hormone secretagogue-receptor 1a (ghs-r1a)) in a urodele amphibian, the japanese fire belly newt (cynops pyrrhogaster). two functional receptor proteins, composed of 378- and 362-amino acids, were deduced from the identified cdna because two candidate initiation methionine sites were found. the long-chain receptor protein shared 80%, 69%, and 59% identities with the bullfrog ghs-r1a, human ghs-r1a and tilapia ghs-r1a-like receptor ... | 2015 | 26172570 |
| possible hormonal interaction for eliciting courtship behavior in the male newt, cynops pyrrhogaster. | reproductive behavior in amphibians, as in other vertebrate animals, is under the control of multiple hormonal substances. prolactin (prl), arginine vasotocin (avt), androgen, and 7α-hydroxypregnenolone (7α-oh preg), four such substances with hormonal activity, are known to be involved in the expression of the tail vibration behavior which is the initial step of courtship performed by the male newt, cynops pyrrhogaster. as current information on the interaction(s) between these hormones in terms ... | 2015 | 26141146 |
| confirmation of the absence of tetrodotoxin and its analogues in the juveniles of the japanese fire-bellied newt, cynops pyrrhogaster, captive-reared from eggs in the laboratory using hilic-lc-ms. | the tetrodotoxin (ttx) contents of the japanese fire-bellied newt, cynops pyrrhogaster, captive-reared from eggs to metamorphosed juveniles with a non-toxic diet for 70 weeks, as well as wild-caught juvenile newts, were investigated using a high-resolution hydrophilic interaction chromatography-lc-ms. ttx was detected in 0- to 22-week-old captive-reared juvenile newts but was not detected (<15 ng/g) in the 36- to 70-week-old newts, while significant levels of ttx (1.3-14 μg/g) were detected in t ... | 2015 | 25986913 |
| reintegration of the regenerated and the remaining tissues during joint regeneration in the newt cynops pyrrhogaster. | urodele amphibians, such as newts, can regenerate a functional limb, including joints, after amputation at any level along the proximal-distal axis of the limb. the blastema can regenerate the limb morphology largely independently of the stump after proximal-distal identity has been established, but the remaining and regenerated tissues must be structurally reintegrated (matched in size and shape). here we used newt joint regeneration as a model to investigate reintegration, because a functional ... | 2015 | 27499865 |
| the newt (cynops pyrrhogaster) rpe65 promoter: molecular cloning, characterization and functional analysis. | the adult newt has the ability to regenerate the neural retina following injury, a process achieved primarily by the retinal pigment epithelium (rpe). to deliver exogenous genes to the rpe for genetic manipulation of regenerative events, we isolated the newt rpe65 promoter region by genome walking. first, we cloned the 2.8 kb rpe65 promoter from the newt, cynops pyrrhogaster. sequence analysis revealed several conserved regulatory elements described previously in mouse and human rpe65 promoters. ... | 2015 | 25490979 |
| functional diversity of voltage-sensing phosphatases in two urodele amphibians. | voltage-sensing phosphatases (vsps) share the molecular architecture of the voltage sensor domain (vsd) with voltage-gated ion channels and the phosphoinositide phosphatase region with the phosphatase and tensin homolog (pten), respectively. vsps enzymatic activities are regulated by the motions of vsd upon depolarization. the physiological role of these proteins has remained elusive, and insights may be gained by investigating biological variations in different animal species. urodele amphibian ... | 2014 | 25347851 |
| a transcriptome for the study of early processes of retinal regeneration in the adult newt, cynops pyrrhogaster. | retinal regeneration in the adult newt is a useful system to uncover essential mechanisms underlying the regeneration of body parts of this animal as well as to find clues to treat retinal disorders such as proliferative vitreoretinopathy. here, to facilitate the study of early processes of retinal regeneration, we provide a de novo assembly transcriptome and inferred proteome of the japanese fire bellied newt (cynops pyrrhogaster), which was obtained from eyeball samples of day 0-14 after surgi ... | 2014 | 25290450 |
| sperm proteases that may be involved in the initiation of sperm motility in the newt, cynops pyrrhogaster. | a protease of sperm in the newt cynops pyrrhogaster that is released after the acrosome reaction (ar) is proposed to lyse the sheet structure on the outer surface of egg jelly and release sperm motility-initiating substance (smis). here, we found that protease activity in the sperm head was potent to widely digest substrates beneath the sperm. the protease activity measured by fluorescein thiocarbamoyl-casein digestion was detected in the supernatant of the sperm after the ar and the activity wa ... | 2014 | 25170808 |
| in silico identification of the genes for sperm-egg interaction in the internal fertilization of the newt cynops pyrrhogaster. | a specific sperm-egg interaction in the oviductal matrix is crucial for internal fertilization of the red-bellied newt, cynops pyrrhogaster. an understanding of the molecular basis of this interaction is expected to elucidate the evolutionary history of internal fertilization in amphibians. recently, deep sequencing technology has provided global gene information even in nonmodel animals, allowing us to understand specific features of the molecular mechanisms underlying fertilization in c. pyrrh ... | 2014 | 26154327 |
| contribution of different ca²⁺ channels to the acrosome reaction-mediated initiation of sperm motility in the newt cynops pyrrhogaster. | initiation of sperm motility in urodeles, which is induced by a sperm motility-initiating substance (smis) in the sequestered granules on the surface of egg jelly, is mediated by the acrosome reaction (ar), which is triggered by an ar-inducing substance (aris) on a sheet-like structure. details of the unique process of the interaction between egg jelly and sperm in these species is still unclear. the current study showed the fine structure of egg jelly in the newt cynops pyrrhogaster, a urodele ... | 2015 | 24355577 |
| spatial and temporal instability of local biotic community mediate a form of aposematic defense in newts, consisting of carotenoid-based coloration and tetrodotoxin. | most animals advertise their unprofitability to potential predators via conspicuous signals. whether the strength of this aposematic signal indicates the quality and quantity of chemical defenses in animals is controversial. here, we investigated the relationship between the conspicuousness of an aposematic signal and toxicity, which likely depends, at least in part, on dietary sources, in the newt cynops pyrrhogaster. our results indicate that the magnitude of the aposematic signal was not corr ... | 2013 | 24014098 |
| distinct ca2+ channels maintain a high motility state of the sperm that may be needed for penetration of egg jelly of the newt, cynops pyrrhogaster. | activation state of sperm motility named "hyperactivation" enables mammalian sperm to progress through the oviductal matrix, although a similar state of sperm motility is unknown in non-mammalian vertebrates at fertilization. here, we found a high motility state of the sperm in the newt cynops pyrrhogaster. it was predominantly caused in egg jelly extract (je) and characterized by a high wave velocity of the undulating membrane (um) that was significantly higher at the posterior midpiece. an ins ... | 2013 | 23980623 |
| molecular cloning of pepsinogens a and c from adult newt (cynops pyrrhogaster) stomach. | the full-length cdnas of three pepsinogens (pgs) were cloned from the stomach of newt, cynops pyrrhogaster, and nucleotide sequences of the full-length cdnas were determined. molecular phylogenetic analysis showed that two pgs, named pgc1 and pgc2, belong to the pepsinogen c group, and one pg, named pga, belongs to the pepsinogen a group. the sequences contain an open reading frame (orf) encoding 385 amino acid residues for pgc1, 383 amino acid residues for pgc2 and 377 amino acid residues for p ... | 2013 | 23701991 |
| molecular genetic system for regenerative studies using newts. | urodele newts have the remarkable capability of organ regeneration, and have been used as a unique experimental model for more than a century. however, the mechanisms underlying regulation of the regeneration are not well understood, and gene functions in particular remain largely unknown. to elucidate gene function in regeneration, molecular genetic analyses are very powerful. in particular, it is important to establish transgenic or knockout (mutant) lines, and systematically cross these lines ... | 2013 | 23305125 |
| phylogeny and historical demography of cynops pyrrhogaster (amphibia: urodela): taxonomic relationships and distributional changes associated with climatic oscillations. | we investigated the phylogenetic relationships and estimated the historical demography of the japanese fire-bellied newt, cynops pyrrhogaster, from japanese mainlands using 1407-bp sequences of the mitochondrial dna (nadh6, trnaglu, cyt b) and 1208-bp sequences of nuclear dna (rag-1) genes. phylogenetic trees based on mitochondrial dna revealed four major haplotype clades (northern, central, western, and southern clades) within this species. degree of genetic differentiation among major haplotyp ... | 2013 | 23103571 |
| lens regenerates by means of similar processes and timeline in adults and larvae of the newt cynops pyrrhogaster. | it is widely accepted that juvenile animals can regenerate faster than adults. for example, in the case of lens regeneration of the newt cynops pyrrhogaster, larvae and adults require approximately 30 and 80 days for completion of lens regeneration, respectively. however, when we carefully observed lens regeneration in c. pyrrhogaster at the cellular level using molecular markers in the present study, we found that lens regeneration during the larval stage proceeded at similar speed and by means ... | 2012 | 22930574 |
| sperm motility initiation by egg jelly of the anuran, discoglossus pictus may be mediated by sperm motility-initiating substance of the internally-fertilizing newt, cynops pyrrhogaster. | the egg jelly of discoglossus pictus contains sperm motility-activating activity, the molecular basis of which has not been studied. discoglossus pictus sperm initiated motility immediately after immersion in egg-jelly extract, as well as after immersion in hyposmotic solution, which initiates sperm motility in the external fertilization of anuran amphibians. sequential treatment of the d. pictus sperm with these two solutions revealed the predominant effect of hyposmolality in initiation of mot ... | 2012 | 22805164 |
| involvement of the neurosteroid 7α-hydroxypregnenolone in the courtship behavior of the male newt cynops pyrrhogaster. | reproductive behavior in amphibians, as in other vertebrate animals, is controlled by multiple hormones. a neurosteroid, 7α-hydroxypregnenolone, has recently been found to enhance locomotor activity in the male newt, cynops pyrrhogaster. here, we show that this neurosteroid is also involved in enhancing the expression of courtship behavior. intracerebroventricular (icv) injection of 7α-hydroxypregnenolone enhanced courtship behavior dose-dependently in the sexually undeveloped males that had bee ... | 2012 | 22796546 |
| hematological- and neurological-expressed sequence 1 gene products in progenitor cells during newt retinal development. | urodele amphibians such as japanese common newts have a remarkable ability to regenerate their injured neural retina, even as adults. we found that hematological- and neurological-expressed sequence 1 (hn1) gene was induced in depigmented retinal pigment epithelial (rpe) cells, and its expression was maintained at later stages of newt retinal regeneration. in this study, we investigated the distribution of the hn1 protein, the product of the hn1 gene, in the developing retinas. our immunohistoch ... | 2012 | 22719773 |
| gastrulation and pre-gastrulation morphogenesis, inductions, and gene expression: similarities and dissimilarities between urodelean and anuran embryos. | studies of meso-endoderm and neural induction and subsequent body plan formation have been analyzed using mainly amphibians as the experimental model. xenopus is currently the predominant model, because it best enables molecular analysis of these induction processes. however, much of the embryological information on these inductions (e.g., those of the spemann-mangold organizer), and on the morphogenetic movements of inductively interacting tissues, derives from research on non-model amphibians, ... | 2012 | 22634398 |
| metamorphosis inhibition: an alternative rearing protocol for the newt, cynops pyrrhogaster. | the newt is an indispensable model animal, of particular utility for regeneration studies. recently, a high-throughput transgenic protocol was established for the japanese common newt, cynops pyrrhogaster. for studies of regeneration, metamorphosed animals may be favorable; however, for this species, there is no efficient protocol for maintaining juveniles after metamorphosis in the laboratory. in these animals, survival drops drastically after metamorphosis as their foraging behaviour changes t ... | 2012 | 22559962 |
| effects of overtraining on extinction in newts (cynops pyrrhogaster). | the overtraining extinction effect (oee), a phenomenon in which extended training facilitates extinction, has been found in mammals and reptiles. however, fish have never shown oee. no study has yet investigated oee in newts, a representative amphibian species. we tested whether newts, cynops pyrrhogaster, show oee in a straight-array task. all animals received five trials per day and were given a piece of dried worm during reinforced trials. they showed significant acquisition and extinction ef ... | 2012 | 22468939 |
| evidence for true fall-mating in japanese newt cynops pyrrhogaster. | the mating season of japanese newt cynops pyrrhogaster is generally thought to occur once a year in spring to early summer, during the months of april to june, as in many other japanese amphibians. however, in fall, from september to october, we often observed breeding colored males demonstrating a mating behavior with females in the field. in this study, in order to identify their true mating season, we anatomically and histologically investigated the annual maturation cycle of gonads and repro ... | 2011 | 21967224 |
| lectin histochemical study on the olfactory bulb of the newt, cynops pyrrhogaster. | the function and/or morphological features of the vomeronasal olfactory system remain unclear in aquatic animals, although the system appeared first in urodeles based on phylogenic data. we examined the lectin binding patterns in the olfactory bulb of a semi-aquatic urodele, the japanese red-bellied newt, cynops pyrrhogaster, using 22 different lectins. eleven of the lectins showed specific binding to the nerve fibres and glomeruli in the olfactory bulb. among these, wheat germ agglutinin, pokew ... | 2011 | 21592192 |
| expressing exogenous genes in newts by transgenesis. | the great regenerative abilities of newts provide the impetus for studies at the molecular level. however, efficient methods for gene regulation have historically been quite limited. here we describe a protocol for transgenically expressing exogenous genes in the newt cynops pyrrhogaster. this method is simple: a reaction mixture of i-scei meganuclease and a plasmid dna carrying a transgene cassette flanked by the enzyme recognition sites is directly injected into fertilized eggs. the protocol a ... | 2011 | 21527918 |
| development of ca²(+) signaling mechanisms and cell motility in presumptive ectodermal cells during amphibian gastrulation. | this study investigated the development of ca²(+) signaling mechanisms and their role in initiating morphogenetic cell movement in the presumptive ectoderm of japanese newt (cynops pyrrhogaster) during gastrulation. histochemical staining using fluorescently labeled ryanodine and dihydropyridine probes revealed that dihydropyridine receptor (l-type ca²(+) channels) appeared in stage 12b embryos, while ryanodine receptors were expressed in both stage 11 and 12b embryos. transmission electron micr ... | 2011 | 21261609 |
| localization of three types of arginine vasotocin receptors in the brain and pituitary of the newt cynops pyrrhogaster. | the distribution of three types of arginine vasotocin (avt) receptors in the brain and pituitary of the newt cynops pyrrhogaster, namely, the v1a-, v2-, and v3/v1b-type receptors, was studied by means of in situ hybridization and immunohistochemistry. mrna signals and immunoreactive cells for the v1a-type receptor were observed in the telencephalon (mitral layer of the olfactory bulb, dorsal and medial pallium, lateral and medial amygdala, bed nucleus of the decussation of the fasciculus telence ... | 2010 | 21079998 |
| expression of cytochrome p450 side-chain cleavage enzyme mrna and production of pregnenolone in the brain of the red-bellied newt cynops pyrrhogaster. | it is becoming clear that the vertebrate brain has the capability of forming steroids de novo, the so-called "neurosteroids". to understand neurosteroidogenesis in the brain, it is essential to demonstrate the formation of pregnenolone, a main precursor of neurosteroids. in amphibians, the pregnenolone formation from cholesterol is still unclear, although the brain accumulates pregnenolone, pregnenolone sulfate and 7α-hydroxypregnenolone. this study was addressed to obtain basic information abou ... | 2011 | 21050853 |
| sperm motility-initiating activity in the egg jelly of the externally-fertilizing urodele amphibian, hynobius lichenatus. | low osmolality initiates sperm motility during the external fertilization of aquatic anuran amphibians. it is thought that this process occurs also in urodeles, but this has not been fully examined in these species. we report here that fertilization was achieved in the externally fertilizing hynobiid, hynobius lichenatus, by direct insemination onto the egg jelly surface without initial exposure of the sperm to a hypoosmotic solution. to identify the factors in addition to low osmolality that in ... | 2010 | 21039127 |
| simple and efficient transgenesis with i-scei meganuclease in the newt, cynops pyrrhogaster. | newts have been recognized as an ideal model for body-parts regeneration after traumatic injury since the 18(th) century. however, molecular mechanisms underlying regeneration remain a mystery because of technical limitations. in the current study, to break this obstacle, we established a simple and efficient transgenic protocol for the newt cynops pyrrhogaster by adapting an i-scei microinjection technique, as well as a two-aquarium-tank (tat) system that allows us to constantly obtain fertiliz ... | 2010 | 20981826 |
| temperature-dependent aposematic behavior in the newt cynops pyrrhogaster. | aposematic animals advertise their unprofitability to potential predators via morphological and behavioral signals. strong signals are detectable and memorable for the predators, and such signals would therefore be expected to be most effective. however, many apparently well-defended animals do not have very conspicuous signals. to better understand this paradoxical phenomenon, i compared intra-individual variation in an immobile aposematic behavior of the newt cynops pyrrhogaster under differen ... | 2010 | 20608843 |
| changes in the olfactory response to amino acids in japanese newts after transfer from an aquatic to a terrestrial habitat. | amphibians are capable of smelling both volatile and water-soluble (e.g., amino acids) odorants. adult japanese newts, cynops pyrrhogaster, live mostly in water, except during hibernation, but sometimes on land. to examine olfactory responses of the newts to adaptation to a short-term stay on land (land adaptation), we measured the magnitude of the olfactory response at five different time points (land adaptation time: 0, 30, 54, 90, and 114 h after transfer from an aquatic to a terrestrial habi ... | 2010 | 20377357 |
| origin of the prechordal plate and patterning of the anteroposterior regional specificity of the involuting and extending archenteron roof of a urodele, cynops pyrrhogaster. | we analyzed the notochord formation, formation of the prechordal plate, and patterning of anteroposterior regional specificity of the involuting and extending archenteron roof of a urodele, cynops pyrrhogaster. the lower (ldmz) and upper (udmz) domains of the dorsal marginal zone (dmz) of the early gastrula involuted and formed two distinct domains: the anterior fore-notochordal endodermal roof and the posterior domain containing the prospective notochord. cygsc is expressed in the ldmz from the ... | 2009 | 19643103 |
| identification of egg-jelly substances triggering sperm acrosome reaction in the newt, cynops pyrrhogaster. | our previous studies have shown that the acrosome reaction (ar) occurs in egg-jelly of the japanese newt, cynops pyrrhogaster. this is analogous to the substances of echinoderms but distinct from those of many other vertebrates derived from the egg envelope or its derivative, the zona pellucida. to identify the ar-inducing substances in newt egg jelly, a monoclonal antibody (mab) was generated against the jelly by screening the culture supernatants to find the one that best neutralized the ar-in ... | 2009 | 18937322 |
| the roles of pericystic cells and sertoli cells in spermatogonial proliferation stimulated by some growth factors in organ culture of newt (cynops pyrrhogaster) testis. | we have previously shown fsh promotes spermatogonial proliferation and their differentiation into primary spermatocytes in organ culture of newt testicular fragments. several growth factors identified in newt testis, such as stem cell factor (scf), insulin-like growth factor (igf)-i, and neuregulin (nrg)1, also stimulate spermatogonial proliferation in the organ culture. however, any growth factor added in vitro might not work on spermatogonia directly, but act on somatic cells such as sertoli c ... | 2008 | 18755191 |
| evidences for direct involvement of microtubules in cleavage furrow formation in newt eggs. | this paper aims at examining the effect of colchicine, a microtubular poison, on the process of furrow formation in whole eggs and egg fragments as well as the process of artificial induction of furrow-like dents, in eggs of the newt, cynops pyrrhogaster. to apply colchicine locally to eggs, the eggs were slit across or along a furrow in a colchicine solution during first cleavage. when a slit was made across or in front of a growing furrow at the onset of its growth, the furrow quickly ceased g ... | 1998 | 18429669 |
| stathmin expression during newt retina regeneration. | japanese common newts (cynops pyrrhogaster) have high ability to regenerate their injured organs including neural tissues, for example, the neural retina belonging to central nervous system. we attempted to clarify the molecular mechanism underlying the formation of a neural network during newt retina regeneration, and focused on the microtubule dynamics controlled by stathmin family proteins. stathmin is a small cytoplasmic phosphoprotein known to be a microtubule regulator. we isolated a clone ... | 2007 | 17707372 |
| heart formation and left-right asymmetry in separated right and left embryos of a newt. | during vertebrate cardiac development, the heart tube formed by fusion of right and left presumptive cardiac mesoderms (pcms) undergoes looping toward the right, resulting in an asymmetrical heart. here, we examined the right and left pcms with regard to heart-tube looping using right- and left-half newt embryos (cynops pyrrhogaster ). in the half embryos, the rightward (normal) loop of the heart tube was formed from the left pcm, irrespective of the timing of its separation, while the leftward ... | 2007 | 17554678 |
| establishment of high-resolution fish mapping system and its application for molecular cytogenetic characterization of chromosomes in newt, cynops pyrrhogaster (urodela, amphibia). | urodele amphibians (newts and salamanders) are important animal models for understanding regeneration mechanisms and genome evolution. we constructed ideograms of brdu/dt- and c-banded karyotypes in the japanese fire-belly newt, cynops pyrrhogaster, which is useful as a model animal with extremely high ability of regeneration. we also established a high-resolution fish mapping system for newts, and localized satellite dna sequences, 18s rdnas, telomeric (ttaggg)n repeats and seven functional gen ... | 2007 | 17525830 |
| molecular cloning of three types of arginine vasotocin receptor in the newt, cynops pyrrhogaster. | three types of cdna encoding the arginine vasotocin (avt) receptors from the newt, cynops pyrrhogaster were cloned and the gene expression of each receptor analyzed in the organs and tissues of the newt. the deduced amino acid sequence of one type of avt receptor, consisting of 418 amino acid residues, showed a high degree of sequence identity with the mammalian arginine vasopressin (avp) v1a receptors (61-68%). the second type of cdna, encoding an amino acid sequence consisting of 367 amino aci ... | 2007 | 17367790 |
| egg jelly of the newt, cynops pyrrhogaster contains a factor essential for sperm binding to the vitelline envelope. | the acrosome reaction of newt sperm is induced at the surface of egg jelly and the acrosome-reacted sperm acquire the ability to bind to the vitelline envelope. however, because the substance that induces the acrosome reaction has not been identified, the mechanism by which the acrosome-reacted sperm bind to the vitelline envelope remains unclear. we found here that a dolichos biforus agglutinin (dba) specifically mimicked the acrosome reaction immediately upon its addition in the presence of mi ... | 2007 | 17366620 |
| size-selective junctional barrier and ca(2+)-independent cell adhesion in the testis of cynops pyrrhogaster: expression and function of occludin. | in urodeles which has testicular structure different from that in mammals, blood-testis barrier was reported to exist like in mammals. however, molecular and functional analyses of the components of the blood-testis barrier in urodeles have not been reported yet. toward elucidation of the barrier functions and their molecular components in newt testis, we aimed to isolate occludin cdnas and obtained two kinds of occludin partial cdnas (occludin 1 and 2) encoding the putative second extracellular ... | 2008 | 17342736 |
| evidence for notch signaling involvement in retinal regeneration of adult newt. | involvement of notch signaling in retinal regeneration by transdifferentiation of pigment epithelium cells was investigated using the adult newt cynops pyrrhogaster. during retinal regeneration, cells expressing notch-1 first appeared in the regenerating retina one to two cells thick (stage e-3) originated from the retinal pigment epithelium (rpe) cells, and increased in number as the regenerating retina increased in thickness. notch-1 expression was decreased in the central retina in associatio ... | 2007 | 17217933 |
| cynodal, the japanese newt nodal-related gene, is expressed in the left side of the lateral plate mesoderm and diencephalon. | the nodal and nodal-related genes play fundamental roles during deuterostome left-right axis formation. several of these genes show left-sided expression in the lateral plate mesoderm and brain region. we have isolated the nodal-related gene, cynodal, from cynops pyrrhogaster. cynodal mrna is detected at the marginal zone and left side of several tissues. the left-sideness of cynodal mrna expression is highly conserved throughout vertebrate evolution. however, cynodal mrna expression shows littl ... | 2006 | 16377258 |
| structure of the respiratory tract of the red-bellied newt cynops pyrrhogaster, with reference to serotonin-positive neuroepithelial endocrine cells. | to investigate the distribution of serotonin-positive neuroepithelial endocrine (nee) cells in the respiratory tract of the red-bellied newt cynops pyrrhogaster, serial sections of the respiratory tract were stained using immunohistochemical methods for serotonin, a periodic acid-schiff method and hematoxylin-eosin staining. the respiratory tract of the red-bellied newt consisted of a tubular laryngotrachea and two pulmonary sacs. serotonin-positive solitary nee cells were distributed widely thr ... | 2005 | 15960315 |
| expression of aromatase mrna in the abdominal gland of the newt, cynops pyrrhogaster. | as a step to see whether the local aromatization mechanism exists in the newt, cynops pyrrhogaster, cdna cloning and characterization of newt cytochrome p450 aromatase (p450arom) were conducted. newt p450arom cdna was obtained from a c. pyrrhogaster ovarian cdna library. by rt-pcr and in situ hybridization, an intense p450arom mrna expression was detected in the abdominal gland. employing biochemical techniques combined with hplc and tlc analyses, we also demonstrated the conversion of testoster ... | 2005 | 15891058 |
| localization of prolactin receptor in the newt brain. | in the male newt cynops pyrrhogaster, prolactin (prl) acts directly on the central nervous system and induces courtship behavior. as a step to elucidate the localization of neurons on which prl acts, we developed a polyclonal antibody against an oligopeptide having a sequence completely identical with a part of the sequence of prl receptors (prlrs) of two species of newts, c. pyrrhogaster and c. ensicauda, and performed an immunohistochemical study with this antibody. prlr-immunoreactive cells w ... | 2005 | 15856311 |
| seasonal expression of lhbeta and fshbeta in the male newt pituitary gonadotrophs. | seasonal changes in lhbeta and fshbeta mrna levels were examined in the pituitary gland of the adult male newt, cynops pyrrhogaster, using in situ hybridization histochemistry and a quantitative real-time rt-pcr method. the annual fluctuation of lhbeta mrna and fshbeta mrna levels in the pituitary gland displayed a close relationship with seasonal changes in testicular function. the values obtained by both methods showed similar fluctuation. the levels of lhbeta mrna were always exceeded those o ... | 2005 | 15804512 |
| tissue interaction between the retinal pigment epithelium and the choroid triggers retinal regeneration of the newt cynops pyrrhogaster. | complete retinal regeneration in adult animals occurs only in certain urodele amphibians, in which the retinal pigmented epithelial cells (rpe) undergo transdifferentiation to produce all cell types constituting the neural retina. a similar mechanism also appears to be involved in retinal regeneration in the embryonic stage of some other species, but the nature of this mechanism has not yet been elucidated. the organ culture model of retinal regeneration is a useful experimental system and we pr ... | 2005 | 15766753 |
| downregulation of otx2 in the dedifferentiated rpe cells of regenerating newt retina. | cynops pyrrhogaster (the japanese common newt) regenerates neural retina from retinal pigmented epithelium (rpe) cells. otx2 is a transcription factor that is involved in rpe cell differentiation. to understand the role of otx2 during transdifferentiation of rpe cells, we cloned a cynops otx2 cdna, and explored its expression by rt-pcr, immunohistochemistry and in situ hybridization. the expression of otx2 was compared with the localization of a proliferating cell marker (pcna), rpe cell markers ... | 2005 | 15763275 |
| processing of multiple forms of preprosodefrin in the abdominal gland of the red-bellied newt cynops pyrrhogaster: regional and individual differences in preprosodefrin gene expression. | peptides derived from the post-translational processing of preprosodefrin were isolated from an extract of the abdominal glands of male red-bellied newts cynops pyrrhogaster obtained 5 months prior to the onset of the breeding season. structural characterization of the peptides showed that the pheromone sodefrin (sipskdallk) is stored in a biologically inactive cooh-terminally extended form (sipskdallkisa). it follows, therefore, that the activation of a protease that cleaves at a lys-ile bond t ... | 2004 | 15374655 |
| peptide pheromones in newts. | this article reviews the current state of understanding of reproductive pheromones in amphibians, focusing mainly on the purification and characterization of peptide pheromones in newts of the genus cynops, molecular cloning of cdnas encoding the pheromone molecules, and hormonal control of secretion of these pheromones. pheromones that attract sexually developed female cynops pyrrhogaster and c. ensicauda newts were isolated from the male abdominal glands. the c. pyrrhogaster and c. ensicauda p ... | 2004 | 15374654 |
| effect of bullfrog lh and fsh on newt testes under different temperatures. | environmental temperature plays important roles for amphibian gonadal function. in this study, we examined the responses of testicular tissue of adult male newts (cynops pyrrhogaster) to amphibian gonadotropins both in vitro and in vivo under different temperatures. when minced testes were incubated in vitro at different temperatures (8-37 degrees c) under an atmosphere of 95% o(2)-5% co(2) for 3h with bullfrog luteinizing hormone (lh) or follicle-stimulating hormone (fsh), lh stimulated testost ... | 2004 | 15242745 |
| marked increase in the rate of ocular lens regeneration in the newt, cynops pyrrhogaster, following partial body exposure to low dose x-rays. | in recent years, concern over the stimulating effects of low-dose x-rays has been growing. therefore, the effects of low-dose x-irradiation on lens regeneration in the newt were examined. newts were subjected to sham or whole-body x-ray exposure at a dose of 0.2 gy or 0.4 gy, delivered at a rate of 0.43 gy min(-1). the eyeballs were fixed in formalin solution, embedded in paraffin and assessed histologically. on day 14 after lens removal, unexposed animals showed the formation of a hollow epithe ... | 2004 | 14988138 |
| gravitational effects on apoptosis of presumptive ectodermal cells of amphibian embryo. | the effects of simulated microgravity (clinostat rotation at 6 rpm) on the presumptive ectodermal cells of amphibian embryos were examined. when morulae of cynops pyrrhogaster developed under the influence of simulated microgravity, the thickness of the presumptive ectoderm was greater significantly. embryonic cells isolated from the presumptive ectoderm of morulae were cultured for one day under the influence of simulated microgravity. the number of cells was greater after such clinostat rotati ... | 2004 | 14981778 |
| developmental biology of urodele amphibians in microgravity conditions. | among the urodele amphibians, only cynops pyrrhogaster and pleurodeles waltl, two species of the salamandridae family, were used in space experiments. the advantages for using urodeles reside (i) in reproduction: a few months after natural breeding, females can lay eggs in absence of males after a hormonal treatment, because spermatozoa were preserved in the cloacal pelvic glands of matted females, (ii) in the rate of development which is slower in cynops and pleurodeles than in the anuran xenop ... | 2003 | 14631631 |
| involvement of arginine vasotocin in reproductive events in the male newt cynops pyrrhogaster. | effects of arginine vasotocin (avt) on reproductive events such as courtship behavior, pheromone release, and spermatophore discharge were investigated in the male newt cynops pyrrhogaster. avt enhanced the incidence and frequency of androgen-induced courtship behavior. in this case, avt was likely to act centrally because the behavior was evoked with a much smaller amount of avt when the hormone was administered intracerebroventricularly than when given intraperitoneally. involvement of endogen ... | 2003 | 14613729 |
| abnormal spermatogenesis at low temperatures in the japanese red-bellied newt, cynops pyrrhogaster: possible biological significance of the cessation of spermatocytogenesis. | in newt testis, spermatocytes never appear during winter, because secondary spermatogonia die by apoptosis just before meiosis. in the current study, we examined the effect of low temperatures on spermatogenesis. incubation of newts at low temperatures (8, 12, 15 degrees c) induced defects in spermatogenesis in a temperature-dependent manner. at 8 degrees c, multinucleated giant cells (mgcs) were observed in spermatocytes and spermatogenesis never proceeded beyond meiosis. although spermatocytes ... | 2003 | 12874800 |
| molecular basis of spectral tuning in the newt short wavelength sensitive visual pigment. | previously we reported the sequence of the member of the short wavelength sensitive 2 (sws2) family of vertebrate visual pigments from the retina of the japanese common newt, cynops pyrrhogaster[takahashi, y. et al. (2001) febs lett. 501, 151-155]. now we have expressed the apopigment and regenerated it with a1 retinal. its absorption maximum, 474 nm, is greatly red shifted compared to other known sws2 pigments (418-455 nm). to determine the amino acid residues that control its spectral tuning, ... | 2003 | 12755604 |
| experimental study of the embryogenesis of gastrointestinal duplication and enteric cyst. | the theory of gastrointestinal duplication and enteric cyst embryogenesis was verified by examining the developmental process of this experimentally induced anomaly. in cynopus pyrrhogaster (amphibian) embryos (stage 18), the dorsal midline structures (including the neural plate and notochord) were split regionally to induce partial separation of the notochord and gut anlage endoderm herniation between the split elements of the notochord. following this procedure, the embryonic development was t ... | 2003 | 12740704 |
| morphological and biochemical changes in carotenoid granules in the ventral skin during growth of the japanese newt cynops pyrrhogaster. | the color of the ventral skin of the japanese adult newt cynops pyrrhogaster is red, whereas that of the small juvenile newts at metamorphosis is creamy. xanthophores in the red skin have many ring carotenoid vesicles (rcv) and a few homogenous carotenoid granules (hcg), as reported earlier. to understand the reason for this change in coloration of the ventral skin of the newt, we carried out histological and biochemical studies to see whether the size and the number of carotenoid granules (hcg ... | 2003 | 12719646 |
| characteristics of sperm motility induced on the egg-jelly in the internal fertilization of the newt, cynops pyrrhogaster. | most urodeles undergo internal fertilization and sperm are directly inseminated onto the surface of egg-jelly. feature of sperm motility induced on the egg-jelly was examined in the newt, cynops pyrrhogaster. when sperm were directly inseminated onto an egg-jelly, sperm motility was immediately induced on its surface. the egg-jelly of c. pyrrhogaster was composed of six sublayers that were added by turns in oviduct. when the eggs with various sets of the sublayers were obtained and sperm were in ... | 2003 | 12692394 |
| unique expression patterns of matrix metalloproteinases in regenerating newt limbs. | the process of regeneration of urodele limbs includes a drastic remodeling of extracellular matrices (ecms) that is induced by matrix metalloproteinases (mmps) and is thought to be one of the triggers of the regeneration. we studied this remodeling in limbs of japanese newt, cynops pyrrhogaster, by using five genes of newt mmps (nmmps) as probes: nmmp9, nmmp3/10-a, nmmp3/10-b, and nmmp13 that had been characterized previously, and nmmpe that was newly cloned in the present study. nmmpe was 502 a ... | 2003 | 12557215 |
| seasonal changes in neurosteroid concentrations in the amphibian brain and environmental factors regulating their changes. | up to now the regulatory mechanisms, which govern the concentrations of neurosteroids in the brain, are unclear. seasonal breeders may serve as excellent models to understand physiological changes in neurosteroid levels and their regulatory mechanisms. the present study first investigated immunohistochemically the localization of cytochrome p450 side-chain cleavage enzyme (p450scc) and 3beta-hydroxysteroid dehydrogenase/delta(5)-delta(4)-isomerase (3betahsd) in the brain of the newt cynops pyrrh ... | 2003 | 12493609 |
| localization of gamma-tubulin and cyclin b during early cleavage in physiologically polyspermic newt eggs. | to understand the mechanism of the very slow block to polyspermy in physiologically polyspermic eggs of the newt cynops pyrrhogaster, we used confocal laser microscopy to determine the distribution of gamma-tubulin and cyclin b1 in fertilized eggs. more gamma-tubulin was localized in the animal hemisphere than in the vegetal. the centrosomes of the principal sperm nucleus and the zygote nucleus had much accumulated gamma-tubulin, but little gamma-tubulin was associated with the centrosomes of th ... | 2002 | 12492507 |
| establishment of the organizing activity of the lower endodermal half of the dorsal marginal zone is a primary and necessary event for dorsal axis formation in cynops pyrrhogaster. | the formation of the head and trunk-tail organizers in the dorsal marginal zone (dmz) of an amphibian embryo is thought to require spatial and temporal interactions between the nieuwkoop center and the dmz. recent studies of the xenopus embryo suggested that intra-dmz interaction is also needed to establish the regional specificity of the dmz. however, it is not yet clarified when and how the final pattern of the head and trunk-tail organizers is established. to analyze the intra-dmz interaction ... | 2002 | 12382945 |
| egg transport in the coelom of the newt cynops pyrrhogaster. i. the ovulated egg is transported to the ostium by the ciliary movement of coelomic epithelial cells. | we investigated the mechanism of egg transport in the newt not only by inserting various conditioned eggs into the recipient's body but also by placing them on the coelomic epithelia of the opened body cavity in the adult female newt. most of the inserted coelomic eggs were oviposited, while 4 of 14 inserted de-jellied uterine eggs and 3 of 10 inserted de-jellied fertilized eggs were oviposited. the coelomic eggs placed on the coelomic epithelia were transported toward the ostium and entered the ... | 2002 | 12193806 |
| blastopore formation and dorsal mesoderm induction are independent events in early cynops embryogenesis. | the independent roles of blastopore formation and dorsal mesoderm induction in dorsal axis formation of the cynops pyrrhogaster embryo were attempted to be clarified. the blastopore-forming (bottle) cells originated mainly from the progeny of the mid-dorsal c and/or d blastomeres of the 32-cell embryo, but were not defined to a fixed blastomere. it was confirmed that the isolated dorsal c and d blastomeres autonomously formed a blastopore. ultraviolet-irradiated eggs formed an abnormal blastopor ... | 2002 | 12175365 |
| opsin expression in adult, developing, and regenerating newt retinas. | japanese common newts (cynops pyrrhogaster) have an ability to regenerate their neural retina even as adults. although extensive research has been carried out attempting to understand this retinal regeneration, the molecules characterized in newt retina are limited. we isolated cdnas encoding three putative opsins (cp-rh, -lws and -sws1), in addition to cp-sws2 [takahashi et al., febs lett. 501 (2001) 151-155] from a cdna library of adult newt retina. our immunohistochemical and in situ hybridiz ... | 2002 | 12106689 |
| peptide and protein pheromones in amphibians. | purification, characterization and biological activity of urodele and anuran sex-pheromones were reviewed. female-attracting pheromones obtained from the abdominal gland of cynops pyrrhogaster and c. ensicauda males are peptides consisting of 10 amino acid residues being designated sodefrin and silefrin, respectively. each pheromone attracted only conspecific females. molecular cloning of cdnas encoding sodefrin and silefrin revealed that both are generated from precursor proteins. synthesis of ... | 2002 | 11997210 |
| sequence analysis and expressional regulation of messenger rnas encoding beta subunits of follicle-stimulating hormone and luteinizing hormone in the red-bellied newt, cynops pyrrhogaster. | two distinct cdnas encoding beta subunits of follicle-stimulating hormone (fsh) and luteinizing hormone (lh) were cloned from the cdna library constructed for the pituitary of the red-bellied newt, cynops pyrrhogaster, and sequenced. the newt fshbeta and lhbeta cdnas encode polypeptides of 129 and 131 amino acids, including signal peptides of 20 and 19 amino acids, respectively. the number and position of cysteine and n-glycosylation in each of the beta subunits of fsh and lh, which are consider ... | 2002 | 11967191 |
| study of cynops pyrrhogaster notochord differentiation using a novel monoclonal antibody. | two monoclonal antibodies which reacted specifically with the notochord of the early cynops pyrrhogaster embryo were screened. the antigen molecules were detected within and around the notochord. they were first found mostly between the neural plate and the dorsal part of the notochord in the early neurula (stage 15). they were subsequently detected between the notochord and the somite in the advanced embryo, and they were last detected between the notochord and the underlying endoderm. whole-mo ... | 2002 | 11940099 |
| regional specification of the head and trunk-tail organizers of a urodele (cynops pyrrhogaster) embryo is patterned during gastrulation. | the dorsal marginal zone (dmz) of an amphibian early gastrula is thought to consist of at least two distinct domains: the future head and trunk-tail organizers. we studied the mechanism by which the organizing activities of the lower half of the dmz (ldmz) of the urodelean (cynops pyrrhogaster) embryo are changed. the uninvoluted ldmz induces the notochord and then organizes the trunk-tail structures, whereas after cultivation in vitro or suramin treatment, the same ldmz loses the notochord-indu ... | 2002 | 11900459 |
| egg-jelly structure promotes efficiency of internal fertilization in the newt, cynops pyrrhogaster. | egg-jelly is composed of a network of fibrous components and contains substances regulating the sperm-egg interaction. many studies on the latter have been conducted, whereas the role of the egg-jelly structure in fertilization has not yet been fully assessed. in this study, we examined the fertilization efficiency in the presence and absence of the structure around the egg of the newt, cynops pyrrhogaster, using a gelatin gel system. although de-jellied eggs of c. pyrrhogaster can be fertilized ... | 2002 | 11857465 |
| follicle-stimulating hormone is indispensable for the last spermatogonial mitosis preceding meiosis initiation in newts (cynops pyrrhogaster). | we previously reported that mammalian fsh induced differentiation of secondary spermatogonia into primary spermatocytes in organ culture of newt testicular fragments, whereas in medium lacking fsh primary spermatocytes never appeared. here, we investigated why spermatogonia fail to form primary spermatocytes in the absence of fsh. spermatogonia maintained proliferative activity and viability at about half the level of those cultured in the presence of fsh, progressed into the seventh generation, ... | 2002 | 11751258 |
| secretory glands of tetrodotoxin in the skin of the japanese newt cynops pyrrhogaster. | intra-tissue distribution of tetrodotoxin (ttx) in the skin of larva, juvenile, and adult japanese newt cynops pyrrhogaster was investigated by means of a monoclonal antibody-based immunoenzymatic technique. in the investigation, ttx was localized at immature glands in juvenile, and at the granular cells composing of granular and mixed glands in adult specimens under a light microscope. no specific stain was recognized in larval section. a duct like structure extending from the granular gland to ... | 2002 | 11689234 |
| expression of a novel matrix metalloproteinase gene during cynops early embryogenesis. | matrix metalloproteinases (mmps) are thought to play important roles in the gastrulation of cynops pyrrhogaster embryos. mmp cdnas were cloned from cynops pyrrhogaster and we report here a novel mmp called cymmp, which has strong similarity to mmp-21 (xmmp) in xenopus. reverse transcription-polymerase chain reaction (rt-pcr) analysis demonstrated that cymmp mrna was already present in cleavage stage embryos. the amount of the mrna then gradually decreased, but increased again starting in late ga ... | 2001 | 11606053 |