Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| 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 |
| differential expression of neurofilament 200-like immunoreactivity in the main olfactory and vomeronasal systems of the japanese newt, cynops pyrrhogaster. | expression of neurofilament 200 (nf200)-like immunoreactivity was examined in the main olfactory system and the vomeronasal system of the japanese newt, cynops pyrrhogaster, using anti-porcine nf200 monoclonal antibody (clone n52) to investigate the differences in phenotypical characteristics between these systems. the entire nasal cavity was a flattened single chamber consisting of the main nasal chamber (mnc) and the lateral nasal sinus (lns) communicating with each other. the olfactory epithe ... | 2005 | 16082118 |
| 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 |
| amphibian pheromones and endocrine control of their secretion. | amphibian sex pheromones of 3 urodele (cynops pyrrhogaster, c. ensicauda, and plethodon jordani) and 1 anuran (litoria splendida) species have been isolated and characterized and found to be either small peptides or larger proteins. each pheromone secreted by the male acts on conspecific females. endocrine control of pheromone secretion has been best studied in cynops. the c. pyrrhogaster pheromone, sodefrin, and the c. ensicauda pheromone, silefrin, are generated from their precursor proteins. ... | 2005 | 15891015 |
| 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 |
| prolactin acts centrally to enhance newt courtship behavior. | the effects of intracerebroventricular (icv) and intraperitoneal (ip) injections of ovine prolactin (prl), antiserum against newt prl, and antibody against the newt prl receptor on the expression of courtship behavior of male newts, cynops pyrrhogaster, were studied to see whether prl acts centrally or peripherally to induce the behavior. injections of prl by either route into gonadotropin-primed males enhanced the expression of the behavior dose-dependently. the minimum effective amount of ovin ... | 2005 | 15748718 |
| generation of transgenic newt cynops pyrrhogaster for regeneration study. | to take advantage of the ample potential for tissue regeneration by the newt, a technique to create transgenic newt was developed. the technique was based on a procedure for producing transgenic xenopus, but modified to adapt to the different sperm morphology and to overcome the refractoriness of newt eggs to activation by normal cleavage. sperm was collected from mature testes early in winter, permeabilized with digitonin, but without treatment of egg extract. efficient egg activation was achie ... | 2005 | 15712266 |
| daily and circadian variations of the pineal and ocular melatonin contents and their contributions to the circulating melatonin in the japanese newt, cynops pyrrhogaster. | daily and circadian variations of melatonin contents in the diencephalic region containing the pineal organ, the lateral eyes, and plasma were studied in a urodele amphibian, the japanese newt (cynops pyrrhogaster), to investigate the possible roles of melatonin in the circadian system. melatonin levels in the pineal region and the lateral eyes exhibited daily variations with higher levels during the dark phase than during the light phase under a light-dark cycle of 12 h light and 12 h darkness ... | 2005 | 15684585 |
| 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 |
| spatio-temporal expression of a daz-like gene in the japanese newt cynops pyrrhogaster that has no germ plasm. | to investigate the germ cell specification in urodeles, we cloned a daz-like sequence from the japanese newt cynops pyrrhogaster, cydazl, and raised antibodies specific to cydazl. cydazl is a homologue of the human daz (deleted in azoospermia), dazl, and xenopus dazl genes, which are involved in gametogenesis or germ cell specification. during gametogenesis, expression of cydazl mrna and cydazl protein was detected at first in the small previtellogenic oocytes in females but was not localized as ... | 2004 | 15490230 |
| 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 |
| hormonal control of meiosis initiation in the testis from japanese newt, cynops pyrrhogaster. | meiosis is an event that occurs prerequisitely and specifically in gametogenesis. however, the mechanisms of conversion from mitosis to meiosis are poorly understood. i will review the results so far obtained by us using newt testis as a model system, and discuss about the extrinsic mechanism(s) controlling the conversion from mitosis to meiosis. in the newt spermatogonia enter meiosis in the 8th generation after 7 mitotic divisions. we developed organ and reaggregate culture systems with a chem ... | 2004 | 15277712 |
| 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 |
| a survey of blastocystis infection in anuran and urodele amphibians. | blastocystis infection in amphibians was surveyed in three species of anuran and one species of urodele amphibians captured at two distinct locations in japan. all three species of frogs were highly infected with blastocystis, while 69 individual urodele newts, cynopus pyrrhogaster, were negative for infection. eleven blastocystis isolates (47.8%) were recovered from 23 rana nigromaculata leopard frogs. twenty-three (92%) of 25 rana catesbeiana bullfrogs and all (100%) of 24 bufo japonicus japon ... | 2004 | 15177714 |
| 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 |
| [membrane potential in kidney tubules of triturus pyrrhogaster]. | 1961 | 14496151 | |
| cytological observations on the epithelium of the gallbladder in urodele amphibian triturus pyrrhogaster. | 1954 | 14356692 | |
| restitution of the eye from the iris after removal of the retina and lens together with the eye-coats in the newt, triturus pyrrhogaster. | 1965 | 14346508 | |
| an observation of the mast cell, especially the dendrite-type tissue mast cell in triturus pyrrhogaster (boie). | 1965 | 14289867 | |
| strontium and calcium reabsorption in renal tubules of the newt, triturus pyrrhogaster. | reabsorption of calcium in the proximal tubule cannulated in vivo exceeded reabsorption of strontium. the diuretics diamox and salyrgan depressed the reabsorption of calcium but not strontium. | 1964 | 14107462 |
| transmissibility and some histopathology of a spontaneously originated visceral tumor in the newt, triturus pyrrhogaster. | 1963 | 14098909 | |
| the fine structure of tissue mast cells in triturus pyrrhogaster (boie). | 1963 | 14046091 | |
| studies on amphibian yolk 1. the ultrastructure of the yolk platelet. | the yolk platelets of mature eggs and young embryonic cells of all amphibian species studied (rana pipiens, triturus pyrrhogaster, diemictylus viridescens, rana nigromaculata, and bufo vulgaris) have a superficial layer of fine particles or fibrils (ca. 50 a in diameter), a central main body with a crystalline lattice structure, and an enclosing membrane approximately 70 a in thickness. electron micrographs of the main body reveal hexagonal net (spacing ca. 70 a), square net (spacing ca. 80 a), ... | 1963 | 13962448 |
| influence of ovarian extract upon the sex differentiation of terminal crest in the testis of triturus pyrrhogaster (boie). | 1961 | 13904272 | |
| on the commissura postoptica in the brain of a newt, triturus pyrrhogaster. | 1955 | 13297330 | |
| ribonucleic acid and protein in the growing oocytes of triturus pyrrhogaster. | 1953 | 13076194 | |
| 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 |
| food habit of the juvenile of the japanese newt cynops pyrrhogaster. | the previous study showed that the red coloration of the ventral skin of the japanese newt cynops pyrrhogaster was associated with the number of carotenoid vesicles and the content of carotenoid in the pigment cell of the skin. to elucidate the mechanism for the red coloration of the skin of the newt, we studied the food habit of the juvenile from the japanese newt cynops pyrrhogaster. sixty-two juveniles were collected in fukue island in nagasaki prefecture from november 2000 to may 2002 and di ... | 2003 | 12867714 |
| 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 |
| lectin histochemical study on the olfactory organ of the newt, cynops pyrrhogaster, revealed heterogeneous mucous environments in a single nasal cavity. | expression patterns of glycoconjugates were examined by lectin histochemistry in the nasal cavity of the japanese red-bellied newt, cynops pyrrhogaster. its nasal cavity consisted of two components, a flattened chamber, which was the main nasal chamber (mnc), and a lateral diverticulum called the lateral nasal sinus (lns), which communicated medially with the mnc. the mnc was lined with the olfactory epithelium (oe), while the diverticulum constituting the lns was lined with the vomeronasal epit ... | 2003 | 12698361 |
| 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 |
| cpzpc, a newt zpc molecule, localizes to the inner surface of the egg envelope. | zona pellucida-3 is an essential molecule for the binding of sperm to the egg envelope and for induction of the acrosome reaction in mice. its homologous molecules, zpcs, have been widely identified in the eggs of many vertebrates, except for urodeles. in this study, to investigate the participation of zpc in newt fertilization, we cloned the cdna of newt zpc from the ovary of cynops pyrrhogaster by reverse transcription polymerase chain reaction (rt-pcr). the cdna was constructed from 1,397 nuc ... | 2003 | 12653251 |
| 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 |
| matrix metalloproteinase-21, the human orthologue for xmmp, is expressed during fetal development and in cancer. | we have characterized a novel human matrix metalloproteinase (mmp-21) from human placenta dna complementary to rna (cdna). the 569 amino acid translation of the cdna includes all the typical features of an mmp family member, namely a signal sequence, a prodomain with a prcgvpd motif, a zinc-binding catalytic domain with an heighvlgl sequence, and a hemopexin-like domain flanked by two cysteine residues. furthermore, mmp-21 has a furin activation sequence, but no transmembrane sequence nor a cyto ... | 2002 | 12490321 |
| comparative peptidomics of the endocrine pancreas: islet hormones from the clawed frog xenopus laevis and the red-bellied newt cynops pyrrhogaster. | electrospray mass spectrometry coupled with reverse-phase hplc was used to identify peptides in the molecular mass range 3000-6000 da in extracts of the pancreata of the clawed frog xenopus laevis (anura: pipidae) and the red-bellied newt cynops pyrrhogaster (caudata: salamandridae). amino acid sequences of insulins, peptides derived from the post-translational processing of proglucagons and pancreatic polypeptide were determined by automated edman degradation. three molecular forms of insulin w ... | 2002 | 12475387 |
| experimental analysis of gravitational effects on amphibian gastrulation. | the effects of simulated microgravity on blastopore (bp) formation were analysed in xenopus laevis and cynops pyrrhogaster embryos. simulated microgravity produced by clinostat rotation shifted the bp-forming region toward the vegetal pole, more markedly in cynops embryos than in xenopus embryos. the simulated microgravity induced aggregation of endoderm cells at the center of the embryo and separation between the endoderm and presumptive mesoderm (pm). these findings suggest that clinostat trea ... | 2002 | 12402923 |
| 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 |
| comparison of the morphology of the inner ear between newts and frogs in relation to their locomotory capability. | the ultrastructural differences between the inner ears of japanese red-bellied newts (cynops pyrrhogaster) and black-spotted pond frogs (rana nigromaculata) were investigated. scanning electron microscopic observations showed apparent morphological differences in the shape of the ampulla cristae and the localization of the striola in the saccular macula. there were differences in the length of the kinocilia of the sensory hairs in each sensory region. in addition, the diameters of the bundles of ... | 2002 | 12130811 |
| 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 |
| an ultrastructural and carotenoid analysis of the red ventrum of the japanese newt, cynops pyrrhogaster. | the ventral skin of the wild japanese newt cynops pyrrhogaster is creamy at metamorphosis, but turns red when mature. the color of the ventral skin of laboratory (lab)-reared newts stays yellow throughout their life. however, the mechanism for the red coloration of this animal still remains unknown. in this study, we have performed ultrastructural and carotenoid analyses of the red ventrum of wild and lab-reared japanese newts. using electron microscopy, we observed a number of xanthophores havi ... | 2002 | 12100492 |
| experimental split cord malformations. | to induce experimental split cord malformations (scms) produced through the surgical induction of a dorsal midline fistula. | 2002 | 12053040 |
| 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 |
| 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 |
| 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 |
| development of gravity-sensing organs in altered gravity conditions: opposite conclusions from an amphibian and a molluscan preparation. | researchers examined early otolith development in microgravity using fertilized eggs of the japanese newt, cynops pyrrhogaster in space flight. ground experiments examined statocyst, embryonic statolith volume, and statoconia in the post-metamorphic marine mollusk aplysia californica reared at 1-g and 2-5.7-g. results indicate that exposure to hypergravity decreased the otolith mass to compensate for increased weight in aplysia. in the cynops, there was no compensatory difference in otolith mass ... | 1997 | 11540698 |
| astronewt: early development of newt in space. | astronewt experiment explores the effects of earth gravity on the early development of japanese red-bellied newt, cynops pyrrhogaster. since female newts keep spermatophore in cloaca, fertilized eggs could be obtained without mating. fertilization of newt's egg occurs just prior to spawning, so that gonadotrophic cues applied to females in orbit leads to laying eggs fertilized just in space. a property of newt being kept in hibernation at low temperature may be of great help for the space exp ... | 1996 | 11538624 |
| formation of otoconia in the japanese red-bellied newt, cynops pyrrhogaster. | pre-mated adult female newts and fertilized eggs will be flown on the international microgravity laboratory-2 flight, in 1994. one objective of the flight will be to observe the influence of microgravity on the development of the gravity-sensing organs in the inner ear. these organs contain sensory hair cells covered by a layer of dense stones (otoconia). gravity and linear acceleration exert forces on these masses, leading to excitation of the nerve fibers innervating the hair cells. if the pro ... | 1994 | 11537935 |
| cytopathologic observations of the lung of adult newts (cynops pyrrhogaster) on-board the space shuttle, columbia, during the second international microgravity laboratory experiments. | four adult female japanese newts, cynops pyrrhogaster, were carried for 15 days aboard the orbiting space shuttle, columbia, in july of 1994, as part of the second international microgravity laboratory, iml-2 aquatic animal experiments. these previously fertilized newts, after stimulation with chorionic gonadotropin by a spaceflight adapted injection procedure, deposited numerous eggs for study of early development during weightlessness. the primitive saccular lungs of the two newts which surviv ... | 1995 | 11536733 |
| comparative study of sequential expression of the organizer-related genes in normal cynops pyrrhogaster embryos and mesodermalized ectoderm. | an artificially mesodermalized ectoderm (me) of early cynops pyrrhogaster gastrula acquires the organizer property; the me is able to induce the secondary axis. the expression of organizer-related genes was investigated during the mesodermalizing process of the me. the expression of c. pyrrhogaster organizer-related genes, such as bra, gsc, lim-1, chd and noggin, were analyzed. cynops pyrrhogaster shh expression was also investigated. the organizer-related genes were activated by 12 h after the ... | 2001 | 11473542 |
| distribution of blue-sensitive photoreceptors in amphibian retinas. | previously, we reported that an opsin (rc-ms) belonging to the sws2 group opsins is expressed in bullfrog green rods [hisatomi, o. et al., febs lett., 1999, 447, 44-48]. an anti-rc-ms antiserum recognized the cones of the japanese common newt, cynops pyrrhogaster, which has no green rods. we isolated a cdna encoding an sws2 group opsin (cp-sws2) from this newt and found that cp-sws2 is expressed in a small population of the cones. our results suggest that sws2 opsins can be expressed in either g ... | 2001 | 11470275 |
| toxicity and toxin profiles of the newt, cynops pyrrhogaster from western japan. | a total of 382 specimens of a japanese newt, cynops pyrrhogaster, were collected from western japan during 1996 to 1999, and assayed for their individual, geographical, sexual, seasonal variations, and anatomical distribution of toxicity by mouse. most of the specimens tested showed toxicity scores ranging from 5 to 370 mu/g, where no seasonal, but large individual, sexual, and regional variations of toxicity were clearly recognized. among the parts, skin and muscle showed higher toxicity scores ... | 2001 | 11405279 |
| isolation of the third component of complement and its derivative with anaphylatoxin-like activity from the plasma of the newt cynops pyrrhogaster. | the third component of complement (c3) of a newt, cynops pyrrhogaster, was purified using a fast protein liquid chromatography technique. the purified newt c3 consists of two polypeptide chains (the molecular masses of the alpha and beta-chains of c3 were 120,000 and 70,000, respectively) linked by disulfide bonds. the alpha-chain retained an internal thiolester bond that was cleaved with methylamine, and the n-terminal amino acid sequence of the alpha-chain was xvqlidakagkaakf. digestion of new ... | 2005 | 11356226 |
| cloning of dynein intermediate chain cdna of the newt cynops pyrrhogaster. | to isolate genes whose expression is up-regulated after initiation of meiosis, we employed an mrna differential display method using rna extracted from newt testis fragments in the spermatogonial and spermatocyte stages. we report here isolation of a spermatocyte stage-specific cdna clone encoding a newt homologue of dynein intermediate chain (ic). the newt dynein ic cdna was found to encode a polypeptide consisting of 694 amino acid residues with 66.8% and 45.8% amino acid sequence similarity t ... | 2001 | 11347905 |
| an experimental animal model of split cord malformation. | in this study, we examined an experimental animal model of split cord malformation (scm) produced by the surgical induction of a fistula. in cynopus pyrrhogaster neurulae (stage 18.5 +/- 0.5), the neural plate was incised and divided to construct a fistula that mimicked a neurenteric canal. after the procedure, the development of these embryos was examined morphologically and histologically. following incubation, hemicords, hemicords with their own heminotochords, and dermal sinus were observed ... | 2000 | 11182638 |
| molecular cloning of newt prolactin (prl) cdna: effect of temperature on prl mrna expression. | a partial prolactin (prl) cdna was specifically pcr amplified from a cdna library constructed from pituitary mrnas of the newt (cynops pyrrhogaster) and cloned into plasmid vectors. one clone thus obtained contained a 739-bp insert encoding the c-terminal amino acid sequence of the mature hormone molecule. using this clone as a probe, the full-length newt prl cdna was screened from the cdna library. the prl cdna clone thus obtained consisted of 1024 bp encoding the entire sequence of the mature ... | 2001 | 11178884 |
| injection of a sperm extract triggers egg activation in the newt cynops pyrrhogaster. | unfertilized eggs of the newt cynops pyrrhogaster are arrested at the second meiotic metaphase. the primary signal for egg activation is a transient increase in [ca2+](i), which is triggered by the fertilizing sperm and propagates over the egg cortex as a ca2+ wave. we injected an extract of cynops sperm (se) into unfertilized eggs and induced a wave-like [ca2+](i) increase which resulted in activation and resumption of meiosis. the se-injected eggs showed degradation of cyclin b1 and dna replic ... | 2001 | 11161564 |
| newt prolactin and its involvement in reproduction. | the amino acid sequence of newt (cynops pyrrhogaster) prolactin deduced from the nucleotide sequence of its cdna showed a relatively high homology with sequences of chicken and sea turtle prolactins as well as with those of anuran prolactins. cynops prolactin receptor transcripts were detected in various tissues and organs, suggesting that prolactin plays multiple roles in urodeles. urodele prolactin was purified from the pituitaries of c. pyrrhogaster. antiserum against this prolactin was used ... | 2000 | 11149387 |
| identification and characterization of newt rad (ras associated with diabetes), a gene specifically expressed in regenerating limb muscle. | formation of the blastema is a key event for limb regeneration in urodele amphibians, and skeletal muscle has been thought to be a major origin of the multipotent blastemal mesenchyme. in the present study, we used differential display to identify the genes expressed differentially in the muscle at the amputation site. we have isolated a cdna clone that was upregulated during limb regeneration of the japanese newt, cynops pyrrhogaster. deduced amino acid sequence revealed that the cloned cdna wa ... | 2001 | 11146509 |
| molecular cloning, functional characterization, and gene expression of a follicle-stimulating hormone receptor in the testis of newt cynops pyrrhogaster. | we previously demonstrated in vitro that mammalian follicle-stimulating hormone (fsh) stimulates the proliferation of newt secondary spermatogonia and their differentiation into primary spermatocytes. in the current study, we isolated a cdna from newt testis that encodes a fsh receptor (fsh-r). the total sequence homology in the deduced protein of the newt was approximately 70% with mammalian fsh-rs. mammalian cells, transiently transfected with the cloned newt fsh-r cdna, displayed specific bin ... | 2000 | 10944452 |
| hormonal influence on the olfactory response to a female-attracting pheromone, sodefrin, in the newt, cynops pyrrhogaster. | sodefrin is a female-attracting pheromone isolated from the abdominal glands of male newts, cynops pyrrhogaster. previously, the preference of conspecific female newts for sodefrin was shown to be completely abolished by plugging the bilateral nostrils, indicating that it acts on the olfactory organ. to determine the sensitivity of the olfactory receptor cells to sodefrin, electro-olfactograms (eogs) in response to sodefrin solution were recorded from the ventral nasal epithelium of sexually dev ... | 2000 | 10874171 |
| hormonal control of urodele reproductive behavior. | hormonal control of expression of courtship behavior and of development of structures related to the reproductive behavior in two species of japanese newts, cynops pyrrhogaster and cynops ensicauda, was described. prolactin (prl) and androgen were essential factors for eliciting courtship behavior. in addition, arginine vasotocin markedly enhanced the expression of courtship behavior. prl induced migration to water, in which courtship and oviposition take place, and converted the integument from ... | 2000 | 10874169 |
| significance of egg-jelly substances in the internal fertilization of the newt, cynops pyrrhogaster. | japanese newt, cynops pyrrhogaster, undergoes internal fertilization as do most urodeles. in this study, we focused on the roles of egg-jelly in fertilization of c. pyrrhogaster and characterized the substances associated with those roles. when dry sperm were directly inseminated onto the egg, normal fertilization occurred without the presence of water. egg-jelly extract (je) prepared with steinberg's salt solution contained the activity for the initiation of sperm motility. a substance of about ... | 2000 | 10874160 |
| distribution of dorsal-forming activity in precleavage embryos of the japanese newt, cynops pyrrhogaster: effects of deletion of vegetal cytoplasm, uv irradiation, and lithium treatment. | two types of axis-deficient embryos developed after deletion of the vegetal cytoplasm: wasp-shaped embryos and permanent-blastula-type embryos. in situ hybridization revealed that neither type of axis-deficient embryo expressed goosecoid or pax-6. brachyury was expressed in the constricted waist region of the wasp-shaped embryos but was not expressed in the permanent-blastula-type embryos. further, we examined the effect of uv irradiation on japanese newt embryos. surprisingly, uv-irradiated jap ... | 2000 | 10864468 |
| prolactin induces apoptosis in the penultimate spermatogonial stage of the testes in japanese red-bellied newt (cynops pyrrhogaster). | cell death is a common feature during spermatogenesis and, in some seasonal breeding animals, is often observed at the transition stage from spermatogonia to spermatocytes. in the japanese red-bellied newt, we have previously shown that this cell death is caused by the elevated titer of plasma prl that occurs after animals are transferred to low temperature, suggesting that cell death causes the cessation of spermatocytogenesis from late autumn to early spring. in the present report, first we sh ... | 2000 | 10830286 |
| initiation of sperm motility in the newt, cynops pyrrhogaster, is induced by a heat-stable component of egg-jelly. | sperm motility in amphibians is thought to be initiated by a decrease in environmental osmolarity. however, fertilisation in the newt, cynops pyrrhogaster, is achieved in an environment without osmotic change. we show here that sperm motility initiating activity is present in jelly layer extract (je). je was gel-filtrated and a single peak with sperm motility initiating activity was detected in the fraction corresponding to about 50 kda. the activity was strengthened by heat treatment of je at 1 ... | 1999 | 10717951 |
| expression of helix-loop-helix type negative regulators of differentiation during limb regeneration in urodeles and anurans. | the urodele is capable of regenerating its limb by forming a blastema even in the adult. by contrast, the anuran, which is phylogenetically close to the urodele, loses this ability during metamorphosis and forms blastema-like tissues that develop only into a spike-like structure in the adult. in order to compare the molecular mechanism of the formation and maintenance of the blastema between the urodele and anuran, the genes encoding helix-loop-helix (hlh) type negative regulators of differentia ... | 1999 | 10646803 |
| production of a recombinant newt growth hormone and its application for the development of a radioimmunoassay. | complementary dna (cdna) encoding newt (cynops pyrrhogaster) growth hormone (ngh) was cloned from a cdna library constructed from mrnas of newt pituitary glands and was expressed in escherichia coli. based on northern blot analysis using the cdna as a probe, the ngh mrna was estimated to be 940 bases in length. the recombinant ngh (nghr) had a molecular mass of 22 kda as determined by sds-page and possessed considerable bioactivity as determined in a xenopus cartilage assay. using the nghr, we p ... | 2000 | 10620427 |
| immunohistochemical localisation of amelogenin-like proteins and type i collagen and histochemical demonstration of sulphated glycoconjugates in developing enameloid and enamel matrices of the larval urodele (triturus pyrrhogaster) teeth. | the presence of collagen in enameloid distinguishes it clearly from true enamel, but little is known about the phylogenetic relationship between these 2 tissues. it has previously been reported that amelogenins are the principal proteins of the enamel matrix, that type i collagen and chondroitin sulphates are the predominant matrices in dentine, and that amphibian and reptilian aprismatic enamels, contain no sulphated glycoconjugates, although certain sulphated substances are secreted into mamma ... | 1999 | 10580861 |
| expression of genes of type i and type ii collagen in the formation and development of the blastema of regenerating newt limb. | we cloned cdnas of alpha1(i) and alpha1(ii) collagen, and studied their expression profiles in regenerating limbs of newts, cynops pyrrhogaster. the expression of the alpha1(i) gene was markedly up-regulated at the early bud stage of the blastema. in situ hybridization experiments revealed that the alpha1(i) gene was expressed in not only mesenchymal cells of the blastema, but also the basal cells of the wound epidermis at the wound healing stage when the epidermal basement membrane was absent. ... | 1999 | 10474166 |
| 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 |
| endoderm differentiation and inductive effect of activin-treated ectoderm in xenopus. | when presumptive ectoderm is treated with high concentrations of activin a, it mainly differentiates into axial mesoderm (notochord, muscle) in xenopus and into yolk-rich endodermal cells in newt (cynops pyrrhogaster). xenopus ectoderm consists of multiple layers, different from the single layer of cynops ectoderm. this multilayer structure of xenopus ectoderm may prevent complete treatment of activin a and subsequent whole differentiation into endoderm. in the present study, therefore, xenopus ... | 1999 | 10466926 |
| sperm surface heparin/heparan sulfate is responsible for sperm binding to the uterine envelope in the newt, cynops pyrrhogaster. | the sperm-binding properties of egg envelopes are investigated in the newt, cynops pyrrhogaster. sperm binding was only seen on the uterine envelope when acrosome-reacted sperm were inseminated. no acrosome-intact sperm bound to the envelopes. by scanning electron microscopic observation, acrosome-reacted sperm were revealed to bind to a seat-like structure present on the surface of the uterine envelope. sperm binding to the uterine envelope was inhibited by treatment of eggs with heparin or hep ... | 1999 | 10445507 |
| rise of intracellular ca2+ level causes the decrease of cyclin b1 and mos in the newt eggs at fertilization. | unfertilized eggs of the newt, cynops pyrrhogaster, are arrested at the second meiotic metaphase, with activity of the m-phase promoting factor (mpf) maintained at a high level. after fertilization, the eggs resume the cell cycle, and emit the second polar body. when the change in [ca2+]i in the fertilized eggs was monitored by aequorin, an early increase in [ca2+]i was observed 5-10 min after insemination and continued for about 30 sec. a late increase in [ca2+]i then occurred 10-15 min after f ... | 1999 | 10369395 |
| elevation of plasma prolactin concentrations by low temperature is the cause of spermatogonial cell death in the newt, cynops pyrrhogaster. | temperature plays an important role in reproduction of urodeles. spermatogenesis in newts is arrested when the environmental temperature lowers. we found that transfer of newts, cynops pyrrhogaster, to low temperature (8 and 12 degrees c) caused cell death of spermatogonia just before meiosis and elevation of prolactin concentration in the newt plasma. injection of a dopamine antagonist (pimozide), which is known to increase the plasma prolactin concentration, to the newt caused significant incr ... | 1999 | 10082633 |
| sodefrin: a novel sex pheromone in a newt. | the abdominal gland in the male red-bellied newt, cynops pyrrhogaster, is the source of a female-attracting pheromone. an attempt was made to isolate and characterize the female-attracting pheromone in the abdominal glands of male newts. the active substance, named sodefrin (from the japanese 'sodefuri' which means 'soliciting') has been isolated and shown to be a novel decapeptide with the sequence, ser-ile-pro-ser-lys-asp-ala-leu-leu-lys. its minimum effective concentration in water is 0.1-1.0 ... | 1999 | 10051096 |
| cloning of cdna for newt wt1 and the differential expression during spermatogenesis of the japanese newt, cynops pyrrhogaster. | to investigate the function of wilms' tumor 1 (wt1) during spermatogenesis, cdna for newt wt1 homolog was cloned and the expression of wt1 in newt testes was examined. the cdna is 2089 bp in length and encodes 426 amino acid (aa) residues. the deduced aa sequence shares 76 and 79% homology with human and xenopus wt1, respectively. northern blot analysis shows that wt1 mrna, 3.2 and 4.5 kb in length, are expressed in the testis and kidney. both wt1 mrna species are detected in various stages of s ... | 1998 | 9865970 |
| a critical role for the optic vesicle in lens development; a reinvestigation of free lens formation in cynops pyrrhogaster. | the role of the optic vesicle in lens development was reinvestigated in cynops pyrrhogaster. to study the necessity for the optic vesicle in early lens development, the optic anlages of stage 17-27 embryos were ablated and the frequency of free lens formation was examined with lens specific markers. free lens formation was not observed when operations were performed prior to contact between the head surface epidermis and the optic vesicle (stages 17-18). on the contrary, free lens formation occu ... | 1998 | 9810703 |
| isolation and characterization of a gene expressed mainly in the gastric epithelium, a novel member of the ep37 family that belongs to the betagamma-crystallin superfamily. | ep37 family proteins are non-lens members of the betagamma-crystallin superfamily, of which expression is observed in integumental tissues of the japanese newt, cynops pyrrhogaster. in the present study, a gene was isolated that has high homology with ep37 and is transcribed mainly in the gastric epithelial cells and hence designated gep. the predicted amino acid sequence of the gep cdna contains four betagamma-crystallin motifs in the n-terminal half, as is the case in the integumental ep37 pro ... | 1998 | 9783472 |
| 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 |
| production of otoconia in the endolymphatic sac in the japanese red-bellied newt, cynops pyrrhogaster: light and transmission electron microscopic study. | the formation of otoconia in the endolymphatic sac (es) of the larval newt, cynops pyrrhogaster, has been studied by light and transmission electron microscopy. some of the epithelial cells of the es contain an abundance of swollen vesicles, golgi complexes, rough endoplasmic reticula and ribosomes at the late larval stages 50 and 51, approximately 26-30 days after eggs are laid. five days later, at stage 52, crystals are present in the vacuoles between the epithelial cells. serial sections indi ... | 1998 | 9726680 |