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accumulation of pigment granules around nuclei in early embryos of anura (amphibia).a dark spot was found to appear in each blastomere of the vegetal surface of blastulae of rana rugosa, hyla arborea. the spot divided into two before division of the blastomere, so that one new spot was allotted to each daughter cell. these dark spots were formed at early blastula stage, and persisted until the end of yolk plug stage. cytological observations showed that each dark spot corresponds to a mass of accumulated pigment granules around the nucleus of a blastomere. the accumulation incr ...19854078534
segmentina (polypylis) hemisphaerula (gastropoda: planorbidae): a new molluscan intermediate host of a human intestinal fluke neodiplostomum seoulensis (trematoda: diplostomatidae) in korea.three species of the pulmonate snails of the family planorbidae have been reported from korea, gyraulus convexiusculus, hippeutis (helicorbis) cantori, and segmentina (polypylis) hemisphaerula. of these 3 species, only h. cantori is reported as the molluscan intermediate host of neodiplostomum seoulensis, 1 of the important snail-borne human intestinal trematodes in korea. however, s. hemisphaerula was also found to be an intermediate host for n. seoulensis. in field-collected snails, h. cantori ...19968604110
calnexin: its molecular cloning and expression in the liver of the frog, rana rugosa.a 2.2-kb cdna clone encoding the endoplasmic reticulum (er) resident protein, calnexin (clx), was isolated from the frog rana rugosa liver cdna library and sequenced. the sequence encoded 622 amino acids and was 77% similar to mammalian clxs and 56% to mouse clx-t. in the phylogenetic tree, mouse clx-t was clearly diverged from other clxs including frog. the amino acid sequence of clx showed regions similar to those in frog calreticulin (clt), although clx, but not clt, contained a histidine-ric ...19968654561
molecular cloning and expression of the kif3a gene in the frog brain and testis.kif3a is a member of the kinesin superfamily proteins (kifs), but its gene has been cloned only in mouse and sea urchin. we have cloned a homolog of kif3a from the frog, rana rugosa (rrkif3a). the sequence encoded a 699 amino acid protein that shares 93% similarity with mouse kif3a (mkif3a) and 69% with sea urchin kinesin-related protein (spkrp85). the putative atp-binding domain was completely identical to that of mkif3a and spkrp85. the level of rrkif3a mrna appeared to be high in the brain an ...19979520632
molecular cloning and expression of the sf-1/ad4bp gene in the frog, rana rugosa.sf-1/ad4bp is a transcriptional factor that was originally found to be a mammalian homologue of the drosophila ftz-f1 (fushi tarazu factor 1) (), and transcribed from a gene designated the ftz-f1 gene (). ftz-f1 gene-deficient mice lack adrenal glands and gonads. besides mammals, however, the sf-1/ad4bp cdna has only been isolated to date in fish and birds. to understand its role(s) for adrenal and gonadal development in vertebrates, cloning of this gene in animals other than mammals is required ...19989831646
two sox9 messenger rna isoforms: isolation of cdnas and their expression during gonadal development in the frog rana rugosa.sox is a family of sry-related testis-determining genes. we have isolated two different mrna isoforms of the frog sox9 gene from adult frog testis cdnas. one form (sox9 alpha) encodes a 482 amino acid protein containing the hmg box, whereas the other form (sox9 beta), which completely lacks the hmg box, is a truncated 265 amino acid protein of sox9 alpha. sox9 alpha is 82% similar to mouse, 86% to chicken, and 77% to trout sox9 at the amino acid level. sox9 expression was upregulated in embryos ...200010682837
ftz-f1alpha is expressed in the developing gonad of frogs.fushi tarazu transcription factor-1 (ftz-f1), a member of the nuclear hormone receptor superfamily, is a regulator for fushi tarazu gene expression in drosophila. its expression pattern during organogenesis in vertebrates, however, is not known yet. in this study, we cloned a frog ftz-f1 homologue (rrftz-f1alpha) and analyzed its expression and localization during gonadal development of the frog rana rugosa. cloned rrftz-f1alpha cdna encoded a protein of 501 amino acids including the regions i-i ...200011072086
maternal control of sex ratio in rana rugosa: evidence from dna sexing.parental control of primary sex ratio has been reported in a mammal (red deer), some birds, and a snake. however, it remains uncertain whether other vertebrates including amphibia can control sex ratio. in this paper, we examined the possibility in a wild population of the japanese frog rana rugosa which has female heterogamety. sex ratios of their eggs were determined using dna markers. the eggs were sampled in the field from may to august in 1998. each egg was then sexed by polymerase chain re ...200011091308
expression of dax-1 during gonadal development of the frog.dax-1, a member of the nuclear hormone receptor superfamily of transcription factors, is known to be involved in gonadal development in mammals. to date, dax-1 has only been isolated in reptiles, birds and mammals. the expression of dax-1 is down-regulated in the developing testis, but persists in the ovary of mice (swain et al., nat. genet. 12 (1996) 404) and chicken (smith et al., j. mol. endocrinol. 24 (2000) 23). curiously, there is no sex difference in the expression patterns of dax-1 in th ...200111738819
wnt4 expression in the differentiating gonad of the frog rana rugosa.wnt4, a member of the wnt family, is known to influence the sex-determination cascade. in mice having a targeted deletion of wnt4, masculinization occurs in xx pups. therefore, in addition to sry, wnt4 is also involved in sex determination in mice. in humans, a chromosomal duplication of the wnt4 causes feminization of xy-individuals. thus, for better understanding of the mechanism of sex determination in vertebrates, it is necessary to examine the expression of wnt4 at early gonadal development ...200515988165
molecular cloning and expression in gonad of rana rugosa wt1 and fgf9.sry (sex-determining region on the y chromosome) is required for testicular differentiation in mammals. in addition to sry, other genes such as wt1, fgf9, dax1, dmrt1 and sox9 are widely accepted to be involved in the sex determination in vertebrates. however, the roles of these genes during sex determination still remain unclear in amphibians. this study was undertaken to examine the expression of wt1 and fgf9 in the developing gonad of amphibians. we first isolated the wt1 cdna from the frog r ...200516219985
expression of dmrt genes in the gonads of rana rugosa during sex determination.sex is determined by various transcription factors. dmrt1, a gene that contains the dm domain (doublesex/mab-3 dna-binding motif), is known to be one of the critical factors required for testicular development in vertebrates. recently, other dm domain-containing genes (dmrt genes) were isolated in mice and fish. in mice, three of the seven known dmrt genes are expressed in the embryonic gonad. in amphibians, however, only dmrt1 and dmrt4 have been cloned. to clarify the role(s) of dmrt genes in ...200717409722
expression of lhx9 isoforms in the developing gonads of rana rugosa.lhx9 is a lim-homeodomain (hd) transcription factor. transcripts of the lhx9 gene are present in the urogenital ridges of mouse embryos. in lhx9-deficient mice, a discrete gonad is not formed (birk et al., 2000). to date, however, the role of lhx9 in gonad formation has not been studied in animals other than chicks and mice. thus, this study was aimed at determining whether or not lhx9 is expressed in the developing gonads of amphibians. we first isolated cdnas of lhx9 and four isoforms, named l ...200718217486
an evolutionary witness: the frog rana rugosa underwent change of heterogametic sex from xy male to zw female.there are two basic types of heterogamety for genetic sex determination in animals and plants: male heterogamety (xx/xy) and female heterogamety (zz/zw). although apparently in opposition, the two distinct types may in fact be interchangeable. for example, in amphibians it has been shown that the heterogametic sex was originally female and may have become male at some branching point in their phylogenetic evolution. in particular, there is evidence that the male heterogametic sex determination o ...200818391544
melanocortin 4 receptors interact with antimicrobial frog peptide analogues.we have developed fluorescence polarization (fp) assays of human melanocortin 4 receptor (mc4r) in 384-well microtiter plates using tamra-ndp-msh as a tracer. the rank order of potency of agonists and antagonists agrees well relative to the published assays: shu9119>mtii>ndp alphamsh>alphamsh. we have screened libraries of korean plant extracts and frog peptide analogues in search of mc4r ligands using fp assays and cell-based cre luciferase reporter assays. we report that flgflfkvask, flgwlfkva ...200616579969
correlation between the activities of alpha-helical antimicrobial peptides and hydrophobicities represented as rp hplc retention times.ptp7 is a 13-amino acid residue peptide designed from gaegurin 6, an antimicrobial peptide isolated from skin secretions of rana rugosa. in order to examine the effect of hydrophobicity on antimicrobial activity, a series of ptp7 derivatives were constructed and analyzed the activity against bacteria and artificial membrane. we found that the mean hydrophobicity by simple summation of hydrophobicity of each constituent amino acid did not necessarily describe the hydrophobic property of antimicro ...200515894405
anti-thyroid hormonal activity of tetrabromobisphenol a, a flame retardant, and related compounds: affinity to the mammalian thyroid hormone receptor, and effect on tadpole metamorphosis.the thyroid hormone-disrupting activity of tetrabromobisphenol a (tbbpa), a flame retardant, and related compounds was examined. tbbpa, tetrachlorobisphenol a (tcbpa), tetramethylbisphenol a (tmbpa) and 3,3'-dimethylbisphenol a (dmbpa) markedly inhibited the binding of triiodothyronine (t3; 1 x 10(-10) m) to thyroid hormone receptor in the concentration range of 1 x 10(-7)-1 x 10(-4) m, while bisphenol a and 2,2-diphenylpropane were inactive. tbbpa, tcbpa, tmbpa and dmbpa did not exhibit thyroid ...200415680168
estrogen biosynthesis in the gonad of the frog rana rugosa.in certain species of amphibians gonadal differentiation is influenced by steroid hormones. in the case of the frog rana rugosa testosterone given to tadpoles reverses sex from female to male, while the opposite reversal - male to female - can be achieved using estradiol-17β. in this study, we investigated whether cyp19 (p450 aromatase), the enzyme responsible for a production of estradiol-17β, was present in the differentiating gonad of r. rugosa. initially, we immunized rabbits against frog cy ...201021036175
Phase-II conjugation ability for PAH metabolism in amphibians: Characteristics and inter-species differences.The present study examines amphibian metabolic activity - particularly conjugation - by analysis of pyrene (a four ring, polycyclic aromatic hydrocarbon) metabolites using high-performance liquid chromatography (HPLC) with fluorescence detector (FD), a mass spectrometry detector (MS) system and kinetic analysis of conjugation enzymes. Six amphibian species were exposed to pyrene (dissolved in water): African claw frog (Xenopus laevis); Tago's brown frog (Rana tagoi); Montane brown frog (Rana orn ...201121819814
role of c-terminal heptapeptide in pore-forming activity of antimicrobial agent, gaegurin 4.gaegurin 4 (ggn4) is an antimicrobial peptide of 37 amino acids isolated from the skin of a frog, rana rugosa. ggn4 has a disulfide bond between the residues 31 and 37, which is highly conserved among the antimicrobial peptides isolated from skin of the genus, rana. however, the role of this c-terminal heptapeptide motif is not well understood. in this work, we compared the membrane effects of the full-length ggn4 (c37) and ggn4 1-30 (c30), which is devoid of the c-terminal seven amino acids to ...200415357670
expression of p450 aromatase protein in developing and in sex-reversed gonads of the xx/xy type of the frog rana rugosa.gonadal differentiation in some species of amphibians is sensitive to steroids. the phenotypic sex of xx/xy-type frogs such as rana rugosa can be reversed from female to male by injection of testosterone into tadpoles, but little is known about the molecular mechanism of this sex reversal. to elucidate the mechanism of the sex differentiation, we examined the role of p450 aromatase (p450arom), an enzyme that converts testosterone to estrogen, during gonadal differentiation of amphibians. in this ...200415201061
effects of high gravity on amphibian development.in order to clarify the possible effects of high gravity environments on eggs and developing embryos, rana rugosa and xenopus laevis fertilized eggs and early embryos were raised in 2 g, 5 g, 7 g and 10 g up to the hatched tadpole stage. the results showed that: (1) high gravity significantly retarded the development of eggs and embryos beginning treatment before the blastula stage and induced various abnormalities, including two heads and microcephally suggesting that high gravity is apt to dis ...200314676383
[studies on the parasites of korean amphibia: 1. trematodes of amphibians]an investigation on the trematodes of korean amphibians was carried out during the period from april to september of 1976. a total of 883 amphibians of 6 species were examined. these frogs, toads and salamanders were collected in the areas of the han river side. and also these amphibians comprised 775 rana nigromaculata, 53 rana rugosa, 21 hyla arborea japonica, 2 bufo bufo gargarizans, 2 gallula tornieri and 30 hynobius leechi. out of the results of this work, 7 species of trematodes belonging ...197612913435
[the infection status of sparganum and gnathostoma in frogs of southern part of korea]a survey on the infection status of sparganum and gnathostoma in frogs was carried out in 11 areas in gyeongsangnam-do and cheonlanam-do province, a southern part of korea. 1. among 626 frogs examined, 4 percent were infected with sparganum, but none with gnathostoma. the infection rates of sparganum were variable according to the areas. those from kimhae, sunchun, jinhae, sachun, kosung, keoje, and hadong were 16 %, 9.1 %, 9.1 %, 4.1 %, 2 %, 2 %, and 1.5 % respectively, but frogs from hapchun, ...198312902672
the prototype of sex chromosomes found in korean populations of rana rugosa.the seventh largest chromosome in japanese populations of the frog rana rugosa morphologically evolved as a sex chromosome. the sex chromosome is xx/xy type in one geographic form and zz/zw type in another. in contrast, the seventh chromosomes are still homomorphic between the sexes in the other two geographic forms: they are more subtelocentric in the kanto form and subtelocentric in the western japanese form. to identify a prototype of the sex chromosomes, we extended our investigation in this ...200212900563
cyclosporin a inhibits thyroid hormone-induced shortening of the tadpole tail through membrane permeability transition.regression of the tadpole tail through muscule cell apoptosis is one of the most spectacular events in amphibian metamorphosis. accumulated evidence has shown that mitochondrial membrane permeability transition (mpt) plays a crucial role in apoptosis. previously we reported that cyclosporin a (csa) suppressed 3,5,3'-triiodothyronine (t(3))-induced mitochondrial swelling, which was coupled with cytochrome c (cyt.c) release through mpt [comp. biochem. phys. 130 (2001) 411-418]. to further clarify ...200312831767
an immunohistochemical study on the neuropeptide-producing endocrine cells in the alimentary tract of wrinkled frog, rana rugosa (ranidae).the regional distribution and relative frequency of neurohormonal peptides-producing endocrine cells were demonstrated in the alimentary tract of wrinkled frog, rana rugosa, using eight types of specific antisera raised against mammalian regulatory peptides. the alimentary tract of frog was divided into six portions from esophagus to rectum. most of the cells in the epithelial lining portion, between epithelial cells, were generally spherical or spindle shaped having long cytoplasmic process tha ...200312620241
solution structure of the antimicrobial peptide gaegurin 4 by h and 15n nuclear magnetic resonance spectroscopy.gaegurin 4 (ggn4) is a 37-residue antimicrobial peptide isolated from the skin of a korean frog, rana rugosa. this peptide shows a broad range of activity against prokaryotic cells but shows very little hemolytic activity against human red blood cells. the solution structure of ggn4 was studied by using circular dichroism (cd) and nmr spectroscopy. cd investigations revealed that ggn4 adopts mainly an alpha-helical conformation in trifluoroethanol/water solution, in dodecylphosphocholine and in ...200010785392
ligand binding inhibitors of a1 adenosine receptor from rana rugosa are phospholipase a2s.inhibitors of the a1 adenosine receptor were isolated from the skin extract of korean frog, rana rugosa. the frog-skin extract was prepared by an electrical shock and fractionated with c4 followed by c18 reverse-phase hplc. two a1 receptor inhibitors were isolated using a filter binding assay and the molecular masses of the proteins were estimated by matrix-assisted laser desorption ionization time-of-flight mass spectrometry to be 15 347 and 15 404 da, respectively. the inhibitory activity was ...200010691971
the origin and differentiation of the heteromorphic sex chromosomes z, w, x, and y in the frog rana rugosa, inferred from the sequences of a sex-linked gene, adp/atp translocase.sex chromosomes of the japanese frog rana rugosa are heteromorphic in the male (xx/xy) or in the female (zz/zw) in two geographic forms, whereas they are still homomorphic in both sexes in two other forms (hiroshima and isehara types). to make clear the origin and differentiation mechanisms of the heteromorphic sex chromosomes, we isolated a sex-linked gene, adp/atp translocase, and constructed a phylogenetic tree of the genes derived from the sex chromosomes. the tree shows that the hiroshima g ...19989866197
testicular cycles in three species of korean frogs: rana nigromaculata, rana rugosa, and rana dybowskii.seasonal changes in testicular structure and function in three species of korean frogs (rana nigromaculata, r. rugosa, and r. dybowskii) having different breeding seasons and habitats were examined throughout the year. r. nigromaculata live in rice fields and breed in early may. their gonadosomatic index (gsi) and testis weight decreased slightly from may until july, but increased markedly from august to high levels through december. the diameter (cross-sectional area) of seminiferous tubules ch ...19989707480
molecular cloning of cdna for the zeta isoform of the 14-3-3 protein: homologous sequences in the 3'-untranslated region of frog and human zeta isoforms.14-3-3 proteins constitute a family of well-conserved eukaryotic proteins that possess diverse biochemical activities such as regulation of gene transcription, cell proliferation and activation of protein kinase c. at least 7 subtypes (alpha to theta) of 14-3-3 protein are known, but the zeta subtype of this protein has been cloned only in mammals. we cloned the zeta subtype of 14-3-3 protein (14-3-3 zeta) from the frog, rana rugosa. the sequence encoded 245 amino acids that share 92% identity w ...19979450388
structural differences between xx and zw sex lampbrush chromosomes in rana rugosa females (anura: ranidae).in this study we investigated the morphology and pairing behavior of sex lampbrush chromosomes of xx and zw females of rana rugosa from five localities in japan. whereas lampbrush chromosomes of xx females from hiroshima and isehara had subterminally located centromeres and showed remarkable similarity, those of xx females from hamakita had the centromeres in the middle. analysis of landmark configurations revealed that chromosome xq of hamakita females closely resembled a part of xq of hiroshim ...19968854883
strong expression of the calreticulin gene in the liver of rana rugosa tadpoles, but not adult frogs.in the present paper we report the purification of calreticulin (clt) from livers of the frog, rana rugosa, the cloning and sequencing of its cdna, and the clt gene expression. clt with m(r) = 52 kda, estimated by sds-page, was purified from frog livers. using rat clt cdna as a probe, a 2.4-kilobase frog cdna clone was isolated from a frog liver cdna library. the cdna encoded 419 amino acids including an 18-residue nh2-terminal signal sequence that was 76% homologous to the rat clt sequence and ...19968795287
motion sickness in amphibians.we explored the question of whether amphibians get motion sickness by exposing anurans (frogs) and urodeles (salamanders) to the provocative stimulus of parabolic aircraft flight. animals were fed before flight, and the presence of vomitus in their containers after flight was used to indicate motion-induced emesis. none of the species that we studied vomited during the 8 to 10 parabolas of each flight. however, at least one specimen from each of the anuran species rana rugosa, rana nigromaculata ...19938216158
isolation and characterization of novel antimicrobial peptides, rugosins a, b and c, from the skin of the frog, rana rugosa.three antimicrobial peptides were isolated from the skin of rana rugosa. the major component, designated rugosin a, consisted of 33 amino acid residues and had structural homology (45%) with brevinin-2 of rana porosa brevipoda. this peptide strongly inhibited the growth of gram-positive bacteria (e.g. staphylococcus aureus 209p). the second peptide (rugosin b), a minor component, also had 33 amino acid residues, but was less homologous (33%) with brevinin-2. this peptide exhibited a striking ant ...19957612013
interspecific variation in the emetic response of anurans.1. the emetic response of seven species (four genera) of frogs to apomorphine hydrochloride, copper sulfate, antimonyl potassium tartrate and mechanical stimulation at the esophageal orifice was surveyed. xenopus laevis and rhacophorus schlegelii were more sensitive to systemically administered apomorphine than were the other species tested. 2. the sensitivity of rana rugosa to apomorphine varied with the season. 3. all of the species showed vigorous vomiting behavior after the oral administrati ...19911687529
the studies on the active peptide in the skin of rana rugosa. ii. the structure of ranatensin-r, the new ranatensin analogue, and granuliberin-r, the new mast cell degranulating peptide. 1979445685
the studies on the active peptide on smooth muscle in the skin of rana rugosa, thr6-bradykinin and its analogous peptide, ranakinin-r. 1979445684
diversity in the origins of sex chromosomes in anurans inferred from comparative mapping of sexual differentiation genes for three species of the raninae and xenopodinae.amphibians employ genetic sex determination systems with male and female heterogamety. the ancestral state of sex determination in amphibians has been suggested to be female heterogamety; however, the origins of the sex chromosomes and the sex-determining genes are still unknown. in xenopus laevis, chromosome 3 with a candidate for the sex- (ovary-) determining gene (dm-w) was recently identified as the w sex chromosome. this study conducted comparative genomic hybridization for x. laevis and xe ...200818850318
some observations on the fine structure of the epidermal-dermal junction in the skin of the frog tadpole, rana rugosa. 20144210759
comparative chromosome mapping of sex-linked genes and identification of sex chromosomal rearrangements in the japanese wrinkled frog (rana rugosa, ranidae) with zw and xy sex chromosome systems.there are regional variations of sex chromosome morphologies in the japanese wrinkled frog, rana rugosa (2n = 26): heterogametic zz/zw-type and xx/xy-type sex chromosomes, and two different types of homomorphic sex chromosomes. to search for homology between the zw and xy sex chromosomes and the chromosome rearrangements that have occurred during sex chromosomal differentiation in r. rugosa, we performed chromosome mapping of sexual differentiation genes for r. rugosa by fish. three genes, ar, s ...200818484182
application of metamorphosis assay to a native japanese amphibian species, rana rugosa, for assessing effects of thyroid system affecting chemicals.the aims of this study were to assess the utility of a metamorphosis assay for detecting thyroid hormone-disrupting chemicals using rana rugosa, a domestic frog species in japan, and to compare species differences in sensitivity to thyroxine (t(4)) and propylthiouracil (ptu) among r. rugosa, xenopus laevis and xenopus (silurana) tropicalis. tadpoles of r. rugosa (tk stages iii/iv) were exposed to standard test chemicals for acceleration (t(4)) and inhibition (ptu) of metamorphosis for 28 days in ...200919394694
gaegurin-6 stimulates insulin secretion through calcium influx in pancreatic beta rin5mf cells.gaegurin-6, an antimicrobial peptide that belongs to the alpha-helix family, was isolated from the skin of rana rugosa. gaegurin-6 contains a hydrophobic motif at the n-terminus and a helical region at the c-terminus. although gaegurin-6 has been implicated in cell signaling, the precise role in insulin secretion is currently unknown. we have attempted to determine whether gaegurin-6 affects insulin secretion and tried to elucidate the relationship between the structural motifs and biological ac ...201019651162
promoter activity and chromosomal location of the rana rugosa p450 aromatase (cyp19) gene.sex is determined genetically in amphibians, but is reversed occasionally by steroid hormones. the phenotypic sex of some amphibian species can be reversed from male to female by estrogens. estrogens, which are synthesized from testosterone irreversibly by the enzyme p450 aromatase (cyp19), are essential for ovarian development in vertebrates. cyp19 expression is reportedly regulated by steroidogenic factor-1 (sf-1), also designated as ad4bp, in fish and mammals. however, it is unknown if this i ...200616547409
habitat connectivity and resident shared predators determine the impact of invasive bullfrogs on native frogs in farm ponds.habitat connectivity is considered to have an important role on the persistence of populations in the face of habitat fragmentation, in particular, for species with conservation concern. however, it can also impose indirect negative effects on native species through the spread of invasive species. here, we investigated direct and indirect effects of habitat connectivity on populations of invasive bullfrogs and native wrinkled frogs and how these effects are modified by the presence of common car ...201424827433
odorous and non-fatal skin secretion of adult wrinkled frog (rana rugosa) is effective in avoiding predation by snakes.the roles played by nonfatal secretions of adult anurans in the avoidance of predation remain unknown. the adult wrinkled frog (rana rugosa) has warty skin with the odorous mucus secretion that is not fatal to the snake elaphe quadrivirgata. we fed r. rugosa or fejervarya limnocharis, which resembles r. rugosa in appearance and has mucus secretion, to snakes and compared the snakes' responses to the frogs. compared to f. limnocharis, r. rugosa was less frequently bitten or swallowed by snakes. t ...201324278410
molecular cloning and characterization of anti-müllerian hormone (amh) from the japanese wrinkled frog, rana rugosa.the role of anti-müllerian hormone (amh) during gonad development has been studied extensively in many species of mammal, bird, reptile, and fish but remains unresolved in amphibians. in male mammalian embryos, sox9 activates amh expression, which initiates regression of the müllerian ducts. however, sox9 (sry-related hmg box 9) is unlikely to initiate amh in chicken, because amh precedes sox9 expression in this species. to clarify whether amh is involved in testicular differentiation in amphibi ...201525714810
eimeria tiliquae n. sp. (apicomplexa: eimeriidae) from the shingleback skink (tiliqua rugosa rugosa).a new species, eimeria tiliquae n. sp. is described from a shingleback skink (tiliqua rugosa rugosa). sporulated oocysts (n=50) are spherical to subspherical, with colourless trilaminate oocyst wall, 0.7±0.1 (0.5-0.75) thick. oocyst with 4 spheroidal to subspheroidal sporocysts. oocyst length, 13.7±0.9 (12.0-16.3); oocyst width, 12.8±0.9 (11.5-15.0); oocyst length/width (l/w) ratio, 1.07±0.05 (1.0-1.2). micropyle, oocyst residuum and polar granule absent. sporocysts with globular sporocyst resid ...201323201215
molecular cytogenetic characterization of telomere-specific repetitive dna sequences in rana rugosa.we performed a molecular cloning of the glutamic oxaloacetic transaminase (got1) gene from r. rugosa, and determined its chromosomal location. this gene was reportedly localized near the sex-determining region of the zw sex chromosomes in the frog buergeria buergeri; however, the got1 gene was mapped to the distal end of chromosome 9 in r. rugosa using a got1 cdna fish probe. this was also the case when a 46.3 kb genomic clone containing exon 8 and 9 and the 3'-neighboring region of the got1 gen ...201121328702
extraordinary diversity in the origins of sex chromosomes in anurans inferred from comparative gene mapping.sex determination in frogs (anurans) is genetic and includes both male and female heterogamety. however, the origins of the sex chromosomes and their differentiation processes are poorly known. to investigate diversity in the origins of anuran sex chromosomes, we compared the chromosomal locations of sex-linked genes in 4 species: the african clawed frog (xenopus laevis), the western clawed frog (silurana/x. tropicalis), the japanese bell-ring frog (buergeria buergeri), and the japanese wrinkled ...201526089094
different chemical cues originating from a shared predator induce common defense responses in two prey species.in freshwater ecosystems, inducible defenses that involve behavioral or morphological changes in response to chemical cue detection are key phenomena in prey-predator interactions. many species with different phylogenetic and ecological traits (e.g., general activity patterns and microhabitats) use chemical cues to avoid predators. we hypothesized that prey species with a shared predator, but having different ecological traits, would be adapted to detect different chemical cues from the predator ...201323065237
effects of water management, connectivity, and surrounding land use on habitat use by frogs in rice paddies in japan.in japan, rice paddies play an important role as a substitute habitat for wetland species, and support rich indigenous ecosystems. however, since the 1950s, agricultural modernization has altered the rice paddy environment, and many previously common species are now endangered. it is urgently necessary to evaluate rice paddies as habitats for conservation. among the species living in rice paddies, frogs are representative and are good indicator species, so we focused on frog species and analyzed ...201222943781
early 1900 s detection of batrachochytrium dendrobatidis in korean amphibians.the pathogenic fungus batrachochytrium dendrobatidis (bd) is a major conservation concern because of its role in decimating amphibian populations worldwide. we used quantitative pcr to screen 244 museum specimens from the korean peninsula, collected between 1911 and 2004, for the presence of bd to gain insight into its history in asia. three specimens of rugosa emeljanovi (previously rana or glandirana rugosa), collected in 1911 from wonsan, north korea, tested positive for bd. histology of thes ...201525738656
limb regenerative capacity of four species of japanese frogs of the families hylidae and ranidae.the regenerative capacity of limbs was investigated by amputation of limbs at the zeugopodium in postmetamorphic froglets and adults of various sizes in four species of japanese frogs, all of which showed some regeneration at these ages. in hyla arborea japonica and rana brevipoda porosa most young froglets regenerated their limbs well; however, the rate of regeneration decreased with the age of amputation, and the limb became nonregenerative in adults. limbs of adults in rana rugosa and r. japo ...19827120419
acetyl-l-carnitine suppresses thyroid hormone-induced and spontaneous anuran tadpole tail shortening.mitochondrial membrane permeability transition (mpt) plays a crucial role in apoptotic tail shortening during anuran metamorphosis. l-carnitine is known to shuttle free fatty acids (ffas) from the cytosol into mitochondria matrix for β-oxidation and energy production, and in a previous study we found that treatment with l-carnitine suppresses 3, 3', 5-triiodothyronine (t3 ) and ffa-induced mpt by reducing the level of ffas. in the present study we focus on acetyl-l-carnitine, which is also invol ...201323489246
an x-linked body color gene of the frog rana rugosa and its application to the molecular analysis of gonadal sex differentiation.we identified a sex-linked, recessive body color gene, presently designated w (whitish-yellow), in the frog rana rugosa from the iwakuni population in western japan. this is the first time a sex-linked body color gene was found in amphibians so far. in this population of r. rugosa, males are the heterogametic sex, but the sex chromosomes are still homomorphic. when heterozygous males (ww), which were produced by crossing a whitish-yellow female (ww) found in the field and a wild-type male (ww) o ...201121832826
isolation and characterization of novel microsatellite loci in the wrinkled frog.the wrinkled frog, rana rugosa, is a species complex that inhabits plains and mountains near freshwater bodies throughout east asia, encompassing china, korea, japan, and the russian primorye region. although extensive efforts are required to estimate cryptic diversity in the r. rugosa complex, no specifically designed microsatellite loci are available. here, novel and polymorphic microsatellites were isolated based on the construction of a microsatellite-enriched library and characterized using ...201626909906
isolation and characterization of the cyp17a1 gene and its processed pseudogene in rana rugosa.cyp17a1 expression is up-regulated in the gonad in rana (glandirana) rugosa tadpoles treated with androgens to induce female-to-male sex-reversal. in this study, we isolated the cyp17a1 gene and its processed pseudogene from r. rugosa. the former was found to consist of 8 exons, and the latter a single-exon gene, designated cyp17a1p. the sequence of the promoter region of cyp17a1 differed from that of cyp17a1p. we found several consensus binding-sites for candidate transcription factors includin ...201121664481
up-regulation of fshr expression during gonadal sex determination in the frog rana rugosa.in vertebrates, gonadal production of steroid hormones is regulated by follicle-stimulating hormone (fsh) and luteinizing hormone (lh) via their receptors designated fshr and lhr, respectively. we have shown recently that steroid hormones are synthesized in the differentiating gonad of tadpoles during sex determination in the frog rana rugosa. to elucidate the role of gonadotropins (gths) and their receptors in the production of gonadal steroid hormones during sex determination, we isolated the ...201121521644
accumulation and pharmacokinetics of estrogenic chemicals in the pre- and post-hatch embryos of the frog rana rugosa.amphibian eggs spawned in water are exposed immediately to various chemicals present in their water. the present study aimed to investigate the accumulation and pharmacokinetics of 17α-ethynylestradiol (ee(2)), bisphenol a (bpa), and nonylphenol (np), as well as 17β-estradiol (e(2)), in the pre-hatch and post-hatch embryos of the frog rana rugosa. fertilized eggs were exposed to chemicals at a final concentration of 500 nm in breeding water for two days, then the embryos with jelly coats were re ...201623160672
isolation and characterization of vasa in the frog rana rugosa.we cloned a cdna encoding vasa, a member of the dead (asp-glu-ala-asp) family of proteins, from the ovary of the frog rana rugosa. comparative alignment of amino acid sequences with known vasa from several species of vertebrate showed that the r. rugosa orthologue shares eight conserved regions with vasa from other vertebrates. vasa gene expression was restricted to the testis and ovary among ten different tissues examined. vasa expression showed no sexual dimorphism during sex determination in ...201020623802
structural changes in gonadal basement membranes during sex differentiation in the frog rana rugosa.here we report that structural changes in gonadal basement membranes during sex differentiation in the frog rana rugosa are revealed using an antibody to its laminin component. immunohistochemical staining indicated that the first sexual dimorphism appeared in testicular cords and ovarian cavities in differentiating gonads of tadpoles at st. 25-3w, three weeks after they reached st. 25. during development, as the testis enlarged, testicular cord partitions appeared to form by invagination of the ...201020535767
meiotic recombination counteracts male-biased mutation (male-driven evolution).meiotic recombination is believed to produce greater genetic variation despite the fact that deoxyribonucleic acid (dna)-replication errors are a major source of mutations. in some vertebrates, mutation rates are higher in males than in females, which developed the theory of male-driven evolution (male-biased mutation). however, there is little molecular evidence regarding the relationships between meiotic recombination and male-biased mutation. here we tested the theory using the frog rana rugo ...201626791621
molecular cloning and characterization of oocyte-specific pat1a in rana rugosa frogs.the pat1 gene is expressed in the immature oocytes of xenopus, and is reportedly involved in regulating the translation of maternal mrnas required for oocyte-maturation. however, it is still unknown when pat1a first appears in the differentiating ovary of amphibians. to address this issue, we isolated the full-length pat1a cdna from the frog rana rugosa and examined its expression in the differentiating ovary of this frog. among eight different tissues examined, the pat1a mrna was detectable in ...201526136381
androgen receptor of the frog rana rugosa: molecular cloning and its characterization.the androgen receptor(ar) gene is located on the z and w sex chromosomes in the frog rana rugosa, designated z- and w-ar, respectively. among various tissues of an adult frog, ar expression levels were highest in the testis and brain. in the testis, ar was expressed in germ cells. ar expression occured in developing embryos from stage 21 and was very high in the gonad of a male tadpole before the onset of sex determination. when z- and w-ar were expressed in xenopus a6 cells, they activated andr ...200919722274
sox3: a transcription factor for cyp19 expression in the frog rana rugosa.cyp19 is expressed at a high level in the gonad of the female tadpole of the frog rana rugosa during sex determination. to identify sequence elements important for expression of cyp19, we isolated a genomic clone (approximately 40 kbp) carrying r. rugosa cyp19 and analyzed the nucleotide sequence of the 5'-flanking region to search for potential transcription factor binding sites. sox (sry-related hmg box) protein and sf1 binding sites were found in the ovary-specific promoter region of cyp19. b ...200919481139
independent degeneration of w and y sex chromosomes in frog rana rugosa.the frog rana rugosa uniquely possesses two different sex-determining systems of xx/xy and zz/zw, separately in the geographic populations. the sex chromosomes of both types share the same origin at chromosome 7, and the structural differences between x and y or z and w were evolved through two inversions. in order to ascertain the mechanisms of degeneration of w and y chromosomes, we gynogenetically produced homozygous diploids ww and yy and examined their viability. tadpoles from geographic gr ...201222143254
solution structure and membrane interaction mode of an antimicrobial peptide gaegurin 4.we have applied nmr spectroscopy to determine the high-resolution structure of gaegurin 4, a 37-residue antimicrobial peptide from rana rugosa, under varying hydrophobic conditions. even in 100% h2o, gaegurin 4 contains a nascent turn near its c-terminal rana box. under a more hydrophobic condition it forms two amphipathic helices, one long encompassing residues 2-23 and the other consisting of residues 25-34, similar to what has been observed in cecropin a. functional implication of the helix-b ...200717141187
establishment of transactivation assay systems using fish, amphibian, reptilian and human thyroid hormone receptors.thyroid hormones are essential for the regulation of a wide range of biological processes associated with normal development and metabolism in vertebrates. for the screening of chemicals with a potential thyroid hormone and anti-thyroid hormone activities, we have established transient transactivation assay systems using thyroid hormone receptors (trα and trβ) from three frog species (xenopus laevis, silurana tropicalis and rana rugosa), a fish (oryzias latipes), an alligator (alligator mississi ...201323112079
the yellow mutation in the frog rana rugosa: pigment organelle deformities in the three types of chromatophore.crossing experiments revealed that a single recessive gene mutation (yellow) gives rise to the yellow phenotype of rana rugosa in japan. ultrastructural observation of dermal chromatophores showed that the pigment organelles; melanosomes, pterinosomes, and reflecting platelets, all had structural deformities. this suggests that the yellow gene acts at the level of a primordial pigment organelle common to the three types of chromatophore.200111549112
expression of ftz-f1alpha in frog testicular cells.fushi tarazu transcription factor-1 (ftz-f1), a member of a nuclear hormone receptor superfamily, is a transcriptional regulator for fushi tarazu gene expression in drosophila (ueda et al., '90). we have cloned a homologue (rrftz-f1alpha) of the ftz-f1 gene of the frog rana rugosa. the gene, in frogs, has been shown to have high expression level in the testis (nakajima et al., 2000). in this study, the rt-pcr analysis showed that the ftz-f1alpha mrna level in adult frogs did not change throughou ...200111471148
isolation and structural characterization of novel rugosin a-like insulinotropic peptide from the skin secretions of rana saharica frog.skin secretions of rana saharica were evaluated for the isolation and characterization of novel insulinotropic peptides. crude secretions obtained from young adult frogs by mild electrical stimulation of the dorsal skin surface were purified by reversed-phase hplc yielding 80 fractions. in acute incubations with glucose-responsive brin-bd11cells, fractions 36-43, 46-54 and 57-63 showed the significant 2-8-fold increase in insulin-releasing activity (p<0.001) compared with 5.6mm of glucose alone. ...200516269346
structural organization and expression of the gaegurin 4 gene of rana rugosa.gaegurin 4 (ggn4) is a member of the antimicrobial peptide subfamily isolated from the skin of rana rugosa. we cloned gdna encoding ggn4 to study its gene organization and regulation of expression. the ggn4 gene occurs in single copy in the r. rugosa genome and contains a single intron of about 3.4 kb. the transcription start site is located 68 bases upstream of the translation initiation codon. the ggn4 gene was expressed both in xenopus kidney epithelial cells (a6) and in xenopus oocytes using ...200011004488
involvement of androgen receptor in sex determination in an amphibian species.in mice and humans, the androgen receptor (ar) gene, located on the x chromosome, is not known to be involved in sex determination. in the japanese frog rana rugosa the ar is located on the sex chromosomes (x, y, z and w). phylogenetic analysis shows that the ar on the x chromosome (x-ar) of the korean r. rugosa is basal and segregates into two clusters: one containing w-ar of japanese r. rugosa, the other containing y-ar. ar expression is twice as high in zz (male) compared to zw (female) embry ...201424826887
alteration of the sex determining system resulting from structural change of the sex chromosomes in the frog rana rugosa.rana rugosa in japan is divided into four geographical races on the basis of the karyotype of the sex chromosomes: one in which heteromorphic sex chromosomes occur in the female sex (zw/zz-system), another in which they are present in males (xx/xy-system), and the remaining two in which no heteromorphism is seen in either sex. the last two inherit the xx/xy sex determining system. y and z chromosomes in the former two are of the same karyotype as the no. 7 chromosomes seen in one of the latter t ...200010653970
is a sex-determining gene(s) necessary for sex-determination in amphibians? steroid hormones may be the key factor.amphibians have 2 genetic sex-determining systems, one with male (xx/xy) and one with female (zz/zw) heterogamety. while the ancestral state of sex-determination is thought to be female heterogamety, male and female heterogametic types were probably once interchangeable. the japanese frog rana rugosa has both xx/xy and zz/zw systems within a single species in certain local populations. however, steroid hormones can alter the phenotypic sex epigenetically. in r. rugosa, steroidogenic enzyme expre ...201322797358
antimicrobial activity and conformation of gaegurin-6 amide and its analogs.a function of the intra-disulfide bridge located at the c-terminal of rana peptides has not been extensively studied. to investigate the function of the disulfide bridge related to the activity and the structure, we chose gaegurin-6, isolated from rana rugosa as a model peptide and synthesized linear analogs. the reduction of the disulfide bridge resulted in the complete loss of antimicrobial activity while replacements of cysteines by serines retained antimicrobial activity. circular dichroism ...19989880068
the zz/zw sex-determining mechanism originated twice and independently during evolution of the frog, rana rugosa.the japanese frog, rana rugosa, has two distinct sex chromosome types, xx/xy and zz/zw. these two types are found in localized groups, separated geographically by a boundary area predicted to lie somewhere around lake biwa in central japan. to determine this precise boundary, the heterogametic sex of 18 populations around lake biwa was examined by genotyping sex-linked genes. phylogenetic relationships between the populations were also analyzed using mitochondrial 12s rrna gene. results showed t ...200818000521
inhibitor and temperature effect on catalase in the liver of adult diploid and haploid rana rugosa.the authors succeeded in raising a single mature haploid rana rugosa female to the age of 2 years from an egg artificially fertilized with ultraviolet-irradiated sperm. in order to discover why this particular haploid individual should survive so long, hydrogen peroxide detoxifying catalase in the liver of this individual and age-matched diploids was examined and compared for total activity, temperature stability, and chemical inhibition. total activity was found to be significantly higher in th ...19989530823
change of the heterogametic sex from male to female in the frog.two different types of sex chromosomes, xx/xy and zz/zw, exist in the japanese frog rana rugosa. they are separated in two local forms that share a common origin in hybridization between the other two forms (west japan and kanto) with male heterogametic sex determination and homomorphic sex chromosomes. in this study, to find out how the different types of sex chromosomes differentiated, particularly the evolutionary reason for the heterogametic sex change from male to female, we performed artif ...200312807781
comparison of catalase in diploid and haploid rana rugosa using heat and chemical inactivation techniques.the present study examines differences in the hydrogen peroxide (h2o2) detoxifying enzyme, catalase, found in the tails and livers of diploid and haploid rana rugosa. investigative techniques include measurement of catalase activity and tests for temperature stability and chemical inhibition. catalase from the tails of pre-climactic (stage xxiii) haploids was found to be over three times as h2o2 destructive as catalase from similar tails of diploids. catalase from the livers of newly metamorphos ...19979467862
seasonal variations in integumental glycoconjugates of rana rugosa.although environmental conditions can influence the expression of glycoconjugates (gcs) in the epidermis and cutaneous gland of amphibians, seasonal features regarding gcs in frogs have rarely been studied. in the present study, we report the seasonal variations of the integumental gcs in rana rugosa.19979294646
evolutionary changes in sensitivity to hormonally induced gonadal sex reversal in a frog species.the japanese frog glandirana rugosa is unique in that it shows geographic variation in sex chromosome differentiation and heterogametic sex determination. to elucidate the cause of interpopulation differences in gonadal sex differentiation, we investigated hormonally induced sex reversal and the expression patterns of genes associated with sex determination during early tadpole development. we found that sex reversal was easily induced in xx females and xy males of 2 forms (west-japan and east-j ...201627160089
do reactive oxygen species underlie the mechanism of apoptosis in the tadpole tail?although "programmed cell death" has been postulated to underlie the mechanism for the disappearance of the tadpole tail, critical factors that trigger this phenomenon remain to be elucidated. to investigate the mechanism for the disappearance of the tail, changes in morphology, dna status and the enzymes which metabolize reactive oxygen species were determined in the tail of rana rugosa tadpoles. histological examination revealed that apoptotic cell death was apparent in the tail myocytes durin ...19979199892
structural changes in female-to-male sex-reversing gonads of rana rugosa.the phenotypic sex of many species of amphibians is subject to reversal by steroid hormones. the mechanism of this process, however, still remains largely unknown. as a step toward understanding the histological changes during sex reversal in amphibians, we analyzed two- and three-dimensional (2d and 3d) structures of sex-reversing gonads in rana rugosa frogs. 2d views revealed that many oocytes in the wild-type ovary disappeared during female-to-male sex-reversal concomitant with the emergence ...201627076437
antimicrobial peptides from the skin of a korean frog, rana rugosa. 19957733950
antimicrobial peptides from the skin of a korean frog, rana rugosa.six antimicrobial peptides, named gaegurins, were isolated from the skin of a korean frog, rana rugosa, and their amino acid sequences were determined by automated edman degradation. all peptides contain two invariant cysteine residues, one at their c-terminus and the second at the seventh position from the c-terminus. the heptapeptides containing these two cysteine residues, which we designate 'rana boxes', are conserved in the antimicrobial peptides derived from other rana species. each peptid ...19947999137
effects of an augmented nerve supply on forelimb regeneration in the adult mud frog, rana rugosa.forelimbs of the adult mud frog rana rugosa, when amputated midway through the zeugopodium, regenerate heteromorphically. the resulting regenerative outgrowths were mostly rod shaped and consisted of a cartilaginous core, in which the base was ossified, and muscle elongated distally along the cartilage, the whole being covered by connective tissue and skin. the tip of the regenerating muscle reached a point distally about one third of the length of the regenerative outgrowths. when the innervati ...19921447558
sex determination in amphibians.the heterogametic sex is male in all mammals, whereas it is female in almost all birds. by contrast, there are two heterogametic types (xx/xy and zz/zw) for genetic sex determination in amphibians. though the original heterogametic sex was female in amphibians, the two heterogametic types were probably interchangeable, suggesting that sex chromosomes evolved several times in this lineage. indeed, the frog rana rugosa has the xx/xy and zz/zw sex-determining systems within a single species, depend ...200918996493
synthesis of the dodecapeptide amide corresponding to the entire amino acid sequence of granuliberin-r, a new frog skin peptide from rana rugosa. 1978657408
a new mast cell degranulating peptide, granuliberin-r, in the frog (rana rugosa) skin. 1977589733
electron microscopic observations on the parathyroid gland of the edta-treated frog, rana rugosa. 1976825800
some observations on the fine structure of the myotendinous junction in myotomal muscle of the tadpole tail.myotendinous junctions in the myotomal tail muscles of the tadpole of rana rugosa were examined by electron microscopy. at the site of the myotendinous junction, the sarcolemma is covered on its sarcoplasmic aspect by the connecting filament layer and the attachment layer, and on the extracellular aspect by the intermediary later and the external lamina, with associated collagen fibrils. the intermediary layer consists of filamentous structures which closely resemble "microfibrils" (hanak and bö ...19761248047
elastic fibres in the notochord of rana rugosa tadpoles. 19744442088
molecular cloning and gene expression of foxl2 in the frog rana rugosa.foxl2 is a transcription factor that plays a crucial role in the regulation of the early development of the female gonad in mammals and fish. however, little is known regarding its role in ovarian differentiation in amphibians. in this study, we isolated a foxl2 cdna from the ovary of the frog rana rugosa and xenopuslaevis and examined its expression during gonadal sex differentiation in r. rugosa. alignment of known foxl2 sequences from vertebrates showed high identity of the foxl2 open reading ...201718805419
immunohistochemical detection and biological activities of cyp17 (p450c17) in the indifferent gonad of the frog rana rugosa.sex steroids play a crucial role in the gonad differentiation in various species of vertebrates. however, little is known regarding the localization and biological activity of steroid-metabolizing enzymes during gonadal sex differentiation in amphibians. in the present study, we showed by real-time rt-pcr analysis that the expression of cyp17, one of the key steroidogenic enzymes, was higher in the indifferent gonad during sex differentiation in male than in female tadpoles of rana rugosa but th ...200818675354
steroidogenic gene expression during sex determination in the frog rana rugosa.rana rugosa is unique among frog species in that it has two distinct types of sex chromosomes in two separate forms (xx/xy and zz/zw). treatment with sex steroids can reverse its gender from female to male or male to female. this phenomenon makes it a novel model for studying gonadal differentiation. the physiological role of sex steroids in sex differentiation in amphibians is yet unclear, however. to address this issue, we cloned the cdnas of 17betahsd types 8 (17betahsd8) and 12 (17betahsd12) ...200818550057
differential display analysis of gene expression in female-to-male sex-reversing gonads of the frog rana rugosa.sex steroids play pivotal roles in gonadal differentiation in many species of vertebrates. the sex can be reversed from female to male by testosterone in the japanese wrinkled frog rana rugosa, but it is still unclear what genes are up- or down-regulated during the xx sex-reversal in this species. to search the genes for the female-to-male sex-reversal, we employed differential display and 5'/3'-race. consequently, we isolated from the gonads at day 8 after testosterone injection 24 different cd ...200817942098
elevated expression of p450c17 (cyp17) during testicular formation in the frog.sex steroids play decisive roles in gonadal differentiation in many species of vertebrates. the sex can be changed by sex steroids in some species of amphibians, but the mechanism of the sex-reversal is largely unknown. in this study, we cloned and characterized 3 cdnas encoding sex steroid-synthesizing enzymes, i.e., cyp11a1, cyp17 and 3beta-hsd from the frog rana rugosa. rt-pcr analysis showed that the cyp17 expression was much higher in male gonads than in female ones during sex determination ...200817434514
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