presence of prolactin receptors in eel liver and carp kidney and growth hormone receptor in eel liver.1. 125i-labelled ovine prolactin and bovine growth hormone were used to test for the presence of prolactin and growth hormone receptors in membrane prepared from tissues of the white eel anguilla japonica, the carp ctenopharynogodon idellus and the ricefield eel monopterus albus. 2. high levels of specific 125i-labelled ovine prolactin binding were found in white eel liver membranes and carp kidney membranes. 3. high levels of specific 125i-labelled bovine growth hormone binding were detected in ...19911678335
development of a homologous radioimmunoassay for eel prolactin.a highly specific and homologous radioimmunoassay (ria) for the measurement of prolactin (prl) in the plasma and the pituitary of the eel was developed using a rabbit antiserum to eel prl. prl was purified from the pituitary of japanese eel (anguilla japonica). pituitary extracts and plasma from the japanese and european eels exhibited displacement curves parallel to the eel prl standard. plasma and pituitary extracts from chum salmon, rainbow trout, japanese charr, tilapia, goldfish, and carp, ...19912055440
daily cycles in plasma melatonin levels under long or short photoperiod in the common carp, cyprinus carpio.a radioimmunoassay (ria) for plasma melatonin (mlt) was simplified for use with the common carp (cyprinus carpio). plasma was partially purified with sep-pak c18 cartridge before ria. the inhibition curves for the sep-pak c18 fraction from the plasma of carp, goldfish (carassius auratus), yellow tail (seriola quinqueradiata), japanese eel (anguilla japonica), bora (mugil cephalus cephalus), kisu (sillago japonica), ishigarei (kareius bicoloratus), and shimaisaki (rhyncopelates oxyrhynchus) were ...19883197949
characterization of an anionic trypsin from the eel (anguilla japonica).an enzyme, isolated from the pancreas of the eel anguilla japonica and designated as anionic trypsin 1, had a molecular weight of 26,000 and an isoelectric point of 5.5. the amino acid composition of the enzyme was similar to that of bovine cationic trypsin as well as anionic trypsins from other species of fish. the enzyme was stable at ph 6 to 9 in the presence of calcium ions. km and kcat values of the enzyme for n-tosyl-l-arginine methyl ester and n-tosyl-l-lysine methyl ester were quite simi ...19853967484
vibrio vulnificus biogroup 2: new biogroup pathogenic for eels.clinical and nonclinical isolates of the lactose-positive vibrio vulnificus were compared with vibrio strains isolated from lesions on eels (anguilla japonica) cultured commercially in japan. strains were compared phenotypically and antigenically, for pathogenicity to mice and eels, and for genetic relatedness. the strains isolated from diseased eels differed phenotypically from the original species description of v. vulnificus in that they were negative for indole production, ornithine decarbox ...19827138004
a highly repetitive sequence isolated from genomic dna of the medaka (oryzias latipes).a highly repetitive interspersed dna sequence (mre) was isolated from the genome of medaka, oryzias latipes, and characterized. three distinct sequences of mre were cloned and compared. the conserved sequences of mre were approximately 220 bp in length. on average, one copy of mre was present in every 153 kb, and the number of copies of mre in the genome was calculated to be approximately 9800. mre constituted approximately 0.14% of the genome. mre-related sequences were not detected in carp (cy ...19968817927
the small subunit ribosomal rna gene sequence of pleistophora anguillarum and the use of pcr primers for diagnostic detection of the parasite.using the polymerase chain reaction (pcr) and two primers for conserved regions of the small subunit ribosomal rna (ssu-rrna) of microsporidia, a dna segment about 1,195 base pairs long was amplified from a dna template prepared from purified spores of the microsporidian species pleistophora anguillarum. these spores had been isolated from adult eels (anguilla japonica) with "beko disease." a comparison of sequence data from other microsporidian species showed p. anguillarum ssu-rrna to be most ...19989783458
cloning, properties and tissue distribution of natriuretic peptide receptor-a of euryhaline eel, anguilla japonica.during the course of cloning and characterization of natriuretic peptide receptor-a (npr-a) from the euryhaline fish eel, anguilla japonica, we identified a splice variant with unique structural properties that affect ligand-inducible intrinsic guanylate cyclase activity. the variant, generated from a splice between a cryptic donor site and the normal acceptor site, lacked nine amino acid residues (vftktgyyk) in the kinase-like regulatory domain. this deletion of a very short segment resulted in ...19999914494
an enhanced humoral immune response against the swimbladder nematode, anguillicola crassus, in the japanese eel, anguilla japonica, compared with the european eel, a. anguilla.the humoral immune response in the two eel species, anguilla japonica and anguilla anguilla against two fractions of antigens in anguillicola crassus were studied. within species, both eel species showed significantly elevated titres compared with controls when immunized with antigens from anguillicola crassus. in interspecific comparison, anguilla japonica showed significantly elevated titres in comparison with anguilla anguilla. immunization of anguilla anguilla caused a significantly decrease ...199910526415
natural mass infection by heterophyid metacercariae in aquacultured japanese eel in taiwan.a natural mass infection of heterophyid metacercariae in aquacultured japanese eel anguilla japonica in taiwan was observed. of the 28,000 adult eels in 2 ponds, about 25,000 (90%) showed swollen, cloudy and white eyes. although morbidity was about 90%, there was no mortality among the affected eels. histopathological sections showed edema and hemorrhage of the eye. numerous metacercariae were observed in the muscle tissues around the eyeball, the subcutaneous tissue and even in the cartilage. o ...199910073313
monoclonal antibodies to plasma high density lipoprotein (hdl) of eel (anguilla japonica).six week-old female mice (balb/c) injected intraperitonealy with 50 micrograms of eel high density lipoprotein (hdl) emulsified with equal volume of adjuvant three times every two weeks. three weeks after the third injection, hyperimmunized mice were boosted by injection of 100 micrograms of hdl. after 5 days, the best responding mouse to injected hdl was sacrificed, and spleen cells were fused with mouse myeloma cells (sp2/o-ag14), and hybridomas were cultured in a selection medium. monoclonal ...200010904860
a novel stage-specific antigen is expressed only in early stages of spermatogonia in japanese eel, anguilla japonica testis.we produced an antibody that recognized only early stages of spermatogonia in japanese eel testis. this antibody (anti-spermatogonia-specific antigen-1, anti-sgsa-1) recognized a band of about 38 kda in western blot analysis of extracts from eel testis. this antigen was observed by immunohistochemistry only in type-a and early type-b spermatogonia and could not be seen in the late type-b spermatogonia, which appeared after the initiation of spermatogenesis by a single injection of human chorioni ...19989820193
impaired spermatogenesis in the japanese eel, anguilla japonica: possibility of the existence of factors that regulate entry of germ cells into the cultivated male japanese eel, spermatogonia are the only germ cells present in the testis. weekly injections of human chorionic gonadotropin (hcg) can induce complete spermatogenesis from proliferation of spermatogonia to spermiogenesis. in some cases, however, hcg injection fails to induce complete spermatogenesis. testicular morphological observations revealed that hcg-injected eels could be classified into three types based on their testicular conditions. type 1 eels had a well-develop ...19979493828
fish testicular 11beta-hydroxylase: cdna cloning and mrna expression during spermatogenesis.we isolated and characterized a cdna encoding testicular 11beta-hydroxylase, cytochrome p450(11beta) from the japanese eel (anguilla japonica) testis. the cdna contains an open reading frame that encodes a protein of 511 amino acids. the predicted amino acid sequence shares 38-48% homology with those of adrenal p450(11beta) from mammals and frog. transient expression in cos 1 cells confirmed that the protein encoded by this cdna had p450(11beta) activity. northern blotting revealed a single 1.8 ...19968955357
[studies on the crude drugs used for the folk medicine described in "mimi-bukuro"]."mimi-bukuro" is a book written by moriyasu negishi in the edo period. m. negishi (1737-1815) was a magistrate in the town of edo. he was very much interested in listening and recording many kinds of stories, which were told by the various kinds of people, such as public officers, samurais, merchants, doctors, etc. among the stories of this book, some stories were found concerning folk medicine, medicinal substance and charms. in this report, i studied the medicines which were used in these stor ...199511613523
population structure of the japanese eel, anguilla japonica.mitochondrial dna (mtdna) sequences that include (a) a part of the cytochrome b gene, (b) two trna genes, and (c) a part of the noncoding d-loop region of 31 anguilla japonica (japanese eel) and 1 a. marmorata collected from taiwan, japan, and mainland china were determined to evaluate the population structure of japanese eel. among 30 genotypes identified from the 31 japanese eel mtdnas sequenced, there are 58 variable sites, predominantly clustered at the d-loop region. the phylogenetic tree c ...19948170366
involvement of growth hormone and prolactin in the induction of vitellogenin synthesis in primary hepatocyte culture in the eel, anguilla japonica.multihormonal effects of bovine growth hormone (gh) and ovine prolactin (prl) on vitellogenin (vg) synthesis in response to estradiol-17 beta (e2) were electrophoretically examined in primary hepatocyte culture in the eel, anguilla japonica. newly synthesized protein after hormonal treatment was identified as vg by immunoblot and immunoelectrophoresis. a single injection of e2 into hypophysectomized eels failed in the induction of vg synthesis. similarly, e2 alone was insufficient to induce vg s ...19948138119
electron microscope study of vertebrate liver innervation.liver fine structure was studied in various groups of vertebrates to reveal intrahepatic nerves. nerve fibers were found in the connective tissue of the liver in all mammals, birds, and reptiles studied (japanese monkey, crab-eating monkey, rabbit, guinea pig, rat, golden hamster, pigeon, japanese quail, and turtle, pseudemys scripta). nerve fibers also made direct contact with hepatocytes in these animals except for the rat and the golden hamster. intrahepatic nerves were rare or absent in amph ...19817316686
immunocytochemical identification of thyrotropin (tsh)-producing cells in pituitary glands of several species of teleosts with antiserum to human tsh beta subunit.a rabbit antiserum raised against human thyrotropin (tsh) beta subunit (anti-human beta-tsh) was used to identify tsh cells in the pituitaries of five species of teleosts by means of the unlabeled antibody peroxidase-antiperoxidase (pap) technique. the anti-human beta-tsh reacted only with polygonal basophils located in the rostral pars distalis (rpd) in the pituitaries of sexually immature eel (anguilla japonica). in the pituitaries of medaka (oryzias latipes) and white-edged rockfish (sebastes ...19836342806
the effects of bovine prolactin, sea water and environmental calcium on water influx in isolated gills of the euryhaline teleosts, anguilla japonica and salmo gairdnerii. 19744153722
study on a special binding phenomenon of biliverdin in the blood of the eel, anguilla japonica.biliverdin is bound firmly with a plasma protein in the blood of the eel, anguilla japonica. the firm binding, although likely noncovalent, could be formed only in vivo under the experimental conditions. characterization of the carrier protein indicated that it is a serum albumin. a similar phenomenon is not detectable in ten other fish species examined in this study.19854028686
identification and synthesis of [1-asparagine, 5-valine, 9-glycine] angiotensin i produced from plasma of american eel anguilla rostrata.the major peptide produced by incubation of american eel (anguilla rostrata) plasma with the eel kidney extract was identified as [1-asparagine, 5-valine, 9-glycine] angiotensin i (i). two minor peptides were also identified as [1-aspartic acid, 5-valine, 9-glycine] angiotensin i (ii) and [5-valine, 9-glycine] angiotensin i-(3-10)-octapeptide (iii). these structures were further confirmed by comparison of these peptides on high-pressure liquid chromatography (hplc) and high-performance thin-laye ...19853979804
flow cytometric analysis of the neutrophil respiratory burst of ayu, plecoglossus altivelis: comparison with other fresh water fish.neutrophils of vertebrates undergo respiratory burst activity (rba) as a defense mechanism against bacterial infections. we report here that ayu (plecoglossus altivelis) have unusually high rbas even when they are in a healthy condition. kidney and blood leukocytes were obtained from ayu, rainbow trout (oncorhynchus mykiss), carp (cyprinus carpio), eel (anguilla japonica), and pond smelt (hypomesus nipponensis). neutrophil rba was measured by flow cytometry using dihydrorhodamine after stimulati ...200312787685
[the wormicidal substances of fresh water fishes on clonorchis sinensis: ii. preliminary research on the wormicidal substances from mucous substances of various fresh water fishes]the present work which was investigated in july 1979, was to observe the wormicidal effects of the external mucous substances of 9 species of fresh water fishes (cyprinus carpio, parasilurus asotus, anguilla japonica, ophicephalus argus, carassius carassius; golden crusian carp, misgurnus anguillicaudatus, zacco platypus, pseudorasbora parva and carassius carassius; crusian carp) on cercaria, liberated metacercaria and adult of clonorchis sinensis. the mucous substances extracted by ether from t ...198012902746
[experimental studies on the second intermediate hosts of clonorchis sinensis: iii. observations on the relationship between clavate cells of epidermis and infectivity of metacercariae of clonorchis sinensis in fresh-water fish]in order to know relationship between the clavate cells of epidermis and infectivity of metacercariae of c. sinensis. histological investigation of epidermis was carried out on the 26 species of fresh-water fish collected from the main rivers in korea. results were summarized as it follows: 1. in general clavate cell had a single nucleus at its center. however it was observed in liobagrus mediadiposalis and pelteobagrus fuluidraco that clavate cell had two nuclei with and independent so-called l ...197412913471
sodium-retaining activity of chum salmon prolactin in some euryhaline teleosts.sodium-retaining activity of chum salmon prolactin (prl) was examined in several euryhaline teleosts. chum prl was 100 times more potent than ovine prl in maintaining plasma sodium levels in the hypophysectomized killifish, fundulus heteroclitus, transferred from 50% seawater to fresh water. the effects of prls were parabolic, high doses of the hormones being less effective than low doses. when injected into seawater-adapted fry of the ayu, plecoglossus altivelis, or into juvenile rainbow trout, ...19863781235
volume-sensitive taurine transport in fish erythrocytes.taurine plays an important role in cell volume regulation in both vertebrates and invertebrates. erythrocytes from two euryhaline fish species, the eel (anguilla japonica) and the starry flounder (platichthys stellatus) were found to contain high intracellular concentrations of this amino acid (approximately equal to 30 mmol per liter of cell water). kinetic studies established that the cells possessed a saturable high-affinity na+-dependent beta-amino-acid transport system which also required c ...19873585985
birefringent spores differentiate encephalitozoon and other microsporidia from coccidia.tissue sections containing protozoa with birefringent spores indicate an infection by microsporidia. hematoxylin and eosin (he) does not affect spore birefringence, but some special stains (goodpasture, brown and brenn, or gram) obscure it. encephalitozoon cuniculi from an infected puppy, glugea stephani from the winter flounder pseudopleuronectes americanus, and plistophora sp. from the japanese eel anguilla japonica all have birefringent spores. encephalitozoon was studied first and then the t ...19883134761
characteristics and primary structure of a galectin in the skin mucus of the japanese eel, anguilla japonica.the characteristics and primary structure of ajl-1, one of the lectins in the skin mucus of the japanese eel (anguilla japonica), were examined. this lectin exhibited beta-galactoside specific activity in a ca2+ independent manner. we previously reported that its molecular mass was 16,091da, although it was approximately 30 kda as determined by gel filtration, indicating that it is a homodimer having non-covalent bonds. this lectin was composed of 142 amino acid residues having no half-cystinyl ...200414698218
the histochemistry of urea-unmasked glycosaminoglycans in the skin of the eel, anguilla the connective tissues of the dermis and subcutis of the eel skin, the histochemistry of urea-unmasked glycosaminoglycans has been studied by means of combined staining and enzyme digestion procedures. the staining procedures employed were alcian blue (ab) ph 1.0, ab ph 2.5, aldehyde fuchsin (af), periodic acid-schiff (pas), ab ph 2.5-pas, high iron diamine (hid) and low iron diamine (lid) methods, whereas the enzymes used were streptomyces and testicular hyaluronidases, chondroitinases abc a ...19852579932
molecular cloning of eel growth hormone cdna and its expression in escherichia coli.cdna clones coding for growth hormone (egh) of japanese eel (anguilla japonica) have been isolated from a cdna library prepared from pituitary gland poly(a)+ rna. the nucleotide sequence of the egh cdna was determined. it codes for the prehormone of 209 amino acids (aa) including a putative signal peptide of 19 aa. the deduced amino acid sequence was identical with that determined for egh protein. the primary structure of egh was compared with those of other species growth hormones (chum salmon, ...19882468582
human chorionic gonadotropin induces all stages of spermatogenesis in vitro in the male japanese eel (anguilla japonica).in the cultivated male japanese eel, spermatogonia are the only germ cells present in the testis. using a newly developed organ culture system, we obtained evidence that human chorionic gonadotropin (hcg) can induce the entire process of spermatogenesis, in vitro, from spermatogonia to spermatozoa within 24 days. the hcg-induced spermatogenesis in vitro was accompanied by a marked activation of sertoli cells and leydig cells, occurring prior to the beginning of spermatogonial proliferation. thes ...19912060708
c-reactive protein in eel: purification and agglutinating activity.c-reactive protein was highly purified from japanese eel (anguilla japonica) serum by precipitation with phosphatidyl-choline and ca2+. on sds-page, eel c-reactive protein (ecrp) migrated as a single band with a molecular weight of 24,000 under reducing and 23,500 under non-reducing conditions. the molecular weight of native ecrp was estimated to be 120,000 by sephacryl s-300 gel filtration. the ecrp was detected within the albumin region on immunoelectrophoresis. the ecrp showed an agglutinatin ...19911900197
effects of insulin-like growth factor-i and insulin on the in-vitro uptake of sulphate by eel branchial cartilage: evidence for the presence of independent hepatic and pancreatic sulphation factors.the possible roles of insulin-like growth factor-i (igf-i) and insulin in regulating cartilage growth were studied in the teleost anguilla japonica. significant sulphation activity was found in the extracts of pancreas, liver and muscle, but not in those of kidney, intestine or spleen. the hepatic sulphation activity was significantly decreased by hypophysectomy or by fasting for 14 days, suggesting that this activity is regulated by pituitary function and nutritional status. northern blot analy ...19921613424
nephroblastomas in the japanese eel, anguilla japonica temminck and schlegel.nephroblastomas were observed in 50 japanese eel reared at a farm for 5 to 9 months from 1989 after collection in the wild. the tumors, arising from the trunk kidney near the anus, were noted externally as abdominal swellings and varied in size from 30 to 75 mm in maximum diameter. most were elastic, solid, and well encapsulated. histologically, the nephroblastomas were composed of combinations of three main tissue elements. spindle- or oval-shaped cells resembling human blastema cells were obse ...19921314699
first record of ostracods as natural intermediate hosts of anguillicola crassus, a pathogenic swimbladder parasite of eels anguilla spp.the ostracod physocypria nipponica (ostracoda: candonidae) was found (prevalence 14.2%) to be the only intermediate host of the nematode anguillicola crassus (nematoda: anguillicolidae), a pathogenic swimbladder parasite of eels, in a greenhouse-heated culture pond at isshiki, aichi prefecture, japan. japanese eels anguilla japonica from the same pond were found to be infected by adult a. crassus (prevalence 71.8%, intensity 1 to 6). this indicates that a. crassus could complete its life cycle u ...200516231644
characterization of a testicular 17alpha, 20beta-dihydroxy-4-pregnen-3-one (a spermiation-inducing steroid in fish) receptor from a teleost, japanese eel (anguilla japonica).a cdna encoding a nuclear 17alpha,20beta-dihydroxy-4-pregnen-3-one (17alpha,20beta-dp, spermiation-inducing hormone in fish) receptor (dpr) was, for the first time, isolated from an eel testis cdna library. the amino acid sequence of dpr shows high homology with those of human and chicken progesterone receptors. the affinity of the bacterial recombinant dpr ligand binding domain protein for 17alpha,20beta-dp is higher than that of progesterone. in transfection experiments using cos7 cells, the d ...200010620698
recombinant human insulin-like growth factor i stimulates all stages of 11-ketotestosterone-induced spermatogenesis in the japanese eel, anguilla japonica, in this study, we examined the in vitro effects of insulin-like growth factor i (igf-i) in the presence or absence of 11-ketotestosterone (11-kt: the spermatogenesis-inducing hormone) on the proliferation of japanese eel (anguilla japonica) testicular germ cells. initially, a short-term culture (15 days) of testicular tissue with only type a and early type b spermatogonia (preproliferated spermatogonia) was carried out in leibovitz-15 growth medium supplemented with different concentrations of r ...199910491628
cdna cloning of a stage-specific gene expressed during hcg-induced spermatogenesis in the japanese eel.a single injection of human chorionic gonadotropin (hcg) can induce complete spermatogenesis in immature japanese eel (anguilla japonica) testes consisting of only premitotic spermatogonia. proliferation of spermatogonia, meiosis and spermiogenesis begin on 3, 12 and 18 days after hcg injection, respectively. to isolate the genes responsible for regulating the initiation of meiosis, differential mrna display using poly (a)+ rna extracted from testes of eels at different times after hcg treatment ...199910466934
gill lamellar pillar cell necrosis, a new birnavirus disease in japanese eels.since the late 1980s, a birnaviral gill disease has been occurring in japanese eels anguilla japonica reared in warmwater ponds in western regions in japan. diseased eels mostly displayed marked formations of aneurysmal hematomas within gill lamellae and high mortalities. histological examination revealed necrosis of pillar cells and subsequent aggregation of erythrocytes inside the lamellar capillaries, and proliferation of interlamellar epithelia onto the lamellae. gastric gland cells were als ...199910439899
development and differentiation of gonadotropin hormone-releasing hormone neuronal systems and testes in the japanese eel (anguilla japonica).in this study we investigated the relationship between the development of the olfactory, preoptic, and midbrain gonadotropin-releasing hormone (gnrh) neuronal systems and testicular differentiation in eels (anguilla japonica) from embryonic stages through adulthood (5.4-50 cm body length). gnrh-synthesizing neuronal populations were first observed in the youngest fish ( approximately 5.0 cm) at the rostrobasal and caudalmost olfactory bulbs immunoreactive to a "promiscuous" (nonspecific) gnrh an ...199910336833
ultrastructural justification for the transfer of pleistophora anguillarum hoshina, 1959 to the genus heterosporis schubert, 1969.this study presents the ultrastructure of the microsporidian infecting the trunk musculature of anguilla japonica and originally described as pleistophora anguillarum hoshina, 1959. all stages develop within a special structure, the sporophorocyst (spc), which is equipped with a thick dense wall. this wall grows along with the growth of the parasites within it. meronts are uni- to binucleate, which divide and steadily give rise to sporonts. during transition to sporonts the cell coat of the mero ...200011206738
characterization of japanese eel immunoglobulin m and its level in serum.japanese eel immunoglobulin m (igm) was purified from the sera of anguilla japonica immunized with edwardsiella tarda fpu 347 and characterized. analysis of the purified igm on sodium dodecyl sulfate-polyacrylamide gels (sds-page) under reducing and non-reducing conditions revealed that the eel igm was a tetrameric protein with a molecular weight of 790,000; it contained an equimolar heavy chain and light chain with molecular weights of 72,000 and 25,000, respectively. while the n-terminal seque ...200011281270
genome sequence of a vp2/ns junction region of pillar cell necrosis virus (pcnv) in cultured japanese eel anguilla japonica.pillar cell necrosis virus (pcnv) is an aquatic birnavirus that was isolated from farmed japanese eel experiencing mass mortality. in this study, a vp2/ns junction region in genome segment a of pcnv was amplified by reverse transcriptase polymerase chain reaction (rt-pcr) and sequenced. the vp2/ns region in pcnv had the highest homology with that of a strain ab of infectious pancreatic necrosis virus (ipnv). this result revealed that pcnv belongs to birnavirus genogroup ii.200111383565
a novel progestogen receptor subtype in the japanese eel, anguilla japonica.a cdna encoding a second type of a progestogen receptor (epr2) was isolated from the same library as we had previously cloned a functional pr (epr1) in eel testis. the amino acid sequence of the epr2 shows low homology with epr1 (34%), but both prs showed progestogen-dependent transactivation in transfection experiment. tissue distribution of epr2 mrna was clearly different from that of epr1. protein interaction between two prs was demonstrated in vitro by a glutathione s-transferase pull-down a ...200211755535
primary structure and characteristics of a lectin from skin mucus of the japanese eel anguilla japonica.two types of lactose-binding lectins, ajl-1 and ajl-2, were purified from the skin mucus extract of the japanese eel anguilla japonica by lactose affinity chromatography and subsequent gel filtration. the molecular masses of ajl-1 and ajl-2 were 16,091 and 31,743 da, respectively. intact ajl-1 was comprised of two identical 16-kda subunits having blocked n termini and no disulfide bonds. ajl-2 was a homodimer with disulfide bonds. based on the n-terminal amino acid sequence of the ajl-2 monomer, ...200211959866
pcna protein expression during spermatogenesis of the japanese eel (anguilla japonica).spermatogenesis can be initiated by a single injection of human chorionic gonadotropin (hcg) into the cultivated japanese eel, which produces only spermatogonia in the testis. to isolate the genes responsible for regulating spermatogenesis, we performed a differential mrna display using poly (a)+ rna extracted from the testes at different time points after hcg injection. among several cdna clones, the expression of which was initiated before the onset of meiosis, one clone has high homology with ...200212025409
comparative studies between in vivo and in vitro spermatogenesis of japanese eel (anguilla japonica).in order to check the quality of in vitro spermatogenesis of japanese eel, in vitrol 1-ketotestosterone (11-kt) induced spermatogenesis was compared with in vivo spermatogenesis induced by a single injection of human chorionic gonadotropin (hcg) in detail. dna contents of germ cells from in vitro and in vivo testicular fragments were compared using flow cytometry. since the in vitro result of flow cytometry showed prominent 1c peak including spermatozoa and spermatids, the reduction of dna by me ...200212125930
dietary korean mistletoe enhances cellular non-specific immune responses and survival of japanese eel (anguilla japonica).the present study was performed to investigate the immunostimulatory effects of korean mistletoe extract (km-110; viscum album coloratum) on the non-specific immune response and protection against aeromonas hydrophila infection in japanese eel (anguilla japonica). eels were fed under 4 regimes, 0%, 0.1%, 0.5% and 1.0% km-110 mixed diet. on day 14 after feeding, 15 fish from each group were injected i.p. with live a. hydrophila (3 x 10(6)cfu) and the remaining unchallenged fish from each group we ...200818023593
a lectin (cflec-2) aggregating staphylococcus haemolyticus from scallop chlamys farreri.lectins are a family of carbohydrate-recognition proteins which play crucial roles in innate immunity. in this study, a new lectin (cflec-2) gene was cloned from chlamys farreri by est and race approaches. the full-length cdna of cflec-2 was composed of 708bp, encoding a typical long form carbohydrate-recognition domain of 130 residues. the deduced amino acid sequence showed high similarity to brevican in homo sapiens, c-type lectin-1 and lectin-2 in anguilla japonica. the cdna fragment encoding ...200818203621
characterization of a cdna encoding p-450 aromatase (cyp19) from japanese eel ovary and its expression in ovarian follicles during induced ovarian development.a cdna encoding p450 aromatase (cyp19) was isolated from a japanese eel (anguilla japonica) ovarian cdna library. this cdna contains a complete open reading frame encoding 511 amino acid residues. the deduced amino acid sequence is 59% and 65% identical to the catfish and rainbow trout forms, respectively, and 52-54% to mammalian and chicken forms. non-steroidogenic cos-7 cells transfected with the eel cyp19 cdna converted exogenous androstenedione to estrone, thus verifying its identity. northe ...200312568797
ovarian mitochondrial cytochrome b mrna levels increase with sexual maturity in freshwater eels (anguilla spp.).differential display of mrna was used to identify an upregulated gene in ovaries of artificially maturing japanese eels (anguilla japonica). accordingly, mitochondrial (mt) cytochrome b, whose transcript levels increased from early to late vitellogenesis, was isolated, cloned and sequenced. temporal trends in artificially maturing eels were compared with those in naturally and artificially maturing new zealand eels (longfinned eel, anguilla dieffenbachii; shortfinned eel, anguilla australis) by ...200312592438
ecological aspects of the japanese eel, anguilla japonica, collected from coastal areas of japan.the ecological characteristics of 597 yellow and silver-stage japanese eels, anguilla japonica, were examined and compared among collection sites located at three different latitudes of japan (amakusa islands, mikawa bay, and sanriku coast) to provide basic data on this unusual catadromous fish species. eels were sexed and their total length, body weight, age, and growth rate based on otolith analysis was compared among sexes, stages, and collection sites. the overall sex ratio favored females ( ...200718271637
amidated fish ghrelin: purification, cdna cloning in the japanese eel and its biological activity.we purified ghrelin from stomach extracts of a teleost fish, the japanese eel (anguilla japonica) and found that it contained an amide structure at the c-terminal end. two molecular forms of ghrelin with 21 amino acids were identified by cdna and mass spectrometric analyses: eel ghrelin-21, gss(o-n-octanoyl)flspsqrpqgkdkkpp rv-amide and eel ghrelin-21-c10, gss(o-n-decanoyl) flspsqrpqgkdkkpprv-amide. northern blot and rt-pcr analyses revealed high gene expression in the stomach. low levels of exp ...200312630926
vaccination of eels (anguilla japonica and anguilla anguilla) against anguillicola crassus with irradiated l3.the original host of the swimbladder nematode anguillicola crassus, the japanese eel (anguilla japonica) and the recently colonized european eel (anguilla anguilla) were immunized with 40 irradiated (500 gy) 3rd-stage larvae (l3) of this parasite and challenged with an infection of 40 normal l3. the immunization induced a significant reduction of the number of adult worms developing from the challenge infection in a. japonica, but not in a. anguilla. the induced resistance (calculated using the ...200818302804
isolation, characterization and expression of 11beta-hydroxysteroid dehydrogenase type 2 cdnas from the testes of japanese eel (anguilla japonica) and nile tilapia (oreochromis niloticus).the japanese eel (anguilla japonica) and nile tilapia (oreochromis niloticus) 11beta-hydroxysteroid dehydrogenase type 2 (11beta-hsd2) cdnas were isolated from their respective testes cdna libraries. the cdnas predict two peptides of 436 and 406 amino acid residues that share about 42% homology with mammalian 11beta-hsd type 2 proteins. analysis of the tissue distribution pattern by rt-pcr reveals that 11beta-hsd2 is expressed in a wide variety of tissues in tilapia, with higher expression in ki ...200314519098
expression of a biologically active recombinant follicle stimulating hormone of japanese eel anguilla japonica using methylotropic yeast, pichia the japanese eel anguilla japonica, the administration of exogenous gth is necessary for the artificial induction and completion of gonadal maturation due to its gth deficiency under captive conditions. the isolation of native eel gth has not been accomplished, which has made it difficult to fully elucidate the biological functioning of the two gths (fsh and lh) in eel. in this study, we attempted to produce a recombinant japanese eel gth (rjefsh) having biological activity using methylotroph ...200314636631
molecular diversity of skin mucus lectins in fish.among lectins in the skin mucus of fish, primary structures of four different types of lectin have been determined. congerin from the conger eel conger myriaster and ajl-1 from the japanese eel anguilla japonica were identified as galectin, characterized by its specific binding to beta-galactoside. eel has additionally a unique lectin, ajl-2, which has a highly conserved sequence of c-type lectins but displays ca(2+)-independent activity. this is rational because the lectin exerts its function o ...200314662297
natriuretic peptides inhibit adenylyl cyclase activity in dispersed eel gill cells.the effect of natriuretic peptides on forskolin-evoked adenylyl cyclase activity was investigated in dispersed gill cells from the australian short-finned eel (anguilla australis). molecular cloning techniques were employed to identify the putative g-protein-activating motif within the intracellular domain of the eel natriuretic peptide c receptor. eel anp, eel cnp and the npr-c-specific c-anf inhibited the forskolin-stimulated production of cyclic amp. this effect was abolished by pretreatment ...200414760501
lesser known aquarium fish tumor models.the repeated use of particular species for experimental oncology in fish increases their future value by accumulating background information for these models and justifies the establishment of genetic stock centers. however, the wide diversity that exists within the class osteichthyes and chondrichthyes suggests that the ideal surrogate models for studying some types of neoplasms might be found among lesser known species. to help assess cultured fish as surrogates for some other types of human n ...200114961307
the cloning of cyclin b3 and its gene expression during hormonally induced spermatogenesis in the teleost, anguilla japonica.we cloned cyclin b1, b2, and b3 cdnas from the eel testis. northern blot analysis indicated that these cyclin b mrnas were expressed and increased from day 3 onward after the hormonal induction of spermatogenesis, and that cyclin b3 was most dominantly expressed during spermatogenesis. in situ hybridization showed that cyclin b1 and b2 were present from the spermatogonium stage to the spermatocyte stage. on the other hand, cyclin b3 mrna was present only in spermatogonia. although mouse cyclin b ...200415351735
differences in susceptibility of the european eel (anguilla anguilla) and the japanese eel (anguilla japonica) to the swim-bladder nematode anguillicola crassus.the swim-bladder nematode anguillicola crassus originates from the far east where it is a parasite of the japanese eel (anguilla japonica). after a. crassus was introduced to europe, it became a predominant parasite of the european eel (anguilla anguilla). a study performed with experimentally infected eels (98 days, 23 degrees c) revealed significant differences in the susceptibility of the two eel species to this parasite. the recovery rate of 30 administered infective a. crassus larvae (l3) f ...200415521638
a quick method for species identification of japanese eel (anguilla japonica) using real-time pcr: an onboard application for use during sampling compensate for the limited number of morphological characteristics of fish eggs and larvae, we established a convenient and robust method of species identification for eggs of the japanese eel (anguilla japonica) using a real-time polymerase chain reaction (pcr) that can be performed onboard research ships at sea. a total of about 1.2 kbp of the mitochondrial 16s ribosomal rna gene sequences from all species of anguilla and 3 other anguilliform species were compared to design specific primer ...200415690101
purification of follicle-stimulating hormone from immature japanese eel, anguilla japonica, and its biochemical properties and steroidogenic activities.follicle-stimulating hormone (fsh) was purified, for the first time, from immature japanese eel, anguilla japonica, and its biochemical properties were investigated. fsh was extracted from immature eel pituitaries and purified by gel-filtration on sephadex g-100, and two step anion-exchange chromatography: stepwise elution on de-52, followed by gradient elution on tsk-gel super-q using hplc. purification was performed using its molecular mass and the positive reaction with anti-japanese eel (je) ...200515894317
[non-indigenous and non-specific parasitic nematodes--the background and the consequences].introduction of the host is the main reason behind introduction of the parasite, e. g., nematodes. the introduction of the japanese eel (anguilla japonica) in europe in the 1980s resulted in expansion of the swimbladder nematode anguillicola crassus which soon invaded not only populations of the european eel (a. anguilla), but also other local fish. the raccoon (procyon lotor) is native to north america. it is the specific host of strongyloides procyonis and baylisascaris procyonis. more than 90 ...200920209803
distribution of polychlorinated biphenyls in the water, sediment and fish from the pearl river estuary, china.the concentrations and distribution of polychlorinated biphenyls were determined in water, surface sediments and fishes from the estuaries of pearl river, pr china. the results showed that the concentrations ranged from 2.47 ng l-1 to 6.75 ng l-1 in water, from 11.13 ng g-1 to 23.23 ng g-1 in sediments (dry weight) and from 68.64 ng g-1 to 316.85 ng-1 in fish (lipid weight). it was found that the feeding habits of fish were very significant in the accumulation of polychlorinated biphenyls and pa ...200516374930
molecular cloning and gene expression of spo11 during spermatogenesis in the japanese eel, anguilla japonica.spo11 is a protein involved specifically in the meiotic recombination in several species, however, it is little characterized in lower vertebrates. we identified a cdna encoding spo11 from the testis of japanese eel, anguilla japonica. the deduced amino acid sequence of eel spo11 was more than 60% identical with human and mouse spo11s. in order to examine changes in the expression and localization of spo11 during spermatogenesis induced by the injection of human chorionic gonadotropin (hcg) and ...200616426883
novel dna virus isolated from samples showing endothelial cell necrosis in the japanese eel, anguilla japonica.economic loss due to viral endothelial cell necrosis of eel (vecne) of anguilla japonica is a serious problem for the cultured japanese eel market. however, the viral genome responsible for vecne is unknown. we recently developed a rapid determination system for viral nucleic acid sequences (rdv) to determine viral genome sequences. in this study, viral dna fragments were obtained using rdv, and approximately 15-kbp circular full genome sequences were determined using a next-generation sequencin ...201121277610
identification of eel ghrelin in plasma and stomach by radioimmunoassay and histochemistry.the structure of ghrelin has been determined in the japanese eel, anguilla japonica. in this study, we identified immunoreactive ghrelin in extracts from plasma and stomach of the eel by radioimmunoassay (ria) using an antiserum against octanoylated rat ghrelin [1-11]. using the antiserum, we examined localization of ghrelin-immunopositive cells in the eel stomach. detection of ghrelin mrna-expressing cells was also attempted in the eel stomach using a crna probe specific for the eel ghrelin gen ...200616762351
hosts and parasites as aliens.over the past decades, various free-living animals (hosts) and their parasites have invaded recipient areas in which they had not previously occurred, thus gaining the status of aliens or exotics. in general this happened to a low extent for hundreds of years. with variable frequency, invasions have been followed by the dispersal and establishment of non-indigenous species, whether host or parasite. in the literature thus far, colonizations by both hosts and parasites have not been treated and r ...200616768855
the swimbladder nematode anguillicola crassus in the european eel anguilla anguilla and the japanese eel anguilla japonica: differences in susceptibility and immunity between a recently colonized host and the original host.the swimbladder nematode anguillicola crassus originates from asia where it is a parasite of the japanese eel anguilla japonica. after its introduction to europe about 25 years ago, the parasite spread rapidly within the indigenous populations of the european eel anguilla anguilla and subsequently the prevalence and mean intensity appeared to stabilize. under experimental and aquaculture conditions the naïve new host appears to be more susceptible to a. crassus compared to the original host. bot ...200616768856
trichodinid species from the gill of cultured japanese eel, anguilla japonica, with the description of a new species based on light and scanning electron microscopy.trichodinid ciliates infested on the gills of cultured japanese eels, anguilla japonica, were surveyed. a new species was detected in addition to trichodina jadranica and t. acuta, and was described as t. japonica n.sp. scanning electron microscopic observations on the new species revealed an aboral ciliary complex which consisted of long and sparsely arranged marginal cilia, a basal ciliary ring having very short cilia, and a well developed locomotor wreath. a thin anterior septum existed betwe ...201123194613
bacterial pathogens and flora isolated from farm-cultured eels (anguilla japonica) and their environmental waters in korean eel farms.the purpose of this study was to investigate bacterial pathogens and flora in both sick and clinically healthy eels, anguilla japonica, and the environmental rearing waters of korean eel farms. between 2003 and 2010, a total of 621 sick eels were submitted for diagnosis, while 216 healthy eels and 87 environmental water samples were collected during a survey of 26 eel farms in korea. seven different bacterial species were obtained from 183 isolates, which were recovered from the internal organs ...201223357049
transactivation activity of thyroid hormone receptors in fish (conger myriaster) in response to thyroid hormones.we previously isolated cdnas encoding conger eel (conger myriaster) thyroid hormone (th) receptors (trs). in the present study, we investigated the transactivation activities of conger eel trs treated with ths (3,3',5-triiodo-l-thyronine [t3], l-thyroxine [t4], and 3,3',5'-triiodo-l-thyronine [rt3]), or ligands and activators of other nuclear receptors. following transient transfection into the japanese eel (anguilla japonica) hepatocyte cell line hepa-e1, the conger eel trs (ctrs) showed th-dep ...200616820313
molecular characterization of aeromonas species isolated from farmed eels (anguilla japonica).seventy aeromonas strains were identified by phylogenetic analysis using housekeeping genes (gyrb and rpod) in order to investigate etiological agents for aeromoniasis in farmed eels (anguilla japonica). the phylogenetic analysis showed that aeromonas aquariorum (n=22, 31.4%) was the predominant species among the investigated eel strains, followed by aeromonas caviae (n=16, 22.9%), a. veronii (n=13, 18.6%), a. hydrophila (n=12, 17.1%), a. jandaei (n=4, 5.7%), a. media (n=2, 2.9%), and a. trota ( ...201323499189
occurrence of anguillicola crassus (nematoda: dracunculoidea) in japanese eels anguilla japonica from a river and an aquaculture unit in sw taiwan.the infection by swimbladder nematodes of the genus anguillicola (dracunculoidea: anguillicolidae) was examined in 2 populations of the japanese eel anguilla japonica in sw taiwan. wild eels from the kao-ping river were compared with cultured eels from an adjacent aquaculture unit. only the cosmopolitan species anguillicola crassus was present. among wild eels, prevalence of infection varied between 21 and 62%, and mean intensity between 1.7 and 2.7 for adult worms. similar intensity values (1.3 ...200616956057
structural composition and anticoagulant activity of dermatan sulfate from the skin of the electric eel, electrophorus electricus (l.).we determined the disaccharide composition of dermatan sulfate (ds) purified from the skin of the electric eel electrophorus electricus. ds obtained from the electric eel was composed of non-sulfated, mono-sulfated disaccharides bearing esterified sulfate groups at positions c-4 or c-6 of n-acetyl galactosamine (galnac), and disulfated disaccharides bearing esterified sulfate groups at positions c-2 of the uronic acid and at position c-4 or c-6 of galnac. the anticoagulant, antithrombotic and bl ...200717360213
effects of lead, molybdenum, rubidium, arsenic and organochlorines on spermatogenesis in fish: monitoring at mekong delta area and in vitro estimate the influence of water contaminants on fish reproduction in the mekong delta area, we sampled cultivated male catfish (pangasianodon hypophthalmus), investigated testicular development, and measured persistent organic pollutants (pops) and trace element levels in muscle and liver, respectively. various testes sizes were observed although sampling took place during a short period. histological analysis revealed that all developmental stages of germ cells were observed in catfish with ...200717448548
heterosporis anguillarum infections in farm cultured eels (anguilla japonica) in korea.ten eels (anguilla japonica) from a fish farm in korea were examined and diagnosed with a heterosporis infection. the gross lesions on the trunk were uneven and the concave parts were pasty. histopathologically, lyses of the trunk muscles, degenerative muscle fibers and the scattered spores were observed. the sporophorocyst (spc) contained several spores with a variety of shapes. some spc were disrupted and the spores in the spc were scattered in the muscle tissues. macrophages existed near the ...200717519567
base changes in the flic gene of edwardsiella tarda: possible effects on flagellation and motility.edwardsiella tarda is a broad host-range pathogen infecting both animals and humans. e. tarda isolates from red sea bream pagrus major are non-motile, whereas isolates from japanese eel anguilla japonica and japanese flounder paralichthys olivaceus are motile with peritrichous flagella. we compared the flic gene coding for flagellin (flic) in motile and non-motile e. tarda strains isolated from diseased fish. twenty-two amino acid residues differed in the predicted flic amino acid sequences betw ...200717760384
antibiotic resistance and repetitive-element pcr fingerprinting in aeromonas veronii isolates.this study evaluated antibiotic resistance and the related genes in total 47 aeromonas veronii isolates from pet fish, eel (anguilla japonica) and koi (cyprinus carpio) in korea. in comparison with the antibiotic susceptibilities of isolates from eel and koi, those of pet fish were more resistant to ceftiofur, aminoglycosides, tetracycline and nitrofurantoin. and isolates from pet fish showed high prevalences of class 1 integron, quinolones and tetracycline resistance determinants than those fro ...201627690177
the effects of five different glycans on innate immune responses by phagocytes of hybrid tilapia and japanese eels anguilla japonica.the aim of this study was to evaluate the immune responses in hybrid tilapia (nile tilapia oreochromis niloticus x mozambique tilapia o. mossambicus) and japanese eels anguilla japonica after treatment with five glycans: barley, krestin, macrogard, scleroglucan, and zymosan. the effects of the glycans on the innate immune responses of the fish were investigated using the phagocytic index (pi), lysozyme activity, complement opsonization, and activation assay. the results of the lysozyme assay dem ...200718236632
bioconversion by functional p450 1a9 and p450 1c1 of anguilla japonica.we indicated that two p450s (1a9 and 1c1) from japanese eel (anguilla japonica) metabolized 7-ethoxycoumarin, 7-ethoxyresorufin, and flavanone. at first, we constructed expression vectors for two types of p450 (1a9 and 1c1). the reduced co-difference spectra of escherichia coli cells transformed with these plasmids showed soret peaks (450 nm) that were typical of p450s. we performed bioconversion experiments in which substrates were added directly to incubation medium. the resulting metabolite(s ...200818243059
parasite communities in eels of the island of reunion (indian ocean): a lesson in parasite introduction.eel populations from the small rivers on the island of reunion (french overseas department in the indian ocean) were investigated with respect to the occurrence and abundance of helminths during the autumn of 2005. the native species anguilla marmorata (n = 80), anguilla bicolor (n = 23), and anguilla mossambica (n = 15) were studied. six species of helminths were identified, four of them having a definitely nonnative status. furthermore, unidentified intra-intestinal juvenile cestodes and extra ...200818288491
effects of pituitary glycoprotein hormones and thyroid hormones on in-vitro vitellogenin incorporation into organ-cultured oocytes in the japanese eel, anguilla japonica.the objectives of the present study were to establish a long-term culture system for previtellogenic ovarian fragments of the japanese eel (anguilla japonica) and to identify the effects of salmon pituitary glycoprotein fraction (spg), thyroxine (t4), and 3,5,3'-triiodothyronine (t3) on the uptake of vitellogenin (vtg) by cultured ovarian fragments evidenced by the appearance of yolk globules (ygs) within the oocytes. yolk globules first appeared in the oocytes incubated in media containing only ...200818393571
population structure of the parasitic nematode anguillicola crassus, an invader of declining north atlantic eel stocks.probably half of all animal species exhibit a parasitic lifestyle and numerous parasites have recently expanded their distribution and host ranges due to anthropogenic activities. here, we report on the population genetic structure of the invasive nematode anguillicola crassus, a parasite in freshwater eels, which recently spread from asia to europe and north america. samples were collected from the newly colonized naive host species anguilla anguilla (europe) and anguilla rostrata (north americ ...200818727770
purification and characterization of a proteinaceous toxin from the serum of japanese eel anguilla japonica.although eels are well known to contain toxins in the serum, their chemical properties have remained to be clarified for a long time. in this study, a proteinaceous toxin was purified from the serum of japanese eel anguilla japonica by anion-exchange hplc, hydroxyapatite hplc and gel filtration hplc. the toxin was lethal to both mice and crabs; the ld(50) of the purified toxin against mice (intravenous injection) and crabs (injection into body cavity) were estimated to be 670 and 450 mug kg(-1), ...200819015964
rapid determination of arsenic species in freshwater organisms from the arsenic-rich hayakawa river in japan using hplc-icp-ms.speciation analyses of water-soluble arsenicals from freshwater and biological samples collected from the hayakawa river (kanagawa, japan), which contains a high concentration of arsenic, were performed using high performance liquid chromatography/inductively coupled plasma mass spectrometry (hplc-icp-ms). river water contained only arsenate, which is a pentavalent inorganic arsenical. the water bug stenopsyche marmorata contained inorganic arsenicals accounting for 77% of the water-soluble arse ...200919203781
phenotypic traits, virulence-associated gene profile and genetic relatedness of edwardsiella tarda isolates from japanese eel anguilla japonica in korea.edwardsiella tarda is the predominant bacterium in farm-cultured eel in korea. here, we evaluated the heterogeneity of 37 e. tarda isolates derived from japanese eel with various origins (olive flounder, common carp and ornamental fish) between 2003 and 2010. regardless of origins, the biochemical characteristics of e. tarda isolates were homogenous except hydrogen sulfide production, citrate utilization and mannitol fermentation. based on the phylogenetic analysis of 16s rrna, e. tarda isolates ...201424117973
arsenic inhibits in vitro spermatogenesis and induces germ cell apoptosis in japanese eel (anguilla japonica).the precise mechanism and direct effects of arsenic on fish, particularly in reproduction, are not well clarified. the aim of this study is to investigate the direct influence of arsenic on fish spermatogenesis using the japanese eel (anguilla japonica) in vitro testicular organ culture system. eel testicular fragments were cultured in vitro with 0.1-100 microm arsenic with or without human chorionic gonadotropin (hcg) for 6 or 15 days at 20 degrees c. arsenic treatment provoked a dose-dependent ...200919494047
effect of eel galectin ajl-1 on periodontopathic bacterial biofilm formation and their lipopolysaccharide-mediated inflammatory cytokine induction.porphyromonas gingivalis, prevotella intermedia and aggregatibacter actinomycetemcomitans, infectious pathogenic bacteria found in oral biofilm, cause periodontal disease. the inhibitory effect of ajl-1, a galectin present in the skin mucus of the japanese eel anguilla japonica, on biofilm formation by each of these strains was investigated by staining adherent bacteria on culture plates with crystal violet. an atp bioluminescence assay was used to determine whether inhibition of biofilm formati ...200919505801
zinc is an essential trace element for spermatogenesis.zinc (zn) plays important roles in various biological activities but there is little available information regarding its functions in spermatogenesis. in our current study, we further examined the role of zn during spermatogenesis in the japanese eel (anguilla japonica). human cg (hcg) was injected into the animals to induce spermatogenesis, after which the concentration of zn in the testis increased in tandem with the progression of spermatogenesis. staining of testicular cells with a zn-specif ...200919541612
oocyte hydration in the japanese eel (anguilla japonica) during meiosis resumption and this study, to elucidate the mechanisms of oocyte hydration in the japanese eel (anguilla japonica), we examined the in vivo and in vitro morphological changes and hydration process occurring during oocyte maturation and ovulation. we also investigated the effects of the presence of ovarian follicles, aquaporin water permeability (hgcl(2)), and yolk proteolysis (bafilomycin a1) inhibitors, gap junction uncouplers (carbenoxolone and 1-octanol), a 3beta-hydroxysteroid dehydrogenase inhibitor (t ...200919623568
massive encapsulation of larval anguillicoloides crassus in the intestinal wall of japanese eels.abstract:200919832983
steroidogenic activities of follicle-stimulating hormone in the ovary of japanese eel, anguilla clarify the physiological functions of follicle-stimulating hormone (fsh) during oogenesis in japanese eel, anguilla japonica, the steroidogenic activities of recombinant japanese eel fsh (rjefsh) were assessed in the eel ovary. female eel were injected with salmon pituitary homogenate to enhance the ovarian development, and the ovaries at different developmental stages were subjected to steroidogenic bioassay. these ovaries could be classified into three types according to oocyte growth and ...200616297918
characterization of edwardsiella tarda isolated from farm-cultured eels, anguilla japonica, in the republic of korea.we surveyed the occurrence of edwardsiellosis on eel farms and investigated the characteristics of edwardsiella tarda isolated from farm-cultured eels in the republic of korea. the occurrence rate of edwardsiellosis was 72% in the investigated samples. among the edwardsiellosis cases, 46% were found to be mixed infections, with parasites and other kinds of bacteria. some of the biochemical characteristics of the e. tarda isolates were different from those of the previously reported e. tarda isol ...201120716861
electroneutral cation-cl(-) cotransporters nkcc2β and nccβ expressed in the intestinal tract of japanese eel anguilla the present study, we aimed to elucidate the mechanisms of intestinal na(+) and cl(-) absorption in japanese eel, focusing on electroneutral cation-cl(-) cotransporters, nkcc2β and nccβ, expressed in the intestinal tract. first, we cloned cdnas encoding nkcc2β and nccβ from the intestinal tract of japanese eel. in both freshwater- and seawater-acclimated eels, quantitative pcr analysis showed that nkcc2β was predominantly expressed in the anterior and posterior intestines, and that nccβ expre ...201121539929
isolation and identification of a novel inducible antibacterial peptide from the skin mucus of japanese eel, anguilla this study, acetone extracts and acidic extracts were prepared from skin mucus, gill, kidney, liver and spleen of the japanese eel, anguilla japonica, and they exhibited different levels of antibacterial activities against three strains of gram-negative bacteria, edwardsiella tarda, aeromonas hydrophila, aeromonas sp. and one gram-positive bacterium micrococcus leteus. the mucus was chosen as the source of antibacterial peptide for further purification of antibacterial peptides. following the ...201121796440
immunogenicity of pressure inactivated edwardsiella tarda bacterin to anguilla japonica (japanese eel).japanese eel anguilla japonica were immunized with inactivated edwardsiella tarda bacterin preparations (formalin-killed cells, fkc (0.4%), formalin with heat-killed cells, fhkc (0.1% and 70 degreesc for 10 min), heat-killed cells, hkc (70 degrees c for 15 min), potassium chloride-killed cells, kkc (0.6%), tannic acid-killed cells, tkc (0.9%), citric acid-killed cells, cakc (0.9%), pressure-killed cells, pkc (600 psi for 5 min) and electric current-killed cells, eckc (100 ma at 12 v dc for 5 sec ...201122303581
ribose operon repressor (rbsr) contributes to the adhesion of aeromonas hydrophila to anguilla japonica mucus.the characterization of adhesion between pathogenic bacteria and the host is critical. pathogenic aeromonas hydrophila was shown to adhere in vitro to the mucus of anguilla japonica. to further investigate the adhesion mechanisms of a. hydrophila, a mini-tn10 transposon mutagenesis system was used to generate an insertion mutant library by cell conjugation. seven mutants that were impaired in adhesion to mucus were selected out of 332 individual colonies, and mutant m196 was the most severely im ...201728127946
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