bluuebunny/crossref_metadata_2025 huggingface dataset:
Expression of Proopiomelanocortin and Its Cleavage Enzyme Genes in Rana esculenta and Xenopus laevis Gonads
Authors: CAROTTI M , NABISSI M , MOSCONI G , GANGNON F , LIHRMANN I , VAUDRY H , POLZONETTI‐MAGNI A.M
Published: May 2005

Abstract: Proopiomelanocortin (POMC) is the precursor protein of different hormones and neuropeptides, and the POMC‐derived peptides are produced through proteolytic cleavage. Prohormone convertase PC1 and PC2 are enzymes responsible for the cleavage of the POMC prohormone. The coexpression of POMC, PC1, and PC2 genes was previously described in the brain and the pituitary gland of Rana esculenta and Xenopus laevis, but no data are available for the gonad. The present work demonstrates a gonadal POMC convertase gene expression in Rana esculenta and Xenopus laevis.
Fra‐1 Activity in the Frog, Rana esculenta, Testis
Authors: COBELLIS GILDA , LOMBARDI MONICA , SCARPA DONATELLA , IZZO GAIA , FIENGA GIULIA , MECCARIELLO ROSARIA , PIERANTONI RICCARDO , FASANO SILVIA
Published: May 2005

Abstract: Using an anti‐Fos family member antiserum, we previously described, in the testis of Rana esculenta, the presence of a nuclear 43‐kDa protein that we hypothesized to be Fra‐1. Using an antiserum against Fra‐1, we here report on Fra‐1 expression, localization, and putative activity in the R. esculenta testis during the annual reproductive cycle. Western blot analysis confirms that the nuclear 43‐kDa protein is Fra‐1. Immunocytochemistry demonstrates Fra‐1 in peritubular myoid cells (PMC), efferent ducts, and blood vessels. We present, for the first time for a vertebrate, experimental evidence that the expression of Fra‐1 in PMC is related to its activity during sperm transport from the tubular compartment to the efferent ducts.
Analysis of Xenopus Melanotrope Cell Size and POMC‐Gene Expression
Authors: CORSTENS G J H , ROUBOS E W , JENKS B G , VAN ERP P E J
Published: May 2005

Abstract: Flow cytometry was used to separate Xenopus melanotrope cells according to their size. The cells were then submitted to real‐time RT‐PCR to determine the level of POMC‐gene expression. The results show a positive correlation between cell size and gene expression for cells from black‐background (but not white‐background) adapted animals.
Cloning and Expression of Guanylin‐like Peptides in Teleost Fish
Authors: CRAMB GORDON , MARTINEZ ANNE‐SOPHIE , McWILLIAM IAIN S. , WILSON GILLIAN D.
Published: May 2005

Abstract: Homologues of the guanylin peptide family are expressed in teleost fish. Using the eel as a model euryhaline species, cDNAs for three peptides, guanylin, uroguanylin, and renoguanylin, were cloned and found to be expressed within both renal and intestinal epithelia. Seawater (SW) acclimation resulted in upregulation of uroguanylin mRNA expression in the intestinal epithelia of both immature “yellow” and sexually mature “silver” eels. SW acclimation also resulted in an increase in guanylin mRNA in silver eel intestine, whereas there was no change in renoguanylin mRNA expression under any condition. No changes in expression were found in the kidney following SW acclimation.
Features of the Circadian Clock in the Avian Pineal Gland
Authors: CSERNUS V , FALUHELYI N , NAGY A D
Published: May 2005

Abstract: The effects of different environmental factors on the circadian rhythm of melatonin release by chicken pineal glands were analyzed in 5‐day experiments in vitro. Periodic, brief 4‐h illumination at around midnight resulted in phase inversion in 2 days. Exposure to repeated 41°C temperature elevation at around midnight caused no phase shift in the basic melatonin rhythm. Repeated inversion of the polarity of the magnetic field also affected rhythmic melatonin release. Additionally, expressions of Per1, Per2, Per3, Bmal1, Bmal2, Clock, Cry1, and Cry2 clock genes were simultaneously detected in single chicken pineal glands.
Growth Hormone Increases hsc70/hsp70 Expression and Protects against Apoptosis in Whole Blood Preparations from Silver Sea Bream
Authors: DEANE EDDIE E. , WOO NORMAN Y. S.
Published: May 2005

Abstract: Preparations of whole blood, from silver sea bream (Sparus sarba), were used for heat shock protein 70 (hsp70) and apoptosis studies. It was found that the expression of both gene members of the hsp70 family (hsc70 and hsp70) were upregulated during acute heat shock. The transcript abundance of both of these genes was increased when cells were exposed to growth hormone (GH) at concentrations of 10 and 100 ng/mL. It was also found that GH at concentrations of 10 and 100 ng/mL could protect whole blood from camptothecin‐induced apoptosis as determined by DNA fragmentation analysis.
The Advantage of Absolute Quantification in Comparative Hormone Research as Indicated by a Newly Established Real‐Time RT‐PCR: GH, IGF‐I, and IGF‐II Gene Expression in the Tilapia, Oreochromis niloticus
Authors: EPPLER ELISABETH , CAELERS ANTJE , BERISHVILI GIORGI , REINECKE M.NFRED
Published: May 2005

Abstract: We have developed a real‐time RT‐PCR that absolutely quantifies the gene expression of hormones using the standard curve method. The method avoids cloning procedures by using primer extension to create templates containing a T7 promoter gene sequence. It is rapid since neither separate reverse transcriptions nor postamplification steps are necessary, and its low detection level (2 pg/μg total RNA) allows precise absolute quantification. Using the method, we have quantified the gene expression of GH, IGF‐I, and IGF‐II in the tilapia.
Androgen Receptor in the Ovary of Postnatal Bank Vole Females
Authors: GALAS JERZY , SLOMCZYNSKA MARIA , KWASNIK ANNA
Published: May 2005

Abstract: In this experiment, we investigated the influence of the photoperiod upon androgen receptor (AR) distribution and steroid concentrations in ovaries of 21‐day‐old bank vole females. Sections (6 μm) were assayed immunohistochemically. ARs were localized in the nuclei of granulosa cells. The strongest immunoreaction was observed in primary and early antral follicles, and declined during follicular development. P4, A, and E2 contents were measured by RIAs in ovarian homogenates from animals kept in two photoperiods. Ovaries of animals kept in a long photoperiod (18:6 light:dark), which stimulates gonadal activity, contained more P4 than those kept in a short one (6:18 light:dark). There was no difference in levels of A and E2.
Hormonal Control of the IGF System in the Sea Bream Ovary
Authors: GIOACCHINI G , CARDINALI M , MARADONNA F , FUNKENSTEIN B , MOSCONI G , CARNEVALI O.
Published: May 2005

Abstract: Numerous studies have described the presence of an intragonadal IGF system involved in regulation of gametogenesis in teleost fish. In the present study, the in vivo effects of estradiol‐17β (E2) and growth hormone (GH) exposure on IGF‐I, IGF‐II, IGF1R, and IGFBP2 gene expression in sea bream ovary were monitored by RT‐PCR during prereproductive and reproductive periods. The evidence demonstrates that both hormones investigated here affect the ovarian IGF system, showing that it is not only under GH control, but also can be regulated by sexual hormones; this hormonal modulation is related to reproductive phase.
The Use of Real‐Time PCR to Study the Expression of Thyroid Hormone Receptor β2 in the Developing Chicken
Authors: GROMMEN SYLVIA V. H. , DE GROEF BERT , KÜHN EDUARD R. , DARRAS VEERLE M.
Published: May 2005

Abstract: Thyroid hormones and their receptors (TRs) have critical functions in development and metabolism. In chicken, three TRs are known: TRα, TRβ0, and TRβ2. The latter was isolated from chicken eye, but its presence in other tissues has not yet been extensively investigated. We therefore developed a real‐time PCR assay using a Taqman probe and primers based on the unique amino‐terminal region of TRβ2. We detected a strong TRβ2 mRNA signal in the pituitary, confirmed with in situ hybridization, and in several other tissues. TRβ2 mRNA was more abundant in the pituitary of newly hatched chicks than in 15‐day‐old embryos.
Neurodistribution of Androgen Receptor Immunoreactivity in the Male Frog, Rana esculenta
Authors: GUERRIERO G , PRINS G S , BIRCH L , CIARCIA G
Published: May 2005

Abstract: Sexual behavior in vertebrates depends on the cyclic release of steroids and their binding to the brain receptors. Previously, we demonstrated the presence of specific binding of 3H‐testosterone and staining with PG‐21 in the brain of the adult male frog, Rana esculenta. Here, we report our further receptor characterization using an anti‐androgen receptor antiserum, PG‐21, and the androgen site of action in frog brain. Nuclei, which contained cells labeled for the androgen receptor (AR), were mainly identified in the olfactory bulbs, preoptic‐septal region, infundibulum, amygdala, thalamus, tectum, torus semicircularis, and medulla. The neuroanatomical AR staining appears similar to that in other lower vertebrates.
Regulation of the Stress Response in Early Vertebrates
Authors: HUISING MARK O. , METZ JURIAAN R. , DE MAZON AURELIA F. , VERBURG‐VAN KEMENADE B M LIDY , FLIK GERT
Published: May 2005

Abstract: The acute stress response is a key regulatory system for the maintenance of homeostatic equilibrium that is activated upon an imminent or ongoing disturbance of the “milieu interieur”. In general, the stress response in bony fish is similar to that of mammals. The recent cloning and characterization of corticotropin‐releasing hormone‐binding protein (CRH‐BP) in carp (Cyprinus carpio L.) reflects the conservation of the CRH signaling system throughout vertebrates. Now, we can start to investigate the processes that are mediated by the factors that make up this system. The stress response is only one of these processes.
Expression of Aromatase mRNA in the Abdominal Gland of the Newt, Cynops pyrrhogaster
Authors: ITO YOICHI , HIROTA ATSUSHI , NAKAMURA MARIKO , MATSUNAGA MASAHIRO , TSUTSUI KAZUYOSHI , KIKUYAMA SAKAÉ
Published: May 2005

Abstract: As a step to see whether the local aromatization mechanism exists in the newt, Cynops pyrrhogaster, cDNA cloning and characterization of newt cytochrome P450 aromatase (P450arom) were conducted. Newt P450arom cDNA was obtained from a C. pyrrhogaster ovarian cDNA library. By RT‐PCR and in situ hybridization, an intense P450arom mRNA expression was detected in the abdominal gland. Employing biochemical techniques combined with HPLC and TLC analyses, we also demonstrated the conversion of testosterone to estradiol in the abdominal grand. The significance of aromatization of testosterone in this gland is discussed.
Regionally Specific Occurrence of an Active Sodefrin Variant in the Red‐Bellied Newt
Authors: IWATA TAKEO , ISHIZUKA YOKO , NAKADA TOMOAKI , TOYODA FUMIYO , YAMAMOTO KAZUTOSHI , CONLON JOHN M. , KIKUYAMA SAKAE
Published: May 2005

Abstract: Sodefrin (SIPSKDALLK) is a female‐attracting pheromone that is secreted by the abdominal gland of the male red‐bellied newt. We found that mRNA encoding a sodefrin variant, [Val8] sodefrin, is expressed exclusively in specimens captured in the Nara area of Japan. The synthetic peptide was tested for its activity. It attracted females from Nara, but not those from other regions, suggesting that there is a geographic variation in the pheromone molecule and in the responsiveness to the pheromone. Employing an abdominal gland extract and synthetic substrates, the possibility of generation of the putative pheromone, [Val8] sodefrin, from the precursor molecule was demonstrated.
Androgen Metabolism in Invertebrates and Its Modulation by Xenoandrogens: A Comparative Study
Authors: JANER G , LeBLANC G A , PORTE C.
Published: May 2005

Abstract: Marisa cornuarietis (Mollusc), Hyalella azteca (Crustacean), and Paracentrotus lividus (Echinoderm) demonstrated the ability to metabolize androgens through different pathways catalyzed by 5α‐reductases (5α‐R), hydroxysteroid dehydrogenases (HSD), hydroxylases, sulfotransferases (SULT), and fatty‐acid acyl‐CoA acyltransferases (ATAT). Interspecies differences and tissue‐specific distribution of those enzymatic activities were observed. Xenobiotics, such as triphenyltin, tributyltin, and fenarimol, interfered with some of the pathways studied, namely, testosterone sulfation, testosterone esterification, and 5α‐R activity. The work evidenced different sensitivity of those pathways to androgenic compounds, together with interphyla differences in androgen metabolism.
The Involvement of Thyroid Hormone Metabolism in Gilthead Sea Bream (Sparus auratus) Osmoregulation
Authors: KLAREN PETER H. M. , GUZMÁN JOSÉ M. , MANCERA JUAN MIGUEL , GEVEN EDWIN J. W. , FLIK GERT
Published: May 2005

Abstract: We have investigated the effect of adaptation to low salinity water on the thyroid status of the euryhaline teleost, Sparus auratus. We show that, following low salinity adaptation, the plasma T4 concentration increases and branchial deiodination activities of T4, T3, and rT3 decrease. Moreover, branchial and hepatic enzyme activities that are putatively involved in thyroid hormone metabolism respond differentially in low salinity conditions. Our results indicate the involvement of thyroid hormones in Sparus auratus osmoregulation. Moreover, the gills appear well equipped to play an important role in the modulation of plasma thyroid hormone titers.
Time‐Course Effects of Centrally Administered Native Urotensin‐II on Motor and Cardioventilatory Activity in Trout
Authors: LANCIEN F , LEPRINCE J. , MIMASSI N , MABIN D , VAUDRY H , LE MÉVEL J.C
Published: May 2005

Abstract: Although in most vertebrate species urotensin‐II (UII) is synthesized in neurons of the central nervous system, little is known regarding the physiological actions of UII in the brain. We have investigated the effects of intracerebroventricular (ICV) administration of synthetic trout UII (1, 5, and 50 pmol) on total motor activity (ACT), ventilatory frequency (VF), ventilatory amplitude (VA), and heart rate (HR) in the unanesthetized trout. ICV injection of UII increased ACT in a dose‐dependent manner, and the maximal effect was observed at a dose of 5 pmol. At doses of 1 and 5 pmol, UII did not affect VF, VA, or HR. At the highest dose tested (50 pmol), UII not only increased ACT, but also significantly activated VF, VA, and HR. In contrast, ICV injection of synthetic trout angiotensin‐II (5 pmol) did not produce any effect on ACT, VF, or VA, but sharply increased HR. These data provide the first evidence that UII can act centrally to induce motor activity in a nonmammalian vertebrate species.
Subtype‐Specific Pharmacological Properties of the Melanocortin Receptors in Chicken
Authors: LING MARIA K. , SCHIÖTH HELGI B.
Published: May 2005

Abstract: The melanocortin (MC) receptors belong to the family of G‐protein‐coupled receptors and have five subtypes (MC1‐5) in mammals and chicken. We have expressed the chicken MC1‐5 (cMC1‐5) receptors and seven allelic variants of the cMC1 receptor and performed pharmacological characterization of these receptors. Three variants of the cMC1 receptor, all sharing a Glu to Lys mutation in position 92, are associated with dark feather coloration, and these were pharmacologically described as constitutively active. The pharmacological characterization of the cMC1‐5 receptors provides insight of how this receptor family has evolved and useful information for the use of chicken in physiological experiments.
Environmental Agent Susceptibility Assessment Using Existing and Novel Biomarkers as Rapid Noninvasive Testing Methods
Authors: MANDICH A , BENFENATI E , CRONIN M T D , GOKSØYR A , GRØSVIK B E , KLOAS W , VAN CAUWENBERGE A , VIGANÒ L
Published: May 2005

Abstract: This study is part of a project aimed at developing and validating novel noninvasive methods for the detection of biomarkers of endocrine disrupters (EDs) directly in the mucus of aquatic species, to identify novel functional biomarker(s) for EDs, and to verify their applicability for field studies. The multidisciplinary approach chosen aims at the development of an integrated testing strategy utilizing in vitro protocols to identify water and sediment fractions with potential endocrine‐disrupting activity; the identification, characterization, and measurement of new biomarker(s) for EDs; the development and validation of a dipstick‐based test method; and the development of (computer‐assisted) predictive models. Some results of the first year of the project are presented here.
Characterization of PrPc‐Immunoreactive Cells in Monkey (Macaca fascicularis) Gastrointestinal Tract
Authors: MARCOS Z , BODEGAS M E , SESMA M P , GUEMBE L
Published: May 2005

Abstract: The gastrointestinal tract (GIT) is one of the most likely entry sites for the pathological isoform of prions (PrPsc). To understand how PrPsc crosses the digestive mucosa, it is crucial to characterize the cells expressing normal prion protein (PrPc). By means of double immunofluorescence applied to sections of the monkey GIT, we demonstrated that, in the stomach, PrPc immunostaining occurs in subsets of histamine, somatostatin (Som), ghrelin (Ghr), gastrin (G), and serotonin (5HT) cells. In the small and large bowels, PrPc cells were found in subpopulations of cells immunolabeled for 5HT, Som, G, and peptide YY (PYY).
Comparative Study of PrPc Expression in Rat, Monkey, and Cow Gastrointestinal Tract
Authors: MARCOS Z , BODEGAS M E , SESMA M P , GUEMBE L
Published: May 2005

Abstract: The gastrointestinal tract (GIT) appears to be the main site of entry for the pathological isoform of prions (PrPsc). To understand how the PrPsc internalization process occurs, it is important to characterize the cell types that express normal prion protein (PrPc) along the GIT. To do so, we studied the distribution of PrPc in the rat, monkey, and cow GIT. Using Western blot analysis, we found that PrPc is expressed in all digestive regions of the three species. Immunoreactivity for PrPc was found throughout the GIT in epithelial cells sharing the neuroendocrine (NE) phenotype. Immunostained cells appeared scattered throughout the epithelium of fundic and pyloric glands as well as in intestinal villi and crypts.
Developmental Expression of NPY/PYY Receptors zYb and zYc in Zebrafish
Authors: MATHIEU M.URA , TROMBINO SONYA , ARGENTON FRANCESCO , LARHAMMAR DAN , VALLARINO M.URO
Published: May 2005

Abstract: This study describes the developmental expression of zYb and zYc receptors in zebrafish. RT‐PCR demonstrated that both mRNAs are present from 24‐hour postfertilization (hpf) and that their expression increased during larval development. Whole‐mount in situ hybridization showed zYb mRNA expression in the epithalamus (24 hpf), telencephalon, hypothalamus, rhombencephalon (24‐96 hpf), mesencephalon (48‐96 hpf), hatching gland, and otic vesicle (48‐64 hpf). zYc mRNA is expressed in the epithalamus (24 and 96 hpf), telencephalon (48‐96 hpf), spinal cord, notochord (64 hpf), and hatching gland (96 hpf). These results show that zYb and zYc receptors are expressed during ontogeny, suggesting a role for neuropeptide Y (NPY) and/or peptide YY (PYY) in organogenesis.
Structure of Msj‐1 Gene: A Comparative Analysis
Authors: MECCARIELLO R. , TEDESCHI G , MONSURRÒ M R , CHIANESE R. , COBELLIS G , PIERANTONI R. , FASANO S
Published: May 2005

Abstract: Msj‐1 gene encodes a DnaJ protein highly expressed in spermatids and spermatozoa of both rodents and amphibians. We isolated and characterized the msj‐1 gene in mice. A bioinformatic approach was then used to predict the putative promoter region, chromosomal localization, and its presence in the human genome. The analysis of msj‐1 genomic sequence revealed that msj‐1 is an intronless gene. Interestingly, two regions (A and B, separated by 10,682 bp) on human chromosome 2 having respectively 78% and 77% nucleotide identity with the murine msj‐1 coding region were identified. This suggests the existence of an msj‐1‐like gene also in humans.
Characterization of an RFamide‐Related Peptide Orphan GPCR in C. elegans
Authors: MERTENS I , VANDINGENEN A , CLYNEN E , NACHMAN R J , DE LOOF A , SCHOOFS L
Published: May 2005

Abstract: We cloned and characterized an orphan FMRFamide‐related peptide (FaRP) GPCR in Caenorhabditis elegans. We synthesized numerous structurally different FaRPs that were found in the C. elegans genome by bioinformatic analysis and used them to screen cells expressing the C26F1.6 receptor. Two peptides ending in M(orL)VRFamide elicited a calcium response in receptor‐expressing mammalian Chinese hamster ovary cells. The response was dose‐dependent and appeared to be very specific; that is, none of the other FaRPs were active, not even closely related peptides also ending in M(orL)VRFamide, which are encoded by the same peptide precursor. Pharmacological profiling with a truncated series of the most active peptide revealed that the full peptide sequence is necessary for receptor activation.
Cloning and Characterization of Ecdysone Receptor and Ultraspiracle cDNAs from Spodoptera litura
Authors: NAGATA SHINJI , MARUYAMA TAKAFUMI , OHIRA TSUYOSHI , WATARU SHUHEI , NAGASAWA HIROMICHI
Published: May 2005

Abstract: The insect molting hormone, ecdysone, induces a series of events critical for ecdysis, beginning with the formation of a complex between ecdysteroid receptor (EcR) and its partner protein, ultraspiracle (Usp). In the present study, we cloned cDNAs encoding EcR and Usp by RT‐PCR and 5′‐/3′‐RACE from the common cutworm, Spodoptera litura, a destructive agricultural pest insect in East Asia. Hexahistidine‐tagged recombinant EcR and Usp of S. litura were expressed in E. coli, and the proteins, after refolding, exhibited the specific binding to an ecdysone analogue in vitro.
Ligand‐Dependent Protein Interactions of the Estrogen Receptors Using the Yeast Two‐Hybrid System
Authors: OFTEDAL BERGITHE E. , LADSTEIN SIGVE , TELLE WENCHE , MALE RUNE
Published: May 2005

Abstract: The protein‐interacting ability of estrogen receptor beta (ERβ) and estrogen receptor alpha (ERα) from Atlantic salmon (Salmo salar) was studied using the yeast two‐hybrid system. The salmon ERβ shared features with other nuclear receptors regarding dimerization, forming a homodimer and heterodimer with ERα. The activation of salmon ERs by estradiol‐17β was shown to be necessary for dimerization. Furthermore, the xenoestrogens, 4‐nonylphenol and bisphenol A, were shown to promote ER dimerization in the yeast two‐hybrid system.
Involvement of Adenylyl Cyclase Signaling Mechanism in Insulin and IGF‐I Coregulation of Fundamental Cell Processes
Authors: PERTSEVA M.N
Published: May 2005

Abstract: The discovery of the adenylyl cyclase signaling mechanism (ACSM) of insulin and related peptides allows for advancing the hypothesis of its participation in regulatory action on cell growth, apoptosis, and metabolism. The following evidences were obtained: (1) The order of efficiency of insulin and IGF‐I growth‐promoting action and their antiapoptotic effect coincides with that of the peptide‐activating action on AC. (2) The growth‐promoting and antiapoptotic effects of insulin and IGF‐I are distinctly reproduced by cAMP. (3) The anabolic effects of insulin and IGF‐I activation on glycogen synthesis and the pentosophosphate pathway are inhibited by cAMP.
The Activities of Antioxidant Enzymes and Monoamine Oxidase and Uncoupling Protein 1 Content in Brown Fat of Hypo‐ and Hyperthyroid Rats
Authors: PETROVIC N. , CVIJIC G , DJORDJEVIC J , DAVIDOVIC V
Published: May 2005

Abstract:We have studied the activities of antioxidant enzymes (AOE), namely, copper‐zinc superoxide dismutase (CuZnSOD), manganese superoxide dismutase (MnSOD), and catalase (CAT), and the activity of catecholamine‐degrading enzyme monoamine oxidase (MAO) and uncoupling protein 1 (UCP1) content in brown fat (BF) of hypo‐ and hyperthyroid rats. We found that hypothyroidism decreased BF UCP1 content and increased MAO, MnSOD, and CAT activities. T3 increased UCP1 content and MnSOD activity and decreased CuZnSOD, MAO, and CAT activities, while T4 significantly altered (decreased) only CAT activity. This study shows that UCP1 content and MAO and AOE activities in rat BF are notably affected by changed thyroid status.
Sea Bream (Sparus auratus) Estrogen Receptors: Phylogeny and Tissue Distribution
Authors: PINTO P , PASSOS A.L , POWER D M , CANÁRIO A.V M
Published: May 2005

Abstract: Most estrogen actions are mediated by two estrogen receptor subtypes (ERα and ERβ). While a single ERβ appears to be present in higher vertebrates, two forms of ERβ encoded by different genes have recently been isolated in some teleost fish species. We investigated whether this also applies to the hermaphrodite sparid sea bream (Sparus auratus) and cloned a second ERβ (sbERβ2) in this species. We have also compared the tissue distribution of the three receptors as yet identified in sea bream, designated sbERα, sbERβ1, and sbERβ2.
Fish Community Characterization in Two Stretches Upstream and Downstream of the Lambro River Confluence with the Po River
Authors: PUZZI C , BOTTERO S , CEVASCO A , MASSARI A , MONTEVERDE M , PEDEMONTE F , BERTOLOTTI R , VIGANÒ L , MANDICH A
Published: May 2005

Abstract: This study aimed to characterize the fish community in two stretches of the Po River, upstream and downstream of the Lambro River confluence, to verify the environmental effects of the presence of endocrine disrupters (EDs). More than 5000 specimens were captured, identified at the species level, and recorded for biometric parameters. Plasma, liver, and gonad fragments were sampled for histological and biochemical analyses. Few specimens belonging to carp and barbel showed gonads with the concomitant presence of male and female tissues and altered plasma levels of vitellogenin and sex steroids; thus, these species will be considered for successive environmental studies.
Activity of Purine Catabolism Enzymes during the Reproductive Cycle of Male and Female Brown Trout (Salmo trutta)
Authors: RESENDE A D , ROCHA E , LOBO‐DA‐CUNHA A
Published: May 2005

Abstract: In order to detect predicted changes in purine catabolism during the annual reproductive cycle of brown trout, we measured the activity of xanthine dehydrogenase, urate oxidase, and allantoinase. In kidney, only xanthine dehydrogenase was detected. In female liver and kidney, the activity of these enzymes was higher in May and decreased during vitellogenesis, with urate oxidase being undetectable in this period. In male liver, a similar variation pattern was found; however, in kidney, high activities were found in both May and December. These results suggest an influence of sex hormones in trout purine catabolism, especially in females.
Evolution of the Thyroid Hormone Distributor Protein Transthyretin in Microbes, C. elegans, and Vertebrates
Authors: RICHARDSON SAMANTHA J. , HENNEBRY SARAH C. , SMITH BRIAN J. , WRIGHT HANNAH M.
Published: May 2005

Abstract: Transthyretin (TTR) is an extracellular thyroid hormone distributor protein in vertebrates, whose structure has been highly conserved between fish and humans. However, the ligand preferentially bound by TTR has changed during evolution from 3′,3,5‐l‐triiodothyronine (T3) to 3′,5′,3,5‐l‐tetraiodothyronine (T4). We identified genes in the genomes of >50 species of nonvertebrates, which could code for TTR‐like proteins. Molecular modeling suggested most would have similar 3D structures and electrostatic surface potentials to vertebrate TTRs. We amplified TTR‐like genes from a C. elegans cDNA library, demonstrating that it is transcribed. We synthesized recombinant TTR‐like proteins from S. dublin and C. elegans. These proteins form tetramers similarly to vertebrate TTRs, but their ligands remain elusive.
Ghrelin Induces Growth Hormone (GH) Secretion via Nitric Oxide (NO)/cGMP Signaling
Authors: RODRÍGUEZ‐PACHECO F , LUQUE R M , GARCÍA‐NAVARRO S , GRACIA‐NAVARRO F , CASTAÑO J P , MALAGÓN M.M
Published: May 2005

Abstract: Ghrelin, a recently discovered 28‐aa peptide, stimulates GH release through a mechanism involving PLC‐ and cAMP‐related signaling pathways. Recently, nitric oxide (NO) and its mediator, cGMP, have been shown to be required for the response of somatotropes to various regulators (GHRH, somatostatin, leptin). Here, we explore the possible role of the NO synthase (NOS)/NO/guanylate cyclase (GC)/cGMP signaling pathway in ghrelin‐induced GH release from cultured pig somatotropes using blockers or activators of this route.
Neurotoxicity of Polychlorinated Biphenyls (PCBs) by Disturbance of Thyroid Hormone‐Regulated Genes
Authors: ROELENS S.A , BECK V , AERTS G , CLERENS S. , VANDEN BERGH G , ARCKENS L , DARRAS V M , VAN DER GEYTEN S.
Published: May 2005

Abstract: PCBs are known as neurotoxic compounds. Part of this neurotoxicity could be due to an alteration of the expression of TH‐regulated genes in brain. To identify such genes, brain protein extracts of hypo‐ and hyperthyroid as well as PCB‐treated embryos were compared by fluorescent 2D‐DIGE. In total, we observed 109 differentially expressed proteins, of which 17 differed with both PCB and hypo‐ or hyperthyroid treatment. It was found that the interaction of PCBs with the expression of TH‐regulated genes is congener‐specific and that both hyperthyroidism‐ and hypothyroidism‐related effects occur.
Pleiotropic Action of Insulin‐like Peptides of Mollusk, Anodonta cygnea
Authors: SHIPILOV V.N , SHPAKOV A O , RUSAKOV YU I
Published: May 2005

Abstract: Insulin‐related peptides (IRPs) from ganglions of mollusk, Anodonta cygnea, were purified and characterized (IRP1‐IRP13) using insulin and insulin‐like growth factor‐I (IGF‐I) radioreceptor test systems. The IRPs were able to bind to insulin and IGF‐I receptors. Dose‐dependent curve slopes indicated that most IRPs bind with higher affinity to IGF‐I receptors than to insulin receptors. The IRP regulatory action on the activity of the adenylyl cyclase signal system showed that these peptides stimulated adenylyl cyclase and GTP‐binding activity of G‐proteins to the same extent as insulin and IGF‐I. The data obtained suggest polyfunctional IRP action that apparently is determined by the molecular structure of individual isoforms.
Sensitivity of Adenylyl Cyclase Signaling System of the Mollusk Anodonta cygnea Ganglions to Serotonin and Adrenergic Agonists
Authors: SHPAKOV A.O , SHIPILOV V N , BONDAREVA V M
Published: May 2005

Abstract: For the first time, the adenylyl cyclase system (ACS) sensitive to biogenic amines in the mollusk Anodonta cygnea ganglions was revealed and characterized. Serotonin and isoproterenol stimulated AC activity and GTP‐binding activity of heterotrimeric G‐proteins. The AC‐stimulating action of serotonin and isoproterenol was blocked by cyproheptadine and adrenergic antagonists, respectively. Using synthetic C‐terminal peptides of G‐protein alpha‐subunit, it was shown that the biogenic amines realized their action on the ACS through different G‐protein types: serotonin and isoproterenol activate Gs‐protein, while adrenaline preferably activates Gi‐protein.
A Survey on the Expression of IGF‐I in the Early Developing Bony Fish with Special Emphasis on the Tilapia, Oreochromis niloticus
Authors: SHVED NATALLIA , BERISHVILI GIORGI , D'COTTA HELENA , BAROILLER JEAN‐FRANÇOIS , EPPLER ELISABETH , SEGNER HELMUT , REINECKE M.NFRED
Published: May 2005

Abstract: The present study investigates the expression of IGF‐I in the early developing tilapia (Oreochromis niloticus). IGF‐I was detected very early in ontogeny (4‐5 days postfertilization, DPF), first in liver and in organs involved in growth and metabolism, thus suggesting a high physiological impact of IGF‐I in growth, metabolism, and organogenesis.
Stimulation of Midgut Stem Cell Proliferation and Differentiation by Insect Hormones and Peptides
Authors: SMAGGHE GUY , VANHASSEL WENDY , MOEREMANS CLARINA , DE WILDE DAAN , GOTO SHINTARO , LOEB MARCIA J. , BLACKBURN MICHAEL B. , HAKIM RAZIEL S.
Published: May 2005

Abstract: Stem cells derived from midguts of the caterpillar, Spodoptera littoralis, can be induced to multiply and differentiate in vitro. Ecdysone (E) and 20‐hydroxyecdysone (20E) had a concentration‐dependent effect: E was more active in cell proliferation and 20E in differentiation. Ecdysteroid receptors in midgut stem cell nuclei were stained with the antibody 9B9. In addition, α‐arylphorin and four midgut differentiation factors (MDF) specifically stimulated proliferation and differentiation of stem cells, respectively. The activity of a panel of peptide growth factors and hormones on growth and metamorphosis of the insect midgut is discussed.
Molecular Evolution and Subfunctionalization of Nkx2.1 in the Rainbow Trout
Authors: SUZUKI MASAKAZU , HIDAKA YOSHIE , UEMAE YOUJI , TANAKA SHIGEYASU
Published: May 2005

Abstract: Because specification of duplicated genes is considered to be a major driving force for diversity and evolution, it is important to understand the function of the duplicated genes. In mammals, Nkx2.1 is essential for the differentiation of thyroid follicular cells and for the transcription of thyroid‐specific genes. We have cloned four distinct Nkx2.1 cDNAs from the rainbow trout, Oncorhynchus mykiss. In the present article, we will characterize the trout Nkx2.1 mRNAs and show their tissue distribution, their transcriptional activities, and their expression during early development.
Immunocytochemical and Phylogenetic Distribution of Aquaporins in the Frog Ventral Skin and Urinary Bladder
Authors: TANAKA S. , HASEGAWA T , TANII H , SUZUKI M
Published: May 2005

Abstract: We recently cloned three cDNAs encoding frog aquaporin (AQP‐h1, BAC07470; AQP‐h2, BAC82379; and AQP‐h3, BAC07471) from the ventral pelvic skin of the tree frog, Hyla japonica. The present study demonstrated that Hyla AQP‐h2 was translocated from cytoplasmic pools to the apical plasma membranes of the granular cells in the bladder after antidiuretic hormone stimulation and that Hyla AQP‐h2 and AQP‐h3 behaved similarly in the ventral pelvic skin. Further, we found that terrestrial and tree frogs, but not aquatic and semiterrestrial‐adapted frogs, absorbed water from their ventral pelvic skin by AQP‐h3‐like protein in concert with AQP‐h2‐like protein.
Ontogeny of 3β‐Hydroxysteroid Dehydrogenase and 5α‐Reductase in the Frog Brain
Authors: VALLARINO M.URO , MATHIEU M.URA , DO‐REGO JEAN‐LUC , BRUZZONE FEDERICA , CHARTREL NICOLAS , LUU‐THE VAN , PELLETIER GEORGES , VAUDRY HUBERT
Published: May 2005

Abstract: The distribution of 3β‐hydroxysteroid dehydrogenase (3β‐HSD) and 5α‐reductase (5α‐R) has been studied in the frog brain during development. Soon after hatching, 3β‐HSD‐ and 5α‐R‐immunoreactive (ir) cells appeared first in the olfactory bulb and in the rhombencephalon. Subsequently, 3β‐HSD‐ir cells were seen in the hypothalamus and cerebellum, whereas 5α‐R‐ir cells were visualized in the pallium, preoptic nucleus, posterocentral nucleus, cerebellum, and pituitary gland. At stages XIII‐XVIII, additional 3β‐HSD‐ and 5α‐R‐ir cells appeared in several regions of the telencephalon, diencephalon, and mesencephalon. At stages XIX‐XXI, the number of 5α‐R‐ir cells increased in the preoptic nucleus. These observations indicate that biosynthesis of biologically active steroids occurs in the brain of tadpoles, suggesting that neurosteroids may play a role in brain development.
Calcium Influx through Voltage‐Operated Calcium Channels Is Required for Proopiomelanocortin Protein Expression in Xenopus Melanotropes
Authors: VAN DEN HURK M J J , SCHEENEN W J J M , ROUBOS E W , JENKS B.G
Published: May 2005

Abstract: Melanotrope cells of Xenopus laevis generate transitory increases in intracellular Ca2+, known as Ca2+ oscillations. These oscillations arise from the influx of Ca2+ through voltage‐operated Ca2+ channels (VOCCs). Such oscillations are the driving force for secretion of a‐melanophore‐stimulating hormone (α‐MSH) from the cell. The influx of Ca2+ through VOCCs initiates the mobilization of intracellular Ca2+ to generate a Ca2+ wave. The function of the Ca2+ wave in the melanotrope is unknown, but its presence in the nucleus suggests a role in the regulation of gene expression, perhaps that of proopiomelanocortin (POMC), the precursor protein for α‐MSH. To determine the possible function of Ca2+ waves in Xenopus melanotropes, we addressed whether functional VOCCs, which are an established requirement for both secretion and Ca2+ wave initiation, are also required to maintain POMC gene expression.
ACE Inhibitor Captopril Reduces Ecdysteroids and Oviposition in Moths
Authors: VERCRUYSSE L. , GELMAN D , VAN DE VELDE S , RAES E , HOOGHE B , VERMEIRSSEN V , VAN CAMP J , SMAGGHE G
Published: May 2005

Abstract: By using the selective ACE inhibitor captopril, we studied the effect of the angiotensin converting enzyme (ACE) on larval growth, metamorphosis, and reproduction in a lepidopteran species, the cotton leafworm, Spodoptera littoralis. Captopril was detrimental to adult formation and oviposition, and in female moths it elicited decreasing ecdysteroid levels, but increasing trypsin activities. Our results suggest that captopril downregulates oviposition by two independent pathways. Apparently, oviposition is influenced by a complex interaction of ACE, trypsin activity, and ecdysteroid levels.
Regulation of Thyroid Hormone Availability by Iodothyronine Deiodinases at the Blood‐Brain Barrier in Birds
Authors: VERHOELST C H J , VAN DER GEYTEN S , ROELENS S A , DARRAS V M
Published: May 2005

Abstract: It is accepted that type II iodothyronine deiodinase (D2) is predominantly found in brain, where it maintains homeostasis of thyroid hormone (TH) levels. The current study describes the production of a polyclonal D2 antiserum and its use in the comparison of D2 protein distribution with that of type I (D1) and type III (D3) deiodinase protein in the chicken choroid plexus (CP). Immunocytochemistry showed high D2 protein expression in the epithelial cells of the CP, whereas the D1 and D3 proteins were absent. Furthermore, dexamethasone treatment led to an upregulation of the D2 protein in these cells.
Melatonin Plays a Crucial Role in the Regulation of Rhythmic Clock Gene Expression in the Mouse Pars Tuberalis
Authors: VON GALL CHARLOTTE , WEAVER DAVID R. , MOEK JULIANE , JILG ANTJE , STEHLE JÖRG H. , KORF HORST‐WERNER
Published: May 2005

Abstract: Circadian rhythms in physiology and behavior are driven by a central clock residing within the hypothalamic suprachiasmatic nucleus (SCN). Molecularly, the biological clock is based on the transcriptional/translational feedback loop of clock genes (mPer, mCry, Clock, and Bmal1). Circadian expression of clock genes is not limited to the SCN, but is found in many peripheral tissues. Peripheral rhythms depend on neuroendocrine/neuronal output from the SCN. Melatonin, the hormone of darkness, represents an important neuroendocrine output of the circadian clock. The hypophyseal pars tuberalis (PT) is one of the main target regions for melatonin. The aim of the study was to test whether mPer, mCry, Clock, and Bmal1 are rhythmically expressed in the mouse PT and how the absence of melatonin receptors affects clock gene expression. We analyzed clock gene expression by in situ hybridization and compared wild‐type (WT), melatonin 1 receptor knockout (MT1 ko), and melatonin 2 receptor knockout (MT2 ko) mice. mPer1, mCry1, Clock, and Bmal1, but not mPer2 and mCry2, were rhythmically expressed in the PT of WT and MT2 ko mice. In the PT of MT1 ko mice, expression of mPer1, mCry1, Clock, and Bmal1 was dramatically reduced. We conclude that melatonin, acting through the MT1 receptor, is an important regulator of rhythmic clock gene expression in the mouse PT.
Brain‐Derived Neurotrophic Factor in the Hypothalamo‐Hypophyseal System of Xenopus laevis
Authors: WANG LIANGCHUN , CALLE MARINELLA , ROUBOS ERIC W.
Published: May 2005

Abstract: Brain‐derived neurotrophic factor (BDNF) is immunocytochemically demonstrated in the magnocellular nucleus and neural lobe of the pituitary gland of the amphibian Xenopus laevis. Immunoelectron microscopy shows BDNF in secretory granules of type A neurohemal axon terminals in the neural lobe of pituitary gland. It is proposed that BDNF released from the neural lobe acts as a neurohormone stimulating the secretory activity of the melanotrope cells in the intermediate pituitary lobe.
Glomerular Effects of AVT on the In Situ Perfused Trunk Preparation of the Dogfish
Authors: WELLS ALAN , ANDERSON W GARY , HAZON NEIL
Published: May 2005

Abstract: The effects of arginine vasotocin on the pattern of glomerular perfusion in an elasmobranch fish were examined using an in situ perfused renal trunk preparation. A significant antidiuresis was coupled with a marked reduction in the proportion of filtering glomeruli (86%‐25%) and an increase in the proportion of perfused but not filtering (10%‐53%) and non‐perfused glomeruli (4%‐22%). However, the reduction in filtering glomeruli was greater than predicted by measurements of urine flow rate and glomerular filtration rate alone, suggesting that alterations in single nephron glomerular filtration rate may occur.
Brain Expression of Tyrosine Hydroxylase and Its Regulation by Steroid Hormones in the European Eel Quantified by Real‐Time PCR
Authors: WELTZIEN F‐A , PASQUALINI C , LE BELLE N , VIDAL B , VERNIER P , DUFOUR S.
Published: May 2005

Abstract: In the eel, dopamine inhibits pubertal development. To investigate the regulatory mechanisms involved, we developed a quantitative real‐time RT‐PCR assay for measurement of brain expression of tyrosine hydroxylase (TH), the rate‐limiting enzyme in the biosynthesis of dopamine. TH expression was highest in the olfactory bulb, followed by the di‐/mesencephalic areas and the telencephalon/preoptic area. TH expression in the optic lobes and hindbrain was low or below the detection limit. In vivo treatment with testosterone, but not estradiol, resulted in increased TH expression in the forebrain, except the optic tectum, but not in the hindbrain. The results were confirmed by in situ hybridization.
Structure and function of the notochord: an essential organ for chordate development
Authors: Stemple Derek L.
Published: May 2005

The notochord is the defining structure of the chordates, and has essential roles in vertebrate development. It serves as a source of midline signals that pattern surrounding tissues and as a major skeletal element of the developing embryo. Genetic and embryological studies over the past decade have informed us about the development and function of the notochord. In this review, I discuss the embryonic origin, signalling roles and ultimate fate of the notochord, with an emphasis on structural aspects of notochord biology.
BOP, a regulator of right ventricular heart development, is a direct transcriptional target of MEF2C in the developing heart
Authors: Phan Dillon , Rasmussen Tara L. , Nakagawa Osamu , McAnally John , Gottlieb Paul D. , Tucker Philip W. , Richardson James A. , Bassel-Duby Rhonda , Olson Eric N.
Published: May 2005

The vertebrate heart is assembled during embryogenesis in a modular manner from different populations of precursor cells. The right ventricular chamber and outflow tract are derived primarily from a population of progenitors known as the anterior heart field. These regions of the heart are severely hypoplastic in mutant mice lacking the myocyte enhancer factor 2C (MEF2C) and BOP transcription factors, suggesting that these cardiogenic regulatory factors may act in a common pathway for development of the anterior heart field and its derivatives. We show that Bop expression in the developing heart depends on the direct binding of MEF2C to a MEF2-response element in the Bop promoter that is necessary and sufficient to recapitulate endogenous Bop expression in the anterior heart field and its cardiac derivatives during mouse development. The Boppromoter also directs transcription in the skeletal muscle lineage, but only cardiac expression is dependent on MEF2. These findings identify Bopas an essential downstream effector gene of MEF2C in the developing heart, and reveal a transcriptional cascade involved in development of the anterior heart field and its derivatives.
IQGAP1: a key regulator of adhesion and migration
Authors: Noritake Jun , Watanabe Takashi , Sato Kazumasa , Wang Shujie , Kaibuchi Kozo
Published: May 2005

The dynamic rearrangement of cell-cell adhesion is one of the major physiological events in tissue development and tumor metastasis. Polarized cell migration, another key event, is a tightly regulated process that occurs during tissue development, chemotaxis and wound healing. Rho-family small GTPases, especially Rac1 and Cdc42, play pivotal roles in these processes through one of their effectors, IQGAP1. Recent studies reveal that IQGAP1 regulates cadherin-mediated cell-cell adhesion both positively and negatively. It captures and stabilizes microtubules through the microtubule-binding protein CLIP-170 near the cell cortex, leading to establishment of polarized cell morphology and directional cell migration. Furthermore, Rac1 and Cdc42 link the adenomatous polyposis coli (APC) protein to actin filaments through IQGAP1 at the leading edge and thereby regulate polarization and directional migration.
Real-time pattern recognition in statistical process control: A hybrid neural network/decision tree-based approach
Authors: Guh Ruey-Shiang
Published: May 2005

Pattern recognition is an important issue in statistical process control because unnatural patterns displayed by control charts can be associated with specific causes that adversely impact on the manufacturing process. A common problem of existing approaches to control chart pattern (CCP) recognition is false classification between different types of CCP that share similar features in a real-time process-monitoring scenario, in which only limited pattern points are available for recognition. This study proposes a hybrid learning-based system that integrates neural networks and decision tree learning to overcome the classification problem in a real-time CCP recognition scheme. This hybrid system consists of three sequential modules, namely feature extraction, coarse classification, and fine classification. The coarse-classification model employs a four-layer back propagation network to detect and classify unnatural CCPs. The fine-classification module contains four decision trees used in a simple heuristic algorithm for further classifying the detected CCPs. Simulation experiments demonstrate that the false recognition problem has been effectively addressed by the proposed hybrid system. Compared with conventional control chart approaches, the proposed system has better performance in terms of recognition speed and also can accurately identify the type of unnatural CCP. Although a real-time CCP recognizer for the individual's (X) chart is the specific application presented here, the proposed hybrid methodology based on neural networks and decision trees can be applied to other control charts.
A methodology for developing company-specific design process models
Authors: Cross M , Sivaloganathan S
Published: May 2005

A number of design models have been proposed by design researchers, but they have not been adopted by industry because they are too generic. To be successful, companies have to manage effectively both project risk and concurrent development. The stage gate model is a suitable mechanism to achieve the required control within a commercial environment and there is evidence of its adoption by industry. The number of stages used depends on the degree of risk and the control needed in the project. Design methods are techniques that can assist designers to develop new products and knowledge can be classified as basic or specialist. This paper summarizes 100 key design methods from basic knowledge and suggests when they should be used. There are also company-specific design methods, which fall in the specialist knowledge category. An effective commercial design model should incorporate, firstly, a stage gate process that has stages defined to suit the project risk and to provide the control needed, secondly, the required level of concurrency, thirdly, appropriate basic design methods in the different stages, and, fourthly, appropriate specialist design methods in the different stages. This paper proposes a six-stepped methodology for developing such a company-specific design process model.