296 research outputs found
Crossregulation of the Thyroid Hormone and Corticosteroids in Amphibians and Fish: The Effects of Endocrine Disruption
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Plasma 11-deoxycorticosterone (DOC) and mineralocorticoid receptor testicular expression during rainbow trout Oncorhynchus mykiss spermiation: implication with 17alpha, 20beta-dihydroxyprogesterone on the milt fluidity?
Background: In rainbow trout (Oncorhynchus mykiss), the endocrine control of spermiation is not fully understood. Besides IIketotestosterone (IIKT) and 17alpha, 20beta-dihydroxyprogesterone (MIS), the potential physiological ligand of the mineralocorticoid receptor (MR) II-deoxycorticosterone (DOC), is a credible candidate in O. mykiss spermiation regulation as spermiation is accompanied with changes in aqueous and ionic flows. Methods: In this study, we investigated potential roles of DOC during spermiation 1) by describing changes in blood plasma DOC level, MR mRNA abundance during the reproductive cycle and MR localization in the reproductive tract 2) by investigating and comparing the effects of DOC (10 mg/kg) and MIS (5 mg/kg) supplementations on sperm parameters 3) by measuring the in vitro effect of DOC on testis MIS production. Results: The plasma concentration of DOC increased rapidly at the end of the reproductive cycle to reach levels that were 10-50 fold higher in mature males than in immature fish. MR mRNA relative abundance was lower in maturing testes when compared to immature testes, but increased rapidly during the spermiation period, immediately after the plasma rise in DOC. At this stage, immunohistochemistry localized MR protein to cells situated at the periphery of the seminiferous tubules and in the efferent ducts. Neither DOC nor MIS had significant effects on the mean sperm volume, although MIS treatment significantly increased the percentage of males producing milt. However, a significant reduction in the spermatocrit was observed when DOC and MIS were administrated together. Finally, we detected an inhibitory effect of DOC on testis MIS production in vitro. Conclusion: These results are in agreement with potential roles of DOC and MR during spermiation and support the hypothesis that DOC and MIS mechanisms of action are linked during this reproductive stage, maybe controlling milt fluidity. They also confirm that in O. mykiss MIS is involved in spermiation induction
Transcriptional Assessment by Microarray Analysis and Large-Scale Meta-analysis of the Metabolic Capacity of Cardiac and Skeletal Muscle Tissues to Cope With Reduced Nutrient Availability in Gilthead Sea Bream (Sparus aurata L.)
The effects of nutrient availability on the transcriptome of cardiac and skeletal muscle tissues were assessed in juvenile gilthead sea bream fed with a standard diet at two feeding levels: (1) full ration size and (2) 70 % satiation followed by a finishing phase at the maintenance ration. Microarray analysis evidenced a characteristic transcriptomic profile for each muscle tissue following changes in oxidative capacity (heart > red skeletal muscle > white skeletal muscle). The transcriptome of heart and secondly that of red skeletal muscle were highly responsive to nutritional changes, whereas that of glycolytic white skeletal muscle showed less ability to respond. The highly expressed and nutritionally regulated genes of heart were mainly related to signal transduction and transcriptional regulation. In contrast, those of white muscle were enriched in gene ontology (GO) terms related to proteolysis and protein ubiquitination. Microarray meta-analysis using the bioinformatic tool Fish and Chips (http://fishandchips.genouest.org/index.php) showed the close association of a representative cluster of white skeletal muscle with some of cardiac and red skeletal muscle, and many GO terms related to mitochondrial function appeared to be common links between them. A second round of cluster comparisons revealed that mitochondria-related GOs also linked differentially expressed genes of heart with those of liver from cortisol-treated gilthead sea bream. These results show that mitochondria are among the first responders to environmental and nutritional stress stimuli in gilthead sea bream, and functional phenotyping of this cellular organelle is highly promising to obtain reliable markers of growth performance and well-being in this fish species. © 2014 Springer Science+Business Media New York.This work was funded by the EU seventh Framework Programme by the AQUAEXCEL (Aquaculture Infrastructures for Excellence in European Fish Research, FP7/2007-2012; grant agreement no. 262336) project. Additional funding was obtained from the Generalitat Valenciana (research grant PROMETEO 2010/006) and the Spanish Government through AQUAGENOMICS project (Consolider-Ingenio-2010 Programme).Peer Reviewe
Network on « Genetics of adaptation and animal welfare »
Relations between genetics and animal welfare raise numerous questions as genetic characteristics are
involved in many aspects of animalsâ abilities to adapt to farming conditions, whether intensive or extensive.
These questions are related to the genetic mechanisms of adaptation, to the consequences on animal
welfare of the selection implemented up until now, and to the future improvements of the selection
process. A network on the genetics of adaptation and animal welfare was built up within the
multidisciplinary project âAgri Bien-ĂȘtre Animalâ to review current knowledge. It aims also at providing
usable references for regulatory discussions, as well as promoting synergies and exchanges between
research units, development organisations and breeders.Les interrogations sur les
relations entre gĂ©nĂ©tique et bien-ĂȘtre des animaux sont d'autant plus nombreuses que les
caractéristiques génétiques interviennent dans de nombreuses composantes des capacités
d'adaptation des animaux Ă leurs conditions d'Ă©levage, que celles-ci soient intensives ou
extensives. Les questions portent à la fois sur les mécanismes génétiques de l'adaptation,
les consĂ©quences en matiĂšre de bien-ĂȘtre des sĂ©lections opĂ©rĂ©es jusqu'Ă prĂ©sent et la
conduite à tenir dans les futurs schémas de sélection. Un réseau Génétique de l'adaptation
et bien-ĂȘtre a donc Ă©tĂ© crĂ©Ă© au sein du programme interdisciplinaire INRA « Agri Bien-ĂȘtre
Animal » pour faire le point des connaissances acquises. L'objectif est de fournir ainsi des
références utilisables lors des discussions réglementaires et de faciliter les synergies et
les échanges entre unités de recherche, organismes de développement et professionnels de la
sélection
Generation and analysis of a 29,745 unique Expressed Sequence Tags from the Pacific oyster (Crassostrea gigas) assembled into a publicly accessible database: the GigasDatabase
Background: Although bivalves are among the most-studied marine organisms because of their ecological role and economic importance, very little information is available on the genome sequences of oyster species. This report documents three large-scale cDNA sequencing projects for the Pacific oyster Crassostrea gigas initiated to provide a large number of expressed sequence tags that were subsequently compiled in a publicly accessible database. This resource allowed for the identification of a large number of transcripts and provides valuable information for ongoing investigations of tissue-specific and stimulus-dependant gene expression patterns. These data are crucial for constructing comprehensive DNA microarrays, identifying single nucleotide polymorphisms and microsatellites in coding regions, and for identifying genes when the entire genome sequence of C. gigas becomes available. Description: In the present paper, we report the production of 40,845 high-quality ESTs that identify 29,745 unique transcribed sequences consisting of 7,940 contigs and 21,805 singletons. All of these new sequences, together with existing public sequence data, have been compiled into a publicly-available Website http://public-contigbrowser.sigenae.org:9090/Crassostrea_gigas/index.htm l. Approximately 43% of the unique ESTs had significant matches against the SwissProt database and 27% were annotated using Gene Ontology terms. In addition, we identified a total of 208 in silico microsatellites from the ESTs, with 173 having sufficient flanking sequence for primer design. We also identified a total of 7,530 putative in silico, single-nucleotide polymorphisms using existing and newly-generated EST resources for the Pacific oyster. Conclusion: A publicly-available database has been populated with 29,745 unique sequences for the Pacific oyster Crassostrea gigas. The database provides many tools to search cleaned and assembled ESTs. The user may input and submit several filters, such as protein or nucleotide hits, to select and download relevant elements. This database constitutes one of the most developed genomic resources accessible among Lophotrochozoans, an orphan clade of bilateral animals. These data will accelerate the development of both genomics and genetics in a commercially-important species with the highest annual, commercial production of any aquatic organism
Vuorovaikutteisen suunnittelun haasteet ja mahdollisuudet metsÀtalouden vesiensuojelussa
Rapport de l'expertise scientifique collectiveLes animaux peuvent-ils Ă©prouver des Ă©motions, peuvent-ils penser, ont-ils une histoire de vie ? Depuis lâAntiquitĂ©, les philosophes ont proposĂ© des rĂ©ponses contrastĂ©es Ă ces questions. Du XIXĂšme siĂšcle Ă nos jours, la rĂ©flexion sur ce que sont les animaux sâest enrichie dâapports scientifiques : thĂ©orie de lâĂ©volution, Ă©thologie, neurophysiologie, sciences cognitives. Mais la conscience animale reste toujours lâobjet de dĂ©bats importants dans la communautĂ© scientifique. Ainsi en 2012 un groupe de scientifiques de premier plan a Ă©prouvĂ© la nĂ©cessitĂ© de publier un manifeste intitulĂ© « DĂ©claration de Cambridge sur la Conscience », qui Ă©nonce quâ«âŠune convergence de preuves indique que les animaux non humains disposent des substrats neuro-anatomiques, neurochimiques et neurophysiologiques des Ă©tats conscients ainsi que la capacitĂ© dâexprimer des comportements intentionnels...».Les connaissances actuelles, dont cette expertise collective propose une synthĂšse, montrent que les animaux possĂšdent un large Ă©ventail de capacitĂ©s cognitives associĂ©es Ă des comportements plus ou moins complexes. Les formes de conscience Ă©tudiĂ©es chez les humains supposent des capacitĂ©s cognitives distinctes que lâon retrouve chez certains animaux. Peut-on en postuler que ceux-ci ont des formes de consciences Ă©quivalentes Ă celles de lâhomme, sans ĂȘtre forcĂ©ment identiques ?LâĂ©tude des niveaux et des contenus de la conscience chez les animaux est en passe de devenir un enjeu scientifique important en raison de la complexitĂ© du sujet et des controverses quâil ne manquera pas de susciter. Enfin, les acquis scientifiques dans ce domaine invitent Ă reprendre les rĂ©flexions morales concernant les relations que les hommes entretiennent avec les animaux (et particuliĂšrement avec les animaux domestiques
11ÎČ-Hydroxysteroid dehydrogenase type 1 contributes to the balance between 7-keto- and 7-hydroxy-oxysterols in vivo
Abstract11ÎČ-Hydroxysteroid dehydrogenase 1 (11ÎČHSD1; EC 1.1.1.146) generates active glucocorticoids from inert 11-keto metabolites. However, it can also metabolize alternative substrates, including 7ÎČ-hydroxy- and 7-keto-cholesterol (7ÎČOHC, 7KC). This has been demonstrated in vitro but its consequences in vivo are uncertain. We used genetically modified mice to investigate the contribution of 11ÎČHSD1 to the balance of circulating levels of 7KC and 7ÎČOHC in vivo, and dissected in vitro the kinetics of the interactions between oxysterols and glucocorticoids for metabolism by the mouse enzyme.Circulating levels of 7KC and 7ÎČOHC in mice were 91.3±22.3 and 22.6±5.7nM respectively, increasing to 1240±220 and 406±39nM in ApoEâ/â mice receiving atherogenic western diet. Disruption of 11ÎČHSD1 in mice increased (p<0.05) the 7KC/7ÎČOHC ratio in plasma (by 20%) and also in isolated microsomes (2 fold). The 7KC/7ÎČOHC ratio was similarly increased when NADPH generation was restricted by disruption of hexose-6-phosphate dehydrogenase.Reduction and oxidation of 7-oxysterols by murine 11ÎČHSD1 proceeded more slowly and substrate affinity was lower than for glucocorticoids. in vitro 7ÎČOHC was a competitive inhibitor of oxidation of corticosterone (Ki=0.9ÎŒM), whereas 7KC only weakly inhibited reduction of 11-dehydrocorticosterone. However, supplementation of 7-oxysterols in cultured cells, secondary to cholesterol loading, preferentially slowed reduction of glucocorticoids, rather than oxidation.Thus, in mouse, 11ÎČHSD1 influenced the abundance and balance of circulating and tissue levels of 7ÎČOHC and 7KC, promoting reduction of 7KC. In health, 7-oxysterols are unlikely to regulate glucocorticoid metabolism. However, in hyperlipidaemia, 7-oxysterols may inhibit glucocorticoid metabolism and modulate signaling through corticosteroid receptors
Combined genetic and functional genomic approaches for stress and disease resistance marker assisted selection in fish and shellfish. AQUAFIRST. Final management report
Contribution à la purification et à la caractérisation de la prolactine de saumon Oncorhynchus tschawytscha
Ce sont les travaux de Stricker et Grueter (1928) qui les premiers établissent l'existence d'une hormone hypophysaire possédant des propriétés de stimulation de la lactation chez la lapine, la prolactine. Riddle et al., (1931) montrent que cette hormone stimule la muqueuse du jabot de pigeon produisant alors une sorte de lait destiné à nourrir les jeunes : cette propriété de la prolactine est à l'origine d'un dosage biologique (test du jabot de pigeon) qui permet l'isolement de la prolactine de mouton (Riddle et al., 1932, Riddle et al., 1933). L'existence d'une telle hormone chez les poissons est étudiée dÚs 1937 par Leblond et Noble mais les résultats des tests d'implantation d'hypophyses de poisson sur les jabots de pigeon s'avÚrent négatifs
Combined genetic and functional genomic approaches for stress and disease resistance marker assisted selection in fish and shellfish. AQUAFIRST. Final report (Part 1)
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