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Auteur Kiilerich, P.; Geffroy, B.; Valotaire, C.; Prunet, P. url  doi
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  Titre Endogenous regulation of 11-deoxycorticosterone (DOC) and corticosteroid receptors (CRs) during rainbow trout early development and the effects of corticosteroids on hatching Type Article scientifique
  Année 2018 Publication Revue Abrégée General and Comparative Endocrinology  
  Volume Numéro Pages  
  Mots-Clés 11-Deoxycorticosterone; Cortisol; Development; Fish; Glucocorticoid receptor; Mineralocorticoid receptor  
  Résumé Clear evidence for a physiological role of the mineralocorticoid-like hormone 11-deoxycorticosterone (DOC) and the mineralocorticoid receptor (MR) in fish is still lacking. Efforts to demonstrate an osmoregulatory role for this hormone has so far not been conclusive, while a few scattered studies have indicated a role for DOC in development and reproduction. In this study, we investigate the onset of de novo DOC synthesis in parallel with endogenous corticosteroid receptor mRNA production from fertilization to the swim-up stage in rainbow trout. Whole egg DOC content decreased from fertilization until hatching followed by an increase to pre-fertilization levels just after hatching. Onset of de novo transcription of corticosteroid receptor mRNA’s was observed shortly after the midblastula transition; initially glucocorticoid receptor 2 (GR2) followed by MR and then GR1. Non-invasive introduction of DOC or cortisol at fertilization resulted in altered corticosteroid receptor regulation and accelerated hatching date, suggesting a regulatory role in trout ontogenesis of both hormones through MR signaling pathway. The results presented in this study suggest a possible physiological role of the DOC-MR signaling pathway during fish ontogenesis, at fertilization and just after hatching.  
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  Langue Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 0016-6480 ISBN Médium  
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  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2363  
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Auteur Stier, A.; Viblanc, V.A.; Massemin-Challet, S.; Handrich, Y.; Zahn, S.; Rojas, E.R.; Saraux, C.; Le Vaillant, M.; Prud'homme, O.; Grosbellet, E.; Robin, J.-P.; Bize, P.; Criscuolo, F. url  doi
openurl 
  Titre Starting with a handicap: phenotypic differences between early- and late-born king penguin chicks and their survival correlates Type Article scientifique
  Année 2014 Publication Revue Abrégée Functional Ecology  
  Volume Numéro Pages  
  Mots-Clés corticosterone; early-life conditions; growth; individual quality; oxidative stress; phenotypic plasticity; reproductive timing; telomere  
  Résumé * The exceptionally long (c. 11 months) growth period of king penguin chicks (Aptenodytes patagonicus) is interrupted by the Austral winter. As a consequence, penguin chicks born late in the breeding season have little time to build-up their energy reserves before the drastic energy bottleneck they experience during winter and face greater risks of mortality than early-born chicks. * Whereas it is well known that breeding adults alternate between early- and late-breeding attempts, little is known on the phenotype of early- and late-chicks, and on the potential existence of specific adaptive phenotypic responses in late-born individuals. * We investigated phenotypic differences between early- and late-chicks and tested their survival correlates both before the winter and at fledgling. Chicks were sampled 10 days after hatching to measure body mass, plasma corticosterone levels, oxidative stress parameters and telomere length. * Late-chicks were heavier than early-chicks at day 10. Late-chicks also had higher corticosterone and oxidative stress levels, shorter telomere lengths and suffered from higher mortality rates than early-chicks. For both early- and late-chicks, high body mass close to hatching was a strong predictor of survival up to, and over, the winter period. * In late but not early-chicks, high corticosterone levels and long telomeres were significant predictors of survival up to winter and fledging, respectively. * Our study provides evidence that late- and early-king penguin chicks showed marked phenotypic differences 10 days after hatching. We provide an integrative discussion on whether these differences may be adaptive or not, and to what extent they may be driven by active maternal effects, indirectly induced by environmental effects, or stem from individual differences in parental quality.  
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  Langue Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 1365-2435 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel LL @ pixluser @ collection 319  
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