Differential regulation of gonadotropin expression (LH and FSH) in European eel, Anguilla anguilla

• Main Author: Aroua, Salima
• Other Authors: Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Département Milieux et Peuplements Aquatiques, Muséum national d'Histoire naturelle (MNHN), Université Pierre et Marie Curie - Paris VI, Sylvie Dufour
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2008
• Subjects: eel; teleost; silvering; puberty; experimental maturation; sexual steroïds; activin; gonadotropins; anguille; téléostéen; reproduction; argenture; puberté; maturation expérimentale; stéroïdes sexuels; activine; cortisol; IGF-1; gonadotropines; [SDV.BDLR]Life Sciences [q-bio]/Reproductive Biology; Anguilla anguilla; European eel
• Online Access: https://theses.hal.science/tel-00811792; https://theses.hal.science/tel-00811792/document; https://theses.hal.science/tel-00811792/file/these_salima_aroua.pdf

Texte intégral moins articles (sous droits ?) Differential Regulation of Luteinizing Hormone and Follicle-Stimulating Hormone Expression during Ovarian Development and under Sexual Steroid Feedback in the European Eel (Neuroendocrinology 2005;81:107-119) + Endocrine Evidence that Silvering, a Secondary Metamorphosis in the Eel, Is a Pubertal Rather than a Metamorphic Event (Neuroendocrinology 2005;82:221-232) The eel has a complex life cycle with an oceanic reproduction phase and a growth phase in continental waters. The growth phase ends with a " secondary metamorphosis " or silvering. This is the last stage in the eel's life cycle which is accessible in natural conditions. Natural sexual maturation has never before been observed and the development of the gonads stays blocked because of a deficit in the gonadotropins LH and FSH. Understanding the regulation mechanisms of eel LH and FSH is of fundamental interest for the development of eel pubertal control and a challenge which must be overcome in order to succeed in regulating the reproduction of this endangered species. After the development of molecular tools we have studied the LH and FSH subunits; this shows that only the gonadotropic axis is active during silvering. An increase in FSHß then in LHß was seen without any activation of the thyrotropic or somatotropic axes, meaning that silvering is a pubertal event rather than a metamorphosis. There was also observed a differential regulation of expression of LHß and FSHß during experimental sexual maturation with a selective amplification of LHß. Thanks to the use of primary cell cultures of eel pituitary glands we can show that sex steroids (estradiol and androgens); gonadal peptides (activin/follistatin) and metabolic factors (IGF-I and cortisol) exert direct effects on the expression of LHß and FSHß and could be involved in the differential regulation of gonadotropins. L'anguille a un cycle de vie complexe avec une reproduction océanique et une croissance dans les eaux continentales. La phase de ...