Skip to Main content Skip to Navigation
Theses

Contribution à l’étude du rôle et du mode d’action de Fsh et de Lh dans le testicule de truite

Abstract : In vertebrates, spermatogenesis is under the direct control of two pituitary gonadotropic hormones named Fsh and Lh. In salmonids, the 2 hormones are differentially secreted in the plasma through the reproductive cycle, suggesting that Fsh and Lh are involved in the regulation of different steps of the process. Unlike in mammals, both fish gonadotropins exert a strong steroidogenic activity and, besides, some authors reported for their receptors a much lower selectivity towards the two ligands. Yet, their respective roles are not established in fish. Furthermore, the mechanisms of Fsh action that would not be mediated by steroids are poorly investigated. In trout, we showed that each gonadotropin mainly acts through its cognate receptor. The analysis of the variations of testicular transcriptome following an in vitro treatment with reproductive hormones (Fsh, Lh and androgens) permitted 1- to reveal that Fsh and Lh have distinct effects on gene expression, 2- to highlight two mechanisms of Fsh action, one dependent on the steroid production and the second one independent of that production, 3- to identify several Fsh regulated factors involved in cellular interactions and particularly in the control of germ cell proliferation / differentiation (anti mullerian hormone, midkine, insulin-like growth factor 1b, follistatin-like 3 and activin), 4- to propose an involvement of Fsh in late events of sperm maturation and release. In addition to knowledge on endocrine and molecular regulations in trout, this work provides a fund of knowledge useful in other teleosts to decipher the action of Fsh in triggering puberty onset. Finally, we showed that an immunization against the gonadotropin receptors is a potential method to delay sexual maturation in farmed fish.
Document type :
Theses
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-00940041
Contributor : Abes Star :  Contact
Submitted on : Friday, January 31, 2014 - 11:38:23 AM
Last modification on : Friday, September 4, 2020 - 9:02:15 PM

File

SAMBRONI_Elisabeth.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-00940041, version 1

Collections

Citation

Elisabeth Sambroni. Contribution à l’étude du rôle et du mode d’action de Fsh et de Lh dans le testicule de truite. Sciences agricoles. Université Rennes 1, 2013. Français. ⟨NNT : 2013REN1S092⟩. ⟨tel-00940041⟩

Share

Metrics

Record views

806

Files downloads

2321