Characterization of gonadotropins and their receptors in a chondrichthyan, Scyliorhinus canicula, fills a gap in the understanding of their coevolution.

Autor: Jeanne F; Université de Caen Normandie, MNHN, SU, UA, CNRS, IRD, Laboratoire de Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), UMR 8067, 14032 Caen cedex 5, France., Pilet S; Université de Caen Normandie, MNHN, SU, UA, CNRS, IRD, Laboratoire de Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), UMR 8067, 14032 Caen cedex 5, France., Klett D; INRAE, CNRS, UMR Physiologie de la Reproduction & des Comportements, 37380 Nouzilly, France., Combarnous Y; INRAE, CNRS, UMR Physiologie de la Reproduction & des Comportements, 37380 Nouzilly, France., Bernay B; Université de Caen Normandie - Plateforme PROTEOGEN, US EMerode, 14032 Caen cedex 5, France., Dufour S; Université de Caen Normandie, MNHN, SU, UA, CNRS, IRD, Laboratoire de Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), UMR 8067, 14032 Caen cedex 5, France., Favrel P; Université de Caen Normandie, MNHN, SU, UA, CNRS, IRD, Laboratoire de Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), UMR 8067, 14032 Caen cedex 5, France., Sourdaine P; Université de Caen Normandie, MNHN, SU, UA, CNRS, IRD, Laboratoire de Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), UMR 8067, 14032 Caen cedex 5, France. Electronic address: pascal.sourdaine@unicaen.fr.
Jazyk: angličtina
Zdroj: General and comparative endocrinology [Gen Comp Endocrinol] 2024 Nov 01; Vol. 358, pp. 114614. Date of Electronic Publication: 2024 Sep 24.
DOI: 10.1016/j.ygcen.2024.114614
Abstrakt: In Gnathostomes, reproduction is mainly controlled by the hypothalamic-pituitary-gonadal (HPG) axis, with the involvement of the pituitary gonadotropic hormones (GTH), follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which activate their cognate receptors, FSHR and LHR, expressed in gonads. Each GTH consists of a common α subunit and of a specific FSHβ or LHβ subunit. Chondrichthyes (holocephalans and elasmobranchs) is a sister group of bony vertebrates. This position is highly favorable for the understanding of the evolution of endocrine regulations of reproduction among gnathostomes. Surprisingly, the characterization of gonadotropins and their receptors is still limited in chondrichthyes. In the present study, GTH and GTHR sequences have been identified from several chondrichthyan genomes, and their primary structures were analyzed relative to human orthologs. 3D models of GTH/GTHR interaction were built, highlighting the importance of the receptor hinge region for ligand recognition. Functional hormone-receptor interactions have been studied in HEK cells using the small-spotted catshark (Scyliorhinus canicula) recombinant proteins and showed that LHR was specifically activated by LH whereas FSHR was activated by both FSH and LH. Expression profiles of GTHs and their receptors were explored by real-time PCR, in situ hybridization and immunohistochemistry during spermatogenesis, along the male genital tract and other tissues, as well as in some female tissues for comparison. Tissue-expression analyses showed that the highest levels were observed for fshr transcripts in testis and ovary and for lhr in specific extragonadal tissues. The two receptors were expressed at all stages of spermatogenesis by both germ cells and somatic cells, including undifferentiated spermatogonia, spermatocytes, spermatids, somatic precursors and Sertoli cells; differentiated Leydig cells being absent in the testis of S. canicula. Receptors were also expressed by the lymphomyeloid epigonal tissue and the testicular tubules. These results, suggest a wide range of gonadotropin-regulated functions in Elasmobranchs, as well as functional redundancy during spermatogenesis. These extended functions are discussed in an evolutionary context in which the specificity of gonadotropin signaling must have contributed to the evolution of gonadal cells' morphology and function.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)
Databáze: MEDLINE