- Marine Ecosystems and oRganisms reSEArch Lab
Keywords: Elasmobranchs – Spermatogenesis – Steroidogenesis – Spermatogonial Stem Cells – Cell Biology.
Identification of early markers of spermatogenesis in the lesser-spotted dogfish (Scyliorhinus canicula L.)
Spermatogenesis begins with the multiplication and differentiation of diploid spermatogonia and ends with the production of highly specialized haploid cells, the spermatozoa. The continuous production of male gametes is conditional upon the ability of spermatogonial stem cells (SSC) to renew themselves while preserving their stem cell characteristics. This takes place within a precise microenvironment constituting the “niche” and involving autocrine and paracrine factors, the latter being secreted by the surrounding somatic cells. Our studies focus on the identification and functional characterization of SSCs and the molecular players that control their self-renewal and differentiation, using a Chondrichthyan model, the lesser-spotted dogfish (Scyliorhinus canicula). The identification of molecular markers is carried out by transcriptomic and proteomic approaches on purified cells or testicular zones. Our studies also allow us to address the evolution of the germline stem cell niche in Gnathostomes.
Evolution of GnRH systems and their regulatory neuropeptides in the endocrine and paracrine controls of spermatogenesis in the lesser-spotted dogfish Scyliorhinus canicula.
The hypothalamic-pituitary system is essential for the regulation of reproduction, and its evolutionary history has led to a specialization of its regulatory peptides, whereas in invertebrates, they exhibit broader tissue distribution and biological functions. These peripheral functions may have persisted in vertebrates, and their study constitutes an emerging theme for understanding the influence of environmental factors on reproduction.
In an evolutionary context, it is important to include Chondrichthyans as the sister group to Osteichthyans (Bony Vertebrates) to better understand the evolution of GnRH systems and their regulatory neuropeptides (KNDy: Kisspeptin, Neurokinin, Dynorphin; RFRP3, the mammalian ortholog of GnIH).
In charge of the teaching units: “Reproduction and Development” (L2), ” Developmental Biology and Regeneration” (L3), “Introduction to Biotherapies” (M1 Biology and Health) “Student Professional Project” (M1 Biology and Health and M1 AquaCaen)
Member of the Pedagogical and Scientific Committee (CPS) of the Normandy Doctoral School of Integrative Biology, Health, and Environment (EdN BISE 497).