The spermatogonial stem cell (SSC) niche is the subject of numerous studies in Osteichthyes (mammals, fish, etc.), with relatively well-conserved cellular markers and regulatory pathways. In contrast, these aspects are rarely documented in Chondrichthyes, the sister group to Osteichthyes, nearly a quarter of whose species are threatened due to overfishing. We therefore chose the small-spotted catshark, Scyliorhinus canicula, a species abundant on our coasts, to explore the regulation of spermatogonial stem cells in sharks and compare it to that of other Vertebrates. The cells of the germline niche are characterized at the molecular level, and the in vitro maintenance of these cells now allows for the functional study of paracrine factors involved in the regulation of the SSC niche.

Keywords: reproductive biology, spermatogonial stem cells, paracrine factors, small-spotted catshark

The Pacific oyster, Crassostrea gigas, is a highly studied species in our team due to its aquaculture interest. However, the understanding of the molecular mechanisms governing its development and various physiological processes is limited by the lack of in vivo functional analysis tools. We are developing gene invalidation in this species through a CRISPR/Cas9 approach.

Keywords: developmental biology, in vivo functional analysis, Pacific oyster