ETD

• corticogenesis
• mitotic spindle
• neurodevelopment
• non-human primates
• OPN3
• opsin

The way the nervous system develops is an elaborate series of molecular and cellular mechanisms. Recently, to better understand the molecular substrate of this complex phenomenon, transcriptional studies have been performed, indicating OPN3 as a gene enriched in human neural progenitors.
In humans, there are few reports about OPN3 presence: in adulthood, it is described in the brain, skin, eyes, gastrointestinal tract, ovaries and testes, and adipocytes while, concerning prenatal stages, there are limited reported data. Indeed, the divergences in OPN3 expression between the embryonic and adult stages remain to be determined, as well as its role in human and NHP cortical development.
This thesis project aims to investigate the expression and the potential role of OPN3 in human and NHP using tripotent neocortical neural stem cell (NES cell) lines in light of evolutive differences. We reported the presence of four isoforms of the OPN3 transcript finding differential expression between human and NHP NES cell lines. Moreover, we validated the presence of OPN3 in these cell lines by performing western blot analysis. Further, we dig into the protein localization in NES cells during cell cycle progression, with a particular interest in M-phase localization. To do that, we made use of immunofluorescence analyses in human and NHP cell lines, finding a peak of expression of OPN3 during late mitotic phases. The validation of OPN3 presence and localization in the developing neocortex could be the first step to clarify the role of a non-visual opsin in an extra-retinal location, with emphasis on the mechanisms underlying the sensing of the blue light from inside the brain.