Rôle de la lumière sur le développement du système visuel des embryons et le comportement des juvéniles de Sepia officinalis
The objective of our project, taking place in two steps, is to test the role of the capsule of cuttlefish eggs in the light perception of the embryo. Actually, the influence of light on the development of aquatic organisms is not well known. Eggs of Sepia officinalis, laid in the tidal area, are protected from light by a black capsule. During the experimentation phase, three different photoperiods will be tested on two series of eggs, with and without capsule. The first step has allowed to test the experimental structure and to determine the lower developmental stage (the critical point for a high survival rate). The second step will allow to determine if morphological modifications appear and if expression of target genes (PNR, Opsin, dac..) vary in eye and optic lobes (integrative center of complex cognitive behaviors of cephalopods). The possibility to access to the early development, at the Biological station of Roscoff (UPMC), allows to describe, in a comparative and evolutionary approach, the impact of environmental factors on molecular mechanisms during the biological cycle of Sepia officinalis, an aquatic species with an economic interest.