α-Transducin and α-gustducin immunoreactive cells in the stomach of common sole (Solea solea) fed with mussel meal

Vertebrates perceive a variety of exogenous substances using two main chemosensory systems, taste and olfaction. The taste perception occurs through the interaction of taste receptors associated with specific G protein subunits such as a-transducin (Gatran) and a-gustducin (Gagust). Aquatic vertebrates are also provided with a chemosensory system consisting of solitary chemosensory cells distributed to the oropharynx and skin. In this study, we identified Gatran and Gagust-immunoreactive cells intermingled with non-labeled epithelial cells in the gastric mucosa of the common sole. A long-term diet with increasing concentrations of mussel meal in the protein component of a conventional fish meal-based diet induced a dose-dependent increase in the gastric epithelial area and density of Gatran and Gagust immunoreactive cells. These findings suggest that taste-related molecules are regulated by changes in diet formulation in common sole aquaculture.