Mast cells in goldfish (Carassius auratus) gut: Immunohistochemical characterization

The common goldfish is the most widespread teleosts in the world. Due to its peculiar characteristics, such as the high resistance, easy availability and stabulation, and for its evolutionary characteristics, this fish lends itself to be one of the most used experimental models. This study aimed to characterize the mast cells in the intestine of Carassius auratus using anti‐TLR‐2, anti‐S100, anti‐VIP, anti‐serotonin (5‐HT) and anti‐Piscidin antibodies. The intestine of goldfish, like that of all vertebrates, plays an important role in the immunology of the animal. The gut‐associated lymphoid tissue GALT is an immune component containing several specific cells such as lymphocytes, macrophages and mast cells. In addition, the presence of goblet cells in the intestinal epithelium strengthens the defence system, secreting many cytokines and chemokines and displaying antibacterial properties. Our results show mast cells labelled with antibodies that are highly conserved between fish and mammals, demonstrating an active role of these cells in the immune response.