The oyster is endowed with efficient immune mechanisms that are successful in fighting most infectious diseases. The protozoan parasite Perkinsus marinus, however, causes Dermo disease in oysters and is responsible for the catastrophic decline of oyster populations and damage to the estuarine ecosystem along the Atlantic and Gulf coasts of North America. In invertebrate and vertebrate species, recognition of microbial pathogens is achieved in part by carbohydrate-binding proteins named lectins. The recent discovery of a lectin (CvGal) that binds to pathogenic bacteria, microalgae, and the parasite P. marinus, has led to the hypothesis that CvGal represent a mechanism for recognition of pathogens and algal food, and that this defense and feeding mechanism is subverted by P. marinus to gain entry into the host. This project will test this hypothesis by characterizing CvGal and other related proteins in the oyster and investigating the biological role(s) of CvGal within the context of immune defense, feeding, and host-parasite interactions. By thoroughly investigating CvGal and other galectins in the oyster, novel insight will be gained into yet undescribed biological functions of lectins in immune and feeding functions, and a more thorough understanding of entry mechanisms of intracellular parasites of medical and veterinary relevance. Given the regional relevance of oyster disease, this project may contribute to novel intervention strategies to restore natural and farmed oyster populations. The oyster is also well suited for classroom integration of fundamental scientific principles of immune recognition and host-parasite biology. This project will involve the participation of undergraduates and high school students and teachers mostly from underrepresented minorities from the Baltimore area, both as interns at the bench and in the classroom, through partnerships with SciTech, an affiliated educational program located at the Center of Marine Biotechnology, and training programs such as ExPERT (NSF), Chesapeake Teacher Research Fellowship (NOAA), Living Classrooms, Ingenuity, Baltimore Community College, and mentorship programs from Howard and Baltimore Counties.