An early critical step during animal development is the separation of ectoderm, cells that produce the epidermis (skin) and central nervous system (brain/spinal cord), from endomesoderm, the cells that produce the intestine and internal organs. In most animals this process is strongly influenced by a molecular polarity present in the unfertilized egg termed the Animal-Vegetal (AV) axis. In general, cells derived from the egg's animal pole produce ectoderm, while vegetal pole-derived cells produce endomesoderm. This separation of developmental potential is frequently mediated by localized activation of a highly conserved signaling cascade called the canonical Wnt (cWnt) pathway. How AV egg polarity regulates restricted activation of cWnt signaling at one pole of embryos is not well understood, but the PI's group has shown that in sea urchins and in the sea anemone Nematostella, this process occurs by the localized 'activation' of a key Wnt pathway protein called Disheveled (Dvl). Using biochemical techniques the PI's group has identified candidate proteins that are hypothesized to restrict Dvl activity to one end of the embryo. Hence, the goal of this research is to use molecular methods to functionally analyze how the identified candidate proteins regulate Dvl activity in sea urchins and Nematostella. This work will elucidate the molecular mechanisms that regulate the earliest separation of cell potential in animal embryos, and provide critical insight into the development and evolution of complex animals. The research involves graduate and undergraduate students, including students from groups under-represented in science. Public outreach includes an ongoing program with a local public high school teacher aimed at getting new immigrant students from Haiti and Central and South America interested in biology.
