The development of a vertebrate organism from a single fertilized egg is a complex series of events involving both cell proliferation and specialization. Many of these events have been shown to be mediated by intercellular signals. One such family of signaling factors is the Wnt gene family, which is comprised of at least 20 related vertebrate genes (Wodarz and Nusse, 1998). Wnt genes encode cysteine-rich polypeptides possessing 50-60% amino acid identity which are thought to be secreted signaling molecules involved in cell growth, survival, and/or differentiation. My laboratory is particularly interested in the role(s) of these signals in directing pluripotential chick somite cells to become skeletal muscle. Although several Wnt family members have been shown to be sufficient and necessary for the induction of myogenesis in vertebrates, it has been impossible to fully analyze the cellular function and regulation of Wnt protein activity as soluble Wnt protein and good antibody reagents have been unavailable. One of the goals of the proposed work is to generate Wnt protein and antibody reagents using strategies that had previously been developed in the Pl's lab. The development of these key reagents will allow the determination of 1) what activities Wnt proteins have on developing chick somites 2) how the range of activity of Wnt proteins is controlled in chick somite development and 3) how specificity of Wnt signaling is achieved in chick somite development. Another goal of this project is to give students (with particular emphasis on under-represented minorities) an opportunity to do "hands-on" research. The intellectual and technical aspects of this project are quite accessible to both undergraduate and graduate students. This project will provide students with an excellent opportunity to utilize the techniques of biochemistry, molecular biology, cell biology, and developmental biology to address a scientific problem. Students will also be trained to keep good lab notebooks, critically analyze their data, orally present their data, prepare posters for meetings, and prepare manuscripts.