This award provides funding for a Research Experiences for Undergraduates Site at Carleton College. The project provides support for a 10 week summer research experience for nine undergraduates from Carleton College and other regional colleges and universities. Pre-participation reading requirements will provide students with an adequate foundation for meaningful scientific investigation. During the summer students will work in a one-to-one relationship with a research supervisor in the laboratory. Weekly seminars will provide students with the opportunity to discuss research plans and results as well as to delve into primary scientific articles. To further focus and unify the student participants, a theme of developmental regulation has been selected. Six of the eight projects relate directly to this theme and mid-summer seminars will be used to discuss current literature in this area. Projects will include investigations of: the mechanisms of action and the chemical characteristics of a possibly-steroid pheromone produced by Oedogonium, functional structure of Hensen's node in the chick embryo, regulation of floral development in tobacco, effect of B chromosomes in maize on developmental processes, structure and function of the glucocorticoid receptor in rat liver, development of neural connections in Helisoma, variation of sex expression in composites and effect of gregarine parasites on population biology of capitellid polychaetes. Opportunities to complete research and writing during winter break will be available.