Findings from a study, which examined the development of leadership skills and roles among the teachers in a professional development school (PDS), indicate the emergence of a nontraditional teacher leadership paradigm at the PDS. In contrast to typical teacher leadership models, in which carefully selected and screened teachers are placed in leadership positions, the teacher leadership paradigm that has emerged is characterized by a form of collective leadership in which teachers develop expertise reflecting individual interests. The Learning/Teaching Collaborative (L/TC) is a PDS, which was initiated in a Brookline (Massachusetts) elementary school in 1987 by two teachers to improve the work of teachers, reform preservice teacher education, and mainstream special needs students more effectively. Four components of the L/TC are team teaching, school-university collaboration, special education inclusion, and alternative professional teaching time (APT). APT allows teachers at least one day per week to assume an alternative role (e.g., curriculum writer, researcher, student teacher supervisor, college teacher). The eight teachers who were interviewed for this study indicated that the PDS nurtured teacher leadership, leadership activities grew naturally out of professional interests and working in teams, teaching practices changed significantly, and professional relationships improved. Teachers experienced the greatest growth and development in the following areas: team teaching and collaboration, preservice teacher education, curriculum development, research, and governance. (Contains 49 references.) (IAH)