The objective of this application is to train predoctoral students in Developmental Biology. Twenty-eight faculty members propose continuation of a broad, interdisciplinary training program. These faculty members use molecular, cell biological, and genetic approaches to address fundamental problems in developmental biology. Participating faculty have appointments in a total of eleven basic science and clinical departments within the university. All have extremely active research programs. An annual retreat, symposium/journal club series, joint research meetings, shared supervision, and a variety of collaborations promote productive interactions among laboratories and trainees. The program is conducted within the broader context of the Program in Biological Sciences, a consortium of eight University of California, San Francisco graduate programs with more than 100 participating faculty. It attracts students of exceptionally high caliber. The features of the proposed training program that are especially attractive to prospective students are the following: (a) a wide choice of laboratories for thesis research, (b) a laboratory rotation system, (c) an excellent set of courses, (d) a tutorial in how to present a seminar, (e) a highly cooperative spirit, and (f) an awareness that graduate training is important to the faculty at University of California, San Francisco. The investigators strive to facilitate the intellectual growth and scientific skills of each trainee so that each graduates as an independent scientist who will be able to contribute to the field for many decades to come.