One of the most exciting areas of modern biology is the study of embryonic development. The use of genetic engineering/recombinant DNA technology has revolutionized the way in which questions are asked and answered in this rapidly advancing field. Recent studies in model systems such as Drosophila, nematode, and Xenopus (among others) have provided new insights into the molecular mechanisms utilized to establish cellular identities and generate the pattern of differentiation that is critical to multicellular organisms. Information being gained and experimental tools being developed in these model systems are leading to important advances in our understanding of developmental mechanisms used in all organisms, including mammals. This course provides an up-to-date and in-depth view of ongoing research in selected areas of developmental biology. Topics are introduced by lectures, but substantial class time is devoted to discussion. Reading assignments from the current scientific literature highlight the experimental approaches being used. How information from model systems is being applied to mammalian embryos is discussed. Prerequisite: Biol 3051, or permission of instructor. Enrollment limited to 20 students; writing intensive. Credit 3 units.