This award provides support for the participation of eight US scientists in a joint US-Japan seminar on "Molecular Biology of Marine Invertebrate Development". In the last 15 years, primarily through advances in the field of molecular biology, considerable progress has been made in our basic understanding of the major issues involved in development. The study of marine invertebrate embryos has played an important role in this progress by providing a good model for analyzing the fundamental problems of development. For example, sperm-egg interactions in general and fertilization in particular have always been areas where marine invertebrate research has lead the way. Another area of immense importance is how genes preside over the complex process of morphogenesis, and the accessibility of marine embryos makes them a particularly favorable material for the study of this process. Development- al biology of marine invertebrates has been a traditionally active field of research in both the US and Japan since the beginning of this century and this seminar should therefore provide an excellent forum for researchers in the two countries to compare results and discuss future research in this area. The seminar is to be held on April 3-6 1991 at the Kewalo Marine Laboratory of the University of Hawaii, Honolulu, Hawaii. The co-organizers are Professor Fred H Wilt, Molecular cell biology unit, University of California, Berkeley, and Professor Hiraku Shimada, Department of Zoology, Hiroshima University, Japan. Specific topics to be discussed at the seminar will concentrate on cell-cell interactions including (1) the biology of cell-environmental interactions; (2) the molecular biology of morphogenesis; and (3) specific gene expression. The seminar is especially timely as the last seminar in this topic, between these two countries, was held ten years ago and enormous advances have been achieved since that time. It is expected that ongoing collaborative projects and exchanges of scientists will occur as a result of this seminar.