We are applying for partial support of the 1991 Gordon Research Conference on Developmental Biology (Trudi Schupbach and Harold Weintraub co- chairmen). The purpose of this conference is to bring a group of outstanding senior and junior scientists together for a period of five days in New Hampshire. This group will discuss the most recent advances in the field of development and cell differentiation. This conference has been held for over 18 years and has become a tradition in the field as an important forum for exchanging ideas, reporting new advances in Developmental Biology, and subjecting these developments to critical analysis. Every session centers on unravelling one (or more) of the mechanisms by which different aspects of Eukaryotic development proceed. Apart from the immediate benefits of the exchange of information, this gathering of a group of very productive scientists in the field will help to formulate new questions and to devise new experimental approaches in one of the most rapidly moving and challenging areas of modern biology. The topics that will be covered in the conference include: Embryonic axis formation, Embryonic pattern formation, Molecular control of gene expression, Receptors and cell signalling, Tissue specification, Pathways of developmental control, Cytoplasmic localization, Protein structural motifs used in developmentally important molecules.