The Second Biennial Mammalian Developmental Genetics Workshop will be held in Bar Harbor, 11-15 September, 1991. This second meeting builds on the highly successful workshop held in Bar Harbor in 1989. Emphasis will be placed on the mouse as a model species, with sessions on mouse developmental mutations, imprinting, the genetic control of gametogenesis, the genetic control of morphogenesis, the genetic control of lineage determination and functional analysis of developmental genes through gene targeting. There will be an informal afternoon discussion of the Genetic Control of Implantation led by an invited speaker. Keynote presentations will focus on genes that control development in insects and mammals, and on the genetics of human development. Each session will begin with an invited 60 minute presentation providing an overview of the research problems and progress for the subject of that section. These overviews will be followed by three 20 minute more narrowly focused, complementary presentations. Presenters will be selected by the Organizers from attendee applications. Attendance will be limited to 100. Participation of graduate students and postdoctoral fellows is encouraged. Abstracts will be provided to attendees but will not be published. Poster presentations are encouraged. The other major mouse developmental genetics meetings are the Gordon Conference on Embryogenesis and Gametogenesis and the Cold Spring Harbor- Heidelberg Mouse Molecular Genetics meeting. Because the subject emphasis is different and because it is held in the """"""""off-year"""""""" of the Gordon Conference and during the year when the Mouse Molecular Genetics Workshop is held in Heidelberg, the Bar Harbor Workshop complements these meetings in subject and timing.