The Chlamydomonas Genetic Stock Center serves as a central repository to receive, catalogue, preserve and distribute stocks of nuclear and chloroplast mutants of the green alga Chlamydomonas reinhardtii and other Chlamydomonas species in which extensive genetic analysis has been done. The Center also acts as a clearinghouse for genetic and molecular mapping data on Chlamydomonas, continually updates an extensive bibliography of pertinent references, and provides information to users on culture methods, techniques for genetic analysis, and other aspects of Chlamydomonas research. Genetic mapping data are compiled by the Center for publication every two years. During the next five years, the Center will also begin collecting and maintaining clones of Chlamydomonas nuclear and chloroplast DNA. This project will provide partial funding for the Chlamydomonas Center for the next five years.