Affiliation: | aDepartment of Genetics, Harvard Medical School, Boston, MA, 02115.;bCold Spring Harbor Laboratories, Cold Spring Harbor, NY, 11724;;cDepartment of Molecular Genetics, The Ohio State University, Columbus, OH, 43210;;dHoward Hughes Medical Institute, Cold Spring Harbor Laboratories, Cold Spring Harbor, NY, 11724;;eHoward Hughes Medical Institute, Harvard Medical School, Boston, MA, 02115 |