This book presents selected papers from the international symposium on "Gene Manipulation and Expression" held in the Bechyne Castle, in South Bohemia, Czechoslovakia, on September 3 to 7, 1984. The symposium was sponsored by Academician J.Riman, vicepresident of the Czechoslovak Academy of Sci­ ences and director of the Institute of Molecular Genetics of the Czechoslovak Academy of Sciences, and by corresponding member of the Czechoslovak Academy of Sciences Prof. V.Krumphanzl, president of the Czechoslovak Society for Microbiology and director of the Institute of Microbiology of the Czechoslovak Academy of Sciences, with Dr. K.Mikulik of the same Institute acting as chairman of the Organizing Committee. The book is divided into