THE McCOLLUM- PRATT INSTITUTE SYMPOSIUM ON “CHEMICAL BASIS OF HEREDITY” JUNE 19-22nd, 1956 AT THE JOHNS HOPKINS UNIVERSITY BALTIMORE, MARYLAND The McCollum-Pratt Institute of The Johns Hopkins University was founded in 1948 to investigate the importance of inorganic ions in the metabolism of plants and animals. One of the functions of the Institute is to bring together outstanding authorities in the field of Biochemistry and Physiology. Therefore the Institute has held each year a symposium devoted to the discussion of a particular area within these major fields. In 1950 the major topic of discussion was Copper Metabolism and in 1951 and 1952 the general problems concerned with the intermediary metabolism of phos- phorus and phosphorus-containing compounds were reviewed. Various fundamental concepts related directly or indirectly to the mechanism of enzyme action were discussed during the 1953 symposium. In 1954 a symposium on Amino Acid Metabolism was held while the major topic for review last year was Inorganic Nitrogen Metabolism. The current symposium, 1956, is concerned with various biological and chemical aspects of heredity. We would like to acknowledge this year the support of the Atomic Energy Commission in helping defray part of the expense of the Symposium. PROGRAM OF EVENTS teleinlemiebinieiemicie TUESDAY, JUNE 19, 1956 8:30 A.M. 9:15 A.M. Session I 9:30 A.M. 10:15 A.M. 11:00 A.M. 12:00 Noon 1:30 P.M. 2:10 P.M. 2:50 P.M. 3:15 P.M. 3:30 P.M. Registration Introductory Comments—W. D. McHlroy, Director McCollum-Pratt Institute Cellular Units of Heredity Moderator: Dr. Bentley Glass, Dept. of Biology Johns Hopkins University, Baltimore A. The Role of the Nucleus in Heredity Dr. George W. Beadle, Dept. of Biology California Institute of Technology, Pasadena B. Chromosome Structure Dr. Hans Ris, Dept. of Zoology University of Wisconsin, Madison Discussion Lunch—Faculty Club C. Size of the Nuclear Unit of Heredity Dr. Seymour Benzer, Biophysical Laboratory Purdue University, Lafayette, Ind. D. Pseudoallelism and Abberent Recombination Phenomena Dr. H. K. Mitchell, Dept. of Biology California Institute of Technology, Pasadena Discussion Recess E. Role of the Cytoplasm in Heredity Dr. David L. Nanney, Dept. of Zoology University of Michigan, Ann Arbor 4:10 P.M. F. Mutability of Genetic Units Dr. Marcus Rhoades, Dept. of Botany University of Illinois, Urbana 5:00 P.M. Discussion 5:30 P.M. Refreshments—Faculty Club 6:15 P.M. Dinner—Faculty Club WEDNESDAY, JUNE 20, 1956 Session IJ Role of the Nucleus, Nucleic Acids and Associated Structures in Cell Division and Protein Synthesis Moderator: Dr. Boris Ephrussi, Laboratoire de Genetique Université de Paris, Paris 9:00 A.M. A. Chemical Changes during Cell Division Dr. Daniel Mazia, Dept. Zoology University of California, Berkeley 9:40 A.M. B. The Nucleus and Protein Synthesis Dr. Vincent Allfrey, Rockefeller Institute for Medical Research, New York 10:20 A.M. Discussion 10:45 A.M. C. Nucleic Acids and Protein Synthesis Dr. Sol Spiegelman, Dept. of Bacteriology University of Illinois, Urbana 11:25 A. M. Discussion 12:00 Noon Lunch—Faculty Club Srssion ITI Nucleic Acids as Transforming Agents Moderator: Dr. 8. Luria, Dept. of Bacteriology University of Illinois, Urbana 1:30 P.M. A. Transformation of Cellular Characteristics by DNA Dr. H. Ephrussi Taylor, Laboratoire de Genetique Université de Paris, Paris 2:10 P.M. Dr. R. D. Hotchkiss, Rockefeller Institute of Medical Research, New York 2:50 P.M. Discussion 3:30 P.M. Recess 3:45 P.M. B. Properties of the Transforming Principle Dr. S. Zamenhof, Dept. of Biochemistry Columbia University, New York 4:30 P.M. Discussion 5:30 P.M. Refreshments—Faculty Club 6:15 P.M. Dinner—Faculty Club THURSDAY, JUNE 21, 1956 Szesston IV Viruses as Bearers of Heritable Characteristics Moderator: Dr. Roger Herriott, School of Hygiene and Public Health, Johns Hopkins University 9:00 A.M. A. Transduction Dr. Philip Hartman, Dept. of Bacteriology Harvard University, Cambridge 9:40 A. M. Discussion 10:00 A.M. B. Lysogenicity Dr. Francois Jacob, Pasteur Institute, Paris 10:40 A. M. Discussion 11:00 A.M. C. The Nature of the Progeny of Virus Reconstituted from Protein and Nucleic Acid of Different Strains of Tobacco Mosaic Virus Dr. H. Fraenkel-Conrat and Dr. Robley Williams Virus Laboratory, Univ. of California, Berkeley 11:40 A.M. Discussion 12:00 Noon Lunch—Faculty Club Session V Nucleic Acids—Chemical Composition and Structure Moderator: Dr. Paul Doty, Dept. of Chemistry Harvard University, Cambridge 1:30 P.M.