THE UNIVERSITY OF ROCHESTER 601 ELMWOOD AVENUE MEDICAL CENTER AREA CODETIO. SCHOOL OF MEDICINE AND DENTISTRY - SCHOOL OF NURSING STRONG MEMORIAL HOSPITAL DEPARTMENT OF MICROBIOLOGY Frank E. Young, M.D., Ph.D. December 1, 1977 Professor and Chairman 275-3407 Dr. Joshua Lederburg Professor of Genetics Stanford University Medical Center Department of Genetics Stanford, California 94305 Dear Josh: Enclosed is the manuscript that I discussed with you over the phone. I believe this process of integration is extremely important in B. subtilis and shows an analogy between transformation and lysogeny. We are currently testing the recombination against pMB9. Please feel free to show the manu- script and discuss it with your students as I mentioned in our conversation. Could it be reviewed rapidly? I believe it is an important communication that could significantly influence the current level of thinking on rDNA. Possible reviewers include Stan Cohen, John Spizizen and Don Helinski in addition to yourself. Thanks for your consideration. Sincerely, FEY: jm Enc.