AUG oC 31974

Buke University Medical Center

DURHAM, MONTH CAROLINA
27716

68 4—
PEDIATRIC METABOLISM DIVISION TELEPHONE 919-~—684—3729

August 19, 1974

Doctor Joshua Lederberg

Department of Genetics

Stanford University Medical School
Palo Alto, California

Dear Doctor Lederberg:

Doctor Kaplan called me recently and asked that I contact you regarding the status
of the " DNA macromutations" in bacteria.

While working with Dr. Kaplan at Brandeis, we felt we had encountered this phenomenon
with Pseudomonas testosteroni. Dr. Kwan Sa You, then a graduate student and
currently working with Bill Allison at UCSD, wrote his thesis around the work we
did together. Since that time, little has been done in the area and the consensus
is that the phenomenon represents culture contamination. I was unsuccessful in
' obtaining additional funds to explore this concept and have therefore not been
able to pursue it. It must seem that I am an iconoclast when I say that I still
believe that the phenomenon exists.

In any case, I am enclosing three reprints that bear on our system. Additional
information is available in Kwan Sa You's thesis. I have a number of ideas for a
further approach to this problem should another bacterial system present itself.
If I can be of any further assistance, please let me know.

Sincerely yours,

COLRQ. 70. (Coa

Charles R. Roe, M.D.
CRR/ELA

Enclosure