ALBERT EINSTEIN COLLEGE OF MEDICINE 
OF YESHIVA UNIVERSITY 
1300 MORRIS PARK AVENUE, BRONX, N.Y. 10461 • CABLE:EINCOLLMED, N.Y. 
DEPARTMENT OF MOLECULAR BIOLOGY 
PHONE: (212) 430-2000 
August 18, 1978 
Dr. Donald Fredrickson 
Director 
National Institutes of Health 
Washington, D.C. 
Re: Inclusion in the revised 
guidelines of Caulobacter 
as an organism which naturally 
exchanges chromosomal genes 
with E. coli 
Dear Dr. Fredrickson: 
I have just received a copy of Bert Ely's manuscript which he has 
submitted to Genetics for publication. This manuscript amply demonstrates 
the transfer of chromosomal genes between E. coli and Caulobacter. It 
is, therefore, quite appropriate that Caulobacter be included on the list 
of exchangers in Appendix A of the proposed revision of the NIH Guidelines 
for Recombinant DNA Research. Such an inclusion would greatly facilitate 
experiments in progress in my own laboratory on the organization and ex- 
pression of the Caulobacter genome during the course of cell differentiation. 
Similar studies are concurrently progressing in several other laboratories 
studying Caulobacter . 
The overall revision of the guidelines will permit work in the areas 
of microbial gene expression to proceed at a faster rate and in general 
to be more productive. I feel the Recombinant DNA Committee has done an 
excellent job in revising the guidelines, and that the revisions are both 
realistic and logical. 
Lucille Shhpiro ^ 
Siegfried Ullmann 
Professor of Molecular Biology and 
Chairman of the Department 
LS/ ac 
[A— 243 
