Testimony before the HEW Committee reviewing proposed revised guidelines 
for recombinant DNA research. 
September 15, 1978 
Daniel Nathans, M.D. , Professor and Director, Department of Microbiology, 
Johns Hopkins University, School of Medicine, Baltimore, Md. 
For the record I want to summarize my scientific background and interests 
in relation to this testimony. I was educated in medicine, specializing in 
internal medicine, and subsequently went into molecular biology and microbiology. 
For the past 16 years I have taught medical microbiology to students of medicine 
at Johns Hopkins. My research, supported by the National Cancer Institute and 
the Whitehall Foundation, has centered on the molecular biology of tumor viruses. 
Part of my research involves recombinant DNA methods to study aspects of tumor 
virus interactions with cells. I was a member of the committee that in 1973 
called for NIH guidelines for recombinant DNA research, and earlier this year, 
I served on the committee that recorrmended changes in the guidelines dealing with 
viruses. 
The main point of my testimony is that the proposed revisions of the guidelines 
are justifiable on the basis of recent experience with recombinant DNA and a 
rational re-consideration of potential hazards of microorganisms containing 
recombinant DNA. I also believe that the revisions will allow a more natural and 
creative development of research in those many areas of biology and medicine to 
which recombinant DNA methods are applicable, resulting in advances that would not 
occur under the present guidelines. 
I need not recite the experience with recombinant DNA over the past four 
years. On the one hand, the great promise of the methodology is being realized; 
and on the other, no single instance of harmful effect has been reported. During 
these years also additonal instances of natural interspecies recombination of DNA 
between microbes, or between viruses and cells, have been described that make it 
appear that such genetic interchange is widespread in nature. Therefore, there 
is now less concern both about the imminent "escape" of an artificial pathogen 
and about the novelty of microbes carrying genes from distant species. 
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