PART I— PRINCIPAL FINDINGS 
Actual and Potential Benefits 
THE TECHNIQUE AND ITS SCIENTIFIC SIGNIFICANCE 
In recombinant DNA research, specific sections of a DNA molecule 
are extracted from an organism or constructed biochemically and then 
inserted into another DNA sequence. The so-called recombinant DNA 
molecule is then introduced into a host organism where it can survive 
and replicate in cell division. This technique of artificial genetic ex- 
change may be perfoi'med with organisms that commonly exchange 
DNA or with genetic material from two very dissimilar organisms, 
such as a mammal and a bacterium. 
The host organism used in the vast majority of experiments is a 
strain of the common bacterium Escherichia coli. In addition to its 
single large chromosome containing DNA, E. coii has one or more 
independently replicating smaller loops of DNA known as plasmids. 
The plasmids are relatively easily isolated from the bacteria and 
broken open by restriction enzymes. The foreign DNA is linked to the 
plasmid DNA and its circular form restored. The plasmid “vector” 
is then returned to the whole cell bacterium where it can resume 
replication, duplicating not only the native DNA sequence but also 
the foreign one. If, in addition, the foreign DNA molecule carries 
with it the mechanism which regulates its expression, it may produce 
the protein or other chemical for which it codes. 
The development of this technique is widely regarded as a major 
advance in the biological sciences, both as a means of studying basic 
biological phenomena and as a technology with numerous beneficial 
applications. In his testimony to the subcommittee, Philip Handler, 
President of the National Academy of Sciences, described DNA re- 
combination as a research tool of “extraordinary power” for under- 
standing the structure and functioning of the genetic apparatus. He 
referred to a recent report. “The Risks and Benefits of Recombinant 
DNA Research Performed Under the NIH Guidelines” (November 1, 
1977), by a panel convened by the National Research Council of the 
Academy, which cited work using preselected genes of various animals 
including fruit flies, frogs, and sea urchins. The report states that 
“the distribution of likely regulatory sequences along cellular chromo- 
somes has been mapped, using cloned recombinant DNA segments, 
and has suggested an unexpected mobility of genes.” Similar experi- 
ments are being done with plants. These and other developments are 
contributing to an understanding of the general principles of chromo- 
somal organization, genetic regulation, and inheritance as well as 
genetic abnormalities. 
According to Stanford Professor Stanley Cohen, in a letter to the 
subcommittee, more than 250 scientific investigations involving recom- 
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[Appendix B — 265] 
