8 
environment; second, that research may ultimately lead to genetic 
manipulation of human beings; and third, that interference with 
natural evolutionary processes may do incalculable ecological damage. 
In Philip Handler’s opinion, only the first of these apprehensions is 
amenable to scientific evaluation; the latter concerns involve issues 
of basic social values that merit public discussion but are not yet 
capable of being resolved. 
Public controversy and scientific assessments of the risks of recom- 
binant DMA research have therefore focused primarily on its effects 
on public health and the environment. Researchers have studied the 
scientific literature and conducted new experiments to determine 
whether there is any evidence lending credence to speculations about 
new pathogenic forms of life. In the meantime, the NIH guidelines 
are intended to insure use of appropriate biological and physical con- 
tainment methods. In cases where the presumption of risk is strong 
and cannot be offset by an important benefit, the experiments have 
been prohibited until more data are available. 
Most speculations of risk cite the lack of knowledge about possible 
changes in function of the recombined DNA molecule. It is suggested 
that the joining of a foreign gene with other genes of an organism or 
vector or the characteristics of the new gene itself might produce some 
unexpected adverse activity in the new cell environment. If so, the 
escape of the organism or the accidental transfer of the recombinant 
DNA molecule to another organism might cause disease in the labora- 
tory worker or human beings, animals, or plants in the surrounding 
environment. 
EXPERIMENTS WITH U E. COLl” K-12 AS THE HOST ORGANISM 
The principal host cell employed in current DNA recombinant re- 
search is the K-12 strain of E. coli. Apprehensions about the use of 
K-12 arise in part from the fact that other taxonomically related 
strains of E. coli inhabit the human intestine. Several of these “wild” 
strains may, under certain circumstances, cause disease. Furthermore, 
•because of the dissemination of human intestinal waste products in the 
environment, it has been suggested that widespread release of E. coll 
K-12 containing a recombinant molecule could have serious adverse 
effects if interactions occurred with the E. coli strains normally pres- 
ent in the human gut or with other organisms in the environment. 
Frank Young of the University of Rochester pointed out in his 
testimony to the subcommittee that all strains of E. coli are not alike. 
He has identified more than 580 biotypes of E. coli exhibiting a wide 
spectrum of pathogenicity ranging from nonpathogenic forms to 
strains which produce various toxins. Young emphasized that it is 
necessary to examine the K-12 strain in detail in order to determine 
whether it poses any hazard. 
Philip Handler listed the several questions about K-12 that the spe- 
cial panel of the National Research Council addressed in its Novem- 
ber 1977 report. Could the use of this host cell lead to epidemics 
through some modifications produced by introducing new genomic ma- 
terial by DNA recombinant techniques? Could the recombinant DNA 
molecule transferred experimentally to the K-12 cell be transferred 
[Appendix B — 268] 
