6 
binant DXA have been published in the last 4 years. The Xational 
Institutes of Health, which has supported a large proportion of this 
research, is presently funding approximately 375 proejcts. 
APPLICATION’S OF RECOMBINANT DNA TECHNOLOGY 
Laboratories supported by both public and private funds are already 
working on possible applications of the technique in medicine, indus- 
try, ana agriculture. Officials of the Pharmaceutical Manufacturers 
Association reported that three member firms are engaged in recom- 
binant DXA research and three others are financing experiments being 
conducted in universities. PMA President Joseph Stetler cautioned 
that “a substantial amount of basic research will be necessary before 
the feasibility of recombinant DXA technology in commercial devel- 
opment can be determined with any degree of accuracy.” Researchers 
and knowledgeable observers have, nonetheless, become increasingly 
optimistic in recent months. Several witnesses predicted that at least 
a few commercial uses of recombinant DXA will be developed within 
5 or 10 years. 
Products f rom micro-organisms 
The application most often mentioned involves the propagation of 
large quantities of microorganisms with recombinant DXA for the 
production of a useful product, followed by the extraction of the prod- 
uct and destruction of the cell material and other byproducts. This 
procedure may become a source of animal proteins such as antibodies, 
blood-clotting factors, human hormones, and antigens or of industrial 
enzymes for fermentation and other biochemical manufacturing proc- 
esses. Although unproven, it is hoped that the technique will be more 
efficient than present laborious or costly methods of synthesis and 
extraction, provide a source for products in short supply, or produce 
substances with entirely new commercial uses. 
There has been notable progress in the development of this process. 
In the spring of 1977, researchers at the University of California 
Medical School at San F rancisco. successfully introduced and cloned 
in E. coli bacteria the gene which codes for the production of insulin 
in rats, although the material lacked the mechanism which controls the 
production of insulin. More recently, a team of Harvard University 
and Joslin Diabetes Foundation scientists achieved the synthesis of rat 
proinsulin, the precursor protein. In the opinion of William Rutter, a 
member of the San Francisco research group, it will be possible to 
produce human insulin in bacteria inexpensively and in greater quan- 
tity than is now available. As an added benefit, the insulin o.tained in 
this manner may not induce production of antibodies in diabetic 
patients. 
Another accomplishment within the past year by scientists at UCSF, 
the City of Hope Medical Center, and the Salk Institute involved the 
incorporation into E. coli of the gene for the mammalian hormone 
Somatostatin, accompanied by the genetic material necessary for ex- 
pression. In this case, the gene was synthesized chemically since it has 
not been isolated from the exceedingly complex mammalian DXA 
sequence. A small amount of somatostatin was obtained from the bac- 
terial culture. Somatostatin is secreted by the hypothalamus and acts 
[Appendix B — 266] 
