22 
of these genes in an organism that is extremely well understood, perhaps 
the best understood organism on our planet [ Escherichia coli ] . 
We might also learn how defects in the structure of such genes alter 
their function and their regulation. But there is still some question as 
to whether the genes of higher organisms can be expressed after their 
introduction into _E. coli . It is quite clear that the genes from bacteria, 
any bacterium, are likely to be expressed in E^. coli . , but there is still 
some question about whether the genes of animal cells or plant cells can 
in fact be normally expressed in this simple organism. 
Is this a fundamental or a technical obstacle? The answer is that we 
don't know at the moment. Whether or not this obstacle can be surmounted, 
I believe has a very important bearing on the question of evaluating both 
the potential benefits and the risks that accompany these experiments. I 
may have a chance to come back to that later. 
Although there hasn't yet been a practical application of the new 
techniques, there is every reason to believe that they will in fact have a 
very significant impact on medicine, industry, and agriculture. This meth- 
odology offers us the prospect of isolating genes that code for pharmaco- 
logically important substances. Specifically, the genes for insulin, 
growth hormone, or immunoglobulins could be isolated and propagated in a 
simple bacterium such as _E. coli . And if, as I said before, these foreign 
genes were expressed in the bacterium, then these organisms could well be- 
come factories for producing some of society's most needed supplies. 
The production of antibiotics and vitamins could be revolutionized by 
eliminating the need to grow and process exotic bacterial and fungal strains 
or to use specialized tissues as a source for these precious agents. Both 
might be synthesized by _E. coli in a simple medium. 
There are also important potential benefits to expanding the world 
food supply. The availability of natural and artificial fertilizers limits 
certain crop yields. But atmospheric nitrogen is an infinite source of am- 
monia, if only we could harness the microbial potential for nitrogen fixa- 
tion. Experts in this field suggest that the introduction of the nitro- 
genase system from bacteria into plants or into symbiotic organisms is 
imminent and promises great rewards. 
It is also conceivable that crop production could be increased by in- 
troducing genes which increase the efficiency of photosynthesis, or which 
enhance the nutritive value of plant products. 
I have no doubt that in time the opportunities will expand as the 
methodology becomes more sophisticated. The isolation of genes puts us at 
the threshhold of a new form of medicine, with the treatment of crippling 
genetic diseases through the replacement of defective genes by their normal 
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