E. coli at Work

Scientists use bacteria to make a human hormone

Advocates of recombinant DNA research have been insisting that potential benefits from the ingenious new technique of genetic engineering far outweigh any dangers that it could pose. Last week scientists testifying before a Senate subcommittee lent strong support to that argument. They revealed that a group of California researchers has spliced a man-made gene into a bacterium, and then, for the first time, used the altered microbe to make a copy of a mammalian brain hormone that can act biologically in humans. The accomplishment brought closer the day when scarce and costly hormones and enzymes needed for treatment of genetic disorders can be produced inexpensively and on a large scale.

An important step in this direction had already been taken last spring when scientists at the University of California in San Francisco succeeded in transplanting a rat insulin gene into the DNA of a laboratory strain of the bacterium Escherichia coli. The bug then multiplied into countless duplicate bacteria, each containing the insulin gene, but incapable of producing insulin. In the work announced last week, Microbiologist Herbert Boyer of the University of California, San Francisco, along with Biochemist Arthur Riggs of the City of Hope Medical Center near Los Angeles and Physiologist Wylie Vale of the Salk Institute in San Diego synthesized copies of the gene for somatostatin, a hormone in the brains of mammals that inhibits the secretion of pituitary growth hormone. Then they chemically inserted the genes into the DNA of E. coli bacteria, which multiplied and began manufacturing somatostatin.

Dr. Philip Handler, president of the National Academy of Sciences, who revealed the research at the Senate hearings, called the achievement "a scientific triumph of the first order." Indeed it is:

the researchers who first isolated somatostatin needed nearly half a million sheep brains to produce 5 mg. (.00018 oz.) of the substance. Using their recombinant DNA technique, the California researchers required only 2 gal. of bacterial culture to obtain the same amount.

This file is automatically generated by a robot program, so viewer discretion is required.