Joshua Lederberg, who won a Nobel Prize for discovering that bacteria could have sex, thereby establishing the foundation of modern genetics and biotechnology, died of pneumonia Saturday in New York City. He was 82.
The prodigy's pioneering work while he was still in graduate school made him one of the first researchers to manipulate genes in a living organism. It opened the door to an understanding of how bacteria evolved and the mechanisms by which they develop and transfer antibiotic resistance.
It also set the stage for a long and fruitful career in space biology and artificial intelligence, as well as four decades on government advisory commissions on health policy, national security and arms control.
As president of Rockefeller University in New York City from 1978 to 1990, he was instrumental in the renovation of many of the scientific research institution's facilities and the construction of new ones.
"Josh was one of the most creative scientists of our times," said molecular biologist Stanley N. Cohen of Stanford University. "He thought more broadly and more deeply about more things than anyone I've ever known. His death is a loss to all of us."
When Lederberg began his research immediately after World War II, biologists had a very limited understanding of genetics and bacterial reproduction. Pioneering molecular biologist Oswald Avery had discovered in 1944 that deoxyribonucleic acid, or DNA, was the material that encoded the genetic information of life, including bacteria.
Inspired by the findings, Lederberg took a leave of absence from Columbia University medical school and began studying pneumococci and Escherichia coli with Edward L. Tatum of Yale University. At the time, bacteria were thought to be simple organisms that reproduced by cell division and thus produced offspring that were genetically identical to the parent -- that is, clones.
Within a year, the pair were able to show that E. coli underwent a sexual stage in which it could mate and exchange genetic information, a process called recombination or conjugation. When bacteria in the sexual stage came into contact, they could exchange rings of DNA -- separate from their nuclear DNA -- that Lederberg dubbed plasmids.
That nomenclature did not catch on until the 1970s, however, when it became clear that genes encoded in the plasmids were the mechanism by which bacteria transferred antibiotic resistance from one organism to another.
