Lederberg, Joshua

(1925- ) American geneticist and microbiologist who received the Nobel prize in 1958 for his work in bacterial genetics.

He shared the prize with George W.

Beadle and Edward L.

Tatum, who won 'for their discovery that genes act by regulating definite chemical events.' Josh Lederberg was born in Montclair, New Jersey, the son of a rabbi.

Lederberg's interest in a scientific career began quite early.

His family moved to New York City when Lederberg was a child, and Lederberg was able to attend Stuyvesant High School, which concentrated in the sciences.

In New York Lederberg was also able to take advantage of facilities such as the American Institute, which made laboratory space and equipment available to talented high school science students.

Upon graduating from high school at 16, Lederberg took advantage of a local scholarship to attend Columbia University.

He did not see combat service during World War II, but, from July 1943, he was enrolled in the US Navy's V-12 training program, which combined an accelerated premedical and medical curriculum, with active service as a hospital corpsman in a US Naval Hospital.

The work that led to Lederberg's Nobel began in 1945, when he was a medical student.

The previous year Oswald T.

Avery, Colin MacLeod, and Maclyn McCarty had published their paper identifying DNA as the 'transforming principle.' This work, which spoke to the chemical nature of the gene, inspired Lederberg to investigate the possibility of sexual reproduction in bacteria, which at the time were understood to reproduce asexually.

Lederberg's mentor at Columbia, Francis J.

Ryan, encouraged Lederberg to apply for a position in Edward L.

Tatum's laboratory at Yale.

Lederberg took a leave of absence from Columbia to work with Tatum at Yale; he never returned to medical school.

Lederberg's work, which formed the basis for his Ph.D.

Dissertation, demonstrated that bacteria can in fact reproduce through sexual recombination, and opened up the genetics of microorganisms to the traditional methods of the field.

These methods are central to the conduct of biotechnology and genetic engineering, an industry to which Lederberg has been a consultant since its inception.

Lederberg's name is now mentioned in most textbooks of genetics and microbiology not only for his demonstration of bacterial conjugation, but also for his discovery (with Norton D.

Zinder) of transduction (a virus-mediated form of bacterial genetic recombination); for coining the term plasmid to denote extra-chromosomal genetic material; and for his development of the technique of replica plating.

His productive investigations into bacterial genetics led to his winning the Nobel Prize at the age of 33, for the work he initiated at age 20.</P> Shortly after receiving the Nobel Prize, Lederberg joined the new Department of Genetics at Stanford University's School of Medicine.

In 1978, he was appointed President of Rockefeller University.

He became a professor emeritus in 1990. Adapted from biographical information provided courtesy of the National Library of Medicine.