Joshua Lederberg

On 13, 1946, Lederberg married fellow scientist Esther Miriam Zimmer, who later became a noted microbiologist and a pioneer in bacterial genetics. For twenty years they worked together in different projects. However, personal competition slowly drove them apart and the couple divorced in 1966.

In 1968, Lederberg married psychiatrist Marguerite Stein Kirsch. The couple had a daughter named Anne Lederberg. Lederberg also had a stepson, David Kirsch, from Marguerite’s previous marriage. The couple remained married until his death.

Joshua Lederberg died on February 2, 2008, in New York. He was survived by his wife and two children.

Joshua Lederberg was born on May 23, 1925, in Montclair, New Jersey. His father, Zwi H. Lederberg, was a Rabbi. His mother, Esther nee Goldenbaum, migrated from Palestine just two years prior to his birth. He was the eldest of his parent’s three sons.

When Joshua was six months old, the family moved to New York City and settled down in Washington Heights, a neighborhood in borough of Manhattan. He began his schooling at Public School 46 and later shifted to Junior High School 164.

Finally he graduated from Stuyvesant High School in 1941. While at school, Lederberg was allowed to conduct research in cytochemistry after school hours through American Institute Science Laboratory program. Works of H.G. Wells, Bernard Jaffe and Paul De Kruif also influenced him a lot.

After passing out from school, Joshua received a tuition scholarship from Hayden Trust. With that he enrolled at the University of Columbia as a premedical student with zoology as his major and received lab space to work on cytophysiology of mitosis in plants and theuses of genetic analysis in cell biology.

In 1942, he came in contact with Francis Ryan, who awakened in him an interest for biochemical genetics. He slowly began to find scientific research more challenging than the medical studies.

Lederberg had an idea that bacteria passed down exact copy of genetic information and consequently, all cells in the lineage became its clone. He now began to work on that at the Columbia University. His work caught the attention of his mentor Francis Ryan, who recommended him to Edward L. Tatum.

Tatum was then working at the University of Yale on bacteria. He invited Lederberg to join his laboratory. Subsequently, Lederberg took one year’s leave from Columbia University and joined Tatum at Yale in March 1946. Here he was supported by Jane Coffin Childs Fund.

After intensive research with an Escherichia coli bacterium Lederberg and Tatum were able to establish that E-coli entered a sexual phase during which it could share genetic information through bacterial conjugation. In the same year, they published their findings in a paper titled, ‘Gene Recombination in Escherichia coli’.

As his one year leave from the Columbia University came to an end Lederberg decided not to return. Instead he decided to remain at Yale and earn his PhD, receiving the degree in 1948.

Meanwhile in 1947, he was appointed as an Assistant Professor of Genetics at the University of Wisconsin. In 1950, he was promoted to the post of Associate Professor and became a full Professor in 1954.

Lederberg is best remembered for his work on bacterium Escherichia coli. Earlier scientists were of the opinion that bacteria could only reproduce asexually; i.e. by splitting itself into two. Lederberg worked with Edward Tatum to show that E-coli could also reproduce sexually.

In a paper titled ‘Gene Recombination in Escherichia coli’, published in 1946, they showed that the amalgamation of two different strains of a bacterium resulted in genetic recombination, which led to the formation of a new bacterium. They also established that genetic systems of bacteria were quite analogous to that of higher organisms.

Lederberg is also remembered for his work on a phenomenon now known as transduction. In 1952, he along with Norton D. Zinder showed that bacterial gene could be transferred from one bacterium to another by means of a virus called bacteriophage

His work on astrobiology is also quite significant. When Sputnik was launched in 1957, it was Lederberg who cautioned that extraterrestrial microbes may gain entry into earth’s atmosphere onboard the spacecraft. He suggested that spacemen as well as spacecrafts should be quarantined on return to earth and checked for such microbes.