Love in the Laboratory

This chapter describes the marriage of two prodigies and how it represented a fruitful alliance of complementary research personalities: the brilliant theoretician and the skillful experimenter. Esther Zimmer and Joshua Lederberg were two of the youngest scientists to attend the 1946 summer symposium at Cold Spring Harbor. Edward Tatum arranged for his protégé, young Lederberg, to present his stupendous discovery of bacterial conjugation, showing that bacteria could mate and recombine their genes. Zimmer and Lederberg began a short romance and married five months later. The young couple moved near the campus of Yale University, where Joshua wrote up his thesis and Esther researched Neurospora genetics with Norman Giles. The following summer, Tatum negotiated with Yale to grant an accelerated PhD to Joshua. The University of Wisconsin offered him an assistant professorship, and Joshua and Esther moved to Madison in 1947. There they established the first research program in bacterial genetics.

Behind the Laboratory Doors

This chapter compares Esther Lederberg’s role with that of other notable women scientists whose achievements exhibited creative laboratory skills. Esther’s career peaked in 1956 when the Society of Illinois Bacteriologists jointly bestowed the Pasteur Medal on the Lederberg couple. Usually, Joshua Lederberg was the public face of their research program. Esther’s place was behind the laboratory doors where she managed the lab and performed the experiments. For over a hundred years, this was the typical arrangement for women and their male associates. Prestigious faculty positions and accolades were unattainable for so many women in science. For Esther and many of her female colleagues, the thrill of discovery was enough reward. Esther valued the camaraderie of the brilliant personalities that made up the circle of pioneering researchers. Stanley Falkow called her a kind of Boswell of bacterial genetics. Her extensive photographic collection is a who’s who of molecular biology, many as their younger selves.

A Hidden Legacy

This biography of Esther Zimmer Lederberg highlights the importance of her research work, which revealed the unique features of bacterial sex, essential for our understanding of molecular biology and evolution. A Hidden Legacy relates how, she and her husband Joshua Lederberg established the new field of bacterial genetics together, in the decade leading up to the discovery of the DNA double helix. Their impressive series of achievements include: the discovery of λ‎ bacteriophage and of the first plasmid, known as the F-factor; the demonstration that viruses carry bacterial genes between bacteria; and the elucidation of fundamental properties of bacterial sex. This successful collaboration earned Joshua the 1958 Nobel Prize, which he shared with two of Esther’s mentors, George Beadle and Edward Tatum. Esther Lederberg’s contributions, however, were overlooked by the Nobel committee, an example of institutional discrimination known as the Matilda Effect. Esther Lederberg should also have been recognized for inventing replica plating, an elegant technique that she originated by re-purposing her compact makeup pad as a kind of ink stamp for conveniently transferring bacterial colonies from one petri dish to another. Instead, the credit for the invention is given to her famous husband, or, at best, to Dr. and Mrs. Lederberg. Within a few years of winning the Nobel Prize, Joshua Lederberg divorced his wife, leaving Esther without a laboratory, cut off from research funding, and facing uncertain employment. In response, she created a new social circle made up of artists and musicians, including a new soulmate. She devoted herself to a close-knit musical ensemble, the Mid-Peninsula Recorder Orchestra, an avocation that flourished for over forty years, until the final days of her life.

Strange Genetics

This chapter relates how, in the 1950s, Esther and Joshua Lederberg and their colleagues uncovered a whole new kind of genetic transfer involving plasmids and viruses. In plants and animals, genetic recombination is integrated within the processes of sexual reproduction. Imagine if you could trade genes with strangers at will! That’s what bacteria can do. Esther Lederberg’s discoveries of the F-plasmid and the λ‎ bacteriophage were happy accidents that occurred while she working to complete her dissertation research. Serendipity happens to those who are very attentive, broadly experienced, and open to surprises. Esther Lederberg discovered a transferable factor, the F-factor, that could transform recipients into donors. Then she discovered a lysogenic virus, hiding harmlessly inside the chromosome of its bacterial host. These two surprising discoveries showed that bacteria could transfer genes and pieces of chromosomes horizontally, as opposed to the classical inheritance of plants and animals which pass on genetic traits vertically, down through generations.