The Central Importance of E. coli and λ‎ Phage in the New Molecular Biology

Abstract

This chapter considers two of the most important legacies of the Lederbergs’ pioneering work: the discoveries of the model organisms that would dominate molecular biology, E. coli and λ‎ bacteriophage. The Lederbergs’ introduction of E. coli as a convenient model organism shifted the direction of molecular genetics. Barbara McClintock’s discovery of jumping genes remained unappreciated for decades, until the field of molecular biology caught up to validate her transposable elements in bacteria. The discovery of restriction enzymes—the molecular scissors for precisely cutting DNA at specific sites, a prerequisite for genetic recombination techniques—emphasized the versatility of bacteriophage λ‎ as a powerful experimental tool. The discovery of specialized transduction by Larry Morse and Esther Lederberg hinted at the mechanisms of “host restriction.” Werner Arber and Daisy Dussoix discovered restriction endonucleases by building upon Esther Lederberg’s research with λ‎ phage and the differences between E. coli B and K-12.