Max Planck Institute for the History of Science
Reprint 24 (1995)
Hans-Jörg Rheinberger
"A Short History of Molecular Biology"
Page 26, paragraph 2

      In 1951 Joshua Lederberg and Norton Zinder described the phenomenon of virally derived "transduction", and Esther Lederberg observed Lysogeny of the E.-coli strain K12. She called the involved phages "LAMBDA".

      In 1953 Hayes characterized a high frequency recombinant DONOR VARIANT of K12 (Hfr Hayes). Wollman and Jacob started working with this strain. Studying the kinetics of recombination of multiple mutants of K12, they came upon a trick which would prove successful: When the process of conjugation is interrupted mechanically at specific times (through centrifugation), one could reverse the transfer of different characters temporarily. 'Mapping by mating' became a key for indexing bacterial chromosomes (Jacob and Wollman 1958). The index could be made by the number of minutes which a factor needed in order to transfer from the donor to the recipient. The gene for Beta-Galactosidase stood at 25 minutes, the one for Lambda phage at 26."

      It should be noted that Esther Lederberg's seminal discovery of "Lambda phage lysogeny" in Escherichia coli in K12 took place in 1950, not 1951 . Esther Lederberg was the sole researcher who made this discovery. Later research by Joshua Lederberg, Norton Zinder and E. R. Lively (1951) is at times confused with Esther Lederberg's 1950 discovery (a confusion made in the above paragraph)^{1, 2}. As an interesting historical note: due to the importance of Escherichia coli K12, Esther Lederberg felt that due to the importance of her discovery of this lysogenic phage, it should be given the name of the next letter in the alphabet after the letter "K" (used for K12). Thus she named this lysongenic phage "λ" (lambda)³. Esther M. Lederberg's 1950 paper is the first recorded use of the name "λ" for λ-phage.

¹  Lederberg, E. M., 1950, "Lysogenicity in Escherichia coli strain K-12", Microbial Genetics Bulletin, 1, pp. 5-9, Jan. 1950, Univ. of Wisconsin [Evelyn Maisel Witkin, Editor], Ohio State University, ISSN: 0026-2579, call No. 33-M-4, OCLC: 04079516, Accession Number: AEH8282UW (click for further information).

²  Lederberg, E. M., Lederberg, J., Jan. 1953, "Genetic studies of lysogenicity in Escherichia coli", Genetics 38(1):51-64

³  Personnal communication with Matthew Simon