Читать книгу Snyder and Champness Molecular Genetics of Bacteria - Tina M. Henkin - Страница 37

In 1946, Joshua Lederberg and Edward Tatum (see Suggested Reading) discovered a different type of gene exchange in bacteria. When they mixed some strains of E. coli with other strains, they observed the appearance of recombinant types that were unlike either parent. Unlike transformation, which requires only that DNA from one bacterium be added to the other bacterium, this means of gene exchange requires direct contact between two bacteria. It was later shown to be mediated by a genetic element that replicated separately from the chromosome, called a plasmid, in a process that was subsequently called conjugation (see chapter 5).