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.