Fig. 2

Specialized transduction by E. coli prophage λ. a Illustration of specialized transduction. The prophage λ genome is integrated into the host chromosome. Upon induction of the prophage, the prophage genome is excised and replicated. The phage structural genes are expressed, phage particles are produced and the replicated phage genome is packaged into phage heads. Ultimately, the phages are released to the environment by lysis of the host cell. Imprecise excision of the prophage λ genome happens at low frequency and leads packaging of the host chromosome into phage heads. These parts of the host chromosome can be transferred to new host genomes in the process called specialized transduction. b Genome coverage pattern associated with prophage λ induction and specialized transducing prophage λ. The upper box shows coverage patterns for whole genome sequencing reads and purified phage particle reads mapped to the E. coli genome. c In the lower box, an enlargement of the purified phage read coverage for the prophage λ region is shown (log scale). The positions of the gal and bio operons, which are known to be transduced by prophage λ, are indicated [27]