Integration of the bacteriophage HP1c1 genome into the Haemophilus influenzae Rd chromosome in the lysogenic state

Restriction fragments hybridizing to phage HP1c1 DNA were identified in digests of DNA from lysogenic strains of Haemophilus influenzae. The results showed that the cohesive ends of the mature phage DNA were joined in lysogens and that the phage genome was covalently linked to the host DNA, indicating that lysogeny involves recombination between specific sites on the phage and host chromosomes. The site on the phage chromosome at which this recombination occurred was between 110 and 750 base pairs of the left end on the mature phage genome.