Analysis of the Regulation of the Transposition Functions of Bacteriophage Mu by Using

Bacteriophage Mu is unique among bacterial viruses because it displays many characteristics of transposable elements; it can integrate at random locations in host DNA, it uses a transposition mechanism to replicate its DNA, and it can cause the same DNA rearrange-ments (inversions, deletions, duplications, and trans-positions) associated with movable genetic elements (for a review, see Toussaint and Resibois 1983). One way to look at Mu is as a giant transposable element capable of packaging itself into phage particles. As with all transposable elements, the transposition pro-cess of Mu must be regulated to ensure the survival of the host population, since uncontrolled transposition would inevitably lead to the destruction of the host ge-netic material. In this regard, it can be said that M