Bacteriophage Mu integration: On the mechanism of Mu-induced mutations

Abstract

Infection of Escherichia coli with bacteriophage Mu leads to an increase in the mutation frequency in a wide variety of genes. Taylor (1963) has proposed that these mutations are caused by the integration of the Mu prophage into the gene. The experiments reported in this paper show that the Mu prophage is genetically located at or near the site of the Mu-induced mutation in accord with Taylor's proposal. A Mu-induced chl-D mutation between the λ prophage attachment site and the gal operon prevents λ from transducing gal genes. It is possible to isolate λ-transducing particles from lysates of this strain which carry portions of the Mu prophage. These particles are packaged in λ capsids. Further aspects of Mu mutagenesis are discussed.