Isolation of ara-lac gene fusions in Salmonella typhimurium LT2 by using transducing bacteriophage Mu d (Apr lac).
A specialized Mu transducing phage containing a gene encoding ampicillin resistance and the lac structural genes without the lac promotor [Mu d(apr lac)] has been constructed and used to create gene fusions in Escherichia coli (M. J. Cadadaban and S. N. Cohen, Proc. Natl. Acad. Sci. U.S.A. 76:4530--4533, 1979). Transposition of the Mu d(Apr lac) phage to chromosomal sites can result in lac expression being controlled by a chromosomal promoter. We have constructed an Escherichia coli K-12 strain in which the Mu d(Apr lac) phage is integrated into an F factor. The F+::Mu d(Apr lac) was  then transferred by conjugation into a Salmonella typhimurium strain that was sensitive to L-arabinose. Strains containing gene fusions were selected as L-arabinose-resistant colonies after partial induction of the phage. Two classes of ara-lac fusion strains were isolated: (i) araC-lac fusions in which the expression of beta-galactosidase synthesis was constitutuve and not inducible by L-arabinose; and ((ii) fusion of the lac genes to the ara structural genes in which the expression of beta-galatosidase synthesis was induced 263-fold by L-arabinose.
D001089:Arabinose / Q000378:metabolism; D003090:Coliphages / Q000235:genetics; D005696:Galactosidases / Q000235:genetics*; D005786:Gene Expression Regulation; D005796:Genes; D009876:Operon; D011995:Recombination, Genetic; D012486:Salmonella typhimurium / Q000235:genetics*; D014161:Transduction, Genetic; D001616:beta-Galactosidase / Q000235:genetics*
D001089:Arabinose; D005696:Galactosidases; D001616:beta-Galactosidase