Lactose genes fused to exogenous promoters in one step using a Mu-lac bacteriophage: in vivo probe for transcriptional control sequences.

Abstract

GeneticsLactose genes fused to exogenous promoters in one step using a Mu-lac bacteriophage: In vivo probe for transcriptional control sequences Communicated by A. Dale Kaiser, May 10, 1979 ABSTRACT The lactose structural genes, without the lactose promoter, have been incorporated into the bacteriophage Mu genome to form a Mu-lac specialized transducing phage. This phage also carries a gene encoding resistance to ampicillin (Ap) [Mu(Ap, lac)J. After infection and upon establishment of lysogeny, the Mu(Ap, lac) genome can integrate into apparently random sites in the Escherichia coli chromosome. When integration occurs within a gene in the orientation of its transcription, the lactose structural genes are so situated that they become expressed solely from the promoter of that gene. Thus, expression of the lactose genes of Mu(Ap, lac) can be used as an assay for transcription of that gene and for functional and mutational studies of gene regulation.

The Use of Mudlac Transposons as Tools for Vital Staining to Visualize Clonal and Non-clonal Patterns of Organization in Bacterial Growth on Agar Surfaces

“…Two general classes of explanation may be invoked for how colonies become organized clonally and non-clonally. (1) There are no specific control mechanisms involved, but cellular proliferation and metabolism create physical and chemical gradients that generate concentric zones and influence clonal proliferation (Pirt, 1967 ;Cooper et al, 1968 ;Wimpenny, 1979Wimpenny, ,1981. (2) Bacterial development on agar involves the operation of morphogenetic regulatory systems that are analogous to those controlling the development of complex multicellular structures in higher organisms.…”

“…It is obvious, therefore, that bacterial colonies are specific structures whose contours are subject to hereditary determination. Observation of bacterial growth on agar for several weeks reveals reproducible patterns of morphogenesis (Legroux & Magrou, 1920;Cooper et al, 1968). Thus, we can legitimately enquire about the development of bacterial colonies and pose questions about the mechanisms which organize bacterial cells and control expression of hereditary information as they proliferate on agar surfaces.…”

“…The use of P-galactosidase for bacterial histochemistry is greatly enhanced because expression of this enzyme and of P-galactoside permease can be placed under a wide variety of control systems by the use of Mudlac transposable elements developed by Casadaban and his colleagues (Casadaban & Cohen, 1979;Casadaban & Chou, 1984; B. de Castilho, F. Richaud, P. Olsen & Ahbreciutions : XGal, 5-bromo-3-ch~oro-3-indolyl-~-~-galactoside ; Km, kanamycin; Tp, trimethoprim ; Cm, chloramphenicol; Gm, gentamicin.…”

The colicin G, H and X determinants encode microcins M and H47, which might utilize the catecholate siderophore receptors FepA, Cir, Fiu and IroN

“…For further characterization of the toxin, we screened for mutants of strain DSM 6601 that were unable to produce this activity. To identify the encoding genes, strain DSM 6601 was mutagenized with the transposing phage Mud1(Amp, lac) (Casadaban & Cohen, 1979). One out of 50 mutants, strain H5445, did not produce the bactericidal activity.…”

In VivoCloning of Arylsulfatase-Tyramine Oxidase Genes inrecStrains ofKlebsiella aerogenes

“…1 "'3) This property and the development of the transposon Mu dl(Apf lac) for fusion of genes 4 ) indicate that the Mu genomes and RP4: : Mu plasmid should be very useful for in vivo genetic engineering.…”