The scrA gene coding for sucrose EnzymelI of the phosphoenolpyruvate dependent phosphotransferase system previously isolated from Streptococcus mutans was fused in vitro to the promoterless lacZ" gene to monitor the expression of the scrA gene. The scrA :: lacZ gene fusion was introduced back into S. mutans GS-5IS3 by two independent transformation procedures involving either linear or plasmid ...

A new mutation in Escherichia coli, designated gcvA1, that results in noninducible expression of both gcv and a gcvT-lacZ gene fusion was isolated. A plasmid carrying the wild-type gcvA gene complemented the mutation and restored glycine-inducible gcv and gcvT-lacZ gene expression. These results suggest that gcvA encodes a positive-acting regulatory protein that acts in trans to increase expres...

J. Croce, G. Lhomond, C. Gache (France) Coquillette, a sea urchin T-box gene of the Tbx2 subfamily, is expressed asymmetrically along the oral–aboral axis of the embryo and is involved in skeletogenesis 561 S.J. Gaunt, D. Drage, A. Cockley (UK) Vertebrate caudal gene expression gradients investigated by use of chick cdx-A/lacZ and mouse cdx-1/lacZ reporters in transgenic mouse embryos: evidence...

We report the developmental regulation of a lacZ reporter transgene fused to the promoter region of the human keratin 6a gene. In mouse embryos, the transgene is expressed in the periderm (the outermost layer of embryonic epidermis), as are the endogenous keratin 6 alpha and beta genes. A subset of periderm cells, localized to temporary epithelial fusions, is known to contain keratin 6 protein,...

By fusing the transcriptional and translational start signals of lacZ to envZ, we have obtained high-level synthesis of a truncated EnvZ protein (EnvZ115) in which the first 38 amino acids of EnvZ are replaced with the first 8 amino acids of LacZ. Using this construct, we have partially purified the EnvZ115 protein and demonstrated that this protein can be phosphorylated in vitro. We suggest th...

Implants of mammary glands from a single mammary fat pad in a H253 transgenic female mouse heterozygous for a lacZ-labeled X chromosome were analyzed at various time points following transplantation into the epithelium-cleared mammary fat pads of immune-compromised mice. The results show that the lacZ-marked X chromosome, demonstrated by nuclear-associated X-gal staining, was confined to a sing...

Cell-to-cell communication mediated by the evolutionary conserved Notch signalling pathway regulates cell fate decisions and patterning in various tissues in diverse organisms (Artavanis-Tsakonas et al., 1995, Science 268, 225-232). Signalling between neighboring cells is transduced by binding of DSL and Notch proteins which interact as ligand (DSL) and receptor (Notch). Mouse Delta1 (delta-lik...

Tn5 lacZ mutants were generated with Azospirillum brasilense 7030 by mating that strain with Escherichia coli strains carrying suicide plasmid pCIB100 or pCIB110. Kanamycin-resistant Azospirillum colonies were obtained with a maximum frequency of 10(-6) per recipient cell. The potential of Tn5 lacZ for random transposon mutagenesis coupled to transcription analysis in A. brasilense 7030 was dem...

Neuronal PAS domain protein 2 (NPAS2) is a basic helix-loop-helix (bHLH) PAS domain transcription factor expressed in multiple regions of the vertebrate brain. Targeted insertion of a beta-galactosidase reporter gene (lacZ) resulted in the production of an NPAS2-lacZ fusion protein and an altered form of NPAS2 lacking the bHLH domain. The neuroanatomical expression pattern of NPAS2-lacZ was tem...

To understand the mechanisms regulating the tissue non-specific alkaline phosphatase (TNAP) activity during development, we characterized cis-transcriptional regulatory elements. In embryonic cells and tissues, TNAP expression was driven preferentially by the exon 1A (E1A) promoter, one of the two promoters previously defined. Transcriptional activity of E1A promoter was up-regulated by retinoi...