BACKGROUND Quantifying plant gene expression by flow cytometry (FCM) would allow multidimensional cell-parameter analysis on a per-cell basis, thereby providing insight into the cellular mechanisms of plant gene regulation. Here we sought to establish quantitation by FCM of plant hormone (abscisic acid, ABA)-inducible green fluorescent protein (GFP) expression and to compare the method directly...

The arabinose-inducible promoter P(BAD) is subject to all-or-none induction, in which intermediate concentrations of arabinose give rise to subpopulations of cells that are fully induced and uninduced. To construct a host-vector expression system with regulatable control in a homogeneous population of cells, the araE gene of Escherichia coli was cloned into an RSF1010-derived plasmid under cont...

Photodynamic therapy (PDT) is a promising cancer treatment involving the administration of a tumor-localizing photosensitizer followed by the photochemical generation of cytotoxic singlet oxygen. PDT elicits strong transcriptional activation of a variety of genes including stress response genes belonging to the glucose-regulated protein (grp) family. Oxidative stress and hypoxia can activate GR...

We have characterized two new transgenic Xenopus lines enabling transgene expression using the Tet-On inducible system. An inducer line expresses the doxycycline- (Dox-) activated transcription factor rtTA under control of the ubiquitous promoter CMV. A responder line enables Dox-inducible expression of a dominant positive thyroid hormone receptor via a tetracycline responsive transgenic promot...

The adenovirus EIa-inducible early EIIa (EIIaE) promoter is comprised of several sequence elements essential for constitutive and induced expression. We report here the purification of the host-cell factor that interacts with the major upstream element of this promoter, extending between positions -90 and -70 with respect to the main EIIaE cap site and exhibiting enhancer properties. The purifi...