Glucocorticoids are insufficient for neonatal gene induction in the liver.

Glucocorticoids and their receptor (GR) play a key role in perinatal gene induction. In the liver, the GR is essential for the neonatal induction of a number of genes, including that coding for tyrosine aminotransferase (TAT). To assess the function of the GR in the perinatal period, we have compared the activity of two types of glucocorticoid responsive elements in transgenic mice; one is the Tat gene glucocorticoid-responsive unit (GRU), an assembly of numerous binding sites for transcription factors, including the GR; the other is a simple dimer of high-affinity GR binding sites (GREs).

Messenger RNA deadenylylation precedes decapping in mammalian cells.

In yeast, the major mRNA degradation pathway is initiated by poly(A) tail shortening that triggers mRNA decapping. The mRNA is then degraded by 5'-to-3' exonucleolysis. In mammalian cells, even though poly(A) tail shortening also precedes mRNA degradation, the degradation pathway has not been elucidated.

Sequence, structure and evolution of the ecdysone-inducible Lsp-2 gene of Drosophila melanogaster.

The Lsp-2 gene encodes a major larval serum protein (hexamerin) of Drosophila melanogaster. Transcription of Lsp-2 is controlled by 20-hydroxyecdysone. Here we report the analysis of the structure of the Lsp-2 gene including the adjacent 5' and 3' sequences.

In vivo footprinting of the interaction of proteins with DNA and RNA.

Analysis of the interaction of proteins with either DNA or RNA sequences by in vivo footprinting involves two steps: (i) the in situ modification of nucleic acids by the footprinting reagent and (ii) the visualization of the footprints. Ligation-mediated PCR (LM-PCR) procedures provide a level of sensitivity and specificity that is suitable for visualization of footprints of single-copy genes or low-abundance mRNAs in higher eukaryotes. In this article, we discuss several of the technical aspects of these multistep procedures that contribute to the quality of the results, particularly the parameters that affect the specificity and fidelity of the reactions: (i) the design of the primers, which is important to achieve optimal specificity; (ii) the choice of polymerases so that the amplified material represents faithfully the initial nucleic acid population; and (iii) the impact of the plateau effect within the PCR on the interpretation of the data.