ausblenden:
Schlagwörter:
Animals
Base Sequence
Binding Sites/physiology
Caenorhabditis elegans
Caenorhabditis elegans Proteins/*genetics/*metabolism/physiology
Fluorescence Polarization
*Gene Expression Regulation
Genes, Regulator/genetics/*physiology
Genes, Reporter/genetics
Green Fluorescent Proteins
Molecular Sequence Data
Oligonucleotides
Receptors, Cytoplasmic and Nuclear/*genetics/*metabolism/physiology
Response Elements/*genetics
Reverse Transcriptase Polymerase Chain Reaction
Saccharomyces cerevisiae
Sequence Analysis, DNA
Signal Transduction/physiology
Zusammenfassung:
Intracellular receptor DAF-12 regulates dauer formation and developmental age and affects Caenorhabditis elegans lifespan. Genetic analyses place DAF-12 at the convergence of several signal transduction pathways; however, the downstream effectors and the molecular basis for the receptor's multiple physiological outputs are unknown. Beginning with C. elegans genomic DNA, we devised a procedure for multiple rounds of selection and amplification that yielded fragments bearing DAF-12-binding sites. These genomic fragments mediated DAF-12-dependent transcriptional regulation both in Saccharomyces cerevisiae and in C. elegans; that is, they served as functional DAF-12 response elements. We determined that most of the genomic fragments that displayed DAF-12 response element activity in yeast were linked to genes that were regulated by DAF-12 in C. elegans; indeed, the response element-containing fragments typically resided within clusters of DAF-12-regulated genes. DAF-12 target gene regulation was developmental program and stage specific, potentially predicting a fit of these targets into regulatory networks governing aspects of C. elegans reproductive development and dauer formation.
