Enhanced yeast one-hybrid assays for high-throughput gene-centered regulatory network mapping

The authors describe the enhanced yeast one-hybrid platform for large-scale screening of protein-DNA interactions and test its performance by mapping Caenorhabditis elegans gene regulatory networks. Also in this issue, Hens et al. describe an alternative platform for this purpose and apply it to screen for transcription factor–DNA interactions in Drosophila melanogaster. A major challenge in systems biology is to understand the gene regulatory networks that drive development, physiology and pathology. Interactions between transcription factors and regulatory genomic regions provide the first level of gene control. Gateway-compatible yeast one-hybrid (Y1H) assays present a convenient method to identify and characterize the repertoire of transcription factors that can bind a DNA sequence of interest. To delineate genome-scale regulatory networks, however, large sets of DNA fragments need to be processed at high throughput and high coverage. Here we present enhanced Y1H (eY1H) assays that use a robotic mating platform with a set of improved Y1H reagents and automated readout quantification. We demonstrate that eY1H assays provide excellent coverage and identify interacting transcription factors for multiple DNA fragments in a short time. eY1H assays will be an important tool for mapping gene regulatory networks in Caenorhabditis elegans and other model organisms as well as in humans.