Regulating gene expression: surprises still in store

Understanding how genes constitute and contribute to the regulatory networks that result in phenotypic diversity is the major challenge of the post-genome era. Recently, it has been shown that major players in gene regulation can be identified by genome-wide linkage analysis of whole-genome gene expression profiles that were obtained in segregants from yeast strains. Surprisingly, these important elements in regulatory variation are dispersed across several gene ontology classes. Therefore, the regulatory role of transcription factors seems less than was previously anticipated.