Among the many potential sites of gene regulation, 79 were predicted to be definitive new regulatory sites. The investigators also discovered 43 new genes and determined that 515 suspected genes are not genes at all. The findings revised the estimated number of genes in the S. cerevisiae genome from 6,331 to 5,773.
"This is the first step in understanding the gene-regulation network in a simple cell," says principal investigator Mark Johnston, Ph.D., professor of genetics and interim chair of genetics. "This work also will provide guidelines for analyzing the regulatory network of human cells, which will be a much more complex task."
Regulatory sequences are important, Johnston notes, because they are the basis of development. For example, a liver cell differs from a brain cell not because they have different genesboth cells have the same set of genesbut because of the genes they use. And thats determined by the regulatory sequences that activate one set of genes in the liver and another set in the brain. A variety of diseases, including cancer, are caused by problems in gene regulation.
Identifying gene regulatory sites is not easy, however. These regions serve as docking sites for DNA binding proteins that turn the gene on or off. They lack the typical DNA patterns that help scientists recognize the body of the gene, which contains information about the structure of a protein.
Johnston and his colleagues compared the genomes of S. cere
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Contact: Darrell E. Ward
wardd@msnotes.wustl.edu
314-286-0122
Washington University School of Medicine
29-May-2003