Genomic analysis of control of cell type

Abstract

In mammalian development, a single fertilized egg grows into a complex organism, comprised of organs and tissues made up of hundreds of different specialized cell types. All of these cells contain the same genome, but express distinct sets of genes and proteins, which give the cells their specialized functions. Understanding how this process occurs is one of the fundamental goals of biology. Research using new technology for high-resolution genome-wide location analysis and gene expression profiling has allowed characterization of the transcriptional regulatory circuitry of cells in unprecedented detail. From this research emerges an improved understanding of how these cells work, how they malfunction in disease, and several general principles. This thesis describes several studies designed to understand the transcriptional regulatory circuitry of three different medically important cell types; embryonic stem cells, regulatory T cells and MLL leukemia cells.