Gene expression control, patterning and growth during development

During animal development, one single cell -the fertilized egg- give rise to a great variety of different tissues and organs. These cells have the same DNA sequence, however acquire different morphologies and functions depending on the set of genes they activate. The spatial and temporal regulation of gene expression is mediated by the binding of transcription factors (TFs) to discrete non-coding DNA sequences named cis-regulatory modules (CRMs) or enhancers. It has been estimated that the number of enhancers in an organism overpass by far the number of coding genes, being approximately the 40% of the total genome in humans. While we extensively know the genetic code that translates into proteins, the code that defines an enhancer and its activity pattern is still a mystery. One of the general questions we want to address is how the regulatory information that defines the spatio-temporal activity of an enhancer is encoded by the 4-letter alphabet of the DNA. We use the fruit fly as a model as it offers a powerful model system for analysing gene regulation, and has provided the foundation for much of what we know about development and how genes control organism pattern, shape and size.