Genetic networks in development

    Coordinators: Sean Carroll (Wisconsin) and Lewis Wolpert (UCL).
Embryonic development is governed by a complex spatio-temporal process of differential gene expression. This process executes a developmental program “hardwired” in DNA. The program involves the interpretation of the external signals: the morphological gradients and interactions with other cells. There is now a great deal of information identifying signals and transcription factors responsible for the determination of cell fates and hence of the spatial organization of the embryo. There is also a growing number of dissected and analyzed cis-regulatory modules detailing the interactions of transcription factors with DNA. While multitude of fundamental mysteries (e.g. role and regulation of chromatin structure) remain it appears to be fruitful to make attempts at synthesis. The challenge would be to develop a system-level approach which could integrate the signaling and transcription control networks and would connect the molecular level description of development on one side with the engineering concepts such as adaptive and robust control as they may apply to biology, on the other.
The mini-workshop will address developmental phenomena largely on the example of the fruit fly Drosophila. Below is a partial list of topics and questions to be addressed by the mini-workshop:
 Generation and interpretation of morphogen gradients
 Signaling pathways (e.g Dpp, Wg, HH, Notch). Combinatorial use of different signals in different developmental stages.
 Organization of complex promoters which control programmed transcription of genes. Combinatorial control of gene expression (by transcription factors).
 Robustness and size compensation of morphogen gradients. Origin of stability of developmental patterns with respect to variation in the levels of various signals. Role of positive and negative feedback loops which modulate the response and buffer the variations.
 Genetic networks in development: modeling approaches.
 How does the regulatory network underlying development evolve? What are the sources of diversity?.

Preliminary schedule: