28 Sep 2012
Departments of Statistics, Ecology & Evolution; Molecular Genetics & Cell Biology
University of Chicago
Two central questions in biology are, first, the control of biological form by DNA sequence, and second, understanding the basis of the remarkable resilience of biological systems to perturbations of all kinds, a phenomenon known as "robustness" or "canalization". I will describe some attempts to answer aspects of these questions using the early Drosophila embryo as an experimental system together with a stack of three theoretical models related by coarse-graining steps. I will emphasize the finest scale problem, control of transcription by regulatory sequences. After considering some fundamental issues regarding theories about this phenomenon, I will explain how these issues were addressed in a specific theory. This theory provides an explanation of why eve stripe 2 enhancers from many species, bearing partial or even no homology to to the melanogaster enhancers, can nevertheless drive expression identical or very close to that driven by the melanogaster enhancer for that stripe. If time permits, I will also explain how two additional models, each obtained by specific approximations to the model of transcriptional control, can be used to solve certain specific problems in embryonic error correction.
current theory lunch schedule