Abstract

The question of how pattern is established during development continues to be one of the most fundamental problems in biology. While much attention has focused on static mechanisms such as the interpretation of morphogen gradients, it is becoming clear that the temporal dynamics of gene regulatory networks also contribute to pattern formation. In this pub talk, we will illustrate this point with two examples from Drosophila segmentation. These examples, drawn from our respective PhD projects, involve different tiers of the Drosophila segmentation cascade and contrasting modelling approaches, but converge at very similar developmental and evolutionary conclusions. First, Berta will describe how a quantitative, data-driven model of the gap gene network reveals how observed anterior shifts of posterior gap gene domains can be explained as the emergent property of an underlying “damped oscillator” regulatory mechanism. Next, Erik will describe how logical modelling of the pair-rule gene network reveals that these gap gene dynamics are in fact crucial inputs for downstream patterning processes. Finally, we will discuss how these findings help reconcile the simultaneous mode of segmentation seen in Drosophila with the ancestral, sequential mode of segmentation that is characteristic of most other arthropods.