3 minutes to precisely measure morphogen concentration
Morphogen gradients provide concentration-dependent positional information along polarity axes. Although the dynamics of the establishment of these gradients is well described, precision and noise in the downstream activation processes remain elusive. A simple paradigm to address these questions is the Bicoid morphogen gradient that elicits a rapid step-like transcriptional response in young fruit fly embryos.
a simple model based only on the cooperative binding of Bicoid is not sufficient to describe the spatiotemporal dynamics of early hb expression.
During development, the first thing that an embryo needs to know is the orientation of its body.
although our model is able to reproduce the fast dynamics of the process, it fails to reproduce the steepness of the boundary suggesting that a more complex approach is needed to capture the additional mechanisms involved.
This also raises the question of understanding how precision in the downstream processes required for embryo segmentation is achieved at the scale of the whole embryo.
Common Design 