We are often told that “there is no ID research published in peer reviewed journals“. I receive Nature E-Alerts in a number of biological research fields. Almost every time I read the abstracts and even the titles, or spend more time delving into the detail, I hear “Intelligent Design” silently screamed from the pages. Am I deluded, or do others hear it too? Here is a recent example.
Sharp boundaries of Dpp signalling trigger local cell death required for Drosophila leg morphogenesis Nature Cell Biology – 9, 57 – 63 (2006) http://www.nature.com/ncb/journal/v9/n1/abs/ncb1518.html
Morphogens are secreted signalling molecules that govern many developmental processes. In the Drosophila (fruit fly) wing disc, a specific transforming growth factor (Dpp) forms a smooth gradient and specifies cell fate. Neighbouring cells have similar amounts of Dpp protein, and if a sharp discontinuity in Dpp activity is generated between these cells, cell death is triggered to restore graded positional information. To date, it has been assumed that this selective cell death process is only activated when normal signalling is distorted.
We now show that a similar process occurs during normal development: rupture in Dpp activity occurs during normal segmentation of the distal legs of Drosophila. The sharp boundary of Dpp is the signal that induces the selective cell death required for the morphogenesis (crafting) of a particular structure of the leg, the joint.
Our results show that Dpp could induce a developmental programme not only in a concentration dependent manner, but also by the creation of a sharp boundary of Dpp activity. Furthermore, the same process could be used either to restore a normal pattern in response to artificial disturbance or to direct a morphogenetic process.