Briscoe and his group discovered a novel mechanism that allows cells to integrate the time of exposure and the concentration of the morphogen Shh to subsequently mount a graded response. In other words, different concentrations of the morphogen activate a signal within the receiving cell for different periods of times. Cells in turn respond to different durations of the signal by activating different genes and therefore becoming different types of nerve cells.
"The discovery that concentration is effectively converted into time is a major shift in our understanding of how a graded signal acts to regulate genes," stated David Wilkinson, Head of Genetics and Development at NIMR, in his nomination of Briscoe for the EMBO Gold Medal.
James Briscoe's contribution to the understanding of how cell identity is specified in a given spatial setting has established a new paradigm that may also apply in many other contexts. In addition to Shh, a number of other secreted molecules members of different protein families have also been implicated in acting as morphogens to pattern other tissues. "It is possible that other morphogens could use a similar mechanism to control cells, for example early in embryo development during gastrulation," explains the Gold Medal winner.
"James's discoveries have revealed general principles that may apply to many other contexts in which graded signals and downstream transcription factors control cell identity," confirmed David Wilkinson.
Robb Krumlauf, former Head of Division at NIMR who helped to recruit Briscoe to the institute, points out his outstanding qualities at the bench: "At NIMR James rapidly established an independent and creative line of research in his own group. His work is highly rigorous, hits the heart of a problem, and continues to be timely and of wide general interest."
|Contact: Suzanne Beveridge|
European Molecular Biology Organization