"How do hearts, wings or flowers get their shape?" asks Professor Enrico Coen from the John Innes Centre. " Unlike man-made things like mobile phones or cars, there is no external hand or machine guiding the formation of these biological structures; they grow into particular shapes of their own accord."
"Looking at the complex, beautiful and finely tuned shapes produced by nature, people have often wondered how they came about. We are beginning to understand the basic genetic and chemical cues that nature uses to make them."
So, how does this happen? In a recent breakthrough, funded by the Biotechnology and Biological Sciences Research Council (BBSRC), scientists on Norwich Research Park have begun to answer this question, using the snapdragon flower as a convenient subject.
In the snapdragon flower, two upper petals and three lower petals form defined shapes, precisely coming together to form a tube with a hinge. When a bee lands on the lower petals the hinge opens up the flower, allowing access to nectar and pollen. The shape of petals is known to be affected by four genes, but precisely how these genes work in combination to produce the specialised flower shape, and how this shape evolved, was unknown. The same is true for many organ shapes, but the snapdragon flower provides a good system to study this problem, as it is genetically well characterised and growth can be followed at the cellular level.
By changing when and how the genes involved in growth are turned on and off, and tracking how these changes affect the development of shape over time, the researchers got pointers as to how genes control the overall shape. They then used computer modelling to show how the flower could generate itself automatically through the application of some basic growth rules.
A key finding was that genes control not only how quickly different regions of the petal grow, but also their orientations of growth. It is as if each cell has a c
|Contact: Andrew Chapple|
Norwich BioScience Institutes