Final Report Summary - MORPHOGEN (Morphogenetic growth control by time derivatives of signaling)
To achieve this, we undertook an approach at the interface between physics and biology. We develop a model based on theoretical physics and used this framework to design experiments which allow us to measure properties of the morphogen such as its diffusion and its destruction. We also looked at the trafficking inside cells to determine the precise route of spreading through the cells in the tissue. Once we understood the trafficking route we were ready to tackle the key question: what is that changes in the cells so that the morphogen reach can be longer and longer as the tissue grows. We found that what changes is the capability of cells to recycle the morphogen molecules that they have uptaken. We then study the machinery (the factors) behind those changes. These factors are molecules in the intercellular space, so called heparane sulfate proteoglycans and their binding proteins.
This was studied first in the wings of flies. We then looked in the pectoral fins of fish. There we found that the same principles apply. What we studied in the wings is not an oddity of flies, but seem correspond to universal principles during embryogenesis and development that are conserved from insects to vertebrates.