But before engineers can make the leap to concrete technologies, research scientists must first uncover how underlying biological processes function.
Because cloning whole organs from single cells requires understanding the way that the embryo develops into an organism, scientists worldwide study how animals grow before they are ever born. Before cells gain an identity - as a blood cell or an immune cell - they can be turned into whatever specialized cell is needed.
Among those researchers are three UC Berkeley biologists, who conducted a study in Xenopus frogs published yesterday in the journal Nature. The findings began to answer long-held questions about the way cells move during embryonic development.
"We think it is important to see how we develop from an egg into an organism," said Richard Harland, a UC Berkeley professor. "There are two interesting aspects of development - producing the cells which later become tissues and the other side is that the cells have to arrange properly so that the organs and tissues form in the right place. The second is less understood, and is what we studied."
In vertebrates, one of the most important steps in the development of embryos is the origination of the gastrula, which has three germ layers and permits the eventual creation of tissues. If cells do not migrate properly during this stage, the undeveloped organism is doomed.
"During the formation of the gastrula, the embryo forms three layers," Harland said. "It is from these layers that all of the organs come from."
The UC Berkeley team studied the underlying controls governing the eventual formation of the gastrula, and found that the same control mechanism used in early development is also used in the later stages.
"We examined how the formation of the gastrula is controlled," Harland said. "We hope not only to understand gastrulation but also to start understanding other processes are at work at other times during development."
The UC Berkeley biologists found that the molecule dishevelled - long known to be involved in the very early stages of development - is a key regulator in the migration of cells to form the gastrula.
"We have identified a new cellular signalling pathway that has not been realized in vertebrates," said John Wallingford, a postdoctoral fellow and the study's lead author. "This allows us to start looking at a new mechanism by which cells can understand where they are in their environment."
In order to determine the way that the molecule works, the researchers deleted portions of the protein, which changes the way the whole molecule functions. They then studied what happened to the gastrula when the molecule was not functioning in its normal capacity.
"Dishevelled is clearly important for early development, but it is not known how important it is in vertebrate systems," Wallingford said. "When we manipulated the molecule, the Xenopus do not gastrulate correctly and the embryo does not have its normal shape. Instead of a long, thin tadpole, what you get is more circular."
Among those involved in the study was Kevin Vogeli, an undergraduate majoring in molecular and cell biology.
He could not be reached for comment yesterday because he is out of town at the national rugby championships being held in Florida.