Researchers at Geneva university have demonstrated how the backbone of a foetus is formed. The process is driven by a molecular clock, which activates the two sets of genes that build up individual vertebra. The entire process takes only two days.
It's the first time scientists have been able to demonstrate how the genes concerned build the backbone. The process is the same for all vertebrates, and in humans takes place about three weeks after conception.
The research team's findings, published in the journal "Cell", reveal that a molecular clock controls the growth of the spine by sending out a signal which activates one set of genes. The signal is sent every 90 minutes.
Functions of the vertebrae
The team from the institute of zoology and animal biology found that the clock also helps to determine the type of vertebra by activating the other set of genes at the same time.
Individual vertebra correspond to different sections of the body, and must therefore be built accordingly. The second set of genes "decide" which of 30 different functions is given to each vertebra.
The scientific community already knew that these two sets of genes were responsible for building the spine, but until now nobody had shown that they work together.
The process helps to explain why members of a same species all have the same backbone. "If it is one and the same mechanism which helps build and differentiate the vertebrae, you have very few mistakes," said Denis Duboule, head of the Geneva team.
"If there were two different mechanisms, there would be far more opportunities for mistakes," Duboule told swissinfo. "But it also explains how mistakes do occasionally occur, because the two sets of genes are sometimes slightly out of sync."
Practical applications only in a few years time
Now that the mechanism is clear, the researchers have to tackle the question of why the backbone varies from species to species. "If you look at snakes, they can have up to hundreds of vertebrae with ribs. We have to find out why," said Duboule.
Practical applications of this basic research are still some way off.
"In maybe 15 to 20 few years, we may be able to develop therapeutic agents to counter genetic syndromes which involve this mechanism," Duboule told swissinfo. "But we might be able to improve diagnostic tools to prevent these syndromes."
swissinfo with agencies