London, Nov 4 A new study of zebrafish has put scientists in the U.S. a step closer to unravelling the mechanism behind body part regeneration, a power possessed by some animals but not humans.

The search for the holy grail of regenerative medicine-the ability to "grow back" a perfect body part when one is lost to injury or disease-has been under way for years, yet the steps involved in this seemingly magic process are still poorly understood.

Some animals like earthworms, crayfish and tadpoles perform this miraculous feat effortlessly, reports The Telegraph.

Scientists know the process involves mechanisms normally found in developing embryos, but are still not clear about what they are.

Now, the new study on zebrafish has helped scientists identify a key cellular pathway that appears to trigger regeneration by switching on certain genes.

"This is the first real molecular insight into what is happening during limb regeneration," said lead author Dr Scott Stewart, from the Salk Institute in La Jolla, California.

"Until now, how amputation is translated into gene activation has been like magic. Finally, we have a handle on a process we can actually follow," he added.

The researchers focused on a biological "priming" system that keeps embryonic cells ready to become whatever kind of tissue they are destined to be.

They found a particular enzyme, or biological catalyst protein, seemed to be crucial to the process.

The researchers now plan to take a closer look at the enzyme and find out how it operates.

They also intend to determine how the genes are switched off again once regeneration is complete. (ANI)