their lives; frogs, which can only regenerate new limbs during a limited period during their fetal development; and chicks, which cannot regenerate limbs.
To manipulate animals' regeneration ability, the Salk researchers used inhibitory and excitatory factors for Wnt signaling, which they delivered directly to the remaining bulge after they cut a limb from the experimental embryos.
In adult zebrafish and salamanders, they found that blocking Wnt signaling with the inhibitory factors, prevented normal regeneration. And, conversely, when they treated mutant adult zebrafish that cannot regenerate with the excitatory agent, the ability to regenerate their fins was rescued, Belmonte says.
Using an inhibitory agent on frogs before the regeneration-enabled developmental window closed resulted in loss of that ability, but treating them with the excitatory agent after they had lost their regenerative capacity induced new limb growth.
They then performed the key experiment, successfully testing the ability of an excitatory factor to produce limb regeneration in chick embryos. "The signal restarted the process, and genes that were involved in the initial development of the limb were turned back on," Belmonte says. "It is simply amazing."
The procedure was tricky, however. Belmonte noted that if Wnt signaling is activated for too long of a period in these animals, cancer results. "This has to be done in a controlled way, with just a few cells for a specific amount of time," he says. "The fact is that this pathway is involved in cell proliferation, whether it is to generate or regenerate limbs, control stem cells, or produce cancer."
RI Page: 1 2 3 Related medicine news :1
. Regeneration of muscle2
. Limb Regeneration In Humans: A Future Possibility3
. Research Throws Light On Regeneration of Hearing Cells4
. Oncomodulin- Path To Nerve Regeneration5
. Growth Factor Aids in Regeneration of Heart Blood Vessel6
. Regeneration After Spinal Cord Injury7
. Rescuing Injured Hearts by Enhancing Regeneration8
. Vanderbilt Performs States First Stem Cell Heart Regeneration Therapy9
. UF Launches Project to Bridge the Regeneration Gap10
. Liver Regeneration may Be Simpler Than Previously Thought11
. Liver Regeneration Unplugged