Scientists Regrow Chicken Wing

An anonymous reader writes "Unlike salamanders and lizards, most animals have lost the ability to replace missing limbs. But a research team in San Diego has been able to regenerate a wing in a chick embryo — a species not known to be able to regrow limbs — suggesting the potential for such regeneration exists innately in all vertebrates, including humans." From the article: "Manipulating Wnt signaling in humans is, of course, not possible at this point, Belmonte says, but hopes that these findings may eventually offer insights into current research examining the ability of stem cells to build new human body tissues and parts. For example, he said Wnt signaling may push mature cells go back in time and 'dedifferentiate' into stem-like cells, in order to be able to then differentiate once more, producing all of the different tissues needed to build a limb."

Comments

Sliding scale

[MichaelSmith]

From TFA:

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."

Turn it down to 0 and you eventually die of old age. Turn it up to 11 and you die of cancer. If the human equivalent can be found we may have a whole class of very old people who debate ways of achieving the right balance.

If something like this is under trial in 20 years or so I will definitely be giving it a go.

Re:Deevolution?

[RsG]

It isn't a question of it being an energy drain, it's a question of how long the injury affects you. If it's a choice between getting hurt then regenerating over a period of weeks (during which the wound will affect your ability to function), and getting hurt then healing with scarring over a period of days (thus shortening the vulnerable period), then the latter makes more sense for us. The former makes more sense for reptiles, who can go for weeks to months without food, which we obviously cannot. Remember that doing the job right takes time, whereas a quick and dirty fix does not.

Of course, in reality it probably isn't a clear cut either/or scenario, but more likely a spectrum ranging from one extreme to the other (faster healing versus complete healing). In that sense, we do regenerate (our wounds heal, don't they?), we just don't regrow lost limbs, or heal without permanent marks.

Re:Deevolution?

[Dunbal]

most of our genetic code doesn't actually *do* anything as far as we can tell

      Emphasis mine. Just because we don't know what "junk DNA" is for doesn't mean it's not useful. When we manage to build a cell without junk DNA and have it work perfectly, we'll be able to prove that there's no use to it. It might even just be there for padding, like the polystyrene pellets in a box. Just because you throw them out right away doesn't mean there's no use to them - they protect what you really needed to protect inside the box. The more junk you have, the more likely that mutation is going to happen in a "junky" area rather than the genes you actually need...