Zebrafish Regenerative Ability May Lead To Help In Humans

esocid tips us to news out of Duke University Medical Center, where researchers have discovered a type of microRNA that is related to the ability of zebrafish to regenerate lost or damaged organs. This is the result of a study initiated after it was discovered that zebrafish were able to recover from "massive injury" to the heart through their own regenerative biology. The scientists hope to be able to use this information to bring about similar healing in humans. Zebrafish have also been helpful in cancer research. "In zebrafish, one or more microRNAs appear to be important to keep regeneration on hold until the fish needs new tissue, the Duke researchers say. In response to an injury, the fish then damp down levels of these microRNAs to aid regrowth. Poss and many other cell biologists believe that mammals may have the same tissue regeneration capability as zebrafish, salamanders and newts, but that it is locked away somewhere in our genome, silenced in the course of evolution."

Re:wouldn't get my hopes up

[gravesb]

Exactly. There must be some evolutionary reason to turn it off, as it seems that this gene, in and of itself, would lead to sturdier off-spring, and thus propagate. It would be interesting to know why it got turned off, though. Rampant cancer, maybe?

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Homeotherms

[overshoot]

Rampant cancer, maybe?

That would be my guess. There's a good bit of research where they tinkered with mouse genes to accelerate or slow telomere erosion, and found that the natural mouse is pretty close to the maximum lifespan possible. Faster erosion causes the mice die of old age sooner, but slower erosion results in more cancer deaths.

Regeneration may well have similar costs. Since all of the natural regenerators are poikilotherms, I would speculate that their overall lower metabolic rate has less risk of cancer. Giving up regeneration may well be the price we pay for warm blood.

Re:Can we grow our heads back?

[foobsr]

where someone loses their head and an autodoc manages to grow one back

Hmm ...

Quote: "But they got him into the autodoc anyway. It was a puppeteer-shaped coffin, form-fitted to Nessus himself, and bulky Puppeteer surgeons and mechanics must have intended that it should handle any conceivable circumstance. But had they thought of decapitation?

They had. There were two heads in there, and two more with necks attached, and enough organs and body parts to make several complete puppeteers. Grown from Nessus himself, probably; the faces on the heads looked familiar.
From Ringworld, by Larry Niven."

CC.

Speed

[KillaGouge]

I always though it was because that it is simply faster and easier to let the body scab over the wound then to try to let the internal structure regenerate. So the human body developed the scabbing ability so that humans who did get injured could quickly escape whatever injured them.