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Our closest worm kin regrow body parts, raising hopes of regeneration in humans

washington.edu

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Re: Our closest worm kin regrow body parts, raising hopes of regeneration in humans

#51

Post by shripadk »

MichaelBurge wrote: post #6

It seems like the cells in a worm are relatively position-independent, so they can regrow using only local information. If you lopped off your leg, a cell would need to know how much of the leg to regrow to get to the kneecaps, how much to grow to get to the foot, or more. If you chopped off a foot, it seems hard to know which parts need to be regrown and which don't. There's a lot of complexity in a foot.

I remember seeing a story on BBC a while ago about how one guy, who lost the top portion of his finger while operating a toy in his hobby shop, was able to regrow it completely. It only took 4 weeks to regrow, including the nails, fingerprints et al., exactly as it was before using extracellular protein from pig bladder. Here is a link to the story: https://www.youtube.com/watch?v=NEnLK0oJCa8

Re: Our closest worm kin regrow body parts, raising hopes of regeneration in humans

#52

Post by Jtsummers »

avodonosov wrote: post #26
jonknee wrote: post #15

Earlier quoted context omitted.

> If somehow we can stay alive as a species long enough we very well might be able to discover the secret to regeneration and immortality in some way. Hopefully we won't figure that out before we figure out how to not overcrowd Earth.

Forbid procreation for those who chosen immortality. If you decided to spawn children, then free space for them - die. (Or go cryopreservation and be kept in a small box occupying little space. In this case you and your decedents can live in turns: they live for one century while you sleep frozen; next century other way around).

May want to read "2 B R 0 2 B" by Vonnegut.

Re: Our closest worm kin regrow body parts, raising hopes of regeneration in humans

#53

Post by andars »

kazinator wrote: post #43

"Why can't we break off half a microchip, and then rebuild the missing part so it works again? We have all the mask artwork and silicon wafers ..."

This doesn't strike me as a reasonable analogy.

1) Microchips don't grow autonomously in the first place, unlike organisms.

2) The article's point is that not only do humans have the "mask artwork and silicon wafers", but also the genes that other organisms use to regenerate portions of their body. A closer equivalence would be "the instructions on how to rebuild the missing half of the microchip from what remains".

Re: Our closest worm kin regrow body parts, raising hopes of regeneration in humans

#54

Post by traviswingo »

badminton1 wrote: post #29
traviswingo wrote: post #9

I'm a huge believer that humans can cherry-pick the best traits of many different species and apply them to ourselves. It might sound like science fiction right now, bit give it time and we humans will have unlocked some crazy things that we claimed to be "impossible." It's always impossible until it's done. And to be honest, I think the second something is thought of, it becomes possible. I live for this shit.

Well, it depends what you consider to be "the best". If you have watched the olympics, you can see that different body types are better suited for different sports. A basketball player playing ping pong or viceversa? probably not very successful.

I meant things that pertain to longevity - like jellyfish that don't die but simply "restart" their lives, or regeneration. If you look at tardigrades, there is a lot that is possible that we cannot yet do. But yeah, I understand where you're going.

Re: Our closest worm kin regrow body parts, raising hopes of regeneration in humans

#55

Post by astrodust »

badminton1 wrote: post #36

Probably because limb regeneration wasn't a favored trait during our evolution. e.g: we managed to survive and be fertile without it. Rather than limb regeneration we evolved pain and fear to prevent losing a limb in the first place. A similar question would be why aren't fruit toxic so animals stop eating them? Because they pass their genes anyways. Rather than that, animals that were too good at eating fruit, destr…

Don't think that just because natural selection tended to favor a particular thing that it's necessarily a good thing.

Some sheep have the most ridiculous horns because of how they compete for mates. If, in some alternate world, those sheep became intelligent and lived in a civilized society where such a thing was no longer relevant the horns themselves might have little worth other than prestige. They serve no functional purpose.

Humans have survived in spite of our relative weaknesses. We've got a seriously screwed up head, nothing in there is oriented correctly, and parts of our body are on the verge of self-destructing even at the best of times. We were never intended by nature to live more than twenty years, everything past that is actually quite unnatural, as everything in your body starts falling apart at that point because from the perspective of natural selection taking place fifty thousand years ago you've either bred and done your duty, or you're dead weight.

There's a lot of mistakes in our DNA that time will correct, but we can always jump start that process by making a few tweaks today.

Re: Our closest worm kin regrow body parts, raising hopes of regeneration in humans

#56

Post by mhalle »

There was an interesting Science Friday segment on this topic back in August 2016:

http://www.sciencefriday.com/segments/a-hand-a-fin-a-gene/

A couple of comments made by the guests during the discussion (from memory):

* there is a theory that humans/vertebrates actively repress regenerative abilities,

* children under the age of about five have the ability to regrow cut-off fingertips,

* the genetic instructions for growing a hand (or fin) consist of the thumb and little finger, and the rest get interpolated.

Re: Our closest worm kin regrow body parts, raising hopes of regeneration in humans

#57

Post by marvy »

reasonattlm wrote: post #19

The interesting studies are all in zebrafish and salamanders, not worms. One of the more intriguing of the recent ones is this from last year, strongly reinforcing the theory that most species lost proficient regeneration due to evolutionary battles between cancer and aging. The greater question is perhaps why there are any proficient regenerators among the vertebrates rather than why we can't do it. https://www.ucsf…

That is sufficiently interesting to make me wish I could upvote it twice. But. What I really want to hear about is the opposite experiment. Take something that has ARF, and see what happens if you take it out.

Re: Our closest worm kin regrow body parts, raising hopes of regeneration in humans

#59

Post by mparlane »

Grishnakh wrote: post #28
meric wrote: post #3

Earlier quoted context omitted.

And perhaps some people might risk the chance of cancer to grow their body parts back.

Perhaps it could be turned on and off as needed: lose a finger in an accident, and take a drug to turn regeneration on. Grow your finger back in a week, and then take another drug (or stop taking the first drug) to go back to normal.

Your comment was either flagged or downvoted in to oblivion... I have vouched for it as I can't see any reason for either...

Re: Our closest worm kin regrow body parts, raising hopes of regeneration in humans

#60

Post by MichaelBurge »

cmdrfred wrote: post #21
MichaelBurge wrote: post #6

It seems like the cells in a worm are relatively position-independent, so they can regrow using only local information. If you lopped off your leg, a cell would need to know how much of the leg to regrow to get to the kneecaps, how much to grow to get to the foot, or more. If you chopped off a foot, it seems hard to know which parts need to be regrown and which don't. There's a lot of complexity in a foot.

This has to be a solved problem unless the womb offers some sort of telemetry.

In that case, the entire organism is forming. It can use techniques like forming the general structure before filling in the details. It could be that forming the general structure is carefully scripted by chemistry, while the details are mostly position-independent.

Bones can have their lengths determined by biological clocks that operate over years. Examples of clocks are hormone release cycles, which the rest of the body uses for signaling. But, a new leg wouldn't have access to the global clock, since it would've shut off if the affected parts are fully-developed.

Bones and muscles might have their final shapes partially determined by outside forces. The biggest one is gravity. It may be that people develop longer legs in space, or their spines don't develop correctly. A leg intended to be regrown on an adult might not have time to be shaped in this manner.

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