Scientists Demonstrate Mammalian Regeneration Through a Single Gene Deletion

Post by arethuza » Thu, Jan 13, 2011, 9:17 AM UTC

chc wrote: post #7

Zak wrote: post #2

I think an important question to research here is why p21 evolved in mammals. The article says knocking it out doesn't appear to increase cancer rates, which would have been my first and only guess.

My guess would be that regeneration is too big a drain on the metabolism. Compared to the animals with that ability, mammals have positively ridiculous energy needs already. It may be that better healing from wounds is not sufficiently useful to make up for the strain that the healing itself entails.

Post by pygy_ » Thu, Jan 13, 2011, 11:41 AM UTC

6ren wrote: post #13

pygy_ wrote: post #11

Earlier quoted context omitted.

Google? If you follow the link at the bottom of the article will lead you to the PNAS paper. You'll learn that the mice strain is called MRL[1]. It can regenerate its ears, cartillage[2], cardiac muscle after cold-induced lesions[3] but sadly not after infarction/reperfusion[4] and digits (to some extent, in neonate mice)[5]. There may be more. [1] http://www.pnas.org/content/107/13/5845.full [2] http://www.eurekaler…

I expect the full effects are not very dramatic, else it would have been noticed earlier, since MRL are commonly used in experiments. I find it reassuring that this unknown thing was right on our doorstep, and it makes me wonder what other amazing discoveries are just out of reach (or even within reach...) The world is more complex than we see; all we need do is look (a lot...) - There is more in heaven and earth tha…

Post by btilly » Thu, Jan 13, 2011, 1:47 PM UTC

ckuehne wrote: post #10

srean wrote: post #5

Earlier quoted context omitted.

To survive natural selection the gene must give the animal some reproductive advantage. I can understand that promoting longevity beyond the reproductive stage of one's life cycle affords no such benefit. But one still has to account for the fact that the lack of the gene appears to increase the survivability in the reproductive pahse as well. Something more must be going on.

Strictly speaking, it must give the _gene_ a reproductive advantage, not necessarily the animal. Often, these two advantages are aligned. But they need not be. This is the case in kin altruism. And this is also, why "promoting longevity beyond the reproductive stage of one's life cycle" affords sometimes very much such benefits. Example: grandparents can help raising their children's children (and their children's ch…

Post by ckuehne » Thu, Jan 13, 2011, 2:15 PM UTC

btilly wrote: post #16

ckuehne wrote: post #10

Earlier quoted context omitted.

Strictly speaking, it must give the _gene_ a reproductive advantage, not necessarily the animal. Often, these two advantages are aligned. But they need not be. This is the case in kin altruism. And this is also, why "promoting longevity beyond the reproductive stage of one's life cycle" affords sometimes very much such benefits. Example: grandparents can help raising their children's children (and their children's ch…

It should be noted that the difference is much more extreme for ants than it can be for mammals due to a genetic quirk where a female ant shares 50% of her genes with her children and 75% with her sisters. (Therefore having more sisters is better than having children.)

Post by JoeAltmaier » Thu, Jan 13, 2011, 3:12 PM UTC

DavidSJ wrote: post #19

lotusleaf1987 wrote: post #4

Earlier quoted context omitted.

Maybe somehow it speeds up the system of evolution by keeping life expectancies shorter, thereby increasing turnover (death and new births)? I have no clue just throwing that out there.

Individual organisms don't work for "the system of evolution"'s benefit. They work for themselves.