fredreload

When you grow a tree, new sprout comes out, so the tree begins from age 0. The question I have about the limb is, does it start from progenitor cell that is already age 5, or progenitor cell of age 0 and quickly catch up to the current age of the lizard? I mean for a complete regeneration the age of the limb and age of the lizard has to match, that means something sped up the aging process for the limb

If I am a lizard at 5 years old, and my right arm limb is amputated, and I regenerate it all the way from progenitor cells, what is the age of this limb when it is fully regenerated?

This video says it all

Hmm, I'm making a comparison between microRNA and the transcription factors mentioned here by Shinya Yamanaka. He was able to revert any cell to stem cell by adding simply four transcription factors. Now microRNA is able to change gene expression for lizards by turning genetic switches on and off as shown here, which is essential for lizard's tail regeneration, I assume it applies for all lizard regeneration. Now lastly for amphibians, the regeneration forms a blastema at the wound site which consists of progenitor cells, or I think stem cells. So in short lizard can make stem cells with microRNA, human also have microRNA, and I speculate that it could also turn any cell into stem cell by changing the gene expression. So we study what these four transcription factors do, and we create an artificial microRNA that would revert cells to stem cells at wound site for our own regeneration P.S. What transcription factors do is essentially modifying gene expression too =/? I am not really sure. "Transcription factors perform this function alone or with other proteins in a complex, by promoting (as an activator), or blocking (as a repressor) the recruitment of RNA polymerase (the enzyme that performs the transcription of genetic information from DNA to RNA) to specific genes." P.S. Alright, after studying, transcription factors act as an activator or repressor for the the rate that a particular sequence appears on mRNA. MicroRNA can also be used for gene expression to see if it gets transcribed to RNA. Note that one is mRNA and the other is RNA so they are still different, I will look into the differences over Lunar Festival P.S. Here's a comparison between transcription factors and miRNA, this guy writes good

Well, it's all about personal preference, some prefer Asian girls, some prefer American girls, I prefer both being Asian

Right my question is kind of vague, if you are still interested at this point let me know, I think I can apply this to gene sequencing

So I was reading how specialized cell is reverted to stem cell with transcription factors, which are proteins. What I want to know is essentially how it "controlling the rate of transcription of genetic information from DNA to messenger RNA" as Wikipedia says. If someone can provide me some insight of this it would be cool, especially what it means by "rate of transcription". How does it differ from what microRNA does?

http://www.eurostemcell.org/stem-cell-videos-and-films

So as lizard regenerate tail. If I update my body at age 82 or later on a cell by cell basis going from specialized cell to stem cell then back to the same specialized cell it was except this time it is much younger over a one week period, have I achieved immortality? So for example, me at age 82 or later decided to update my body starting from the cell on my head, for each neuron I reset it back to stem cell, then back into the same neuron it was before, only this time it is much younger, possibly of age 30. Then I do the same for all other cells until it reaches my toe over a one week period, in which now all my cells are 30 years old, is immortality achieved? Theory, by reverting the specialized cell back to its stem cell state I speculate that these proteins essentially repaired all the oxidized damages in my cell. Now here is a confusing area, the entire body's cell should age at the same rate as I've pointed out in another thread. If my right arm is of age 82, I would assume that my left arm is also of age 82. If indeed they are programmed to age at the same rate, then it is possible to reverse this process and goes backward 82,81,80. But since I've never heard of such a case, I would assume that by reverting to stem cell they are capable of fixing all the damages done to the cell. Now that the stem cell is set, we can transform it back into specialized cell again. Only this time it is of age 30. I'm referring to the pluripotent stem cell, this is triggered by transcription factors, but I was wondering if the same thing can be triggered by miroRNA. Second question is whether the actual damage to the specialized cell is repaired. Lastly I need to age the cell back to 30 years old, for the lizard case I would guess that the age of the tail regenerated is the same age as the lizard currently is in. I would like to know if this time frame can be controlled.

Is there a similarity between these four proteins and microRNA?

It both takes miRNA for lizard and human but why's human's inferior in regeneration?

P.S. Or hack the cell to regenerate itself for eternal youth P.S. What I should be asking is what turns on the gene expression at the wound site and how it is controlled, gene expression = convert to stem cells

Summary: Lizard revert cells at wound site to form a blastema, which is kind of like the lizard stem cells. Humans might/might not revert cells at wound site to form stem cells, but reverting cell to stem cell only take 4 genes P.S. So we can copy the lizard's regeneration technique and see what triggers the cells at the wound site to dedifferentiate and form our own type of stem cells, inspired by X-Files

As they've pointed out, the regeneration mechanism has to do with metabolism, like eating spicy food to induce metabolism for old people I dunno, maybe at certain age it's beyond repair? Beats me P.S. Hmm, but any cell can be reset back to its stem cell state though, here

Hmm, here is a study on regeneration of lab rat I was talking about. I was thinking it also applies to human, that by switching on and off certain genes allow limb to regrow and organs to repair. Yes it only applies to mouse 5 weeks and younger and it does not work for organs at this point, but humans might be able to do the same. Once you switch on the genes just do a full body update and you are good as new, theoretically speaking.

Well alright, as long as it looks like a hand and it's useable, the DNA contains a structure of how our body should look like, why do you think the tail looks like a tail and a finger looks like a finger when regenerated, the DNA knows it. The trick is to hack the cell and have it think it should regenerate P.S. I've read somewhere that by inhibiting a particular gene have helped the lab rat regenerate limbs, but that also increases the chance for cancer P.S. I also don't think how the regenerated limb would differ by much, I think the regeneration process just needs some fine tuning P.S. I don't know about memory though, how brain heals

Alright so we've all heard people growing back their cut finger with cellular matrix or amphibian with limb regeneration. Now assuming a limb is amputated, how does the body knows what structure it should grows back? For instance if I am missing my middle finger, it will have to grow back with the exact same length and size without missing a single cell(let's assume scar tissue is not the case). Now let's say I want to trigger a particular cell to renew itself without having a wound, it should also possible. All wounds heal, so it should be possible to trigger the entire body to recover from a wound, without having a wound. Now what is left is the strength of such regeneration, lizard does it by de-differentiating the cells. There is also the age of the cell. If the lizard is 5 years old, the regrown limb is also 5 years old but not of age zero. Once we get these two factors under control, we should be able to renew any part of our body as we please. All we need is to pretend that a wound occurs at a particular place and have the cell de-differentiate and renew at that spot. What do you think? P.S. This is assuming all wounds regenerate

Hmm right my question is that, we agree at embryonic stage if we swap the DNA of the zygote it can become anything. But after the zygote stage, let's say the cells stops differentiating as a dog body. Can it still turn into a bear? I know our DNA is constantly replicating, but from a dog to a bear, the dog needs to gain a few hundred pounds here. That means every cell needs the fundamental ability to replicate a stem cell and differentiate it into bear parts. So then I got the idea that if you got a block of stem cells(the size of a bear), you can change the stem cells' gene expression and sculpture it into a bear. As for the age of this being? Haven't got there yet P.S. I mean even for cancer cells I don't think the cancer cells differentiate I missed your post lol, does the tail begin to regenerate as lizard stem cells or do they replicate from bone and skin cells? I heard the lizard's DNA is twice as long as ours P.S. Wait that means it's possible, because DNA knows your shape you grow into in order to regenerate a tail or a limb hmm. Instead of healing a wound you turn normal cell into stem cell to grow into a bear, some type of link? P.S. You signal the entire body to do a repair

Let's say you modify every single DNA of a dog to the DNA of a bear, does the dog grows into a bear? I'm thinking it is possible, unfortunately I've never heard of growing an extra arm out of the body, not even through Crispr/Cas9. I'm saying it in the post-zygote stage P.S. If not we'll have to rely on stem cells since it is capable of differentiating, rather than growing it from scratch it's more like sculpturing

Thanks for the reply

Well then, something tells me that cell differentiation has nothing to do with DNA protein production but with gene expression. Does the cell differentiate during replication stage and does it have anything to do with protein production, I'm confused on this one Possible answer: 1. Cell type is capable of changing from one type to another muscle->bone through protein production ( I don't see this happening though it's always muscle->stem cell->bone or stem cell->bone) 2. Cell type is defined during replication, zygote->blastomere, cell differentiation occurs during replication. Part of the DNA works for differentiation, another part works for protein production after it is set? (I don't see how part of the DNA is for gene expression, then another part is for production) P.S. Ultimately something is governing the change in gene expression, well they call it epigenetics

It looks really cool, looks like a portal or some sort, got any explanation for it ? On another note my equation becomes (x+y)(x-y) on top and bottom, which looks like a saddle

Hi Sensei, can you clarify on this one? Did you take the derivative or something? I know my equation becomes z=1, I'm just not sure why that is the case. If you take a look at z=(x+y)/(x-y) it looks like a spiral, so how come a spiral multiplies by another spiral becomes z=1? Also get me a chart on x-y=z, many thanks

So this is an equation I found with interesting properties. Pretty much x+y=z and x-y=z are linear equations of 2 equations 2 unknowns. If you solve for this equation you get x=z and y=0. Now I haven't got a chart for x-y=z, Google shows the x+y=z chart but not the other one, if you have it please show me. Now for z=(x+y)/(x-y) it generates an interesting chart in google, same goes for z=(x-y)/(x+y). I'm not sure if they are off by 180 degrees or simply upside down. Now when you multiple the two together you get z^2=1 which is z=1 not z=0. This seems to be an interesting property and if someone can give me an explanation on this it would be cool. To sum up: 1. Get me a chart for x-y=z 2. z=(x+y)/(x-y) and z=(x-y)/(x+y) looks interesting, when you multiply them together you get z=1, why is that and what does that mean?

Hmm, no unique solution noted