Cells

Okay, so apparently once again I'm going to talk about biology. So just bare with me.

First of all. I assume you know how cells specialize. At first when a person is just a blob of cells they're all the same and can come what ever cell type, but then they change and can only become a handful of different kinds of cells, until they finally become some cell type, and then there's no going back. This I assume you know, because it is very basic biology.

On a more accurate level, that you might not know, is how this happens.

So, there are a lot of different genes in the DNA of a human (or any other creature on Earth), and the reason that cells are different is that there is a different set of genes expressed in those cells.

How the expression of genes is controlled is very briefly explained like this:
There are a lot of proteins that regulate the expression of genes. Those proteins bind to the DNA, and can either inhibit the expression of that gene, or promote it. There are usually many proteins regulating a single gene, and the proteins can be spread out along a long part of the DNA, on either side of the place where the gene starts. A single protein can also work in regulating more than one gene. Anyway, those proteins together work to regulate which genes work in a certain cell and which don't.
Also, the DNA is packed around some proteins. All of it, more loosely or less, depending on the place. And the genes that aren't needed in the cell at all can be packed tightly out of the way.

Ok, so that's a very brief explanation of that I read fifteen pages of yesterday.

Anyway, this is the cool part:
It is possible, if you have the right equipment, to take the DNA and change the proteins that regulate the expression of genes. And once you take away the proteins that were there, and add the right combination or other regulatory proteins, the cell changes its cell type.
You can make liver cells into perfectly functional nerve cells.
I mean, it's that simple. The right combination of proteins, and that's it.

Of course, doing this is probably practically not quite that simple. Especially since you first have to know which proteins are required in a certain type of cell.

But still, it's crazy.

It also means that it's possible to turn any kind of cell into a stem cell.
It's possible to make stem cells.

Also, because it's possible to turn a cell into a different kind of cell, it's possible to make completely new tissue from someone's own cells.

I've understood they've been working on that. Actually in last month's Tiede there was an article about this. It's not possible yet, but probably in the future. To grow extra organs. For people who need them. From their own cells.
Just like that. No more immune suppressants after transplants.

It's just that I remember being taught that cells differentiate, and then if you want stem cells you need to find stem cells. And now...

And all that just by changing...

Ohmygod why are they singing!?

Sorry, watching Buffy while writing.

And all just by changing some proteins in a cell. In reality it's all so very, very complicated if you get into any detail, but at the same time it's so... simple.

The world is pretty amazing.


~matu