![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
Here I am, back at school. It is hectic, but pleasantly so. I am taking a class on chromosomes, a class on protein characterization, and a bunch of seminars. Plus, I am doing research. I shall explain a little, and feel free to ask questions after. This is a slightly specialized information.
There is a kind of modification that can be made to DNA called methylation. It is the addition of an extra -CH3 group to a base of DNA. There are two reasons to do this. The first is that, in response to viruses, biology developed a kind of protein called a nuclease, which breaks down nucleic acids. However, nucleases cannot break down methylated DNA, so the way to break down viral DNA but not your own is to methylate your own gene and then release the enzyme. You are protected, but the virus . . .
The other reason, and the one we scientists think actually evolved first, is the use of metylation to act as a "switch" in turning genes on and off. Only a small portion of the gene, which is called the promoter, needs to be methylated. When it is, all the proteins that bind to the DNA and do the transcription are physically blocked, so the whole gene is turned "off" by only a few methylated locations. It is also possible to methylate only parts of the promoter, which causes the gene to be transcribed less without turning it off completely.
In fact, people are now starting to look at how the genes in cells are methylated. It turns out that, say, retinal cells have entirely different gene methylation patterns than liver cells. It makes sense, because retinal cells and liver cells need to make entirely different proteins, and so they turn different proteins off as well. And of course, as in everything else, cancer cells bear about as much resemblance to normalcy as a boat anchor does to a flying squirrel.
As you can imagine, with such a small modification causing such massive changes, methylation is very tightly controlled. One of the things we as scientists want to know is: how is it controlled? That is what the lab in which I am rotating this term does. So far, this has translated to making lots of soup, in which my favorite bacteria will live if I have done it right, and also making chemical jello, which jiggles.
Anyway, enough Science! for the day. Question time.
There is a kind of modification that can be made to DNA called methylation. It is the addition of an extra -CH3 group to a base of DNA. There are two reasons to do this. The first is that, in response to viruses, biology developed a kind of protein called a nuclease, which breaks down nucleic acids. However, nucleases cannot break down methylated DNA, so the way to break down viral DNA but not your own is to methylate your own gene and then release the enzyme. You are protected, but the virus . . .
The other reason, and the one we scientists think actually evolved first, is the use of metylation to act as a "switch" in turning genes on and off. Only a small portion of the gene, which is called the promoter, needs to be methylated. When it is, all the proteins that bind to the DNA and do the transcription are physically blocked, so the whole gene is turned "off" by only a few methylated locations. It is also possible to methylate only parts of the promoter, which causes the gene to be transcribed less without turning it off completely.
In fact, people are now starting to look at how the genes in cells are methylated. It turns out that, say, retinal cells have entirely different gene methylation patterns than liver cells. It makes sense, because retinal cells and liver cells need to make entirely different proteins, and so they turn different proteins off as well. And of course, as in everything else, cancer cells bear about as much resemblance to normalcy as a boat anchor does to a flying squirrel.
As you can imagine, with such a small modification causing such massive changes, methylation is very tightly controlled. One of the things we as scientists want to know is: how is it controlled? That is what the lab in which I am rotating this term does. So far, this has translated to making lots of soup, in which my favorite bacteria will live if I have done it right, and also making chemical jello, which jiggles.
Anyway, enough Science! for the day. Question time.
