October 10, 2010

Yeah, yeah, yeah

I've been a very bad blogger, I know. I'm working on it. I am, I am, I am.

To start with making it all up to you, I'm going to dive into my old schoolwork. Because I know you all really enjoy that (I know that a lot of you don't. But I'm doing it anyways.) Yay!

From what I can tell, I left off work in the middle of the Science Research folder of freshman year. So, basically, back when I actually did work for that class, instead of just continually reformatting my paper.

The first article is a study which found that leukemia with slower cell division is more successful, partly because it allows them to avoid therapies designed to destroy cells that divide quickly (this is why hair falls out during radiation: it divides quickly. At least, I think that's why...). Scientists found this by studying the p21 gene. I wonder if all p-genes are related to cancers.

The second article is about which transcription factors must be turned on to render somatic cells pluripotent. Prior to this study, Oct4, Sox2, c-Myc and Klf4 were needed to change fibroblasts into stem cells (genes have such fun names). This work found that Esrrb can replace the last two entirely, as it regulates expression of Klf4 in stem cells. It can also bind to the reprogramming factors Nanog and Oct4, thus inspiring (not the right verb, but whatever) pluripotency.)

The third article is no longer at the link I have. According to my notes, embryonic stem cells are derived from preimplantation embryos, which I've known since I did my independent study project on stem cells in sixth grade, but it apparently is still a piece of information that needs to be included in discussions of science. These cells have normal karyotypes, but I don't remember what karyotypes are (google newsflash: it's the number and appearance of chromosomes in eukaryotic cells). These cells have high telomerase activity, and telomerase is that protein that reverses telomere reduction and is totally going to cure aging someday. The cells have pluripotent markers and can divide for an ├╝ber-long time. If they differentiate into neurons (or, as Sadie would say, nyoo-rons), various growth factors, antagonists thereof, and morphogens become activated. I miss bio, but not enough to give up physics. Apparently, though scientists try to control this, they have trouble making all cells differentiate to the same thing. It still sounds cool, though.

The fourth article is about how the reprogramming factors work. Scientists examined when in the cell cycle and to what genes the pluripotency factors bind, and they found some nifty stuff. I just got really distracted by the fact that I now have access to Cell, where the actual journal article I couldn't read way back when I was doing this research is located. There are pictures. I can see them! I love summerschool's database access.

The last article is basically investigating the whole chimeric embryo thing. It found that differences in karyotypes and mitochondria will prevent inter-species hybrids from being formed. These scientists made a bunch, and none of them divided particularly much. I was kind of confused, because I thought human-animal hybrids were illegal, but apparently not.

I have now relearned something today.


Ginny said...

I miss chem, but I'm also not willing to give up physics. Or English, because then I won't graduate.