Friday, April 13, 2007

elegant worms

Added: 4/15/07 10:08 PM

The lab that I joined four months ago studies the mechanisms of aging in tiny (1 mm long) worm called Caenorhabditis elegans. These worms are particularly suitable for studying aging as they live only around 20 days, and therefore, we do not have to wait too long to see if a tested chemical or genetic manipulation has an effect on their lifespan. Other advantage of these worms is that it is relatively straightforward to disrupt in them the function of specific genes using technique called RNA interference (RNAi). By doing that we can find genes that are involved in the aging process: if we silence (switch off) the gene A and worms will live longer, that means that a normal function of the gene A is to shorten the lifespan of the worm. Alternatively, if after switching off of the gene B worms live longer, then it is likely that the function of this gene is to prolong the life of the worm. [BTW: The guy who introduced C. elegans into the biological laboratories (Sydney Brenner) and the guys who discovered the RNA interference (Andrew Fire and Craig C. Mello) got Nobel Prizes for Medicine (Brenner in 2002, and Fire and Mello in 2006)].

Why do we care how long these worms live? Well, because luckily it seems that many genetic pathways are conserved between worms, flies, mice and (most certainly also) humans. So if we find that a certain gene has an influence on the lifespan of not only worms, but also flies and mice, then we can be almost sure that it will also influence the lifespan of humans. And once we know genes that are involved in aging, we try to understand the function of the proteins they encode (proteins are basic building blocks of our body, genes are only information storage units; one gene encodes information which says what one particular protein should look like and what it should do in our body). And once we know the function of the protein of interest, then we can attempt to make drugs that will affect its function in the way that we will make us live longer. At least this is what we hope will happen.

The movie that I attached to this post I found on youtube. It shows bunch of worms at different developmental stages (smaller are younger, bigger are older) moving around on the agar plate (of course since they are so tiny we look at them through the microscope). As you can see one of these worms is slightly different than the others: it is green. That’s another thing that we can do to (in) worms – we can mark single proteins with a color (like here with green) in order to investigate their expression pattern and cellular distribution (and potentially function). The person that made this movie is clearly more interested in this green worm than in the others, so what he wants to do is to separate this worm from the rest and to do that he uses a pick (btw: he seems pretty clumsy to me). We call it “transfer” as the worm gets transferred to the new agar plate. Transfer of worms is a basic daily activity of anybody working with them. Looks like lots of fun, ha?

Added: 4/15/07 11:53 PM

I just came back home from work and joined John, Kristina and their guests for dessert. One of the guys that I did not meet before asked me standard questions like: where are you from? where do you work? what do you do? So I said that I am Polish and that I am a scientist. He asked what kind of scientist, so I replied that a biologist. He wanted to know more specifically what I worked on, so I told him that I was studying the molecular mechanisms of aging in C. elegans. Then he asked if I were aware that caloric restriction had been shown to prolong the lifespan of rats and he continued explaining that to me... Do I look that stupid?