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Science! An introduction to worms

June 22, 2010 8 comments

Though my blog thus far may have led you to believe otherwise, the NSF is not paying for us to be in China just to have an all-around good time. They also want us to do some science and gain some valuable research experience while we’re here. As such we all chose a few top picks for which lab we’d work in and depending on various factors were placed into one of those labs.  The lab I’m in is that of Dr. Zengyi Chang. I was interested in his work because his site and biography said that they studied proteins related to the aging process, a topic that I think is fairly interesting because I’d like to do my best to prevent aging.  Andrew Bernier is in the same lab as me this summer. Most of the students with our group have their own labs but Andrew and I and another pair, Taylor Carlson and Lester Sabo, are both in the same lab.

When Andrew and I first met Dr. Chang he asked a bit about the program and was very inviting but a bit disconcertingly unprepared in terms of what we would do.   He asked us what we wanted to do in the lab, we said we didn’t know what was going on in his lab and he proceeded to sit thinking for a few minutes. Eventually he called in one of his students and conferred with her. The decision was that we would help her, Anastasia Ngozi (who is from Nigeria, originally), with working on dauer formation in C. elegans.  And now, a brief introduction to C. elegans.

Caenorhabditis elegans is a species of roundworm.  It is a common, well-studied model organism.  It is harmless (as far as I am aware) to those working with it, it feeds on E. coli bacteria, another model organism that is easily cultured in the lab, the developmental fate of every cell in its body has been determined, it’s life-cycle is rapid (3 days from egg to reproducing adult under good conditions), it is a eukaryote so it is evolutionarily slightly similar to humans, and it grows to about 1mm in length, so it is visible to the naked eye.

I mentioned earlier that the lab is studying dauer formation, and to understand that statement I need to bring in a handy-dandy chart of the C. elegans life cycle.

The C. elegans life cycle
The normal life cycle for C. elegans takes about 3 days (for an egg to become a sexually mature adult worm).  The worms proceed through 4 larval stages which are characterized by different physiological markers before becoming adults.  They go through this normal life cycle when living in a place with plenty of food, enough space, at a nice temperature, and away from any chemical dangers.  In the face of unfavorable circumstances such as a lack of food, overcrowding, high temperature, or toxic environment developing worms have the capability to enter a dormant state called “dauer” from L1 instead of proceeding on to L2.  (Dauer is pronounced dow (as in dow chemical)-err (as in “err… what?”) and is simply the name for the dormant state of C. elegans.) If a worm enters dauer it stops pharyngeal pumping (it stops eating), forms plugs at both ends of its digestive tract (it’s not eating anyway, right?), and only moves if it needs to actively escape from danger (such as a scientist poking it with a platinum wire).
So I’m working with C. elegans for the next couple of months and I’ll do my best to keep you informed on the why’s what’s and how’s of the whole shebang.  Hopefully you’ll get to hear from some of my fellow Americans about what they’re researching too(I’ll try to force them to write guest posts).