The Worm

Caenorhabdis elegans (C. elegans, for short) is a worm that is about 1 millimeter in size. It lives in the soil, eats bacteria, and lives for about 2 weeks. At first glance, this little critter does not seem exciting. However, I am quickly finding out this week that C. elegans is at the front line of science research in the fight against human diseases.

You see, C. elegans is what biologists call a model organism. Studying genetic diseases in humans is really hard because humans live for a long time and are all very different from each other. Also, it's not really acceptable to do experiments on humans and their DNA. So instead of human studies, biologists use organisms like this worm.

You might think, "what can a worm teach us about humans?" Actually, they can teach us a lot - just think of all the things they have in common with us: they are animals, they are made of cells, they have digestive, nervous, and reproductive systems. Most of all, worms and humans evolved from the same ancestor, so even though we look different, we share a lot of genes.

Take a look at the video of C. elegans moving across the plate:

When you are ready, check out this introduction to the worm. I'll post more about the experiments we are doing tomorrow.

DNA Science, Long Island Style

Hello again from The Dolan Learning Center at Cold Spring Harbor.

This past week has been a blur of extracting, amplifying, slicing, and analyzing DNA. Last week, we analyzed several different sections of the human genome (that means all of the DNA that we have in our cells).

One of the great experiments was something the police and FBI use to solve crimes. I was able to extract and amplify a section of the DNA that is called D1S80. Everybody gets two copies of this gene (one from mom, one from dad) and there are lots of different kinds you can inherit. It is a section of DNA that repeats itself. So, some people have 18 repeats, others have 19, 20, 21, all the way up to 44. So this is one of the ways that geneticists can tell two people apart from each other. My results were that I have a copy that is 21 and one that is 27.

In the picture you can see our instructor pointing to the results we saw in our gel electrophoresis. You can learn more about this by going to this link: www.dnai.org, and clicking on Applications, and then Human Identification.

We begin work with nematodes or round worms today. I'll post more tomorrow when I have some great pictures!