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The Gene Hunters

 
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Falling in love with DNA
By Dr. Nancy Hopkins
Adapted/Updated from her MIT Convocation Address, 1998. Hopkins takes Alan Alda on a tour of her MIT Lab in "Fishing for Baby Genes."

4 pages: | 1 | 2 | 3 | 4 |

Photo of Nancy HopkinsI went to college thinking I would be a math major. Then one day I happened to hear a lecture by a professor named James D. Watson. Jim Watson, along with Francis Crick, was the discoverer of the structure of DNA, the molecule that genes are made of. At the end of the hour, I was not a math major. I was in love with DNA- for life. The field I had discovered was molecular biology.
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The Secret of Life

It was clear that DNA and this new field of molecular biology held the secret of life. Genes are lengths of those long, stringy, DNA molecules, and each gene carries- in code- the information to make one protein. Each protein is a complex molecular device that carries out a specific task within a cell. Collectively, our proteins make us what we are. It was apparent to all of us lucky enough to stumble into that classroom that if you understood how genes and their proteins worked you would understand life at the molecular level, and one day -some day- you could even answer every interesting question you had ever wanted to ask about being human. For example: How do you make a hand? What is a memory? How does a cell become cancer? Why do I look like my mother? It was the possibility of finding the answers to these questions that was totally intoxicating, totally passion provoking. Addictive.




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In my own case, the fascination sparked by one undergraduate class has led me to a laboratory at MIT that today is full of zebrafish. Zebrafish are small, 2-inch long fish from the Ganges River. Why zebrafish?

I am a developmental biologist. The question that fascinates developmental biologists is simple but profound, How does a single cell, the fertilized egg, develop into an animal? Early developmental biologists realized that this amazing event involves three cellular processes. First, the fertilized egg cell has to divide to make billions of cells. Second, the cells have to differentiate into many types- skin cells, muscles cells, eye cells, et c. Third, the cells have to take up the correct position in 3D space- a process called pattern formation.


How do you make a hand? What is a memory? Why do I look like my mother?

Consider my hand and foot. They are about the same size. They both contain the same cell types- skin, bone, muscle, and blood. But they are different shapes, due to the process of pattern formation. Without pattern formation, development would not produce an animal. It would yield a blob.

A triumph of modern biology has been to demonstrate that it is genes - acting through the proteins they encode - that tell cells when and how to divide. It is genes that tell cells how to become different types and it is genes that instruct cells how to form specific shapes and structures. The goal of developmental biology now is to identify the genes that do this in vertebrate animals and then to find out how they do it.

Photo of  zebrafish
 

These zebrafish are more similar to humans than they appear.

Of course, our first choice of organisms to study would be humans. But we find that humans seldom volunteer for the type of experiments biologists do. Some of our experiments require that you de-construct the organism. Yet others require that the animals mate whenever and to whomever we request. Any volunteers? I thought not. But as you will see, we can study human genes by studying fish genes.
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4 pages: | 1 | 2 | 3 | 4 |


Photos: N. Hopkins; Rolf Karlstrom - University of Massachusetts, Amherst and Don Kane - University of Rochester

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