Unit 2: Genomics   Exercise 1

Objectives:

1. Learn about the process by which DNA sequence is determined.
2. Find out how data are prepared for submission to the databases.
3. Consider issues of sequence data quality and reliability.
4. Learn some of the terminology used in genomics.

Introduction:

The Human Genome Project was one of the largest and most expensive international science projects ever undertaken. It also stands the best documented genome sequencing effort.

This activity takes advantage of the excellent descriptions of this project available online. The links below direct you to elegant materials not only on the project, but on the underlying chemistry, biochemistry, and molecular biology.

There are summary questions at the end of this section. Read them through before you start the activities in this exercise. You can answer them as you go, or answer them afterward. Points = 5. Due on September 30, 2003.

Preparation:

1. Review the recommended text sections on the Central Dogma, DNA chemistry, and genome sequence assembly.

2. Also take note of the review articles linked on the Unit 2 main page.

Activity:

1. Start with the article from the Human Genome Users Guide entitled Introduction: putting it together. Pay particular attention to the section on Determining the human sequence: a brief overview. You may need to look up terms in a glossary or molecular biology text. Make a list of terms you don't recognize, and note any for which you can't find a reasonable definition.

2. Oak Ridge National lab has developed a very nice web site with answers to frequently-asked questions about genome sequencing projects. The URL is http://www.ornl.gov/TechResources/Human_Genome/faq/seqfacts.html. In particular, familiarize yourself with the sections on What is DNA sequencing? and How is DNA sequencing done?

3. Check out the primer on molecular genetics for a thorough background. You can step through the tutorial or use the Table of Contents to navigate through the hypertext. You will likely want to return to this resource as you work on the project.

Summary Questions:

Please limit your answers to the set of questions to a maximum of one and a half double-spaced pages [12 pt font]. This length should be sufficient for your comments and any appropriate copy/pasted examples. [You need not retype or copy/paste the questions as part of your responses.]

1. What is DNA sequencing and how is it done?

2. Describe in general terms the phases of a genome sequencing project.

3. What is the difference between draft sequence and finished sequence?

4. Explain how a physical DNA map is different from a genetic map.

5. List five terms you looked up in the glossary, or wished you had.

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