DOE Genomes
-

Human Genome Project Information


Sequencing

DNA Sequencing and Sequence Variation


Basic Information
 FAQs
 Glossary
 Acronyms
 Links
 Genetics 101
 Publications

 Meetings Calendar
 Media Guide

About the Project
 What is it?
 Goals
 Landmark Papers
 Sequence Databases
 Timeline
 History
 Ethical Issues
 Benefits
 Genetics 101
 FAQs

Medicine &
the New Genetics

 Home
 Gene Testing
 Gene Therapy
 Pharmacogenomics

 Disease Information
 Genetic Counseling

Ethical, Legal,
Social Issues

 Home
 Privacy Legislation

 Gene Testing
 Gene Therapy
 Patenting
 Forensics
 Genetically Modified Food
 Behavioral Genetics
 Minorities, Race, Genetics
 Human Migration

Education
 Teachers
 Students
 Careers
 Webcasts
 Images
 Videos
 Chromosome Poster
 Presentations
 Genetics 101
 
Genética Websites en Español

Research
 Home
 Sequence Databases
 Landmark Papers
 Insights

Publications
 Chromosome Poster
 Primer Molecular Genetics
 List of All Publications

  ???Search This Site


 Contact Us
 Privacy Statement

 Site Stats and Credits
 Site Map

The Human Genome Project was completed in 2003. One of the primary research areas was DNA sequencing. This page details that research.

The HGP's emphasis was on obtaining a complete and highly accurate reference sequence (1 error in 10,000 bases), largely continuous across each human chromosome. Scientists believe that knowing this sequence is critically important for understanding human biology and for applications to other fields.

A"working draft" of the human genome DNA sequence was completed in June 2000, published February 2001. The working draft comprises shotgun sequence data from mapped clones, with gaps and ambiguities unresolved. Draft sequence provides a foundation for obtaining the high-quality finished sequence and also is a valuable tool for researchers hunting disease genes. See Feb. 2001 and April 2003 Science and Nature papers analyzing the sequence.

Human DNA Sequence Goals

  • Achieve coverage of at least 90% of the genome in a working draft based on mapped clones by the end of 2001.
  • Finish one-third of the human DNA sequence by the end of 2001.
  • Finish the complete human genome sequence by the end of 2003.
  • Make the sequence totally and freely accessible.

Sequence Variation
A goal also focused on identifying individual variations in the human genome. Although more than 99% of human DNA sequences are the same across the population, variations in DNA sequence can have a major impact on how humans respond to disease; environmental insults such as bacteria, viruses, toxins, and chemicals; and drugs and other therapies.

Methods have been developed to detect different types of variation, particularly the most common type called single-nucleotide polymorphisms (SNPs), which occur about once every 100 to 300 bases. SNP maps are helping scientists identify the multiple genes associated with such complex diseases as cancer, diabetes, vascular disease, and some forms of mental illness. These associations are difficult to establish with conventional gene-hunting methods because a single altered gene may make only a small contribution to disease risk.

Human Genome Sequence Variation Goals

  • Develop technologies for rapid, large-scale identification and scoring of single-nucleotide polymorphisms and other DNA sequence variants.
  • Identify common variants in the coding regions of the majority of identified genes during this 5-year period.
  • Create a SNP map of at least 100,000 markers.
  • Develop the intellectual foundations for studies of sequence variation.
  • Create public resources of DNA samples and cell lines.

Text adapted from F. Collins, Ari Patrinos, et al., "New Goals for the U.S. Human Genome Project: 1998–2003," Science 282: 682-689 (1998). For a more detailed explanation of sequencing, see the U.S. DOE Primer on Molecular Genetics. See HGP Goals for more details on the project's goals.

Area HGP Goal Standard Achieved Date Achieved
DNA Sequence 95% of gene-containing part of human sequence finished to 99.99% accuracy 99% of gene-containing part of human sequence finished to 99.99% accuracy April 2003
Capacity and Cost of Finished Sequence Sequence 500 Mb/year at < $0.25 per finished base Sequence >1,400
Mb/year at <$0.09 per finished base
November 2002
Human Sequence Variation 100,000 mapped human SNPs 3.7 million mapped human SNPs February 2003

Abstracts

Web Sites for Accessing HGP Sequence

BAC End Sequencing

Sequence data from both ends of mapped BAC (bacterial artificial chromosomes) clones provide researchers with a series of markers spaced approximately every 3000 to 4000 bases across the genome. Researchers use these markers as "sequence tag connectors" (STCs) to identify the specific clones needing to be sequenced to extend sequenced regions further along the chromosomes and for other uses in large-scale sequencing efforts.

Related Articles from Human Genome News

Send the url of this page to a friend


Last modified: Friday, September 19, 2008

Home * Contacts * Disclaimer

Base URL: www.ornl.gov/hgmis

Office of Science Site sponsored by the U.S. Department of Energy Office of Science, Office of Biological and Environmental Research, Human Genome Program