What is the Human Genome Project?

National Human Genome Research Institute

National Institutes of Health
U.S. Department of Health and Human Services


What is the Human Genome Project?

From the DNA Day Museum Kit Manual

The Human Genome Project (HGP) is an international research effort to determine the DNA sequence of the entire human genome. Contributors to the HGP include the National Human Genome Research Institute (NHGRI) of the National Institutes of Health (NIH), which initiated its funding of the HGP in 1988; the U.S. Department of Energy (DOE), where discussions of the HGP began as early as 1984; numerous universities and laboratories throughout the United States; and international partners in the United Kingdom, France, Germany, Japan and China.

The essential completion of the HGP is an important milestone in the history of genetics research. In 1911, Alfred Sturtevant, then an undergraduate researcher in the laboratory of Thomas Hunt Morgan, realized that he could - and had to, in order to manage his data - map the locations of the fruit fly (Drosophila melanogaster) genes whose mutations the Morgan laboratory was tracking over generations. Sturtevant's very first gene map can be likened to the Wright brothers' first flight at Kitty Hawk. In turn, the Human Genome Project can be compared to the Apollo program bringing humanity to the moon.

HGP researchers deciphered the human genome using three tools: producing what are called linkage maps, complex versions of the type originated in early Drosophila research, through which inherited traits (such as those for genetic disease) can be tracked over generations; making maps that show the locations of genes for major sections of all our chromosomes; and determining the order, or "sequence," of all the bases in our genome's DNA.

The HGP already has revealed that there are probably somewhere around 30,000 human genes. The existing and ultimate products of the HGP will give the world a resource of detailed information about the structure, organization and function of the complete set of human genes and other functional elements found in DNA. This information can be thought of as the basic set of inheritable "instructions" for the development and function of a human being.

The International Human Genome Sequencing Consortium published the first draft of the human genome in the journal Nature in February 2001 with the sequence of the entire genome's three billion base pairs some 90 percent covered at an accuracy of 99.9%. A startling finding of this first draft is that the number of human genes appears to be significantly fewer than previous estimates, which ranged from 50,000 genes to as many as 140,000. The essentially complete 'finished' version of the human genome is scheduled to be completed two years earlier than originally anticipated, in April, 2003. Sequence finishing requires much more time and resources than the draft sequence, because all possible efforts are made to close gaps and resolve difficult regions. This final version will be 99.99% accurate at the base pair level and 95% of the three billion base pairs will be represented.

Upon publication of the draft of the genome, in February, 2001, Francis Collins, the director of NHGRI, noted that the genome could be thought of in terms of a book with multiple uses: "It's a history book - a narrative of the journey of our species through time. It's a shop manual, with an incredibly detailed blueprint for building every human cell. And it's a transformative textbook of medicine, with insights that will give health care providers immense new powers to treat, prevent and cure disease."

The HGP also sponsors efforts to characterize the entire genomes of several other organisms used extensively in biological research, such as mice, rats, fruit flies and flatworms. These efforts support each other, because most organisms have many similar, or "homologous," genes with similar functions. Therefore, the identification of the sequence or function of a gene in a model organism, for example, the flatworm C. elegans, has the potential to help find and explain a homologous gene in human beings, or in one of the other model organisms. We can compare the landscape of the human genome with that of older species and identify evolutionarily conserved regions of DNA. This will allow us to identify sections of DNA that are functionally very important because they haven't changed over millions of years of evolution. The genes found in these regions of the genome may constitute some basic building blocks of life.

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Last Reviewed: May 4, 2012