The first comprehensive comparison of the genetic blueprints of humans and chimpanzees shows that our closest living relatives share perfect identity with 96 percent of our DNA sequence, an international research consortium reported today.

In a paper published in the Sept. 1 issue of the journal Nature, the Chimpanzee Sequencing and Analysis Consortium, which is supported in part by the National Human Genome Research Institute (NHGRI), one of the National Institutes of Health (NIH), describes its landmark analysis comparing the genome of the chimp (Pan troglodytes) with that of human (Homo sapiens).

“The sequencing of the chimp genome is a historic achievement that is destined to lead to many more exciting discoveries with implications for human health,” said NHGRI Director Francis S. Collins, M.D., Ph.D. “As we build upon the foundation laid by the Human Genome Project, it’s become clear that comparing the human genome with the genomes of other organisms is an enormously powerful tool for understanding our own biology.”

The chimp sequence draft represents the first non-human primate genome and the fourth mammalian genome described in a major scientific publication. A draft of the human genome sequence was published in February 2001, a draft of the mouse genome sequence was published in December 2002 and a draft of the rat sequence was published in March 2004. The essentially complete human sequence was published in October 2004.

“As our closest living evolutionary relatives, chimpanzees are especially suited to teach us about ourselves,” said the study’s senior author, Robert Waterston, M.D., Ph.D., chair of the Department of Genome Sciences of the University of Washington School of Medicine in Seattle. “We still do not have in our hands the answer to a most fundamental question: What makes us human? But this genomic comparison dramatically narrows the search for the key biological differences between the species.”

The 67 researchers who took part in the Chimp Sequencing and Analysis Consortium share authorship of the Nature paper. Most of the work of sequencing and assembling the chimp genome was done at the Broad Institute of the Massachusetts Institute of Technology and Harvard University, Cambridge, Mass., and the Washington University School of Medicine in Saint Louis. In addition to those centers, the consortium included researchers from institutions elsewhere in the United States, as well as Israel, Italy, Germany and Spain.

The DNA used to sequence the chimp genome came from the blood of a male chimpanzee named Clint at theYerkes National Primate Research Center in Atlanta. Clint died last year from heart failure at the relatively young age of 24, but two cell lines from the primate have been preserved at the Coriell Institute for Medical Research in Camden, N.J.