The Human Genome Project Completes the Map of Human Chromosome 7

The Human Genome Project Completes the Map of Human Chromosome 7

July 1997

BETHESDA, Md. - A team of scientists, led by Dr. Eric Green of the National Human Genome Research Institute (NHGRI), has spent nearly eight years developing a physical map of the chromosome, which contains an estimated five percent of the human genetic blueprint.

The NHGRI team used bits of human DNA isolated in yeast cells to localize more than 2,000 "landmarks" on chromosome 7. The landmarks are spaced at intervals of about 79,000 base pairs, the fundamental units of DNA. The goal for the Human Genome Project is to map such a landmark every 100,000 base pairs. Chromosome 7 is the second human chromosome to have exceeded this goal, with the X chromosome being finished a few months ago. Chromosome 7 contains a total of 170 million base pairs.

With a physical map of human chromosome 7 in hand, the NHGRI team is now working closely with scientists at Washington University School of Medicine and the University of Washington to start sequencing the chromosome from beginning to end, base pair by base pair. By sequencing the entire human genome and its roughly three billion base pairs, scientists hope to identify all of the approximately 100,000 genes in the human blueprint by early next century.

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