Scientists reported June 26 that they have assembled working drafts of the human genome.
This milestone was announced jointly by the publicly funded Human Genome Project and by Celera Genomics.
The Human Genome Project’s work involved placing large fragments of DNA in the correct order to cover all of the human chromosomes and determining the DNA sequence of these chromosomes.
The raw data in the working draft consisted of overlapping fragments covering 97 percent of the human genome, of which sequencing already has been done for about 85 percent.
The Human Genome Project research centers in the United States, Britain, France, Germany, Japan and China have produced more sequence data than were expected at this stage: more than 22.1 billion bases of raw sequence data, comprising overlapping fragments that total 3.9 billion bases and providing a sevenfold sequence coverage of the human genome.
As a result, the working draft is much closer to the finished form. About 50 percent of the genome sequence is in near-finished form or better, and 24 percent of it is in completely finished form. The average accuracy of all of the DNA sequence in this assembly is 99.9 percent.
The sequence information from this publicly funded project is freely released to the world with no restrictions on its use. The information is scanned daily by scientists in academia and industry, as well as by commercial database companies providing information services to biotechnologists.
Celera Genomics reported that it had completed its own first assembly of the human genome DNA sequence, using an approach complementary to that of the Human Genome Project. They announced that they have sequenced 99 percent of the human genome.
"Successful completion of the working draft of the human genome is a major first step, which will greatly speed up the identification of new genes involved not only in congenital diseases, but also in normal and abnormal wound repair," says Kenneth M. Yamada, M.D., Ph.D., Chief of the Craniofacial Developmental Biology and Regeneration Branch at the National Institute of Dental and Craniofacial Research.
"The next steps will take years to decades to complete," he continues. "Early benefits to dentistry may be in reconstructive surgery, but it is no longer impossible to dream of learning how to regenerate teeth and replace salivary tissue in patients with xerostomia."
