The Human Genome Project
The Human Genome Project began in 1990 under James Watson, and aimed to fully sequence the human genome, along with the laboratory mouse, fruit fly, and E. coli. It was one of the single largest investigational scientific research projects ever undertaken, and work contributing to the project took place at universities and research centres all over the world. It was estimated that the project would take 15 years; however, due to advances in the field of genomics and the international cooperation of many research centres, the sequencing of the human genome was announced to be completed in April 2003, two years earlier than predicted.
Why is the sequencing of the human genome only 92.3% complete
For the most part the largest challenge to the completion of the sequencing of
the entire human genome has been difficulties with current technology in
sequencing highly repetitive sections of DNA. Both the central regions of the
chromosomes (the centromeres) and the very end of the chromatids (telomeres)
have highly repetitive sections of DNA.
Politics and the Human Genome Project
Celera Genomics began to attempt to sequence the human genome in 1998, as a
privately funded project. The project was intended to finish ealier than the
publicly funded Human Genome Project for a much lower cost. Craig Venter, former
president of Celera Genomics, attempted to patent the sequences determined by
his company, although agreed to publish their data annually under the Bermuda
Statement (compared the the Human Genome Project, which published its findings
daily). However, in 2000 President Clinton prevented Celera Genomics from
patenting their results, allowing the information to be published for the free
use of researchers. This sent shares in Celera Genomics plummeting.
However, both projects continued and the competition between the two served to
increase the both the rate of work and depth of the results. Finally there came
some agreement between the two parties when plans were made to pool data.
However, once Celera Genomics had received the data from the Human Genome
Project, they refused to publish their results in the freely available public
Materials and methods
The DNA samples that were used for the Human Genome Project were sourced from
female blood samples and sperm samples from men. Many samples were collected but
only a few were used for the genome sequencing in order to protect the identity
of the donors.
The Human Genome Project used both whole-genome shotgun sequencing and shotgun
sequencing in its genome mapping. In shotgun sequencing, large sections of DNA
are broken down into smaller fragments, called reads. This is performed many
times in order to generate a great number of reads of different sizes. The
overlapping ends of the reads can be used to determine the sequence of the DNA.
In reality, long repetitive sections produce similar reads that could have
originated from different sections of the DNA - hence it is difficult to
sequence the centromeres and telomeres.
Benefits of the HGP
- There is the possibility of identifying genes which give a predisposition to a certain disease; not only could this provide genetic testing for individuals but could also allow a better understanding of the cause of the disease in question
- An international database allows easy collaboration between worldwide research centres; scientists can enter information about gene products and functions into the database
- New aspects of evolution can be studied; the Human Genome Project found that humans and mice share most of their genomes
- Allows an understanding of how response to disease, predisposition to disease, and responses to treatment differs between ethnic groups
Useful external links: