Genome - Sequencing and Mapping

Sequencing and Mapping

In 1976, Walter Fiers at the University of Ghent (Belgium) was the first to establish the complete nucleotide sequence of a viral RNA-genome (bacteriophage MS2). The next year, Phage Φ-X174, with only 5386 base pairs, became the first DNA-genome project to be completed, by Fred Sanger. The first complete genome sequences for representatives from all 3 domains of life were released within a short period during the mid-1990s. The first bacterial genome to be sequenced was that of Haemophilus influenzae, completed by a team at The Institute for Genomic Research in 1995. A few months later, the first eukaryotic genome was completed, with the 16 chromosomes of budding yeast Saccharomyces cerevisiae being released as the result of a European-led effort begun in the mid-1980s. Shortly afterward, in 1996, the first genome sequence for an archaeon, Methanococcus jannaschii, was completed, again by The Institute for Genomic Research.

The development of new technologies has made it dramatically easier and cheaper to do sequencing, and the number of complete genome sequences is growing rapidly. The US National Institutes of Health maintains one of several comprehensive databases of genomic information. Among the thousands of completed genome sequencing projects include those for mouse, rice, the plant Arabidopsis thaliana, the puffer fish, and bacteria like E. coli.

New sequencing technologies, such as massive parallel sequencing have also opened up the prospect of personal genome sequencing as an important diagnostic tool, as pioneered by Manteia Predictive Medicine. A major step toward that goal was the completion in 2007 of the full genome of James D. Watson, one of the co-discoverers of the structure of DNA.

Whereas a genome sequence lists the order of every DNA base in a genome, a genome map identifies the landmarks. A genome map is less detailed than a genome sequence and aids in navigating around the genome. The Human Genome Project was organized to map and to sequence the human genome. A fundamental step in the project was the release of a detailed genomic map by Jean Weissenbach and his team at the Genoscope in Paris.