The realization in the early 1980s that even large genomes, such as the human genome, could be sequenced sparked serious planning efforts to sequence the human genome. The official Human Genome Project (HGP) envisaged a 15-year timescale, commencing on October 1st, 1990. In addition to sequencing the human genome, the HGP had three other goals: to develop mapping and sequencing technologies; to carry out genome projects for five model organisms; and to investigate the ethical, legal, and societal implications.
The prioritized model organisms were the bacterium Escherichia coli, the yeast Saccharomyces cerevisiae, the roundworm Caenorhabditis elegans, the fruit fly Drosophila melanogaster, and the mouse Mus musculus. The first four were known to have substantially smaller genomes than the human genome and so were expected to be test beds to evaluate and then refine genome sequencing strategies and methodologies. The bulk of the sequencing for the more complex human and mouse genomes was expected to be carried out in the later stages, after learning from the smaller genome projects and extracting maximum benefit from technological improvements.
Because of the large scale involved, the HGP was biology’s first Big Project. The ultimate aim was to achieve a periodic table for biology, based on genes rather than elements. The publically funded HGP was also a truly international endeavor. It came to be represented by the International Human Genome Sequencing Consortium of 20 different centers in the USA, UK, Japan, France, Germany, and China and was marked by extensive data sharing and collaboration on strategy, methodology, and data analysis.
Much of the genome sequencing technology was concentrated in a few very large genome mapping and sequencing centers with industrial-scale resources and massive data-analysis capabilities. Interacting with these centers was a worldwide network of small laboratories mostly attempting to map and identify disease genes and typically focusing on very specific subchromosomal regions. In addition to publically funded research efforts, privately funded research programs pursued similar but parallel sequencing projects.
The first framework maps for the human genome were genetic maps for individual chromosomes. The genetic maps were of low resolution but they provided the backbone on which to build a series of ever-more-detailed physical maps, culminating in clone contigs for each chromosome that were then used for the final sequencing stage.
