The first methods for sequencing DNA were developed in the mid-1970s. At that time, scientists could sequence only a few base pairs per year, not nearly enough to sequence a single gene, much less the entire human genome. By the time the HGP began in 1990, only a few laboratories had managed to sequence a mere 100,000 bases, and the cost of sequencing remained very high. Since then, technological improvements and automation have increased speed and lowered cost to the point where individual genes can be sequenced routinely, and some labs can sequence well over 100 million bases per year.
Beginning in the late 1990s, the scientific community witnessed a remarkable climax of accomplishments related to DNA sequencing. In addition to the historic sequencing of the human genome, sequences have now been generated for the genomes of several key model organisms, including the mouse (Mus musculus); the rat (Rattus norvegicus); two fruit flies (Drosophila melanogaster and D. pseudoobscura); two roundworms (Caenorhabditis elegans and C. briggsae); yeast (Saccharomyces cerevisiae) and several other fungi; a malaria-carrying mosquito (Anopheles gambiae) along with a malaria-causing parasite (Plasmodium falciparum); two sea squirts (Ciona savignyi and C. intestinalis); a long list of microbes; and a couple of plants, including mustard weed (Arabidopsis thaliana) and rice (Oryza sativa). Sequencing work is well underway on the honey bee (Apis mellifera), and is just getting started or expected to begin soon on the chimpanzee (Pan troglodytes), the cow (Bos taurus), the dog (Canis familiaris) and the chicken (Gallus gallus).The relative genetic simplicity of many of these model organisms make them ideal terrain for future technology development.
Although providing a single reference sequence of the human genome is an extraordinary achievement, further advances in sequencing technology are necessary so large amounts of DNA can be manipulated and compared with other genomes quickly and cheaply. Comparing differences among long stretches of DNA - one million bases or more - taken from many individuals should yield an enormous amount of information about the role of inheritance in disease susceptibility, response to environmental influences and even evolution.
Beginning in the late 1990s, the scientific community witnessed a remarkable climax of accomplishments related to DNA sequencing. In addition to the historic sequencing of the human genome, sequences have now been generated for the genomes of several key model organisms, including the mouse (Mus musculus); the rat (Rattus norvegicus); two fruit flies (Drosophila melanogaster and D. pseudoobscura); two roundworms (Caenorhabditis elegans and C. briggsae); yeast (Saccharomyces cerevisiae) and several other fungi; a malaria-carrying mosquito (Anopheles gambiae) along with a malaria-causing parasite (Plasmodium falciparum); two sea squirts (Ciona savignyi and C. intestinalis); a long list of microbes; and a couple of plants, including mustard weed (Arabidopsis thaliana) and rice (Oryza sativa). Sequencing work is well underway on the honey bee (Apis mellifera), and is just getting started or expected to begin soon on the chimpanzee (Pan troglodytes), the cow (Bos taurus), the dog (Canis familiaris) and the chicken (Gallus gallus).The relative genetic simplicity of many of these model organisms make them ideal terrain for future technology development.
Although providing a single reference sequence of the human genome is an extraordinary achievement, further advances in sequencing technology are necessary so large amounts of DNA can be manipulated and compared with other genomes quickly and cheaply. Comparing differences among long stretches of DNA - one million bases or more - taken from many individuals should yield an enormous amount of information about the role of inheritance in disease susceptibility, response to environmental influences and even evolution.
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