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Whole genome sequencing (also known as WGS, full genome sequencing, complete genome sequencing, or entire genome sequencing) is a laboratory process that determines the complete DNA sequence of an organism's genome at a single time. This entails sequencing all of an organism's chromosomal DNA as well as DNA contained in the mitochondria and, for plants, in the chloroplast. Whole genome sequencing should not be confused with DNA profiling, which only determines the likelihood that genetic material came from a particular individual or group, and does not contain additional information on genetic relationships, origin or susceptibility to specific diseases.〔Kijk magazine, 01 January 2009〕 Also unlike full genome sequencing, SNP genotyping covers less than 0.1% of the genome. Almost all truly complete genomes are of microbes; the term "full genome" is thus sometimes used loosely to mean "greater than 95%". The remainder of this article focuses on nearly complete human genomes. High-throughput genome sequencing technologies have largely been used as a research tool and are currently being introduced in the clinics. In the future of personalized medicine, whole genome sequence data will be an important tool to guide therapeutic intervention. The tool of gene sequencing at SNP level is also used to pinpoint functional variants from association studies and improve the knowledge available to researchers interested in evolutionary biology, and hence may lay the foundation for predicting disease susceptibility and drug response. ==A brief history of whole genome sequencing== The shift from manual DNA sequencing methods such as Maxam-Gilbert sequencing and Sanger sequencing in the 1970s and 1980s to more rapid, automated sequencing methods in the 1990s played a crucial role in giving scientists the ability to sequence whole genomes. ''Haemophilus influenzae'', a commensal bacterium which resides in the human respiratory tract was the first organism to have its entire genome sequenced (Figure 2.1). The entire genome of this bacterium was published in 1995. The genomes of ''H. influenzae'', other Bacteria, and some Archaea were the first to be sequenced - largely due to their small genome size. ''H. influenzae'' has a genome of 1,830,140 base pairs of DNA.〔 In contrast, eukaryotes, both unicellular and multicellular such as ''Amoeba dubia'' and humans (''Homo sapiens'') respectively, have much larger genomes (see C-value paradox). ''Amoeba dubia'' has a genome of 700 billion nucleotide pairs spread across thousands of chromosomes. Humans contain fewer nucleotide pairs (about 3.2 billion in each germ cell - note the exact size of the human genome is still being revised) than ''A. dubia'' however their genome size far outweighs the genome size of individual bacteria. The first bacterial and archaeal genomes, including that of ''H. influenzae'', were sequenced by Shotgun sequencing.〔 In 1996, the first eukaryotic genome - that of the yeast ''Saccharomyces cerevisiae'' was sequenced. ''S. cerevisiae'', a model organism in biology has a genome of only around 12 million nucleotide pairs. ''S. cerevisiae'' was the first ''unicellular'' eukaryote to have its whole genome sequenced. The first ''multicellular'' eukaryote, and animal, to have its whole genome sequenced was the nematode worm: ''Caenorhabditis elegans'' in 1998 (Figure 2.2). Eukaryotic genomes are sequenced by several methods including Shotgun sequencing of short DNA fragments and sequencing of larger DNA clones from DNA libraries (see library (biology)) such as Bacterial artificial chromosomes (BACs) and Yeast artificial chromosomes (YACs). In 1999, the entire DNA sequence of human chromosome 22, the shortest human autosome, was published. By the year 2000, the second animal and second invertebrate (yet first insect) genome was sequenced - that of the fruit fly ''Drosophila melanogaster'' (Figure 2.3) - a popular choice of model organism in experimental research. The first plant genome - that of the model organism ''Arabidopsis thaliana'' - was also fully sequenced by 2000 (Figure 2.4). By 2001, a draft of the entire human genome sequence was published. The genome of the laboratory mouse ''Mus musculus'' was completed in 2002 (Figure 2.5). In 2004, the Human Genome Project published the human genome. Currently, thousands of genomes have been sequenced. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Whole genome sequencing」の詳細全文を読む スポンサード リンク
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