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A bacterial artificial chromosome (BAC) is a DNA construct, based on a functional fertility plasmid (or F-plasmid), used for transforming and cloning in bacteria, usually ''E. coli''. F-plasmids play a crucial role because they contain partition genes that promote the even distribution of plasmids after bacterial cell division. The bacterial artificial chromosome's usual insert size is 150-350 kbp. A similar cloning vector called a PAC has also been produced from the bacterial P1-plasmid. BACs are often used to sequence the genome of organisms in genome projects, for example the Human Genome Project. A short piece of the organism's DNA is amplified as an insert in BACs, and then sequenced. Finally, the sequenced parts are rearranged ''in silico'', resulting in the genomic sequence of the organism. BACs were replaced with faster and less laborious sequencing methods like whole genome shotgun sequencing and now more recently next-gen sequencing. ==Common gene components== ;''repE'': for plasmid replication and regulation of copy number. ;''parA and parB'': for partitioning F plasmid DNA to daughter cells during division and ensures stable maintenance of the BAC. ;A selectable marker: for antibiotic resistance; some BACs also have lacZ at the cloning site for blue/white selection. ;''T7 & Sp6'': phage promoters for transcription of inserted genes. 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「Bacterial artificial chromosome」の詳細全文を読む スポンサード リンク
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