Shotgun Sequencing

In shotgun sequencing, random samples of cloned DNA, e.g., the segments of a cosmid are sequenced at random. Whole-genome pairwise shotgun procedure sequences paired ends of cloned DNAs of varying sizes and fragmented them into a larger number of contigs ordered with the aid of high-power computers. If there are still gaps between the contigs those are filled in by “finishing.” The hierarchical shotgun sequencing procedure is based on mapped clones generated by BACs. The Double-barrel shotgun sequences the DNA from both ends. The short sequences are arranged into longer tracts by computers. The Full shotgun sequence indicates that the cloned inserts have been covered about 8–10 times. Half shotgun coverage is only 4–5-fold random sequence. DNA sequencing, first-draft sequence, contig, completion, WGS, scaffolds in genome sequencing, human genome, genome projects; Bankier AT 2001 Methods Mol Biol 167:89; whole genome shotgun (WGS) products: http://www.ncbi.nlm.nih.gov/projects/WGS/WGSprojectlist.cgi....