Shotgun Sequence Assembly

Shotgun sequencing is the most widely used technique for determining the DNA sequence of organisms. It involves breaking up the DNA into many small pieces that can be read by automated sequencing machines, then piecing together the original genome using specialized software programs called assemblers. Due to the large amounts of data being generated and to the complex structure of most organisms’ genomes, successful assembly programs rely on sophisticated algorithms based on knowledge from such diverse fields as statistics, graph theory, computer science, and computer engineering. Throughout this chapter we will describe the main computational challenges imposed by the shotgun sequencing method, and survey the most widely used assembly algorithms.