BAC as tools for genome sequencing

Genome sequencing represents the state-of-the-art technology for large-scale gene discovery, cloning and decoding. Bacteria-based large-insert clones, including bacterial artificial chromosome (BAC), bacteriophage P1-derived artificial chromosome (PAC) and large-insert conventional plasmid-based clone (PBC), are desirable resources and have offered numerous potentials for accelerated sequencing of large, complex genomes. They are not only capable of cloning large DNA fragments of complex genomes (> 100 kb) in bacteria, but also are stable in host cells, have low levels of chimeric clones and facilitate DNA purification. These features of bacteria-based large-insert clones, especially the simplicity of DNA purification, have greatly facilitated their use in current genomics research and large-scale genome sequencing. In this article, we introduce BACs, PACs and PBCs as the tools for the development of sequence-ready clone-based physical maps and the large-scale sequencing of large complex genomes. We review the genome sequencing of Drosophila melanogaster, Arabidopsis thaliana and human in which BACs and PACs are utilized as major tools. Finally, the perspectives of BACs, PACs and PBCs as tools for large-scale sequencing of large, complex genomes will be discussed.