Published online 12 August 2005
Article |
Using multiple alignments to improve seeded local alignment algorithms
Department of Computer Science, Stanford University Stanford, CA 94304, USA
*To whom correspondence should be addressed. Tel: +1 650 289 0295; Fax: +1 650 725 1449; Email: flannick{at}cs.stanford.edu
Received June 8, 2005. Revised July 6, 2005. Accepted July 27, 2005.
Multiple alignments among genomes are becoming increasingly prevalent. This trend motivates the development of tools for efficient homology search between a query sequence and a database of multiple alignments. In this paper, we present an algorithm that uses the information implicit in a multiple alignment to dynamically build an index that is weighted most heavily towards the promising regions of the multiple alignment. We have implemented Typhon, a local alignment tool that incorporates our indexing algorithm, which our test results show to be more sensitive than algorithms that index only a sequence. This suggests that when applied on a whole-genome scale, Typhon should provide improved homology searches in time comparable to existing algorithms.
Correspondence may also be addressed to Serafim Batzoglou. Tel: +1 650 723 3334; Fax +1 650 725 1449; Email: serafim{at}cs.stanford.edu