DSIM: A Distance-Based Indexing Method for Genomic Sequences

• Main Authors: CAO, Xia, OOI, Beng-Chin, PANG, Hwee Hwa, TAN, Kian-Lee, TUNG, Anthony K. H.
• Format: text
• Language: English
• Published: Institutional Knowledge at Singapore Management University 2005
• Subjects: Computation methods; data compression; data structures; database systems; indexing; Data sequences; Distance based Sequence Indexing Method (DSIM); Genomic sequences; Human genome; Databases and Information Systems; Numerical Analysis and Scientific Computing
• Online Access: https://ink.library.smu.edu.sg/sis_research/276; https://ink.library.smu.edu.sg/context/sis_research/article/1275/viewcontent/DSIM_edited_.pdf
• Institution: Singapore Management University

In this paper, we propose a Distance-based Sequence Indexing Method (DSIM) for indexing and searching genome databases. Borrowing the idea of video compression, we compress the genomic sequence database around a set of automatically selected reference words, formed from high-frequency data substrings and substrings in past queries. The compression captures the distance of each non-reference word in the database to some reference word. At runtime, a query is processed by comparing its substrings with the compressed data strings, through their distances to the reference words. We also propose an efficient scheme to incrementally update the reference words and the compressed data sequences as more data sequences are added and new queries come along. Extensive experiments on a human genome database with 2.62 GB of DNA sequence letters show that the new algorithm achieves significantly faster response time than BLAST, while maintaining comparable accuracy.