Designing seeds for similarity search in genomic DNA
Journal of Computer and System Sciences - Special issue on bioinformatics II
ExonHunter: a comprehensive approach to gene finding
Bioinformatics
Hi-index | 0.00 |
Hidden Markov models (HMMs) are routinely used for analysis of long genomic sequences to identify various features such as genes, CpG islands, and conserved elements. A commonly used Viterbi algorithm requires O(mn) memory to annotate a sequence of length n with an m-state HMM, which is impractical for analyzing whole chromosomes. In this paper, we introduce the on-line Viterbi algorithm for decoding HMMs in much smaller space. Our analysis shows that our algorithm has the expected maximum memory Θ(mlog n) on two-state HMMs. We also experimentally demonstrate that our algorithm significantly reduces memory of decoding a simple HMM for gene finding on both simulated and real DNA sequences, without a significant slow-down compared to the classical Viterbi algorithm.