|
Evolutionary Genomics Group Department of Computational Molecular Biology |
|
|
|
|
|
|||
|
|||
|
Authors: Philipp W Messer, Ralf Bundschuh, Martin Vingron, Peter F Arndt Title: Alignment Statistics for Long-Range Correlated Genomic Sequences Abstract: It is well known that the base composition along eukaryotic genomes is long-range correlated. Here; we investigate the effect of such long-range correlations on alignment score statistics. We model the correlated score-landscape by means of a Gaussian approximation. In this framework; we can calculate the corrections to the scale parameter λ of the extreme value distribution of alignment scores. To evaluate our approximate analytic results; we perform a detailed numerical study based on a simple algorithm to efficiently generate long-range correlated random sequences. We find that the mean and the exponential tail of the score distribution are in fact influenced by the correlations along the sequences. Therefore; the significance of measured alignment scores in biological sequences will change upon incorporation of the correlations in the null model. Reference: Lecture Notes in Computer Science 3909 (2006) 426-440 Links: [Journal] [Fulltext (pdf)] |