PASCAL - Pattern Analysis, Statistical Modelling and Computational Learning

Leveraging Sequence Classification by Taxonomy-based Multitask Learning
Christian Widmer, Jose Leiva, Yasemin Altun and Gunnar Raetsch
In: RECOMB 2010(2009).


In this work we consider an inference task that biologists are very good at: deciphering biological processes by bringing together knowledge that has been obtained by experiments using various organisms, while respecting the differences and commonalities of these organisms. We look at this problem from an sequence analysis point of view, where we aim at solving the same classification task in different organisms. We investigate the challenge of combining information from related organisms, whereas we consider the relation between the organisms to be defined by a tree structure derived from their phylogeny. Multitask learning, a machine learning technique that recently received considerable attention, considers the problem of learning across tasks that are related to each other. We treat each organism as one task and present three novel multitask learning methods to handle situations in which the relationships among tasks can be described by a hierarchy. These algorithms are designed for large-scale applications and are therefore applicable to problems with a large number of training examples, which are frequently encountered in sequence analysis. We perform experimental analysis on synthetic data sets in order to illustrate the properties of our algorithms. Moreover, we consider a problem from genomic sequence analysis, namely splice site recognition, to illustrate the usefulness of our approach. We show that intelligently combining data from $15$ eukaryotic organisms can indeed significantly improve the prediction performance compared to traditional learning approaches. On a broader perspective, we expect that algorithms like the ones presented in this work have the potential to complement and enrich the strategy of homology-based sequence analysis that are currently the quasi-standard in biological sequence analysis.

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EPrint Type:Conference or Workshop Item (Paper)
Additional Information:Computational Biology
Project Keyword:Project Keyword UNSPECIFIED
Subjects:Computational, Information-Theoretic Learning with Statistics
ID Code:6109
Deposited By:Yasemin Altun
Deposited On:08 March 2010