ESTMAP: a system for expressed sequence tags mapping on genomic sequences

The completion of a number of large genome sequencing projects emphasizes the importance of protein-coding gene predictions. Most of the problems associated with gene prediction are caused by the complex exon-intron structures commonly found in eukaryotic genomes. However, information from homologous sequences can significantly improve the accuracy of the prediction. In particular, expressed sequence tags (ESTs) are very useful for this purpose, since currently existing EST collections are very large. We developed an ESTMAP system, which utilizes homology searches against a database of repetitive elements using the RepeatView program and the EST Division of GenBank using the BLASTN program. ESTMAP extracts "exact" matches with EST sequences (>95% of homology) from BLASTN output file and predicts introns in DNA comparing ESTs and a query sequence. ESTMAP is implemented as a part of the WebGene system (http://www.cnr.it/webgene).