Construction of an EST database for Bombyx mori and its applications

To build a foundation for the genome analysis of Bombyx mori, we have constructed an EST database. Since gene expression patterns deeply depend on tissues as well as developmental stages, we analysed many cDNA libraries prepared from various tissues and different developmental stages to cover the whole set of Bombyx genes. So far, the Bombyx EST db contains 26,000 ESTs from 32 cDNA libraries, which are grouped into about 9,500 non-redundant ESTs. Based on the EST db, we prepared a microarray containing 6,000 non-redundant ESTs for functional studies as well as for genome analysis. In addition, we have constructed a high quality BAC library for Bombyx mori characterized by an average insertion size of about 170 kb with 11-fold redundancy. We are constructing Bombyx BAC contigs by filter hybridization using non-redundant ESTs as probes.