Comparison of EST libraries from seven beetle species: towards a framework for phylogenomics of the Coleoptera.

Relatively little is known about Coleoptera genes and genomes and how these compare in different taxa. We describe here the construction, DNA sequencing and sequence comparisons of cDNA libraries from seven beetle species. A total of 6717 bacterial colonies were screened for cDNA insert containing plasmids and 2784 size selected clones were 5'- and 3'-end sequenced to produce 1620 assembled sequences. Similarity comparisons with existing protein sequence databases revealed that 65.1% had matches (E < 10(-4)) in other organisms, with greater numbers of matches in Drosophila melanogaster than Caenorhabditis elegans and Saccharomyces cerevisiae databases. tBlastX comparisons also revealed numerous similarity hits (E < 10(-20)) in intra- and interlibrary comparisons. These results show the potential of small cDNA libraries for discovery and comparative analysis of genes useful for phylogenomic and functional studies.