Please cite:

For the database and web server:

Heger, A. and Ponting, CP.. (2007). Optic: orthologous and paralogous transcripts in clades. Nucleic Acids Res, Database issue 2008

For fly gene predictions and orthologs:

Heger, A. and Ponting, CP.. (2007). Evolutionary rate analyses of orthologs and paralogs from 12 drosophila genomes. Genome Res 17, 1837-1849.