An AceDB Fmap showing two alternatively spliced isoforms of a gene with WormBase WS52 identifier F54A4.7. The correct gene structures are in blue, with the Fgenesh and GAZE predictions shown in green and red, respectively.Genefinder splice-site predictions are the colored horizontal hooked bars running vertically down the righthand-side of the panel. (a) Both Fgenesh and GAZE fail to correctly identify the initial exon of either isoform. (b) An enlargement of the 5′ ends of the second exons of the two correct gene structures, showing alternative acceptor splice sites. These alternatives are supported by alignments of ESTs to the genome byEST_GENOME (shown in yellow). Although only one of the two alternative acceptors belongs to the predicted gene structure, the posterior feature probabilities reported by GAZE provide evidence for both, as explained in the text.