Figure 4

SmVAL group 1 and group 2 gene structures are unique and likely evolved from a common ancestral gene within the genus. All SmVAL gene structures were manually assembled by comparison of laboratory derived cDNA sequences to assembled genomic sequences (SchistoGeneDB, version 4). A) Representative group 1 SmVAL gene structure and B) representative group 2 SmVAL gene structure over the SCP/TAPS encoding exons. Exons are represented by boxes with introns represented by lines. The phases of introns are indicated above the arrows. Exons are coloured to show regions encoding important protein features; predicted signal peptides (yellow), SCP/TAPS domain (red) and the remaining ORF (blue). The position of the six conserved cysteines in the group 1 SmVAL proteins is indicated. The single asterisk (*) indicates an intron conserved in all group 2 genes except SmVAL11.