Biolistic transformation of Schistosoma mansoni with 5′ flanking regions of two peptidase genes promotes tissue-specific expression

The gene-regulatory elements controlling peptidase expression in Schistosoma mansoni are unknown. A genomic DNA library was constructed from which 5′ flanking fragments of the cathepsins F (SmCF; 649 bp) and B2 (SmCB2; 810 bp) peptidase genes were isolated. These were cloned into a GFP-expression vector for biolistic transformation of schistosomes. Both fragments promoted expression of GFP that was localised in the gut for SmCF and tegument for SmCB2, consistent with previous immunochemical data. Promoter-deletion of the SmCF gene indicated the importance of one or more transcription factor binding sites in the first 169 bp for both GFP-expression and its tissue specificity.