Whole mount in situ hybridization methodology for Schistosoma mansoni

The genome sequence for Schistosoma mansoni has been determined, allowing the complete protein complement to be predicted. However, few functional genomics techniques have been developed for use in S. mansoni, limiting the usefulness of the sequence data. Here we describe a whole mount in situ hybridization (WISH) method that can be used to identify the tissue-specific expression of transcripts in S. mansoni. Using this protocol we determine the tissue-specific expression of tetraspanin 2, a female-enriched tetraspanin, phenol oxidase, the secretory Cu/Zn superoxide dismutase, and an Argonaute family member. The localization of these transcripts by WISH correlates with prior studies performed using immunohistochemistry and/or in situ hybridization on tissue sections. WISH can be adapted to screen multiple transcripts, thus identifying novel targets for drugs or vaccines.