Characterization of the Schistosoma transcriptome opens up the world of helminth genomics

Abstract

Among the metazoan parasites that cause debilitating disease in man, schistosomes are the first group for which near-complete transcriptome complements have been described. This new genomic information will have an enormous impact on all future investigations into the biology, pathogenesis and control of schistosomiasis.

Figure 1

The schistosome life cycle. Schistosomes reproduce asexually in freshwater snails; a larval form, the cercaria, is released from the snail and can burrow into the skin of the definitive host, man. In humans, schistosomes migrate to the bloodstream where they mature into adult worms. Eggs produced by the female worm are released into the environment where they hatch into a second larval form, the miracidia, which can infect the snail. Adapted and reproduced with permission from [28].

Figure 2

Deposition of new Schistosoma EST structural information into public databases has dramatically increased the amount, diversity and coverage of both S. mansoni and S. japonicum genomes. Although the efforts of the Schistosoma Genome Network [3] led to an annual increase in the amount of non-redundant transcriptome information for both S. mansoni and S. japonicum, it was not until the EST sequencing projects of Hu et al. [4] and Verjovski-Almeida et al. [5] that a near-complete description of each parasite's genomic complement was obtained. Together, this transcriptome information will lead to exponential advances in the understanding of parasitic helminths and will provide vital structural components to be used in post-genomic research activities (see Table 1).