The expressed sequence tag (EST) approach that we have used in the
Schistosoma mansoni Genome Project is a powerful technique for
the discovery of new genes of the parasite. In a recent comparative
study of gene expression in distinct developmental stages of the
parasite life cycle using the EST strategy, we identified 466
different genes. From this total, 427 were novel and 333 of them could
not be identified based on homologies with database sequences. The
high frequency of some of these "unknown" genes in different cDNA
libraries suggests that they might have important roles in the biology
of S. mansoni and thus may constitute possible targets for drug
design or vaccine production. One of these genes, highly abundant in
one of four adult worm libraries that we are studying in our
laboratory, was selected for further characterization.
