Cloning and characterization of a Schistosoma mansoni cDNA clone with a specific antigenic expression during development in a vertebrate host

Approximately 2.0 x 10 cDNA clones of an Schistosoma mansoni gt11 cDNA library were screened in duplicate with serum from infected mice corresponding to distinct phases of infection. A cDNA clone (7/1) was isolated and recognized only by seven week serum. The clone was subcloned in pGEX-2T and Western-blot studies showed a specific antigenic expression confirming that only serum from the chronic phase is capable of recognizing this antigen. Dot-hybridization with RNA from different developmental phases of the parasite showed that the corresponding 7/1 RNA is expressed in all phases of parasite development in vertebrate hosts.