CLONING AND CHARACTERIZATION OF A SCHISTOSOMA-MANSONI CDNA CLONE WITHA SPECIFIC ANTIGENIC EXPRESSION DURING DEVELOPMENT IN A VERTEBRATE HOST

Approximately 2.0 x 10 cDNA clones of an Schistosoma mansoni lambda gt 11 cDNA library were screened in duplicate with serum from infected mi ce corresponding to distinct phases of infection. A cDNA clone (7/1) w as isolated and recognized only by seven week serum. The clone was sub cloned in pGEX-2T and Western-blot studies showed a specific antigenic expression confirming that only serum from the chronic phase is capab le of recognizing this antigen. Dot-hybridization with RNA from differ ent developmental phases of the parasite showed that the corresponding 7/1 RNA is expressed in all phases of parasite development in vertebr ate hosts.