Approximately 2.0 x 10 cDNA clones of an Schistosoma mansoni lambda 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.
