SCHISTOSOMA-MANSONI USE OF A SUBTRACTIVE CLONING STRATEGY TO SEARCH FOR RFLPS IN PARASITE-RESISTANT BIOMPHALARIA-GLABRATA

A subtractive cloning strategy has been applied for the identification of two cDNA clones whose corresponding transcripts were elevated in S chistosoma mansoni-resistant (BS-90) compared to susceptible (M-line) snails. Clone pBS11 encoded a 1.9-kb transcript that was more elevated compared to a 500-bp transcript encoded by clone pBS12. Consequently, more attention was focused on the molecular characterization of clone pBS11. Results showed that the transcript encoded by this clone was e xpressed in the albumen gland and was developmentally regulated. Seque nce analysis of pBS11 demonstrated the presence of an open reading fra me that corresponded to a novel Biomphalaria glabrata albumen,aland ge ne product. Comparative Southern analysis of the resistant and suscept ible snail lines using pBS11 as probe indicated the presence of a BamH I and EcoRI RFLP between the two strains. (C) 1996 Academic Press, Inc .