Biomphalaria glabrata: gene discovery, expression, profiling and interval mapping to elucidate mechanisms of resistance to Schistosoma mansoni. (360G-Wellcome-068589_Z_02_A)

To promote an understanding of snail-schistosome interactions and development of novel intermediate host-based control strategies an EST gene discovery approach is proposed, to increase significantly the genomic database of B. glabrata, the intermediate host of Schistosoma mansoni, a major schistosome infecting man. There is international interest to commence genome sequencing of this important mollusc, and parasite resistance is the trait currently perceived as the most crucial. Isolation of transcripts by gene discovery approaches, and identification of those involved in resistance, by microarray analyses, will create the initial impetus for a genomic analysis of B. glabrata. Quantative trait loci (QTLs) will be identified through interval mapping, using preliminary linkage maps, incorporating genome-wide markers, using populations segregating for schistosome resistance. Combining microarrays with mapping will accurately identify candidates conferring resistance, separating causal from secondarily effected differentially expressed genes. The map position of each transcript will be improved progressively, and genes differentially expressed between resistant and susceptible snails and lying within a QTL will be further characterized. This work will provide the initial impetus for further genomic characterization of B. glabrata, allowing for future integration of parasite and intermediate host genomics to elucidate their co-evolution and suggest novel interventions.