Determine the extent of similarity of gene expression in in-vitro compared to in-vivo grown Schistosomes.

The schistosomulum is the main target of vaccine- induced protective immunity; however, most studies have utilized schistosomula produced by mechanical transformation of infective larvae followed by in vitro culture rather than larvae isolated directly from the lungs of infected mammals. Using transmission electron microscopy, we demonstrated that there was little difference in the ultrastructure of Schistosoma japonicum schistosomula obtained by the two methods. However, significant differences in gene expression profiles were apparent when we used an oligonucleotide microarray to compare the gene expression profiles of schistosomula obtained in vivo from lung tissue with those maintained in vitro, and with adult worms of S. japonicum. Keywords: Comparison of culturing conditions Two comparisons with replicates were done. Design 1 used two dye-swapped arrays to compare In vivo grown S. japonicum lung schistosomula (Chinese strain) to adult mixed sex schistosome (Chinese strain). Design 2 used three replicated arrays to compare In vivo grown S. japonicum lung schistosomula (Chinese strain) to in vitro cultured S. japonicum schistosomula (Chinese strain).