Tissue localization and stage-specific expression of the phospholipid hydroperoxide glutathione peroxidase of Schistosoma mansoni.

The tissue localization and the stage-specific expression of the phospholipid hydroperoxide glutathione peroxidase of Schistosoma mansoni (SmPHGSHpx) have been determined. An antiserum raised against the C-terminal region of the predicted protein sequence was used for immunocytochemical investigations. The native protein is expressed only in female and egg vitelline cells and is practically absent from male worm tissue. Western blot data confirmed these results and showed the complete absence of SmPHGSHpx from cercariae. However, Northern blotting indicated the presence of the corresponding mRNA at all life-cycle stages investigated. The sequence determination of the 5' flanking region of the SmPHGSHpx gene revealed the presence of an extended TATA box (5'-TAAATA-3') at -32, a possible CAAT box at -75 and a putative monomeric estrogen response element 5'-GGTCAA-3' at position -486. In addition, direct and inverted repeat elements are present.