Stage-specific surface antigens during the morphogenesis of Trypanosoma cruzi: developmentally regulated expression of a glycosyl-phosphatidylinositol anchored glycoprotein of amastigotes Leia mais sobre Stage-specific surface antigens during the morphogenesis of Trypanosoma cruzi: developmentally regulated expression of a glycosyl-phosphatidylinositol anchored glycoprotein of amastigotes