title: Schistosoma japonicum: excretory-secretory products of the eggs during miracidial development.
abstract: The release pattern of excretory-secretory (E-S) products of Schistosoma japonicum eggs was investigated using eggs cultured in a chemically defined medium (MEMSE-J) for 16 days. The amount of protein released in culture supernatants was greater in 0- to 4-day and 12- to 16-day cultures than in 4- to 12-day cultures. The protein composition of E-S products and soluble extracts of newly laid eggs (N-SEA) and in vitro matured eggs (M-SEA) was analyzed by SDS-PAGE. Silver staining patterns of N-SEA and M-SEA were found to be similar except for the band at approximately 66 kDa, which appeared in highest concentrations in N-SEA. Western blot analysis with human infected sera showed antibody recognition of a 140- to 160-kDa antigen present in E-S products from mature eggs, while E-S products from immature eggs were unreactive. When either [35S]methionine or [3H]glucosamine was added to the culture medium, newly synthesized proteins or glycoproteins of the SEA and E-S products were labeled. Incorporation of both isotopes into SEA appears to correlate with developmental activity of the eggs. In contrast, release of E-S proteins and glycoproteins is more apparent as the miracidium matures. These results suggested that the source of E-S products from immature eggs is likely to be the collapsing vitelline cells and that of E-S products from mature eggs to be mainly miracidial secretions.
authors.affiliation: Department of Parasitology, National Institute of Health, Tokyo, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kawanaka
authors.forename: C E
authors.initials: CE
authors.lastname: Carter
mesh_terms: D000818:Animals; D000947:Antigens, Helminth / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D002241:Carbohydrates / Q000032:analysis; D004591:Electrophoresis, Polyacrylamide Gel; D005944:Glucosamine / Q000378:metabolism; D006023:Glycoproteins / Q000032:analysis / Q000096:biosynthesis / Q000378:metabolism; D015801:Helminth Proteins / Q000032:analysis* / Q000096:biosynthesis / Q000378:metabolism; D008715:Methionine / Q000378:metabolism; D008970:Molecular Weight; D010063:Ovum / Q000276:immunology*; D012549:Schistosoma japonicum / Q000254:growth & development / Q000276:immunology / Q000378:metabolism*; D016622:Silver Staining
chemical_list: D000947:Antigens, Helminth; D002241:Carbohydrates; D006023:Glycoproteins; D015801:Helminth Proteins; D008715:Methionine; D005944:Glucosamine