Synthesis and release of proteins homologous to excretory-secretory antigens during embryogenesis of Setaria digitata.

Localization of antigens homologous to excretory-secretory proteins in developing embryos of Setaria digitata has been carried out by indirect fluorescent antibody test, [14C] labelling studies and Western blotting. Indirect fluorescent antibody test showed binding of excretory-secretory antibodies at perivitelline space. The fluorescent antibody binding was almost absent at small morulae stage and increasing in intensity in the successive developmental stages with maximum at coiled microfilaria stage. Hatched microfilaria did not show the presence of antigens by immunofluorescence. Immunocomplex of excretory-secretory antiserum against "amniotic fluid" collected from developing embryos of Setaria digitata labelled with [14C] amino acids showed highest radioactivity at coiled and tadpole stages and differed significantly from small morulae, big morulae and hatched microfilaria. Immunoblot analysis of amniotic fluid showed two proteins, 16·5 and 11 kDa, to be highly antigenic. The antigenic protein (11 kDa) content as seen by immuno blotting increased during embryogenesis and decreased at the stage of hatching.