Identification of a putative eggshell precursor protein of the female Schistosoma japonicum.
In adult worms of Schistosoma japonicum, a prominent radiolabelled female-specific protein (34 kDa) was demonstrated on fluorography of SDS gels with the pulse incorporation of 14C-tyrosine in vitro, though it was difficult to detect major female-specific proteins by direct staining methods. This female-specific protein was demonstrated to localize exclusively in the vitelline cells by indirect immunofluorescence using the rabbit anti-34 kDa female protein antiserum. It was shown that 14C-tyrosine was selectively incorporated into the vitelline cells by the pulse labelled autoradiographs. Two days after the exposure of worms to radio-tyrosine, the shells of eggs in the uterus were demonstrated to have become radioactive, indicating that 14C-tyrosine-labelled protein was used as a material for the eggshell. In the fluorograph of proteins extracted from newly laid eggs in vitro, the prominent band was not found at the 34 kDa region, but a lot of radioactivity appeared at higher than 100 kDa. The results suggested that a 34 kDa female protein was a precursor of the eggshell and became a much larger protein molecule as a result of cross-linking during eggshell hardening.
Kawanaka
M
M
Department of Parasitology, National Institute of Health, Tokyo, Japan.
D000818:Animals; D001345:Autoradiography; D015153:Blotting, Western; D003720:Densitometry; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005455:Fluorescent Antibody Technique; D015801:Helminth Proteins / Q000032:analysis*; D011498:Protein Precursors / Q000032:analysis*; D012549:Schistosoma japonicum / Q000032:analysis*
D015801:Helminth Proteins; D011498:Protein Precursors