Physiological and biochemical studies on egg formation in Schistosoma japonicum.
| Project/Area Number |
61570201
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
寄生虫学(含医用動物学）
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| Research Institution | 国立予防衛生研究所 |
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Principal Investigator |
KAWANAKA Masanori Dept. Of Parasitology, NIH, 寄生虫部, 室長 (50109964)
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| Co-Investigator(Kenkyū-buntansha) |
ENDO Takuro Dept. of Parasitology, NIH, 寄生虫部, 室長 (90072959)
AGUI Nobuaki Dept. of Medical Entmology, NIH, 衛生昆虫部, 室長 (30109962)
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| Project Period (FY) |
1986 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1988: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1987: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1986: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | Schistosoma japonicum / in vitro culture / egg formation / エクジステロイド / 卵黄蛋白質形成 |
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| Research Abstract |
1. The insect moulting hormone, ecdysteroids, were detected by the combined use of radioimmunoassay and HPLC in adult schistosome japonicum. In Medium RPMI 1640 with faetal calf serum(+10%), adult Schistosoma japonicum produced normal eggs within maintenance for 4 days in vitro. During the period of normal egg deposition in vitro, the amount of ecdysteroids of worm pairs decreased by 80%. The large amount of ecdysteroids found in newly laid eggs. The cultured worms released ecdysteroids to the medium. These data suggest an analogous role to that in insects;e.g., in stimulating vitellogenesis or in a process for eggshell formation.
2. A female specific protein with an apparent mol wt of 34,000 (34Kp) was demonstrated by either direct staining of SDS gels or by radiorabelling of parasites with ^<14>C-amino acids and autoradiography of SDS gels. An immunohistochemical study using specific antiserum to 34Kp this protein located exclusively in vitelline glands. This protein is synthesized and stockpiled by vitelline cells of females during the period of normal egg formation in vitro.
3. In order to study the incorporation of amino acids into the 34Kp which located in vitelline glands, adult worms were incubated in the medium with ^<14>C-tyrosine, ^<35>S-methionine and ^<14>C-glycine, respectively. The process was followed by the autoradiography of SDS gels and by histological autoradiography. The experiment reveals that the rapid incorporation into 34Kp located vitelline glands occur when ^<14>C-tyrosine was used in the incubation medium. Two days after labelling with ^<14>C-tyrosine, radioactivity was detected in the shells of newly formed eggs in the uterus. The autoradiography of SDS gel with material from newly deposited eggs of ^<14>C-tyrosine treated worms showed poor radioactivity in the region of mol wt 34,000. The results indicate that tyrosine-rich 34Kp of the vitelline cells was utilized as a precursor in the formation of the eggshell.
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Report
(4 results)
Research Products
(6 results)
