1993 Fiscal Year Final Research Report Summary
Detection of Germ Cell Line in Marine Invertebrate
| Project/Area Number |
03640604
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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 |
動物発生・生理学
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| Research Institution | Okayama University |
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Principal Investigator |
YAMAMOTO Masamichi Fac.Sci., Okayama Univ.Prof., 理学部, 教授 (50011565)
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| Co-Investigator(Kenkyū-buntansha) |
SHIRAI Hiroko Fac.Sci., Okayama Univ.Assoc.Prof., 理学部, 助教授 (50090478)
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| Project Period (FY) |
1991 – 1993
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| Keywords | cephalopod / ascidian / starfish / germ cell / gonad / meiosis / ovary / testis |
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| Research Abstract |
1. The origin of the germ cell and the early processes of the gonad formation were clarified in a octopus, Octopus ocellatus. The earlygerm cells apear in the pericardial cavity. In the female, the germ cells begin meiosis just before hatching while in the females the germ cells enter into meiosis 7 weeks after hatching.
2. The origin of the germ cell and the process of sex differentiation of the gonads were elucidated in a solitary ascidian, Ciona intestinalis. The germ cells first appear in the juvenile just after metamorphosis in contact with the degenerating tissue mass which arises near the esophagus. The form a spherical body (early gonad), which divides into the testis and the ovary during migration along the wall of the stomach to the pyloric portion.
3. The origin of the germ cell and the process of gonad formation became clear in a star fish, Asterina pectinifera. The germ cells, about 10 in number, originate in the third coelomic pouch of the brachyolaria larvae. The enter into the haemal system and form the gonads after metamorphosis.
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