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1992 Fiscal Year Final Research Report Summary

Molecular Mechanisms of Sperm-Egg Interactions in the Ascidians

Research Project

Project/Area Number 02044053
Research Category

Grant-in-Aid for international Scientific Research

Allocation TypeSingle-year Grants
SectionJoint Research
Research InstitutionTokyo Institute of Technology

Principal Investigator

HOSHI Motonori  Department of Life Science, Tokyo Institute of Technology, 生命理工学部, 教授 (20012411)

Co-Investigator(Kenkyū-buntansha) MARINO Rita  Department of Cell and Developmental Biology, Stazione Zoologica 'Anton Dohrn', 研究員
PINTO M.ROSA  国立酵素, タンパク質化学研究所, 研究員
DALE Brian  Department of Cell and Developmental Biology, Stazione Zoologica 'Anton Dohrn', 主任研究員
DE Santis RO  国立ナポリ臨海実験所, 部長
USUI Noriko  Department of Anatomy, Teikyo University School of Medicine, 医学部, 助教授 (50082136)
CHIDA Kazuyoshi  Department of Life Science, Tokyo Institute of Technology, 生命理工学部, 助手 (70222130)
MATSUMOTO Midori  Department of Life Science, Tokyo Institute of Technology, 生命理工学部, 助手 (00211574)
NISHIDA Hiroki  Department of Life Science, Tokyo Institute of Technology, 生命理工学部, 助教授 (60192689)
ROSARIA Pinto M.  Institute of Protein Biochemistry and Enzymology, C.N.R.
SANTIS Rosaria De  Department of Cell and Developmental Biology, Stazione Zoologica 'Anton Dohrn'
Project Period (FY) 1990 – 1992
KeywordsAscidians / sperm-egg interactions / self-sterility / membrane fusion / lysin / protease / glycosidase / glycoprotein
Research Abstract

The ascidians are hermaphrodite and many species are seif-sterile. Using two species of self-sterile solitary ascidiansas model systems, Ciona intestinalis (Enterogona) and Halocynthia roretzi (Pleurogona), molecular mechanisms underlying the sperm-egg interactions were studied.
We postulated previously that a sperm glycosidase (e.g., alpha-L-fucosidase in Ciona) and corresponding sugar chains of the vitelling coat (VC) mediate the binding of ascidian sperm to the homologous VC. Several lines of experimental evidence has further supported this hypothesis in both Ciona and Halocynthia. In H. roretzi, we have purified the major VC glycoprotein of about 70 kDa. It has terminal fucose residues and presumably serves as a sperm-receptor. Its amino acid sequence was partially revealed.
A chymotrypsin-like protease was purified from Ciona sperm as a VC-lysin and proved to digest the outermost thin layer of the VC. It was also shown that a Zn^<++>-dependent metalloprotease is involved in sperm-eg … More g fusion in Ciona.
By using in vitro fertilization assay of oocytes from Ciona ovaries, we have found that self-sterility is controlled by products, presumably a glycoprotein, of the overlying follicle cells. When fully-grown ovarian oocytes with a germinal vesicle were incubated in sea water at room temperature, they underwent germinal vesicle breakdown within 20 minutes and became fertile, and eventually acquired self-sterility within a maximum of 3 hours of incubation. When they were deprived of follicle cells by gentle shaking before incubation, most of them remained self-fertile even after 3 hours. If follicle cell-free oocytes were incubated with the free follicle cells, they became self-sterile as well as follicle cell-intact oocytes.
The acquisition of self-sterility was accompanied by an ultrastructural change in the VC fixed with tannic acid : an electron-dense, thin layer appeared on the outer surface of the VC after 3 hours of incubation. This was the layer digested by the chymotryptic lysin in the sperm. Therefore it is suggested that the induction of acrosome reaction is the site modulated by allo-recognition between sperm and VC. Less

  • Research Products

    (10 results)

All Other

All Publications (10 results)

  • [Publications] Pinto,M.R.,Hoshi,M.,Marino,R.,Amoroso,A.&De Santis,R.: "Chymotrypsin-like Enzymes Are Involved in Sperm Penetration through the Vitelline Coat of Ciona intestinalis egg" Molecular Reproduction and Development. 26. 319-323 (1990)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] De Santis,R.,Pinto,M.R.,Marino,R.,USUI,N.&HOSHI,M.: "Acquisition of Self-Sterility in Ascidian Oocytes" Proceeding of the 6th Annual Meeting of JSIR 1992. 161-163 (1992)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Marino,R.,De Santis,R.,Hirohashi,N.,Hoshi,M.,Pinto,M.R,&Usui,N.: "Purification and Characterization of A Vitelline Coat Lysin from Ciona intestinalis Spermatozoa" Molecular Reproduction and Development. 32. 383-388 (1992)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] De Santis,R.,Shiraka-wa,H.,NAKADA,K.,MIYAZAKI,S.,Hoshi,M.,MARINO,R.&Pinto,M.R.: "Evldence that Metalloendoproteases Are Involved in Gamete Fusion of Ciona intestinalis,Ascidia" Developmental Biology. 153. 165-171 (1992)

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] HOSHI,M.: "Egg-Coat Glycoconjugates as Biolongical Signals for Spermatozoa" Proceedings of the 7th Annual Meeting of JSIR 1993.

    • Description
      「研究成果報告書概要(和文)」より
  • [Publications] Pinto, M.R., Hoshi, M., Marino, R., Amoroso, A. & De Santis, R.: "Chymotrypsin-like Enzymes Are Involved in Sperm Penetration through the Vitelline Coat of Ciona intestinalis egg" Molecular Reproduction and Development. 26. 319-323 (1990)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] De Ssntis, R., Pinto, M.R., Marino, R., Usui, N. & Hoshi, M.: "Acquisition of Self-Sterility in Ascidian Oocytes" Proceedings of the 6th Annual Meting of Jsir. 161-163 (1992)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Marino, R., De Santis, R., Hirohashi, N., Hoshi, M., Pinto, M.R. & Usui, N.: "Purification and Characterization of A Vitelline Coat Lysin from Ciona intestinalis Spermatozoa" Molecular Reproduction and Development. 32. 383-388 (1992)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] De Santis, R., Shirakawa, H., Nakada, K., Miyaaki, S., Hoshi, M., Marino, R. & Pinto, M.R.: "Evidence that Metalloendoproteases Are Involved in Gamete Fusion of Ciona intestinalis, Ascidia" Developmental Biology. 153. 165-171 (1992)

    • Description
      「研究成果報告書概要(欧文)」より
  • [Publications] Hoshi, M.: "Egg-Coat Glycoconjugates as Biological Signals for Spermatozoa" Proceedings of the 7th Annual Meeting of JSIR. (1993)

    • Description
      「研究成果報告書概要(欧文)」より

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Published: 1994-03-24  

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