2002 Fiscal Year Final Research Report Summary
Lymnaea project - elucidation of mechanisms of molluscan shell formation
| Project/Area Number |
11440153
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Stratigraphy/Paleontology
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| Research Institution | University of Tsukuba (2002)
The University of Tokyo (1999-2001) |
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Principal Investigator |
ENDO Kazuyoshi Univ. of Tsukuba, Institute of Geoscience, Associate Prof., 地球科学系, 助教授 (80251411)
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| Project Period (FY) |
1999 – 2002
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| Keywords | shell formation / morphogenesis / biomineralization / molluscs / Lymnaea / shell proteins / Hox genes / developmental genetics |
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| Research Abstract |
In order to obtain basic insight into developmental genetics of the pulmonate snail Lymnaea, we have conducted histological observations at various developmental stages. We have also prepared cDNA libraries for mRNA extracted from embryos of both before and after formation of the protochonch, and from adult mantle, muscle, and midgut gland tissues. Shell matrix proteins were analyzed using SDS-PAGE, and three prominent bands were separated. Subtraction cloning for the mantle specific genes using the digestive gland as a reference, resulted in isolation of a gene fragment encoding a member of P-type ATPases, as well as a fragment for a transcription factor containing a Zn-finger domain. So as to reverse genetically study functions of those gene products, basic techniques for microinjections and RNA interference for this species are now being developed. Concerning the shell matrix proteins of marine bivalves, we have isolated an extremely acidic protein, named Aspein, with 60% Asp residues, from the pearl oyster Pinctada fucata. The transcript for Aspein is shown to be specific to the calcitic prismatic layer part of the shell, suggesting that Aspein is involved in prismatic architecture formation and/or calcite precipitation.
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