1999 Fiscal Year Final Research Report Summary
REGULATORY MECHANISMS OF DORSO-VENTRAL AXIS FORMATION IN AMPHIBIAN EMBRYO.
Project/Area Number |
09680721
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Developmental biology
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Research Institution | NIIGATA UNIVERSITY |
Principal Investigator |
MAENO Mitsugu NIIGATA UNIVERSITY, FACULTY OF SCIENCE, ASSOCIATE PROFESSOR, 理学部, 助教授 (10190315)
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Project Period (FY) |
1997 – 1999
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Keywords | Xenopus laevis / homeobox / dorso-ventral axis / organizer / BMP-4 / dominant-negative / neural induction / FGF |
Research Abstract |
I have investigated several cDNA clones, which encode for ventralizing agents. Among these factors, the roles of msx-1 and msx-2 in the dorsoventral axis formation have been extensively analyzed. These transcriptional repressor proteins were expressed in presumptive ectoderm and mesoderm ventrally, but not dorsally, at gastrula stage. Both msx-1 and msx-2 possessed a similar ventralizing activity, but that of msx-2 was higher than of msx-1, as revealed by the injection of RNA into dorsal blastomeres. The secondary axis induced by the injection of tBR was rescued by simultaneous injection of msx-1/msx-2. Furthermore, if VP-16/msx-1 fusion RNA, which was expected to function as a dominant negative msx-1, was injected into the ventral blastomeres, partial Secondary axis was formed. Therefore, msx-1 and msx-2 transduce a main tract of BMP-4 signaling. Msx factors also have a role in neural tissue induction in ectodermal cells. If msx-1 was coinjected with neural inducer genes such as noggin or cerberus, the expression of N-CAM was completely suppressed. As also shown in tBR (which directly induces neural tissue in animal cap), VP 16/msx-1 fusion RNA was able to induce neural tissue directly in animal cap cells. The results indicate that msx proteins play a central role in establishing dorso-ventral axis and in neural tissue formation in gastrulating embryo, by antagonizing the expression of organizer genes. The expression and function of GATA-1 (another transcriptional regulator) and BMP-1 (metalloprotease) in Xenopus embryo have been also investigated in this study.
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Research Products
(12 results)
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[Publications] Lin, J. J., Maeda, R., Ong, R., Kim, J., Lee, L. M., Kung, H. F., and Maeno, M.: "XBMP-1B (Xtld), a Xenopus homolog of dorso-ventral polarity gene in Drosophila, modifies tissue phenotypes of the ventral explants."Develop. Growth Differ.. 39. 43-51 (1997)
Description
「研究成果報告書概要(欧文)」より
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[Publications] Maeda, R., Kobayashi, A., Sekine, R. Lin, J. J., Kung, H. F., and Maeno, M.: "Xmsx-1 modifies mesodermal tissue pattern along dorsoventral axis in Xenopus laevis embryo."Development. 124. 2552-2560 (1997)
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「研究成果報告書概要(欧文)」より
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[Publications] Takeda, M., Saito, Y., Sekine, R., Onizuka, I., Maeda R., and Maeno, M.: "Xenopus msx-1 regulates the dorso-ventral axis formation by Xwnt-8-mediated pathway."Comp. Biochem. Physiol.. (In press.).
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「研究成果報告書概要(欧文)」より
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[Publications] Ishimura, A., Maeda, M., Takeda, M., Kikkawa, M., Daar, I. O. and Maeno, M.: "Involvement of BMP-4/msx-1 and FGF pathways in neural induction in Xenopus embryo."Develop. Growth & Differ.. In press..
Description
「研究成果報告書概要(欧文)」より