| Project/Area Number |
12680723
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Developmental biology
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| Research Institution | Tokyo Women's Medical University |
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Principal Investigator |
YOKOYAMA Takahiko Tokyo Women's Medical University Department of Anatomy and Developmental.Biology,Joshu, 医学部, 助手 (70191525)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2001: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 2000: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | left / right asymmetry / inv (3) situs inversus / ankyrin / intracellular localization / xenopus |
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| Research Abstract |
Establishment of left-right asymmetry in internal organs is essential for normal development of vertebrates. The inυ mutant in mice shows a constant reversal of left-right asymmetry. We have cloned the inv gene. The gene was novel. Therefore, its biochemical and cell biological functions were undefined. Using yeast two hybrid system, we discovered that calmodulin binds with inv protein at two sites (IQ1 and IQ2). The binding was confirmed by a Gel-overlay assay. The binding of calmodulin to the IQ2 site occurred in the absence of Ca2+, whereas it was inhibited in the presence of Ca2+. We also found that injection of mouse inυ mRNA into the right blastomere of Xenopus embryos at two-cell stage randomized the left-right asymmetry and altered patterns of Xnr-1 and PitX2 expression. Importantly, inυ RNA lacking the IQ2 site was unable to randomize left-right asymmetry in Xenopus embryos, implying that the IQ2 site is essential for inυ to randomize the left-right asymmetry in Xenopus. These results suggest a possiblity that calmodulin-binding regulates inυ function.
To see whether inυ gene has any effect on cultured cells, we introduced inυ gene into cos cells. Long-term cultured cos cells that carry inυ gene tends to show hyperploidity, suggesting a possiblity that the gene may affect cytokinesis.
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