| Project/Area Number |
01044077
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| Research Category |
Grant-in-Aid for international Scientific Research
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| Allocation Type | Single-year Grants |
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| Section | Joint Research |
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| Research Institution | Kyoto University |
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Principal Investigator |
SATOH Noriyuki Kyoto University, Faculty of Science ; Associate Prof., 理学部, 助教授 (30025481)
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| Co-Investigator(Kenkyū-buntansha) |
FEFFERY Will カリフォルニア大学, デイビス校・ボデガ海岸研究所(米国), 教授
JEFFERY Wiliam R. Bodega marine Laboratory, University of California U. S. A. ; Professor
JEFFERY Will カリフォルニア大学デイビス校ボデガ海洋研究所(米国), 教授
西方 敬人 日本学術振興会, 特別研究員 (80212116)
真壁 和裕 日本学術振興会, 特別研究員 (60222288)
WILLIAM R. J カリフォルニア大学, ボデガ臨海実験所(米国), 教授
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| Project Period (FY) |
1989 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥9,400,000 (Direct Cost: ¥9,400,000)
Fiscal Year 1991: ¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1990: ¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 1989: ¥2,900,000 (Direct Cost: ¥2,900,000)
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| Keywords | cellular Differentiation / Muscle cells / specific genes / Regulation of expression / Egg cytoplasmic factors / Ascidian embryos / 筋肉細胞分化 / 筋肉アクチン遺伝子 / 直接発生 / シス・エレメント / ロイシン・ジッパ- / 特異的遺伝子発現 / 分化決定因子 / 卵細胞質 / アクチン遺伝子 / ミオシン重鎖遺伝子 |
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| Research Abstract |
Presumptive muscle cells of early ascidian embryos have an extreme potential of autonomous differentiation. This potential is attributed to prelocalized egg cytoplasmic factors or determinants. The aim of our project is to understand the molecular nature of factors.
The first approach to the problem includes an isolation and characterization of muscle-specific genes and analysis of regulatory factors for the gene expression. We have isolated cDNA clones for myosin-heavy chain and muscle-type actins. Expression of the muscle-specific genes begins around the time of gastrulation, and is restricted to presumptive muscle cells. It has been shown that the ascidian embryo synthesizes several different actin mRNAs. These mRNAs differ from one another in the nucleotide sequences of their 3'non-coding regions, although the sequences of the coding region are almost identical. One of the clones, HrcMA4 contains an open reading frame of 1137 bp and a 100 bp non-coding region followed by a poly (A) tail. Using a specific probe consisting mainly of 3'non-coding region, we have isolated several genomic DNA fragments containing HrMA4 gene. Characterization of the gene shows that HrMA4 is interrupted by two introns ; the position of them resembles to that of vertebrate skeletal muscle actin genes. In addition, it becomes clear that HrMA4 and several other muscle-actin genes form a cluster.
The second approach is to characterize macromolecules of the myoplasm, which is thought to contain the cytoplasmic factors. We have made several monoclonal antibodies which specifically recognize the myoplasmic components. One of the antibodies blocks muscle development when it is injected into fertilized eggs. Characterization of the antigenic polypeptide has revealed that the protein is related to cytoskeletal proteins.
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