| Project/Area Number |
17591142
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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 |
Embryonic/Neonatal medicine
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| Research Institution | HIROSHIMA UNIVERSITY |
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Principal Investigator |
OBARA Masanobu Hiroshima University, Graduate School of Science, Associate Professor, 大学院理学研究科, 助教授 (60132479)
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| Co-Investigator(Kenkyū-buntansha) |
YOSHIZATO Katsutoshi Hiroshima University, Graduate School of Science, Professor, 大学院理学研究科, 教授 (20095516)
KASHIWAGI Akihiko Hiroshima University, Graduate School of Science, Visiting Professor, 大学院理学研究科, 客員教授 (50106796)
HARA Tetsuaki Hiroshima University, Hospital, Associate Professor, 病院・助教授 (30198890)
KAWADA Norifumi Oosaka City University Medical School, Graduate School of Medicine, Associate Professor, 大学院医学研究科, 助教授 (30271191)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2006: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2005: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | cytoglobin / heme-protein / transgenic forg / anencephaly / neural tube disclosure / molecular embryogenesis / in vitro fertilization / head organizer genes |
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| Research Abstract |
Cytoglobin (Cygb) is originally found as a cytoplasmic protein that is dramatically upregulated in activated stellate cells in fibrotic rat liver. Although the biological function of this protein still remains to be unclear, the protein may be involved in the regulation of intracellular oxygen concentrations via its heme-binding domain.
Recently, we generated transgenic frogs bearing Cygb gene to investigate the function of Cygb in vivo. A transgene bearing cDNAs of Cygband EGFP was constructed, mixed with sperm nuclei, and microinjected into unfertilized Xenopus eggs by the method developed by Kroll and Amaya. The transgenesis of EGFP gene was monitored through a fluorescent microscope. A high level of mRNA expression of Cygb in transgenic embryos was confirmed by RT-PCR. The resulting transgenic embryos at neural stage showed the disclosure of neural tubes at a high frequency. At the tail bud stage, most embryos showed anomaly in head structures as well as the shortening of the A-P axis. These phenotypes were similar to those of human anencephaly. Based on these results, we now hypothesize that Cygb may be involved in the head organization during early development of Xenopus leavis embryos.
On the other hand, we also conducted molecular evolutional study with Xenopus leavis and Iguana iguana. The study on Cygb gene expression and protein distribution strongly indicates a similar function between Cygb and Mb, thus we hypothesize that Cygb in muscle cells compensates for the lack of Mb for the storage and the intracellular transportation of oxygen in the Amphibia. However, interestingly, Cygb in the heart was exclusively localized in nuclei, which suggests a role of this globin in gene regulation.
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