| Project/Area Number |
15570170
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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 | Saitama University |
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Principal Investigator |
YAMASU Kyo Saitama University, Faculty of Science, Associate Professor, 理学部, 助教授 (60230439)
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| Co-Investigator(Kenkyū-buntansha) |
NIKAIDO Masataka Saitama University, Faculty of Science, Assistant Professor, 理学部, 助手 (70344950)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 2004: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 2003: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | animal development / brain formation / transcriptional regulation / vertebrate / anteroposterior axis / promoter analysis / zebrafish / mutant screening |
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| Research Abstract |
1.During the formation of hindbrain in zebrafish embryos, hoxb1b is expressed in the neural plate with its anterior boundary at the r3-r4 border, providing the positional information. In order to know the regulatory mechanism of hoxb1b transcription, I conducted the promoter analysis using gene transfer with GFP as a reporter. As a result, two regulatory regions were identified in the upstream DNA (-1.8 and -4.6 kb) which drove the GFP expression at late stages (somitogenesis) and two regulatory regions in the downstream DNA (+1.5 and +4.7) that drove GFP at earlier stages (gastrula). It also became clear that the downstream two regions mediate the responsiveness to retinoic acid that is known to pattern the hindbrain in vertebrate embryos.
2.gbx2 and fgf8 are both expressed in the primordial anterior hindbrain of the early neural plate and pattern the midbrain-hindbrain boundary region (MHB). I conducted the promoter analyses as for hoxb1b. For gbx2, the upstream region at -6.9 kb was shown to be sufficient for transcription in the anterior hindbrain and diencephalon, while two downstream regions of fgf8 at +10.6 and +15.1 kb could drive reporter expression in the anterior hindbrain in addition to the otic vesicle and optic stalk. Additional regulatory regions have also been identified in the flanking region of fgf8 that drove expression in a number of embryonic regions where fgf8 is expressed in embryos.
3.In order to identify regulatory genes that govern the brain formation without any bias, progeny fish of ENU-treated male fish were screened for anomalies in the embryonic brain as a pilot experiment, leading to establishment of several mutant lines showing abnormal phenotypes such as in the midbrain, dorsal diencephalon, and axis formation.
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