| Project/Area Number |
18570203
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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 | Kumamoto University |
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Principal Investigator |
SHIMAMURA Kenji Kumamoto University, Institute of Molecular Embryology and Genetics, Professor (70301140)
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| Co-Investigator(Kenkyū-buntansha) |
YOSHIDA Michio Institute of Molecular Embryology and Genesitcs, 発生医学研究センター, Assistant Professor (80305002)
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| Project Period (FY) |
2006 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥4,110,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥510,000)
Fiscal Year 2007: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
Fiscal Year 2006: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Keywords | neural development / cell lineage / telencephalon / pattern formation / regionalization / comparative biology / neuroepithelium / forebrain / 神経幹細胞 / 領域特異性 |
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| Research Abstract |
It is believed that cellular diversity found in the various regions of the brain is primarily derived from regionally distinct properties of the neural progenitors. To elucidate the extent to which the regional differences found in the mature brain structures depend upon the early neuroepithelial regionality, we decided to conduct a fate map study based upon gene expression, using Cre/loxP recombination system. We have generated transgenic mouse lines in which a tamoxifen-inducible form of Cre recombinase (CreERT2) was driven under the control of Six3 locus, a gene expressed in the anterior forebrain primordium in a temporary dynamic pattern. We took a knock-in strategy to recapitulate precisely the expression of endogenous Six3 gene. Three neomycin-resistant ES clones as well as mouse lines derived from those clones were established. A Cre-reporter line Rosa26R was crossed with the heterozygous of Six3-CreERT2neo and tamoxifen was delivered to the mother which enables Cre to excise the floxed stop cassette that transcriptionally activates lacZ reporter. While the LacZ-expressing cells were to be detected as the descendant of the progenitors that expressed Six3 at a given time, we found very few X-gal cells within the Six3-expressing domains of the forebrain which were variable among the specimens and within them sometimes (laterally asymmetric) due to very low level of Cre-expression. It was essentially the same, even after the FRT-flanked pgk-neo-pA cassette was excised by crossing with the CAGGS-Flpw mice, although the number of LacZ-positive cells was significantly increased. We thus concluded that these lines are not to be used for the stage-specific lineage analysis of the Six3-expressing domains. Although these mice turned out to be inappropriate for our original purpose, recombination in small subsets of cells in those domains could potentially be useful for detailed analysis (e. g. mosaic) as a Cre-driver line for the conditional knock out studies.
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