2003 Fiscal Year Final Research Report Summary
Analysis of RNA sorting mechanisms in the ascidian embryos.
| Project/Area Number |
14580710
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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 | The University of Tokushima (2003)
Kyoto University (2002) |
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Principal Investigator |
MAKABE Kazuhiro The University of Tokushima, Faculty of integrated arts and sciences, associate professor, 総合科学部, 助教授 (60222288)
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| Project Period (FY) |
2002 – 2003
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| Keywords | ascidian / matenal factors / EST / RNA / localization / UTR |
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| Research Abstract |
We have isolated many RNAs localized in the ascidian eggs. It is noteworthy to have found RNAs as localized functional molecules in the ascidian eggs, which are known to be "mosaic" eggs. Six RNAs we studied are localized at the posterior-vegetal region of the egg, named the postplasm. This region is reported to be involved in the anterior-posterior axis formation and generation of unequal cleavages of early blastomeres. We, therefore, designated these RNAs the postplasmic RNAs. The detailed analysis of their expression patterns revealed that they are categorized into two groups (type I and type II) based on their transport pathways. Microinjection experiments of labeled synthetic RNAs into the unfertilized eggs suggested that small elements in the 3 'UTR of the RNAs are necessary and sufficient to proper localization. There is no obvious conserved sequence in the regions, but the injection assay. using portions of the 3'UTRs identified 50-nucleotide elements responsible for the localization. In order to investigate molecular mechanisms of RNA sorting in the ascidian eggs and embryos, we are currently trying to isolate sequence-specific RNA-binding proteins which bind to the identified elements from the ascidian egg extract using gel shift, east-western and UV-cross link techniques and analyze on the biochemical characteristics of the proteins. On the other hand, we revealed that the postplasmic RNAs distribute at specific sites in the CAB region of the embryo at the electron microscopic level. These will shed a light to the whole molecular mechanisms on the RNA sorting in the ascidian eggs and embryos.
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