| Project/Area Number |
11694224
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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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 | Tokai University |
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Principal Investigator |
KIMURA Minoru Tokai Univ., Sch. Of Med., Professor, 医学部, 教授 (10146706)
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| Co-Investigator(Kenkyū-buntansha) |
SATO Masahiro Tokai Univ., Inst. Of Medical Sciences, Associate Professor, 総合医学研究所, 助教授 (30287099)
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| Project Period (FY) |
1999 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥10,100,000 (Direct Cost: ¥10,100,000)
Fiscal Year 2001: ¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2000: ¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 1999: ¥3,500,000 (Direct Cost: ¥3,500,000)
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| Keywords | mouse / preimplantation / gene expression / maternal RNA / traslation / poly(A) addition / zygotic expression / fertilized egg / 卵形成 / poly(A)化 / 初期胚 / 接合子 / 発現調節 / 卵母細胞 |
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| Research Abstract |
In early embryogenesis of various species, there is a transition of matemal RNA to zygotic RNA, which is thought to play an important role in molecular programming of later stage of development. We first found in mice that one type of maternal RNA, which was first isolated in our laboratory and termed "SSEC-D(stage-specific embryonic clone-D)", exhibited a transient extension of poly (A) strand at its 3' end with a peak at 18h after fertilization (corresponding to the late 1-cell stage) and a gradual degradation of the poly(A) strand thereafter. Based on this finding, we have examined this phenomenon in more detail in the past three years, and obtained several findings as mentioned below.
1. Transient increase in the size of SSEC-D RNA is due to addition of poly (A) strand at its 3' end, and it requires new protein synthesis. 2. It is possible to perform Northern blot analysis using 10-20 zygotes and early embryos due to improvement of mRNA detection system. 3. Transient extension of RNA was also observed in zygotes after cytoplasmic injection experiments using in vitro synthesized RNAs containing EGFP cDNA ligated to various sizes of 3'-noncoding region of SSEC-D RNA. Thus, this phenomenon is already programmmed. 4. Addition of poly(A) spanning 300-400 nucleotides can release the translationally suppressed state of the maternal RNA iteself. 5. This poly(A) extension is dependent on the sequence of SSEC-D RNA itself and poly(A) sequence at its 3' end region. 6. It becomes possible to concentrate cDNAs enriched with maternal RNAs by improving the uptake of biotin labeled ATP by zygotes.
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