| Project/Area Number |
12460122
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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 |
Applied animal science
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| Research Institution | THE UNIVERSITY OF TOKYO |
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Principal Investigator |
SAKAI Senkiti Graduate School of Agricultural and Life Sciences Animal Breeding, THE UNIVERSITY OF TOKYO, Professor, 大学院・農学生命科学研究科, 教授 (80114487)
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| Co-Investigator(Kenkyū-buntansha) |
AOKI Fugaku Graduate School of Frontier Science, THE UNIVERSITY OF TOKYO, Associate Professor, 大学院・新領域創成科学研究科, 助教授 (20175160)
IMAKAWA Kazuhiko Graduate School of Agricultural and Life Sciences Animal Breeding, THE UNIVERSITY OF TOKYO, Associate Professor, 大学院・農学生命科学研究科, 助教授 (00291956)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥16,200,000 (Direct Cost: ¥16,200,000)
Fiscal Year 2001: ¥6,100,000 (Direct Cost: ¥6,100,000)
Fiscal Year 2000: ¥10,100,000 (Direct Cost: ¥10,100,000)
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| Keywords | mammary gland aging / aging and poly(A) / aging and mammary function / mRNA and half-life / casein mRNA / mRNA half-life / lactation curve / マウス乳腺 / 泌乳の調節機構 / mRNAのポリA / 転写後調節 |
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| Research Abstract |
In mice, the mammary gland begins to synthesize milk prior to parturition. Milk production reaches a maximum at 12-13 days of lactation and is terminated at around 18 day. During lactation, mitosis does not occur. Thus, the milk-synthesizing activity of the mammary gland changes during lactation. Using the pregnant and lactating mouse mammary gland, the relationship between the poly(A) tail of casein mRNA and the ageing of the mammary gland was examined. The poly(A) tail of casein mRNA was determined by the digestion with RNase H in the presence and absence of oligo(dT). The mRNA half-life was determined by the presence of mRNA synthesis inhibitor, alfa-amanitin. The poly(A) tail length was about 50 nucleotides but elongated to about 100 nucleotides upon the onset of lactation. Approximate half-life of casein mRNA changed from 10 h to 19 h after the onset of milk synthesis. At the end of lactation, casein mRNA had the short poly(A) tail and a short half-life. The poly(A) tail shortening did not observe in the cytoplasm. Thus, we concluded that the mammary gland determined the casein mRNA stability through the change in the poly(A) tail length.
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