Project/Area Number |
05404007
|
Research Category |
Grant-in-Aid for Scientific Research (A)
|
Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Breeding science
|
Research Institution | The University of Tokyo |
Principal Investigator |
HIRAI Atsushi The University of Tokyo, Graduate School of Agricultural and Life Science, Professor, 大学院・農学生命科学研究科, 教授 (60023470)
|
Co-Investigator(Kenkyū-buntansha) |
TSUTSUMI Nobuhiro The University of Tokyo, Graduate School of Agricultural and Life Science, Asso., 大学院・農学生命科学研究科, 助教授 (00202185)
多々良 敦 東京大学, 農学部, 助教授 (60114542)
武田 元吉 東京大学, 農学部, 教授 (90134501)
|
Project Period (FY) |
1993 – 1996
|
Project Status |
Completed (Fiscal Year 1996)
|
Budget Amount *help |
¥33,500,000 (Direct Cost: ¥33,500,000)
Fiscal Year 1996: ¥4,800,000 (Direct Cost: ¥4,800,000)
Fiscal Year 1995: ¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 1994: ¥4,400,000 (Direct Cost: ¥4,400,000)
Fiscal Year 1993: ¥21,500,000 (Direct Cost: ¥21,500,000)
|
Keywords | Gene expression / Mitochondrial genome / Rice / transcription / 転写地図 / 反復配列 / PRS |
Research Abstract |
The mitochondrial genomes of higher plants are much larger and more complex than those of other eukaryotic organisms. The structural complexity of the genomes has been associated with rearrangements among repeated sequences and the presence of many chloroplast-derived sequences. Following evidence shows the mode of gene expression in the mitochondrial genome of rice is also complex and flexible. Using in vitro capping/ribonuclease protection experiments and primer extension analyzes, we identified the transcription initiation sites of mitochondrial genes. The alignment of sequences surrounding the initiation sites of genes revealed a conserved sequence motif, particularly CRTA motif. The two gene clusters rps3-rpl16 and nad3-rps12 are separated from each other and are expressed as the individual transcription units in many plants. However, the four genes were located within a region of 6kbp in rice mitochondria, and all four genes were co-transcribed. The 76 bp sequence found in the upstream region of rrn26 is duplicated in the upstream region of trnfM.It was demonstrated that the transcription of trnfM and rrn26 starts from these sequences in the upstream regions of the respective genes. A chloroplast-derived tRNA gene, trnH was transcribed in rice mitochondria using mitochondrial specific promoter sequence. On the other hand, the mitochondrial specific gene, nad9 was transcribed together with the chloroplast-derived sequence. It shows a chloroplast-derived sequence is utilized as a promoter for nad9.
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